The Research In Selection Of The Forms Of Building Foundation In Loess Ridge Area

Foundation engineering is an important part of construction engineering. It's a critical factor Whether the design of foundation engineering is reasonable or whether the construction quality of it is good. It affects whether the building is safe and economic reasonable. YanAn locates in the loess plateau, which is a typical loess ridge area. The ground of there having own characters, foundation design and construction is complicated, and there are plenty of problems to improve and solve.This paper analyzes and looks into the situation of constructive geology of YanAn. Considering the characters of loess ridge area, such as complex and changeable landforms, strong regional characteristics, and hardness to handle, and according to the engineering geological features of rock-soil body , this paper analyzes the soil layers which are suitable to be the basic bearing stratum, divides them into several types , and points out which kind of building foundation is proper for different layers of soil.Basic on analyzing the commonly used building foundations and the bearing stratum of loess ridge area, this paper differentiates between the structure loading(high-rise building, multistoried building and low-rise building),then makes choice between shallow foundation and pile foundation, through calculating the bearing capacity of foundation soil and the deformation of foundation. Furthermore, the paper analyzes economic factors when both shallow foundation and pile foundation can be used, and addresses reasonable building foundations that are acceptable. Measures to take in handling problems existing in the process of foundation building, such as the foundation on overlaying bedrock with big surface grade, fill foundation, the foundation on rough ground covered with hard and soft soil, and the foundation on collapsible loess are also suggested in this paper.The researching result of this paper is helpful with selection of the styles of building foundation in YanAn, or in other loess ridge areas. It also has important meaning in carrying through the basic principles regulated in the standards, such as"safe and suitable for use, advanced in technology, economical and reasonable, quality guaranteed and environmental". It has reference valuation and guiding meaning in construction building, especially in area plan and design. Finally, the researching result has fine economic and social benefit in turn the scheme brought out by YanAn government into reality in which the central district is built on hills.