基础理论与实验研究

基于修正Lemaitre应变等价性假设的岩石损伤模型

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  • 1. 中南大学 土木工程学院,湖南 长沙 410075;2. 中南大学 高速铁路建造技术国家工程实验室,湖南 长沙 410075
李海潮,男,1991年生,男,硕士研究生,主要从事岩土材料本构特性等方面的研究工作。

收稿日期: 2015-07-02

  网络出版日期: 2018-06-05

基金资助

国家重点基础研究发展计划(973)项目(No. 2014CB047001)。

A constitutive damage model of rock based on the assumption of modified Lemaitre strain equivalence hypothesis

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  • 1. School of Civil Engineering, Central South University, Changsha, Hunan 410075, China; 2. National Engineering Laboratory for High Speed Railway Construction, Central South University, Changsha, Hunan 410075, China

Received date: 2015-07-02

  Online published: 2018-06-05

Supported by

This work was supported by the National Program on Key Basic Research Project of China (2014CB047001).

摘要

基于损伤力学和损伤阀值的概念,认为岩石在较小应力状态下为弹性阶段。当应力达到屈服状态时,发生连续损伤;而当完全损伤时,其应力-应变具有残余强度的变形特征。在此基础上,采用三参数Weibull分布描述岩石损伤演化机制,同时对Lemaitre应变等价性假设进行修正,考虑岩石内部损伤后沿着局部断裂带发生相对滑动变形所产生的滑动摩擦力,最终建立起新的岩石损伤模型。通过与试验结果进行对比分析,结果表明,所建立的损伤模型能够准确地描述岩石在低应力水平下的弹性变形和残余强度变形特征,在实际的工程中具有广泛的适用性。

本文引用格式

李海潮,张 升, . 基于修正Lemaitre应变等价性假设的岩石损伤模型[J]. 岩土力学, 2017 , 38(5) : 1321 -1326 . DOI: 10.16285/j.rsm.2017.05.012

Abstract

Based on damage mechanics and the concept of damage threshold, rock behaves elastically at the beginning of loading, and successive damage is followed when the stress reaches the yield state. Until rock is completely damaged, the stress-strain curve shows deformation characteristics of residual strength. In this study, three-parameter Weibull distribution function is adopted to describe the evolution of rock damage. Meanwhile, the Lemaitre strain equivalence hypothesis is modified by considering the friction force caused by the relatively slipping deformation of rock along pre-existing local cracks. Finally, a new constitutive damage model is proposed to precisely describe deformation characteristics of residue strength and the elastic deformation at the low confining pressure. Furthermore, the proposed model is also verified by experimental results, which indicates that the model can be widely applied to practical engineering projects.
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