All railway supports of the Crimean bridge are ready (video). A floating crane crashed into the support of the Crimean Bridge

“The 256 support is back in the scaffolding, the frames are being knitted, concrete is being supplied. They write that it is cracked. All this is not without reason,” user Krymets said on Twitter.

Of the 595 bridge supports, 256, located almost in the middle of the Kerch Strait, cracked in two places, the cracks are clearly visible in the photo, reports Kuresh.info.

Currently, workers have reassembled the frame around the support to prevent further destruction and restore it. The support is located 8 kilometers from the shore. Experts argued that the supports would not even withstand the load of an empty railway line, not to mention the launch of trains. In this area, at the beginning of 2018, a subsidence of one meter of supports was already recorded.

On forums, pro-Russian Crimeans are confident in the success of the bridge construction:

Earlier it was reported that the builders of the Kerch Bridge were constructing metal spans of a road overpass in the sea on the Embankment - Fairway section in the area of ​​the Kerch Peninsula.

On February 14, information appeared that the supports of the bridge across the Kerch Strait, which should connect Russia with the occupied Crimean peninsula of Ukraine,

On the Crimean side, the bridge supports are subsiding at a rate of up to 89 millimeters per year. But the railway arch in the center of the bridge, on the contrary, rises by three centimeters in the same time, and the automobile arch falls by approximately the same distance.

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Moreover, part of the Crimean Bridge is in a dangerous zone - the soil is shifting in the area of ​​Tuzla Island. If we were talking only about the fate of the bridge, Ukrainian “specialists” would only rejoice. However, according to Kyiv, we're talking about about the threat to human life and health, the negative impact on the Black Sea.

The rise of the arch of the railway part of the Crimean Bridge is 30 millimeters per year, while the arch of the automobile section drops by 32 millimeters per year, Ukrainian data cites “This indicates the instability of the seabed in the places where the supports are installed. All this has Negative influence to the Black Sea,” the Tsargrad TV report quotes.

The conclusions of the “experts” of the Ukrainian Ministry on issues of temporarily occupied territories were made, apparently, on the basis of satellite maps Russian service"Yandex". At least some of the photographs they presented match, writes.

According to department officials, the results of their research indicate instability of the seabed in the places where the supports are installed. The situation is also complicated by severe winter conditions operation, conveys their opinion.

The Crimean Bridge is the longest in Russia, its length is 19 kilometers. The railway part of the crossing is planned to open in 2019. Traffic on the road section was opened in mid-May of this year; Russian President Vladimir Putin was the first to cross the Kerch Strait.

Traffic was temporarily restricted on one section of the Crimean Bridge to eliminate the consequences of an incident in which a floating crane collided with a bridge support. This was reported to RBC at the Crimean Bridge information center.

Early in the morning on Saturday, September 8, in the Kerch Strait strong wind tore off its anchor a floating crane, which was located at an anchorage at a distance from the highway due to a previously issued storm warning. The crane crew tried to take control of the ship and stop its movement, but the ship ended up nailed to the support of the 227th road part of the bridge, at the 154th km of the A-290 highway (this is the section between Tuzla Island and the fairway).

At this time, according to the Windy portal, which tracks wind changes in various water areas, a strong easterly wind of 27–28 knots (14 m/s) was blowing in the Kerch Strait, which corresponds to seven points on the Beaufort scale. In the open sea under such weather conditions, wave heights can reach 4 m.

As a result, the boom of the floating crane damaged one of the lighting masts; in addition, several meters of the bridge barrier were bent. Specialists from the Crimean Bridge operational service are currently working on site and are conducting diagnostics of the structures.

The crane itself was towed from the side Sea of ​​Azov.​ The press service emphasized that the work to eliminate the consequences of the incident was complicated by storm conditions. At 8:30 Moscow time, the tugboat still managed to pick up the crane and pull it to safe distance from the bridge.

Later, RBC was informed at the Crimean Bridge information center that traffic on all lanes of the highway had been restored. “Damage to road construction elements does not affect the safety of traffic on the highway: expansion joints not damaged, no changes in geometry; roadbed no harm; the barrier fence is deformed over a 10-meter section, but there are no breaks,” the report says.

At the same time, due to storm winds, the speed limit remains on the A-290 highway along the Crimean Bridge Vehicle up to 40 km/h.

At the same time, in the waters of the Kerch Bay, another tug, Shkval, was in distress, on which there was a crew of seven people. They all managed to transfer to a life raft, which was drifting along a stormy strait off the coast of Crimea. After some time, all crew members were brought on board by sailors from the dry cargo ship Sarych, which was passing by. As Vladimir Ivanov, assistant to the head of the Crimean department of the Ministry of Emergency Situations, assured, none of those rescued in medical care does not need.

