荆州长江公铁两用特大桥引桥承台施工技术  

Construction Technology of Approach Span Platform of Jingzhou Yangtze River Highway and Railway Shared Super-long Bridge

作　　者：赵强[1] 

机构地区：[1]中国铁道科学研究院铁道建筑研究所,北京100081

出　　处：《铁道建筑》2016年第3期45-49,共5页Railway Engineering

摘　　要：蒙西华中铁路荆州长江公铁两用特大桥是我国第一座跨越长江的重载铁路桥梁。本文从承台基坑支护及开挖、桩头环切和垫层施工、钢筋工程、模板工程、混凝土工程5个方面详细介绍了其引桥承台的施工技术。实践表明:根据基坑开挖深度、土层性质、周围环境及地下水情况,分别采用放坡开挖、钢板桩支护开挖的施工方案,可节约成本;对于地下水位较高的基坑,采用插打钢板桩止水、设置截水、排水和抽水设施等措施可降低地下水位;放坡开挖时易造成基坑坍塌,采用钢板桩支护能够避免坍塌,降低基坑开挖难度;采取温控监测和布置冷却水管相结合的手段能够有效地控制承台内外温差,避免温度裂纹的产生。Jingzhou Yangtze River highway and railway shared super-long bridge on Mengxi- Huazhong Railway is the first heavy rail bridge across the Yangtze River. This article introduced the platformconstruction technology of approach bridge fromfive aspects,including excavating and supporting foundation pit,cutting annularly at pile top,bedding course construction,steel reinforcement work,formwork installation and concrete work. According to the depth of excavating foundation pit,soil properties,surrounding environment and groundwater conditions,two excavation methods with slope or steel sheet piles,can be used to decrease cost. If the ground water level is relatively high around the foundation pit,the measures ofinserting steel sheet pile to retain water or installing facilities of cutting,draining and pumping water can be used to lower the ground water level. Excavation with slope may cause collapse of foundation pit while steel sheet pile supporting can be useful to avoid collapse and reduce the driving difficulty. The combination of monitoring temperature and using cooling water pipes can efficiently control the temperature difference between inside and outside of platform,avoiding temperature crack.

关 键 词：长江公铁两用特大桥 承台施工 大体积混凝土施工 基坑开挖 

分 类 号：U448.12[建筑科学—桥梁与隧道工程]