307 structures have been completed, which are now gradually taking over the spans - 160 thousand tons of metal structures. Information center "" reports this. “This is not just the completion of the installation of supports for the railway. All supports of the Crimean Bridge are ready: both road and railway. A titanic work has been carried out. Thousands of piles for these supports are buried to great depths: in some areas - more than 100 meters. Difficult soil and frequent storms greatly complicated the work, but everything was done efficiently and on time,” said Arkady Rotenberg, Chairman of the Board of Directors of STROYGAZMONTAZH. The final one was railway support No. 254 in Kerch Strait in the area between the fairway and the Crimean coast. It consists of a foundation on 16 tubular piles submerged under different angles to a depth of 70 meters, and bodies from steel reinforcement and hydraulic concrete. “The support has been brought to the design level - 33 meters from the water level, almost 12 storeys high. The final stage was the concreting of its upper elements, on which they will later be installed special devices– supporting parts. “Spans are placed on them,” said Alexey Dvoeglazov, project manager at the Crimean Bridge construction site. “The supporting parts, a kind of balancers, will provide the necessary angular and linear movements of the spans, invisible to the naked eye, in the event of thermal expansion of the metal or possible seismic vibrations.” Read: The main stage of construction of the railway part of the Crimean Bridge today is the installation of spans. This one is complicated technological process is carried out in all offshore and onshore construction sites. In total, more than 15 kilometers of the route have already been blocked by spans at 8 construction sites. “The builders have completed the construction of all railway supports of the Crimean Bridge. There are 307 such supports in total, 85 of which are located in the waters of the Kerch Strait. The work was quite difficult and took place in difficult weather conditions. But, despite this, the builders coped with their task and completed all the railway supports with a slight advance. They are quite massive, differ from automobile ones primarily in their overall dimensions, and the last support we completed was support 254 on the fairway section, its height is about 33 meters - this is about a 12-story building. The foundation of this support consists of 16 tubular piles, their immersion depth is about 70 meters. In general, if we talk about the foundations of the railway component of the transport crossing, then maximum depth dives at construction sites were more than 100 meters. Work is underway to assemble the spans and slide them. To date, about 130 thousand tons of metal structures have been assembled. The sliding is carried out in offshore areas. Both transverse and longitudinal. The work is progressing according to schedule. Also, as the scope of work becomes available, work is underway on laying the rail and sleeper grid,” said Leonid RYZHENKIN, Deputy General Director of the STROYGAZMONTAZH company. Read: The spans assembled on stands are placed on land supports using cranes, and on sea supports they are lifted using jacks in longitudinal and transverse ways. On the completed spans, the superstructure of the track is formed sequentially from the side of the Taman coast railway: on this moment More than 9 out of 38 km of rail and sleeper grating have been laid.
All supports of the Crimean Bridge are ready. Video
Completion of the installation of spans on land and at sea is planned for the first quarter of 2019. in autumn next year The superstructure of the track will be completed on the bridge. Rail traffic will open in December 2019.It is about to collapse, that cracks are clearly visible on one of the supports (256A), that the opening of the bridge is cancelled...
The real situation with the supports of the Crimean Bridge
All the supports of the Crimean Bridge are in order; information about cracks in them is another myth.
The corresponding comment appeared on the bridge's official Facebook page.
“All my supports are in order, and this news really cracked and added to the collection of #Crimeanbridgemyths,” says a comment about a message about a cracked support.
Even people far from construction have already realized: something is wrong with this support. It turned out to be more massive than the others. With some additional jumper.
Smart people realized: if the mass of the support was increased by creating an additional bridge between the columns, then the problem was clearly not in the foundations. If something was falling through there somewhere and the piles were being sucked into hell, then there would be no point in increasing the weight of the structure. Everything is in perfect order with the foundation and grillage.
The problem was, apparently, in the columns themselves, or in one of the columns. The problem was solved by linking two independent columns, from the grillage to the crossbar, into one solid structure, arranging a special blind lintel.
Either the technology was violated during concreting, which resulted in the formation of voids (cavities), or during the longitudinal sliding of the spans they were in such a hurry that they broke the weak reinforced concrete - it doesn’t matter. Be that as it may, the support columns were constructed defectively and were not suitable for the possible dynamic loads from seismic forces for which they were designed.