Later, Marine Directorate LLC, which manages the Kerch ferry crossing, announced the suspension of the crossing due to worsening weather conditions and increased wind speeds of up to 20 m/s.

At the end of October 2017, the bridge spans of the road part of the Crimean Bridge almost approached (were pushed) to the peak point of the transport crossing - the arched spans over the Kerch-Yenikalsky Canal.

The installation of column formwork began on support No. 256A -

Let me immediately draw your attention to the fact that the foundation grillage and support body were ready a long time ago. In the further analysis of the situation, we will assume that they are an unshakable stronghold. There were no problems with them and no problems arose when pouring the support columns. No piles under the support were sucked in anywhere, the grillage was not warped, and the body of the support was not cracked. Monolith! A reliable and heavy-duty monolith, which now carries a slightly larger load than originally planned.

Let me remind readers of this picture -

We are only interested in the support columns themselves.

This photo clearly shows that the bodies of the supports evenly change in height - they move like a ladder. This suggests that we are seeing a harmonious design solution that combines high reliability and elegant designs. There were no diaphragm bridges between the support columns included in the project.

If anyone has not yet gotten their bearings, then time No. 256 is the third in a row from the channel support of the arched span (No. 253A). In the photo, there are cranes with yellow arrows standing next to her.

An important fact: the sliding to the arches came from both sides -

No one announced any social competition, but there were some exciting moments. On the wave of success, in euphoria, after the installation of the arched spans, each side wanted to quickly get to the cherished final point by the new year.

At the beginning of November, a press tour was organized for inspired bloggers -

Their reports are good and colorful. But no details. Everyone unanimously illuminated the erected arches; no one looked towards the usual supports.

The avant-back was already beginning to hang over support No. 256A -

Reference: Avant-bec (French avant-bec) is a temporary cantilever structure used when installing bridge spans using the longitudinal sliding method. The structure is attached from the front to the superstructure being moved up. The length and mass of the foreback are specified in such a way that superstructure it does not capsize along with it until the avant-back reaches the first support of the bridge. The use of a foreback leads to a reduction in construction costs, as it allows the sliding of the span without the construction of intermediate supports. Great Russian Encyclopedia.

Kerch Bridge from the Kerch fortress on November 4, 2017.

Here the data differs somewhat: the filling could have been completed on the 5th. At least as of October 6, the columns were filled -

Let's take a close look at the spatial reinforcement frames of the columns -

As you can see: thick longitudinal reinforcement, and with frequent transverse piping.

I have already explained earlier: concrete works very well in compression and very poorly in tension. The strength differs by 10 - 15 times. Reinforcing bars are always placed in areas of expected tension reinforced concrete structure. That is, specifically in the support columns, the reinforcement does not bear a compressive load. It is needed to prevent bending of columns, with subsequent destruction.

Think about it... What loads can cause support columns to bend? Thus causing tension in some areas and compression in others. Did everyone bend plasticine bars as a child? Have you seen how one side cracks and the other wrinkles? Who later bent the pipes? What did you see on the walls of the pipes?

So, any pillars and piles are reinforced symmetrically to the center of their cross section. Columns can be reinforced symmetrically to an axis passing through their center. Pillars and piles are reinforced like this -

It's very simple and clear example. The load on such a structure can act from any direction. For example: a windshield on a lamp post. That is why the horizontal sections of such structures almost always have the correct geometric shape - round or square.

The columns of the Crimean Bridge supports are oval in their cross section. Their cross section is somewhat elongated parallel to the longitudinal axis of the bridge, towards the spans. For better resistance to longitudinal loads from transport. The metal spans of the bridge rest on the crossbar, which, in turn, transfers the load to the columns. The spans are mounted on articulated movable and fixed supports. They are not pinched in the crossbars and do not cause any torques in the column bodies.

The columns of the bridge supports bear their own weight, the weight of the crossbar, partly the weight of the spans and the lateral load from vehicles. Under their influence, they compress and try to deviate from their vertical axis.

Let's not go into the wilds -

For those interested in more details - here .

Here it is -

Was it already possible to load the column?

Here is a graph of concrete strength gain -

What, you had to wait 28 days? No, of course not. On the third day, the concrete had already gained about 40% of its strength. Spatial weight reinforcement cage The crossbar no longer exerted any harmful excessive compression on the column.

Once again: the reinforced frame of the column close up -

I hope there is no need to voice the weight of the formwork. They can easily be ignored. The strength of concrete on the sixth day is 55-60%.

