FRP-Retrofitting RC Bridges for Stabilization in Earthquakes
Journal Title: Trends in Civil Engineering and its Architecture - Year 2018, Vol 1, Issue 4
Abstract
The purpose of this abbreviated paper is to analyze the applicability of FRP (fiber-reinforced polymer)-strengthening systems for retrofitting RC (reinforced-concrete) highway bridges to stabilize structural members under earthquake conditions. Three earthquakes in California, with multiple bridge failures, drove the requirement to improve bridge design and methods of structurally upgrading critical bridge components to withstand impacts of earth tremors. Retrofitting RC bridges by encasing and strengthening bridge bents with FRP-systems provides an effective method of mitigating the impacts of earthquake loading. This analysis considers types of retrofitting applications on bridge bents and the advantages of FRP systems to increase structural member axial capacity and ductility in columns and beams. Transportation infrastructure destruction in earthquakes can be extensive, particularly when older RC bridges are not designed to current earthquake codes. Bridges constructed before the 1970's, in Europe, Asia, and the USA, and not retrofitted, have a potential risk of failure, even in moderate earthquakes. Recent California earthquakes (last 45 years) caused multiple modes of failure in RC bridge critical structural elements. The primary causes of bridge collapses were insufficient ductility in the bridge columns, inadequate lap-splice length in the potential plastic hinge regions, and insufficient transverse reinforcement. Retrofitting existing RC bridge bents (columns and beams) is an efficient and cost effective rehabilitation technique to improve seismic performance. Major techniques for structural rehabilitation of RC bridges include encasing columns and beam column joints using steel, FRP, RC jackets, and adding new steel bracing structural elements [1]. Retrofitting circular/rectangular bridge columns by adding cylindrical or elliptical steel jackets in the plastic hinge region is an effective measure to enhance shear strength and flexural ductility. As an alternative to steel jackets, advanced FRP composite material have been developed for retrofitting concrete columns, resulting in significantly improved hysteretic response and increased ductility.The unique properties of carbon FRP (CFRP) with its high strength, low weight, and ease of application provide an ideal material for strengthening RC bridge columns and beams for gravity-load designed multi-column bridge bents. Retrofitting older highway bridges to mitigate loss of service ability in seismic events is a cost- effective option compared to the high cost of bridge replacement. Three earthquakes produced far reaching changes in California seismic codes and bridge design philosophy. Occurred in southern California with a magnitude 6.6, lasting 12 seconds at a depth of 13km. Thrust faulting ruptured a 19km segment of the San Fernando fault with a maximum slip of 2 meters, causing twelve overpass bridges to fail falling onto freeways below. Damage to bridge structures varied from minor cracking to complete loss of bridge sections.
Authors and Affiliations
Kenneth C Crawford, Stojan Krsteski
Keywords
Related Articles
- EP ID EP605085
- DOI 10.32474/TCEIA.2018.01.000120
- Views 56
- Downloads 0
Structural Insulated Panels: State-of-the-Art
This article aims to review and illuminate the latest research conducted on structural insulated panels (SIP) together with the latest information of the current experiment carried out by the authors. The authors attempt...
Waste to Worth - Sludge Containing Calcium Carbonate into Useful Building Materials - an Indian Context
Human activities on earth produce in considerable quantities of wastes more than 2,500 million tons per year, including industrial and agricultural wastes from rural and urban societies. This creates serious problems to...
Polyurea Coated and Plane Reinforced Concrete Panel Behavior under Blast Loading: Numerical Simulation to Experimental Results
This research investigated the behavior of reduced scale standard reinforced concrete panels coated with various polyurea systems under blast loading. The blast mitigation performance of four coatings including two plain...
FRP-Retrofitting RC Bridges for Stabilization in Earthquakes
The purpose of this abbreviated paper is to analyze the applicability of FRP (fiber-reinforced polymer)-strengthening systems for retrofitting RC (reinforced-concrete) highway bridges to stabilize structural members unde...
Application of Preplaced Aggregate Concrete to Convert the Ballasted Railway Tracks into Slab Tracks
One of the most critical restrictions of ballasted railway tracks maintenance is the ballast undercutting and sieving over the railway bridges and tunnels. In recent years with respect to the development of in-place conc...