Integral Abutment Bridge for Louisiana\u2019s Soft and Stiff Soils [Report]

2016PDFTech ReportVoyiadjis, George Z.Cai, Steve C. S.Alshibli, KhalidLouisiana State University. Department of Civil and Environmental EngineeringLouisiana. Dept. of Transportation and DevelopmentUnited States. Federal Highway AdministrationLouisiana. Dept. of Transportation and DevelopmentLouisianaBridge abutmentsSoft soilsSoilsSiltsIntegral abutment bridgeIn situ full scale pile behaviorbridge bent-pile interactionintegralabutment analysissoft and stiff soilsIAB finite element analysisFHWA/LA.13/517LTRC Project No. 07-4ST / SIO No. 30000131Integral abutment bridges (IABs) have been designed and constructed in a few US states in the past few decades. The initial purpose of building such bridges was to eliminate the expansion joints and resolve the joint-induced problems. Although IABs have been widely accepted due to their satisfying performances, they have not been largely applied in practice. Some of the reasons can be attributed to the uncertainties of the structural and geotechnical behaviors of such bridges under the temperature variations, shrinkage and creep of materials, traffic loads, etc. Recently, the first two full IABs were constructed on soft and stiff soil conditions in Louisiana by the Louisiana Department of Transportation and Development (DOTD). This report presents the field instrumentation plans and monitoring results for two bridges: Caminada Bay Bridge, constructed on mainly fine sand and silty sand deposit, and Bodcau Bayou Bridge, on a relatively lean and fat clay with low plasticity.Finite element modeling was also conducted to understand and assess the bridges\u2019 performances. Based on the available information of the bridges, with the monitoring results, 3D numerical models were implemented and validated in the study, where the pile-soil and abutment-backfill interaction behaviors were considered. The concerning parameters are varied through a parametric study to further investigate their effects on the bridge thermal performances under the other complicated structural and geotechnical conditions.95