Lateral Earth Pressure Coefficient of Soils Subjected to Freeze–Thaw

Artificial frozen soils (AFS) have been used widely as temporary retaining walls in strata with soft and water-saturated soil deposits. After excavations, frozen soils thaw, and the lateral earth pressure penetrates through the soils subjected to freeze–thaw, and acts on man-made facilities. Therefore, it is important to investigate the lateral pressure (coefficient) responses of soils subjected to freeze–thaw to perform structure calculations and stability assessments of man-made facilities. A cubical testing apparatus was developed, and tests were performed on susceptible soils under conditions of freezing to a stable thermal gradient and then thawing with a uniform temperature (F_nonuni–T_uni). The experimental results indicated a lack of notable anisotropy for the maximum lateral preconsolidated pressures induced by the specimen’s compaction and freeze–thaw. However, the freeze–thaw led to a decrement of lateral earth pressure coefficient $K0$⁠, and $K0$ decrement under the horizontal F_nonuni–T_uni was greater than that under the vertical F_nonuni–T_uni. The measured $K0$ for normally consolidated and over-consolidated soil specimens exhibited anisotropic characteristics under the vertical F_nonuni–T_uni and horizontal F_nonuni–T_uni treatments. The anisotropies of $K0$ under the horizontal F_nonuni–T_uni were greater than that under the vertical F_nonuni–T_uni, and the anisotropies were more noticeable in the unloading path than that in the loading path. These observations have potential significances to the economical and practical design of permanent retaining walls in soft and water-saturated soil deposits.