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- 2018
浅埋暗挖隧道CRD工法优化与现场试验研究
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Abstract:
CRD工法是浅埋暗挖隧道的常用施工方法,但存在施工工序复杂,隔墙拆除困难,进度慢等问题。为改进CRD工法存在的不足,以杭州紫之隧道浅埋暗挖段为研究对象,采用理论分析、数值计算和现场试验等手段,对CRD工法的开挖工序、临时支护结构型式、开挖步距以及临时支护拆除方式等关键技术进行优化研究,探索出一套完整的优化工法体系,并结合现场试验进行验证。研究结果表明:优化工法提高了初期支护闭合成环速度,保证了整体支护结构在施工过程中的合理转化,有效地控制了拱顶及地表沉降的发展,同时,下台阶作业空间增大,提高了开挖及出渣效率,平均进度提高到原工法的1.45倍。
CRD excavation method is a common construction method for shallow buried tunnel, but there are some problems such as complicated construction process, difficult demolition of partition wall, slow progress and so on. In order to improve the shortcomings of CRD construction method, this paper took an urban underground road tunnel in Hangzhou as a research object. Based on theoretical analysis, field test and numerical simulation, the optimization for the key technologies of CRD was studied, including temporary support structure type, excavation pitches and temporary supporting of removal schemes. A set of optimal excavation method was derived and then verified through the field test. The results show that: the optimal method improves the closing speed of primary support, ensures the overall support structure reasonable transformation in the construction process, and controls the development of crown and ground settlement effectively. At the same time, the method increases the working space of lower bench, and the average progress is increased to 1.45 times of the original construction method