HIGHWAY DESIGN MANUAL REVISION NO. 63 - CHAPTER 19 . PDF

29d ago
1 Views
0 Downloads
297.95 KB
10 Pages
Transcription

New York StateDepartment ofTransportationEBENGINEERINGBULLETIN11-015Expires one year after issue unless replaced soonerTitle: HIGHWAY DESIGN MANUAL REVISION NO. 63 - CHAPTER 19 - REINFORCEDCONCRETE BOX CULVERTS AND SIMILAR STRUCTURESTarget Audience :: Manufacturers (18): Local Govt. (31): Agencies (32)Approved:: Surveyors (33): Consultants (34): Contractors (39)( )/s/Stephen A. ZarghamStephen A. Zargham, P.E.Director, Design Quality Assurance Bureau5/19/11DateADMINISTRATIVE INFORMATION: This Engineering Bulletin (EB) is effective with the letting of January 12, 2012. This EB does not supersede any other issuance.PURPOSE: The purpose of this EB is to issue a limited revision to Chapter 19 of the Highway DesignManual - Reinforced Concrete Box Culverts and Similar Structures.TECHNICAL INFORMATION: This EB is being issued concurrently with EI 11-004 Reinforced Concrete Three-sided Structuresand Precast Concrete Box Culverts.Chapter 19 is being revised to comply with FHWA requirements for buried structures. FHWA isrequiring that buried structures, including the wingwalls and headwalls, on which States initiatepreliminary engineering after October 1, 2010, be designed by the Load and Resistance FactorDesign (LRFD) Specification. Buried structures include box culverts, three-sided frames, andpipes.Sections being modified are: 19.5 Design Guidelines for Reinforced Concrete Culverts,19.6 Computer Design and Analysis Program, and 19.14 References.TRANSMITTED MATERIALS: None.This revision and the entire Highway Design Manual are available, free of charge, in a downloadableAdobe Acrobat format on the NYSDOT internet site. Go to the NYSDOT Home page(https://www.nysdot.gov ) and click on “Site Index,” “H,” and “Highway Design Manual.”CONTACT: Questions regarding the technical information included in this revision should be addressedto Ed Timperlake of the Office of Structures at (518) 457-9869 or via e-mail [email protected] General questions regarding the Highway Design Manual should beaddressed to Kevin Stanley of the Design Quality Assurance Bureau at (518) 485-8612 or via e-mail [email protected] .

HIGHWAY DESIGN MANUALREVISION 63CHAPTER 19: REINFORCED CONCRETE BOXCULVERTS AND SIMILAR STRUCTURES(Limited Revision)MAY 19, 2011

SectionChanges19.5Updated Section 19.5 to refer to NYSDOT LRFD Bridge DesignSpecifications as the required design criteria.19.6.Changed software reference from NYSDOT Culvert Program to ETCulvert.19.14Updated References.5/19/11

CHAPTER 19REINFORCED CONCRETE BOX CULVERTS AND SIMILAR STRUCTURESContentsPage19.1INTRODUCTION . 19-119.2SELECTION CRITERIA . 19-319.3PROJECT DEVELOPMENT PROCEDURES FOR BRIDGE SIZE CULVERTS . 19-419.3.119.3.219.3.319.3.419.3.519.4FOUNDATIONS . 19-719.4.119.4.219.4.319.4.419.5Structure Type Selection . 19-4Precast Arch and Arch-Topped Unit Guidelines . 19-4Precast Frame Unit (Three-Sided Structure) Guidelines . 19-5Details/Contract Plans . 19-6Quality Assurance Reviews . 19-6Rock. 19-7Earth or Granular Soil . 19-7Precast Frames, Arch-Topped Units and Arches . 19-8Wingwalls. 19-8DESIGN GUIDELINES FOR BOX CULVERTS . 19-919.5.1 Design Method . 19-919.5.2 Dead Load and Earth Pressure . 19-919.5.3 Live Load . 19-1019.5.4 Wall Thickness Requirements . 19-1019.5.5 Concrete Strength . 19-1019.5.6 Reinforcement Requirements. 19-1119.5.7 Skewed Precast Units . 19-1119.5.8 Detailing Requirements. 19-1119.5.9 Load Rating Requirements . 19-1119.5.10 Span-to-Rise Ratios . 19-1219.6COMPUTER DESIGN AND ANALYSIS PROGRAM . 19-135/19/11

