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CHAN KH Assessing the Effectiveness of Temporary Works for Hong Kong Construction (6954) FIG Congress 2014 Engaging the Challenges, Enhancing the Relevance Kuala Lumpur, Malaysia, 16 21 June 2014 1 Assessing the Effectiveness of Temporary Works for Hong Kong Construction Chan KH, Hksar, CHINA Key words: Temporary Works, Bamboo Scaffolding, Metal Scaffolding, Suspended Working Platform, Tower Working Platform. Summary Bamboo Scaffolding (BS) is opined as less safe, highly flexible, lower cost and less durable; whilst possessing fewer established rules to follow or to be controlled in comparing with Metal Scaffolding (MS), Suspended Working Platform (SWP) and Tower Working Platform (TWP). BS may consist of hidden defects that exist in its traditional design and structural form; while the other systems are contended as more rigid/controllable and thus results with lower accidental rate; which may be more adopted by major stakeholders. The central aim of this research is to study the various Temporary Works commonly adopted for alteration and addition projects in Hong Kong; and details the comparison between BS, MS, SWP and TWP in respect of their design, statutory requirements, capacity, material properties, construction method, cost, safety, durability, effectiveness, and security to the building occupiers. Quantitative approach by means of questionnaires is adopted, which will be dispatched to major stakeholders like facilities managers, owners, occupiers, contractors, subcontractors, consultants, and relevant professionals. Collected data will be analysed and cross examined to justify the effectiveness of these systems in view of the critical factors like design, statutory requirements, capacity, material properties, construction method, cost, safety, and durability. Thus, a more precise picture would be drawn to gauge the appropriateness of using each system considering its uniqueness, application, special feature and value for money; for further reference by the industry and academia.

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CHAN KH

Assessing the Effectiveness of Temporary Works for Hong Kong Construction (6954)

FIG Congress 2014

Engaging the Challenges, Enhancing the Relevance

Kuala Lumpur, Malaysia, 16 – 21 June 2014

1

Assessing the Effectiveness of Temporary Works for Hong Kong

Construction Chan KH, Hksar, CHINA

Key words: Temporary Works, Bamboo Scaffolding, Metal Scaffolding, Suspended

Working Platform, Tower Working Platform.

Summary

Bamboo Scaffolding (BS) is opined as less safe, highly flexible, lower cost and less

durable; whilst possessing fewer established rules to follow or to be controlled in

comparing with Metal Scaffolding (MS), Suspended Working Platform (SWP) and

Tower Working Platform (TWP). BS may consist of hidden defects that exist in its

traditional design and structural form; while the other systems are contended as more

rigid/controllable and thus results with lower accidental rate; which may be more

adopted by major stakeholders.

The central aim of this research is to study the various Temporary Works commonly

adopted for alteration and addition projects in Hong Kong; and details the

comparison between BS, MS, SWP and TWP in respect of their design, statutory

requirements, capacity, material properties, construction method, cost, safety,

durability, effectiveness, and security to the building occupiers.

Quantitative approach by means of questionnaires is adopted, which will be

dispatched to major stakeholders like facilities managers, owners, occupiers,

contractors, subcontractors, consultants, and relevant professionals. Collected data

will be analysed and cross examined to justify the effectiveness of these systems in

view of the critical factors like design, statutory requirements, capacity, material

properties, construction method, cost, safety, and durability. Thus, a more precise

picture would be drawn to gauge the appropriateness of using each system

considering its uniqueness, application, special feature and value for money; for

further reference by the industry and academia.

