石灰改良膨胀土强度试验

Experiment on the strength of lime-treated expansive soil

以某边坡膨胀土为研究对象,在对石灰改良膨胀土的抗剪强度形成机理进行分析的基础上,用土力学中常用的快剪试验进行抗剪强度试验,研究了养护时间、初始含水率、掺灰率等与石灰改良膨胀土的凝聚力及内摩擦角的关系,根据试验结果,提出了综合考虑初始含水率与掺灰率的抗剪强度计算公式。结果表明:养护时间与抗剪强度参数不是直线关系,1～7d养护时间的增大值比7～28d大,初始含水率和龄期对凝聚力的影响比内摩擦角的影响大。此外,引用其他学者的试验数据分析了CBR值与养护时间、初始含水率、掺灰率等的关系,结果显示CBR值随着掺灰率的增大而增大,CBR值与初始含水率的关系与击实曲线类似。结合文中试验结果提出了采用最优含水率+3%为最优施工含水率。

Taking a slope of expansive soil as the research object, based on the analysis of shear strength formation mechanism of lime-treated expansive soil, the method of CQ test was used to study the relationship of curing-time.initial water content and lime rate, with the cohesion and the internal friction angle. According to the results of the tests, the author proposed the shear strength for- mula considering initial watercontent and lime rate. The results show that the relationships between cu- ring-time and the shear strength parameters are not linear , the increased 1~7 d curing-time is more than that of 7~28 d, and the influences initial water content and curing-time on the cohesion are greater than that of the internal friction angle. The author used the other author＇s test results to analyze the relation- ship between CBR and curing-time, initial water content, line rate. The results show that the CBR in- creased with lime rate and the relationship between CBR and initial water content is similar to the com- paction curves. Through the tests results the author proposes the optimum water content ＋3% as the optimal construction water content. 3 tabs, 9 figs, 12 refs.