-Galla S Kiran Kumar,Bureau Chief Telagana (Andhra Pradesh)
In the Polavaram project, the guide bund being constructed at the top of the spillway on the left side has collapsed. Its construction has been carried out at a height of about 26 meters from the bottom with a length of about 500 meters.
When the construction was almost completed, the incident
occurred on the left side of the
spillway
.
PoIn the Lavaram project, the guide bund being constructed at the top of the spillway on the left side has collapsed. Its construction has been carried out at a height of about 26 meters from the bottom with a length of about 500 meters. Megha Engineering Company, the monopolist of the project works, is also doing these works. When the construction which was undertaken less than a year ago was almost completed, a crack appeared in the middle of the guide bund and it sagged towards the approach channel. An embankment built as part of the guidebund, the stones in it slid down. Due to this, the retaining wall collapsed. Some engineers suspect that the guide bond may have sagged due to the lack of proper cutoff. The Polavaram project authority was informed about this. The officials of Polavaram Authority and the members of the Dam Design Review Panel will have to take a decision on why the guide bund has sagged, what are the reasons and how to correct it. Some cracks occurred on Friday and Saturday.
Review by the Chairman of the Central Water Society
When it came to know that the guide bond has collapsed, Kendra Jal Sangam Chairman Khushwinder Vohra, Engineer-in-Chief C. Narayana Reddy, Chief Engineer Sudhakar Babu, SE Narasimhamurthy and other experts reviewed it in a video conference. He suggested that the experts of Akritula organization should visit Polavaram and identify and analyze the reasons for the sagging of the guideline. They want to decide what immediate action should be taken. Engineers have been ordered to investigate and find a way to solve this problem and report to the Central Water Corporation immediately. The Polavaram project engineer is going to meet the leaders of the central water association on Tuesday to discuss this issue.
What is a guideline?
PoInitially there was no proposal for the construction of this guideline in the Lavaram project. As part of the construction of the project, the natural flow of Godavari was changed. An approach channel was dug and the river diverted through the spillway. On the basis of these statistics, a prototype of the Polavaram project was created at the Central Hydropower Research Center in Pune and a model study was conducted on the flow and other aspects of the project. In this sequence, it has been found that Godavari flow velocity is higher on the left side of Polavaram spillway. Due to this, large eddies are formed near the spillway on the left side of Polavaram. This is expected to cause some disturbance to the spillway. Based on these 3D model studies, Polavaram Project Dam Design Review Panel and Central Water Society experts discussed. It is proposed to construct a guidebund above the spillway to solve the problem. Absence of this guidebund structure at the spillway, It is calculated that if the width at the mouth of the approach channel is not increased, the velocity of Godavari flow will be 13.6 m/s on the left side, 9.2 m/s in the middle of the spillway and 2.5 m/s on the right side. It is calculated that the river flow velocity will decrease to 4 meters per second on the left side, 5.5 meters per second in the middle and increase to 4 meters per second on the right side if some other measures are taken along with the construction of guidebund and widening of the mouth of the approach channel. That is, it was decided that the flow velocity of Godavari along the length of the spillway could be corrected with the construction of this guidebund, and its construction was undertaken. It is calculated that if some other measures are taken, the velocity of the river flow will decrease to 4 meters per second on the left side, 5.5 meters per second in the middle and increase to 4 meters per second on the right side. That is, it was decided that the flow velocity of Godavari along the length of the spillway could be corrected with the construction of this guidebund, and its construction was undertaken. It is calculated that if some other measures are taken, the velocity of the river flow will decrease to 4 meters per second on the left side, 5.5 meters per second in the middle and increase to 4 meters per second on the right side. That is, it was decided that the flow velocity of Godavari along the length of the spillway could be corrected with the construction of this guidebund, and its construction was undertaken.
