某黄土深基坑开挖变形预测分析  

PREDICTION ANALYSIS OF FORCED DEFORMATION OF A LOESS DEEP FOUNDATION PIT EXCAVATION

作　　者：严长江 李旺 张子辰 YAN Changjiang;LI Wang;ZHANG Zichen(School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China)

机构地区：[1]兰州交通大学土木工程学院,兰州730070

出　　处：《低温建筑技术》2023年第3期101-104,共4页Low Temperature Architecture Technology

摘　　要：某高速铁路黄土深基坑工程采用桩锚撑支护体系,开挖范围广、开挖深度大、受力复杂、危险程度高.文中依托工程对基坑开挖与支护过程进行有限元分析,探究在不同开挖工况、不同位置下,支护结构及土体受力变形规律,并通过数值模拟结果分析基坑开挖过程的安全性.结果表明地表最大沉降5.9mm,出现在距坑边3m左右处;坑底隆起量偏大,达到28.3mm,底板施工后,其值能降低27.3%以上;桩身的侧向位移最大仅为10.7mm,位移曲线呈现明显的"鼓肚状"变形;支护结构设计能够满足相关规范的变形控制要求,设计参数合理可行,有足够的安全储备.A high-speed railway loess deep foundation pit project adopts a pile anchor support system,which has a wide excavation range,large excavation depth,complex stress,and high risk.Based on this project,the finite element analysis of foundation pit excavation and supporting process is carried out to explore the deformation law of supporting structure and soil under dfferent excavation conditions and diferent positions.The rationality of design parameters and the safety of foundation pit are analyzed by numerical simulation results.The results show that the maximum surface settlement is 5.9mm,which occurs at about 3m from the edge of the pit.The uplift of the bottom of the pit is too large,reaching 28.3mm.After the construction of the bottom plate,the value can be reduced by more than 27.3%.The maximum lateral displacement of the pile is only 10.7mm,and the displacement curve shows obvious bulging deformation.The design of supporting structure can meet the deformation control requirements of relevant specifications.The design parameters are reasonable and feasible with enough safety reserves.

关 键 词：黄土深基坑工程 桩锚撑支护 支护结构设计 

分 类 号：TU444[建筑科学—岩土工程]