济南典型地层基坑空间效应规律研究

针对山东省会文化艺术中心基坑开挖过程，利用有限元软件PLAXIS 3D建立了能够考虑基坑空间效应的三维整体有限元模型；得到了基坑阴角、阳角及开挖宽度对支护结构的影响，并对其做了深入分析；总结了考虑基坑开挖深度、宽度以及支护结构插入深度的基坑变形公式，分析了坑趾系数、深度比等因素对外坑支护结构的影响，明确了济南地区基坑空间效应规律；对整体计算、单元计算以及二维计算结果进行了对比。结果表明:考虑空间效应的基坑整体计算方法更为合理；对于超深超大基坑，建立三维计算模型时考虑空间效应对基坑支护结构及周边环境影响，对把握基坑整体工作机理，避免安全事故，以及精细基坑设计的整体布局和空间优化具有借鉴及参考意义。

Study on Spatial Effect of Foundation Pit in Typical Strata of Jinan

Aiming at the excavation process of Shandong Provincial Capital Culture and Art Center, a three-dimensional finite element model considering the spatial effect of foundation pit was established by using finite element software PLAXIS 3D. The influences of the negative angle, the positive angle and the excavation width of the foundation pit on the supporting structure were obtained, and the deep analysis was made. The formulas of foundation pit deformation considering the depth and width of foundation pit and the insertion depth of supporting structure were summarized. The influences of pit toe coefficient and depth ratio on the pit supporting structure were analyzed, and the spatial effect of foundation pit in Jinan was clarified. The results of integral calculation, cell calculation and two-dimensional calculation were compared. The results show that the integral calculation method of foundation pit considering spatial effect is more reasonable. For the three dimensional calculation model of the super deep and super large foundation pit, considering the influences of spatial effect on the supporting structure and surrounding environment, it has reference significance for grasping the whole working mechanism of foundation pit, avoiding accidents, and the overall layout and space optimization of fine design of foundation pit.