Holdfast Training Services Trial Blog

This week I have been treated to a short city break to Birmingham to attend the in house 3 day Lain O’Rourke surveying course. The course was an excellent opportunity to brush up on surveying knowledge and proved to be more challenging then I first thought and it has helped to cement in my mind that surveying needs to be taught over a greater period then is afforded to Margret and her team in the PET course programme. Whilst much of the theory is understood by many on the course the practical application and use of a total station is a little less well understood. I would even go as far to say non existent as I struggled to find the big red on button on the latest version of the Leica total stations we were using. Having found the on button and now successfully navigated myself around the menu system I feel a little more confident in the use of a total station but a skill I fear will easily be lost if not put to use fairly quickly.

On returning to Liverpool street on Thursday I was faced with an issue of buildabiltiy. A steel structure designed to be robust and provide protection to personnel operating within its perimeter from incensed plant operators swing excavator buckets about was in fact so robust it couldn’t be built……..WTF. It had only taken 3 months to complete the designs and have it specially fabricated by a steel structures specialist and now we were going to be defeated by our own designs.

The issue was that were two I beams connected one end plate to another’s flange the designer had incorporated two web stiffeners top and bottom. This then prevented the perpendicular I beam from being lowered into position by the web stiffener. A morning of discussions ensued during which it was discussed about removing the top stiffener and replacing it, or completely removing it. Given that the purpose of the web stiffener in is to stiffen the web against buckling due to the compression of the flange and that in this case both web stiffeners would be required. The real issue was that the detailed calcs that supported the design were less detailed than one of my design exercise calcs and no one could seem to agree on the loading that the structure would have to resist, both permanent, imposed and accidental. Prophesising over all likely laods was brought to an abrupt halt as I gazed out of the window to watch the sub contractor bending one of the columns over to allow the beam to fit. Given that time was/is against us the requirement of the web stiffener suddenly became less of an issue and we turned our attention to managing the problem, and if I remember my lecture with the great orator this could have been avoided had we managed the engineering at the start. Your thoughts please.

My primary project is the construction of a Headquarters Building for the US Defence Logistics Agency – a $81 million project that should be complete Oct 15.  Artistic overview below:

An interesting point to blog-share….Radon…??? I was curious as to what the holes indicated by the yellow arrows were?  Well, they are to allow for the spread and extraction of radon across the area beneath the concrete floors.  Radon is a natural occurring gas that is radioactive and causes the highest number of lung cancer cases in the USA amongst non-smokers.  Little did I know, but the Pennsylvania area (Appalachians) has the one of the highest concentrations of radon in the USA.    You will note an aggregate bed – this is approx. 0.2m thick upon which the non-structural concrete floor is laid;  the compacted aggregate provides a bed upon which to lay the concrete floor but also a permeable band for the radon to move through.

Weather has been a major issue with progress – one has to approach a problem differently in these climates.  Despite local advice, the contractors cracked on with completing all the steel for the entire building – made sense from their point of view as its easy to continue one thing whilst you’re on a roll and all equip is on site.  The problem now is that none of the concrete can be laid, particularly inside the building as it is too cold.  To expand on this: there has only been 5 days since the end of November where temps have been above 5 deg C…the min temp needed to apparently maintain  satisfactory curing.  Our advice was to put up steel in one segment of the building; clad in the precast concrete walls in order to allow them to have an enclosed space to heat easily, where stairwells and flooring could then be poured. Instead contractors are making the best of a bad situation and installing M&E in as much of the building as possible.  The photo below shows the site last month….it looks exactly the same this afternoon as another bout passes through!