论文部分内容阅读
为研究岩溶地区水库蓄水不同条件下动水压力驱动下的碳酸盐岩溶蚀作用机制。以乌江流域某水电站坝前地区碳酸盐岩为研究对象,利用自行研制的开放体系压力溶蚀实验系统,对不同动水压力(0～2.0MPa)条件下CO2水溶液溶蚀碳酸盐岩的过程进行实验模拟,其结果显示,动水压力增大会引起碳酸盐岩的溶蚀作用加剧,溶解速率曲线随动水压力的变化而发生显著改变;随动水压力的增大,岩石的化学溶解量和机械破坏量同时增大,两者的比值随着压力增大逐渐趋于1:1,两者之间存在耦合关系。采用扫描电镜与压汞试验相结合的方法进行微观研究发现,动水压力对碳酸盐岩的溶蚀作用不仅发生于岩石表面,使表面溶孔增大并加深,产生次生孔隙和次生矿物,同时还改变着岩石的内部孔隙结构,降低其渗透性并弱化结构面的连接。
In order to study the mechanism of carbonate dissolution driven by hydrodynamic pressure under different conditions of reservoir impoundment in karst areas. Taking the carbonate rock in the dam area of a hydropower station in the Wujiang River basin as the research object, the open system pressure corrosion experiment system developed by ourselves was used to study the carbonate carbonate dissolution under different hydrodynamic pressure (0 ~ 2.0MPa) The experimental results show that the increase of hydrodynamic pressure causes the dissolution of carbonate rocks to aggravate, and the dissolution rate curve changes significantly with the change of hydrodynamic pressure. With the increase of hydrodynamic pressure, the chemical dissolution of rock and The amount of mechanical damage increases at the same time, and the ratio of the two tends to be 1: 1 as the pressure increases. There is a coupling relationship between the two. The microscopic study on the combination of scanning electron microscopy and mercury intrusion porosimetry shows that the dissolution of hydrodynamic pressure on carbonate rocks not only occurs on the rock surface but also increases and deepens the surface pores and produces secondary pores and secondary minerals , While also changing the internal pore structure of the rock, reducing its permeability and weakening the structural surface connections.