深基坑工程对现有桥梁桩基变形的影响分析
Research on Influence of Deep Foundation Pit Engineering on Deformation of Existing Bridge Pile Foundations
刘海涛 1姬海 2邓科2
作者信息
- 1. 珠海交通集团路桥开发建设有限公司,广东 珠海 519060
- 2. 中交公路规划设计院有限公司,北京 100010
- 折叠
摘要
城市交通基础设施建设条件日趋复杂.由于道路快速化改造,新建明挖下穿隧道近距离穿越既有桥梁桩基时,造成桥梁桩基水平位移,影响桥梁结构的安全.通过计算分析华南地区典型软基地质条件修建下穿隧道进行基坑开挖引起桥梁桩基的位移,对比分析不同支护条件下的基坑开挖对桥梁桩基位移的影响.结果表明:不同基坑围护结构的刚度对桩基位移影响显著,采用ϕ0.8m、ϕ1.0m、ϕ1.2m钻孔灌注桩作为支护结构时,桥梁桩基的水平移位分别为 9.4mm、6.3mm、4.5mm.同时,基坑的基底处理方式对桩基的位移、基坑的整体安全、桥梁的安全也具有重要的作用.结合监测成果,基坑采用ϕ1.2m钻孔灌注桩围护结构+高压旋喷桩基底处理方案时,基坑和桥梁桩基水平位移的控制效果较好.
Abstract
The construction conditions of urban transportation infrastructure have been becoming increasingly complicated.Due to the rapid transformation of roads,when new open cut tunnels pass through existing bridge pile foundations around,the excavation of the tunnel foundation pit maybe cause horizontal displacement of the bridge pile foundation,which will affect the safety of the bridge structure.Being based on the calculation and analysis on the displacement of bridge pile foundation caused by the excavation of tunnel foundation pit under the typical deep soft foundation geological conditions in Southern China,the influence of the excavation of foundation pit on the displacement of bridge pile foundation under different conditions has been studied.It has been found that the rigidity of different foundation pit retaining structure has obvious influence on the displacement of pile foundation.When the retaining structure adopts ϕ0.8m,ϕ1.0m,ϕ1.2m bored cast-in-place piles,the horizontal displacement of bridge pile foundation is 9.4mm,6.3mm and 4.5mm respectively.The foundation treatment at the bottom of the foundation pit is important for the displacement of the pile foundation and the overall safety of the foundation pit and bridge.Based on the monitoring results,the horizontal displacement control effect of the foundation pit and bridge pile foundation will be better when the ϕ1.2m diameter bored pile enclosure structure and the 80%replacement rate high-pressure rotary jet grouting pile foundation treatment plan are used for the foundation pit.
关键词
下穿隧道/基坑/桥梁桩基/变形影响Key words
underpass tunnel/foundation pit/bridge pile foundation/deformation effect引用本文复制引用
出版年
2024
NETL
NSTL
万方数据