Summary of Activities

In a third-generation structure, an Internet-GIS Integrated monitoring capability for the ground and the foundation using smart sensors (e.g. optical fibres) and GPS technologies should form part of the overall integrated monitoring system so that early warning of excessive slope and foundation movements is possible and the effects of such movements on the integrity of the entire structural system can be assessed. At the Centre, an integrated and automatic system for slope monitoring and warning has been developed.  This integrated system includes automatic conventional instrumentation (in-place inclinometers, pore water pressure transducers, TDR, and rain gauges) and a high-accuracy multi-antenna GPS package. An integrated Slope Monitoring and Warning System has been developed, tested and tried in the field.

Research is needed to develop intelligent foundation systems for third-generation structures. The Centre’s research in this area covers:

• Development of the base isolation stratgy from pile foundation
• Global Positioning System (GPS) and Interferometric Synthetic Aperture Radar (InSAR);
• Monitoring of building structures, landslides and land settlement;
• Crustal deformation and earthquakes;
• Sea level changes and associated environmental problems;
• Image Analysis for Generating a Boulder Map.

The conventional slope monitoring system and the GPS system were installed in a loose fill slope test site in Kadoorie Agriculture Research Centre in Yuen Long of Hong Kong (see the following photos) from 2/2/02 to 23/11/02.

The full view

The loose fill slope after failure

The relationship of the maximum displacement along the casing profile measured from the in-place inclinometers with time

Displacement profile measured from in-place inclinometers from 1/Nov/02 to 13/Nov/02

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Representative Projects

• High Precision Automatic Measurement of Natural and Cut Slope Deformations to Prevent Disasters (funded by the RGC)
  
• Landslide Modelling Using Data of Slope Deformation Monitoring (funded by RGC)
  
• Atmospheric Effects in Interferometric Synthetic Aperture Radar (InSAR) Measurements in HK and Southern China (funded by RGC)
  
• CRC for Ground Engineering and Technology (funded by RGC and industry)
  
• GPS and GIS for Urban Hazards Mitigation (Funded by PolyU)
  
• Development of Long Gauge Length Fibre Optic Sensors for Monitoring Landslides (Funded by PolyU)
  
• Development of Structural Health Monitoring and Management System Based on Geographic Information System Technology (Funded by PolyU)
  
• 03-date    Integration of GIS, CAD and Virtual Reality for Construction, Principal Investigator (funded by PolyU and Tsinghua University)
  
• Global Positioning System and Geographic Information System for Urban Hazards Monitoring (Funded by PolyU)

	Schematic of a smart pile foundation to isolate the ground motion from the structure
	Image processing technology for boulder detection, in slope safety studies
	Settlement of the HK airport measured with satellite radar technology (InSAR)

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Major Facilities

• An integrated Slope Monitoring and Warning System:
  • (a) conventional instruments and
  • (b) a multi-antenna GPS package with data communication hardware and software.
• Over 10 geodetic GPS receivers
• Patented multi-antenna GPS system
• InSAR data processing facility
• Terrestrial laser scanning system
• Low-coherence reflectometer system
• Fibre Bragg grating sensor systems
• Tunable laser and optical spectrum analyzer.
• SLOPE 2000 (self developed software)
  • B.D. approved program with approval number G0115. 
  • Local users - GEO, several consultant firms and contractor firms in Hong Kong
  • Oversea users - Italy, China, Taiwan, Argentina, Syria, USA
  • Education - used for teaching in PolyU, CityU, UST and some other universities outside Hong Kong
• PLATE 1.0 (self developed software)
  • Purpose : Analysis of thin and thick plate, suitable for raft foundation, pile cap, transfer plate.
  • User : Housing Authority
• High accuracy strain (temperature) measurement system using fiber Bragg gratings as sensors and gas absorption lines as multi-wavelength references
  • Chinese Patent, filed on 12 April 2001.

