<p><p><h2>QC/QA Guidelines</h2>Material properties of the reinforced fill soil should be established prior to placement and during construction to ensure correct/recommended soil shear strength, gradation, electrochemical properties, PI, and soundness. Compaction moisture control should be ± 2% of optimum moisture, w_opt. Compaction density should achieve no less than 95% of maximum dry density. The contractor should be required to submit a quality control plan detailing measurements and documentation that will be maintained during construction to assure consistency in meeting specification requirements. Reinforcements should be inspected for any defects. Lift thickness should be monitored and random samples of reinforcement selected for testing. Special attention should be given to material handling and storage, the construction sequence, corrosion protection for metallic reinforcement and UV protection for geosynthetics, soil compaction restrictions, and details for drainage requirements and utility construction. Ensure all materials delivered on site correspond to the approved shop drawings and check labels to verify whether they match the certification documents.</p><p>Monitor soil compaction, moisture content, and density throughout construction. A minimum frequency of one compaction control test within the reinforced soil zone per lift for every 150 feet of wall is recommended. Monitor soil reinforcement placement and alignment. Prevent or minimize wrinkles in geosynthetic soil reinforcement from the soil placement and compaction process.</p><p>Construction quality is achieved by meeting established requirements, as detailed in project plans and specifications, including applicable codes and standards. Quality Control (QC) and Quality Assurance (QA) are terms applied to the procedures, measurements, and observations used to ensure that construction satisfies the requirements in the project plans and specifications. QC and QA are often misunderstood and used interchangeably. Herein, Quality Control refers to procedures, measurements, and observations used by the contractor to monitor and control the construction quality such that all applicable requirements are satisfied. Quality Assurance refers to measurements and observations by the owner or the owner's engineer to provide assurance to the owner that the facility has been constructed in accordance with the plans and specifications.</p><p>The components of QC/QA monitoring programs for Reinforced Soil Slopes are shown in Tables 1, 2, and 3. The entries in the table are a list of typical items, not a list of all methods that could be used for QC/QA. Some QC procedures and measurement items may also serve as QA procedures and measurement items.<br><h3>TABLE 1. TYPICAL EXISTING QC/QA PROCEDURES AND MEASUREMENT ITEMS</h3><table class='tablepress' id='tablepress-2035'><thead><th><center>QC or QA</th><th><center>Material or Process</th><th><center>Items</th></thead><tbody><tr><td ><center>QC</td><td ><center>Material Related</td><td >• Soil shear strength, gradation & PI
• Soil reinforcement tensile strength

</td></tr><tr><td ><center>QC</td><td ><center>Process Control</td><td >• Monitor soil compaction
• Monitor soil reinforcement placement geometries

</td></tr><tr><td ><center>QA</td><td ><center>Material Related</td><td >• Soil shear strength and gradation testing
• Soil reinforcement coupon testing
• Soil reinforcement manufacturer’s certification

</td></tr><tr><td ><center>QA</td><td ><center>Process Control</td><td >• Monitor thickness of soil lifts
• Monitor soil reinforcement placement geometries
• Monitor soil reinforcement quantities
</td></tr></tbody></table><br><h3>TABLE 2. PERFORMANCE CRITERIA USE IN QC/QA MONITORING PROGRAMS</h3><table class='tablepress' id='tablepress-2036'><thead><th><center>Topics</th><th><center>Items</th></thead><tbody><tr><td ><center>Material Parameters</td><td >• Soil shear strength
</td></tr><tr><td ><center>System Behavior</td><td >• Surficial erosion resistance
</td></tr></tbody></table><br><h3>TABLE 3. EMERGING QC/QA PROCEDURES AND MEASUREMENT ITEMS</h3><table class='tablepress' id='tablepress-2037'><thead><th><center>Topics</th><th><center>Items</th></thead><tbody><tr><td ><center>Material Related</td><td >• None noted</td></tr><tr><td ><center>Process Control</td><td >• Intelligent soil compaction</td></tr></tbody></table></p></p>