SYNOPSIS

The Hulu Langat-Ampang Tunnel is a dual-purpose tunnel system constructed for the Langat 2 Water Supply Project to store and transmit potable water for water supply to Ampang and northern Kuala Lumpur. The tunnel system consists of twin tunnels of nominally 3.2-meter clear diameter traversing the high terrain of the Hulu Langat-Bukit Sungai Putih Forest Reserve from its inlet portal at Hulu Langat to its outlet portal at Ampang Jaya for a length of approximately 2.2 km. The tunnel's construction uses the New Austrian Tunnelling Method (NATM) method in the initial section, followed by drilling and blasting the rock.

This half-day seminar will share many lessons learnt and underground experiences. It will cover three main components of Langat 2, including the ground investigation work, which is crucial in identifying the project's ground profile. Then, it will follow with the tunnel design using the NATM and the construction stage of Langat 2.

The tunnel's design involves the NATM for the initial section, followed by drilling and blasting the rock. This method provides flexibility and adaptability in the construction process. It entails the sequential excavation of small tunnel sections while providing immediate support using elements such as rock bolts, steel ribs, shotcrete, and wire mesh. The NATM allows engineers to respond to the actual ground conditions encountered during tunnel excavation, ensuring safety and stability throughout the construction process.

This seminar also will present the drill and blast tunneling technique in more detail. This tunneling method involves using explosives, and the drilling rigs are used to drill blast holes on the proposed tunnel surface to a designated depth for blasting. Once blasting is carried out, waste rocks and soils are transported out of the tunnel before further blasting. Most tunneling construction in rock involves ground between two extreme conditions of hard rock and soft ground. Hence, adequate structural support measures are required when adopting this tunneling method, which will also be presented here.


BIODATA OF SPEAKER

1) Mr. JOHARI SINAL@ZAINAL

Mr Johari Sinal@Zainal has 31 years of experience as a Civil Engineer with Water Engineering, Civil & Structural Engineering, and retail and operation experience from a multinational company. He has obtained experience in water pipeline design and other water-related structures (consultancy), construction of flood mitigation projects & highway construction (contractors), water distribution industry (SYABAS), and more than 12 years in the oil & gas industry (service station construction, design work, permitting– dealing with governments & local authorities, maintenance and marketing operation – Mobil, ExxonMobil, ProJet & Sinclair Knight Merz). Currently, he is working with Pengurusan Aset Air Berhad (PAAB), managing Langat 2 Phase 1 and Phase 2.


2) P. Geol. YON BASIRAH

P.Geol. Yon Basirah is a registered Professional Geologist with the Board of Geologists Malaysia with 14 years of experience in the geologist field. She is mostly involved in geological and geotechnical analyses and site investigation. She previously managed the construction of a 2.2km twin tunnel under Langat 2 Water Treatment Plant, which covered the scope of the geological mapping and geological evaluation for tunnels. She is also in additional temporary support and proposing the ground treatment whenever cavities or geological overbreak are encountered during the excavation process of Langat 2.


3) Ir. ANDRI ABDUL RAHMAN

Ir. Andri Abdul Rahman is an Associate Director at SMHB Sdn. Bhd. With 36 years of experience in design, supervision of construction, contract administration and project management of water supply headworks including earthfill dams, tunnels, intakes, pipelines, treatment works, distribution works and reservoirs. Ir. Andri was engaged as lead engineer for the design Langat 2, of the twin horseshoe-shaped tunnels of nominal 3.2 m clear diameter and approximately 2,200 m length with reinforced concrete lining by New Austrian Tunnelling Method (NATM). The tunnel is to be excavated in mostly moderately weathered rock and concrete lined as water conduit.


4) Mr. YASIR ALI

Graduated in civil engineering in 2009, Mr. Yasir ali has been working at tunnelling projects particularly NATM, underground control rock blasting works and infrastructure. Currently working at Protext Construction (M) Sdn. Bhd. since 2016 as Project  coordinator  role  and  did  various  projects  i.e.  NATM Tunnelling  in  Ulu-Jelai hydroelectric Power project, Construction of 9 Cross Passages in SSP Line 2, Rock excavation of underground stations with supporting works i.e. Conlay station, Titiwangsa Station, Bandar Malaysia station, Intervention shaft 3 with 30meter diameter and 33meter depth excavation and RC lining works, Hulu Langat P6A twin water storage tunnel and currently working on Nenggiri Hydroelectric Power Project for Main Diversion and Access Tunnel construction and RC Lining works. Having expertise to work in various types of geological profiles, i.e., Limestone, Granite, Shale, and sandstone, and conduct tunnelling works with shallow ground cover and urban areas with live traffic on the surface.