Apartment 12 stories basic design report

INTRODUCTION This basic design report has been prepared on the basis of identifying the criteria, assumptions, design data, feasible structural options and design approach for the selec

HOI AN SOUTH DEVELOPMENT LIMITED

NKC CONSULTANCY CO LTD

NOVEMBER 2017

STRUCTURAL BASIC

DESIGN REPORT

STRUCTURAL, INFRASTRUCTURE &

MEPF DESIGN SERVICES

Email: consulting.engineer@nkc.com.vn

Approved by:

Dr Vinh Tran – Chairman Date: 11 / 2017

INVESTOR

HOI AN SOUTH DEVELOPMENT LIMITED

Duy Hai Commune – Duy Xuyen District

Quang Nam Province

GENERAL DIRECTOR

CONSULTANT

STRUCTURAL, INFRASTRUCTURE &

MEPF DESIGN SERVICES

A1-00.01 Complex M1,

74 Nguyen Co Thach, An Loi Dong Ward,

District 2, Ho Chi Minh City Tel:+(84.8) 3744 6801; Fax:+(84.8) 3744 6851

Email:consulting.engineer@nkc.com.vn

Website:www.nkc.com.vn

CHAIRMAN

Dr VINH TRAN

SUMMARY OF ISSUES

APPENDICES

APPENDIX E TYPICAL PILE CAP DESIGN

APPENDIX F TYPICAL TIE BEAM DESIGN

APPENDIX G TYPICAL FLOOR SLAB DESIGN

1 INTRODUCTION

This basic design report has been prepared on the basis of identifying the criteria, assumptions, design data, feasible structural options and design approach for the selection of the optimum option for the development of next phase of the project

2 THE PROJECT

2.1 Project Description

This project is titled as “Staff Village”, located in Duy Hai Commune, Duy Xuyen District, Quang Nam Province, Viet Nam The development consists of 6 tower in which 2 towers have 8 storeys, 4 towers having 9 storeys, and a two-storey main building for administration and facilities

2.2 Partners

Design & Build Contractor Cofico Construction Joint Stock Company No 1 C&S and MEP Consultant NKC Consultancy Co Ltd

3 STANDARDS FOR STRUCTURAL DESIGN

3.1 Applicable Codes and Standards

The project shall be designed based on Vietnamese standards for all structural elements except columns and core wall are designed based on Eurocodes standards

Structural Design Standards

Standards For Design of Reinforcement Concrete Structures TCVN 5574: 2012 Piled Foundations – Vietnamese Design Standard TCVN 10304 : 2014

3.2 Computer Programs

The following computer programs will be used for the analysis and design of the structure:

ETABS Version 13.1.2 Analysis of general space structure

SAFE Version 12.3.1 Analysis and Design of foundation

PLAXIS Version 8.0 Analysis and Design of diaphragm wall

Excel spread sheet Design of reinforced concrete elements

ADSEC Version 8.0 Design of reinforcement for columns/ walls

4 GEOTECHNICAL DATA

4.1 Introduction

This report establishes the general basis for the geotechnical design of the project

The design criteria, design assumptions, design data and analysis methodology for the geotechnical design of the project is identified This report will form part of the guideline and control document for the detailed design and analysis of the porject which will be developed later on

4.2 Borehole Location Plan

Total of 5 boreholes In which, the boreholes CBH20 to CBH24 are depth 80m, it is necessary for the extraction of soil samples and execution of tests

4.2.1 Borehole Log

Summary below is the illustrated composition of the borehole log CBH20 to CBH24 as recorded in the Soil Investigation Report prepared by South Branch of Vietnam Institute for Building Science and Technology untertaken in September 2016

BOREHOLE LOG LOCATION LAYOUT

BOREHOLE LOG SECTION CBH20 TO CBH24

4.2.4 Geotechincal Parameters

The principle geotechnical parameters considered most appropriate for use in the geotechnical

design of this project are summarised in Table below

5 FOUNDATION DESIGN

5.1 Proposed Foundations

The proposed foundation systems is the precast prestressed circular piles with the diameter of 400mm

to provide the support for the lift core walls and the columns/shear walls of the buildings

The isolated columns/ shear walls of the building are supported by isolated pile caps with 2 or more piles The isolated pile caps are connected and stabilised by the orthogonal tie beams system

Loading from the upper floors are transferred to the columns/shear walls and the walls systems, from wihich they are in turn transferred down to the pile caps and hence to the ground via the friction and end bearing capacities of the piles

