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| Deformation and strength behaviors of unsaturated loess considering the influence of closed gas phase |
| QIN Biao1，LI Xi?an1，WANG Li2，CHAI Hao1 |
(1. School of Geological Engineering and Geomatics，Chang?an University，Xi?an，Shaanxi 710054，China；2. College of
Architecture and Civil Engineering，Xi?an University of Science and Technology，Xi?an，Shaanxi 710054，China) |
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Abstract Loess is susceptible to significant changes in strength and volumetric strain under loading or wetting. In this study，to address the soil response induced by wide variations of saturation under hydro-mechanical action，an elastoplastic model considering the entire possible range of suction and stresses is developed by focusing on the case of multi-phase coupling in unsaturated loess，using the generalized effective stress and modified suction as the stress variables. This model unifies the situation of gas phase closure caused by high saturation into the generalized effective stress framework，introduces the damage parameter for the influence of closed gas on soil，and uniformly describes the deformation and strength of unsaturated loess under wide variations of saturation. The reasonableness and reliability of the model have been verified through the corresponding stress and hydraulic path tests. The results show that the proposed model can better reflect the loading effect of unsaturated loess influenced by the closed gas. It adeptly reflects not only the coupled hardening of the solid-liquid phase but also accurately portrays the influence of closed gas on deformation and strength under different hydro-mechanical actions.
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2024, Vol. 43 
