Earthwork Activities in Private Housing Industry
LAM YUEN SIONG
A project report submitted in partial fulfilment of the requirement for the
award of the degree of Master of Science (Construction Management)
Faculty of Civil Engineering
Universiti Teknologi Malaysia
NOVEMBER 2005
iv
For my loving wife, Ho Chee Peng, and daughters
Christine, Stephanie, Odelia and Gene….
v
ACKNOWLEDGEMENT
My special thanks and sincere gratitude to my supervisors, Assoc. Prof.
Aziruddin Ressang and Mr Bachan Singh, for their wise counsel and professional
comments and suggestions throughout our discussion has been a potent source of
inspiration. Their constant encouragement and able guidance without which it would
not have been possible for me to achieve this master project.
I whole heartedly thank all the academic and non-academic staff of the School
of Post Graduate Studies and the Civil Engineering Post Graduate Office of
University Teknologi Malaysia.
I am very grateful to all the respondents who participated in this study and
help me realize this master project, for it would not have been possible without all of
your contribution.
I also wish to thank Jasin Construction Development Sdn. Bhd. for allowing
me to conduct my study in one of their project without which I would not be able to
complete this study.
Last but not least I wish to thank my dear wife, Ho Chee Peng, and my
obedient and understanding daughters, Christine, Stephanie, Odelia and Gene who
unfailingly offered comfort and love throughout my studies.
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ABSTRAK
Kejayaan dan kegagalan sesebuah projek perumahan bergantung kepada
aktiviti kerja tanah kerana aktiviti kerja tanah adalah aktiviti pertama dalam projek
perumahan. Dalam pelbagai situasi, keadaan yang tidak dapat diramalkan boleh
mempengaruhi anggaran perlaksanaan serta output jentera menyebabkan tempoh
aktiviti sebenar lebih panjang daripada tempoh perancangan. Tujuan kajian ini adalah
untuk mengkaji operasi pemindahan tanah dalam projek perumahan, mengkaji kadar
penghasilan permindahan tanah dalam projek perumahan, mengenalpasti masalah
yang dihadapi oleh pihak kontraktor semasa aktiviti permindahan tanah dan untuk
mengenalpasti faktor-faktor yang mempengaruhi harga tender kontraktor. Data
dikumpul dari organisasi pembinaan melalui soal selidik. Data yang diperolehi
dianalisa dengan kaedah indeks purata. Perbandingan pengeluaran pemindahan tanah
menggunakan kitaran purata masa berdasarkan kepada jadual anggaran permindahan
tanah dan kajian masa dan pergerakan yang dijalankan di tapah bina dilakukan. Hasil
kajian didapati secara am, prosedur kerja tanah bagi projek perumahan tidak
mengambil berat tentang persekitaran dan kawalan kualiti, meyebabkan kerja kerja
pemindahan tanah tidak mengikut spesifikasi piawai JKR. Tiada perbezaan yang
ketara bagi pengeluaran permindahan tanah di antara jadual anggaran pemindahan
tanah berbanding dengan kajian masa dan pergerakan semasa pembinaan. Masalah
dihadapi oleh kontraktor berpunca daripada keputusan klien dan kepastian asas
pelantaran akhir projek, rekabentuk daripada perunding dan maklumat ukur tanah
yang tidak tepat. Harga tender kontraktor dipengaruhi oleh reputasi klien untuk
membayar serta kelarasan penjualan rumah oleh klien.
