BE Magazine - Volume 5, Issue 1 - (Page 25) CIVIL v Modeling the dam and surrounding area involved generation of 8 million triangles of digital terrain Merging data to build models Modeling the project area required GESS to import GIS-format files for existing topography, then use Bentley tools to model the site contours. The features of the dam supplied in 2D format were modeled in their correct geographic location. Since road rerouting was in the planning phase, the delivered model required additional details such as signage, road painting, and vehicles. Geo-referenced grayscale aerial images were resized and draped over the topography without losing clarity. Using on-site digital images, GESS also simulated the natural vegetation, including more than 5 million trees. “Bentley’s technology is the only comprehensive integrated solution that could be used to optimize the workflow and minimize the manipulation of the digital data to model the surrounding topography, proposed dam, and rerouted road,” Forbes said. “We were able to minimize reworking the original design, integrate various data formats, generate accurate 3D models, and create realistic visualizations that could be viewed via simplistic tools such as Adobe Reader, Internet Explorer, Windows Media Player, or a DVD player.” The De Hoop Dam project progressed through the subsequent external review process quicker than most projects of its size and scope. After extensive public outreach, DWAF made further recommendations to mitigate the potential impacts of development, including maintaining minimum environmental flows required for water management on the Olifants River in Kruger National Park. Given the overriding need to provide disadvantaged communities with decent potable water and stimulate economic development, the ministry issued a revised record of decision in October 2006 to authorize the De Hoop Dam, subject to specific conditions that would minimize the impact on Kruger National Park and the catchment area. Site clearance began in June 2007, and construction is expected to be completed by early 2010. DWAF expects water delivery to begin by April 2011. In addition to supplying water to developing communities in the Olifants and Mogalakwena/Sand Catchments, the De Hoop Dam will enable mining development to expand, contributing to the employment of thousands of residents. It might also supply water to the lower dam of a proposed hydroelectric plant to power further development in the region. BE Award Finalist On the Fast Track 3D modeling helps evaluate design alternatives for innovative new bridge in India T he Jubilee Bridge in Kolkata, India, spans the river Hooghly between the Bandel and Naihati railway stations. It opened in 1887, the year of the Golden Jubilee marking the 50th anniversary of Queen Victoria’s reign. Designed and built by Sir Bradford Leslie, the Jubilee Bridge is a bow-string bridge type with a central balance cantilever grade 360 feet long supported on two piers 120 feet apart. The suspended girders at each end measure 420 feet. A vital railway link, the bridge was originally constructed for a double line with 12-foot track centers. The advent of wider stocks and heavier axle loads prompted the railway to convert the bridge to a single-line gauntleted track bridge in 1910. The Jubilee Bridge is still operational, but has strict speed restrictions that hinder the smooth flow of rail traffic. India’s Eastern Railways planned a replacement bridge and in 1987 commissioned RITES Ltd. to carry out detailed studies and determine Volume 5, Issue 1 | BE MAGAZINE 25
For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.