（1 华蓝设计(集团)有限公司， 南宁 530011； 2 重庆大学土木工程学院， 重庆 400045）

［摘要］本文结合某实际工程，采用FLAC3D数值模拟，分析软土地区基坑底加固对悬臂式排桩支护结构的侧移、侧压力、地表沉降分布情况和变化规律，并结合现场监测数据与理正深基坑软件的计算结果进行对比验证。结果表明：排桩的侧移最大值出现在排桩顶部，坑底加固可使侧移减小1/3~1/2；坑底加固基本不改变排桩上土侧压力；地表沉降最大值发生在基坑边缘，坑底加固可使地表沉降减小约1/2；提出了坑底加固的深度和宽度的建议值。

［关键词］坑底加固； 数值分析； 软土地区； 深基坑

中图分类号： TU46+3 文献标识码： A文章编号：  1002-848X(2016)S2-0540-05

Analysis on effect of foundation pit bottom reinforcement on pile cantilever retaining structure

Liao Sunjing1， Wu Shuguang2

(1 Guangxi Hualan Design & Consulting Group, Nanning 530011, China;

2 School of Civil Engineering, Chongqing University, Chongqing 400045, China)

Abstract: A practical project using FLAC3D numerical simulation, analysis of soft soil foundation reinforcement on the bottom row of piles cantilever structure lateral, lateral pressure, surface subsidence distribution and variation, and with the rationale for deep excavation software calculations combined with field monitoring data contrast verification. The results showed that: the maximum lateral row of piles in pile top, bottom lateral reinforcement can reduce 1/3~1/2; Bottom Strengthening basic soil without changing the lateral pressure on the pile; maximum surface subsidence occurred in the pit edge, bottom reinforcement surface subsidence can be reduced by about 1/2. Bottom reinforcement and proposed recommendations depth and width values.

Keywords: pit bottom reinforcement; numerical analysis; soft soil area; deep foundation pit