科研之友
微信
新浪微博
Facebook
分享链接
摘要
On the basis of the upper bound theorem, the stability of shield tunnel face under seepage effect was analyzed using a three-dimensional discrete mechanism. Under the consideration that the seepage effect can be equated to the power rate of pore pressure, the method for seepage stability analysis under three-dimensional discrete failure mechanism was proposed to derive the corresponding formula of the power rate of pore pressure. Based on the fitting equation of the pore pressure distribution around the excavation face, the total power rate of pore pressure in the three-dimensional discrete failure mechanism was calculated. According to the principle of reciprocal internal and external power, the expression of critical support force of excavation face under seepage flow was further derived, and the optimum upper solution for the critical support force was obtained. The results of the critical supporting force obtained were verified by numerical simulation and existing examples, which proved the effectiveness of the proposed method. This method was used to study the influence of water table height and permeability performance on the critical supporting pressure, including the shape of the failure mass. Some calculation charts were also provided, to meet the need of rapid calculation and analysis in engineering.
