Pakistan Water and Power Development Authority, Islamic Republic of Pakistan

Diamer Basha Dam Project

Bidding Documents (Contract MW-1) Part ll: Particular Technical Specifications
Volume 3A - Technical Specifications For Main Dam and Appurtenant Structures i
PART II - PARTICULAR TECHNICAL SPECIFICATIONS
CHAPTER 13 – PERMANENT ACCESS BRIDGE

TABLE OF CONTENTS

13. PERMANENT ACCESS BRIDGE........................................................13-1

13.1 INTRODUCTION.....................................................................................................13-1

13.2 GEOMETRIC DESIGN............................................................................................13-1

13.2.1 Waterways.....................................................................................................13-1
13.2.2 Bridge Widths and Vertical Clearances.........................................................13-1
13.2.3 Span..............................................................................................................13-2
13.2.4 Alignment, Profile and Super Elevation.........................................................13-2
13.2.4.1 Horizontal Alignment............................................................................................ 13-2
13.2.4.2 Vertical Alignment and Longitudinal Slope...........................................................13-2
13.2.4.3 Super Elevation.................................................................................................... 13-2
13.3 DESIGN CRITERIA AND STANDARDS FOR DETAILED DESIGN.........................13-3
13.3.1 Expected Geotechnical Conditions................................................................13-3
13.3.1.1 Geology and expected Materials..........................................................................13-3
13.3.1.2 Foundation conditions and geotechnical aspects.................................................13-3
13.3.2 Design Criteria...............................................................................................13-3
13.3.3 Submission to the Engineer...........................................................................13-4
13.3.4 Shop drawings and details............................................................................13-5
13.4 CONSTRUCTION MATERIALS..............................................................................13-6
13.4.1 Substructure..................................................................................................13-6
13.4.1.1 Abutments............................................................................................................ 13-6
13.4.1.2 Retaining Walls.................................................................................................... 13-6
13.4.1.3 Anchor blocks....................................................................................................... 13-6
13.4.1.4 Bridge Bearings.................................................................................................... 13-6
13.4.2 Superstructure...............................................................................................13-7
13.4.2.1 Main Bearing Cables and Hangers.......................................................................13-7
13.4.2.2 Bridge Deck.......................................................................................................... 13-7
13.4.2.3 Finishes................................................................................................................ 13-7
13.4.2.4 Wearing course.................................................................................................... 13-7
13.4.2.5 Road Marking....................................................................................................... 13-7
13.4.2.6 Railing.................................................................................................................. 13-7
13.4.2.7 Traffic signs.......................................................................................................... 13-8
13.4.2.8 Roadway Drainage...............................................................................................13-8
13.4.2.9 Lighting................................................................................................................. 13-8
13.5 FABRICATION AND QUALITY CONTROL..............................................................13-8

13.6 DELIVERY AND ERECTION...................................................................................13-8

13.7 OPERATION AND MAINTENANCE........................................................................13-9

13.8 WARRANTY............................................................................................................ 13-9

13.9 MEASUREMENT AND PAYMENT..........................................................................13-9

Pakistan Water and Power Development Authority, Islamic Republic of Pakistan
Diamer Basha Dam Project
Bidding Documents (Contract MW-1) Part ll: Particular Technical Specifications
Volume 3A - Technical Specifications For Main Dam and Appurtenant Structures ii

LIST OF TABLES
Table 1: Design floods for Permanent Access Bridge............................................................................13-1

LIST OF FIGURES
Figure-1: Clearance Diagram for the transportation of the Main Transformer.......................................13-2
Pakistan Water and Power Development Authority, Islamic Republic of Pakistan
Diamer Basha Dam Project
Bidding Documents (Contract MW-1) Part ll: Particular Technical Specifications
Volume 3A - Technical Specifications For Main Dam and Appurtenant Structures 1
13. PERMANENT ACCESS BRIDGE
13.1 INTRODUCTION

Permanent access bridge shall accommodate access to the right bank of the Indus River, during
construction for facilitating transport of equipment for hydro-mechanical and electrical
equipment. After impounding of reservoir, the bridge shall provide access to the settlements
located on the right bank.
The Contractor shall design, supply, fabricate and construct permanent access bridge across
Indus River in accordance with the requirements stipulated in this Chapter and as approved by
the Engineer.
This chapter provides the minimum requirements for bridge roadway and facility widths, vertical
under-clearances and design live loads. All elevations, water levels, dimensions etc. shown on
the drawings are tentative which may vary as per project requirements.