CHAN KH

Assessing the Effectiveness of Temporary Works for Hong Kong Construction (6954)

FIG Congress 2014

Engaging the Challenges, Enhancing the Relevance

Kuala Lumpur, Malaysia, 16 – 21 June 2014

2

Assessing the Effectiveness of Temporary Works for Hong Kong

Construction

CHAN KH, HKSAR, CHINA

1. Introduction

In Hong Kong, most buildings are constructed with reinforced concrete structural

frames, using homogenous tiles for external wall finishing; and resulting in cracking,

debonding, spalling and delamination. During such renovation at building façade,

temporary work such as BS, MS, SWP or TWP are required to provide safe access

for carrying out repair, maintenance, demolition and refurbishment works. BS is

commonly used in Hong Kong, yet its accidental rate is high. The Labour

Department (HKSARLD, 2012) summarizes that 31 fatal accidents relate to the

adoption of BS in recent years. Regarding the high fatality rate of “Person Fell From

Height”, proper selection of temporary works and safety set-up should be considered

at the out-set. The possible causes of accidents will be examined hereof, with respect

to the common practice, construction, cost, safety level and statutory requirements of

these temporary works.

Fig. 1 A Double-row bamboo scaffolding with recommended erection standard

CHAN KH

Assessing the Effectiveness of Temporary Works for Hong Kong Construction (6954)

FIG Congress 2014

Engaging the Challenges, Enhancing the Relevance

Kuala Lumpur, Malaysia, 16 – 21 June 2014

3

Fig. 2 Proper working platform of a double-row bamboo scaffolding

Fig. 3 A Metal Scaffolding

CHAN KH

Assessing the Effectiveness of Temporary Works for Hong Kong Construction (6954)

FIG Congress 2014

Engaging the Challenges, Enhancing the Relevance

Kuala Lumpur, Malaysia, 16 – 21 June 2014

4

Fig. 4 Various types of SWP

Fig. 5 Safety eyebolt of SWP

CHAN KH

Assessing the Effectiveness of Temporary Works for Hong Kong Construction (6954)

FIG Congress 2014

Engaging the Challenges, Enhancing the Relevance

Kuala Lumpur, Malaysia, 16 – 21 June 2014

5

Fig. 6 A typical layout of TWP of fixed type

Fig. 7 A Typical layout of TWP of mobile type

CHAN KH

Assessing the Effectiveness of Temporary Works for Hong Kong Construction (6954)

FIG Congress 2014

Engaging the Challenges, Enhancing the Relevance

Kuala Lumpur, Malaysia, 16 – 21 June 2014

6

2. Literature review

Limited researches have been conducted locally regarding how temporary works are

selected in building renovation. Most studies only stress on technical, material

properties, computer modelling and analysis; but seldom on comparing BS, MS,

SWP and TWP. It is crucial to assess the choice of access equipment, statutory

requirement, common practice, application, construction, installation cost, and safety

levels.

BS is one of China’s oldest construction craft skills created some 5,000 years ago. It

is widely used in the construction industry; reasons being economical, convenient for

erection to accommodate in different locations, and facilitate various construction

processes. For renovation works, a double-row BS is commonly adopted. This

scaffolding consists of 2 layers, with the inner layer at 150-300 mm from building

façade (known as finishing scaffolding) while the outer layer at 700 mm from inner

layer (known as working scaffolding). Working platforms are erected between them.

BS scaffolders always start to erect the two main vertical posts. The vertical member

would be tied by 7 mm-wide plastic tapes with horizontal ledgers. Three standards

(vertical members overhung by ledgers not resting on ground or brackets) will be

erected between the main vertical posts. Standards are tied to building facade by 6

mm mild steel bars. Thus a typical bamboo scaffold in 3m lengths with five bamboo

poles is erected with 750 mm spacing between two adjacent standards.

MS works with the same functions as BS. MS is initially used 90 years ago in

London to support the big tents in circus by SGB – Scaffolding Great Britain in 1913,

which are the originators of steel scaffoldings. In Hong Kong, SGB was operating

since 1981 and had supplied and designed formwork and falsework to some

construction projects. MS are normally designed by a structural engineer, based on

the manufacturer’s specifications and complied with BS5973 and BS1139. To ensure

the quality and safety are fully complied with the requirement and standards, an

Independent Checking Engineer is employed to check the design and site control.

