The Rehabilitation Alternative Huey P. Long Bridge Case Study. Bruce E. Peterson, P.E. Project Manager Modjeski and Masters, Inc.

Transcription

1 The Rehabilitation Alternative Huey P. Long Bridge Case Study Bruce E. Peterson, P.E. Project Manager Modjeski and Masters, Inc. March 22, 2010

2 Replacement vs. Rehabilitation Project Background Introduction 4 Construction Contracts Main Bridge Substructure Main Bridge Superstructure Truss Widening Railroad Modifications Approaches and Main Bridge Deck Widening EXISTING BREAK Project Status Project Timeline Construction Photographs PROPOSED WIDENING

3 Replacement vs. Rehabilitation Bridge construction represents a large capital investment. Through time, all bridges receive routine maintenance. However, eventually they must be replaced or rehabilitated. Beyond the obvious difference in cost, there are other significant differences between these two approaches. How is the decision made? What influences the choice between these two alternatives?

4 Replacement vs. Rehabilitation Louisiana Dept. of Transportation and Development (LADOTD) Methodology for Selecting and Programming Bridges for Replacement and Rehabilitation Priority for the selection of bridges for replacement or rehabilitation with Federal bridge replacement funds based on three (3) parameters: 1. Structural adequacy 2. Functional adequacy and serviceability 3. Essential for public use

5 Replacement vs. Rehabilitation The three parameters are based on the following information: 1. Structural deficiency 2. Posted bridges (weight limits below statutory limits) 3. Traffic count (ADT) 4. Class of highway 5. Available detour routes 6. Bridge geometry (particularly bridges < 20 ft. wide) 7. Bridge inspection reports 8. Local district recommendations for replacement (submitted annually)

6 Replacement vs. Rehabilitation Federal Highway Administration (FHWA) formula for prioritizing bridges Overall rating called a sufficiency rating Sufficiency rating assigns a numeric value ranging from 0 to 100 to a given bridge with the following percentage points applied to each parameter ITEM WEIGHT Structural Adequacy 55 % Functional Adequacy and Serviceability 30 % Essential For Public Use 15 %

7 Replacement vs. Rehabilitation Requirement for replacement: Sufficiency Rating < 50 Classification as structurally deficient or functionally obsolete Requirement for rehabilitation: Sufficiency Rating < 80

8 Replacement vs. Rehabilitation As previously noted there are three elements to the Sufficiency Rating 1. Structural Adequacy 2. Functional Adequacy and Serviceability 3. Essential for Public Use Let s examine each in detail.

9 Replacement vs. Rehabilitation Structural Adequacy Most important factor in evaluation process as a bridge failure could be catastrophic Determined from: List of posted bridges (bridges with load restrictions) Bridge inspection reports Local district recommendations

10 Replacement vs. Rehabilitation Functional Adequacy and Serviceability Bridge geometry a key element Clear roadway width most important factor Narrow bridges, if structurally adequate, can be widened rather than replaced Determined from: Bridge inspection reports Local district recommendations

11 Replacement vs. Rehabilitation Functional Adequacy and Serviceability (con d) Serviceability is related to factors such as Stream scour Maintenance for movable bridges Deck deterioration Other important factors include frequency and severity of marine, railroad, and automotive traffic accidents

12 Replacement vs. Rehabilitation Essential For Public Use Determined by the: Traffic count (ADT) Class of highway Available detour routes Structural and functional adequacy of the bridge is evaluated with the traffic count in order to minimize exposure to unsafe conditions Example: two bridges with the same degree of inadequacy, the one with the higher traffic volume would receive the higher priority

13 Replacement vs. Rehabilitation Essential For Public Use (con d) Bridges located on a truck or school bus route or crosses a major river or stream receive extra attention Non-redundant routes (no available detours) receive a higher priority than bridges on redundant routes

14 Replacement vs. Rehabilitation How Select? Numerous rational methods available Recommended procedure for State of Louisiana 1. Compile 3 lists Bridges with lowest sufficiency rating Bridges with the highest priority based on local district recommendations Bridges that are most severely posted for load restrictions 2. Generally, if a bridge makes all three lists, it will have a high priority for replacement

