Optimization of Stabilization of Highway Embankment Slopes Using Driven Piles, Phase 1

摘要

This study determined the feasibility of using driven piles to stabilize highway embankment slopes. The activities performed under this study were a detailed literature review, a national survey of state DOTs, a review of inspection and stabilization mitigation reports, targeted field inspections, a cost comparison analysis, and a finite element study. The results of this study show that driven piles can be a cost-effective solution to stabilizing highway embankment slopes. The literature review showed that there has been significant research done concerning the lateral capacity of piles. This research tends to be focused on different applications, but still shows that piles have significant lateral capacity. The survey conducted shows that several DOTs have used driven piles to stabilize highway embankment failures and most of these departments would recommend future use. Also three DOTs have performed similar research using plastic pins to stabilize embankments. The site visits allowed the research team to identify two sites, the Muddy Pass slide and also the Rye slide, as potential sites for investigation under Phase II of the project. These slides in particular had broad shoulders along the highway that provide better accessibility. The cost comparison analysis showed that for a particular slope, driven piles would cost $41 per linear foot of road stabilized. This was compared to drilled shafts and launched soil nails which had estimated costs of $32 and $130 per linear foot, respectively. The finite element study showed that the factor of safety for a stabilized slope could be significantly improved with pile installation.