ISS对不同初始含水率膨胀土的改良效果研究

IMPROVEMENT EFFECT OF IONIC STABILIZER ON EXPANSIVE SOILS WITH DIFFERENT INITIAL MOISTURE CONTENTS

离子固化剂（ISS）对膨胀土改良后，膨胀土稳定性会改善。为了分析研究不同初始含水率的膨胀土经过ISS改良效果，进行了膨胀土改良前后的剪切试验、界限含水率试验和自由膨胀率试验。通过改良前、后土体的抗剪强度、塑限、液限、塑限指数、自由膨胀率的变化规律研究，得出膨胀土的初始含水率在11％～30％区间时，改良后土体的膨胀性得到了消除，抗剪强度得到了明显提高；初始含水率不在11％～30％区间时土样改良后仍具有一定膨胀性，抗剪强度提高不明显。这是因为，当膨胀土烘干时，靠毛细吸力吸附的固化剂量不能与所有黏土颗粒进行反应；当膨胀土饱和时，靠溶液渗透到膨胀土表面的固化剂也不能与所有黏土颗粒进行反应。该试验结果对膨胀土现场改良时含水率的确定具有重要的指导意义。

The stability of expansive soil can be improved after its treatment with ionic stabilizer（ISS）.Laboratory tests of direct shear,water ratio limit and free expansive rate are conducted,before and after the soil is meliorated, to analyze the ISS improvement effect on the expansive soils with different initial moisture contents.Results show that the expansibility of the soil has been eliminated.The shear strength is improved dramatically when the initial moisture content is at the range of 1 1%to 30%.However,little effects are revealed outside the boundaries.The ionic stabilizer is neither adsorbed by capillary suction when the soil is dried nor stuck to soil surface due to the penetration of the solution in saturated state can react with all the clay particles.Findings of the experiment are of great significance in determining the initial moisture content when site improvements on expansive soil with ISS.