MPC
Research Projects (2008-09)

Identifying Number

MPC-302

Project Title

Enabling Innovative Steel Plate Girder Bridges: Simple Made Continuous

University

Colorado State University

Project Investigators

John van de Lindt

Description of Project Abstract

In compliance with Federal requirements all DOT bridge design processes must start with a bridge type selection process which is then followed by a design of the type selected. For very large bridges, both a steel and concrete design are completed and allowed to compete for low bid. However, for bridges of other size/length which often carry rural routes over trunkline roadways, it is not mandated that a complete design of both types be completed. Currently steel bridges in the Mountain Plains state of Colorado are outnumbered 20:1 by concrete bridges. This is mainly due to a limited number of steel mills near Colorado. In addition, rolled sections only come in standard sizes and limit a designers ability to optimize steel use. J. van de Lindt recently completed a study for CDOT that focused on developing design charts for rapid bidding of simple-made-continuous bridges using rolled sections. That project included the development of an influence line software package for CDOT that enables them to design and cost a bridge using rolled steel section in a matter of minutes.

Unfortunately, while this is a big step in the right direction to make steel competitive in the Mountain Plains state of Colorado, as mentioned above it does not effectively utilize the volume of steel for each bridge. It is proposed here to develop a similar approach for plate girders. This is obviously much more complicated since plate girders are limited to particular cross sections – their advantage from a competitive bid standpoint, but their disadvantage from an analysis standpoint! However, by automating this process much the same as the software provided to CDOT, this process is possible.

In addition, a type selection process that incorporates design innovation typically applied by the designer of steel bridges would more accurately reflect the final cost of steel structures and assure that the lowest cost structure type was selected.

Project Objectives

The primary objective of this work is to develop a method by which simple-made-continuous steel plate girder bridges can be bid competitively with concrete bridges in regions where steel bridges lose bids by a 1:20 ratio.

Project Approach/Methods

The approach taken in this work can be separated into the following three tasks:

• Task 1-Extensive Literature Review-This task will consist of reviewing studies in the literature on plate girder bridges and determining the most efficient and most used design details so that they can be included in the design and costing process. In addition, a survey of state departments of transportation where steel plate girder bridges are more common will be conducted. This will include procuring any typical details and categorizing them for use in the development of the method,
• Task 2-Modification of Analysis Program-In this task, the existing software program Colorado State University – Continuous Beam Analysis (CSU-CBA) will be modified to include a module that optimizes the cross section based on the span, cost, number of girders required/desired, etc. Within this module will be the need to satisfy all AASHTO-LRFD requirements. In addition, the simple-made-continuous design approach which uses the concrete deck and shear studs to develop composite action will be employed.
• Task 3-Development of Design Charts-The design charts will include costing such that they represent the least expensive alternative to create continuous steel bridges using plate girders. In order to accomplish this, the unit cost pay items complied by the research team will be used to develop design charts that provide cost per unit area for practical spans and girder depths. This will be done for both simply supported and typical continuous designs, i.e. 50ft-70ft-50ft, etc. In order to ensure the lowest costs the following steel vendors which supply steel to several of the Mountain Plains states will be contacted:

AFCO Steel PO Box 231-72203-0231 1423 E 6th Street Little Rock, Ar 72202-2717 501-340-6325 Warren Lenon QC Mgr wlenon@afcosteel.com	Egger Steel Co. 909 South 7th Avenue PO Box E Sioux Falls, SD 57101 605-336-2490 Fred Hlebichuk Plant Mgr fhlebichuk@eggersteel.com	Grand Jct Steel 1101 3rd Avenue Grand Jct, Co 81501 970-242-4015 Jeff Bishop Engineering Dept Mgr jbishop@gj-steel.com
Big R Mfg PO Box 1290 Greeley, Co 80632-1290 970-356-9600 Jim Corbin QC Mgr bigrmfg@bigrmfg.com	Roscoe Steel & Culvert PO Box 20978 Billings, Montana 59806 406-656-2253 Carl Solheim QC Mgr	Trinity Industries 617 E Sycamore Denton, Tex 76205 940-382-5418 Michael Miller Plant Mgr Mike.miller@trin.net
Universal Industrial Sales, Inc PO box 699 Pleasant Grove, Utah 84062 801-785-0505 David Lund QC Mgr dave@uismail.com	Utah Pacific Bridge & Steel PO Box 516 Pleasant Grove, Utah 84062 801-785-3557 Rick Rasmussen Project Mgr rick@utahpacific.com	Zimmerman Metals Inc 201 E 58th Ave Denver, Colo 80216 303-294-0180 Larry McCubbin QC Mgr

Additional fabricators will be contacted also but are not included in the proposal for brevity. In addition, Calvin Schrage and Conn Abnee of the National Steel Bridge Alliance (NSBA) have agreed to fully cooperate and work with the PI’s to (potentially) further the use of steel for Colorado bridges.

MPC Critical Issues Addressed by Research

This work addresses MPC focus areas:

Focus Area #15: Improved Infrastructure Design– Enabling bridges that are more cost effective and potentially easier and less expensive to maintain will help reduce cost to the Mountain Plains states.

Contributions/Potential Applications of Research

The results of this research can be applied at the state level for bidders and fabricators.

Technology Transfer Benefits

The results of this work will be made immediately available to the state DOT’s in the Mountain Plains Consortium states. Technology transfer will be enabled through a project web page and

Time Duration

July 1, 2008 – June 30, 2009

Total Project Cost

$84,450

MPC Funds Requested

$35,450

TRB Keywords

Continuous spans, steel design, cost assessment, LRFD