Applied Mechanics and Materials Vols. 204-208

Abstract: This article through the analysis of prestressed anchor cable and concrete pouring pile in support of their respective characteristics of the force, in a number of supporting more challenging and demanding conditions, the prestressed anchor and bored concrete pile combined support method, play to their respective support advantage to gain better engineering effect. This paper describes the support principle and key procedure.

Abstract: This thesis introduces the contents of backfill compactness and the detection method. And it also introduces the effects of backfill compactness in engineering: it is an important basis to judge the reliability and stability of backfill foundation. In addition, it takes the maximum dry density detection of on-site backfill and the compacted backfill compactness detection of foundation at Linan contrustion site of Hangzhou Hangyang Heat Exchange Equipment Co., Ltd. for example to specify the engineering application of detections of backfill compactness. At last it puts forward problems existing in the engineering detection on compacted backfill compactness: the variance of the actual maximum dry density and maximum dry density achieved by indoor compaction experiment. And it also provides a corresponding solution called the correction for maximum dry density in sieved gravel soil.

Abstract: A new technique is proposed to calculate nonlinear settlement for foundation by using the data of plate loading test (PLT) and standard penetration test (SPT) or other in-situ tests. Firstly, hyperbolic curve is fitted out from the data of PLT and the tangent modulus equation of soil is established, then correctional tangent modulus (CTM) equation is established by feedback adjusting according to the fitting curve of PLT; Secondly, the CTM equations of different stratified soil at different depth are determined by soil parameters of SPT or other in-situ tests according to linear correlation; Finally, the nonlinear settlement of foundation is calculated by the layerwise summation method. An engineering application of settlement prediction for the largest oil tank in China indicated that this technique is able to calculate the entire nonlinear settlement from initiation to ultimate limit state and obtain accurate results, and it is suitable for cohesionless soil with high permeability.

Abstract: Based on the method of strength reduction, numerical simulations were carried out to analyze the stability of the cutting slope. The direct shear tests of slope soil samples with different water content were carried out, and the safety factors of stability of the cutting slope were investigated with different cohesions and internal friction angles. At last, displacements and safety factors of stability of the slope with drains and without drains were calculated, and the observations of displacement of the cutting slope in field were also carried out. The results show that: The water content of the slope soil has great effects on the strength parameters, the cohesion and the internal friction angle decrease with the increase of the water content, and the effect is more significant on the cohesion than that on the internal friction angle. The safety factor of stability for the slope increases with the increase of the strength parameters, hence it increases with the decrease of the water content. The section of the slope without drains in the field is unstable, while the section with drains maintains stable.

Abstract: The fault breaks continuous ground stress distribution. The rock mass in fault zone is weak and broken, it becomes stress decreasing zone. The paper, which is combined with engineering practice and rock mechanics test, numerically simulates geological environment of fault zones and analyzes faults trend direction influence on ground stress distribution in the metal mine. The results demonstrates that deep faults breaks down the continuity of ground stress distribution, principle stresses in lower wall of faults are smaller than it in hanging wall while high deep ground stresses are in cross district of hanging-wall of fault-zone and ore bed

Abstract: The stress equilibrium equation of anisotropic solids, coupled to the hydrodynamic seepage equation and heat transfer equation of saturated fractured rocks, are studied here based on the standard space of physical presentation, in which an new thermo-hydro-elastic model is induced. A set of uncoupled equation of heat and hydraulic propagations in anisotropic saturated fractured rocks is deduced. From them, two new phenomena of heat and hydraulic propagation are obtained, which are affected by both anisotropic subspaces of solids and thermo-mechanical and hydro-mechanical coupling coefficients. Based on these laws, we discuss the heat and hydraulic wave behaviour for isotropic solids.

Abstract: A series of uniaxial compression tests on frozen soil with weight water content of about 40~150% were carried out at -2.0°C--0.2°C. The effect of soil type, size of ice particle, temperature, water content and strain rate on stress-strain behaviors is analyzed according to the experimental data. The results show that the stress-strain behavior of frozen soil with high temperature and high water content can be sorted into two classes including strain softening and strain hardening, and it changes with various soil types, temperatures, water contents, strain rates, and sizes of ice particle.

Abstract: A structural failure model is presented for the rock mass with a discontinuous weak structural plane. The present model takes into account the effect of weakening of both deformation and strength parameters. And it can degenerates into classical Mohr-Coulomb model or Jaeger model according to corresponding conditions. The numerical tests by Particle Flow Code demonstrate that the capability and performance of the proposed model in capturing behaviors of the mass rock.

Abstract: The choice of supporting plan for a foundation excavation plays a leading role in the optimizing design. For those foundation pits with complex circumstances, a reasonable and optimized supporting construction should be designed to meet the requirements of the surrounding environmental factors. These factors are arranged and rated through a relatively simple analytic hierarchy process (AHP) so as to determine how they affect the design plan of the supporting system. Through ratings and comparisons of relevant factors, a rating method for different design plans is proposed based on AHP analysis. Several supporting plans for a practical excavation engineering in Kunming are analyzed and compared through above method and a reasonable and optimized design plan is selected.

Abstract: The failure of slope is a gradual accumulation process. Under the effect of many interior and exterior factors, some parts in the slope reach yield with the increase of stress; sliding surface forms gradually till complete transfixion; with the plastic strain continuous increases, overall failure happens on the slope. Traditional analysis method cannot display the mechanic conditions and the whole process of deformation, transfixion of sliding surfaces and failure. Meanwhile, FEM strength reduction can quantitatively show the deformation features and the process of occurrence and development of sliding surface. Based on the previous researches, the paper classifies slopes according to the features of rock and soil and the slope structure. Through analyzing the graphs of deformation and the nephograms of plastic strain under different reduction factors or safety factors, the researchers can directly find the deformation tendency of slopes and the whole process of the extension, transfixion and failure of sliding surface with the reduction of safety factor. So, the failure mechanism of slope can be found intuitively, which can provide effective basis for the prevention and governance of slopes.