摘要
采用弹性支点法(m法),得出了作用在支护结构上主动和被动土压力、土抗力和稳定性安全系数。结果表明过高地估计软弱煤层的力学性质和错误地选用地质剖面进行设计,导致护坡桩嵌固深度不足,被动区软弱煤岩层不能提供足够的土抗力是基坑发生过大踢脚变形的主要原因。加固设计采用了钢筋混凝土支撑、锚杆和被动区注浆方法。其中采用锚杆水平分力平衡作用在支撑体系上的水平剪切力,采用潜孔冲击高压旋喷注浆技术加固软弱煤岩层,解决了加固设计和施工的两个难点问题。
Elastic fulcrum method（ m method） is adopted to analyze the active and passive soil pressures on retaining structure,as well as the soil resistance and safety factor of overall stability of the accidental excavation. It is revealed that the soil properties of a weak coal layer is highly overestimated in the original excavation design,and incorrect soil profile is selected for retaining system calculation,therefore the socket-in length of retaining piles is too short. As a result,the extreme deformation of kick-off failure pattern happened in the accidental excavation is mainly due to insufficient soil resistance from the weak coal layer. In remedy design,RC bracing,ground anchor,and grouting in passive zone are applied. Two particular difficulties are successful solved,one is to counterbalance the lateral forces on bracing system by ground anchors,and the other is to strengthen the weak coal layer by high pressure grouting using submerging impact method.
出处
《建筑科学》
CSCD
北大核心
2017年第9期116-122,共7页
Building Science
关键词
基坑
桩锚支护
分布土反力
被动土压力
excavation
anchored pile retaining
distributive soil resistance
passive soil pressure