PILE CAPS AND TIE BEAMS LAYOUT

7 9' 9 10 11 11' 12 13 14 15

8

3D PILE CAP MODEL

5.2 Design Limit states

Piles and foundations shall be based on two limit states, namely Limit states 1 and 2 as below:

Limit State 1: includes calculations

+ Ultimate capacity of pile follow soild strength

+ Ultimate Capacity of pile and pile cap follow pile material

+ Stability of bored pile and pile cap

Basic load combination and special load combination (seimic load, wind load ) shall be applied in Limit sate 1

Limit State 2: includes calculations

+ Settlements of bored pile and foundation

+ Transverse displacement of pile and foundation

+ Formation and development crack of pile and pile cap

Basic load combination and service load combination shall be applied in limit state 2

5.3 Design Methodology

The design methodology used to determination of the load capacity of the bored piles and

diaphragm wall panels will be based on Vietnamese Standard TCVN 10304: 2014 The site

supervision work, control the entire construction process and workmanship have also been

addressed in the design

5.4 Analysis of Differential Settlement

Differential settlement has often caused damages to the structures and the remedial works have often mounted to very figures and difficulties Therefore estimation and overcome the possibility of differential settlement is necessary rightaway during the design period Differential settlement can be overcome by the following methods:

 Foundations must be appropriately designed to ensure the settlements of the foundations are comparable

 Relatively even distribution of building weight on plan

 Use deep foundation technique to transfer loads into the good soil layers, this would minimise the foundation settlements

 Design of the superstructure to be flexible in order to cater for certain amount of differential settlement, if occurs

 Provide additional reinforcement at locations where the differential settlement is likely to occur

7 9' 9 10 11 11' 12 13 14 15

8

6 LATERAL STABILITY SYSTEM - COLUMNS / STAIR WALLS

Lateral stability of the building is provided by a Columns–Stair walls System The system consists of reinforced concrete stair walls and columns which are mostly located on orthogonal axes The stair walls are located around the staircase shafts to form the end-core system and the columns are located around the perimeter and along the central corridor of the building Refer to relevant structural drawings for further details In order to optimise the design, columns/walls are designed such that their sizes reducing with height, however the ease of construction dictates that there should be many changes in columns/walls dimensions within the building, therefore the columns/ walls are arranged into zones, within each zone the columns/walls sizes are unchanged

Stair walls are linked by spandrel beams, which are arranged above the location of door openings Spandrel beams are very important in terms of distribution of forces between the walls The size of spandrel beams must be arranged such that to be appropriate with architectural and services system’s requirements

7 SUPERSTRUCTURE DESIGN

7.1 Level 1 Floor to Roof

Based on the architectural drawings in terms of layout and spacing between columns, the structural system for the ground floors is traditional reinforced concrete beam/ slab system This floor consists of pile caps having depth of 1000mm, tie beams having dimensions of 500X700mm The slab thickness is 200mm sitting on top of 100mm blinding concrete

Dead load and live load from the floors above will be transmitted to the stair walls and columns system This vertical structural system is mainly reinforced concrete structure will in turn transmit the floor loading

to the foundations

Finishes inside the ground floor, in general, to be 50mm for the floors and the toilet areas, a step down

of 50mm is provided in the toilet areas

General arrangement of a typical floor for level 2 to roof is shown as below.General arrangement of a typical ground floor is shown as below

Floor Level (FFL)

Floor height Column size Core wall

7 9' 9 10 11 11' 12 13 14 15

8

7 9' 9 10 11 11' 12 13 14 15

8

7 9' 9 10 11 11' 12 13 14 15

8

8 STRUCTURAL DESIGN DATA

8.1 Design Loadings

8.1.1 Gravity load

The dead load which includes the self-weight of the structure and super imposed dead load (finishes,

partition and services) will be assessed based on the Architect’s specification

8.1.2 Live Load and Finishes

Based on TCVN 2737: 1995 and tabulated in details in Appendix B for each area based on functional

requirements

Live load reduction

Live Loads on Horizontal Elements

For load items 1-5 in Table 3 of TCVN 2737, live load on horizontal elements, such as floor slabs main

and secondary beams, may be reduced by a factor below:

1 1

6 0 4 0

A / A

.

A > A2 = 36m2)

2 2

5 0 5 0

A / A

.

