Hi-tech used to build Padma Bridge
The quality of the Padma Bridge construction work has not been compromised. This bridge is built with the latest technology and materials in the world. The piles of this bridge have been laid up to a maximum depth of 122 meters.
Sophisticated technology has been used to prevent earthquakes besides the Padma Bridge has touched five world records in technology. Where is the deepest pile and pendulum bearings used to build this mega structure.
River training was the first step to build Padma Bridge. For this, the latest technology engineering has been adopted to rule 6.5 km long Padma Bridge project. That is Guide Bond with Falling Apron. This engineering shield is made by digging 20 to 25 meters using modern dredger. Heavy stones or heavy bags of geo-textile sand are left on the slope.
As a result, if for some reason the soft soil of that part breaks down and moves downwards, the heavy stones or bags placed on it fall further down and form a hard layer, which prevents the river from changing its course.
According to the engineers, during the construction of the two-storey Padma Bridge made of steel and concrete with dredgers, the maximum dredger could be excavated using 15 to 18 meters. But for the improvement in technology, the capacity of the Padma Bridge has increased to 32 meters.
In addition, the rocks that are placed on the banks of the river during river rule have been fully calculated with GPS to easily determine the course and nature of the river. In the case of Padma Bridge, GPS engineering has been used for river management and piling.
In addition, the image of the change in the course of the river during the design of the bridge has been made using satellite images.
Padma Bridge construction team member, Prof Ainun Nishat, said the river Padma is an alluvial river, which is flowing like a snake through the sedimentary rock. It is also a whimsical river because of its diverse character. Its edges are also very broken. The construction of such a large bridge over such a huge and fast flowing river was a huge engineering challenge. One of the stones used to meet this challenge weighs from 800 kg to one ton. The world's three largest dredgers were brought. Through them, a bottom layer has been created by filling relatively thick sand in a 800 kg geobag at the bottom of the river.
Piling comes after river governance. Another new technology has been used in Padma bridge pilling. With that technology, piling has been dug in Padma about 122 meters. Is the deepest piling in the world in the construction of bridge structures on the river. That is about height of a 40 storey building.
Here a 3m diameter steel tube is inserted into the ground with a slightly curved hammer. These hammers were brought from Germany. The weight bearing capacity of the pile has been increased by screen grouting (superficial cement layer) on the surface of the piling. Where is 100 ton bearings have been installed at the junction of pillar and steel structure. Usually two bearings are placed on the bridge. But three bearings have been used at the junction of two spans on the Padma Bridge.
Executive engineer Dewan Abdul Quader, of the Padma Bridge, said the new design had to be done as there was a layer of clay in the deep bottom of the Padma River. In this design, a total of 32 piles were made of 16 poles number 1 and 42. A total of 154 piles were placed on 22 poles, seven in each besides a total of 108 piles were placed on six of the 18 poles.
Finally, sophisticated technology has been used on the Padma Bridge to prevent earthquakes alongside centuries of sustainable technology. Friction pendulum bearings (FPB) technology has been used to prevent all the vibrations that occur in the ground during an earthquake from reaching the bridge's superstructure. Using it will not affect the structure of the main bridge even if the piling of the bridge is moved during an earthquake.
According to the design, the Padma Bridge is capable of handling a load of about 10,000 tonnes. But in the world such tests can be tested for only 8 thousand tons of load. The rest will be tested in the scale model. The use of FPB technology has reduced the construction cost of the Padma Bridge around 100 million dollar. If it was not used, it would have cost 8 piling instead of 6 per pillar. Piling is mainly done by carrying the load of the building, so that the soil does not move and erode under the pressure of the structure.
Besides, the main infrastructure of the Padma Bridge has state-of-the-art CCTV cameras. In addition to general lighting facilities, the bridge has architectural lighting to enhance the lighting and beauty. Radio Frequency Identification (RFID) has been used for automatic toll collection. A total of 14 Electronic Toll Collection (ETC) booths have been set up at both ends of the bridge. The bridge has gas, electricity and optical fiber transport facilities as well.