地铁浅埋暗挖法穿越既有桥梁施工变形控制  

Deformation Control of Crossing Over Existing Bridge by Shallow Tunneling

作　　者：苏洁[1] 张顶立[1] 牛晓凯[1,2] 

机构地区：[1]北京交通大学,隧道及地下工程教育部工程研究中心,北京100044 [2]北京市市政工程研究院,北京100037

出　　处：《北京工业大学学报》2009年第5期611-620,共10页Journal of Beijing University of Technology

基　　金：北京市科技计划重点资助项目(D08050603130804);国家高技术研究发展计划“863”资助项目(2006AA11Z119).

摘　　要：地铁浅埋暗挖法穿越既有桥梁施工时,会对邻近桥梁桩基产生不利影响,使得既有桥梁产生较大的安全使用风险.因此在穿越施工时,应当采取必要的技术措施对这种不利变形进行控制,以保证既有桥梁结构安全.以北京地铁5号线18标区间隧道浅埋暗挖法穿越雍和宫桥施工为例,给出隧道施工穿越既有桥梁的变形控制方案.首先,在施工前通过数值模拟并结合工程经验,确定桥桩变形的阶段及总体控制标准,为施工过程控制提供参照指标;其次,穿越前在桥区类似地层中设置监测主断面进行监测试验,得到桥区地层变形基本规律,同时进行注浆试验,确定出适宜的注浆材料及注浆参数,为优化施工方案提供依据;最后,在施工中依据工前确立的阶段控制标准,通过对各主要施工步序进行动态控制,来实现总体的控制目标.监测结果表明:桥梁实际差异沉降量仅为控制值的58.4%,达到了控制要求,保证了既有桥梁的安全.该控制方案的成功应用,可为类似工程提供重要的借鉴及指导.When shallow tunnels crosses through existing bridges,there will be unfavourable influence on adjacent bridge pile,and even more serious safety risk for exsiting bridges during operating.So,to control this unfavored deformation,necessary techniques must be adopted in order to keep the existing bridge safe during construction.In this paper,by taking Yong He Gong station to He Ping Li North Street station interval of line 5 in Beijing for example,deformation control method of crossing over existing bridge by shallow tunneling is presented.Firstly,combinating numerical modelling with project experiences before tunneling,the stage and total control criterion of bridge pile deformation are detemained.Secondly,according to monitoring test of main monitoring section in bridge areas,soil deformation rule in this area are obtained. At the same time,grouting test is adopted to determine suitable grouting material and parameters which supply evidence for optimizing methods.Finally,based on the stage control criterions,dynamic control is adopted for main construction steps to realize total control target during tunnelling.The measured data shows that actual differential settlement of bridge is up to 58.4%of control standard,meets the control requirement and makes existing bridge safe.Successful application of this control method can provide important reference for similar projects.

关 键 词：浅埋暗挖法 既有桥梁 变形控制 注浆试验 监测试验 

分 类 号：U455[建筑科学—桥梁与隧道工程]