杨学林 施祖元  益德清
    （浙江省建筑设计研究院 杭州 310006）

[提要]  根据深基坑工程的施工特点，提出了考虑分步开挖影响的带支护结构的计算方法。讨论了水平支撑体系的等效刚度、内支撑与围护墙的变形协调等问题。工程实例表明，在支护结构计算中考虑分步开挖的影响后，内力与变形计算结果与实测值较接近。
[关键词]  深基坑 支护结构  围护墙 水平支撑 分步开挖

The multi-braced retaining structure has been widely applied to deep excavation engineering in soft clay. A calculation method for retaining structure considering the effects of steped excavation is presented, according to the construction characteristics of deep excavation engineering. Some problems are discussed, such as the mechanical mode and equivalent stiffness of hornontal bracing system, the deformation compatibility between the bracing and retaining wall. Finally, two excavation cases are given, which indicate that the effects of steped excavation can not be neglected in the calculation of the structure.
Keywords:  deep pit; retaining structure; steped excavation; horizontal bracing