基于煤岩蠕变力学实验的西原模型改进与分析

Improvement and Analysis of Nishihara Model Based on Coal and Rock Creep Mechanics Experiment

在煤层气钻采和煤炭开采过程中,由煤岩蠕变引起的工程失稳现象时有发生,严重制约了煤层气与煤炭资源的勘探和开发。为深入探讨煤岩的蠕变规律,利用我国煤层气钻采和煤炭开采主要地区-山西晋城地区煤岩进行了蠕变力学实验研究,分析不同轴向荷载条件下煤岩应变与时间的关系。并根据该地区煤岩的蠕变力学特性,构建了适合于该地区的改进西原模型及相应的本构方程。通过实验验证与对比分析:改进的西原模型能更好的反映该地区煤岩蠕变特征,尤其是煤岩所受荷载大于长期强度时效果有显著提升。

In the process of coal-bed methane drilling and coal mining,engineering instability caused by coal and rock creeping happens from time to time,which severely restricts the exploration and development for coal-bed methane resources and coal resources.In order to study the creeping laws of coal and rock,we take experiments with coals from Jincheng in Shanxi,which is the main CBM drilling and coal mining area in China,to analyze the relationship between strain and time in different axial loading. Based on the creep property of coal,we built the modified Nishihara model and constitutive equation for this region. Through the experiments,it can be easily found that modified Nishihara model has a better reflection to creep property for this region,especially when coal and rock suffered the load is greater than the long-term strength of condition,this model can reflect better.