VERTICAL BEARING CHARACTERISTICS OF COMPLEX HIGH FILL SOIL-PILE SYSTEM IN LOESS AREA

To select the appropriate type of building foundation and to study the bearing characteristics of pile foundations in deep filling soil, the similarities and differences of the law and distribution of the moment, as well as the axial force and the skin friction along the drilling pile in dig area, dig and fill area and fill area under axial load at different levels are studied by ABAQUS software. In succession to this, the curve of settlement and load in different site of geological conditions was analyzed, Furthermore, the bearing capacity of drilling piles in different sites was predicted. Results shows that the bearing type of the drilling piles behave as end-support friction piles in site of dig and fill area and drilling pile shows larger positive moment and negative friction near the interface of dig and fill area; with the all level to vertical load, the settlement of drilling pile in fill area is greater than the others, the bearing capacity is the weakest, while the settlement of drilling pile in dig area is the minimum, the bearing capacity is the best. The suggestions of bars reinforcement design and construction measures to reduce the negative skin friction and enhance the bearing performance of drilling pile are proposed combined with codes and related literature. The conclusion can provide the reference for design and construction of building pile in this project and projects in other deep filling soil.