GEOTEXTILE APPLICATIONS IN GOLF COURSE CONSTRUCTION

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1 GEOTEXTILE APPLICATIONS IN GOLF COURSE CONSTRUCTION Geotextiles can be an economic and worthwhile consideration in golf course construction. The high rainfall removal rate requirement and variability of soils found on any golf course are the determining factors as to the needed geotextiles applications. Design engineers need to be aware of the CBR (California Bearing Ratio), K (Coefficient of soil permeability) and how they relate to AASHTO M-288 Specifications. The following comments have been reviewed by golf course architects and civil engineers and are only useful when using sound engineering principles. The voids in a soil are not isolated cavities that hold water like storage reservoirs but are interconnected, small, irregular passageways through which water can flow. The coefficient of permeability, K, is a constant (having the dimensions of velocity) that expresses the ease with which water passes through a soil. Ordinarily it is reported with the dimensions of centimeters per second or feet per minute but occasionally for very impervious soils, feet per day may be used. Because of the numerous, complex factors that influence the permeability coefficient, only crude estimates of its magnitude can be made from a knowledge of the character of the soil. Tests must be performed to obtain the coefficient with any certainty. The California Bearing Ratio usually abbreviated CBR, is a semi-empirical index of the strength and deflection characteristics of a soil correlated to a certain standard crushed stone. The value, which can be determined by testing, gives the design engineer the necessary information to properly assess the load carrying ability of the soil to arrive at roadway and parking area design thickness, and other structural designs. EROSION CONTROL Woven soil fence materials are effective in controlling surface erosion as well as boundary staking. Some manufacturers are producing an orange silt fence material for combined erosion control and safety applications. The size of the silt fence stakes and fabrics is dependent on the severity of erosion to be controlled. RIPRAP PROTECTION Non woven and woven geotextiles, when placed between riprap products, have been successful in prolonging the life and effectiveness of riprap projects. One can rely on AASHTO M288 specifications when designing to these applications.

2 EROSION CONTROL APPLICATIONS - AASHTO M288 Unprotected Riprap Class A (V-Course, Sharp Aggregate Material) Protected Riprap Class B (Smooth, No Sharp Aggregate Material) Grab Strength (lbs.) ASTM D Puncture Strength (lbs.) ASTM D Mullen Burst (psi) ASTM D Trap. Tear (lbs.) ASTM D SUBSURFACE DRAINAGE APPLICATIONS - AASHTO M288 Class A Class B Backfill Material Coarse Stone < 95% Compaction Grab Strength (lbs.) ASTM D Puncture Strength (lbs.) ASTM D Mullen Burst (psi) ASTM D Trap. Tear (lbs.) ASTM D Permeability ASTM D-4491 K Fabric Soil > K Factor Fabric AOS Mentioned above GREENS CONSTRUCTION Considering the high drainage requirements and the moisture distribution requirements of the various soil layers, the use of geotextiles on golf greens is not recommended. Geotextiles are not recommended to replace any soil layer on the green. However, lightweight geotextiles, such as ADS Drain Guard, are successful in golf greens when incorporated as pipe drain covers. Geotextiles may also be considered under the initial soil layer to add support and separation to the golf green in unstable soil conditions (river bank areas, over high organic soils, near wet land protected areas). A moisture barrier with very low permeability is recommended to line the sidewall of golf green. This releases the moisture condition on the green and prevents dry spot conditions around the perimeter of the green (often seen when greens are placed in soils with extreme textural differences). TEES, BUNKERS, SAND TRAPS When you inspect your sand traps, notice the darker soil on top and lighter soil on the bottom. This reinforces the thought that most contamination of the sand traps occurs from the surface

3 down, due to trimming residue, wind erosion, raking and deposits from the golfer shoes. The rapid drainage requirement in sand traps requires that perforated drainpipes be wrapped with lightweight geotextiles, similar to ADS Drain Guard. Geotextiles may also be helpful for stabilization and support of tees, bunkers, and sand traps when installed in unstable soil conditions (see shaping & contouring hints). BRIDGE CONSTRUCTION This is an ideal opportunity to use geotextiles as a separator between the native soil and the gravel, which is placed, on both sides of the bridge. This will add to the support the gravel will provide. CART PATHS Medium weight nonwoven fabrics separate the gravel from the native soil and will prolong the life of the gravel underlying cart paths. This easy installation will minimize the maintenance costs, increase the life of the installation, and eliminate the potential for potholes on the cart path. Placing 4 oz. Geotextiles under the gravel base material can reduce the amount of gravel required and aid in preventing soil contamination to the base layer. Separating the gravel from the native soil will insure the performance of the gravel under the cart path. TOP SOIL MANAGEMENT When top soil storage areas are stock-piled on high elevations, geotextiles may not be necessary for support; however, if the top soil is stored on highly permeable soils, a geotextile with low AOS (high permeability) opening size may be used. This allows for a separation layer between the permeable soil and topsoil, preventing the topsoil from being absorbed into the more permeable soil. Fabrics with high AOS may have problems with caking. Woven-monofilaments should be considered. EARTH MOVING Some municipalities will require soil erosion control procedures until the new turf is established. Silt fence material can be used to meet these requirements. The size of the stakes and strength of the fabric varies with the severity of the erosion to be controlled. AASHTO M288 recommends a maximum AOS of 84 and maximum grab strength of 90 lbs. SHAPING & CONTOURING (See notes on Top Soil Management)

