scholarly journals Optimizing the Compaction Characteristics and Strength Properties of Gravelly Soils in terms of Fine Contents

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Mingzhi Zhao ◽  
Gang Liu ◽  
Longxiang Deng ◽  
Yangang Li
Keyword(s):  
Mechanical Properties ◽  
Water Content ◽  
Triaxial Test ◽  
Soil Structure ◽  
Fine Particles ◽  
Strength Properties ◽  
Coarse Grained ◽  
Dry Density ◽  
Engineering Practice ◽  
Gravelly Soils

Gravelly soils are widely adopted as civil construction materials in engineering practice. Although the influence mechanism of fine contents (FCs) on the mechanical behavior of gravelly soils has been emphasized in the previous studies, few discuss the compaction and strength properties concurrently. Besides, FCs of gravelly soils were discussed separately in many cases regardless of the variation in water content. In this study, modified Proctor compaction test and medium-sized triaxial test were performed to investigate the mechanical properties of gravelly soils containing different magnitudes of fine contents. It is shown that an optimum FC exists for gravelly soils although the value of the optimum FC varies with grading curves of the coarse-grained portion. By adjusting FC in the gravelly soils, not only could the maximum dry density ρdmax be improved but also the optimum saturation degree Sropt rises significantly, and synchronously, the minimum air void ratio v a min decreases notably. Besides, fine particles are just right to fill with the voids formed by the coarse-grained skeleton for the optimum FC sample. The soil structure corresponding to the optimum FC status can be termed as a densely filled skeleton structure, which is the densest and most stable. As fine contents increase or decrease from the optimum value, soil structure will loosen and deteriorate the mechanical properties. In addition, the increase in water content has quite different effects on strength properties of gravelly soils with different FCs in a triaxial test due to the opposite effects of pore water softening and negative pore pressure strengthening. Such results are expected to provide guidance for the preparation of gravelly soils in engineering practices.

scholarly journals Mechanical Properties of Tailings Sample with Different Moisture Contents under Dry and Wet Cycles

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Ling-ling Wu ◽  
Yao-hui Guo ◽  
Kai-wen Tong ◽  
Lin Hu ◽  
Qing Yu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Water Content ◽  
Moisture Absorption ◽  
Water Pressure ◽  
Hunan Province ◽  
Dry Density ◽  
Initial Water Content ◽  
Sand Sample ◽  
Stress Strain ◽  
Tailings Sand

Due to precipitation infiltration, evaporation of water, and rising and falling of the wetting line, the tailings are in a cyclical moisture absorption-dehumidification state for a long time. The mechanism of change of physical and mechanical properties of tailings during the dry and wet cycle is related to the safe operation of the entire tailings dam. In order to explore the variation of the mechanical behavior of tailings in a tailings pond in Hunan Province with the number of dry and wet cycles under different initial water content conditions, the tailings sand samples with moisture content of 6.10%, 10.40%, 14.00%, 18.20%, and 21.00% were subjected to 0 to 6 times of moisture absorption and desorption cycles at natural dry density, and then, the stress-strain relationship curves, pore water pressure, failure mode, and shear dilatancy of these samples were tested by triaxial consolidation undrained shear test. The test results showed that when the number of moisture absorption and desorption cycles increases, the strength of the tailings sand sample was weakened, and the strength tended to be stable after 3∼5 cycles. In addition, the stress-strain curve of the sample with lower water content dropped sharply. However, the pore pressure of tailings sand samples with different water contents under different wet and dry cycles all showed a phenomenon of increasing first and then decreasing in general.

Mechanical Properties of Bentonite-Sand Mixtures Under Triaxial Stress Condition

1994 ◽  
Vol 353 ◽  
Author(s):  
M. Umedera ◽  
A. Fujiwara ◽  
N. Yasufuku ◽  
M. Hyodo ◽  
H. Murata
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Water Content ◽  
Triaxial Compression ◽  
Confining Pressure ◽  
Strength Properties ◽  
Compression Tests ◽  
Optimum Water Content ◽  
Triaxial Compression Tests ◽  
Optimum Water

AbstractA series of triaxial compression tests is being conducted under the drained condition on bentonite and sand mixtures, known as buffer, in saturated and optimum water content states to clarify the mechanical properties of the buffer.It was found that the mechanical properties of bentonite and sand mixtures are strongly influenced by water and bentonite contents: shear strength in a saturated state is less than that in an optimum water content state; shear strength decreases rapidly with increasing bentonite content. Strength properties are much dependent on confining pressure.

