To see the other types of publications on this topic, follow the link: Dry soil mixing.
Journal articles on the topic 'Dry soil mixing'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Dry soil mixing.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Timoney, Martin J., Bryan A. McCabe, and Alan L. Bell. "Experiences of dry soil mixing in highly organic soils." Proceedings of the Institution of Civil Engineers - Ground Improvement 165, no. 1 (February 2012): 3–14. http://dx.doi.org/10.1680/grim.2012.165.1.3.
Full text
2
Jendrysik, Klaudia, Monika Kiecana, and Hubert Szabowicz. "Preliminary results of dry Deep Soil Mixing soil-cement composite testing." MATEC Web of Conferences 251 (2018): 01025. http://dx.doi.org/10.1051/matecconf/201825101025.
Full textAbstract:
This paper provides results of testing made for soil-cement mixtures in dry mixing technology. This technology is greatly dependent on existing soil condition; hence the results are of highly random nature. Material used in testing was distinguished with high organic content and low humidity. Tests were carried out in laboratory of Wroclaw University of Technology on 145 samples as ordered by Menard Polska Ltd. Company. Samples were prepared and stored under laboratory conditions and then, after various maturation time, were destroyed in a testing machine. The purpose was to determine the stress-strain curves used to find strength properties, strain at failure, modulus of elasticity, secondary modulus of elasticity versus cement content. Test confirmed improvement of soil strength properties after addition of cement binder. The results may be used to determine the most economic binder-to-soil ratio.
3
Kiecana, Monika, Piotr Kanty, and Klaudia Łużyńska. "Optimal control time evaluation for “dry DSM” soil-cement composites." MATEC Web of Conferences 251 (2018): 01023. http://dx.doi.org/10.1051/matecconf/201825101023.
Full textAbstract:
Soil improvements with hydraulic binders are a widespread practice in foundation works. They vary depending on the mixing method (jet grouting hydraulic, deep soil mixing -mechanical), medium type (wet/water, dry/air) and binder type (cement, lime, fly ash or mixtures). The produced component’s strength changes in time thus its control should change in time as well. The paper presents the results of laboratory testing of an organic soil component mixed in dry method. The process of samples preparation and testing methodology of compressive strength and stiffness is described. Volatility of the parameters in time is considered. On the basis of the results, recommendation for optimal quality control time and its methodology for soil-cement components might be proposed.
4
Wen, Shu Lian, and Qing Hong Zhang. "Analysis for Engineering Example of Dry Jet Mixing Pile Consolidating Foundation." Applied Mechanics and Materials 256-259 (December 2012): 120–24. http://dx.doi.org/10.4028/www.scientific.net/amm.256-259.120.
Full textAbstract:
Dry jet mixing pile is the general technique of composite ground consolidation , which is used in foundation treatment of soft soil under highway. It has a widespread applying due to so many advantages. This passage adopts an example of dry jet mixing pile combined with Longkou Shugang expressway engineering, it aims to state that dry jet mixing pile consolidating foundation along intertidal zone would obviously improve bearing capacity, strength and compressive modulus of foundation soil, reduce settlement and make a difference of consolidating foundation in according to data analysis of field or laboratory experiment. This technique is an effective way to solve the Jump Car problem and economic and quick.
5
Al-Obaidi, Ahmed, Marwa Al-Mukhtar, Omar Al-Dikhil, and Saeed Hannona. "Comparative Study between Silica Fume and Nano Silica Fume in Improving the Shear Strength and Collapsibility of Highly Gypseous Soil." No.1 27, no. 1 (March 15, 2020): 72–78. http://dx.doi.org/10.25130/tjes.27.1.10.
Full textAbstract:
Soils with highly gypsum content signify known as soils that exhibit collapsibility and sudden failure when being submerged to wetting. Many of the constructions built on this soil showed cracked and/or collapsed at some parts as these soils immersed or leached with water. The utilization of extremely fine materials, for example, Microscale or Nanoscale, is generally utilized these days. This research compared the use of Silica fume (SF) (micro material) and Nano Silica fume (NSF) (Nanomaterial) to explore the capability of these very fine materials to mend the shear strength and collapsibility properties of highly gypseous soils. The soil as Poorly Graded Sand (SP) was used, with a gypsum amount equal to 62%. A succession of direct shear tests and double odometer tests were carried on dry and submarined specimens of soil at various percentages of SF and NSF. The obtained results indicate that mixing the highly gypseous soils with SF or NSF improved the engineering properties of these soils, especially for the wet condition. The average increment in apparent cohesion when adding SF (5-20) percentage varies between (140-310) % in dry soil and (20-40) % in soaked soil. Same results obtained when mixing the gypseous soils with (1-5) % of NSF. Also, the Nanomaterial provided an improvement of the friction angle in dry and submerged cases respectively. Considering that, the SF gives adverse results upon the friction angle of the soil. The SF and the NSF both condensed the dangers of gypseous soil collapsibility. Consequently, the use of NSF can be assertively suggested to improve the engineering characteristics of highly gypseous soils when compared with SF, where only mixing of 3% of NSF gives the best results.
6
Prokopowicz, Piotr, Klaudia Łużyńska, Klaudia Jendrysik, and Grzegorz Nowak. "Technologia DSM DRY badania i projektowanie." BUILDER 269, no. 12 (November 29, 2019): 6–9. http://dx.doi.org/10.5604/01.3001.0013.5789.
Full textAbstract:
W artykule celem autorów jest przybliżenie odbiorcom technologii Deep Soil Mixing Dry, przedstawienie wyników programu badawczego przeprowadzonego na Politechnice Wrocławskiej we współpracy z firmą Menard Polska, a także podanie wskazówek do wykonania podobnych badań w przyszłości oraz projektowania wzmocnienia podłoża.
7
Nowak, Grzegorz, and Piotr Kanty. "Mass Stabilization as reinforcement of organic soils." E3S Web of Conferences 97 (2019): 04046. http://dx.doi.org/10.1051/e3sconf/20199704046.
Full textAbstract:
The decreasing number of places suitable for constructing buildings forces people to creatively develop newer methods of soil reinforcement. One of these methods is the deep soil mixing. This technology has been firstly developed and applied in Japan in the 1970s. Initially, it was used to create DSM (Deep Soil Mixing) columns. In the subsequent years, it was also developed in Scandinavia. Over time, the deep mixing technology was modified and developed, and in addition to the wet method, also the dry method was started to be used, while in addition to the cement binder, also lime binders and fly ashes were used. Technologies consisting of the deep mixing of cement with soil are very popular due to the wide range of applications and relatively low implementation costs. The method of Mass Stabilization (MS) is a soil reinforcement method that is analogical to DSM and it consists of mixing large volumes of soil with cement. This article describes the method of dry Mass Stabilization of organic soils. It cites the analyzed laboratory tests of soil-cement material manufactured in MS technology. The tests included the creation of 140 material samples, and subsequently the performance of compression strength test on them, along with the registration of stress path. The main aspect of these tests consisted of increase in the primary deformation modulus over time, depending on the amount of applied cement. Also, an example of the project to strengthen the layer of aggregate mud under the floor in the hall is demonstrated. The reinforcement was implemented in the MS technology.
8
Wardani, Sri Prabandiyani Retno, Muhrozi Muhrozi, Andi Retno Ari Setiaji, and Danny R. Riwu. "Stabilisasi Tanah Ekspansive dengan Menggunakan Tanah Putih untuk Tanah Dasar di Daerah Godong Kabupaten Grobogan Jawa Tengah." MEDIA KOMUNIKASI TEKNIK SIPIL 24, no. 1 (August 24, 2018): 1. http://dx.doi.org/10.14710/mkts.v24i1.16275.
Full textAbstract:
Problematic soils such as expansive soils are common in Indonesia. There are several methods to overcome the damage caused by expansive soil, such as by mixing the soil with additives. Some researchers have conducted research by mixing additives into expansive soil (cement, lime, fly ash etc), which work to increase soil strength and reduce swelling. Considering that the people in Buraen Village of Kabupaten Kupang use white soil as a substitute for cement, where the white soil has chemical constituents almost the same as those owned by cement, and contain CaO as it has lime, it is necessary to do research to determine the effect of white soil on physical and mechanical properties of expansive soil, so it can be used as an additive. This research was conducted at Soil Mechanics Laboratory, Civil Engineering Department, Engineering Faculty, Diponegoro University, Semarang.with soil sample from Godong, Central Java and white soil in Buraen Village of Kupang Regency, which purpose to find out the change of physical and mechanical properties of expansive soil that have been given some variation of mixture of white soil to the dry weight of the soil, with optimum moisture content from standard Proctor test results. The results of this study indicate that white soil can be used as an additive and the use of OMC for mixing is the OMC of expansive soil.
