Field Tests on Deformation Property of Self-Weight Collapsible Loess with Large Thickness

Abstract

To study the deformation property of large-thickness self-weight collapsible loess and to understand the moisture migration law and matrix suction characteristics, a 40-m-diameter soaking test was conducted in the field with self-weight collapsible loess at a thickness of 36.5 m. The results showed that (1) the field collapse deformation law of the large-thickness self-weight collapsible loess varied in two periods, namely, the soaking period and the water cutoff period; (2) during the soaking test, the distribution of crack patterns appeared from local to overall, from near to far, and from dense to sparse, then gradually extended; (3) the volumetric moisture content changed in different soil locations; (4) suction developed steadily before soaking, whereas with a large amount of water, suction dropped steeply within a short time; and (5) the water content of soil above 20 to 25 m increased rapidly and soon reached saturation, whereas the water content of soil below that depth increased slowly and reached saturation with difficulty. The test results may be useful for similar projects in the area of self-weight collapsible loess with large thickness, and to help revise Chinese codes for building construction in collapsible loess regions.