Ryan Corey

Laboratory Study on Geosynthetic Protection of Buried Steel-Reinforced HDPE Pipes from Static Loading

AbstractGeosynthetic layers above a pipe can potentially reduce the deflection and strain in the pipe attributable to static loads. This paper discusses the laboratory results of shallowly buried steel-reinforced high-density polyethylene (HDPE) pipes subjected to static loads with or without geogrid. In the testing, static loads were applied to a steel plate seated on the ground with a 0.61-m-diameter steel-reinforced HDPE pipe buried in a compacted-sand trench. Four static loading tests were run with two different base courses and geogrids inside and above the trench. The test section was instrumented to record pipe deflections, earth pressures, and strains in the pipe wall and geogrid. Installation deflections were monitored and compared with a theoretical model. The measured earth pressures were compared with those estimated by the current AASHTO live-load distribution method. Reduced deflections and strains of the pipe were recorded as a result of the geogrid reinforcement. The type of base course al...

Laboratory Evaluation of Deformations of Steel-Reinforced High-Density Polyethylene Pipes under Static Loads

A new product, steel-reinforced high-density polyethylene (SRHDPE) pipe, with high-strength steel reinforcing ribs wound helically and covered by corrosion-resistant high-density polyethylene (HDPE) resin inside and outside has obvious advantages. To investigate the behavior and performance of such a new pipe, three parallel plate tests were conducted in air. The deflection profiles of the pipes and the strains on both steel and polyethylene plastic were measured. No cracking was observed on the plastic during the experiment. The photogrammetry technology was effective in measuring the deflection profiles of the pipes during loading. The light detection and ranging (LiDAR) technology could obtain three-dimensional images of the pipes but was suitable for stationary targets. Strain gauge data indicated the occurrence of out of plane buckling of the steel ribs at failure and the strain incompatibility between the steel ribs and the plastic cover during loading.

Back-Calculation of Resilient Modulus and Prediction of Permanent Deformation for Fine-Grained Subgrade under Cyclic Loading

AbstractSubgrade of roadways is subjected to repeated traffic loading at different loading intensities. The resilient modulus of subgrade is one of the important parameters for the design of paveme...

Equivalent Modulus of Geogrid-Stabilized Granular Base Back-Calculated Using Permanent Deformation

AbstractGeogrids have been increasingly used for stabilization of base courses and subgrade. In the design of the geogrid-stabilized roads, the benefit of geogrids is usually quantified by a modulu...

Numerical Modeling of Installation of Steel-Reinforced High-Density Polyethylene Pipes in Soil

AbstractSteel-reinforced high-density polyethylene (SRHDPE) pipe uses steel ribs to carry loads and plastic cover to prevent the steel ribs from corrosion so that it overcomes the disadvantages of ...

Numerical Analysis of Soil Stress Distribution Under Restrained and Eccentrically Loaded Footings Considering Soil Strength

One potential way to prevent overturning and increase efficiency of an eccentrically loaded footing is to hold the back of the footing down into the ground with a structural member such as a cable. A previous numerical analysis by the authors showed that under a specific condition by assuming a linearly elastic soil, a simplified model could be developed based on the elastic cracked concrete beam model to estimate soil stress distribution under the restrained and eccentrically loaded footing. In practice, however, soil has a limited shear strength, which is often described using the Mohr-Coulomb failure criterion. Under eccentric loading, the soil may yield near the edge of the footing. This study involved the finite difference numerical modeling of square concrete reinforced footings, on a homogenous mass of soil, restrained at the tension side with steel cables. The foundation soil was modeled as a linearly elastic perfectly plastic material with the Mohr-Coulomb failure criterion. The numerical models included an applied moment but not a vertical load and self weight of the footing. From the output of the numerical model, the bearing stresses underneath the footing and the tension forces in the steel cable were analyzed and compared with those based on the linearly elastic model. The comparison showed that the bearing stresses near the edges were limited after the consideration of the soil strength based on the Mohr-Coulomb failure criterion. The analysis showed that cable anchorage in the tension side of the footing significantly increased the moment capacity as compared with the free footing.