Wilson Acoustics Limited

Transcription

1 Hong Kong Institute of Acoustics - Vibration Seminar Series Seminar 1 TBM Groundborne Noise Prediction Models Wilson Ho, Banting Wong Wilson Acoustics Limited

2 Contents 1. TBM GBN Projects in HK Wilson Ho TBM GBN Study in various tunnel projects in HK 3 Types of TBM GBN Prediction Models Direct Measurement Approach & Its Limitations 2. Modular Prediction Approach Banting Wong Hammer Impact Test Line Source / Point Source Excitation TBM Operation Mode & Excitation Force Wilson Acoustics Limited

3 Client TBM Groundborne Noise Projects In the past 10 years, Wilson Ho has been involved in a number of TBM groundborne noise projects, ranging from different TBM types and tunnel diameters. Tunnel EIA Year Tunnel Constr TBM Dia, m Type of TBM (Tunnel Boring Machine) MTR Quarry Bay Congestion Relief Work Open Mode Hard Rock KCR West Rail Kwai Tsing Tunnel Earth Pressure Balance DSD Kai Tak Transfer Scheme Slurry KCR Lok Ma Chau Spurline Earth Pressure Balance CLP Chi Ma Wan Tunnel Open Mode Hard Rock KCR/MTR Kowloon Southern Link Slurry CLP Castle Peak Tunnel Double Shield Hard Rock DSD HK West Drainage Tunnel ? 8.3 Double Shield Hard Rock MTR West Island Line ? 6.3 Slurry MTR Express Rail Link ? 9.2 Earth Pressure Balance Wilson Acoustics Limited 3

4 Wilson Ho Published Papers Due to confidentiality of individual projects, the seminar is based on information in Wilson Ho published papers Wilson Ho, Banting Wong, Andy Raine and Ken Kwok (2009) Groundborne Noise and Vibration Impact from Rock Tunnel Boring Machines, Hong Kong Tunnelling Conference 2009, P Ken K.F. Kwok, Andy Raine, Adman Chu & Wilson Ho (2009) Environmental Paper Award Submission - Green Cable Tunnel Construction At Castle Peak HKIE Journal 2009, awarded the 1st runner up paper. Wilson Ho, Alan Crockett and Andy Raine (2006) Measurement and Prediction of Groundborne Noise and Vibration from a Tunnel Boring Machine, Technical Acoustics, 2006, 25(6), P Sam Tsoi, Wilson Ho, Nick Antonio and Glenn Frommer (2001) Railway Groundborne Noise prediction through Vibration Measurements of a Tunnel Boring Machine, Proceedings of the 8th International Congress of Sound and Vibration, Hong Kong, Issac Ng, Edmond Wong and Wilson Ho (2001) Co-existence of Construction Work and Tranquility A Myth or Reality, Proceedings of the 8th International Conference of Sound and Vibration 2001, pp Wilson Acoustics Limited

5 TBM Groundborne Noise Projects Client Tunnel EIA Year Tunnel Constr TBM Type of TBM Dia, m (Tunnel Boring Machine) MTR Quarry Bay Congestion Relief Work Open Mode Hard Rock KCR West Rail Kwai Tsing Tunnel Earth Pressure Balance DSD Kai Tak Transfer Scheme Slurry KCR Lok Ma Chau Spurline Earth Pressure Balance CLP Chi Ma Wan Tunnel Open Mode Hard Rock KCR/MTR Kowloon Southern Link Slurry CLP Castle Peak Tunnel Double Shield Hard Rock DSD HK West Drainage Tunnel ? 8.3 Double Shield Hard Rock MTR West Island Line ? 6.3 Slurry MTR Express Rail Link ? 9.2 Earth Pressure Balance Wilson Acoustics Limited 5

6 West Rail Kwai Tsing Tunnel DB320 (Earth Pressure Balance TBM) HK West Drainage Tunnel (Double Shield Hard Rock) Quarry Bay Congestion Relief Work (Open Mode Hard Rock TBM) Open Mode Hard Rock TBM Double Shield Hard Rock

7 MTR Quarry Bay Congestion Relief Work ( ) Ref. Wilson Acoustics Limited 7

8 MTR Quarry Bay Congestion Relief Work 6.2m Open-mode hard rock TBM Wilson Acoustics Limited 8

9 MTR Quarry Bay Congestion Relief Work Sound level meter Residential Building Measurement of transfer function TBM cutter head Tunnel Partially Decomposed Granite 6.2m Open mode hard rock TBM Accelerometer Measurement on vibration propagation losses 9

10 MTR Quarry Bay Congestion Relief Work ~6dB for doubling distance i.e. very small soil damping, even for high frequency vibration Ref. Proceedings of the 8th International Conference of Sound and Vibration (2001), pp Wilson Acoustics Limited 10

11 MTR Quarry Bay Congestion Relief Work overall linear vibration level at 6m from cutting face ~ 0.1mm/s ~55dB(A) Ref. Proceedings of the 8th International Conference of Sound and Vibration (2001), pp Wilson Acoustics Limited 11

