ĐATN thanh dat

Graduation Project: LAKE COMMERCIAL CENTER – Thanh Hoa City

Contents
Preface

PART I: ARCHITECTURE
I. GENERAL INTRODUCTION ...................................................................... 10
1. Location .................................................................................................... 11
2. Scale and general features ......................................................................... 11
II. ARCHITECTURE SOLUTION ................................................................... 12
1. Design of master plan ................................................................................ 12
2. Architecture design ................................................................................... 13
3. Traffic inside the building ......................................................................... 16
III. TECHNICAL AND INFRASTRUCTURE SOLUTIONS ........................... 16
1. Lighting system ......................................................................................... 16
2. Ventilation system..................................................................................... 16
3. Electrical system ....................................................................................... 16
4. Water supply and drainage system ............................................................ 16
5. Fire protection system ............................................................................... 17
6. Waste disposal system ............................................................................... 17

PART II: STRUCTURE
CHAPTER I: STRUCTURAL SOLUTION ...................................................... 19
I. STRUCTURAL DESIGN OF HIGH-RISE BUILDINGS .............................. 19
II. SOLUTION FOR MATERIALS .................................................................. 19
III. SOLUTION FOR SUPPORTING STRUCTURE ........................................ 21
1. Basic bearing structure for high rise building ............................................ 21
2. Bearing structure selection ........................................................................ 22
IV. SOLUTION FOR FLOOR .......................................................................... 23
1. Flat floor – band beam solution ................................................................. 23
2. Prestressed slab without beam solution...................................................... 24

3. Select the feasible solution for slab ........................................................... 26
V. SELECTION OF PREMILINARY DIMENSION OF ELEMENTS ............. 27
1. Premilinary dimensions of core and column .............................................. 27
2. Premilinary dimension of slab ................................................................... 28

Student: Bui Thanh Dat – Class: 55XE

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Graduation Project: LAKE COMMERCIAL CENTER – Thanh Hoa City
3. Premilinary dimension of beam ................................................................. 30
CHAPTER II: LOADS ....................................................................................... 31
I. DEAD LOAD ................................................................................................ 31
1. Seft weight ................................................................................................ 31
2. Finish load ................................................................................................ 31
3. Dead load of brick wall and glass wall ...................................................... 35
4. Dead load of roof water tank ..................................................................... 37
II. LIVE LOADS............................................................................................... 38
III. WIND LOAD .............................................................................................. 40
1. Dead wind load ......................................................................................... 40
2. Live wind load .......................................................................................... 41
3. Total wind load applying on building ........................................................ 46
4. Check the top displacement the building ................................................... 47
CHAPTER III: FRAME AXIS 4 DESIGN ........................................................ 48
I. INTERNAL FORCES IN COLUMNS AND BEAMS OF AXIS 4 ................ 48
II. LOAD COMBINATIONS ............................................................................ 62
1. Internal forces of column........................................................................... 62
2. Internal forces of beam .............................................................................. 82
III. CALCULATION OF BEAM REINFORCEMENT ..................................... 98

1. Principles .................................................................................................. 98
2. Calculation of rebars of beam B-103 ( 6th floor) ...................................... 102
3. Calculation of rebar of beams .................................................................. 103
4. Calculation of shear reinforcement .......................................................... 110
IV. CALCULATION OF REINFORCEMENT OF COLUMNS ..................... 113
1. Principle .................................................................................................. 113
2. Calculation of column C-4 1st floor ......................................................... 116
3. Calculation of column at other levels ...................................................... 121
4. Stirrup arrangement ................................................................................. 122
V. DESIGN FRAME NODE AND CONNECTION POSITION ..................... 126
CHAPTER IV: FOUNDATION DESIGN ....................................................... 128
I. DESIGN DOCUMENT ............................................................................... 128
1. Design document of building................................................................... 128
2. Geologic document ................................................................................. 129
3. Geologic section...................................................................................... 130
4. Geologic assessment ............................................................................... 131
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Graduation Project: LAKE COMMERCIAL CENTER – Thanh Hoa City
II. SELECTION OF FOUNDATION SOLUTION.......................................... 131
1. Satmp pile ............................................................................................... 132
2. Bored pile................................................................................................ 132
3. Method selection ..................................................................................... 133
III. BORED PILE FOUNDATION DESIGN .................................................. 133
1. Preliminary dimension of pile ................................................................. 133
2. Loading capacity of piles determination .................................................. 135
3. Determination of number and arrangement of piles ................................. 138

