TABLE OF CONTENTS

1.General 21.1Basic Design Concept 21.2List of bridge 21.3Major Change from Feasibility Study 21.4Typical Cross Section 4

2.Design conditions 52.1Applied Design Standards and Specifications 52.2Design Criteria 52.3Materials 7

3.Bridge of Package 8 83.1Review of span arrangement 83.2Substructure 123.3Superstructure of hollow slab girder 153.4Superstructure of I girder 19

General1.

1.1Basic Design Concept

Bridges and structures design in this project is for phase I. Phase II is considered only for a setting of vertical clearance.

Detailed design was carried out based on the result of Feasibility Study unless there was no change in design conditions such as future plans,geotechnical conditions and topographical conditions.

1.2List of bridge

Bridge and viaduct length, location and bridge type is shown in following table.

List of Bridge

Name of Bridge ChannelLength

(m)

Span Arrangement

(m)

Type of

Structure

Do Xuan Hop

Flyover

from Km2+972.4

to Km3+442.6479.2 7@30+2@24.925+7@30

PC Hollow

Slab

Ba Hien Bridge

Left Bridge :

from Km3+847.4

to Km3+924.8

83.7 3@25.7 PC I girder

1

Right Bridge :

from Km3+827.4

to Km3+904.8

1.3Major Change from Feasibility Study

Span arrangement and general issue

Name of Bridge Design Change

Do Xuan Hop

Flyover

Type of bridge was changed from Super-T girder in FS 2007 to PC HollowSlab in order to make a consideration of architectural aspects at HCMC PCrequest because the structure is located within the urban area.

HCMC requested to allow traffic to enter the expressway from Do Xuan Hopstreet without the need to go through RR2 or Nguyen Thi Dinh Street (whichwill become one-way street). In accordance with the concept, the type of DoXuan Hop intersection was designed as roundabout. And the location of pierswas designed to avoid roundabout.

For the reasons mentioned above, span arrangement was changed from 11spans (11@40m) to 16 spans (7@30m+2@25m+7@30m).

Ba Hien Bridge

Ba Hien Bridge was designed as I-girder as same as F/S.

The shape of bridge changed from squared bridge in FS 2007 to skew bridge inorder to make a consideration of direction of flow in Ba Hien River.

The structures around connection part of rampways, which are difficult toconstruct in Phase II, shall be constructed at the same time of rampwayconstruction in this Project. Therefore, according to the ramp way of RR2 ICplan in phase II, the width of bridge adapt to the one in phase II, and thewidth of left bridge become wider as the section number increase.

Detail design of structure

Name of Bridge Design Change

Do Xuan Hop

Flyover

From structure examination, pile type was changed from RC piles (40 x 40 cm)to bored piles (D=1.2m).

Footing thickness was increased from 1.5m to 2.0m.

Pier cross section was changed from rectangle to oval.

The bridge pier was designed graceful form with a curve based on aestheticstudy.

Girder height is 1.4m.

Type of bridge was changed from Super-T girder to PC Hollow Slab withchange of span length (from 40m to 30m).

Planting and foundation of slab for planting was designed between bridges ofeach direction.

Ba Hien Bridge

From structure examination, pile type was changed from RC piles (40 x 40 cm)to bored piles (D=1.2m).

Footing thickness was increased from 1.5m to 2.0m.

Pier cross section was changed from oval to circle.

Pier thickness was increased from 1.4m to 2.0m.

Girder height is 1.45m, not changed from F/S 2007.

The width of left bridge becomes wider (from 19.76m to 22.08m) as the sectionnumber increase.

MSE (Mechanically Stabilized Earth) wall was designed as retaining wall withreinforced soil wall system.

Planting and foundation of slab for planting was designed between bridges ofeach direction.

1.4Typical Cross Section

Typical cross sections of bridge are shown in following figures.

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Figure 1.4-1 Typical Cross Section of Urban Expressway (Do Xuan Hop Flyover)

Figure 1.4-2 Typical Cross Section of Urban Expressway (Ba Hien Bridge)

2.Design conditions

2.1Applied Design Standards and Specifications

Following Vietnamese standards and specifications have been applied in the bridge design.

