非饱和软粘土在水位波动下的变形响应

Deformation Response of the Unsaturated Soft Clay under Water Level Fluctuations

近海环境下沉积的软粘土工程性质差,常具有较强的触变性和流变性,在地下水位反复波动的情况下,软土层会发生明显的沉降变形和回弹变形。为研究非饱和软土在地下水位波动下的变形特性,对取自于上海地下水位波动带内的非饱和软土进行试验。利用常规的固结仪,通过多次人工加水、排水模拟水位的循环升降,总结水位波动及波动次数对非饱和软土变形影响的规律,并讨论产生相应规律的机理。为解释地下水抽取与回灌形成的水位波动及工程施工荷载耦合作用下非饱和软土的变形规律提供依据。

Soft clay that deposits offshore has poor engineering properties,strong thixotropic and rheological property.Under the fluctuation of the water level,significant settlement deformation and rebound deflection might occur.Unsaturated Shanghai soft clay from the water fluctuation zone was used to conduct experiments for its deformation characteristics.The cyclic watering and draining conditions in the conventional oedometers were manually created in order to simulate the impact of the water level fluctuations as well as the cyclic numbers on the deformation properties of unsaturated soft soils.Results of these tests can be used in the interpretation of the unsaturated soft soil properties impacted by the groundwater level fluctuation induced by the cyclic extraction and recharge of groundwater.