Controlling base movement of MSE walls using recycled plastic pins

Abstract

Sliding failure of Mechanically Stabilized Earth (MSE) retaining walls is a common problem when the shearing resistance developed between the wall base and foundation soil is insufficient. Highway MSE wall base failures can cause significant maintenance, repair, and cost implications for the state department of transportation. Controlling base movement using Recycled Plastic Pins (RPP) can be a potentially cost-effective and sustainable solution. RPPs are primarily manufactured from recycled plastics and have been successfully used for stabilizing shallow slope failures. The objective of the current study is to demonstrate the effectiveness of using RPPs for increasing the sliding resistance of an MSE wall. Four field test sections were constructed, out of which three were reinforced with different combinations of RPP sizes and spacings, while one was left unreinforced as a control section. Regular performance monitoring of the test sections was conducted using vertical inclinometers along with earth pressure plates. More than a year of results indicated a 75–88% reduction in lateral displacement of the reinforced wall base when compared with the control section. Additionally, the lateral earth pressure on the wall facing was decreased by 55–72% in the reinforced sections compared to the control section.