vii
ABSTRACT
The success and failure of a housing project depends on the earthwork
activities as it is the first activity in any housing development project. In many
instances, many unforeseen circumstances that affect the estimates of plant
performance, output, and hence the duration of activities, fall short of the actual
situation once construction start. The purpose of this study is to study the
earthmoving operation in a private housing development project, to study the
earthmoving production in a private housing development project, to identify the
problems faced by the contractors during the earthmoving activities and to identify
the factors that influence the contractors pricing during bidding. Data was gathered
from the local construction organizations by means of a survey questionnaire which
was further analyzed using the average index computation to portray the ranking of
the associated factors. A comparison of earthmoving production using the average
cycle time based on earthmoving production estimating table and the motion and time
study conducted at one of the project site. The finding revealed that generally
earthwork procedure for private housing project does not emphasize on the
environmental and quality control and thus the works carried out do not follow the
standard JKR specification. It was apparent that there is not much variation from the
earthmoving production estimating table for the excavator cycle time as compare to
the excavator cycle time from the motion and time study during construction. The
main problems that the contractor faced stem from the client’s decision and
confirmation on the final platform levels of the projects, the design provided by the
consultant and the inaccurate survey information. The final pricing during bidding
was highly influence by the client’s reputation to pay and the financial status which
normally depends on the sale of the houses built.
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TABLE OF CONTENTS
CHAPTER TITLE PAGE
CHAPTER I INTRODUCTION
1.1 Introduction 1
1.2 Background of study 4
1.3 Statements of problem 7
1.4 Objective of study 8
1.5 Scope of study 9
1.6 Significant of research 9
CHAPTER II EARTHMOVING IN HOUSING PROJECT
2.1 Introduction 11
2.2 Setting out 12
2.3 Erosion control 13
2.4 SITE CLEARING 14
2.4.1 Removal of structures, trees, bushes, etc 14
2.4.2 Removal of stumps, roots, etc. 14
2.4.3 Top soil 14
2.4.4 Disposal of Material 15
2.5 EXCAVATION 15
2.5.1 General 15
2.5.2 Over Excavation 16
2.5.3 Removal of Excavated Material From Site 16
ix
2.5.4 Removal of Unsuitable Material 17
2.5.5 Excavation of Rock 17
2.5.6 Storage and Handling of Explosives 18
2.5.7 Blasting 18
2.5.8 Safety Measures 19
2.5.9 Insecure Material 19
2.6 EMBANKMENTS 20
2.6.1 General 20
2.6.2 Material 20
2.6.3 Placement of Fill Material 20
2.6.4 Rock Fill Embankment 21
2.7 COMPACTION 22
2.7.1 General 22
2.7.2 Compaction Trials 22
2.7.3 Degree of Compaction 23
2.7.4 Moisture Control 23
2.7.5 Rock Fill Compaction 24
2.7.6 Confined area 24
2.7.7 Dewatering and Drainage 24
2.7.8 The Permitted Deviations for General Site
Excavation / Filling Level and Slope Surface.
25
CHAPTER III ESTIMATING AND TENDERING
EARTHWORKS IN HOUSING PROJECT
3.1 Introduction 26
3.2 Methods Of Obtaining Tenders And Types Of Contract 27
3.3 The Importance of The Estimate 31
3.3.1 The Estimate and the Tender 31
3.3.2 Tender Evaluation 32
3.4 Bidding Strategy 33
3.4.1 Factors to Be Considered While Making Out 33
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Analysis for a Project
3.4.2 Preplanning 35
3.5 Method of Estimating 36
3.5.1 A Queuing Analysis 37
3.5.2 The Waiting Line Theory 38
3.5.3 Earthmoving Production Estimate From
Production Table
40
3.5.4 Construction Schedule 42
CHAPTER IV EARTHMOVING EQUIPMENTS, SELECTION,
MATCHING AND PRODUCTION OUTPUT
4.1 Introduction 43
4.2 Types of Earthworks Equipment Used in Housing
Project
44
4.2.1 Bulldozers 44
4.2.2 Excavators 45
4.2.3 Trucks 45
4.2.4 Scrapers 46
4.2.5 Motor graders 47
4.2.6 Earth Compactor 47
4.3 Earthmoving Production Estimate, Sizing And
Matching
48
4.3.1 Procedure for Equipment Design 48
4.3.2 Cycle Time 49
4.3.3 Corrections To Cycle Time 50
4.3.4 Production Estimates for Excavators And
Sizing Of Hauling Units
51
4.3.5 Time and Motion Studies on Earthmoving
Production
51
4.3.6 Sizing And Matching of Hauling Units 54
4.4 Job And Management Factors on The Output Rate 56
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4.4.1 The Effect of Job Conditions on The Output
Rate
57
4.4.2 The Effect of Management Conditions on The
Output Rate
58
CHAPTER V
METHODOLOGY OF STUDY
5.1 General 60
5.2 Methodology Approach 61
5.2.1 Literature Review 61
5.2.2 Identifying problem statement 62
5.2.3 Survey Questionnaire 62
5.2.4 Time and Motion Recording Sessions 63
5.2.5 Interviews 63
5.2.6 Compilation of Findings, Analyses and
Conclusion
63
5.3 Methodology Work Flow and Time Frame 65
