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1
Burkovič, Kamil, Martina Smirakova i Pavlina Matečková. "Testing and Modelling of Concrete Pile Foundations". Key Engineering Materials 738 (czerwiec 2017): 287–97. http://dx.doi.org/10.4028/www.scientific.net/kem.738.287.
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Foundation of building on concrete piles is often used when it is necessary to carry the load into larger depth as by common foundation. Bearing capacity of piles or piled raft foundation is wide area to research. This paper deals with experimental load test of concrete pile and with their numerical modelling. Several types of foundation construction were tested and two kinds will be presented and compared in this paper - reinforced concrete foundation slab and raft foundation (made of reinforced concrete foundation slab supported by drilled reinforced concrete pilot). These types of foundation constructions were constructed as models, in a reduced scale, approx. 1:10. The size had to be adjusted due to limited capacity of the testing equipment and financial reasons. Except measuring of the foundation behaviour, there was also carried out measurement of the adjacent terrain.The aim of this paper is to compare the behaviour of rigid slab and the piled raft. The measurement results will be then compared with the results of numerical modelling.
2
Sokolov, Nikolay. "An approach to increasing the load-bearing capacity of drilled injection piles". E3S Web of Conferences 274 (2021): 03016. http://dx.doi.org/10.1051/e3sconf/202127403016.
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The problem of strengthening weak or overloaded bases is an important objective of underground space development. It is especially urgent if there are alternating weak layers in the base. The paper presents a practical geotechnical case of strengthening the overloaded base of a reinforced concrete foundation plate for a 25-storey residential building under construction. Combined soil piles that consist of Jet (type 1) soil concrete piles reinforced along the longitudinal axis with drilled injection piles made by electric discharge technology (EDT piles) are used as buried structures. This method of arrangement of a combined buried reinforced concrete structure is conditioned by the need to increase the load-bearing capacity of a pile in soil by two or more times.
3
Khan, M. Kamran, M. Hesham El Naggar i Mohamed Elkasabgy. "Compression testing and analysis of drilled concrete tapered piles in cohesive-frictional soil". Canadian Geotechnical Journal 45, nr 3 (marzec 2008): 377–92. http://dx.doi.org/10.1139/t07-107.
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When pile driving is difficult and (or) economically not viable, cast-in-place piles are indispensable. Tapered piles, which have top cross-sections larger than the bottom cross-sections, have the potential for substantial advantages over conventional straight-sided piles. This paper investigates the construction and performance of innovative drilled concrete tapered piles. A full-scale pile load-testing program was conducted to evaluate the axial compressive capacity of drilled concrete tapered piles in frictional soil. One straight and three tapered augers were designed and manufactured to produce six piles. The piles that were constructed and tested included four tapered and two straight piles. The testing results showed that tapered piles with a taper angle varying between 0.95° and 1.91° had a load carrying capacity up to 50% higher than the straight-sided piles with equal volume. It should be noted, however, that the experimental results are site specific. Moreover, an analytical expression was developed to evaluate the pile taper effect on its shaft capacity in terms of a taper coefficient, Kt. The value of Kt evaluated from the analytical expression compared well with experimentally measured values. Finally, a two dimensional nonlinear finite element analysis was conducted to simulate the load test conditions, and it proved to be successful.
4
Sheikh, Shamim A., i Michael W. O'Neill. "Long-term behavior of expansive concrete drilled shafts". Canadian Journal of Civil Engineering 13, nr 2 (1.04.1986): 213–17. http://dx.doi.org/10.1139/l86-029.
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The research reported here is a continuation of work reported earlier in which it was concluded that the use of expansive cement concrete increased the side resistance of drilled shafts (bored piles) in stiff clay by as much as 50% over that in normal concrete shafts and reduced the settlement by about 50%. The conclusions were based on tests conducted at a concrete age of about 2 months. A year and a half later, the three shafts (one made with normal concrete and two made with expansive concrete) were tested again and the same comparatively better behavior of expansive concrete shafts was observed. The base capacities of all the shafts increased over this period owing to the consolidation of soil caused by residual base stresses following the initial tests. The shafts were later extracted for visual observation and coring. The compression tests on concrete cores obtained from various depths along the shafts indicated that expansive concrete behaves as a sound structural material in the long term. The gains in strength and stiffness of expansive concrete over normal concrete over a period of 2 years were found to be significant. Key words: base bearing capacity, bored pile, cement (expansive), concrete (structural), drilled shaft, expansion, frictional capacity, long-term behavior, settlement.
