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1
Huang, Yi, and Geoffrey Hewings. "More Reliable Land Price Index: Is There a Slope Effect?" Land 10, no. 3 (March 4, 2021): 261. http://dx.doi.org/10.3390/land10030261.
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This paper focuses on the physical attributes of land that intrinsically limit land use and possibly affect land values. In particular, we investigate if the slope of a land does decrease its price and investigate the role of land slope in forming more reliable constant-quality land price indices and aggregate house price indices. We find that, while land slopes do decrease the land price per unit, they have a small effect on the quality-adjusted land price indices in selected neighborhoods in Auckland, New Zealand, where sloped terrain is common.
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Mao, Luo Jian, Qian Xu, Zheng Jian, and Ying Zhu. "Dynamic Responses of Slope under the Effect of Seismic Loads." Applied Mechanics and Materials 438-439 (October 2013): 1587–91. http://dx.doi.org/10.4028/www.scientific.net/amm.438-439.1587.
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In order to study the seismic response of slope under the effect of seismic load, a numerical model was established by ANSYS program. It was mainly analyzed the dynamic responses of slope under the effect of both general earthquake and rare one. The results indicate that under general earthquake, slope deforms a little, there is small stress within slope, and small tensile stress on the top of slope; under rare earthquake, slope deforms greatly, slope surface has large displacement, and there is larger tensile strain on the slope top. At the same time, stress concentration effects expand further within slope and slope toe. Consequently, with regard to slopes in higher fortification intensity area, some steps should be taken to strengthen slope in order to improve slope seismic stability.
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Blenkinsop, Glen M., Ying Liang, Nicholas J. Gallimore, and Michael J. Hiley. "The Effect of Uphill and Downhill Slopes on Weight Transfer, Alignment, and Shot Outcome in Golf." Journal of Applied Biomechanics 34, no. 5 (October 1, 2018): 361–68. http://dx.doi.org/10.1123/jab.2017-0310.
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The aim of the study was to examine changes in weight transfer, alignment, and shot outcome during golf shots from flat, uphill, and downhill slopes. Twelve elite male golfers hit 30 shots with a 6-iron from a computer-assisted rehabilitation environment used to create 5° slopes while collecting 3-dimensional kinematics and kinetics of the swing. A launch monitor measured performance outcomes. A shift in the center of pressure was found throughout the swing when performed on a slope, with the mean position moving approximately 9% closer to the lower foot. The golfers attempted to remain perpendicular to the slope, resulting in weight transfer toward the lower foot. The golfers adopted a wider stance in the sloped conditions and moved the ball toward the higher foot at address. Ball speed was not significantly affected by the slope, but launch angle and ball spin were. As the coaching literature predicted, golfers were more likely to hit shots to the left from an uphill slope and to the right from a downhill slope. No consistent compensatory adjustments in alignment at address or azimuth were found, with the change in final shot dispersion resulting from the lateral spin of the ball.
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LAN, SHIYONG, YIGUANG LIU, BINGBING LIU, PENG SHENG, TAO WANG, and XINSHENG LI. "EFFECT OF SLOPES IN HIGHWAY ON TRAFFIC FLOW." International Journal of Modern Physics C 22, no. 04 (April 2011): 319–31. http://dx.doi.org/10.1142/s0129183111016270.
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In this paper, we propose a novel slope cellular automaton (CA) model to depict some physical properties of traffic flow with slopes. In our model, we present the effect of slopes on the acceleration/deceleration capabilities and safety distance of the vehicles in highways as in real traffic situations. By numerical simulations, we investigate the dependence of the vehicle capacities in highways on the length and grade of slopes. It is shown that the larger the slope grade, the more significant the effect of slopes on the traffic flow is. Especially when the slope grade is beyond a certain value (i.e. |σ| > 3%), the effect of slopes on traffic flow becomes quite markedly.
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Kwon, Young-Hoo, Lonn Hutcheson, Jeffrey B. Casebolt, Joong-Hyun Ryu, and Kunal Singhal. "The Effects of Railroad Ballast Surface and Slope on Rearfoot Motion in Walking." Journal of Applied Biomechanics 28, no. 4 (August 2012): 457–65. http://dx.doi.org/10.1123/jab.28.4.457.
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The purpose of this study was to investigate the effects of transversely sloped ballasted walking surface on gait and rearfoot motion (RFM) parameters. Motion analysis was performed with 20 healthy participants (15 male and 5 female) walking in six surface-slope conditions: two surfaces (solid and ballasted) by three slopes (0, 5, and 10 degrees). The gait parameters (walking velocity, step length, step rate, step width, stance time, and toe-out angle) showed significant surface effect (p= .004) and surface-slope interaction (p= .017). The RFM motion parameters (peak everted/inverted position, eversion/inversion velocity, and acceleration) revealed significant surface (p= .004) and slope (p= .024) effects. The ballasted conditions showed more cautious gait patterns with lower walk velocity, step length, and step rate and longer stance time. In the RFM parameters, the slope effect was more notable in the solid conditions due to the gait adaptations in the ballasted conditions. Ballast conditions showed reduced inversion and increased eversion and RFM range. The RFM data were comparable to other typical walking conditions but smaller than those from running.
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Nian, T. K., R. Q. Huang, S. S. Wan, and G. Q. Chen. "Three-dimensional strength-reduction finite element analysis of slopes: geometric effects." Canadian Geotechnical Journal 49, no. 5 (May 2012): 574–88. http://dx.doi.org/10.1139/t2012-014.
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The vast majority of slopes, both natural and constructed, exhibit a complex geometric configuration and three-dimensional (3D) state, whereas slopes satisfying the assumption of plane strain (infinite length) are seldom encountered. Existing research mainly emphasizes the 3D dimensions and boundary effect in slope stability analysis; however, the effect of complex geometric ground configuration on 3D slope stability is rarely reported. In this paper, an elastoplastic finite-element method using strength-reduction techniques is used to analyze the stability of special 3D geometric slopes. A typical 3D slope underlain by a weak layer with groundwater is described to validate the numerical modeling, safety factor values, and critical slip surface for the 3D slope. Furthermore, a series of special 3D slopes with various geometric configurations are analyzed numerically, and the effects of turning corners, slope gradient, turning arcs, and convex- and concave-shaped surface geometry on the stability and failure characteristics of slopes under various boundary conditions are discussed in detail.
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Cao, Xing Song, Yang Zhou, and Shi Xiong Liu. "Stability Analysis on Surface Layer of an Expansive Clay Slope with Consideration of Expansive Pressure." Advanced Materials Research 790 (September 2013): 353–57. http://dx.doi.org/10.4028/www.scientific.net/amr.790.353.
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Weathering effects, expansive pressure and pore water pressure are investigated to evaluate their effect on expansive clay slope stability. In particular, the effect of expansive pressure is analyzed to consider its effect on the stability of surface layer of the slope. In this paper, the distribution of expansive pressure in a slope is evaluated and used to analyze the stability of the surface layer of a clay slope. The proposed analysis method is applied in the third ring road project in Chengdu, China, where there are expansive clay slopes. Reasonable results are achieved.
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Breinbjerg, Olav. "Slope Diffraction Coupling Effect." Electromagnetics 18, no. 2 (March 1998): 179–206. http://dx.doi.org/10.1080/02726349808908580.
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Picard, Ghislain, Marie Dumont, Maxim Lamare, François Tuzet, Fanny Larue, Roberta Pirazzini, and Laurent Arnaud. "Spectral albedo measurements over snow-covered slopes: theory and slope effect corrections." Cryosphere 14, no. 5 (May 7, 2020): 1497–517. http://dx.doi.org/10.5194/tc-14-1497-2020.
