Completed Building Above Existing SMART Tunnel

The photo shows the completed at-grade building structure of the Intervention Shaft 2 (IVS2) located in Kampung Pandan Roundabout, Kuala Lumpur. The building is part of the KVMRT Line 2 project, resting on top of an existing SMART tunnel. We were appointed to perform a cost-effective alternative design for the foundation structure, to counter the original design of 20 metres long bored pile. As the site is underlained by shallow limestone layer at approximately 6 mbgl and an existing tunnel structure, construction of bored piles will be risky and require highly skilled contractor.

We had proposed a shallow strip foundation as the supporting part of the IVS2 structure resting on top of mass concrete above the bedrock layer adjacent to the SMART tunnel. Our design included the geotechnical and structural design for the strip footing and prestressed transfer beam to transfer all the building loads onto the strip footing. On top of that, a detailed impact assessment was carried out to check the structural behaviour and displacement of existing SMART tunnel caused by the foundation loadings. Our alternative design had benefited the Client in cost, time and ease of construction.

*Photo source: MMC GAMUDA KVMRT (T) SDN BHD LinkedIn Page.

Post-tensioned Transfer Plates & Carpark Slabs for Integrated Development in PJ

We had provided our prestressed concrete design consultancy service for one of the upcoming integrated development in Section 13, PJ called ATWATER. Our scopes include design and supervise the 2 nos. of post-tensioned transfer plates for 2 residential tower blocks supporting up to 23 and 26 storeys, respectively.

The carpark slabs were also constructed using post-tensioned concrete method. There are 6 levels of PT car parks designed by us for this project.

Cambodia Project: Roof Top

This is the latest photo of our building project in Sihanoukville, Cambodia. Curtain wall construction is toward completion and installation of roof top structure is on-going. It is indeed a majestic building with a wonderful view of ocean in the background.

Value Engineering in Temporary Work

We had designed the temporary sheet pile wall up to 5m deep excavation of sewage treatment plant for our project in Cambodia. It was the alternative design to the Contractor’s temporary work proposal.

Our temporary work design had saved the Client approximate USD$100,000 or 45% of the original cost based on Contractor’s proposal. This made possible because our experience in similar type of works and detailed understandings of the subsoil profiles, soil parameters, water level and adjacent structure loadings.

The excavation and structural works completed in March 2021 and installation of system is on-going.

Embankment Slope Failure

We were appointed to carry out design and supervise the rectification work on embankment slope failure at North-South Expressway near Kuala Kangsar. Total length and height of failure area are approximately 55m and 5m, respectively. The cause of failure is likely due to water infiltration into voids below the embankment shoulder drain and guardrail posts which constructed recently after pavement rehabilitation work.

The remedial measures include stabilisation of the embankment slope with rock fill and stone pitching as well as new drainage system. Overall construction works were completed within 3 months which including design work and this was made possible when the consultant and design & build contractor both working hand in hand.

Stage 1 High Slope Rehabilitation Complete

Finally, the Stage 1 slope rehabilitation work in LPT 2 had completed after about 11 months of construction. This project was delayed due to nationwide MCO as well as implementation of strict SOP to control COVID-19 virus pandemic. The rock fill at the lower berm is temporary maintained at the lowest slope berm as this would serve as construction access for Stage 2 work. Hopefully the Stage 2 work will start soon.

Beware on what underneath the ground!

We never know what is underneath us, there are always uncertainties exist below ground. These uncertainties may be significant to the design of foundation and underground structure.

In this shallow foundation project, we had gone through an interesting experience about the contrary of expected and actual condition beneath our site. The challenging part about this project is the existing SMART tunnel is right below the proposed building. Desk studies were carried out to understand more about the location and dimensions of the tunnel based on available information and drawings given to us. The original design of strip foundation was proposed to be sitting on top of rock. To confirm the feasibility of our design, soil investigations and rock probing tests were carried out. The results showed it was desirable in a way it is within our design assumptions.

Everything seemed to be going smoothly until the contractor started excavation to begin the construction of strip footing. The actual site condition contradicted to our expectation, there were many abandoned structures from the previous construction of SMART tunnel such as RC wall, gabion wall, pipes and even concrete column. Worse still, the rock edges alignment located away from our design assumptions, in which part of the proposed strip footing is not supported directly on rock, due to the over-excavation during construction of SMART tunnel. To solve this issue, we had to revise our design as well as proposing ground treatment work to suit the actual site condition.

From this experience, we can learn that uncertainties always exist below the ground since we have no clear vision on it, even though quite number of investigation works were carried out. Hence, we are encouraged to have more careful considerations on the uncertainties below ground in foundation and underground structures designs and always be prepared for design changes to suit the actual site condition during construction.

Author: Si Jet

Strip Foundation System with PT Transfer Beams

We designed alternative foundation system for a building over the existing SMART tunnel in KVMRT Line 2 project. The original design was bored pile with pile cap.

The site is underlying by limestone rock which was disturbed during construction of SMART tunnel. An cost-effective design using strip footing was proposed as an alternative to minimise the construction risk of bored piling work which is very near to the existing tunnel. The footing is generally placed on top of limestone rock. Pre-stressed transfer beams will then be constructed to transfer all the loads from the building above SMART tunnel onto the strip footings.

The construction is currently on-going at site.

High Slope Rehabilitation Work

We have been appointed by a Design & Build Contractor to provide the detailed design for a slope rehabilitation work project in LPT2, Terengganu.

The existing slope comprises of 9 to 13 berms with a maximum height of approximately 80m from the expressway level. Most of the drains are in poor conditions; they are cracked, spalled, broken or covered up by vegetation and siltation. There were numbers of gullies and scoured surface on slope berms and slope surface.

As the slope is large, the rehabilitation work is divided into 4 stages for implementation. For Stage 1 and 2, the loose cut slope surface will excavated away and then backfilled with well-compacted rock. The construction is currently on-going at site.

Innovative Temporary Shoring System

Our 1st innovative soldier pile system design using steel I-beam and sheet pile at one of our Johor project sites in Electrified Double Track project.

Excavation below ground level is required for construction of reinforced soil wall of approach bridge abutment. The total excavation depth is about 6.6m and located beside the existing road.