Luận văn tốt nghiệp Tiếng Anh: GRADUATION THESIS CABLESTAYED BRIDGE

preface In the development of our country today, we need to build more and more structure to serve the demand of human life. In which, Transport is the important field that is considered with large investment and concern of society. We need to get more and more skillful engineer to update the modern technology of the world and build for us many modern structures with high quality and aesthetic. After 5 years learnt in the University of Transport and Communications, with the willing of myself and the wholeheart teaching of my teachers, I have been grant many experiences with help me in the future. This graduation thesis is the result of 5 years studied in this university. It is the summary of my studying process. During making this graduation thesis, I have been helped by my lecturers in the Department Bridge and Tunnel (UTC) for finishing my thesis. During make this graduation thesis, because of the time and my limited knowledge, so there is no doubt that I will get some mistakes. I hope I can take advice of our lecturers to make my finished graduation thesis and learn by experience in the future. Finally, I absolutely give a thanks to Prof.Dr. Nguyen Ngoc Long and all lecturers in the Department of Bridge and Tunnel(UTC), and especially, Dr Tran The Truyen who advise me about what is best to finish my graduation thesis. Thank you for all Ha Noi, May 2010 Nguyen hoang locPREFACE 2010 NGUYEN HOANG LOC Page 5 Comment of guide lecturer ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... 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..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .....................................................................................................................................PREFACE 2010 NGUYEN HOANG LOC Page 7 Comment of student Đây là nội dung cho các bạn khóa Cầu Đường khác tham khảo. Phần tham khảo thứ nhất này là phần tôi đã hoàn thành từ ngày 2542010. Thứ nhất,tôi khuyên các bạn ngành Cầu thuộc các lớp khác ngoài lớp Cầu Đường Anh có khả năng tiếng anh thì cố gắng phấn đấu làm và bảo vệ đồ án tốt nghiệp bằng Tiếng Anh. Điều này rất có lợi cho sự thăng tiến và giúp ích cho công việc của các bạn. Các bạn bảo vệ ĐATN bằng Tiếng anh thuộc bất kỳ lớp nào trong trường giao thông đều được cấp giấy chứng nhận do nhà trường cấp và không có gì khác biệt so với các bạn thuộc lớp Cầu Đường Anh.Nếu các bạn có điều gì cần trao đổi thì có thể email cho tôi theo địa chỉ : Nguyenhoangloc2015gmail.com (Civil Engneer – Mr Loc) Thứ hai, ngay từ cuối năm thứ 4 hay càng sớm càng tốt các bạn hãy thực hành cho mình khả năng sử dụng Excel thật tốt (bao gồm cả VBA) để có thể lập ra các bảng tính chuyên nghiệp, giúp cho qua trình làm ĐATN. Ở đây tôi sẽ nêu một số nội dung chính về công việc chuẩn bị cho làm ĐATN Cầu Dây Văng. + Chuẩn bị bảng tính : Móng cọc đài cao Kiểm toán trụ mố. Kiểm toán tháp cầu. Tính duyệt mặt cầu – dầm ngang – tai đeo, dây văng. Tính duyệt dầm chủ, lưu ý là dầm đơn năng (TT) hoặc dầm đa năng. Bảng tính DCNL Cầu Dây Văng. và một số bảng tính quan trọng khác. + Chuẩn bị khả năng về phần mềm chuyên ngành. o MidasCivil (có thể học phần mềm tại trung tâm của Thầy Vĩnh (giảng viên Cầu Hầm –ĐHGTVT 0936922370) o FBPier o RM2006 o Có thể nghiên cứu them về SAP o Autocad các bạn tự học. Thứ ba, các bạn nên tổ chức thời gian để thực hiện từng phần mà mình đặt ra theo kế hoạch, như vậy qua trình làm ĐATN sẽ dễ dàng hơn. Thứ tư, các câu hỏi khi bảo vệ tiếng anh các bạn email tôi sẽ gửi cho. Cuối cùng tôi chúc các bạn thành công, bảo vệ ĐATN bằng Tiếng anh tốt (Hội đồng bảo vệ có thể gồm: Thầy Hâu, T. Tuấn