REINFORCED CONCRETE BOX CULVERTS AND SIMILAR STRUCTURES19-9design assistance is required, contact the Regional Structures Engineer or the StructuresDesign and Construction Division. If assistance in the determination of appropriate type ofwall is required contact the Geotechnical Engineering Bureau or Regional GeotechnicalEngineer.Wingwall alignment is highly dependent on site conditions and should be evaluated on acase-by-case basis. The angle(s) of the wall(s) on the upstream end should direct thewater into the culvert. It is also desirable to have the top of the wall elevation at its endabove the design high water elevation to prevent overtopping of the wall.When precast wingwalls are allowed the designer should be aware of potential conflicts withROW, M&PT, utilities, etc. The footprint of the footing and excavation, especially for bintype walls, can be extensive. Note(s) should be placed on the plans alerting the Contractorto these requirements when they exist.Due to the skew and/or grade differences between the precast culvert unit and precastwingwalls it is necessary to do a cast-in-place closure pour between the culvert end unit andthe wingwalls. A closure pour is not required if cast-in-place wingwalls are used. See thecurrent BD-CBx sheets for details.19.5DESIGN GUIDELINES FOR REINFORCED CONCRETE CULVERTSReinforced concrete box culverts (prismatic precast or cast-in-place, four-sided or threesided) subjected to either earth fill and/or highway vehicle loading shall be designed inaccordance with NYSDOT LRFD Bridge Design Specifications and the guidelines inSections 19.5.1 - 19.5.10.19.5.1 Design MethodThe design and analysis method shall be in accordance with NYSDOT LRFD Bridge DesignSpecifications.19.5.2 Dead Load and Earth PressureThe dead load on the top slab shall consist of the pavement, soil, and the concrete slab.For simplicity, assume the pavement as soil.The following criteria shall be used in determining dead load and earth pressures for design:SoilConcreteLateral earth pressure5/19/11 319 kN/m , (120 pcf)24 kN/m3, (150 pcf)2.9 kPa max., 1.45 kPa min.(60 pcf max., 30 pcf min.)§19.5.2

19-10REINFORCED CONCRETE BOX CULVERTS AND SIMILAR STRUCTURES19.5.3 Live LoadReinforced concrete box culverts shall be designed for HL-93 vehicle live load and theNYSDOT Design Permit Vehicle.19.5.4 Wall Thickness RequirementsExterior wall thickness requirements for reinforced concrete box culverts shall be controlledby design, except that minimum exterior wall thickness requirements have been establishedto allow for a better distribution of negative moment, corner reinforcement as follows:CLEAR SPAN 2.44 m 2.44 m & 4.27 m 4.27 m & 6.096 m 6.096 mMINIMUM EXTERIORWALL THICKNESS150 mm200 mm250 mm300 mmInterior wall thickness, in multicell applications, shall be controlled by design but shall not beless than 150 mm in any instance.19.5.5 Concrete StrengthReinforced concrete box culverts shall be designed for the following concrete strengths:PrecastCast-in-place§19.5.5f'c 35 MPa, min. to 50 MPa, max. (increments of 5 MPa)f'c 21 MPa5/19/11

REINFORCED CONCRETE BOX CULVERTS AND SIMILAR STRUCTURES 19-1119.5.6 Reinforcement RequirementsReinforcement shall be either bar reinforcement, welded wire fabric (plain), or welded wirefabric (deformed) in accordance with NYSDOT LRFD Bridge Design Specifications.When the fill height over the box culvert is less than 600 mm, all reinforcing steel in the topmat of the top slab shall be epoxy-coated or the concrete shall contain corrosion inhibitor.All faces of reinforced concrete box culverts not requiring design or distributionreinforcement shall be reinforced with the equivalent of #13 bar reinforcement at 300 mmcenters in each direction. Under no circumstances shall any reinforcement be spacedgreater than 300 mm.Shear reinforcement and/or slab and wall thicknesses shall be designed to have adequateshear capacity in accordance with NYSDOT LRFD Bridge Design Specifications.19.5.7 Skewed Precast UnitsSkewed precast culvert sections shall be designed for whichever of the following twoconditions controls:The skewed end clear span analyzed without the skew effect.The square end clear span analyzed with the skew effect.19.5.8 Detailing RequirementsThe minimum reinforcing bar cover requirements for cast-in-place and precast box culvertsshall be as indicated in Section 15 of the Bridge Manual.Top and bottom slab, outside-face, transverse steel shall be full-length bars, unless splicedto top and bottom corner reinforcing steel.19.5.9 Load Rating RequirementsBridge-size culverts, as defined by the Uniform Code of Bridge Inspection, shall require thesubmission of two (2) copies of detailed load rating calculations prepared in accordancewith the current AASHTO Manual for Bridge Evaluation with all interim provisions in effect.Calculations shall be certified and stamped by a professional engineer currently registeredand authorized to practice in New York State and shall specify which method (AllowableStress or Load Factor) was used in load rating computations. Load ratings will also becomputed by the Load and Resistance Factor Rating (LRFR) method.Bridge-size precast box culverts shall be load rated by the fabricator’s licensed professionalengineer and the both load ratings shall be shown on the approved fabrication drawings,5/19/11§19.5.9

