循环荷载作用下红黏土累积变形研究

通过GDS动三轴设备对赣南红黏土进行了一系列排水条件下的大次数循环试验，研究不同循环应力比、固结应力比及围压对赣南红黏土累积变形特性的影响。结果表明：在不同固结应力比、固结压力和循环应力比条件下，红黏土的累积应变都呈现出先迅速累积，后增长变缓，最终稳定的趋势；在一定的循环次数之后，不同初始固结应力和不同初始应力比条件下累积应变与循环次数之间的变形规律呈现为线性关系，且初始固结应力和初始固结应力比越小，其线性相关性越好；不同循环应力比下赣南红黏土的平均累积应变速率与循环次数之间也呈现出明显的线性关系。此外，基于以上关系建立了赣南红黏土在长期循环荷载作用下的累积变形预测模型，并通过对比验证了该模型的可行性。

Accumulative Deformation of Red Clay in Southern Jiangxi under Cyclic Loading

Accumulative deformation characteristics of red clay in southern Jiangxi, China, subjected to drained cyclic triaxial loading, were investigated at different cyclic stress ratios, confining pressures, and consolidation ratios. Results indicated that the accumulative strain of red clay showed a tendency, first, toward rapid accumulation, then slow growth, and finally, stability under different cyclic stress ratios, confining pressures, and consolidation ratios. After a certain number of cycles, the cumulative strain and cycle number under different initial consolidation stress levels and initial stress ratios showed a linear relationship, with the smaller the initial consolidation stress and initial stress ratio, the better the linear correlation. There was also an obvious linear relationship between the average cumulative strain rate and the number of cycles under different cyclic stress ratios. Based on the relationship, the cumulative deformation prediction model under long-term cyclic load was established for red clay in southern Jiangxi, and feasibility of the formula was verified by comparison.