颗粒破碎对绢云母片岩强度和变形影响的试验研究

发布时间：2018-03-23 17:37

本文选题：绢云母片岩　切入点：相对破碎率　出处：《岩土力学》2014年11期

【摘要】：为进一步弄清颗粒破碎对软岩粗粒料强度、变形的影响,开展2组不同初始干密度下的绢云母片岩粗粒料的固结排水三轴试验,分析了绢云母片岩粗粒料颗粒破碎规律,并探讨了颗粒破碎对绢云母片岩粗粒料力学性质的影响。结果表明,绢云母片岩粗粒料相对破碎率随围压的增加而增大,但颗粒破碎增幅速率受初始干密度影响较大,颗粒破碎与围压之间的关系可用线性关系描述;由于初始孔隙率的影响,使得试样在同一应力水平下高密度试样颗粒破碎明显高于低密度试样;颗粒破碎对高密度试样抗剪强度降低的影响高于低密度试样,导致两种干密度试样的应力-应变曲线在某处出现相交,最终出现初始密度低的试样抗剪强度大于初始密度高的试样抗剪强度的现象;高密度试样孔隙率较小,其剪胀因子一直保持在1附近,而低密度试样孔隙率较大,受颗粒破碎和剪胀的影响迟缓一些,低密度试样体变较高密度要大些,但整体上由于颗粒破碎和剪胀的影响,绢云母片岩粗粒料的体变均不大。
[Abstract]:In order to find out the effect of particle breakage on the strength and deformation of soft rock coarse grain, two groups of consolidation and drainage triaxial tests of sericite schist coarse grain at different initial dry densities were carried out, and the fragmentation law of sericite schist coarse grain was analyzed. The effect of particle breakage on the mechanical properties of sericite schist coarse grain is discussed. The results show that the relative breakage rate of sericite schist increases with the increase of confining pressure, but the increase rate of particle breakage is greatly affected by the initial dry density. The relationship between particle breakage and confining pressure can be described by linear relation, because of the influence of initial porosity, the particle breakage of high density specimen is obviously higher than that of low density specimen at the same stress level. The effect of particle breakage on the decrease of shear strength of high density specimen is higher than that of low density sample, which results in the stress-strain curve of two kinds of dry density specimen intersecting somewhere. Finally, the shear strength of the specimen with low initial density is higher than that of the sample with high initial density, and the porosity of the sample with high density is smaller, and the shear expansion factor of the specimen with high density is always around 1, but the porosity of the sample with low density is larger than that of the sample with high initial density. The effect of particle breakage and shear dilatation is slower and the bulk of low density sample is larger than that of high density sample, but on the whole due to the influence of particle breakage and shearing expansion, the bulk change of sericite schist coarse grain is not large.
【作者单位】：中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室;浙江省工程勘察院;
【基金】：国家自然科学基金(No.51079142) 中国科学院重点部署项目(No.KZZD-EW-05) 湖北省谷城至竹溪高速公路科技项目(No.GZL-KJ-02-01)
【分类号】：TU45

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