Test On Soft Foundation Improved By Dry Jet Mixing Pile

As a kind of method to treat the soft soil foundation, DJM has many advantages such as constructing expediently, expenses cheaply, reinforcing soft soil to big thickness, and it is widespread used in our country; It has obtained better economic and social benefits. But on account of that studies of it's reinforcing theory and breaking theory etc. are still not perfect, and applications in actual projects also appeared some problems. For safety and economics of projects, important project usually confirms feasibility of DJM composite foundation by experiment, and provides gist for design, construction, examination and inspection.On the basis of introducing the mechanism of reinforcing by DJM composite foundation, flows of design and construction, ways of examination. This text combines the project of student apartment, and estimates the reinforcing effect in theory by loading test, meanwhile the paper discusses the breaking theories of single and composite foundation, analyzes and compares the results of load test using different methods, and finally gives the bearing capacity vale of single and composite foundation. At the same time, it analyzes the relationship between the length of pile and value of descending and the relationship between the length of pile and bearing capacity in detail, and giving the relationship line between the length of pile and value of descending. In the end, it gets the relationship between the non-limited stiffness of cement soil and N₁₀ by analyzing the results of low strain dynamic test.In a word, it satisfied the needs for project by experiments study works listed in the text. At the meanwhile, it provides a beneficial study for foundation treatment of soft soil, and has reference to similar projects, also provides beneficial theories and references for engineering application of DJM composite foundation.