关键词: MogiCoulomb强度准则, 圆形隧洞, 围岩-衬砌结构, 渗流效应, 衬砌渗透系数, 衬砌厚度

Abstract:  In order to study the influence of pore water on the stability of hydraulic tunnel during construction, the MogiCoulomb strength criterion is adopted based on the elasticplastic theory, and the elastoplastic zone of liningsurrounding rock is taken as research object. The analytical solutions of circular tunnel under different working conditions are derived, including the stress of surrounding rocklining structure, tunnel wall displacement, and surrounding rock plastic zone radius. Relying on a hydraulic tunnel project in Xinjiang, the calculation and analysis are carried out to obtain the influence laws of seepage effect, lining permeability coefficient, and lining thickness on the stability of surrounding rocklining structure. The conclusions are as follows: （1）Seepage effect will greatly change the stress distribution of lining and surrounding rock, reducing the support reaction of lining to surrounding rock can worsen the tunnel stability. （2）Reduction of the lining permeability coefficient will increase the seepage water pressure at the interface between lining and surrounding rock, reducing the reaction force can increase the radius of surrounding rock plastic zone and tunnel wall displacement. （3）Increasing the lining thickness will change the distribution of seepage field and weaken the support amplification effect caused by increasing lining thickness, which can significantly limit the development of surrounding rock plastic zone in the initial stage, but the subsequent effect is poor.

Key words:  , MogiCoulomb strength criterion, circular tunnel, surrounding rocklining structure, seepage effect, lining permeability coefficient, lining thickness