半明半暗法在公路隧道洞口段的研究

Study on Construction of Portal Section of Half-buried Tunnel

隧道洞口段设计与施工的优劣,直接关系到隧道的安全进洞及今后的安全运营。以黄衢南高速公路蕉坞隧道洞口设计施工为例,探讨了半明半暗施工方法的特点及其对隧道洞口稳定性的影响。介绍了半明半暗法隧道进洞方案在蕉坞隧道中的具体施工步骤。为验证该方法的合理性,本文采用数值分析方法对最终方案进行了数值模拟,并与现场监测数据进行了比较,结果表明了"半明半暗"法进洞方案的合理性与可行性。其工程经验对今后类似的工程具有一定的借鉴与指导意义。

The success or fail in design and construction of tunnel portal is directly related to the safety of tunnel excavation and its future operation.Based on design and construction of Qiaowu tunnel of Huang-Qu-Nan expressway,the stability of tunnel portal section by the method of half-buried tunnel construction was discussed.Application of half-buried construction method was introduced and numerical simulation was used to analyze the final scheme,meanwhile,the numerical data and the in-situ monitoring data in the tunnel construction have been compared.Results show that application of the method of half-buried at Qiaowu tunnel portal section was successful and effectual,and the result given in this paper could be used as a primary guidance to the design for underground cavern.