Polymer-Enhanced Soft Armoring: An Erosion and Sediment Control Measure for Construction Fill Slopes

摘要

Construction fill slopes on highway projects present a unique environmental challenge that involve prevention of erosion and the associated transport of sediment by stormwater runoff, prior to the establishment of a vegetative stand. The objective of this research is to investigate the use of a polymerenhanced soft armoring technique as a temporary erosion and sediment control measure on compacted 3:1 fill slopes that are common in highway construction applications. Polymer-enhanced soft armoring consists of installing a soft, pliable open-weave mat (i.e. jute, coir, coconut, hemp, burlap, etc.) on the disturbed soil surface along with a site-specific, dry-granular polyacrylamide (PAM). The addition of PAM allows the chemical treatment to bond with soil particles, thereby enhancing the stability of the surface. This research uses intermediate-scale testing procedures under simulated rainfall conditions. We evaluated the effectiveness of a polymer-enhanced soft armoring consisting of an open-weave, jute matting with PAM applied at a rate of 35 lbs/acre (39.2 kg/ha). Through comparative analyses, the performance of the soft armoring was quantified against the following conditions: (1) bare soil, (2) openweave jute matting, and (3) open weave, jute matting with dry, granular PAM applied at 35 lbs/acre (39.2 kg/ha) (polymer enhanced soft armoring). Data collected include surface runoff volumes, turbidity values, and the total amount of eroded soil. Results of the analyses help understand the performance of the polymer-enhanced soft armoring technique in preventing erosion and reducing the amount of sediment in stormwater runoff.