The strength of concrete columns is about 80%.

A day later, everything was ready for sliding the spans onto support No. 256A -

Now let's consider the following: which forces acted on the support columns during longitudinal sliding.

The most dangerous stresses occurred at the junction of the column with the support body (point A) -

From the force of the longitudinal slider, through friction, a moment of force arose at the base of the column. It will also arise from possible vibrations of the spans during an earthquake. At the same point "A". From the school physics course we know: the moment is equal to the force multiplied by the shoulder. The column is rigidly clamped in the support body. The column is tall. It could have cracked there. It shouldn’t crack so much that even the Maidans in Kyiv would see a crack the size of a fist. And very thin cracks. The presence of which became possible only after the formwork was removed, not even visually, but by ultrasonic testing.

The strength of the concrete structures of the Crimean Bridge is determined ultrasonic method .

Maybe there were no cracks at all, but the product simply did not pass the test for some other reason.

Good news -

You see: the slide on the Kerch side initially lagged behind. That is, there was some incentive to speed up the work.

If they were in a hurry to move things along at an accelerated pace and assembled the formwork on two crossbars at once, perhaps there was no time to dismantle the old formwork at that moment. And perhaps they knew about the slight tilt of the column that occurred during the slide. The slide is accompanied by constant geodetic control. Anything that deviates by a millimeter will be immediately noticed.

Please note: on the Tuzla side the formwork is on only one support. On the side of Kerch, the formwork contains columns of three entire supports: No. 254A, No. 255A and the one we are considering - No. 256A -

Personally, even then I had a reasonable suspicion: no matter how the columns had to be repaired. Everything went fine, but anything can happen. Precisely because very serious requirements are imposed on the structures of the Crimean Bridge, it is absolutely clear: any defective detail that is revealed by construction control will be corrected in the most serious manner.

Let's sketch out such a simple graph of the strength of the column, for clarity -

Vertical - the strength of the product in quiet conditions is 100%. Horizontal - earthquake magnitude on the Richter scale. The tendency of the structure to collapse with increasing seismic activity is shown in a simplified manner. At a magnitude of 0.0, everything is fine; if the magnitude of the earthquake exceeds 9.0, the structure is completely destroyed. The red round spot on the yellow field is the area in which the already solved problem of the column was located. It lay somewhere in the area of ​​a magnitude 7 earthquake. How and with what did its small defect threaten in our earthquake-free days? Nothing and no way.

All sorts of Ukrainian mead experts live at the negative levels of the horizontal scale. In the illusory delirium of which the bridge collapses on its own.

The Kerch side was almost the first to advance -

The unofficial unspoken competition was almost won.

And then ultrasonic inspectors came to the support columns...

As we already understand: no one initially intended to build any jumpers (diaphragms) between the support columns.

Oh! What are these boys doing at the base of the column?

Remember the diagram above, which is with the moment?

My December fears were justified: it was impossible to do without repairs. And it was already clear that he would be more thorough. In the photo above it’s just a small thing. Repairs were still to come.

An earthquake causes shear stress. In the longitudinal direction of the bridge axis, the column would not have fallen anywhere due to shaking. Its spans are held as if in a vice. But if it shook with a shift earth's crust, but across the axis of the transition, the spans swayed to the side, the column could have fallen.

Why is such a diaphragm needed there -

This is an increase in the rigidity of the support structure across the transition axis. So that the lateral seismic shock does not break the columns.

Asphalt was not yet delivered for the span then. Not because the columns would not have held up, there was simply no need for it yet. It was necessary to lower the span structures from the slides to the regular landing sites.

There was no talk of creating an additional jumper then -

The treatment process did not bring the support structure to the required safety margin. Subsequent monitoring showed this. Author's supervision responded professionally. Changes have been made to the project. That's why the diaphragm appeared.

Should the official information center of the Crimean Bridge have covered this epic with the support? Answer: NO! Consumers need a high-quality bridge - this is the main thing. And the bridge is being built very well. It's moments like these that speak to this. No one ignored the identified defects and did not decoratively cover up the beauty. It’s like this: let’s open it, and then we’ll see. They gouged it out as expected. Completely oblivious to the show. To reduce the stench from all sorts of “experts,” curtains were erected on the scaffolding.

Just think: the support stood in the forests until mid-April. While it was being repaired and strengthened there, a bunch of trucks carrying asphalt passed over it. Nothing settled anywhere, no column collapsed in the sea.

I already said: ironically, support No. 256A became the strongest of all. Which is great.