Mechanical properties and failure modes of stratified backfill under triaxial cyclic loading and unloading

作     者：Wang Jie Song Weidong Cao Shuai Tan Yuye 

作者机构：School of Civil and Resource EngineeringUniversity of Science and Technology BeijingBeijing 100083China State Key Laboratory of High-Efficient Mining and Safety of Metal Mines of Ministry of EducationBeijing 100083China 

出 版 物：《International Journal of Mining Science and Technology》 (矿业科学技术学报（英文版）)

年 卷 期：2019年第29卷第5期

页      面：809-814页

核心收录：

学科分类：081901[工学-采矿工程] 0819[工学-矿业工程] 0709[理学-地质学] 0808[工学-电气工程] 08[工学] 0818[工学-地质资源与地质工程] 0708[理学-地球物理学] 0807[工学-动力工程及工程热物理] 0815[工学-水利工程] 0813[工学-建筑学] 0814[工学-土木工程] 

基　　金：the National Natural Science Foundation of China(No.51374033) the Key Projects of the National Key Research and Development Program(No.YS2017YFSF040004). 

主　　题：Stratified backfill Triaxial cyclic loading and unloading Mechanical properties Failure modes Deformation modulus 

摘      要：Multiple filling of gobs will lead to a layered structure of the backfill.To explore the influence of layering structure on the mechanical properties and failure modes of backfill,different backfill specimens were prepared with a cement/sand ratio of 1:4,a slurry concentration of 75%,and backfilling times of 1,2,3 and 4,separately.Triaxial cyclic loading and unloading experiments were carried out.The results show that with an increase in backfilling time,the peak strength of backfill decreases as a polynomial function and the peak strain increases as an exponential function.The cyclic load enhances the linear characteristic of backfill deformation.The loading and unloading deformation moduli have a linear negative correlation with the backfilling time.The unloading deformation modulus is always slightly higher than the loading deformation modulus.The failure modes of stratified backfill are mainly characterized by conjugate shear failure at the upper layer and tensile failure across the layer plane,and there is usually no damage in the lower layer away from the loading area.