降雨入渗对流变介质隧道边坡稳定性的分析

Analysis of stability of tunnel-slope with rheological medium under rainfall infiltration

针对在建公路边坡,受切破、降雨和施工等影响引起边坡及铁路偏压隧道的严重变形,采用三维有限差分数值模拟。计算程序FLAC3D以塑性力学、流变力学和渗流力学为理论依据,利用改进的黏弹塑性流变模型,分析山区挖方边坡和坡顶隧道联合稳定性的过程。通过自编的计算程序,对隧道边坡各种工况力学-流变-渗流进行数值模拟计算,根据计算所得的位移和孔隙压力等值线分布特征,分析其潜在滑动带和隧道破坏影响区,确定其重点加固的范围。应用结果表明,工程抗滑桩桩顶位移监测数据与数值计算结果比较吻合,改进的黏弹塑性流变模型能较好地描述岩土类材料的流变特性。

Pointed to being built highway slope, the slope displacement with the effect of bias tunnel shows to vary because of cutting slope, rainfall and construction. The combined stability between cutting slope and bias tunnel in mountainous area is analysed by the finite difference program FLAC^3D. The combined stability are studied and the scope is ascertained in slope without cutting, reinforcement and rainfall, according to the displacement contours and the distribution character of the pore water pressure and shear failure region on base of plastic mechanics, theologic mechanics and seepage mechanics with a modified viso-elastoplastic creep model. The comparison is carried out to reinforce slope, which the combined reinforcement is accepted as double antislide pile. The results show that the testing displacement data are consistent with numerical calculation. Simultaneously, the creep model is felicitous to characterize the rheological behaviour of rock and soil.