Bình, Thầy Nhiệm, Thầy Truyền, Thầy Tiến, Thầy Duy hoặc hơn)PREFACE 2010 NGUYEN HOANG LOC Page 8 CONTENTS chapters Design contents page Design requirement 3 preface 4 Comment of leading lecturer 5 Comment of checking lecturer 6 CONTENTS 7 General introduction 8 Volume i Preliminary design OF BRIDGE ALTERNALTIVES 9 CHAPTER I THE PREMILINARY DESIGN OF THE 1st ALTERNATIVE CABLESTAYED BRIDGE 9 CHAPTER II THE PREMILINARY DESIGN OF THE 2sd ALTERNATIVE PRESTRESSED CONCRETE BRIDGE 45 CHAPTER III the premininary design of the 3rd alternative composite bridge 78 CHAPTER IV Bridge alternative selection 118 VOLUME II TECHNICAL DESIGN 121 CHAPTER V general view of detail design CABLESTAYED bidge 121 Chapter vi Internal force redistribution of cables 124 Chapter vii DECK AND TRANSVERSE BEAM 145 Chapter viii Abutment calculation 174 Chapter ix design of bridge pylon 207 Chapter x Design of bridge beam 243 CHAPTER XI CONSTRUCTION PLANNING AND DESIGN 286 REFERENCE REFERENCE 329PREFACE 2010 NGUYEN HOANG LOC Page 9 GENERAL INTRODUCTION I Specification for bridge design Specification: 22TCN – 272 – 05 Ministry of Transport Design load : HL – 93 II Structural scale Permanent bridge with service life > 100 years III Navigation clearance Level i H = 10 m B = 80 m IV Bridge width Traffic lane : 2x4.5m width Pedestrain lane : 2x1.5m width Design speed V=60kmh V Geologic feature Layer 1 : Clay , 2 m thick Layer 2 : Sandy soil , 8 m thick Layer 3 : Alluvial sand , 15 m thick Layer 4 : Medium sand , unlimited thick VI bridge profile The top of bridge center curve is circular curve ,R=5000m Longitudinal slope : i=3%| English Bridge and Road – Course 46 THESIS GRADUATE DESIGN of CABLESTAYED BRIDGE A thesis submitted in partial fulfillment for the degree Engineer of Engineering In the Department of Tunnel and Bridge Faculty of Civil Engineering University of Communications and Transport May 2010UNIVERSITY OF TRANSPORT AND COMMUNICATIONS 2010 CHAPTER I: THE PREMILINARY DESIGN OF THE 1st ALTERNATIVE CABLESTAYED BRIDGE N G U Y E N H O A N G L O C E N G L I S H B R I D G E A N D R O A D – C 4 6CHAPTER I: THE PREMILINARY DESIGN OF THE 1st ALTERNATIVE CABLESTAYED BRIDGE 2010 NGUYEN HOANG LOC Page 10 CHAPTER I: THE PREMILINARY DESIGN OF THE 1st ALTERNATIVE CABLESTAYED BRIDGE I General introduction In the trends of industrialization and modernization in Viet Nam, infrastructure construction is the essential problem. In the other hand, transport construction, maintenaince and upgrade is important. One of the needed requirement for the nowand thefuture bridge is: not only satisfy the need of modern transportation but also has an economic, easthetical bridge to make a symbol of Viet Nam in the future. In the past, when designing the bridge, the designer often used the steel bridge, concrete bridge and prestress concrete bridge…with the simple or continuous span. These types of bridge are just economic with the small and medium length. Therefore, we need to design a bridge with longer span, simple construction and has an easthetical shape. Researching some developed and developing country, we can see that, with the span of 50  150m, the prestress concrete bridge which is erected with the cantilever method has highly effective. The maximum span from this type of bridge is 240m ( Hamana Bridge, Japan). However, the limited economical span of this type is just only 200m. The cablestayed bridge is the nondeformed structure, so it can ensure the good rigidity. The system works like a girder is placed on elastic bearings (cable). The increase of elastic bearing not only doesn’t make the increasement of cable mass and the compression in the girder, but also

