Experimental study on delamination frost heave of steel fiber-improved soil

The segregation frost heave caused by water migration is the main source of frost heave, and the water migration law is the key factor to reveal the mechanism of frost heave of soils in the freezing process. In order to explore the mechanism of inhibiting the frost heave of steel fiber-improved soil, the one-dimensional frost heave tests on the steel fiber-improved soil under the layered independent water supplement condition are carried out by using the improved frost heave devices. The following conclusions are obtained. Firstly, the frost heave in the lower part of the sample will cause the drainage of the unfrozen soil in the upper part, and the amount of water discharged from the middle and upper soil layers of the sample with steel fiber content of 0.5% during the freezing process accounts for 1.22% and 3.45% of the corresponding water inflow. Secondly, the steel fiber added in the soils can obviously reduce the water supply in the freezing process. Compared with the sample without steel fiber, the water replenishment in the middle and upper layers of the sample with steel fiber content of 0.5% decreases by 10.19% and 17.87%. Thirdly, the increase of content and length of the steel fiber can promote the water discharge from the sample and inhibit the growth of ice lens in the soils, which can reduce the amount of external water intake and reduce the frost heave deformation. The research results show that the drainage effects and the restriction of ice lens growth caused by the steel fiber are the main reasons for the inhibition of frost heave in the steel fiber-improved soil.