Experimental study and failure mechanism analysis of novel bolt‐weld joint for prefabricated steel–concrete underground silo walls

Abstract This study addresses the challenge of assembly in prefabricated underground grain silos (UGSs) by developing a novel bolt‐welding joint for a steel–concrete composite structure. A comprehensive evaluation was carried out through full‐scale testing and numerical analysis on two specimens (6 and 10 bolts) to examine the bending bearing capacity. The main research findings were as follows: Firstly, the 6 bolts specimen exhibited 10.4% greater structural stiffness (excluding the failure stage), 34.6% reduced midspan deflection at peak load, while retaining 97.2% of the peak load of the 10 bolts specimen. Secondly, increasing the number of bolts from 6 to 10 resulted in more concrete damage, leading to significantly accelerated stiffness degradation of the specimen. Thirdly, a formula for calculating the peak load has been developed through parameter analysis of ABAQUS. The formula demonstrates good accuracy ( R 2 value is 0.994). When parameters are changed individually, single‐parameter prediction errors remain below 1.3%, while multiparameter compounded errors stay under 2% compared to the numerical result. This research provides a scientifically grounded and practically useful reference for the design of wall joints in prefabricated UGSs.