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DEPARTMENT OF BRIDGE AND TUNNEL

GRADUATION THESIS

CABLE-STAYED BRIDGE

APPROVED BY : DR TRAN THE TRUYEN CHECKED BY : PROF.DR NGUYEN NGOC LONG PREPARED BY : NGUYEN HOANG LOC

CLASS : ENGLISH BRIDGE AND ROAD – COURSE 46

HA NOI, MAY 2010

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NGUYEN HOANG LOC Page 4

In the development of our country today, we need to build more and more

structure to serve the demand of human life In which, Transport is the important

field that is considered with large investment and concern of society We need to

get more and more skillful engineer to update the modern technology of the world

and build for us many modern structures with high quality and aesthetic

After 5 years learnt in the University of Transport and Communications, with

the willing of myself and the whole-heart teaching of my teachers, I have been

grant many experiences with help me in the future

This graduation thesis is the result of 5 years studied in this university It is the

summary of my studying process During making this graduation thesis, I have

been helped by my lecturers in the Department Bridge and Tunnel (UTC) for

finishing my thesis

During make this graduation thesis, because of the time and my limited

knowledge, so there is no doubt that I will get some mistakes I hope I can take

advice of our lecturers to make my finished graduation thesis and learn by

experience in the future

Finally, I absolutely give a thanks to Prof.Dr Nguyen Ngoc Long and all

lecturers in the Department of Bridge and Tunnel(UTC), and especially, Dr Tran

The Truyen who advise me about what is best to finish my graduation thesis

Thank you for all!

Ha Noi, May 2010

Nguyen hoang loc

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Trang 4

Trang 5

thứ nhất này là phần tôi đã hoàn thành từ ngày 25-4-2010

- Thứ nhất,tôi khuyên các bạn ngành Cầu thuộc các lớp khác ngoài lớp Cầu Đường Anh có khả năng tiếng anh thì cố gắng phấn đấu làm và bảo vệ đồ án tốt nghiệp bằng Tiếng Anh Điều này rất có lợi cho sự thăng tiến và giúp ích cho công việc của các bạn Các bạn bảo vệ ĐATN bằng Tiếng anh thuộc bất kỳ lớp nào trong trường giao thông đều được cấp giấy chứng nhận do nhà trường cấp và không có gì khác biệt so với các bạn thuộc lớp Cầu Đường Anh.Nếu các bạn có điều gì cần trao đổi thì có thể e-mail cho tôi theo địa chỉ :

Nguyenhoangloc2015@gmail.com (Civil Engneer – Mr Loc)

- Thứ hai, ngay từ cuối năm thứ 4 hay càng sớm càng tốt các bạn hãy thực

hành cho mình khả năng sử dụng Excel thật tốt (bao gồm cả VBA) để có thể

lập ra các bảng tính chuyên nghiệp, giúp cho qua trình làm ĐATN Ở đây tôi

sẽ nêu một số nội dung chính về công việc chuẩn bị cho làm ĐATN Cầu Dây Văng

+ Chuẩn bị bảng tính :

- Móng cọc đài cao

- Kiểm toán trụ - mố

- Kiểm toán tháp cầu

- Tính duyệt mặt cầu – dầm ngang – tai đeo, dây văng

- Tính duyệt dầm chủ, lưu ý là dầm đơn năng (TT) hoặc dầm đa năng

- Bảng tính DCNL Cầu Dây Văng

- và một số bảng tính quan trọng khác

+ Chuẩn bị khả năng về phần mềm chuyên ngành

o Midas/Civil (có thể học phần mềm tại trung tâm của Thầy Vĩnh

(giảng viên Cầu Hầm –ĐHGTVT - 0936922370)

- Thứ tư, các câu hỏi khi bảo vệ tiếng anh các bạn e-mail tôi sẽ gửi cho

- Cuối cùng tôi chúc các bạn thành công, bảo vệ ĐATN bằng Tiếng anh tốt (Hội đồng bảo vệ có thể gồm: Thầy Hâu, T Tuấn Bình, Thầy Nhiệm, Thầy Truyền, Thầy Tiến, Thầy Duy hoặc hơn)

