PUBLICATIONS

Journal Papers

Conference Papers

1. Fei Xie, Wallace W.L. Lai, Xavier Dérobert. GPR-based Depth Measurement of Buried Objects based on Constrained Least-square Fitting Method of Reflections, Measurement, 164, 108330, 2021. >>

 

2. Tess X.H. Luo and Wallace W.L. Lai, Antonios Giannopoulos. Forward modelling on GPR responses of subsurface air voids, Tunnelling and Underground Space Technology incorporating Trenchless Technology Research, 103: 103521, 2020. >>

 

3. Tess X.H. Luo and Wallace W.L. Lai. GPR pattern recognition of shallow subsurface air voids. Tunneling and Underground Space Technology, 99, 103355, 2020. >>

 

4. Tess X.H. Luo and Wallace W.L. Lai. Subsurface diagnosis with time-lapse GPR data, IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 13, 935-940, 2020. >>

 

5. Phoebe T.W. Wong, Wallace W.L. Lai, Janet F.C. Sham and Chi-Sun Poon. Hybrid non-destructive evaluation methods for characterizing chloride-induced corrosion in concrete, NDT&E International, 107:102123, 2019. >>

 

6. Bella W.Y. Cheung and Wallace W.L. Lai. Field validation of water-pipe leakage detection through spatial and time-lapse analysis of GPR wave velocity, Near Surface Geophysics, 17: 231-246, 2019. >>

 

7. Tess X.H. Luo, Wallace W.L. Lai, Ray K.W. Chang, Dean Goodman. GPR imaging criteria, Journal of Applied Geophysics, 165: 37–48, 2019. >>

 

8. Janet F.C.Sham, Wallace W.L.Lai, Wing Chan, Lin Koh Chee. Imaging and condition diagnosis of underground sewer liners via active and passive infrared thermography: A case study in Singapore, Tunnelling and Underground Space Technology, 84:440-450, 2019. >>

 

9. K. L. Siu and Wallace W. L. Lai. A lab study of coupling effects of electromagnetic induction on underground utilities. Journal of Applied Geophysics, 164:26-39, 2019. >>

 

10. Fei Xie, Chivas Gi-Wah Wu, Wallace Wai-Lok Lai, Janet Fung-Chu Sham. Correction of multi-frequency GPR wave velocity with distorted hyperbolic reflections from GPR surveys of underground utilities. Tunnelling and Underground Space Technology, 76:76-91, 2018. >>

 

11. Wallace Wai-Lok Lai, Xavier Dérobert, Peter Annan. A review of Ground Penetrating Radar application in civil engineering: A 30-year journey from Locating and Testing to Imaging and Diagnosis. NDT & E International, 96: 58-78. 2018. >>

 

12. Wallace Wai-Lok Lai, Ray K.W. Chang and Janet F.C. Sham. A blind test of nondestructive underground void detection by ground penetrating radar (GPR) Journal of Applied Geophysics 149: 10-17, 2018. >>

 

13. Wallace Wai-Lok Lai, Missoni Leong-Ying Ho, Ray K.W. Chang, Janet F.C. Sham, Chi-Sun Poon. Tracing and imaging minor water seepage of concealed PVC pipe in a reinforced concrete wall by high-frequency ground penetrating radar. Construction and Building Materials, 151: 840–847, 2017. >>

 

14. Janet F. C. Sham and Wallace W. L. Lai. Development of a new algorithm for accurate estimation of GPR's wave propagation velocity by common-offset survey method. NDT & E International, 83:104–113, 2016. >>

 

15. Wallace W.L. Lai, Thomas Kind, Janet F.C. Sham, Herbert Wiggenhauser. Correction of GPR wave velocity at different oblique angles between traverses and alignment of line objects in a common offset antenna setting. NDT&E International 82: 36–43, 2016. >>

 

16. Wallace Wai-Lok Lai, Ray K.W.Chang, Janet F.C. Sham and K. Pang. Perturbation mapping of water leak in buried water pipes via laboratory validation experiments with high-frequency ground penetrating radar (GPR). Tunneling and Underground Space Technology 52: 157–167, 2016. >>

 

17. Pun-Cheng L.S.C., Wallace W.L. Lai and Ray K.W. Chang. Exploring utility system SDI – Managerial and technical perspectives. Tunneling and Underground Space Technology 54: 13-19, 2016. >>

 