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Abstract. Surface albedo is an essential variable to determine the Earth's surface energy budget, in particular for snow-covered areas where it is involved in one of the most powerful positive feedback loops of the climate system. In situ measurements of broadband and spectral albedo are therefore common. However they are subject to several artefacts. Here we investigate the sensitivity of spectral albedo measurements to surface slope, and we propose simple correction algorithms to retrieve the intrinsic albedo of a slope from measurements, as if it were flat. For this, we first derive the analytical equations relating albedo measured on a slope to intrinsic direct and diffuse albedo, the apportionment between diffuse and direct incoming radiation, and slope inclination and aspect. The theory accounts for two main slope effects. First, the slope affects the proportion of solar radiation intercepted by the surface relative to that intercepted by the upward-looking, horizontal, sensor. Second, the upward- and downward-looking sensors receive reduced radiation from the sky and the surface respectively and increased radiation from neighbouring terrain. Using this theory, we show that (i) slope has a significant effect on albedo (over 0.01) from as little as a ≈1∘ inclination, causing distortions of the albedo spectral shape; (ii) the first-order slope effect is sufficient to fully explain measured albedo up to ≈15∘, which we designate “small-slope approximation”; and (iii) for larger slopes, the theory depends on the neighbouring slope geometry and land cover, leading to much more complex equations. Next, we derive four correction methods from the small-slope approximation, to be used depending on whether (1) the slope inclination and orientation are known or not, (2) the snow surface is free of impurities or dirty, and (3) a single or a time series of albedo measurements is available. The methods applied to observations taken in the Alps on terrain with up to nearly 20∘ slopes prove the ability to recover intrinsic albedo with a typical accuracy of 0.03 or better. From this study, we derive two main recommendations for future field campaigns: first, sloping terrain requires more attention because it reduces the measurement accuracy of albedo even for almost invisible slopes (1–2∘). Second, while the correction of the slope effect is possible, it requires additional information such as the spectral diffuse and direction partitioning and if possible the actual slope inclination and aspect, especially when the absence of impurities can not be assumed.
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Liu, Hanxiang, Tong Qiu, and Qiang Xu. "Dynamic acceleration response of a rock slope with a horizontal weak interlayer in shaking table tests." PLOS ONE 16, no. 4 (April 21, 2021): e0250418. http://dx.doi.org/10.1371/journal.pone.0250418.
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The weak interlayer in a rock slope often plays a significant role in seismic rockslides; however, the effect of weak interlayer on the seismic slope response and damage process is still not fully understood. This study presents a series of shaking test tests on two model slopes containing a horizontal weak interlayer with different thicknesses. A recorded Wenchuan earthquake ground motion was scaled to excite the slopes. Measurements from accelerometers embedded at different elevations of slope surface and slope interior were analyzed and compared. The effect of the weak interlayer thickness on the seismic response was highlighted by a comparative analysis of the two slopes in terms of topographic amplification, peak accelerations, and deformation characteristics as the input amplitude increased. It was found that the structure deterioration and nonlinear response of the slopes were manifested as a time lag of the horizontal accelerations in the upper slope relative to the lower slope and a reduction of resonant frequency and Fourier spectral ratio. Test results show that under horizontal acceleration, both slopes exhibited significant topographic amplification in the upper half, and the difference in amplification between slope face and slope interior was more pronounced in Slope B (with a thin weak interlayer) than in Slope A (with a thick weak interlayer). A four-phased dynamic response process of both slopes was observed. Similar deformation characteristics including development of strong response zone and macro-cracks, vertical settlement, horizontal extrusion and collapse in the upper half were observed in both slopes as the input amplitude increased; however, the deformations were more severe in Slope B than in Slope A, suggesting an energy isolation effect of the thick interlayer in Slope A.
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Fan, Wenchen, Ping Cao, Ke Zhang, Kaihui Li, and Chong Chen. "Stability Assessment and Optimization Design of Lakeside Open-Pit Slope considering Fluid-Solid Coupling Effect." Mathematical Problems in Engineering 2015 (2015): 1–11. http://dx.doi.org/10.1155/2015/691826.
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Chengmenshan copper mine, located at Jiujiang city in the Jiangxi Province, is a rarely lakeside open-pit mine in China. Since the open-pit is very close to Sai Lake, the seasonally changed water level and the distance between lake and slope have great influence to the stability of open-pit slope. Based on the drill data and geological sections, a numerical model of the slope is built. With the fluid-mechanical interaction associated, the stability of the slopes is numerically analyzed, in which different lake water levels and lake-slope distances are taken into consideration. The comparative analysis shows that a larger lake-slope distance can promise better slope stability and weaken the sensitivity of slope stability to water. The stability of slopes with different heights is analyzed to find that the stability weakens and the sensitivity is enhanced with the height increasing. To the most serious situation, the slope height and the lake water level being 238 m and 17.2 m, respectively, theFsvalue equals 1.18945 which is extremely closed to the allowable safety factor of 1.20 for slope design. According to the minimumFsfor slope design, the minimum distance between lake and open-pit slope is found to be 60 m.
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Zhou, Lin, Guangya Ding, Jie Tan, Xiaoxia Zhao, and Jun Wang. "Seismic Response of Concrete-Canvas Reinforced Slopes: Influence of Tilt Degrees for Reinforcement." Journal of Earthquake and Tsunami 14, no. 03 (January 28, 2020): 2050011. http://dx.doi.org/10.1142/s1793431120500116.
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A series of shaking table tests were conducted on reinforced slopes to study the slope dynamic characteristics. The influence of concrete-canvas tilt degrees on the seismic response was studied. By considering the effects of different concrete-canvas tilt degrees, the seismic responses of the reinforced slopes were analyzed, along with the accelerations, crest settlements, and horizontal displacements. The failure patterns of different model slopes were compared using white coral sand marks placed at designated elevations to monitor the internal slide of the reinforced slopes. Several round markers were placed on the slope surface to compare the deformation before and after shaking with different amplitudes. The results indicated that with the increase in concrete-canvas tilt degrees, a better reinforcing effect was obtained, and 30° reinforcement reached a threshold level, the slide-out point shifts from the crest of the slope to the middle of the reinforced model. The bottom 2/7th zone of the slope was relatively stable during the earthquake and the reinforcement was ineffective at the bottom of the slope. When both considered the influence of reinforcing effect and construction difficulty, 20° is the suitable tilt degree in concrete-canvas reinforced slopes. The characteristics of increasing strength of the concrete canvas make it suitable for the application in slope protection.
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Fu, Suhua, Baoyuan Liu, Heping Liu, and Li Xu. "The effect of slope on interrill erosion at short slopes." CATENA 84, no. 1-2 (January 2011): 29–34. http://dx.doi.org/10.1016/j.catena.2010.08.013.
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Jiang, Hao Hao. "Effect Evaluation of Slope Protection for Herbs Based on the Principal Component Analysis." Applied Mechanics and Materials 117-119 (October 2011): 1181–84. http://dx.doi.org/10.4028/www.scientific.net/amm.117-119.1181.
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Slope protection with vegetation is a new technology which is using vegetation to preserve water and soil, so reduce slope instability and corrosion, simultaneously beautify ecological environment. Using vegetation for slope protection can protect slope, and can overcome the shortcoming of traditional slope protection ways.This article takes Northeast Forestry University tree farm as an experimental field. According to climatic conditions of northeast area, soil texture conditions of highway slopes and other conditions, this text selects 6 different common herbs to plant, observes ecology compatibility and preserving soil ability of each kind of plant, then uses mathematical method to appraise slope protection effect of each kind of plant.Results indicate that different type of grass has different slope protection effect.
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Nian, Ting Kai, Bo Liu, and Ping Yin. "Seafloor Slope Stability under Adverse Conditions Using Energy Approach." Applied Mechanics and Materials 405-408 (September 2013): 1445–48. http://dx.doi.org/10.4028/www.scientific.net/amm.405-408.1445.
