How are the bridge pillars built underwater?

First make a sealed cofferdam cage and go down to the water, and drain the water in it after sinking (the water will continue to seep, and the water should be pumped all the time during the construction); Construction in cages. Lay the foundation, lower the steel cage, inject cement, and remove the cofferdam cage after the cement of the pier base is solidified, and continue the construction above.

This is the first method of pier pouring. The second method is relatively simple, does not need the first kind of so cumbersome section by section, it is to do is to enclose the area of the bridge construction, block the flow of the river water, and then drain the water of the enclosed area, so that the construction of the bridge is equivalent to the same as the construction on land, the operation is more convenient, this method is not very high on the technical requirements, and the operation is relatively simple.

The bottom is inserted into the water with an iron caisson (the upper part is higher than the water surface), and the upper part is connected with iron or reinforced concrete, and the whole sinks after each section of height (the mud in the lower part of the caisson is washed into mud with a water pipe at the bottom, and the mud water is pumped and discharged to the outside, so that the caisson gradually sinks under its own weight).

The steel cofferdam, the sleeve, the bottom is inserted into the mud, the upper part is higher than the water surface, the entire construction range of the pier is set up, and the construction is carried out after draining the water.

For a group of steel pipe piles, a plurality of long steel pipe piles are driven into the water, and then reinforced concrete is made on the top of the steel pipe piles; It is also possible to put reinforced concrete in the steel pipe pile.

Bridges are an important tool to connect the two banks of the river. If there are no bridges, there is no way to communicate with many places, or you need to take a long detour to reach them, and bridges are the tools that simplify the complex, so to speak, the emergence of bridges, directly or indirectly shorten the distance between the two regions.

The land is built with a mound of earth, and then the soil is dug out after the construction is completed. The "Jade Wrench" platform is a resource sharing platform for construction and related industries. Recruitment, job search, machinery rental and sales, material procurement, construction waste trading, and project financing are all on the Jade Wrench platform. ‍‍

First make a sealed cofferdam cage and go down to the water, and drain the water in it after sinking (the water will continue to seep, and the water should be pumped all the time during the construction); Construction in the cage, then lay the foundation, lower the steel cage, inject cement, and remove the cofferdam cage after the cement of the pier base is solidified and stable, and continue the construction above.

Cofferdam refers to the temporary enclosure structure built for the construction of permanent water conservancy facilities in the construction of water wide and retaining projects. Its function is to prevent water and soil from entering the construction site of the building, so as to drain the water in the cofferdam, excavate the foundation pit, and build the building. Generally, it is mainly used in hydraulic construction, except as part of a formal building, and the cofferdam is generally dismantled after use.

In the construction of bridge foundation, when the bridge pier and platform foundation are located below the surface water level, various forms of earth weirs are built according to local materials; In rivers with deep water and large flow velocity, wooden sheet piles or steel sheet piles (single or double) cofferdams can be used, and double-layer thin-walled steel cofferdams are mostly used at present. The function of the cofferdam can not only waterproof and enclose water, but also support the pit wall of the foundation pit.

The spacing of the bridge piers (not called columns) is selected by the design, and the span should be determined at the beginning of the design, so that the spacing of the piers is determined. In fact, the spacing of the general span is about the same as that of the river, but the main channel is wider.

A bridge with a cable-stayed cable (meaning rope) on the bridge is a bridge type, that is, a cable-stayed bridge, and the cable-stayed bridge pulls up the bridge structure, which is consistent with the cable-stayed function in the suspension bridge, but it is not vertical, it is cable-stayed. The tensile force of the cable is calculated, and the tensioning sequence is also certain, and the force is very large, dozens of tons and hundreds of tons.

The bridge is divided into many spans, such as the Hangzhou Bay Bridge is also composed of multiple parts, and the content of the general bridge is similar to that of the general bridge, but it has to consider the influence of the tide in the bay more.

Compared with the general inland rivers, it is necessary to pay attention to the influence of salt in the seawater on the structure in the water, and epoxy resin steel bars are often used to enhance anti-corrosion.

Hello, the piers of the bridge must not only hit the bottom of the river, but also cross the bottom of the river and hit the "hard" foundation. The general construction method is to use the "cofferdam method", that is, to build a "cofferdam" where the bridge piers need to be built, and then the water in the "cofferdam" is pumped clean, and then it is the same as the method of building bridge piers on land. For deep-water bridge foundations, bored piles are generally used.

Deep-water water boreholes, generally using boats. The rig is fixed to the ship, and the ship is held in place by giant anchors and cables. After setting the drilling position according to the measurement, sink into the steel casing, play the role of positioning and isolating water, and then go down into the drilling tool, drill into a hole, the hole forming process generally adopts mud wall protection, after the hole is formed, the reinforcement cage is poured underwater, and the high pile is formed, and then the high pile bearing platform construction is carried out, and the water bridge pier becomes.

Construction of the underwater column of the bridge: the method of cofferdam is adopted, and the water is drained within a certain range to make the underwater column;

Fix the pillar on the shore and move it underwater. But if you have to get the depth right, you can do it.

1. The piers of the bridge should not only hit the bottom of the river, but also cross the bottom of the river and hit the "hard" foundation;

2. The general construction method is to use the "cofferdam method", that is, to build a "cofferdam" where the bridge pier needs to be built;

3. Then the water in the "cofferdam" is pumped out, and the method of hitting the bridge pier is the same as that on land;

4. Underwater pouring of concrete to form a high pile, and then carry out the construction of the high pile cap, and the water pier will be successful.

Many people may wonder when they see the piers of the bridge going deep into the water, or the dam, are these buildings built in the water? Actually, it's mostly the cofferdam's fault! So what exactly is a cofferdam and what role does it play?

Let's find out!

One of the most important tasks in building a bridge in the water is to lay the foundation. The foundation is generally a pile foundation, and a concrete cast-in-place pile is mostly used. The specific construction process is more troublesome, and it is not clear in one or two sentences.

To put it simply, build a construction platform in the water, then set the pile position on the platform, and then insert the casing made of steel pipes into the soil layer at the bottom of the water, then drain the water in the casing, and then use a drilling rig to form a hole in the casing, and then pour concrete into a pile.

Of course, there are many more things that go into the actual construction.