What Lies Beneath? Design from the Ground Up

Making sure the base to your pitch or track is fit for purpose is a very straight forward civil engineering exercise. In the UK research carried out for over 60 years in the highways sector provides transferable design principals to sports facilities construction which means that there are no excuses not to follow proper design principals. Understanding basic design principals goes a long way to avoiding problems.

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Site investigations
It's an old mantra but you need to be fully aware of the history of the site and the prevailing ground conditions which are going to support your pitch or track. It is not possible to cover this using a risk assessment process. There needs to be a desk top study done of the site to assess historical use, backed up using a geotechnical survey which tests and characterises the moisture conditions, bearing capacity, and contamination, just to name some of the site conditions you need to know about before you cut ground.

Recipe or design
Too often, the base of a pitch or track is built using a standard approach because either it has worked in the past or this "is the way it is always done." But a recipe approach can be very costly if the sub soils are not up to the job. Applying 250mm of crushed stone over a sensitive soil will result, at some point, in settlement. This settlement will happen even without loading the surface. Knowing about a problem prior to the application of the sub base means that measures such as strengthening the sub soils can be incorporated into the works – geotextiles, stabilisation and (even dare I say it) a thicker layer of crushed stone. A recipe approach is, at its very best, risky. But at its worst, it results in the turf and pad being lifted to effect remedial works. Designing the base to deal with the ground conditions may result in higher costs up front, but it will save a huge hit in remedial works later on.

How do you know it’s right?
The term Key Stage Inspections (KSI) is now common in pitch and track language and it is well understood in the industry. Setting standards which can then be measured is a process used by most engineering consultants and is called up in some large framework contracts. When a standard is called up, for example, for bearing capacity or infiltration rates, these properties can be measured by an independent test institute. Testing may indicate a pass or fail result. When there is a failure, an engineer can assess the implication of it on the permanent works, and instruct remedial works if required.

TYPICAL KEY STAGE INSPECTION REGIME

TYPICAL KEY STAGE INSPECTION REGIME

The best outcome
This process works and can be easily evidenced. Old projects that were designed properly and originally built to proper standards are showing us that only minimal remedial works are required to restore these facilities. An example is UCD Dublin, now on its third refurbishment without any major defect corrections because it was built properly in the first place.