9
Kim, Woo‐Sik, Nguyen Minh Tam, and Du‐Hwoe Jung. "Experimental study on strength of cement stabilized clay." Journal of Engineering, Design and Technology 3, no. 2 (July 1, 2005): 116–26. http://dx.doi.org/10.1108/17260530510815358.
Full textAbstract:
This paper describes the effect of factors on the strength characteristics of cement treated clay from laboratory tests performed on cement mixed clay specimens. It is considered that several factors such as soil type, sample preparing method, quantity of binder, curing time, etc. can have an effect on strength characteristics of cement stabilized clay. A series of unconfined compression tests have been performed on samples prepared with different conditions. The results indicated that soil type, mixing method, curing time, dry weight ratio of cement to clay (Aw), and water‐clay to cement (wc/c) ratio were main factors which can have an influence on unconfined compressive strength, modulus of elasticity, and failure strain of cement stabilized clay. Unconfined compressive strength of soil‐cement samples prepared from dry mixing method was higher than those prepared from wet mixing method.
10
Kawamura, Masashi, and Yoshio Kasai. "Compressive Strength and Density of Fly-Ash Substituted Soil-Cement Concrete." Key Engineering Materials 302-303 (January 2006): 376–83. http://dx.doi.org/10.4028/www.scientific.net/kem.302-303.376.
Full textAbstract:
Soil-cement concrete can be manufactured by mixing portland cement, water and on-site soil and has been studied by the authors. This study deals with compressive strength and density of soil-cement concrete where the portland cement was partially substituted with fly-ash. Saturated surface-dry condition of on-site soils has never been taken into account in the conventional mix design whereas experiments of determining the saturated surface-dry conditions were carried out with the help of the concept of effective water content to assure the quality and the designed strength. Effects of fly-ash on the strength and density of soil-cement concrete were studied by altering cement-fly-ash ratio, soil-sand ratio, binder-water ratio and age under a constant unit water content
11
Sharo, Abdulla A., Ahmed Mohammed Ashteyat, Ahmed S. Alawneh, and Bashar Ali Bany Khaled. "The use of oil shale fly ash to improve the properties of Irbid soil." World Journal of Engineering 15, no. 5 (October 1, 2018): 614–25. http://dx.doi.org/10.1108/wje-10-2017-0325.
Full textAbstract:
Purpose The purpose of this paper is to evaluate the possible use of oil shale as a soil stabilizing agent for expansive soils. Design/methodology/approach An experimental work has been fulfilled to investigate the influence of oil shale ash (OSA) on the geotechnical behavior of the expansive soil of Irbid, Jordan. Three swelling-shrinkage soils were considered in this study along with various percentages of OSA varying at 2, 4, 6, 8, 10 and 12 per cent by dry weight of the soil. A series of laboratory tests were conducted on the soil samples before and after mixing it with OSA. These tests were soil classification, Atterberg limits, compaction test, falling head permeability test, unconfined compression test, free swelling, swelling pressure and California bearing ratio (CBR) test. Findings Laboratory tests results indicated that OSA is effective in improving the texture and strength of the treated soil by reducing plasticity index, swelling potential and swelling pressure and moderately enhancing soil strength properties including the unconfined compressive strength (qu), maximum dry unit weight (γd-max.) and CBR test. Originality/value OSA showed potential as a low-cost soil stabilizing agent for swell-shrink soils.
12
Ballard, Donna, Juanita Popenoe, Bradford Bearce, and Jeffrey Skousen. "STRAWBERRY GROWTH AND DEVELOPMENT IN THREE MINESOILS AMENDED WITH SLUDGE, HARDWOOD BARK OR A SUDAN-SORGHUM GREEN MANURE CROP." HortScience 28, no. 4 (April 1993): 256D—256. http://dx.doi.org/10.21273/hortsci.28.4.256d.
Full textAbstract:
Strawberry (Fragaria × Anaassa cv. Tribute) plants were planted in 15 cm standard pots filled with overburden soils from three West Virginia surface mine sites. Initial pH levels were 6.5, 4.4, and 3.6. Prior to planting pH levels were adjusted with CaCO3 to 6.5-6.7 in each soil. Each soil was amended by mixing in 60.85 g/pot (62.5 dry kg/ha) of sewage sludge, Sudan-sorghum hybrid green manure crop, hardwood residues, or unamended. A dry fertilizer (.10-.045-,089, N-P-K) was also mixed into the soil at a rate of 0.5 g/pot (454 kg/ha). Plants were grown from 3-6 to 10-16, 1992, on which date harvests and measurements were performed. The sludge treatments significantly increased fresh and dry weight accumulation, number of leaves, leaf area, and number of runners per plant above that of the control plants. The hardwood residues amendment delayed first date of ripe fruit and decreased average fruit fresh weight in one of the soils. Hardwood residues also decreased leaf number in another soil. The pH levels were raised to 6.8-7.3 by the sludge in all soils and remained at or near these values during the growing period.
13
Ijimdiya, Thomas Stephen, and Friday Elaigwu. "The Effect of Compactive Efforts on the Hydraulic Conductivity Behaviour of Oil Contaminated Lateritic Soils." Advanced Materials Research 367 (October 2011): 27–31. http://dx.doi.org/10.4028/www.scientific.net/amr.367.27.
Full textAbstract:
Large quantities of oil contaminated soils result from pipeline vandalization, onshore and offshore oil spills every year in Nigeria. An extensive laboratory program was carried out to determine the effect of varying compactive efforts on the hydraulic conductivity behaviour of oil contamination lateritic soils. Hydraulic conductivity tests were carried out on both the natural and oil contaminated soil samples at the Reduced British Standard Light (RBSL), British Standard Light (BSL), West African Standard (WAS) and British Standard Heavy (BSH) compaction energies. Contaminated specimens were prepared by mixing the lateritic soil with maximum 6 % oil concentration by weight of dry soil. The results obtained indicated a decrease in the hydraulic conductivity of the contaminated soil samples with increasing compactive efforts.
14
Arbili, Mohamed M., Mehmed Karpuzcu, and Mohammed M. Ali. "Impact of Silica Fume on the Strength Characterizes of Contaminated Soil." Polytechnic Journal 10, no. 1 (June 30, 2020): 6–11. http://dx.doi.org/10.25156/ptj.v10n1y2020.pp6-11.
Full textAbstract:
In this paper a silica fume (SF) utilized as an admixture for improving the strength characterizes of contaminated soil and create new useful soils. Compaction test and direct shear test are used to evaluate the strength properties of clean and contaminated soil. Mixing SF with contaminated soil by crude oil is a rare study carried out. The strength characterizes of clean and polluted soil with crude oil was investigated. Three amount of light crude oil is combined with soils artificially in the percentage of 3%, 6%, and 9% by dry weight. However, three portions of SFs are used in the experimental work, which are 0%, 12%, and 18%. In the compaction test, results show that optimum moisture content (OMC) decreases with increasing degree of contamination, inversely while adding SF, OMC is increased. Maximum dry density dramatically decreased with an increasing amount of SF and crude oil. The shear strength properties enhance by utilizing SF where observed that the cohesion in clean soil is increased from 25.3 to 40.3 kPa and in contaminated soil by 9% crude oil is raised from 12.3 to 18.6 kPa so that SF can be rate as a successful material to enhance the soil properties.
15
Hsu, Sung Chi, Huan Yang Chiang, and Ji Yuan Lin. "Effect of Gradation and Cement on the Properties of Soil-Cement Mixtures." Advanced Materials Research 535-537 (June 2012): 1719–22. http://dx.doi.org/10.4028/www.scientific.net/amr.535-537.1719.
Full textAbstract:
Eight non-plastic soils with different gradation are used for this research to study the appropriate choice of soil-cement mixture for a earth and rock-fill dam construction project. The properties of soil-cement materials are influenced by several factors, including type and proportion of soil, cementitious materials, water content, compaction, uniformity of mixing, curing conditions, and age of the compacted mixture. Based on the experimental results, the maximum dry density will increase with an increase in cement content for soils with low fines content. However, no significant variation was noticed for soils with higher fines content. For given cement content, the maximum density of soil-cement mixture also has a positive correlation with the average grain size, D50, and uniformity coefficient of gradation, Cu. Based on USBR criteria and experimental results, a minimum of 11% of cement content are suitable for soil-cement application on the dam construction. Coarser grain soils are more applicable than finer grain soils to soil-cement construction.
