SENSIBILITY ANALYSIS OF INFLUENCING FACTORS OF SLOPE WITH WEAK INTERLAYER BASED ON ORTHOGONAL DESIGN METHOD

In the engineering, the existence of the weak interlayer has an important influence on the slope stability. Weak interlayer is a vital reason of instability and failure of slope. Since the orthogonal design method has great advantages in the sensitivity analysis of slope stability, the method is applied to the analysis of slope stability with weak interlayer. The cohesion, internal friction angle and unit weight of quartz sand gravel rock, the cohesion, internal friction angle and unit weight of the weak interlayer(Mica-quartzose schist) as well as earthquake acceleration were selected to carry out the stability analysis of the slope with weak interlayer based on the orthogonal design method. The influence of each parameter on the slope stability coefficient was analyzed by range method and variance method, and the results of the two calculation methods and the advantages and disadvantages of the two methods were compared and analyzed. It is found that, combined with the actual situation as well as the results of these two calculation methods, the influence of parameters on the stability of the hydropower station slope with weak interlayer is as follows: earthquake acceleration internal friction angle of the weak interlayer cohesion of the weak interlayer cohesion of quartz sand gravel rock. Three other parameters had litter effect on the stability of the slope, it is unnecessary to rank these three parameters. Compared with the variance method, although the range method is more simple and rapid, the calculation results are too coarse. Therefore, it is recommended to use the variance method to analyze the results of the orthogonal test.