This assessment is based on
the criteria and guidelines for evaluation and assessment of hazard to life as
stated in Annex 4 of the TM-EIAO and covers the scope outlined in Section 3.4.11 of the EIA Study
Brief.
9.2
Scope of Hazard to
Life Assessment
A summary of the requirements on the Hazard Assessment for the Project as specified in Section 3.4.11 of the EIA study brief (ESB-156/2006) is reproduced below.
Ma Tau Kok Gas Works (MTKGW) – The Applicant
shall investigate methods to avoid and/ or minimise risks from drawing towngas
into the tunnel through the supply-air-only ventilation building at the
junction of To Kwa Wan Road and San Ma Tau Street, in the event of potential
gas leak from MTKGW. The Applicant shall carry out hazard assessment to
evaluate potential hazardous scenarios from MTKGW to the
operation of the Project. The hazard assessment shall include the following:
1.
Identification
of hazardous scenarios requiring Quantitative Risk Assessment (QRA) associated
with the draw in of towngas leak from the MTKGW;
2.
Execution
of a QRA expressing population risks in both individual and societal terms;
3.
Comparison
of individual and societal risks with the criteria for evaluating hazard to
life stipulated in Annex 4 of the TM-EIAO; and
4.
Identification
and assessment of practicable and cost-effective risk mitigation measures,
including the consideration for alternative siting for the supply-air-only
ventilation building at the junction of To Kwa Wan Road and San Ma Tau Street.
Explosives – The Applicant shall investigate
alternative construction method to avoid the use of explosives. If there is use
of explosives for the construction activities and the storage or blasting
location is in close vicinity of populated areas, LPG
fuelling station and/ or Potentially Hazardous Installation site (e.g. Ma Tau
Kok Gas Works), the Applicant shall carry out hazard assessment as follow:
1.
Identify
hazardous scenarios associated with the transport, storage and use of
explosives and then determine a set of relevant scenarios to be included in a
Quantitative Risk Assessment (QRA);
2.
Execute
a QRA of the set of hazardous scenarios determined in (1), expressing
population risks in both individual and societal terms;
3.
Compare
individual and societal risks with the criteria for evaluating hazard to life
stipulated in Annex 4 of the TM-EIAO; and
4.
Identify
and assess practicable and cost-effective risk mitigation measures.
During the design development of the Project, the originally proposed fresh air supply ventilation building at the junction of To Kwa Wan Road and San Ma Tau Street has been removed. Hence studying on the possibility of released towngas being drawn into the Central Kowloon Route (CKR) tunnel is not necessary.
Different tunnel construction methods have been considered for CKR in the alternative construction method technical report [9-34], and non-blasting method has been adopted where it is feasible.
The two basic methods for constructing a bored tunnel are the tunnel boring machine (TBM) method and the drill-and-blast method. The TBM method entails using a TBM to bore through the ground to form a circular tunnel, which is then lined with concrete. However, each bore of the CKR tunnel will have a minimum width of about 17m, which is considered large for a bored tunnel. Hence, an extremely large and powerful TBM would be required for CKR. Currently, such large TBM does not exist. Besides, CKR will pass through very hard granite that could cause extreme wear and tear to the TBM and cause excessive downtime.
By comparison, the drill-and-blast method is considered the most practicable and effective method for constructing the bored tunnel section of CKR. This method is the traditional method for boring through hard rocks, such as granite, and has been used successfully in many previous road projects in Hong Kong. It entails a cyclic process of drilling small holes into the tunnel face, filling the holes with explosives and blasting the rock into smaller fragments to ease removal of rocks. Given that CKR is located in an urban environment, the blasting will be strictly controlled to minimise vibrations at the various buildings and structures above the tunnel.
In certain locations, the drill-and-break method (i.e. a non-blasting technique) will be used. The drill-and-break method normally entails an alternative cyclic process of drilling the tunnel face with small drills to form a “Swiss cheese” structure in the rock, which can then be broken up using rock breakers. This method is however laborious, and will only be used when the work channel is passing close to various sensitive structures.
In view of the presence of existing MTRC Tsuen Wan Line (TWL), East Rail Line (ERL), future Kwun Tong Line Extension (KTE) and Shatin to Central Link (SCL), to control the blasting vibration within the Railway Protection Limits required by MTRC, a low charge weight will be applied at blasting sections near the Tsuen Wan Line, East Rail Line, future Kwun Tong Line Extension and Shatin to Central Link to minimise the vibrations.
Due
to the limited daily mucking out capacity, one blasting operation cycle per day
will be adopted in CKR. Besides, owing to lack of suitable locations, it is
considered that no temporary explosive magazine should be established.
Sufficient time for execution of the blasting works is put into consideration
in the project implementation programme with the assumptions that one explosive
delivery per day is achieved, sufficient time will be allowed for execution of
each blast. Delivery of explosives (cartridged emulsion explosives and
detonators) and explosive accessories (detonating cords and cast boosters) will
be performed by Mines Division daily from the Government Explosives Depot,
using Mines Division’s explosive delivery vehicles, arriving at Ho Man Tin
(HMT) access point of CKR project. Explosives required at all three access
points will be unloaded at the HMT offloading point. Explosives required at Yau
Ma Tei (YMT) and Ma Tau Kok (MTK) access points will then be delivered from HMT
access points by the appointed contractors using approved vehicles. Risks
arising from the transport and use of explosives will be evaluated according to
the location and frequency of blasting for the Project. The overall layout plan for Central Kowloon Route is shown in Appendix 9.1.
The scope of this Hazard to Life Assessment report includes the following items:
· Transport of explosives (cartridged emulsion explosives and other blasting accessories including detonator, detonating cord and cast booster) from the Mines Division vehicle offloading point (proposed offloading point is at Ho Man Tin) to other CKR construction sites (Yau Ma Tei and Ma Tau Kok); and
· Use of explosives during construction of the CKR, including the use of cartridged and bulk emulsion explosives.