16
Laffan, M. D., and T. J. Kingston. "Earthworms in some Tasmanian forest soils in relation to bioturbation and soil texture profile." Soil Research 35, no. 6 (1997): 1231. http://dx.doi.org/10.1071/s96076.
Full textAbstract:
Soil properties and earthworm population density were examined for 5 forest soils derived from Silurian-Devonian sandstones (Mathinna Beds) in north-eastern Tasmania. The soils occur along gradients of altitude, rainfall, and forest type; they include 2 with texture-contrast and 3 with gradational soil profile types. The density and biomass of the most abundant earthworm species Megascolex montisarthuri, and of all earthworm species combined, were found to be greater in gradational than in texture-contrast soils. A greater proportion of the earthworms in gradational soils than in texture-contrast soils was found to occur at soil depths exceeding 10 cm. The contrast was most pronounced between the 2 texture-contrast soils and the single gradational soil that occur under dry eucalypt forest. This paper explores the hypothesis that bioturbation of surface and subsurface layers by earthworms is an important mixing process that in gradational soils outweighs the counter tendency for soil particles to sort and thus form texture-contrast profiles.
17
Pu, Huimei, Weifeng Song, and Jinkui Wu. "Using Soil Water Stable Isotopes to Investigate Soil Water Movement in a Water Conservation Forest in Hani Terrace." Water 12, no. 12 (December 15, 2020): 3520. http://dx.doi.org/10.3390/w12123520.
Full textAbstract:
Water conservation forests significantly contribute to the stability of mountain agricultural ecosystems in Hani Terrace. In this study, we analyzed the relationship between the stable isotopic composition of soil water and precipitation to determine the mechanisms of soil water movement in the small watershed of Quanfuzhuang. We observed significant seasonal variations in soil water sources: antecedent precipitation was the dominant supply during the dry season, and current precipitation dominated during the rainy season. The recharge ratio of precipitation to soil water in the grassland was significantly higher than that in the arbor land and shrubland. The influence of water infiltration, old and new soil water mixing, and soil evaporation on the soil water stable isotopes gradually decreased from the surface (0–20 cm) to the deep (60–80 cm) soil. We observed significant seasonal variability in average soil water δ18O in the upper 0–60 cm and lower variability at 60–100 cm. The average soil water δ18O was generally higher in the dry season than in the rainy season. The mixing of old and new water is a continuous and cumulative process that is impacted by soil structure, soil texture, and precipitation events. We therefore identified a significant time delay in soil water supply with increasing soil depth. Moreover, the piston flow of soil water co-occurred with preferential flow, and the latter was the dominant supply during the rainy season.
18
Santana, Teresa, João Gonçalves, Fernando Pinho, and Rui Micaelo. "Effects of the Ratio of Porosity to Volumetric Cement Content on the Unconfined Compressive Strength of Cement Bound Fine Grained Soils." Infrastructures 6, no. 7 (June 26, 2021): 96. http://dx.doi.org/10.3390/infrastructures6070096.
Full textAbstract:
This paper presents an experimental investigation into the effects of porosity, dry density and cement content on the unconfined compressive strength and modulus of elasticity of cement-bound soil mixtures. A clayey sand was used with two different proportions of type IV Portland cement, 10% and 14% of the dry mass of the soil. Specimens were moulded with the same water content but using four different compaction efforts, corresponding to four different dry densities. Unconfined compression testing was conducted at seven days of curing time on unsoaked samples. The results showed that the compressive strength increased with the increase in cement content and with the decrease in porosity. From the experimental data, a unique relationship was found between the unconfined compressive strength and the ratio of porosity to volumetric cement content for all the mixtures and compaction efforts tested. The equation developed demonstrates that it is possible to estimate the amount of cement and the dry density to achieve a certain level of unconfined compressive strength. A normalized general equation was also found to fit other authors’ results for similar soils mixed with cement. From this, a cement-bound soil model was proposed for the development of a mixing design procedure for different soils.
19
Kosheleva, Olga, Alexander Koshelev, and Stanislav Shinkarenko. "Forest-Growing Conditions and State of Pine and Birch Species in the Northern Part of the Suburban Zone of Volgograd." Natural Systems and Resources, no. 1 (October 2019): 37–46. http://dx.doi.org/10.15688/nsr.jvolsu.2019.1.5.
Full textAbstract:
The article presents the results of the assessment of forest conditions and the state of forest cultures of Scots pine and Silver birch in the suburban area of Volgograd. The relevance of the study is due to the need to select productive and resistant to dry conditions mixing schemes of tree species for the organization of forest-park areas in suburban areas of large cities. Studies were conducted on the example of a key area of 0,7 hectares in the northern part of the city. Soil forest availability was determined by the granulometric composition, organic matter content and groundwater level. Soil sections of light chestnut soils are described, the characteristics of the main physicochemical indicators of soils are given. A profile of groundwater occurrence has been compiled and its relationship with the relief of the site is shown. The condition of forest cultures was assessed by bonitet, stock and vital status of the stand. High vitality indicators of pine and birch testify to the optimal conditions for the growth of forest crops under dry pinery. The conducted research allowed recommending, during the silvicultural works in the north of the suburban zone of Volgograd, the cool way of mixing pine with birch to create highly productive and sustainable protective forest stands.
20
Jendrysik, Klaudia, Michał Pachnicz, and Paweł Dudziński. "Parameters of the constitutive model of geomaterials formed with the use of DSM dry technology." E3S Web of Conferences 97 (2019): 02028. http://dx.doi.org/10.1051/e3sconf/20199702028.
Full textAbstract:
Numerical modelling of geomaterials is always complex due to the variability of parameters within the soil massif (created in the natural geological processes) and the orthotropy caused by this. In the case of the soil substrate modification with the use of hydraulic binders, this issue is complicated even more due to the fact the degree of mixing can be differentiated for various areas, while in the dry mixing technology, it is additionally differentiated with the depth of consolidation stress. Additional factor that makes it difficult to predict the behaviour of stabilised soil is the possible content of organic parts. Due to the development of substrate reinforcement technology, as well as the growing market for such works, a need emerged to provide parameters of the numerical model for various materials or, at least, to provide a method for reverse analysis on the basis of available data. This paper presents an example of calibration of the selected numerical model (through parameter selection of this model) based on the conducted examinations of cubic sample in the conditions of uniaxial compression. The results of laboratory tests, reverse analysis in the numerical model with a pre-selected strength hypothesis and finally, the recommendations for selection of the model in calculations of real structure on a reinforced substrate, are demonstrated.
21
Abbas, Jawdat, and Hamad Al-Luhaibi. "Influence of Iron Furnaces Slag on Collapsibility and Shear Strength of Gypseous Soil." No.1 27, no. 1 (March 15, 2020): 65–71. http://dx.doi.org/10.25130/tjes.27.1.09.
Full textAbstract:
Gypseous soil is one of the soils that suffer from problems and suffers from a reduction of shear strength and collapse when exposed to water immersion or water filtration in it. Many researchers have tried to solve these problems in different ways and by using many materials as additives to improve the performance and efficiency of this soil. In this research, the behavior of soil with a high content of gypsum (61.49%) is examined, using iron slag which is a by-product of the iron making process in melting furnaces, used as an additive in proportions (2, 4, 6, 8, 10., 12) %, by dry mixing method with soil. Tests are carried out to determine the effect of this substance on the shear strength parameters. The effect of water immersion on soil cohesion (c) is reduced until it reaches (c) in the case of immersion a value very close to the value in the dry state at slag ratio (10) %. This is the optimum ratio of slag to improve the value of (c). Whereas for the value of (ø), with the increase of the slag rate for both wet and dry cases, the value of (ø) increases, where (ø) reaches the highest value at; the slag rate (10) % for the dry state, and the slag rate (8) % for the soaked case. Whereas for the collapse potential (Cp), adding the slag reduces the value of the soil collapse potential (Cp), from (10.6) to the soil without additives until (0.95) for the slag rate (12) %. Then the soil becomes problematic soil.
22
Gupta, V. K., R. A. Jangid, and Seema Yadav. "Dielectric studies and microwave emissivity of alkaline soil of Alwar with mixing of gypsum." Material Science Research India 7, no. 2 (February 8, 2010): 519–24. http://dx.doi.org/10.13005/msri/070227.