4. Pile check ................................................................................................ 141
5. Pile cap check ......................................................................................... 144
6. Design reinforcement for pile cap............................................................ 147
7. Foundation beam system ......................................................................... 150
8. General ckeck of bored pile foundation ................................................... 152
CHAPTER V: POST-TENSIONING SLAB DESIGN .................................... 159
I. CALCULATION BASE .............................................................................. 159
1. Calculation methodology......................................................................... 159
2. Method of calculating internal forces of reinforced concrete slab ............ 159
II. MATERIALS ............................................................................................. 160
1. Concrete .................................................................................................. 160
2. Rebar....................................................................................................... 160
3. Strand...................................................................................................... 160
III. DIMENSION OF STRUCTURE ............................................................... 161
IV. LOADS ..................................................................................................... 162
1. Load cases ............................................................................................... 162
2. Load combination ................................................................................... 162
V. TENDON PROFILE .................................................................................. 163
1. Creating strips for calculation .................................................................. 163
2. Tendon profile ......................................................................................... 166
VI. EFFECTIVE STRESS OF TENDON ........................................................ 169
1. Stress loss due to friction ......................................................................... 169
2. Anchorage set slip losses ......................................................................... 169
3. Stress losses due to other reasons ............................................................ 171
VII. CALCULATING AND ARRANGING TENDONS ................................ 172
VIII. CHECK STRESS IN SLAB ................................................................... 174
1. Stress check at initial service load ........................................................... 174
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Graduation Project: LAKE COMMERCIAL CENTER – Thanh Hoa City
2. Serviceability check at service load ......................................................... 177
IX. CHECK STRENGTH CONDITION (ULIMATE STATE) ....................... 179
X. CHECK DEFLECTION OF SLAB ............................................................ 184

PART III: CONSTRUCTION
CHAPTER I: FORMWORK DESIGN ............................................................ 187
I. FORMWORK AND TECHNICAL REQUESTS ......................................... 187
1. Technical requests ................................................................................... 187
2. Types of formwork .................................................................................. 188
II. DESIGN FORMWORK FOR COLUMN ................................................... 194
1. Design parameters ................................................................................... 194
2. Loads apply on column formwork ........................................................... 194
3. Check column formwork ......................................................................... 195
III. DESIGN FORMWORK FOR BEAM ....................................................... 196
1. Design parameters ................................................................................... 196
2. Design bottom formwork ........................................................................ 197
3. Design side formwork ............................................................................. 201
IV. DESIGN FORMWORK FOR SLAB ........................................................ 203
1. Design parameters ................................................................................... 203
2. Loads apply on slab formwork ................................................................ 204
3. Check slab formwork .............................................................................. 205
4. Check upper girder (8x12 cm) ................................................................. 206
5. Check under girder (10x12 cm) ............................................................... 207
6. Check combination support ..................................................................... 208
V. DESIGN FORMWORK FOR CORE WALL ............................................. 208
1. Design parameters ................................................................................... 208
2. Loads apply on core wall formwork ........................................................ 209

3. Check core wall formwork ...................................................................... 210
CHAPTER II: CONSTRUCTION TECHNOLOGY ...................................... 211
I. GENERAL CONSTRUCTION METHOD .................................................. 211
II. COLUMNS AND CORE WALL CONSTRUCTION ................................. 212
1. Surveying and positioning work .............................................................. 212
2. Reinforcing work .................................................................................... 212
3. Installing formwork ................................................................................. 213
4. Concrete work ......................................................................................... 214

Student: Bui Thanh Dat – Class: 55XE

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Graduation Project: LAKE COMMERCIAL CENTER – Thanh Hoa City
5. Uninstall formwork (removal) ................................................................. 215
III. BEAMS AND SLAB CONSTRUCTION.................................................. 215
1. Installing formwork ................................................................................. 215
2. Reinforcing work .................................................................................... 216
3. Concrete work ......................................................................................... 218
4. Curing concrete ....................................................................................... 220
5. Uninstall formwork (removal) ................................................................. 221
6. Defects rectification ................................................................................ 222
IV. STAIRCASE CONSTRUCTION .............................................................. 223
V. CALCULATION WORK VOLUME ......................................................... 223
1. Calculation of concrete volume ............................................................... 224
2. Calculation of reinforcement volume ...................................................... 225
3. Calculation of formwork volume ............................................................. 226
VI. CHOOSE CONSTRUCTION MACHINES .............................................. 227
1. Choose tower crane ................................................................................. 227

