Contract No. NE/2015/01 Tseung Kwan O Lam Tin Tunnel - Main Tunnel and Associated Works

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1 Contract No. NE/2015/01 Tseung Kwan O Lam Tin Tunnel - Main Tunnel and Associated Works Leighton China State Joint Venture December 2016

2 Notice This document and its contents have been prepared and are intended solely for Leighton - China State Joint Venture s information and use in relation to Contract No. NE/2015/01 Tseung Kwan O Lam Tin Tunnel and Associated Works. Atkins China Ltd assumes no responsibility to any other party in respect of or arising out of or in connection with this document and/or its contents. Document history Job number: Document ref: OR005 Revision Purpose description Originated Checked Reviewed Authorised Date Rev 0.0 First Submission Rev 1.0 Second Submission Client signoff Client Leighton China State Joint Venture Project Document title Job no Copy no. Contract No. NE/2015/01 Tseung Kwan O Lam Tin Tunnel - Main Tunnel and Associated Works Document reference OR005 Atkins BHMP Revision 1.0 December

3 Table of contents Chapter Pages 1. Introduction Background Purpose of this Report Report Structure 2 2. Monitoring Parameters, Schedule and Methodology Monitoring Locations Construction Works and Monitoring Schedule Monitoring Procedure Monitoring Parameters and Alert, Alarm and Action Levels Specification of the Monitoring Equipment for Vibration Monitoring Specification of the Monitoring Equipment for Building Settlement and Building Tilting 5 3. Mitigation Measures Mitigation Measures when Exceedance recorded 6 Tables Table 2-1 Monitoring Parameters and AAA Levels Table 2-2 Minimum General Specification Requirements Based on ISEE (2000) Table 3-1 Mitigation Measures for the Monitoring Figures Figure 2-1 Location of Cha Kwo Ling Tin Hau Temple and Monitoring Locations Figure 2-2 Example of a Tiltmeter (Left) and a Bronze Tilt Plate (Right) Figure 2-3 Example of a Building Settlement Marker Atkins BHMP Revision 1.0 December

4 1. Introduction 1.1. Background In 2002, Civil Engineering and Development Department (CEDD) commissioned an integrated planning and engineering study under Agreement No. CE 87/2001 (CE) Further Development of Tseung Kwan O (TKO) Feasibility Study to formulate a comprehensive plan for further development of TKO New Town. It recommended to further develop TKO to house a total population of 450,000 besides the district s continuous commercial and industrial developments. At present, the Tseung Kwan O Tunnel is the main connection between TKO and other areas in the territory. To cope with the anticipated transport need, the TKO Study recommended the provision of Tseung Kwan O Lam Tin Tunnel (TKO-LT Tunnel) and Cross Bay Link (CBL) to meet the long-term traffic demand between TKO and the external areas. The TKO-LT Tunnel, together with the proposed Trunk Road T2 in Kai Tak Development (KTD) and Central Kowloon Route (CKR), will form Route 6 in the strategic road network. Route 6 will provide an east-west express link between Kowloon and TKO areas. Upon completion, this strategic route will also provide the necessary relief to the existing heavily trafficked road network in the central and eastern Kowloon areas, and reduce the related environmental impacts on these areas. The Tseung Kwan O Lam Tin Tunnel and Association Works Investigation (hereafter referred to as the Project ) is a Designated Project under the Environmental Impact Assessment Ordinance (EIAO). An application (No. ESB-195/2008) for an Environmental Impact Assessment (EIA) Study Brief under section 5(1) of the Environmental Impact Assessment Ordinance was submitted by the CEDD on 17 July 2008 with a Project Profile (No. PP-361/2008) for the Project. An Environmental Impact Assessment (EIA) Study (EIA Report Register No.: AEIAR-173/20) for the Project has been undertaken as part of the Assignment, which was approved with conditions on 11 July 2013 and the current Environmental Permit (EP) (EP-458/2013/B) for the Project was granted on 31 December The Project has been divided into multiple contracts, the construction works for Main Tunnel and Associated Works (hereafter referred to as the Contract Works ) are under the Contract No. NE/2015/01. Condition 3.7 of the EP (EP-458/2013/B) states that Monitoring of vibration impacts should be carried out when the construction works are less than 100m from the temple. A maximum ppv at 5mm/s is adopted for this building. Tilting and settlement monitoring should be applied on the Cha Kwo Ling Tin Hau Temple. The Permit Holder shall, no later than one month before the commencement of work, submit to the Director for approval three hard copies and two electronic copies of a proposal plan (plan shall be certified by the ET Leader and verified by the IEC before submission) with details for the mitigation measures and monitoring of impacts on built heritage. Atkins China Limited has been commissioned by Leighton China State Joint Venture to assist in the preparation of a (BHMP) as required under Condition 3.7 of the EP detailing the mitigation measures and vibration monitoring plan. It should be noted that this BHMP is applicable for Contact No. NE/2015/01 of the Project only Purpose of this Report This BHMP is prepared to comply with Condition 3.7 of the current EP (EP-458/2013/B) for the Contract works under Contact No. NE/2015/01. Atkins BHMP Revision 1.0 December

