王北凹隧道洞口及浅埋段安全风险评估及控制措施

受山区地形的限制，山岭隧道洞口及浅埋段地质条件一般较为恶劣，容易造成洞口失稳、大变形等风险，对隧道的安全施工形成较大隐患。基于王北凹隧道的地质勘察资料、水文地质资料及相关设计资料，通过专家调查法对隧道洞口及浅埋段风险源进行辨识与排序，对其失稳可能发生的风险等级进行了分析，并提出了相应的风险控制措施。

Safety Risk Assessment and Control Measures for Shallow-buried Portal Section of Wangbeiao Tunnel

As being limited with mountainous topography,there is normally quite seriousgeological conditions for the shallow-buried portal section of tunnels,which will easily cause risks as as portal instability or large deforma-tion and may lead to quite high danger for safety of tunnel construction.Based on geological survey,hydrogeolo-gy and design data of Wangbeiao Tunnel,the risk factors for the shallow-buried portal section of tunnel have been recognized and sorted by experts investigation method,the risk level of the possible instability has been ana-lyzed,and the risk control measures have been put forward.