13.2 GEOMETRIC DESIGN

Unless specifically noted in the provisions, the geometric design standards provided in this
section shall refer to the AASHTO - A Policy for Geometric Design of Highways and Streets
(Latest). The bridge and allied components shall be designed for a design speed of 60 km/hr.

13.2.1 Waterways

To assure a safe passage for a 100 year design flood (Q100) and debris an adequate hydraulic
opening must be provided. In addition a minimum freeboard of 5000 mm for the 10,000-year
flood (normal operation condition for the spillway) shall be considered as satisfying normal
hydraulic clearance requirements. The tentative design water levels are given in the following
TABLE-1. Design based on actual water levels shall be carried out by the Contractor for
approval by the Consultants.
Table 1: Design floods for Permanent Access Bridge

Discharge Maximum Water Level

[m3/s] [masl]
Q100 14,300 966.80
Q10.000 20,170 970.00

13.2.2 Bridge Widths and Vertical Clearances

Inside clear width of bridge roadway shall be min. 7.3m plus shoulders and inside clear width of
walkways (on either side of the bridge) shall be 1.2m.
Minimum vertical clearances requirements help accommodate the movement of large vehicles
for maintenance operations, utility work, and construction, electrical and mechanical equipment.
To facilitate the movement of general vehicles a minimum vertical clearance of 5.5m should be
kept. However, for the transportation of the main transformers the tentative clearance of the
following Clearance Diagram in FIGURE-1 is provided. Exact clearance values shall be used for
the bridge design as per requirements of equipment manufacturer/vendor.
 Pakistan Water and Power Development Authority, Islamic Republic of Pakistan
Diamer Basha Dam Project
Bidding Documents (Contract MW-1) Part ll: Particular Technical Specifications
Volume 3A - Technical Specifications For Main Dam and Appurtenant Structures 2

Figure-1: Clearance Diagram for the transportation of the Main Transformer

13.2.3 Span

The maximum main span length is given by the following requirements and constrains:
 Clearance for water crossing
 Altitude of right and left bank access road
 Due to the expected river bed degradation and the high sediment load of
the river Indus, a foundation in the river bed should be avoided
As result of these constrains the minimum tentative length of the main span (centre to centre of
the expansion joints) shall be approximately 200 m.

13.2.4 Alignment, Profile and Super Elevation

2.4.1 Horizontal Alignment

The alignment of a bridge is controlled by the KKH-Highway, the design speed and traffic
volume. To guarantee a simple structural system for the Permanent Access Bridge the
horizontal alignment should be straight.
The minimum radius of curves in the approach road must exceed 25.0 m. Spiral alignments and
compound curve alignments on structures should be avoided.

2.4.2 Vertical Alignment and Longitudinal Slope

The tentative elevation of the Permanent Access Bridge is 975.00 m asl (given by the right and
left bank approach road). The bridge deck shall be cambered to offset dead load and appear
flat. All vertical load carrying members shall be perpendicular to the ground (horizon) after the
bridge is erected and dead loads applied.
A longitudinal slope should be avoided.
2.4.3 Super Elevation
Bridge roadway shall be cambered 1.5 % and the walkways 2.0 % of the total span length.
Transitions in the cross slope of a bridge deck should be avoided whenever possible.
 Pakistan Water and Power Development Authority, Islamic Republic of Pakistan
Diamer Basha Dam Project
Bidding Documents (Contract MW-1) Part ll: Particular Technical Specifications
Volume 3A - Technical Specifications For Main Dam and Appurtenant Structures 3
13.3 DESIGN CRITERIA AND STANDARDS FOR DETAILED DESIGN

13.3.1 Expected Geotechnical Conditions

3.1.1 Geology and expected Materials

In the foundation areas on both banks the bedrock consists of massive, slightly to unweathered
hard gabbronorite rock. On the left bank a thin layer of overburden material mainly consisting of
alluvial gravels and river deposited sand is expected in the area of the pylon. Its thickness is
expected not to exceed 5 m.

