| 摘 要： | - At the sites of the harbours along the coast of China, especially in the vicinity of the mouth of the Yellow River, the Yangtze River and the Pearl River, the soil strata often consist of recently deposited alluvial sediment. Therefore, under the foundations of harbour engineering structures there are always soft clays of considerable thickness. In this paper, the definition of soft clay is at first given according to the Chinese Foundation Code of Harbour Engineering. Then the physical and mechanical properties of some soft clays at the sites of harbour along the coast of China are summarized. These soft clays are classified into four types according to their physico-mechanical characteristics: very soft clay (mud), soft (muddy) clay, soft (muddy) silty clay and very soft clay (mud) mixed with lumps of sand. It is seen from the collected data that the physico-mechanical characteristics for soft clay of the same type at various sites along the coast of China are very similar, which implies that these soft clays may be formed from the similar geological origin and in similar environmental condition. It is well known that the soft clay with such unfavourable engineering properties as high water content, low shear strength, high compressibility and low permeability, is a rather weak foundation for structures, hence there would be frequently some problems happened during the construction of structure on it. However, these problems more or less can be avoided, provided that the soft clay strata have been explored, tested and analyzed carefully and appropriate measures are taken during construction. The problems usually encountered in the construction on soft clay are deformation and stability. The experiences and lessons learned on these respects in China are illustrated with 10 case histories of different types.
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