Performance and capacity assessment of reinforced concrete bridge piers considering the current load and resistance factor design provisions and plastic hinge length in Kansas.

PDFTech ReportK-TRAN: KSU-11-5C1883Reinforced concrete bridgesBridge piersBridge designLoad factorShear strengthEarthquake resistant designServiceabilityRetrofittingPerformance measurementHingesKansasKansas. Dept. of Transportation. Bureau of Materials & ResearchEsmaeily, AsadShirmohammadi, FatemehKansas State University. Transportation CenterUS Transportation CollectionKansas Department of Transportation (KDOT) has implemented the new AASHTO-LRFD provisions in the state specificLRFD design procedure (KDOT LRFD). Most of the existing bridges constructed before the new provisions, have been designedbased on the old provisions. In this study, these changes have been assessed based on the latest pertinent research, and tworepresentative bridges, representing state bridges designed and constructed based on the new and old code versions have beenstudied and their performance were analyzed considering their real performance and new code revisions.In general, the two representative bridges provided by KDOT for this study, can safely address the demanded loadsconsidering their actual strength and bridge structural-redundancy and load redistribution process. So, there is no immediateconcern in terms of serviceability or collapse of these bridges under demanded loads, including the extreme vehicular impact load.However, the calculated shear strength of most of the columns designed and constructed based on the old codes may not be enoughconsidering the new vehicular impact load required by the new code revisions.While no immediate action seems to be necessary in terms of serviceability and safety of these bridges, engineeringjudgment and a realistic case-based performance assessment is needed to decide if enhancement of the shear strength and theamount of lateral reinforcement within the plastic hinge length is necessary. Proper methods to retrofit these types of columns asdetailed in Chapter 4 can be used, once a decision is made for a case to implement the aforesaid enhancement. The case-basedappropriate retrofitting method can be specified for each case considering the column geometry, service load, reinforcement detailsand material properties