Recently

geosynthetic clay liners (GCL) have been more and more used in different anti-seepage engineering projects; and bentonite’s microstructure in GCLs after hydration has great influences on its long-term hydraulic properties and mechanical characteristics. Based on quantitative analysis of bentonite’s microstructure in GCLs after hydration

the influence of liquids is discussed and the mechanism of the influence is revealed by chemical analysis of liquids. The results show that: ①when the hydration liquid is landfill leachate

the pore volume density of bentonite is the biggest

and the ratio of large pores is the highest; ②the reasons of the above rule lie in two aspects. On one hand

thickness of montmorillonite surface double-layer is the smallest because of high cation concentration in landfill leachate. On the other hand

the ratio of large cations on montmorillonite surface is the highest because of more frequent cation exchange.