陈彦军

摘 要：该项目为灞河下穿明挖隧道，是十四运会重难点项目。隧道全长2896m，下穿600m全宽主河道，隧道距橡胶坝坝体不足100m，隧道底界距淤泥层顶约14m淤泥，淤泥沉淀时间短，呈软塑～流塑状，超深泥流态淤泥开挖围护难度大，可参考经验少，通过总结研究及实践，攻克了关键技术难关，提高了施工效率，节约了投资，保证了安全质量及工期。

关键词：乒乓球;显示动力学理论;新材料;碰撞动力学

中图分类号：U655.5 文献标识码：A 文章编号：1001-5922（2021）05-0173-04

Research and Application of Key Technologies of Reclaimed Material Cofferdam for Ultra-deep Muddy Undercrossing Tunnel

Chen Yanjun

（Shaanxi Railway Institute，Weinan 714099， China ）

Abstract：This project is an open-cut tunnel under the Bahe River， which is an important and difficult project of the 14th National Games. The total length of the tunnel is 2.896 kilometers， which passes through the main river channel with a width of 600 meters. The distance between the tunnel and the rubber dam body is less than 100 meters， and the bottom boundary of the tunnel is about 14 meters away from the top of the silt layer. The silt has a short settling time， which is in the form of soft plastic ～ flowing plastic. It is difficult to excavate and protect the ultra-deep mud flow silt， and there is little reference experience. By summarizing the research and practice， the key technical difficulties have been overcome， the construction efficiency has been improved， the investment has been saved， and the safety quality and the construction period have been guaranteed.

Key words：underpass tunnel; Ultra-deep silt; Enclosure; work efficiency

西安浐灞生態区灞河隧道隧道下穿600m全宽主河道，主线设计总长2896m，双向六车道，并在过河段设置紧急逃生通道及综合管廊，隧道断面为矩形单箱三室，钢筋混凝土结构，空间高度为6.2m，隧道采用明挖工艺。该项目隧道2020年3月份中标，计划2021年6月份竣工通车。

1 项目面临的重难及需攻克的关键技术

（1）灞河因城市景观需求，在下游位置设置了橡胶拦水坝进行蓄水，在坝体一侧，形成了平均深达到7m以上的淤泥，因淤泥沉淀时间短，表面呈泥流态，不能作为围堰的直接持力层，即使是加固淤泥层，机械无法直接在淤泥层顶部施工。

（2）隧道设计位置距橡胶坝坝体较近（约 75～120m），隧道底界距淤泥层顶约14m，隧道采取明挖开挖方式并下穿主河道，且灞河底下的土层是粉质粘土与细、中砂交替出现，存在承压水，开挖基坑易产生基坑突涌，类似可参考经验少，需要多种工艺的相互结合才能有效解决围护安全，其设计及施工难度大。

3）该项目为2021年十四届运……