摘要
原地浸矿法是现有离子型稀土矿山唯一的高效绿色开采方法,浸矿后离子型稀土在干湿循环作用下的力学特性影响着浸矿后边坡的稳定性。为研究浸矿后离子型稀土在干湿循环作用下的力学特性,选取赣南地区浸矿后的稀土样,利用固结不排水三轴试验,并结合核磁共振技术,测试了不同干湿循环次数下试样的强度特性和孔隙变化,得到干湿循环前、后试样的应力-应变曲线、孔隙水压力发展曲线和横向弛豫时间T2分布。结果表明:干湿循环作用下,试样初始刚度有所增大,试样强度降低,围压大小和干湿循环次数共同决定了孔隙水压力的发展。黏聚力c和内摩擦角φ随干湿循环次数增加而减小,第一次干湿循环后的降幅最大,内摩擦角的弱化幅度小于黏聚力。从横向弛豫T2谱发现,干湿循环过程会使土体产生微裂隙;并且随着干湿循环次数增加,裂隙累积扩展。
In-situ leaching is the only efficient green mining method for the ion-absorbed rare earth mine. The machamical properties of leached ion-adsorption rare earth under wetting-drying cycles is dominant impact on the stability of the slope. In order to study the mechanical properties of leached ion-adsorption rare earth ore under wetting-drying cycles,the leached ion-adsorption rare earth ore in south Jiangxi area was took as a soil specimen,and consolidated-undrained triaxial test was conducted. The strength and pore water pressure characteristics were tested.The nuclear magnetic resonance technique was used to test the specimen to obtain the variable rule of relaxation time.The results showed that the initial stiffness coefficient increased and strength decreased under drying-wetting cycles.The pore water pressure developing curve was determined by confining pressure and the number of wetting-drying cycles. Cohesion and internal friction angle decreased under wetting-drying cycles. The decreasing amplitude was significant in the first wetting-drying cycle. And the weakening amplitude of internal friction angle was smaller than that of cohesion. According to crosswise relaxation time T2 distribution, it was concluded that microfissure accumulated and extended under wetting-drying cycles.
作者
钟文
陈新
查道欢
李永欣
月福财
韩建文
王晓军
ZHONG Wen CHEN Xin ZHA Daohuan LI Yongxin YUE Fucai HAN Jianwen WANG Xiaojun(School of Resources and Environment Engineering, Jiangxi University of Science and Technology, Ganzhou 341000,China Jiangxi Key Laboratory of Mining Engineering,Jiangxi University of Science and Technology, Ganzhou 341000 ,China)
出处
《工业建筑》
CSCD
北大核心
2017年第10期104-109,共6页
Industrial Construction
基金
国家自然科学基金项目(51504102
51564012)
江西理工大学青年英才支持计划
江西省研究生创新基金(YC2016-S320)
关键词
孔隙水压力
黏聚力
内摩擦角
微裂隙
核磁共振
pore water pressure
cohesion
internal friction angle
microfissure
nuclear magnetic resonance