5
Hidden, Scott, i Nariman Abar. "Predesign Foundation Load Test Program for US-17 (Wilmington) Bypass over Northeast Cape Fear River". Transportation Research Record: Journal of the Transportation Research Board 1736, nr 1 (styczeń 2000): 19–23. http://dx.doi.org/10.3141/1736-03.
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The North Carolina Department of Transportation is currently conducting a predesign foundation load test for a new bridge over the Northeast Cape Fear River near Wilmington, North Carolina. The primary purpose of the load test program is to determine whether concrete piles can penetrate a very dense and cemented sand layer and what side friction and tip bearing capacities should be used for the design of the drilled piers. Significant cost savings could be realized if pile foundations instead of drilled piers could support the approach spans of the bridge. For this determination, three concrete piles will be installed 30 m into the ground. Significant cost savings could also be realized by making a more accurate determination of the drilled pier capacities. For this determination, the side friction and tip bearing capacities of the dense Peedee sands and the underlying hard marine clays will be determined with Osterberg cell tests on two 2130-mm-diameter drilled piers. The different subsurface layers (muck, alluvial sands, and Peedee sands) will also be tested laterally with both static and statnamic testing to assist in the foundation design. The load test program incorporates an NCHRP research program on pile groups. The program includes testing a reusable instrumented steel pile group and frame at various sites in various soil conditions around the United States. The load test program results to date, the effect of the results on the foundation design, and the construction, testing, and instrumentation of the drilled piers are described.
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Khalili-Tehrani, Payman, Eric R. Ahlberg, Changsoon Rha, Anne Lemnitzer, Jonathan P. Stewart, Ertugrul Taciroglu i John W. Wallace. "Nonlinear Load-Deflection Behavior of Reinforced Concrete Drilled Piles in Stiff Clay". Journal of Geotechnical and Geoenvironmental Engineering 140, nr 3 (marzec 2014): 04013022. http://dx.doi.org/10.1061/(asce)gt.1943-5606.0000957.
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Zhao, Heng, Shuai Zhou i Ming-hua Zhao. "Load transfer in drilled piles for concrete-rock interface with similar triangular asperities". International Journal of Rock Mechanics and Mining Sciences 120 (sierpień 2019): 58–67. http://dx.doi.org/10.1016/j.ijrmms.2019.06.003.
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Park, Kyungho, Daehyeon Kim, Gyudeok Kim i Wooyoul Lee. "Evaluation of the Pullout Behavior of Pre-Bored Piles Embedded in Rock". Materials 14, nr 19 (26.09.2021): 5593. http://dx.doi.org/10.3390/ma14195593.
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The subject of this study is dry process caisson tube method cofferdam (hereinafter called C.T cofferdam). This C.T cofferdam is designed to use the skin friction of the drilled shaft embedded into the rock for stability of buoyancy. A pre-bored pile embedded in the bedrock was pulled out due to the buoyancy of the C.T cofferdam at the pier (hereinafter called P) 2 of the OO bridges under construction, to which this was applied. In this study, in order to solve this problem, the adhesion force applied with the concept of skin friction and the pre-bored pile of drilled shaft according to domestic and foreign design standards were identified; the on-site pull-out load test was used to calculate the pull-out force; and the skin friction of the drilled shaft and pre-bored pile embedded into the bedrock were compared and analyzed. In addition, the pull-out behavior of the pre-bored pile embedded in the bedrock was analyzed through numerical analysis. The adhesion strength tested in the lab was 881 kN for air curing of concrete and 542 kN for water curing of concrete, and the on-site pull-out test result was 399.7 kN. As a result of the numerical analysis, the material properties of the grout considering the site conditions used revealed that the displacement of the entire structure exceeded the allowable limit and was unstable. This appears to have lowered the adhesion strength due to construction issues such as ground complexity and both seawater and slime treatment, which were not expected at the time of design.
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Lee, Woojin, Won-Je Lee, Sang-Bae Lee i Rodrigo Salgado. "Measurement of pile load transfer using the Fiber Bragg Grating sensor system". Canadian Geotechnical Journal 41, nr 6 (1.12.2004): 1222–32. http://dx.doi.org/10.1139/t04-059.