Study on the Clay Mechanical Characteristics of “Ripping Up the Bottom” in the Yellow River

2012 ◽  
Vol 212-213 ◽  
pp. 108-112 ◽  
Author(s):  
Wen Sheng Dong ◽  
Xiu Fang Jiang ◽  
Xian Feng He ◽  
Ying Ying Zai
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Mechanical Strength ◽  
Water Content ◽  
Critical Condition ◽  
Mechanical Characteristics ◽  
Yellow River ◽  
The Yellow River ◽  
Dry Density ◽  
The Relationship

Aim to the high sandy river “ripping up the riverbed” phenomenon, by experiment, analyzing the relationship between clay dry density, water content, plasticity index and its shear strength, and its mechanical properties. Create the conditions for studying clay mechanical strength and the critical condition of “bottom tearing scour”.

scholarly journals Pengaruh Abu Cangkang Sawit Terhadap Kuat Tekan Dan Kuat Lentur Batubata

2018 ◽  
Vol 3 (1) ◽  
pp. 61
Author(s):  
Herman . ◽  
Rolly I
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Physical Properties ◽  
Water Content ◽  
Strength Test ◽  
Basic Material ◽  
Dry Density ◽  
Soil Mixture ◽  
Palm Shell

This research was conducted to increase the value of compreive strength by adding palm shell ash to the base soil of brick. The palm oil shell was got from the result of the disposal of  Incasari Raya Factory Damasraya. The soil as the basic material of the brick was got from the brick’s manufactory Gunung Sariak Padang. The persentage of palm shell ash in the soil mixture was 0%, 5%, 15% and 25% from the soil dry weight. The test consisted of physical properties test and mechanical properties test. The physical properties test consisted of water content test, spesific gravity test, Atterberg limit test, and grain size analysis test.The mechanical properties test consisted of compaction test, compressive strength test and flexural strength test. The water content in manufacture brick was 0,85% γd maximum on wet side optimum of the soi. All the process of the brick is manufactured with manual fabrication. The result of the test showed that the values of spesific gravity (Gs), plastic limit (PL), shrinkage limit (SL),maximum dry density, optimum of water content, and compressive strength of brick increased. Mean while the liquid limit (LL),passing of sieve no. 200 in three days care, plastic index (PI), decreased. For flexural strength, at first increased, along with addition percentage from palm shell ash, this value inclined decreased. The optimum result was got 5%        palm shell ash in the soil mixture.

Study on Influence of Freeze-Thaw Cycles on the Physical-Mechanical Properties of Loess

2012 ◽  
Vol 442 ◽  
pp. 286-290
Author(s):  
Gui Quan Bi
Keyword(s):  
Mechanical Properties ◽  
Water Content ◽  
Water Distribution ◽  
Early Stage ◽  
Frozen Soil ◽  
Dry Density ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
Filling Water

Loess foundations in seasonally frozen soil region are subject to severe effect of freeze-thaw cycles. This often results in water redistribution and structure weakening. So it is very important to study the physical-mechanical properties of loess under freeze-thaw cycles. In this paper, systematic study was carried out using freeze-thaw cycle machine. The impacts of freeze-thaw cycles on the physical-mechanical properties of loess including deformation, water distribution and dry density under the condition of filling water to loess samples were investigated. The results proved that the freeze-thaw cycles can increase the water content gradually from the bottom to the top in the loess samples under water supplied condition. The water content gradient reaches maximum at the freeze-thaw interface. The loess samples deform sharply at the early stage of the freeze-thaw cycles and then reach a stable status. The freeze-thaw cycles decrease the dry density of the loess samples gradually. The dry density at the top is lower than that at the bottom, due to more severe freeze-thaw effect at the top of the samples.

Strength Criteria of Jointed Rock Mass in Unloading Area

2013 ◽  
Vol 275-277 ◽  
pp. 348-351
Author(s):  
Fei Wang ◽  
Xu Li Liang ◽  
Jian Po Du
Keyword(s):  
Mechanical Properties ◽  
Rock Mass ◽  
Triaxial Test ◽  
Strength Criterion ◽  
Jointed Rock ◽  
Strength Properties ◽  
Jointed Rock Mass ◽  
Strength Criteria ◽  
Structural Plane ◽  
Strength Based

The strength properties of the rock under unloading conditions are essentially different from the rock under loading conditions. At present, the study on the mechanical properties of unloading rock mass is common, but the research for unloading strength properties of jointed rock mass, especially the influence of structural plane on unloading strength is seldom. The paper studied the failure characters of unloading rock mass, and the influences of structural plane properties on unloading strength based on triaxial test are considered emphatically. Finally the strength criterion of unloading rock mass is proposed in this paper.