18. Wallace Wai-Lok Lai, Ka-Kin Lee, Chi-Sun Poon. Validation of size estimation of debonds in external wall’s composite finishes via passive Infrared thermography and a gradient algorithm. Construction and Building Materials 87: 113–124, 2015. >>

 

19. Wallace Wai-Lok Lai, Thomas Kind, Sabine Kruschwitz, Jens Wöstmann, Herbert Wiggenhauser. Spectral absorption of spatial and temporal ground penetrating radar signals by water in construction materials NDT&E International 67: 55–63, 2014. >>

 

20. Shuxian Hong, Wallace Wai-Lok Lai, Gerd Wilsch, Rosemarie Helmerich, Robert Helmerich, Tobias Günther, Herbert Wiggenhauser. Periodic mapping of reinforcement corrosion in Intrusive chloride contaminated concrete with GPR, Construction and Building Materials, 66: 671–684, 2014. >>

 

21. Shuxian Hong, W.L. Lai & Rosemarie Helmerich (2014): Experimental monitoring of chloride-induced reinforcement corrosion and chloride contamination in concrete with ground-penetrating radar, Structure and Infrastructure Engineering: Maintenance, Management, Life-Cycle Design and Performance, DOI: 10.1080/15732479.2013.879321 >>

 

22. W.L. Lai, T. Kind, M. Stoppel, H. Wiggenhauser. Measurement of accelerated steel corrosion in concrete using ground penetrating radar (GPR) and a modified half-cell potential method, ASCE Journal of Infrastructure Systems, 19(2): 205-220, 2013. >>

 

23. W.L. Lai, Y.H. Wang, S.C. Kou, C.S. Poon. Dispersion of ultrasonic guided surface wave by honeycomb in early-aged concrete NDT&E International, 57: 7–16, 2013. >>

 

24. W. L. Lai, S. C. Kou, C. S. Poon, W. F. Tsang, K. K. Lee. A  durability study of externally bonded FRP-concrete beams via infrared thermography (IRT) and quasi-static shear test, Construction and Building Materials, 40: 481–491, 2013. >>

 

25. W. L. Lai and C.S. Poon. Applications of nondestructive evaluation techniques in mandatory building inspection scheme, HKIE Transactions, 19(4): 34-41, 2012. >>

 

26. W. L. Lai, K. K. Lee, S. C. Kou, C. S. Poon, W.F. Tsang. A study of full-field debond behaviour and durability of CFRP-concrete composite beams by pulsed infrared thermography (IRT), NDT&E International, 52: 112-121, 2012. >>

 

27. W.L. Lai, S. C. Kou, C. S. Poon, Unsaturated Zone Characterization in soil through transient wetting and drying using GPR Joint Time-Frequency analysis and Grayscale Images, Journal of Hydrology, 452–453, 1–13, 2012. >>

 

28. W.L. Lai, T. Kind, H. Wiggenhauser. Frequency-dependent dispersion of high-frequency ground penetrating radar wave in concrete, NDT&E International, 44(3): 267-273, 2011. >>

 

29. W.L. Lai, T. Kind, H. Wiggenhauser. Using ground penetrating radar and time-frequency analysis to characterize construction materials, NDT&E International, 44(1): 111-120, 2011. >>

 

30. W.L. Lai, T. Kind, H. Wiggenhauser. A Study of Concrete Hydration and Dielectric Relaxation Mechanism using Ground Penetrating Radar (GPR) and Short Time Fourier Transform (STFT), EURASIP (European Association for Signal Processing) Journal on Advance in Signal Processing, Vol. 2010, Article ID 317216, doi:10.1155/2010/317216, 2010. >>

 

31. W. L. Lai, S. C. Kou, C. S. Poon, W. F. Tsang, C. C. Lai, Characterization of the Deterioration of Externally Bonded CFRP-Concrete Composites using Quantitative Infrared Thermography, Cement and Concrete Composites, 32(9): 740-746, 2010. >>

 

32. W. L. Lai, S. C. Kou, C. S. Poon, W. F. Tsang, C. C. Lai, Effects of elevated temperatures on interfacial delaminations, failure modes and shear strength in externally-bonded CFRP beams using infrared thermography, gray-scale images and direct shear test, Construction and Building Materials, 23: 3152–3160, 2009. >>

 

33. W.L. Lai, S.C. Kou, W.F. Tsang and C.S. Poon. Characterization of concrete properties from dielectric properties using ground penetrating radar, Cement and Concrete Research, 39(8): 687-695, 2009. >>

