Slope Stabilization with Recycled Plastic Pins

Abstract

A scheme to stabilize minor slope instabilities is currently being developed. The scheme uses a distributed network of “pins” fabricated from recycled plastics and other waste materials to provide positive reinforcement of a soil mass. Although the application is similar to stabilization of slopes with soil nails or micropiles, significant modifications to conventional design and construction are necessary to account for the reduced strength and increased ductility and creep exhibited by plastic materials compared with concrete and steel. Using recycled plastics has the advantage of providing reinforcing members with low susceptibility to degradation and provides a market for materials that otherwise might be buried in a landfill. An extensive investigation is under way to evaluate the potential for using recycled plastic pins (RPPs) to stabilize minor slope failures. This evaluation includes quantification of appropriate material and engineering properties of RPPs, evaluation of RPP resistance to degradation in various environments, development and evaluation of suitable mechanisms for installing RPPs, evaluation of RPP resistance to driving stresses, development of a design procedure that accounts for the reduced structural capacity of RPPs compared with steel or concrete members, and installation and monitoring of several full-scale field demonstration sites. The ongoing evaluation program that is described focuses on laboratory tests to determine fundamental engineering and material properties, field driving trials to evaluate potential driving mechanisms, and preliminary development of a suitable procedure for designing RPP stabilization schemes.

Cost-Effective and Sustainable Road Slope Stabilization and Erosion Control

“…Mechanical stabilization techniques include retaining walls, mechanically stabilized earth, geosynthetically reinforced soil, and other in-situ reinforcement techniques. For anchoring shallow soils, use of in-situ earth reinforcements and recycled plastic pins has been reported in slope stabilization (Pearlman et al 1992;Loehr et al 2000).…”

Numerical Modeling for Remedial Measures of Shallow Slope Failure Using Recycled Plastic Pins

“…Plastic pins are less susceptible to chemical and biological attack than other structural materials and are lightweight meaning smaller installation equipment and transport cost (Loehr et al, 2000). Plastic pins are fabricated from recycled plastics and other waste materials (polymers, sawdust, fly ash), to provide positive reinforcement of a soil mass.…”

Three-Dimensional Stability Analysis of a Homogeneous Slope Reinforced with Micropiles

“…The use of micropiles to stabilize an unstable slope has been widely adopted in recent years (e.g., [1][2][3][4][5][6]). A micropile is a small-diameter (typically less than 300 mm), drilled, and grouted nondisplacement pile that is typically reinforced.…”

“…[7] described a procedure for the calculating of the resistance provided by micropiles, assuming that the limit state is the failure of the micropile in bending. Loehr et al [4] also proposed a simplified method for predicting the limit resistance of recycled plastic reinforcement for application to stabilization of minor slopes. In their method, two failure mechanisms are considered to determine the distribution of limit lateral resistance along the reinforcing members: failure of soil around or between reinforcing members and structural failure of the reinforcing member due to mobilized forces from the surrounding soil.…”

“…Therefore, the solution for conventional piles cannot be easily adapted for the situation of micropiles. Sun et al [9] developed a limit equilibrium approach for the design of micropiles, and the design procedure includes (1) choosing a location for the micropiles within the existing slope; (2) selecting micropile cross section; (3) estimating the length of the micropile; (4) evaluating the shear capacity of the micropiles group; (5) calculating the spacing required to provide force to stabilize the slope; and (6) the design of the concrete cap beam. Esmaeili et al [6] presented three experimental models of embankments of 10 m in height on a scale of 1/20 to set up a number of loading tests.…”