2. Choose concrete pumps ........................................................................... 231
3. Choose concrete truck ............................................................................. 232
4. Concrete vibrators. .................................................................................. 233
CHAPTER III: POST-TENSIONING SLAB CONSTRUCTION.................. 235
I. GENERAL INTRODUCTION .................................................................... 235
II. PT SLAB CONSTRUCTION SEQUENCES .............................................. 235
III. MATERIALS ............................................................................................ 236
1. Strand...................................................................................................... 236
2. Live end anchorage and dead end anchorage ........................................... 237
3. Anti-bursting reinforcement .................................................................... 238
4. Bar chair ................................................................................................. 238
5. Ducting ................................................................................................... 238
6. Plastic grout vent and plastic grout hose .................................................. 239
7. Tape ........................................................................................................ 240
8. Grout mixture .......................................................................................... 240
IV. EQUIPMENTS ......................................................................................... 241
1. Hydraulic stressing jack .......................................................................... 241
2. Hydraulic pump....................................................................................... 241
3. Frame jack .............................................................................................. 241
4. Grout mixer ............................................................................................. 242
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Graduation Project: LAKE COMMERCIAL CENTER – Thanh Hoa City
V. STORAGE AND HANDLING .................................................................. 242
1. Storage .................................................................................................... 242
2. Handling ................................................................................................. 243
VI. WORKING PLATFORM ......................................................................... 243

VII. INSTALLATION WORKS ..................................................................... 244
1. Installation of tendons ............................................................................. 244
2. Installation of live end anchorages .......................................................... 246
3. Definition of tendon profiles ................................................................... 246
4. Finishing works before pouring concrete ................................................. 247
5. Pouring concrete ..................................................................................... 248
6. Installation of anchor block ..................................................................... 248
7. Stressing of tendons ................................................................................ 249
8. Grouting of tendons................................................................................. 251
VIII. REPARE METHODS ............................................................................. 253
1. Installation and pouring concrete problems ............................................. 253
2. Stressing problems (broken strand, slippage strand…) ............................ 253
3. Grouting problems (stuck at grout hose, tendon blocked…) .................... 254
IX. SAFETY REQUIREMENTS AND PRECAUTION MEASURES ............ 254
1. Lifting of material and equipment ........................................................... 254
2. PT tendon installation.............................................................................. 254
3. PT tendon stressing ................................................................................. 255
4. Grouting .................................................................................................. 255
CHAPTER IV: CONSTRUCTION SCHEDUAL ........................................... 256
I. MAJOR PRINCIPLES IN CONSTRUCTION ORGANIZATION .............. 256
II. CONSTRUCTION OGANIZATION METHOD ........................................ 257
III. VOLUMNE AND WORKERS OF WORKS............................................. 258
IV. LIST OF TASKS ...................................................................................... 263
V. ESTABLISH SCHEDUAL DIAGRAM ..................................................... 263
CHAPTER V: CONSTRUCTION SITE LAYOUT DESIGN ........................ 264
I. GENERAL CONCEPT ................................................................................ 264
II. BASIC PRINCIPLES ................................................................................. 264
III. DESIGN SEQUENCE............................................................................... 265
1. Material supply on site. ........................................................................... 265
2. Calculate temporary house on site. .......................................................... 266

3. Water supply on site. ............................................................................... 267
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Graduation Project: LAKE COMMERCIAL CENTER – Thanh Hoa City
4. Electricity supply on site. ........................................................................ 268
IV. SAFETY IN CONSTRUCTION ............................................................... 270
1. Training, implement, examination of safety ............................................ 270
2. Occupational safety in each stage of construction .................................... 271
3. Safety in working with equipment, machines on site ............................... 273
4. Environmental management .................................................................... 274
REFERENCES

