INFLUENCE DIAGRAMS FOR STRESSES AND DISPLACEMENTS IN THREE-LAYER PAVEMENT SYSTEMS FOR AIRFIELDS. PART 2

Abstract : The report presents influence diagrams for vertical stresses, shear stresses, and surface deflections in three-layer pavement systems, which are intended to provide the essential background and bases for evaluating the character and effectiveness of layered system reinforcing action. The vertical stress and shear stress transmission characteristics and critical regions, and the surface deflection performances are developed for nine three-layer concrete pavement systems for a range of layer modulii ratios; and ratios of layer 2 to layer 1 thickness. The effectiveness of reinforcing action, deflection performances, and shear stress performances in critical regions are treated and compared. Two-layer and three-layer thickness and layer modulii equivalences are developed and treated to illustrate methods for evaluating and for improving shear stress and deflection performance by modifications of layer modulii ratios and layer thicknesses. The major objectives are to develop a 'feeling', intuition, and judgments regarding deflection and shear stress performances of layered pavements, and to develop relationships and methods for evaluating layer thickness and modulii ratios, and criteria for rational and effective design for multi-layer pavement system for airfields and for ensuring satisfactory pavement performances and long life.