Technological features of the construction of supports of the Crimean Bridge
Concrete is a material that works very well in compression. It doesn't hold a tensile load at all. The compressive strength of concrete is 10 - 15 times greater than the tensile strength of concrete. That’s why they came up with reinforced concrete - installing reinforcement in tension zones.
In calm everyday conditions, the problematic support would stand with cracks and shells. Nothing would have happened to her. Weight spans the bridge would press on the support columns through the crossbar with a static load. Miserly dynamic load there would also be no effect from passing vehicles. No terrible stresses would arise in the stretch zones. But if it had shaken the earth’s crust, more dynamically, shaking the support across the axis of the bridge, then trouble might have happened to the support. It won't happen anymore.
Don't forget, the bridge is built with a huge margin of safety. It is designed for a magnitude nine earthquake. Because of this, even the slightest production jamb will be strengthened so much that it won’t seem like much.
Video of support 256 filmed in different time frames
Current photo of the 256th pillar of the Crimean Bridge as of May 08, 2018.
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 highway 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 Azov Sea. 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 managed to pick up the crane and pull it to a 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; the road surface was not damaged; the barrier fence is deformed over a 10-meter section, but there are no breaks,” the report says.
At the same time, due to the storm wind, the speed limit for vehicles on the A-290 highway over the Crimean Bridge remains limited 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 change to life raft, which drifted along the 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.
During the construction of the Crimean Bridge, its supports, contrary to all norms, were installed on semi-solid/semi-liquid clay of low density and on loose and porous silt.
Israeli blogger Eli Belenson wrote about this in his blog on OBOZREVATEL, who for a long time analyzed all the documents about the progress of the construction of the bridge. He also pointed out a certain fact: as soon as flagrant violations were announced online, previously available information immediately disappeared.
He emphasized that geology became the Achilles heel of the structure; it was precisely because of the inadequacy of the soil for the construction of the bridge that his project was rejected by Soviet experts.
"Usually, serious engineering structures, such as railway bridges, where serious loads are expected, are usually based on solid soil foundations. To do this, special piles are drilled or driven, which rest on these very hard soils. If we support a massive structure on an insufficiently solid foundation, its individual parts or the entire structure may sag unevenly, become deformed and, ultimately, collapse,” the blogger wrote.
According to Eli Belenson, in the case of a railway bridge, unacceptable subsidence or deformation can lead after some time to disaster - we will be talking about huge economic losses and human casualties.
“Soviet and then Russian GOSTs forbade resting such structures on anything other than a solid rock foundation... Not even on sand. And not on clay. But, as we see from the above geosurveys, at the depth at which, according to the construction plans, the CM should support the piles (up to 58 meters deep), no rock foundation was found (see the bottom line of the table, highlighted in red). Moreover, not even sand was found there. But this is not enough - they didn’t even find clay there,” the expert pointed out.
According to him, the upper layers are silt - loose and porous, and then there are sands and sandy loams of varying degrees of density, several clay inclusions, and the lower layer, on which the bridge piles actually rest, is semi-solid clay.
“Now imagine that we are not just talking about an almost twenty-kilometer railway bridge, with huge loads and huge windage (storms, waves, side winds, trains), but we are also talking about a seismically dangerous zone, where tremors regularly occur different strengths. The designers of the new bridge claim that it is enough to drive the piles 58 meters and everything will be fine, but is this semi-solid clay suitable as a base for the supports? – asked Eli Belenson.
According to him, previously the requirements to rest the piles on a rock foundation were prescribed in Building codes and rules, but later they strangely disappeared from the document on June 17, 2017.
He also pointed out another glaring nuance, according to which the geo-surveys before the start of construction were carried out poorly, and this turned out to be when the bridge was already being built in full swing.
“The Kerch/Crimean Bridge project seems to me potentially dangerous. I consider it immoral to assume this and remain silent. If I made a mistake somewhere, I will be glad to receive a professional and evidence-based refutation. It will be much worse if people die as a result of the operation of the bridge, and I will know that I understood that this could happen, but was silent,” concluded Eli Belenson.
Tags: Crimean bridge
