v

Abstract:

In construction industries, blasting is the predominate method for

fragmentation when dealing with protruded rock. The issue of fly-rock is critical to

the operation of all sites that employ this method especially if it is near to highly

sensitive or populated area. This paper takes a risk-based approach to identifying,

analysis and managing the fly-rock hazard. The outcomes of the boulder blast should

not be underestimated as the fly-rock hazard is less predictable than the primary

blasting. A study in the United Kingdom mines and quarries inspectorate (2007)

revealed that more than 80 percent of incidents were associated with this type of

blasting. The basic cause of fly-rock generation is mismatch between the energy

available and the work to be done. This mismatch can be caused by an abrupt

decrease in rock resistance (geological weakness), overcharging, inappropriate blast

design and inaccurate drilling. In this study, 6 cases of actual blasting operation and

their effect of throw due to the amount of explosive used to break a certain volume of

rock (powder factor) is examined. A range of various amount of powder factor and

distance of throw from initial position of blast are presented. It can be concluded that

the wild fly-rock risk can be controlled by managing the powder factor for a given

blasting situation.

vi

ABSTRAK

Dalam industri pembinaan, letupan adalah suata kaedah biasa untuk

memecahkan massa batuan. Isu batu liar adalah sangat penting kerana ia sangat

sensitif kepada persekitaran terutamanya di kawasan yang berdekatan penduduk.

Kajian ini menggunakan pendekatan berdekatan berasaskan risiko untuk

mengenalpasti, analisis dan menguruskan bahaya batu liar. Hasil dari letupan batu

tidak boleh dianggap remeh kerana bahaya batu liar ini tidak dapat diramal secara

tepat daripada letupan primer. Kajian di United Kingdom (2007) menunjukkan

bahawa lebih daripada 80 peratus insiden dikaitkan dengan letupan primer dan

sekunder. Punca utama dari kejadian batu liar adalah kerana ketidaksesuaian antara

tenaga yang sedia dan beban yang harus dilakukan. Ketidakseimbargan ini

disebabkan oleh penurunan mendadak dalam kelemahan geologi, jumlah bahan

letupan, yang berlebihan, rekabentuk letupan yang tidak sesuai. Dalam kajian ini, 6

kes operasi peledakan dan pengaruhnya terhadap lemparan batu dikaji. Berbagai

jumlah faktor peledak dan kesannya terhadap lemparan batu disajikan.

Kesimpulannya, risiko batu liar dapat dikawal dengan menguruskan faktor peledak

yang sesuai untuk situasi letupan yang dijalankan.

vii

TABLE OF CONTENTS

CHAPTER TITLE PAGE

1 INTRODUCTION

DECLARATION ii

DEDICATION iii

ACKNOWLEDGEMENT iv

ABSTRACT v

ABSTRAK vi

TABLE OF CONTENTS vii

LIST OF APPENDICES xiv

LIST OF TABLES Xv

LIST OF FIGURES xvi

LIST OF SYMBOLS xviii

1.1 Background 1

1.2 Problem Statement 2

1.3 Research Objectives 3

1.4 Scope of Study 4

1.5 Significance of Study 4

1.6 Site Location 4

1.7 Geology of Site 5

viii

LITERATURE REVIEW

CHAPTER 2 TITLE PAGE

2.1 Introduction 7

2.2 Geological Condition of Site 8

2.3 Rock Strength 9

2.4 Blast Criteria 10

2.5 Blasting in Surface Excavation 14

2.6 Burden 14

2.7 Spacing 15

2.8 Powder Factor 16

2.9 Loading Density 16

2.10 Stemming 18

2.11 Explosive Criteria 22

2.11.1 Type of explosive 23

2.11.2 Dynamic 23

2.11.3 Slurry Explosive 23

2.11.4 Emulsions 24

2.11.5 Physical Properties 25

2.11.6 Sensitiveness 25

ix

LITERATURE REVIEW

CHAPTER 2 TITLE PAGE

2.11.7 Water Resistance 25

2.11.8 Sensitivity of Explosive 27

2.11.9 Velocity of Detonation 27

2.11.10 Detonation Pressure 28

2.11.11 Density of Explosive 29

2.11.12 Strength of Explosive 30

2.11.13 Volume of Rock Being Blasting 30

2.12 Secondary Blasting 30

2.13 Explosive Defined 33

2.13.1 Explosive Classification 34

2.13.2 Charge Distribution 36

2.13.3 Powder Factor or Specific Charge or Blast 36

2.14 Calculating Powder Factor 37

2.14.1 Powder Factor Approximation 38

2.14.2 Formulate For Powder Factor 39

x

LITERATURE REVIEW

CHAPTER 2 TITLE PAGE

2.15 Economic of Explosive 40

2.15.1 Cost of Energy 41

2.15.2 Energy Factor 43

2.16 Rock Fragmentation 45

2.16.1 Effects Of Powder Factor to Rock Throwing 45

2.16.2 Blasting Physics and Rock Properties 46

2.17 Fly-Rock (throw) Phenomena 47

2.17.1 Primary Causes of Throw Rock Generation 49

2.17.2 Terminology for Fly-Rock 49

2.17.3 Review of Fly-Rock Mechanisms 50

2.17.4 Fly-Rock Mechanisms 52

1

CHAPTER 1

INTRODUCTION

1.1 Background

Blasting operations can be applied in various conditions such as in mining,

open pit, quarries, slope works and else which require one. The main purpose of

blasting operation is the rock fragmentation, and is considered to be essential to