9.3
Hazard to Life Assessment Objectives and Risk Criteria
The main objective of this Hazard to Life Assessment is to demonstrate that the Risk Criteria set in Annex 4 of the TM-EIAO will be met during the construction of the CKR, and to identify practical mitigation measures where applicable to ensure the risk criteria are met, with particular focus on:
· Identifying hazardous scenarios during transport and use of explosives for blasting operations;
· Preparing a Quantitative Risk Assessment (QRA) to estimate risks to the surrounding population in both individual and societal terms;
· Comparing individual and societal risks with the Risk Criteria set in Annex 4 of the TM-EIAO to determine the acceptability of the CKR Project in terms of risk; and
· Recommending practicable and cost effective risk mitigation measures to demonstrate the compliance with the Risk Criteria, if the risk is not “Acceptable”.
As set out in Annex 4 of the TM-EIAO, the risk criteria comprise two components as follows:
1. Individual Risk Criteria: The maximum level of off-site individual risk should not exceed 1 in 100,000 per year, i.e. 1 x 10-5 per year.
2. Societal Risk Criteria: The Societal Risk Criteria can be presented graphically as in Appendix 9.2. It is expressed in terms of F-N curves, which are lines plotting the frequency of occurrence (F) with N or more fatalities per year at the facility of concern. There are three areas shown:
· Acceptable where risks are adequately low that no action is necessary;
· Unacceptable where risks are so high that they should usually be reduced regardless of the cost or else the hazardous activity should not proceed; and
· ALARP (As Low As Reasonably Practicable) where the risks associated with the hazardous activity should be reduced to a level “as low as reasonably practicable”, in which the priority of measures is established on the basis of practicability and cost to implement versus risk reduction achieved.
9.4
Approach of the
Hazard to Life Assessment
This section outlined the approach adopted in this Hazard Assessment (HA) for transport and use of explosives in the Project. The HA consists of the following tasks:
1. Data/ Information Collection
3. Frequency Assessment
4. Consequence Assessment
5. Risk Analysis
6. Risk Mitigation and Recommendations
Data/ Information Collection
Relevant data/ information for the Project, such as population data, types and properties of explosives, blasting location and schedules, recommended charge weights, and explosives transport conditions, have been collected.
Population data in the vicinity of the blasting locations are obtained through detailed estimation based on population planning data and site survey. Road traffic population have been considered using representative figures from the Annual Traffic Census [9-38] to estimate the road traffic population. Pedestrian densities have also been applied to account for the pedestrian population along the explosives delivery route.
Hazard Identification
A review of industry incidents involving explosives, registered in relevant databases, has been carried out with regard to the types of explosives used and the operations for the CKR Project. Incidents which are applicable in the context of the CKR Project have been analysed in Section 9.10. Potential causes of hazard events have been carefully identified, and a set of relevant scenarios to be included in the HA for further assessment has been determined with reference to similar studies. Details of hazard identification are given in Section 9.9.
Frequency Assessment
The likelihoods of occurrence of the identified hazardous scenarios have been estimated using best available incident data. Frequency data used in recent risk assessments regarding explosives, such as the MTR West Island Line (WIL) EIA [9-1], MTR Express Rail Link (XRL) EIA [9-12], and Kwun Tong Line Extension EIA [9-39] have been referred and adopted. The frequencies documented in relevant data source have been reviewed to reflect the specific operations at the blasting locations along the CKR Project. Details of frequency assessment for transport and use of explosives are given in Section 9.11 and Section 9.12 respectively.
Consequence Assessment
The consequences have been established for every outcome developed from initial event by using internationally well recognised consequence modelling software to assess the impacts from overpressure, building collapse, fireball and thermal radiation, excessive ground vibration and other possible hazards. Quantity of explosives at a hazardous source is estimated from the blasting and the Project explosives transport schedule. Fatality probabilities of various hazardous event outcomes have been evaluated at a number of end-point criteria in each type of hazard outcome. Details of consequence assessment are illustrated in Section 9.13.
Risk Analysis
From the above analyses, societal and individual risk levels are calculated for the whole CKR Project during construction using internationally well recognised risk summation software. By summing up all hazard events, individual risk and societal risk associated during the construction of the Project are obtained and compared with the criteria set out in Annex 4 of the TM-EIAO to determine their acceptability. Details of risk analysis are given in Section 9.14.
Risk Mitigation and Recommendations
If the estimated off-site individual risk level is found to be higher than 1 x 10-5 per year or the societal risk level is found to be at the “ALARP” or “Unacceptable” region, risk mitigation measures will be identified to reduce the risk level for the compliance of the risk guidelines. Risk levels of the mitigated scenario will be assessed. Cost-Benefit Analysis (CBA) is a widely used method to evaluate the cost-effectiveness of mitigation measures and may be used to demonstrate whether reasonably practicable measures have been taken to reduce risk levels.
9.5
Project
Description and Assessment Information
Highways Department (HyD) of the Hong Kong SAR Government proposes to construct a 3-lane trunk road across Central Kowloon, linking West Kowloon in the west and the proposed Kai Tak Development (KTD) in the east. It will connect with West Kowloon Highway at Yau Ma Tei Interchange with the road network at Kowloon Bay and the future Trunk Road T2 at KTD, which will connect to the Tseung Kwan O – Lam Tin Tunnel (TKO – LTT). This route is known as Central Kowloon Route (CKR). CKR, Trunk Road T2 and TKO – LTT will form a strategic highway link, namely Route 6, connecting West Kowloon and Tseung Kwan O.
The construction of CKR was previously targeted for completion in 2016. The current target is to start construction of CKR in 2015 for completion and commissioning in end 2020. The construction programme for the Project (bored tunnel) in time chainage diagram is illustrated in Appendix 9.3.
In view of the topography and geology of the
Ho Man Tin and Ma Tau Kok areas, the central section of CKR comprises mainly of
deep bored tunnel. The proposed bored tunnel would run in underlying rock
strata below ground to avoid affecting the buildings, roads and utilities at
ground level.
The deep bored tunnel will be constructed by
the drill-and-blast method. This is commonly used for excavation of hard rock
tunnels. In view of tunnelling by TBM is not feasible given the large diameters
involved and the extreme wear and tear expected due to the hard rock strata, it
is an economical method and less restricted by site conditions and equipment
set-up by the drill-and-blast method.
The location of the tunnel section where the
drill-and-blast method will be used is
shown in the legend of “proposed bored tunnel” in Appendix 9.1. The Longitudinal Profile is shown in Appendix 9.4. The three access points of the tunnel construction are marked as A (Yau
Ma Tei near Shanghai Street), B (Ho Man Tin near service reservoir) and C (Ma
Tau Kok near Kowloon City Pier Bus Terminus). Delivery routes between the
Delivery Point (B) and the Access Points (A and C) are shown in Appendix 9.5.
