The root pile, a new type of pile foundation with a variable cross-section, is introduced. The mechanism of root piles under uplift and lateral loading and the construction process are presented and discussed. The bearing capacity of root piles under uplift loading, lateral loading, and combined uplift and lateral loading was compared with that of conventional straight piles through field loading tests, which were performed on two straight piles and two root piles. The results indicate that the uplift and lateral bearing capacity of root piles is significantly greater than that of straight piles; the combined uplift and lateral loading has almost no influence on the uplift bearing capacity of single piles, but would weaken their lateral bearing capacity; the roots are engaged gradually from the top to the bottom under uplift loading; the resistance of the roots increased substantially because of the interaction between the soil and roots; however, the side friction of the pile shaft above the roots decreased because of this interaction. Increasing the burial depth of the roots could improve the performance of the roots for building applications.

介绍了根桩，这是一种新型的具有可变横截面的桩基。介绍并讨论了根桩在抗拔和侧向荷载作用下的作用机理及施工过程。通过在两个直桩和两个根桩上进行的野外荷载试验，将根桩在竖向荷载，侧向荷载以及组合的竖向和竖向荷载下的承载力与常规直桩进行了比较。结果表明，根桩的抗拔力和侧向承载力明显大于直桩。竖向荷载和水平荷载共同作用对单桩的竖向承载力几乎没有影响，但会削弱它们的横向承载力。在隆起作用下，根部从上到下逐渐啮合。根系的抵抗力由于土壤和根系之间的相互作用而大大增加。但是，由于这种相互作用，桩身根部上方的侧向摩擦减小了。增加根部的埋葬深度可以提高根部在建筑应用中的性能。