BRIDGE RATING. Prepared for MASSACHUSETTS DEPARTMENT OF TRANSPORTATION HIGHWAY DIVISION BOSTON. ST Monsignor William Casey Highway.

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1 BRIDGE RATING Prepared for MASSACHUSETTS DEPARTMENT OF TRANSPORTATION HIGHWAY DIVISION BOSTON ST Monsignor William Casey Highway over Washington Street & Amtrak/MBTA Rail Road BRIDGE NO. B (4EX) VOLUME 1 OF 3 January 29, 2010 May, 2010 Date of Inspection Date of Rating Submitted by: HNTB Corporation MNTB 31 SI. James Avenue, Suite 300 Boston, MA (617)

2 I..MASSACHUSETTS DEPARTMENT OF TRANSPORTATION HIGHWAY DIVISION INTEROFFICE MEMORANDUM TO: Walter Heller, District 6 Highway Director ATTN: Maintenance Engineer A~.' ~ V <P ~ FROM:., 10i<GlAwlVL t- Q:)C.VtCA&W1(~ Alexander K. Bardow, P.E., Director of Bridges and Structures DATE: January 19,2012 RE: National Bridge Inspection Standards (NBIS) Bridge Rating and Posting Boston: ST203 ARBORWAY /WASH ST&AMTK&ORNG BRIDGE NO: B BIN NO: 4EX STRUCTURE NO: B EX-DOT-NBI A rating report for the subject bridge (copy filed with the District Bridge Inspection Unit) has been completed by HNTB Corporation, dated May 1, In accordance with the Board Action taken, item #20 dated 12/28/11, this bridge is to be POSTED as follows: TYPE "H" (2 axles) TYPE "3" (3 axles) TYP.E "3S2" (5 axles) 14 TONS 14 TONS 14 TONS Please direct your personnel to post the bridge within 30 working days, provide an alternate route for vehicles exceeding the posted limits and notify the local officials of the action.taken. Please be advised that some deficienci~s were reported in the rating report.{see attached letter by Director of Bridges and Structures to NBIS file dated 12/14/11) with recommendations to be addressed through repairs or rehabilitations. The District Bridge Inspection Unit shall code all related items in the inventory appropriately and submit changes with the monthly compliance report upon verifying that you have complied with this warrant.. GK/gk cc: BIE (3). DBIE,D-6 State Police Attachment: Letter to NBIS file dated 12/14/11

3 The Commonwealth ofm.assachu.$etts Massachusetts Department oftransportation -lijghway Division MISCELLANEOUS,ITEM Action Reqt(ested: ;::;:B~ri~d:t:o:ge::..:P:;..:o::.:!s~tin::Jg~ ~ ----._-.:. 1 Type of Contract:.0...;,...='"7=.1%=="":"..,----" -'-'----,-,,-- Contract #: --"- Division.: BRIDGES AND STRUCTURES Project I.D. #: --'-"-- Project/Location:, Bostoil/ B / S,T203 ARBORWAY/ W~SH ST&AMTK&ORNG Vendo,rlParty Name and Ad.«.lress: _..., ,... -,-- Accolln.t No.: _,...,-- Federal Aid No.: _..;.;...",...,.;...,-- Description: Subject: NATIONAL BRIDGE INSPECTION STANDARDS (NBIS) BRIDGE POSTING ~-"'BRlljGE NO; 8-16,.367 (4EX). STRUCTURE NO: B EX-DOT-NBI. Attached is a copy of the Idad rating repqrt summary sheets containing a r$commendation by Alexander K. BCitdow, P.E., Director of Bridges and Structures,, dated 12/14/11, to post the bridge ~s follows: TYPE "HIt (2 a,xle?s) Loading 14 TONS TYPE "3" (3 axles) Loading 14 TONS TYPE "3S2 11 (5 a~es) Loading 14 TONS I I recommend that the Bridge No. ~ be posted for the above? listed load limits for the best interest of the Commo[1wealth and the safety of the traveling public. ire' 6r of Bridges and, St-rudtires Alexander K. Bardow, P.E..; ",N{t- Admmistratgt: ' Secretary/CEO Date Date DOT MISe-ITEM Item No.: _ d-,o. ( Date: OI:'C.. 9Q 2011