3.1.2 Foundation conditions and geotechnical aspects

On the left bank the abutment is lying on sound gabbronorite rock. Any obviously weakened
material at surface like boulders, scree and remnants of alluvial or colluvial deposits have to be
removed. Generally, it is expected that after an excavation depth of 2 m in bedrock the rock
mass is revealing good foundation conditions. Depending on the actual conditions during
excavation, the Contractor may reduce the excavation depth after prior approval of the
Engineer.
The geotechnical conditions for the anchor block on the left abutment are similar as described
before.
On the right bank, the geotechnical conditions for the abutment and anchor block are similar as
expected on the left bank.

The geological/geotechnical conditions mentioned above are guidelines for the Contractor. The
Contractor, however, shall acquire all necessary information about the site and soil
conditions. The engineering design and construction of the bridge abutments, piers, footing
and anchors shall be performed accordingly.

13.3.2 Design Criteria

The Permanent Access Bridge must be designed according to AASHTO LRFD Bridge Design
Specifications (Latest Edition). The design methodology shall be "Load and Resistance Factor
Design (LRFD)".
The bridge shall be designed to carry not less than the AASHTO live load and the Main
Transformer Transport Vehicle (tentative load approx. 150 ton). However, design shall be based
on actual loads which may vary as per project requirements.
The structural calculations shall incorporate but not be limited to the following loads:
 Dead loads and Superimposed dead loads
 Live loads
 Ice loads
 Wind loads (wind speed= 100mph)
 Force effects due to creep, shrinkage, Settlement, temperature gradient, uniform
temperature etc.
 Forces from post-tensioning
 Hydrostatic and hydrodynamic loads
 Earth surcharge loads
 Earth pressure loads
 Seismic loads
Pakistan Water and Power Development Authority, Islamic Republic of Pakistan
Diamer Basha Dam Project
Bidding Documents (Contract MW-1) Part ll: Particular Technical Specifications
Volume 3A - Technical Specifications For Main Dam and Appurtenant Structures 4
 Seismic inertia force
 Earthquake dynamic earth pressure

The vertical deflection and lateral deflection of the bridge under dead loads, live loads and
lateral loads should be within the permissible limits specified in the relevant codes and
standards.

Also vibration requirements of the relevant codes and standards shall be fulfilled. Vibrations
shall not cause damage to the structure and shall not cause discomfort or concern to users of
the bridge.

