Holdfast Training Services Trial Blog

So I’ve had a request from one of you excited civils out there to expand upon my throw away comment this morning about a deck collapse on site. I should have known that simply mentioning a concrete pour would have caused a ‘Civil Twitch’

Three days before a site closure for the Easter long weekend a concrete deck pour had been scheduled. In the region of 300m^3 were scheduled to be poured on a deck half suspended over a previously poured concrete slab and half over formwork suspended off a sloped batter. Halfway through the pour the formwork gave way and a partial deck collapsed occurred causing the site to be evacuated and effectively closed for five days.

No one was injured during the incident – Through the use of exclusion zones and Partially due to the fact that the collapse occurred half an hour before a scheduled evacuation rehearsal – The site staff had been prepped and ready for an emergency drill.

Investigation into the incident uncovered a number of key failings which led to the deck collapse:

1. The Pre pour formwork inspection by an engineer had occurred a number of days before the pour.

2. A significant amount of rainfall had occurred the night before the pour – enough to cause standing water in the basement of the project– changing the condition of the batter upon which the formwork supports had been placed. (effectively the surface of the batter had water running down it, an

3. The ‘shelves’ cut into the batter to place the formwork supports on were insufficient to distribute the load

4. No post rain, or pre pour inspection occurred the morning of the pour (no Question 2.4 moment, Has the situation changed?)

The result? an industrial investigation, union action, a new site manager and add 4 weeks and thousands of dollars to your program please!

Life at the Sydney business school build has been suitably hectic, hence my recent lack of blogging, For which I thoroughly apologise. A deck collapse on a concrete pour before Easter put the construction program back 3 -4 weeks and ended the reign of the somewhat haphazard site manager. The new site manager has been keen to drive things forward in terms of remediation and it has been all hands to the pump in order to attempt to recover lost time.

Tasks that have been added to my gradually growing portfolio of responsibilities has been the running of the services section of the weekly site subcontractors meeting – deconflicting issues between the subcontractors on site and managing the services portion of the four weekly program in conjuction with the site foremen. As the vertical of the building increases (The western end of the building is due to pour the first slab of the top floor later this week) and formwork is removed from the lower levels, access for services trades has opened right up and managing the trades in the lower levels has become a real challenge,- The application of deconfliction is apparently a new concept! The value of careful (military esque!) sequencing and programming is being demonstrated to the organisation and is gathering momentum. Construction of the higher levels of the building has also required me to design and arrange the installation of temporary, charged fire hydrant and hozereel systems for the lower floors in order to meet increasingly stringent health and safety requirements during construction.

This week saw the last slab on ground pour for the main building of the business school, a momentous occasion which has meant that across the site we are no officially ‘Out of the Mud’ which means for the most part that I can begin to stop being concerned (as Angela is) at the risk of In ground services strikes. This is less the two big ones which are coming up – Undergrounding of overhead power cables in the streetway (a seemingly innocuous task less, were it not for the fact that the area in question is a minefield of existing services including a number of high pressure gas mains) and the construction of a new chamber HV substation, in an area that has had temp 3 phase power for one of the sites tower cranes run through the ground. Needless to say I’m heavily involved in designing the methodology for both these tasks.

Procedurally I have had my hands full as well – Reviewing and rewriting the Site’s electrical works management plan as well as Activity Method Statements for the installation of services (The overarching Health and Safety Framework for the services installation).
Quality Assurance and problem solving on site continue apace. Delays to the BIM 360 role out has meant that clash detection, recording and solving on site as the services trades role through the building has been undertaken manually, with myself as the primary conduit.

The entire services team has now relocated to site, and while the other two members of the team continue to be focussed on completing the design, my focus remains primarily on the construction as well as being the main mechanical services engineer. This will expand over the coming weeks as the Services Manager goes on a 5 week holiday, next Friday, and as a result a gradual hand over of responsibilities has begun to myself and the AV and commissioning Engineer. Sink or swim time. Watch this space!