4 THE COMMONWEALTH OF MASSACHUSETTS MASSDOT - HIGHWAY DIVISION INTEROFFICE MEMORANDUM TO: NBIS File FROM: Alexander K. Bardow, P. E.,~r of!l,?";;" & structur"es ly/f-4j/i/:ll... DATE: December 14, 2011 RE: BRIDGE RATING BOSTON ST 203 MONSIGNOR WILLIAM CASEY HIGHWAY OVER WASHINGTON STREET & AMTRAK/MBTA BRIDGE NO. B (4EX) BIN = 4EX Based upon the rating report prepared by HNTB Corp. dated May 2010, and the Special Member Inspection dated January 17, 2011 it is recommended that Bridge No. B (4EX) BE POSTED FOR 14 TONS. The recommended channelization, reducing vehicular traffic to one lane in each direction while channelization live loads away from the critical elements, is complete. The controlling element of the structure for both the inventory and operating stress level requirements is beam 12, in span 1, at midspan, for all posting vehicles. The inventory rating values were calculated to' be 4.4 tons, 5.7 tons and 7.2 tons and the operating rating values are 20.2 tons, 25.9 tons and 33.0 tons, for the H20, Type 3, and Type 3S2 trucks respectively. There is ample capacity at the operating level to justify the 14 TON posting. Overall, the structure is in critical to fair condition. The bridge was constructed in The structure consists of 20 simple spans with a concrete filled steel grid deck on rolled steel beams with built-up' fascia girders supported by reinforced concrete piers and abutments. The following is recommended to improve and maintain the condition of the structure. All preventive maintenance and inspection procedures should continue on normal and regular intervals. This structure is scheduled for replacement under Proj ect File No with a current advertising date of April 13, (Continued)

5 NBIS FILE December 14, 2011 PAGE 2 OF 2 RE: B (4EX) RATING REPORT The following load rating data shall be entered into the 40 Database by the Ratings and Overloads Unit. Item 63 1 (Load Factor Method) Item Metric Tons Item 65 1 (Load Factor Method) Item Metric Tons INV H English Tons OPR H English Tons INV Type 3 = 5.7 English Tons OPR Type 3 = 25.9 English Tons INV Type 3S2 = 7.2 English Tons OPR Type 3S2 = 33.0 English Tons INV HS20 = 5.9 English Tons OPR HS20 = 27.1 English Tons Rating Report Y Date of Last Rating Report = 5/10 Computer File - Y Computer File Type = VIRTIS HRBlmt cc: Rating Reports (Bridge and District copies) l

6 BRIDGE RATING Prepared for MASSACHUSETTS DEPARTMENT OF TRANSPORTATION HIGHWAY DIVISION BOSTON ST Monsignor William Casey Highway over Washington Street & Amtrak/MBTA Rail Road BRIDGE NO. B (4EX) January 29,2010 May, 2010 Date of Inspection,".' --:::-Da-:-'te"-'-of:-::R:-:at:-ing- HNTB Corporation 31 St. James Avenue, Suite 300 MNTB Boston, MA (617)

7 INDEX BOSTON ST 203 MONSGR CASEY OVER WASH ST, AMTK&MBTA B (4EX) DESCRIPTION PAGE SUMMARY OF BRIDGE RATING... 1 BREAKDOWN OF BRIDGE RATING LOCATION MAP DESCRIPTION OF BRIDGE RATING ANALYSIS ASSUMPTIONS AND CRITERIA EVALUATION OF RATING AND RECOMMENDATIONS AVAILABLE PLANS TRUCK LOADINGS APPENDICES Appendix A Inspection Reports Appendix B Photographs Appendix C Computations Appendix D Computer Input and Output Appendix E Old Rating Report

8 SUMMARY OF BRIDGE RATING TOWN/CITY: BOSTON CARRIES: ST 203 MONSGR CASEY BRIDGE NO. B OVER: WASH ST&AMTK&MBTA BIN NO. 4EX RATINGS (TONS) Allowable Stress Ratings for Load Posting Purposes Load Ratings in English Tons VEHICLE TYPE INVENTORY OPERATING H2O TYPE TYPE 3S HS MS 18 Load Factor Ratings in Metric Tons Provided in Compliance with the December 1995 FHWA NBIS Coding Guide INVENTORY OPERATING Item 66 MS Equivalent Item 64 MS Equivalent 10.7 MS MS9.9 A posting recommendation has been made based on the results of this Rating Report. This recommendation is contained in the "Memorandum to the NBIS File" for this bridge dated Director of Bridges and Structures Date