19-12REINFORCED CONCRETE BOX CULVERTS AND SIMILAR STRUCTURESwhich are to be included in the record plans. Cast-in-place box culverts shall be load ratedby the licensed professional engineering designer and the load rating shall be shown on thecontract plans. Load rating calculations shall be based on the AASHTO HS or MS live-loadvehicle for the Allowable Stress or Load Factor rating and HL-93 live load vehicle for theLoad and Resistance Factor Rating. Inventory and operating values shall be reported ineither English or metric tons. Level one load ratings shall be maintained in the RegionalOffice.19.5.10 Span-to-Rise RatiosThree-sided box culverts and frames with clear span-to-rise ratios that exceed 4-to-1 arenot recommended. Designers of these units typically compute moments, shears, andthrusts based on fully pinned support conditions that are able to resist horizontal forces andprevent horizontal displacements. When span-to-rise ratios exceed 4-to-1, frame momentdistribution is more sensitive to support conditions, and positive moments at mid-span cansignificantly exceed computed values even with relatively small horizontal displacement offrame leg supports.If it is necessary to use a three-sided frame with a span-to-rise ratio in excess of 4-to-1, thestructure should be analyzed for mid-span positive moment using pin-roller supportconditions. Fully pinned support conditions could be used if site and construction conditionsare able to prevent horizontal displacement of frame leg supports. Such a condition mayexist if footings are on rock, and frame legs are keyed into footings with adequate detailsand construction methods.§19.5.105/19/11

REINFORCED CONCRETE BOX CULVERTS AND SIMILAR STRUCTURES 19-1319.6COMPUTER DESIGN AND ANALYSIS PROGRAMThis section provides an overview of the software currently used by NYSDOT for designand analysis of reinforced concrete culverts. It should not be construed as an endorsementof any software by NYSDOT. Unless noted by contract, consultants to NYSDOT are notrequired to use this software. Users should refer to the corresponding manuals for moredetailed instructions and limitationsThe current version of ETCulvert by Eriksson Technologies is used by the Office ofStructures. It has been distributed to NYSDOT Regional Structures personnel and is alsoused by the Precast Concrete Association of New York (PCANY). Questions regarding theuse of this program or how to obtain a copy and/or a User’s Manual should be addressed toEriksson Technologies at www.lrfd.com.ETCulvert will design and/or analyze a one-cell reinforced concrete box culvert withprismatic members (precast or cast-in-place), with or without bottom slab in accordance withthe design criteria in NYSDOT LRFD Bridge Design Specifications or AASHTO StandardSpecifications for Highway Bridges. The program will design wall and slab thicknesses andrequired reinforcement for a box culvert and provide the bar schedule and Load Rating.5/19/11§19.6

19-34 REINFORCED CONCRETE BOX CULVERTS AND SIMILAR STRUCTURES19.14 REFERENCES1.AASHTO Bridge Design Specifications, 4th Edition 2007 with 2008 and 2009interims, American Association of State Highway and Transportation Officials, 444North Capital Street, N. W. Suite 249, Washington, D. C. 20001.2.Standard Specifications for Highway Bridges, 17th Edition 2002, AmericanAssociation of State Highway and Transportation Officials, 444 North Capital Street,N. W. Suite 249, Washington, D. C. 20001.3.Standard Specifications of Construction and Materials, May 4, 2006, and alladdendums, Design Quality Assurance Bureau, New York State Department ofTransportation, Albany, NY 12232.4.Model Drainage Manual, 2005, American Association of State Highway andTransportation Officials, 444 North Capital Street, N. W. Suite 225, Washington, D.C. 20001.5.Bridge Manual, 4th Edition, April 2006, and all addendums, Structures Design andConstruction Division, New York State Department of Transportation, Albany, NY12232.6.Bridge Detail Sheets BD-CBx, Structures Design and Construction Division, NewYork State Department of Transportation, Albany, NY 12232.§19.1412/16/05

19-12 REINFORCED CONCRETE BOX CULVERTS AND SIMILAR STRUCTURES §19.5.10 5/19/11 which are to be included in the record plans. Cast-in-place box culverts shall be load rated by the licensed professional engineering designer and the load rating shall be shown on the contract plans. Load rating calculations shall be based on the AASHTO HS or MS ...