Navi Mumbai Metro
The Navi Mumbai Metro is a rapid transit system under construction in the Indian city of Navi Mumbai, Maharashtra. The completed system will consist of six elevated rail corridors covering a total distance of 117.3 kilometres (72.9 mi). The planning and construction of the Navi Mumbai Metro is being overseen by the City and Industrial Development Corporation (CIDCO). The foundation stone for the project was laid on 1 May 2011, and the first line is expected to open in 2016.
Due to Navi Mumbai’s growing population and the anticipated future demand for public transport, the government envisaged developing metro rail corridors in Navi Mumbai in addition to the suburban rail system and bus based public transport system, in order to establish better North-South and East-West connectivity between all the residential nodes, and to improve connectivity with Mumbai’s transportation system. The Delhi Metro Rail Corporation (DMRC), which was entrusted with the task of conducting feasibility study, proposed connectivity by metro rail, due to various merits on account of it being energy efficient, pollution free and occupying less land space as compared to other modes of transport. The DMRC proposed six metro corridors in Navi Mumbai, but out of these, Uran-Ranjanpada-Nerul and Ranjanpada-Kharkopar-Seawoods were later decided to be made as suburban railway corridors. In total five lines were finalized for development in phases.
The Navi Mumbai Metro project received formal approval on 29 April 2010, and a public hearing on 21 May 2010 reported no major objections to the plan. as the implementing agency of the Belapur-Pendhar-Kalamboli-Khandeshwar line, under the Indian Tramway Act 1886, by the Government of Maharashtra on 30 September 2010. The state government later asked the CIDCO to implement the Navi Mumbai Metro project under the Central Metro Act.
The metro’s foundation stone was laid on 1 May 2011 by Chief Minister Prithviraj Chavan, and general foundation work on the system’s first phase commenced in October 2011. In March 2012, CIDCO released the metro’s complete master plan, including a proposed connection to the Mumbai Metro. Following the approval for the implemention of the Navi Mumbai International Airport, the master plan of Navi Mumbai’s connectivity was reviewed. The consultancy contract was awarded to LEA Associates South Asia Pvt. Ltd. to review the Master Plan and suggest new airport connectivity for Mumbai by various means of transport. LEA Associates South Asia Pvt. Ltd. recommended lines from Mankhurd to Panvel and Sewree-Kharkopar-Airport as metro rail corridor. A final list of 5 corridors was finalized based upon DMRC and LEA Associates South Asia Pvt. Ltd’s. recommendations.
In February 2013, thousands of villagers in the Navi Mumbai area protested against CIDCO’s inaction on local housing developments and its failure to provide restitution for locals affected by infrastructure projects. The protesters pledged to “shut down the CIDCO head office and all development projects in the region. These will include the metro project and any progress on the airport project”.
The superstructure of a large part of the viaduct comprises simply supported spans. However at major crossings, over or along the existing bridge, special steel or continuous units are provided. Normally, the Box Girder having a soffit width of approximately 9.70m accommodates the two tracks situated at 4.1 m centre to centre (c/c). The Box Girder superstructure, for almost all the simply supported standard spans, is constructed by precast prestressed segmental construction with epoxy bonded joints. The max spans c/c of piers of standard simply supported spans constructed by precast segmental construction technique were proposed as 28 m. The usual segments are 3m in length except the Diaphragm segments, which are 2m each. The other standard spans (c/c of pier) comprises 25m, 31m & 22m, which are made by removing/adding the usual segments of 3m each from the centre of the span. The pier segment was finalized based on simply supported span of 31m, and the same was also kept for all simply supported standard span. For major crossing having spans greater than 31m, special units normally of 3 – span construction or steel girders were envisaged. All these continuous units (in case provided at obligatory location) were constructed by cast-in-situ balanced cantilever construction technique.
The viaduct superstructure is supported on single cast-in-place RC pier. The shape of the pier follows the flow of forces. For the standard spans, the pier gradually widens at the top to support the bearing under the box webs. To prevent the direct collision of vehicle to pier, a Jersey Shaped crash barrier of 1m height above the existing road level was provided all around the pier. A gap of 25mm was also provided in between the crash barrier and outer face of the pier. The shape of the upper part of the pier was dimensioned so that a required clearance of 5.5m is always available on road side beyond vertical plane drawn on outer face of crash barrier. An outward slope of 1:200 was provided at pier top for the drainage due to spilling of rainwater. The orientation and dimensions of the piers for the continuous units or steel girder (simply supported span) have to be carefully selected to ensure minimum occupation at ground level traffic. Since the vertical and horizontal loads will vary from pier to pier, this was catered to by selecting the appropriate structural dimensions.