CHAPTER VI DATA ANALYSIS
6.1 General 68
6.2 Earthwork activities in a housing projects 76
6.2.1 Operation of earthmoving activities 76
6.2.2 Time and Motion Study 79
6.2.3 Significant problems that the contractor faced
during the earthmoving activities
82
6.2.4 Method of obtaining tenders 84
6.2.5 Factors that influence the pricing during
bidding
85
6.2.6 The project site detail information need to 87
xii
consider during tendering
CHAPTER VII CONCLUSION AND RECOMMENDATIONS
7.1 General 89
7.2 Earthwork activities in a housing project 90
7.3 General Conclusion 93
7.3.1 Earthmoving Operation in a Housing
Development Project
94
7.3.2 The Earthmoving Production in a Private
Housing Project
95
7.3.3 Problems Faced by the Contractors during The
Earthmoving Activities
96
7.3.4 Factors that influence the pricing during
bidding
97
7.4 Recommendation for Improvements 97
7.5 Summation 99
REFERENCES 100
APPENDICES 103
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LIST OF TABLES
TABLE
NO
TITLE PAGE
4.1 Corrections to cycle time 50
4.2 Factors for job and management conditions 59
5.1 Allocation of Time for Undertaking the Study 67
6.1 Percentage distribution of respondent’s organization
registered with PKK
68
6.2 Percentage distribution of respondent’s organization
registered with CIDB
69
6.3 Percentage distribution of respondent’s organization
involvement in the building earthwork construction
70
6.4 Percentage distribution of respondent’s scale of
earthwork project
71
6.5 Percentage distribution of respondent’s scale of
earthwork project in terms of volume (M3)
72
6.6 Percentage distribution of respondent’s experience 73
6.7 Percentage distribution of respondent’s nature of projects
undertaken
74
6.8 Percentage distribution on respondent’s level of
agreement that Private Development Projects were more
preferred compared to Government Projects
75
6.9 The priorities in the ranking order for selecting the
sequence of earthwork activities
77
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6.10 Percentage distribution on the decision making during
the construction period
78
6.11 Earthmoving production base on production estimating
table
80
6.12 Time and Motion Study 81
6.13 Ranking of problems faced by the contractor during the
earthmoving activities
83
6.14 Type of tender practice by private developer 84
6.15 Ranking of factors that influence the contractors pricing
during bidding
86
6.16 Ranking of factors need to consider during bidding 88
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LIST OF FIGURES
FIGURE
NO
TITLE PAGE
3.3 Schematic representation of excavator-truck operation 39
4.1 Time study for an excavator 53
4.2 Time study for a wheel-type scraper 55
5.1 Methodology Flow Chart 66
6.1 Percentage distribution of respondent’s organization
registered with PKK. and CIDB
69
6.2 Percentage distribution of respondent’s organization
involvement in the building earthwork construction
70
6.3 Scale of Earthwork Project undertaken by Respondent’s
Organization
71
6.4 Percentage distribution of respondent’s scale of
earthwork project in terms of volume (M3)
72
6.5 Percentage distribution of respondent’s experience 73
6.6 Percentage distribution of respondent’s nature of
projects undertaken
74
6.7 Determination if private development projects were
more preferred compared to Government projects
75
6.8 The lead role in making decision during the construction
period
78
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LIST OF APPENDICES
ITEM TITLE PAGE
A Production Estimating Table 104
B Time and Motion Observation Sheet for Hauling Unit 105
C Time and Motion Observation Sheet for Excavator 106
D Survey Questionnaire Sample 107
CHAPTER I
INTRODUCTION
1.1 INTRODUCTION
The rapid development of the housing construction industry in Malaysia in
recent years and the magnitude of the present-day constructions involved the
movement of large amount of earth excavations, cuttings and embankments may
be a substantial part of the overall project. These operations are relatively
repetitive and machine-oriented, being performed under the pressure to improve
productivity, efficiency and safety. (Jagman Singh, 1980) described the
conventional procedures for equipment management involving selection,
performance, estimating, maintenance, repairs and replacements etc. are not
enough in view of their incapability of approximating the real life phenomena
closely. These procedures usually provide estimates that are quite off the true
values. As the problems of management become more complex, the divergence of
results as obtained through conventional procedures and actual results becomes
greater. To a housing developer time is of the essence and the duration for the
completion of the projects will be as short as possible. To achieve the success of
the project within cost and time will require adequate planning and
implementation of earthworks and earthwork activities.