Explosives will only be used for blasting from Chainage 1440 to 4230. The
proposed blasting strategy, which has been adopted in this Hazard Assessment,
is summarised below:
· There is no dedicated explosive magazine for the CKR project.
· Mines Division will directly deliver explosives (detonators, cartridged emulsion explosives) and explosive accessories (detonating cords and cast boosters) to the HMT access point, and contractors are responsible to deliver explosives to the other two access points (i.e. from HMT to YMT and from HMT to MTK). The explosive delivery by the Mines Division and the contractors will be once per day and six days per week.
· There is no overnight storage of explosives at the CKR worksites.
· As a contingency measure, it is feasible to destroy limited quantities of unused mini-cast boosters, detonating cords and detonators on-site in accordance with Section 5.4 of Mines Division Practice Note No. 1.
· Occasionally, there would be unused cartridged emulsion explosives at the work sites. Unused cartridged emulsion explosives will be transported by Mines Division from Ho Man Tin to Government Explosives Depot for temporary storage, which is permitted as an emergency contingency measure. Nevertheless, contractors are required to transport the unused cartridged emulsion explosives from YMT to HMT and from MTK to HMT.
· This assessment also consider the potential uncertainties. These uncertainties may include the longer period of trial blasting when compared with the hazard assessment assumption, unforeseen ground conditions which restrict the use of bulk emulsion explosives, the use of low allowable charge weight due to the presence of sensitive receivers which restrict the use of bulk emulsion explosives, actual construction programme may differ from the envisaged construction programme, resulting in a higher number of explosive delivery trips (from HMT to YMT and from HMT to MTK). Return trips of unused explosives (from YMT to HMT and from MTK to HMT) will be generally avoided, nevertheless, are possible due to some uncertainties in the project implementation, therefore they are also considered in this assessment. Overall, these uncertainties (additional explosive deliveries as well as return trips of unused explosives) are addressed by 20% increase in the number of explosives delivery trips based on previous project experience as a contingency scenario.
· There will be only one blast per blast face per day.
· In the blasting design, bulk emulsion explosives will be used as far as practicable; the demarcation charge weight of the cartridged emulsion explosives and bulk emulsion explosives is 0.5 kg per delay.
· Non-electric detonators (i.e. shock tube detonators) will be adopted in the CKR project, which is the basis for the hazard assessment of use of explosives in accordance with previous EIA studies. If the CKR contractor decides to use electronic detonator in the future (i.e. construction stage), they should carry out and submit the quantitative risk assessment amendment for the use of the specific electronic detonators to EPD and relevant parties to seek the corresponding statutory approval.
Three types of explosives will be used for the CKR tunnel construction by the drill-and-blast method, namely:
· Cartridged emulsion explosives;
· Bulk emulsion explosives; and
· Detonators, cast boosters and detonating cords.
Both cartridged and bulk emulsion explosives contain mainly ammonium nitrate, water, and a hydrocarbon such as fuel oil. Cartridged emulsion explosives also contain 2-3% aluminium powder, which is added to increase the explosion temperature and hence its power.
Cartridged Emulsion Explosives
Cartridged emulsion explosives (CEE) are small diameter explosives packages. They are used for mining, quarrying and general blasting work. They are packaged in a range of plastic films with the tips clipped at each end, or wrapped in waxed paper. They are classified as Dangerous Goods (DG) Category 1 “explosive” in Hong Kong, and have an equivalence of 0.96 kg TNT per kg of CEE.
Cartridged emulsion explosives are detonator sensitive, and hence do not require the use of a booster to make them detonate. When cartridged emulsion explosives are used, the required number of sticks equivalent to the design charge weight will be loaded into each blast hole.
CEEs will normally be used during the “trial blast” phase of a project. For hazard assessment purpose, cartridged emulsion explosives will be adopted where the MIC (maximum instant charge) does not exceed 0.5kg/delay. Once successful trial blasts have been concluded, it is expected that contractors will prefer using bulk emulsion explosives for safety, economic and flexibility reasons.
Bulk Emulsion Explosives
Bulk emulsion explosive has a similar composition to CEEs except that it does not contain aluminium. Before sensitising, the bulk emulsion has a density of 1,380-1,400 kg/m3. It is not considered as an “explosive” and is classified as a DG Category 7 “strong supporter of combustion” in Hong Kong.
The
bulk emulsion precursor (BEP)
is stable under normal conditions and there is no major fire hazard before
sensitisation. Hazards associated with bulk emulsion precursor are mainly due to its oxidising properties causing
irritation to eyes and skin.
Explosion is considered possible only under prolonged fire, supersonic shock or very high energy
projectile impact.
Prior to sensitizing, it is not considered
as an explosive, and hence transport of bulk emulsion precursor is not
within the scope of this study.
Detonators, Cast Boosters and Detonating Cords
Detonators are small devices that are used to safely initiate blasting explosives in a controlled manner. Detonators are classified as DG Category 1 “explosive” in Hong Kong. Although detonators contain the most sensitive types of explosives in common use, they are constructed in a manner such that they may be handled and used with minimal risk. They are packaged in a manner that, if accidentally initiated, they should have no serious effects outside the package.
Non-electric detonators initiate detonation mainly by chemical reactions. They are manufactured with in-built delays that are of various durations. This is to facilitate effective blasting to allow blast holes to be initiated sequentially one at a time, rather than instantaneously, thereby enhancing the practical effects of the blast and reducing the effects of vibration.
The small quantity of explosive in a detonator is usually inadequate to reliably initiate many bulk explosives so they are used in conjunction with larger, less sensitive explosives – a cast booster – to boost the explosion. A cast booster is a small device, in which a detonator is inserted and the whole assembly is then placed in the end of the blasthole, once assembled it is called a primer.
Detonating cord is a thin, flexible tube with an explosive core. It detonates continually along its length and is suitable for initiating other explosives that are detonator sensitive, such as cartridged emulsion. The core of the cord is a compressed powdered explosive, usually PETN, and it is initiated by the use of a detonator. These explosives are used as part of the initiating system to initiate the main blasting explosives.
