Challenges in Design & Construction of Elevated Grade Separators with Wide Deck & Single Central Pier, in urban areas.

India’s transport sector is large and diverse; it caters to the needs of 1.25 billion people. Roads are the dominant mode of transportation in India today. They carry almost 90 percent of the country’s passenger traffic and 65 percent of its freight. Cognizant of the need to create an adequate road network to cater to the increased traffic and movement of goods, Government of India has recently allotted Rs 640 billion (US$ 9.55 billion) to National Highway Authority of India (NHAI) for roads and highways and Rs 270 billion (US$ 4.03 billion) for rural roads under PMGSY scheme (as on 20th April 2017). One of the impediment in the fast progress of road infrastructure is acquisition of land & related regulatory hurdles. Completion of as many as 112 projects of NHAI is delayed on account of such factors. There is a restriction of the available width and to spread the road horizontally. Therefore, present trend in urban areas is to go for elevated grade separators, wherein both surface level as well as elevated road can be fully utilised for traffic movement. By avoiding costly land acquisition, it results in reduction in cost of the project and certainly segregate local and fast moving traffic, thereby further increasing speed of movement. Design and Construction of such elevated corridors however poses many challenges to structural engineers. Restricted work space during construction adds to the challenge and brings out many innovative solutions to the problems. This paper discusses case studies of number of such projects for which the authors are presently associated in design and construction planning. These projects are in various stages of construction.