Abstract:A new-style composite pile is obtained by inserting a prestressed concrete pile into a cement-mixing pile. To study the bearing capacity and failure mode of the composite pile under lateral loading,the lateral loading tests of two composite piles with/without pile cap are carried out and the failure modes and property of interaction of pile and soil are obtained. As a new-style pile,its key characters are analyzed,such as critical load,limit load,lateral deformation,failure modes of two composite piles with/without pile cap,influence of lateral resisting-force coefficient of soil and pile cap on lateral bearing capacity and failure mode. To reasonably evaluate the test results,the limit load and deformation are also analyzed. Test and analysis results show that the pile cap plays an important role in resisting lateral load and the property of resisting lateral force of the composite pile with pile cap is higher than that of the composite pile without pile cap. Composite piles with pile cap have better lateral bearing capacity. Pile cap changes the failure mode between prestressed concrete pile and cement soil into the failure mode between cement soil and soil. To calculate the lateral bearing capacity of composite piles,the calculation formulae of lateral bearing capacity based on critical method and turning point method are studied and the turning point method shows more reasonable and operational than the critical method in application.