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9

CHAPTER II

ALTERNATIVE PRESTRESSED CONCRETE BRIDGE

45

CHAPTER III

alternative composite bridge

78

CHAPTER IV Bridge alternative selection 118

CHAPTER V general view of detail design

Chapter vi Internal force redistribution of

CHAPTER XI CONSTRUCTION PLANNING AND

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GENERAL INTRODUCTION

I - Specification for bridge design

- Specification: 22TCN – 272 – 05 Ministry of Transport

- Design load : HL – 93

II- Structural scale

Permanent bridge with service life > 100 years

III- Navigation clearance

Level i

H = 10 m

B = 80 m

IV- Bridge width

-Traffic lane : 2x4.5m width

- Pedestrain lane : 2x1.5m width

- Design speed V=60km/h

V - Geologic feature

Layer 1 : Clay , 2 m thick

Layer 2 : Sandy soil , 8 m thick

Layer 3 : Alluvial sand , 15 m thick

Layer 4 : Medium sand , unlimited thick

VI - bridge profile

- The top of bridge center curve is circular curve ,R=5000m

- Longitudinal slope : i=3%

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| English Bridge and Road – Course 46

THESIS GRADUATE

DESIGN of CABLE-STAYED BRIDGE

A thesis submitted in partial fulfillment for the degree Engineer of

Engineering

In the Department of Tunnel and Bridge Faculty of Civil Engineering University of Communications and Transport

May 2010

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2010

CHAPTER I: THE PREMILINARY DESIGN

OF THE 1st ALTERNATIVE CABLE-STAYED

BRIDGE

N G U Y E N H O A N G L O C - E N G L I S H B R I D G E A N D R O A D – C 4 6

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CABLE-STAYED BRIDGE

I - General introduction

- In the trends of industrialization and modernization in Viet Nam, infrastructure construction is the essential problem In the other hand, transport construction, maintenaince and upgrade is important

- One of the needed requirement for the now-and- the-future bridge is: not only satisfy the need of modern transportation but also has an economic, easthetical bridge to make a symbol of Viet Nam in the future

- In the past, when designing the bridge, the designer often used the steel bridge, concrete bridge and prestress concrete bridge… with the simple or

continuous span These types of bridge are just economic with the small and medium length

- Therefore, we need to design a bridge with longer span, simple construction and has an easthetical shape

- Researching some developed and developing country, we can see that, with the span of 50  150m, the prestress concrete bridge which is erected with the cantilever method has highly effective The maximum span from this type of bridge

is 240m ( Hamana Bridge, Japan) However, the limited economical span of this type is just only 200m

- The cable-stayed bridge is the non-deformed structure, so it can ensure the good rigidity The system works like a girder is placed on elastic bearings (cable) The increase of elastic bearing not only doesn’ t make the increasement of cable mass and the compression in the girder, but also make the reduction of flexural moment in the girder., especially when it subjected to the dead load Therefore, the cable-stayed bridge can spread larger span length when the mass is increased neglectable

- Moreover, in the development history of bridge, the cable-stayed bridge has had a large concern of the researchers, designers and architects From the time the first cable-stayed bridge built at Stralsund, Sweden, in 1955, the cable-stayed bridges are built all over the world

- One favorite basic characteristic of this type of bridge is the diversity The bridge can has different span length, cable plane or cable layout The shape and the height of the pylon are also the beautiful characteristic

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reasonably erection technology, and diversity are one of the important building of many country

- In Viet Nam, the first cable-stayed bridge was built in 1976 at Dakrong (Quang Tri) but by the end of February in 1999 this bridge was collapsed, and then until 2000, this bridge is fixed with reinforce concrete Another cable-stayed bridges are My Thuan Bridge (Tien Giang - Vinh Long) in 1998 - 2001 , Han river Bridge (Da Nang), Bai Chay Bridge, Can Tho Bridge…

II - general description

II.1 - design specifications

- The specification : 22TCN - 272 - 05 of the Ministry of Transport

II.2 - Structural layout

- Span length: 132.5+276+132.5

- The height of pylon : 75.2 m from the pylon bot

- The cross-section has constraint height with the shape TT

- The length of one panel 10m

- Number of cables on one pylon: 4x13=52 cables

- Cross beams are placed at the entired length of girders, with the spacing 5m

III - Span calculation

III.1 – Selection of the span plot

The cable-stayed bridge can has one, two or three spans , in which the spans cable-stayed bridge is popular It has many advantages of structure, bearing capacity as well as construction technology

thee-Studying the characteristics of geology-geometry-topography-hydrology and surrounding architecture, the conditions of zone’ s economy-society-politics, I decide to choose the cable-stayed bridge alternative with two cable plane symmetric to the pylon

