Compression behavior of sand-clay mixtures and formation mechanism of coarse granulesand skeleton
Wu Zilong1, Zhu Xiangyang2, Deng Yongfeng1, Liu Huashan3
1. Southeast University, Nanjing 210096, China; 2.Lianyungang Port Group, Lianyungang 222100, China; 3.Construction department of Ganyu port, Lianyungang 222100, China
Abstract：To study the compression behavior of the clay-sand mixtures, the oedometer experiments were conducted based on a series of soils with different sand-clay mixing ratios and water contents, so that the formation mechanism of the coarse granule skeleton can be investigated. The main results show that although the common indices (e/eL and Iv) used for evaluating and normalizing the behavior of pure clays can be extended to the sand-clay mixtures, the obvious difference in compression behavior between the pure clay and the sand-clay mixtures indicates that the applicability of these indices to the sand-clay mixture should be reevaluated. The internal mechanism causing the difference may be attributed to the formation of sand skeleton, while before and after the formation of sand skeleton, the compression behavior of the mixture was governed by clay and sand, respectively. By introducing the four-phase system of sand-clay mixture, the formation mechanism of sand skeleton was clarified based on the void ratios of clay and sand, and then the difference in compression behavior between the pure clay and sand-clay mixture was interpreted. Finally, a method of predicting the formation of the sand skeleton was proposed, and according to the method the threshold between two compression mechanisms can be determined. The research results should be helpful for clarifying the compression mechanism of the sand-clay mixture, and can be referred when calculating the settlement of ground composed of this kind of soils.
