基坑开挖对桩锚支护体系土体侧压力的影响

INFLUENCE OF FOUNDATION PIT EXCAVATION ON SOIL LATERAL PRESSURE OF PILE ANCHOR SUPPORT SYSTEM

桩锚支护体系因施工方便、对施工空间要求小、控制变形能力强等特点而被广泛采用。土压力的准确计算是基坑设计的关键。为了研究桩锚支护体系中,基坑开挖对土体侧压力的影响,在具体基坑工程现场,利用钻孔法在土体中埋设土压力盒,基坑开挖过程中实时监测。以现场监测数据为依据,总结出不同深度土压力的变化。结果表明:随基坑开挖,桩侧土压力总体呈减小的趋势;同一水平位置上,桩侧土压力随深度的增加而增大;随基坑开挖,风化岩处桩侧土压力趋于平缓。

With the rapid development of cities in China,the excavation of foundation pit is developing towards a larger and deeper trend.Pile anchor support system is widely used because of its convenient construction,small requirements for construction space and strong ability to control deformation.The accurate calculation of earth pressure is the key of foundation pit design.In order to study the influence of foundation pit excavation on the lateral pressure of soil in the pile anchor support system,the earth pressure box is embedded in the soil by drilling method in the specific foundation pit engineering site,and the real-time monitoring is carried out in the process of foundation pit excavation.Based on the field monitoring data,the changes of earth pressure at different depths are summarized.The results show that the earth pressure on the pile side decreases with the excavation of foundation pit.At the same horizontal position,the earth pressure on the pile side increases with the increase of depth.With the excavation of foundation pit,the earth pressure at the pile side of weathered rock tends to be gentle.