全尾砂固结体固结过程孔隙与强度特性实验研究

Experimental study on the pore and strength properties of cemented unclassified during the consolidation process

为探明全尾砂固结体在固结过程中的孔隙与力学参数变化规律及其间的定量关系,以不同条件下全尾砂固结体为研究对象,采用压汞法、单轴压缩和剪切试验等方法,着重分析其孔隙率、平均孔径、单轴抗压强度、内聚力和内摩擦角的变化规律.结果表明:养护龄期显著改变固结体的孔径尺寸及分布,随着养护龄期的增加,微小孔径(10~100nm)比例增加,孔隙率降低;在养护龄期28d之内,不同灰砂质量比和质量分数固结体的单轴抗压强度增长规律随龄期变化基本相同,皆遵循指数函数曲线增长规律,强度增长曲线趋势与灰砂质量比、料浆质量分数以及养护龄期正相关;灰砂质量比、质量分数和养护龄期对固结体的内聚力影响显著,对内摩擦角影响较小;单轴抗压强度、内聚力和内摩擦角均与孔隙率、平均孔径呈非线性负相关,基本遵循指数函数y=ae^(-bx)的定量关系;孔隙率对单轴抗压强度影响显著.

Mercury intrusion porosimetry（MIP）and uniaxial compression and shear tests for unclassified tailings consolidation mass were conducted to investigate the quantitative relation between pore structure and mechanics parameters of consolidation mass samples during consolidation process,especially focusing on the change rule of the porosity,mean pore size,cohesion,friction and uniaxial compression strength（UCS）.The results show that the curing time significantly affects pore characteristics including size distribution.With the increase of curing time,the proportion of the small pores（pore diameter belongs to 10～100nm）increases and the porosity decreases.Within the curing time of 28 days,the UCS change rules of different cement-tailing ratios and mass concentrations are almost on the same development laws,following the growing law of the exponent function.The UCS growth trend positively correlatesto the cement-tailing ratio,mass concentration and curing time.The influence of cement-tailing ratio and mass concentration on the cohesion of consolidation mass is larger than the parameters on the friction.The UCS,cohesion and friction have a good quantitative relation with the porosity and the mean pore,in accordance with the growth function of y=ae^-bx.The porosity exerts a profound effect on the UCS growth during the consolidation process.