基于Weibull分布页岩围压下的动态损伤本构模型研究  

Shale dynamic damage constitutive model based on Weibull distribution under variable confining pressure

作　　者：白宇 赵康朴 刘依 胡智航 白爽 杨巍 BAI Yu;ZHAO Kang-pu;LIU Yi;HU ZHI-hang;BAI Shuang;YANG Wei(Chengyuan Mining Development Co.,Ltd.,Liaoyang 111200,Liaoning,China;School of Mechanics and Civil Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China)

机构地区：[1]成远矿业开发股份有限公司,辽宁辽阳111200 [2]中国矿业大学(北京)力学与建筑工程学院,北京100083

出　　处：《工程爆破》2023年第6期61-67,99,共8页Engineering Blasting

摘　　要：采用分离式霍普金森压杆(SHPB)和被动围压套筒装置,研究了页岩在不同围压条件下的冲击压缩力学性能。试验结果表明:在无围压条件下,页岩试件强度具有显著的应变率相关性,页岩动态抗压强度随应变率提高而提高;被动围压的加载作用显著提高了页岩试件的完整性,页岩试件的离散性减弱,页岩表现出显著的均质岩体特征。建立了基于Weibull分布的页岩动态损伤本构模型,并通过试验结果计算了不同应变率下的Weibull分布参数;将试验所得围压变化曲线代入到本构模型中,比较验证了无围压和变围压条件下的动态损伤统计本构模型适用性和合理性,验证发现,模型曲线与试验曲线相吻合,在变围压条件下本文所构建的本构模型依然适用,可为页岩气开发过程中的工程模拟提供一定的参考。The impact compression mechanical properties of shale under different confining pressure conditions were studied by using a split Hopkinson pressure bar and a passive confining sleeve device.The test results show that under the condition of no confining pressure,the strength of shale specimens has significant strain rate correlation,and the dynamic compressive strength of shale increases with the increase of strain rate;the loading effect of passive confining pressure significantly improves the shale specimens.The integrity of the shale specimens is weakened and the shale exhibits significant homogeneous rock mass characteristics.The dynamic damage constitutive model of shale based on Weibull distribution is established.The Weibull distribution parameters under different strain rates are calculated by the test results.The confining pressure curves obtained from the test are substituted into the constitutive model to verify the non-confining pressure.The applicability and rationality of the dynamic damage statistical constitutive model under variable confining pressure conditions.It is found that the model curve is consistent with the experimental curve.Under the condition of variable confining pressure,the constitutive model constructed in this paper is still applicable and can be shale gas.Engineering simulation during development provides a certain reference.

关 键 词：页岩 被动围压 WEIBULL分布 动态损伤本构模型 SHPB 

分 类 号：TU452[建筑科学—岩土工程]