论文部分内容阅读
汾渭盆地是我国乃至世界上地裂缝最为发育、灾害最为严重的地区。考虑在漫长的地质历史过程中黄土的流变特性对地裂缝破裂扩展模式的影响,采用分级循环加卸载方式,对西安地区长安地裂缝(fc1)带Q3原状黄土进行了不同围压下的固结不排水三轴流变特性试验,得到了地裂缝带Q3原状黄土的蠕变加、卸载曲线和应变速率与时间关系曲线。试验结果表明,不同围压下地裂缝带Q3原状黄土表现为低应力下为减速蠕变,高应力下为减速蠕变和等速蠕变的特征。并基于统一流变力学模型理论,建立了适用于西安地区地裂缝带Q3原状黄土的三维蠕变本构模型,获得了相应的本构模型参数。该成果为研究隐伏地裂缝破裂扩展模式及其力学机制奠定了基础。
Fen-Wei basin is the most developed in China and the world, the most serious disaster areas. Considering the influence of the rheological characteristics of loess on the crack propagation mode during the long geologic history, the cyclic loading and unloading method was adopted to simulate the Q3 undisturbed loess with fc1 belt in Chang’an of Xi’an Results of the undrained triaxial rheological tests show that creep plus unloading curves, strain rates and time curves of Q3 undisturbed loess in ground fissure zone are obtained. The test results show that the Q3 undisturbed loess under the different confining pressure shows slow-creep under low stress and slow-creep and constant-velocity creep under high stress. Based on the unified rheological model theory, a three-dimensional creep constitutive model for Q3 intact loess in fissure zone in Xi’an is established, and corresponding constitutive model parameters are obtained. This result lays the foundation for studying the mode of implicit crack propagation and its mechanical mechanism.