Research on Un-Linear Deformation Characteristics of Unsaturated Clay with General Triaxial Test

2011 ◽  
Vol 243-249 ◽  
pp. 3117-3122
Author(s):  
Xi Zhong Shen ◽  
Jin Xia Zhang ◽  
Min Zhang
Keyword(s):  
Water Content ◽  
Unsaturated Soil ◽  
Triaxial Test ◽  
Triaxial Tests ◽  
Dry Density ◽  
Deformation Characteristics ◽  
Stress Difference ◽  
Main Stress ◽  
Unsaturated Clay ◽  
Chang Model

Difficult in soil-water characteristic curve achieved, existence of non-uniqueness and indistinct in influence of unlinear deformation characteristics of soil about density and water content, deformation characteristics of unsaturated soil were studied difficultly with general triaxial test, thus direct application of unlinear Duncan-Chang model in unsaturated soil was restricted. General triaxial tests with combined dry density and water content are carried out, changing rules of parameters of Duncan-Chang model are summarized, mathematical functions between dry density, saturation and parameters of the model are established. Analysis shows that deformation characteristics of unsaturated clay are influenced obviously by saturation and dry density. Among them, the larger the saturation, the higher strain becomes under the condition of the same dry density and main stress difference, and the less the dry density, the higher strain becomes under the condition of the same saturation and main stress difference. Moreover, the main parameters of Duncan-Chang model keep close correction with dry density and saturation, and the both mutual effect can be expressed by multiplication. This shows that mechanical characteristics of unsaturated soil can be studied with general triaxial test, thus it will be used easily in project.

scholarly journals Significance of Stone Waste in Strength Improvement of Soil

2020 ◽  
Vol 1 (1) ◽  
pp. 32
Author(s):  
Amit Kumar ◽  
Kiran Devi ◽  
Maninder Singh ◽  
Dharmender Kumar Soni
Keyword(s):  
Compressive Strength ◽  
Water Content ◽  
Fine Particles ◽  
Industrial Wastes ◽  
Dry Density ◽  
Regression Equations ◽  
Human Beings ◽  
Maximum Dry Density ◽  
Optimum Water Content ◽  
Optimum Water

The evolution of industries is essential for the economic growth of any country; however, this growth often comes with exploitation of natural resources and generation of wastes. The safe disposal and utilisation of industrial wastes has become essential for sustainable development. A possible approach would be to utilize these wastes in construction industries. The stone industry is one such flawed industries that generates waste in dust or slurry form; this leads harmful impacts on human beings, animals, and surrounding areas which, in turn, can lead to soil infertility. In the present study, stone waste was examined for its influence on maximum dry density (MDD), optimum water content (OMC) and unconfined compressive strength (UCS) of soil experimentally. Stone waste was used at 0%, 4%, 8%, 12%, 16% and 20% by weight of soil and UCS tests were conducted at maturing periods of 7, 14 and 21 days. Test results reported that the incorporation of stone waste improved the compressive strength value significantly. Maximum dry density was enhanced; however, optimum water content was reduced with the use of stone waste in soil due to its fine particles. Linear regression equations were also derived for various properties.

scholarly journals Influence of Rock Block Content on Compaction Characteristics of Graded Coarse-Grained Fillers

2021 ◽  
Vol 9 ◽  
Author(s):  
Lili Cai ◽  
Shengnian Wang ◽  
Xinqun Gao ◽  
Guoyu Li
Keyword(s):  
Water Content ◽  
Engineering Application ◽  
Rock Block ◽  
Coarse Grained ◽  
Dry Density ◽  
Empirical Formulas ◽  
Maximum Dry Density ◽  
Compaction Characteristics ◽  
Compaction Curve

The bearing capacity, stability, and durability of subgrade are affected by the compaction quality of fillers to a large extent. In this study, samples of graded coarse-grained fillers with different rock block contents were designed and prepared with the aid of an improved continuous gradation equation for coarse-grained soils. Then standard compaction tests of these samples with different water content conditions were conducted to understand the influence of rock block content on the compaction characteristics of graded coarse-grained fillers. Results show that the compaction curve peaks of graded coarse-grained fillers always increase with the rock block content. The maximum dry density of graded coarse-grained fillers increases linearly with the rock block content in approximation, while the optimal water content is the opposite. The optimal water content of graded coarse-grained fillers decreases in nonlinearity with characteristics of rapidly first and then slowly. Two empirical formulas about the rock block content were summarized for predicting the maximum dry density and optimal water content of graded coarse-grained fillers. The results of this study can provide a reference for the engineering application of graded coarse-grained fillers.

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