Numerical study on the optimum layout of soil-nailed slopes

作者：Fan Chia Cheng^*; Luo Jiun Hung

来源：Computers and Geotechnics, 2008, 35(4): 585-599.

DOI：10.1016/j.compgeo.2007.09.002

• soil nails
• optimum layout
• optimal nail orientation
• factor of safety
• finite element analysis
• soil-nailed slopes

This paper presents a numerical study on the optimum layout of soil nails to stabilize slopes. Effect of nail orientation and geometric layout on the overall stability of soil-nailed slopes with various geometric conditions is investigated using the non-linear finite element approach. Stability of soil-nailed slopes is evaluated in terms of factor of safety. The optimal nail orientation for slope angle of 90 degrees, 80 degrees, 70 degrees, 60 degrees, 50 degrees, and 40 degrees are 0 degrees, 8 degrees, 16 degrees, 23 degrees, 30 degrees, and 40 degrees, respectively, for soil-nailed slopes with a horizontal backslope. The optimal nail orientation in relation to the horizontal plane increases with a decrease in the gradient of soil-nailed slopes, and it increases with an increase in the gradient of backslopes. Nail length at the lower 1/3 part of the slope is more important to the overall stability of slopes than those at other parts, especially for soil-nailed walls. Effect of arrangement of vertical spacing of nails on the stability of soil-nailed slopes is insignificant if number and amount of nails used in slopes remain unchanged.