为探明孔隙水对施工期水工隧洞稳定性的影响，基于弹塑性理论，采用MogiCoulomb强度准则，以衬砌-围岩弹塑性区为研究对象，推导圆形隧洞不同工况时围岩-衬砌结构应力、隧洞洞壁位移和围岩塑性区半径的解析解。 依托新疆某水工隧洞工程展开计算分析，得到渗流效应、衬砌渗透系数和衬砌厚度对围岩-衬砌结构稳定性的影响规律。得出以下结论： 1)渗流作用会极大改变衬砌和围岩的应力分布，减小衬砌对围岩的支反力会使隧洞稳定性变差； 2)降低衬砌渗透系数会增大衬砌-围岩交界面渗透水压力，减小支反力会使围岩塑性区半径和洞壁位移有所增大； 3)增加衬砌厚度会改变渗流场分布，弱化增加衬砌厚度提供的支护增幅效果，这在开始阶段能明显限制围岩塑性区发育，但后续效果不佳。
In order to
study the influence of pore water on the stability of hydraulic tunnel during
construction, the MogiCoulomb strength criterion is
adopted based on the elasticplastic theory, and the
elastoplastic zone of liningsurrounding rock is taken
as research object. The analytical solutions of circular tunnel under different
working conditions are derived, including the stress of surrounding rocklining 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 rocklining 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.
