The latest progress of Padma Bridge

[Doctor Strange]

Sometimes, I say people in BD are superstitious, although BD posters here would say the guys lamenting in the video are just believers of their faith. Is it a good example of faith or superstition? May I think, they are very very pious Muslims? Should they not be encouraged to spread their anti-bridge faith throughout our society?

There are some believers trying to make sense with modern society relating faith. But often they make some silly mistakes which makes them joke. They arent hurting anyone so should take easy. What he said makes sense, if you consider the dams and what happened to Bihar due to Farakka barrage. Doesnt make much sense with Padma bridge though but I think there are examples, flow of river is affected due to bridge construction. As you were sharing your bridge construction related knowledge in other threads, may be you can shed some light into this.

Effect of bridge pier on waterways constriction: a case study using 2-D mathematical modeling
CONCLUSION From this study it can be anticipated that if the water ways become constrict, bank erosion and scour beyond expected may be happened. To avoid this drastic situation, river training work from 1km upstream to 1 km downstream may be recommended and continuous monitoring should be conducted during and after construction of such type of structure at stated situation.
http://www.iabse-bd.org/old/20.pdf

 

[bluesky]

There are some believers trying to make sense with modern society relating faith. But often they make some silly mistakes which makes them joke. They arent hurting anyone so should take easy. What he said makes sense, if you consider the dams and what happened to Bihar due to Farakka barrage. Doesnt make much sense with Padma bridge though but I think there are examples, flow of river is affected due to bridge construction. As you were sharing your bridge construction related knowledge in other threads, may be you can shed some light into this.

Effect of bridge pier on waterways constriction: a case study using 2-D mathematical modeling
CONCLUSION From this study it can be anticipated that if the water ways become constrict, bank erosion and scour beyond expected may be happened. To avoid this drastic situation, river training work from 1km upstream to 1 km downstream may be recommended and continuous monitoring should be conducted during and after construction of such type of structure at stated situation.
http://www.iabse-bd.org/old/20.pdf

I am, as usual, very novice in bridge construction like in many other matters. I used only my common sense to speak about certain subjects. I will do the same here. I think, the link above is of academic value and has very little relevance to the actual construction of bridge piers. Although the piers give resistance to the flow of water, the design engineers try to offset the constriction by shaping the piers round/parabolic at the two longitudinal ends and placing them parallel to the direction of flow.

Directions of actual river flows are measured and are then input in the open channel hydraulic lab tests to know the effects of the piers. Note that the direction of flow is not always exactly the same across the river. Well, the lab tests may give results only with an academic value than it is practical. Nevertheless, the tests are conducted in all the civilized and developed countries.

I do not think, Padma Bridge will constrict the flow, because the river is too wide. Bank erosion will be avoided by constructing levies (dikes) along the two banks. There will be certain amount of silt accumulation at the bottom of piers, but it is not like Farakka Barrage. Bridge piers in Padma will be located more than 100m apart. So, there are plenty of spaces in between for an uninterrupted flow. I think, there is little to worry about although our superstitious Mulla people are spreading rumors.

About dikes: I have not seen a single dike in BD which has been correctly designed/constructed. Chinese and Koreans follow the similar wrong design concept. Only the Japanese have a perfect design concept. However, the Japanese do not bid to get construction jobs that are labor-intensive and not technology-intensive. Construction of dike is one such labor-intensive work.