SWP is widely used in Hong Kong as gondolas, to carry site personnel or engineers

for working at height during installation of curtain walls and windows, window

cleaning, façade treatment, bridges chimneys, silos and other structures, etc. It can be

classified as permanent or temporary. The COP covers the safety requirements of

these working platforms suspended by ropes, chains, or lifting gear and capable to

the use and operation of the suspended working platforms as well as the related

supporting activities such as test and examination of the suspended working

platforms.

TWP is a rising and descending platform which is mechanically driven along a lattice

mast made of steel. It is not primarily designed for conveyance of persons. TWP is

used as a temporary working place for supporting workers, materials, tools and

equipment for building refurbishment, renovation, repairs and other construction

CHAN KH

Assessing the Effectiveness of Temporary Works for Hong Kong Construction (6954)

FIG Congress 2014

Engaging the Challenges, Enhancing the Relevance

Kuala Lumpur, Malaysia, 16 – 21 June 2014

7

works. It is designed by a structural engineer, constructed by a registered contractor

and examined by a registered examiner per statutory requirements. The installation

of TWP depends on site situations. The mast section will be rested on ground or sit

on steels to support brackets and secured by wall-tie anchorage. The delivery of

materials on the TWP is carried out at ground level. The material is often placed at

table level with a TWP platform. The material can be loaded to the platform with the

assistance of lifting equipment fixed to platform, this procedure permits short

transport distance of heavy material, which means that the body avoids a long and

static loading per COP on Design and Construction of Tower Working Platforms

(HKSARLD, 2012).

In 2011, totally 28,518 industrial accidents are recorded, including 34 fatal cases. Of

these, 9,026 injuries and 28 deaths happen in construction sites. There is a drop of

22.8% in accident figure and 23.5% in accident rate for the year of 2012 (HKSARLD,

2012). In the first three quarters of 2012, a total of 4900 accidents are recorded,

representing a significant drop of 32% when compared with 7200 in the same period

of 2011 (HKSARLD, 2013).

CHAN KH

Assessing the Effectiveness of Temporary Works for Hong Kong Construction (6954)

FIG Congress 2014

Engaging the Challenges, Enhancing the Relevance

Kuala Lumpur, Malaysia, 16 – 21 June 2014

8

2011

9206

28

80302

114.6

4

0.3

49

2010

11925

29

79599

149.8

1

0.3

64

2009

14078

47

70941

198.4

5

0.6

63

2008

19588

56

79007

247.9

3

0.7

09

2007

18559

41

81629

227.3

6

0.5

02

2006

16469

51

76907

219.8

6

0.6

81

2005

15268

63

65611

232.7

0

0.9

60

2004

16422

51

59710

275.0

3

0.8

54

2003

16573

80

56226

294.7

6

1.4

23

2002

18815

48

62232

302.3

4

0.7

71

No. of

Acc

iden

ts

No. of

Fat

alit

ies

*E

mplo

ym

ent

Acc

.rat

e/1000

Work

ers

Fat

alit

y

rate

/1000

Work

ers

*T

he

emp

loym

ent

size

only

cover

s m

anual

work

ers

on c

onst

ruct

ion s

ites

.

Ta

ble

1 In

du

stri

al

Acc

iden

ts i

n C

on

stru

ctio

n I

nd

ust

ry (

2002 –

2011)

CHAN KH

Assessing the Effectiveness of Temporary Works for Hong Kong Construction (6954)

FIG Congress 2014

Engaging the Challenges, Enhancing the Relevance

Kuala Lumpur, Malaysia, 16 – 21 June 2014

9

Over the past 10 years (2002 – 2011), there has been a very significant reduction in

the number of industrial accidents. However, the accidents toll of working-at-height

is still high. In 2011, 9 out of 28 fatal accidents are identified as “person fell from

height” and over 32% construction fatalities occur by such causes. Furthermore, in

2012, 15 out of 24 fatal accidents are caused by falling from height, with 6 cases

involving BS work, being the highest among recent years. When comparing with the

fatality rate in 2011, it rises sharply from 32.1% to 62.5%; which trigger for a

detailed engineering study for BS towards improving the safety.

