Technical “
Planning permission can become a drawn out affair. Apart from the long term
programming of local authorities, there is the possible conflict with immediately adjacent landowners
Final grading of the seedbed
serious consideration, if funds are restricted - and a realistic option is to leave it out and concentrate on ensuring no run-off water enters the pitch and a good cross-gradient of 1:50 to 1:70 is created.
PLANNING PERMISSION Undulating farmland
Seeking planning permission can become a drawn out affair. Apart from the long term programming of local authorities, there is the possible conflict with immediately adjacent landowners. However, the main stumbling block is often access and traffic control. These investigations take much time and months and need to be put aside to resolve the situation and attain official planning permission.
TIMING OF THE DEVELOPMENT Digging trial pits is the only way ...
The main desire is to create a playing surface without losing more than a season. There is not always a choice when to commence works. Ideally, earthworks and primary drainage should be completed in the late summer and the grass sown in late August/early September - especially when no irrigation system is installed. If forced to commence earthworks in the autumn, there is always the probable problem of working in wet conditions and the inevitable need to discontinue works. Starting again in the spring can be fraught with setbacks where soil conditions remain very wet.
... to assess the soil’s characteristics
Where grass is sown in the autumn, there is good establishment well into November and grass cover should be dense enough to support play in May/June. Where slit drains are to be installed in the early summer, there is the possibility that the slits would not have grassed over by the beginning of the playing season in August - and this is essential as uncovered slits can quickly become contaminated with adjacent heavy loam topsoil. Recovery is entirely dependent on the rainfall received and rapid recovery can be achieved with special care by the contractor in compacting and narrowing back the width of the sand slit. At worst, delay in achieving cover means losing a second playing season.
IMPLEMENTING THE DESIGN
Time spent in arriving at a final design is invaluable. Management can improve the playing surface, but shortcomings in design cannot be remedied without significant upheaval and considerable expense.
Special care is needed in clearing the slit drains
130 I PC AUGUST/SEPTEMBER 2015
Once planning permission has been secured, the client will either deal solely with the chosen contractor or will engage a consultant to undertake the full professional responsibility. Working directly with the contractor, the client
must rely completely on his integrity and the investigations he has completed in arriving at the final design.
On site, all decisions are taken by the contractor and quality control is in the hands of day to day superintendence on site. Unforeseen circumstances will arise, together with the need for minor variations, and the contractor’s action taken may not always be in the best interests of the client.
Under the control of a consultant, detailed working drawings should produce the design with final levels and an accurate assessment of the earthwork quantities. In addition, specifications produced, together with a schedule of quantities, ensure that selected contractors could quote for the same specified work. There is generally specific site information and the contract is managed under either the JCT or ACE General Conditions of Contract. The consultant oversees the operation and his presence at critical stages and at times of dispute and variation can prove invaluable and cost-effective. The approval of materials imported onto site, and methods undertaken, can prove far reaching in the eventual success of the development.
In addition to sound civil engineering practices, the emphasis on grading and drainage provisions become the background in the success or failure of the project.
Grading
Establishing satisfactory gradients on a pitch are vital in promoting surface water run-off. The authoritative bodies - Sport England, the Football Foundation and the Institute of Groundsmanship - are silent in prescribing minimum gradients. Secondary slit drains are not a common feature of school and local authority pitches, and it has become very evident that waterlogged conditions have arisen in puddled areas that have developed on account of minimal gradients. There is simply nowhere for surplus water to go.
It is acceptable to aim for minimum gradient between goals and create the effective gradient across the pitch. There are two options open to designers.
1. Single gradient crossfall
This is the most common design and should rely on promoting water run-off to the one side of the pitch, where it is collected in a collector drain or left to discharge to lower ground.
In cut to fill developments, this form of grading is preferable and relatively steep gradients of 1:50 are hardly noticeable with the backdrop of
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