5 1.3. Report Structure Section 1 Introduction Section 2 Monitoring Parameters, Schedule and Methodology Section 3 Mitigation Measures Atkins BHMP Revision 1.0 December

6 2. Monitoring Parameters, Schedule and Methodology 2.1. Monitoring Locations One (1) vibration monitoring point, one (1) building settlement monitoring point and one (1) building tilting monitoring point are proposed for the vibration impacts monitoring of the construction works. The building settlement marker and the tiltmeter will be placed on the wall of the Cha Kwo Ling Tin Hau Temple and the vibration monitoring point is located within the Cha Kwo Ling Tin Hau Temple. Confirmation from the Cha Kwo Ling Tin Hau Temple on the installation of these monitoring equipment will be obtained by the contractor. The locations of the monitoring points are shown in Figure 2-1. Figure 2-1 Location of Cha Kwo Ling Tin Hau Temple and Monitoring Locations Cha Kwo Ling Tin Hau Temple Child Giving Rock LEGEND SITE BOUNDARY 100M FROM THE CHA KWO LING TIN HAU TEMPLE CHA KWO LING TIN HAU TEMPLE VIBRATION MONITORING POINT BUILDING SETTLEMENT POINT TILTMETER 2.2. Construction Works and Monitoring Schedule According to the current construction schedule, construction works that will be conducted within 100m from the Cha Kwo Ling Tin Hau Temple include road works, slope works and construction of the barging point. These are scheduled to commence on 24 January 2017 and tentatively ends in June During the period of the construction works conducted within 100m from the Cha Kwo Ling Tin Hau Temple, monitoring on settlement and tilting will be conducted once a day for the Cha Kwo Ling Atkins BHMP Revision 1.0 December

