Study on Damage Evolution Mechanism of Rock-Soil Mass of Accumulation Slope Based on Shaking Table Test

To investigate the seismic dynamic characteristics of the accumulation slope, a slope of the Zheduo Mountain tunnel along the Sichuan-Tibet Railway in China was selected as the prototype, based on dimensional analysis and similarity principle, two groups of model tests were carried out at 50° accumulation slope and 60° accumulation slope to obtain the dynamic response influenced by different amplitude of seismic wave. A transfer function analysis method suitable for shaking table test is proposed. Based on the data pretreatment method of eliminating trend terms and digital filter, the frequency response function was calculated by method of average periodic chart. And the variation of frequency response function was analyzed by Pearson correlation coefficient. At last, the least square iteration method was used for modal analysis. It is found that the transfer function changes obviously when both the slopes are destroyed, the weak interlayer has a significant influence on seismic wave transmission. The modal analysis results show that with the increase of the excitation intensity, the natural frequency decreases and the damping ratio increases.

Study on the Disturbed Zone of High Red Bed Accumulation Slope by Numerical Simulation

The high red bed accumulation slope is a particular type in red beds areas that widely spreads in China. The red bed accumulation is of low intensity and poor engineering property, which can easily cause engineering disease. Therefore, the key issue is cutting the stability in slope engineering. Use stress analysis to determine the disturbed zone of the area directly, the project derives disturbed zone slope stability factor and propose the analytical method steps for the theoretical basis of high slope construction stability and the retaining structure design. Use MIDAS/GTS finite element analysis software to simulate two typical red bed accumulation slopes of Guangyuan-Bazhong expressway. The result reveals that the method is feasible and effective through main stress analysis by a reasonable simulate model. For the typical characteristics of high red bed accumulation slope cutting instability, the project provides the reference of design.

Back Analysis about Shear Strength and Deformation Parameters of High Excavated Accumulation Slope in Xiaowan Hydropower Station

Proper mechanical parameters of slope rock mass are the premise which ensures the smooth progress of slope stability calculation. By analyzing the geological information of the yinshuigou accumulation slope on ridge 2 in Xiaowan hydropower station, and according to the deformation and damage in the excavation of the accumulation slope, this paper inverts the shear strength parameters of the accumulation slope by using 2D rigid limit equilibrium method. On base of unloading rock mass mechanics methods, the stress and strain analysis to the accumulation slope is studied by using 3D finite difference method, and by contrast of the monitoring displacement and calculated displacement in slope-direction about the key point of the accumulation slope , the article inverts the deformation parameters of the accumulation slope. Finally, the shear strength parameters in the contact zone are ascertained as: C=0.04MPa, Φ=30°, and the deformation parameter of the accumulation slope is changed from the initial 1.5MPa to 0.95MPa by the damage unloading.