| With the development of national economy, the construction of large-scale building for example high-rise building , large-scale bridge and so on have been constructed, as key foundation on this type of building——large-sized cast-in-place pile applied more and more widespread. Designation of full diameter cast-in-place is satisfied with engineering load and economic security, the determination of pile bearing capacity is the key whether the whole pile foundation is satisfied with engineering request At present, the methods for determining pile bearing capacity are static test, dynamic test(low strain dynamic test, high strain dynamic test), statnamic test and self-balanced test. The several methods have been applied in many engineer experience, obtained some achievement. Owing to the deficiency of experience technology or theory, several test methods have been some question. Static load test is visual and credible, but high cost and taking time, it is difficult to define suitable reactive system. Dynamic test fast and handy, pile body quality detective result is credible. Dynamic component is high, the credibility of testing result is worse; it is only used as indirect method. Statnamic method includes the merit of static test and dynamic test, testing result is same as static test, which is popular in the world, but study on the method is lack. In addition, reactive system of this method is difficult to realize. Self-balanced test that device is simple, doesn't occupy ground and isn't need of anchor pile or pressure platform. However the stress condition of pile between the test and the real engineering is different. There is some question to converse this method to static test. Therefore, there are many types of pile testing method, and perfect development. However there is some flaw and shortage in respective method. A new kind definition method of pile foundation is introduced in the paper, study on this aspect is deficient in the world. There is more firm theory base in simulation test method, it can simulate engineering geology property of the real pile better, consider the respective factors effect on the pile bearing capacity, such as strata environment ,making pile craft. System and deep study on this method will offer the new method and new path of the definition of pile bearing capacity. The simulation test method for determining pile bearing capacity is principally studied in the paper. ①feasibility analysis is made for the simulation test method, and the similarity of lateral friction and tip resistance is introduced. Considering strata environment and making pile craft, with the laboratory middle shearing friction test lateral friction is simulated, obtain frictional strength parameters C ,? . Based on the property of rock resist compression, using similarity theory the performance of pile end , by laboratory triaxial test tip resistance is achieved. ②through detailed engineering geology reconnaissance the geology condition of testing pile is certain, by laboratory test the index in the property of physics and mechanics can be obtained, and the stress~displacement will be drew out. The test data and curve is disposed. ③in the process of the definition of pile bearing capacity, there are three methods on interacting between pile and soil, one is strata weight determining normal stress between pile and soil, the other is analysis method on finite element method, the last is strata weight...
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