SMART Shear Keys for Multi-Hazards Mitigation of Diaphragm-Free Girder Bridges – Phase II

The goal of this multi-phase project is to prevent the out-of-plane rupture of concrete girders and flexural damage to lateral restrainers under earthquake loads and floated-and-displaced bridge superstructures under hurricane events by exploring and developing a novel concept of diaphragm-free girder bridges with Sliding, Modular, Adaptive, Replaceable, and Two-dimensional (SMART) shear keys. Each key is composed of three precast concrete modules arranged in an L-shape that are horizontally and vertically post-tensioned with replaceable unbonded steel bars to form two wedged sliding surfaces. When installed next to a girder and anchored into its capbeam support, the key provides controllable horizontal and vertical friction forces during natural hazards and regulates corresponding displacements over time. The first phase aims to: (1) characterize novel SMART shear keys under cyclic loads, (2) develop a friction-gap model of the shear keys for inclusion in computational modeling and simulation of bridges, and (3) understand and evaluate the effect of SMART keys on the seismic behavior of a small-scale bridge bent subjected to ground accelerations. The objectives of this research are: (1) to understand the system behavior and responses of a simplified highway bridge, particularly the torsional effect of spatially-distributed SMART shear keys under strong multi-component earthquakes, and (2) to develop a strategy and algorithm for optimal placement of SMART shear keys, and to understand and develop a similitude law of SMART shear keys for the prediction of their behavior and responses through small-scale model tests.

• Record URL:
  http://matc.unl.edu/research/research_project.php?researchID=564

Language

• English

Project

• Status: Completed
• Funding: $164918
• Contract Numbers:

  69A3551747107

• Sponsor Organizations:

  Office of the Assistant Secretary for Research and Technology

  University Transportation Centers Program
  Department of Transportation
  Washington, DC  United States  20590

  Mid-America Transportation Center

  University of Nebraska-Lincoln
  2200 Vine Street, PO Box 830851
  Lincoln, NE  United States  68583-0851
• Managing Organizations:

  Mid-America Transportation Center

  University of Nebraska-Lincoln
  2200 Vine Street, PO Box 830851
  Lincoln, NE  United States  68583-0851
• Project Managers:

  Stearns, Amy

• Performing Organizations:

  Missouri University of Science & Technology, Rolla

  Department of Engineering
  202 University Center
  Rolla, MO    65409
• Principal Investigators:

  Chen, Genda

• Start Date: 20190101
• Expected Completion Date: 20191231
• Actual Completion Date: 20220630
• USDOT Program: University Transportation Centers Program
• Source Data: 91994-29

Subject/Index Terms

• TRT Terms: Algorithms; Earthquake resistant design; Friction; Girder bridges; Highway bridges; Load tests; Precast concrete; Seismicity; Shear properties
• Subject Areas: Bridges and other structures; Design; Highways; Maintenance and Preservation;

Filing Info

• Accession Number: 01692266
• Record Type: Research project
• Source Agency: Mid-America Transportation Center
• Contract Numbers: 69A3551747107
• Files: UTC, RIP
• Created Date: Feb 5 2019 4:24PM