9 BREAKDOWN OF BRIDGE RATING TOWN/CITY: BOSTON CARRIES: ST 203 MONSGR CASEY BRIDGE NO. B OVER: WASH ST&AMTK&MBTA BIN NO. 4EX BRIDGE ELEMENT 4-1/4 CONC. FILLED STEEL GRID DECK 5 SPAN INVENTORY RATING BY WORKING STRESS METHOD (ENGLISH TONS) H20 TYPE 3 TYPE 3S2 OPERATING RATING BY WORKING STRESS METHOD (ENGLISH TONS) HS20 H20 TYPE 3 TYPE 3S2 HS TYPICAL SPAN SDWLK BEAM B2, B13 TYPICAL SPAN SDWLK BEAM B2, B13 TYPICAL SPAN INT. BEAM B3-B6, B9-12 TYPICAL SPAN INT. BEAM B3-B6, B9-12 TYPICAL SPAN MEDIAN BEAM B7 & B8 TYPICAL SPAN MEDIAN BEAM B7 & B SPAN 1 BEAM 8 SPAN 1 BEAM 8 SPAN 1 BEAM 12 SPAN 1 BEAM 12 SPAN 1 BEAM 13 SPAN 1 BEAM

10 BREAKDOWN OF BRIDGE RATING Cont. TOWN/CITY: BOSTON CARRIES: ST 203 MONSGR CASEY BRIDGE NO. B OVER: WASH ST&AMTK&MBTA BIN NO. 4EX BRIDGE ELEMENT SPAN 9 BEAM 2 SPAN 9 BEAM 2 SPAN 9 BEAM 3 SPAN 9 BEAM 3 SPAN 9 BEAM 7 SPAN 9 BEAM 7 INVENTORY RATING BY WORKING STRESS METHOD (ENGLISH TONS) H20 TYPE 3 TYPE 3S2 OPERATING RATING BY WORKING STRESS METHOD (ENGLISH TONS) HS20 H20 TYPE 3 TYPE 3S2 HS SPAN 11 BEAM 2 SPAN 11 BEAM 2 SPAN 11 BEAM 3 SPAN 11 BEAM 3 SPAN 11 BEAM 7 SPAN 11 BEAM SPAN 13 BEAM 2 SPAN 13 BEAM 2 SPAN 13 BEAM 3 SPAN 13 BEAM 3 SPAN 13 BEAM 5 SPAN 13 BEAM

11 BREAKDOWN OF BRIDGE RATING Cont. TOWN/CITY: BOSTON CARRIES: ST 203 MONSGR CASEY BRIDGE NO. B OVER: WASH ST&AMTK&MBTA BIN NO. 4EX BRIDGE ELEMENT SPAN 13 BEAM 7 SPAN 13 BEAM 7 SPAN 13 BEAM 8 SPAN 13 BEAM 8 SPAN 13 BEAM 9 SPAN 13 BEAM 9 SPAN 13 BEAM 13 SPAN 13 BEAM 13 INVENTORY RATING BY WORKING STRESS METHOD (ENGLISH TONS) H20 TYPE 3 TYPE 3S2 OPERATING RATING BY WORKING STRESS METHOD (ENGLISH TONS) HS20 H20 TYPE 3 TYPE 3S2 HS SPAN 14 BEAM 2 SPAN 14 BEAM 2 SPAN 14 BEAM 3 SPAN 14 BEAM 3 SPAN 14 BEAM 7 SPAN 14 BEAM SPAN 15 BEAM 2 SPAN 15 BEAM 2 SPAN 15 BEAM 3 SPAN 15 BEAM

12 BREAKDOWN OF BRIDGE RATING Cont. TOWN/CITY: BOSTON CARRIES: ST 203 MONSGR CASEY BRIDGE NO. B OVER: WASH ST&AMTK&MBTA BIN NO. 4EX BRIDGE ELEMENT SPAN 15 BEAM 6 SPAN 15 BEAM 6 SPAN 15 BEAM 7 SPAN 15 BEAM 7 SPAN 15 BEAM 8 SPAN 15 BEAM 8 SPAN 15 BEAM 12 SPAN 15 BEAM 12 SPAN 15 BEAM 13 SPAN 15 BEAM 13 INVENTORY RATING BY WORKING STRESS METHOD (ENGLISH TONS) H20 TYPE 3 TYPE 3S2 OPERATING RATING BY WORKING STRESS METHOD (ENGLISH TONS) HS20 H20 TYPE 3 TYPE 3S2 HS SPAN 16,17,&19 BEAM 2 SPAN 16,17,&19 BEAM 2 SPAN 16,17,&19 BEAM 3 SPAN 16,17,&19 BEAM 3 SPAN 16,17,&19 BEAM 7 SPAN 16,17,&19 BEAM

