STUDY ON RESPONSE OF CONCRETE BRIDGE DUE TO CONSTRUCTION DEFECTS

Abstract

Different types of defects in a bridge structure can be cracking, delamination, honeycombing, improper casting of pedestal, poor drainage system, inappropriate placing of bearing, improper seating of girder etc. It is well documented that the bridges constructed in the last couple of decades are showing considerable signs of distress in the early stages of their design life and lead to collapse without serving the intended designed service period of 100 years. To maintain the structure, it is necessary to conduct a systematic inspection in accordance with the structure and the available guidelines in order to detect defects at an early stage. It is also significant to accumulate the data collected during the field inspection and maintenance activities without ignoring any distress. During bridge construction, skilled supervision is crucial to make sure that the structure is structurally sound so that it can avoid structurally deficient bridges. Periodical inspection after the construction will make the structure more efficient and long-lasting. In this study, the field survey has been done to identify the defects and elaborate on the codal provisions. The method used for assessing the behaviour of the structure due to defect is modelling and analysis of the bridge in STAAD pro software. With the consideration of defect, additional unexpected moments are generated in the girder and diaphragm for which the structure was not originally designed. In general, steel reinforcement is provided for required moments in the structures. If additional unexpected moments are generated, then damage can occur in the structure and affect the service life of the structure. The present study highlights that the collection of data can provide information about the possible defects with their causes for a meaningful conclusion about the service life of the structure.