9.6
Transport of
Explosives for the CKR Project
Delivery of explosives and accessories (cartridged emulsion explosives and detonators, etc.) will be performed by Mines Division daily from the Government Explosives Depot, using Mines Division’s explosives delivery vehicles, arriving at Ho Man Tin (HMT) access point of the CKR Project. All of the explosives required at all access points will be unloaded at the HMT offloading point. Explosives required at Yau Ma Tei (YMT) and Ma Tau Kok (MTK) access points will then be delivered from HMT access point by the appointed contractors using approved trucks.
The type and quantity of explosives to be
used at each Access Point for each month during the construction period where
blasting is required are estimated and summarised in Table 9.1. Based on the estimates from Table 9.1, Table 9.2 shows the amount of Category 1 Dangerous Goods explosives carried by Mines Division / contractor’s vehicles.
To collect data of rock characteristics and for ground
vibration prediction, trial blasting will be carried out at the initial stage
of shaft blasting (Access Point B) and tunnel blasting (Access Points A, B
& C). Cartridged emulsion explosives will be used in the trial blasting.
One blast per face per day will be arranged. After trial blasting, bulk emulsion
explosives will be used instead, where the amount of Category
1 Dangerous Goods explosives required to be transported will be
significantly reduced. Bulk emulsion explosives will be adopted as
far as practicable. Information on estimated delivery schedule of Category 1 Dangerous
Goods (cartridged emulsion explosives, detonators etc.) by contractor’s approved
vehicles are shown in Appendix 9.6.
The maximum quantity of explosives that a
contractor can transport is limited to 200 kg on a Mines Division approved
truck. Detonators excluding detonating cord shall be transported in a separate
approved truck, which shall not be carrying other types of Category 1 Dangerous
Goods at the same time. Detonator
packages will be classified as HD 1.4B or HD 1.4S (articles which present no
significant hazard outside their packaging). Packaged in such a way, the
consequences potentially leading to fatalities will be limited to remain within
the explosive truck boundaries. For accidental initiation of small amount of
explosives, the UK HSE has estimated only the persons in close proximity to the
explosion in the work room could be killed or injured. Therefore, accidental
detonation of the detonators on the delivery truck is not further assessed in
this study, which is consistent with the WIL EIA [9-1].
As a contingency measure, limited quantities
of the unused mini-cast boosters, detonators and detonating cords, those
explosives would be destroyed on site. Moreover, the destruction of explosives
should only be carried out in a controlled blast covered by the Blasting Permit
issued under the Dangerous Goods Ordinance. The destruction of large amounts of
explosives at underground blasting sites will not be permitted.
Mines Division will permit limited
quantities of unused explosives to be stored temporarily in Government
Explosives Depot, as an emergency contingency measure.
Table 9.1 Amount of Explosives Required at Each
Access Point
|
Month-year |
Bulk Emulsion Explosive Consumption from Access Point A |
Bulk Emulsion Explosive Consumption from Access Point B |
Bulk Emulsion Explosive Consumption from Access Point C |
Cartridged Emulsion Explosive Consumption from Access Point A |
Cartridged Emulsion Explosive Consumption from Access Point B |
Cartridged Emulsion Explosive Consumption from Access Point C |
Detonator |
Cast Booster |
Total Explosive Required |
Number of Blast Faces in a Day |
Access Points for the Month |
|
Kg /day |
Kg /day |
Kg /day |
Kg /day |
Kg /day |
Kg /day |
Kg /day |
Kg /day |
Kg /day |
|||
|
Jul-15 |
0 |
0 |
0 |
0 |
170.1 |
0 |
0.8 |
112.1 |
283 |
1 |
B |
|
Aug-15 |
0 |
0 |
0 |
0 |
177.8 |
0 |
0.7 |
96.2 |
275 |
1 |
B |
|
Sep-15 |
0 |
217.1 |
0 |
0 |
12.4 |
0 |
0.4 |
58.1 |
288 |
1 |
B |
|
Oct-15 |
0 |
370.7 |
0 |
0 |
12.4 |
0 |
0.4 |
58.1 |
442 |
1 |
B |
|
Nov-15 |
0 |
