基于flac3D深基坑开挖模拟与支护设计

本科生毕业论文（设计）题目：基于flac3D深基坑开挖模拟与支护设计指导教师:职称:评阅人:职称:摘要随着城市化过程中不断涌现的高层建筑和超高层建筑以及城市地下空间的开发，深基坑工程越来越多，深基坑工程项目的规模和复杂性日益增大，给深基坑工程的设计和施工带来了更大的挑战。在这样的背景下，深基坑支护结构设计和变形量预测已成为岩土工程领域的重要研究课题之一。本文以武汉市万达广场深基坑工程作为研究对象，利用勘查资料和深基坑支护结构设计要求，比选合理的基坑支护方案并进行相应的计算设计。同时，本文针对深基坑工程变形量验算等难以解决的问题引用了flac3D数值模拟方法，对基坑开挖、支护结构施工进行全方位的模拟监测，将计算设计结果和模拟计算结果进行对比验算，得出比较合理的支护结构设计方案和变形量控制方案。根据基坑实际情况和勘查资料，本文选择的围护方案为以大直径混凝土排桩、双排桩、角撑与对顶撑相结合的内支撑为主的多种联合支护方案，结合坡顶大面积卸土减载、坑内被动区加固的措施。计算部分主要设计计算大直径混凝土排桩（钻孔灌注桩）桩长、内力和配筋，而对卸土减载、内支撑结构、坑内被动区加固和降水设计只进行了简要的说明；flac3D模拟部分主要从建立模型、设置大直径混凝土排桩、放坡开挖、放坡坡面土钉施工、预应力锚索（代替内支撑）施工和基坑主体开挖为顺序进行建模计算，最后进行变形量监测、分析，输出桩单元、锚单元的内力分布情况并给出相应的结论与建议。本文以常规计算和数值模拟相结合的方式进行参考对比，常规计算和数值模拟分析结果非常接近，给出了有效合理的安全系数。关键词：深基坑支护设计flac3D模拟数值模拟AbstractWiththeurbanizationprocess,high-risebuildingsandsupertallbuildingsarecontinuouslyemerging.Asaresult,undergroundspacedevelopmentprojectanddeepexcavationprojectbecomemoreandmore.Atthesametime,thescaleandcomplexityofdeepexcavationincreasingbigger.theymakethedesignandconstructionofdeepexcavationtofacegreaterchallenges.Sostructuraldesignanddeformationpredictionofdeepexcavationhasbecomeanimportantresearchissueinthefieldofgeotechnicalengineering.Inthispaper,thedeepexcavationofWandaPlaza,Wuhanisstudied.Andusingsurveydataandstructuraldesignofdeepexcavationrequirementstoselectreasonablefoundationpit,thentoconductthecorrespondingdesign.Themeantime,ascheckingthedeformationofdeepexcavationisadifficultproblems,itusesflac3Dnumericalsimulationmethodtomonitortheprogressofdeeppit’sexcavation,construction.Thencomparingthedesignresultsofthecalculationandsimulationresultstoobtainedreasonablesupportstructuredesignandcontrolprogramofdeformation.Accordingtotheactualsituationandexplorationdata,theenvelopeoflargediameterpilesconcretepiles,anglebraceandtopbraceonthecombinationofavarietyofinternalsupport-basedprogramsareselected,combinedwithslopeToplargedumploadsheddingandthereinforcementmeasuresofpitpassivezone.1)Thecalculationpartofthepapermainlyintroducethedesignandcalculationoflargediameterconcretepilesorboredpile,andtherestjustbrieflyintroducethedumpingloadshedding,internalsupportstructure,thepitdesignofpassivezonestrengtheningandprecipitation.2)Withflac3D,successivelystudythemodelbuilding,settinglargediameterconcretepiles,slopingexcavation,soilnailingconstruction,pre-stressedcable(insteadofinternalsupport)constructionandexcavationforthefoundationpit.Finally,conductthedeformationmonitoring,outputpileelement,theinternalforcedistributionanalysisinanchorageunit.Andthen,providethecorrespondingconclusionsandrecommendations.Inthispaper,conventionalcalculationsandnumericalsimulationmethodsareused.Andtheirresultswereveryclose.Soitcangiveaneffectiveandreasonablesafetyfactorthroughthecombinationofthesemethods.Keywords:deepexcavationdesignflac3Dnumericalsimulation目录第一章绪论...................................................................................................................................1第一节选题思路...........................................................................................................1第二节设计流程...........................................................................................................1第二章工程概况及场地工程地质条件.......................................................................................3第一节工程概况.........................................................................................................3第二节场地工程地质条件...........................................................................................4第三章A-OPQRSA段基坑支护结构设计...................................................................................10第一节设计依据.......................................................................................................10第二节设计参数.......................................................................................................10第三节A-OPQRSA段基坑支护方案选择................................................................11第四节A-OPQRSA段基坑减载放坡设计................................................................13第五节A-OPQRSA段基坑支护桩设计....................................................................13第六节A-OPQRSA段基坑地下水控制方案设计....................................................24第四章基于flac3D基坑开挖模拟分析.....................................................................................27第一节关于flac3D的概述.........................................................................................27第二节基坑维护方案.................................................................................................27第三节计算模型及参数.............................................................................................28第四节初始应力计算.................................................................................................29第五节支护桩施工.....................................................................................................31第六节模拟分层开挖和设定锚杆.............................................................................32第七节设置采样记录变量.........................................................................................34第八节计算结果分析........................