Earthmoving operations in the Malaysian housing industries normally
consist of a continuous process of the following phases:
2
Phase 1: Site preparation
Demarcation of site boundary
Clearing and grubbing – vegetation, and debris (e.g., tree, brush,
buried vegetation, trash, stumps, roots, etc.)
Stripping top soil
Phase 2: Bulk excavation and filling
Cutting and filling
Load, haul and dump
Spread and compact
Phase 3: Finish work
Formation of roads and building platforms
Grade and trim to finish level
Phase 1: Site preparation
The earthwork starts with the demarcation of the site boundary and
preparation for the materials to be moved. Site clearing consist of clearing,
grubbing and stripping topsoil in the area designated in the drawings. Clearing
consist of cutting and/or taking down, removal and disposal of everything above
ground level. Grubbing consist of the removal and disposal of surface
vegetation, the bases of stumps, roots, the underground parts of structures, and
other obstructions to a depth of at least 0.5 metre below ground level.
Stripping of top soil consist of the removal of topsoil to an average depth
of at least 150mm below ground level, from the areas within cuttings and
embankments and stockpiling for reuse for any purpose such as the soiling of
slopes of cuttings and embankment, and benches.
3
Phase 2: Bulk excavation and filling
Bulk excavation consist of materials excavated from the designated high
areas to the required depths and levels in accordance with the drawings, for
formation of roads, open spaces and building platforms within the limits of the
contract area.
Filling, consist of the excavation of suitable materials from high areas and
other approved sources is used for filling up of designated low areas to the
required levels in accordance with the drawings for formations of roads, open
spaces and building platforms. Filling can only be carried out after the original
ground has been cleared and any trees or organic materials removed. All materials
used in embankments and as fill is then compacted as soon as practicable after
being placed and spread.
Phase 3: Finish work
Surface finish for the formations of roads and building platforms shall be
finished fair, free of potholes, gullies and depressions where water may
accumulate. The surface of slopes shall be trimmed to an even profile.
In Malaysian housing industry earthmoving operation, normally involve
excavators loading a fleet of trucks and their proper matching in size is quite
important. The current procedures for equipment management involving selection,
performance, estimating, maintenance, repairs and replacements etc. are not
enough in view of their incapability of approximating the real life phenomena
closely. These procedures usually provide estimates which are quite off the true
values. As the problems of management become more complex, the divergence of
results as obtained through current procedures and actual results becomes greater.
The sizing of the haul units and estimation of production of the team is done using
4
average values of arrival rate of trucks at the loader and loading rate by the
excavator. Experience, however, indicates that this procedure does not give
accurate results, and the performance as estimated is usually on the higher side.
The reason is that the arrival and the loading of the trucks at the excavator are
random phenomena which cannot be approximated by working with average
values.
Some other procedures have, therefore, to be devised which would help
analyze the problems in a more realistic manner in order to complete the project in
time and within estimated cost. Motion and time study conducted at the start of
the project and by comparing it with the earthmoving production estimating table
offers the prospect of a useful management and monitoring tool.
