基坑开挖支撑方案的现场实测与研究

Field Monitoring of a Deep Excavation Supporting Program

通过对北京地铁某线标段的基坑开挖过程进行现场监测,研究分析该方案在实施过程中围护结构水平位移、钢支撑内力、桩体内力及桩土压力的分布和变化规律。研究表明:桩体位移变化值较小;钢支撑内力最大值远小于规范报警值;桩内力和土压力所得数值均在安全范围内,对类似基坑开挖支撑方案的设计及其优化具有重要的参考价值。

This paper presents field observation results of a deep excavation for construction of a metro in Beijing. During con- struction, the horizontal displacement of the supporting structure, the stress in the steel strut, and the earth pressures on the soldier piles are monitored. From the monitoring results, it is concluded that the horizontal displacements of the soldier piles are very small; the stress in the steel strut is much smaller than the threshold stress of 80% of yield stress of steel. Both the stresses and the earth pressures acting on the soldier piles are within the safety limits. These results could serve as a reference for the design and construction of similar deep excavation supports.