Experimental study on effect of assembly process on seismic performance of modular precast composite shear wall structures

Abstract

Modular buildings utilize prefabricated volumetric modules to resist gravity and lateral loads and can achieve a high prefabrication level. Different from cast-on-site reinforced concrete structures, the seismic performance of precast structures is affected by the construction process. This study investigated the effect of assembly process on the seismic performance of an innovative modular precast composite shear wall structure. Contrastive shaking table tests were carried out on two 1/4-scaled modular models, one by the fully modular precast method and the other by the modular cast-on-site method. Test results showed that the bottom vertical joints were the most critical components and dominated the failure patterns for both modular models. The weakening of screw threads induced by the small model size and assembly process decreased the ultimate capacity of the modular precast model. The modular precast model showed up to a 6.7 % lower initial frequency and 17.6 % lower initial damping ratio than the modular cast-on-site model. The assembly process had no essential influence on the displacement and acceleration responses before vertical joint failure but significantly increased the displacements as the joints approached failure in the limit state. The test work highlights the importance of ensuring bolt strength and protecting bolt threads in practical engineering applications.