TUCSS Annual Lecture 2023

Event details

TUCSS Annual Lecture 2023 – Wednesday, 25 October 2023

A Case Study on Understanding TBM Operation in Weathered Granite (Mixed Ground) using TBM Data

by Mr. Nick Shirlaw, C.Eng, MICE

ABSTRACT

Modern pressurised TBMs are highly instrumented and generate huge volumes of data during tunnelling. However, compared with the geotechnical instrumentation that is installed to monitor ground movements during tunnelling there is less understanding of how to use and interpret the TBM data. The TBM data is the product of the interaction between the TBM and the ground. The first step in analysis is to derive the forces and torque generated during tunnelling. As the TBM parameters are interactive between themselves as well as with the ground, the next step is to combine two or more TBM parameters and to study how the result is affected by changes in the ground conditions. Parameters were combined to calculate Specific Energy, Field Penetration Index, the FDT ratio, the Torque Factor and the strength of rock excavated. The results could be used to assess the nature of the ground conditions encountered. The data can also be used to understand the operation of the TBM and how it can be improved. A case study of slurry TBM tunnelling in weathered granite in Hong Kong is used to demonstrate how the data can be interpreted. The TBM data provided detail on the ground conditions such as structural features in the saprolite and the weathered rock that cannot be obtained from vertical boreholes. The data was used to assess how changes to the TBM improved performance in sticky clay. It could also be used to improve advance rates in highly variable rock and to identify the potential for a cascading failure of the discs.

ABOUT THE SPEAKER

Nick Shirlaw has 50 years of experience, mostly in underground construction. He has worked on several major subway projects, including the Tsuen Wan and Island Lines in Hong Kong, Phases 1 and 2 of the Singapore MRT system, the Taipei TRTS, the Rapid Transit Expansion Program in Toronto and the North-East and Circle lines in Singapore. He is a former Director of Golder Associates (Singapore) Pte. Ltd. and was a part time lecturer on underground construction at the National University of Singapore.

He has been involved in pressurized (EPB and slurry) TBM tunnelling in soft and mixed ground for nearly 40 years. A particular focus of his work has been the ground movements associated with urban tunnelling, and the control of those ground movements. He prepared Report 249 on ‘Ground control for slurry TBM tunnelling’ for the Geotechnical Engineering Office in Hong Kong. He has carried out detailed assessments on the operating face pressures for EPB and slurry shield tunnelling for contractors in Singapore, Hong Kong and Australia.

Nick is a life member of TUCSS and has lived and worked in the UK, UAE, Hong Kong, Singapore, Taiwan, and Canada.

TIME AND PLACE

The Annual Lecture will take place at Mochtar Riady Auditorium at Singapore Management University Admin Building, 81 Victoria Street Singapore 188065 on Wednesday, 25 October 2023 at 19:00hours. The presentation will be approximately 45 mins long with 15 mins of questions/discussion afterwards.

PROGRAMME

6.30PM           Registration & Refreshments

7.00PM           TUCSS Annual Lecture on “A Case Study on Understanding TBM Operation in Weathered Granite (Mixed Ground) using TBM Data”

7.45PM           Question & Answer

8.00PM           End

INVITATION

TUCSS Annual Lecture 2023 is open to current TUCSS Members only. Seats are on first-come-first-served basis and limited to 300 persons.

REGISRATION

Members are to sign up for the seminar via their TUCSS account on the TUCSS Website. The deadline for registration is on Thursday, 12 October 2023 or when total registered participants reaches 300 whichever comes earlier.

*TUCSS Corporate Members limited to 3 registrations only. For TUCSS Corporate members, please email us the following email information (name, TUCSS Corporate membership number, company name, email address, PE/RE/RTO number if applicable)

PDU/STU

Points have been applied and pending approval.

Speaker

Nick Shirlaw

C.Eng, MICE