深层覆土地铁区间明挖段隧道变形监测方案设计与实施

摘要发展城市有轨交通是现代城市发展的具体趋势，是缓解交通压力的重要举措、优化出行效率的重要办法。“十四五”规划中，沈阳处于全面振兴发展、国家经济强市的重要阶段，沈阳市大力推动地铁建设，故对沈阳地铁施工进行变形监测分析。本文主要以东大营街站至农业大学站区间深层覆土地铁区间明挖段隧道变形监测方案与实施，确定监测方法、监测精度、监测范围、预警等级，以GNSS静态测量为平面坐标控制点布设方法，以国家二等水准测量以附近高程控制点联测获得高程数据。共布设3个平面控制点和三个高程基准点，其高程分别为51.6623m、51.5319m、51.5395。使用徕卡全站仪对对支护桩桩顶水平位移、立柱水平位移进行监测，使用天宝电子水准仪对支护桩桩顶垂直位移、立柱竖向位移、基坑地表沉降进行监测，利用测斜仪对支护桩桩体围护桩变形进行数据采集，对高架桥的桥桩进行沉降数据采集来监测周边环境的变形来预防施工过程中土力卸载及其它原因导致的基坑形变，从而确保其形变在可控范围值，确保施工安全，避免因结构破坏造成的安全事故。既完善又科学的变形监测的工作思路，为施工健康提供保障。结果表明：基坑变形规律呈现先外扩后收缩的变形规律，基坑地表为先抬升后下沉的形变趋势，同时支护桩桩体围护桩变形最大发生在土体-砂石层交换层，最大形变量为19.84mm,形变较大临近预警值。周边高架桥变形无较大扰动，四墩桥墩差异沉降也很稳定。施工中将土-砂交换层的支撑更换为钢支撑或钢混支撑可极大的减少该处的形变，进一步提高工程安全。关键词：明挖隧道：变形监测：围护结构AbstractThe development of public transportation is the direction of modern urban developmentand an important measure to control air pollution and traffic congestion in big cities.We willgive priority to the development of urban public transport,continue to deepen the constructionof national public transport in cities,and increase the share rate of urban green transport.During the 14th Five-Year Plan period,Shenyang is in the key stage of all-round revitalizationand the construction of a national central city,and vigorously promotes the construction anddevelopment of rail transit,among which the subway is dominated by rail transit.Thedeformation monitoring during the construction of Shenyang metro plays an important role inthe safety development and construction of the project,so the deformation monitoring andanalysis of Shenyang metro construction are conducted.This paper mainly in dongda camp street station to agricultural university station intervaldeep covering land iron open section tunnel deformation monitoring scheme andimplementation,determine the monitoring method,monitoring accuracy,monitoring scope,warning level,through the horizontal displacement,vertical deformation,ensure constructionsafety,avoid safety accidents caused by structure damage.The perfect and scientific thinkingof deformation monitoring can guarantee the construction health.The results show that the deformation law of the foundation pit shows the deformationlaw of first expansion and then contraction,and the surface of the foundation pit is thedeformation trend of first lifting and then sinking.At the same time,the deformation of thesupporting pile retaining pile is the largest in the soil-sand layer exchange layer,the maximumshape variable is 19.84mm,and the deformation is larger and close to the warning value.Thedeformation of the surrounding viaduct has no large disturbance,and the differentialsettlement of the four piers is also very stable.The replacement of the support of the soil-sandexchange layer with steel support or steel concrete support can greatly reduce the deformationthere and further improve the safety of the project.Keywords:pen-cut tunnel;deformation monitoring;envelope structure目录摘要Abstract..…1绪论，1.1研究背景1.2研究的目的及意义1.3国内外研究现状1.3.1国内研究现状…1.3.2国外研究现状31.4研究的主要内容2研究区概况….52.1地理位置.52.2项目概况52.3项目工程地质概况.….52.4项目水文