Type of Accident No. of

Injury

No. of

Fatalities

Fatality

Rate

Trapped in or between objects 175

Injured whilst lifting or carrying 1350

Slip, trip or fall on same level 1741

Fall of person from height 771 9 (15)* 32.1%

(62.5%)*

Striking against fixed or stationary object 1140

Striking against or struck by moving object 2162 2 7.1%

Stepping on object 123

Exposure to or contact with harmful

substance

77

Contact with electricity or electric discharge 29 4 14.3%

Trapped by collapsing or overturning object 36 9 32.1%

Struck by falling object 346 3 10.7%

Struck by moving vehicle 46 1 3.6%

Contact with moving machinery or object

being machined

621

Drowning 1

Exposure to fire 24

Exposure to explosion 6

Injured by hand tool 420

Injured by fall of ground 5

Asphyxiation 0

Contact with hot surface or substance 94

Injured by animal 0

Injured in workplace violence 0

Others 39

TOTAL 9206 28 (24)* 100%

*figures in 2012

Table 2 Industrial Accident in Construction in 2011

In recent years, tragic accidents relate to temporary works, resulting in horrifying

causalities and fatality. There have been 24 fatal accidents in the industry in 2012.

CHAN KH

Assessing the Effectiveness of Temporary Works for Hong Kong Construction (6954)

FIG Congress 2014

Engaging the Challenges, Enhancing the Relevance

Kuala Lumpur, Malaysia, 16 – 21 June 2014

10

Of them, 15 were caused by falling from height, with 6 involving BS. This is the

highest in recent years. Serious accidents may lead to permanent incapacity or even

death of employees. In addition, most temporary works exist for a long period

without any maintenance. The reasons for such failure are:

General design fault.

Lake of proper inspection.

Workers do not follow the rules of safety.

Insufficient knowledge to refusal of safety equipment.

Lack of proper and regular repair and maintenance.

Existence of unauthorized alteration and/or addition.

Turning to legislation, the relationship between legislation, accident rate and

Temporary Works will be examined. Here below is a summary of relevant COP and

Ordinance.

Hong Kong Regulation, Ordinance and

Code of Practice

Areas of Relevance to Temporary

Works

The Construction Site (Safety) Regulations Bamboo Scaffolding, Metal

Scaffolding, Suspended Working

Platform and Tower Working

Platform

The Factories and Industrial Undertakings

Ordinance

Bamboo Scaffolding, Metal

Scaffolding, Suspended Working

Platform and Tower Working

Platform

Code of Practice on Wind Effects, Hong

Kong, 1983

Bamboo Scaffolding, Metal

Scaffolding, Suspended Working

Platform and Tower Working

Platform

The Factories and Industrial Undertakings

(Safety Management) Regulation;

Bamboo Scaffolding, Metal

Scaffolding,

The Occupation Safety and Health

Ordinance

Bamboo Scaffolding, Metal

Scaffolding,

Code of Practice for Metal Scaffolding

Safety

Metal Scaffolding

Code of Practice for Bamboo Scaffolding

Safety

Bamboo Scaffolding

The Factories and Industrial Undertakings

(Suspended Working Platforms)

Regulation

Suspended Working Platform

Code of Practice for the Safe Use of

Suspended Working Platform

Suspended Working Platform

The Building Ordinance Chapter 123 Suspended Working Platform

Factories and Industrial Undertakings Suspended Working Platform

CHAN KH

Assessing the Effectiveness of Temporary Works for Hong Kong Construction (6954)

FIG Congress 2014

Engaging the Challenges, Enhancing the Relevance

Kuala Lumpur, Malaysia, 16 – 21 June 2014

11

(Lifting Appliances and Lifting Gear)

Regulations

Engineers Registration Ordinance

(Cap.409)

Suspended Working Platform

The Builders’ Lifts and Tower Working

Platforms (Safety) Ordinance

Tower Working Platform and

Builders’ Lift

Code of Practice on the Design and

Construction of Tower Working Platform.

