摘要
以应力波在煤岩体中的产生及传播规律为研究对象,分析并揭示了水射流冲击煤岩体时水锤作用是诱导形成应力波的主要因素,并建立水射流冲击煤岩体简化计算模型,研究了水锤压力峰值、扰动半径及持续时间与射流速度和射流半径之间的关系;对水锤作用下的应力波传播规律进行探讨,指出不同弱面上水锤压力引起的应力波及入射波和反射波在煤岩体传播过程中存在叠加效应,研究了"V"型裂隙尖端应力集中现象及射流孔道内流体增压机理。在理论分析的基础上,利用非线性有限元方法,揭示了煤层在水射流冲击作用下的应力波演化过程。研究结果为水射流破煤机理研究提供了理论基础,并为水力化造缝增透技术实现低渗,难抽煤层快速、精准增透提供了依据。
Taking the generation and propagation of stress wave in coal and rock mass as the research object,it is studied and revealed that water hammer is the main factor inducing the formation of stress waves when water jet impingement on coal and rock mass. And the simplified calculation model of water jet impacting on coal and rock mass is established,and the relationship between jet pressure peak value,disturbance radius and duration,jet velocity and jet radius is studied. The propagation law of stress wave under water hammer is also studied. It is pointed out that the stress wave caused by water hammer pressure on different weak surfaces and the incident wave and reflected wave existsuperposition effect in the propagation process of coal and rock mass, the stress concentration phenomenon at the crack tip of the ‘V ＇ type and the fluid supercharging mechanism in the jet channel. Based on the theoretical analysis,the stress wave evolution of coal seam under the impact of water jet is revealed by the nonlinear finite element method. The research results provide a basic theory for the study of the mechanism of water jet coal breaking,and provide a reliable reference for the realization of low permeability, rapid and accurate penetration of coal seam with hydraulic fracturing technology.
作者
陈德敏
CHEN Demin(State Key Laboratory of Gas Chongqing 400037,China;Disaster Monitoring and Emergency Technology,China Coal Technology and Engineering Group Chongqing Research Institute,Chongqing 400039,China)
出处
《重庆理工大学学报（自然科学）》
CAS
北大核心
2018年第7期118-123,150,共7页
Journal of Chongqing University of Technology：Natural Science
基金
国家科技重大专项(2016ZX05045-004)
关键词
水射流
应力波
煤岩体
数值模拟
water jet
stress wave
coal and rock
numerical simulation
