Contract No. NE/2015/01 - files.cinotech.com.hk · Contract No. NE/2015/01 Tseung Kwan O – Lam...

Contract No. NE/2015/01

Tseung Kwan O – Lam Tin Tunnel Main Tunnel and Associated Works

(GEN-0008D)

Report No. TKOLTT-RPT-GEO-00057

Built Heritage Mitigation Plan

Leighton China State Joint Venture

NE/2015/01 - Built Heritage Mitigation Plan | Jul 2018

LCS-CAC-TMP-203 Rev 01 Page 1 of 16 2 August 2018

Contents

1 Introduction .............................................................................................................................. 3

1.1 Background ..................................................................................................................... 3

1.2 Purpose of this Report ..................................................................................................... 4

1.3 Replacement of Tilting Measurement by Building Settlement Point Measurement ........... 4

1.4 Additional Tilting Measurement........................................................................................ 4

1.5 Report Structure .............................................................................................................. 5

2 Monitoring Parameters, Schedule and Methodology ................................................................ 5

2.1 Monitoring Locations ....................................................................................................... 5

2.2 Construction Works and Monitoring Schedule.................................................................. 6

2.3 Monitoring Procedure ...................................................................................................... 7

2.4 Monitoring Parameters and Alert, Alarm and Action Levels ............................................. 7

2.5 Specification of the Monitoring Equipment for Vibration Monitoring ................................. 7

2.6 Specification of the Monitoring Equipment for Building Settlement .................................. 8

2.7 Specification of the Monitoring Equipment for Tilting Measurement ................................. 8

3 Mitigation Measures............................................................................................................... 10

3.1 Mitigation Measures when Exceedance Recorded ........................................................ 10

Appendices ................................................................................................................................... 11

Appendix A ................................................................................................................................... 12

Letter to Chinese Temples Committee from ER ............................................................................ 12

Appendix B ................................................................................................................................... 13

Alert, Alarm and Action (AAA) Levels of Level Ground .................................................................. 13

Appendix C ................................................................................................................................... 14

Proposed Location for Installation Tilting Markers ......................................................................... 14

Appendix D ................................................................................................................................... 15

Proposed Methodology for Tilting Measurement ........................................................................... 15

Appendix E ................................................................................................................................... 16

Monitoring Plan of Tin Hau Temple in Conforming Drawing .......................................................... 16


NE/2015/01 - Built Heritage Mitigation Plan | July 2018


Revision History and Plan Approval

Note: Those changes in the latest version were underlined.

Revision Date Prepared by Reviewed by Approved by

00 19-Dec-16 Ivan Ting - Atkins Wing Wong - Atkins Wing Wong - Atkins

01 22-Dec-16 Ivan Ting - Atkins Wing Wong - Atkins Wing Wong - Atkins

02 26-Aug-17 Kathy Lau Max Ngok Justin Taylor

03 19-Dec-17 Kathy Lau Max Ngok Justin Taylor

04 16-Jul-18 Ka Hung Lam Max Ngok Anthony John




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-173/2013) 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/C) for the Project was granted on 20 January 2017.

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/C) 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.”

A Built Heritage Mitigation Plan (BHMP) was previously prepared and submitted by Atkins China Limited commissioned by Leighton – China State Joint Venture (LCSJV) in December 2016. The BHMP is required under Condition 3.7 of the EP detailing the mitigation measures and vibration monitoring plan, and it is applicable for Contract No. NE/2015/01 of the Project only. In this submission, LCSJV has taken up the responsibility to revise the BHMP so that




mutually-agreed changes by LCSJV and the Engineer regarding instrumentation are addressed.

1.2 Purpose of this Report

This BHMP is prepared to comply with Condition 3.7 of the current EP (EP-458/2013/C) for the Contract works under Contract No. NE/2015/01.

1.3 Replacement of Tilting Measurement by Building Settlement Point Measurement

In BHMP Rev.01, 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 were to be placed on the wall of the Cha Kwo Ling Tin Hau Temple and the vibration monitoring point would be within the Cha Kwo Ling Tin Hau Temple.

During a site meeting with the Chinese Temple Committee which carried out in April 2017, the Chinese Temples Committee rejected the installation of tilt plate on the wall for the reason of causing potential damage to the Tin Hau Temple’s wall surface, in which the letter to Chinese Temples Committee from ER is attached in Appendix A. As agreed with the Engineer, the tilting measurement was replaced by ground settlement point measurement.

As a result, in BHMP Rev.02, replacement of tilting monitoring by ground settlement point measurement is recorded. The purpose is to measure any potential differential settlement of the Tin Hau Temple, which could be resulted in tilting of the building. Alert, Alarm and Action (AAA) levels for the ground settlement point measurement were proposed.

On 13 November 2017, comments from EPD were received. It was suggested in EPD’s comments to use multiple building settlement points to measure tilting instead. Therefore, LCSJV has obtained consent from the Chinese Temple Committee via ER on 18 December 2017, and carried out installation of 2 nos. of building settlement points on the walls of the Temple.