1.2 BACKGROUND OF STUDY
In the earthmoving industry for a housing project is a constant challenge
to a contractor’s vision, ingenuity and to his experience and it has been termed the
biggest gamble in the business field. This is mainly due to a combination of
various factors which influence the operation performance, among them,
earthwork characteristics, job-site conditions, equipment characteristics, and
construction methods.
The operation performance can be measured by several performance
criteria, which can be classified into time (duration), cost, and safety. It is evident
that effective operations are a multi criteria problem. However, in this section, the
focus is on the duration and cost of operations.
The production rate can be calculated by dividing the number of units
produced by the duration of earthwork operations, and the minimization of project
duration is highly dependent on the production rate. There are a wide variety of
factors that affect the duration of earthwork operations. Considering the
significance of their influence, the affecting factors can be categorized into four
5
groups (Automation in Construction 12 (2003) 1-13, Kim and Jeffrey), which are
closely correlated with each other:
Work characteristics
Magnitude of the job (quantity of earth to be moved)
Layout and space constraint
Job-site conditions
Weather
Soil types and conditions
Haul road and gradients.
Equipment characteristics
Capacity (production rate)
Efficiency
Cycle time (combination of excavators and trucks)
Unexpected breakdown rate of equipment.
Economic haul distance
Motion and path planning strategy
Management
Planning the sequence of work
Method of construction.
Select a proper number of equipment
6
In the first group, Magnitude of the job (quantity of earth to be moved) is
directly related to the duration of earthwork operations. Obviously, different
magnitude of the job will result in different duration. Even the same type of work
will have different work durations due to the differences in work volume, site
conditions, construction methods, and so forth. The layout and space constrain
affects the productivity of equipment in the given project. Concurrent activities of
multi equipment interfere with each other because of their requirement for
workspace within a confined area.
There are several affecting factors associated with the job site conditions
which include weather, soil conditions, and road conditions. As for Malaysian
weathers which is unpredictable greatly affects the duration of the earthwork
operations. In general, bad weather decreases the efficiency of construction
equipment. Various types of soil create different levels of difficulty in stripping
and excavating soil, and are related to the rolling resistance that affects both
production rate and the financial investment of an earthwork contractor. The haul
road and gradient is related with the effectiveness of haul and return trip of
construction equipment.
Equipment is an important resource for earth moving construction projects
that require a large concentration of construction equipment. In housing project,
the selection of equipment is directly affected by the magnitude of the job. In an
equipment-intensive project, it is clear that the proper equipment selection will
result in the minimization of project duration and the maximization of output of
work tasks.
The last group, management of operations, includes construction method,
planning the sequence of work tasks, and allocating the proper amount of required
equipment. For example, if two or more equipment fleets are involved in
earthwork operations at the same time at a constrain area, to transport the stripped
7
soil to the fill area, there will be space interference that will result in the decrease
of productivity. To avoid this problem, the combination and number of
equipments to be used for interference free sequence of work tasks should be
planned in advance. Depending on the work environment and hauling distance, a
variable amount of construction equipment should be assigned to each equipment
fleet rather than a fixed amount throughout the earthwork operation process.
Among various affecting factors, planning the sequence of work tasks,
equipment selection, and equipment motion and path planning are controllable
factors to minimize the duration of earthwork operations.
1.3 STATEMENTS OF PROBLEM
The common choices of machineries for bulk excavation in housing
projects are combination of excavators and dump trucks. Like many construction
activities, earthworks are planned using data from previous projects together with
manufacturer’s performance charts. In many instances, many unforeseen
circumstances that affect the estimates of plant performance, output, and hence the
duration of activities, fall short of the actual situation once construction start. To
understand the project the researcher conducted a study on the earth work
activities carried out in various projects by interviewing with the project site
people. From the interview the researcher found that most of the projects were
either delay or cost overrun and it was due to 1) low bid, 2) insufficient
knowledge of job conditions, 3) adverse weather conditions, 4) improper selection
of construction equipment and 5) inefficient management and supervision. How
far these factors given will affect the project, here a study will be conducted.
