成都膨胀土(岩)地区地铁深基坑围护桩体系设计探讨

成都地铁2号线穿越成都市东部膨胀土（岩）地区，是国内首次大范围在膨胀土（岩）条件下修建地铁工程。当地铁深基坑采用内支撑＋围护桩体系设计时，必须考虑水平膨胀力的荷载性质和大小对深基坑的影响。运用理正深基坑计算软件计算常规下围护桩的内力设计值，再用MIDAS/GEN有限元软件对深基坑膨胀土(岩)的水平膨胀力进行分析，并提出合理的设计方法，工程实践证明，设计方法合理，工程安全可靠。可为此类设计提供参考。

On Design of Retaining Pile System of Deep Foundation Pit for Metro in Expansive Soil (Rock) Area in Chengdu

Chengdu metro line 2 passes the expansive soil (rock) area in the east of the city, which is the first largest metro project under such condition in the country. When the system of internal support plus retaining pile is designed, the influence of loading character and value of the horizontal expansive force on the deep foundation pit must be taken into consideration. In this paper, the design internal force of the retaining pile under normal condition was calculated with F SPW software and the horizontal expansive force in the expansive soil (rock) with MIDAS/GEN software, and then the proper design method was proposed. The engineering practice has proved that the design method is reasonable and the engineering is safe and reliable, offer reference to the similar design.