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Graduation Project: LAKE COMMERCIAL CENTER – Thanh Hoa City
PREFACE
In the career of building and protecting country, construction is essential
contributing important roles. Along with country's continuous development in the
past years, field of capital construction generally and civil engineering construction
in particular have invested by Government and Party and having deservedly proud
achievements. In the next years, in order to implement the career of modernization
and industrialization, Construction must precede a step; serve purposes of socioeconomic development.
In the recent years, the government is investing much in Construction; advanced
constructing technologies are applied in Vietnam. To apply in fact, civil engineers’

level must be better and better. To satisfy demands of development, The National
University of Civil Engineering is opening scope and raising quality of training.
After learning and gathering knowledge in the National University of Civil
Engineering, now I am designing a graduation project with title: LAKE
COMMERCIAL CENTER. I am guided directly by Prof, Dr Phan Quan Minh and
Dr. Pham Dang Khoa. I sincerely thank Mr. Minh, Mr. Khoa, and other teachers
teaching and assisting me during the learning process and fulfilling the project.
I have tried to do my project best with my knowledge, but it is not very good
because of time and some other reasons. I hope advices, remarks and suggestions of
teachers and all of you.
Thank to you sincerely!
Ha Noi, June-2015
Student

Bui Thanh Dat

Student: Bui Thanh Dat – Class: 55XE

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Graduation Project: LAKE COMMERCIAL CENTER – Thanh Hoa City

PART I

ARCHITECTURE
(10%)
INSTRUCTOR: Prof, Dr. PHAN QUANG MINH
DIVISION OF REINFORCED CONCRETE
STUDENT

: BUI THANH DAT

CLASS

: 55XE

STUDENT ID : 2627.55
TASKS:
-

General introduction of the building

-

Architecture solution of the building

-

Drawing plans layout and sections

-

Technical and infrastructure solutions

Student: Bui Thanh Dat – Class: 55XE

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Graduation Project: LAKE COMMERCIAL CENTER – Thanh Hoa City
I. GENERAL INTRODUCTION
In the recent years, Vietnam’s economy has changed dramatically along with the
rapid growth of the other countries in Asia. The reconstruction and construction
of infrastructure is needed in the open door period. On the other hand, the
replacement of low-rise buildings by high-rise buildings is very necessary to
resolve land issues as well as changing the urban landscape to deserve with the
stature of a large city.
Thanh Hoa is one of the biggest provinces in Vietnam, located 150km from
Hanoi. This province has an important role that is being the northern tip of
central Vietnam. Thanh Hoa City, with approximate 400,000 in population, is
the capital city of Thanh Hoa province, which is situated in the east and has been
center of politic, economy, culture, education and entertainment of Thanh Hoa
Province for a long time.
The land of the city is now depleted while the demand of land for business is
increasing. Therefore, the construction of a high-rise building that combines
both commercial and leasing agencies is essential and appropriate to deal with
those above issues. Because of these reasons, the “Lake Commercial Center –
Thanh Hoa City” is licensed to build.

Figure 1.1: Side facade of Lake Commercial Center
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Graduation Project: LAKE COMMERCIAL CENTER – Thanh Hoa City
1. Location
Lake Commercial Center is a big project built in a golden land of Thanh Hoa
City, with four facades:

-

Front: Le Hoan Street

-

Back side: Dinh Cong Trang Street

-

Right side: Nguyen Trai Street

-

Left side: Tong Duy Tan Street

Figure 1.2: Location of Lake Commercial Center
The building, with synchronized infrastructure, is expected to become the most
important business center of the city.
2. Scale and general features
The total construction area is about 10,000 m2, including 3220 m2 for building
and the rest area is used for green campus system, sports ground, and internal
traffic.
The project consists of 20 above stories, plus a basement. The basement is used
for car parking and level 5 is a technical storey (machines, air conditionings,
etc…).
The total high of the building is 70.4 meter from  0.00 m and the basement is at
-3.300 m.
The basement is parking lots and some technical elements. Levels 13 are used
for supermarket and entertainment services. Levels 419 are offices for lease.

The 20th level is the roof (lift technical room, roof water tank).
Lake Commercial Center is the typical feature of urbanization in modern trends.
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Graduation Project: LAKE COMMERCIAL CENTER – Thanh Hoa City
 Technical and economical parameters
Construction density: K0 is a ratio between building construction area and the
total area of the plot of land (%).
K0 =

3220
SB
.100%  32.2%
.100% =
SL
10000

Where: SB = 3220 m2 is the area of building.
SL = 10000 m2 is the area of plot of land.
It is clear that the construction density is not over 40%. This is in accordance
with the standard TCXDVN 323:2004.
The coefficient of land use: HSD is a ratio between the total floor area and the
area of plot of land.
HSD =