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The effects of ocean waves on the stability of seafloor slopes are of great importance in marine environment. The stability of a seafloor slope considering wave-induced pressure is analyzed using the kinematic approach of limit analysis combined with a strength reduction technique. A seafloor slope without waves is considered first. Furthermore, waved-induced pressure is considered to act on the surface of slope as an external load to analyze the effects on the stability of slope by waves. The results show that the adverse effect of waves on slope stability increases with an increase of the wave height as well as a decrease of the water depth.
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JI, Xiao-Lei, and Ping YANG. "The effect of bermuda grass root morphology on the displacement of slope." MATEC Web of Conferences 275 (2019): 03004. http://dx.doi.org/10.1051/matecconf/201927503004.
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During recent years, with the drastic development of highway, lots of slopes are produced which cause the increase of geological disasters including soil erosion on the slope and shallow sliding surface, it makes significant impact on the ecological environment. Adopting ecological protection technique of plant slope protection not only can prevent geological disasters, but also benefit the protection of ecological environment. In the paper, bermuda grass, as one kind of ordinary slope protection plants, was chosen as specimen, and the root-soil composite was regarded as organic system which consists of soil and root system; the effect of root morphology on displacement of slope surface under the function of rain erosion and slope runoff erosion was studied and analyzed by using nonlinearity finite calculation method. The result indicates Bermuda grass root system can defense the rain erosion of slope surface soil, restrain the soil displacement and prevent water and soil erosion of slope.
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Jin, Qi Wen, Qian Xu, Tong Ning Wang, and Fei Geng. "Seismic Performance Analysis of Fill Slope with Pre-Stressed Anchors." Applied Mechanics and Materials 353-356 (August 2013): 2052–56. http://dx.doi.org/10.4028/www.scientific.net/amm.353-356.2052.
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Pre-stressed anchors were widely used to strengthen slopes, in this passage the dynamic responses of fill slope with pre-stressed anchors under the effect of seismic load were simulated by ANSYS program. And it was mainly analyzed the effect of pre-stress anchors on seismic performances of slope under general earthquake. The results indicate that changing the value of pre-stress has little effect on slope deformation, but has larger effect on stress distribution in slope. And with the increases of pre-stress value, stress response on the top of slope is small, the stress concentration in slope is alleviated, while the stress on slope toe increases a little, the seismic stability of slope is improved to some extent. And these conclusions may provide some theory basis for slope seismic design and study.
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Debabeche, Mahmoud, Sonia Cherhabil, Amin Hafnaoui, and Bachir Achour. "Hydraulic jump in a sloped triangular channel." Canadian Journal of Civil Engineering 36, no. 4 (April 2009): 655–58. http://dx.doi.org/10.1139/l08-136.
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The hydraulic jump in a sloped triangular channel of 90° central angle is theoretically and experimentally examined. The study aims to determine the effect of the channel's slope on the sequent depth ratio of the jump. A theoretical relation is proposed for the inflow Froude number as function of the sequent depth ratio and the channel slope. An experimental analysis is also proposed to find a better formulation of the obtained relation. For this motive, six positive slopes are tested. The relations obtained are recommended for designing irrigation ditches.
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Xiaoli, Guo, Yan Jiancheng, Li Xueliang, Wen Xin, and Li Xingli. "Study on shaping slope stability of dump in eastern grassland open-pit mine." E3S Web of Conferences 194 (2020): 04043. http://dx.doi.org/10.1051/e3sconf/202019404043.
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The dumps in the open-pit mining area in the eastern grassland are prone to landslides due to the fragile ecological environment, so it is inevitable to reshape the dump slopes. In order to explore a more scientific method for slope shaping of open-pit mine dump, slope stability analysis were used to compare effect of three types of slope-type (wave-shaped, slope-shaped and step-shaped slope shaping method)in outside dumping site of Baori Hiller open-pit mine. The results show that the slope stability is negatively correlated with the slope angle, and the stability of different shaping slopes is realized as wave-shaped slope (F=2.711)> Slope-shaped slope(F=2.513)>Step-shaped slope(F=1.047), in which the wave type and slope type are all within the safe range, but the step type slope is unstable; in consideration of cost, stability and erosion resistance, it is better to set the slope angle of the dump to 15°.The wave-shaped shaping method of the natural dumping of the excavation field outside the Baori Hiller open-pit mine has the best effect and is worth promoting.
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R. Srinivasan and B. A. Engel. "Effect of Slope Prediction Methods on Slope and Erosion Estimates." Applied Engineering in Agriculture 7, no. 6 (1991): 779–83. http://dx.doi.org/10.13031/2013.26302.
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Olfert, I. Mark, and G. Kim Prisk. "Effect of 60° head-down tilt on peripheral gas mixing in the human lung." Journal of Applied Physiology 97, no. 3 (September 2004): 827–34. http://dx.doi.org/10.1152/japplphysiol.01379.2003.
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The phase III slope of sulfur hexafluoride (SF6) in a single-breath washout (SBW) is greater than that of helium (He) under normal gravity (i.e., 1G), thus resulting in a positive SF6-He slope difference. In microgravity (μG), SF6-He slope difference is smaller because of a greater fall in the phase III slope of SF6 than He. We sought to determine whether increasing thoracic fluid volume using 60° head-down tilt (HDT) in 1G would produce a similar effect to μG on phase III slopes of SF6 and He. Single-breath vital capacity (SBW) and multiple-breath washout (MBW) tests were performed before, during, and 60 min after 1 h of HDT. Compared with baseline (SF6 1.050 ± 0.182%/l, He 0.670 ± 0.172%/l), the SBW phase III slopes for both SF6 and He tended to decrease during HDT, reaching nadir at 30 min (SF6 0.609 ± 0.211%/l, He 0.248 ± 0.138%/l; P = 0.08 and P = 0.06, respectively). In contrast to μG, the magnitude of the phase III slope decrease was similar for both SF6 and He; therefore, no change in SF6-He slope difference was observed. MBW analysis revealed a decrease in normalized phase III slopes at all time points during HDT, for both SF6 ( P < 0.01) and He ( P < 0.01). This decrease was due to changes in the acinar, and not the conductive, component of the normalized phase III slope. These findings support the notion that changes in thoracic fluid volume alter ventilation distribution in the lung periphery but also demonstrate that the effect during HDT does not wholly mimic that observed in μG.
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Turpin-Legendre, E., and J. P. Meyer. "Slope effect on pushing forces." Work 41 (2012): 5516–18. http://dx.doi.org/10.3233/wor-2012-0867-5516.
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Tagarelli, Vito, and Federica Cotecchia. "The Effects of Slope Initialization on the Numerical Model Predictions of the Slope-Vegetation-Atmosphere Interaction." Geosciences 10, no. 2 (February 24, 2020): 85. http://dx.doi.org/10.3390/geosciences10020085.
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Deep slope movements and, eventually, slope failure, have been often interpreted to be due to slope-vegetation-atmosphere interaction on slopes formed of clayey materials in the Italian Southern-Eastern Apennines, as reported in the literature. Such slopes are generally formed of flysch, within which clay is the main lithotype. Such clays are characterized by a disturbed meso-fabric, as an effect of the intense tectonics. The paper presents the results of coupled hydromechanical numerical analyses of the slope-vegetation-atmosphere interaction for a clay slope representative for the geomechanical scenario where such climate-induced deep slope movements have been repeatedly recorded. In the analyses, different model initialization procedures and parameter values were adopted. The comparison of the numerical results with the site data is aimed at assessing the effects of the soil-vegetation-atmosphere interaction taking place in the top strata of the slope, on the stress-strain conditions across the whole slope, and on the slope stability. The comparison between the numerical results of the analyses carried out entailing different initialization stages are intended to evaluate the influence of such a stage on the model predictions. It is found that only when the slope model initialization accounts for the slope loading history, developed over geological time, the numerical predictions get close to the site observations. In such case, the numerical results confirm that deep movements consequent to progressive failure may take place in clay slopes due to the slope-vegetation-atmosphere interaction.
