Study On The Dynamic Response For Compression-type Anchorage System Under The Action Of Earthquake In Landslide Prevention

Anchor(cable)is one of the main methods in slope/landslide treatment engineering as a flexible supporting structure, and that not only plays an important role in engineering but also presents nice seismic performance under the earthquake. At present, people have carried out lots of engineering practice in landslide anchorage engineering, but the dynamic response of slope, the effect and the dynamic response of anchor under the earthquake are rarely reported.To solve this problem, in this paper, combining the vibration table model test with the ABAQUS infinite element numerical simulation of research methods; we will study the dynamic responses of landslide and anchor in compression-type anchorage system.Conclusions have been presented as follows:(1)Under the action of Wenchuan wave the PGA amplification coefficient of each monitoring point which is in superficial and inner landslide increases gradually with the increasing height of landslide; however, the PGA amplification coefficient has no obvious difference in superficial and inner landslide.(2)Under the action of sinusoidal wave three types make the PGA amplification coefficient become larger and the landslide responses more significant:(1)low frequency,middle to high magnitude,(2)middle frequency, middle magnitude,(3)high frequency, low magnitude; and the results of numerical simulation is consistent with the experimental results,verifying the rationality of the experimental results.(3)Under different seismic action the difference of the ground motion parameters leads to the obvious discrepancy of the response of acceleration of the landslide. It is necessary to input different seismic forces to carry out the seismic design of anchor for the same landslide supporting design..(4)Under the action of Wenchuan wave, the strain laws of single anchor at different points are as follows: under different acceleration amplitude, strain shows a trend of gradually increasing from sliding surface to the position of bearing body; namely,the peak strain is near the bearing body.In the same column, the roles of the peak value of anchors′strain are as follows: with the increasement of the seismic intensity, the response of strain peak in the top and bottom of layers is more obvious than other layers.(5)Under the action of sinusoidal wave, the strain laws of single anchor in different peakof acceleration are as follows: the laws are consistent with the strain distribution laws under the action of Wenchuan wave; namely, under different acceleration amplitude, strain shows gradually increasing trend from sliding surface to the position of bearing body.In the same column, the roles of the peak value of anchors′strain are as follows: with the increase of the amplitude of the acceleration, when the vibration frequency is 5Hz, the peak strain of anchors in the bottom of layer is more obvious than others; at 10 Hz, the peak strain of anchors in the top and bottom of layers is more obvious; at 15 Hz,the response of the peak strain in the top of layer is the most obvious.(6)In different vibration frequency, the strain laws of single anchor at different points are as follows: with the increasement of vibration frequency, when the acceleration amplitude is0.1g, the peak strain of anchors increases gradually; at 0.2g, the peak strain shows “increasing at first, then decreasing”,the peak strain is highest at 10Hz; at 0.6g, the peak strain decreases gradually.(7)The results of numerical simulation analysis show that: in the static condition,displacement value of landslide is 0; in the dynamic condition, with the increasement of time,the displacement increases gradually.Moreover, in the same frequency and peak acceleration,with the increasement of the height of slope, the displacement also increases.(8)The result of sinusoidal wave which has different time length affecting the PGA amplification coefficient shows that: with the increase of the length of time, the value of the PGA amplification coefficient does not have significant discrepancy; namely, the effect of time length on the PGA amplification coefficient is not obvious.(9)The result of the time length affecting the peak value of displacement shows that: the length of time is longer, the peak value of displacement is bigger.