S F 32230


 3.223
S L 10000

Where: SF  32230 m2 is the total floor area of the building,
excepting basement and roof.
SL = 10000 m2 is the area of plot of land.
Obviously, this coefficient is smaller than 5. This is in accordance with the
standard TCXDVN 323:2004.
II. ARCHITECTURE SOLUTION
1. Design of master plan

TONG DUY TAN STREET

3

5

1

LE HOAN STREET

2

B

MAIN ENTRANCE

ÐU ? NG ÐINH CÔNG TRÁNG

ENTRANCE

4

1 CENTER BUILDIN G
2 SPORT AREA
3 OPENCAST PARKIN G LO TS
4 YARD W ITH SELF-ENCLO SED BRICKS
5 FOUNTAIN

ENTRANCE

ENTRANCE

NGUYEN TRAI STREET

Figure 1.3: Master plan of Lake Commercial Center
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Graduation Project: LAKE COMMERCIAL CENTER – Thanh Hoa City
Based on the feature of the plot of land, the requirement of the standards and
regulations of the state, the design of master plan must be based on the use
function of building’s type, technology lines to have clear functional zones and
is also in accordance with the approved urban planning, to ensure scientific and
aesthetic. The layout and architectural spaces have to ensure the requirements
for fire protection, lighting, ventilation, noise, and isolation distance.
For Lake Commercial Center, the front area is used for landscape and yard, so
people can easily access to the building. Internal traffic is linked to external

public-traffic of the city to have ventilation. There is signage at each
intersection.
Around the building are ring roads, huge yards that the fire truck can access and
handle incidents. There is also a large sports ground in the backside.
2. Architecture design
Design of level plans
Basement: technical rooms, underground water tank, parking area for car and
motorbike. The underground surface is sloping, 0.1%, to the drainage ditch.
Level 1: the main large hall is the welcoming place of guests who use office and
services. Supermarket is in the front huge space. Besides, some areas next to the
core are used for clubs.
Level 2-3: all areas are used for business: supermarket, stores, etc… Each level
1-2-3 is spacious with 4.5 m high.
Level 4: is divided into two parts: one for office and the other for a nice bar.
Level 5: is a technical storey of the building where technical rooms, equipment,
and system are located.
Level 6-19: consist of two large areas around the vertical transportation axis.
Sanitation system is used for all stories including two WC areas at two sides.
The lobby system is arranged logically to ensure escaping requirement when
incidents suddenly happen.
Roof: lift technical room and roof water tank.

Student: Bui Thanh Dat – Class: 55XE

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Graduation Project: LAKE COMMERCIAL CENTER – Thanh Hoa City
1

3

2

4

25200
200

8400

8400

6000

8400
19600

2400

Water box
s4

Water box

s5

s5

s4

vk3

G

G

dk1

dw1

dw1

s4
s6

10800

10800

9000

s4

9000

7

7
s4

s4

s6

F

F
vk4

Office for lease 01
3

9000

9000

s15
Office for lease 01
3

s4

s4

E

E

dk2

Water box

dk3
Conditioning box
dk4
45000

vk5

9000

Office for lease 01
3

27400

9000

27400

dk4

dk4

Landfill

Landfill

dk4

D

D

dk2
Electrical box

9000

s4

s4

Office for lease 02
3

9000

45000

dk4
3

Office for lease 02
3

s15
vk4

C

C
s6

dw1

dw1

7

7

s4

s4

B

9000

s4
dk1

10800

9000

s4

10800

s6

B
vk3
s4

s5

s5

Water box
6000
200

s4

Water box
19600

8400

2400

8400

8400

25200

1

2

3

4

Figure 1.4: Typical floor plan layout
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Graduation Project: LAKE COMMERCIAL CENTER – Thanh Hoa City
Design facade
Lake Commercial Center is kind of big project in Thanh Hoa with modern
architecture that consists of big blocks combined with glasses and colorful paint.
Around the building is glass wall system, windows, and painted wall. This
creates a modern and luxurious building.