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Each of the girder has advantages and disadvantages According to the accretion trends, the use of any section base on ensuring the bearing capacity and having the simplest construction technology, which suitable with erection capacity and

Therefore, I decide to use the cross-section of girder similar with the cross-section

in My Thuan Bridge (erected) The My Thuan Bridge has 3 spans with length 150 +350 +150m, the cross-section has 2 main girder with the shape of two-meters trapezium, 25 centimeters slab thickNess and 5.2 meters cross beam spacing Cables is anchored at the cross beam which placed outside the girder

According to bridge statistics in the world and in Viet Nam, the ratio of girder height and length is h

cable-I use the single strand type with 7 wires 5 (diameter of 15,2 mm) In addition, I use the strands which can reduce the expansion of strand ( due to the displacement caused by self weight when subjected to live load)

The strands are pretension separately and assembled into group in the anchor block The work of installing the cable is very simple because the cable is installed with strand one by one and no form traveler is needed

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strands and strands are clamped by the 3 segments cotter

Using the 7 fiber strands cable and clamp anchor is the premium alternative III.4 - The shape and cross-section of pylon

- Pylon height is chose to satisfy some requirements:

+) Ensure the connection between cables and pylon

+) Ensure the inclined angle of cables is suitable for bearing capacity demand:

Inclined angle of mid cable is a = 22.5 25 o

- From these analysis, I choose the pylon has some typical parameters such as:

+) Total pylon height h th = 72.5 m

+) Height from the cap to beam bottom hct= 15 m

+) Height from beam bottom to nearest cable htt = 37.155m

+) Height of cable spacing : hdv =18 m

+) Height from the top anchor to the pylon top hdt = 2.5m

- The table of calculating inclined angle of cable:

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b - cables angle at mid span

III.5 - Force calculation

III.5.1 - Calculation of the dead load

1- Dead load in stage I

- Dead load in stage I including:

+) Main girder self weight: DCdc

+) Weight of cross beam: DCdn

+) Weight of tail : DCtd

DCITC = DCdc+ DCdn+ DCtd Main girder self weight: DCdc

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- Standard dead load in stage I

2 - Dead load in stage II

- Dead load in stage II including:

+) Weight of barrier

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+) Weight of wearing surface

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- Calculation of the dead load in stage II

+) Standard dead load

DWIITC = qclcc+ qch+ qle+xe =32.2 kN/m +) Calculation ofd dead load

DWIItt = g DWIITC = 1,5x32.2 = 48.3 KN/m

3 - Summary the dead load in two stages

III.5.2 - Calculation of the live load

1 - The live load according to the specifications 22TCN - 272 - 05

- The live load HL 93 follows the specifications 22TCN - 272 - 05 Depend onf the shape of the influence line, we have to placed live load to get the maximum load effect

+) Load modifier : hi = 1

+) Load factor : gi = 1,75

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2 - Calculation of the load distribution factor

- Steps to Calculation of the load distribution factor

+) Consider the slab is the cantilever beam placed in the rigid bearing (main girder)

+) Draw the bearing reaction influence line

+) Place the unfavorable load according to the transversal direction

+) Determind the Y-value of influence line

+) Calculation of the load distribution factor:

- We can see the table

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section

III.6.1 - Determining the cable

- Using the seven-wire stranded cables of the VSL company with the parameters as follows:

+) The nominal diameter: 15,2 mm

+) The yield strength : fpy = 1670 Mpa

+) The ultimate strength : fpu = 1860 Mpa

+) Using strength : f = b.fpu

b = 0,45 with the major load combination

b = 0,5 with the additional load combination

b = 0,56 with the erection load combination

=> The using strength of cable with the major load combination is:

fsa = 0,45.1860.102 = 837 Mpa

III.6.2 - Calculting the cable internal force

1 - Calculating the cable internal force due to dead load in stage I

a- Formulas

- The cable internal force in stage I is Calculation ofd with the erection stage layout The formula is:

+) Internal force in the cable i

+) Internal force in mid cable

b- Cable internal force table due to dead load in stage I

i

I tt i

Sin

d g S



.



