DPWH_Standard_Specifications_on_Bridges_(Design_Parameters).pptx

Bridge

1. BRIDGE DESIGN PARAMETERS SEMINAR: CONSTRUCTION METHODS AND TECHNIQUES FOR BRIDGES DATE : September 10, 2019 DPWH Standard Specifications on Bridges

2. Outline: Part 1. Introduction to Bridge Engineering Part 2. Design Philosophies & Parameters

3. Part 1: Introduction to Bridge Engineering

4. Sample General Elevation Plan

5. Sample General Plan

6. Sample General Elevation Plan

7. What is a Bridge? A structure built to span physical obstacle such as a body of water, valley, or road, for the purpose of providing passage over the obstacle. A structure carrying a road over a waterway, road or other feature, with a clear span over 3.00 meters along the centerline between the inside faces of supports. A bridge may have an independent deck supported on separate piers and abutments, or may have a deck constructed integral with supports ( Ref:DGCS 2015)

8. Bridge Superstructure Bridge Alignment A Normal Bridge is a structure where the superstructure is perpendicular to the substructure.

9. Bridge Superstructure Bridge Alignment A Skew Bridge is a structure where the superstructure is not perpendicular to the substructure . The skew angle is the deviation of the substructure centerlines and reference lines from the perpendicular lines to the bridge axis. θ

10. Bridge Superstructure Bridge Alignment A Curved Bridge is a structure or portion of the structure that follows a horizontal or vertical curve alignment.

11. Types / Classification of Bridges According to Materials used for Main Structural Members Timber Bridge Concrete Bridge

12. Types / Classification of Bridges According to Materials used for Main Structural Members Prestressed Concrete Bridge Steel Bridge

13. Types / Classification of Bridges According to Usage Temporary – a bridge with a short life span due to deterioration and/or design limitations, including: Timber trestle bridge that normally requires members to be replaced after three years. Bailey bridges not designed in accordance with a Bridge Code and subject to early fatigue failure, subject to the number of load cycles.

14. Types / Classification of Bridges According to Usage Permanent A bridge with a design life of fifty years and usually of concrete or steel construction.

15. Types / Classification of Bridges According to System of Design Simple Spans Consists of separate beams for each span, supported on bearings that allow rotation of the girders at each end under loads. Continuous Spans Superstructure is made continuous over one or more supports.

16. Types / Classification of Bridges According to System of Design Cantilever Bridge Bridge built using structures that project horizontally into space, supported at only one end.

17. Types / Classification of Bridges According to System of Design Arch Bridge Bridge with abutments at each end and a supporting structure shaped as a curved arch.

18. Types / Classification of Bridges According to System of Design Suspension Bridge Type of bridge in which the roadway is hung below two or more suspension cables on vertical suspenders.

19. Types / Classification of Bridges According to System of Design Cable Stayed Bridge One or more towers from which cables support the bridge deck. Harp Fan

20. Types of Bridges (Philippines) Deck Girder Bridges Reinforced Concrete Deck Girders (RCDG)

21. Types of Bridges (Philippines) Deck Girder Bridges Prestressed Concrete Girders (PSCG)

22. Types of Bridges (Philippines) Deck Girder Bridges Prestressed Concrete Girders (PSCG) Standard AASHTO I-Girders 305 102 76 279 127 127 711 406 152 305 152 76 381 152 152 914 152 457 406 178 114 483 191 178 1143 559 178 508 203 152 584 229 203 1372 660 203 1067 127 76 102 1067 254 203 203 1829 102 660 TYPE I TYPE II TYPE III TYPE IV TYPE V

23. Types of Bridges (Philippines) Deck Girder Bridges Steel Girders

24. Clear Width of Bridges Minimum Roadway Width DGCS 1982 Updated DGCS 1 Lane 4.00 m 4.00 m 2 Lanes (rural) 6.70 m 7.32 m 2 Lanes (urban) 7.30 m 7.32 m Farm-to-Market Roads - 5.60 m More than 2 lanes variable Refer to Highway Design Requirements

