水泥土劣化深度-时间关系预测

为研究水泥土劣化深度-时间关系,进行了水泥土室内劣化,建立了水泥土的劣化深度、完全劣化深度和劣化过渡层深度与时间的幂函数关系式。试验结果表明:水泥土初始强度对劣化水泥土贯入阻力曲线性状无明显影响;劣化水泥土是劣化程度随时间增大的非均质体,由强度几乎为0的完全劣化层、强度随深度增加的劣化过渡层以及强度可看成与同龄期标准养护水泥土相同的未劣化区共3部分组成。水泥土劣化深度、完全劣化深度和劣化过渡层深度均随水泥土初始强度增大而减小。劣化深度-时间关系预测式(幂函数)中,系数分别为90 d劣化龄期的水泥土劣化深度、完全劣化深度和劣化过渡层深度,指数A取值与劣化类型、室内劣化试验或现场劣化试验无关,均可取0.6。此时,计算结果与试验结果具有较好的一致性,可利用该式预测固化土劣化深度。

Prediction of Deterioration Depth of Cement Soil over Time

The exponential functions of deterioration depth, complete deterioration depth and deterioration transition layer depth over time were established via indoor deterioration test on cement soil. The experimental results showed that the initial strength of cement-soil had no significant influence on the penetration resistance curve of degraded cement-soil. As an inhomogeneous body with the deterioration degree increasing with time, degraded cement-soil was composed of three parts: the completely degraded layer with a strength of almost zero, the transition layer whose strength increased with depth, and the undegraded zone whose strength could be regarded as the same as the standard curing cement-soil of the same age period. The deterioration depth, complete deterioration depth and transition layer depth of cement-soil reduced with the augment of the initial strength of cement-soil. In the prediction formula of deterioration depth against time, the coefficients were respectively the deterioration depth of cement-soil at 90 days of deterioration, the complete deterioration depth, and the deterioration transition layer depth. The value of the index was 0.6 regardless of the degradation type, indoor degradation test or field degradation test. At this time, the calculation results were consistent with the test results, and the formula could be used to predict the deterioration depth of cement-soil.