Laboratory study for effects of vacuum preloading on physical and mechanical properties of soft clayey soils

摘要

A new triaxial apparatus was designed and manufactured. It is able to apply surcharge and combined vacuum-surcharge pressures on soil samples, and allows for monitoring of excess pore-water pressure, axial strain or settlement, and volumetric strain during the process of consolidation. Tests were performed using the apparatus on undisturbed soft clayey soil samples, which were collected from Wenzhou, Zhejiang Province, China, at average natural water content 72. 5% . The consolidation behavior of theclay has no rigorous difference, whether it is consolidated under the vacuum, surcharge, or combined vacuum-surcharge preloading. The study shows that some physical properties of the soft clayey soils are changed and mechanical properties are improved to support excessive loads transferred to the soil foundation due to construction.