坑外堆载对某高铁车站深基坑变形性状的影响分析  

Analysis on the Influence of External Heap Load on the Deformation Characteristics of the Deep Foundation Pit of A High-Speed Railway Station

作　　者：曾建明 胡继强 饶有权 马梦倩 ZENG Jianming;HU Jiqiang;RAO Youquan;MA Mengqian(China Railway Construction Group Co.,Ltd.,Beijing 100040,China;Hunan Zhongda Design Institute Co.,Ltd.,Changsha 410075,China;School of Civil Engineering,Central South University,Changsha 410075,China)

机构地区：[1]中铁建设集团有限公司,北京100040 [2]湖南中大设计院有限公司,湖南长沙410075 [3]中南大学土木工程学院,湖南长沙410075

出　　处：《西北工程技术学报》2024年第4期356-363,共8页Ningxia Engineering Technology

基　　金：中铁建设集团有限公司技术开发项目(基础-常德2021357QT2022018)。

摘　　要：针对基坑开挖施工时存在的建筑材料和土方等堆载现象,基于基坑现场监测数据分析了堆载对基坑周围地表沉降、桩顶竖向位移和桩顶水平位移的影响,运用MIDAS/GTS软件模拟了堆载作用下深基坑开挖全过程,研究了不同堆载大小和堆载距离对深基坑开挖中周围地表沉降和围护结构深层水平位移的影响。结果表明:当基坑周围存在堆载时,基坑周围地表沉降、支护桩桩顶水平和竖向位移值均显著增大,其中地表沉降和桩顶沉降随时间的变化规律几乎相同;堆载大小对基坑周围地表沉降和支护桩水平位移的影响均十分显著,堆载越大,地表沉降和支护桩水平位移值越大,因此工程中应严格控制堆载量;随着堆载距离的增大,最大地表沉降点逐渐外移,坑壁地表沉降值逐渐减小,当堆载距离大于6m后,坑壁地表沉降值趋于稳定,堆载距离对支护桩水平位移影响很小。In light of phenomena such as heap loads from building materials and earthwork during foundation pit excavation construction,this study analyzes the influence of heap loads on surface settlement around the foundation pit,vertical displacement of the pile tops,and horizontal displacement of the pile tops,based on on-site monitoring data.MIDAS/GTS software was used to simulate the entire process of deep foundation pit excavation under the influence of heap loads.The effects of different heap load magnitudes and distances on surface settlement around the deep foundation pit and the deep horizontal displacement of the retaining structure during excavation are also investigated.The results show that when heap loads are present around the foundation pit,the surface settlement,as well as both the horizontal and vertical displacement values of the pile tops,increase significantly.The patterns of surface settlement and pile top settlement over time are almost identical.The magnitude of heap loads has a significant effect on surface settlement around the foundation pit and horizontal displacement of the supporting piles.The larger the heap load,the larger the surface settlement and horizontal displacement of the supporting piles.Therefore,the magnitude of heap loads should be strictly controlled in engineering projects.As the distance from the heap load increases,the point of maximum surface settlement gradually moves outward,and the surface settlement of the pit wall decreases.When the heap load distance exceeds 6 m,the surface settlement of the pit wall stabilizes,and the heap load distance has minimal influence on the horizontal displacement of the supporting piles.

关 键 词：基坑开挖 地表沉降 水平位移 堆载 数值分析 现场监测 

分 类 号：TU753[建筑科学—建筑技术科学] U231.4[交通运输工程—道路与铁道工程]