Development of Bridge Girder Movement Criteria for Accelerated Bridge Construction

End diaphragms connect multiple girders to form a bridge superstructure system for effective resistance to earthquake loads. Concrete girder bridges that include end diaphragms consistently proved to perform well during previous earthquake events. However, whether concrete bridges without end diaphragms are definitively inadequate in seismic performance is yet to be answered. The 2010 Chile Earthquake indicated that properly designed bridge girders and their lateral movement stoppers (shear keys) may perform equally well with those with end diaphragms. In this report, a feasibility study on the design of girder bridges without end diaphragms is presented. This study is particularly significant in the context of accelerated bridge construction since concrete diaphragms are often cast in place and eliminating them can save field erection time and cost. The key to make the no-diaphragm concept work is to understand how multiple girders can work together during a transverse earthquake excitation without breaking the girders and bridge deck. Specifically, a three-dimensional finite element model of a representative concrete girder bridge with and without end diaphragms is established and analyzed to understand the effects of various design parameters (e.g. diaphragm height, diaphragm thickness, the coefficient of friction between girders and their supporting elements, the number and size of shear keys) on transverse girder movement capacity. Numerical results indicate that properly designed end diaphragms can increase the transverse capacity of a bridge by making individual girders work together but can be substituted by shear keys placed between the strengthened girders. In doing so, both transverse capacity and stiffness of the bridge superstructure can be significantly increased. Shear keys are more reliable than the friction mechanism. In particular, movable shear keys are more effective in distributing loads among multiple girders.

[1]  E. Ramm,et al.  Three‐dimensional extension of non‐linear shell formulation based on the enhanced assumed strain concept , 1994 .

[2]  P. Bowen,et al.  Changes in portlandite morphology with solvent composition: Atomistic simulations and experiment , 2011 .

[3]  Donald W. White,et al.  Refined 3D finite element modeling of partially-restrained connections including slip , 2002 .

[4]  Anil K. Chopra,et al.  Dynamics of Structures: Theory and Applications to Earthquake Engineering , 1995 .

[5]  Abdul Wahed Mohammed,et al.  First Full-Depth Deck-Panel Accelerated Bridge Construction Project in Michigan: Constructability Challenges and Lessons Learned , 2014 .

[6]  Sami Megally,et al.  Capacity Evaluation of Exterior Sacrificial Shear Keys of Bridge Abutments , 2006 .

[7]  Theodoros Tzaveas,et al.  Pushover Analysis of Inelastic Seismic Behavior of Greveniotikos Bridge , 2002 .

[8]  China Earthquake Reconnaissance Report: Performance of Transportation Structures during the May 12, 2008, M7.9 Wenchuan Earthquake , 2011 .

[9]  A. Hillerborg,et al.  Analysis of crack formation and crack growth in concrete by means of fracture mechanics and finite elements , 1976 .

[10]  Peter Fajfar,et al.  Consistent inelastic design spectra: Strength and displacement , 1994 .

[11]  G. Powell,et al.  Improved iteration strategy for nonlinear structures , 1981 .

[12]  C. S. Cai.  Discussion on AASHTO LRFD Load Distribution Factors for Slab-on-Girder Bridges , 2005 .

[13]  Jeeho Lee,et al.  Plastic-Damage Model for Cyclic Loading of Concrete Structures , 1998 .

[14]  Ming Zhang,et al.  Three-dimensional finite element analysis of the foot during standing--a material sensitivity study. , 2005, Journal of biomechanics.

[15]  Anil K. Chopra,et al.  A Modal Pushover Analysis Procedure to Estimate Seismic Demands for Buildings: Theory and Preliminary Evaluation , 2001 .

[16]  R. Goel,et al.  Role of Shear Keys in Seismic Behavior of Bridges Crossing Fault-Rupture Zones , 2008 .

[17]  C. S. Cai,et al.  Quantification of Intermediate Diaphragm Effects on Load Distributions of Prestressed Concrete Girder Bridges , 2009 .

[18]  Hanbin Ge,et al.  Applicability of pushover analysis-based seismic performance evaluation procedure for steel arch bridges , 2004 .

[19]  Ekkehard Ramm,et al.  Strategies for Tracing the Nonlinear Response Near Limit Points , 1981 .

[20]  Dushyant Arora,et al.  Accelerated Bridge Construction (ABC) Techniques for Heavy Lift (HL) & Materials Off-Loading Facility (MOF) , 2013 .

[21]  Sami Megally,et al.  Seismic Response of Sacrificial Exterior Shear Keys in Bridge Abutments , 2007 .

[22]  Peter Fajfar,et al.  A Nonlinear Analysis Method for Performance-Based Seismic Design , 2000 .

[23]  Frieder Seible,et al.  SEISMIC RESPONSE OF SACRIFICIAL SHEAR KEYS IN BRIDGE ABUTMENTS. , 2002 .

[24]  Zhongguo John Ma,et al.  Improved Longitudinal Joint Details in Decked Bulb Tees for Accelerated Bridge Construction: Fatigue Evaluation , 2010 .