基于微裂隙变形与扩展的岩石冻融损伤本构模型研究

发布时间：2018-01-30 23:18

本文关键词： 冻胀力裂隙扩展弹性模量冻融循环塑性特征　出处：《岩土力学》2015年12期 　论文类型：期刊论文

【摘要】：在冻融条件下岩石微裂隙中的水发生相变,体积膨胀,对微裂隙产生很大的冻胀力,当冻胀力超过岩石的抗拉强度时,微裂隙扩展。温度升高时,水又进入新的微裂隙,如此反复循环造成了岩石的损伤。据此,将岩石中的微裂隙等效为扁平状椭圆裂隙,基于断裂力学建立了单条微裂隙下裂隙扩展长度与冻胀力的关系,考虑岩石中微裂隙的分布,将岩石冻融条件下的应变分解为初始损伤应变、附加损伤应变和塑性应变,建立了弹塑性冻融损伤本构模型。最后,通过岩石冻融试验对该模型的合理性进行了验证,结果表明,该模型能够较好地模拟岩石在不同冻融次数下的应力-应变关系曲线。
[Abstract]:Under the condition of freezing and thawing, the water in the rock microfissures undergo phase transformation and volume expansion, which results in a great frost heave force on the microcracks. When the frost heave force exceeds the tensile strength of the rock, the microfracture expands and the temperature rises. The water enters into the new microfissure again and again, which causes damage to the rock. Accordingly, the micro-fracture in the rock is equivalent to the flat elliptical fissure. Based on fracture mechanics, the relationship between crack propagation length and frost heaving force is established. Considering the distribution of microcracks in rock, the strain under freeze-thaw condition is decomposed into initial damage strain. The damage constitutive model of elastic-plastic freeze-thaw damage is established by adding damage strain and plastic strain. Finally, the rationality of the model is verified by rock freeze-thaw test, and the results show that the model is reasonable. The model can well simulate the stress-strain curve of rock under different freezing and thawing times.
【作者单位】：中国地质大学(北京)工程技术学院;中铁七局集团有限公司勘测设计院;
【基金】：国家自然科学基金(No.41162009) 中央高校基本科研基金(No.53200859243)~~
【分类号】：TU45
【正文快照】： Foundation item:Project supported by the National Natural Science Foundation of China(Grant No.41162009)and Basic Research Funds for CentralUniversities(Grant No.53200859243).1引言耐久性和实用性是寒区工程建设的重要指标,在寒区建设和资源开采过程中,会遇到很

【参考文献】