饱水时间对板岩物理力学特性劣化影响的试验研究

Experimental Study on the Effect of Slate Rock Mechanics Properties Degradation by the Saturation-time

通过单轴压缩试验、直剪试验和为期120 d饱水三轴压缩试验,结合板岩成分,研究了板岩在饱水之后的力学性质变化和水物理化学损伤机理。研究表明:自然浸水条件下,在最初4 d吸水率变化较大,约8 d之后板岩吸水率趋于稳定,但水岩作用依旧存在且明显滞后于吸水率的变化;随饱水时间的增长,各项力学参数试验均有衰减,饱水60 d后,板岩峰值强度趋于稳定。板岩水物理损伤主要受库区水环境影响,水物理损伤主要受水流导致矿物颗粒间胶结物和碎屑的运移和扩散,这与水化学损伤的水环境p H等密切相关。通过质量与强度变量,从宏观上量化评估板岩损伤劣化程度。

The mechanical properties changes and hydro-physico-chemical damage mechanism of slate after water saturation were studied by uniaxial compression tests,direct shear tests and a 120-day saturated triaxial compression experiment. The study reveals that under the condition of natural water immersion,the water absorption rate changes greatly in the first 4 d,and after about 8 d the water absorption rate of the slate tends to be stable,but the water-rock interaction is still lagging behind the water absorption. The mechanical properties parameters are decaying with the growth of water saturation time,after water saturation for 60 d,the peak strength of slate tends to be stable. The physical damage of slate water is mainly affected by the water environment of the reservoir area. The hydro-physico-chemical damage is mainly caused by the migration and diffusion of cement particles and debris,which is closely related to the p H of water environment. A quantitative assessment of the extent of slate damage from the macroscopic can be made through the quality and intensity variables.