13.3.3 Submission to the Engineer

The Contractor shall submit to the Engineer two copies of each of the following:
 Shop drawings, details and calculations in accordance with Clause 13.3.4; incorporating all
alterations and amendments such that they accurately reflect the details as constructed.
 Details of proposed source of supply of steel and dates of rolling;
 Details of proposed welding procedures;
 Details of proposed programme, sequence and methods of fabrication/ erection
/installation /construction with supporting calculations and details of Construction Plant;
 Mechanical test certificates and chemical analyses for all steel including fasteners to be
used in the Permanent Works before such steel is incorporated;
 Records of approval tests of welding procedures before commencement of any welding;
 Welder's approval test certificates current at the date of fabrication for the appropriate
classes of welding before such welders are employed on the fabrication;
 Results of the agreed quality controls applied to the welded fabrication work.
 Concrete bridge, composite bridge and steel bridge options alongwith their comparison with
respect to construction time, cost, aesthetics, durability, maintenance, constructability etc.
(The Engineer can choose from various structural configurations proposed by the Contractor
for Construction. Alternately, The Engineer can ask the Contractor for new Structural
configuration/arrangement which the Contractor shall design and execute within the
specified time with no additional cost to the Project).
 Complete detailed technical specifications of the bridge for approval from the Engineer
 Bridge full scale load testing program
 Main report including, but not limited to, sections on standards utilized, design criteria,
meteorological data related to wind speeds and snow loads, structural system description,
verification of free board, discussion of quantitative assessment results with table showing
demands/capacities/factors of safety, compliance with permissible limits, geotechnical report
(including soil type, all design parameters like bearing pressure, active pressure, passive
pressure, sliding coefficients, seismic parameters, and slope stability / landslide analysis,
etc.), hydraulic analysis report (with freeboard verification and highest design flood depth;
aerial site imagery shall be provided showing that bridge abutments have been installed
outside the flood plan of the river), scour analysis report, traffic analysis report, and
recommendations for repair, retrofit, and/or maintenance, detailed construction methodology
etc.
 Manufacturer data sheets listing standards, capacities, and installation information for any
manufactured parts used on the bridge (wire rope, clamps, turnbuckles, anchors etc.) in
Pakistan Water and Power Development Authority, Islamic Republic of Pakistan
Diamer Basha Dam Project
Bidding Documents (Contract MW-1) Part ll: Particular Technical Specifications
Volume 3A - Technical Specifications For Main Dam and Appurtenant Structures 5
order to ensure that manufactured parts have been installed and utilized correctly as per the
manufacturer specifications.
 As-Built drawings in PDF and CAD including all topography, elevations, structural
information (geometry, cable profile, size, quantity, material grades, and manufacturer
designations), details required to illustrate the as-built conditions etc.
 BIM-based (Autodesk Revit etc.) Bridge model for optimization of design, construction
sequences, construction scheduling, construction management, construction process
monitoring, as-built conditions, facility management, future repair/maintenance/retrofit etc.
 Operation, maintenance and repair manual identifying any daily, weekly, monthly, annual or
other time bound inspection and maintenance programs/tasks alongwith inspection &
maintenance plans, inspection and condition assessment forms covering all bridge
components in line with relevant standards, maintenance checklists and guidance, efficient
maintenance systems for collecting & analyzing data from monitoring/supervision/
maintenance/operation, details of spare parts and their availability, details of supporting
system & access facilities (for inspection) & their incorporation in the design, details of
bridge inspection vehicle, complete system for replacement of bearings,
corrosion/deterioration protection, bidding document for the award of future maintenance
contract by the Client etc.
 Training manual covering bridge maintenance and repairs including the provision of
refresher training covering operation, inspection, maintenance and repair/retrofit activities to
the local Client personnel. The manual shall include, but not be limited to subjects on access
platform for maintenance/repair/retrofit, replacement of bearings, bridge inspection vehicle,
wire rope material specifications, environmental conditions, bridge and wire rope failures,
proper installation/selection of wire rope end preparation, clamps, turnbuckles etc. The
training manual provided to the Client shall cover requisite brochure, graphics, technical
checklists with comprehensive instructions etc.
 HSE (Health, Safety & Environment) management Plan / Program
 Detailed portfolio/profile of the Designer selected by the Contractor for the Design of bridge
along with requisite experience of similar or larger span bridges

13.3.4 Shop drawings and details

Not less than 60 days prior to the commencement of fabrication of any given structure or
element, the Contractor shall submit to the Engineer for his approval two copies of the under-
noted submittals in order ensure the safety, suitability and adequacy of the Permanent Works
designed by the Contractor:
 Shop drawings;
 Detailed Supporting design calculations covering all geometric, geological/geotechnical,
hydrological/hydraulic and structural aspects with specific reference to codes and standards
 Computer models of super-structure and sub-structure components of the bridge covering
all specified loads;
 Details of all connections together with calculation sheets confirming that the connections
will withstand the imposed forces and moments.
 Details of Galvanization and other corrosion/rust/deterioration protection
The Contractor shall forward each submission in accordance with dates to be agreed with the
Engineer having regard to the approved programme and the need to give the Engineer
adequate time to consider each submission.
 Pakistan Water and Power Development Authority, Islamic Republic of Pakistan
Diamer Basha Dam Project
Bidding Documents (Contract MW-1) Part ll: Particular Technical Specifications
Volume 3A - Technical Specifications For Main Dam and Appurtenant Structures 6
Each submission shall be complete in all respects and in sufficient detail to enable the Engineer
to fully understand and evaluate the Contractor's design. Each drawing shall be complete with a
legend.
Each submission shall have been thoroughly checked by an engineer appointed by the
Contractor with appropriate qualifications and experience and shall be accompanied by a
signed statement to that effect.
If in the opinion of the Engineer the Contractor's submissions do not meet the requirements of
the Contract, the Engineer will notify the Contractor who shall make appropriate amendments to
the submissions and, shall forward three further copies within 30 days of the Engineer's
notification. The procedure described above shall apply to all resubmissions.
The Contractor shall supply to the Engineer four copies and one reproducible of the drawings
approved by the Engineer and four copies of the specifications and other information approved
by the Engineer.
Fabrication shall not be started until the Engineer has approved the relevant shop drawings and
once such approval has been given, no alterations shall be made to the shop drawings without
the further approval of the Engineer.
The bridge designer selected by the Contractor for the design of Bridge should have a requisite
experience of the design of similar bridges with equivalent or larger spans.

