WIXLIB

January 20213.7WATER LOADS: WA3.7.5Change in Foundations Due to Limit State for ScourC3.7.5Delete the Commentary to Article 3.7.5 and replace it with thefollowing:Designing for large scour depths is impractical for pile foundationsat abutments given the conservatism of the current state ofpractice. Based on NYSDOT’s experience and design methodology,the excess resistance of the abutment battered piles sufficientlycounter balances the decrease in lateral resistance and thetheoretical increase in displacement that the design modelspredict for a scour event.Therefore, because of the inherent conservatism in NYSDOT’scurrent state of practice combined with NYSDOT’s inspectionprogram, a rigorous lateral analysis for scour events isunnecessary for typical pile abutment foundations. Large, critical,signature structures, or other economically significant structuresexposed to unusual scour risk may warrant a rigorous lateralanalysis.

January 20213.8WIND LOAD: WL AND WS3.8.1Horizontal Wind Loading3.8.1.1Exposure Conditions3.8.1.1.2Wind SpeedDelete the second sentence in Article 3.8.1.1.2 and replace itwith the following:In the absence of more precise information, the 3-second gustwind speed for areas designated as a Special Wind Region inFigure 3.8.1.1.2-1 may be taken as 115 MPH.

January 20213.8WIND LOAD: WL AND WS3.8.1Horizontal Wind Load3.8.1.2Wind Load on Structures: WS3.8.1.2.1GeneralDelete Table 3.8.1.2.1-1 Gust Effect Factor, G and replace it with thefollowing:Structure TypeSound Barriers Mounted on the GroundSound Barriers Mounted on a StructureAll other StructuresGust EffectFactor, G0.851.001.00

January 20213.9ICE LOADS: IC3.9.2Dynamic Ice Forces on Piers3.9.2.1Effective Ice StrengthDelete Article 3.9.2.1 and replace it with the following:In the absence of more precise information, a value of 24.0 ksfmay be used for the effective ice crushing strength.The height of action of the Dynamic Ice Load shall be the OrdinaryHigh Water elevation.

January 20213.9ICE LOADS: IC3.9.2Dynamic Ice Forces on Piers3.9.2.2Crushing and FlexingC3.9.2.2Delete the following definition:“Sf freezing index, being the algebraic sum, Σ(32 – T), summedfrom the date of freeze-up to the date of interest, in degree days.”and replace with:Sf freezing index. Values for each county of New York are givenin Fig. C3.9.2.2-1. For a bridge crossing a county line or a lineseparating areas with different values of Sf, the smaller value of Sfshould be used.Delete the following:“As a guide, Neill (1981) indicates the following valueswindy lakes without snowaverage lake with snowaverage river with snowsheltered small river with snowfor α:0.80.5-0.70.4-0.50.2-0.4”and replace with:In the absence of more precise information, the following valuesmay be used for α:All lakesAll rivers0.700.50

CATTARAUGUS NE1300STEUBEN1350MONROE1300Figure C.3.9.2.2-1-Freezing Index SfCHAUTAUQUA1350ERIE1350GENESEE1300NIAGARA 45018502000NYC (BRONX, KINGS,NEW YORK, QUEENS, 5502000LEWIS1850JEFFERSON1850ST. CHENECTADY1400January 2021C3.9.2.2 (continued)

January 20213.9ICE LOADS: IC3.9.3Static Ice Loads on PiersAdd the following at the end of the article:When the designer determines that static ice loads should beconsidered in the design of a member, the Static Ice Force maybe assumed to be the product of a 7.5 ksf pressure applied overa depth equal to the thickness of the ice, not to exceed 2.0 ft.The height of action of the Static Ice Load shall be the OrdinaryWater elevation.Static Ice Loads shall not be combined with Dynamic Ice Forces.C.3.9.3Add the following at the end of the commentary:In the absence of more precise information, the thickness of icecan be estimated using the procedure in C3.9.2.The maximum ice pressure developed in the static condition isknown to have an upper limiting value of 7.5 ksf due to crackingand creep relaxation of ice pressures.For an ice sheet having a thickness greater than 2.0 ft., the forceper unit width does not depend on ice thickness, because the icelayer below the 2.0 ft. depth does not undergo a change intemperature.

January 20213.10EARTHQUAKE EFFECTS: EQ3.10.1GeneralDelete the first paragraph of Article 3.10.1 and replace it withthe following:Bridge Operational Categories are defined in Article 3.10.5.Bridges defined as “other” shall be designed to have a lowprobability of collapse but may suffer significant damage anddisruption to service when subject to earthquake ground motionsthat have a 7% probability of exceedance in 75 years. Partial orcomplete replacement may be required. Higher levels ofperformance may be used with the authorization of the bridgeowner.Add the following after the last paragraph:For bridges located in the counties of Bronx, Kings, New York,Queens, Richmond, Nassau, Rockland, and Westchester (definedas the Downstate Zone), delete Section 3.10, including allsubsequent articles, and replace it with Blue Page A3.10. Forseismic analysis and design procedures, all remaining sections ofthe LRFD Bridge Design Specifications along with the NYS BluePages shall be followed.