13 BREAKDOWN OF BRIDGE RATING Cont. TOWN/CITY: BOSTON CARRIES: ST 203 MONSGR CASEY BRIDGE NO. B OVER: WASH ST&AMTK&MBTA BIN NO. 4EX BRIDGE ELEMENT SPAN 18 BEAM 2 SPAN 18 BEAM 2 SPAN 18 BEAM 3 SPAN 18 BEAM 3 SPAN 18 BEAM 7 SPAN 18 BEAM 7 INVENTORY RATING BY WORKING STRESS METHOD (ENGLISH TONS) H20 TYPE 3 TYPE 3S2 OPERATING RATING BY WORKING STRESS METHOD (ENGLISH TONS) HS20 H20 TYPE 3 TYPE 3S2 HS SPAN 20 BEAM 2 SPAN 20 BEAM 2 SPAN 20 BEAM 3 SPAN 20 BEAM 3 SPAN 20 BEAM 7 SPAN 20 BEAM SPAN 6 BEAM 2 SPAN 6 BEAM

14 BREAKDOWN OF BRIDGE RATING Cont. TOWN/CITY: BOSTON CARRIES: ST 203 MONSGR CASEY BRIDGE NO. B OVER: WASH ST&AMTK&MBTA BIN NO. 4EX BRIDGE ELEMENT 4-1/4 CONC. FILLED STEEL GRID DECK 5 SPAN INVENTORY RATING BY LOAD FACTOR METHOD (METRIC TONS) OPERATING RATING BY LOAD FACTOR METHOD (METRIC TONS) MS18 MS (EQUIV.) MS18 MS (EQUIV.) 32.7 MS MS30.4 TYPICAL SPAN SDWLK BEAM B2, B13 TYPICAL SPAN SDWLK BEAM B2, B13 TYPICAL SPAN INT. BEAM B3-B6, B9-12 TYPICAL SPAN INT. BEAM B3-B6, B9-12 TYPICAL SPAN MEDIAN BEAM B7 & B8 TYPICAL SPAN MEDIAN BEAM B7 & B MS MS MS MS MS MS MS MS MS MS MS MS SPAN 1 BEAM 8 SPAN 1 BEAM 8 SPAN 1 BEAM 12 SPAN 1 BEAM 12 SPAN 1 BEAM 13 SPAN 1 BEAM MS MS MS MS MS MS MS MS MS MS MS MS

15 BREAKDOWN OF BRIDGE RATING Cont. TOWN/CITY: BOSTON CARRIES: ST 203 MONSGR CASEY BRIDGE NO. B OVER: WASH ST&AMTK&MBTA BIN NO. 4EX BRIDGE ELEMENT SPAN 9 BEAM 2 SPAN 9 BEAM 2 SPAN 9 BEAM 3 SPAN 9 BEAM 3 SPAN 9 BEAM 7 SPAN 9 BEAM 7 INVENTORY RATING BY LOAD FACTOR METHOD (METRIC TONS) OPERATING RATING BY LOAD FACTOR METHOD (METRIC TONS) MS18 MS (EQUIV.) MS18 MS (EQUIV.) 19.8 MS MS MS MS MS MS MS MS MS MS MS MS138.2 SPAN 11 BEAM 2 SPAN 11 BEAM 2 SPAN 11 BEAM 3 SPAN 11 BEAM 3 SPAN 11 BEAM 7 SPAN 11 BEAM MS MS MS MS MS MS MS MS MS MS MS MS137.0 SPAN 13 BEAM 2 SPAN 13 BEAM 2 SPAN 13 BEAM 3 SPAN 13 BEAM 3 SPAN 13 BEAM 5 SPAN 13 BEAM MS MS MS MS MS MS MS MS MS MS MS MS

