Abstract

Lime treatment combined with vacuum preloading has been used in the treatment of dredging slurry for many years. Previous studies have indicated that particle grading, which is one of the essential properties of slurry, could affect the pore-size distribution and compression characteristics of slurry and thus affect the efficacy of the lime treatment and vacuum preloading. However, the effect of particle grading has not yet been examined quantitatively. This study investigated the compressibility of lime-treated slurries with different particle gradings using a one-dimensional oedometer for compression testing. A series of laboratory model tests were carried out to examine the effect of particle grading on the efficacy of lime-treated slurry with vacuum preloading. The results showed that particle grading significantly influences optimal lime content. For clay or low-plasticity silt, the optimum lime content for lime treatment combined with vacuum preloading was found to be 2%. When slurry contains increased silt and sand grains, more lime is required to achieve effective lime treatment. However, excessive lime would reduce the efficacy of lime treatment on the compressibility and permeability of the soil.

摘要

石灰处理与真空预压相结合已用于疏浚泥浆处理多年。以往的研究表明，作为浆料基本特性之一的颗粒级配会影响浆料的孔径分布和压缩特性，从而影响石灰处理和真空预压的效果。然而，颗粒分级的影响尚未得到定量检验。本研究使用一维 oedometer 进行压缩测试，研究了具有不同颗粒等级的石灰处理浆料的可压缩性。进行了一系列实验室模型试验，以检查颗粒分级对真空预压石灰处理浆料效果的影响。结果表明，颗粒级配显着影响最佳石灰含量。对于粘土或低塑性粉土，石灰处理与真空预压相结合的最佳石灰含量为 2%。当泥浆中含有更多的淤泥和沙粒时，需要更多的石灰来实现有效的石灰处理。然而，过量的石灰会降低石灰处理对土壤可压缩性和渗透性的影响。