25. Number of Girders

26. Parts of a Bridge Superstructure Deck Slab Girder Diaphragm (End & Intermediate) Post & Railing Sidewalk Expansion Joint Bearing Substructure Abutment Pier Coping Foundation (Column, Wall, Bored Pile, RC Pile, Isolated Footing, etc ) Wingwall Approach Slab

27. Parts of a Bridge Superstructure SIDEWALK INTERIOR SLAB FUTURE WEARING SURFACE POST RAILING EXTERIOR SLAB DIAPHRAGM GIRDER HAUNCH

28. RAILING SIDEWALK BRIDGE DECK EXPANSION DAM APPROACH SLAB Parts of a Bridge POST

29. GIRDER INTERMEDIATE DIAPHRAGM END DIAPHRAGM Parts of a Bridge

30. EXPANSION BEARING ELASTOMERIC BEARING PAD Parts of a Bridge

31. Bridge Substructure Abutment Support the ends of a bridge or extreme end of a multi-span superstructure and which usually retain or support the road approach embankments. Abutments normally support wing walls to retain the approach embankments. Piers Transmit the load of the superstructure to the supporting ground and acts as intermediate supports between abutments. The piers may be subject to stream, collision and impact loads.

32. Parts of a Bridge Substructure - Abutment WINGWALL BACKWALL COPING STEM COLUMN APPROACH SLAB RISER FOOTING PILE CAP PILES WALL

33. Parts of a Bridge Substructure - Pier RISER PEDESTAL COPING COLUMN WALL FOOTING PILES PILE CAP

34. GIRDER COPING BEAM COLUMN SHAFT BOREDPILE Parts of a Bridge

35. GIRDER COPING POST, RAILING, & SIDEWALK COLUMN SHAFT BORED PILE WINGWALL Approach Railing SLOPE PROTECTION Parts of a Bridge

36. Steel Girder Bridge

37. Post-Tensioning of the Girder

38. Part 2: Design Philosophies & Parameters

39. Reference Codes BSDS 2013 DGCS 2015 AASHTO 2012 DPWH BLUEBOOK 2013

40. DPWH Bridge Design Specifications Covers design for construction, alteration, repair, and retrofitting highway bridges and related highway structures Earthquake effects shall be in accordance with BSDS Covers mainly seismic design of bridges based on LRFD seismic design method Use of localized seismic response acceleration contour map coefficients

41. Governing Laws and Department Memorandum Department Order No. 75 series of 1992 “ DPWH ADVISORY FOR SEISMIC DESIGN OF BRIDGES” “The basic philosophy is for the bridge to resist small to moderate earthquakes in the elastic range without significant damage. In case of large earthquakes, a bridge may suffer damage but this should not cause collapse of all or any of its parts and such damage should readily be detectible and accessible for inspection and repair.”

42. Governing Laws and Department Memorandum Department Order No. 180 series of 2015 “ LRFD BRIDGE SEISMIC DESIGN SPECIFICATION 1 ST EDITION, 2013” The DPWH LRFD Bridge Seismic Design Specifications (BSDS) has been prepared to address the issue in the reliability of our transport infrastructures, such as bridges, in times of natural disasters. The destructive effects on public and private infrastructure of recent large-scale earthquakes demonstrate the need to update our design guidelines.

43. Governing Laws and Department Memorandum Department Order No. 45 series of 2016 Load and Resistance Factor Design (LRFD) Bridge Seismic Design Specifications 1 st Edition 2013 “A one-year transition period is given for the adaptation and familiarization on the new guidelines, criteria and specifications during which bridge engineers have a choice of two standards : 1. Load Factor Design (present design method) 2. Load and Resistance Factor Design (DGCS Vol. 5, BSDS) After this transition period, use of DGCS 2015 and BSDS is mandatory .”

