短时冻区冰雪消融对残积土坡非平衡渗流与稳定性作用机理分析

发布时间：2018-05-26 17:37

本文选题：残积土坡 + 短时冻区　；参考：《工程科学与技术》2017年06期

【摘要】：为揭示短时冻区冰雪消融对残积土坡非平衡渗流与稳定性作用机理,分别基于非饱和渗流模型与非平衡流模型,分析福建省冰雪消融诱发某一边坡的失稳原因,并研究不同大孔隙直径、间距、弯曲率及长度对考虑非平衡流的边坡水分场与安全系数的影响规律。结果表明:非平衡渗流相比于非饱和渗流对于边坡稳定性的影响明显更大,采用非平衡流理论可合理解释冰雪消融条件诱发残积土边坡失稳机理;增大大孔隙直径可增大大孔隙域与周围基质域的水分交换量,减缓水流的优先传导作用并使孔隙水压力增长,从而使边坡稳定性降低;增加大孔隙长度,延长了水分的传导路径,削弱大孔隙域内水分的积累效果,对于边坡安全系数有一定影响;增加大孔隙弯曲率对于基质域含水率及边坡安全系数影响很小,可忽略不计。边坡安全系数与大孔隙间距之间存在安全系数最小的临界间距,间距过大导致大孔隙群的优先流效应无法发挥;间距过小导致大孔隙间非平衡流相互叠加与干扰,削弱大孔隙对于深处孔隙水压力的影响。因此,对于短时冻区冰雪消融诱发含大孔隙边坡的失稳问题,应考虑非平衡流的影响,尤其是大孔隙间距与长度的影响。
[Abstract]:In order to reveal the mechanism of ice and snow ablation on non-equilibrium seepage and stability of residual soil slope in short-time frozen area, the reasons of instability of a slope induced by ice and snow ablation in Fujian Province were analyzed based on unsaturated seepage model and non-equilibrium flow model, respectively. The influence of different macropore diameter, spacing, bending ratio and length on the water field and safety factor of slope considering non-equilibrium flow is studied. The results show that the influence of non-equilibrium seepage on slope stability is much greater than that of unsaturated seepage. The theory of non-equilibrium flow can reasonably explain the mechanism of slope instability induced by ice and snow ablation conditions. Increasing the pore diameter can increase the water exchange between the large pore region and the surrounding matrix domain, slow down the preferential conduction of water flow and increase the pore water pressure, so as to reduce the slope stability and increase the length of the macropore. The water conduction path is prolonged and the effect of water accumulation in macroporous domain is weakened, which has a certain influence on slope safety factor, while increasing macroporosity bending ratio has little effect on water content and slope safety factor in matrix domain, which can be ignored. There is the minimum critical spacing between the safety factor of slope and the spacing of macropores, which leads to the failure of the preferential flow effect of the macroporous group, the superposition and interference of the non-equilibrium flow between the macropores, and the unbalance flow between the macropores is superposed and interfered with each other. The effect of macropores on pore water pressure is weakened. Therefore, the influence of non-equilibrium flow, especially the influence of the spacing and length of macropores, should be considered for the instability of slope with macroporous induced by ice and snow ablation in short-time frozen area.
【作者单位】：福州大学土木工程学院;福州大学数学与计算机科学学院;
【基金】：国家自然科学基金资助项目(41302215;41772297) 福建省自然科学基金资助项目(2014J01185)
【分类号】：TU43

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