不同含水率煤体单轴压缩力学特性及损伤统计模型研究  

Mechanical properties and statistical damage model of coal with different moisture contents under uniaxial compression

作　　者：王凯 蒋一峰[1,2] 徐超 WANG Kai1,2 ,JIANG Yifeng1, 2, XU Chao1,2(1. Beijing Key Laboratory for Precise Mining of lntergrown Energy and Resources, China University of Mining and Technology （Beijing）, Beijing 100083, China; 2. School of Resource and Safety Engineering, China University of Mining and Technology （Beijing）, Beo＇ing 100083, China)

机构地区：[1]中国矿业大学(北京)共伴生能源精准开采北京市重点实验室,北京100083 [2]中国矿业大学(北京)资源与安全工程学院,北京100083

出　　处：《岩石力学与工程学报》2018年第5期1070-1079,共10页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家重点研发计划(2016YFC0600708);国家自然科学基金资助项目(51474219;51604278)~~

摘　　要：为了研究水分对煤体力学特性的影响,制备不同含水率的原煤煤样和型煤煤样,进行单轴压缩力学试验。根据试验结果,讨论2种煤样的变形特性随含水率变化的规律,分析煤样的力学参数和含水率的关系,对比不同含水率下2种煤样的破坏方式。研究结果表明,随着含水率增大,2种煤样的应力–应变曲线的压密阶段区间增大,弹性阶段区间缩小,屈服阶段更加显著。2种煤样的含水率和力学参数拟合关系相同,抗压强度与含水率呈负线性关系,峰值应变与含水率呈正线性关系,弹性模量与含水率呈负指数关系。从干燥状态到饱水状态,发生破坏后,原煤煤样依次表现为剪切破坏、拉伸–剪切组合破坏,型煤煤样依次表现为剪切破坏、拉伸破坏、拉伸–剪切组合破坏。在力学试验的基础上,考虑煤体压密阶段的应力–应变关系,建立考虑含水率的煤体分段式损伤本构模型,对试验结果进行了验证。拟合结果显示理论曲线和试验数据具有较高的拟合度,模型适用于分析不同含水率的煤体单轴压缩力学问题。研究结论为受煤体水分影响的煤矿工程的分析和设计提供了参考。In order to study the influence of moisture on the mechanical properties of coal,raw coal and briquette coal samples with different moisture contents were prepared,and the uniaxial compression tests were carried out. Based on the test results,the deformation characteristics of two types of coal samples with various moisture contents were discussed,the relationship between the mechanical parameters and moisture contents of coal samples were analyzed and the failure modes of two coal samples with different moisture contents were compared. The results show that,as the moisture content increases,the width of the compaction phase in the stress-strain curve increases,the width of the elastic phase decreases and the yield phase becomes more visible. The fitting relationships between the moisture content and mechanical parameters of two types of coal samples are the same.The moisture content and the compressive strength have a negative linear relationship,the peak strain and the moisture content have a positive linear relationship,and the elastic modulus and the moisture content have a negative exponential relationship. From the dry state to the saturated water state,the raw coal samples show shear failure and combined tensile-shear failure in turn,while the briquette samples show shear failure,tensile failure and combined tensile-shear failure. The segmented constitutive model of coal mass damage considering moisture content and the stress-strain relationship in the compaction stage of coal was established. The fitting results show that the theoretical curve is consistent with the experimental data.

关 键 词：岩石力学 原煤煤样 型煤煤样 含水率 单轴力学压缩试验 本构模型 

分 类 号：TU45[建筑科学—岩土工程]