pjhealy
Civil/Environmental
- Apr 23, 2007
- 16
How to model an athletic (football/soccer) field with sub-drains, pre- and post-development conditions?
The existing field is 8" loam/sand mix over 8" gravel base over 4" perforated PVC pipe sub-drains spaced 25' apart (slope=0.025) within gravel, running to 6" solid PVC collector pipes (headers) to daylight. The underlying soils are C-series (fine sandy loam).
The proposed field will be synthetic surface (FieldTurf or Sportexe) which has a 2" or 2.5" thick silica sand/rubber mix infill over a 2 or 4-layer synthetic mat with punched or formed holes to drain. The mat has the fiber blades of 'grass' woven within. One manufacturer (Sportexe) claims their mat will handle 15" per hour min. The mat will be placed over a 2" top layer of 'final grade aggregate' crushed stone (0.5" minus) over a 6" base layer of crushed stone (2" minus). The whole field is surrounded by a concrete curb to which the mat is affixed. This will create a 'pond' situation. A network of composite sub-drains will be spaced 15' apart. The drains will lie within the base stone layer over a geotextile fabric over the underlying soil. The field surface has a minimum pitch (s=0.005), crowned at the center, longitudinally. The sub-drains may be pitched up to s=0.020 (stone base layer thickness will vary). The sub-drains will collect on the edges into 12" headers, thence to a detention pond.
Thanks,
Ken Strom / Patrick Healy
The existing field is 8" loam/sand mix over 8" gravel base over 4" perforated PVC pipe sub-drains spaced 25' apart (slope=0.025) within gravel, running to 6" solid PVC collector pipes (headers) to daylight. The underlying soils are C-series (fine sandy loam).
The proposed field will be synthetic surface (FieldTurf or Sportexe) which has a 2" or 2.5" thick silica sand/rubber mix infill over a 2 or 4-layer synthetic mat with punched or formed holes to drain. The mat has the fiber blades of 'grass' woven within. One manufacturer (Sportexe) claims their mat will handle 15" per hour min. The mat will be placed over a 2" top layer of 'final grade aggregate' crushed stone (0.5" minus) over a 6" base layer of crushed stone (2" minus). The whole field is surrounded by a concrete curb to which the mat is affixed. This will create a 'pond' situation. A network of composite sub-drains will be spaced 15' apart. The drains will lie within the base stone layer over a geotextile fabric over the underlying soil. The field surface has a minimum pitch (s=0.005), crowned at the center, longitudinally. The sub-drains may be pitched up to s=0.020 (stone base layer thickness will vary). The sub-drains will collect on the edges into 12" headers, thence to a detention pond.
Thanks,
Ken Strom / Patrick Healy