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Jones, Marshall B. "Slope-Controlled Performance Testing." Proceedings of the Human Factors Society Annual Meeting 32, no. 14 (October 1988): 836–37. http://dx.doi.org/10.1518/107118188786762153.
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Cognitive-ability tests, though promising in other respects, generally show pronounced practice effects and have weak test-retest reliabilities. One reason for the low reliabilities appears to be that practice effects themselves vary from individual to individual, so that subjects differ not only in the levels at which they are performing when testing ends but also in the slopes leading up to those levels. Since slope of the performance curve late in practice has been shown to affect performance at reacquisition (retest), uncontrolled variation in slope may lower test-retest reliability. A possible approach to this problem is experimentally to control slope during testing so that all subjects are improving at roughly the same rates when testing ends. The expected effect is that, with inter-subject differences in slope controlled, the temporal stability of cognitive-ability tests will improve. If temporal stability improves, however, predictive validities ought also to improve.
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Raza, Awais, Wuyi Wan, and Kashif Mehmood. "Stepped Spillway Slope Effect on Air Entrainment and Inception Point Location." Water 13, no. 10 (May 20, 2021): 1428. http://dx.doi.org/10.3390/w13101428.
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Spillway is a crucial hydraulic structure used to discharge excess water from the dam reservoir. Air entrainment is essential to prevent cavitation damage on the spillway, however, without air entrainment the risk of cavitation over the spillway increases. The most important parameter for the determination of air entrainment in stepped spillways is the inception point. The inception point is the location where the air starts to inter into the water flow surface over the spillway. It occurs when the turbulent boundary layer meets the free surface. The location of the inception point depends upon different parameters like flow rate, geometry, step size, and slope of the spillway. The main aim of this study was applying numerical simulation by using the realizable k-ϵ model and the volume of fluid (VOF) method to locate the location of the inception point. For this purpose, by using different stepped spillways with four different slopes (12.5°, 19°, 29°, and 35°) different flow rates were simulated, which gives the location of the inception point of different channel slopes of stepped spillways at different flow rates. The results demonstrated that the inception point location of mild slopes is farther from the crest of the spillway than the steep slope stepped spillway. Non-aerated flow zone length increases when the channel slope decreases from steep to mild slope.
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Liu, Chuanzheng, Gang Wang, and Wei Han. "Effect of Slip Surface’s Continuity on Slope Dynamic Stability Based on Infinite Slope Model." Mathematics 7, no. 1 (January 8, 2019): 58. http://dx.doi.org/10.3390/math7010058.
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The slip surface is an important control structure surface existing in the landslide. It not only directly affects the stability of the slope through the strength, but also affects the stress field by affecting the propagation of the stress wave. Many research results have been made on the influence of non-continuous stress wave propagation in rock and soil mass and the dynamic response to seismic slopes. However, the effect of the continuity of the slip surface on the slope dynamic stability needs further researches. Therefore, in this paper, the effect of slip surface on the slope’s instantaneous safety factor is analyzed by the theoretical method with the infinite slope model. Firstly, three types of slip surface model were established, to realize the change of sliding surface continuity in the infinite slope. Then, based on wave field analysis, the instantaneous safety factor was used to analyze the effect of continuity of slip surface. The results show that with the decreasing of slip surface continuity, the safety factor does not simply increase or decrease, and is related to slope features, incident wave and continuity of slip surface. The safety factor does not decrease monotonically with the increasing of slope angle and thickness of slope body. Moreover, the reflection of slope surface has a great influence on the instantaneous safety factor of the slope. Research results in this paper can provide some references to evaluate the stability of seismic slope, and have an initial understanding of the influence of structural surface continuity on seismic slope engineering.
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Bernhardson, Andrew S., Zachary S. Aman, Grant J. Dornan, Bryson R. Kemler, Hunter W. Storaci, Alex W. Brady, Gilberto Y. Nakama, and Robert F. LaPrade. "Tibial Slope and Its Effect on Force in Anterior Cruciate Ligament Grafts: Anterior Cruciate Ligament Force Increases Linearly as Posterior Tibial Slope Increases." American Journal of Sports Medicine 47, no. 2 (January 14, 2019): 296–302. http://dx.doi.org/10.1177/0363546518820302.
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Background: Previous work has reported that increased tibial slope is directly correlated with increased anterior tibial translation, possibly predisposing patients to higher rates of anterior cruciate ligament (ACL) tears and causing higher rates of ACL graft failures over the long term. However, the effect of changes in sagittal plane tibial slope on ACL reconstruction (ACLR) graft force has not been well defined. Purpose/Hypothesis: The purpose of this study was to quantify the effect of changes in sagittal plane tibial slope on ACLR graft force at varying knee flexion angles. Our null hypothesis was that changing the sagittal plane tibial slope would not affect force on the ACL graft. Study Design: Controlled laboratory study. Methods: Ten male fresh-frozen cadaveric knees had a posterior tibial osteotomy performed and an external fixator placed for testing and accurate slope adjustment. Following ACLR, specimens were compressed with a 200-N axial load at flexion angles of 0°, 15°, 30°, 45°, and 60°, and the graft loads were recorded through a force transducer clamped to the graft. Tibial slope was varied between −2° and 20° of posterior slope at 2° increments under these test conditions. Results: ACL graft force in the loaded testing state increased linearly as slope increased. This effect was independent of flexion angle. The final model utilized a 2-factor linear mixed-effects regression model and noted a significant, highly positive, and linear relationship between tibial slope and ACL graft force in axially loaded knees at all flexion angles tested (slope coefficient = 0.92, SE = 0.08, P < .001). Significantly higher graft force was also observed at 0° of flexion as compared with all other flexion angles for the loaded condition (all P < .001). Conclusion: The authors found that tibial slope had a strong linear relationship to the amount of graft force experienced by an ACL graft in axially loaded knees. Thus, a flatter tibial slope had significantly less loading of ACL grafts, while steeper slopes increased ACL graft loading. Our biomechanical findings support recent clinical evidence of increased ACL graft failure with steeper tibial slope secondary to increased graft loading. Clinical Relevance: Evaluation of the effect of increasing tibial slope on ACL graft force can guide surgeons when deciding if a slope-decreasing proximal tibial osteotomy should be performed before a revision ACLR. Overall, as slope increases, ACL graft force increases, and in our study, flatter slopes had lower ACL graft forces and were protective of the ACLR graft.
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Ai, Ze Min, Jiao Yang Zhang, Hong Fei Liu, Sha Xue, and Guo Bin Liu. "Influence of slope aspect on the microbial properties of rhizospheric and non-rhizospheric soils on the Loess Plateau, China." Solid Earth 9, no. 5 (October 9, 2018): 1157–68. http://dx.doi.org/10.5194/se-9-1157-2018.
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Abstract. Slope aspect is an important topographic factor in the micro-ecosystem environment, but its effect on the microbial properties of grassland rhizospheric soil (RS) and non-rhizospheric soil (NRS) remain unclear. A field experiment was conducted at the Ansai Research Station on the Loess Plateau in China to test the influence of slope aspects (south-facing, north-facing, and northwest-facing slopes, all with Artemisia sacrorum as the dominant species) on RS and NRS microbial biomass carbon (MBC) contents, phospholipid fatty acid (PLFA) contents, and the rhizospheric effect (RE) of various microbial indices. Soil samples were collected from the three slope aspects, including rhizospheric and non-rhizospheric region, and analyzed to determine the various related microbial indices. The results showed that MBC content differed significantly among the slope aspects in RS but not in NRS, and the RE for MBC content in the south-facing slope was larger than that in the north-facing slope. RS total, bacterial, and Gram-positive bacterial PLFA contents in the south-facing slope were significantly lower than those in the north- and northwest-facing slopes, and RS Gram-negative bacterial (G−) and actinomycete PLFA contents in the south-facing slope were significantly lower than those in the north-facing slope. In contrast, NRS total, bacterial, and G− PLFA contents in the north-facing slope were significantly higher than those in the south- and northwest-facing slopes, and NRS fungal and actinomycete PLFA contents in the north- and south-facing slopes were significantly higher than those in the northwest-facing slope. RE for all PLFA contents except fungal in the northwest-facing slope were higher than those in the south-facing slope. Slope aspect significantly but differentially affected the microbial properties in RS and NRS, and the variable influence was due to an evident RE for most microbial properties.
