STUDY ON DYNAMIC CALCULATION METHOD FOR FRAME SUPPORTING STRUCTURE WITH PRE-STRESS ANCHORS

Considering the nature of the mutual influence between a structure and its supporting soil, a dynamic calculation model of a supporting frame with pre-stress anchors for the slope stability is established. According to the actual working mechanism of the frame with pre-stress anchors, the free segment and anchorage body of an anchor is respectively simplified two section uniform elastic round rods. The interaction between soil and anchors is treated with a linear spring and a damped system related with velocity. The influence of the frame upon the anchor is simplified for equivalent mass. Under the condition of a horizontal earthquake excitation, the vibration equation is deduced based on being mentioned ahead, and the analytical solutions are obtained. The method is applied to a case record for illustration of its capability. In order to verify the method, a 3-D nonlinear finite element software (ADINA) is used to analyze the seismic performance of this case, the results of comparison with that of the proposed approach and that of the finite element method and that of a shaking table test show a good agreement. The results of analysis reveal that this simplified calculation model is feasible. The seismic displacement response, the anchors axial force increment response, the distribution of axial force along slope height and anchors axis can be obtained through the established model. The calculation model provides a new approach for the earthquake analysis and aseismic design of slope stability supported by a frame with pre-stress anchors.