基坑围护结构稳定性研究

基坑围护结构稳定性研究摘要随着我国大规模建筑基坑和地下工程的发展，许多由基坑围护结构稳定性导致的问题逐步凸现出来。然而，由于渗流场的复杂性，目前基坑支护工程中对基坑围护稳定性的影响因素考虑大多不合理。因此，研究基坑工程的围护结构稳定性的影响因素的土体变形分析方法，具有重要的理论意义和实践意义。针对上述情况，在总结前人研究成果的基础上，根据深基坑开挖特点，通过使用迈达斯软件建立了有限元计算模型，对深基坑围护结构稳定性及周围土体变形的影响因素等问题进行了数值模拟研究，重点对影响基坑围护稳定性的各因素进行了有限元数值模拟分析。以佛山环球国际广场基坑工程为例进行了基坑围护稳定性因素进行研究。分别分析基坑开挖步距、土体内摩擦角、基坑支护等相关因素对于基坑围护稳定性的影响。并通过以上研究，揭示深基坑围护变形的影响因素及规律，以期给工程实践以理论指导，使工程设计人员对基坑围护结构稳定性有更进一步的认识，从而更好地改善施工作业条件，保证工程的安全性。关键词：深基坑支护有限元法分析围护结构稳定性AbstractWithChina'smassiveconstructionpitandundergrounddevelopmentprojects,manyoftheproblemscausedbythestabilityofthefoundationpitgraduallyexposed.However,duetothecomplexityoftheflowfield,thecurrentexcavationprojectinthestabilityofthefoundationpitofthefactorsconsideredmostunreasonable.Therefore,thestudyexcavationofthefactorsaffectingthestabilityofretainingthesoildeformationanalysishasimportanttheoreticalandpracticalsignificance.Fortheabove,thesummaryresultsofpreviousstudiesbasedonthecharacteristicsofdeepexcavation,usingMidassoftwaretobuildafiniteelementmodelofdeepfoundationpitstabilityanddeformationofthesurroundingsoilfactorsissuessuchasnumericalsimulations,focusingontheimpactonthestabilityofthefoundationpitofthefactorsthatFEManalysis.OfFoshanInternationalPlazaexcavationasanexampleofthefoundationpittostudythestabilityfactor.Stepawayfromtheexcavationwereanalyzed,thesoilfrictionangleofthebody,excavationandotherrelatedfactorsaffectingthestabilityofthefoundationpit.Andtheabovestudyrevealstheimpactofdeepfoundationpitdeformationfactorsandthelawinordertogivetheoreticalguidancetoengineeringpractice,sothatengineershaveabetterstabilityofthefoundationpitofknowledge,soastobetterimprovetheconstructionworkconditionstoguaranteethesafetyoftheproject.Keywords:deepexcavationFiniteElementAnalysisRetainingstructureThestability目录第一章绪论............................................................................................................................11.1引言......................................................................................................................................11.2基坑工程的背景和特点......................................................................................................11.2.1基坑工程背景...................................................................................................................11.2.2基坑工程中目前存在的主要问题...................................................................................21.3国内外基坑工程发展状况和研究现状..............................................................................31.4课题的研究目标、内容和方法..........................................................................................41.4.1研究目标...........................................................................................................................41.4.2研究内容...........................................................................................................................41.4.3拟解决的关键问题...........................................................................................................4第二章有限元法的基本原理................................................................................................62.1有限元的基本原理...........................................................................................................62.1.1有限单元法的发展简介.................................................................................................62.1.2有限单元法的基本思想.................................................................................................62.2有限元软件MIDAS/GTS简介........................................................................................7第三章有限元模型的建立....................................................................................................93.1基坑建模中的基本情况......................................................................................................93.1.1地质情况及水文地质条件...............................................................................................93.1.2基坑支护方案以及降水方法...........................................................................................93.2有限元模型的建立..............................................................................................................93.2.1.基本假定...........................................................................................................................93.2.2，计算区域以及边界条件................................................................................................93.2.3岩土的特性.......................................................................................................................93.2.4有限元网格划分和单元设置.........................................................................................113.2.5荷载分级.........................................................................................................................113.2.6数值模拟工况.................................................................................................................113.2.7计算模型及参数选取.....................................................................................................113.2.8其它影响因数分析...........