Shaking table test study on seismic optimization comparison of multi-anchor piles for strengthening soil slopes under earthquake
PAI Lifang1，2，WU Honggang2，3，4，MA Huimin5
(1. China Academy of Railway Sciences，Beijing 100081，China；2. China Northwest Research Institute Co.，Ltd.，of CREC，Lanzhou， Gansu 730000，China；3. China railway Landslide Engineering Laboratory，Lanzhou，Gansu 730000，China；4. Western Environmental Geotechnical and Site Rehabilitation Technology Engineering Laboratory，Lanzhou，Gansu 730000，China；
5. Railway Scientific Research Institute Co.，Ltd.，Chengdu，Sichuan 610000，China)
Abstract：To study the distribution characteristics and spatial variation of acceleration and dynamic soil pressure response of slope strengthened by multi-anchor pile under earthquake action，the optimal seismic performance of multi-anchor pile is discussed. In this paper，the regional spatial distribution characteristics along the pile elevation are obtained through the preliminary analysis of time-domain characteristics of stability，acceleration and dynamic earth pressure of multi-anchor pile slope model by large shaking table test. Based on the above analysis，the correlation of the damage level of slope strengthened by multi-anchor pile was obtained by using Fourier change and statistical probability scatter matrix operation. This circuit was then used to calculate regional differences in Sd for seismic deformation failure values，with or without optimization of this SPECTR of multi-anchored pile slope model. The results show that：(1) Under the action of different earthquake intensities，the slope model shows the spatial coupled deformation continuous effect of regional damage and failure，and the spatial distribution of the amplitude of acceleration and moving earth pressure shows the outstanding response to the unoptimized lateral amplitude of pile structure. (2) The difference of acceleration lag along the elevation is mainly caused by the propagation stage after the main earthquake，the correlation between the seismic earth pressure and acceleration response of each group before the pile occurs in the same earthquake area is very weak，and the ground motion characteristic of the foreshock is not simply repeated superposition of the ground motion sequence of all levels. (3) Polystyrene foam (EPS plate) was used as shock absorbing layer，and energy dissipation spring was used as multi-anchor pile to improve the optimization of self-coordination device of anchor head，which played a buffering and energy dissipation role on the deformation of slope body under earthquake action. The optimization effect was related to the position of shock absorbing layer. (4) Under the action of low and medium strength earthquakes，the telescopic deformation of the anchor head energy-dissipating spring device improves the deformation coordination of the pile with multiple anchor points along the elevation，and can improve the seismic wave propagation characteristics of the pile. (5) Under the action of high-strength earthquake，the sliding surface of pile is highly sensitive to earthquake，and EPS has plastic deformation，which increases the relative displacement value on the optimized side，and is easy to cause“bulging”failure or shear failure on the sliding surface of multi-anchor pile，which is easy to become the seismic weak link of multi-anchor pile. These results are helpful to provide theoretical basis for the optimal seismic design of multi-anchor pile.
牌立芳1，2，吴红刚2，3，4，马惠民5. 地震作用下多锚点桩加固土质边坡的抗震优化对比振动台试验研究[J]. 岩石力学与工程学报, 0, (): 320-320.
PAI Lifang1，2，WU Honggang2，3，4，MA Huimin5. Shaking table test study on seismic optimization comparison of multi-anchor piles for strengthening soil slopes under earthquake. , 0, (): 320-320.
