由于在开发软土层很厚(达30～40米)的西比利亚、远东和其它地区时,应用打入桩的平均长度有增大的趋势,故组合桩得到了广泛的发展。从1964年开始试用这种桩,而刭1981年应用量已达刭13万立方米以上。已经积累了许多组合桩实际应用经验,并对组合桩在沉桩过程中以及在静荷载作用下它们的性状进行了一系列的研究。但是,某些问题(例如沉桩过程中桩的稳定性,桩位偏差的 Due to the tendency to increase the average length of driven piles in the development of Siberian, Far East and other areas where the soft soil layer is very thick (up to 30-40 meters), the composite pile has been widely developed. The trial of this kind of pile began in 1964, and the application of the pile reached more than 130,000 cubic meters in 1981. Many practical experiences of composite piles have been accumulated, and a series of studies have been conducted on the properties of composite piles in the process of pile sinking and under static load. However, some issues (such as pile stability during pile driving, pile position deviation