长短桩组合围护结构在深厚软土基坑中的应用

The application of long-short pile combination support in deep-thick soft soil foundation pit

排桩是常用的基坑支护结构类型,在深厚软土基坑设计中其通常按满足最不利安全系数的最长桩长布置,桩长应同时满足基坑整体稳定性、抗隆起稳定性、抗踢脚稳定性及变形控制等要求,造成排桩支护某些安全系数偏大、排桩的抗弯承载能力不能充分发挥、工程造价偏高、工期偏长等问题。本文以福州某深厚软土基坑支护为例,采用长短桩组合围护结构设计方案,既满足设计要求,又降低工程造价,可为类似工程提供借鉴。

Row piles are commonly used types of support structures in foundation pit engineering. Layout of piles usually according to the longest pile length that meets the most unfavorable safety factor in the design of deep soft soil foundation pits. The pile length should satisfy the requirements such as overall stability,resistant heave stability,anti-lift stability and deformation control of the foundation pit. Meeting the requirements may cause some safety factors of the row pile support to be too large,the bending resistance of the piles cannot be fully used,the construction cost is high,and the construction period is too long. Taking a deep soft soil foundation pit support project in Fuzhou as an example,this paper adopts the design scheme of long and short pile combined retaining structure,which meets the design requirements and reduces the project cost,furthermore,provides reference for similar projects.