生石灰添加对北方粉质盐碱渠基土冻胀融沉改良研究

Study on improvement of frost heave and thaw settlement of silty Saline-Alkali canal foundation soil by adding quicklime

为控制和改善由于北方寒区冻融过程所导致的渠道基土的冻胀变形等现象,丰富盐碱渠基土改良相关工程的理论和经验。研究采用室内试验的方式,选择能对生石灰改良渠基土冻胀融沉特征产生影响的生石灰掺量、冷端温度以及含水率3个因素,在不同梯度水平条件下进行单因素冻融试验,通过探讨各因素对生石灰改良粉质粘土冻胀率和融沉系数的影响规律,确定改良的最佳掺量条件。结果显示,生石灰最佳掺量为12%,且尽量降低渠基土的初始含水率,可达到控制冻胀变形,防止冻胀破坏的目的。相关结论可为相关工程应用提供有益的借鉴和思考。

In order to control and improve the frost heave deformation of canal foundation soil caused by freeze-thaw process in northern cold region,and enrich the theory and experience of saline-alkali canal foundation soil improvement engineering,the study selected three factors,namely,quicklime content,cold end temperature and water content,and carried out a series of laboratory testsunder different gradient levels.By discussing the influence of various factors on the frost heave and thawing settlement coefficient of quicklime improved silty clay,the optimum content conditions are determined.The results show that the optimum content of quicklime is 12%,and the initial moisture content of canal foundation soil can be reduced as much as possible,which can control frost heave deformation and prevent frost heave damage.The relevant conclusions can provide useful reference and thinking for related engineering applications.