不均衡开挖对基坑环形支撑系统影响的数值分析研究

Numerical Analysis of Influence of Unbalance Excavation on Ring Bracing System of Foundation Excavation

通过采用三维连续介质有限元软件建立基坑支护体系模型,分别模拟均衡开挖和不均衡开挖,对比研究不均衡开挖对基坑环形支撑系统变形和受力的影响。不均衡开挖将造成环形支撑系统整体变形量增大,尤其先开挖区域影响更加严重,此外各部位杆件内力发展也不均衡,支撑系统最大变形和内力在基坑开挖初期阶段就会凸显,对基坑安全预警工作十分不利。据此进一步探讨在考虑不均衡开挖的基坑环形支撑系统设计中,如何采取必要的技术措施,确保基坑工程和周边环境的安全。

3D continuous medium finite element software is used to build a model of foundation excavation supporting system,and simulate the conditions of balanced excavation and unbalanced excavation.Through numerical analysis and comparative study,the effect of unbalance excavation on the deformation and stress of ring bracing system of foundation excavation is discussed.Unbalanced excavation will increase the overall deformation of the supporting system,especially in the initial excavation area.In addition,the internal force development of supporting system is also unbalanced.The maximum deformation and internal force of the supporting system will be highlighted in the initial stage of excavation,which is very unfavorable to the safety warning work of excavation.On the basis of this,the necessary technical measures are taken to ensure the safety of the foundation excavation and the surrounding environment in the design of the ring bracing system for unbalanced excavation.