A method for determining the critical stable section of tunnel based on parametric modeling and strength reduction method was proposed.By defining the key point coordinates of the numerical model,the parametric modeling of multi-center circular cross-section tunnel based on FLAC3D was realized.The ratio of the safety factor obtained by strength reduction calculation to the target value of the safety factor is defined as the size adjustment factor.When the size adjustment factor is greater than 1,it means that the calculated safety factor is greater than the target safety factor,and the tun-nel excavation section is less than the critical stability section.The tunnel geometry size can be multi-plied by the size adjustment coefficient,so that the tunnel excavation section is enlarged in equal pro-portion.On the contrary,it means that the tunnel excavation section is larger than the critical stable section,and the tunnel geometry size is multiplied by the size adjustment coefficient,so that the tun-nel excavation section is reduced in equal proportion.Through FLAC3D built-in FISH language pro-gramming,according to the size adjustment coefficient,the tunnel excavation section is adjusted in e-qual proportion until the size adjustment coefficient is equal to 1,and the iteration is terminated to ob-tain the final critical stable section.
关键词
参数化建模/临界断面/强度折减法/安全系数/台阶法
Key words
parametric modeling/critical stable cross section/strength reduction method/factor of safety/bench excavation
维普
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