Here’s more information about how the structure at the top of the Umno tower plunged and pierced vertically 30 metres deep into the road and the soft soil below.
And this is a technical explanation of what happened:
About the wind wing-walls of the Menara Umno, architects and planners TR Hamzah & Yeang Sdn Bhd had this to say:
The building has wind wing-walls to direct wind to special balconies zone that serve as pockets with “air-locks” (having adjustable doors and panels to control the percentage of openable windows) for natural ventilation. This building is probably the first high-rise office that uses wind as natural ventilation for creating comfort conditions inside the building. Other claims of ‘natural ventilation’ in high-rise towers, use natural ventilation simply as a source of fresh air-supply to the interior and not for internal comfort. For internal comfort as in this building, a higher level of air-change per hour is required. Here, we tried to introduce natural ventilation at point of entry (rather than create suction at the leeward side). To create pressure at the inlet, a system of ‘wing-walls’ to “catch” the wind from a range of likely directions. The wing-walls are attached to a balcony-device with full-height sliding-doors. The placements of the wing-walls and air-locks within the floor- plate are based on the architect’s assessment from the locality’s wind-data. The wing-wall cum air-lock device is of course experimental, and site verification with CFD analysis indicate that this device worked reasonably well. Experiences from the project, would enable the architect to further develop the device for other projects.
The soil conditions are described as very soft to soft clay, with resistance only at 30-55m below surface, while the water table was about 3 metres below ground level. Perhaps this is why the 50-metre long structure easily pierced 30 metres into the road.
A total of four test boreholes were conducted, each to a depth of about 64m for the sub-structure design. Generally, these borelogs indicate the site to be underlain by successive layers of very soft to soft clay, followed by medium stiff to very stiff silt and silty sand. Ground water table is generally between 2.7m to 3.5m below Ground level.
Column loadings vary from 3,200 Tonnes to 1,800 Tonnes for the widely -spaced columns. For the more closely spaced columns, the loading is about 740 Tonnes.
In the selection of foundation for the structure, shallow foundation like pad footing and raft was considered to be obviously not suitable in view of very poor soil (N – value of 3) to a depth of 9m below Ground level. Bored piling was not adopted in consideration of high water table with silty sand and low N-values at the upper layers. The requirements of long length of steel casings associated with boring in such soil to prevent collapse of bore holes would not merit value engineering decision.
For such soil condition and medium range column loadings, it was considered most appropriate to adopt driven reinforced concrete piles. Further reasons to justify the use of driven r.c. piles are that they are economical (especially, when compared to steel piles) and could be installed relatively quickly….
Essentially, these piles are skin friction piles which mobilise the good soil resistance properties at depth of 30 to 55m….
Now we hear that the tower owner failed to submit its safety report, due every 10 years, in 2011. We can build great structures with so-called ‘eco designs’ (check out the cardboard plastered on the windows of the tower), but do we have a maintenance and safety culture to match?
Is it true that the MPPP issued the contractor a special permit to start work two years before the building plans were submitted in 1997?
Are Umno, BN and federal government projects exempted from prior local council approval?
Obviously, there was a design or construction flaw. How was the certificate of fitness for the building approved, if at all? Is the remaining concrete slap jutting out from the tower-top securely fastened?
Did Umno really need a 21-storey, keris-shaped tower in Penang? Or was this another one of their “satu lagi” unnecessary extravagant projects?
The other issue is that our architects and planners perhaps never foresaw a day when climate patterns would become more extreme – thanks to our reckless degradation of the environment in pursuit of “economic growth” and the trappings of “progress”.