Figure I.5: Front facade of Lake Commercial Center
Design section
Section shows the internal content of the building, dimension of basic
components, and function of rooms.
Based on the using feature and requirements of sanitation, ventilation for each
area, the high of each level is selected as the following:
-

Basement: 3.3 m

-

Level 1-2-3: 4.5 m

-

Level 5 (technical): 2.4 m

-

Level 4, 619: 3.3 m

-

Roof: 5 m

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Graduation Project: LAKE COMMERCIAL CENTER – Thanh Hoa City
3. Traffic inside the building
The vertical transportation system consists of five lifts, two staircases (1.25 m
and 1.05 m). Furthermore, there are also two escape staircases at two building’s
sides.
The horizontal transportation is arranged suitable for moving requirement. That
is based on the function of each area.
At the floor 1-2-3, there are also two escalators that for transportation service of

super market.
III. TECHNICAL AND INFRASTRUCTURE SOLUTIONS
1. Lighting system
Natural light is fully utilized. The window systems in all facades are glazed. In
addition, artificial light is also arranged so that it can cover all points that need
lighting.
2. Ventilation system
Through the window system, natural ventilation is fully utilized. Besides, there
is air conditioning system. The pipe system is laid in the vertical and horizontal
technical box, distributes evenly to the places of consumption.
3. Electrical system
The medium voltage line 15KV goes to the substation through the underground
pipe system. There is also backup power, two generators, located in the
basement of the building. When main power is lost, the generators will serve the
following cases:
-

The fire protection system

-

Lighting system and protection

-

Working offices

-

Vertical transport system

-

Computer system and other critical services.

4. Water supply and drainage system
Water supply
Water from the water supply system of the city goes into the underground tank
situated in the basement of the building. Water is pumped to the roof tank
automatically, and then follows the technical pipeline to the consumptions.

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Graduation Project: LAKE COMMERCIAL CENTER – Thanh Hoa City
Drainage
Rainwater on the roof, logia, balcony, and domestic wastewater is collected to
se-no leading to the treatment tank. Handled water will be given to the drainage
system of the city.
5. Fire protection system
Fire alarm system
Fire alarm detection devices are arranged in each room at every floor, public
place of each floor. Fire alarm network is mounted alarm clocks and lamps. The
management department controls fire as soon as receive the fire signal.
Firefighting system
This system is designed based on the fire prevention requirements and other
relevant standards (including fire preventing component, escape exits,
firefighting water). CO2 cylinders are set at the intersections in all stories.

6. Waste disposal system
Waste of each floor will be collected and taken downstairs technical storey,
basement by waste collection tube. The waste is processed every day.

Student: Bui Thanh Dat – Class: 55XE

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Graduation Project: LAKE COMMERCIAL CENTER – Thanh Hoa City

PART II

STRUCTURE
(45%)
INSTRUCTOR: Prof, Dr. PHAN QUANG MINH
DIVISION OF REINFORCED CONCRETE
STUDENT

: BUI THANH DAT

CLASS

: 55XE

STUDENT ID : 2627.55
TASK:
-

Select solution in structure

-

Design structure plan of typical floor

-

Calculation of loads

-

Design frame of axis 4

-

Design foundation

-

Design post-tensioning slab

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Graduation Project: LAKE COMMERCIAL CENTER – Thanh Hoa City
CHAPTER I

SOLUTION IN STRUCTURE

I. STRUCTURAL DESIGN OF HIGH-RISE BUILDINGS
High rise building is a building that its height directly affects to the design,
construction and function. In structure, a building is considered as a high rise
building if its rigidity is mostly affected by horizontal loads.
The design of high rise buildings is an important task of design engineer in
terms of choosing solution in structure for high rise building. The structural
system of a building is a primary component that is subjected by loads and
transfers them to earth. The choosing solution for structure task is related to
other tasks such as: plan layout, shape, storey height, technical construction
requirement, construction schedule, and construction costs.
Loads applying on high rise building:
Gravity: is a vertical load that has fixed position, set point, direction,
dimensional and value during using time: self weight, loads of sound
insulation layer and heat insulation…
Climate loads: change by time and applied position. They occur in wind,
temperature changing, moisture, and rain…
Seismic loads: is inertia forces appeared when soil base moves.
Artificial loads: is the loads appeared due to human actions, machine and
other equipment. This load has changing applying position, direction,
dimensional and value.
Therefore, in high rise building design, we should pay attention to complex
problems such as: load determination, load combination, calculation diagram,
foundation structure, horizontal bearing capacity, general buckling and dynamic.
II. SOLUTION FOR MATERIALS
Choosing materials for bearing structure of high rise building must based on the
following basic standards:
Materials must have rate between strength and weight as much as
possible.
High deformability will overcome the low bearing capacity of materials
or structure.

