大孤山尾矿细砂力学性质试验研究

发布时间：2018-04-10 13:54

本文选题：尾矿 + 细砂　；参考：《辽宁科技大学》2017年硕士论文

【摘要】：尾矿坝作为一种特殊的水工建筑物,与普通的挡水坝有很大区别,尾矿坝的安全稳定对矿山生产、周围生态环境以及附近居民的生命财产安全至关重要。应用SLB-1型应力应变控制式三轴剪切渗透试验仪,对大孤山尾矿库的尾矿细砂进行了三轴压缩试验研究,分析研究了尾矿细砂在不同应力路径和固结度下的变形破坏特性。(1)通过尾矿砂的筛分实验以及K0固结试验,确定尾矿砂试样属于细砂,尾矿砂的静止侧压力系数为0.23。(2)通过对尾矿细砂在3种不同主应力比下的固结不排水试验,以及对应力应变曲线的分析,获得了主应力比对尾矿细砂变形特性的影响。随着主应力比的不同,尾矿细砂抵抗变形的能力有很大区别,在主应力比较小时,试样本身容易发生变形突变,产生破坏。在主应力比较大时,轴向力即使增加到很大,试样的轴向变形量依然很小;主应力比不同时,即使轴压相同,由于围压不同,试样所反映的抗剪强度有很大区别。(3)尾矿细砂由于堆积时间、空间的不同和排水条件各异,在尾矿库中的固结程度也大不相同。为研究尾矿细砂在不同固结度下的力学性质,进行了多种固结度下的固结不排水试验。试验结果表明当固结度不同时,主应力差的峰值变化幅度并不随着固结度单调增加,在围压100kPa下主应力差的峰值变化幅度可从356.8kPa到479.5kPa;粘聚力随着固结度的增加逐渐减小,内摩擦角变化幅度比较小。
[Abstract]:As a special hydraulic structure, tailings dam is very different from common dam. The safety and stability of tailings dam is very important to mine production, the surrounding ecological environment and the life and property safety of nearby residents.The triaxial compression test of fine tailing sand in Dagushan tailings reservoir was carried out by using SLB-1 type stress and strain control triaxial shear permeation tester.The deformation and failure characteristics of tailing fine sand under different stress paths and consolidation degrees are analyzed and studied. Through the screening experiment of tailings sand and the K0 consolidation test, it is determined that the tailings sand samples belong to fine sand.The static lateral pressure coefficient of tailings is 0.23.m2) the influence of principal stress ratio on the deformation characteristics of fine tailing sand is obtained through the consolidation undrained test of tailings fine sand under three different principal stress ratios and the analysis of stress-strain curve.With the difference of principal stress ratio, the ability of fine tailing sand to resist deformation is very different. When the principal stress ratio is small, the specimen itself is prone to deformation, mutation and failure.When the principal stress is relatively large, the axial deformation of the specimen is still very small even if the axial force is increased to a large extent, and when the principal stress ratio is different, even if the axial pressure is the same, because of the different confining pressure,The shear strength reflected by the specimen is very different. (3) due to the different accumulation time, different space and different drainage conditions, the consolidation degree of the tailings fine sand in the tailings reservoir is also very different.In order to study the mechanical properties of tailing fine sand under different consolidation degrees, undrained consolidation tests were carried out under various consolidation degrees.The experimental results show that the range of peak variation of principal stress difference does not increase monotonously with consolidation when consolidation degree is different, the peak value of principal stress difference can range from 356.8kPa to 479.5 KPA under confining pressure 100kPa, and the cohesive force decreases gradually with the increase of consolidation degree.The variation of the angle of internal friction is relatively small.
【学位授予单位】：辽宁科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD926.4

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