Structures Design Guidelines | July 2006
SDG - Introduction |

# Introduction

## I.1 General

A. These FDOT Structures Design Guidelines, (SDG) incorporate technical design criteria and include additions, deletions, or modifications to the requirements of the AASHTO/LRFD Bridge Design Specifications (LRFD).

B. This manual provides engineering standards, criteria, and guidelines for developing and designing bridges and retaining walls for which the Structures Design Office (SDO) and District Structures Design Offices (DSDO) have overall responsibility.

C. Information on overhead sign structures, high-mast light poles, and miscellaneous roadway appurtenances as well as general administrative, geometric, shop drawing, and plans processing may be found in the Plans Preparation Manual.

## I.2 Format

A. The SDG chapters are organized more by “component,” “element,” or “process” than by “material” as is the LRFD. As a result, the chapter numbers and content of the SDG do not necessarily align themselves in the same order or with the same number as LRFD. LRFD references are provided to quickly coordinate and associate SDG criteria with that of LRFD. The LRFD references may occur within article descriptions, the body of the text, or in the commentary and are shown in boldface type within brackets; i.e., [1.3], [8.2.1].

B. The SDG are written in the active voice to Structural Designers, Professional Engineers, Engineers of Record, Structural Engineers, and Geotechnical Engineers engaged in work for the Florida Department of Transportation.

## I.3 Authority

Section 334.044(2), Florida Statutes.

## I.4 Scope

The use of this manual is required of anyone performing structural design or analysis for the Florida Department of Transportation.

## I.5 Abbreviations

ACI | American Concrete Institute
AISC | American Institute of Steel Construction
AREMA | American Railway Engineering and Maintenance-of-Way Association
AWS | American Welding Society
DSDE | District Structures Design Engineer
DSDO | District Structures Design Office
FHWA | Federal Highway Administration
FDOT | Florida Department of Transportation
LRFD | Load and Resistance Factor Design
PPM | Plans Preparation Manual
SDG | Structures Design Guidelines
SDM | Structures Detailing Manual
SDO | Structures Design Office
SSDE | State Structures Design Engineer
SSPC | Steel Structures Painting Council
TAG | Technical Advisory Group
TDB | Temporary Design Bulletin
Abbreviations in the PPM.

## I.6 References (07/06) July 2006 Deleted 4. Guide Specifications for Design and Construction of Segmental Concrete Bridges, 2nd Edition.
Per TDB C06-04, added 2006 Interims (excluding Section 6) to LRFD Bridge Design Specifications, 3rd Edition (2004), Added 2006 interim to Commentary. Added reference to AASHTO Guide Specifications for Horizontally Curved Highway Bridges (2003)
Jan 2006 added 2003 interim to 1999 Segmental Design and Const Guide Specs for Segmental.

A. AASHTO Publications

1.) ANSI/AASHTO/AWS D1.5-2002 Bridge Welding Code (2002) with 2003 and 2005 interims.

2.) Construction Handbook for Bridge Temporary Works, 1st Edition (1995).

3.) Guide Design Specifications for Bridge Temporary Works, 1st Edition (1995).

4.) Guide Specifications for Design of Pedestrian Bridges, 1st Edition (1997).

5.) Guide Specifications for Structural Design of Sound Barriers (1989) with 1992 and 2002 interims.

6.) LRFD Bridge Design Specification, 3rd Edition (2004), with 2005 Interim Revisions excluding Section 6 and 2006 Interim Revisions excluding Section 6. (See Commentary.)

7.) LRFD Movable Highway Bridge Design Specifications, 1st Edition (2001) with 2002 interim.

8.) Standard Specifications for Structural Supports for Highway Signs, Luminaires and Traffic Signals (1994) with 1998 interim.

9.) Guide Specifications for Horizontally Curved Steel Girder Highway Bridges (2003).

Commentary: Section 6 of the LRFD 2005 and 2006 Interim Revisions includes a new, comprehensive model for designing both straight and curved steel girder bridges. The Department is evaluating the effects of the new model and has not adopted Section 6. For other FDOT steel requirements and exceptions, see SDG Chapter 5
.

