Its been a while

I have been neglecting this blog because I have been swamped with work. I figured it was about time I got back on to it and let you know what I had been up to.

Since the Alexandra Hills Hotel project, which incidentally is currently being erected, I have been busy with several scanning and detailing projects. I have continued to learn a lot and develop my workflows and I have also learned that its not always nice giving people bad news. To follow is a rundown of the most interesting work I have been doing since then.

To start with I was contracted to scan a station footbridge in Sydney for a detailer who was adding a steel roof. This was a problem for me as I couldn't get there fast enough for the project timeline. Instead I used a colleague in Adelaide who flew out there for me with his scanner and did the survey on my behalf.

This worked out well and we delivered all of the laser scan survey extracts for Tekla Structures to the detailer in about 2.5 days! The scan quality is excellent and was done with a Faro Focus 3D Scanner.

The next project that has kept me busy was a impressive and complicated canopy at No 1 William Street in Brisbane. The steel fabricator required my services to survey the canopy in his fabrication yard to establish its true geometry as they were having problems fitting the rafters to the tube frame. The Rafters and Tubes had been made in different workshops.

William St Canopy in Yard

The first scan was delivered and adjustments made. I was then asked to go back and re-scan as a further inspection was required. Again the massive canopy was in the fabricators yard. It was only about 4m up to its highest point so was easy to scan and get good results. When the scans were inserted into Tekla Structures the detailers could see instant improvements in the Rafter and Tube Geometry and fix what was not so good.

The tube section of the canopy was erected back in May and I was again asked to scan it in its erected position. This way the fabricator could re-check how the massive rafters would fit prior to their installation. The scan was performed on a very busy site and was problematic. I couldn't enter one area due to overhead works and had to turn the scan resolution and quality up to try to get a decent image of about a quarter of the canopy. Along with the scan I shot every end plate in 6 locations with the Total Station just to ensure we had the data we needed. The result was an excellent scan survey. In fact even at over 10m away the scan shows the outlines of bolt holes. I was not expecting that! Results were delivered for Tekla Structures in 24hrs and I learned that its hard to deliver bad news. The canopy was significantly different over the length of the rafters. It had grown.

This is the point of these surveys. Sometimes you have to deliver bad news. Its not nice but it saves money in the end as site work to alter anything that has been prefabricated incorrectly is very expensive. Using the scan data the fabricator was able to rectify the problems and save costly site delays.

The Busy Site area at William Street

The erected canopy

The other project that has taken a lot of my time was layout work at a site at 310 Ann street in Brisbane. Mulherin Rigging asked me to set out holes for site drilling. This all sounds fairly simple but it was a 15 floor building with hundreds of holes on each floor to be marked. The holes were in the walls and roof slabs and were problematic and time consuming to mark out manually. Below is an installed version of beam i was marking out drillings for. To compound the difficulty factor an error had been made in reading the original site survey and nobody had thought to compare 1 floor to the next. Each floor had a central column which was assumed to be in the same position on every floor. It wasn't. I had to take the BIM model from the drafting company and move the drilling locations around so they suited the central column on each floor. It took a lot of office based work but I made the changes and the steel work was installed without incident.

Installed steelwork

Marked positions and laser on new position

Trimble RTS 773 hard at work

The Trimble RTS773 performed perfectly and I was able to mark out 3 1/2 bays per day at more than 80 holes per bay. (Manually they could do 2 at best). More importantly the RTS increases the accuracy of the mark out as all holes are relative to each other as you only tend to set the RTS up in 2 or 3 locations and use the same reference points. This way human error can be reduced significantly.

310 Ann St Steelwork installed

All in all its been a very busy few months and I hope in continues.

Ian BrightmanComment