Applied Mechanics and Materials Vols. 501-504

Abstract: In order to study characteristics of soil strength freeze-thaw weakening in the Songhua River Songpu bank，basic physical parameters tests and triaxial compression tests were performed on that paragraph bank .The results showed that: after thawing the sample cohesion will drop substantially, the internal friction angle will increase greatly and soil shear strength will increase significantly; the cohesion of sample after repeated freezing and thawing will significantly decline，internal friction angle of soil will greatly increase，the soil shear strength will increase after the first freezing and thawing，with the increase in the number of freeze-thaw cycles, the soil shear strength will significantly decline. The results can provide Songhua slope stability analysis with a scientific basis.

Abstract: Drucker-Prager Model in consideration of creep property is deduced in detail, and the finite element model under Coupled Deformation and Seepage Fields is developed, which takes into account the effect of plastic deformation, saturation and void ratio on the properties of soil materials, the effect of water and soil interaction. The deformation of one soil slope is calculated by FEM during seepage. The results calculated show that the displacements calculated completely agree with the objective law. The way used may provide reference to engineering practice.

Abstract: Based on twin failure mechanism of fracture and shear , the bilinear transitional strength decomposition formula reflecting the nonlinear strength of rock material is proposed,.The decomposed brittle shear formula is integrated and finally the unified strength theory formula characterized by nonlinearity of Hoek-Brown criterion is established. It makes the unified strength theory characterized by nonlinearity of empirical strength criterion, rock mass strength reduction, etc. Besides, it contributes to promote the accuracy and applicability of unified strength theory in rock strength and rock mass strength,especially for the hard rock failure analysis.

Abstract: The mechanical properties of intact rock and rock containing structural plane are very different. From the diversion tunnel of Jinping deep rock site to retrieve the complete block of marble, after a high confining pressure triaxial compression simulation tectonic movements, the formation of structural plane, it represents the mechanical properties of the original rock. On the surface of the marble structure containing triaxial compression creep tests, the results showed: at low confining pressure, the weak marble surface as micro-damage accumulation, the emergence of non-uniform partial destruction, while at high confining pressure, creep curve better continuity and integrity; different confining pressures, marble initial rheology and stability both appear rheological phase, accelerated phase rheological obvious; different confining pressures, the same stage of the axial stress steady flow rate compared with the confining pressure increases, the axial steady state flow rate becomes smaller; marble under test showed the rheological properties, the use of Nishihara model can better demonstrate the rheological properties and determine the rheological parameters for other practical engineering reference.

Abstract: According to the experiments study of sulfuric acid saline soil, the formula of compression coefficient with the changes of moisture content, salt content, initial dry density and temperature is presented, and the law of single influencing factor on sulfuric acid saline soil compression are analyzed in the paper.

Abstract: Factors such as density and confining pressure effect on the compressive strength were analyzed by comparing the experimental results under different conditions, the parameters of Cambridge model were worked out with the data from consolidation test.

Abstract: When constructed the bored pile in sand layer, it is easily to appear the under-reaming and hole collapsed phenomenon. Then it will lead to the engineering disasters, such as hole collapsed, burying drilling and super party amount of concrete. Through the mechanics analysis of the fine sand in the hole process, we found that the mud turbulence will be broken in the drilling process which can cause the water in the hole to be turbulent fluctuation. The result of turbulent fluctuation is making the slurry wall inside and outside the test pressure difference exceeds the wall shear strength which results in the wall off block. At the end, the sand soil collapse dropping leads to the engineering disaster.

Abstract: Using fine sand as aggregate, bentonite, gypsum and cement as cementing materials, wood powder as admixture, through two stage proportioning tests for similar material to swelling rock, the similar material displaying expansive properties of swelling rock is obtained. Physical and mechanical performance experiment indicates that the similar material could meet swelling characteristics and other physical and mechanical requirement of swelling rock, which could be used in similar material model test for swelling rock.

Abstract: The subgrade of the most roads is easy to be of instability under the cyclic loading action of the vehicles with the soil unsaturated. The main idea of this paper is that researching the unsaturated red clay which is common in the subgrade building of Jiangxi province with the pressure plate test and triaxial shear test. And the main equipments are the pressure plate apparatus and triaxial shear apparatus. In the research, c,φ value of the unsaturated red clay under different confining pressure and matrix suction are obtained and it can be shown in the tests that with the same matrix suction, while clay content of the clay soil sample is small its volumetric water content is small; and with the same volume moisture content, with small clay content matrix suction of the soil sample is small similarly. At the same time, we found that within the low substrate suction range, with the change of the soil sample moisture content bigger and the smaller the clay content, the influence the increase of matrix suction on the volumetric moisture content is smaller; with the same clay content in soil samples, the bigger the matrix suction the greater the value of c, φ of the unsaturated red cohesive soil ;with the same matrix suction, the smaller the clay content of the soil, the greater the value of c and the smaller the value of φ.

Abstract: Based on collecting the regional survey data and prospecting the study region of geothermal geology and geothermal fluid characteristics, evaluate the geothermal energy reserves and the recoverable reserves of geothermal water uses geothermal reserve method and analytical method in Julang Pasture, and evaluates the geothermal fluid quality comprehensively. The above evaluation provides a preliminary basis for sustainable development, utilization and protection of geothermal resources in that region.