Applied Mechanics and Materials Vols. 170-173

Abstract: The strength reduction method is applied in the analysis of slope stability, strength reduction, into the finite element program for calculating, until computations convergence. Combined with the engineering example, comparison of slope stability finite element method and the traditional limit equilibrium method the results show that, based on the strength reduction finite element analysis of slope stability is feasible.

Abstract: The wetting-drying effect of expansive soils plays an important role in slope stability analysis. According to the depth of atmospheric effect and the field observation data of moisture content, laboratory experiments on the strength of expansive soil with two wetting-drying cycle amplitudes were performed to discuss on the wetting-drying effect of expansive soil. The results show that the shear strength of expansive soil decreases with increasing number of cycles and finally reaches to a constant state. The value and cycle number of the constant state reduce with increase of amplitude of variation of water content. Furthermore, the stability analysis of expansive soil slope is studied with considering the wetting-drying effect. The results may provide the reference for the parameter selection in slope design.

Abstract: Relying on the research of highway engineering of Sichuan province, the disadvantage influence of continuing and strong rainfall on bedding rock slop along the highway in this research is taken into account. In the numerical calculation, both limiting equilibrium analysis and numerical calculation method are used to evaluate the body of landslide stability. According to the result of synthesized methods, the conclusion can be summarized: under the continuing and strong rainfall circumstance, the bedding landslide is easy to lose stability, and this condition becomes an important influence element. The solution schemes of construction based on the conditions of rainfall can be determined.

Abstract: The shear strength of expansive soil has the obvious varying property with the changing of seasonal climatic. Based on Palmgrem-Miner linear accumulative damage theory, laboratory experiments on the strength of expansive soil combining with different wetting-drying cycle amplitudes were performed to discuss on the fatigue accumulative damage of expansive soil in the alternation of wetting-drying environment. The results show that：(1)The applying sequence of high (low) cycle amplitudes have significant effect upon the fatigue accumulative damage of expansive soil, and the strength attenuation of expansive soil is mainly controlled by the high circulate amplitude. (2) The Palmgrem-Miner linear accumulative damage criterion can basically reflect the fatigue accumulative damage process of expansive soil in the alternation wetting-drying environment, and the value of damage score “D” is close to 1 when the strength of expansive soil is stabled.

Abstract: On the basis of quantitative analysis, based on a real landslide of a specific profile of C, cohesion, internal friction angle and finite element mesh for landslide stability factor sensitivity. Through the analysis and calculation to determine the stability coefficient and the parameters related to changes in the relationship between, find out the effect on the stability of the most sensitive factors.

Abstract: Fast drained and consolidated mechanism of soft soil under excessive pore water pressure generate excessive pore water pressure in the soft soil through the addition of vertical and horizontal drainage channel as well as the applied load, because the drainage path is significantly reduced, the seepage velocity speed up and water excreted rapidly under the excessive pore water pressure, also, the effective stress increase rapidly between the soil particles and accelerate consolidation of soft soil so as to improve the strength of soft soil.

Abstract: According to complex geological environment of underground space，drilling parameters were obtained based on the research of drilling process. As a sensor for collecting the date of drilling parameter, photoelectric encoder was chosen to combine field test. The change curve of drilling depth with torque in different strata was collected successfully by using photoelectric encoder and can reflect the change of torque during drilling. It is found that there are different response characteristics in different strata, but these response characteristics show the certain orderliness.

Abstract: Strength reduction method is widely used in the slope stability analysis. However, it is short of unified instability evaluation standard at present. And the different numerical calculation methods also influence the safety factor of strength reduction method. Taking a typical slope in this paper, the same model meshes are established in ABAQUS FEM and FLAC^3D FDM by using the self-compiled model transformation program ABAQUS-FLAC^3D. Then the same elastic-plastic constitutive and yield criterion are both employed in ABAQUS FEM and FLAC^3D FDM. The safety factors obtained from the two numerical calculation methods are compared, and the results are also compared with that of Spencer limit equilibrium method. It is observed the safety factors calculated by ABAQUS FEM are slightly higher than that of FLAC^3D FDM for the same instability evaluation standards. Moreover, the safety factors obtained from the run-through of plastic zone and the saltation of the displacement at characteristic point are much closer to that of Spencer limit equilibrium method. Hence the combination of the run-through of plastic zone and the saltation of the displacement at characteristic point as the slope instability evaluation standard is suggested in this paper. Meanwhile, the correctness of self-compiled improved strength reduction method is verified by comparing with the result of FLAC^3D built-in strength reduction method.

Abstract: In this article, with rich production of Chinese gooseberry in Zhouzhi County of Shaanxi Province as an example, conducted an application of GIS based soil fertilization management. First, soil nutrient data (9 kinds) is interpolated as raster with GIS methods; then nutrient level is graded, and composite nutrient level is graded. At last, composite evaluation model, output-fertilize model is constructed. This method is a successful application of GIS based data management and spatial analysis in the use of soil fertilization management, and make soil nutrient data management with raster and soil nutrient data composite analysis as reality. So it is a useful request and is meaningful in theory and application realm.

Abstract: The Hukeng granite body locates in southeast limb of Wugongshan compound anticline, where developed large scale tungsten deposit that is an important part of poly-metallic metallogenetic belt in South China. The thermal history of the Hukeng granite has been studied based on zircon U-Pb dating, whole rock Rb-Sr dating and K-Ar dating of muscovite from the same rock body. From the beginning of zircon crystallization to the closure of whole rock Rb-Sr system, the Hukeng granite body had a relatively fast cooling rate (65°C/Ma), and from the closure of whole rock Rb-Sr system to the closure of K-Ar system of muscovite, the granite body had a very fast cooling rate (208.3°C/Ma). The Hukeng granite body had a very short cooling period (<5Ma) and experienced a rapid cooling process.