Table 2.1-1 Applied Vietnamese Standards and Specifications

22 TCN-272-05 Specification for Bridge Design

22TCN221-95 Transport Project in area with earthquakes Design Standard

TCVN 5729-97 Expressways design specifications

TCVN 4054-2005Highways design specifications (applied for connections,collector roads)

Following international standards and specifications are also applied as reference after getting approval of the client.

Table 2.1-2 Applied International Standards and Specifications

AASHTO LRFD Bridge Design Specifications

AASHTO LRFD Bridge Construction Specifications

ASTM A 416-85 Prestressed steel for reinforcing concrete

Standard Specifications for Highway Bridges (Japan Road Association, 2002)

2.2Design Criteria

1)Load combinationThe load combination for Limit State Condition is given based on Article 3.3 of 22TCN-272-05.

Load2.

Dead Load

Applied dead load for design calculation is summarized as the following:

Table 2.2-1 Unit Weight

MaterialDensity[kN/m3 (kg/m3)]

Bituminous Wearing Surfaces 22.1 (2250)

Compacted Sand, Silt or Clay 18.9 (1925)

Concrete Plain 23.5 (2400)

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MaterialDensity[kN/m3 (kg/m3)]

Reinforced 24.5 (2500)

Loose Sand, Silt or Gravel 15.7 (1600)

Soft Clay 15.7 (1600)

Steel 77.0 (7850)

Water 9.8 (1000)

(Source: 22 TCN-272-05)

Live Load

HL-93 shall be applied as live load for the design of the bridge.

Figure 2.2-1 Design Vehicular Live Load HL-93

Other loads are applied in accordance with 22 TCN-272-05.

3)Vertical ClearanceThe vertical clearance of overpass and underpass will be decided based on the road category and discussion with the local authority.

Table 2.2-2 Vertical Clearance for Roads and Railways

CategoryVertical Clearance[m]

Remark

Other 3.20

National and Provincial Highway 4.50

Expressway 5.00 Throughway

Railway 6.00

(Source: TCVN5729:97)

4)Navigation Clearance

Navigation clearances for existing canals have been confirmed by Waterway Unit under Department of Transportation of Ho Chi Minh City,with the letter No. 745/KDS-QLKT-CL dated 22 July 2010, main contents as shown in Table 1.2.1-5:

Table 2.2-3 Navigation Clearance

No. Canal (Bridge in the Project) Required Navigation Clearance

1 Ba Cua (Do Xuan Hop Flyover) W=13, H=3m

2 Ba Hien (Ba Hien Bridge) N/A (Not planned as river traffic way)

Sseismic Design5.

Seismic effect will be considered for the bridge design and applied acceleration coefficient in this project is accordance with 22 TCN-272-05and TCXDVN 375:2006.

Zone of Maximum Seismic Intensity: Imax 6 (MSK-64)Seismic Zone 1

Acceleration Coefficient: A 0.09Table 2.2-4 Acceleration Coefficient for each Package

Package Acceleration Coefficient Location

8 0.0856, 0.0747 District 2, District 9, HCMC

4

(Source: 22TCN221-95)

2.3Materials

1)Reinforcing barTable 2.3-1 Reinforcing Bar

Round bar CI

Yield strength 240MPa

Tensile strength 380MPa

Elastic modulus 200,000MPa

Deformation bar CIII

Yield strength 400MPa

Tensile strength 600MPa

Elastic modulus 200,000MPa

Source : TCVN 1651 85

Concrete2.

The following concrete classes and modulus are used.

Table 2.3-2 Concrete Class and Modules

Class Strength Modulus Structure

C50 50MPa 38,007MPa Precast girder (Super T)

C35 35MPa 31,799MPaCIP deck slab inc. link slab,Crossbeam of Super T,Hollow slab

C30 30MPa 29,440MPaAbutment, Piers Bored pile,Precast concrete plank forSuper T

C25 25MPa 26,875MPaParapet, Pedestal oflamp-post, Approach slab

C20 20MPa - Sealing concrete

C10 10MPa - Blinding concrete

Notes, Strength is based on cylinder strength (MPa)

Pre-stressing Strands2.