15 Replacement vs. Rehabilitation Sufficiency Rating Posted Bridges List STRUCTURAL ADEQUACY Bridge Inspection Report District Recommendations Sufficiency Rating Bridge Geometry, Accidents, etc. FUNCTIONAL ADEQUACY AND SERVICEABILITY Bridge Inspection Report District Recommendations Sufficiency Rating Highway Class and Traffic Count (ADT) ESSENTIALLITY TO THE PUBLIC Available Detour Routes District Recommendations Traffic Type FINAL ORDER OF PRIORITY Source: LADOTD Bridge Design Manual

16 Replacement vs. Rehabilitation Other Considerations - Replacement Pros: 1. New structure would meet all current standards Loads Geometry Highway standards 2. New Construction Do not have to connect new components with existing ones. Reduced potential for surprises during construction 3. Estimating construction cost potentially more accurate Cons: 1. Potential for greater environmental impacts 2. Potential for greater costs 3. Potential need for more right-of-way 4. Can require time for public to agree on a location and other impacts related to a new structure 5. Can take more time from start of planning to final completion and delivery to public 6. Removal of an historic structure

17 Replacement vs. Rehabilitation Other Considerations - Rehabilitation Pros: 1. Have the potential to reuse existing elements, thus saving time and money 2. Potentially less environmental impacts 3. Potentially less right-of-way requirements 4. Can fix some legacy issues that do not meet current standards or are less than desirable Cons: 1. Increased potential for problems and unknown discoveries with the existing structure 2. Greater demands on determination of existing conditions, details, geometry, etc. in order to produce accurate plans 3. Ability to meet all current standards may be difficult 4. Accurate estimation of construction costs can be difficult 5. Modification of an historic structure

18 Replacement vs. Rehabilitation Other Considerations (con d) Environmental Historic structure? Impacts? Remaining life of structure Structural condition (corrosion) and capacity Remaining fatigue life

19 Replacement vs. Rehabilitation Other Considerations (con d) Owner s Concerns and Issues 1. Time required to perform the work 2. Funding Available local funding? Federal funds available? 3. Public Wants the work completed yesterday Does not want to be inconvenienced during the work Low cost (no increased direct costs; e.g.. taxes, tolls, etc.) While doing this work, why not fix these other problems and/or address other needs... it s only a little more $$ (scope creep)

20 Replacement vs. Rehabilitation Where does the Huey P. Long Bridge fit within this criteria? Structurally Adequacy? - GOOD Excellent condition; adequate strength Reduced fatigue life of stringers and floorbeam brackets Functionally Adequacy and Serviceability? - POOR 18 feet wide roadways Barriers not current standards Essential For Public Use? - ESSENTIAL Few Mississippi River crossings in metro region; essential for highway traffic Only rail crossing of Miss. River south of Baton Rouge

21 Location New Orleans Metro Area French Quarter Huey P. Long Bridge

22 Before the Bridge

23 Before the Bridge

24 Construction of The Existing Bridge

30 Background Huey P. Long Bridge Completed in December 1935, the bridge is one of the longest railroad bridges in the world.

31 Background Huey P. Long Bridge Combined railroad highway bridge 2 tracks 4 lanes 9 ft. width

32 Background Huey P. Long Bridge Very heavily built Carries largest modern RR load without distress Many years of service life remaining

33 Project Background By widening the existing structure rather than constructing a new river crossing: Reduce environmental impact, property takings. Reduce project cost. Reuse existing right-ofway and traffic corridors. Final report published April 1988.

34 Project Background EXISTING PROPOSED WIDENING

35 Project Background Study of new bridge in corridor; 5 alternates considered. High cost and large amount of ROW; project dropped. LADOTD authorized M&M to perform conceptual widening study. 3 widening alternates considered Geotechnical investigation of soil capacity under caissons Present Preliminary Design Main Bridge; Fatigue Evaluation. Line and Grade Study Approaches. Environmental Processing Agency Consensus Completion of final design plans; main bridge widening, railroad modifications, and approaches, Construction main bridge substructure widening, railroad modifications, and main bridge superstructure widening.

