Abstract:

Through triaxial permeability tests and conventional permeability tests on reshaped Yangling loess of different dry densities, we analyzed the rules of permeability coefficient variation of the saturated loess respectively in gas-free pure water with pH=7.0, and acetic acid solution with pH=3.0, pH =4.0 and pH=5.0. We also investigated the degradation of loess permeated with acid solution. The research provides basis for analyzing the strength variation and the stability of loess structures permeated with acid solution. The results are as follows: (1) the permeability coefficient of saturated loess decreases with the growth of dry density; (2) with a constant dry density, the permeability coefficient reduces along with the increasing of confining pressure; (3) the largest permeability coefficient appears when the loess is permeated with acid solution with pH=3.0 in short-term, and with the rise of pH value, the permeability coefficient decreases as a result of the dissolving of insoluble salts by hydrogen ions of acid solution, forming new seepage channels. The permeability coefficient of pure water with pH=7.0 is between that of acid solution with pH=3.0 and pH=4.0. It is because that the pure water used in the test is boiled and gas-free, while there is small amount of gas in the acid solution for the test;(4) the permeability coefficient reduces with the increasing of time. 

Key words: reshaped loess, acid solution, permeability test, penetrability