冲击荷载下碱化水稻秸秆基尾砂胶结充填体的力学性能及能耗特征  

Mechanical Properties and Energy Consumption Characteristics of Alkalized Rice Straw Based Cemented Tailings Backfill Under Impact Load

作　　者：喻海根 王石 宋学朋 魏美亮 刘武 陶铁军 张帅[1,2] YU Haigen;WANG Shiu;SONG Xuepeng;WEI Meiliang;LIU Wu;TAO Tiejun;ZHANG Shuai(School of Resources and Environmental Engineering,Jiangxi University of Science and Technology,Ganzhou,Jiangxi 341000,China;Jiangxi Province Key Laboratory of Mining Engineering,Jiangxi University of Science and Technology,Ganzhou,Jiangxi 341000,China;College of Civil Engineering,Guizhou University,Guiyang,Guizhou 550025,China)

机构地区：[1]江西理工大学资源与环境工程学院,江西赣州市341000 [2]江西省矿业工程重点实验室,江西赣州市341000 [3]贵州大学土木工程学院,贵州贵阳550025

出　　处：《矿业研究与开发》2022年第3期46-53,共8页Mining Research and Development

基　　金：国家自然科学基金项目(51804134,51804135);江西省自然科学基金项目(20181BAB216013);江西理工大学清江青年英才支持计划资助项目(JXUSTQJYX2019007)。

摘　　要：为了解中等应变速率下碱化水稻秸秆基尾砂胶结充填体的动载强度、应力-应变、能量演化及破坏形态特征,采用分离式霍普金森压杆系统对不同掺量碱化水稻秸秆(经NaOH溶液碱化处理)的尾砂胶结充填体进行了单轴单次冲击荷载试验。试验结果表明:充填体的动态抗压强度与平均应变率呈正相关关系,碱化水稻秸秆的掺入可有效提高充填体的动态抗压强度,且随碱化水稻秸秆掺量的增加,充填体的动态抗压强度先增大后减小,最佳掺量为0.3%,动态抗压强度最大增幅为26.81%;单次冲击荷载下,掺碱化水稻秸秆的充填体相比于未掺碱化水稻秸秆的充填体应变更大,但破坏程度更小;同一应变率下,充填体的单位体积吸收能和单位质量破碎耗能均随平均应变率的增大呈现类似指数增长规律,掺碱化水稻秸秆的充填体具有更高的能量水平、吸能性能,且破碎时需要消耗更多的能量;单次冲击荷载下,充填体的破坏形态主要为宏观上的轴向主裂纹拉伸破坏及压碎破坏,当平均应变率超过临界应变率时,充填体破坏形态多为压碎破坏;碱化水稻秸秆在充填体基体内部起到桥连作用,从而减缓充填体裂纹的扩展与能量的释放,使掺碱化水稻秸秆的充填体具有更高的临界应变率,显著提高充填体的稳定性与完整性,有利于改善井下作业环境的安全性。In order to observe the characteristic rules of dynamic load intensity,stress-strain,energy evolution and failure morphologythe alkalized rice straw based cemented tailings backfill under medium strain rate,the split Hopkinson pressure bar(SHPB)system was used to carry out the uniaxial single impact load tests on the cemented tailings backfill with different contents of alkalized rice straw(alkalized by NaOH solution).The test results are concluded as follows.Firstly,the dynamic compressive strength of the backfill is positively correlated with average strain rate,and can be effectively improved by the addition of alkalized rice straw.With the increase of alkalized rice straw content,the dynamic compressive strength of the backfill first increases and then decreases.The optimal addition amount is 0.3%,and the biggest increase of dynamic compressive strength is 26.81%.Secondly,under single impact load,the strain of backfill mixed with alkalized rice straw is larger than that without alkalized rice straw,but the damage degree was smaller.Thirdly,under the same strain rate,the energy absorption per unit volume and the crushing energy consumption per unit mass of the backfill show a similar exponential growth law with the increase of the average strain rate.The backfill with alkalized rice straw has a higher energy level,higher energy absorption performance and more energy consumption during crushing.Fourthly,under single impact load,the failure form of the backfill is mainly axial main crack tensile failure and crushing failure on the macro level,and when the average strain rate exceeds the critical strain rate,the failure form of the backfill is mostly crushing failure.The alkalized rice straw could form a bridging role in the inner matrix of the backfill,thereby slows down the crack propagation and energy release,so that the backfill with alkalized rice straw has a higher critical strain rate,the stability and integrity of the backfill is significantly improved,and the safety of the underground operation environme

关 键 词：尾砂胶结充填体 碱化水稻秸秆 冲击荷载 力学性能 能耗特征 SHPB 

分 类 号：TD315[矿业工程—矿井建设]