Low decomposition: those materials are preferred to be used when the
building is subjected by repeated load.
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Graduation Project: LAKE COMMERCIAL CENTER – Thanh Hoa City
High monolithism: When vibrating, building shouldn’t separate its
components.
Reasonable costs: A high bearing capacity building is always connected
to reasonable costs.
Nowadays, the following materials are commonly used for high rise building in
all over the world:
Steel:
Advantages:
The main feature of steel structure is high capacity so that it has small
dimension although enough bearing capacity. Steel structure has high
elasticity, high deformability in order to fit with high rise building that
subjected by high horizontal loads. Steel structure is suitable for buildings
required large using space, high height, large span (station, opera, and
museum).
Disadvantages:
It is hard to ensure the construction quality of steel structure because it
requires profession and sensitive. On the other hand, steel building has high
costs even during using time. In Vietnam, steel buildings are commonly not
suitable with temperature. When fire occurs, steel building is easily broken.
Reinforced concrete:
Advantages:
Nowadays, reinforced concrete is commonly used due to the development of

science and technology. This kind of structure is simply constructed and has
common materials, stable to environment. Furthermore, we can utilize the
high compression of concrete and high tension of steel because of their
cooperation. For high rise building, reinforced concrete structure has high
reliability about strength and stability.
Disadvantages:
Reinforced concrete structure requires big size component, high self weight.
This causes the complex choosing solution in structure. It is difficult to fit
reinforced concrete structure with architecture design.

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Graduation Project: LAKE COMMERCIAL CENTER – Thanh Hoa City
Furthermore, composite material between steel and concrete is also suitable
for high rise building and is studied for a long time in the world. In Vietnam,
however, this kind of structure is not commonly used and has limited studying
and limited application.
 Therefore, based on the above analysis and supply capacity, construction
schedule, local materials, the Lake Commercial Center (21 stories, 70.4 m
high) is suitable with reinforced concrete:
-

Concrete B35: Rb = 195 kG/cm2, Rbt = 13 kG/cm2.

-

Rebar type AIII: Rs = 3650 kG/cm2.

III. SOLUTION FOR SUPPORTING STRUCTURE
1. Basic bearing structure for high rise building
Frame system
This system is created from vertical bars (columns) connecting with
horizontal bars (beams), called “node”. The plane frames are connected to
each other in order to make a space frame.
In order to increase the horizontal rigidity of frame, braces are added at some
span along its height. This component works as a horizontal rigid wall.
Advantages:
Construction method is simple. This system has large space, flexible plan,
and meets all using requirement of the building.
Disadvantages:
The horizontal rigidity of frame is small, so that horizontal load bearing
capacity is low. The beams have big depth that affects to using function and
increases the building’s height. Frame system is suitable for low rise building
(less than 20 stories for reinforced concrete frame)
Wall system
In this kind of structure, plane walls are the main bearing elements. In
building where walls are installed in one direction, the stability of building in
perpendicular direction is ensured by rigid walls.
For high rise building, horizontal load is big so that the wall plates are
designed to bear all horizontal and vertical loads. The horizontal load is
transferred to wall plates through slab system that is absolutely considered as
rigidity in its plane. Therefore, rigid walls work as continuous beams with
high depth of section.

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Graduation Project: LAKE COMMERCIAL CENTER – Thanh Hoa City
Advantages:
By using wall system we can remove the concentration of stress at beamcolumn connection. This system will have torsional rigidity if the walls are
connected to each other. It also has great horizontal load bearing capacity, so
that this system is suitable for building requiring partition space (house,
hotel…).
Disadvantages:
Using space is limited by walls. The walls has high weight, high rigidity so
that the effect of earthquake is big. The buildings will wall system is
commonly less than 20 stories.
Core system
Rigid walls are connected to each other to form a closed (or open) space
frame, call “core”. Core has blank box in shape and receives loads then
transfers them to earth.
Most of the inner space is used for vertical transportation equipment (lift,
staircase), technical pipe system (water pipe, electrical pipe).
The main advantage of this system is its high bearing capacity of horizontal
load and high torsional rigidity. The core works as a big continuous beam
fixed to foundation.
Box system
In this kind of system, slabs are directly supported by walls and do not need
any other inner supporters.
For outside walls (box cover), we use “square grid” method, that means the
distance between columns is small and the horizontal beams have big height.
This diagram is used for high rise building from up to 60 stories.
Space grid with braces is also used to create box cover. The braces can
increase the horizontal rigidity and torsional rigidity of building, and they
can recover the deformation of horizontal beams. This diagram is commonly

used for high rise building with enormous height (more than 80 stories).
2. Bearing structure selection
The features that directly affect to structural solution of building:
The height of the typical storey is small, just 3.3 m. It is needed to pay
attention to slab solution to ensure the clear height.
Columns span is large (9.0 m in longitudinal and 8.4 m in horizontal) so
beams have to over big span. This building is used for office and mall so
brick walls are installed not many.