13.4 CONSTRUCTION MATERIALS

The following construction materials are given for suspension bridge option as shown in the
drawings. However, this option is not final and Contractor can suggest other materials for
Concrete bridge, Composite bridge and steel bridge options.

13.4.1 Substructure

4.1.1 Abutments
Concrete and Reinforced Concrete according to standard specifications

4.1.2 Retaining Walls

Concrete and Reinforced Concrete according to standard specifications

4.1.3 Anchor blocks

Concrete and Reinforced Concrete according to standard specifications

4.1.4 Bridge Bearings

Bridge bearings transfer superstructure loads to the substructure while also providing for the
thermal movement and rotation of the superstructure.
The Permanent Access Bridge requires special bearings to handle the extreme loads,
movements, and rotations. The bearings shall be designed by the Contractor, in accordance
with international standards.
The steel parts of all bearings, including weathering steel, shall be painted due to concern for
the bearing steel being in contact with water for long periods of time and the resulting durability
concerns with uncoated weathering steel. Painting of the bearing steel is covered under the
Standard Specifications and the cost is included in the bearing items.
 Pakistan Water and Power Development Authority, Islamic Republic of Pakistan
Diamer Basha Dam Project
Bidding Documents (Contract MW-1) Part ll: Particular Technical Specifications
Volume 3A - Technical Specifications For Main Dam and Appurtenant Structures 7
13.4.2 Superstructure

4.2.1 Main Bearing Cables and Hangers

The selection of cable type and design (analysis) of the main bearing cables (e.g. Parallel Wire
Cables, Parallel Strand Cables or equivalent) and hangers’ cables shall be done by a
professional design engineer having vast experience in suspension bridges design with similar
or larger spans. The design should be done according to international standards.
All cables and other bridge components shall have adequate corrosion-resistant in accordance
with international standards.

4.2.2 Bridge Deck

All structural members shall have a minimum thickness of material of at least 6mm.
Unpainted Weathering Steel bridges shall be fabricated from ASTM A242 or ASTM A588 steel
for plates and structural shapes and ASTM A606 or ASTM A847 for tubular sections. Minimum
yield (Fy) shall be greater than 50,000 psi. Galvanized/painted Steel bridges shall be fabricated
from ASTM A572 (or equiv.), Fy greater than 50,000 psi and tubular sections from ASTM A500
(or equiv.), Fy greater than 50,000 psi (Client can ask the Contractor to go for unpainted or
galvanized/painted option).
Field splices shall be bolted with High Strength ASTM A325 bolts (or equiv.); type 3 bolts are
required for weathering steel bridges.
Welding materials shall be in strict accordance with the American Welding Society (AWS)
Structural welding code (or equiv.). Filler metal (min. thickness 8 mm) shall be used for the
particular welding process required. Welders should be certified in accordance with international
standards.

4.2.3 Finishes
All exposed surfaces of the bridge shall be sand blasted in accordance with the Steel Structures
Painting Council (SSPC) Surface Preparation Specification No. 6 "Commercial Blast Cleaning"
(or equivalent).
Bridge shall be galvanized/painted by the bridge Contractor. The contractor shall have an AISC
(or equiv.) certified shop with sophisticated paint endorsement. The bridge shall be painted with
an epoxy primer ("Devran 4170" by Devoe Coatings) followed by an Aliphatic Urethane Gloss
Enamel topcoat ("Devthane 4708" by Devoe Coatings) or approved equal. The Bridge shall be
provided with paint for touch up after erection.
4.2.4 Wearing course
Wearing course according to the NHA Pakistan Specifications and as shown in the drawings.

4.2.5 Road Marking

Road marking according to the Chapter on Road and Pavement Works of this Specification.

