应用从奥地利引进的大型岩土分析软件FINAL分析了不同围岩参数对运行期衬砌受力影响的敏感性,得知围岩参数的准确性对于衬砌厚度的设计有较大影响;根据江源隧洞现场监测资料反演得出分析洞段围岩参数,以此参数为依据研究了4种支护方案下运行期衬砌的受力情况:①不考虑一次支护条件;②考虑一次支护钢拱架;③考虑洞段整体超挖衬砌厚度增加情况;④同时考虑②、③情况。分析结果表明:在考虑一次支护的作用后,衬砌轴力及应力明显降低;洞室整体性超挖相当于增大了衬砌的厚度,使得衬砌轴力增大,应力减小。
The geotechnical software FINAL introduced from Austria is used to analyze that influence of mechanical parameters of surrounding rock on the sensitivity of lining of hydraulic tunnel at operating period.The lining stress sensitivity under the different rock parameters is obtained.The above analysis shows that the accuracy of the surrounding rock parameters have a greater impact on the design of the lining thickness;the parameters of surrounding rock can be determined through the back analysis method in terms of in-situ monitored data of Jiangyuan Tunnel.On the basis of these parameters,the lining subject to the stress conditions in the operating period under supporting schemes of 4 kinds is studied: ①Don't consider a conditional effect of shoring;② consider one steel support influence;③Consider an increase in lining thickness in the case of overall over excavation in the tunnel section;④Also considered②,③.The analytical results indicate: after considering one-time supporting role,the lining axial force and stress obviously decrease;overall over-excavation of the tunnel room means equally to increase lining thickness,whereby making lining axial force increase and stress decrease.