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A series of laboratory and field tests were performed to evaluate the applicability of an optical fiber sensor system in the instrumentation of piles. A multiplexed sensor system, constructed by arranging several Fiber Bragg Grating (FBG) sensors along a single line of optical fiber, is capable of measuring local axial strains as a function of wavelength shifts. The distributions of axial load in three model piles and a field test pile evaluated from the strains measured by FBG sensors are found to be comparable, in terms of both magnitude and trend, with those obtained from conventional strain gauges. This suggests that the FBG sensor system is an effective tool for the analysis of the axial load transfer in piles. The successful instrumentation of a soilcement injected precast (SIP) pile using FBG sensors suggests that the use of these sensors in drilled shafts and other types of cast in situ concrete piles is feasible. With the rapid advance of optical fiber sensor technology, the economics of the use of optical fiber sensors in this type of instrumentation is expected to improve significantly in coming years.Key words: pile foundation, load transfer, fiber optic sensor, Fiber Bragg Grating sensor.
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Sheinin, V. I., A. M. Dzagov, E. S. Kostenko, A. P. Manzhin, D. I. Blokhin, I. B. Maksimovich i V. N. Soboleva. "Determining the Strength Characteristics of Concrete in Drilled Piles from Tests on Extracted Core Specimens". Soil Mechanics and Foundation Engineering 53, nr 2 (maj 2016): 119–24. http://dx.doi.org/10.1007/s11204-016-9374-8.
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NI, SHENG-HUOO, KUO-FENG LO i YAN-HONG HUANG. "NONDESTRUCTIVE INTEGRITY EVALUATION OF PC PILE USING WIGNER-VILLE DISTRIBUTION METHOD". Modern Physics Letters B 22, nr 11 (10.05.2008): 959–64. http://dx.doi.org/10.1142/s021798490801567x.
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Nondestructive evaluation (NDE) techniques have been used for years to provide a quality control of the construction for both drilled shafts and driven concrete piles. This trace is typically made up of transient pulses reflected from structural features of the pile or changes in its surrounding environment. It is often analyzed in conjunction with the spectral response, mobility curve, arrival time, etc. The Wigner-Ville Distribution is a new numerical analysis tool for signal process technique in the time-frequency domain and it can offer assistance and enhance signal characteristics for better resolution both easily and quickly. In this study, five single pre-cast concrete piles have been tested and evaluated by both sonic echo method and Wigner-Ville distribution (WVD). Furthermore, two difficult problems in nondestructive evaluation problems are discussed and solved: the first one is with a pile with slight defect, whose necking area percentage is less than 10%, and the other is a pile with multiple defects. The results show that WVD can not only recognize the characteristics easily, but also locate the defects more clearly than the traditional pile integrity testing method.
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Kovalev, Vladimir A. "Process diagrams of the driving pile construction in the perforated pipe casing". Stroitel stvo nauka i obrazovanie [Construction Science and Education], nr 4 (31.12.2019): 2. http://dx.doi.org/10.22227/2305-5502.2019.4.2.
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Introduction. Driving piles in drilled wells are a new trend in pile foundation engineering. Further research and development are devoted to the improvement of structural and process diagrams of these piles in order to increase the bearing capacity mainly on their side surface, mainly in weak clay soils. Materials and Methods. The options of flow and process diagrams of driving piles in perforated (penetrated) wells in various soil conditions are studied taking into account the existing regulatory documents and earlier developments on increasing the bearing capacity of driving piles in perforated (penetrated) wells. Results. The main process operations of the driving piles installation in the soil conditions under consideration include perforation (penetration) of the well with a casing with a loose puncher shoe to the base layer of the soil; formation of a well (cavity) in the base layer of the well by means of immersion of the puncher shoe; installation of a shoe reamer in the puncher shoe and formation of a spread foundation made of hard soil material above; immersion of a casing pipe with holes outside the pipe casing; filling of the casing with hard and bulk soil material; removal of the casing and driving (immersion) into the pipe casing of the precast concrete pile filled with bulk soil material with simultaneous formation of additional local broadening and possible compacted soil zones on the sections of holes along the outer contour of the pipe casing. Conclusions. The proposed structural and process diagrams of driving piles in perforated (penetrated) wells allow to significantly expand the scope of their application in terms of soil conditions, increase the side surface bearing capacity of piles and reliability of the construction of the types of foundations under consideration.
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Ukleja, Janusz. "Application of Spatial Supporting Construction as an Effective Method for Stabilising a Landslide". Geosciences 10, nr 11 (6.11.2020): 440. http://dx.doi.org/10.3390/geosciences10110440.