16 BREAKDOWN OF BRIDGE RATING Cont. TOWN/CITY: BOSTON CARRIES: ST 203 MONSGR CASEY BRIDGE NO. B OVER: WASH ST&AMTK&MBTA BIN NO. 4EX BRIDGE ELEMENT SPAN 13 BEAM 7 SPAN 13 BEAM 7 SPAN 13 BEAM 8 SPAN 13 BEAM 8 SPAN 13 BEAM 9 SPAN 13 BEAM 9 SPAN 13 BEAM 13 SPAN 13 BEAM 13 INVENTORY RATING BY LOAD FACTOR METHOD (METRIC TONS) OPERATING RATING BY LOAD FACTOR METHOD (METRIC TONS) MS18 MS (EQUIV.) MS18 MS (EQUIV.) 33.4 MS MS MS MS MS MS MS MS MS MS MS MS MS MS MS MS130.5 SPAN 14 BEAM 2 SPAN 14 BEAM 2 SPAN 14 BEAM 3 SPAN 14 BEAM 3 SPAN 14 BEAM 7 SPAN 14 BEAM MS MS MS MS MS MS MS MS MS MS MS MS169.2 SPAN 15 BEAM 2 SPAN 15 BEAM 2 SPAN 15 BEAM 3 SPAN 15 BEAM MS MS MS MS MS MS MS MS

17 BREAKDOWN OF BRIDGE RATING Cont. TOWN/CITY: BOSTON CARRIES: ST 203 MONSGR CASEY BRIDGE NO. B OVER: WASH ST&AMTK&MBTA BIN NO. 4EX BRIDGE ELEMENT SPAN 15 BEAM 6 SPAN 15 BEAM 6 SPAN 15 BEAM 7 SPAN 15 BEAM 7 SPAN 15 BEAM 8 SPAN 15 BEAM 8 SPAN 15 BEAM 12 SPAN 15 BEAM 12 SPAN 15 BEAM 13 SPAN 15 BEAM 13 INVENTORY RATING BY LOAD FACTOR METHOD (METRIC TONS) OPERATING RATING BY LOAD FACTOR METHOD (METRIC TONS) MS18 MS (EQUIV.) MS18 MS (EQUIV.) 22.7 MS MS MS MS MS MS MS MS MS MS MS MS MS MS MS MS MS MS MS MS108.9 SPAN 16,17,&19 BEAM 2 SPAN 16,17,&19 BEAM 2 SPAN 16,17,&19 BEAM 3 SPAN 16,17,&19 BEAM 3 SPAN 16,17,&19 BEAM 7 SPAN 16,17,&19 BEAM MS MS MS MS MS MS MS MS MS MS MS MS

18 BREAKDOWN OF BRIDGE RATING Cont. TOWN/CITY: BOSTON CARRIES: ST 203 MONSGR CASEY BRIDGE NO. B OVER: WASH ST&AMTK&MBTA BIN NO. 4EX BRIDGE ELEMENT SPAN 18 BEAM 3 SPAN 18 BEAM 3 SPAN 18 BEAM 3 SPAN 18 BEAM 3 SPAN 18 BEAM 7 SPAN 18 BEAM 7 INVENTORY RATING BY LOAD FACTOR METHOD (METRIC TONS) OPERATING RATING BY LOAD FACTOR METHOD (METRIC TONS) MS18 MS (EQUIV.) MS18 MS (EQUIV.) 14.6 MS MS MS MS MS MS MS MS MS MS MS MS138.2 SPAN 20 BEAM 2 SPAN 20 BEAM 2 SPAN 20 BEAM 3 SPAN 20 BEAM 3 SPAN 20 BEAM 7 SPAN 20 BEAM MS MS MS MS MS MS MS MS MS MS MS MS107.5 SPAN 6 BEAM 2 SPAN 6 BEAM MS MS MS MS

19 BREAKDOWN OF BRIDGE RATING Cont. TOWN/CITY: BOSTON CARRIES: ST 203 MONSGR CASEY BRIDGE NO. B OVER: WASH ST&AMTK&MBTA BIN NO. 4EX SIDEWALK SPAN 14 FASCIA GIRDER SPAN 14 FASCIA GIRDER SPAN 14 BEAM B1 & B14 SPAN 14 BEAM B1 & B14 SPAN 14 CANTILEVER BRACKET MOMENT SPAN 14 CANTILEVER BRACKET SPAN 14 CANTILEVER BRACKET CONNECTION INVENTORY RATING BY WORKING STRESS METHOD SPECIAL SNOW REMOVAL LOADING (TONS) OPERATING RATING BY WORKING STRESS METHOD SPECIAL SNOW REMOVAL LOADING (TONS)

