高应变率冲击荷载下节理花岗岩损伤机制研究  

Damage mechanism of jointed granite under high strain rate impact loading

作　　者：王智德[1] 钱梦凡 李杰[1,2] 司莹莹 江俐敏 WANG Zhi-de;QIAN Meng-fan;LI Jie;SI Ying-ying;JIANG Li-min(School of Civil Engineering and Architecture,Wuhan University of Technology,Wuhan,Hubei 430070,China;Wuhan Geotechnical Engineering and Surveying Co.Ltd.Wuhan,Hubei 430000,China;School of Architectural Engineering,Wuhan Polytechnic,Wuhan,Hubei 430070,China)

机构地区：[1]武汉理工大学土木工程与建筑学院,湖北武汉430070 [2]武汉市勘察设计有限公司,湖北武汉430000 [3]武汉职业技术学院建筑工程学院,湖北武汉430074

出　　处：《岩土力学》2024年第7期1917-1928,共12页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.42077228,No.51374163);磷资源开发利用教育部工程研究中心开放基金资助(No.LKF202004);武汉市城乡建设委员会科技计划项目(武城建[2017]12号-201740,武城建[2019]68号-201941)。

摘　　要：针对冲击荷载作用下贯通节理花岗岩动力响应特征和能量演化规律这一研究目标,以含不同倾角节理花岗岩为研究对象,基于不同倾角节理岩体损伤力学理论模型,开展了高应变率下不同节理倾角花岗岩的分离式霍普金森压杆(split Hopkinson pressure bar,简称SHPB)冲击试验,完成了高应变率下花岗岩的损伤特征研究,获取了岩体动态力学性质和能量耗散特征。研究结果表明:(1)基于Druck-Prager准则和Weibull强度分布准则,结合弹性波理论,建立了不同倾角节理岩体的应力-应变理论模型,该模型能够较好地反映花岗岩的抗压强度、弹性模量随节理倾角变化的动态力学特性,具有较强的倾角效应;(2)相同冲击荷载下,随节理倾角的增大,能量反射系数呈线性上升趋势,能量传递系数呈线性下降趋势,岩样的峰值应力逐渐而减小;相同节理倾角下,随冲击荷载增大,能量反射系数先增大后减小,能量传递系数先减小再增大,能量吸收率随节理倾角的增大而减小;(3)当冲击荷载相同时,完整岩样、节理倾角θ=0°和θ=15°岩样的破碎程度较大,而节理倾角θ=30°和θ=45°岩样的破碎程度较小;当节理倾角相同时,随冲击荷载增大,超过岩样最大抗压强度时,岩样由剪切和拉伸破坏逐渐转化成压碎破坏,且破碎程度也随之增大。To study the dynamic response characteristics and energy evolution of through-jointed granite under impact load,granite with different dip joints was selected as the research object.Using the theoretical model of damage mechanics for jointed rock masses with varying dip angles,a series of SHPB(split Hopkinson pressure bar)impact tests was conducted on granite samples under high strain rates.The dynamic mechanical properties and energy dissipation characteristics of the rock samples were obtained.The results indicate that:(1)based on the Druck-Prager criterion,the Weibull strength distribution criterion,and the theory of elastic waves,the stress-strain model of jointed rock mass with different dip angles is established.This model can effectively reflect the dynamic mechanical properties of granite as the joint dip angle changes and exhibits a strong dip effect.(2)As the dip angle of the joints increases,the energy reflection coefficient rises linearly,the energy transmission coefficient decreases linearly,and the peak stress of the rock samples gradually decreases.Under the same joint dip angle,as the impact load increases,the energy reflection coefficient first increases and then decreases,the energy transmission coefficient first decreases and then increases,and the energy absorption rate decreases with the increase of the joint dip angle.(3)When the impact load is the same,the fragmentation degree of intact rock samples and those with joint dip angles of 0°and 15°is greater,while the fragmentation degree of rock samples with joint dip angles of 30°and 45°is smaller.When the joint dip angle is the same,as the impact load increases and exceeds the maximum compressive strength of the rock samples,the failure mode gradually transitions from shear and tensile failure to crushing failure,and the degree of fragmentation also increases.

关 键 词：不同倾角 节理花岗岩 SHPB冲击试验 能量耗散 高应变率 

分 类 号：TU451[建筑科学—岩土工程]