January 20213.10EARTHQUAKE EFFECTS: EQ3.10.2Seismic Hazard3.10.2.1General ProcedureC3.10.2.1 Delete the fourth and fifth paragraphs of the Commentary toArticle 3.10.2.1.

January 20213.10EARTHQUAKE EFFECTS: EQ3.10.2Seismic Hazard3.10.2.2Site Specific ProcedureDelete Article 3.10.2.2 and replace it with the following:A site-specific procedure to develop design response spectra ofearthquake ground motions shall be performed when required byArticle 3.10.2 and may be performed for any site. The objectiveof the site-specific procedure should be to generate a responsespectrum for the 1,000 year return period earthquake for spectralvalues over the entire period range of interest. An additionalresponse spectrum for a 2,500 year return period earthquake isrequired for critical bridges. The uniform-hazard accelerationresponse spectrum for rock below soil at the bridge site shall bebased on the 2009 AASHTO spectra for the 1,000 year earthquakeand shall be based on the 2009 NEHRP spectra for the 2,500 yearearthquake.Where analyses to determine site soil response effects arerequired by Article 3.10.3.1 for Site Class F soils, the influence ofthe local soil conditions shall be determined based on site-specificgeotechnical investigations and dynamic site response analysesusing appropriate rock spectra.Where response spectra are determined from a site-specific study,the spectra shall not be lower than two thirds of the responsespectra determined using the general procedure of Article3.10.2.1 in the region of 0.5TF to 2.0TF of the spectrum where TFis the bridge fundamental period.

January 20213.10EARTHQUAKE EFFECTS: EQ3.10.5 Operational ClassificationAdd the following after the last paragraph:Seismic Performance CriteriaCritical Bridge: A critical bridge must provide immediate access afterthe lower level (functional) event and limited access after the upperlevel (safety) event and continue to function as a part of the lifeline,social/survival network and serve as an important link for civildefense, police, fire department and/or public health agencies torespond to a disaster situation after the event, providing a continuousroute. Any bridge on a critical route shall be classified as critical ifthere is no readily accessible detour, and shall at a minimum beclassified as essential if there is such a detour.Any bridge that crosses a critical route, whose collapse would blockthe critical route, shall at a minimum be classified as essential if thereis no readily accessible detour for the critical route. However, thebridge owner may classify such bridges as critical with theconcurrence of the DCES.The designated detour for the critical route shall also be treated as acritical route.It is expected that relatively few bridges will be classified as critical.Critical bridges would generally be limited to those on life safetyroutes in an urban area or on the approaches to an urban area. Criticalbridges would also be located on routes to a defense facility that haslimited access. Bridges on limited access highways in rural areaswould generally not be classified as critical unless they are majorstructures. The designation of a bridge as critical is at the discretionof the Regional Director/Bridge Owner and it is to be documented inthe Design Report and included in the Site Data Package.

January 20213.10.5 (continued)Critical bridges shall be analyzed for two earthquake hazard designlevels: a lower level event (functional evaluation/design level) havinga 7% probability of being exceeded in 75 years (1,000 year returnperiod), and an upper level event (safety evaluation/design level)having a 3% probability of being exceeded in 75 years (2,500 yearreturn period). These analysis requirements shall apply to criticalbridges located within Seismic Zone 1 as well. A site specific analysisis required for critical bridges, except for single-span bridges locatedon non-liquefiable soil sites. In the case of long span bridges, theeffects of spatial variation on the seismic ground motions must alsobe considered.Critical bridges shall survive the upper level event (2,500 year returnperiod) with repairable damage (see definition of damage levels).Traffic access following this event may be limited; within 48 hours foremergency/defense vehicles and within months for general traffic.After the lower level event (1,000 year return period) the bridge shallsuffer no damage to primary structural elements and minimal damageto other components (see definition of damage levels). Access afterthis event shall be immediate to all traffic with an allowance of a fewhours for inspection.Essential Bridge: An essential bridge must provide at least limitedaccess after a lower level event and serve as an important link forcivil defense, police, fire department and/or public disaster situationafter the event, providing a continuous route. A bridge that crossesan essential route, whose collapse would block the essential route,shall also be classified as essential if there is no readily accessibledetour for the essential route. The designated detour for the essentialroute shall also be treated as an essential route.Essential bridges should include those on interstate highways andothers of importance as determined by the Regional Director/BridgeOwner. The designation of a bridge as essential is to be documentedin the Design Report and included in the Site Data Package.

