Explosive Demolition scheduled for 10th June, 2012.
Regular visitors to this site will know that C&D Consultancy are employed by Safedem Limited on a number of projects throughout Scotland, and that we feature their explosive demolition prowess regularly on the site.
Recent projects featured have been Safedem carry out successful Sighthill Flats demolition and Safedem & Brandis A/S join forces to implode 2 tower blocks and both of those clips showed concrete tower blocks being demolished.
Petershill Drive, Red Road Estate
C&D have had no involvement with this first section of Red Road (with the exception of safety audits) but we feel that we must comment on what we expect to happen on the day.
The demolition of 153 – 213 Petershill Drive on the Red Road Estate on 10th June will look significantly different to those implosions listed above and other previous explosive demolition projects carried out in Glasgow as the tower is a steel frame rather than a concrete frame.
We felt that we should highlight the differences between the two types of structures and how they behave on detonation and set out what we expect Safedem’s goals and objectives to be in advance of the demolition operation.
Following the detonation we fully anticipate that there may be a perception, to the untrained eye, that the operation has not gone to plan as the resultant pile of debris will not be as neat and tidy as previous blasts from Safedem and will, most probably, resemble a game of “pick up sticks” as the steel will not, of course, disintegrate during the blast.
Collapse Mechanism / Blast Design
The collapse mechanism and blast design has taken into account the complexity of the steel structure and the limited area around the structure available as a drop area and it will be Safedem’s intention to rotate the top portion of the structure to the west, leaving the lower portion of the structure largely intact.
On completion of the operation we fully anticipate that the remaining portion of the structure / debris pile will be as high as 8 to 10 storeys. The debris pile will not be the traditional pile of rubble as seen in previous Glasgow explosive demolitions and it may look untidy and widespread in comparison to previous blowdown operations, this is because steel will not crush and break but will remain largely intact albeit twisted and distorted.
The explosives being utilised are a combination of steel cutting charges and kicking charges which will cut the steel columns before they are then physically kicked out of position by further explosives, removing the structural support and inducing a collapse. It is very important to their overall objective to physically remove the cut column section to allow the building to drop and rotate. It should be noted that we fully anticipate that steel sections will be visible ‘leaving the structure’ from the west elevation. These sections are all tied back with wire ropes, however the appearance of ejecta may cause alarm, concern and adverse comment.
Summary
- The structure is extremely complex with steelwork of varied types and thicknesses.
- The explosives being used are cutting and kicking charges, they will cut the column then kick it clear.
- The top portion of the building is being rotated to the west.
- The bottom portion of the structure (as much as 8 to 10 storeys) will remain post detonation.
- There is potential for Airblast which can cause ‘collateral damage’ given certain weather and atmospheric conditions.
- The initiation will sound very loud, however our calculations show that the noise level at the exclusion zone boundary will be less than 120 decibels.
- There will be visual evidence of ‘ejecta’ but this is contained by wire ropes.
- The debris pile will be widespread but within the identified drop zone / landing area to the west of the block.
And when you watch it on Youtube on this site on the morning of 11th June and think that it doesn’t look as neat and tidy as other Safedem blowdowns remember that “We told you so.”
Posts
No comments:
Post a Comment