 

34. W.L. Lai, S. C. Kou, C.S. Poon, W.F. Tsang, S.P. Ng and Y.Y. Hung. Characterization of flaws embedded in externally bonded CFRP on concrete beams by infrared thermography and shearography, Journal of Nondestructive Evaluation, 28: 27–35, 2009. >>

 

35. S.C. Kou, G. Lee, C.S. Poon and W.L Lai. Properties of lightweight aggregate concrete    prepared with PVC granules, Waste Management, 29(2): 621-628, 2009. >>

 

36. W. L. Lai and W. F. Tsang, Characterization of Pore Systems of Air/Water-cured Concrete Using Ground Penetrating Radar (GPR) through Continuous Water Injection, Construction and Building Materials, 22(3): 205-256, 2008. >>

 

37. W. L Lai., W. F Tsang., H. Fang, D. Xiao, Experimental Determination of Bulk Dielectric Properties and Porosity of Porous Asphalt and Soils using GPR and a Cyclic Moisture Variation Technique, Geophysics, 71(4): K93-K102, 2006. >>

 

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1. S. Y. Chiu, Wallace W. L. Lai, Janet F. C. Sham, Miranda C.Y. Lui, “Influence of cover depth towards quantitative size estimation of delaminations in external wall using passive infrared thermography”, The 3rd QRIT Conference Asia, Tokyo, 2019, pp. 61-62.

 

2. Janet F. C. Sham, Wallace W. L. Lai, S. Y. Chiu, “Effects of thermal contrast on size estimation of debonds in different external wall’s composite finishes via passive infrared thermography and a modified gradient algorithm”, The 3rd QRIT Conference Asia, Tokyo, 2019, pp. 63-64.

 

3.  Phoebe T.W. Wong, Wallace Wai-Lok Lai, Chi-Sun Poon. Laboratory Validation of Corrosion-induced delamination in concrete by ground penetrating radar, 17th International Conference on Ground Penetrating Radar 2018, Rapperswil, Switzerland (shortlisted in the best paper award).

 

4.  Bella W.Y. Cheung and Wallace Wai-Lok Lai. Field-scale Validation of Water Pipe Leak by Spatial and Time-lapsed Measurement of GPR Wave Velocity, 17th International Conference on Ground Penetrating Radar 2018, Rapperswil, Switzerland (shortlisted in the best poster award).

 

5.  X. Luo, Ray K.W. Chang and Wallace W.L. Lai. Development of a change detection method on underground air void identification by time-lapse GPR 3D imaging, 17th International Conference on Ground Penetrating Radar 2018, Rapperswil, Switzerland.

 

6.  F. Xie, Wallace W.L. Lai, Janet F.C. Sham and X. Dérobert. A modified algorithm for accurate GPR wave velocity estimation with common offset setting antenna, 17th International Conference on Ground Penetrating Radar 2018, Rapperswil, Switzerland.

 

7. Mick Atha, Wallace W.L. Lai and Ray Chang K.W. GPR Surveys and Excavation Ground-Truthing at the San Tau Backbeach Site, Hong Kong. 16th International Conference of Ground Penetrating Radar (13-16 June 2016), Hong Kong.

 

8. Janet F.C. Sham, Wallace W.L. Lai and H. C. Leung. Dielectric Hysteresis of Heterogeneous Water Distribution observed in Soil’s Wetting and Drying Process by GPR. 16th International Conference of Ground Penetrating Radar (13-16 June 2016), Hong Kong.

 

9. Wallace W.L. Lai, Janet Fung-Chu Sham and Fei Xie.  Correction of GPR wave velocity with distorted hyperbolic reflection in underground utility’s GPR survey. 16th International Conference of Ground Penetrating Radar (13-16 June 2016), Hong Kong.

 

10. Phoebe T. W. WONG, Wallace W. L. LAI and Motoyuki S. Time-frequency spectral analysis of step frequency continuous wave and impulse ground penetrating radar. 16th International Conference of Ground Penetrating Radar (13-16 June 2016), Hong Kong.

 

11. J. F.C.  Sham and W.W.L Lai. A New Algorithm for More Accurate Estimation of Wave Propagation Velocity by Common-Offset Survey Method. International Symposium Non-Destructive Testing in Civil Engineering 15-17 Sep 2015, p. 305-315.

