TUCSS Monthly Seminar no. 253

Event details

TUCSS Monthly Seminar No. 253 – Thursday, 20 June 2024, 6.30 pm

Innovative Features in DTSS2 Conveyance System

by Dr. V Ganeshan, PD/DTSS2, AECOM Singapore Pte Ltd

Abstract

In Phase 2 of Deep Tunnel Sewerage System (DTSS2) project, new features in the construction and operations of the system are introduced. These include parallel flow paths for sewage, microorganism influenced corrosion resistant concrete (MICRC) to enhance structural durability, tunnel isolation gates to facilitate inspection/repair and built-in fibre optic monitoring system for checks on tunnel integrity. In Phase 1 of DTSS, corrosion resistance is mainly entrusted to the HDPE liner protecting the otherwise, exposed OPC concrete substrate of the tunnels and shafts. In DTSS2, MICRC was adopted for the construction of the shafts with gates and also, in the secondary linings of the segmental tunnels. All tunnels continue to have the HDPE liner over the MICRC secondary lining as an additional line of defence against the corrosive environment. Accelerated durability tests were conducted on samples of various proposed MICRC design mixes before these were accepted for construction. The challenge of access and lack of inspection of the trunk tunnels and hence, the means to carry out repairs, have been major concerns for DTSS. To overcome this, selected shafts are fitted with gates such that the flow can be diverted, and a portion of tunnel isolated for access to perpetrate inspection and/or repairs. The trunk tunnels (South and Industrial Tunnels) and link sewers are planned such that any section of the trunk tunnels can be made “dry” for access. Fibre optic cables are installed throughout the lengths of the deep tunnels, to permit continuous monitoring of the tunnel structural integrity. Three longitudinal and numerous circumferential cables (wherever future major activities are expected to take place) are cast in the secondary lining of the tunnels.     

Speaker 

Ganeshan has over 40 years of experience in civil and geotechnical engineering design and construction. These include deep excavation, tunnelling, deep foundations, land reclamation, ground improvement and instrumentation works. Amongst his most recent projects are LTA Circle Line 6 and Polder Reclamation at Pulau Tekong. In Deep Tunnel Sewerage System Phase 2 project, he leads the programme management team as Project Director and assumes the role of Superintending Officer for the bored tunnels and the associated hydraulic structures contracts. He is a Professional Engineer in the Civil, Geotechnic and Tunnelling disciplines, Accredited Checker in Geotechnical Engineering and a Fellow Member of ICE, London. He has been serving on TUCSS steering committee for more than 10 years.

Time and Place

The presentation will take place electronically on Thursday, 20 June 2024 at 18:30 hrs. The presentation will take approximately 45 minutes, follow by 15 minutes of questions/discussion.

Invitation

This is the 253^rd 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, 10 June 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

V. Ganeshan

PD/DTSS2, AECOM Singapore Pte Ltd