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Buttresses constitute a spatial supporting construction (SSC) that can convey large loads coming from the pressure of unstable soil on deeper, more stable layers to make it safer with respect to the load-bearing capacity. They make the counteraction against the pressure, which initiates sliding when the forces to move the landslide body, not balanced by the internal frictional forces in the soil. Some specific features of known construction elements were used in the buttress, such as sheet pile walls and drilled piles. Although beneficial in this case, the specific shape of the axis of the wall made from piles and sheets formed a wave created from circle sections (in plan view). Thus, a stable steel buttress was formed. The interaction of the buttress with the soil mass pressure over it, which stabilises the landslide mass, was considered. To further strengthen the buttress, a reinforced concrete slab was added on the upper edge of the thin walls of sheets and piles, thereby integrating and stiffening the whole structure. The application of the concrete slab enabled the use of the stabilisation role of additional forces (become from its weight and above laysoil)to stabilise the buttress. The results of this study achieved a substantial stabilising effect, increasing maximal forces reacting against the pressure of the unstable soil block. Assumptions madeand the applied calculations confirm thestability of the buttress (by increasing the stability of the whole slump block of landslide) are described. Two cases are presented to illustrate the stabilisation and control of movement in which the block body moves along inadvance of the determined slip surface.
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Youssouf, Touré, Tianlai Yu, Dembélé Abdramane, Assogba Ogoubi Cyriaque i Diakité Youssouf. "Force Performance Analysis of Pile Behavior of the Lateral Load". Infrastructures 4, nr 2 (28.03.2019): 13. http://dx.doi.org/10.3390/infrastructures4020013.
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This study was focused on the performance of the pile force at the lateral load of an arched bridge. The effect of the compression of arch bridges creates a large horizontal load. Therefore, it is one of the most important factors in the dimensioning of piles. The study aims to make a comparative study between the results obtained in the field, and those obtained by a 3D model defined as a Finite Element (FE) of a drilled pile, subjected to different lateral loads applied at exact time intervals. Moreover, the study was intended to determine the influence of the lateral load applied to a different pile diameter using the FE model. Thus, the unified FEA software Abaqus™ by Dassault systèmes® carried out various processing procedures, namely soil FE modeling, pile FE modeling, soil-pile interface, Mesh, and boundary conditions, to carry out an effective and predictive piles behavior analysis. Based on the Mohr-Coulomb criterion, the soil is considered to be stratified with elastoplastic behavior, whereas the Reinforcement Concrete Pile (RCP) was assumed to be linear isotropic elastic, integrating the concrete damage plasticity. Since the bridge is an arched bridge, the lateral load induced was applied to the head of the piles through a concentrated force to check the pile strength, for which the displacement, stress and strain were taken into account throughout, along the pile depth. The lateral displacement of the pile shows a deformation of the soil as a function of its depth, with different layers crossed with different lateral loads applied. Thus, from the study comparing the results of the FE measurements with the data measured in the field, added to the statistical analyses are as follows: Decrease of the displacement and stress according to the diameter, taking into account the different diameter. The foundations receive loads of the superstructure to be transmitted to the ground. Thus, the piles are generally used as a carrier transmitting loads on the ground. One of the important factors in the durability of the bridge depends more on the strength of these piles. This makes it necessary to study the reinforced concrete foundations because of their ability to resist loads of the structure, and the vertical and lateral loads applied to the structure. This implies an evaluation of the responses of the RCP according to the different lateral loads.
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Zhou, Jiaquan, Chuanbo Zhou, Qinggao Feng i Tan Gao. "Analytical Model for Load-Transfer Mechanism of Rock-Socketed Drilled Piles: Considering Bond Strength of the Concrete–Rock Interface". International Journal of Geomechanics 20, nr 6 (czerwiec 2020): 04020059. http://dx.doi.org/10.1061/(asce)gm.1943-5622.0001672.
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Qian, Yongmei, Mingxiao Li, Ruozhu Wang i Yujie Jin. "Theoretical study on the load carrying capacity of concrete drilled and expanded piles with different stiffness under horizontal load". IOP Conference Series: Earth and Environmental Science 760, nr 1 (1.04.2021): 012002. http://dx.doi.org/10.1088/1755-1315/760/1/012002.
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Yang, Zhijun, Qing Fang, Bu Lv, Can Mei i Xudong Fu. "An Investigation into the Effect of Cracking on the Response of Drilled and Postgrouted Concrete Pipe Pile under Lateral Loading". Advances in Materials Science and Engineering 2020 (23.01.2020): 1–12. http://dx.doi.org/10.1155/2020/5373958.
