Study On Seismic Response Characteristics Of Layered Rock Slope With Tunnel

The "5 · 12" Wenchuan Earthquake caused a large number of casualties and huge economic losses. Earthquake is the main factor that induces slope instability and the occurrence of secondary geological disaster such as landslides, collapses and debris flows. Strong sudden, destructiveness, and secondary disasters are the outstanding characteristics of earthquake disasters. There are vast territory, much mountains, unique geological environment and active tectonic in China, and earthquakes happen frequently in central and Western regions. In recent years, with the rapid development of the national economy, a large number of Comprehensive Hydroelectricity, mountain highway, passenger dedicated railway and other large projects will be constructed. Because of the terrain environment, engineering cost and other factors, these projects may appear tunnel or underground mined out area under the slope. Therefore, the seismic response and seismic stability of the slope with cavern is particularly prominent. The research in this thesis is supported by the National Natural Science Foundation Project. "Seismic Catastrophe Behavior and Anti-seismic Performance Evaluation of Rock Slope Containing Underground Caverns" (number:51204125). The large-scale shaking table model test of Layered rock slope with underlying tunnel was performed to study the dynamic response of the rock slope under the action of earthquakes. The finite element software MIDAS GTS/NX was used to simulate the process of earthquake, and the results of the shaking table test were verified by numerical simulation. The main research work is as follows:(1) Shaking table model designBased on the similarity theory, the large-scale shaking table test of the layered rock slope with similar ratio of 1:10 was designed and completed. This thesis introduces the design principle of the similarity relation of the model test, the boundary treatment method of the model box and the layout of the monitoring points. The main physical similarity constants were determined, and the similar materials were selected according to the principle of similarity. The Da Rui wave, Wen Chuan wave and Kobe wave are used as the excitation waves, and the loading scheme of test was designed.(2) Analysis of dynamic response of layered rock slope with underlying tunnelBased on analysing the data of shaking table test, the dynamic responses characteristic of rock slope under different seismic waves, different excitation strength and direction, including horizontal and vertical seismic acceleration and seismic displacement, were discussed. According to the discussion about the dynamic responses of seismic acceleration and seismic displacement, the distribution characteristics of seismic acceleration amplification coefficient along the slope height were obtained and the influence rules of transducers location and ground motion parameters including seismic waveform, earthquake amplitudes and excitation were explored.(3) Numerical simulation of dynamic response of layered rock slope with underlying tunnelIn terms of the test design scheme, the finite element software MIDAS GTS/NX is used to simulate 3-dim modeling of the layered rock slope with underlying tunnel. The comparison results of finite element numerical simulation and shaking table test were illustrated by the example of Wenchuan seismic wave with different earthquake amplitudes (WC-XZ) and the input excitation intensity of 0.2g (WC-X, WC-Z, WC-XZ, DR-XZ and K-XZ). Results show that the fitting degree of model test and numerical simulation is significant and on the basis of this,the model of layered rock slope is simulated to discuss the influence of underlying tunnel to seismic dynamic response of layered rock slope.