• DEVELOPMENT OF AN ANALYTICAL APPROACH FOR DESIGN AND REHABILITATION OF FLEXIBLE PAVEMENTS

Abstract

Highway network is an important factor for the social and economic development of any region or country. The economic development of the nation links its direct benefits with the efficient system of transportation. An efficient highway network requires well designed pavements. Pavements are classified into two categories viz. in India Rigid and Flexible. Flexible pavements contributes about 98% of the total length of road network. Various design method of flexible pavement which are quite suitable for other countries may not be suitable for Indian conditions due to variation In the available construction material, traffic conditions, environmental condition, quality of construction and construction practices Present IRC method of flexible pavement design also suffer with the deficiencies of adhoc selction of pavement thickness with different range of cumulative number of standard axles. All these limitation make it necessary to evolve an analytical approach for design and rehabilitation of flexible pavements based on stress strain relationship. Hence a simplified and practical analytical approach for design and rehabilitation of flexible pavements, utilising the data of material properties (E and p ) of different layers and failure criteria, (i.e.) limiting horizontal tensile strain at the bottom of wearing course (Er) and limiting vertical compressive strain at the top of-subgrade CE), have been developed in the present study. Design charts have been developed for deisgn & rehabilitation of flexible pavements for different soil subgrade,- between different cumulative no. of standard axle loads and total granular thickness in terms of WBM !, during development of these charts the available IRC specification are used in selecting the thickness of different layers. Cost analysis have been done for various optimal design sections and finally optimal design sections are recommended by satisfying structural and economic criteria. The present, suggested approach can directly be utilised by field engineers for design and rehabilitation of flexible pavements.