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Full-Text Articles in Engineering
Effect Of Subgrade Conditions On Pavement Analysis And Performance Prediction: A Study For Idaho Conditions, Md Jibon
Boise State University Theses and Dissertations
The Mechanistic-Empirical (M-E) pavement design approach detailed in the Mechanistic-Empirical Pavement Design Guide (MEPDG), and subsequently implemented through AASHTOWare® Pavement ME Design relies extensively on detailed material properties that ultimately govern the analysis and performance prediction results. For unbound materials like soils and aggregates, Resilient Modulus (MR) is the most critical input parameter affecting layer response under vehicular and environmental loading. Representing a material’s ability to ‘recover’ after loading, resilient modulus is determined in the laboratory through repeated load triaxial testing. Although the original test protocol to measure the resilient modulus value of a soil or aggregate …
Effect Of Particle Breakage On Ballast Permanent Deformation — A Study Using The Discrete Element Method, Beema Dahal
Effect Of Particle Breakage On Ballast Permanent Deformation — A Study Using The Discrete Element Method, Beema Dahal
Boise State University Theses and Dissertations
The ballast layer comprises relatively large (often as large as 63 mm) angular particles that mainly function to dissipate train-induced stresses from crossties to the underlying subgrade soils and to provide rapid drainage for surface water. Moreover, the ballast layer is also critical towards ensuring a smooth riding track profile, dampening dynamic loads, as well as providing lateral, longitudinal and vertical resistance against excessive track deformations. Under train loading and during track maintenance processes like tamping, individual ballast particles can undergo significant breakage leading to fouling of the ballast layer. The fouling mechanism leads to gradual deterioration in ballast shear …