 

12. F.W.Y.Chan and W. W.L. Lai. HKAS Proficiency Testing Programmes for Evaluation of Performance of Accredited Laboratories. International Symposium Non-Destructive Testing in Civil Engineering 15-17 Sep 2015, p. 504-507.

 

13. Wallace W.L. Lai. Vision to the Underground Utility Professional Discipline in Hong Kong, The 4th International conference on Utility Management & Safety (ICUMAS) Summit, Beijing on 14-16 Nov 2014.

 

14. Wallace W.L. Lai. Spectral shift and absorption of ground penetrating radar signals in a wetted sand column, 15th International Conference on Ground Penetrating Radar (GPR 2014), Brussels, Belgium on 30 June to 4 July 2014, paper no. 0127.

 

15. W.L. Lai and C.S. Poon. Durability and debond evaluation of high-rise  concrete buildings using infrared thermography. First International Conference on Performance-based and Life-cycle Structural Engineering. 5-7 Dec 2012, Hong Kong.

 

16. W.L. Lai and C.S. Poon. Boundary and size estimation of debonds in external wall finishes of high-rise buildings using Infrared thermography, 11th Quantitative Infrared Thermography (QIRT 2012) Naples, Italy on 11-14 June 2012, paper no. QIRT 2012-279.

 

17. W.L. Lai and C.S. Poon. GPR data analysis in time-frequency domain, 14th International Conference on Ground Penetrating Radar (GPR 2012), Shanghai, China on 4-8 June 2012, paper no. 0083.

 

18. W.L. Lai, K.K.Lee, S.C.Kou, C.S.Poon, W.F.Tsang. A study of full-field debond behavior of CFRP-reinforced concrete beams, RILEM Conference on "Advances in Construction Materials through Science and Engineering", 2011, paper no. 176.

 

19. B. J. Zhan, W.L. Lai, S.C. Kou, C.S. Poon, W.F. Tsang. Correlation between accelerated steel corrosion in concrete and ground penetrating radar parameters, RILEM Conference on "Advances in Construction Materials through Science and Engineering", 2011, paper no. 178.

 

20. W.L. Lai, T. Kind, H. Wiggenhauser. Effects of high chloride contamination on direct wave of ground penetrating radar, Structural Materials Technology (SMT) Conference, 16-20 Aug 2010, New York, US.

 

21. W.L. Lai, T. Kind, H. Wiggenhauser. Detection of accelerated reinforcement corrosion in concrete by Ground Penetrating Radar, International Conference on Ground Penetrating Radar, 21-25 June 2010, Leece, Italy.

 

22. W.L. Lai, S. C. Kou, C.S. Poon, W. Tsang, K.K. Lee. A Study of Using Full-field Thermographic Technique to Characterize the Shear Behaviour of Externally Bonded CFRP-concrete Composites, 4th International Conference on Structural Health Monitoring on Intelligent Infrastructure (SHMII-4) 22-24 July 2009, Zurich, Switzerland. No. 578.

 

23. C.S. Poon, W. L. Lai, S. C. Kou, W. F. Tsang and C. C. Lai. A Quantitative Study on Bond Behavior between Fiber-reinforced Polymer (FRP) and Concrete Interface Using Infra-red Thermography (IRT), The First Asia-Pacific Conference on FRP in Structures, 12-14 December 2007, Hong Kong, 717-721, 2007.

 

24. W. L. Lai and S. Tsang, Characterization of Soil Texture by Dielectric Properties using Ground Penetrating Radars operating at Different Frequencies of Cyclic Variation of Moisture Content of Soils, Society of Exploration Geophysics International Exposition and Seventy-Fifth Annual Meeting, 1192-1195, 2005.

 

25. W. L. Lai and S. Tsang, Experimental Evaluation of Honeycombed Concrete by Surface Penetrating Radar, American Society of Non-Destructive Testing Fall Conference & Quality Testing Show 2005, Columbus, Ohio, USA, 435-438, 2005.

 

26. X. Z. Shuang, K. Wong., W. L. Lai and Kwok Z., Pitfall of GPR Survey in Dielectric Property Calibration, 4th Asian Symposium on Engineering Geology and the Environment, 2004, Hong Kong.

 

27. W. L. Lai, S Tsang and F. Chan, A Preliminary Study of Data Fusion Techniques (DFTs) on Evaluation of Defective Concrete by Pulsed Radar and Ultrasonic System, British Institute of Non-Destructive Testing Conference, 139-144, 2003, UK.

 

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