既有建筑下增层开挖排桩支护体系研究

Study on the pile supported system of supplementary excavation beneath constructed buildings

总结分析了既有建筑增层开挖与新建基坑开挖的差异,针对既有支护结构在增层开挖过程中会出现承载力不足的问题,提出通过补入新增支护结构形成双排桩组合支护体系,并阐述了双排桩支护体系的施工工序、类型与受力特性,指出在增层开挖工程中应当保留既有支护结构,合理利用既有基础结构作为支撑,并根据开挖深度和现场环境选取合适的排桩分布类型。

Analysis of the differences between the new pit excavation and the existing pit excavation, the existing supporting structure will occur the problem of insufficient bearing capacity. By adding a new supporting structure compose a double-row piles system. This paper mainly analy-zes the construction process, types and characteristics of the double row pile supporting system, point out that the existing retaining structure should be kept and the existing structure can be used as the support, and according to the excavation depth and site environment selected appro-priate pile arrangement type