Abstract: This study explores and analyzes the relevant theories and practical applications of the reduction factor for the axial capacity of pile in mudstone. The range of the reduction factor and the accurate axial capacity of piles in strongly weathered mudstone formation are investigated. This paper presents pile project case history of the east block of North Railway Station in Gulou District, Xuzhou City. The mudstone properties are tested through remolded mudstone samples, and the reduction coefficient of the axial capacity of piles in mudstone reshaping samples under different test conditions is also investigated. The results show that the reasonable value range of the uniaxial compressive strength reduction coefficient of mudstone reshaped samples is between 0.75 and 0.85. The reasonable value range of the triaxial compression strength reduction coefficient is between 0.4 and 0.6. The reasonable range of the reduction coefficient of lateral static pressure strength is between 0.7 and 0.9. The large variation of axial capacity of precast prestressed reinforced concrete pile in mudstone in the practice is also modified based on the investigation results.

Key words: Remolded Mudstone Samples, Laboratory Tests, Axial Capacity of Pile, Reduction Factor