相邻深基坑同步开挖的相互影响研究

Study on Interaction of Two Adjacent Excavations Constructed Simultaneously

为研究近距离相邻的深大基坑同步开挖的可行性以及实践中的关键技术措施,本文结合某工程案例采用有限元软件Midas对实际开挖工况进行了三维有限元计算,对支护系统的整体性状、围护桩的承载力及变形进行了详细分析,并与监测数据相比较,得出了若干结论,可供类似项目参考:(1)在合理安排施工况的前提下,相邻基坑同步开挖是技术可行的;(2)实施过程中,除确保围护结构的承载力和变形应满足相应要求外,在施工过程中还应防止两个基坑所夹持的中间土体的流失,确保支撑体系的传力连续。

To research the interaction of two excavations constructed simultaneously and the key measures taken in the practice,three-dimensional simulation was studied based on two projects using the finite element software Midas. The parameters and the steps taken were according to the support system design. The behavior of the support system and the soldier piles were analyzed. The simulation result was also compared with the monitoring data,to seek the difference between the theory and practice. Some conclusion and deduction was given that maybe helpful to other projects. The main conclusion is as follows:( 1) It is practicable to construct two excavations simultaneously if the steps are set to be appropriate;( 2) besides the pile capacity and deflection,the conservation of the soil between the two adjacent excavations should be estimated for the transmission of the force on the support system.