	The patented multi-antenna GPS
	A view of GIS Lab, with most update GIS software, image processing system, photogrammetry system, digitizer and plotter for GIS, remote sensing related research and training.
A Major slope for a National Project in Beijing using SLOPE 2000
A Major slope for a National Project in Taiwan with 10 types of soil using SLOPE 2000
Contour for Maximum Mx envelope (using PLATE)
Deflection of plate along a specified section (using PLATE)
Finite element mesh for a circular plate (using PLATE)

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Selected Publications

• Chen, Y.Q., Ding, X.L., Huang, D.F. and Zhu, J.J. (2000) A Multi-Antenna GPS System for Local Area Deformation Monitoring, Earth, Planets and Space. Vol. 52, No. 10, pp. 873-876.
• Ding, X.L. and Qin, H. (2000) Geotechnical Instruments in Structural Monitoring, Journal of Geospatial Engineering, Vol. 2, No. 1, pp. 45-56.
• Ding, X.L., Ren, D., Montgomery, B. & Swindells, C. (2000) Automatic monitoring of slope deformations using geotechnical instruments, Journal of Surveying Engineering, ASCE, Vol. 126, No. 2, pp. 57-68.
• Ding, X.L., Chen, Y.Q., Huang, D.F., Zhu, J.J., Tsakiri, M. and Stewart, M. (2000) Slope monitoring using GPS: a multi-antenna approach, GPS World, No. 3, Vol. 11, pp. 52-55.
• Liu, G.X., Ding, X.L., Chen, Y.Q., Li, Z.L. and Li, Z.W. (2001) Monitoring land subsidence at the Chek Lap Kok Airport Using InSAR Technology, Chinese Science Bulletin. Vol. 46, No. 21, pp. 1778-1782. (English Ed.)
• Ding, X.L., Huang, D.F., Yin, J.H., Chen, Y.Q., Lau, C.K., Yang, Y.W., Sun, Y.R., and Chen, W. (2002) A New Generation of Multi-Antenna GPS System for Landslide and Structural Deformation Monitoring, Advances in Building Technology, Anson, M., Ko, J.M. and Lam, E.S.S. (eds.), pp.1611-1618. Elsevier.
• Liu, G.X, Ding, X.L., Chen, Y.Q. Li, Z.L., Li, Z.W. (2003) The Pre- and Co-Seismic Ground Displacements of the 1999 Chi-Chi Earthquake from ERS-SAR Interferometry, Chinese Journal of Geophysics, Vol. 45, pp. 165-174.
• Ding, X.L., Huang, D.F., Yin, J.H., Chen, Y.Q., Lau, C.K., Yang, Y.W., Sun, Y.R., Chen, W., He, X.F. (2003) Development and Field Testing of a Multi-Antenna GPS System for Deformation Monitoring, Wuhan University Journal of Natural Sciences, Vol. 8, No. 2B, pp. 671-676.
• Ding, X.L., Liu, G.X., Li, Z.W., Li, Z.L., Chen, Y.Q. (2003) Ground Settlement Monitoring in Hong Kong with Satellite SAR Interferometry, Photogrammetric Engineering and Remote Sensing, (in press).
• Liu, G.X., Ding, X.L., Li, Z.L., Li, Z.W., Chen, Y.Q. (2003) Pre- and Co-Seismic Ground Deformations of the 1999 Chi-Chi, Taiwan Earthquake, Measured with SAR Interferometry, Computers and Geosciences, (in press).
• Gong JM, Chan CC, Zhang M, Jin W, MacAlpine JMK, Liao YB, Fiber Bragg grating current sensor using linear magnetic actuator, OPT. ENG., 41(3)  MARCH 2002.
• Gong JM, MacAlpine JMK, Jin W, Liao YB, Locating acoustic emission with an amplitude-multiplexed acoustic sensor array based on a modified Mach-Zehnder interferometer, APPLIED OPTICS 40(34), 6199-6202, DEC 2001.
• Gong JM, MacAlpine JMK, Cahn CC, Jin W, Zhang M, Liao YB, A novel wavelength detection technique for fiber Bragg grating sensors, IEEE PHOTONICS TECHNOLOGY LETTERS, 14 (5): 678-680, May 2002.
• Yuan LB, Zhou LM, Jin W, J. Yang, Low-coherence fiber-optic sensor ring network based on a Mach-Zehnder interrogator, OPT LETT 27 (11): 894-896 JUN 1 2002
• Ho HL, Jin W, Chan CC, Zhou Y, Wang XW, A fiber Bragg grating sensor for static and dynamic measurands, SENSOR ACTUAT A-PHYS 96 (1): 21-24 JAN 31 2002  