4.2.6 Railing
All railings shall have a smooth inside surface with no protrusions or depressions. All ends of
angles and tubes shall be closed and ground smooth. In accordance with AASHTO (or equiv.),
railings for pedestrian use should be a minimum of 1.10 m above the floor deck.
Continuous guard rails shall be located on both sides of the carriage way, according to standard
specifications.
 Pakistan Water and Power Development Authority, Islamic Republic of Pakistan
Diamer Basha Dam Project
Bidding Documents (Contract MW-1) Part ll: Particular Technical Specifications
Volume 3A - Technical Specifications For Main Dam and Appurtenant Structures 8
4.2.7 Traffic signs
Traffic signs according to the Chapter on Road and Pavement Works of this Specification and
as shown in the drawings.

4.2.8 Roadway Drainage

Road drainage according to the Chapter on Road and Pavement Works of this Specification and
as shown in the drawings.

4.2.9 Lighting
Lighting according to the Chapter on Road and Pavement Works of this Specification and as
shown in the drawings.

13.5 FABRICATION AND QUALITY CONTROL

Permanent Access Bridge contractor shall be certified by an international Institute to have the
personnel, organization, experience, capability, and commitment to produce fabricated structural
steel for major steel bridge Structures with sophisticated paint endorsement.
To ensure quality control during bridge fabrication, the bridge supplier shall be the designer and
fabricator of the bridge and shall not assign, sublet, or subcontract any part of the bridge
fabrication.
Workmanship, fabrication, and shop connections shall be in accordance with international
standards.
The bridge shall be inspected by a Certified Weld Inspector that is qualified e.g. under the AWS
QC-1 program. This inspection shall include as a minimum requirement the following: review of
shop drawings, weld procedures, welder qualifications and weld testing reports, visual
inspection of welds and verification of overall dimensions and geometry of the bridge. A report
shall be produced indicating the above items were reviewed.
All structural elements used in the bridge shall be identified by heat number of the steel member
used. Specific mill test reports and individual welder certificates shall be tracked and kept on file
to be provided at the request of the owner or engineer.
Welding operators shall be properly accredited experienced operators, each of whom shall
submit satisfactory evidence of experience and skill in welding structural steel with the kind of
welding to be used in the work, and who have demonstrated the ability to make uniform good
welds meeting the size and type of weld required.
All welding shall utilize E70 or E80 series electrodes. The weld process used shall be Flux Core
Arc Welding (FCAW) or Gas Metal Arc Welding (GMAW) or Shielded Manual Arc Welding
(SMAW per ANSI/AASHTO/AWS D1.5) "Bridge Welding Code (or equiv.)."

13.6 DELIVERY AND ERECTION

The Bridge will be delivered by truck to a location nearest to the site accessible by roads.
Hauling permits and freight charges are the responsibility of the contractor.
Contractor shall be responsible for delays in the delivery/erection due to inclement weather,
delays in permits, re-routing by public agencies or other circumstances etc.
The Contractor shall have complete information of the actual lifting weights, attachment points
and all necessary information to install the bridge. Unloading, splicing, bolting, and proper lifting
equipment is the responsibility of the Contractor.
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Diamer Basha Dam Project
Bidding Documents (Contract MW-1) Part ll: Particular Technical Specifications
Volume 3A - Technical Specifications For Main Dam and Appurtenant Structures 9
The contractor shall install the anchor bolts in accordance with the manufacturer's anchor bolt
spacing dimensions. All grounding and lightning protection shall be the responsibility of the
contractor.

13.7 OPERATION AND MAINTENANCE

The Contractor will be responsible for Operation and Maintenance of Permanent Access Bridge
from the date that the said facility is available for use at site till the completion of Contract MW-1
including routine visual inspection, maintenance, repair etc. of all its members while ensuring
uninterrupted flow of traffic during the construction/maintenance period and during its use by
other Contractors. All labour, staffing, equipment, consumable parts, material and related parts,
repair/ replacement costs etc. required for operation and maintenance of the Bridge shall be
included in the cost of bridge. Likewise, cost of full-scale bridge testing shall also be included in
the cost of Bridge.

13.8 WARRANTY

The Contractor shall provide a warranty against defects in material and workmanship for a
period of ten years beyond the defects notification period.

13.9 MEASUREMENT AND PAYMENT

The cost of designing and constructing the permanent access bridge across the Indus River
including operation and maintenance shall be paid as a lump sum item. Payment for this item
will be made as per the milestones submitted by the Contractor and approved by the Engineer
in accordance with the Clause 57.2 of Conditions of Contract.