Consequently, the potential for contractors’ losses on earthwork is large: this will
lead to contractual claims to recover those losses. Staples et al. (1992) estimated
that the annual value of earthworks claims during the early 1990s ran into many
millions of pound.
8
The selection of equipment is very important, for its selection and
operation determine both cost and time. Methods and equipment which give the
minimum unit cost within the construction schedule have to be adopted. A cubic
metre forms the basis of calculation. The contractor figures costs and profit on a
cubic metre basis. If his estimates are correct and his bid low, he clinches the
contract. But he should know that the simple cubic metres on the basis of which
he bids differ from the loose cubic metres which he actually hauls. It seldom
weights the same and expands when disturbed. When hauling the cubic metre, a
dump truck will need to overcome rolling resistance. The contractor should also
reckon the cost and time in loading and dumping accelerating, breaking and
shifting gears. Lastly he should remember that neither people nor machines work
60 minute hours and should make allowance for operation fatigue and routine
maintenance. All these considerations should determine the final time of cubic
metre. Experience and practical judgement, of course, play an important role and
the key to success.
Earthmoving operations are a major part of housing construction projects.
Because of their labour and plant intensity, the planning, estimating, monitoring
and control is crucial to both cost and duration of the project. Earthworks are the
first activity for a housing project and are considered by many to be indicators to a
success or failure of the project as a whole. The fact that quite often contractors
have gone bankrupt establishes that success is more elusive today in every area of
construction. This may be due to various reasons such as hard competition and
tighter economic conditions. But at many jobs contractors have lost mainly due to
bad management, wrong selection of equipment and unrealistic assumptions made
in the bids like work characteristics and job site condition.
1.4 OBJECTIVES OF THE STUDY
This study is to analyze and identify the different constrain that affect the daily
work output production rate and cost by earthwork contractors specialized in bulk
9
excavation and filling platform for housing development in Malaysia. In this study
we shall only consider excavators and dump trucks.
The objectives of the study are:
1. To study the earthmoving operation in a private housing
development project.
2. To study the earthmoving production in a private housing
development project.
3. To identify the problems faced by the contractors during the
earthmoving activities.
4. To identify the factors that influences the contractors pricing
during bidding.
1.5 SCOPE OF STUDY
This study focuses on the bulk earthwork excavation for private housing
development projects which has either been completed or currently in progress.
One of the project sites will be selected to conduct a time and motion study to
study the excavator and truck cycle time. The targeted participants would
comprise of contractors involved in earthwork for private housing development
projects in the state of Johore, Selangor and Negri Sembilan.
1.6 SIGNIFICANCE OF RESEARCH
The earthmoving industry continues to challenge construction men,
possibly largely because no two earthmoving jobs are the same. Each present its
own problems; each differs from another; and each requires different (or at least,
‘modified’) approach. It has been rightly said that “earthmoving is the biggest
gamble in the construction world”. Proper emphasis should be given to a basic
10
principle: “Reduce downtime, achieve optimum equipment utilisation and
increase production at minimum cost”.
The rapid development of the housing construction industry in Malaysia in
recent years and the magnitude of the present day constructions involved the
movement of large amount of earth excavations, cuttings and embankments may
be a substantial part of the overall project. The developers are more concerned
with time and cost and since time is of the essence it was also noted that the
duration is short and cost reduced. This study attempts to examine the sequence of
earthwork activities carried out in a private development project that will
influence the pricing during bidding and to complete the project in time. The study
aims to look at the effects of using the earthmoving production estimating table
and identify some of the problems that may arrive during construction using
motion and time study. The study also aims at identifying the problems faced by
the contractors during construction and the factors that will influence the pricing
during bidding. The researcher hope that the introduction of the motion and time
study of daily trips the contractors, engineers and client or developer will enhance
the awareness on the important of tracking the actual earthmoving production that
will have consequential influence to the duration and cost. Hence to improve and
strengthen their organization, in order to increase the awareness at an early stage
the actual project performance and to achieve the completion of the project
performance within time and cost for every construction development carried out
by them.
100
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101
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