Finite Element Analysis of Concrete Approach Slab on Soil Embankment

Current AASHTO specifications for structural design of bridge approach slabs do not take into account the interaction of slabs with the underlying soil. Consequently, the slabs experience a distress primarily in the form of cracking, also known as "the bump at the end of the bridge" because they are not designed to sustain the effects of differential settlements. Passing of large heavy vehicles over distressed slabs generates impact loads that cause further damages to bridges and pavements and may become a safety concern. In addition, the accumulation of settlement over time necessitates frequent maintenance, thus increasing the whole life cycle costs of bridges and incurring additional costs due to the associated traffic disruptions. While several different suggestions have been proposed for the alleviation of this problem (Stark et. al., 1995; Monley and Wu, 1993; Helwany et al., 2003) none of them have been widely accepted or implemented. It is because of a sheer number of bridges, including 25,620 in Kansas alone, and 590,111 in the U.S. that the current design approach negatively affects the resilience, durability, safety and economy of transportation infrastructure. Kansas has the fourth largest number of bridges, following Texas, Ohio and Illinois. In addition, according to Bakeer et al. (2005) Kansas was also the second state to build the integral bridge in 1935. Today Kansas has about 1,000 integral bridges. This type of a bridge is more sustainable choice than its non-integral counterpart because it boasts multiple advantages. However, the bridge approach settlement in integral bridges is even more significant due to a complex soil-structure interaction. Significant differential settlements occur below the approach slab because integral bridges accommodate thermal expansions and contractions of the deck through the cyclic deformation in the adjacent soil. Devising a design that will enable the approach slabs to sustain larger differential settlements will directly contribute to the increased resilience, longevity, safety and economy of transportation lifelines, thus increasing their overall sustainability rating.

• Record URL:
  http://transport.ksu.edu/research/2009%20Projects/KSUTC-09-5.pdf

Language

• English

Project

• Status: Active
• Funding: $30000.00
• Contract Numbers:

  RE-0430-05; HPD-R043

  KSUTC-09-6

• Sponsor Organizations:

  Kansas State University Transportation Center

  Kansas State University
  Department of Civil Engineering
  Manhattan, KS  United States  66506
• Project Managers:

  Stokes, Robert

• Performing Organizations:

  Kansas State University Transportation Center

  Kansas State University
  Department of Civil Engineering
  Manhattan, KS  United States  66506
• Principal Investigators:

  Peric, Dunja

• Start Date: 20090601
• Expected Completion Date: 0
• Actual Completion Date: 20110630
• Source Data: RiP Project 21753

Subject/Index Terms

• TRT Terms: Bridge approaches; Bridge decks; Bridge design; Bridge substructures; Bridges; Embankments; Finite element method; Jointless bridges; Life cycle costing; Research projects; Settlement (Structures); Soil structure interaction
• Uncontrolled Terms: Approach slabs
• Subject Areas: Bridges and other structures; Finance; Highways;

Filing Info

• Accession Number: 01462119
• Record Type: Research project
• Source Agency: Kansas State University Transportation Center
• Contract Numbers: RE-0430-05; HPD-R043, KSUTC-09-6
• Files: RIP
• Created Date: Jan 3 2013 1:58PM