TRX Vehicular Tunnel (Contract C3)

The Tun Razak Exchange, (TRX) is a 70-acres development in the heart of Kuala Lumpur for KL’s Future Ready Central Business and International Financial District. The master plan includes a 10-acres public park, a total of 26 buildings and over 21 million ft² of total building Gross Floor Area (GFA) spread across offices, residential premises, hotels, retail outlets, F&B and cultural offerings. TRX, which sits at a point where Jalan Sultan Ismail (JSI) and Jalan Tun Razak (JTR) converge is served by MRT Line 1 and 2 interchange station. Dewan Bandaraya Kuala Lumpur (DBKL), the Federal Government of Malaysia and TRX City Sdn. Bhd. upgraded and expanded JTR for better traffic flow, ease of traffic movement with respect to ‘in and out’ at the upcoming financial district as well as direct connection to major expressways. The traffic dispersal system and improvement of roads around the vicinity includes the TRX Ingress and Egress tunnels, are connection to Setiawangsa Pantai Expressway (SPE), Maju Expressway (MEX) and SMART tunnel to ensure smooth traffic flow into and out of TRX.

Technical Description

EDP Consulting Group Sdn. Bhd. was involved in providing consulting engineering for Civil, Structural, Geotechnical and Mechanical & Electrical Services for the proposed traffic dispersal works which consists of four underground road tunnels with a total length of approximately 5km. These underground road tunnels are constructed by using open cut construction with temporary Contiguous Bored Pile wall and temporary steel strutting due to space constraint and also close proximity of the tunnel alignment with existing structures. There is a part of the TRX Ingress and Egress tunnel of approximately 50m in length where the tunnels crossed below Jalan Tun Razak and SMART portal. At these crossings forepoling tube umbrella system is adopted as temporary roof support for the tunnel construction instead of conventional open cut method of construction. The system comprises a series of 108mm diameter of forepoling tubes installed beneath both Jalan Tun Razak and SMART portal from the jacking pit which was constructed within TRX site. As the tunnel is located in KL Limestone Formation, the construction of these road tunnel has also to deal with karst features of the Limestone Formation. Top-down construction was adopted for TRX Ingress and Egress connecting to SMART tunnel in order to minimize the disturbance to the existing public road. These SMART connection tunnels are supported by 1000mm diameter Secant Pile Wall and 1500mm diameter Hand Dug Caisson Wall at area where working and headroom is constraint by the existing bridge structure. RC top slab with vertical tie wall supporting the existing SMART tunnel roof slab is constructed before excavation works and wall opening construction to connect both TRX and SMART tunnel is carried out. Mechanical, electrical, firefighting, tunnel ventilation and civil infrastructure utilities were also designed to cater the needs for the tunnel.

Project Highlights, Achievement and Recognition:

• Design and construction of alternative structural support to existing SMART Tunnel to form an approximately 70m in length of connection between SMART and TRX Tunnel
• Construction of pipe roof jacking by using forepoling tube umbrella system for TRX Ingress and Egress tunnel which crossed below Jalan Tun Razak and existing SMART portal.