12 TBM Groundborne Noise Regulations Groundborne Noise Criteria under NCO and EIAO 10dB(A) below airborne noise limits Daytime Noise Criteria: 55 to 65dB(A), (EIAO) Evening Noise Criteria: 50 to 55dB(A), (NCO) Nighttime Noise Criteria: 35 to 40dB(A), (NCO) Construction Noise Permit (CNP) is required for TBM operation after 1900 hours. Evaluated based on L eq,5min Critical frequency range ~ Hz Groundborne Noise of TBM Wilson Acoustics Limited 12

13 MTR Quarry Bay Congestion Relief Work Left: Incomplete noise enclosure at Shaft N for TBM launch shaft Right: Noise enclosure for drill & blast excavated shaft TBM Groundborne Noise Monitoring was conducted during daytime. When it exceeded the night-time noise limit, night TBM work would be ceased. Ref. Wilson Acoustics Limited 13

14 TBM Tunnelling Practice 24-hour TBM operation is a general practice for tunnelling work if allowed. Reliable GBN prediction model is required for CNP application. Construction Programme Avoid TBM stopping at unfavorable geology (faults) Difficult to restart TBM Water leakage Ground collapse Wilson Acoustics Limited 14

15 Examples of Excitation Force Level under Various Thrusting Pressure Photograph of the cutter head Ref. Wilson Ho, Alan Crockett and Andy Raine, Measurement and Prediction of Groundborne Noise and Vibration from a Tunnel Boring Machine, Technical Acoustics, Vol.25 No.6, December Wilson Acoustics Limited 15

16 Examples of Point Source Response Photograph of the Impact Hammer Ref. Wilson Ho, Alan Crockett and Andy Raine, Measurement and Prediction of Groundborne Noise and Vibration from a Tunnel Boring Machine, Technical Acoustics, Vol.25 No.6, December Wilson Acoustics Limited 16

17 PPV, L max,fast, L max,slow, L eq Vibration Levels The average values of PPV, L max,fast and L max,slow are 14dB, 6dB and 3dB above the L eq levels respectively. Ref. Wilson Ho, Alan Crockett and Andy Raine, Measurement and Prediction of Groundborne Noise and Vibration from a Tunnel Boring Machine, Technical Acoustics, Vol.25 No.6, December

18 Continuous Real-time Vibration Monitoring in Internet with Automatic Alarms 2 nd Action Level 25mm/s PPV 12 1 st Action Level 12mm/s PPV Wilson Acoustics Limited 18

19 TBM GBN Prediction Models Direct Noise & Vibration Measurement KCRC - DB320 Kwai Chung Tunnel ( ) MTRC - Quarry Bay Congestion Relief Work ( ) KCRC Kowloon Southern Link Tunnel ( ) Line Source Excitation Model KCRC Kowloon Southern Link Tunnel ( ) KCRC Lok Ma Chau Tunnel ( ) Point Source Excitation Model CLP Chi Ma Wan Tunnel ( ) CLP Castle Peak Tunnel ( ) DSD HK West Drainage Tunnel (2009-~) Wilson Acoustics Limited 19

20 Direct N&V Measurement - Methodology Prediction using interpolation of previous measurement results at similar distance, similar geology at cutting face, similar geology along transmission path, similar TBM type, similar thrusting force, similar rotation speed, similar no. of cutter disc and its design, etc Wilson Acoustics Limited 20

21 Direct N&V Measurement - Methodology GBN projection from ground vibration level Ln = Lv + BCF + BVR + CTN L n ~ ground-borne noise level L v ~ ground vibration level outside building, ref 10-6 in/s BCF ~ building coupling factor -3 ~ -15dB depending on building structure BVR ~ building vibration response -1 ~ -2dB floor to floor attenuation 6 ~ 15dB for concrete structure CTN ~ conversion to noise 0 ~ 5dB subject to room acoustic response Wilson Acoustics Limited 21

22 N&V Level Against Distance 22

23 Direct N&V Measurement - Vibration Data 23

24 Direct N&V Measurement - Vibration Data Due to confidentiality issues, individual project groundborne noise data is removed from the slides. 24

25 Direct Measurement Method - Limitations Source and transmission path variations could not be separated, e.g. change in TBM thrust / geology strata High Prediction Uncertainty Wilson Acoustics Limited 25

26 Modular Approach 26

27 Contents 1. TBM GBN Projects in HK Wilson Ho TBM GBN Study in various tunnel projects in HK 3 Types of TBM GBN Prediction Models Direct Measurement Approach & Its Limitations 2. Modular Prediction Approach Banting Wong Hammer Impact Test Line Source / Point Source Excitation TBM Operation Mode & Excitation Force Wilson Acoustics Limited

28 Modular Approach

29 Wilson Acoustics Limited Hammer Impact Test - Source (TBM Excitation Force)

30 Hammer Impact Test - Propagation (Soil Transfer Mobility)

31 Hammer Impact Test - Receiver (Building Vibration Response)

32 Hammer Impact Test In Borehole Taiwan Taoyuan International Airport MRT Impact Hammer Wilson Acoustics Limited Vibration Sensor

