Effect evaluation of shotcrete vegetation mulching technique applied to steep concrete-face slopes on a highway of Taiwan

The Shotcrete Vegetation Mulching Technique (SVMT) was introduced to revegetate existing steep concrete-face slopes. By mixing cement and greening additives with hydraulic mulching materials in a particular proportion and directly spraying the mixture on steep concrete-face slopes, SVMT was proven to be superior to several traditional methods. SVMT can make a slope surface resistant to erosion within a short time (the uniaxial compressive strength of the slope was higher than 294.3 kN/m2 on the 14th day), create an environment suitable for plant growth (the vegetation coverage rate on the 90th day was higher than 90%) and foster a plant community capable of natural succession (competition and succession among Bermudagrass, turf-type tall fescue, hairy beggarticks, chamber bitter, oriental false hawksbeard, American burnweed, Pacific Island silvergrass, and inchplant were observed), effectively improving wildlife habitat and increasing biodiversity (small arthropods were found on the site, including spiders, grasshoppers, ants, ladybirds, etc.). Furthermore, the ecological engineering effects of SVMT on the experiment site were evaluated according to Mitsch and Jorgensen’s 19 Ecological Design Principles. It was found that the site treated with SVMT conformed to principles 2, 3, 8, 10, 11, and 16.