PS加固坎儿井井壁黄土的工程特性试验研究

冻融循环引起的井壁剥落是坎儿井破坏的初始阶段和主要形式.为探究高模数硅酸钾(PS)加固井壁的工程特性,进行了PS改良坎儿井黄土冻融循环后的冻胀与强度试验.结果表明:掺入PS可显著提高土样的起始冻胀含水率,并大幅削弱土体冻胀量,但冻胀量并不随PS掺量的增加而降低,掺量过大使孔隙水分存在部位发生变化是其主要原因.随着PS掺...

Experimental study on engineering characteristics of loess reinforced by PS in Karez sidewall

Sidewall spalling caused by freeze-thaw cycles is the initial stage and main form of Karez failure. In order to explore the engineering characteristics of high modulus potassium silicate (PS) reinforced sidewall, frost heave and strength tests of PS modified Karez loess after freeze-thaw cycles were carried out. The results show that PS can significantly increase the initial frost heaving water content, and greatly reduce the frost heaving amount of the soil samples, but the frost heaving amount does not decrease with the increase of PS content, mainly because the location of pore water changes with the increase of PS content. With the increase of PS content, the shear stress-strain curve transits from hardening to softening. At the same time, the curve before yield presents the transition characteristics of upward convex to approximate linear to downward convex, which indicates that the soil texture gradually changes from friction type to solidified type. With the increase of PS content, the peak strength of the samples increases significantly, among which the cohesion increases greatly, because the internal friction angle decreases with the increase of PS content. 3% PS content is feasible in restraining frost heave and strengthening sidewall for Karez. The research results have certain theoretical and practical significance for the reinforcement of Karez sidewall.