Model validation using induced tensile stress during cracking process measured with desiccation stress tests

¹ Tokyo Institute of Technology, School of Environment and Society, 1528550 Tokyo, Japan
² Kyoto University, Graduate School of Engineering, 6158540 Kyoto, Japan

^* Corresponding author: sawada.m.af@m.titech.ac.jp

Abstract

Tensile stress is internally induced when soil shrinkage due to desiccation is restricted, and cracks occur when the induced tensile stress reaches tensile strength. Various numerical models have been proposed to predict crack initiation; however, the validity of the computed internal stresses during the cracking process has not been assessed, although the internal stresses directly influence the crack initiation. The aim of this study was to demonstrate the effectiveness of a laboratory-based desiccation stress test, which measures the induced tensile stress until crack initiation. Desiccation stress tests were performed on unsaturated sandy soil with two different water contents. The measured tensile stress until cracking was numerically simulated using a hypo-elastic model based on the skeleton stress considering the suction effects. The computed tensile stress was consistent with the measured values throughout the cracking process in both cases, with different initial water contents. Stress-based validation using the results of the desiccation stress test demonstrated that the proposed constitutive model yields reliable estimations of the internal tensile stress in unsaturated soils until crack initiation.