44. Governing Laws and Department Memorandum RA 9184 for Memorandum Circular No. 16 series of 1994 Conduct of Soil Analysis and Boring Tests of the Project Sites before undertaking Design, Preparing POW and Cost Estimates and Bidding of Government Infrastructure Projects Headquarters Philippines Coast Guard (HPCG) / CG-8 Memorandum Circular No. 01-14, April 16, 2014 Navigational Clearance for Road Bridges and Other Structures and Navigable Inland Waters

45. Codes and Other References DGCS 1982 Updated DGCS Standard Specifications for Highway Bridges, adopted by the American Association of State Highway and Transportation Officials (AASHTO) 1977 American Association of State Highway and Transportation Officials (AASHTO) 2012, LRFD Bridge Design Specification DPWH Standard Specifications Highways and Bridges, Revised 1972 or latest edition DPWH Standard Specifications for Highways, Bridges and Airports 2013 D PWH Bridge Seismic Design Specifications, December 2013 (JICA Study)

46. DESIGN DATA AVAILABLE INFORMATION RELEVANT TO THE BRIDGE PROJECT SHOULD BE COMPILED, INCLUDING THE FOLLOWING BUT NOT LIMITED TO: Topographic maps of bridge site and stream catchment area Geotechnical information History of any prior or existing bridges at the site, (i.e. date of construction, performance during past floods and earthquakes) Road Right of Way (RROW)

47. Topographic / Hydrographic Survey SURVEYS SHALL ALSO OBTAIN AND DOCUMENT ALL OTHER SITE INFORMATION RELEVANT TO DESIGN INCLUDING: Topographic/hydrographic survey of river channel and flood plains - Distance of, whichever is larger : - 5 times the width of river - 100m / 200 m

48. For new bridge cross sections over channel length: - 20 m intervals, 11 cross sections (5 upstream, 5 downstream, 1 centerline)

49. For existing bridges, cross sections over channel length: - 20 m intervals, 12 cross sections ( 5 upstream, 5 downstream, 1 at each bridge face)

50. Geotechnical Investigation SHALL BE UNDERTAKEN FOR THE DESIGN OF ALL BRIDGE FOUNDATIONS: At least one borehole at the proposed location of each abutment and pier For piers or abutments 30m wide , minimum of two borings Additional boreholes shall be drilled when there is significant difference between adjacent boreholes or in areas where subsurface condition is complex In case centerline is realigned, confirmatory boreholes should be conducted

51. Geotechnical Investigation 5. Borehole Depth If foundation type has not been identified, Minimum depth: 30 m (ordinary soil) 3 m (sound rock) In case bearing layer is not yet encountered, boring shall be continued until preferred layer is encountered and/or upon the instruction of the geotechnical engineer 6. Tests on Borehole Samples Standard Penetration Test (SPT) – max interval of 1.5 m and every change in soil stratum Laboratory Tests

52. Geotechnical Investigation 7. Required information in GEOTECHNICAL INVESTIGATION REPORT a. Borehole location plan (with coordinates and elevations) b . Depth of Boreholes c . Soil stratigraphy d. Soil parameters e. Allowable bearing capacity f. Anticipated settlement g. Rock Quality Designation (RQD) h. Shear wave velocity i . Liquefaction potential j . Recommended foundation type

53. Geotechnical Investigation

54. Existing Bridge Data INSPECTION SHALL BE CONDUCTED TO REVIEW THE HYDRAULIC PERFORMANCE OF EXISTING BRIDGES IN TERMS OF: Constriction Inadequate waterway Excessive backwater High flood velocities under the bridge or severe scouring

55. DESIGN REQUIREMENTS BRIDGE LOCATION AND ALIGNMENT BRIDGE WATERWAY AND LENGTH SPAN ARRANGEMENT FREEBOARD BRIDGE DECK DRAINAGE

56. Bridge Location and Alignment River morphology - m inimize risk from river channel movements and determine meander belt River training works – for unstable streams/ rivers with wide active zones Bridge location – normal to the river, along straight channels, avoid sharp bends (scouring and channel shifting) Alluvial fans – avoid due to hydraulic problems