Full textAbstract:
The real and imaginary parts of dielectric constant (ε' and ε") of alkaline soil of Alwar with mixing of gypsum (0.0% to 10.0%, gravimetrically) determined at 34.50C temperature and at a single microwave frequency 9.78 GHz by wave guide cell method. Mixture of soil and gypsum is prepared at various moistness of soil varying from 0.0% to 12.0%. The ε' and ε" of gypsum are also determined. It was observed that ε' and ε" increases as percentage concentration of gypsum in the soil increase. It was observed that the effect of gypsum mixing on dielectric properties is more significant at higher level of soil moisture content. Further, microwave emissivities are estimated from measured values of ε' and ε" for dry and wet mixture of, soil and gypsum at various observation angles (00-800) for horizontal polarization. It was observed that emissivity of soil decreases as the percentage concentration of gypsum in the soil increases.
23
Liu, Songyu, and Roman D. Hryciw. "Evaluation and Quality Control of Dry-Jet-Mixed Clay Soil-Cement Columns by Standard Penetration Test." Transportation Research Record: Journal of the Transportation Research Board 1849, no. 1 (January 2003): 47–52. http://dx.doi.org/10.3141/1849-06.
Full textAbstract:
Dry jet mixing has been widely used since the 1980s for stabilization of soft soil. The quality and strength of the dry-jet-mixed columns must be evaluated to confirm the success of the stabilization. The standard penetration test (SPT) is shown to be a simple and effective method for this task. The strength characteristics along the length of the column were determined, and correlations between the SPT blow count and the unconfined compressive strength were developed.
24
Ma, Qinghua, Hongliang Tang, Zed Rengel, and Jianbo Shen. "Banding phosphorus and ammonium enhances nutrient uptake by maize via modifying root spatial distribution." Crop and Pasture Science 64, no. 10 (2013): 965. http://dx.doi.org/10.1071/cp13266.
Full textAbstract:
Localised supply of phosphorus (P) plus ammonium improves root proliferation and nutrient uptake by plants grown on calcareous soils, but how nitrogen (N) forms (ammonium and urea) and placements affect maize (Zea mays L.) root distribution and nutrient uptake is not fully understood. A soil column study was conducted with four N and P combinations including P plus urea (UP), mono-ammonium phosphate (MAP), di-ammonium phosphate (DAP) and P plus ammonium sulfate (ASP), and two fertiliser application methods (banding in the 10–25 cm layer or mixing throughout the 45-cm soil profile). Shoot N and P content increased by 11–31% and 14–37% in the treatments with banding P plus ammonium (MAP, DAP or ASP) compared with banding UP and the mixing treatments. Shoot N and P uptake rates per root dry weight or root length were higher with banding P plus ammonium than their respective mixing treatments. Banding P plus ammonium increased root-length density in the fertiliser-banded layer compared with banding UP and the mixing treatments. The results show that modifying root spatial distribution by banding P plus ammonium leads to an increase in N and P uptake rates, and consequently enhances nutrient accumulation by maize.
25
Chu, Jian, Volodymyr Ivanov, Viktor Stabnikov, Jia He, Bing Li, and Maryam Naemi. "Biocement: Green Building- and Energy-Saving Material." Advanced Materials Research 347-353 (October 2011): 4051–54. http://dx.doi.org/10.4028/www.scientific.net/amr.347-353.4051.
Full textAbstract:
Cement and chemical grouts have often been used for soil strengthening. However, high cost, energy consumption, and harm to environment restrict their applications. Biocement could be a new green building- material and energy-saving material. Biocement is a mixture of enzymes or microbial biomass with inorganic chemicals, which can be produced from cheap raw materials. Supply of biocementing solution to the porous soil or mixing of dry biocement with clayey soil initiate biocementation of soil due to specific enzymatic activity. Different microorganisms and enzymes can be used for production of biocement.
26
Wang, Qiang, Rui Tang, Qun Cheng, Xiankun Wang, and Fang-ling Liu. "Research on Static Triaxial Mechanical Properties of New CementSoil Reinforced with Polypropylene Fiber." Advances in Materials Science and Engineering 2014 (2014): 1–10. http://dx.doi.org/10.1155/2014/532327.
Full textAbstract:
Through the laboratory test, the mechanical properties of cementsoil with adding desulfurization gypsum, fly ash, and polypropylene fiber were studied. Three different percentages (0%, 0.5%, and 1.0%) of polypropylene fiber were mixed into new cementsoil for which the cement content is 15% of the dry soil weight, the desulfurization gypsum content is 2% of the dry soil weight, and the fly ash content is 1.0% of the dry soil weight. The new cementsoil strength reinforced with polypropylene fiber was studied by triaxial test under different polypropylene fiber mixing ratio, different age, and different confining pressure. The experimental results show that, compared with ordinary soil, the deviatoric stress and the peak shear strength reinforced with polypropylene fiber have different amplitude increase. At the same time, the internal friction angle of new cementsoil with polypropylene fiber increases slightly with the growth of the age. The stress-strain curve of the polypropylene fiber cementsoil has the typical work hardening characteristic and has the characteristics of bulge fracture.
27
Kudakwashe Hove, Justina Johannes, Gervasius Hatutale, Simon Kamwele Awala, and Petrus Ausiku. "Growth and yield response of Swiss chard (Beta vulgaris (L.) to media mixture ratios of sand, acacia soil, and goat manure." Magna Scientia Advanced Biology and Pharmacy 1, no. 1 (November 30, 2020): 018–24. http://dx.doi.org/10.30574/msabp.2020.1.1.0015.
Full textAbstract:
Northern Namibian soils are predominantly sandy. A mixture of Acacia soils, sandy and goat manure is frequently used for growing various plants. However, the extent to which variations in proportions of these substrates affect growth and yield is not known. The study was conducted at the University of Namibia, Ogongo campus during the period April to August 2020 to determine optimum mixing ratios for sandy, Acacia erioloba soil and goat manure on the growth and yield of Swiss chard. Treatments were Sandy, Acacia soil and goat manure mixed in 5 different ratios of respectively; 1:2:1; 2:3:2; 1:1:1, 2:1:2, 1:1:2 and Acacia soil (control). Samples from each mixture used for pot filling were taken to the soil laboratory for textural analysis. A complete randomized experiment with 8 replications was laid under the University’s shade house. Measured parameters were plant height, leaf area, fresh and dry matter weight and chlorophyll content. Results showed that media was significantly different across all the measured parameters at 1 % probability level. The medium mixture 2:3:2 outperformed the rest of the mixtures in almost all the parameters. The results of the study indicated that acacia soil alone is not optimum for pot filling but must be supplemented with substrate that is rich in mineral content like goat manure. However, the mixing ratio is a key consideration for optimal vegetable production. We recommend the use of media mixture 2:3:2 to improve yield of Swiss chard.
28
Zakarka, Mindaugas, Šarūnas Skuodis, Giedrius Šiupšinskas, and Juozas Bielskus. "Compressive strength and thermal properties of sand–bentonite mixture." Open Geosciences 13, no. 1 (January 1, 2021): 988–98. http://dx.doi.org/10.1515/geo-2020-0289.
Full textAbstract:
Abstract Sand–bentonite mixtures are used in road embankments as a protective material for protecting underground high-voltage cables and utility pipelines supplying water and gas etc. The sand–bentonite mixtures provide benefits while laying high-voltage cables. The purpose of this study is to determine the proportions as well as mechanical and thermal properties of a dry-mixed sand–bentonite mixture and to investigate the suitability of such mixtures for installation around high-voltage underground power lines in road embankments. When selecting a sand–bentonite mixture, the following requirements must be ensured: the compressive strength must be greater than 0.5 MPa after 24 h; the thermal resistivity must be greater than 1.2 K m/W (thermal conductivity 0,833 W/(K m)); and the moisture content of the sand–bentonite mixture must be less than 13%. The following materials were used when selecting the bentonite mixture: bentonite, 0–4.0 mm fraction sand, cement (CEM I 42.5R), and water. In this study, six groups of samples were formed, in which the parts of concrete, sand, cement, and water were added in different proportions. The strength and thermal conductivity of the samples were analyzed. Studies about the use of bentonite around high-voltage cables have revealed the need for wet mixing of bentonite suspensions. The required thermal conductivity properties of the soil were not achieved by dry mixing. This method of mixing can be useful only in cases when the thermal conductivity of the mixed soil is not relevant, because the work can be continued after a day.
29
Cornish, PS. "Glyphosate residues in a sandy soil affect tomato transplants." Australian Journal of Experimental Agriculture 32, no. 3 (1992): 395. http://dx.doi.org/10.1071/ea9920395.