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Mangnejo, D. A., S. J. Oad, S. A. Kalhoro, S. Ahmed, F. H. Laghari, and Z. A. Siyal. "Numerical Analysis of Soil Slope Stabilization by Soil Nailing Technique." Engineering, Technology & Applied Science Research 9, no. 4 (August 10, 2019): 4469–73. http://dx.doi.org/10.48084/etasr.2859.
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Slope instability may be a result of change in stress conditions, rise in groundwater table and rainfall. Similarly, many slopes that have been stable for several years can abruptly fail due to changes in geometry, weak soil shear strength or as the effect of an external force. Debris flows (i.e. slope failures) take place without any warning and can have devastating results. So, it is vital to understand the slope failure mechanism and adopt safety prevention measures. Soil nailing is one of the widely used stabilization techniques for soil slopes. In this study, soil nail technique is proposed to upgrade the existing slope in clay. A parametric study was conducted to understand the effects of different nail diameter (i.e. 25mm and 40mm) and nail inclination (i.e. 200, 250, 300, 350 and 400) on slope stability. Morgenstern-Price (i.e. limit equilibrium) method was used to determine the factor of safety of the slope. It was found that the factor of safety of the existing slope improved significantly with three rows of 40mm diameter nail at an inclination of 400.
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Barvor, Yamah Joy, Sher Bacha, Cai Qingxiang, Chen Shu Zhao, Nisar Mohammad, Izhar Mithal Jiskani, and Naseer Muhammad Khan. "Research on the coupling effect of the composite slope geometrical parameters." Mining of Mineral Deposits 15, no. 2 (2021): 35–46. http://dx.doi.org/10.33271/mining15.02.035.
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Purpose. To analyze the coupling effect between composite slope geometrical parameters. Methods. The slope angle and excavation depth are coupled with load which is waste dump in this case. Several models were created and analyzed to capture their coupling effect and interactions using FLAC/Slope. Findings. When the slope angle and excavation depth are coupled with a load such as that of a waste dump, the factor of safety decreases. But a suitable dumping position can prove vital to enhancing stability. The primary cause of this phenomenon is that the stresses induced by the waste dump decrease as the dump is moved away from the crest of the slope and the stress induced within the zone of active wedge beneath the dump reduces on the reference slip plane. Hence, it can be said that the position of the waste dump in the formation of a composite slope plays a key role in enhancing stability. Factor of safety have the same influence pattern for all parameters induced by stress as that of influence rule. The results obtained from the finite element stress analysis are the same with those obtained for the slope stability analysis. Originality. The current research presents for the first time the coupling effect of the composite slope geometrical parameters and the results of finite element stress analysis, which are similar to those of slope stability analysis. Practical implications. The current research results can be used to effectively analyze and design the composite slopes in soft rocks specially in surface mines.
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Zhao, Yuxia, Liqun Wang, and Han Li. "Effect of Freeze-Thaw on the Stability of a Cutting Slope in a High-Latitude and Low-Altitude Permafrost Region." Applied System Innovation 3, no. 3 (September 4, 2020): 36. http://dx.doi.org/10.3390/asi3030036.
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In order to study the influence of freeze-thaw cycles on the stability of cutting slopes in high-latitude and low-altitude permafrost regions, we selected a cutting slope (the K105+700–800 section of National Highway 332) in the Elunchun Autonomous Banner in Inner Mongolia as the research object. Located in the Greater Xing’an Mountains, the permafrost in the Elunchun Autonomous Banner is a high-latitude and low-altitude permafrost. The area is also dominated by island-shaped permafrost, which increases the difficulty of dealing with cutting slopes, due to its morphological complexity. Surface collapse, caused by freeze-thaw erosion in this area, is the main reason for the instability of the cutting slope. Indoor freeze-thaw tests, field monitoring, and an ABAQUS numerical simulation model were conducted so as to quantify the decrease in rock strength and slope stability under freeze-thaw conditions. The following conclusions were drawn. (1) As the number of freeze-thaw cycles increased, the compressive strength of the rock specimens obtained from this slope gradually decreased. After 50 freeze-thaw cycles, the uniaxial compressive strength measured by the test decreased from 40 MPa to 12 MPa, a decrease of 37%. The elastic modulus value was reduced by 47%. (2) The safety factor of the slope—calculated by the strength reduction method under the dynamic analysis of coupled heat, moisture, and stress—gradually decreased. After 50 freeze-thaw cycles, the safety factor of the slope was only 0.74. (3) Reasonably reducing the number of freeze-thaw cycles, reducing the water content of the slope, slowing down the slope, and increasing the number of grading steps can effectively improve the stability of the slope. The results of this study can provide a reference for the design and stability analysis of slopes in permafrost regions of the Greater Xing’an Mountains.
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Faug, Thierry, Mohamed Naaim, and Florence Naaim-Bouvet. "Experimental and numerical study of granular flow and fence interaction." Annals of Glaciology 38 (2004): 135–38. http://dx.doi.org/10.3189/172756404781814870.
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AbstractDense snow avalanches are regarded as dry granular flows. This paper presents experimental and numerical modelling of deposition processes occurring when a gravity-driven granular flow meets a fence. A specific experimental device was set up, and a numerical model based on shallow-water theory and including a deposition model was used. Both tools were used to quantify how the retained volume upstream of the fence is influenced by the channel inclination and the obstacle height. We identified two regimes depending on the slope angle. In the slope-angle range where a steady flow is possible, the retained volume has two contributions: deposition along the channel due to the roughness of the bed and deposition due to the fence. The retained volume results only from the fence effects for higher slopes. The effects of slope on the retained volume also showed these two regimes. For low slopes, the retained volume decreases strongly with increasing slope. For higher slopes, the retained volume decreases weakly with increasing slope. Comparison between the experiments and computed data showed good agreement concerning the effect of fence height on the retained volume.
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Hossein, Yazarlou, Parsakhoo Aidin, Habashi Hashem, and Soltauninejad Soltan Ali. "Effect of the skid trail cross section and horizontal alignment on forest soil physical properties." Journal of Forest Science 63, No. 4 (April 27, 2017): 161–66. http://dx.doi.org/10.17221/108/2016-jfs.
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Horizontal alignment and cross section characteristics of a skid trail in a ground-based skidding system including curves, wheel ruts and cross slope can impact on the forest soil. In this study the measurement of cross section and vertical alignment of skid trail in Bahramnia forestry plan was done using a levelling instrument. Horizontal alignment of skid trail including straight routes and curves was taken using polar methods. A 3D map of skid trail was produced in AutoCAD Civil3D software. Soil bulk density was measured after sampling the soil with a core sampler. Results showed that in straight routes, soil bulk density increased by increasing the cross slope of skid trail. Moreover, soil porosity decreased with the increasing cross slope. There was a significant difference between cross slopes in soil moisture. On curves, maximum bulk density occurred when the cross slope was 10%. Findings about soil porosity and moisture on curves of skid trails were similar to those of straight routes. Based on our findings, soil bulk density in wheel ruts was significantly lower than that in the middle part of skid trail. Soil bulk density in the silty soil texture of studied skid trails was a little more than ideal bulk density, so it cannot affect and restrict root growth.
