考虑应变软化、剪胀和渗流的水工隧洞解析解

Analytical solutions of hydraulic tunnels considering strain softening, shear dilation and seepage

基于统一强度理论和弹脆塑性软化模型,考虑不同工况下主应力顺序、岩石应变软化、剪胀和渗流等综合影响,推导了圆形水工压力隧洞应力和洞壁位移解析解。通过工程算例,比较本文方法与传统方法的不同,说明考虑第一主应力的变化和渗流体积力更符合工程实际,并得出统一强度理论参数、软化特性参数和剪胀特性参数对隧洞切向应力和洞壁位移的影响特性。隧洞设计时,应依据围岩材料特性合理地选取统一强度理论参数,并考虑由于软化特性参数和剪胀特性参数的减小对隧洞切向应力和洞壁位移增大的影响。该结果为圆形水工压力隧洞弹塑性分析提供了理论依据,对工程设计有一定的参考价值。

Based on the unified strength theory and the elastic-brittle-plastic softening model, analytical solutions of stress and tunnel wall displacement for circular hydraulic pressure tunnels are deduced considering the principal stress orders under different engineering conditions, rock strain softening, shear dilation and seepage. Comparisons are made between the results obtained in this paper and those of the traditional methods through an engineering example. It can be found that it more accords with the engineering practice to consider the variation of the maximal principal stress and volumetric force of seepage. The effects of the unified strength theory parameter, strain softening characteristic parameters and shear dilation characteristic parameter on the tunnel tangential stress and tunnel wall displacement are discussed. In tunnel design, the unified strength theory parameter should be reasonably adopted according to surrounding rock material properties. The increasing effects on the tunnel tangential stress and tunnel wall displacement also should be considered with the decrease of the strain softening characteristic parameters and shear dilation characteristic parameter.