Full textAbstract:
Glyphosate residues in a loamy sand soil were suspected of damaging transplanted tomatoes at Gosford in 1990. Field and glasshouse experiments were conducted to determine whether phytotoxic residues of glyphosate persist in this soil type and, if so, under what conditions. In the glasshouse experiment, visible symptoms of glyphosate toxicity occurred in tomato seedlings transplanted into soil that was sprayed 1, 5 or 15 days earlier with glyphosate (360 g a.i.L) at 4 L productha. Glyphosate also reduced plant dry weight (16 days after transplanting), but only where soil nutrient deficiencies were corrected after transplanting. In this case, seedlings transplanted 15 days after spraying suffered an average reduction in dry weight of 57%. Greater reductions in dry weight occurred where superphosphate (43 kg Pha) was mixed through soil before spraying (75 v, 35% reduction). In the field, glyphosate residues reduced plant dry weight 16 days after transplanting, even when transplanting followed spraying by up to 9 days, and possibly as many as 30. At 9 days, reductions of 50, 74 and 78% were recorded with glyphosate (360 g a.i./L) applied at 2, 4 and 8 L/ha, respectively. Effects of glyphosate on fruit yield were significant (P<0.05), but much smaller than effects on earlier plant dry weights. The phytotoxicity of glyphosate residues in this loamy sand appears to result from a combination of inherently low P sorption capacity and application of superphosphate, leading to low adsorption of glyphosate by soil. This may be exacerbated when dry conditions occur between application and planting. On the present evidence, a plant-back period of 3 weeks could be considered safe when transplanting tomatoes into this sandy soil, provided some mixing of soil occurs at transplanting. It is recommended that farmers perform a simple bioassay to confirm safety.
30
Babatunde, Annafi Qaudri, Eberemu Adrian Oshioname, Yohanna Paul, and Osinubi Kolawole Junwolo. "Effect of Elapsed Time after Mixing on the Strength Properties of Lime–Iron Ore Tailings Treated Black Cotton Soil as a Road Construction Material." Infrastructures 5, no. 11 (October 25, 2020): 89. http://dx.doi.org/10.3390/infrastructures5110089.
Full textAbstract:
The study evaluated the effect of elapsed time after mixing on the strength properties of lime and iron ore tailings (IOT) treated black cotton soil (BCS) (an expansive tropical black clay) as road construction material. BCS was treated with 0, 2, 4, 6, and 8% lime and 0, 2, 4, 6, 8, and 10% IOT content by dry weight of soil. Tests carried out include Atterberg limits, compaction, unconfined compressive strength (UCS), California bearing ratio (CBR) (unsoaked condition), and microstructure of specimens. Statistical analysis was done using MINI-TAB software. Results show that the liquid limit (LL) of BCS–lime–IOT mixtures decreased with increase in lime and IOT content. The LL values of all the treated BCS increased between 0 and 1 h elapsed time after mixing. On the other hand, the plastic limit (PL) of BCS decreased with increase in lime and IOT content while the plasticity index (PI) decreased from 27.7 to 22.9% for 0% lime/0% IOT content and from 30.6 to 26.6% for 0% lime/10% IOT content. Maximum dry density (MDD) of BCS increased while optimum moisture content (OMC) decreased with higher IOT content. The natural BCS recorded OMC value of 25.6% decreased to 15.2% for 8% lime/10% IOT treatment. The strength (i.e., UCS and CBR values) increased with increase in lime/IOT contents between 0 and 2 h elapsed time after mixing. Peak values were recorded for 8% lime/8% IOT treatment for all lime content considered. Regression analysis shows a strong relationship between the strength properties and the soil parameters. An optimal 8% lime/8% IOT treatment of BCS for elapsed time after mixing not exceeding 2 h was established and is recommended as sub-base material for low-trafficked roads.
31
AlJassar, Hala K., Marouane Temimi, Dara Entekhabi, Peter Petrov, Hussain AlSarraf, Panagiotis Kokkalis, and Nair Roshni. "Forward Simulation of Multi-Frequency Microwave Brightness Temperature over Desert Soils in Kuwait and Comparison with Satellite Observations." Remote Sensing 11, no. 14 (July 11, 2019): 1647. http://dx.doi.org/10.3390/rs11141647.
Full textAbstract:
In this study, we address the variations of bare soil surface microwave brightness temperatures and evaluate the performance of a dielectric mixing model over the desert of Kuwait. We use data collected in a field survey and data obtained from NASA Soil Moisture Active Passive (SMAP), European Space Agency Soil Moisture and Ocean Salinity (SMOS), Advanced Microwave Scanning Radiometer 2 (AMSR2), and Special Sensor Microwave/Imager (SSM/I). In situ measurements are collected during two intensive field campaigns over bare, flat, and homogeneous soil terrains in the desert of Kuwait. Despite the prevailing dry desert environment, a large range of soil moisture values was monitored, due to precedent rain events and subsequent dry down. The mean relative difference (MRD) is within the range of ±0.005 m3·m−3 during the two sampling days. This reflects consistency of soil moisture in space and time. As predicted by the model, the higher frequency channels (18 to 19 GHz) demonstrate reduced sensitivity to surface soil moisture even in the absence of vegetation, topography and heterogeneity. In the 6.9 to 10.7 GHz range, only the horizontal polarization is sensitive to surface soil moisture. Instead, at the frequency of 1.4 GHz, both polarizations are sensitive to soil moisture and span a large dynamic range as predicted by the model. The error statistics of the difference between observed satellite brightness temperature (Tb) (excluding SMOS data due to radio frequency interference, RFI) and simulated brightness temperatures (Tbs) show values of Root Mean Square Deviation (RMSD) of 5.05 K at vertical polarization and 4.88 K at horizontal polarization. Such error could be due to the performance of the dielectric mixing model, soil moisture sampling depth and the impact of parametrization of effective temperature and roughness.
32
Huang, Meng Yun, Jun Lai Xiong, Ji Bing Tang, and Chi Long. "Experimental Study on Shear Strength of Expansive Soil Improved by Lime - Weathered Sand." Applied Mechanics and Materials 446-447 (November 2013): 1441–47. http://dx.doi.org/10.4028/www.scientific.net/amm.446-447.1441.
Full textAbstract:
This paper ananlyzes and contrasts the direct shear test of the expansive soil with different weathered sand dosage (mass ratio) and different lime dosage (mass ratio) in the case of the expansive soil with some water content and dry density .And try to analyzes and researches the impact of expansive soil improved by weathered sand and lime shear strength index . The direct shear test by the expansive soil mixed with different proportions of weathered sand and lime can be concluded that: mixing the weathered sand to improve the shear strength of expansive soil is effective, and cohesion gradually decreases with the increase of doped proportion of sand and the angle of internal friction first increases with the increase of doped proportion of sand and then decreases ;mixing of lime is effective to improve the shear strength of expansive soil, and cohesion gradually decreases with the increase of doped proportion of lime and angle of internal friction first increases and then decreases with the increase of doped proportion of lime. The shear strength of improved expansive soil can meet the subgrade filling with soil standards and at the same time the expansive soil improved by weathered sand and lime reduces the amount of lime and reduce project cost when to achieve the same shear strength standards.
33
Snodi, Lamyaa Najah, Yahya Atemimi, and Fauziah binti Ahmad. "Effect of stabilizers on the shear strength of residual soil." MATEC Web of Conferences 162 (2018): 01019. http://dx.doi.org/10.1051/matecconf/201816201019.
Full textAbstract:
In this paper, chemical stabilizer was used for soil characteristics improvement. Styrene Butadiene Rubber (SBR) polymer and lime is effectively used as an inexpensive and easily applied material for soil stabilization and its response performance was evaluated. This research studied improving the engineering properties of Residual soil by mixing it with varying percentages of chemical stabilizer. An evaluation of the effectiveness and performance of SBR and Lime as a soil stabilizer was performed over a series of laboratory tests for geotechnical soil properties. Residual soil used in this study was lateritic soil. The soil was mixed with various amounts of stabilizer for polymer (SBR) {2.5, 5, 10 and 12.5 %} and for lime {1.25,2.5,5 and 10%} by weight and then compacted at the optimum moisture content (OMC) and maximum dry unit weight (MMD). The original soil and the stabilized samples were subjected to unconfined compression test to determine their strength at different curing times (7,14 and 28 day). The results showed a reduction in the plasticity index. The results showed an increase in strength.
34
Rahil, Falah H., Husam H. Baqir, and Nabeel J. Tumma. "Effect of Heating Borehole Spacing on Plasticity of Expansive Soil." Engineering and Technology Journal 38, no. 7A (July 25, 2020): 1062–68. http://dx.doi.org/10.30684/etj.v38i7a.79.