396.3 |
0 |
0 |
12.4 |
0 |
0.3 |
38.9 |
448 |
1 |
B |
|
Dec-15 |
0 |
850.7 |
0 |
0 |
12.4 |
0 |
0.3 |
42.8 |
906 |
1 |
B |
|
Jan-16 |
0 |
853.9 |
0 |
0 |
12.4 |
0 |
0.3 |
35.6 |
902 |
1 |
B |
|
Feb-16 |
0 |
749.6 |
0 |
0 |
12.4 |
0 |
0.2 |
27.8 |
790 |
1 |
B |
|
Mar-16 |
0 |
777.2 |
0 |
0 |
12.4 |
0 |
0.2 |
27.8 |
818 |
1 |
B |
|
Apr-16 |
0 |
815.9 |
0 |
0 |
12.4 |
0 |
0.2 |
27.8 |
856 |
1 |
B |
|
May-16 |
1088.8 |
2330 |
0 |
8.5 |
80.2 |
22.8 |
1.9 |
107.9 |
3640 |
6 |
A & B &C |
|
Jun-16 |
529.9 |
1510.5 |
0 |
6.5 |
71.3 |
22.6 |
1.9 |
91.5 |
2234 |
6 |
A & B &C |
|
Jul-16 |
495.7 |
1256.9 |
0 |
22.3 |
67.4 |
20.6 |
2.3 |
88.1 |
1953 |
6 |
A & B &C |
|
Aug-16 |
436.2 |
990.9 |
0 |
22.6 |
67.0 |
20.7 |
2.4 |
92.7 |
1633 |
6 |
A & B &C |
|
Sep-16 |
510.6 |
805.5 |
0 |
13.7 |
45.5 |
17.3 |
2.9 |
105.6 |
1501 |
6 |
A & B &C |
|
Oct-16 |
437.4 |
736.7 |
0 |
11.5 |
32.8 |
17.1 |
3.0 |
107.6 |
1346 |
6 |
A & B &C |
|
Nov-16 |
346.6 |
625.8 |
0 |
9.1 |
24.0 |
16.9 |
2.1 |
104.7 |
1129 |
6 |
A & B &C |
|
Dec-16 |
0 |
702.8 |
0 |
12.7 |
42.9 |
17.2 |
3.0 |
107.3 |
886 |
6 |
A & B &C |
|
Jan-17 |
0 |
658.3 |
0 |
12.7 |
35.7 |
17.2 |
2.9 |
101.5 |
828 |
6 |
A & B &C |
|
Feb-17 |
0 |
717.3 |
0 |
12.7 |
26.2 |
15.4 |
3.0 |
94.2 |
869 |
6 |
A & B &C |
|
Mar-17 |
0 |
790.2 |
0 |
8.9 |
38.2 |
12.1 |
3.2 |
107.7 |
960 |
6 |
A & B &C |
|
Apr-17 |
0 |
779.8 |
0 |
11.4 |
48.0 |
12.1 |
3.2 |
110.4 |
965 |
6 |
A & B &C |
|
May-17 |
0 |
843.2 |
0 |
14.9 |
28.6 |
14.9 |
2.8 |
93.3 |
998 |
6 |
A & B &C |
|
Jun-17 |
0 |
850.1 |
0 |
14.9 |
28.7 |
14.6 |
2.9 |
102.1 |
1013 |
6 |
A & B &C |
|
Jul-17 |
136.9 |
788.9 |
0 |
22.6 |
45.5 |
14.6 |
2.8 |
116.6 |
1128 |
6 |
A & B &C |
|
Aug-17 |
162.9 |
571.7 |
0 |
24.4 |
157.5 |
14.6 |
2.4 |
108.6 |
1042 |
6 |
A & B &C |
|
Sep-17 |
386.2 |
573.8 |
0 |
6.7 |
173.7 |
14.5 |
2.5 |
138.4 |
1296 |
6 |
A & B &C |
|
Oct-17 |
440.3 |
563.9 |
0 |
11.1 |
174.2 |
14.5 |
2.3 |
125.7 |
1332 |
6 |
A & B &C |
|
Nov-17 |
517.0 |
558.0 |
0 |
5.2 |
22.3 |
14.5 |
2.2 |
118.7 |
1238 |
6 |
A & B &C |
|
Dec-17 |
600.4 |
572.1 |
0 |
6.8 |
22.1 |
14.5 |
2.1 |
105.9 |
1324 |
6 |
A & B &C |
|
Jan-18 |
723.6 |
936.4 |
0 |
6.2 |
50.2 |
14.8 |
2.1 |
104.9 |
1838 |
6 |
A & B &C |
|
Feb-18 |
723.6 |
1232.7 |
0 |
6.2 |
54.0 |
14.5 |
2.1 |
105.3 |
2138 |
6 |
A & B &C |
|
Mar-18 |
822.4 |
1664.4 |
0 |
6.1 |
70.8 |
16.0 |
2.0 |
100.8 |
2682 |
6 |
A & B &C |
|
Apr-18 |
822.4 |
1490 |
0 |
11.5 |
43.0 |
16.4 |
2.0 |
106.3 |
2492 |
6 |
A & B &C |
|
May-18 |
987.1 |
1476.7 |
0 |
12.8 |
266.0 |
16.4 |
2.3 |
154.9 |
2916 |
6 |
A & B &C |
|
Jun-18 |
987.1 |
1155.5 |
0 |
12.8 |
183.5 |
18.4 |
2.5 |
181.6 |
2541 |
4 |
A & B &C |
|
Jul-18 |
1023.7 |
894.6 |
0 |
12.3 |
253.2 |
18.4 |
2.3 |
155.5 |
2360 |
4 |
A & B &C |
|
Aug-18 |
1023.7 |
873.2 |
0 |
12.3 |
49.1 |
18.7 |
2.0 |
111.9 |
2091 |
4 |
A & B &C |
|
Sep-18 |
930.4 |
799.9 |
0 |
11.3 |
29.9 |
18.7 |
1.7 |
75.6 |
1867 |
4 |
A & B &C |
|
Oct-18 |
834.3 |
592.2 |
0 |
10.9 |
22.9 |
18.3 |
1.8 |
89.2 |
1570 |
4 |
A & B &C |
|
Nov-18 |
0 |
630.4 |
0 |
0 |
51.6 |
19.8 |
1.5 |
79.4 |
783 |
4 |
B & C |
|
Dec-18 |
0 |
621.9 |
0 |
0 |
23.6 |
21.4 |
1.3 |
68.0 |
736 |
4 |
B & C |
|
Jan-19 |
0 |
616.9 |
0 |
0 |
23.4 |
21.3 |
1.3 |
70.2 |
733 |
4 |
B & C |
|
Feb-19 |
0 |
597.2 |
0 |
0 |
40.1 |
23.9 |
1.3 |
74.6 |
737 |
4 |
B & C |
|
Mar-19 |
0 |
484.4 |
0 |
0 |
20.4 |
23.7 |
1.2 |
73.9 |
604 |
4 |
B & C |
|
Apr-19 |
0 |
224.1 |
0 |
0 |
260.8 |
24.7 |
1.3 |
88.2 |
599 |
4 |
B & C |
|
May-19 |
0 |
128.8 |
0 |
0 |
136.8 |
25.3 |
1.3 |
87.3 |
379 |
4 |
B & C |
|
Jun-19 |
0 |
161.6 |
0 |
0 |
200.7 |
0 |
0.7 |
94.8 |
458 |
4 |
B |
|
Jul-19 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
- |
- |
|
Aug-19 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
- |
- |
Note:
[1]
Site A: Yau Ma Tei (YMT)
[2]
Site B: Ho Man Tin (HMT)
[3]
Site C: Ma Tau Kok (MTK)
[4]
Mines Division’s Delivery Point of Explosives is at Site B
Table 9.2 Amount
of DG Category 1 Explosives Required at
Each Access Point (Carried by Mines Division / Contractor’s Vehicles)
|
Month-year |
Explosive Required at Access Point A |
Explosive Required at Access Point B |
