The Experimental Research On Handling Collapsible Loess Foundation With Replacement Cushion And Lime- Loess Compaction Pile

Loess is powder-based,low natural moisture content, more pores, brown or yellow, calcareous clay soil. Collapsible loess is a kind of loess whose soil additional deformation will be significant because of its structure damage under the action of water and gravity stress or additional stress or overlying soil stress. In Shanxi,collapsible loess is widespread, and more and more construction projects are built in the loess, but the collapsibility characteristics of loess is a very negative factor to various types of engineering, which is the main reason that causes building structures cracking and sinking, especially in recent years, large building is more and more, and thick, large collapsible loess foundation treatments are also emerging and increasing,building built in the loess, often occurs hazards associated with the nature of the loess, So collapsible loess research and treatment is necessary, and it is also important in the engineering field. The main work of this paper include:Firstly, by the microscopic analysis of the causes and mechanism of collapsibility the nature of collapsibility and the origin of collapsibility coefficient have been revealed.Introducing and analysing the common collapsible loess treatment methods which is used in wet areas to eliminate the foundation collapsibility, especially analyzing the advantage of the replacement method(the whole piece cushion handling) and lime soil pile in handling the collapsibility of loess foundation. Combined with engineering examples, respectively analyzing the loess foundation treatment effect of replacement method and lime soil pile method to provide guidance for the foundation treatment in Guanzhong area and surrounding buildings,which have practical significance.Secondly, observing the settlement of the building which used replacement method and lime soil pile method to plot time-settlement, and using the growing exponential approach to fit settlement- time curve, which can predict the total settlement of replacement method foundation and lime soil pile method foundation. From the amount of settlement, we can conclude which method is better in foundation treatment in the area, the result is that lime soil pile foundation treatment method in the area is more suitable to promote.Finally, introducing the concept of the engineering cost, and listing the project bill of replacement method and lime soil pile method. From the project bill, we can conclude which method is better, the result is that lime soil pile is better.