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Graduation Project: LAKE COMMERCIAL CENTER – Thanh Hoa City
Lift system is located in the center of the building (in longitudinal direction)
combined with escape stairs. Therefore, boundary walls of this area can be
used as core walls.
At two side (in longitudinal direction), walls are installed around the
staircase to increase horizontal load bearing capacity.
Number of storey: 21
Height: 70.4 m
From those above analysis, the Lake Commercial Center seems to be suitable
with frame-core system combined structure.
This kind of structure system creates large spaces, simply architecture
arrangement. Core walls are located at lift and staircase areas. Because this
structure has high flexural rigidity and torsional rigidity so that most of
horizontal load is bear by core walls. Besides, core walls also bear their own
weight.
Walls that are installed at two side of the building contribute to the bearing

capacity of building (in longitudinal direction). They combine with the core to
generate the general torsional rigidity.
Frame system participates to bear vertical loads and a part of horizontal load.
Slab system plays a role of connecting and transferring horizontal load. Depend
on slab structure, columns can be considered to bear horizontal load or not. On
the other hand, brace system or frame-brace system is depended on how the
frame works.
IV. SOLUTION FOR FLOOR
The Lake Commercial Center - 21 stories, 70.4 m high, 3.3m high of typical
level, large column span (9.0 m and 8.4 m), is suitable with the following slab
solutions:
-

Reinforced concrete flat floor with band beam.

-

Pre-stressed reinforced concrete flat floor without beam.

To choose the most feasible alternative, it is needed to analyze both advantages
and disadvantages of each solution.
1. Flat floor – band beam solution
The flat floor – band beam solution is similar to the normal beam-and-slab floor.
The difference is that the architecture requires flat beam to have enough using
space.
On the other hand, for this alternative, we need to reduce the beam depth and
increase the beam wide.

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Graduation Project: LAKE COMMERCIAL CENTER – Thanh Hoa City
Advantages:
The band beam has big wide that help reduce the design span of slab, so that the
depth and weight of slab can be decreased. The deflection of slab is also limited.
With band beam, the frame is more rigid and works as frame-brace diagram.
Column contributes to horizontal load bearing.
Band beam can increase the shear resistant at tip of column. This is extra-over in
compare to other solution (without beam).
The calculation theory of this solution is quite finished – similar to normal
beam-and-slab solution.
Disadvantages:
The construction of slab-beam is quite complicated, especially when installing
formwork -> waste.
For large span building, it is needed to put more secondary beam or increase the
slab depth. This is not convenient at partition position (in office)
The beam reduces the clearance height (because of technical system), especially
in office, supermarket (mall).
2. Pre-stressed slab without beam solution
The main feature of this solution is that reinforced concrete elements will be
initially stressed. Tensile stress appears at all area of element, therefore it will
reduce the tensile stress caused by load in service period.
Advantages:
Benefit of function:
To subject similar load, pre-stressed concrete use less concrete and steel volume
than other solution => reduce floor’s depth.

Figure 2.1.1: Reduce floor’s height

Student: Bui Thanh Dat – Class: 55XE

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Graduation Project: LAKE COMMERCIAL CENTER – Thanh Hoa City
The pre-stressed slab is thin so that number of storey will be increased and the
total height of building will be decreased.

Figure 2.1.2: Reduce height of building
Pre-stressed slab creates large span and is more flexible. The number of columns
decreases and we can easily divide the inner space and install technical system.

Figure 2.1.3: Reduce number of columns
Benefit of investment:
Although the cost of materials is high, the total cost of building with big floor
area and large span will less than that of normal reinforced concrete from 5% up
to 20%.

Figure 2.1.4: Example of benefit for invested cost
Student: Bui Thanh Dat – Class: 55XE

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