success of breaking protruded rock. This process provides appropriate material

granulation that will be suitable for excavation and transportation. The blasting

process, however, remains a potential source of numerous hazards. Even though

blasting techniques have been improved, there are still reports indicating blast-related

accidents involving people and structures. Since fly-rock and a lack of blast area

security constitute the majority of all blasting area, the cause and control of these

hazards and activates are discussed. Blasting of boulders is chosen as topic as we

would like to focus on the impact of powder factor to fly-rock without any influence

or aid of discontinuity in the breakage.

Powder factor represents the amount of explosive energy applied to each

specific volume of blasted material. It can be expressed in terms of kilograms of

explosive used for each cubic meter for rock. It is the indicator of consumption of

explosive in a shot. Terminology relating to fly-rock in the literature is inconsistent,

so it is necessary to define the terms of throw and fly-rock as used in this paper

(Little, 2007).

2

Throw- the planned forward movement of rock fragments that form the muck-

pile within the blast zone.

Fly-rock- the undesired propulsion of rock fragments through the air or along

the ground beyond the blast zone by the force of the explosive that is contained

within the blast clearance zone.

As the boulder blasting is concerned, the powder charge is surround by free

faces, less explosive is required to break a given amount of rock then in primary

blasting. Usually, this kind of blast is more violent than the primary blast.

Any fragment of rock produced by blasting that cannot be handled by the

mining equipment is referred to as boulders or oversize. The sizes of these blocks

depend upon each operation and during the same should be set aside for

fragmentation.

Blasting theory is one of the most interesting, challenging, and controversial

areas of the explosives engineering. It encompasses many areas in the science of

chemistry, physics, thermodynamics, shock wave interactions, and rock mechanics.

In broad terms, rock breakage by explosives involves the action of an explosive and

the response on the surrounding rock mass within the realms of energy, time and

mass.

 

 

1.2 Problem Statement

 

 

Boulders can be easily found in granitic area when performing earthwork

leveling. These boulder need to be broken and handled efficiently by the loading

equipment by blasting works. Although boulder employs relatively smaller amount

3

of charge, the potential of safety hazards must not be underestimated because the fly-

rock is less predictable than primary blasting.

Although this blasting operation will help in reducing the cost and time to

excavate the hard materials, the performance of the blasting operation will be

affected if it is not controlled and managed well. Beside, blasting operation is a

process where we need to consume explosives to break, destroy and extracting the

rocks for construction. Means, this process is obviously dangerous and need extra

precaution during the activity. To have a secure blasting process with less fly-rock

projection, ground vibration or preventing from any bad incidents to happened, the

blasters or the people involved in this industry need to have a perfect location to

place the explosives. Not only that, they also need to ensure that the explosives in

places correctly in the holes with the right depth and the right amount of explosives

powders. So, this study is conducted to see the effectiveness of blasting depending

on the powder factor and also amount of explosive that conditions affect fly-rock and

throwing rock at blast process of boulder.

1.3 Research Objectives

 

 

This study is carried out in order to have a better understanding on the effect

of powder factor to the boulder blasting. The objectives of the study are listed below:

1) To investigate the effect of powder factor to blasting process in granitic

boulders at the project site.

2) To determine the distance of throw of the rock fragments during blasting

operation.

4

1.4 Scope of Study

This study focus on the effect of powder factor to the throw of rock fragments

in boulder blasting at Technology Park, Johor Bahru.

1.5 Significance of the Study

This study will provide a better understanding the relationship between

powder factor and fly-rock on boulder blasting. This knowledge may be advantages

for people that involves in the different site location with similar geological

condition (granitic area) as it will shortened the time needed for consideration of the

proper powder factor needed to be applied in such blast.

1.6 Site Location

This study was carried out at proposed factory site located at Technology Park

Johor Bahru. The site location is shown in Figure 1.3. The purpose of the blasting

work is to level down the protruded rock for construction of factory.

5

1.7 Geology of Site

The site consists mainly of granite rock. Granite is formed by plutonic

cooling of magma. The rock material is l ight in colour with white and

pink spotted and is regarded as coarse grained granite Photographs

showing the rock material mass is shown in Figure 1.1.

Figure 1.1. Geology Map of Site Blast Operation at Taman Teknologi Johor.

6

Figure 1.2. Overview of the Site.

Figure 1.3. An Aerial View of the Site.

Taman       Teknologi  Johor