Full textAbstract:
This paper presents the effect of spacing between boreholes heating on plasticity of expansive soils. The expansive soils used were prepared artificially by mixing Kut clay with different percentages of bentonite. Nine laboratory models of expansive soils having dry unit weight of 17.8 kN/m3 with 6% initial water content were prepared inside a steel box of (300 mm × 300 mm × 400 mm height). A special heating system generates 400 Co for six hours was designed and manufactured for this purpose using 12 mm diameter electric heaters inserted through boreholes. Square pattern boreholes of 170 mm length with spacing (4.16d, 6.25d and 8.33d) were used. A representative sample were taken after heating from the center of the square pattern for measuring the plasticity of the soils. The results showed that the plasticity index remarkedly decreases compared with that before heating and increases with increasing bentonite and the spacing. It is also indicated that an expansive soil could be changed from high to low plasticity
35
Yeates, JS, and DG Allen. "Low effectiveness of three rock phosphates as phosphorus fertilizers and liming materials on an acid clay-loam." Australian Journal of Agricultural Research 38, no. 6 (1987): 1033. http://dx.doi.org/10.1071/ar9871033.
Full textAbstract:
The effectiveness of three finely ground rock phosphates (PRs) was compared with ordinary superphosphate (OSP) for subterranean clover growth and for increasing soil bicarbonate-extractable P levels over two successive 8-week periods on a very acid clay-loam (pH (0.01 M CaCl2) 4.3) in a glasshouse experiment. All PR sources were poorly effective compared to OSP. Maximum dry matter and P uptake of each PR source was less than that of OSP at each harvest. Relative to surface application, mixing throughout the soil reduced the effectiveness of OSP for dry matter and P uptake, but had little effect on the PR sources. Relative to OSP, the effectiveness of PR sources did not increase at the second harvest. Bicarbonate-extractable P levels for soil-incorporated Island PR plateaued below the highest rate applied. Phosphorus uptake by the herbage at harvests 1 and 2 was not well related to soil bicarbonateextractable P levels at harvest 1, and source dependency was indicated. Soil pH was markedly increased by each of PR sources at application rates within the rates required to reach maximum dry matter and P yield. Increased soil pH at high PR applications is likely to have reduced PR dissolution, and contributed to low agronomic effectiveness. Dry matter yield at both harvests was dependent on P concentration in the tops, regardless of the P source or method of P application. A higher soil buffering capacity for pH, P or Ca than was present in this soil seems necessary for sufficient PR dissolution to achieve the same agronomic effectiveness as OSP.
36
Ganfoud, Ahmed Abouleid, Almustanser-Bellah Mukhtar Gargney, and Ahmed Ibrahim Ekhmaj. "Effect of Different Applications of Cactus, Rachis of Date Palm Trees and Compost on Hydraulic Properties of Sandy Soil." Journal of Misurata University for Agricultural Sciences 1, no. 2 (June 30, 2020): 479–94. http://dx.doi.org/10.36602/jmuas.2020.v01.02.35.
Full textAbstract:
This laboratory study aims to investigate the effect of adding dry grinders of Cactus (Opuntia ficus-indica) and palm leaf bases (Rachis) and commercial soil enhancer (Compost) with different mixing ratios (2.5, 5.0, 7.5%, by weight) on improving hydraulic properties of sandy soil. Hydraulic properties included the water retention capacity, the saturated hydraulic conductivity, and the moisture content at tension values of 0.3, 1, 10 and 15 bar. These properties were estimated at the beginning of the experiment, and after six months, during which moisture and drying cycles had taken place. Through the obtained results, it was found that all additives improved the soil hydraulic properties, so that the values of the soil retention capacity and soil moisture content versus tension increased. On the other hand, all additives reduced the values of the hydraulic conductivity. The results also indicated lack significant effect of time (at the level of 5%). The different mixing ratios did not significantly affect the hydraulic conductivity (at the level of 5%). However, the results showed that the rachis grinders and the mixture consisting of rachis and cactus outperformed in hydraulic properties as compared with other treatments.
37
Gupta, M. K., R. K. Srivastava, and A. K. Singh. "Bench Scale Treatability Studies of Contaminated Soil Using Soil Washing Technique." E-Journal of Chemistry 7, no. 1 (2010): 73–80. http://dx.doi.org/10.1155/2010/463175.
Full textAbstract:
Soil contamination is one of the most widespread and serious environmental problems confronting both the industrialized as well as developing nations like India. Different contaminants have different physicochemical properties, which influence the geochemical reactions induced in the soils and may bring about changes in their engineering and environmental behaviour. Several technologies exist for the remediation of contaminated soil and water. In the present study soil washing technique using plain water with surfactants as an enhancer was used to study the remediation of soil contaminated with (i) an organic contaminant (engine lubricant oil) and (ii) an inorganic contaminant (heavy metal). The lubricant engine oil was used at different percentages (by dry weight of the soil) to artificially contaminate the soil. It was found that geotechnical properties of the soil underwent large modifications on account of mixing with the lubricant oil. The sorption experiments were conducted with cadmium metal in aqueous medium at different initial concentration of the metal and at varying pH values of the sorbing medium. For the remediation of contaminated soil matrices, a nonionic surfactant was used for the restoration of geotechnical properties of lubricant oil contaminated soil samples, whereas an anionic surfactant was employed to desorb cadmium from the contaminated soil matrix. The surfactant in case of soil contaminated with the lubricant oil was able to restore properties to an extent of 98% vis-à-vis the virgin soil, while up to 54% cadmium was desorbed from the contaminated soil matrix in surfactant aided desorption experiments.
38
Blackwell, PS, TW Green, and KA Olsson. "The size and horizon of origin of fragments produced by deep ripping texture contrast soils." Soil Research 25, no. 2 (1987): 211. http://dx.doi.org/10.1071/sr9870211.
Full textAbstract:
Two texture contrast soils were cultivated by deep ripping when they were drier than their lower plastic limits. The size distribution and soil horizon-of-origin of the resulting fragments were measured. One soil, a transitional red-brown earth, had either been previously uncultivated below the A horizon or had been deep ploughed and gypsum added two years previously. There was much fragmentation and mixing of soil from both of the horizons. Fine soil (<2 mm diam.) from the A horizon reached the lower depths of the trough made by the ripping and coarse soil from the B horizon (>50 mm) was brought to near the surface. The fragment size distributions were characteristically bimodal. Fragments of the fine mode (<2 mm) came mainly from the A horizon, fragments of the coarse mode (11-25 mm or larger) came mainly from the B horizon. In the laboratory, clods from the deep ripped soil were crushed at the same low water potential (air dry). The crushing energy per unit mass (specific crushing energy) was inversely proportional to the normalized geometric mean diameter of the fragments produced. Suggestions are made for modelling the effects of deep ripping.
39
Ghosheh, Hani Z., Khalid M. Hameed, Munir A. Turk, and Abbas F. Al-Jamali. "Olive (Olea europea) Jift Suppresses Broomrape (Orobanchespp.) Infections in Faba Bean (Vicia faba), Pea (Pisum sativum), and Tomato (Lycopersicon esculentum)." Weed Technology 13, no. 3 (September 1999): 457–60. http://dx.doi.org/10.1017/s0890037x00046029.
Full textAbstract:
Olive jift is a solid by-product of olive (Olea europea) oil processing. Greenhouse experiments were conducted to evaluate olive jift effect on broomrape (Orobanchespp.) infections on three crops. Soil—jift mixtures were used as potting medium in ratios of 1:0, 1:1, and 3:1 soil to jift. Broomrape seeds were evenly incorporated in the potting media at 0, 150, 300, 450, 600, 750, and 900 seeds/kg. Pots planted with faba bean or pea were inoculated with seeds ofO. crenataForsk., whereas pots planted with tomato were inoculated with seeds ofO. lavandulaceaReichenb. Jift in soil reduced broomrape germination and infection on all three hosts regardless of inoculation densities. Pea was not infected with broomrape in jift-containing media at any inoculation density, whereas only sporadic broomrape infections were observed in faba bean and tomato grown in jift-mixed soils. Fresh and dry weights of all crops were not adversely affected by mixing jift with soil. These results suggest a possible use of jift as an inexpensive organic material for broomrape control.
40
Xiang, Xian Chao, Guo Sheng Jiang, and Chang Qi Zhu. "Testing Study on DJM Pile Composite Foundation under Flexible Load." Advanced Materials Research 168-170 (December 2010): 2513–17. http://dx.doi.org/10.4028/www.scientific.net/amr.168-170.2513.