Tower Working Platform

Table 3 Ordinance and COP for Temporary Works in Hong Kong

These regulations are established to protect the construction workers; to ensure

minimum standard of health and safety can be kept. Generally, the statutory

requirements of BS are similar to MS which are monitored/supervised by the

HKSAR Labour Department. In respect of its safety standard, contractors must

comply with Construction Site (Safety) Regulation, Occupational Safety and Health

Ordinance, COP for Bamboo Scaffolding Safety, and COP for Metal Scaffolding

Safety.

The Construction Sites (Safety) Regulations (HKSAR, 2012) mainly regulates the

construction and maintenance of scaffolds; erection, alteration and dismantling of

scaffolds by competent workman under the immediate supervision of a competent

person; the inspection of scaffold by competent persons both periodically and after

exposure to weather conditions likely to have altered the strength or stability of the

scaffold; the provisions of safe access to or egress from the scaffolds and the

precautions for preventing falls from the scaffolds. The general duties imposed by

Section 6A of the Factories and industrial Undertaking Ordinance (HKSAR, 2012)

are also important control measures.

3. Research Methodology

Questionnaire is well prepared to collect relevant primary data for critical analysis,

which will be dispatched to major stakeholders like consultants, contractors,

subcontractors, owners, occupiers and facilities managers to solicit their views of

using temporary works regarding:

The degree of acceptance of temporary works, such as BS, MS, SWP and TWP.

The major considerations in selection of temporary works.

The characteristic of various types of temporary works.

How temporary works are adopted in building renovations.

The scores/points given by respondents will be analysed and tabulated to formulate

consolidated opinions/statement respectively.

4. Findings and analysis of questionnaire

CHAN KH

Assessing the Effectiveness of Temporary Works for Hong Kong Construction (6954)

FIG Congress 2014

Engaging the Challenges, Enhancing the Relevance

Kuala Lumpur, Malaysia, 16 – 21 June 2014

12

62 out of 105 number of questionnaires have been received – a 59% response rate, as

tabulated below.

Category of organisation No. of

responses

% of

responses

Facilities Management & Maintenance 28 45%

Building Contractor 13 21%

Plant & Machinery 8 13%

Safety Consultant 4 6.5%

Government Department 4 6.5%

Others 5 8%

Total 62 100%

Table 4 No. of responses to questionnaire

Most respondents have a high recognition towards BS and SWP; moderate to high

recognition for MS; and less recognition to TWP, especially from facilities

management and maintenance (even 18 out of 28, i.e. 64.3% consider low to

moderate recognition for TWP).

1 To what degree you recognize/accept Temporary Works for external wall

renovation?

Highe

st

High Moderat

e

Lo

w

Lowes

t

Points

1.1 Recognition/acceptance of

Bamboo Scaffolding

21 21 15 5 307

1.2 Recognition/acceptance of Metal

Scaffolding

26 26 10 228

1.3 Recognition/acceptance of

Suspended Working Platform

(Gondola)

12 20 25 5 264

1.4 Recognition/acceptance of Tower

Working Platform

7 32 16 7 170

Table 5 Degree of Recognition of Various Temporary Works

According to the survey, the major considerations for external wall renovation are

level of safety to construction workers, installation cost, effectiveness, statutory

requirements, local control and strengths of materials. Less concerned issues are

security to building occupiers, aesthetic, design and construction method.

