深基坑开挖滑动面与支护锚杆内力的计算

摘要

以银川地区某商业综合体的深基坑开挖支护为对象，研究深基坑开挖过程中使用中空注浆锚杆护坡的机理。首先对深基坑分步开挖没有锚杆支护产生的塑性应变及水平位移进行了计算，确定了边坡滑动面的位置，计算出的无支护分层开挖深基坑所形成的塑性贯通区域和瑞典法计算的滑动面相似。其次根据滑动面的位置选择锚杆的支护方式和长度，对设计采用的锚杆的内力进行了计算，锚杆的受力随着开挖而动态变化。计算结果说明，中空注浆锚杆护坡是一种经济可行的加固措施。%T he supports for the evacuation of deep foundation pit of a commercially integrated building in Yinchuan, Ningxia autonomous region was taken as the object. T he mechanism of hollow grouting bolt in the process of evacuation for slope protection was researched. Firstly,the plastic stress and lateral displacement of layer evacuation process with no bolt supporting are calculated. And then the location of the sliding surface was identified. T he plastic through area without supporting layer excavation of deep foundation pit is similar to the sliding surface calculated by the Sweden method. Secondly,according to the location of the sliding surface to choose the supporting approach and length,then carries out internal force calculation for the bolt used. T he internal force changes w ith the proceed of the excavation. T he results indicate that the hollow grouting bolt is an economical and practical choice for reinforcement.