蒙自重塑膨胀土膨胀变形特性与施工控制研究

Expansion characteristics and construction control of remolded Mengzi expansive soil

利用普通固结仪,进行了蒙自重塑膨胀土浸水、浸盐、浸酸的膨胀变形试验,系统研究了不同初始状态下膨胀土膨胀变形特性。利用Does Response模型较好地模拟了膨胀土浸水膨胀时程规律。通过膨胀土变形三元回归分析,得出了蒙自膨胀土膨胀变形与上覆压力、初始含水率、初始干密度的定量关系。膨胀土浸盐、浸酸膨胀变形规律与浸水时相似,但由于盐溶液的渗透压力,使得浸盐膨胀变形率降低;酸溶液浓度越高,其膨胀变形率越大,稳定时间越长。膨胀土膨胀变形规律的研究,为工程设计、施工与边坡稳定性评价提供了重要指标。

Swelling tests on remolded Mengzi expansive soil immersed with water, salt water and acid water were carded out by use of the simple consolidometers. Swelling characteristics of the expansive soil under different initial conditions were studied. The Dose Response model was used to fit the rules of swelling time interval for expansive soil immersed with water. The quantitative relationship among the swelling and over burden pressure, initial water content and initial dry density was attained by use of the ternary regression analysis. The rules of swelling for samples immersed with salt or acid water were similar to those of samples immersed with water. The swelling ratio of samples immersed with salt water was lower because of the seepage water pressure of salt water. The higher the concentration of the acid water, the higher the swelling ratio of samples and the longer the stabilization time. The important index obtained could be provided to the engineering design, construction and stability evaluation of expansive soil slopes.