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The cracks are likely to initiate on a lateral loaded pile and would cause greater deflection at the pile head. However, there is a lack of thorough investigation into the effect of cracking on the response of the lateral loaded pile. In this article, a full-scale field test was carried out to investigate the behavior of Drilled and Postgrouted Concrete Pipe Pile under lateral loads. A novel analysis method for the lateral loaded pile, which can take the cracking effects into consideration, was proposed, and the validity was verified by the test results. With the proposed method, the cracking effects on flexural rigidity, displacement, rotation, and bending moment of the pile were studied. In brief, cracking effect would dramatically reduce the flexural rigidity of the pile, remarkable increase the displacement and rotation of the pile top, and slightly decrease bending moment of the pile. Unambiguously, the results show that the proposed method can excellently predict the response of laterally loaded piles under cracking effects.
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Hertlein, Bernard H., i William H. Walton. "Assessment and Reuse of Old Foundations". Transportation Research Record: Journal of the Transportation Research Board 1736, nr 1 (styczeń 2000): 48–52. http://dx.doi.org/10.3141/1736-07.
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Little is known about the foundations beneath many historic buildings and bridges. For rehabilitation projects, it is important to know the nature of the foundation system and its condition. In replacement projects, cost savings and sometimes environmental benefits can be gained from the reuse of existing foundations in new structures. In large cities, almost any new construction involves the demolition of a previous structure, which poses the problem of what to do with the old foundations. Many are too deep to be removed economically, and some are almost certain to be in the way of proposed new foundations. It is therefore a great advantage if they can be incorporated into the new design, but to do this, the engineer must have accurate information about the foundation type and depth to estimate load-bearing capacity. The authors have worked on a number of projects in the last few years that have included increasing the load on or reusing existing foundations. Information about foundation type and depth has been gained from the use of specialized nondestructive tests. In many cases, the authors also had access to archive information that included soil borings in the vicinity to correlate with test data. The methods used to assess existing foundations and allow their inclusion in the design of new foundation systems are discussed, and case histories are given for concrete drilled shafts, timber piles, and steel sheet piles.
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Wrana, Bogumił, i Jan Wrana. "Buildings of the John Paul II Center – a challenge for civil engineering and architecture". Budownictwo i Architektura 19, nr 4 (2.11.2020): 109–24. http://dx.doi.org/10.35784/bud-arch.2139.
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The buildings of the John Paul II Centre (CJPII) are located in Cracow-Łagiewniki on a heap of limestone sediments from the former "Solvay" Sodium Plant in Cracow. The area is called "White Seas" (Białe Morze) and is located in the natural depression of the Wilga river valley, between Św. Józefa hill in the north and Borkowska Hill (Góra Borkowska) in the south-west. The limestone sediments as a building substrate for CJPII buildings is unprecedented ground in the world and thus a challenge for civil engineering. The height of the heap reaches about 15 m and has retained the consistency of a white pulp until today. CJPII buildings are objects of the third geotechnical category, founded on a foundation slab of 0.8-m thickness, and in the central part of 0.45-m thickness. The slab is based on 200 reinforced concrete CFA-type drilled piles with a diameter of 1000 mm and 650 mm and length up to 26 m. The load-bearing structure of the CJPII buildings is a reinforced concrete frame and shell structure. The symbolism of the urban complex (e.g. the scale of the market square in Wadowice), located on a system of 200 piles above the post-industrial landfill/heaps of sediments, is ensured with architectural solutions referring to places connected with the life of John Paul II – during the occupation in 1940-1944 he was a student of Jagiellonian University in Cracow and the worker of the Solvay factory in the Podgórze district, in 1958 he became a bishop of Cracow, in 1967 – the cardinal (architectural details from the St. Mary Church and the Wawel Cathedral), 1978-2005 – the pilgrim-pope from Rome, who confirmed the mission of the Church continuing the tradition depicted in the early-christian churches on the wall mosaics (the Basilica of San Vitale and the Basilica of Sant’ Apollinare Nuovo in Ravenna).
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Vasilyev, V. I., M. V. Vasilyeva, S. P. Stepanov, N. I. Sidnyaev, O. I. Matveeva i A. N. Tseeva. "Numerical Solution of the Two-Phase Stefan Problem in the Enthalpy Formulation with Smoothing the Coefficients". Herald of the Bauman Moscow State Technical University. Series Natural Sciences, nr 4 (97) (sierpień 2021): 4–23. http://dx.doi.org/10.18698/1812-3368-2021-4-4-23.