With the newly installed tilting markers from August 2018, the additional two BSP points (THT-BSP-02 & THT-BSP-03) will be deleted and monitoring work will stop while only THT-BSP-01 remains.

1.4 Additional Tilting Measurement

On 14th June 2018, AECOM, LCSJV and CKL village stakeholders (Chinese Temples Committee) had held a joint inspection for tilting measurement for Tin Hau Temple.

The Chinese Temple Committee had no objection to the installation of the 8 monitoring markers (4 monitoring points in total) on the wall of Tin Hau Temple. One monitoring point consists of 2 monitoring markers. The proposed tilting measurement setup is attached in Appendix C that traditional tilting plates would not be used. Black/white markers are used




instead. LCSJV would submit monthly monitoring report and construction work will suspend once building settlement exceeds AAA levels. (Alert, Action, Alarm).

The proposed location of 8 monitoring markers are attached in Appendix C.

1.5 Report Structure

• Section 1 – Introduction

• Section 2 – Monitoring Parameters, Schedule and Methodology

• Section 3 – Mitigation Measures

2 MONITORING PARAMETERS, SCHEDULE AND METHODOLOGY

2.1 Monitoring Locations

In this updated BHMP Rev.04, one vibration monitoring point and one building settlement monitoring point are proposed for the vibration impacts monitoring of the construction works. The building settlement point was installed on one side of the Temple. The vibration monitoring point would be within the Cha Kwo Ling Tin Hau Temple.

From August 2018 onwards, there will be four tilting measurement points, and the measurement will be taken weekly.

The locations of the monitoring points are shown in the below Figure 2-1.




Figure 2-1 Location of Cha Kwo Ling Tin Hau Temple and Monitoring Locations

*Original THT-BSP-2 & THT-BSP-3 will be deleted.

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 were scheduled to commence on 24 January 2017 and tentatively ends in June 2020. During the period of the construction works conducted within 100m from the Cha Kwo Ling Tin Hau Temple, monitoring on settlement will be




conducted once a day for the Cha Kwo Ling 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.

2.3 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 be more than 10 minutes.

Settlement monitoring will be conducted by surveyors manually.

Tilting measurement will be carried out by LCSJV monitoring team weekly.

2.4 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

ppv: 5mm/s

Maximum Allowable

Vibration Amplitude: 0.1mm

Building Settlement Point 6mm 8mm 10mm

Building Tilting (1) 1:2000 1:1500 1:1000

2.5 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 Requirement

Frequency Range 2 to 250 Hz, within zero to -3dB of an ideal flat response

Accuracy +/- 5 % or +/- 0.5 mm/s, whichever is larger, between 4 and 125 Hz

Transducer density < 2.4 g/cc

Digital sampling 1000 samples/sec or greater, per channel

Operating temperature -12 to 49°C

2.6 Specification of the Monitoring Equipment for Building Settlement

Building settlement will be measured via a settlement marker attached to the wall of Cha Kwo Ling Tin Hau Temple by adhesive tape. Figure 2-2 shows a sample of the installed instrument.

Figure 2-2 Building Settlement Point

2.7 Specification of the Monitoring Equipment for Tilting Measurement

Tilting measurement will be measured via a marker (in Black/White) attached to the walls of Cha Kwo Ling Tin Hau Temple by adhesive tape. Figure 2-3 shows a sample of the installed instrument.

More details regarding the measurement methodology can be found in Appendix D.




Figure 2-3 Tilting Measurement Point

*the marker will be in black/white during installation, Fig 2-3 demonstrates a sample only




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:

Level Contingency Action

Alert Level • The Engineer shall be informed immediately.

• 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.

Alarm Level • 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

• 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

Action Level • 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.




APPENDICES




APPENDIX A

LETTER TO CHINESE TEMPLES COMMITTEE FROM ER




APPENDIX B

ALERT, ALARM AND ACTION (AAA) LEVELS OF LEVEL GROUND




APPENDIX C

PROPOSED LOCATION FOR INSTALLATION TILTING MARKERS

*Red Color - Adopted*Blue Color - Not Adopted

Total 4 monitoring points (ie.8 settlement markers) will be installed on four sides of building based on inspection on 14th June 2018

AdoptedAdopted Adopted

Adopted Not Adopted




APPENDIX D

PROPOSED METHODOLOGY FOR TILTING MEASUREMENT

Proposed tilting measurement set-up

Detachable

Steel Angle

Sticker Mark #1

(1.5m from Mark #2)

Pump Wire

Sticker Mark #2

Pump Cone

Caliper

Measure distance between the wall and pump wire at

locations #1 and #2. Since AAA level = 1/2000,

1/1500, 1/1000, the difference in measurement

between the two points cannot exceed 0.75mm,

1mm, 1.5mm

Calculation

Pump cone can be

placed in engine oil

to increase stability

where necessary




APPENDIX E

MONITORING PLAN OF TIN HAU TEMPLE IN CONFORMING DRAWING

FOR CONSTRUCTION

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