57. Bridge Waterway and Length Approximate River Width, B B = ( c ) Q 3/4 * Q = discharge c = coefficient ranging from 0.5 – 0.8, determined considering flood plain obstruction (refer to Table 3-1 of DGCS Volume 3 Water Projects) 2. Desirable minimum bridge span length, L L = 20 + 0.005Q ** * Developed in a study conducted in Japan ** Design standard by Ministry of Construction in Japan

58. Span Arrangement Pier location To meet navigational clearance requirements To give minimum interference to flood flow To be placed parallel with direction of river current To avoid scour and debris blockage / constriction Provision for passing debris Increase span length and vertical clearance Select proper pier type Provide debris deflectors

59. Clearance DGCS 1982 Updated DGCS Hydraulic Clearance / Freeboard Rivers carrying debris : 1.5 m Other bridges: 1.0 m Rivers carrying debris : 1.5 m Other bridges: 1.0 m 2. Vehicular Vertical Clearance (above roadway) Not less than 4.80 m plus allowance for resurfacing Not less than 4.88 m plus allowance of 0.15m for future road resurfacing 3. Navigational Permit should be taken from Headquarters of the Philippine Coast Guard (HPCG) Vertical clearance = HWL + HV + K HWL = highest water level recorded within the area of responsibility HV = height of vessel K = 1.0 m allowance

60. Clearance - additional clearance requirements not included in previous DGCS Air Clearance Height clearance permit shall be secured from the Civil Aviation Authority of the Philippines (CAAP) Underpass Not less than 4.88 m vertical clearance for entire width (or between curbs) Tunnels Not less than 4.88 m vertical clearance (exclusive of wearing surface) Through – Truss Bridge Min. vertical clearance from roadway to overhead cross bracing: 5.3 m

61. BRIDGE AESTHETICS Consider appearance of bridge in terms of shape, proportion, balance, texture, and color Designers must consider appearance as a major design objective along with strength, safety, and cost. A new bridge should consider the role, form, and design of an existing bridge when it is located in close proximity to that existing bridge. Aesthetically pleasing bridges need not be more expensive than ordinary simple bridges. Cost and appearance need to be balanced in the design. Designers should have an understanding of the natural, built, and community context of a bridge that would influence the design (e.g. topography, biodiversity, landscape, views to and from bridge location)

62. BRIDGE AESTHETICS Proportion between the depth of the superstructure and bridge spans (Normal value: 15 – 20) Symmetrical bridges are generally more pleasing than other layouts and should be adopted where possible.

63. BRIDGE AESTHETICS

64. LOAD MODIFIERS Load modifier For strength limit state Ductility, η D 1.05 Non-ductile components and connections 1.00 Conventional designs and details complying to AASHTO 0.95 Additional ductility-enhancing measures specified Redundancy, η R 1.05 Non-redundant members 1.00 Conventional levels of redundancy 0.95 Exceptional levels of redundancy Operational Importance, η I 1.05 For critical or essential bridges 1.00 For typical bridges 0.95 For relatively less important bridges For all other limit states, η = 1.00

65. LOAD FACTORS

66. LOAD FACTORS

67. LOAD FACTORS FOR PERMANENT LOADS

68. STRENGTH LIMIT STATES

69. EXTREME EVENT LIMIT STATES

70. SERVICE LIMIT STATES

71. FATIGUE LIMIT STATES

72. DEAD LOADS Weight of all components of the structure, appurtenances and utilities attached thereto, earth cover, wearing surface, future overlays and planned widening

73. DESIGN VEHICULAR LIVE LOAD Vehicular live loading on roadways of bridges or incidental structures, designated HL-93, and shall consist of: Design truck or tandem load Design lane load Each design lane under consideration shall be occupied by either the design truck or tandem, coincident with the lane load, where applicable. The loads shall be assumed to occupy 3.0 m transversely within a design lane.