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To simulate heat transfer processes with phase transitions, the classical enthalpy model of Stefan is used, accompanied by phase transformations of the medium with absorption and release of latent heat of a change in the state of aggregation. The paper introduces a solution to the two-phase Stefan problem for a one-dimensional quasilinear second-order parabolic equation with discontinuous coefficients. A method for smearing the Dirac delta function using the smoothing of discontinuous coefficients by smooth functions is proposed. The method is based on the use of the integral of errors and the Gaussian normal distribution with an automated selection of the value of the interval of their smoothing by the desired function (temperature). The discontinuous coefficients are replaced by bounded smooth temperature functions. For the numerical solution, the finite difference method and the finite element method with an automated selection of the smearing and smoothing parameters for the coefficients at each time layer are used. The results of numerical calculations are compared with the solution of Stefan’s two-phase self-similar problem --- with a mathematical model of the formation of the ice cover of the reservoir. Numerical simulation of the thawing effect of installing additional piles on the existing pile field is carried out. The temperature on the day surface of the base of the structure is set with account for the amplitude of air temperature fluctuations, taken from the data of the Yakutsk meteorological station. The study presents the results of numerical calculations for concrete piles installed in the summer in large-diameter drilled wells using cement-sand mortars with a temperature of 25 °С. The distributions of soil temperature are obtained for different points in time
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Nguyen, Minh Hai, i Bengt H. Fellenius. "Bidirectional cell tests on non-grouted and grouted large-diameter bored piles". Journal of Geo-Engineering Sciences 2, nr 3,4 (17.07.2015): 105–17. http://dx.doi.org/10.3233/jgs-140025.
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Abstract The 37-storey apartment buildings of the Everrich II project in HoChiMinh City, Vietnam was designed to be supported on a piled foundation consisting of bored piles assigned a 22-MN working load per pile. The foundation design included performing bidirectional-cell, static loading tests on four test piles. The soil profile consisted of organic soft clay to about 28 m depth followed by a thick deposit of sandy silt and silty sand with a density that gradually increased with depth from compact to dense, becoming very dense at 65 m depth. In March 2010, the test piles, one 1.5-m diameter pile and three 2.0-m diameter piles, were installed to 80 m through 85 m depth and constructed using bucket drill technique with bentonite slurry and a casing advanced ahead of the hole. The bidirectional-cell assemblies were installed at 10 m through 20 m above the pile toes. The piles were instrumented with pairs of diametrically opposed vibrating wire strain-gages at three to four levels below and six to seven levels above the respective cell levels. After completed concreting, the shaft grouting was carried out throughout a 20 m length above the pile toe for the 1.5-m diameter pile and for one of the 2.0-m diameter piles. The static loading tests were performed about 34 through 44 days after the piles had been concreted. The analysis of strain-gage records indicated an average Young’s modulus value of about 25 GPa for the nominal crosssections of the piles. The average unit grouted shaft resistances on the nominal pile diameters were about two to three times larger than the resistance along the non-grouted lengths. The measured load distribution of maximum mobilized shaft resistances corresponded to effective stress proportionality coefficients, ß, of about 0.2 through 0.3. The ultimate shaft resistance for the pile lengths below the bidirectional cells reached an ultimate value after about 8 to 10 mm movement, whereafter the load-movement was plastic. The pile toe stress-movement responses to toe stiffness were soft with no tendency toward an ultimate value.
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Zhang, Ze Yu, Ji Zhuang Hui, Chang Yan, Shun Peng Cheng i Xue Feng Suo. "Design of Sleeve Piling Machine and Finite Element Analysis of the Sleeve Tubes". Applied Mechanics and Materials 872 (październik 2017): 230–34. http://dx.doi.org/10.4028/www.scientific.net/amm.872.230.
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In order to solve the problems of the easy breakage, transport problems and pile holes shrinkage, a sleeve piling machine was designed. It included a fully used pile frame, a novel pile driver and its piling method. The piling machine integrated the advantages of the diesel hammer piling machine and the vibration hammer piling machine. It is suitable for bored piles and compacted piles. Based on the sleeve pile tubes, the diesel hammer and the vibration hammer worked together to drill. Then the reinforcing cage was lifted by the hoister, the pile tubes were pulled and the concrete were poured with the help of the vibration hammer. All of them can avoid the shrinkage of the pile, the break of the pile, and improve construction efficiency. Besides, finite element analysis of the pile tubes were calculated by ANSYS, the results showed that the strength of the pile tubes was satisfied with the requirements of application. The piling machine and the method were feasible.
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Buijs, J. H. N. "The Susceptability of Computers to Vibration". Journal of Low Frequency Noise, Vibration and Active Control 11, nr 1 (marzec 1992): 23–32. http://dx.doi.org/10.1177/026309239201100104.
