地震荷载下边坡抗滑桩有效加固区与最优加固位置理论

Effective reinforced zone and optimal location of a stabilizing pile under seismic loading

假设边坡滑裂面为对数螺旋曲线,应用极限分析上限定理,根据典型均质边坡的局部失稳模式,分别计算桩前和桩后坡体的局部稳定性,提出抗滑桩有效加固区理论.采用Ito理论考虑桩-土相互作用,分别计算抗滑桩加固边坡的地震安全系数、已知设计安全系数所需的最小桩径或桩间净距及其对应的所需抗力、抗力合力作用点位置和滑面以上桩长.根据计算结果结合工程的安全性、经济性和施工难度可确定合理的设计桩位,通过算例分析地震荷载和岩土物理力学参数对抗滑桩加固边坡的有效加固区的影响.

Assumption that the slope sliding surface is a logarithmic spiral curve and the local instability mode a typical homogeneous slope,and by applying the upper limit theorem of limit analysis and calculating the local stability of the slope before and after the pile respectively,an effective reinforcement area of the anti-slide pile was proposed.In consideration of the pile-soil interaction with the Ito theory,the seismic safety factor of anti-slide pile reinforcement slope and the minimum pile diameter or net distance between piles required by the known design safety factor,as well as the corresponding required resistance,the position of the resultant force of resistance and the pile length above the sliding surface were calculated.According to the resultant calculation and combining with the safety,economy and construction difficulty of the project,a reasonable design pile position could be determined.The influence of seismic load and physical and mechanical parameters of rock and soil on the effective reinforcement area of the slope strengthened by mechanical parameters and the effective reinforcement area of the slope strengthened by anti-slide piles was analyzed through calculation case.