含软弱层顺倾岩体边坡锚固地震响应试验研究

Experimental study on seismic response of anchorage of bedding rock slope with weak layer

首次通过浇筑方式构筑大型相似边坡模型,并进行振动台相似模型试验,且首次测得了地震作用下两锚固界面上的应变,进而深入系统地研究了含软弱层顺倾岩体边坡锚杆杆体和砂浆的地震响应规律。研究发现:地震作用下边坡锚固发生变形,其锚固作用得以发挥,且随地震波的持续输入锚固应变增大,进而达到其峰值,最终锚固破坏失效;其中锚杆杆体的应变响应得到持续增强,而砂浆由于脆性产生裂隙,致使其受到的拉剪力减小,应变响应受到制约;地震作用下锚杆杆体的应变响应可分为拉压循环阶段、张拉阶段、强烈振荡阶段和残余应变阶段4个阶段;砂浆的应变响应可分为拉压循环阶段、张拉阶段和破坏阶段3个阶段;同时,分析了地震作用下锚固边坡中力的相互作用和传递。该研究对岩土锚固理论研究、数值模拟和抗震设计施工均具有重要意义。

A large-scale slope model is built by pouring for the first time,and the shaking table tests on the similarity model are conducted.The strain of two anchorage interfaces is obtained under the earthquake,and the seismic responses of anchor bolts and mortar of the bedding rock slope with weak layer are studied.The results show that responding to the slope deformation under the earthquake,the anchoring role of the anchorage systems works,the systems'strain increases with the continuous input of seismic waves and then reaches the peak value,and finally they fail.The strain response of anchor bolts is continuously enhanced,while the mortar cracks because of brittleness,which leads to a reduction in the tension and shear of the mortar,and a restriction on the strain response.The strain response of bolts under earthquake can be divided into four stages:tension-compression recirculation stage,tension stage,intensive oscillation stage and residual strain stage.The strain response of mortar can be divided into three stages:tension-compression recirculation stage,tension stage and failure stage.Besides,the role and the transfer law of force in anchored slopes under earthquake are analyzed.This research may provide important reference for the theoretical research,numerical simulation and seismic design and construction of ground anchorages.