Full textAbstract:
Dry jet mixing (DJM) piles are widely used in silt foundation treatment to improve foundation stability and control post-construction deformation. As the work mechanism of DJM composite foundation is very complex, though many useful calculation theories have achieved, the theoretical study of DJM pile composite foundation is still far behind engineering practice, the settlement and stress calculation precision is unsatisfied. Then it is still necessary to reveal the work mechanism of DJM pile comprehensively. A field test of DJM pile composite road foundation is carried out and many measurement methods are adopt to collect the test information, such as soil pressure sensors, pore pressure sensors, settlement plates, inclinometer tubes, stratified settlement pipes, multi-point displacement meters in piles and so on. Then the surface settlement, internal deformation and stress developing of soils and piles are monitored Real-time. Through in-site test, the settlement and internal deformation of piles and soils, the stress ratio between pile and soil, and the negative friction around pile are studied.
41
Ma, Binhui, Kai Cai, Xing Zeng, Zhuo Li, Zhiyong Hu, Qiunan Chen, Chengbin He, Bingchu Chen, and Xiaocheng Huang. "Experimental Study on Physical-Mechanical Properties of Expansive Soil Improved by Multiple Admixtures." Advances in Civil Engineering 2021 (May 20, 2021): 1–15. http://dx.doi.org/10.1155/2021/5567753.
Full textAbstract:
The treatment of expansive soil is always a difficult problem in engineering. Using coal gangue, fly ash, and other solid waste to treat expansive soil has gradually become a new way of energy saving and environmental protection. Most of the existing studies focus on using one or two kinds of admixtures to improve expansive soil, but there are few studies on improving expansive soil with multiple admixtures. In this paper, the expansion and shrinkage deformation and strength characteristics of expansive soil modified by coal gangue, fly ash, and lime are studied experimentally. Nine groups of different mixing schemes were designed through orthogonal tests, and the physical and mechanical properties of the improved expansive soil under different mixing ratios were tested. The sensitivity analysis of the test results was carried out to study the effect of each admixture on the improved expansive soil under different mixing ratios, and the optimal mix ratio under different conditions was obtained. The optimal mix ratio is 8% for coal gangue, 11% for fly ash, and 6% for lime. Further scanning electron microscopy (SEM) tests were carried out to analyze the microstructure of the improved expansive soil and explore the improvement mechanism of the multiadmixture. The results show that the optimal moisture content and the maximum dry density of the expansive soil with ash are decreased, and the properties of liquid plastic limit, free expansion rate, shear strength, and unconfined compressive strength of the expansive soil are improved obviously. Through the analysis of the comprehensive balance method, it is found that the content of lime has the greatest influence on the improvement effect of expansive soil, followed by that of coal gangue, and the least is that of fly ash. SEM structure analysis reveals that the particles of improved expansive soil are mainly aggregates, the soil structure is dense, particle agglomeration increases, and the overall structure is stronger. The research results can provide reference for the improvement of expansive soil with various admixtures and the resource utilization of coal gangue, fly ash, and other solid wastes.
42
Campbell, Matthew A., Craig R. Ferguson, D. Alex Burrows, Mark Beauharnois, Geng Xia, and Lance F. Bosart. "Diurnal Effects of Regional Soil Moisture Anomalies on the Great Plains Low-Level Jet." Monthly Weather Review 147, no. 12 (December 1, 2019): 4611–31. http://dx.doi.org/10.1175/mwr-d-19-0135.1.
Full textAbstract:
Abstract The Great Plains (GP) low-level jet (GPLLJ) contributes to GP warm season water resources (precipitation), wind resources, and severe weather outbreaks. Past research has shown that synoptic and local mesoscale physical mechanisms (Holton and Blackadar mechanisms) are required to explain GPLLJ variability. Although soil moisture–PBL interactions are central to local mechanistic theories, the diurnal effect of regional soil moisture anomalies on GPLLJ speed, northward penetration, and propensity for severe weather is not well known. In this study, two 31-member WRF-ARW stochastic kinetic energy backscatter scheme ensembles simulate a typical warm season GPLLJ case under CONUS-wide wet and dry soil moisture scenarios. In the GP (24°–48°N, 103°–90°W), ensemble mean differences in sensible heating and PBL height of 25–150 W m−2 and 100–700 m, respectively, at 2100 UTC (afternoon) culminate in GPLLJ 850-hPa wind speed differences of 1–4 m s−1 12 hours later (0900 UTC; early morning). Greater heat accumulation in the daytime PBL over dry soil impacts the east–west geopotential height gradient in the GP (synoptic conditions and Holton mechanism) resulting in a deeper thermal low in the northern GP, causing increases in the geostrophic wind. Enhanced daytime turbulent mixing over dry soil impacts the PBL structure (Blackadar mechanism), leading to increased ageostrophic wind. Overnight geostrophic and ageostrophic winds constructively interact, leading to a faster nocturnal GPLLJ over dry soil. Ensemble differences in CIN (~50–150 J kg−1) and CAPE (~500–1000 J kg−1) have implications for severe weather predictability.
43
Kanty, Piotr, Monika Kiecana, and Piotr Prokopowicz. "Some remarks on statistic approach to strength testing of soil-cement composites." E3S Web of Conferences 97 (2019): 04045. http://dx.doi.org/10.1051/e3sconf/20199704045.
Full textAbstract:
Results of laboratory testing of organic soil-cement samples are presented in the paper. The research program continues on the authors previously reported experiences with cement - organic soil sample testing. Over 150 compression tests have been carried out altogether. Several samples were cured for over 3 months before they were tested. Several factors, such as: the large amount of the pieces under test, long observation time, carrying out the tests in complex cycles of loading and the possibility of continuous registering the loads and deformation in the axial direction – made it possible to control numerous interdependencies, some of which have been presented in this work. Compressive strength and elastic modulus of cubic samples were examined. Samples were mixed and stored in laboratory conditions. The results clearly point to the fact that designing the DSM dry columns in the organic soil may be linked with a considerable risk and needs special precautions. During in situ mixing, the organic material surrounded by sand layers surely mixes with one another in certain areas. However, it has not been examined and it is difficult to assume such mixing already at the designing stage.
44
Carisa, Celia Nindy, Mokhammad Farid Ma'ruf, and Paksitya Purnama Putra. "STABILIZATION OF EXPANSIVE SOIL WITH MIXING CA(OH)2 (EXPANSIVE SOIL CASE STUDY: JATILUHUR HAMLET, GLAGAH AGUNG VILLAGE, PURWOHARJO DISTRICT, BANYUWANGI REGENCY)." Jurnal Rekayasa Sipil dan Lingkungan 3, no. 1 (June 3, 2019): 17. http://dx.doi.org/10.19184/jrsl.v3i1.9272.
Full textAbstract:
Expansive soils can cause problems in construction due to changing volume changes. The area that is suspected to have an expansive soil type is Glagah Agung village, Purwoharjo District, Banyuwangi. Every season change, the construction of the building is always damaged, especially on the structure of the building. In the rainy season, the land will expand and cause the building to rise, while at the dry season the land will shrink and there is a decline in buildings. In the face of these problems, it is necessary to do special treatment to improve the nature of the expansive soil. One is chemical stabilization, adding chemicals to improve soil properties and reduce their development potential. In this study, the stabilizers used are Ca (OH) 2 lime with a percentage of 4%, 6%, 8%, 10%, 12% with curing time for one day. The results of soil become less plastic with an increase of lime content. The decrease of plasticity index is supported by grain test which is the decrease of clay fraction grain on soil mixed with lime according to the USCS method and AASHTO method. There was a decrease in the percent of original primary soil development which was initially 11.9% decreased to 2.181% 4% lime content, and 0% at 6% to 12%.
Tanah ekspansif dapat menimbulkan masalah dalam konstruksi akibat perubahan volume yang berubahubah. Daerah yang diduga memiliki jenis tanah ekspansif adalah Desa Glagah agung Kecamatan Purwoharjo, Kabupaten Banyuwangi. Setiap pergantian musim, konstruksi bangunan selalu mengalami kerusakan terutama pada struktur dari bangunan. Pada musim penghujan tanah akan mengembang dan mengakibatkan bangunan terangkat, sedangkan pada saat kemarau tanah akan menyusut dan terjadi penurunan bangunan. Dalam menghadapi permasalahan yang terjadi maka perlu dilakukan treatment khusus untuk memperbaiki sifat tanah ekspansif. Salah satunya adalah stabilisasi kimiawi, dengan menambahkan bahan kimia untuk memperbaiki sifat tanah dan mereduksi potensi pengembangannya. pada peneliatian ini, stabilitator yang digunakan adalah kapur Ca(OH)2 dengan prosentase 4%,6%,8%,10%,12% dengan waktu peram (curing) selama 24 jam. Didapatkan hasil tanah menjadi tidak plastis seiring dengan bertambahnya kadar kapur. Penurunan indeks plastisitas didukung dengan pengujian gradasi butiran yaitu berkurangnya butiran fraksi lempung pada tanah yang dicampur dengan kapur menurut metode USCS dan metode AASHTO. Terjadi penurunan persen pengembangan primer tanah asli yang mulanya sebesar 11,9% berkurang menjadi 2,181% kadar kapur 4%, dan 0% pada kadar 6% hingga 12%.
