中文摘要：

目前对于土体的干湿循环过程中变形、强度变化规律研究较多，而对经过多次干湿循环后土-水特征曲线的试验研究较少。由于吸力平衡需要时间太长，对干湿循环过程中土-水特征曲线的研究也多限于单次的干湿循环试验。但考虑到实际岩土工程中气候条件的多变性和自然环境的复杂性，一般土体均要经历多次干湿循环，因此，对多次干湿循环后的土-水特性曲线研究显得非常重要。结合已有的试验数据总结脱湿曲线与吸湿曲线随着干湿循环次数的变化规律，通过引入一个与干湿循环次数有关的函数，提出能预测多次干湿循环后土-水特征曲线的方法。本方法仅需土-水特征曲线的首次干湿循环脱湿与吸湿曲线和塑性指数，就可以预测多次干湿循环后的土-水特征曲线。

英文摘要：

Many researchers focus on deformation and strength of the soils experienced wetting and drying cycles. But few researches have been conducted on soil-water characteristic curve of the soils experienced wetting and drying cycles. Because the processing of suction equalization takes too long time, the studies of soil-water characteristic curve of the soils experienced drying and wetting cycles are mostly limited to a single wetting and drying cycle. But considering the variability of the actual climatic conditions encountered in geotechnical engineering and the complexity of natural environment, generally soils experience many drying and wetting cycles. Therefore the study of the soil-water characteristic curves of soils experienced many drying and wetting cycles is significant. On the basis of the existing experimental data about the variation of the drying and wetting curves with the numbers of drying and wetting cycles, a method is proposed by introducing a function of the number of drying and wetting cycle, which is capable of predicting the soil-water characteristic curve of soils experienced drying and wetting cycles. Once the first drying and wetting curves and plasticity index of the soil are given, the method can predict the soil-water characteristic curve of the soils experienced drying and wetting cycles.