Explosive Required at Access Point C |
|||||||||
|
Detonator |
Detonating Cord |
Cast Booster |
Cartridged Emulsion Explosive |
Detonator |
Detonating Cord |
Cast Booster |
Cartridged Emulsion Explosive |
Detonator |
Detonating Cord |
Cast Booster |
Cartridged Emulsion Explosive |
|
|
Kg/day |
Kg/day |
Kg/day |
Kg/day |
Kg/day |
Kg/day |
Kg/day |
Kg/day |
Kg/day |
Kg/day |
Kg/day |
Kg/day |
|
|
Jul-15 |
0 |
0 |
0 |
0 |
0.8 |
3.0 |
112.1 |
170.1 |
0 |
0 |
0 |
0 |
|
Aug-15 |
0 |
0 |
0 |
0 |
0.7 |
3.0 |
96.2 |
177.8 |
0 |
0 |
0 |
0 |
|
Sep-15 |
0 |
0 |
0 |
0 |
0.4 |
3.0 |
58.1 |
12.4 |
0 |
0 |
0 |
0 |
|
Oct-15 |
0 |
0 |
0 |
0 |
0.4 |
5.0 |
58.1 |
12.4 |
0 |
0 |
0 |
0 |
|
Nov-15 |
0 |
0 |
0 |
0 |
0.3 |
5.0 |
38.9 |
12.4 |
0 |
0 |
0 |
0 |
|
Dec-15 |
0 |
0 |
0 |
0 |
0.3 |
9.9 |
42.8 |
12.4 |
0 |
0 |
0 |
0 |
|
Jan-16 |
0 |
0 |
0 |
0 |
0.3 |
9.9 |
35.6 |
12.4 |
0 |
0 |
0 |
0 |
|
Feb-16 |
0 |
0 |
0 |
0 |
0.2 |
9.9 |
27.8 |
12.4 |
0 |
0 |
0 |
0 |
|
Mar-16 |
0 |
0 |
0 |
0 |
0.2 |
9.9 |
27.8 |
12.4 |
0 |
0 |
0 |
0 |
|
Apr-16 |
0 |
0 |
0 |
0 |
0.2 |
9.9 |
27.8 |
12.4 |
0 |
0 |
0 |
0 |
|
May-16 |
0.5 |
9.8 |
19.1 |
8.5 |
0.7 |
26.1 |
75.2 |
80.2 |
0.8 |
3.2 |
13.6 |
22.8 |
|
Jun-16 |
0.6 |
5.6 |
25.2 |
6.5 |
0.5 |
20.2 |
52.5 |
71.3 |
0.8 |
3.1 |
13.8 |
22.6 |
|
Jul-16 |
0.9 |
5.6 |
13.5 |
22.3 |
0.5 |
15.3 |
59.1 |
67.4 |
0.9 |
3.0 |
15.5 |
20.6 |
|
Aug-16 |
1.0 |
5.3 |
13.5 |
22.6 |
0.5 |
13.2 |
63.8 |
67.0 |
0.9 |
3.0 |
15.5 |
20.7 |
|
Sep-16 |
1.3 |
6.0 |
19.4 |
13.7 |
0.6 |
10.5 |
68.3 |
45.5 |
1.0 |
2.9 |
18.0 |
17.3 |
|
Oct-16 |
1.4 |
5.1 |
21.9 |
11.5 |
0.6 |
8.4 |
67.5 |
32.8 |
1.0 |
2.9 |
18.2 |
17.1 |
|
Nov-16 |
0.6 |
4.4 |
24.5 |
9.1 |
0.5 |
7.4 |
61.8 |
24.0 |
1.1 |
2.8 |
18.4 |
16.9 |
|
Dec-16 |
1.4 |
2.7 |
23.7 |
12.7 |
0.6 |
9.5 |
65.4 |
42.9 |
1.0 |
2.8 |
18.2 |
17.2 |
|
Jan-17 |
1.4 |
2.7 |
23.7 |
12.7 |
0.5 |
7.9 |
59.6 |
35.7 |
1.0 |
2.8 |
18.2 |
17.2 |
|
Feb-17 |
1.4 |
2.7 |
23.7 |
12.7 |
0.4 |
8.3 |
51.0 |
26.2 |
1.2 |
2.8 |
19.5 |
15.4 |
|
Mar-17 |
1.5 |
2.7 |
26.6 |
8.9 |
0.5 |
9.7 |
59.1 |
38.2 |
1.2 |
2.8 |
22.0 |
12.1 |
|
Apr-17 |
1.4 |
2.7 |
24.7 |
11.4 |
0.5 |
10.3 |
63.8 |
48.0 |
1.2 |
2.8 |
22.0 |
12.1 |
|
May-17 |
1.3 |
2.9 |
21.9 |
14.9 |
0.4 |
9.4 |
51.5 |
28.6 |
1.1 |
2.8 |
19.9 |
14.9 |
|
Jun-17 |
1.3 |
2.9 |
21.9 |
14.9 |
0.5 |
9.4 |
60 |
28.7 |
1.2 |
2.8 |
20.1 |
14.6 |
|
Jul-17 |
1.0 |
3.6 |
15.4 |
22.6 |
0.7 |
10.4 |
81.0 |
45.5 |
1.2 |
2.8 |
20.1 |
14.6 |
|
Aug-17 |
0.6 |
4.1 |
13.5 |
24.4 |
0.6 |
6.8 |
75.0 |
157.5 |
1.2 |
2.8 |
20.1 |
14.6 |
|
Sep-17 |
0.6 |
4.9 |
25.8 |
6.7 |
0.7 |
8.2 |
92.4 |
173.7 |
1.2 |
2.8 |
20.1 |
14.5 |
|
Oct-17 |
0.5 |
5.7 |
21.7 |
11.1 |
0.7 |
7.8 |
83.9 |
174.2 |
1.2 |
2.8 |
20.1 |
14.5 |
|
Nov-17 |
0.4 |
6.7 |
24.9 |
5.2 |
0.6 |
6.7 |
73.7 |
22.3 |
1.2 |
2.8 |
20.1 |
14.5 |
|
Dec-17 |
0.4 |
7.9 |
22.4 |
6.8 |
0.5 |
6.6 |
63.3 |
22.1 |
1.2 |
2.8 |
20.1 |
14.5 |
|
Jan-18 |
0.4 |
9.2 |
21.5 |
6.2 |
0.5 |
12.2 |
63.6 |
50.2 |
1.1 |
2.9 |
19.9 |
14.8 |
|
Feb-18 |
0.4 |
9.2 |
21.5 |
6.2 |
0.5 |
14.5 |
63.8 |
54.0 |
1.2 |
2.9 |
20.1 |
14.5 |
|
Mar-18 |
0.4 |
10.7 |
20 |
6.1 |
0.5 |
20.1 |
61.8 |
70.8 |
1.1 |
2.9 |
19.0 |
16.0 |
|
Apr-18 |
0.4 |
10.7 |
16.0 |
11.5 |
0.6 |
15.6 |
71.7 |
43.0 |
1.1 |
2.9 |
18.6 |
16.4 |
|
May-18 |
0.4 |
12.3 |
13.3 |
12.8 |
0.9 |
19.5 |
123.0 |
266.0 |
1.1 |
2.9 |
18.6 |
16.4 |
|
Jun-18 |
0.4 |
12.3 |
13.3 |
12.8 |
1.1 |
15.6 |
151.2 |
183.5 |
1.0 |
2.9 |
17.1 |
18.4 |
|
Jul-18 |
0.4 |
12.6 |
13.3 |
12.3 |
0.9 |
10.6 |
125.1 |
253.2 |
1.0 |
2.9 |
17.1 |
18.4 |
|
Aug-18 |
0.4 |
12.6 |
13.3 |
12.3 |
0.6 |
12.1 |
81.8 |
49.1 |
1.0 |
3.0 |
16.9 |
18.7 |
|
Sep-18 |
0.4 |
11.4 |
15.3 |
11.3 |
0.4 |
10 |
43.4 |
29.9 |
1.0 |
3.0 |
16.9 |
18.7 |
|
Oct-18 |
0.4 |
10.6 |
16.6 |
10.9 |
0.4 |
6.9 |
55.5 |
22.9 |
1.0 |
3.0 |
17.1 |
18.3 |
|
Nov-18 |
0 |
0 |
0 |
0 |
0.5 |
8.2 |
63.5 |
51.6 |
0.9 |
3.1 |
16.0 |
19.8 |
|
Dec-18 |
0 |
0 |
0 |
0 |
0.4 |
7.2 |
53.3 |
23.6 |
0.9 |
3.1 |
14.7 |
21.4 |
|
Jan-19 |
0 |
0 |
0 |
0 |
0.4 |
7.1 |
55.5 |
23.4 |
0.9 |
3.2 |
14.7 |
21.3 |
|
Feb-19 |
0 |
0 |
0 |
0 |
0.5 |
8.3 |
62.0 |
40.1 |
0.8 |
3.3 |
12.7 |
23.9 |
|
Mar-19 |
0 |
0 |
0 |
0 |
0.5 |
5.8 |
61.2 |
20.4 |
0.8 |
3.4 |