4 When shaping and contouring your cuts and fills, consider the benefits using medium strength nonwoven and woven materials. When you work with soils with low CBR ratios (typically clay or organic soils), geotextiles can be effective in improving the loading and/or stability of the fill areas. In parking lot and vehicular pathways, the use of geotextiles can reduce the quantity of gravel necessary to support traffic loads. The key is to provide added loading characteristics without impeding the drainage requirements. AASHTO M288 can be beneficial in evaluating which geotextile to use. STABILIZATION/SEPARATION APPLICATIONS - AASHTO M288 High Survivability Medium Survivability Grab Strength (lbs.) ASTM D-4632 > 270 > 180 > 180 > 115 Puncture Strength (lbs.) ASTM D-4833 > 100 > 75 > 70 > 40 Mullen Burst (psi) ASTM D-3786 < 50 > 50 < 50 > 50 Trap. Tear (lbs.) ASTM D-4533 > 100 > 75 > 70 > 40 Permeability ASTM D-4491 K Fabric > K Soil K of soil > K Soil DRAINAGE Most geotextiles used during drainage applications are used to prevent contamination of soils into aggregate backfill materials or perforated drainpipe. Using geotextiles as a screen helps maintain the natural integrity of the products used in your project. The need for geotextiles as a screen should be evaluated for each particular site, especially french-drain applications. The solution is as easy as wrapping the perforated pipe or aggregate backfill material with nonwoven geotextiles. Very light weight geotextiles should be used to cover the top gravel layer. Lightweight geotextiles should be used to line the sides and bottom of a french-drain. It will be important to know the K factor of the soil, relating the K factor to the fabric permeability factor. To select the proper screen AOS opening size of the fabric, consider the following: Pick the soils gradation sieve size (inches/min) for which 85% of the soil (by weight) will pass. Multiply the sieve size (inches/min) by two. This value should be greater than the AOS of the fabric. AASHTO M288 sets standards for selection of the proper geotextiles. BULKHEADS/RETENTION WALLS Woven-monofilament and nonwoven geotextiles (high AOS) have proven successful in minimizing soil loss due to hydraulic pressures and tides. These fabrics are placed next to the bulkhead or retention wall before filling. Perforated drainpipes should be placed at the bottom to remove excess water. Applications not requiring high strength nonwoven geotextiles with high AOS will work fine.

5 SEED GERMINATION Covering newly seeded greens or turf areas with a lightweight fabric will help retain moisture for better germination. Lighter colored geotextiles will reflect more light and keep the soil cooler, while darker geotextiles will absorb more light and heat the soil more. Use lighter fabrics in the summer and darker in the early spring or late fall. PARKING LOT/DRIVEWAYS Placing medium weight fabrics under the base gravel for parking lot construction will increase the load carrying capability of the gravel and prolong the life of the gravel. Without geotextile installation, you can expect to find soil contamination in the sub-grade material and eventually notice potholes and sink holes within the parking lot or driveways. STABILIZATION/SEPARATION APPLICATIONS - AASHTO M288 High Survivability Medium Survivability Grab Strength (lbs.) ASTM D-4632 > 270 > 180 > 180 > 115 Puncture Strength (lbs.) ASTM D-4833 > 100 > 75 > 70 > 40 Mullen Burst (psi) ASTM D-3786 < 50 > 50 < 50 > 50 Trap. Tear (lbs.) ASTM D-4533 > 100 > 75 > 70 > 40 WINTER GREEN BLANKETS Application of lightweight nonwoven geotextiles over greens and turf areas has proven to be an effective winter time blanket method; however, consider the color of the fabric based on your winter protection needs. Lighter colored geotextiles reflect more light and keep the soil cooler, while darker geotextiles will absorb more light and heat the soil up more. In mild winter areas, lighter colored fabrics may be preferred over the darker variety. Darker colored geotextiles will have the tendency to heat the soil too fast and stimulate the growing cycle premature to the last killing frost. Darker fabrics may be preferred in hard winter areas for their ability to absorb more heat and prevent the killing effects of hard winter weather.