Response of gravity retaining wall with anchoring frame beam supporting a steep rock slope subjected to earthquake loading

Shaking table test and dynamic numerical analysis are carried out to study the seismic behavior of the gravity retaining wall with anchoring frame beam supporting a steep rock slope (inclined at an angle of 40° with the horizontal) by applying one-directional and bi-directional excitations of Wenchuan motion with different intensities. The horizontal and vertical acceleration responses, the dynamic earth pressure are investigated in shaking table test. A comparative and extensive study is performed in terms of the horizontal and the vertical acceleration responses, the dynamic earth pressure, the axial stress of anchor by means of dynamic numerical analysis with Flac3D code. Results show that both the horizontal and the vertical acceleration amplifications present a dramatic increase at the base of the anchoring frame beam, where the acceleration response is greatly amplified. The bi-directional excitation of Wenchuan motion causes a more intensive acceleration response than the one-directional excitation. The nonlinear behavior of anchoring frame beam is much more obvious than that of gravity retaining wall under earthquake loading. The response of dynamic earth pressure is not in phase as that of the inertial force, and quite a big value of residual earth pressure is induced by earthquake loading. The earthquake loading greatly increases the axial stress of anchor in the free zone. The axial stress of anchor decreases rapidly in anchorage zone and tends to zero within a short length.