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Tran, Hung Nam, Duong Nguyen Tran, and Tiep Duc Pham. "HiStudy on the stability of road embankment due to the effect of water level changes on the slopes." Journal of Mining and Earth Sciences 61, HTCS6 (December 31, 2020): 26–32. http://dx.doi.org/10.46326/jmes.htcs2020.04.
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This paper presents a study on the stability of road embankment due to the effect of water level changes on the slope. Two scenarios of the drawdown were considered. The first one is the case of the embankment with the water on one slope and the second one is for the embankment with the water on both two slopes. For the two cases, the water level on one side drops. Effects of various parameters such as the permeability of the road embankment soil, the rate of change in water level on the stability of the slope were evaluated, to found out the principle of the change of stability of the embankment. The results showed that the embankment stability reduces if there is a drawdown of the water level on the slope.
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Li, D., L. Zhang, C. Zhou, and W. Lu. "Risk-based stabilization planning for soil cut slopes." Natural Hazards and Earth System Sciences 9, no. 4 (August 6, 2009): 1365–79. http://dx.doi.org/10.5194/nhess-9-1365-2009.
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Abstract. Risk-based slope stabilization planning integrates the failure probability and the failure consequence systematically and shows promise for use in the practice. This paper attempts to develop a risk-based methodology for stabilization planning for deteriorating soil cut slopes. First, a framework of risk-based stabilization planning for slopes is proposed. Then the time-dependent reliability of deteriorating slopes is analyzed based on observed performance. Thereafter, the slope failure consequence is assessed in terms of expected numbers of fatality. After obtaining the time-dependent risk of slope failure, the time for slope stabilization is determined according to selected risk criteria. Finally, the effect of slope maintenance on the reliability of slopes is evaluated. Based on the analyses, the annual probability of failure of soil cut slopes would increase exponentially in the early stage of service if no maintenance were implemented. As a slope deteriorates, the risk of slope failure increases with time and may reach an intolerable level at a certain time. The risk of slope failure may also reach an intolerable level due to a change of elements at risk. The derived stabilization time depends on the factors that cause the slopes to deteriorate, consequence of slope failure, selected risk criteria, and vulnerability of the affected population.
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Zhou, Zhijun, Chenning Ren, Guanjun Xu, Haochen Zhan, and Tong Liu. "Dynamic Failure Mode and Dynamic Response of High Slope Using Shaking Table Test." Shock and Vibration 2019 (March 25, 2019): 1–19. http://dx.doi.org/10.1155/2019/4802740.
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A shaking table test was performed to study the dynamic response and failure modes of high slope. Test results show that PGA amplification coefficients increased with increasing elevation and the PGA amplification coefficient of the concave slope was slightly larger than that of the convex slope. The slope type affected the dynamic response of the slope. The elevation amplification effect of the concave slope under seismic load was more significant than that of the convex slope; thus, the concave slope was more unstable than the convex slope. Additionally, the PGA amplification coefficient measured on the slope surface was always larger than that inside the slope, and the data show an increasing trend with the broken line. The dynamic amplification effect of the high slope was closely related to the natural frequency of the slope. Within a certain range, the higher the frequency, the more significant the amplification effect. The dynamic failure process of concave and convex slopes was studied through tests. Findings indicate that the dynamic failure modes of the concave slope are characterized by shoulder collapse, formation of the sliding surface, and integral sliding above the slope line. Dynamic failure modes of the convex slope are mainly slips in the soil layer and collapse of the slope near the slope line.
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Wang, Liping, and Ga Zhang. "Pile-Reinforcement Behavior of Cohesive Soil Slopes: Numerical Modeling and Centrifuge Testing." Journal of Applied Mathematics 2013 (2013): 1–15. http://dx.doi.org/10.1155/2013/134124.
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Centrifuge model tests were conducted on pile-reinforced and unreinforced cohesive soil slopes to investigate the fundamental behavior and reinforcement mechanism. A finite element analysis model was established and confirmed to be effective in capturing the primary behavior of pile-reinforced slopes by comparing its predictions with experimental results. Thus, a comprehensive understanding of the stress-deformation response was obtained by combining the numerical and physical simulations. The response of pile-reinforced slope was indicated to be significantly affected by pile spacing, pile location, restriction style of pile end, and inclination of slope. The piles have a significant effect on the behavior of reinforced slope, and the influencing area was described using a continuous surface, denoted asW-surface. The reinforcement mechanism was described using two basic concepts,compression effectandshear effect, respectively, referring to the piles increasing the compression strain and decreasing the shear strain of the slope in comparison with the unreinforced slope. The pile-soil interaction induces significantcompression effectin the inner zone near the piles; this effect is transferred to the upper part of the slope, with theshear effectbecoming prominent to prevent possible sliding of unreinforced slope.
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Mezazigh, S., and D. Levacher. "Laterally loaded piles in sand: slope effect on P-Y reaction curves." Canadian Geotechnical Journal 35, no. 3 (June 1, 1998): 433–41. http://dx.doi.org/10.1139/t98-016.
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An extensive program of centrifuge tests was undertaken to study the effect of slopes on P-Y curves in dry sand. The paper concerns the method developed in a previous series of centrifuge tests to experimentally determine P-Y curves. Bending-moment curves are fitted by local quintic spline functions through a crossed validation method and then differentiated twice. These experimental P-Y curves are validated by back analysis. The program of tests on piles near slopes is given. It includes studies of the effect of distance to the slope, slope angle, and soil properties. Sample preparation method, model piles, and the lateral-loading device are described. Deflection versus load curves, bending-moment curves, and derived P-Y curves for piles close to slopes are compared to horizontal-ground response. The coefficients that can apply to the P-Y reaction curves of the reference piles (a single pile in horizontal ground) are proposed for use in practice.Key words: pile, slope effets, models, centrifuge, bending moment, P-Y reaction curves.
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Collacchioni, Florencia, Claudia D. P. Lagos, Peter D. Mitchell, Joop Schaye, Emily Wisnioski, Sofía A. Cora, and Camila A. Correa. "The effect of gas accretion on the radial gas metallicity profile of simulated galaxies." Monthly Notices of the Royal Astronomical Society 495, no. 3 (January 2020): 2827–43. http://dx.doi.org/10.1093/mnras/staa1334.
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ABSTRACT We study the effect of the gas accretion rate ($\dot{M}_{\rm accr}$) on the radial gas metallicity profile (RMP) of galaxies using the eagle cosmological hydrodynamic simulations, focusing on central galaxies of stellar mass M⋆ ≳ 109 M⊙ at z ≤ 1. We find clear relations between $\dot{M}_{\rm accr}$ and the slope of the RMP (measured within an effective radius), where higher $\dot{M}_{\rm accr}$ are associated with more negative slopes. The slope of the RMPs depends more strongly on $\dot{M}_{\rm accr}$ than on stellar mass, star formation rate (SFR), or gas fraction, suggesting $\dot{M}_{\rm accr}$ to be a more fundamental driver of the RMP slope of galaxies. We find that eliminating the dependence on stellar mass is essential for pinning down the properties that shape the slope of the RMP. Although $\dot{M}_{\rm accr}$ is the main property modulating the slope of the RMP, we find that it causes other correlations that are more easily testable observationally: At fixed stellar mass, galaxies with more negative RMP slopes tend to have higher gas fractions and SFRs, while galaxies with lower gas fractions and SFRs tend to have flatter metallicity profiles within an effective radius.
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Dunn, Matthew, and Robert Hickey. "The effect of slope algorithms on slope estimates within a GIS." Cartography 27, no. 1 (June 1998): 9–15. http://dx.doi.org/10.1080/00690805.1998.9714086.
