Dynamic Response Law Of Slope Protected By Frame Structure With Pre-Stressed Anchors Under Earthquake

Frame structure with pre-stressed anchors has been widely applied for treatment on slopes of railway and highway since it can sufficiently adjust and improve soil strength and stability. However, reaseach work about characteristic and mechanism of this structure has lagged behind its applications, especially study on dynamic characteristic.It made the design being uncertainty. So it is important for designer to research the dynamic characteristics of this supporting structure.Used the Finite Element Analysis software ADINA, dynamic characteristic and reponsese law of slope supported by frame structure with pre-stressed anchors as well as influence of ground motion parameters were discussed after inputting seismic wave with different types, amplitudes and frequencies.A 3-D nonlinear FEM model is given with respect to interaction and coordinated work between soil and supporting flexible structure.Mohr-Coulomb model of ideal elastic-plastic material was used to simulate the soil and a bilinear elastic-plastic model hardening behavior was used to simulate the anchors.Friction angle-element was employed to describe the soil-structure interaction behavior and elastic Isotropical model was used to simulate frame beams,columns and plates.The results indicated that Axial force of anchor, acceleration and displacement of slope, earth pressure and inner force of the frame would gradually increase with the increase of amplitude of seismic wave,and decrease with the increase of seismic wave.The axial force increment of the anchor was non-uniform,and the maximum increment of the tectonic anchor would occur at the front end of anchor,but the others range being maximal near the slip-surface of slope.Peak displacement of slope and acceleration would increase with the increasing slope height, and would be maximum at the top of slope in the process of seismic excitation.The peak earth pressure and peak inner force of the frame would increase at first and then would decrase with the increasing slope height, and would be maximum at the middle or close middle position of slope surface.