高速铁路隧道明挖段失稳机理分析与加固技术

发布时间：2018-11-17 06:42

【摘要】：文章针对田家山隧道明挖段堆积体失稳滑塌问题,采用FLAC3D软件建立了三维仿真模型,并结合现场地表监测点的实测数据,首先从堆积体塑性区分布、位移增量以及锚杆轴力分布等情况,对隧道明挖段开挖支护的全过程进行了复核分析。结果表明:大里程方向导向墙开裂滑塌是由于剪切屈服单元与拉伸屈服单元贯通形成塑性滑层,从而导致浅层牵引式滑塌;小里程方向大变形是由于堆积体内部向隧道临空区移动,导致地表出现拉伸型裂缝,进而表现为蠕滑拉裂。然后对比分析了加固前后隧道上覆堆积体及围岩的变形特征,并优化了隧道开挖的工法、工序。最后根据数值复核结论以及国内外的工程经验,提出了综合加固处理措施,使隧道安全穿越了堆积体,其结论可为今后类似工程提供参考。
[Abstract]:In this paper, aiming at the problem of instability and collapse of deposit in open excavation section of Tianjiashan Tunnel, a three-dimensional simulation model is established by using FLAC3D software. Combining with the measured data of site surface monitoring points, the distribution of accumulation body plastic zone is firstly analyzed. The displacement increment and the axial force distribution of the bolt are analyzed and the whole process of excavation and support in the open excavation section of the tunnel is analyzed. The results show that the crack collapse of the guide wall with large mileage is due to the plastic sliding layer formed by the shear yield element and the tensile yield element, which leads to the shallow traction slide. The large deformation in the direction of small mileage is due to the internal movement of the accumulation body to the tunnel goaf, which leads to the appearance of tensile cracks on the surface of the earth's surface, and then the creeping and pulling cracks. Then, the deformation characteristics of the overlying accumulations and surrounding rocks before and after reinforcement are compared and analyzed, and the tunnel excavation method and procedure are optimized. Finally, according to the conclusion of numerical review and the engineering experience at home and abroad, the comprehensive reinforcement measures are put forward to make the tunnel pass through the accumulation body safely. The conclusion can be used as a reference for similar projects in the future.
【作者单位】：合肥工业大学宣城校区建筑工程系;中国地质大学(武汉)工程学院;湖南城市学院土木工程学院;
【基金】：湖北省自然科学基金重点项目(NO.2013CFA110) 合肥工业大学宣城校区博士产学研启动专项资助基金(NO.XC2015JZBZ21)
【分类号】：U455.4

【共引文献】