B. FDOT Publications

1.) Plans Preparation Manual, Volume 1, January 2006 (Topic No.: 625-000-007)

2.) Plans Preparation Manual, Volume 2, January 2006 (Topic No.: 625-000-008)

3.) Detailing Manual (Topic No.: 625-020-200)

4.) Drainage Manual (Topic No.: 625-040-001)

5.) 2006 Design Standards (Topic No.: 625-010-003)

6.) CADD Production Criteria Handbook.

7.) FDOT Standards for Road and Bridge Construction.

C. Other Publications

1.) AISC LRFD Manual of Steel Construction - Third Edition.

2.) FHWA-NHI-00-043 Mechanically Stabilized Earth Walls and Reinforced Soil Slopes Design and Construction Guidelines.

3.) AREMA Manual for Railway Engineering.

4.) CFR 635.410

## I.7 Coordination

A. Coordinate all plans production activities and requirements between the SDG, SDM, PPM, and LRFD. Each of these documents has criteria pertaining to bridge or structures design projects, and, normally, all four must be consulted to assure proper completion of a project for the Department.

B. Direct all questions concerning the applicability or requirements of any of these or other referenced documents to the appropriate Structures Design Engineer.

## I.8 Distribution

This SDG is furnished via the SDO web page at no charge. The user must regularly check for additions, modifications and bulletins. Address questions regarding this manual and any modifications to:

Structures Design Office

Mail Station 33

Attn: Structures Manual Editor

605 Suwannee Street

Tallahassee, Florida 32399-0450

Tel.: (850) 414-4255

http://www.fdot.gov/structures/

## I.9 Administrative Management

Administrative Management of the Structures Design Guidelines (SDG) is a cooperative effort of SDO staff and the nine voting members of the Technical Advisory Group (TAG).

### I.9.1 The Technical Advisory Group (TAG)

The TAG provides overall guidance and direction for the SDG and has the final word on all proposed modifications. The TAG comprises the State Structures Design Engineer (SSDE) and the eight District Structures Design Engineers (DSDE). In matters of technical direction or administrative policy, when unanimity cannot be obtained, each DSDE has one vote, the SSDE has two votes, and the majority rules.

### I.9.2 SDO Staff

SDO Staff comprises the Assistant State Structures Design Engineers and Senior Structures Design Engineers selected by the SSDE.

## I.10 Modifications

Modifications may be the result of changes in FDOT specifications, FDOT organization, Federal Highway Administration (FHWA) regulations, and AASHTO requirements; or occur from recent experience gained during construction, through maintenance, and research. Manual users are encouraged to suggest modifications and improvements such as design procedures, text clarity, technical data, or commentary. Transmit suggestions in writing to the State Structures Design Engineer, 605 Suwannee St, (MS 33) Tallahassee, FL 32399-0450.

### I.10.1 Adoption of Revisions

Revisions to the SDG are issued by the SDO as Temporary Design Bulletins or Permanent Revisions according to a formal adoption process.

### I.10.2 Temporary Design Bulletins (07/05) July 2005 - Added Paragraphs D through F. per TDB CO5-01.

A. TDB’s are mandatory, supersede the current SDG, and will be issued when the SSDE deems a change essential to production or structural integrity issues and in need of immediate implementation. TDB’s may address issues in plans production, safety, structural design methodology, critical code changes, or new specification requirements.

B. TDB’s are effective for up to 360 calendar days unless superceded by subsequent TDB’s or Permanent Revisions to the SDG. TDB’s automatically become proposed Permanent Revisions unless withdrawn from consideration by the SSDE.

C. TDB’s indicate their effective date of issuance and are numbered sequentially with reference to both the SDG version number and year of issuance. For example, Temporary Design Bulletin No. C98-2 would be the second Bulletin issued in 1998 for SDG.

D. TDBs may be proposed by any DSDE, DSFE or PE in the SDO for consideration by the SSDE. The author must research all affected FDOT policies, criteria and specifications. Proposed TDBs must be submitted to one of the Assistant SSDEs for review, comment and concurrence. If the Assistant SSDE concurs with the proposal, it will be sent to the SSDE for consideration, final approval and publication on the SDO’s website.