33 Hammer Impact Test In Borehole Hong Kong Wilson Acoustics Limited

34 Hammer Impact Test Inside Tunnel HK West Drainage Tunnel Sensor at the excavation face Sensor on the segment ring Impact test at the excavation face Wilson Acoustics Limited

35 Point Source Model Line Source Model Unit: N Unit: N / m 1/2 ( f ) = EFL( f ) + PSR( f ) + BCF( f ) + BVR( f ) CTN ( f ) L n + ( f ) = FDL( f ) + LSR( f ) + BCF( f ) + BVR( f ) CTN( f ) L n + Wilson Acoustics Limited

36 Measuring a point source using line source model tends to overpredict the total force, or vise versa. At greater distance, both models give similar results Bias Error at Critical Frequencies Estimated based on homogenous soil with a damping loss factor of 0.5

37 TBM Excitation Sources EPB TBM / Single Shield TBM (supported by tunnel wall) F cutter Hydraulic Cylinders Double Shield TBM (supported by gripper shoe) F support Tunnel Wall Gripper Shoe F cutter F support Courtesy: Herrenknecht AG

38 Point Source / Line Source EPB TBM / Single Shield TBM Cutterhead Hydraulic Cylinders Tunnel Wall F cutter F support Double Shield TBM Gripper Shoe Tunnel Wall F cutter F support

39 Wilson Acoustics Limited TBM Excitation Force - Influence Factors

40 1 A West Drainage Tunnel ~1km from Western Portal at Cyberport 3 2 C 2 B Wilson Acoustics Limited

41 Rock Types Typical Rock ~ slightly decomposed granite Stiff Rock ~ very strong granite, (fresh to slightly decomposed) Penetration Rate ~ cutting depth in each revolution

42 TBM Operation Modes Typical Rock (Slightly Decomposed Fine Granite) Penetration Rate 1 mm/rev 3 mm/rev 5 mm/rev 6 mm/rev 9 mm/rev 12.5 mm/rev 1.5 RPM O 3 RPM O O O O O 4.5 RPM O 6RPM 8 RPM O O O O Stiff Rock (Very Strong, Fresh to Slightly Decomposed Granite) Penetration Rate 0.5 mm/rev 1 mm/rev 1.5 mm/rev 2 mm/rev 3 mm/rev 3.5 mm/rev 1.5 RPM O 3 RPM O O O O 4.5 RPM O 6RPM O 8 RPM O O O O O O Wilson Acoustics Limited Data Set 2 O Data Set 1

43 Excitation Force & Rotational Speed Source Model ) ~4.6dB per doubling RPM ( Based on Point ~3.5dB per doubling RPM Wilson Acoustics Limited

44 Excitation Force & Penetration Rate 316kN Point Source Model ) ( Based on 3-4dB per doubling PR ~2dB per doubling PR 251kN 200kN 158kN 126kN 100kN 79kN 63kN 50kN 40kN For typical rock, higher penetration rate is more preferable for reducing overall noise exposure Wilson Acoustics Limited

45 Summary 1. Tunnel construction programme may depends on the TBM GBN prediction results. 2. Daytime GBN monitoring is a good method to check whether nighttime TBM construction should be stopped due to noise impact. 3. Continuous real-time vibration monitoring displayed in internet with automatic alarm scan be considered for critical locations. Direct Measurement & Modular Prediction Approaches 4. Prediction based on direct measurement approach may have high uncertainty. 5. Modular prediction approach allows detail study on the source, propagation and receiver response. 6. GBN distance correction shall be assessed at individual frequency band. 7. Excitation Force Level shall be determined for each TBM type in different geologies where practicable. 8. Point Source Response shall be measured at critical locations. Wilson Acoustics Limited

46 Summary 9. Line source model is more appropriate for low frequency vibration prediction for TBM without gripper shoes. 10. Point source model is more appropriate for high frequency vibration prediction (i.e. groundborne noise). TBM Operation Modes 11. Doubling rotational speed leads to 4-5dB increase in Excitation Force Level, depending on geology. 12. Excitation Force Level increases with penetration rate (PR) and achieves maximum at PR of 5-10mm/rev for certain geology. Wilson Acoustics Limited

47 Wilson Acoustics Limited

48 HKIOA Vibration Seminar Series 2010 Seminar 1: TBM Groundborne Noise Prediction Models Speaker: Wilson Ho / Banting Wong, Wilson Acoustics Limited Convener: David Salisbury, MTR Corporation Limited Venue: N003, Hong Kong Polytechnic University Time: 6:30-7:45pm, Wednesday, 6 January 2010 (reception at 6:00pm) Seminar 2: Vibration-based Condition Monitoring Commissioning and Standards Speaker: Ir. Dr. Peter Tse, Smart Engineering Asset Management Laboratory Venue: Room TU201, Hong Kong Polytechnic University Time: 6:45-7:45pm, Wednesday, 10 February 2010 (reception at 6:30pm) Scheduled Seminars Shock and Vibration Data Analysis Vibration Isolation of Buildings Railway Noise Control Using Vibration Absorber The design and engineering of rubber bearings for vibration isolation Active Vibration Control (Speaker not yet confirmed)