石灰改良滨海氯盐渍土的室内试验研究

Treatment of Coastal Chloride Saline Soil by Lime Addition

研究了石灰固化滨海盐渍土物理力学性质的变化规律及其影响因素,结果发现：经石灰改性后,滨海盐渍土的粒度成分得到明显改善,有利于其获得较大的干密度并提高填筑性;塑性指数降低,液限降低;石灰掺量超过3%（质量分数,下同）之后,改性土的砂化作用明显,如石灰掺量为3%~9%时,其塑性特征及粒度成分得到明显改善,强度也得到较好提高,石灰掺量为7%~11%时,其水稳定性及强度得到显著提高,石灰掺量为9%~15%时,其浸水无侧限抗压强度已达到二级和二级以下公路底基层无侧限抗压强度的基本要求,从而为有效利用滨海盐渍土来解决滨海地区道路建设中修筑材料匾乏、土源紧张的问题提供了借鉴与依据.

The physical and mechanical properties of coastal saline soil treated by lime addition and the variation of the properties and factors affecting the properties were investigated.The grain size distribution is improved clearly,which will lead to favorable compaction when the soil is backfilled.Plastic limit is increased and liquid limit is decreased,which leads to a decreased plasticity index.When the lime addition ranges between 3%-9%,major properties,e.g.,plasticity,size distribution and unconfined compressive strength（UCS）,are improved clearly.When the lime addition increases to 7%-11%,the UCS and the immersion stability（i.e.UCS after immersion） of treated soils increase further significantly.When the lime addition increases to 9%-15%,the UCS before and after immersion meet the values required for subbase of the roads of grade Ⅱ or less.The coastal saline soil can be utilized and the scarcity of fills can be solved effectively at coastal regions.