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The computer is now used in many kinds of building. When building contractors are constructing nearby, the vibration sensitivity of disk drives can be a problem. If computers are of vital importance in a production process, the consequences of a possible break-down and information loss because of vibrations cannot be neglected or underestimated. In this paper the information needed to judge the possible risks of damage in practice is discussed The information given by computer manufacturers is, in general, neither complete nor unequivocal. Furthermore, results of vibration measurements in buildings are presented and discussed. Exposure to low frequency vibrations caused by different building activities such as demolition by means of pneumatic drills, driving in sheet piles and last, but not least, driving in piles made of concrete or steel using impact driving techniques are considered. The most sensitive parts of a computer mainframe, the disk drives, in general produce more vibration themselves during read or write operations than that permitted by the computer manufacturer. Although the vibrations caused by building activities are in most cases significantly lower than the computer limits, several cases of breakdown or information loss have occurred. Who is responsible for computer damage?
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Jocelin, Amelinda, i Chaidir Anwar Makarim. "ANALISIS TIANG PANCANG SEBAGAI DINDING PENAHAN TANAH DI DAERAH ALIRAN SUNGAI MENGGUNAKAN PROGRAM PYWALL". JMTS: Jurnal Mitra Teknik Sipil 3, nr 3 (21.08.2020): 923. http://dx.doi.org/10.24912/jmts.v3i3.8375.
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Construction failure may occur due to various things. One of them is used a shallow foundation for a retaining wall. It can possible, but consider environmental condition where there is a heavy flow of water along the wall. Therefore it is necessary to use a deep foundation. Pile are printed concrete products. It is used to support a load and distribute the load to the subgrade. This pile is also equipped with iron reinforcement so that it can guarantee the quality and strength. This calculation is using a closed-form solution. The software used is P-Y Wall which fixes a flexible retaining wall or pile/drill wall. This program will calculate pile deflection, shear forces, and bending moments. In this assessment, variations were made relating to the distance between the piles and the values of L1 and L2. L1 shows the free long pile and L2 shows the long pile entering the ground. Variation 3A with the distance between the piles 100 cm and the length of the pile 15 m. The average value of L1 was 10.8 m for the value and the value of L2 was 4.2 m. Both of deflection and moment can fulfill the qualification, the value is 9,1 m (from 10,8 m) dan 320 kNm (from 399 kN/m).
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Supriyadi, Supriyadi, Ahmad Ridwan i Yosef Cahyo. "STUDY PERENCANAAN PONDASI GEDUNG GUEST HOUSE 6 LANTAI DI KOTA KEDIRI". Jurnal Manajemen Teknologi & Teknik Sipil 3, nr 1 (30.06.2020): 65. http://dx.doi.org/10.30737/jurmateks.v3i1.890.
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The building foundation is a lower structure that functions to carry the weight of the load to the subgrade. The foundation planning study in this study uses a bore pile type of foundation. This study uses the Meyerhoff method based on SPT data received by CV. Arya Duta. In this bore pile foundation planning, the carrying capacity of the bore pile foundation to the ground is 81.00 tons, with a depth of 26 M from the ground surface. The results of the calculation of pile drill piles get P 19.44 tons at the bottom of 26 M while the reinforcement of the pile cap is found in q 1.152 Ton / M (own weight). In the bore pile with spiral support found the results of the analysis data ((D. concrete 600 mm, Blanket 40 mm), (D reinforcement 16 mm, number of reinforcement 10), (D. stirrup 10 mm, Spacing 60 mm)). Based on the overall results of the structure, weight was found 16,771.43 Tons / M. Thus, from the analysis of equivalent lateral force loads (Fi 77.71), it was found that the construction of building structures is earthquake resistant.Pondasi merupakan struktur bawah bangunan yang berfungsi meneruskan berat suatu beban pada bangunan ke tanah dasar. Study perencanaan pondasi pada penelitian ini menggunakan pondasi tipe bore pile. Penelitian ini menggunakan metode Mayerhoff berdasarkan data SPT yang di terima oleh CV. Arya Duta. Pada perencanaan pondasi bore pile ini didapatkan kemampuan daya dukung pondasi bore pile terhadap tanah adalah sebesar 81.00 Ton, dengan kedalaman 26 M dari permukaan tanah. Hasil perhitungan tiang bor pile mendapatkan hasil P 19,44 Ton pada kedalaman 26 M. Sedangkan pada penulangan pile cap di temukan q 1,152 Ton/M (berat sendiri). Pada bore pile dengan tulangan spiral di temukan hasil data analisis ((D.beton 600 mm, Selimut 40 mm), (D tulangan 16 mm, jumlah tulangan 10), (D. sengkang 10 mm, Spasi 60 mm)). Berdasarkan hasil keseluruhan berat struktur ditemukan 16.771,43 Ton/M. Dengan demikian, dari analisis beban gaya lateral ekuivalen (Fi 77,71) didapatkan bahwa, Kontruksi struktur gedung tahan terhadap gempa.