7 Tin Hau Temple. Monitoring of vibration will be conducted during blasting at Cha Kwo Ling area once a day. When there is no blasting to be conducted at the area, vibration monitoring at the Cha Kwo Ling Tin Hau Temple will be conducted once per day when there are piling works or rock breaking works within the 100m from the Cha Kwo Ling Tin Hau Temple Monitoring Procedure Vibrographs (velocity seismograph) will be deployed at each monitoring station to measure and record the PPV and amplitude of ground motion in three mutually perpendicular directions. Vibration monitoring equipment fulfils the requirements stated in the Government guidelines and is calibrated to HOKLAS standards. Vibration monitoring will be conducted during the firing of each blast. If no blasting is to be conducted, monitoring will be conducted during once per day when there are piling works or rock breaking works within the 100m from the Cha Kwo Ling Tin Hau Temple. Each monitoring will not more than 10 minutes. Settlement and tilting monitoring will be conducted by surveyors manually Monitoring Parameters and Alert, Alarm and Action Levels The monitoring parameters and the respective Alert, Alarm and Action (AAA) Levels are given in Table 2-1. Table 2-1 Monitoring Parameters and AAA Levels Parameter Alert Level Alarm Level Action Level Vibration ppv: 4.5mm/s ppv: 4.8mm/s Building Settlement Markers ppv: 5mm/s Maximum Allowable Vibration Amplitude: 0.1mm 6mm 8mm 10mm Building Tilting 1:2000 1:1500 1: Specification of the Monitoring Equipment for Vibration Monitoring Vibration monitoring will be conducted by using vibrographs: Minimate Plus manufactured by Instantel. These vibrographs will be calibrated annually and its performance follows the requirements given in the Guidance Note on Vibration Monitoring (GN-VM) issued by the Civil Engineering and Development Department, which is based on the Performance Specification for Blasting Seismographs by International Society of Explosive Engineers (ISEE (2000)), listed in Table 2-2. It should be noted that other vibrographs comply with the requirements may also be used in the vibration monitoring if necessary. Table 2-2 Minimum General Specification Requirements Based on ISEE (2000) Item Frequency Range Accuracy Transducer density Digital sampling Requirement 2 to 250 Hz, within zero to -3dB of an ideal flat response +/- 5 % or +/- 0.5 mm/s, whichever is larger, between 4 and 125 Hz < 2.4 g/cc Operating temperature -12 to 49 C 1000 samples/sec or greater, per channel Atkins BHMP Revision 1.0 December

8 2.6. Specification of the Monitoring Equipment for Building Settlement and Building Tilting Building settlement will be measured by surveyors via settlement marker and tiltmeter attached to the wall of the Cha Kwo Ling Tin Hau Temple. Figure 2-2 shows a sample of a tiltmeter and a bronze tileplate and Figure 2-3 shows a sample of building settlement marker for reference. Figure 2-2 Example of a Tiltmeter (Left) and a Bronze Tilt Plate (Right) Figure 2-3 Example of a Building Settlement Marker Atkins BHMP Revision 1.0 December

9 3. Mitigation Measures 3.1. Mitigation Measures when Exceedance recorded The actions to be taken when respective AAA Level has been exceeded are given as follows: Table 3-1 Mitigation Measures for the Monitoring Level Contingency Action The Engineer shall be informed immediately. Alert Level The Contractor shall submit an investigation report to describe works being undertaken. To review the instrument responses and to study the cause of undue response. The Contractor shall review and increase the instrumentation monitoring and reporting frequency, if applicable. The Contractor shall submit a detailed plan of action describing the measures to be taken should the concerned instrument reach the action level to the Engineer for approval. The Engineer shall be informed immediately. The active construction works may require to be suspended subject to the Engineer s review of monitoring data. The Contractor shall immediately implement the measures as defined in the detailed plan of action to prevent further ground movement and groundwater drawdown etc. The Contractor shall prepare a detailed investigation report to study the cause of the exceedance Alarm Level The Contractor shall propose a contingency plan for the Engineer s approval in the event that alarm value is reached or exceeded The Contractor shall develop an emergency plan for the Engineer s approval in the event the applied contingency measures cannot control the situation. The Contractor shall meet the Engineer to discuss the instrument response and review the effectiveness of the implemented measures. The Contractor shall carry out design review of the works Atkins BHMP Revision 1.0 December

10 Action Level Level Contingency Action Consideration shall be given to suspend all active construction works and the Engineer shall be informed immediately The Contractor shall immediately implement the measures defined in the contingency plan The Contractor shall implement the measures defined in the emergency plan in the event that the applied contingency measures are found inadequate The Contractor shall provide a complete report to examine the construction method and review the response of the instruments with full history of the monitoring data and construction activities and necessary design update To resume the suspended activities, the Contractor shall demonstrate to the Engineer s satisfaction that it is safe to do so with approval from the Engineer. Atkins BHMP Revision 1.0 December

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