高地应力软岩隧道大变形失稳机理及支护对策研究

Instability Mechanism and Supporting Measure for Highway Tunnel with High Ground Stress and Soft Surrounding Rock

对于高地应力软弱围岩隧道,大变形失稳破坏是一种发生频率较高且危害较大的地质灾害,其支护对策已成为重大的技术难题。以武都西隧道为工程实例,采用现场工程地质调查、理论分析、现场监测等手段,系统研究了其隧道围岩及支护结构的变形特征及失稳机理,从而有针对性地采用"钢花管注浆加固边墙、增设护拱并充填泡沫混凝土、基底注浆加固"支护对策,最后利用现场监测手段对支护效果进行了验证,结果显示该支护对策能够达到预期处治效果,可在类似高地应力软岩隧道中进一步推广应用。

For the tunnel with high ground stress and soft surrounding rock,the deformation instability is a great harm geological hazard which occurs frequently.Its supporting measure has become an important technique issue.Based on the Wuduxi Tunnel,the characteristics of deformation and instability mechanism of surrounding rock and supporting structure are analyzed in this paper by means of the engineering geological investigation,theoretical analysis and field monitoring.The supporting measures include using the steel floral tube to back up sidewall,adding support arch and filling foamed concrete,and grouting reinforcement in basement.Finally,field monitoring is used to check the supporting effect.The result shows that the supporting measure could achieve the desired treat effect and it has reference meaning to similar engineering.