By Raymond
2013-122261
Ministry of Works
Experts have suggested several possible causes for the failure of the scaffolding at the second Penang Bridge construction site in Batu Maung. The suggestions so far are all around the structure of the scaffolding – whether the scaffolding construction materials conformed to standards, whether they were sufficient, whether the construction work was properly carried out, etc.
However, there is another angle of which there has been no mention so far. The experts must also look at the land immediately surrounding the disaster area, particularly towards the sea-fronting side. Land filling works have raised the height of the surrounding areas by about 2 to 3 meters. The land where the collapse occurred is still at its earlier level. This has created a water-retention pond of about one acre in size. Water from last week’s rain can still be seen close to the pillar to which the collapsed scaffolding was attached.
The scaffolding was erected on ground that was dry. Rain (last week it was heavy) turned the low-lying ground into a water retention pond as there is no drainage to quickly remove rainwater from the area. Was the footing of the scaffolding designed and built such that it would remain stable even if the soil beneath it became water-logged?
The weight that had to be supported by the scaffolding was not a few tons, but several hundred tons. So the ability of the footing to remain stable despite heavy rains and water-logging of the ground is a very important factor to look at.
The weather factor should not be ignored. Highland towers was brought down by ground water. As water changes the characteristics of the soil, soil experts should also be brought in to study the soil on which the scaffolding stood and whether its stability was affected by the rain-water softened soil on which it stood. Could even a slight sinking movement of the scaffolding have triggered the collapse like an avalanche in the snow covered mountains? See the three photos attached.
1 Stagnant water at the lower left corner of the picture. There are clear signs that water level is higher after a shower. This is very close to the footings of the scaffolding. The water is from last week’s rain.
2 The footings of the scaffolding which was built on dry ground. The place is now at one end of what could be called a “retention pond”. What is the effect when the ground below the footing is soaked with water (or waterlogged)? Will the footings remain as stable immaterial of the ground water under them and surface water very close to them?
3 The “retention pond” from another side. There is no drainage for rain water to run off the surface quickly after rain. It is retained here and soaks into the ground.
References
YEA, Ray..I totally agree with your point of view. They shouldn't blame the weather for the cause of Penang Bridge to collapse. They should prepare the ways that how to handle the bridge's construction even the weather is bad.
ReplyDeleteI agree with your article. No matter the weather is good or bad, they also must do preparation of handling the bridge's construction properly. The bridge collapse is not the wrong of the weather but the factor of weather cannot be ignored.
ReplyDeleteYes i agree with you this article is very Informative.
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