地铁区间渡线段大幅度突变断面转换施工技术

摘要

北京地铁16号线甘家口站～玉渊潭东门站区间位于三里河路下方，对施工引起的地表沉降控制要求严格。该区间两端各设有一段渡线段，分别采用台阶法、CRD 法及双侧壁导坑法施工，断面类型多，转换频繁；而且存在多处突变断面，断面开挖轮廓相差大，采用扩挖、反向回挖等常规方法不能完成大幅度突变断面转换。为解决大幅度突变断面转换难题，提出在线间增设临时横通道进行转换施工的方案。采用有限元的方法模拟隧道施工过程，对地表沉降进行预测，结合预测结论，制定了减小沉降的针对性措施。通过工程实际应用，解决了大幅度突变断面转换难题，同时确保了渡线区地表沉降满足相关规范及设计要求。%The section of Ganjiakou Station to Yuyuantan East Station for Beijing Subway Line 16 is located below the San-lihe Road and the surface subsidence requirement is strict.A period of crossing the line is located in each interval ends and the step method,the CRD method,the two-side heading construction method are used.The section conversion can not be completed with the method of expanding and reverse digging due to the multiple section types,frequent conversion,more mutation cross sections and the significant difference of section excavation contour.Temporary cross channel transfer be-tween the line is put forward in order to solve transformation problem of large mutation section.Ground settlement is predic-ted by the method finite element analysis and the measures are taken.Through the practical application of the project,it can meet the construction requirements,and achieves better results.