Soil Mechanics and Foundation Engineering最新文献

Based on the results of the research conducted by the authors, a short biography, creative achievements, and interesting facts about the life and work of one of the founders of soil mechanics as a science, Carl Terzaghi, are presented.

In this study, a time-dependent expansion model of mudstone based on the rheological theory is developed. The model is validated with the results of the free expansion test of mudstone under lateral limits. We have explained the physical significance of all the parameters in the model. The ultimate strain of the mudstone flooding expansion is determined by the swelling force and progressive expansion elastic modulus. The expansion model can be used to describe and predict the time-dependent expansion of the mudstone submerged under water. The time-dependent expansion model is introduced to generalize the Einstein’s three-dimensional static stable constitutive relation to a nonstable dynamic three-dimensional constitutive relation.

The modern subway system has greatly alleviated the urban traffic congestion. However, it is difficult to avoid crossing paths with deformation-sensitive structures, such as high-speed railways and bridges, during subway construction. Based on the subgrade project of the Xulan High-Speed Railway under Xi’an Metro Line 1 in Shaanxi, China, this study performs numerical modeling to examine the dynamic load factors generated by high-speed railway operation and analyzes the disturbance and vibration effects of subway shield tunneling on soil layers with different stiffness. As the elastic modulus increases, the vibration response of the structure becomes weaker, which means that the disturbance effect on the soil becomes smaller. The refined simulation analysis of the highspeed rail dynamic load and shield tunneling provides valuable insight for theoretical application and engineering practice, especially regarding the management of disturbances caused by subway shield tunneling on surrounding structures.

This paper presents a dynamic California Bearing Ratio (CBR_d) device that can be used on a prepared pavement foundation layer to obtain a certain parameter of the tested material in the laboratory and in situ in a direct and fast way. For the selected natural material (gravel), it is shown that the laboratory CBR_d can be used to estimate the compaction and bearing capacity, because it correlates well with the parameters of the standard and modified Proctor compaction tests. Comparative tests revealed that there is good correlation between the field CBR_d and the deformation modulus, and dynamic deformation modulus values obtained by field tests.

A method for determining the stability of slopes and the pressure of incoherent soils on fences is described. Conditions for the ultimate equilibrium of the lower, supporting, and upper parts of the slope are considered. Active and passive pressures (loads) are determined from the condition for the ultimate equilibrium of the soil mass. The soil pressure on fences is calculated using the slope stability coefficient. Examples for calculating the critical load on the slope surface and the retaining wall parameters are given.

In this paper, the effect of soil–structure interaction (SSI) on the story acceleration response of a high-rise building due to different earthquakes is investigated. To determine the dynamic response of a 40-story building considering SSI, six different foundation soil conditions and ten different earthquake records are considered. The results show that the SSI effect on the story acceleration response of the high-rise building resting on relatively soft soil types is of critical importance.

This study discusses the issues in increasing the reliability of buildings and structures on Type II loess-like collapsible soils through the construction of basement floors. This study also analyses the effectiveness of using pile foundation options for buildings with basement floors made from driven and bored piles up to 50 m long that cut through collapsible soil of 10–32 m. Results showed that foundations made of driven and augered piles are the most effective in terms of cost, labour intensiveness, and concrete consumption, whereas options using barrettes are the least effective.

A systematic correlation is established between the axial load-carrying capacity of the socketed piles and empirical methods. The axial load-carrying capabilities were calculated with the help of pile load tests for ten single piles in Navi Mumbai, India. Pile load tests were carried out to evaluate the skin friction and base resistance in overlying soil and rock. The test results of axially loaded bored piles socketed into the rock are mentioned in this paper. The pile socket involved rocks of various strengths such as gypsum, limestone, and basalt. In reality, axial capacity is calculated from skin friction of the pile, which occurs owing to a very small settlement in the rock socket. The unconfined compressive strength of the rock is collected from the laboratory test. The load-bearing capability of the socketed piles is determined using several empirical methods, which are usually evaluated by a back-assessment of the in-situ pile load test. However, the significant load-carrying capacity values derived from empirical correlations are found to be reasonably good compared with those estimated from pile load tests.

M. G. Zertsalov [1] carried out a brief review of methods used for calculating the bearing capacity of bored piles in rocky soils along the lateral surface under compressive loading. In this paper, the author sets out to review methods for calculating the bearing capacity of a pile based on the resistance of the rocky soil beneath the pile bottom end.

Breaches of tailings dams have had catastrophic consequences in the mining industry worldwide. Therefore, the characteristics of tailings and their effects on the stability of tailings dams need to be investigated. In this paper, the mechanical properties of uniform tailings and smaller sedimentary tailings are analyzed in laboratory testing. The critical hydraulic gradient of tailings is explored and a tailings dam model is constructed. The results of testing indicate that the strength of tailings gradually decreases with an increase in the content of fine particles smaller than 0.075 mm. The critical content of fine particles is 35% fine particles smaller than 0.075 mm. The strength, cohesion, and internal friction angle of uniform tailings are greater than those of smaller sedimentary tailings. The critical hydraulic gradient decreases with an increase in the content of fine particles smaller than 0.075 mm, and the critical content of fine particles is again approximately 35%. However, the critical hydraulic gradient of smaller sedimentary tailings is higher than that of uniform tailings. An equation is presented to calculate the critical hydraulic gradient of tailings. The seepage failure of the tailings dam can be divided into four parts. An equation is presented to calculate the critical hydraulic gradient of a tailings dam.