The figures quoted below are computer-estimates of the volume of earth
(soil/rock) that would need to be excavated in order to level the terrain
at the Pipeland Farm for five Level Playing Field Pitches.
Presumptions
- Pitch Size of 60m x 120m (36,000 sq.m for
the 5 pitches) plus 1m separation between pitches.
(Using 2m separations would increase the 5-pitch width by
5m, and the total volume and cost by approximately 2 percent.).
- Foundations depth = 0.5m.
- Estimated cost of excavation = £20 per cubic
metre.
- The cost of extensive drainage, catchment and
connection to the main rainwater sewers, plus fair-surfacing and
grassing, all to acceptable standards, plus stabilising the exposed
"earth walls/slopes/revetments", could be at least £10 per square metre.
Cross-sections
The following data has been prepared from ordnance
survey maps.
- There are seven cross-sections running from
south (at left) to north (at right), X3, X4, X5, X6, X7, X8, X9.
They are 100 metres apart (so X3 = EASTING Coordinate 300 on the
Ordnance Survey [OS] map, etc.). X3 is the most westerly one, at
the Hospital boundary, X9 is the most easterly one.
- The vertical heights are in metres above
sea-level. (these were interpolated from the contour lines on the OS
map).
- The horizontal distances are marked from 1000
(at left) to 1400 (at right) at the boundary of the Scooniehill Road
houses. These are the NORTHING Coordinates on the OS map.
- The vertical scale is six times bigger than the
horizontal scale.
Results
DEEP-Excavation-to-Lowest-Point
Volumes
| The Minimum Volume =
33,594 cubic metres. |
This
occurred right at the eastern end
of the site, about halfway between the N and S boundaries (where the
field is more level just before it falls down rapidly to the North at
the housing edge).
|
The nett average
depth of excavation for the 5 contiguous Level Pitches is 0.747m.
|
This is the
depth to reduce the earth to its Lowest Point within the 5 Pitch
block. |
| The gross average +
drains + foundations depth (0.5m more) is 1.247m. |
(Incidentally, the Maximum Volume comes out at 60,156 cubic metres. It
occurred at the western part of the site. Its eastern end is just
above Pipelands Farm Steading, its western edge coming close to the
road-path by the Hospital. Compared with the Minimum location, the
terrain falls more uniformly steeply here over the whole area. The
area actually excludes the even steeper part where it tilts rapidly
down to the North at the housing edge outside the Pitch Areas).
|
The nett average
depth of excavation for the 5 contiguous Level Pitches is 1.337m.
|
(This is the
depth to reduce the earth to its Lowest Point within the 5 Pitch
block). |
| The gross average +
drains + foundations depth (0.5m more) is 1.837m. |
|
Costs
The Excavation Costs
based on the above volumes would lie between £671,880 and £1,203,120.
|
Minimum
33594 cubic metres x £20 per cubic metre = £671,880
Maximum 60156 cubic metres x £20 per
cubic metre = £1,203,120
|
| The cost of extensive
drainage, catchment and connection to the Main Rainwater Sewers, plus
fair-surfacing and grassing, all to acceptable standards, plus
stabilising the exposed "earth walls/slopes/revetments" would add
another £360,000 to the costs of the Playing Fields. |
36000 square
metres x £10 per square metre = £360,000 |
The CUT+FILL alternative
This means excavating only the uphill (southern) half of the long
block, and placing that on the un-excavated lower (northern) half of
the long block so as to create the level playing-field area (at a
slightly higher height above sea-level).
Uphill embankments and downhill revetments would still be required.
However, the downhill revetments would have to extend **further** downhill
to get a safe and stable non-mud-slide edge, because the height of the
levelled playing-field-site stands higher up than it would in the deep
excavation. (The northern edge has been artificially built up). |
 |
That extra earth has to be dug from **somewhere
else**, and rammed and consolidated, etc...
But again, in favour of CUT+FILL, the shallower dig may not meet as much
rock as a DEEP dig.
So although CUT+FILL needs less immediate excavation than a DEEP
excavation,
the extra need for larger revetments to stabilise the northern downhill
edge adds to the overall digging and consolidating - and hence to the CUT+FILL costs.
A reasonable estimate suggests that the cost of CUT+FILL may still come
out somewhere between 65 and 75% of that of DEEP excavation.
Summary
- The overall Pipeland playing field bill could
come out between £1,000,000 and £1,500,000 if the safer DEEP excavation is
used.
- Such an excess would go a long way to cancelling out any short-fall
between Fife Council's upper-bracket and the earlier University's
sale-offer price.
- All this without the dreadful disruption, to the hospital and the local residents, caused by the excavation, and the shipment of the spoil
off-site in huge HGVs, jamming up the Community Hospital narrow
carriageway and the southern roundabout.
- Excavating the playing fields area down to
the lowest practical level is the safest and more desirable plan for a
site with such significant slopes.
- The alternative of a shallower CUT+FILL method requires much more detailed
engineering and constructional procedures. It could reduce the estimated
initial excavation costs by perhaps 35 percent, and might at first seem to
be the cheaper and more attractive option. But it could turn out to be the
more dangerous solution, and in the end as expensive as the much safer
"Lowest Depth" option. This is because of the much larger land-slip-prone
revetments, drainage, etc. needed to shore-up and stabilise the higher
FILL portions of the playing field area where the land slopes are
greatest, leading to a sort of "Hanging Playing Fields of Pipeland"
effect.
- Moreover, the CUT+FILL work would also be saddled with the need for future
regular inspection and maintenance work to safeguard the residential
property, just over the Pipeland site fence, from land-slide and
excessively steep water-run-off. The latter is already a well-documented
and persistent problem troubling the houses in the Scooniehill Road area
that back-up to the Pipeland fields. Any change from significantly sloping
farm fields to a major school site would only make these existing
problems far worse.
- The cross-sections seem to reveal that the
original natural falls of the Pipeland Farm fields appear to have
already been cut-back into when the building site for the Scooniehill
Road houses was being prepared, back in the 1950s. That housing site
would have had to be levelled to grab as much useful building land from
Pipelands Farm as could be done economically at the time.
The sudden sharp increases in gradient can be clearly seen in the
intermediate cross-sections (on the right).
These increased slopes could be part of the cause of the run-off-water
flooding problems that the residents frequently have to report and be
helped with.
That problem won't be helped by further excavation work for the playing
fields.
|