土质隧洞围岩稳定性分析与设计计算方法探讨

Exploration of Stability Analysis and Design Calculation Methods of Surrounding Rocks in Soil Tunnel

论述了以洞周位移量与围岩塑性区大小作为围岩稳定性经验判据的不足，依靠模型试验与力学计算，分析了隧洞破坏机理与形式。由此提出将基于有限元强度折减法求出的围岩安全系数作为稳定分析判据，这种判据有严格的力学依据，有统一的标准，而且不受其他因素的影响。研究了隧洞围岩安全系数（剪切安全系数、拉裂安全系数）与衬砌安全系数的算法以及隧洞设计计算方法。最后以黄土洞室为例，给出了土体隧洞设计计算新方法，并对土体隧洞今后的研究方向提出了几点展望。

The paper proves the deficiency of judging the stability of tunnel by the empirical criterion of displacements of tunnel perimeter or sizes of plastic zones of surrounding rocks. Destruction mechanisms and forms of tunnel are analyzed based on the model tests and the mechanical calculations. The paper puts forward taking safety factors calculated by the strength reduction finite element method as the stability criterion. This criterion is based on the strict mechanic foundation, has a universal standard and can not be affected by other factors. Safety factors of rock, including shear safety factor and tensile safety factor, safety factor of lining and design calculation methods of tunnel are studied. Take loess tunnel for instance, design calculation new methods of tunnel are introduced. It takes an outlook of the future research direction in the end.