Suggestions for Improvement of Domestic Pile Foundation Design Routine -At a Viewpoint of Pile Bearing Capacity-

In the domestic Korean Standard Specifications for Highway Bridges (1996), it is specified that the capacity of pile foundations could be determined by static formula or pile loading test. But, in domestic pile design, preliminarily presumtive design has been routine because pile capacity was determined by semi-empirical SPT formula only. Thus, optimal pile design has not been performed and excessive design has been practiced. In this study, items related to pile capacity computation which was specified in several specifications ere compared, and design routines to be improved in current domestic pile design were examined and their improvement directions were proposed. The proposed optimal pile design procedures are as follows ; first, pile load test should be performed to the test pile selected in preliminary design stage second, based on the test results for test piles, ultimate pile capacity, settlement and axial load transfer behavior should be confirmed ; third, preliminary presumtive pile design may be revised or changed for optimal pile design. These design procedures were included in Design Specifications for Highway Bridge, which is being revised in this year.