2 Major considerations for external wall renovation

Strongl

y

Agre

e

Disagr

ee

Strongl

y

Neithe

r

Point

s

CHAN KH

Assessing the Effectiveness of Temporary Works for Hong Kong Construction (6954)

FIG Congress 2014

Engaging the Challenges, Enhancing the Relevance

Kuala Lumpur, Malaysia, 16 – 21 June 2014

13

Agree Disagr

ee

Agree

Nor

Disagr

ee

2.1 INSTALLATION COST 27 25 5 5 334

2.2 LEVEL OF SAFETY 40 20 2 386

2.3 CAPACITY (e.g. Maximum SWL

& Maximum No. of Persons)

15 25 5 12 257

2.4 EFFECTIVENESS 8 52 2 322

2.5 Adequate STATUTOARY

REQUIREMENT OR LOCAL

CONTROL.

10 45 2 5 311

2.6 STRENGTHS of material. 5 53 4 304

2.7 Degree of SOUND DESIGN AND

CONSTRUCTION METHOD.

35 10 1 16 223

2.8 ABILITY to last for a long time

without deformation (e.g. over 6

months)

4 42 6 4 6 270

2.9 AESTHETIC of Temporary Works

in façade

5 24 16 6 11 226

2.1

0

SECURITY to building occupiers 34 12 12 218

Table 6 Major Considerations for Various Temporary Works

Regarding the merits of adopting Bamboo Scaffolding, there are high scores i.e. 270

points in possibility of reducing installation cost and 302 points in effectiveness in

application, which imply that these 2 considerations are crucial for major

stakeholders; as illustrated below.

1 Advantages of using BAMBOO SCAFFOLDING in external wall

renovation

Highes

t

High Modera

te

Low Lowes

t

Point

s

1.1 Possibility of reducing

installation cost

42 20 270

1.2 Level of safety in application 5 16 26 15 223

1.3 Capacity of such temporary

works (e.g. Maximum SWL &

Maximum No. of Persons)

25 26 11 225

1.4 Effectiveness in application 58 4 302

1.5 Adequacy of statutory 5 15 33 10 229

CHAN KH

Assessing the Effectiveness of Temporary Works for Hong Kong Construction (6954)

FIG Congress 2014

Engaging the Challenges, Enhancing the Relevance

Kuala Lumpur, Malaysia, 16 – 21 June 2014

14

requirement or local control.

1.6 Strength of material 11 36 9 5 186

1.7 Degree of sound design and

construction method

23 20 8 10 201

1.8 Ability for extended use without

deformation (e.g. over 6 months)

10 16 14 15 141

1.9 Aesthetic over façade 9 10 20 15 130

1.1

0

Security to building occupiers 4 22 32 4 154

TOTAL 2061

Table 7 Merits of Adopting Bamboo Scaffolding

Six considerations achieve high score (above 254 points), i.e. level of safety in

application, capacity of Temporary Works, adequacy of statutory requirement or

local control, strength of material, degree of sound design & construction method,

and ability for extended use without deformation; which imply that these 6

considerations are crucial in adopting Metal Scaffolding for major stakeholders; as

illustrated below.

2 Advantages of using METAL SCAFFOLDING in external wall renovation

Highe

st

High Modera

te

Low Lowes

t

Point

s

2.1 Possibility of reducing installation cost 5 10 35 12 214

2.2 Level of safety in application 11 42 9 314

2.3 Capacity of such temporary works. (e.g.

Maximum SWL & Maximum No. of

Persons)

6 46 5 287

2.4 Effectiveness in application 6 21 32 3 249

2.5 Adequacy of statutory requirement or

local control

40 21 1 265

2.6 Strength of material 16 44 2 338

2.7 Degree of sound design and construction

method

6 22 34 254

2.8 Ability for extended use without

deformation (e.g. over 6 months)

6 38 10 5 272

2.9 Aesthetic over façade 15 30 10 185

2.1

0

Security to building occupiers 5 20 20 9 5 218

TOTAL 2596

Table 8 Advantages of Using Metal Scaffolding

CHAN KH

Assessing the Effectiveness of Temporary Works for Hong Kong Construction (6954)

FIG Congress 2014

Engaging the Challenges, Enhancing the Relevance

Kuala Lumpur, Malaysia, 16 – 21 June 2014

15

Three considerations achieve high scores (above 253 points) i.e. possibility of

reducing installation cost, strength of material and security to building occupiers;

which imply that these 3 considerations are crucial in adopting SWP for major

stakeholders; as illustrated below.

