Load-bearing performance of composite bored piles

Strength composite piles have been widely used in the field of civil engineering due to their advantages of convenient construction and high bearing capacity. However, in complex geological areas with boulders in the soil and relatively shallow rock strata, there are disadvantages such as difficulty in pre-mixing and relatively large noise and vibration during pile driving. This paper, combined with an actual project, puts forward a rotary drilling and pile-implanting technique of pouring fine stone concrete after drilling and implanting precast prestressed concrete solid square piles (composite bored piles), which solves the problem that precast piles cannot enter moderately weathered rock strata. Through on-site load tests, the reliability and practicability of this drilled and poured composite pile have been verified. The load transfer law and bearing capacity of the composite bored piles were analyzed using ABAQUS finite element software. The results showed that pour fine concrete after drilling can effectively reduce the settlement of prefabricated piles and improve their bearing capacity; The interface between the prestressed concrete solid core pile and the fine aggregate concrete can effectively transfer the upper load, demonstrating excellent stability and reliability during the loading process. The bored grouted composite pile effectively induces compaction of the surrounding soil during construction, and under the action of the upper load, the lateral friction resistance along the pile shaft can be significantly enhanced.