Seismic behavior of post-tensioned precast wide U beam–column interior joint: a finite element study

Abstract

Due to many advantages over the traditional construction, wide beam–column system has gained the popularity in low–moderate seismic zones. However, the performance of this system in the region of higher seismicity is still questionable. This paper presents the seismic behavior of a typical post-tensioned composite wide beam–column interior joint and relevance of its implementation in different seismic zones of Thailand. The post-tensioned wide beam–column system studied in this paper consists of precast U beam with embedded A-trusses, precast column and cast-in-situ concrete poured over the precast U beam and in the joint region. In this paper, a 3D finite element (FE) model of the full-scale post-tensioned precast wide U beam–column interior joint was developed using the validated constitutive material laws and appropriate boundary conditions in LS-DYNA FE code. The specimen was subjected to displacement-controlled lateral cyclic load. The results of this study revealed force–displacement hysteresis behavior and failure pattern of the U beam–column interior joint. In addition, parametric study was carried out to investigate contribution of the major parameters designed for joint region to the drift capacity and strength of the joint. The drift capacity of the joint was found to be 2.2%, which partially fulfilled the drift demand from various seismic zones of Thailand. Further, a strong-column weak-beam failure mode was exhibited by the analyzed joint.