Seismic Failure Modes and Deformation Capacity of Reinforced Concrete Columns under Cyclic Loads

Abstract

InstructionReinforced concrete (RC) columns are one of the most critical load-bearing components in building structures, highway bridges and subsurface structures. Recent post-earthquake investigations indicate that a large number of bridge piers and structure columns with insufficient and poor seismic details are prone to shear failure, which may result in the overall collapse of bridges and structures under strong seismic attack [1][2][3][4].Studies of engineering practice demonstrate that RC columns under axial force, shear force and bending moment, usually exhibit three failure modes: flexural failure, shear failure and flexural-shear failure [5,6].Recently, considerable efforts have been made to investigate the seismic performance of RC columns, such as Lehman etc. [7], Xiao and Zhang [8], Si etc. [9]. The previous researches have primarily focused on the mechanism of flexural failure, and the fibre model can be used to simulate the flexural characteristic of columns. Brittle shear failure, which occurs before flexural yielding of the longitudinal reinforcement, can be easily identified for RC columns. However, the study of flexuralshear failure ("shear failure after yielding") is still inadequate due to flexure shear interaction. Lynn etc.[10] carried out reversed cyclic loading tests on eight full-scale RC columns, and found that predominant failure modes included flexuralshear failure, shear failure, lap-splice failure, and gravity load collapse, increasing axial load or longitudinal reinforcement ratio could lead to shear failure and lower ductility. Xiao and Martirossyan [11] found that the RC columns with insufficient confining reinforcement ratios could be dominated by flexural-shear failure in the plastic-hinge zones. Sezen [12] tested four full-scale lightly RC building columns to investigate the behaviour of columns with significant stiffness and strength degradation due to shear failure after the flexural strength (i.e. flexural-shear failure), and observed that under the same flexural demand and very high axial load, the specimen had a sudden shear and axial load failure. Si etc.[13] conducted quasi-static tests to study the seismic flexural-shear damage mechanisms and rapid repair techniques for earthquake damaged bridge piers. The failure pattern, strength, ductility and

Multiscale Geomechanical Behavior of Fiber-Reinforced Cementitious Composites Under Cyclic Loading Conditions—A Review

“…This is because the opening of flexural cracks was delayed by fiber bridging effect which leads to crack inclination and the subsequent flexure-shear failure. Similar findings were also obtained in recent publications (Choun and Park, 2015;Ying and Jin-Xin, 2018), which further highlights the effect of fiber reinforcement on the failure patterns of cementitious materials under cyclic shear loading.…”

Cyclic test on a precast reinforced concrete column-to-foundation grouted duct connection

“…Dissipated energy and drift ductility were comparable with those reported by Popa et al (2015) for a cast-in-place specimen pushed up to the same maximum drift and having approximately the same capacity as the specimen described in this paper. Ying and Jin-Xin (2018) showed that column aspect ratio L ∆ /H (i.e., shear span length over column cross-section depth) influences failure mode and ductility of RC columns. Therefore, the remarkable ductility shown by the specimen described in this paper should be regarded with care when using the same connection system but with a different aspect ratio.…”

A Machine-Learning-Based Failure Mode Classification Model for Reinforced Concrete Columns Using Simple Structural Information

“…In a previous study, the DT model classified the failure modes in RC joints [10]. Because the failure modes of columns vary depending on the overall strength [11], energy dissipation capacity, and ductility of RC columns [12], failure grades can be used to aid engineers in selecting optimized characteristics to prevent hazardous failures. Mangalathu et al [13] proposed a RF model for predicting the failure modes of RC columns and shear walls and conducted a study to identify and rank important variables affecting failure modes.…”