S - Kam Ng PhD Dissertation Final.pdf - Digital Repository of CCEE ...

106studies available in literature. The database was established from a total of 96 field dynamictests using PDA and CAPWAP. These 96 data points were randomly split into two groups.The first group of 73 points was used for training the neural network model, while theremaining 23 points were used for testing the model. Six input parameters, soil type, piletype, pile diameter, pile length, time after pile installation, and effective stress at pile tip,were selected in the development of the model. To demonstrate the accuracy of this method,pile resistances estimated by the neural network model were compared with those from fourempirical relationships: Skov and Denver (1988), Svinkin (1996), Skov and Denver (1998)with Long et al. (1999) suggestion, and Svinkin and Skov (2000). The results of thecomparison indicated that the neural network model provided a better prediction, verifiedbased on a higher coefficient of determination (R 2 ) and a smaller root-mean squared error(RMSE). Jeon and Rahman (2007) acknowledged that additional data are needed in futurefor further training of the model to improve the quality of the pile setup estimation.2.9. ReferencesAASHTO. (2004). Interim Guidelines on Foundations, AASHTO LRFD Bridge DesignSpecifications American Association of State Highway and Transportation Officials,Washington, D.C.AASHTO. (2010). Interim Revisions, AASHTO LRFD Bridge Design Specifications.Customary U.S. Units, 5 th Edition 2010, American Association of State Highway andTransportation Officials, Washington, D.C.Abe, S., Likins, G. E. and Morgano, C. M. (1990). ―Three Case Studies on Static andDynamic Testing of Piles.‖ Geotechnical News Magazine, Vol. 8, No. 4: Richmond,B. C., Canada, December, pp. 26-28.Abu-Farsakh, M. Y., Yoon, S. M., and Tsai, C. (2009). Calibration of Resistance FactorsNeeded in the LRFD Design of Driven Piles. Louisiana Transportation ResearchCenter, FHWA/LA.09/449, Federal Highway Administration, U.S. Department ofTransportation, Washington, D.C.Allen, T. M. (2005). Development of Geotechnical Resistance Factors and Downdrag Load