2.

I

tt g g

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So, we select premilinary cables with:

- With the side span

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(kN)

Ai

(essential) (cm2)

Essential wires for

1 side

Selection wires

Ai

(selected wires) (m2)

Cable diameter (m)

Essential wires for

1 side

Selection wires

Ai

(selected wires) (m2)

Cable diameter (m)

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- Internal force due to live load

+) Due to lane load: SLantt = glan qlan v+

+) Due to pedestrian load: SNGtt = gNG qNG v+

+) Due to HL93: Placed one truck into the influence line at the most unfavorable position(the axle spacing can vary from 4,3 - 9 m )

c - Table of cable internal force due to dead load in stage II and live load

A - With the side span

max(kN)

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B - With the midle span

max(kN)

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III.6.3 - Choosing the cross-section of cable

- We can use the formula

+) ful : Calculation ofd strength of cable material, ful = 837 (MPa)

These above formula base on the condition of using the whole capacity of the cable From that, the cross-section of cables are different However, in design calculation, if the differences are little, we can choose the cross-section of some cables similarly, or due to any purpose in design procedure, we can increase or decrease some cables cross-section

- Table of choosing the cable cross-seciton

Side span

Number SI (total)

max (kN)

Ai (cm2)

Essential wires

n for 1 side Selection wires

Ai (m2)

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Essential wires

Ai (m2)

III.6.4 - The good work condition of cable

- To ensure the good work of cable in the process of subjecting the load, the cabel must satisfy some conditions:

+) Ensure the condition of strength

+) Ensure the condition of rigidity: the cable must be checked according to the allowable defomed condition

- The deflection of cable i due to live load is Determination of by using the formula:

``

sin cos

.

cos

1

h i i i

o o

h o o i

A

S l tg

A

S l E

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+) E : Cable Modulus of elasticity

+) So , Sih : Standard internal force in the anchor cable and cable I due to live load

+) Ao,Ai : Area of anchor cable and cable i

+) lo , li : Projection of anchor cable and cable i into plane view

- Rigidity ensuring condition: yi < {y}

IV - Pylon calculation

IV.1 - Pylon structure

- Because of the geometry and geology condition at the pylon place are similar, to make calculation and design easy, we design two identical pylons Therefore, we just need to Calculation of one pylon

- The pylon is the insitu - compact block concrete

- Foundation option: the cap is inside the earth and 1,5m bored cast-in-place piles

- The constitution of pylon:

+) Total pylon height h th = 75.2 m

+) Height from the cap to beam bottom hct= 15m

+) Height from beam bottom to nearest cable htt = 37.155 m

+) Height of cable spacing : hdv =18 m

+) Height from the top anchor to the pylon top hdt = 2,5m

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IV.2 - Design calculation

IV.2.1 - Calculating the weight of pylon:

- To make it simple, I use the table:

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IV.2.2 - Calculation of the water submerger force

- According to the layout, the cap is placed in the earth, so we can Calculation of the total water submerge force by using the formula

Submeg pressure in the foundation

in the elevation view

1 - Calculating the reaction of continuous span

- Using the programme Midas 7.01 to draw the bearing reaction influence line of continuous span:

- Reaction due to dead load of stage I

- Reaction due to live load: We can Calculation of the reaction acting on the

bearing of pylon as below:

+) Use 2 design truck with the spacing 15 m ( axle spacing is 4,3 m )

+) Using the loading effect of 90% value of the reaction + 90% lane load + pedestrian load

n ng

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2 - Calculating the reaction considered the cable internal force

In which:

+)  Si : Sum of cable internal forces due to dead load and live load

- Calculation ofd table of reaction due to cable internal force

dv S

P   sin 

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IV.3 - Check the pylon leg section

- In this preliminary alternative, I just check the pylon leg section according to the center compression condition

kN/m

2

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The cap is designed with the bored cast-in-place pile D = 150cm

IV.5.1 - Calculation of the pile bearing capacity according to the material

- Formula:

In which:

+) fc’ : Compression strength of concrete

+) Ac : Area of concrete in accordance with the pile cross-section

+) fy : Yield strength of steel

+) As : Area of steel in accordance with the pile cross-section

+) j : Buckling factor, j = 0,75

- The table of calculating the bearing capacity of the pile according to the material

IV.5.2 - Calculating the bearing capacity according to the ground

- The table of geological data at the site:

)

85 , 0

coc f A f A

Trang 32

KG/cm

2

φ KG/cm

+) QR : Bearing capacity of pile according to the ground

+) QS = qS AS : Pile skin resistance

+) QP = qP AP : Pile tip resistance

+) qS : Unit pile skin resistance

+) qP : Unit pile tip resistance

+) AS : Area of pile body

+) AP : Area of pile tip

+) jqS : Resistance factor at the body

+) jqP : Resistance factor at the tip

- According to Reese and Wright (1977 ) we have : qP = 0,064 N (Mpa), qS = ∝.Su

Q   Q   Q

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- Table of calculating the bearing capacity of pile due to ground

qs T/m2

Pile tip bearing resistance

Qp

V.1.3 - Calculation of the number of pile

In which :

+) b : The factor considered the type of foundation and the value of moment,

we choose b = 1,5

+) Qcoc : Calculation ofd bearing capacity of the pile

+) P : Total vertical force acting on the cap:

coc

Q P

n

Trang 34

We choose the number of pile is n = 24 (piles)

- The pile length is 42 m

V - Abutment calculation

V.1 - Design dimensions of abutment

V.1.1 - Constitution of A0

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V.1.2 - Basic parameters

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V.3 - Calculating live load acting on abutment

V.3.1 -General principle

1 - Loads acting on the abutment

- The abutment is above the navigational water level so we don’ t need to Calculation of the ship collision load and wind loads Filled earth beside the abutment is in a good compaction with  = 18 KN/m3  = 350

- Loads acting on the abutment including:

3 Vertical reaction due to vertical live load in the span

2 - The checked section of abutment

- Section I-I : Abutment cap section

- Section II-II : Coping wall leg section

- Section III-III : Body wall leg section

- Section IV-IV : Wing wall leg section

V 3 2 - Determination of vertical loads acting on the abutment

Trang 37

- We have the summary table:

The weight of backfill behind abutrment 5282.93

The weight of backfill front of

abutrment

202.18

2 - Determination of load due to live load acting on the span

- Using the programme Midas 7.01 to draw the bearing reaction influence line:

- Internal force due to live load is given with the maximum load effect from these load effects below:

+) Load effect 1 : Truck (with the axle spacing vary from 4,3 to 9 m ) + lane load+ pedestrian load

+) Load effect 2: Tandem + lane load+ pedestrian load

- Placed truck and tandem into the bearing resistance influence line we have:

+) Y value of truck:

+) Y value of tandem:

Trang 38

- The table of loads transfer from span to abutment

Pressure cause by standard dead load at stage

1

kN PttI

-167.7 -209.63 Pressure cause by standard dead load at stage

2

kN PttII

-27.3 -40.95

3 - Determination of load due to live load acting on the transition slab

- Length of transition slab: Lqd = 6.0 (m)

- Width of transition slab: Bqd = 11 (m)

- Draw the bearing resistance influence line on the transition slab at the rested position

Trang 39

+) Total area of influence line: S = 3

+) Area of positive influence line: S+ = 3

+) Area of negative influence line: S- = 0

- Placed the truck and tandem, we have

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Total pressure from transition slap (max(P1,P2)) Pht bqd 243.90 405.17 KN

4- Summary of vertical force transfer into section I-I(bottom of pile cap) with

I strength limit stage

Ptotal = P ht bqd +(Pkcn+DCtt+DWtt )+ Ptt = 405.17 + 6363.21 + 16542.1x1.25 = 27446

kN

V.4 - Calculation of the needed bored cast-in-place pile

The cap is designed with the bored cast-in-place pile D = 150cm

1 -Calculation of the pile bearing capacity according to the material

- Formula:

In which:

+) fc’ : Compression strength of concrete

+) Ac : Area of concrete in accordance with the pile cross-section

+) fy : Yield strength of steel

+) As : Area of steel in accordance with the pile cross-section

85 , 0

coc f A f A

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