20 BOSTON ST 203 MONSGR CASEY OVER WASH ST, AMTK&MBTA RR B (4EX) N 13

21 DESCRIPTION OF BRIDGE BOSTON ST 203 MONSGR CASEY OVER WASH ST &AMTK & MBTA RR B (4EX) Date of Construction: 1953 Date of Reconstruction: 1980 and 1991 Original Design Loading: Posted Limit: Bridge Type: H None Concrete filled steel grid deck on rolled steel beams with built-up fascia girders supported by reinforced concrete piers Skew: Varies between 0!-0 and 26!-56 Spans: Twenty (20) simple spans varying in length from 80 to 107 Width of Bridge Deck: Roadway Width: Roadway Surface: Curbs: Sidewalk/Walkway: Median: Bridge Railing: 80-0 (Out-to-out of bridge) 27-0 curb to curb, typical each travelway. 2 latex modified concrete paving at superelevated roadway sections and an average of 2.94 latex modified concrete paving at crowned roadway sections. 6 by 12 granite curbs at sidewalks and median 11-0 concrete sidewalks on both sides, including steel pedestrian handrail and non-mountable concrete curb with steel traffic guardrail. 4-0 wide by variable height stepped median between travelways at centerline of overpass alignment. Pedestrian Rail: Two-bar steel pipe pedestrian rail atop curb at outside face of sidewalk, both sides of bridge. Traffic Rail: 2-6 high single-bar steel pipe nonmountable traffic guardrail atop concrete curb at inside face of sidewalk, both sides of bridge. 14

22 DESCRIPTION OF BRIDGE Cont. BOSTON ST 203 MONSGR CASEY OVER WASH ST &AMTK & MBTA RR B (4EX) Approach Railing: Pedestrian Rail: Concrete wall/barrier at outside face of sidewalk, both sides of approach Traffic Rail: 2-6 high single-bar steel pipe nonmountable traffic guardrail atop concrete curb at inside face of sidewalk, both sides of approach. Superstructure: The superstructure supporting eastbound and westbound traffic consist of 4! concrete-filled steel grid deck supported on fourteen (14) 36 deep rolled steel beams with welded bottom cover plates with a typical spacing of 5-0. Built-up steel plate girders, curved to match roadway alignment, at each fascia, are supported by cantilever brackets at each pier. Median stringers are supported by cantilever brackets attached to adjacent 36 rolled steel beam. Modifications to Original Superstructure: 1980 repairs included replacement of the bituminous concrete overlay with a latex-modified concrete overlay, bridge joint repairs, and modifications to the bridge drainage system rehabilitation included removal of the fascia girder brick in-fill and concrete safetywalk/parapet and addition of 11-0 wide sidewalks and curb railing on each side of the bridge, and additional drainage repairs. Utilities: 1 diameter conduit attached to the bottom flange of beam B8 servicing under bridge lighting Substructure: The superstructure is supported by nineteen (19) reinforced concrete hammerhead, wall, and straddle bent piers and two (2) reinforced concrete gravity type abutments. Modifications to Original Substructure: 1980 and 1991 repairs included extensive spall repairs at the concrete piers. The 1991 repairs included installation of external post-tensioning to strengthen the hammerhead piers (C, D, E, F, G, H, J, K, L, S, T, and U). Also, in , piers N, P & Q were underpinned as part of the MBTA s Southwest Corridor Project. 15

23 RATING ANALYSIS ASSUMPTIONS AND CRITERIA BOSTON ST 203 MONSGR CASEY OVER WASH ST &AMTK & MBTA RR B (4EX) The inventory and operating load ratings of the bridge were computed in accordance with the provisions of the 2005 MassDOT Bridge Manual, Part I Chapter 7 Bridge Load Rating Guidelines, the first edition of the Manual for Bridge Evaluation (MBE) and the current edition of the Standard Specifications for Highway Bridges, both of which are published by the American Association of State Highway and Transportation Officials (AASHTO). The live load used in establishing these ratings was the standard AASHTO H20, HS20, Type 3 and Type 3S2 trucks as shown in Figure 6B (page 6-117) of the AASHTO MBE. Vehicle ratings for posting purposes were obtained for each of these trucks using the Allowable Stress Method. In addition, a rating was obtained for the MS18 (HS20) vehicle using the Load Factor Method for compliance with the requirements of the December 1995 FHWA NBIS coding guide. Statutory load levels are 20 tons for the H20 truck, 25 tons for the Type 3 truck, 36 tons for the Type 3S2 truck and 36 tons for the Type HS20 truck. Material Properties Based on the review of the available plans and AASHTO guidelines, the following material properties and allowable stresses were utilized for rating purposes: Structural Steel: Fy = 33 ksi fs = ksi (inventory allowable stress) fs = ksi (operating allowable stress) Deck Concrete for Deck Slab: f'c = 2500 psi fc = 1000 psi (inventory allowable stress) fc = 1500 psi (operating allowable stress) n = 10 The bridge deck consists of a 4 " thick, concrete-filled steel grid. No specific cross-section of the steel grid deck was shown in the available structural plans. However, the previous bridge rating from 1979 (See Appendix E) assumed a steel grid deck based on field measurements and discussions with steel grid deck suppliers. For the purpose of this rating, the same steel grid deck was used. The concrete in-fill and steel grid were assumed to act compositely for the rating. 16

