We completed our bridge protection structure for the Mass Rapid Transport System over the waterway in 1999
One of our very first projects in India, which we completed back in 1999 between Delhi and Noida is still successfully serving its purpose 19 years later.
The Delhi Administration proposed a Road Bridge across the river Yamuna for the Mass Rapid Transport System back in 1998. The proposed bridge was about 2Km u/s of the existing Okhla barrage and had a waterway of 554.4m. It was anticipated that the velocity would be very high with the construction of new bridge and hence the piers of the bridge and the bed had to be protected.
The bridge had to meet certain project specific requirements concerning installation of river training works with safety on one side and cost effectiveness on the other. The original design of the river training works for the approach roads (upstream and downstream) and guide bunds (rear side & front side) consisted of a massive apron and slope protection using 1m thick stones by way of pitching. This envisaged rather costly works for which the original tendered estimate was about INR275 million.
The river training works were designed for a discharge of 14,866 m3/s and a maximum velocity of 3.3 m/s. The solution we offered made use of one single layer of 0.5 m thick Gabion Mattress. Our solution of Maccaferri Gabion and Reno Mattress was well accepted by the Noida Administration, CWPRS etc. since there was a reduction in the apron thickness by 50% against the conventional stone protection.
The main factor that contributed to the adoption of Gabion and Reno Mattress technology was the usage of stones of smaller diameter and ease of construction and maintenance. Since there was a reduction in thickness of the proposed pitching from 1m to 0.5m, there was 50% reduction in the quantum of stones. Recourse to turfing in certain reaches of the approach roads also contributed to cost savings. Immediately after the completion of works, the Gabions and the mattresses successfully withstood some reasonably high velocities in the deep channel flow. Application of this technology to this bridge is undoubtedly what made it techno-economically viable.
The structure has withstood heavy floods and many monsoons with very minimal maintenance. Since this structure we have constructed many more that are also still serving their purpose. We are very happy to share this success story with you all.