• Yuan L, W. Jin, L. Zhou, Y. L. Hoo and M. S. Demokan, "Enhanced multiplexing capacity of low-coherence reflectometric sensors with a loop topology," IEEE Photonics Technology Letters, 14 (8), 2002. pp.1157-1159.
• Gong JM, Chan CC, Jin W, MacAlphine JMK, Zhang M, Liao YB, Enhancement of wavelength detection accuracy in fiber Bragg grating sensors by using a spectrum correlation technique, OPT COMMUN 212 (1-3): 29-33 OCT 15 2002
• Yuan LB, Zhou LM, Jin W, et al.,   Multiplexing of fiber-optic white light interferometric sensors using a ring resonator,  IEEE JOURNAL OF LIGHTWAVE TECHNOL 20 (8): 1471-1477 AUG 2002
• Shi CZ, W. Jin, Chan CC,  Zhang M, Ju J, Liao YB, Zhang Y and Zhou Y, "Simultaneous interrogation of multiple FBG sensors for dynamic measurands",  Journal of Optoelectron. Adv. Master. 4(4), 937-939, (2002) .                 
• Yuan L, Zhou L, Jin W, et al. Design of a fiber-optic quasi-distributed strain sensors ring network based on a white-light interferometric multiplexing technique, APPL OPTICS 41 (34): 7205-7211 DEC 1 2002                            
• Yuan LB, Zhou LM, Jin W and Lau KT,  Effect of thermally induced strain on optical fiber sensors embedded in cement-based composites, OPT FIBER TECHNOL 9 (2): 95-106 APR 2003 .
• Chan CC, Shi CZ, Gong JM, Jin W and Demokan MS, Enhancement of the measurement range of FBG sensors in a WDM network using a minimum variance shift technique coupled with amplitude-wavelength dual coding,  OPT COMMUN 215 (4-6): 289-294 JAN 15 2003                                  
• Chan CC, Gong JM, Shi CZ,  Jin W,  Zhang M,  Zhou LM, and Demokan MS, "Improving measurement accuracy of fiber Bragg grating sensor using digital matched filter", SENSOR ACTUAT A-PHYS 104 (1): 19-24 MAR 15 2003.
• Wang ZJ, Zhou Y, Wang XW and Jin W, A fiber-optic Bragg grating sensor for simultaneous static and dynamic temperature measurement on a heated cylinder in cross-flow, International Journal of Heat and Mass Transfer 46(2003) 1893-1992.
• Y. M. Cheng and Y. Tsui, 'Three Dimensional Slope Stability Analysis', Second International Conference on Soft Soil Engineering, Nanjing, 27-30 May, p.560-566.
• Y. M. Cheng, 'Comparison between Methods of Slices and Method of Wedges in Slope Stability Analysis', Journal of Geotechnical Engineering, Vo. 28, no. 1, p. 71-88, 1997.
• Y.M. Cheng, 'Optimization in Slope Stability Analysis', 2nd International Conference on Landslides, Slope Stability & the Safety of Infra-structures, 27-28 July, 1999, Sinagpore, p.133-138.
• Y.M. Cheng and C.K.Lau, 'A Study on factor of safety Evaluation in Slope Stability Analysis', HKIE Transaction, vol.8, no.1, p.28-34, 2001.
• Y.M. Cheng, 'Locations of Critical Failure Surface and some Further Studies on Slope Stability Analysis', Computers and Geotechnics, vol.30,  p.255-267, 2003.
• Y.M. Cheng and L.J. Zhu, 'An Improved Three Dimensional Bishop's method in Slope Stability Analysis', Chinese Journal of Geotechnical Engineering, vol24, no.6, 706-709. 2002.
• L.J. Zhu and Y.M. Cheng 'On the unification of 2D slope stability analysis methods', Chinese Journal of Hydroelectric Engineering, vol.78, 21-29,2002.
• Y.M. Cheng, 'Optimization analysis in slope stability analysis', New technique, material and methods, China Construction Publication, 14-17, 2003.
• Yin, J-H., X.L. Ding, Yuwen Yang, C.K. Lau, D.F. Huang, and Y.Q. Chen (2002).  An integrated system for slope monitoring and warning in Hong Kong. Proceedings of  Advanced Building Technology 2002 (ABT2002), 4-6 Dec 2002, Hong Kong. In "Advances in Building Technology" (edited by M. Anson, J.M. KO, and E.S.S. Lam) by Elsevier, pp.1661-1670.
