粉质黏土-混凝土衬砌接触面冻结强度影响因素显著性分析

冻土与结构接触面的力学性能对寒区工程研究具有重要意义， 容易受到外界因素干扰。为研究不同因素对粉质黏土与混凝土衬砌接触面冻结强度的影响， 设计考虑含水率、 冻结温度、 冻结时间的三水平正交直剪试验。试验结果表明： 在冻结初期， 提高土体含水率， 降低冻结温度， 延长冻结时间有利于接触面早期冻结强度的提升， 且这种作用效果是线性的。基于显著性分析理论， 发现含水率、 冻结温度、 冻结时间对接触面早期冻结强度的显著性等级均为极显著， 三者之中， 冻结温度影响最大， 含水率影响最小。采用多元线性回归， 忽略因素之间的二阶交互作用， 建立了考虑含水率、 冻结温度、 冻结时间作用的粉质黏土与混凝土接触面的冻结强度预测模型， 为类似工程提供科学参考。

Significance analysis of factors of freezing strength between silty clay and concrete lining

The mechanical properties of the interface between the frozen soil and various structures play an important role in most engineering in the cold region， which are affected by many factors. In order to study the influence of the freezing strength of the interface between the silty clay and the concrete lining， the orthogonal direct shear test considering the water content， freezing temperature and freezing time was carried out. Test results reveal that increasing water content， lowering freezing temperature and prolonging freezing time can improve the early freezing strength of the interface， and this promotion is linear at the beginning of the freezing process. Based on the theory of significance analysis， it is found that water content， freezing temperature and freezing time have significant influences on the early freezing strength of interface， while the interaction between the three factors has little effect on the freezing strength. Among the three factors， the significance queue is： freezing temperature > freezing time > water content. The second-order interaction between factors was ignored in the multivariate linear regression analysis. The prediction model of the freezing strength of the interface between silty clay and concrete is established， which is affected by the water content， freezing temperature and freezing time.