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Bernhardson, Andrew S., Zachary S. Aman, Nicholas N. DePhillipo, Grant J. Dornan, Hunter W. Storaci, Alex W. Brady, Gilberto Nakama, and Robert F. LaPrade. "Tibial Slope and Its Effect on Graft Force in Posterior Cruciate Ligament Reconstructions." American Journal of Sports Medicine 47, no. 5 (March 21, 2019): 1168–74. http://dx.doi.org/10.1177/0363546519827958.
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Background: A flattened posterior tibial slope may cause excessive unwanted stress on the posterior cruciate ligament (PCL) reconstruction graft and place patients at risk for PCL reconstruction graft failure. To date, there is a paucity of biomechanical studies evaluating the effect of posterior tibial slope on the loading properties of single-bundle (SB) and double-bundle (DB) PCL grafts. Purpose/Hypothesis: The purpose of this study was to quantify the effect of sagittal plane tibial slope on PCL reconstruction graft force at varying slopes and knee flexion angles for SB and DB PCL reconstructions. The null hypothesis was that there would be no differences in SB or DB PCL graft forces with changes in posterior tibial slope or knee flexion angle. Study Design: Controlled laboratory study. Methods: Ten male fresh-frozen cadaveric knees had a proximal posterior tibial osteotomy performed and an external fixator placed for tibial slope adjustment. SB (anterolateral bundle [ALB] only) and DB PCL reconstruction procedures were performed and tested consecutively for each specimen. The ALB and posteromedial bundle graft forces were recorded before (unloaded force) and after (loaded force) compression with a 300-N axial load. Unloaded and loaded graft forces were tested at flexion angles of 45°, 60°, 75°, and 90°. Tibial slope was varied between −2° and 16° of posterior slope at 2° increments under these test conditions. Results: Modeling for unloaded testing revealed that tibial slope had an independently significant and linear decreasing effect on the force of all PCL grafts regardless of flexion angle (coefficient = −1.0, SE = 0.08, P < .001). Higher knee flexion angles were significantly associated with higher unloaded graft force for all PCL grafts ( P < .001). After the graft was subjected to loading, tibial slope also had an independently significant and linear decreasing effect on the loaded force of all PCL grafts regardless of flexion angle (coefficient = −0.70, SE = 0.11, P < .001). The ALB graft of DB reconstructions had a significantly lower loaded graft force than the ALB graft of the SB PCL reconstruction (coefficient = 14.8, SE = 1.62, P < .001). The posteromedial bundle graft had a significantly lower loaded graft force than the ALB graft in both reconstruction states across all flexion angles (both P < .001). Higher knee flexion angles were also significantly associated with higher loaded graft force for all graft constructs ( P < .001). Conclusion: PCL graft forces increased as tibial slope decreased (flattened) in the loaded and unloaded states. An increased posterior tibial slope was protective of PCL reconstruction grafts. The findings of this study support the effect of tibial slope on PCL grafts that has been noted clinically, and a flat tibial slope should be considered a factor when evaluating the cause of failed PCL reconstructions. Clinical Relevance: The authors validated that decreased tibial slope increased the loads on PCL reconstruction grafts. Patients with flat tibial slopes in chronic tears or revision PCL reconstruction cases should be evaluated closely for the possible need of a first-stage or concurrent slope-increasing tibial osteotomy.
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Assefa, Fikru, Eyasu Elias, Teshome Soromessa, and Gebiaw T. Ayele. "Effect of Changes in Land-Use Management Practices on Soil Physicochemical Properties in Kabe Watershed, Ethiopia." Air, Soil and Water Research 13 (January 2020): 117862212093958. http://dx.doi.org/10.1177/1178622120939587.
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Change in land-use management practices such as cultivation of steep slopes, overgrazing, and no or limited fallow periods, and slope position affects the quality of soils. As a result, assessing soil physicochemical properties and subsequent implications on soil fertility is essential for understanding the influence of agro-ecosystem revolution on agricultural soil quality and efficiency. In this research, we assessed the effect of land-use management practices on selected soil properties under varying terrain slopes and with and without soil conservation measures in a highly disturbed landscape in the northern part of Ethiopia in 2016. Based on the result, for all slope positions considered—namely, lower (1%-15%), middle (15%-30%), and upper (30%-45% and above)—with and without soil conservation, soil moisture content, porosity, silt, and clay proportions were lower in the cultivated land compared with grazing and forestland-use units. Conversely, soil bulk density and the sand fraction were higher in the cultivated land than grazing and forestland units, relatively. Observing changes in a terrain slope position, sand content of forest, grazing, and cultivated land units increased from lower to upper slope position whereas silt and clay fraction generally showed a decreasing trend from lower to an upper slope positions. In all slope positions with and without conservation practice, cation exchange capacity, exchangeable K+, Ca2+, and Mg2+ showed a significant increase from cultivated land to grazing and then forestland. The mean value of pH and electrical conductivity of cultivated lands with and without soil conservation were significantly low in all slope categories. Summarizing the analysis of variance for selected soil chemical properties with different slope positions, except available phosphorous, all chemical properties considered in this study are statistically significant ( P < .05). In summary, the result confirmed that soil properties were strongly influenced by terrain slope, land use, and changes in management practice. Consequently, to conserve soil resources, policymakers need to implement appropriate land conservation strategies based on land-use structure and slope variation.
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Zhu, Wen Xin, and Wan Tao Ding. "Study on the Reinforce Scheme to a Karst Slope of Shuinan Highway." Applied Mechanics and Materials 99-100 (September 2011): 400–405. http://dx.doi.org/10.4028/www.scientific.net/amm.99-100.400.
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There is potential main landslip and thin-layer siliceous rock undisturbed at the lower part of the left side of Karst slop K133＋180. During the course of excavation, due to the effect of gravity, creep and ulcerate flexion slip surface might occur. From the slope geo-mechanics model perspective, this paper proposes two reinforce schemes on the slope based on the slope reinforce project experiences on the slope of similar condition in the area after taking into account the effect of rainfall conditions. The paper also compares the economic efficiency of the two schemes and considers that, provided that the slope design is stable, scheme 2 shall be more economically efficient. As a conclusion, the left slop K133＋180 was reinforced with scheme 2. So far, the slope keeps stable and firm through times of rainfall. The reinforce experience on the Karst slope K133+180 shall be able to act as a useful reference for similar projects.
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Li, Yang, Ling Yu, Weidong Song, and Tianhong Yang. "Three-Dimensional Analysis of Complex Rock Slope Stability Affected by Fault and Weak Layer Based on FESRM." Advances in Civil Engineering 2019 (December 7, 2019): 1–14. http://dx.doi.org/10.1155/2019/6380815.
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Slope stability analysis is the most important problem in slope engineering design and construction. Open-pit slope often spans several strata, many of which are relatively weak. There may be faults and weak layers across the whole rock. It is very necessary to study the instability mechanism and stability analysis of multistratigraphic slopes with faults and weak layers. In this paper, taking a complex three-dimensional slope with fault and weak layer as the research object, the evolution laws of the stress field and damage zone of the slope are analyzed by using the finite element strength reduction method. The results show that the fault and weak layer have different degrees of effect on the slope stability. The fault causes stress concentration and damage to nearby rock mass, and the weak layer causes stress concentration on the slope above it and forms a dangerous slip zone. Then the effect of the fault and weak layer on slope stability is discussed. Because the effect of horizontal structural plane on slope stability is greater than that of the vertical structural plane, the effect of weak layer on slope stability is greater than that of the fault in the slope. The research results can provide a theoretical guidance for the study of slope stability in practical engineering.
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Telhan, Gaurav, Jason R. Franz, Jay Dicharry, Robert P. Wilder, Patrick O. Riley, and D. Casey Kerrigan. "Lower Limb Joint Kinetics During Moderately Sloped Running." Journal of Athletic Training 45, no. 1 (January 1, 2010): 16–21. http://dx.doi.org/10.4085/1062-6050-45.1.16.