24 It was noted in the recent Routine Inspection Report, dated January 29, 2010, under Item 58.2, that there is minor section loss to the underside of the exposed steel ribs. Approximately 1/32 of section loss to the steel ribs was assumed. An effective span length of 4-6 was typically used to compute the governing forces, based on a typical beam spacing of 5-0. The governing deck design forces were determined for the HS20 and H20 truck loading using AASHTO Article for single axle loadings. Similarly, the governing design forces for tandem axle trucks Type 3 and Type 3S2 were determined using MassDOT Bridge Manual section Beams Each span of the structure consist of fourteen (14) 36 deep rolled steel beams spaced at 5-0 with bottom cover plates intermittently welded to the bottom flange of the beam. The beams and cover plates vary in size from beam to beam and span to span. Only the beams supporting the travelways were rated for live load (beams B2 B13). Beams B1 and B14 support the sidewalk and were rated for the special snow plow loading per MassDOT Bridge Manual section Roadway beams B2 though B13 were analyzed using AASHTOWare Virtis version Beams B1 and B14 were rated by hand calculations. In these rating calculations the beams were assumed to be non-composite. During the most recent field inspection, it was observed that the concrete-filled steel grid decking has separated from the beams in many locations, and there are gaps of up to 1 # between the top flange of the beams and the underside of the deck. It was also observed that the steel grid deck is bowing upwards away from the beams in many locations throughout the bridge. Also, while the original plans indicate that the decking was to be welded to the beams, no details of this attachment were shown. As noted in the inspection report under Item 58.2, it is believed that the deck separated from the beams because of impacted rust on top of the top flange. Note that the previous (1979) rating was based on the assumption that the beams act compositely with the deck. Assuming non-composite action between the steel grid and beams significantly reduces the rating of the bridge. Dead loads were applied to the beams and distributed in accordance with MassDOT Bridge Manual section The dead loads include beam self-weight, steel diaphragms, concrete-filled steel grid deck, 2 LMC overlay (based on 10 curb reveal noted in inspection report) at superelevated section, an average 2.94 LMC overlay at crowned bridge sections, sidewalk, traffic barrier, pedestrian barrier, median, and electrical conduit. Live loads and live load distribution factors were determined and applied per MassDOT Bridge Manual section and and AASHTO Specifications. Section losses on main members noted during the most recent inspection were incorporated into the beam ratings. The most significant losses observed were along the sidewalk beams 17

25 B2 and B13, and along the median beams B7 and B8. Based on the inspection, midspan losses of 1/16 and 1/8 were typical at beams B2 and B13 to the bottom and top flange respectively. Also, midspan losses of 1/8 and 1/16 were found at beams B7 and B8 to the bottom and top flange respectively. Additionally, a typical 1/8 loss was assumed to the web near the beam supports for beams B2, B7, B8, and B13. The worst case web loss of 3/16, full height, was noted at the support of beam B2 in span 6. Fascia Girders There are 5-0 deep steel built-up plate girders at each fascia of the bridge. The fascia girders are curved to match the roadway alignment. The fascia girders were initially constructed with brick-infill on the exterior face of the girder from the bottom flange to the top flange. The brick infill, concrete safetywalk, and parapet have since been removed and replaced with an 11-0 sidewalk with a pedestrian railing and curb-mounted guardrail on each side. For this rating, the fascia girders were assumed to only carry loads associated with the sidewalk and railing self weight along with the live load associated with the special snow removal equipment. These girders were rated for operating levels only for the snow removal equipment live loading and also include losses as noted in Item 59.4 of the Routine Inspection Report dated January 29, The effects of curvature were considered per the AASHTO Guide Specifications for Horizontally Curves Steel Girder Highway Bridges Since the fascia girders were expected to rate quite well, only the worst case fascia girder in span 14 was rated. The fascia girders are supported by 14 deep wide flange beams connected to the piers. These supporting beams are cantilevered approximately 4-0 from the face of the pier to the fascia girder. The cantilever beam is attached to the pier with six (6) 1 " diameter anchor bolts. The cantilever beam and connection were rated for snow removal equipment only based on reactions from the fascia girder. Section losses as noted in the inspection report Item 60.2.k were included in the rating of these elements. Sidewalk and Median Stringers Sidewalk and median stringers were assumed to carry dead load only and therefore were not rated. However, it should be noted that the median stringers showed significant deterioration to the stringer and cantilever supporting brackets. Many of these stringers have recently been replaced in-kind but several deteriorated stringers still remain. Substructure The substructure consists of nineteen (19) reinforced concrete piers and two (2) reinforced concrete abutments. In general, the substructure is in poor to serious condition. Emergency repairs were recommended after the routine inspection in January of 2010 to address the wide cracks and large spalls in the unreinforced pedestals at piers K, S, and Q. The majority of the 18

