Test On Soft Foundation Of Area Along Yangzi River Improved By MIP

As a kind of method to treat the soft soil foundation, MIP 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, and considering of complexity of engineering geology condition, important project usually confirms feasibility of MIP composite foundation by indoor and in-situ experiment, and provides gist for design, construction, examination and inspection.On the basis of introducing the mechanism of reinforcing by MIP composite foundation, flows of design and construction, ways of examination and inspection. This text considers the project demands of Chizhou power plant, according to physical and mechanics experiments of different cement-mixture ratio soil, compares difference of physical property between MIP and original soil, analyzes factors of affecting MIP strength, such as ages, kinds of pole etc., and provides gist for experiments in-situ. By load tests in-situ of single pole and composite foundation, analyzes breaking theories of MIP single pole and MIP composite foundation, compares reinforce affection of two types (Dry powder mixing method and Deep bed stirring method) , and recommends Dry powder mixing method that fits to engineering geology condition and the hydrology geologies condition; analsizes and recommends cement-mixture ratio, displacement rate and construction technics which were used in engineering design; By systematical analysis of CPT ,dynamic-sounding test ,digging ,low strain dynamic test, etc., The paper provides standard and basis for monitors in construction, quality examination after construction.At last, the text discusses briefly on development direction of cement soil pole composite foundation, also points out direction for study works later.In a word, it satisfied the needs for project by experiments study works listed in the text. At the meantime, it provides a beneficial study for foundation treatment of soft soil along YangZi River, and has reference to similar projects, also provides beneficial theories and references for engineering application of MIP composite foundation.