Papers by Author: Jie Liu

Abstract: Analyzing and Evaluating the stability of the surrounding rock is an indispensable and important part in the tunnel design. In this paper, the surrounding rock stability of Danba hydropower station diversion tunnel is dealt with, FLAC3Dsoftware is used for stability analysis. Selecting three different cross sections for calculation models, comparing with the displacement and principal stress and the plastic zone which calculated by FLAC3D, we can evaluate their stability and get the best diversion tunnel design.

Abstract: Through the analysis of its geology and geomorphology to calculate the relevant parameters , some hidden problems of slope stability of the mountain road are calculated and analyzed by the finite element method for solving the slope stress and strain and the analysis results of plastic zone , which confirms the slope stability conclusions drawn by the safety factor .

Abstract: In view of highway slope stability problems, this paper puts forward the method that numerical modeling of the road slope by the finite element analysis software —ADINA, with the Gravity Loading Proportion Methodto calculate the slope stability coefficient, deeply research the development process of deformation, breakage characteristics and stability of road high cutting slope. Comparison with the results obtained by the strength reduction FEM proposed by AcademicianYingrenZhengshows that the proposed method is more simple and reasonable to determine slope stability or not.

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: On the basis of unloading rock mass theory, we identify the excavated rock mass parameters by means of neural network training in each step, in which the subjective factors of the parameters selected process have largely been decreased. Through inducing the parameters of inversion into two -dimensional modeling, we aim to do the numerical simulation computing in various conditions. By comparison, the calculated displacement trend of the measuring points following the multi-point extensometers is basically identical with the monitoring displacement trend.

Abstract: The dissertation introduced first simple uniaxial compression test of concrete, and in the specimen under uniaxial compression of the breakage mode reinforced and improved. For tensile destruction and shear failure damage model, bring forward the corresponding calculation model and some model set up compressive strength and tensile strength of the interrelations with each other, analysis of compressive strength and much higher than the tensile strength.In addition, from different model, drew diagrams with Matlab software，analysis of the compressive strength and tensile strength of the intrinsic value of relations.Finally, model for the primary split breakage and that shear failure can be ignored, used the buckling theory and the theory of mutation analysis, and calculated the corresponding critical stress.

Abstract: According to the research of geology condition in Ge-he-yan's back rock mass slope,set up the homologous engineering geology model, carried on parts of qualitative analysises, combined with numerical analysis method based on the unloading rock mass theory, gave the quantitative analysis of the engineering geology model, then got the special deformation mechanism of this slope.

Abstract: The rock mass quality classification method was introduced for the strength parameters and deformation parameters when carrying out quantitative classification and provided a theoretical basis; Introducing unloading rock mechanics theory, the infiltration conditions of the surface, drainage measures , catchment area as well as the subsequent impact of buildings on the slope were considered in order to increase the coverage of evaluation factors; Considering finite element analysis results of three-dimensional model and reference targets selected , one kind of improved numerical analysis method based on fuzzy - accurate evaluation of slope stability was proposed. The method is based on finite element model of the calculation results and the appropriate references selected, having the calculation analysis of certain factors on the slope stability a quantitative treatment, thus objectively established the weight ratio between these factors, avoiding subjective awareness in expert scoring impacting evaluation results too large. With practical engineering analysis it shows: the method is directed against rock slope analysis , make more factors impacting rock slope stability involved in evaluation, and easy to operate.

Abstract: Specific to the improvement in the present research of mechanical response under cyclic loading, this paper, taking the calcareous middle- coarse sandstone as the research subject and the RMT-150C experimental system in which data is recoded by ms magnitude as the platform, develops several related models concerning the unloading rate of triangle waves. The unloading process is divided into lag time segment and non-lag time segment, with criterions and related parameters provided as well. The term apparent elastic modulus is defined. The test data analysis shows that there exist a linear relationship between the apparent modulus and instant vertical force before load damage in non-lag time segment. On the preceding basis, a rate-dependent model of triangular wave un-installation section in non-lag time segment is established. Due to the inability of the loading equipment to accurately input the triangle wave, the average loading rate is amended and a constant term is added into it. The model is proved to be reliable, as the predicted value of the deformation rate and the stress strain curve coincides with measured value. At the same time, the impact of the lag time is pointed out quantitatively and a predication model of lag time segment is set up.