基坑开挖下倾斜长短组合桩受力及土体位移数值模拟  

Numerical Simulation of Force and Soil Displacement of Inclined Longshort Composite Piles under Foundation Pit Excavation

作　　者：杜泽轩 汪东林 孙浩 DU Zexuan;WANG Donglin;SUN Hao(School of Civil Engineering,Anhui University of Architecture,Hefei 230000,China;Anhui Shui'an Construction Group Co.,Ltd,Hefei 230000,China)

机构地区：[1]安徽建筑大学土木工程学院,合肥230000 [2]安徽水安建设集团股份有限公司,合肥230000

出　　处：《安徽工业大学学报（自然科学版）》2024年第5期535-544,共10页Journal of Anhui University of Technology（Natural Science）

基　　金：安徽省住房城乡建设科学技术计划项目(2023-YF024,2023-YF149)。

摘　　要：利用软件Midas GTS NX建立基坑支护模型,模拟分析基坑开挖过程中不同倾斜长短组合桩支护下,基坑土体位移及桩身水平位移与弯矩变化的规律;探讨组合桩桩长分配与长桩倾角对支护效果的影响。结果表明:基坑开挖过程中,随着开挖深度的增加,一定程度地增加长桩倾角能够有效减小土体变形和桩身水平位移,开挖面以下桩身最大弯矩也随长桩倾角的增加而减小;在总桩长一定时,最佳桩长分配受长桩倾角影响存在临界值,在长桩倾角临界值以下最佳桩长分配受倾角变化影响,在长桩倾角临界值以上长桩越长支护效果越好。在同一开挖深度下,桩身水平位移与长桩倾角有关,长桩倾角在开挖面以上相对于开挖面以下对桩身位移影响更大;开挖面以下,部分桩身最大弯矩与桩长成正比。The foundation pit support model was established with the software Midas GTS NX to simulate and analyze the changes of soil displacement of foundation pit,horizontal displacement and bending moment of pile body under different inclined long-short combined pile supports during the excavation process of foundation pit.The influence of pile length distribution of combined pile and inclination angle of long piles on the support effect was explored.The results show that during the excavation process of the foundation pit,with the increase of the excavation depth,increasing the inclination angle of the long pile to a certain extent can effectively reduce the soil deformation and the horizontal displacement of the pile body,and the maximum bending moment of the pile body below the excavation surface decreases with the increase of the inclination angle of the long pile.When the total pile length is constant,there is a critical value for the optimal pile length distribution affected by the inclination angle of the long pile.Below the critical value of the inclination angle of the long pile,the optimal pile length distribution is affected by the change of the inclination angle.Above the critical value of the inclination angle of the long pile,the longer the long pile is,the better the support effect is.At the same excavation depth,the horizontal displacement of the pile body is related to the inclination angle of the long pile,and the influence of the inclination angle of the long pile on the pile body displacement above the excavation surface is greater than that below the excavation surface.The maximum bending moment of the part pile body below the excavation surface is proportional to the pile length.

关 键 词：基坑开挖 基坑支护 组合桩 土体位移 桩身弯矩 桩身位移 数值模拟 

分 类 号：TU473.1[建筑科学—结构工程]