12.7 |
23.7 |
|
Apr-19 |
0 |
0 |
0 |
0 |
0.6 |
4.6 |
76.4 |
260.8 |
0.7 |
3.5 |
11.9 |
24.7 |
|
May-19 |
0 |
0 |
0 |
0 |
0.6 |
3.9 |
76.1 |
136.8 |
0.7 |
3.7 |
11.3 |
25.3 |
|
Jun-19 |
0 |
0 |
0 |
0 |
0.7 |
5.2 |
94.8 |
200.7 |
0 |
0 |
0 |
0 |
|
Jul-19 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
Aug-19 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
Note:
TNT Equivalency:
Detonators = 1.4 (i.e. 1.4kg of TNT per 1kg of
detonators)
Detonating Cords = 1.4 (i.e. 1.4kg of TNT per 1kg of
detonating cords)
Cast Boosters = 1.3 (i.e. 1.3kg of TNT
per 1kg of cast boosters)
Cartridged Emulsion Explosives = 0.96
(i.e. 0.96kg of TNT per 1kg of emulsion)
To minimise the transport risk, delivery routes between the Delivery Point (HMT) and the Access Points (YMT and MTK) have been planned to avoid areas of high population density wherever possible, which are shown in Appendix 9.5. For example, from Ho Man Tin (Site B) to Ma Tau Kok (Site C), the Contractor’s approved vehicles will take “Fat Kwong Street”, “Ma Tau Wai Road (south)” and “To Kwa Wan Road” so as to avoid going into the Lok Man Sun Chuen area; from Ho Man Tin (Site B) to Yau Ma Tei (Site A), the vehicles will take “Fat Kwong Street”, “Chatham Road” and “Gascoigne Road” instead of the densely populated “Waterloo Road”, reason as mentioned above.
The explosives delivery trucks should be approved by Mines Division and should meet the regulatory requirements for transport of explosives. The approved trucks will have the following safety features [9-41]:
· Diesel powered;
· Vehicle’s design, construction and strength complied with the Road Traffic Regulations, Chapter 374, Laws of Hong Kong;
· Cargo compartment with sufficient protection, proper storage facilities, and no electric wiring/devices installed inside;
· Isolated fuel tank with adequate protection;
· Battery and fuel isolation switches;
· Forward mounted exhaust with spark arrestor;
· Four fire extinguishers (2 x 2.5 kg dry powder, 2 x 9 L foam fire extinguishers) for a typical vehicle with gross vehicle weight of 9 tonnes or above;
· Lockable receptacles (of wood lined steel or aluminium) mounted on the vehicle tray;
· Fold down/ up explosives warning signs and rectangular red flag; and
· Fire resisting conduits for electrical wiring and fittings.
9.7
Use of Explosives
for the CKR Project
Blast Design
The blast design shall consider the quantity and type of explosives needed including MIC (maximum instant charge), number of detonators required, as well as the sensitive receivers at the blasting location. The blasting design will be prepared by the Blasting Engineer, in collaboration with the Registered Shotfirer, checked and approved by the Blasting Competent Supervisor, and then submitted to Mines Division for auditing prior to implementation. The blast design will ensure that each detonator will initiate at a different time delay to allow sequential breaking of the rock.
Blast Loading and Execution
For the CKR Project, on each working day, the collection of the correct quantity of explosives and detonators from the Mines Division and/ or Contractor’s approved vehicles will be checked by the Registered Shotfirer, a representative from the supervising engineer (Resident Explosives Supervisor) and a representative from the Contractor, before the blasting actually takes place. The anticipated blasting time will be between 2:00pm to 6:00pm.
To ensure that blasting of different sectors of the blast face occurs in the correct sequence and not simultaneously, the shock tubes from the detonators associated with a particular sector may be bunched together and wrapped with the detonating cord. A bunch block is then attached to the detonating cord. The shock tube tail of the bunch block will itself be ignited by a surface connector. Two surface connectors may be linked in series, with their connected bunch blocks in parallel, to ensure the staggering of the individual detonations across the entire blast face. The bunch block typically has no delay time, as the delay is provided by the surface connector to which its initiating shock tube is connected.