For load items 1-5 in Table 3 of TCVN 2737, live load on vertical elements, such as columns and

walls, and foundation may be reduced by a factor below:

8.1.3 Effect of Temperature Changes

Thermal Coefficient of concrete: 1.0x10-5/ oC

Change in outside temperature: 15 oC

The effect of temperature changes can be directly analysed by Etabs computer program via the

material properties, and can be disregarded for this building

8.1.4 Wind load

Wind load to be calculated based on:

TCVN 2737 -1995: Design loadings and Impacts

TCXD 229 - 1999: Guideline for the calculation of the Dynamic Component of the Wind Loads

Wind Load = Wind Coeff x Design Wind Pressure x Frontal area Based on TCVN 2737, wind load consist of two components, namely static and dynamic The

derivation of these two components are illustrated below:

Static Component:

The standard value of the static component of wind load W at height Z from the base level is

determined from the following formula:

w = wo x k x c

in which:

wo - Values of wind load determined from the zoning map in Appendices D, E and F of TCVN

2737 The value of Duy Xuyen District, Quang Nam province is taken as 0.95 kPa (category B) as in Table 4 of TCVN 2737.

II-k - Coefficient involving changes in height of wind pressure as stipulated in Table 5 of TCVN 2737

(Terrain type: A- Open terrain, with no onstructions higher than 1.5m (coasts, large fields without plants, lake surfaces, etc.)

c - Coefficient for aerodynamic effect as derived in Table 6 of TCVN 2737 and is taken as 1.4.

Dynamic Component:

Dynamic component of wind load have to be included in the wind load calculation where the building

exceeds the 40m in high (Cl 6.2 of TCVN 2737) In addition, for high rise and slender structures,

aerodynamic instability has to be checked

Limit value of vibration frequency f1 (Table 9 of TCVN 2737)

f1 = 0.3 (RC structure)

fL = 1.3Hz (Wind pressure zone II)

Where frequency of fundamental mode f1 is less than the limit value of vibration frequency fL (Cl 6.13.3

of TCVN 2737):

Wp(ji) = Wj x ξi x i x yji Where:

Mj - Concentrated mass of the jth floor of the structure, tonnes;

ξi - Dynamic coefficient corresponding to the ith mode of vibration and the parameter derived from

Figure 2 of TCVN 2737;

γ - Reliability coefficient of wind load;

Wo – Wind pressure (N/mm2)

f1 – Frequency of the fundamental mode of vibration

yji – Transverse displacement of the centre of gravity of the jth floor diaphragm of ith mode of

vibration;

WFj - Standard value of the dynamic component of the wind load on the jth floor, corresponding to

different modes of vibration, kN:

WFj = Wj x ξi x ξj x 

 - For the first mode of vibration,  = 1, whilst for other modes of vibration,  = 1;

Sj - Windward area of jth floor (m2);

ξi - Dynamic pressure coefficient at height Z from the base level as stipulated in Table 8 of TCVN

2737.

For detailed provisions of the ablove calculation procedure, refer to Cl 4.3 to 4.5 of TCXD 299: 1999

The corrective coefficient for building structures with a design life of 100 years is taken as 1.37 in

accordance with Table 4.3 of QC 02: 2009

Combination of the Static and Dynamic components

The internal forces and displacements derived according to the above procedures shall be combined

in accordance with the following formula (Cl 4.12 of TCXD 229):

Where:

X - moment, shear force, axial force and displacement;

X1 - moment, shear froce, axial force and displacement inducd by the static component of the wind

load;

moment, shear force, axial force and displacement induced by the dynamic component of the wind load in the ith mode of vibration;

s - number of modes of vibration

Coefficient of correction for design life more than 100 years has been taken as 1.37 as below

(according to QC 02: 2009 BXD)

8.1.4.1 Displacement Limitation at Top of Building

Requires for the column/wall system, the maximum displacement at the top of the building is H/500,

where H is the building height

Total displacement at the top of the building from the analysis model:

Since f < [ f ]  Satisfy the displacement limitation at top

8.1.4.2 Storey Drift Limitation

Storey Drift Limitation = dr/hs ≤ 1/500 (Clause C5.4 – TCVN 5574: 2012)

in which h is the floor height

Tables below shows the comparison between actual calculated storey drifts for various storey heights:

Story Load Point Item Drift (dr/hs) X (mm) Y Z Check

Story Load Point Item Drift (dr/hs) X (mm) Y Z Check

Story Load Point Item Drift (dr/hs) X (mm) Y Z Check

Story Load Point Item Drift (dr/hs) X (mm) Y Z Check

8.1.5 Seismic load

Seismic design based on TCVN 9386: 2012

From Appendix H, peak ground acceleration: agR = 0.0263g (Duy Xuyen District, Quang Nam