26 piers exhibit spalling and most of the piers have been repaired previously. The substructure was not rated. 19

27 EVALUATION OF RATING AND RECOMMENDATIONS BOSTON ST 203 MONSGR CASEY OVER WASH ST &AMTK & MBTA RR B (4EX) The critical location for rating purposes using the allowable stress method is the flexural midspan bending of beam B13 located in Span 1, with Inventory ratings of 1.0, 1.3, 1.4, and 1.4 tons and Operating ratings of 12.0, 15.5, 19.4, and 16.2 tons for truck types H20, Type 3, Type 3S2, and HS20 respectively. The critical location for rating purposes using the load factor method is the flexural midspan bending of beam B13 located in Span 1, with Inventory and Operating ratings of 10.7 Mtons (MS 5.9) and 17.8 Mtons (MS 9.9) respectively for the MS 18 truck. The primary reason for the low ratings is that the beams were analyzed as non-composite with the deck. Because the controlling inventory rating of the bridge is less than three tons, we recommend that guardrail be installed on the bridge deck to limit traffic to one lane in each direction of travel. The guardrail should be installed so that traffic is diverted away from the controlling beams (B2 and B13) in span 1, 16, 17, and 19. This reconfiguration will significantly reduce the amount of live load distributed to the controlling beams, thus increasing the inventory rating. Two revised lane configurations were considered. One in which traffic is diverted to the median side of the bridge by way of a single thrie beam guardrail and another in which two thrie beams are used to channel traffic along the center of each travelway. The first configuration yields a 3.7 ton H20 rating controlled by span 1, beam B8. The second configuration yields a 4.4 ton H20 rating and is controlled by span 1, beam B12. All the controlling ratings for each rating vehicle are summarized in Appendix C. Based on conversations with staff from Department of Conservation and Recreation, the only trucks permitted on the bridge are snow removal vehicles, which are similar to H10 trucks. The controlling operating rating of the bridge for either configuration is well above H10, as shown in Appendix C. As specified in section of the MassDOT Bridge Manual, Any specific recommendations that shall alter the bridge s load carrying capacity shall include rating calculations, located in Appendix C, that shall indicate the revised rating if the recommendation is implemented, the revised configuration was rated and the revised ratings are summarized in Appendix C. 20

28 AVAILABLE PLANS BOSTON ST 203 MONSGR CASEY OVER WASH ST &AMTK & MBTA RR B (4EX) The following plans were made available to HNTB for use in determining the load rating of this bridge: 1. The Commonwealth of Massachusetts Metropolitan District Commission Parks Division Proposed Bridge Forest Hills Overpass and Traffic Interchange Boston, MA Dated: July 2, Sheets 2. The Commonwealth of Massachusetts Metropolitan District Commission Engineering Division Park Engineering Section Repairs to the Monsignor William J. Casey Overpass Boston, MA Contract No. E80-46PE Dated: February 29, Sheets 3. The Commonwealth of Massachusetts Metropolitan District Commission Parks Engineering and Construction Division Repairs to the Monsignor William J. Casey Overpass Boston, MA Contract No. P C7A Dated: February 28, Sheets 21

29 TRUCK LOADINGS BOSTON ST 203 MONSGR CASEY OVER WASH ST &AMTK & MBTA RR B (4EX) 22