Effect of Drying and Wetting during Curing on Strength-Deformation Characteristics of Cement-Treated Soil

由于地下水位的变化，地下水位附近的地面会伴随着反复的干湿变化。本研究主要探讨水泥土在干燥与湿润状态下，其强度与变形特性之变化。对试样进行了以下三种条件：（1）不干燥和润湿（2）干燥（3）干燥和润湿。通过无侧限压缩试验和三轴压缩试验，研究了试样劣化后力学性能的变化，结果表明，在养护初期即刚放置后干燥，未达到足够的硬度，试样的强度有所提高。然而，在长期养护后干燥和润湿试样的条件下，明确了强度降低。根据劣化引起的强度降低，峰值强度线走向剩余强度线。水泥土的屈服轨迹呈规律性收缩，说明水泥土的劣化现象与泥岩类似。此后，需要进行更详细的实验。

The ground near ground water level receives repetition drying and wetting accompanying due to the change of ground water level. In this study, the change of strength-deformation characteristics of the cement-treated soil received the drying and wetting during curing is clarified. The following three conditions were given to the specimens : (1) no drying and wetting (2) drying (3) drying and wetting. The change of mechanical properties due to deterioration were examined by the unconfined compression test and the triaxial compression test.As a result, the strength of specimen increases under the condition that the specimens were dried during early period of curing, in other word just after placing, which does not get enough hardness. However, under the condition that the specimens were dried and wetted after long-term curing, it was clarified that strength decreased. The peak strength line goes the residual strength line according to the decrease of strength due to deterioration. Moreover, it was become clear that the yield locus shrinks regularly.It was clarified that the deterioration phenomenon of cement-trated soil similar to the mudstone's one. Hereafter, a more detailed experiment is required.