Province)

Extract from TCVN9386-2012 below indicate that in the vicinity of the staff village site the ground

acceleration is less than 0.04g, therefor, there is no need to design the structure subjected to seismic

8.1.6 Structural Data Check

8.1.6.1 Overturning Stability Check

Coefficient of safety against overturning FoS = Mr / M over > 1.5 (TCXD 198: 1997 Clause 2.6.3)

Stabilising Moment Mr

Overturning Moment M over

Table calculates overturning stability about axes X& Y:

Calculation of Stability against wind

Factor of safety against overturning

FoS = Mr / M over = 5680411 / 29334 = 193.64 > 1.5 OK

Factor of safety against overturning

Moment overturning Direction OX (KNm) Story

Floor

elevation

(m)

Story height (m)

Dead Load (KN)

X Centre of Mass (m)

1 Story Cumulative 1 Story Cumulative

(KN)

Moment overturning Direction OY (KNm) Story

Floor

elevation

(m)

Story height (m)

Dead Load (KN)

Y Centre of Mass (m) dx (m)

FoS = Mr / M over = 1207942 / 133865 = 9.02 > 1.5 OK

LOCATION OF CENTRE OF MASS

8.1.7 Summary of Design Criteria

Stability against

overturing Wind–Y: Coef of Safety = 9.02

> 1.5 (TCXD 198: 1997 Item 2.6.3)

Storey drift due to

Period

Mode 1, T = 1.906s, i.e f = 0.525 Hz Mode 2, T = 1.496s, i.e f = 0.668 Hz Mode 3, T = 1.169s, i.e f = 0.855 Hz

8.2.2 Reinforcement

Reinforcement will be either hot rolled high yield or mild steel to Vietnamese strandard

Locally produced based on JIS G 3112 – 1991 or equivalent quality:

High yield steel CB500

fy = 500 N/mm² (10 < đường kính <= 18 mm), ký hiệu T Mild steel CB250

fy = 250 N/mm² (đường kính <= 10 mm), ký hiệu R

8.2.3 Concrete cover

Fire Resistance Period (FRP) will be referred to the architectural drawings and the design of structural

elements will ensure that sufficient concrete cover will be provided to meet the required FRP The cover

the the outermost reinforcing bars are shown on Table below:

Concrete cover to the edge of the main rebar(mm) (Based on section, 5.3, 5.4 of EN1992: 2004 and Appendix F of QCVN 06: 2010/BXD)

Minimum cover to reinforcement shall be the values as shown in the above table or the bar diameter

whichever is the greater one

Minimum cover to reinforcement of element cast directly against soil to be 50mm

Cover to bottom reinforcement of pile cap to be 100mm

Minimum cover to reinforcement of water tank element or watertight construction to be 40mm

8.3 Load cases and load combinations

The following load cases and load combinations shall be used for the design of structural elements:

SDL: Super Dead load

LL: Live load all level except commercial carpark area

LL1: Live load apply for commercial carpark area

Wx Wind load in X-direction

Wxx Wind load in –X-direction

Wy Wind load in Y-direction

Wyy Wind load in –Y-direction

8.4 Load combinations

8.4.1 Load combinations for columns/ walls

EN 1992:

2004 Eurocode – Basis of Structural Design

8.4.2 Load Combinations for other elements

Combinations of forces for the design other elements such as beams, slabs, pile caps, pile reactions

and pile reinforcement

TCVN 2737:1995

APPENDIX A - BUILDING STOREY PARAMETERS

Floor Level (FFL)

thickness

Finishes Structural

Slab Level (SSL)

Column size wall Thick Core wall

APPENDIX B - FLOOR LOADING

Khu vực / Area Cấu tạo / Structure

Dày / thickness (mm)

Tĩnh Tải / Dead load (KN/m 2 )

Hoạt Tải / Live Load (KN/m 2 )

Trần treo / Hanging Ceiling

Trần treo / Hanging Ceiling

TẢI TƯỜNG - WALL LOADING

Tường xây 100 / Wall 100 THK

Tường xây 200 / Wall 200 THK

1.803.60

APPENDIX C - 3D ANALYSIS MODEL

APPENDIX D - WIND LOADING

APPENDIX E - TYPICAL PILE CAP DESIGN

LEVEL 1 FLOOR PLAN