低温饱和岩石未冻水含量与冻胀变形模型研究

发布时间：2018-01-20 00:08

本文关键词： 岩石力学冻岩未冻水含量有效冻胀力冻胀变形　出处：《岩石力学与工程学报》2016年10期 　论文类型：期刊论文

【摘要】：寒区岩石在季节性温度变化下会经历冻胀融缩过程,研究低温岩石中未冻水含量以及冻胀变形规律是进行寒区工程数值仿真和稳定性分析的关键问题。岩石是不同于土体的脆性多孔介质材料,孔隙中的未冻水含量还无法通过实验直接测量;基于累计孔隙体积分布规律,考虑孔隙水的冻结点变化和未冻水膜的影响建立低温岩石未冻水含量理论表达式,实例证明该计算式具有较高的可靠度。假定岩石为弹性孔隙介质,基于孔隙冰与岩石孔隙间的膨胀耦合关系可计算冰压力;利用应变等价原理将孔隙中的冰压力等效为岩石表面的三向拉应力,从而根据弹性理论建立了有效冻胀力下低温饱和岩石冻胀变形模型。结果表明饱和岩石低温冻胀变形与岩石基质的力学参数、岩石孔隙率以及未冻水含量等因素有关。最后通过与2个已有的室内冻胀变形实验对比,说明本文冻胀变形模型的正确性以及实用性。
[Abstract]:Rock in cold region will undergo frost heaving and thawing process under seasonal temperature change. The study of unfrozen water content and frost heave deformation in low temperature rock is the key problem of numerical simulation and stability analysis in cold zone engineering. Rock is a brittle porous medium material different from soil mass. The content of unfrozen water in pore can not be measured directly by experiment. Based on the law of cumulative pore volume distribution, the theoretical expression of unfrozen water content in low temperature rock is established considering the change of freezing point of pore water and the influence of unfrozen water film. Examples show that the formula has high reliability. Assuming that the rock is elastic pore medium, ice pressure can be calculated on the basis of the expansion coupling relationship between pore ice and pore. According to the principle of strain equivalence, the ice pressure in the pore is equivalent to the triaxial tensile stress on the rock surface. According to the theory of elasticity, the model of frost heave deformation of saturated rock at low temperature under effective frost heaving force is established, and the results show that the mechanical parameters of rock matrix and rock heave deformation at low temperature are obtained. The porosity of rock and the content of unfrozen water are related. Finally, the correctness and practicability of this model are proved by comparing with two indoor frost heave deformation experiments.
【作者单位】：中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室;武汉大学岩土与结构工程安全湖北省重点实验室;
【基金】：国家自然科学基金重点项目(41130742);国家自然科学基金青年基金项目(41302237)~~
【分类号】：TU445
【正文快照】： 寒区隧道建设,低温液化气储存以及寒区岩质边坡的稳定性等都会涉及到岩土体的冻融损伤问题[1-3]。低温下岩石孔隙中会发生水冰相变产生冻胀力从而引起孔隙的膨胀变形,而岩石基质在低温下会发生收缩,总体表现为岩石的低温冻胀变形。土体冻胀研究是一个世界性的科学问题,土质路

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