36 Huey P. Long Widening Project START PROJECT WEST BANK RR MOD EAST BANK APPR. END PROJECT WEST BANK APPR. EAST BANK RR MOD MAIN BRIDGE PIER, TRUSS, AND DECK WIDENING

37 Main Bridge Pier Widening START PROJECT WEST BANK RR MOD EAST BANK APPR. END PROJECT WEST BANK APPR. EAST BANK RR MOD MAIN BRIDGE PIER, TRUSS, AND DECK WIDENING

38 Main Bridge Pier Widening EXISTING Pier A Piers I & II Pier III Pier IV PROPOSED WIDENING

39 Widened Pier Steel Frame Caisson Upper Encase Lower Encase

40 Widened Pier - Details The upper portion of the pier widening is composed of a steel frame. The steel frame significantly reduces the loads on the pier by eliminating concrete and permits the center bearing to be jacked, relieving load from the exterior bearings. This is beneficial by reducing load on the end faces of the existing concrete distribution block on top of the existing caisson.

41 Widened Pier - Details The steel frame will also permit more accurate setting and adjustment of the final bearing elevations after the lower encasement is poured. Inspection access will be provided for the steel metalwork in the upper portion of the pier widening.

42 Widened Pier - Details Constructability of Pier Frame Must be constructed around existing pier No construction access from above due to existing superstructure Staged construction Key splice locations.

43 Widened Pier - Details The lower portion of the encasement serves several functions The nose areas are columns to support the widening truss support bearings. The remainder confines the existing pier concrete and granite masonry blocks which currently has minimal reinforcing.

44 Widened Pier - Details

45 Widened Pier - Details

46 Strength of the Existing Concrete One of the major questions for widening the substructure was the strength of the existing concrete. Existing concrete was specified for 2000 psi. Based on construction records, actual strength much higher Using methods to estimate moderate amount of additional concrete strengthening with aging, 4000 psi could be used with confidence for the strength of the existing concrete.

47 Strength of the Existing Concrete PIER AND CAISSON CONCRETE STRENGTHS LOCATION USED Piers 3,800 4,500 8,800 4,000 Caisson 3,300 3,870 7,565 3, = ACI Committee 209, Prediction of Creep, Shrinkage, and Temperature Effects in Concrete Structures (ACI 209R-92) = Properties of Concrete by A. M. Neville

48 Existing Pier Conditions Underwater Acoustic Inspection performed April 2006 by C. H. Fenstermaker & Associates. Piers I, II, III, & IV examined and found to be in good condition. The equipment provided detailed information of the existing conditions. Examination though the use of a diver would be more costly, must be performed in extreme low to no visibility, and is dangerous.

49 Existing Pier Conditions Pier I North Face

50 Existing Pier Conditions Pier II West Nose

51 Main Bridge Truss Widening START PROJECT WEST BANK RR MOD EAST BANK APPR. END PROJECT WEST BANK APPR. EAST BANK RR MOD MAIN BRIDGE PIER, TRUSS, AND DECK WIDENING

52 Main Bridge Truss Widening Cantilever Truss Span Simple Through Truss Span EXISTING PROPOSED WIDENING

53 Cross Sections Existing Bridge

54 Widened Main Bridge Features 2 new trusses added, parallel to existing trusses. Roadways widened from 18 ft. to 43 ft. Currently: 2 9 ft. lanes No offset Proposed: 3 11 ft. lanes 8 ft. shoulder 2 ft. offset

55 Normal terminology for truss bridges would be U.S. & D.S. trusses. Widened HPL Bridge is a multiple truss plane structure U.S. Widening Truss U.S. Existing Truss D.S. Existing Truss D.S. Widening Truss Nomenclature

56 2D versus 3D Analysis and Design Traditional Truss Analysis (2D) Vertical loads, e.g. D & L, supported by main (vertical) trusses Transverse loads, e.g. W, supported by top and bottom lateral trusses, sway frames, and portals

57 2D versus 3D Analysis and Design 3 Dimensional Analysis Used Widened bridge is multiple truss plane system 3D analysis reflects the reality of the structure and its behavior Load sharing will occur and it is beneficial Members not normally supporting live load will have live loads Need to know the amount of live load in non-traditional live load supporting members.