3 Advantages of using SUSPENDED WORKING PLATFORM (GONDOLA) in

external wall renovation

Highe

st

High Modera

te

Low Lowes

t

Points

3.1 Possibility of reducing installation cost 10 16 31 5 253

3.2 Level of safety in application 10 20 11 21 245

3.3 Capacity of such temporary works. (e.g.

Maximum SWL & Maximum No. of

Persons)

5

30 16 10 167

3.4 Effectiveness in application 6 21 21 10 230

3.5 Adequacy of statutory requirement or

local control

31 31 248

3.6 Strengths of material 5 32 20 5 265

3.7 Degree of sound design and construction

method

30 28 4 242

3.8 Ability for extended use without

deformation (e.g. over 6 months)

5 20 20 11 5 222

3.9 Aesthetic over façade 6 20 20 5 5 217

3.1

0

Security to building occupiers 15 10 27 10 256

TOTAL 2345

Table 9 Advantages of Using Suspended Working Platform

Eight considerations achieve high scores (above 252 points) i.e. level of safety in

application, capacity of such Temporary Works, adequacy of statutory requirement

or local control, strength of material, degree of sound design and construction

method, ability for extended use without deformation, aesthetic over facade and

security to building occupiers; which imply that these 8 considerations are crucial in

adopting TWP for major stakeholders; as illustrated below.

4 Advantages of using TOWER WORKING PLATFORM in external wall

renovation

Highes

t

High Modera

te

Low Lowes

t

Points

4.1 Possibility of reducing installation

cost

5 35 16 6 178

4.2 Level of safety in the application 14 32 16 306

CHAN KH

Assessing the Effectiveness of Temporary Works for Hong Kong Construction (6954)

FIG Congress 2014

Engaging the Challenges, Enhancing the Relevance

Kuala Lumpur, Malaysia, 16 – 21 June 2014

16

4.3 Capacity of such temporary works

(e.g. Maximum SWL & Maximum

No. of Persons)

16 16 25 5 277

4.4 Effectiveness in application 23 36 3 229

4.5 Adequacy of statutory requirement or

local control

7 26 29 266

4.6 Strengths of material 11 28 23 286

4.7 Degree of sound design and

construction method

7 42 10 3 295

4.8 Ability for extended use without

deformation (e.g. over 6 months)

6 22 32 2 252

4.9 Aesthetic over façade 7 31 14 5 5 261

4.1

0

Security to building occupiers 6 25 26 5 255

TOTAL 2605

Table 10 Advantages of Using Tower Working Platform

There seems a dilemma of the respondents’ perceptions, as the findings of individual

total point scores (Table 7-10) appear different with the overall judgement (Table 5-

6) of each temporary works. Most respondents reckon that the overall performance of

TWP is better than MS, while MS performs better than SWP, and SWP is better than

BS (Table 7-10). However, most respondents opine that BS is most popular and

highly recommended for external wall renovation in view of its lower cost, flexibility

and effectiveness (Table 5-6); even though they place significantly high scores in

other factors other than lower cost, flexibility and effectiveness. That’s reality, as in

Hong Kong situation. In addition, the recognition of TWP is low to moderate.

6. Conclusion and recommendation

The essential factors in appropriate selection of Temporary Works for external

renovation and its effectiveness are assessed in this study. There is no best

Temporary Work being recognized for external wall renovation. The merits and

demerits of each available Temporary Work need to be assessed critically prior to

selection and project commencement.