45
Salé, L. Y., D. S. Chanasyk, and M. A. Naeth. "Temporal influence of fly ash on select soil physical properties." Canadian Journal of Soil Science 77, no. 4 (November 1, 1997): 677–83. http://dx.doi.org/10.4141/s96-078.
Full textAbstract:
Fly ash, as a source of calcium, has potential for soil structure amendment. This potential was tested by examining the influence of fly ash on select soil physical properties of an easily clodded clay loam soil. Fly ash:soil mixtures were varied from 0 to 100% (vol/vol). Pots of these mixtures were placed into the soil of a reclaimed surface mine and sampled four times during a 15.5-mo period: upon mixing, after one summer, after one summer and a winter and after the second summer. Bulk density, dry aggregate size distribution, penetration resistance (PR) and modulus of rupture (MOR) were assessed on soils within the pots.Adding fly ash up to 25 to 50% generally increased bulk density; adding more decreased it. Bulk density decreased over time for most of the treatments. Adding 12.5 or 25% fly ash produced the greatest percentage of aggregates within the ideal range (0.5 to 4.0 mm). Blunt-end PR was a more sensitive parameter than cone resistance. Adding 25% fly ash resulted in lower MOR while maintaining a desirable level of aggregation, thus reducing cloddiness. In general most properties varied over time, indicating the need to consider the dynamic nature of them in reclamation. Key words: Fly ash, soil reclamation, bulk density, penetration resistance, particle size distribution
46
Uchaipichat, Anuchit. "Consolidation Behavior of Clay Supported by Soil-Cement Column." Key Engineering Materials 861 (September 2020): 452–57. http://dx.doi.org/10.4028/www.scientific.net/kem.861.452.
Full textAbstract:
This paper presents the compression and consolidation behaviors of clay supported by soil-cement column. A series of consolidation tests was performed on kaolin samples supported by soil-cement column with the ratio between diameters of column and soil sample () ranging from 0 to 0.4. All samples with soil-cement column were cured for 28 days under the vertical pressure of 25 kPa. The sample preparation techniques simulating dry deep soil mixing method was developed. The test results showed the elastic region expanded with increasing value of . However, there was no effect of on deformation behavior in the elasto-plastic region. Moreover, the value of was considered constant over the range of testing stress level, for the value of of 0 and 0.2. For the value of of 0.3 and 0.4, the values of in the elastic region was greater than that in elasto-plastic region.
47
Delaria, Erin R., and Ronald C. Cohen. "A model-based analysis of foliar NO<sub><i>x</i></sub> deposition." Atmospheric Chemistry and Physics 20, no. 4 (February 26, 2020): 2123–41. http://dx.doi.org/10.5194/acp-20-2123-2020.
Full textAbstract:
Abstract. Foliar deposition of NO2 removes a large fraction of the global soil-emitted NOx. Understanding the mechanisms of NOx foliar loss is important for constraining surface ozone, constraining NOx mixing ratios, and assessing the impacts of nitrogen inputs to ecosystems. We have constructed a 1-D multibox model with representations of chemistry and vertical transport to evaluate the impact of leaf-level processes on canopy-scale concentrations, lifetimes, and canopy fluxes of NOx. Our model is able to closely replicate canopy fluxes and above-canopy NOx daytime mixing ratios observed during two field campaigns, one in a western Sierra Nevada pine forest (BEARPEX-2009) and the other in a northern Michigan mixed hardwood forest (UMBS-2012). We present a conceptual argument for the importance of NO2 dry deposition and demonstrate that NO2 deposition can provide a mechanistic explanation for the canopy reduction of NOx. We show that foliar deposition can explain observations suggesting as much as ∼60 % of soil-emitted NOx is removed within forest canopies. Stomatal conductances greater than 0.1 cm s−1 result in modeled canopy reduction factors in the range of those used in global models, reconciling inferences of canopy NOx reduction with leaf-level deposition processes. We show that incorporating parameterizations for vapor pressure deficit and soil water potential has a substantial impact on predicted NO2 deposition in our model, with the percent of soil NOx removed within one canopy increasing by ∼15 % in wet conditions compared to dry conditions. NO2 foliar deposition was also found to have a significant impact on ozone and nitrogen budgets under both high- and low-NOx conditions.
48
Tchakalova, Boriana. "Effect of clay content on strength and permeability of plastic loess-cement." Geologica Balcanica 48, no. 2 (August 2019): 25–30. http://dx.doi.org/10.52321/geolbalc.48.2.25.
Full textAbstract:
Plastic soil-cement is a type of soil stabilization used for the treatment of natural soil to improve its engineering properties. It is a hardened material prepared by mixing soil and Portland cement at a water content higher than optimum, usually near the liquid limit, without compaction at optimum water content to maximum dry density. In Bulgaria, this soil stabilization technique has been applied in foundation works in collapsible loess ground in order to replace a part of the collapsible layer, to increase the bearing capacity of the soil base and/or to isolate the geoenvironment from migration of pollutants. The aim of the current paper is to examine the effect of the clay content of the loess soil on the strength and permeability of plastic loess-cement. Results from the investigation indicate that the mechanical and hydraulic properties of the plastic loess-cement highly depend on the presence of clay fraction.
49
MATTILA, P. K. "Ammonia volatilization, nitrogen in soil, and growth of barley after application of peat manure and pig slurry." Agricultural and Food Science 15, no. 2 (December 4, 2008): 138. http://dx.doi.org/10.2137/145960606778644520.
Full textAbstract:
Peat is added to manure, because its low pH and capacity to adsorb ammonia (NH3) give it potential to reduce nitrogen (N) loss. Peat manure was prepared by mixing pig slurry with moderately humified Sphagnum peat. Less than 1% of applied ammoniacal N was volatilized as NH3 from peat manure and pig slurry within 8 h of surface application on clay loam soil according to JTI method. Incorporated manures showed even smaller N loss. The low volatilization was due to the adsorption of manure ammoniacal N by peat, and the infiltration of slurry into harrowed, moist clay soil. In another experiment, peat manure was applied on polypropylene fabric without soil contact. Within the first 3 days there was only 9% reduction in the ammoniacal N of peat manure, but the major part of it was lost during several weeks of dry and warm weather. Peat manure did not cause any major improvements on the growth and N uptake of spring barley in spring and early summer as compared with slurry. Moisture deficit limited the availability of ammoniacal N of manures. As compared with surface application, incorporation of manures increased nitrification of ammonium in the soil, and dry matter mass (1973%) and N uptake of barley. Supplementing manures with inorganic NPK fertilizer increased both dry matter mass (4098%) and N concentration of barley stand.;
50
Hussein, Sarah Adnan, and Haifaa Abd Al-Rasool Ali. "Stabilization of Expansive Soils Using Polypropylene Fiber." Civil Engineering Journal 5, no. 3 (March 18, 2019): 624. http://dx.doi.org/10.28991/cej-2019-03091274.
Full textAbstract:
Current research main aim is to study the effect of adding polypropylene fiber (PPF) on the behavior of expansive soil to reduce the swelling as percentage (0.5, 1 and 2%) of the weight of dry soil. Expansive soil used in this research was prepared artificially by mixing Ca-based bentonite from geological survey and mining company with sandy soil brought from Karbala city as percentage 80% bentonite to 20% sand of dry weight. Multiple laboratory tests have been carried are (Unconfined Compression Test, One-Dimensional Consolidation Test, Swelling Test, Sieve Analysis and Cycle Swell Shrink Test). A conventional odometer cell was modified to allow the study of swell- shrink cycle test to be carried out under controlled temperatures and surcharge pressure. The results showed that the increase in percentage of (PPF) led to decrease the swelling and to increase the unconfined compression strength. The wetting and drying results of (PPF) showed that with continuous cycles the effect of (PPF) keeps on reducing the swelling and the 2% of (PPF) produces less ratio of swell - shrink, which has obtained higher than 57 % in the improvement factor of swell and shrink.