58 2D versus 3D Analysis and Design 3D SAP Computer Model

59 Floorbeam and Hangers Superposition needed to solve final forces in the existing and widened hangers Moment and sequence of construction affect forces

60 Construction and Erection Method and Sequence of Construction provided in Contract Plans Contractor proposed option also available in contract plans Contractor proposed his own method

61 Maintenance of Traffic Through Construction Marine Traffic Maintained same vertical and horizontal clearances Rail Traffic Maintained Vehicular Traffic Maintained by use of staged construction

62 Main Bridge Maintenance of Traffic WORK PERFORMED IN TRUSS WIDENING CONTRACT

63 Main Bridge Maintenance of Traffic - Stage 1 WORK PERFORMED IN TRUSS WIDENING CONTRACT

64 Main Bridge Maintenance of Traffic - Stage 2 WORK PERFORMED IN TRUSS WIDENING CONTRACT PREVIOUS STAGE

65 Main Bridge Maintenance of Traffic - Stage 3 WORK PERFORMED IN TRUSS WIDENING CONTRACT PREVIOUS STAGE

66 Main Bridge Maintenance of Traffic - Stage 4 WORK PERFORMED IN APPROACH AND DECK WIDENING CONTRACT PREVIOUS STAGE

67 Main Bridge Maintenance of Traffic - Stage 4-5 SWITCH TRAFFIC

71 Top laterals, bottom laterals, sway frames, and portal frames must hinge to permit movement Erect rigid part over roadways open to traffic; hinge remaining part. Deflection Issues

72 Railroad Modifications - Westbank START PROJECT WEST BANK RR MOD EAST BANK APPR. END PROJECT WEST BANK APPR. EAST BANK RR MOD MAIN BRIDGE PIER, TRUSS, AND DECK WIDENING

73 Railroad Modifications - Westbank Project Site Railroad LA 18 Hwy. 90 EXISTING

74 Huey P. Long Widening Project Westbank Railroad Modifications LA18 Existing Site Conditions US HWY 90 To Huey P. Long Bridge

75 Huey P. Long Widening Project Westbank Railroad Modifications Replacement Support LA18 Future Roadway US HWY 90 To Huey P. Long Bridge Final Site Conditions

76 Huey P. Long Widening Project Westbank Railroad Modifications

79 Westbank Sequence of Construction 1. Construct foundations for new cross girders 2. Install falsework to lift existing girder spans 3. Begin 24 hour rail traffic closure 4. Lift existing girder spans off steel tower 5. Remove upper portion steel tower 6. Erect cross girders 7. Lower existing girder spans onto new cross girders 8. Restore rail traffic 9. Remove remaining portion of steel tower 24 HOUR RAIL CLOSURE

80 Railroad Modifications - Eastbank START PROJECT WESTBANK RR MOD EASTBANK APPR. END PROJECT WESTBANK APPR. EASTBANK RR MOD MAIN BRIDGE PIER, TRUSS, AND DECK WIDENING

81 Railroad Modifications - Eastbank Clearview Pkwy. EXISTING Project Site Jefferson Hwy

82 Huey P. Long Widening Project Eastbank Railroad Modifications Vacant Gas Station Clearview Pkwy. Power Poles & Power Line To Huey P. Long Bridge Jefferson Hwy. Existing Site Conditions QWEST Line Existing Superstructure and Towers to be Replaced

83 Huey P. Long Widening Project Eastbank Railroad Modifications New Bents Clearview Pkwy. Vacant Gas Station Future Elevated Roadway Future Roadway Final Site Conditions QWEST Line Jefferson Hwy. To Huey P. Long Bridge

84 Huey P. Long Widening Project Eastbank Railroad Modifications

85 Eastbank Sequence of Construction 1. Construct new concrete straddle bents 2. Prepare steel tower and other falsework 3. Begin 24 hour rail traffic closure 4. Remove girders under one of the tracks 5. Erect new girders for one track 6. Re-establish track 7. Restore rail traffic 8. Repeat girder replacement for other track (Steps 3 7 above) 9. Remove steel tower 24 HOUR RAIL CLOSURE

