基坑倾斜长短桩支护数值模拟与工程实例研究  

Numerical Simulation and Engineering Case Study of Inclined Long-short-pile Support for Excavations

作　　者：黄俊辉 林祖锴 HUANG Jun-hui;LIN Zu-kai(Guangzhou Design Institute Group Co.,Ltd,Guangzhou 510620)

机构地区：[1]广州市设计院集团有限公司,广州510620

出　　处：《广州建筑》2024年第4期1-4,共4页GUANGZHOU ARCHITECTURE

摘　　要：依托粤港澳大湾区某倾斜长短桩支护基坑工程实例,采用有限元数值模拟方法研究其开挖稳定性,分析基坑开挖过程中桩顶水平位移及桩后土体深层水平位移响应,通过现场实测数据与数值计算结果进行对比验证分析。结果表明:开挖过程中桩顶水平位移随开挖深度增大而增大,呈较明显的悬臂式分布形式,直桩桩顶位移增长量实测值最大为12 mm,短斜桩次之为6 mm,长斜桩最小为3 mm;位移增长速度由大到小有直桩>短斜桩>长斜桩的关系。直桩最终水平位移呈继续发展趋势,斜桩最终水平位移呈收敛趋势;桩后土体深层水平位移自桩顶向坑底以下逐渐减少,工程实测值受地层起伏变化影响,短斜桩在基坑中部位移先增大后减小,总体仍满足规范规定一级基坑位移控制要求。Based on an example of a inclined long and short pile support foundation pit project in the Greater Bay Area of Guangdong,Hong Kong,and Macao,finite element numerical simulation method is used to study its excavation stability.The horizontal displacement of the pile top and the response of the deep horizontal displacement of the soil behind the pile during the excavation process of the foundation pit are analyzed.The comparison and verification analysis are conducted through on-site measured data and numerical calculation results.The results show that the horizontal displacement of the pile top increases with the increase of excavation depth during the excavation process,showing a more obvious cantilever distribution.The measured increase in displacement of the straight pile top is the maximum of 12 mm,followed by 6 mm for short inclined piles,and 3 mm for long inclined piles;The growth rate of displacement varies from large to small,with a relationship between straight piles,short inclined piles,and long inclined piles.The final horizontal displacement of straight piles shows a continuous development trend,while the final horizontal displacement of inclined piles shows a convergence trend;The deep horizontal displacement of the soil behind the pile gradually decreases from the top of the pile to the bottom of the pit.The measured value of the project is affected by the fluctuation of the strata,and the displacement of the short inclined pile in the foundation pit first increases and then decreases.Overall,it still meets the displacement control requirements of the first level foundation pit specified in the specifications.

关 键 词：基坑 倾斜桩 长短桩 现场试验 有限元法(FEM) 

分 类 号：TU43[建筑科学—岩土工程]