Table 2.3-3 Hollow slab girder

Diameter 12.7*12 strand 12.7*12 strand

ASTM A416

Location to beused

Deck slab Bottom slab

Tensile strength 1860MPa

Yield strength 1670MPa

Elastic modulus 200,000MPa

3.Bridge of Package 8

3.1Review of span arrangement

Do Xuan Hop Flyover

As for Do Xuan Hop Street, connection rampways to the urban expressway was requested to design. In accordance with the concept, the type ofDo Xuan Hop intersection was designed as roundabout. And the location of piers was designed to avoid roundabout. According to thismodification, bridge pier arrangement has been carefully decided so that there will be neither re-arrangement nor interfering of structures in PhaseII. In consideration of urban landscaping, bridge type has been changed to hollow slab girder from Super-T girder.

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Table 3.1-1Comparison in Pier Location of Do Xuan Hop Flyover

Table 3.1-2Comparison in Pier Location of Do Xuan Hop Flyover

No.1 Basic Plan (Round shaped) No. 2 Alternative Plan (Ellipse shaped)

Profile&Plan

Shape of pier changed from squareto circle for not invadingroundabout.

Two pier locations are close toroundabout.

Piers of elevation are crowded.

Crossing length is short.

Shape of pier is square.

Piers locate apart fromroundabout.

Pier location of both up and downroad matches.

Crossing length is more 40m.

Figure 3.1-1Span arrangement of F/S

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Figure 3.1-2Improved span arrangement in D/DBa Hien Bridge

Ba Hien Bridge was designed as I-girder as same as F/S. Widening by RR2 Interchange rampway is in the bridge location and bridge width is aswide as 19.75 - 22.08 m and two (2) piers are installed in one (1) foundation. In consideration of the river flow, the bridge angle is set to skew tokeep a river width of 10m and make the bridge pier shape with circle section.

Figure 3.1-3Span arrangement of F/S

Figure 3.1-41Improved span arrangement of D/D3.2Substructure

Design of pier cap and column1.

Pier shape is rectangler section in a general part. Pier shape are shown below.

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Bridge Shape of pier

Do Xuan Flyover Oval

Ba Hien Bridge Circle

Figure 3.2-1Pier shape of Do Xuan Flyover

Figure 3.2-2Pier shape of Ba Hien bridge

Table 3.2-1Shape of pier

Design results of pier cap and column are shown in following tables.

Table 3.2-2Do Xuan Hop Flyover

Table 3.2-3Ba Hien Bridge

2)Design of pile

The kind of pile is applied bored pile to the bridges. Soil condition of two bridges has thin hard layer, if driven pile is applied, there is possibilitythat drive is impossible by intermediate hard layer. Therefore, bored pile is selected.

Pile type and pile number of bridges of Package 8 are shown in the following table.

Table 3.2-4Pile type and pile number of Package 8 bridge

Bridge Pile type D Number of pile (/pier)

Abutment Pier

Do Xuan HopFlyover

Bored pile D1.2 6,8 5,6

Ba Hien Bridge Bored pile D1.2 8 8

8

Design results of pile are shown in following tables.

Table 3.2-5Do Xuan Hop Flyover

Item EL2

Length Number Force Capacity

Safy

of pile of pile (KN) (KN)

A1 -2.00 61.00 2X8 4472.00 4578.69 1.02

P1, P2 -2.00 71.00 2X5 4495.00 4585.78 1.02

P3 -2.00 71.00 2X5 3825.00 4016.20 1.05

P4, P5 -2.00 81.50 2X5 3825.00 3858.21 1.01

P6 -2.00 61.00 2X5 4840.00 5030.01 1.04

P7 -2.00 61.00 2X5 4840.00 4846.35 1.00

P8 -2.00 61.00 2X5 4328.00 4475.84 1.03

P9 -2.00 66.00 2X5 4840.00 4845.06 1.00

P10 -2.00 71.00 2X5 4840.00 5889.78 1.22

P11 -2.00 66.00 2X5 4495.00 4585.78 1.02

P12 -2.00 66.00 2X5 4495.00 4527.16 1.01

P13 -2.00 66.00 2X5 4495.00 4531.37 1.01

P14,P15 -2.00 61.00 2X5 4495.00 4585.78 1.02

A2 -2.00 66.00 2X8 4224.00 4253.00 1.01

Table 3.2-6Ba Hien Bridge

Item EL2

Length Number Force Capacity

Safy

of pile of pile (KN) (KN)

