超大直径穿黄河盾构隧道施工影响分析及韧性提升研究

Analysis of Construction Influence and Study of Tenacity Enhancement of Super-large Diameter Shield Tunneling across Yellow River

摘要:

针对盾构隧道穿越施工引起建（构）筑物沉降变形及受大变动荷载作用导致结构使用性能降低的问题，依托济南黄岗路穿黄隧道工程，做出以下研究工作：预测外径16.8 m盾构隧道下穿黄河大堤施工引起的沉降变形，从设计、施工角度提出安全控制措施；分析外径16.8 m盾构隧道在运营期间面临的大变动荷载问题，提出结构韧性提升对策。研究结果表明：超大直径盾构隧道穿越施工时引起的大堤沉降满足变形控制要求；通过合理设计穿越线路、管片设置剪力销和增设注浆孔预埋件、设置掘进试验段、加强施工过程管理、加强监测等措施，可大幅降低穿越施工风险；按多工况内力包络进行配筋设计、采用钢纤维混凝土管片和增强管片连接，是提升隧道结构韧性的有效对策。

Abstract:

For the settlement and deformation of buildings (structures) caused by shield tunneling construction and the reduction of structural performance due to the action of large dynamic loads, relying on the Jinan Huanggang Road Crossing Yellow River Tunnel Project, the research is implemented to predict the settlement and deformation caused by the construction of a shield tunnel with an outer-diameter of 16.8 m crossing under the Yellow River embankment, and to propose the safety control measures from the perspectives of design and construction. And the problem of large variable loads faced by the shield tunnel with an outer-diameter of 16.8 m during operation is analyzed and the countermeasures for the tenacity enhancement of the structure are put forward. The results show that the settlement of embankment caused by the super-large diameter shield tunneling meets the requirements of deformation control. The risk of crossing construction can be greatly reduced through the reasonable design of the crossing route, setting up of shear pins in the segments and adding of embedded parts for grouting holes, setting up of tunneling test sections, strengthening of construction process management, enhancing of monitoring and the other measures. The reinforcement design based on the internal force envelope of multiple working conditions and the use of steel fiber reinforced concrete segments and reinforced segment connections are effective countermeasures to enhance the tenacity of tunnel structures.