ENGINEERING CHALLANGES
Challenges in Design and Construction of World’s tallest rail bridge in India At present people have to travel by road on the existing National Highway (NH-37) which is 230km long with several steep gradients, hair-pin bends and weak bridges. It takes more than 10 hours by road, whereas it will be less than 2 hours once the rail line is commissioned. Saibaba Ankala IRSE & Chief Engineer, SECR Indian Railways
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s part of Northeast Policy, Ministry of Railways took up the project of providing rail connectivity to Imphal in Manipur state. As per the detailed survey, the rail alignment takes-off from existing Jiribam railway station in Assam and traverses a length of 111km before connecting to Imphal, running along the picturesque lush green scenery of Northeast, marked by hills, valleys, waterfalls and rivers.
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The rail link has other advantages of strategic importance, ushers economic development of Manipur state with tremendous tourist potential and more importantly, It will also form a vital link of the proposed Trans-Asian Rail Network connecting several countries As the rail line crosses series of hill ranges, several tunnels and viaducts are necessary to maintain the gradient required for a railway line! One of these viaducts is spanning across a gorge of width 700m and depth 141m which is the World’s tallest pier bridge of this category, surpassing the previous record of 139m in a rail line in in Europe. In this paper, it is endeavored to discuss the various challenges encountered and specific techniques developed in designing
and building this World record bridge to make it safe and sustainable. Special Challenges Hilly Terrain The alignment passes through hill ranges of Patkai region (eastern trail of Himalaya), entailing series of tunnels and viaducts. While the high mountains are penetrated by tunnel, the deep gorges need to be spanned by tall viaducts. An alternative to viaducts is high embankments. But this is not a professional solution in the present scenario, considering their susceptible for failures, required huge earth quarries and occupy large spaces, yet requires huge maintenance efforts. Hence a detailed comparative study was made and viaducts are found to be the best choice from considerations of aesthetics, environment, sustainability and economy on long term basis. The tallest of such bridges (Br.No.164) which is explained in this article spans over a gorge of depth 141m and length 703 mtrs. This bridge is slated to become
JANUARY 2020 // Urban Transport Infrastructure
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