基于现场围岩压力监测的黄岩子隧道衬砌结构安全性评价

Safety Evaluation of Lining Structure for Huangyanzi Tunnel Based on On-site Pressure Monitoring of Surrounding Rockmass

对隧道衬砌结构进行安全性评价可以有效的指导施工方案和修正隧道设计以便更加经济、安全地施工。作为邢汾高速公路邢台至冀晋界段全线隧道中的长隧道之一的黄岩子隧道,评价其衬砌结构安全状态对全线隧道稳定性分析具有重要意义。通过改进的现场围岩压力监测手段,对黄岩子隧道出口右幅YK80+383处断面的围岩压力进行实测,并将实测围岩压力值与《公路隧道设计规范》(JTG D70-2004)中的设计围岩压力值进行对比分析。对比结果显示,实测围岩压力值远小于设计围岩压力值,基于规范设计围岩压力值进行设计的黄岩子隧道衬砌结构过于保守,安全储备在合理要求的基础上偏大,具有较大的优化空间。研究结论为黄岩子隧道施工安全评价提供有效的支持,为今后类似衬砌结构设计方案优化调整提供了实测数据。

Tunnel lining safety evaluation can effectively guide the construction program and correct the tunnel design in order to facilicate more economical and safe construction. Huangyanzi tunnel is one of the long tunnels across the border of Xingtai-Jijinjie section route,Xingtai-Fenyang expressway,evaluating the safety status of its lining structure is important for the full range of tunnel stability analysis. Here,the pressure of surrounding rock at the YK80 ＋ 383 cross-section of Huangyanzi tunnel right outlet was measured with the improved on-site monitoring methods,and then compared with the designated pressure value given in the Code for Design of Road Tunnel（ JTG D70-2004）. The comparison results indicate that the measured rock pressure value is far less than the designated value of the Code. The design of Huangyanzi tunnel lining based on the code is so conservative that reasonable optimization is still needed. The research will provide effective support for construction safety of the project and sufficient basis for design optimization and adjustment.