E. TDBs that significantly affect other offices must be composed with the assistance of the affected office. TDBs that significantly affect construction will be issued as a Joint Bulletin with the State Construction Office (coordinate with the State Construction Office on the proper Construction Bulletin number).

F. Proposed TDBs must be formatted to include Requirements, Commentary, Background, Implementation and Contact sections.

1.) Requirements: This section codifies exceptions, revisions and/or additions to policies or criteria as specified in current adopted specifications (i.e. Structures Manual, AASHTO LRFD Bridge Design Specification, etc.). Requirements must reference the specific section) in the Structures Manual or other documents where they are to be incorporated. Revisions to the Department’s Standard Specifications will be handled through the Specifications Office.

2.) Commentary: This section provides the essential technical support behind the new Requirement. It includes references to the literature, both pro and con, that influenced the decision. This section is intended be brief and will be published along with the Requirements in the identified document. If the Requirements are being added to the SDG, the Commentary is added in italics at the end of the amended section.

3.) Background: This section discusses the circumstances that prompted the TDB. It should not duplicate the Commentary but simply facilitate the readers understanding of situations that occurred and the SDO’s response to them. It is also appropriate to make recommendations on policy, criteria and/or specification additions and revisions to other offices in this section.

4.) Implementation: This section specifies the timeline upon which the requirements are to be implemented. Factors to be considered in the implementation plan include funding sources to implement changes to existing design and construction contracts, effect on adopted work program, etc. Implementation plans typically include effective, publishing and letting dates for the Requirements.

5.) Contact: Although the SSDE is the responsible author of all TDBs, this section lists the TDB’s champion. This section lists the bulletin’s key contact name, title, work telephone number and email address.

### I.10.3 Permanent Revisions

Permanent Revisions to the manual are made semi-annually or "as-needed." If the SDO considers an individual revision, or an accumulation of revisions, to be substantive, the manual may be completely rewritten. The following steps are required for adoption of a revision.

A. SDO Staff will assess proposed revisions and develop the initial draft for the SSDE’s approval.

B. The SDO Staff will conduct the necessary research, coordinate the proposed modification with all other affected offices and, if the proposed modification is deemed appropriate, prepare a complete, written modification with any needed commentary. The SSDE’s approval signifies the SDO’s position on the proposed modifications.

C. Proposed modifications will be transmitted to TAG members and others allowing for no less than two weeks review time before the next scheduled TAG meeting. Other parties include, but are not limited to: State Construction Office, State Maintenance Office, State Materials Office, State Roadway Design Office, Organization, Forms and Procedures, and FHWA. DSDE members of TAG will coordinate the proposed modifications with all other appropriate offices at the district level.

D. Each TAG member will review proposed modifications before the meeting where they will be brought forward for discussion. The SDO will review all modification comments received from other FDOT/FHWA offices in preparation for presentation at the meeting. Additional review comments received by the SDO and/or DSDO’s during the review process will be presented for discussion and resolution.

E. Immediately after the TAG meeting, each proposed modification will be returned to the SDO with one of the following recommendations:

1.) Recommended for adoption as presented.

2.) Recommended for adoption with resolution of specific changes.

3.) Not recommended for adoption.

F. Within two weeks after the TAG meeting, the SDO Staff will resolve each recommended modification and the assembled modifications will be provided to the SSDE for final approval.

G. Once approved by the SSDE, the SDG revision modifications will be assigned to the Design Technology Group Leader for final editing.

H. Unless agreed otherwise, the SDG version modifications will be distributed within 4 weeks after receipt of the approved modifications from the SSDE. This period allows the Organization and Procedures Office to update the Standard Operating System and any electronic media before electronic distribution of the SDG.

## I.11 Training

No specific training is necessary for the use of this manual. Major revisions are often presented and discussed at the Biennial Structures Design Conference, annual Construction Conference, and annual PPM update training.