裂隙岩体三维非稳定渗流场与应力场耦合分析

Coupled unsteady 3D seepage and stress fields in fracture rock mass

本文从宏观的角度把裂隙岩体作为等效连续介质模型,编制三维有限元程序对裂隙岩体进行非稳定渗流场与应力场耦合分析,并应用工程算例比较分析研究非耦合与耦合作用条件下三维非稳定渗流场和应力场变化规律。研究结果表明该方法是可行的;与非耦合作用相比,考虑耦合作用减少了断面的渗流量,坝基应力场增大;库水位下降具有一定的滞后效应,且下降速率越大,滞后效应越明显。因此,在岩土体分析中用等效连续介质模型进行三维非稳定渗流场与应力场耦合分析研究,对水利工程、岩土工程、煤炭开采及石油二次开发等领域多场耦合作用研究具有广泛参考和应用研究价值。

With fracture rock mass considered as equivalent continuum medium,a FEM model for analysis of the coupled unsteady 3D seepage and stress fields is developed,and the cases of coupling and no-coupling are analyzed in an engineering example.The results indicate that it is feasible to analyze the seepage and stress coupling in densely fractured rock mass.In comparison with the no-coupling case,seepage-stress coupling reduces the seepage rate and increases the stress of dam foundation.It is also found that when the water level falls,the fall of hydraulic head in the dam foundaion lags in time.A greater falling rate leads to a longer lag.Thus it is necessary to consider the coupling of fracture rock mass.The presented method would have a wide application to the study of multi-fields coupling effect in hydraulic engineering,geotechnical engineering,coal exploiting,second-developed fossil oil,etc.