Dynamic Analysis Of Reinforced Soil Slope Under Bidirectional Earthquake Loading

Compared with traditional slope,reinforced soil slope has many advantages and has been widely used in water conservancy,road,environment and other engineering fields.Studies have shown that the near-field earthquake has a large vertical component,which may affect the stability of the geotechnical structure under earthquake action,but most of the current design codes have not taken it into full consideration.In addition,the antiseismic mechanism of the reinforced soil slope under the bidirectional ground motion is vague,which may bring great hidden danger.Therefore,it is necessary to study the dynamic characteristics of the reinforced soil slope under the bidirectional ground motion and find out the response law behind it,which is of great significance to the rational application of the reinforced soil slope in China.This paper mainly uses the centrifuge model test and numerical simulation research method,through the simulation of reinforced soil composite structure centrifuge test the correctness of the numerical method is verified.Then,based on the engineering background of a highway construction project in Xinjiang,the PLAXIS 2D software is used to analyze the dynamic characteristics of reinforced slopes under the bidirectional and horizontal ground motion.Then,the ground motion intensity is taken as the starting point for the secondary analysis of the results,and the effect of vertical ground motion on the dynamic response of the reinforced slope is discussed,and the response law of the reinforced slope under the bidirectional ground motion is studied.The main research results of this paper are as follows:1.Under the bidirectional earthquake loading,the horizontal displacement of the reinforced slope surface is distributed in a parabolic shape,with a maximum near the top of the slope,and the large settlement appears in the middle of the top of the slope.The acceleration shows a magnifying trend with the increase of height.The maximum reinforcement load in the slope is basically a trapezoidal distribution of small upper and large lower2.Vertical ground motion has a great influence on slope horizontal displacement.When the ground motion intensity is large,the maximum slope horizontal displacement under the bidirectional ground motion can be put about 300% compared with that under the horizontal ground motion.Vertical ground motion harden the soil through compaction,change the soil stiffness and main frequency,but the reinforcement load is mainly determined by the horizontal ground motion,and the vertical ground motion has little influence on the reinforcement load.3.The ground motion intensity parameter can better capture the reinforced slope dynamic responses.It has a strong linear correlation with dynamic response indexs.Correlation between the parameter and these indexs increases when the peak horizontal ground acceleration is fixed with the peak vertical ground acceleration decreases.4.A pseudo-static analysis method with the ground motion intensity parameter as input acceleration is proposed.When the peak vertical ground acceleration is not large compared to the horizontal one,and when the intensity of ground motion is large,this method can better simulate the dynamic response of the reinforced slope,which has a certain guiding significance for the design of the actual reinforced soil slope engineering.