A1L -1.50 69.00 8.00 5054.00 5900.00 1.17

P1L -1.00 69.00 8.00 3664.20 5895.00 1.61

P2L -3.00 69.00 8.00 3720.60 4886.00 1.31

A2L -1.50 73.00 10.00 4401.20 5271.00 1.20

A1R -1.50 71.00 8.00 4129.99 4995.00 1.21

P1R -3.00 69.00 8.00 3341.80 5010.00 1.50

P2R -3.00 69.00 8.00 2996.60 5010.00 1.67

A2R -1.50 71.00 8.00 4205.80 6124.00 1.46

Design result

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Figure 3.2-3Bored Pile D=1.2m

3.3Superstructure of hollow slab girder

Span arrangement and structure type1.

a. Structural properties

Continuous Deck (W=12.25 m, including railing)

b. Girder Arrangement

Girder arrangement of Do Xuan Hop Flyover is 7@30+2@24.925+7@30 m continuous hollow slab girder. The general view of bridge is shownin Figure.

Continuous span length is determined to fill the conditions of construction period and deflection did not become excessive. Assumedconstruction schedule of Package 8 is shown in a figure. In order to complete Do Xuan Hop flyover within construction period of 24-27month,it is necessary to divide into two bridges of 8span, and it needs to construct superstructure simultaneously by 4 parties. In the design,construction joint and jack space is prepared in consideration of this construction process.

Figure 3.3-1Construction Schedule of Package 8

Figure 3.3-2General view of hollow slab bridge

Design of girder2.

a.Member DimensionGirder shape is shown below.

Figure 3.3-3Typical Cross Section of Hollow slab Girderb.Tendon Arrangement

Tendon arrangement of Do Xuan Hop Flyover.

Tendon arrangement of Hollow salb girder is shown below. 23 internal cable of 12.7mm are arranged in web. Tendon is arranged . Tendonarrangement at major section is shown below.

Figure 3.3-4Tendon arrangement of Do Xuan Hop Flyover

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Figure 3.3-5Tendon arrangement of typical section

Design result of girder3.

In analysis, a structure condition is changed and construction schedule is reflected in presumption of creep and shrinkage according toconstruction schedule. Construction sequence taken into consideration in analysis is shown in a figure. And Check results of stress in servicelimit state of Hollow slab girder are shown bellow.

Figure 3.3-6Construction sequence

Figure 3.3-7Concrete Stress of deck slab at Service

Figure 3.3-8Concrete Stress of bottom flange at Service Limit stateThe result of the bending resistance of Strength limit state is shown in the followingfigure.

Figure 3.3-9Result of checking of bending resistance at M-Max and M-Min

4.

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Bearing

a.Rubber BearingThe girder is fixed by rubber bearing at abutment and centre pier. In Do Xuan Hop Flyover, longitudinal displacement is not large and rubberbearing can distribute reaction force of super structure for each pier. Elastic bearing is chose from above reason and durability and cost.

Figure 3.3-1Notes; Anchor bar is installed with rubber bearing for longitudinal unexpected earthquake and transverse movement

0Bearing Arrangement

Figure 3.3-11Rubber Bearing

3.4Superstructure of I girder

Girder arrangement and structure type1.

a.Structural propertiesDiscontinuous Deck ( W=19.75m for right bridge , and from 19.760m to 22.08m for left bridge)

b.Girder ArrangementOne span consists of 8 I girders for right bridge, 9 I girders for left bridge . The typical cross section is shown in Figure.

Figure 3.4-1Typical Cross Section of Viaduct

Design of girder2.

a.Member DimensionGirder shape of I girder for 25.7m span is shown below.

General section Cross beam section

Figure 3.4-2Typical Cross Section of I Girder (Lc=25.7m)b.Tendon Arrangement

Arrangement of I Girder is shown below. 5 strands are arranged for a girder.

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Figure 3.4-3Tendon Arrangement of I Girder (L=25.7m)

Bearing3.

Rubber bearing is adopted due to durability and economical reason. The bearing is widely used for this type of bridge. Above eachintermediate pier, slab is connected with link slab and roadability is improved.

Figure 3.4-4Bearing Arrangement

Figure 3.4-5Rubber Bearing

Expansion Joint4.

A finger type joint is applied for super I-girder.

Figure 3.4-6Type Expansion Joint

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