基于FLAC^(3D)的深基坑开挖与支护数值模拟应用

Application of numerical simulation for excavation and supporting of deep foundation pit based on FLAC^(3D)

针对内撑式排桩深基坑支护开挖过程中地表和围护结构变形的安全性问题,为基坑工程设计与计算提供参考依据,运用FLAC^(3D)软件对营口市某深基坑工程采用内撑式排桩支护进行了开挖模拟,结合理正软件设计计算值和现场实际监测值进行对比分析.结果表明,FLAC^(3D)数值模拟得到的地表和围护结构最大位移值分别为22、25 mm,而理正软件得到的最大位移值分别为22、20 mm,现场实际监测地表和围护结构最大位移值为26和30 mm,在深基坑工程开挖与支护过程中,FLAC^(3D)不仅能够较好地模拟不同工况下的地表沉降和围护结构的水平位移,而且模拟围护结构水平位移效果更好.

In order to solve the deformation security issues of ground surface and supporting structure during the supporting and excavation of internal brace row-pile deep foundation pit and provide the reference basis for the engineering design and calculation of foundation pit, the excavation simulation was conducted with software FLAC3D for a certain deep foundation pit with internal brace row-pile supporting in Yingkou. The comparison and analysis were performed in combination with the actual monitored value and the calculated value obtained with Lizheng software. The results show that the maximum displacement of ground surface and supporting structure obtained with FLAC3D numerical simulation and Lizheng software is 22, 25, 22 and 20 mm, respectively. The maximum displacement of ground surface and supporting structure obtained with the field monitoring is 26 and 30 mm, respectively. In the excavation and supporting processes of deep foundation pit, the software FLAC3D can not only well simulate the horizontal displacement of ground surface subsidence and supporting structure under different operating conditions, but also obtain better simulating effect for the horizontal displacement of supporting structure.