Research On Calculation Method And Response Characteristics Of Multi-anchor Circular Anti-slide Pile Under Earthquake

The western part of China is one of the areas with strong seismic activity.Earthquakes can easily induce large-scale landslides in this structural pattern.In recent years,multi-anchor circular anti-slide piles（hereinafter referred to as multi-anchor circular piles）have been gradually applied to landslide control projects due to the advantages of small masonry volume and outstanding seismic performance.However,due to the complex force transmission mechanism of the structure,there are technical bottlenecks such as theoretical research lagging behind practice,inaccurate identification of dynamic damage sites,and lack of analysis methods for seismic cumulative damage effects,which makes the dynamic calculation and damage evaluation of multi-anchor circular piles a key scientific problem to be solved urgently.In view of this,the calculation method and damage evolution mechanism of multi-anchor circular piles under earthquake were studied by means of theoretical derivation and shaking table test.The main research contents and innovative results are as follows:（1）The development history and engineering application characteristics of multi-anchor circular piles were analyzed.Based on the optimization evolution process of prestressed anchor cable anti-slide piles,the origin,possible layout and construction process of multi-anchor circular piles were elucidated emphatically.（2）A dynamic calculation method of multi-anchor circular piles was proposed.Based on the Winkler elastic foundation beam method,cantilever pile method and pile-anchor deformation coordination principle,a dynamic calculation method suitable for multi-anchor circular piles was proposed by using the principle of phased design.The rationality of the method was verified by the internal force results of the pile obtained by the shaking table test.（3）The seismic response characteristics of the multi-anchor circular piles reinforced landslide were systematically expounded.Based on the phenomenon of shaking table test and the multi-attribute response data of pile body,the macro-disaster evolution process of the slope and the spatial dynamic response mechanism of the pile-anchor-soil system were expounded.（4）A qualitative and quantitative analysis method of the dynamic damage evolution mechanism of multi-anchor circular piles based on energy transfer characteristics was proposed.The damage evolution mechanism of the multi-anchor circular piles was revealed qualitatively from the perspective of seismic wave energy transfer characteristics,and the plastic effect coefficient（PEC）was proposed to evaluate the damage degree of piles quantitatively.The analysis results of PEC were verified by using Arias strength peak ratio(M_Iα,and the seismic cumulative damage effect（SCDE）of multi-anchor circular piles was elucidated systematically.The research results can provide a basis for the theoretical design and structural safety evaluation of multi-anchor circular piles in high-intensity seismic areas.