86 Approaches & Deck Widening START PROJECT WEST BANK RR MOD EAST BANK APPR. END PROJECT WEST BANK APPR. EAST BANK RR MOD MAIN BRIDGE PIER, TRUSS, AND DECK WIDENING

87 Approaches & Deck Widening Start Project Bridge City Ave. Interchange WEST BANK APPROACH Conflict w/ Existing Rdwy

88 Approaches & Deck Widening Cantilever Truss Span Simple Through Truss Span EXISTING PROPOSED WIDENING

89 Approaches & Deck Widening Jefferson Hwy Interchange End Project NOPBRR Spur Conflict w/ Existing Rdwy EAST BANK APPROACH

90 Approaches & Deck Widening

91 Approaches & Deck Widening EB APPR. EB APPR.

92 Approaches & Deck Widening Created using Google SketchUp

93 Approaches & Deck Widening W.P. CAP TRUMPET TRUMPET PC COLUMN FOUNDATION

94 Approaches & Deck Widening TOTAL SUBSTRUCTURE UNITS X 6 COLUMN BENTS 8 x 14 8 x 12 6 x 12 4 x 6

95 Approaches & Deck Widening Column Type 4: 8 x 14 Column Type 3: 8 x 12 Column Type 2: 6 x 12 Column Type 1: 4 x 6

96 Approaches & Deck Widening Trumpet for 8 x 14 Columns Trumpets for 6 & 8 x 12 columns Trumpet for 4 x 6 columns 8 x 14 6 x 12 8 x 12 4 x 6

97 Approaches & Deck Widening Adjust Footing Depth As Necessary Typical Bent Full Height Trumpet Sub- Trumpet Size 1 Sub- Trumpet Size 2

98 Main Bridge Deck Widening WORK PERFORMED IN APPROACH CONTRACT

99 Approaches & Deck Widening West Bank Approach - West Bank Bound East Bank Approach - East Bank Bound

100 Approaches & Deck Widening WB APPR. Location of West Bank Steel Girder Spans West Bank Approach East Bank Bound

101 Approaches & Deck Widening Location of East Bank Steel Girder Spans EB APPR. East Bank Approach West Bank Bound

102 Approaches & Deck Widening

103 Approaches & Deck Widening SWITCH TRAFFIC

104 Project Timeline Project Schedule Main Bridge Substructure Railroad Modifications Superstructure Fabrication & Erection Approaches & Main Bridge Re-decking Work Completed Railroad Modifications Main Bridge Pier Widening Work Under Construction Main Bridge Truss Widening West Bank Approach, Main Bridge Deck Widening, East Bank Approach

105 Project Status Completed Main Bridge Pier Widening Letting Date: December 14, 2005 Notice To Proceed Date: April 10, 2006 Construction Bid: $ 98,826,907 Contractor: Massman Construction Co.

106 Main Bridge Pier Widening EXISTING Pier A Piers I & II Pier III Pier IV PROPOSED WIDENING

107 Main Bridge Pier Widening

111 Main Bridge Pier Widening Distribution Block

125 Main Bridge Pier Widening G&G Steel New Orleans

142 Project Status - Completed Railroad Modifications Letting Date: May 10, 2006 Notice To Proceed Date: August 28, 2006 Construction Bid: $ 13,782,713 Contractor: Boh Bros. Construction Co.

143 Railroad Modifications - Westbank Project Site Railroad LA 18 Hwy. 90 EXISTING

144 Railroad Modifications - Westbank

147 Railroad Modifications - Westbank G&G Steel New Orleans

155 Railroad Modifications - Eastbank Clearview Pkwy. EXISTING Project Site Jefferson Hwy

156 Railroad Modifications - Eastbank

158 Huey P. Long Widening Project Eastbank Railroad Modifications

168 Project Status Under Construction Main Bridge Truss Widening Letting Date: March 28, 2007 Notice to Proceed Date: November 5, 2007 Construction Bid: $ 452,605,568 Contractor: Massman Construction Co., Traylor Brothers Inc., and IHI, Inc.

