Recreation of Small Strains Phenomenon under Pavement Structure and Consequences of Failure to Address It

• Published in: IOP conference series. Materials Science and Engineering 2017-10, Vol.245 (2), p.22005
• Main Authors: Fedorowicz, Lidia, Kadela, Marta
• Format: Article
• Language: English
• Subjects: Constitutive models; Field study; Field tests; Mathematical models; Pavements; Recreation areas; Soils; Stiffness; Subgrades; Systems analysis
• ISSN: 1757-8981; 1757-899X; 1757-899X
• DOI: 10.1088/1757-899X/245/2/022005

This paper describes the small strains phenomenon which occurs in the subgrade under a pavement, a phenomenon documented through in-situ tests and recreated in numerical analyses, which lends a practical engineering aspect to the subject matter. The analyses were preceded by: 1) presentation of the role of constitutive models in structure-subgrade system analysis, 2) reference to methods of modelling in mechanistic procedures and possibility of reliable assessment of criterial values in road structures. These studies were coupled with a description of field tests, which recorded strains in subgrade under a loaded pavement: in zone I directly under the pavement - variable, depending on stiffness of the pavement and the load (about 200÷1000.10-6) and below that, in zone II - 'stabilised' (about 1÷5.10-6). In summary, it has been found that the accuracy of numerical analyses of structure-subgrade systems is dependent on the adopted constitutive model of the soil and the numerical calculation area representing the subgrade. Recreation and analysis of the pavement-subgrade system behaviour employed the MCC(OC) critical state model. It was determined that a reliable response of the computational model to the load path used can be obtained with a model that has been previously properly calibrated. The paper justifies the need to carry out further, directed field tests, coupled with numerical analyses employing relevant constitutive models for description of the soil's performance.