TUCSS

Event details

TUCSS Monthly Seminar No. 256 – Thursday, 24 October 2024, 6.30 pm

Groundwater control in Singapore or: How I learned to love the pressure relief well

by Dr Nicholas Mace, Mott MacDonald Singapore, Technical Director – Geotechnics

Abstract

Based on experience of groundwater issues in deep excavation projects in Singapore, there may be a view that groundwater control is primarily an issue in terms of control of groundwater drawdown and control of resulting ground settlement. There are though, situations where groundwater control can be critical in terms of stability of deep excavations. This issue is clearly more significant, and it is important that this concern is understood by those involved in deep excavation projects.

In this respect, the rather humble pressure relief well is often cast as the villain of the piece where settlements are concerned. However, it performs a simple, but critical function and in certain circumstances may turn out to be the hero.

In broader terms, due to the complexities of local Singapore geology and variability in performance of groundwater control measures, hydrogeological behaviour can be particularly complex. Understanding the likely response of different geologic strata and field permeabilities can have a significant impact on design when it comes to groundwater control and the requirements of local standards.

In such an environment, attention to observations from adequate monitoring schemes and skilled interpretation is critical during construction, and a strategy should be in place for the implementation of appropriate groundwater control measures as construction proceeds.

As excavations in Singapore continue to get deeper, these issues can be expected to become more critical. A deeper understanding of groundwater control should therefore be encouraged throughout the profession.

Speaker

Nicholas Mace is a Technical Director in Mott MacDonald with regional responsibility for Geotechnics. He has worked in Singapore for a total of 19 years. During that time he has been involved in projects including the Kallang-Paya Lebar Expressway, Circle Line, Marina Coastal Expressway, Downtown Line, Thomson Line, Eastern Region Line and the North-South Corridor. Recently he has worked on the Hong Kong Airport Third Runway System reclamation and is currently the Geotechnical Lead for the Changi T5 Master Builder Contract. Nicholas obtained his undergraduate degree from the University of Manchester and his PhD from the University of Southern California. He is a Fellow of the Institution of Civil Engineers.

Time and Place

The presentation will take place electronically on Thursday, 24 October 2024 at 18:30 hrs. The presentation will take approximately 45 minutes, follow by 15 minutes of questions/discussion.

Invitation

This is the 256^th in a series of presentations by TUCSS and is open to current TUCSS Members only. Seats are on first-come-first-served basis and limited to 500 persons.

Registration

Individual Members are to sign up for the seminar via their TUCSS account on the TUCSS Website. The details on how to access the seminar will be sent to the members who has successfully signed up for the seminar, at a date nearer to the seminar. The deadline for registration is on Monday, 14 October 2024 or when total registered participants reaches 500 whichever comes earlier.

*TUCSS Corporate Members limited to 5 registrations only. For TUCSS Corporate members, please email us the following information (name, TUCSS Corporate membership number, company name, email address, PE/RE/RTO number if applicable).

Attendance Policy

For members who require certificate of attendance, please note of the attendance policy:

- Login at the beginning of the seminar (link will be assessable at 18:15 hours)

- Evidence of participation by video switched on throughout the seminar

- Complete the quiz at the end of the seminar before logging out. The duration for the quiz is 15mins.

Certificate of Attendance will be uploaded to the member’s account after the compliance to the Attendance Policy is verified.

PDU/STU

Points have been applied and pending approval.

Speaker

Dr Nicholas Mace

Technical Director - Geotechnics