Vibration Monitoring
It is a requirement to monitor every blast in Hong Kong to record blast induced ground vibrations. When each and every blast is designed, the first parameter to be established is controlling sensitive receiver, which may be a building, structure, slope or utilities; its allowable peak particle velocity (PPV); its radial distance from the blast and the allowable MIC calculated.
A Blasting Engineer is responsible for ensuring that the controlling and other nominated sensitive receivers for each blast are monitored to record the PPV in mm/s. In addition, there may be instances where it is necessary to record air overpressure generated by blasting activities.
Trial Blasts
Trial blasts, conducted with cartridged emulsion explosives, will be carried out for the first series of blasts for the tunnels and different areas or sectors of the project if required. The trial blasts will be used to determine rock characteristics and to collect data to enable site specific constants to be calculated for future vibration prediction (in terms of PPV), and to ensure the blasting monitoring and control procedures are effective. After reliable data is obtained from the trial blasts, Bulk emulsion explosives will be used instead for more effective blasting operations.
Advance Notice of Blasts
As part of the process of issuing a “License to Possess” and a “Permit to Use” dangerous goods, Mines Division will require that highly visible warning notices/ signs be posted at several locations to warn the public that blasting will take place. These warning signs will be posted near the intended blasting location, even though all blasts will be conducted underground. The Contractor is required to display the blasting date and time on the notice.
Public Safety Measures
Public safety measures during the Project can take many forms, such as:
· Site hoarding;
· Security guards;
· Warning signage;
· District Council meetings/ briefings by the Resident Engineer; and
· Public relations programmes.
Additionally, various government departments and industry occasionally provide safety training and inspection, for example the Construction Industry Council (CIC) and the Labour Department.
Safety Management System
Contractors
are required by law to have a comprehensive Safety Management System (usually OHSAS-18001) which is
to be implemented and supervised by on-site safety teams. Annual checks of
documentation and safety records will have to be performed by independent third
party auditors.
Three types of population have been considered for this assessment:
· Building Population;
· Pedestrian Population; and
· Traffic Population.
Building Population
Buildings along the Explosive Delivery Routes
The proposed explosive delivery routes will pass through densely populated residential and commercial regions in the Central Kowloon area. Building population of the areas in the vicinity of the routes is estimated from the 2009-based Territorial Population and Employment Data Matrix (TPEDM) [9-40], the Outline Zoning Plan (OZP) and the Planning Data Zones (PDZ) zone. The whole Hong Kong Special Administrative Region is delineated into 405 “Planning Data Zones”, abbreviated as “PDZ-405 Zones” (which are identical to the 405 “Planning Vision and Strategy Zones” (PVS-405 Zones) adopted in the 2006-based TPEDM at large).
Population
data in year 2017 are estimated
in accordance with the construction time and the period of explosives delivery. Population data in year 2017 is projected based on the 2016 and 2021 planning data of the population as extracted from the
2009-based Territory Population and Employment Data Matrices (TPEDM) [9-40].
Construction staff at the project work sites is not considered as off-site
population and are not included
in population data.
The population data are split into 4 different categories representing different times of the day. This split has been adopted from the one used in the HA for Potential Hazardous Installations (PHIs) (Para. 14A.23) of the Harbour Area Treatment Scheme (HATS) Stage 2A EIA [9-3].
· Weekday day (Mon-Fri 07:00-19:00);
· Weekday night (Mon-Fri 19:00-07:00);
· Weekend day (Sat-Sun 07:00-19:00); and
· Weekend night (Sat-Sun 19:00-07:00).
Indoor population is distinguished from the outdoor population. Indoor population refers to people inside buildings, while outdoor population refers to pedestrians on both sides of the road. The model for estimating fatalities from building population is adopted from the West Island Line (WIL) EIA [9-1]. Cylindrical shaped hazard zones have been applied to estimate the affected population inside buildings, and the height of the cylindrical hazard zone is assumed to be the same as the horizontal hazard distance at 1% fatality probability.
An indoor ratio of 95% is applied to the total population for a building. A presence factor is applied to different types of buildings to account for occupancies during different times of the day. These factors have been assumed with reference to those applied in the HA for PHIs (Para. 14A.23) of HATS Stage 2A EIA [9-3] and the South East Kowloon Development (SEKD) Comprehensive Feasibility Study (CFS) EIA (Para. 9.3.2.9) [9-4]. Day time data for the recreational population group are taken from the population group “Shopping Centre” in HATS Stage 2A EIA [9-3]. Night time data are the average of night time presence factor for population groups "recreational ground" (0%) and "park" (10%) in SEKD CFS EIA [9-4]. Night time presence factor for “Schools” is obtained from the highest value (0.98%) for population locations 3X-R, 3Q-PS, 3Q-SS, 3X-PS, 20, 3M-SS in SEKD CFS EIA and rounded up to 1%. For the 5% night time presence factor for “Schools”, it is an assumption to account for non-curriculum activities during weekend. Since the explosives delivery operation will be arranged at daytime, weekday day and weekend day data are applied to the assessment.
· Residential: weekday day 25%; weekend day 70%; night time 100%;
· Industrial/ commercial: weekday day 100%; weekday night 10%; weekend day 40%, weekend night 5%;
· Recreational: weekday day 50%; weekend day 100%; night time 5%;
· Schools: weekday day 100%; weekend day 5%; night time 1%.
Population of each PDZ zone along the explosives delivery route is obtained and each zone is further broken down into different land uses according to the OZP for further breakdown of Indoor and Outdoor population. Appendix 9.7 shows the PDZ zone along the explosives delivery route and Appendix 9.8 listed the detailed breakdown of the population. Table 9.3 summarises population density for each PDZ-OZP combination. Since the delivery will be carried out at daytime, only daytime population for weekday and weekend is presented in the table.
Table 9.3 Population Density for Roadside Population Area
|
PDZ |
ID |
OZP |
Population Density (persons/m2) |
|||
|
INDOOR |
OUTDOOR |
|||||
|
WDD |
WED |
WDD |
WED |
|||
|
076 |
11 |
|||||