BS is a traditionally accepted trade in Hong Kong construction industry. Its structural

performance cannot be ascertained precisely. Thus, the quality of workmanship is

vital to ensure its rigidity and stability; also for enhancing safety for the workers and

public at large (avoid free falling objects/materials). From this perspective, BS

contractors are suggested to exercise better control upon selecting the raw materials

of bamboo and timber poles before erection.

CHAN KH

Assessing the Effectiveness of Temporary Works for Hong Kong Construction (6954)

FIG Congress 2014

Engaging the Challenges, Enhancing the Relevance

Kuala Lumpur, Malaysia, 16 – 21 June 2014

17

Working within a congested area like BS will have a greater chance of injury, as

workers need to bend his back or stretch himself to fulfill his works e.g. brick laying.

A TWP can eliminate this problem, as it can be adjusted vertically to allow working

comfortably. It can also shorten the construction programme, as workers save time to

perform his works (e.g. repairing, plastering or painting can be done continuously),

and thus reduce labour and rental costs. Falling of workers/objects and slippery of

workers are also crucial, which result from poor workmanship upon erecting BS. The

respondents contend that a TWP can improve safety in this aspect.

To curb the above respective problems, a new scaffolding system is evolved in the

market – Metal-Bamboo Matrix System Scaffold (MBMSS) that combine the

benefits of BS and MS; comprising 60% steel popes and 40% bamboo poles. The

steel popes serve as main poles/ledgers to support the principal loading; thus enhance

the scaffolding’s stability, security and reliability; whilst the bamboo poles reduce

the scaffolding’s total weight and increase the system’s flexibility. Further studies

may be carried out to compare it with other scaffolding systems pursuant to the

findings from this research.

Reference

Hong Kong Special Administrative Region Labour Department (HKSARLD,

2012), Occupational Safety and Health Statistics Bulletin, Occupational Safety and

Health Branch, Hong Kong.

Hong Kong Special Administrative Region Labour Department (HKSARLD,

2012), Accident Statistics for 2011 and the Ten-Year Trend, Occupational Safety

and Health Branch, Hong Kong.

Hong Kong Special Administrative Region Labour Department (HKSARLD,

2012), Green Cross, Occupational Safety and Health Branch, Hong Kong.

Hong Kong Special Administrative Region Labour Department (HKSARLD,

2012), Code of Practice for Bamboo Scaffolding Safety, Occupational Safety and

Health Branch, Hong Kong.

Hong Kong Special Administrative Region Labour Department (HKSARLD,

2012), Code of Practice for Metal Scaffolding Safety, Occupational Safety and

Health Branch, Hong Kong.

Hong Kong Special Administrative Region Labour Department (HKSARLD,

2012), Code of Practice for Safe Use and Operation of Suspended Working

Platforms, Occupational Safety and Health Branch, Hong Kong.

Hong Kong Special Administrative Region (HKSAR, 2012), Construction Site

(Safety) Regulations, Hong Kong.

Hong Kong Special Administrative Region (HKSAR, 2012), Factories and

Industrial Undertakings Ordinance, Hong Kong.

Hong Kong Special Administrative Region (HKSAR, 2012), Factories and

Industrial Undertakings (Safety Management) Regulation, Hong Kong.

Hong Kong Special Administrative Region (HKSAR, 2012), Factories and

Industrial Undertakings (Suspended Working Platform) Regulation, Hong Kong.

CHAN KH

Assessing the Effectiveness of Temporary Works for Hong Kong Construction (6954)

FIG Congress 2014

Engaging the Challenges, Enhancing the Relevance

Kuala Lumpur, Malaysia, 16 – 21 June 2014

18

Hong Kong Special Administrative Region (HKSAR, 2012), Factories and

Industrial Undertaking (Lifting Appliance and Lifting Gear) Regulation, Hong

Kong.

CONTACT

CHAN KH

KH Consultancy

Hong Kong

Tel. +85278912991

Email: [email protected]

© KH 10.13