# Geosynthetic Reinforced Steep Slopes: Current Technology in the United States
## 5 Construction Practices
### Transportation Agency Specifications  
In addition to the aforementioned specifications, several state transportation agencies have implemented similar requirements for construction involving geosynthetic reinforcement. Geosynthetics should be delivered to the jobsite in unopened shipping packages labeled with the supplier's name, product name, quantity, and type designation that corresponds to that required by plans [27]. They should also be accompanied by a manufacturer certified copy of test results (ASTM D4595 for geotextile or ASTM D6637 for geogrid), verifying the ultimate strength of the lots from which the rolls were obtained [20; 51; 52]. Reject all rolls damaged during transport. Rolls should be protected from construction equipment, chemicals, sparks and flames, water, mud, wet cement, epoxy, and like materials [22]. Geosynthetics should also be protected from direct sunlight and temperatures below \(-20\)\({}^{\circ}\)C per Mississippi DOT [53]. Additionally, the reinforcement material must be protected from temperatures above 50 \({}^{\circ}\)C according to Mississippi DOT or above 60 \({}^{\circ}\)C and 70 \({}^{\circ}\)C as per Pennsylvania DOT and California DOT, respectively [21; 28; 53]. Rolls should also be stored elevated from the ground and covered with a waterproof cover.  
Remove all existing vegetation and unsuitable soil materials, including deleterious materials and soils, from the grade. Grade should be proof rolled with five passes of a static, smooth drum, or pneumatic tire roller with a minimum contact pressure of about 0.8 MPa as per Pennsylvania DOT [28]. However, according to Florida DOT, a vibratory or sheepsfoot roller of at least 1.7 MPa on the tamper foot should be used [27]. Any soft areas, as determined by the engineer, should be removed and replaced with backfill. Benching the backcut into competent soil is recommended to improve stability.  
The geosynthetic should be oriented with the direction of maximum strength perpendicular to the slope face with each layer placed to form a continuous mat. Secondary reinforcement should be placed in continuous strips parallel to the slope face, and the geosynthetic must be secured and pulled taut before placing any fill. West Virginia DOT restricts operation of equipment on geosynthetic materials until 15 cm of loose backfill has been placed, although Pennsylvania DOT further limits this to 20 cm [22; 28]. Sudden braking and sharp turning is not allowed. Sheepsfoot or padfoot type compaction equipment is not allowed. Only place the amount of geosynthetic that can be covered in one day and slope the last level of backfill away from the slope face to allow for positive drainage.  
If mechanical connectors are required, the splice mechanism must allow a minimum of 95 percent load transfer from piece to piece of geosynthetic per Florida DOT [27]. Only one joint per length of reinforcement shall be allowed, and the joint shall be made for the full width of the strip by using a similar material with similar strength that uses a connection device supplied or recommended by the manufacturer. Pennsylvania DOT does not allow for any splicing of any geosynthetic [28]. If a geosynthetic is damaged, remove all backfill material from the area plus 1.2 m in all directions beyond the limits of the damage. Patch the damaged area with the same material and overlap the undamaged patch a minimum of 1 m in all directions. Agencies should also consider site specific installation damage testing, especially if relatively coarse, uniformly graded crushed, or otherwise angular aggregate is used as backfill, or if other relatively severe installation conditions are anticipated.