邻域超大附加荷载深基坑空间效应及变形控制

Spatial Effect and Deformation Control of Deep Foundation Pit with Huge Additional Load in Neighborhood

深基坑的空间效应显著,如何对其变形控制是该类工程的关键问题。结合星火站站房基坑工程,运用Midas/GTS NX有限元软件,分析基坑在邻域局部超大附加荷载作用下变形的空间效应,并提出相应的变形控制措施。研究结果显示,在基坑变形的空间效应方面,桩顶水平变形、锚索轴力以及坑外地表沉降之间呈正相关,邻域超大附加荷载会削弱角部效应。在变形控制方面,支护桩桩径对变形控制的效果不明显,但正确的开挖顺序以及合理布置马道方位能有效的约束基坑支护结构的变形。

The spatial effect of deep pit is significant,and how to control its deformation is the key problem of this kind of engineering.In this paper,combined with the Xinghuo Station pit project,using Midas/GTS NX finite meta-software,the spatial effect of the pit deformation under the local huge additional load in the neighborhood is analyzed,and the corresponding deformation control measures are proposed.The results show that in terms of the spatial effect of pit deformation,there is a positive correlation between the horizontal deformation of the top of the pile,the shaft force of the anchor rope,and the subside of the surface of the pit,and the super-large additional load of the adjacent area will weaken the angle effect.In the aspect of deformation control,the effect of support pile diameter on deformation control is not obvious,but the correct excavation order and reasonable arrangement of berm position can effectively restrain the deformation of the base pit support structure.