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Borges, Augusto Bopsin, Renato Vaz Linn, Fernando Schnaid i Samir Maghous. "A simplified numerical approach to the evaluation of residual shaft friction induced by concrete curing in drilled shafts on granular soils". Revista IBRACON de Estruturas e Materiais 13, nr 5 (2020). http://dx.doi.org/10.1590/s1983-41952020000500005.
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ABSTRACT: Conventional interpretation procedures of load tests on instrumented piles rely upon measurements of strains that assume as zero for strains measured at the instant immediately before starting the test as reference configuration. However, some experimental evidence shows that concrete in drilled shafts undergoes strains induced by the curing process comparable in magnitude to the strains measured during the load tests. It is therefore expected that mobilization of shaft friction takes place before the load test. Several authors have performed experimental and numerical analyses aiming to quantify the influence of those pre-load test concrete volumetric strains on the measured bearing capacity using different approaches. The present work aimed to establish a reference framework for the existing and future works on this topic. In order to assess the influence of concrete strains induced by curing process on the shaft friction before the start of the load tests in drilled shafts, several finite element numerical simulations are performed, considering the thermal, autogenous and drying strains. The analyses consider concrete as an isotropic linear-elastic material and the soil as an elastic-plastic material using the Mohr-Coulomb constitutive model natively implemented in the software ABAQUS. The results are interpreted focusing on the relevancy on the bearing capacity and load distribution along drilled shafts considering or not the strains induced by concrete curing.
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Farrag, Rabie. "Shear Demands of Rock-Socketed Piles Subject to Cyclic Lateral Loading". DFI Journal The Journal of the Deep Foundations Institute 14, nr 2 (31.12.2020). http://dx.doi.org/10.37308/dfijnl.20200526.223.
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The determination of internal pile reactions is critical to designing and assessing the structural performance of deep foundations. Internal shear and moment profiles strongly depend on lateral pile-soil interaction, which in turn depends on pile and soil stiffnesses as well as the stiffness contrast between soft and stiff strata, such as occurs at a soil/rock interface. At zones of strong geomaterial stiffness contrast, Winkler-spring-type analyses predict abrupt changes in the internal pile reactions for laterally-loaded foundation elements. In particular, the sudden deamplification of internal moments when transitioning from a soft to stiff layer is accompanied by amplification of pile shear. This “shear spike” can result in bulky transverse reinforcement designs for drilled shaft rock sockets that pose constructability challenges due to reinforcement congestion, increasing the risk of defective concrete on the outside of the cage. This paper presents an experimental research program of three large-scale, instrumented drilled shafts with simulated rock sockets constructed from concrete. Each shaft had a different transverse reinforcement design intended to bound the amplitude of the predicted amplified shear demand, with a particular emphasis on performance of shafts with shear resistance less than the predicted demand and below the code minimum. Test results suggested that the shafts experienced a flexure-dominated failure irrespective of the transverse reinforcement detailing.
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"Full Scale Modeling of Footing Supported on Expansive Soil using Concrete Pile Anchor Foundation (CPAF)." International Journal of Recent Technology and Engineering 8, nr 6 (30.03.2020): 1859–64. http://dx.doi.org/10.35940/ijrte.f8054.038620.
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Buildings constructions over expansive soils are exposed to many problems and cracks. The most damaging issues occur due to differential heave displacements, which cause excessive deformations to the overlying structure up to and beyond its serviceability limit state and, in the worst cases, its ultimate limit state. A site investigation is performed for the study area at Tabuk University, Kingdom of Saudi Arabia. The geotechnical soil properties and swelling characteristics were determined. Visual observations of samples obtained from drilled boreholes at study area revealed reddish brown to grey thinly laminated weathered shale followed by shale formation, the subsurface formation is classified (CH) according to USCS. The research study is aimed at measuring the contact pressure at field and studying the efficiency of concrete pile anchor foundation (CPAF) system in reducing heave of footings constructed on expansive soil. In the field, two full scales reinforced concrete footings with and without concrete anchor piles were constructed on top of the expansive shale. After construction of field prototypes, the test area is wetted for 64 days. Monitoring of the footing movement indicated that the footing upward movement using CPAF system caused a 62% less than the footing constructed directly on expansive shale.