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Abstract Context: Knowledge of the kinetic changes that occur during sloped running is important in understanding the adaptive gait-control mechanisms at work and can provide additional information about the poorly understood relationship between injury and changes in kinetic forces in the lower extremity. A study of these potential kinetic changes merits consideration, because training and return-to-activity programs are potentially modifiable factors for tissue stress and injury risk. Objective: To contribute further to the understanding of hill running by quantifying the 3-dimensional alterations in joint kinetics during moderately sloped decline, level, and incline running in a group of healthy runners. Design: Crossover study. Setting: Three-dimensional motion analysis laboratory. Patients or Other Participants: Nineteen healthy young runners/joggers (age = 25.3 ± 2.5 years). Intervention(s): Participants ran at 3.13 m/s on a treadmill under the following 3 different running-surface slope conditions: 4° decline, level, and 4° incline. Main Outcome Measure(s): Lower extremity joint moments and powers and the 3 components of the ground reaction force. Results: Moderate changes in running-surface slope had a minimal effect on ankle, knee, and hip joint kinetics when velocity was held constant. Only changes in knee power absorption (increased with decline-slope running) and hip power (increased generation on incline-slope running and increased absorption on decline-slope running in early stance) were noted. We observed an increase only in the impact peak of the vertical ground reaction force component during decline-slope running, whereas the nonvertical components displayed no differences. Conclusions: Running style modifications associated with running on moderate slopes did not manifest as changes in 3-dimensional joint moments or in the active peaks of the ground reaction force. Our data indicate that running on level and moderately inclined slopes appears to be a safe component of training regimens and return-to-run protocols after injury.
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Liu, Shunqing, Xianwen Huang, Aizhao Zhou, Jun Hu, and Wei Wang. "Soil-Rock Slope Stability Analysis by Considering the Nonuniformity of Rocks." Mathematical Problems in Engineering 2018 (November 8, 2018): 1–15. http://dx.doi.org/10.1155/2018/3121604.
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Soil-rock slopes are widely distributed around the world, while the commonly adopted method by simplifying it as a uniform media tends to be excessively conservative. In this study, a slope stability analysis method considering the nonuniform characteristics of rocks was proposed. It was found that the distribution, relative position, and shape of rock have significant effect on slope stability. For the influence of distribution, large rocks at the foot of slope have the most significant effect on slope stability while the effect is insignificant when the rocks are on the slope surface. In terms of the relative position of rocks, four plastic expansion modes of bypass, diversion, inclusion, and penetration were put forward through the analysis on the expansion mode of the plastic zone. Moreover, rock shape also has influence on slope stability.
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Natesan Batley, Prathiba, and Larry Vernon Hedges. "Accurate models vs. accurate estimates: A simulation study of Bayesian single-case experimental designs." Behavior Research Methods 53, no. 4 (February 11, 2021): 1782–98. http://dx.doi.org/10.3758/s13428-020-01522-0.
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AbstractAlthough statistical practices to evaluate intervention effects in single-case experimental design (SCEDs) have gained prominence in recent times, models are yet to incorporate and investigate all their analytic complexities. Most of these statistical models incorporate slopes and autocorrelations, both of which contribute to trend in the data. The question that arises is whether in SCED data that show trend, there is indeterminacy between estimating slope and autocorrelation, because both contribute to trend, and the data have a limited number of observations. Using Monte Carlo simulation, we compared the performance of four Bayesian change-point models: (a) intercepts only (IO), (b) slopes but no autocorrelations (SI), (c) autocorrelations but no slopes (NS), and (d) both autocorrelations and slopes (SA). Weakly informative priors were used to remain agnostic about the parameters. Coverage rates showed that for the SA model, either the slope effect size or the autocorrelation credible interval almost always erroneously contained 0, and the type II errors were prohibitively large. Considering the 0-coverage and coverage rates of slope effect size, intercept effect size, mean relative bias, and second-phase intercept relative bias, the SI model outperformed all other models. Therefore, it is recommended that researchers favor the SI model over the other three models. Research studies that develop slope effect sizes for SCEDs should consider the performance of the statistic by taking into account coverage and 0-coverage rates. These helped uncover patterns that were not realized in other simulation studies. We underline the need for investigating the use of informative priors in SCEDs.
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Zhang, Q., J. Wang, and F. Wu. "Spatial heterogeneity of surface roughness on tilled loess slopes in erosion stages." Soil and Water Research 13, No. 2 (April 13, 2018): 90–97. http://dx.doi.org/10.17221/130/2017-swr.
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The main soil erosion areas of the Chinese Loess Plateau are tilled slopes. The knowledge of their spatial heterogeneity will contribute to the understanding of erosion mechanisms on a microtopographic scale. In this study, the spatial heterogeneity of four conventionally tilled slopes was examined under simulated rainfall conditions using a semivariogram-based methodological framework. Results show that all tilled slopes have a relatively stable spatial structure and the erosion stages of all tilled slopes have a similar spatial variability. The rainfall in the splash, sheet, and rill erosion stages has a degree of relief effect, strengthening effect, and relief effect on the surface roughness, respectively. However, the effects of tillage practices and slope gradient on the spatial heterogeneity are much larger than those of the rainfall. The spatial heterogeneity decreases with increasing slope gradient. The general autocorrelation scale of the tilled slopes is 3.15 m and their fractal dimension ranges from 1.59 to 1.85. The tilled slopes have certain anisotropy with respect to the slope direction from 10° to 22.5° while they show isotropy or weaker anisotropy in other directions. In this work, a semivariogram-based methodological framework was established for the spatial heterogeneity of microtopographic-scale slopes. The results also provide a theoretical foundation for future tillage measures on sloping fields of the Loess Plateau.
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Krahn, J., D. G. Fredlund, and M. J. Klassen. "Effect of soil suction on slope stability at Notch Hill." Canadian Geotechnical Journal 26, no. 2 (May 1, 1989): 269–78. http://dx.doi.org/10.1139/t89-036.
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The side slopes of a railway embankment in central British Columbia, constructed with local lacustrine silt, on relatively flat ground, began to fail several years after construction. Shallow instability ultimately developed on both sides of the embankment over a distance of several kilometres. Initially, the soil had a significant apparent cohesive strength. With time, the strength appeared to diminish owing to the dissipation of negative pore-water pressures. The remaining frictional strength was not sufficient to maintain stability, since the slopes were constructed at angles close to the peak effective friction angle of the soil. This case history, together with the laboratory saturated and unsaturated strength test results and field suction measurements, demonstrates the dramatic effect of negative pore-water pressures on near-surface slope stability. Key words: soil suction, slope stability, nonsaturated soils, shear resistance, tensiometers.
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Costa, Jessé C., Francisco J. da Silva, Ellen N. Gomes, Jörg Schleicher, Luiz André Melo, and Daniela Amazonas. "Regularization in slope tomography." GEOPHYSICS 73, no. 5 (September 2008): VE39—VE47. http://dx.doi.org/10.1190/1.2967499.
Full textAbstract:
Seismic imaging in depth is limited by the accuracy of velocity model estimation. Slope tomography uses the slowness components and traveltimes of picked reflection or diffraction events for velocity model building. The unavoidable data incompleteness requires additional information to assure stability to inversion. One natural constraint for ray-based tomography is a smooth velocity model. We propose a new, reflection-angle-based kind of smoothness constraint as regularization in slope tomography and have compared its effects to three other, more conventional constraints. The effects of these constraints were evaluated through angle-domain common-image gathers, computed with wave-equation migration using the estimated velocity model. We found that the smoothness constraints have a distinct effect on the velocity model but a weaker effect on the migrated data. In numerical tests on synthetic data, the new constraint leads to geologically more consistent models.