Large-Scale Model Experiment of Hybrid Mass Damper with Convertible Active and Passive Modes Using Servomotor for Vibration Control of Tall Buildings.

This paper evaluates de deflections (measured at the surface and/or at the top of the subgrade) of unbound pavement materials under cyclic loading. Deflections of three base course materials (Bakel Red Quartzite, Bakel Black Quartzite and Diack Basalt) were investigated using a large-scale model experiment (LSME). The LSME is a prototype-scale pavement test apparatus where cyclic loading is applied and deflections are measured. The LSME replicates field conditions and accounts for scale effects. The LSME results showed that the total, plastic and net plastic deflections of a pavement increase progressively as the number of loading cycles increases. The total deflection decreases as the thickness of the base layer increases. Plastics deflections at the top of the subgrade decrease progressively as the thickness of the base layer is increased. The elastic deflections of the surface and of the base layer decrease gradually with the increasing loading cycles. The elastic deflection at the top of the subgrade decreases with increasing thickness of the base layer. So, rutting can be limited by limiting the elastic deflection at the top of the subgrade. However, this criterion does not account for the rutting caused by the unbound base layers and that of the asphalt concrete.

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Structural Contribution of Geosynthetic-Reinforced Working Platforms in Flexible Pavement

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198105193600106 ◽

2005 ◽

Vol 1936 (1) ◽

pp. 43-50 ◽

Cited By ~ 3

Author(s):

Woon-Hyung Kim ◽

Tuncer B. Edil ◽

Craig H. Benson ◽

Burak F. Tanyu

Keyword(s):

Model Experiment ◽

Large Scale ◽

Elastic Moduli ◽

Granular Layer ◽

Resilient Modulus ◽

Scale Model ◽

Design Guideline ◽

Large Scale Model ◽

Structural Contribution ◽

Soft Subgrade

A study was conducted in the field and with a large-scale model experiment (LSME) to evaluate the structural contribution of a 0.30-m-thick geosynthetic-reinforced granular layer used as a working platform for construction over soft subgrade. The study was conducted in the context of the 1993 AASHTO design guideline, in which the structural number (SN) of the pavement is based on layer coefficients (each defined using a resilient modulus). Working platforms reinforced with geosynthetics had smaller elastic deflections and larger elastic moduli than unreinforced working platforms with the same thickness. Reinforcement factors obtained in the field ranged from 1.2 to 1.8; those obtained in the laboratory ranged from 1.7 to 2.0, with greater reinforcement factors for the less extensible geosynthetics (geogrid, woven geotextile) for a 0.3-m-thick granular working platform. Of the four geosynthetics tested, the geogrid resulted in the greatest increase in modulus. Reinforcing the working platforms with geosynthetics resulted in increases in layer coefficients ranging from 50% to 70%. Similarly, increases in SN for a typical pavement structure were realized, ranging from 3% to 11% when all other factors were equal.

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