January 20213.10.5 (continued)Essential bridges shall be analyzed for a single earthquake hazarddesign level event having a 7% probability of being exceeded in 75years (1,000 year return period). Essential bridges shall survive thedesign event with repairable damage (see definition of damagelevels). Access following the seismic event may be limited: one or twolanes shall be available within 72 hours for emergency vehicles, fullservice within months.Other Bridges: All bridges not classified as critical or essential shallbe classified as Other Bridges. Other bridges shall be analyzed for asingle earthquake hazard design level event having a 7% probabilityof being exceeded in 75 years (1,000 year return period). Otherbridges may suffer significant damage (see definition of damagelevels) although collapse shall not occur. The designation of a bridgeas Other is to be documented in the design report and included in theSite Data Package.Damage Levels – Definitions Minimal Damage: The Bridge should essentially behaveelastically during the earthquake, although minor inelasticresponse could take place. Post-earthquake damage should belimited to narrow flexural cracking in concrete and masonryelements. There should be no permanent deformations tostructural members. Only minor damage or permanentdeformations to non-structural members should take place. Repairable Damage: The extent of damage should be limited sothat the structure can be restored to its pre-earthquake conditionwithout replacement of structural members. Inelastic responsemay occur resulting in: concrete cracking, minor cover spalling andreinforcement yielding; minor yielding of structural steelmembers; some damage to secondary members and nonstructural components; some damage to masonry. Repair shouldnot require complete closure of the bridge. Permanent offsetsshould be small and there should be no collapse.

January 20213.10.5 (continued) Significant Damage: There is no collapse, but permanent offsetsmay occur. Extensive cracking, major spalling of concrete andreinforcement yielding, cracking of deck slab at the shear studs,may force closure for repair. Similar consequences could resultfrom yielding or local buckling of steel members. There could beyielding of member connections, fracture of limited number ofbolts/rivets, serious damage to secondary structural members andnon-structural components, as well as to masonry. In sites withsignificant ground lateral spreading due to liquefaction, largeinelastic deformations might be induced to piles. Liquefactioncould also result in excessive differential settlements. Partial orcomplete replacement may be required in some cases.

January 20213.10EARTHQUAKE EFFECTS: EQ3.10.7Response Modification Factors3.10.7.1GeneralAdd to Article 3.10.7.1 the following:The response modification factors given in Table 3.10.7.1-1 shallbe applied, where applicable, to the seismic design forces thatresult from a 1,000 year return period event. In the case of acritical bridge where a 2,500 year return period event is beingevaluated, the response modification factors for an essentialbridge shall be applied, as shown in the table below.Response Modification Factors – Critical Bridges

January 20213.10.9Calculation of Design Forces3.10.9.1GeneralDelete the first paragraph of the article and replace with the following:For single-span bridges, regardless of seismic zone, there shallbe no required seismic design connection force in the restraineddirection between the superstructure and the substructure.Minimum support lengths at both expansion and fixed bearingsshall be provided as given in Article 4.7.4.4.

January 2021Insert Article 3.10.11 and Appendix A3.10 in between Article 3.10.10 andArticle 3.113.10.11Criteria for Seismic Retrofitting of BridgesProgrammed for Rehabilitation3.10.11.1GeneralFor evaluating and upgrading the seismic resistance of existinghighway bridges, FHWA’s “Seismic Retrofitting Manual forHighway Structures: Part 1 – Bridges” (January 2006, PublicationNo. FHWA-HRT-06-032) is referenced. The provisions of thismanual shall apply to highway bridges of conventional steel andconcrete construction with spans not exceeding 500 ft. TheOwner shall specify and/or approve appropriate provisions fornonconventional construction and for bridges with spansexceeding 500 ft.C3.10.11.1 Conventional bridges include those with slab, beam, box girder,or truss superstructures, and single or multiple-column piers,wall-type piers, or pile-bent substructures. In addition,conventional bridges are founded on shallow or piled footings orshafts. Nonconventional bridges include suspension bridges,cable-stayed bridges, arches, movable bridges, and bridges withtruss towers or hollow piers for substructures.

January 20213.10.11.2 Seismic Performance CriteriaRefer to the FHWA Seismic Retrofitting Manual and the NYSDOTBridge Manual for guidance on the appropriate extent of seismicretrofitting.The following changes to the FHWA Seismic Retrofitting Manualshall be applied: FHWA’s seismic retrofitting manual recommends evaluation ofbridges for lower level earthquake event of 100 years and anupper level event of 1,000 years. Bridges shall be evaluatedonly for the upper level earthquake ground motions with a 7%probability of exceedance in 75 years corresponding to a 1,000year return period.Critical and essential bridges shall be combined in one categoryand will be evaluated

Seismic design shall be in accordance with the provisions in these specifications. Seismic design in accordance with the provisions given in the AASHTO Guide Specifications for LRFD Seismic Bridge Design can be used