169 Main Bridge Truss Widening Cantilever Truss Span Simple Through Truss Span EXISTING PROPOSED WIDENING

170 Main Bridge Truss Widening Industrial Steel Construction Gary, IN New Orleans

171 Main Bridge Truss Widening Truss Monitoring STATIC MONITORING SYSTEM 433 Members (777 Vibrating Wire Strain Gages) 5 Piers (10 Vibrating Wire Tilt Meters) Wind Speed/Direction DYNAMIC (LIVE LOAD) MONITORING SYSTEM 31 Members (50 Electrical Resistance Strain Gages)

172 Main Bridge Truss Widening Work Platform

173 Main Bridge Truss Widening Work Platform

174 Main Bridge Truss Widening Floorbeam Modifications Template Fit Up Check

175 Main Bridge Truss Widening Floorbeam Modifications Installation of Wedge Fill

176 Main Bridge Truss Widening Floorbeam Modifications Installation of Wedge Fill

177 Main Bridge Truss Widening Work on Existing Structure Bottom Chord

178 Main Bridge Truss Widening Work on Existing Structure Top Chord

179 Main Bridge Truss Widening Widening Truss Bottom Laterals

180 Main Bridge Truss Widening Remove Existing Sidewalk Install Temporary Steel Barrier

181 Main Bridge Truss Widening Main Bridge Erection - Methods A B A B B A = Stick Build B = Span by Span

182 Main Bridge Truss Widening Main Bridge Erection

190 Main Bridge Truss Widening Main Bridge Erection December 2009

191 Main Bridge Truss Widening Main Bridge Erection December 2009

192 Main Bridge Truss Widening Contractor s Erection Scheme Span by Span Erection East Anchor Arm Suspended Span Through Truss Span

193 Project Status Under Construction West Bank Approach, Main Bridge Deck Widening, East Bank Approach Letting Date: March 19, 2008 Notice to Proceed Date: May 5, 2008 Construction Bid: $ 433,950,000 Contractor: Kiewit Massman Traylor Constructors

194 Approaches & Deck Widening START PROJECT WEST BANK RR MOD EAST BANK APPR. END PROJECT WEST BANK APPR. EAST BANK RR MOD MAIN BRIDGE PIER, TRUSS, AND DECK WIDENING

195 Approaches & Deck Widening Box Culverts

196 Approaches & Deck Widening At Grade Roadways West Bank

197 Approaches & Deck Widening Foundations - Westbank

198 Approaches & Deck Widening Foundations - Westbank

199 Approaches & Deck Widening Substructure - Westbank

200 Approaches & Deck Widening Substructure - Westbank

201 Approaches & Deck Widening Superstructure - Westbank

208 Approaches & Deck Widening Substructure Pier IVA Created using Google SketchUp

209 Approaches & Deck Widening Substructure Pier IVA

210 The Rehabilitation Alternative Huey P. Long Bridge Case Study

211 Q & A 1. Priority for the selection of bridges for replacement or rehabilitation with Federal bridge replacement funds based on three parameters. Name them.? 2. Of the three parameters above, which is given the highest weight?? 3. What Sufficiency Rating is required for replacement?? 4. Bridge geometry is a key element of Functional Adequacy and Serviceability. What is the most important factor within bridge geometry?? 5. For the case study project, name one key design challenge?? 6. For the case study project, how was approach bent formwork simplified??

212 Q & A 1. Priority for the selection of bridges for replacement or rehabilitation with Federal bridge replacement funds based on three parameters. Name them. Structural adequacy, functional adequacy and serviceability, and essential for public use. 2. Of the three parameters above, which is given the highest weight? Structural adequacy 3. What Sufficiency Rating is required for replacement? < Bridge geometry is a key element of Functional Adequacy and Serviceability. What is the most important factor within bridge geometry? Clear roadway width 5. For the case study project, name one key design challenge? Maintenance of traffic, deflection between existing and widened structures, not imposing deflection induced loads into the existing bridge. 6. For the case study project, how was approach bent formwork simplified? 2/3 s of the forms were the same, and the rest required only simple formwork changes