Case Studies

Mantralayam Bridge, Raichur, Andhra Pradesh

Case overview

The Mantralayam Bridge was to be constructed over the Tungbhadra River in Raichur, Andhra Pradesh. The 560m bridge involved launching of 2 sections of 280m length each from either side. The 280m sections comprised of 7 nos. of 40m sections of 13m width and 9.5m height, weighing 1400MT.

Complexity

The challenge was to maintain the bridge alignment while launching the huge 280m sections of the bridge. The conventional method of assembling a bridge piece by piece had 2 major drawbacks. Apart from being a time consuming affair, this method also did not guarantee the alignment of the bridge after its completion. Therefore, the client was looking for a launching solution which was quick to execute and allowed precise alignment upon completion.

Our Solution

The team at Freight Wings, our parent company, proposed a bridge launching scheme with the help of rollers, hydraulic jacks and push-pull cylinder. The bridge sections were pulled and pushed with the help of 10 nos. of high capacity synchronized push-pull cylinders mounted on RCC pedestals. Controlled movement of structure was carried out with the help of 8 nos. of 100T capacity hydraulic jacks and 44 nos. of 100T capacity skid rollers. The unit was gradually moved over rollers mounted on bed block of abutment and piers till the unit crossed the entire span. To accomplish faster launching, same method was continued from the other end of the bridge, since they provided 2 sets of skid launching equipment. The team successfully installed entire bridge within a short span of time, reducing the construction schedule by half.