摘要
对于矿山地下深部开采存在的地压问题,选取3组料浆浓度充填试件在RMT-150C压力机上经过不同围压三轴压缩后再进行单轴压缩试验,获得经过3组围压压缩后不同料浆浓度试件的应力—应变曲线数据,并结合Lemaitre应变等价原理,得到全尾砂胶结充填体的峰前后损伤值公式和损伤本构方程。从损伤—应变曲线可知:当料浆浓度一定时,增大围压,充填体弹性变形阶段缩短,更早达到屈服极限且峰值损伤值增大,继续增大围压,充填材料峰值损伤值降低;在低围压条件下,增大料浆浓度抑制了峰前损伤增长,但促进峰后损伤增长;在高围压条件下,随着料浆浓度的增大,充填材料损伤值先降低后升高,促进了试件破坏。
In recent years,with the increasing depth of underground mining and the increasing probability of accidents such as goaf collapse and surface subsidence,tailings filling has become one of the most popular methods of composite aggregate filling. It can not only effectively limit ground pressure activities,but also be beneficial to tailings treatment and environmental protection in mining areas.However,the damage and destruction of filling body also threatens the safe production of the mine.With the increasing of underground mining depth,the problem of ground pressure is becoming more and more obvious.By using the whole tailings of a mine and 32.5 type cement,the filling specimens with 100 mm×50 mm(high*diameter)are preparedunder lime-sand ratio of 1∶8,curing age of 28 days,slurry concentration of 66%,70% and 74%. The confining pressure conditions are 0.4,0.7 and 1.0 MPa.The RMT-150C in the Key Laboratory of Mining Engineering of Jiangxi Province was used. The experimental operation was carried out on the hydraulic press. The force(small)- displacement control was adopted in the test process,and the loading rate was 0.002 mm/s.In order to reduce the influence of other factors on the test data,the specimen is regarded as the preparation and maintenance under the same test condition.According to Lemaitre strain equivalence principle,the pre-peak damage value and postpeak damage value are deduced.The damage-strain curves of filling slurry concentration of 70%,damage-strain curves under different confining pressures and different slurry concentration under confining pressures of 0.7 MPa were obtained through experimental data.When the filling slurry is 70%,under the confining pressures of 0.4, 0.7 and 1.0 MPa,the corresponding damage values of peak limit are 0.2111,0.2860 and 0.1920 respectively, showing a trend of increasing first and then decreasing.When the confining pressures is 0.7 MPa,under the slurry concentration of 66%,70% and 74%,the damage values corresponding to the peak limit are 0.303,0.286 and 0.275,respectively,and the whole body shows a decreasing trend in turn.From the damage-strain curves,it can be seen that when the slurry concentration is constant,the increase of confining pressure shortens the elastic deformation stage of filling body,achieves the yield limit earlier and the peak damage value increases.Continues to increase confining pressure,the peak damage value of filling material decreases.At low confining pressure, the increase of slurry concentration inhibits the increase of pre-peak damage but promotes the increase of postpeak damage.At high confining pressure,with the increase of slurry concentration,the damage value of filling materials decreases first and then increases,which promotes the failure of the filling specimens.
作者
杨世兴
付玉华
占飞
YANG Shixing;FU Yuhua;ZHAN Fei(College of Resources and Environmental Engineering,Jiangxi University of Science and Technology,Ganzhou341000,Jiangxi,China;Jiangxi Provincial Key Laboratory of Mining Engineering,Ganzhou 341000,Jiangxi,China;College of Applied Science,Jiangxi University of Science and Technology,Ganzhou 341000,Jiangxi,China)
出处
《黄金科学技术》
CSCD
2019年第1期97-104,共8页
Gold Science and Technology
基金
国家自然科学基金项目"频繁爆破作用下岩体累积损伤演化规律及振动效应研究"(编号:51464015)资助
关键词
深部开采
地压
围压
料浆浓度
损伤值
尾砂充填
应变
deep mining
ground pressure
confining pressure
slurry concentration
damage value
tailings filling
strain
