Abstract:Different from Previous solution，Least Square Model Solution of difference form of integrated exponential functional model is put forward to determine Parameters of integrated exponential function. Combining with field test, analyze the feature of fitted Q-S curve right by integrated exponential functional model. Then, discuss the reason of determining ultimate bearing capacity of single piles by the largest Curvature point of integrated exponential function. Last, For no broken single piles in field test，researched the feasibility of predicting ultimate bearing capacity of single piles and its top settlement by the largest Curvature point of Q-S curve，obtained conditions of predicting ultimate bearing capacity and limitations of predicting top settlement of no damaging single piles.

Abstract:In the geotechnical engineering design, it was difficult yet to estimate the settlement of pile group. Empirical coefficient is adopted to correct pile group settlement in national and regional codes, such as Code for design of building foundation and Technical code for building pile foundation. Great attention should be paid to the relationship between pile settlement and pile engineering practice, because pile and soil medium characteristic, relationship of pile top load and displacement and construction influence are all embodied in pile static load test. So it’s more reasonable that static load test results, that is static load test curve, should be combined with the analysis of pile group settlement. Then calculation method of pile group settlement applied with static load test results is proposed . many researches show pile group interaction theory overestimates interaction effect in pile group, this paper collects 77 observational examples including single pile settlement and pile group settlement, there are 71examples are used in calculating settlement ratio. Lastly six examples are analyzed with pile group settlement method applied with Q-S curve. Analysis results show the method is reasonable, more accurate and has strong regional applicability.