74. DESIGN TRUCK (HL – 93)

75. DESIGN LANE LOAD DESIGN TANDEM

76. DESIGN VEHICULAR LIVE LOAD Vehicular live loading on roadways of bridges or incidental structures, shall be the greater of: 35 kN 145 kN 145 kN 4.3m 4.3 – 9.1m 108 kN 108 kN 1.2m Uniform load of 9.34 kN/ m

77. DESIGN VEHICULAR LIVE LOAD NUMBER OF DESIGN LANES

78. DESIGN VEHICULAR LIVE LOAD MULTIPLE PRESENCE LIVE LOAD

79. DYNAMIC LOAD ALLOWANCE, IM The factor to be applied to the static load, shall be F = 1 + (IM / 100) - shall not be applied to pedestrian loads and design lane load

80. A heavy vehicle such as truck, trailer or van operated on any road or bridge violates the law if it: Exceeds the permissible single axle load of 13,500 kg. or 13.5 metric tons . Exceeds the maximum allowed gross vehicle weight as stipulated in Republic Act 8794 (Anti-Overloading Law) and its regulations published in 2001.

81. Maximum Allowable Gross Vehicle Weight (GVW ) ( RA No. 8794)

82. Seismic Design Procedure

83. Seismic Design Procedure

84. Seismic Design Detailing

85. Substructure and Foundation

86. Substructure and Foundation

87. Operational Classification of Bridges Note: The DPWH or those having jurisdiction shall classify the bridge into one of the three operational categories

88. Seismic performance of bridges as a goal in seismic design is classified into three levels in view of SAFETY, SERVICEABILITY and REPAIRABILITY SAFETY - implies performance to avoid loss of life due to collapse or unseating of the superstructure during an earthquake. SERVICEABILITY - means that the bridge is capable of keeping its bridge function such as fundamental transportation function, role as evacuation routes and emergency routes for rescue. REPAIRABILITY - denotes capability to repair seismic damages. Bridges that are designed and detailed in accordance with AASHTO provisions may suffer damage, but should have low probability of collapse due to seismically induced ground shaking. Seismic Performance

89. Seismic Performance

90. Seismic Performance

91. Seismic Hazard Map Previous Hazard Map New Hazard Map

92. Seismic Hazard (Design Spectra) SPECTRA COORDINATES T Tm Csm 0.000 0.1872 To 0.119 0.4680 0.2-sec 0.200 0.4680 Ts 0.595 0.4680   0.646 0.4313   0.690 0.4036   0.729 0.3821   0.763 0.3651   0.792 0.3514   0.818 0.3403   0.841 0.3311 1-sec 1.000 0.2784   1.250 0.2227   1.500 0.1856   1.750 0.1591   2.000 0.1392

93. Response Modification Factor, R Specifications recognize that it is uneconomical to design a bridge to resist large earthquakes elastically. Columns are assumed to deform inelastically , where seismic forces exceed their design level. This is taken by dividing the elastically computed force effects by an appropriate response modification factor, particularly to columns. Columns should have enough ductility to be able to deform inelastically to the deformation caused by large earthquakes, without loss of post-yield strength.

94. Analysis Requirements

95. Railing & Post Department Order No. 54 series of 2018 “ UPDATED STANDARD PLANS FOR SINGLE SPAN BRIDGES AND ALTERNATIVE BRIDGE RAILINGS”

96. Deck Slab Main: Transverse Top Bars Main: Transverse Bottom Bars Temperature : Longitudina l Top Bars Distribution: Longitudinal Bottom Bars Cantilever Slab Bottom Bars Exterior Slab Interior Slab

97. Girder RCDG PSCG

98. Girder PSCG – TENDON PROFILE

99. Girder ROLLED SHAPE GIRDER BUILT-UP GIRDER

100. Substructure ABUTMENT (MOV.) FIXED PIER

101. Substructure – BORED PILE WITH PERMANENT CASING WITHOUT PERMANENT CASING