下穿高速公路的浅埋大跨隧道开挖力学行为分析

发布时间：2018-05-21 21:16

本文选题：浅埋深 + 大跨度　；参考：《现代隧道技术》2017年05期

【摘要】：深圳市红棉路隧道具有埋深浅(约6 m)、跨度大(16 m左右)、周围围岩软弱、下穿机荷高速公路的距离长等特点。由于机荷高速公路车流量非常大、动态荷载强,因此该隧道施工难度高、风险极大。为研究该隧道开挖过程的力学行为,文章通过数值计算及现场测试方法,获得了隧道下穿高速公路施工过程中地表沉降、隧道拱顶沉降、掌子面挤出位移,初期支护钢拱架应力以及二次衬砌应力的动态变化规律。研究结果表明,在隧道开挖过程中,掌子面前方先行变形的影响范围为1~1.5倍洞跨。隧道掌子面进行锚喷支护加固措施,对减小隧道掌子面的挤出位移作用效果明显。同时,需合理确定支护时机,适当优化施工工序,加快隧道断面闭合时间,加强监控量测,确保隧道成功穿越机荷高速公路。
[Abstract]:The Shenzhen Khmer Cotton Road Tunnel is characterized by shallow buried depth (about 6 m), large span of about 16 m, weak surrounding rock and long distance from the underpass motorway. Because of the high traffic flow and strong dynamic load, the tunnel construction is very difficult and the risk is great. In order to study the mechanical behavior of the tunnel excavation process, the surface settlement, tunnel vault settlement and face extrusion displacement during the construction of the tunnel underpass highway are obtained by numerical calculation and field test. Dynamic variation law of stress and secondary lining stress of initial support steel arch frame. The results show that in the course of tunnel excavation, the first deformation in front of the face of the tunnel has an influence range of 1 ~ 1.5 times of the span of the tunnel. The effect of bolting and shotcreting reinforcement on tunnel face is obvious to reduce the extrusion displacement of tunnel face. At the same time, it is necessary to determine the supporting time reasonably, to optimize the construction procedure properly, to speed up the closing time of tunnel section, to strengthen the monitoring and measurement, and to ensure that the tunnel passes through the mechanical-loaded highway successfully.
【作者单位】：中南大学土木工程学院;高速铁路建造技术国家工程实验室;中国建筑第五工程局有限公司;广东省南粤交通仁博高速公路管理中心;
【基金】：国家自然科学基金重点项目(U1361204) 湖南省研究生科研创新项目(CX2016B050) 中铁一局科技计划项目(2012A021)
【分类号】：U455.4

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