水温循环条件下千枚岩动态力学特性研究  

Study on dynamic mechanical properties of phyllite under water-temperature cycle conditions

作　　者：王连华 冯伟志 王景立[1] WANG Lianhua;FENG Weizhi;WANG Jingli(College of Engineering and Technology,Jilin Agricultural University,Changchun 130118,Jilin,China;China Railway 23rd Bureau Group Corporation Limited,Chengdu 610031,Sichuan,China)

机构地区：[1]吉林农业大学工程技术学院,吉林长春130118 [2]中铁二十三局集团有限公司,四川成都610031

出　　处：《建筑科学与工程学报》2023年第6期157-169,共13页Journal of Architecture and Civil Engineering

基　　金：国家自然科学基金项目(41807245)。

摘　　要：对0°层理倾角千枚岩分别在温度循环自然降温、温度循环冷水降温、干湿循环3种水温劣化条件下开展1、3、5、8、11次劣化处理,而后采用分离式霍普金森杆(SHPB)试验系统开展水温循环条件下千枚岩动力学特性研究。结果表明:温度循环作用将有效缩短千枚岩应力-应变曲线的屈服阶段,干湿循环条件下千枚岩屈服阶段则较为明显,水温耦合作用后延性增强;千枚岩动态峰值抗压强度随着水温循环次数的增加不断减小,服从负指数分布规律;温度循环冷水降温、干湿循环水温耦合作用下千枚岩峰值抗压强度降幅大于温度循环自然降温作用下的抗压强度;千枚岩耗散能比随着水温循环次数的增加均呈动态增长的规律,因此水温循环对千枚岩耗散能比增幅具有放大效应;水温循环次数较少时,千枚岩发生贯穿层理面的压致张裂破坏;随着水温循环次数的增加,千枚岩破坏碎块数逐渐增多,碎块尺寸逐渐减小,分形维数不断增加,破坏模式也逐渐转为张剪破坏的复合破坏模式;水温耦合作用下,千枚岩更易产生多碎块破裂,碎块平均尺寸总体上更低。The phyllite with 0°bedding dip angle was subjected to 1,3,5,8,11 times of deterioration treatment under three water temperature deterioration conditions of temperature cycle natural cooling,temperature cycle cold water cooling and dry-wet cycle,respectively.Then the dynamic characteristics of phyllite under water temperature cycle were studied by using the split Hopkinson press bar(SHPB)test system.The results show that the temperature cycle will effectively shorten the yield stage of the stress-strain curve of phyllite,and the yield stage of phyllite is more obvious under the dry-wet cycle condition,and the ductility is enhanced after the coupling of water temperature.The dynamic peak compressive strength of phyllite decreases with the increase of the number of water temperature cycles,which obeys the negative exponential distribution law.The decrease of peak compressive strength of phyllite under the coupling effect of temperature cycle cold water cooling and dry-wet cycle water temperature is greater than that under the temperature cycle natural cooling.The dissipation energy ratio of phyllite increases dynamically with the increase of water temperature cycle times,so the water temperature cycle has an amplification effect on the increase of dissipation energy ratio of phyllite.When the number of water temperature cycles is small,the pressure-induced tensile fracture failure occurs through the bedding plane.With the increase of the number of water temperature cycles,the number of broken pieces of phyllite increases gradually,the size of broken pieces decreases gradually,the fractal dimension increases continuously,and the failure mode gradually changes into the composite failure mode of tension-shear failure.Under the coupling action of water temperature,phyllite is more prone to multi fragment fracture,the average size of phyllite fragments is generally lower.

关 键 词：千枚岩 分离式霍普金森杆试验 温度循环 干湿循环 动态力学特性 

分 类 号：TU45[建筑科学—岩土工程]