A day in the life of a Senior CAD Technician

Every day in the CAD Department is different! Working as a Project Manager within the Foundation Design Team, for many national house developers, brings new challenges daily.

I am currently Project Manager for a development of 250 residential houses which are to be built on the site of a former greyhound racing stadium. It is my task to oversee the production of a foundation layout & details drawing for the whole site, together with a schedule and design drawings for foundations on each plot.

Today I am to produce detailed foundation drawings for Plots 178-182. This is a row of terraced town houses which runs parallel to a hawthorn hedge along the northern boundary of the site.

Using a topography survey and a planning layout of the site, I've drawn up a preliminary foundation layout drawing. I also used the information contained in an arboricultural survey - or, as we like to refer to it in the office... a tree survey! This identified the tree types on the site and I could then produce zone of influence contours on the foundation layout drawing, to show the minimum foundation depths required. All this went into the preliminary schedule, together with plot references, house types, finished floor levels, proposed and existing ground levels, and Claymaster (heave) requirements.

As with many of our projects at GRM, each department has a role to carry out in the production process, offering help and support to others, working as a team. At the outset of this project a Senior Geologist was assigned, who worked with a Geotechnical Engineer to produce a report with trial pit logs, gas monitoring results and foundation recommendations for the client.

Once I was happy with my preliminary schedule, I sat down with Geologist and together we entered relevant data into the schedule from their report, such as known hazards, unsuitable material depths and anticipated founding strata. Pre-determined calculations within the schedule then establish the foundation requirements for each plot.

This terrace block to Plots 178-182 will need to have pile and ground beam foundations with a voided suspended floor system such as a beam and block floor, basic Radon protection and definitely will require Claymaster heave precautions... my favourite type of foundation to detail!

Yesterday I had a meeting with the client at the GRM offices, they handed over the working drawing house types for each plot and we discussed the progress of the project in line with the drawing programme.

Using these house types, I drafted a sketch block plan for Plots 178-182. This enables our structural team to produce line load calculations; they also position the required piles on the sketch - we often have fun deciphering their requirements!

Now that I have collated all the information, today I can begin to draw-up the pile and ground beam layout drawing. This consists of a block plan and ground beam arrangement, setting out dimensions for each pile position, pile numbers and safe working load for each pile. I also show finished floor levels to establish the location of any steps required and typical external wall sections showing a beam and block floor system with pile and ground beam foundations, within a heave zone, requiring basic Radon protection.

I am hoping today goes well so that I am on target with the drawing programme. I shall continue tomorrow with the reinforcement details drawing for this terrace block. I have to split the ground beam arrangement into separate beams, referred to as cages, and detail all the reinforcement bars required, with suitable lap lengths for each bar to give adequate reinforcement for each cage.

Within my role as Project Manager; I can delegate certain tasks to other colleagues within the CAD Department/Foundation Design Team, such as the Bar Schedule input. This schedule is used by the contractor initially to cost the required reinforcement needed and then as a template to produce the reinforced cages on site.

A detailed foundation drawing will need to be produced for each plot on the site. It's just as well that this type of foundation is my favourite, as this project consists of Plots 1 - 250!

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A day in the life of a Senior CAD Technician