• Ding, X.L., D.F. Huang, J.H. Yin, Y.Q. Chen, C.K. Lau, Y.W. Yang, Y.R. Sun amd W. Chen (2002).  A new generation of multi-antenna GPS system for landslide and structural deformation monitoring. Proceedings of  Advanced Building Technology 2002 (ABT2002), 4-6 Dec 2002, Hong Kong. In "Advances in Building Technology" (edited by M. Anson, J.M. KO, and E.S.S. Lam) by Elsevier, pp.1611-1618.
• Yin, J-H., X.L. Ding, C.K. Lau, Yuwen Yang, D.F. Huang, and Y.Q. Chen (2002).  An integrated automatic monitoring and warning system for rock and soil slopes. In Proceedings of 7th Chinese National Conference on Rock Mechanics and Engineering, September 2002, Xi'an, China.
• Ding, X.L., Huang, D.F., Yin, J.H., Chen, Y.Q., Lau, C.K., Yang, Y.W., Sun, Y.R., Chen, W. and He, X.F. (2002) Development and Field Testing of a Multi-Antenna GPS System for Deformation Monitoring,  Proc. Of 9th International Symposium on GPS/GNSS (CD Rom), Wuhan, China. 7-8 Nov. 6pp. (the paper is published in a special issue of a journal, see [11] below).
• Yin, J-H., X.L. Ding, Yuwen Yang, YQ CHen (2003). Monitoring a soil-nailed Hong Kong using GPS and conventional instruments (in preparation). The 3rd Cross Strait Conference on Structural and Geotechnical Engineering, October 23 25, 2003, Taipei, Taiwan
• Ding, X.L., Huang, D.F., Yin, J.H., Chen, Y.Q. (2002) A new generation of multi-antenna GPS system, Proc. Conference on Land Use, Feng-Chia Unviersity, Taichung, Taiwan, 15 June. 12pp.
• Ding, X.L., Huang, D.F., Yin, J.H., Chen, Y.Q., Sun, Y.R., Yang, Y.W., Chen, W. (2003) A New Generation of Multi-Antenna GPS for Automatic Deformation Monitoring, in Select Works Marking the Scientific and Technological Development in China, pp. 16-18, , pp.2360-2361., Yanshi Publishing House
• Ding, X.L., Huang, D.F., Yin, J.H., Chen, Y.Q., Lau, C.K., Yang, Y.W., Sun, Y.R., Chen, W., He, X.F. (2003) Development and Field Testing of a Multi-Antenna GPS System for Deformation Monitoring, Wuhan University Journal of Natural Sciences, Vol. 8, No. 2B, pp. 671-676.
• Ding, X.L., J.H. Yin,  Y.W. Yang,  D.F. Huang and Y.Q. Chen (2003). Combined Multi-Antenna GPS and Geotechnical Instruments for Landslide Monitoring: Test Results on a Loose Fill Slope.  In Proceedings of  7th South East Asian Survey Congress 3-7 Nov 2003, Hong Kong.
• Shi, W.Z., C.K. Cheung and C.Q. Zhu, 2003, Modeling error propagation of buffer spatial analysis in a vector-based GIS, International Journal of Geographic Information Science Volume 17, Number 3, pp. 251-271.
• Shi, W.Z., B.S. Yang and Q.Q Li, 2003, An Object-Oriented data model for complex objects in three-dimensional Geographic Information Systems. International Journal of Geographical Information Science. Vol. 17, No.5, Pp. 411-430.
• Shi, W. Z. and C.Q. Zhu, 2002, The line segment match method for extracting road network from High-Resolution satellite images. IEEE Transactions on GeoScience and Remote Sensing. Volume 40, Issue 3. pp511-514.
• ZHU, C.Q., W.Z. Shi, W. Z, G. Wan, 2002, Reducing remote sensing image and simplifying DEM data by multi-band wavelet. International Journal of Remote Sensing, Vol. 23, No.3. pp 525-536.

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Contact Information

Contact Person

Prof. K.T. Chau Department of Civil & Structural Engineering The Hong Kong Polytechnic University Kowloon, Hong Kong Fax:     + 852 - 2334 6389 Phone:   + 852 - 2766 6015 E-mail:  cektchau@polyu.edu.hk

Prof. Dr. X.L. Ding Department of Land Surveying & Geo-Informatics The Hong Kong Polytechnic University Kowloon, Hong Kong Fax:     + 852 - 2330 2994 Phone:   + 852 - 2766 5965 E-mail:  lsxlding@polyu.edu.hk

Other Investigators

Prof. J.H. Yin (cejhyin@polyu.edu.hk)
Prof. W. Jin (eewjin@polyu.edu.hk)
Dr. Y.M. Cheng (ceymchen@polyu.edu.hk)
Dr. W.Z. Shi (lswzshi@polyu.edu.hk)