Automotive Black Technology Chapter 1116: : Sleepless nights!

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Underground tunnel construction is not easy, and water seepage is difficult to deal with. But if you add winter in front of these two things, it will be even more troublesome.

According to normal methods, the result of such a leakage must be a shutdown. When spring comes, the ice on the lake surface thaws and the water drains out again. Then a thick layer of concrete is poured at the bottom of the lake to create a waterproof coating.

Then, construction can continue only after the water in the pebble layer where water has seeped has dried up.

It’s easy to say it, but if you really want to do it, it will definitely be a long and extremely cumbersome process.

In fact, after Wang Yuming reported the water seepage and construction environment at the site to China Railway Group, a group of highly qualified engineers were left scratching their heads and unable to do anything.

But when Wang Yuming reported the situation of the two ZXLS-1911s on site, the eyes of the engineers of China Railway Group lit up!

According to normal disposal methods, the artificial lake in Fuzhou People's Park must be treated with anti-seepage treatment. But the problem is that as the new year is approaching, the temperature in Fuzhou has reached the lowest temperature of the whole year - which is minus 26 degrees.

Under such severe cold, it is obviously impossible to still use concrete for anti-seepage treatment; at low temperatures, when the water for hydration of mud in concrete decreases, the hydration slows down and the strength growth also slows down. slow. After all the water present in the concrete freezes, the commercial concrete is completely transformed into a solid state.

Water will freeze into ice, and its volume will increase by approximately 9%. When the moisture content of concrete capillary pores exceeds the 91.70% threshold, freezing will produce an ice expansion stress of approximately 2500kg/cm.

This ice expansion stress value usually causes varying degrees of damage to the concrete. After the concrete is damaged, its strength will be greatly reduced, and deformation and cracking will occur.

If anti-seepage treatment is forcibly carried out on the bottom of the lake in such an environment, the concrete cracks caused by the low temperature will still not be able to prevent water seepage next year.

So the reality is that if you want to drain water from Fuzhou Metro Line 1, you can only wait until spring. During this period, it is obvious that no further construction can be started.

But after learning the performance parameters of ZXLS-1911, we simply calculated the pumping capabilities of these two heaven-defying machines. China Railway Group was called the "Second Railway Corps Division" as early as the 12th Bureau of China Railway. The cadre who was already an engineer slammed the table and worked with a large group of engineers to formulate an emergency solution.

This is the plan that Wang Yuming is currently operating.

What is the content of the plan?

It’s very simple, just use the current temperature under the artificial lake to make some big articles!

In winter, even if the surface of the lake freezes, the bottom of the lake will maintain a certain temperature.

This is because water has abnormal expansion properties.

Water at 4°C has the highest density, so it will sink to the bottom of the lake. The water in the upper part is cooled by the cold wind in winter, and the temperature is between 0-4°C. When the temperature of this water is low, the density becomes higher and sinks to the bottom. If 5°C water appears at the bottom, its density will be small and it will float. Due to the cooling of the cold 0-4°C water, the density will increase again and become 0-4°C.

No matter how hot the water at the bottom becomes, it will sink back to the bottom and return to four degrees after being cooled through circulation.

In other words, no matter how cold the temperature outside is, the temperature under the lake will never be lower than four degrees Celsius above zero! This is why the mud and lake water pumped out by the two ZXLS-1911 units from the bottom of the lake are steaming outdoors.

What China Railway engineers are considering is the greenhouse effect caused by the emptying of the lake and the penetration of sunlight through the ice. The current temperature at the bottom of the lake is likely to be higher than 4 degrees, reaching about 6 degrees Celsius.

But this temperature is far from allowing concrete to initially set.

However, a group of experienced drivers quickly found a new way. That's... lime!

Although the lake is currently drained, the ice layer on the lake still exists. If lime is poured into the lake bottom, heat will be generated. The existence of ice layer will play a certain role in thermal insulation.

But because the temperature in Fuzhou City is too low, the insulation time will definitely not be too long. It is estimated that based on the current temperature in Fuzhou, the minimum temperature required to maintain the solidification of concrete at the bottom of the lake is one night.

If we seize this opportunity, we can completely prevent seepage of the artificial lake within a short time.

The current situation is no longer possible for China Railway.

In Fuzhou, where there are many foreign guests, water seepage in China Railway's underground infrastructure project has become news. At this juncture when the news spreads at home and abroad, they must seize the opportunity to make up for their mistakes. Reclaim that China’s infrastructure is invincible!

......

When state-owned enterprises like China Railway are serious, their efficiency in operation is absolutely terrifying.

In less than forty minutes after the plan was sent, a steady stream of steaming concrete on the truck body was transported from all directions to Fuzhou People's Park for use!

The long fleet of commercial concrete filled the entire road in front of the convention and exhibition center. In order to keep transportation channels as smooth as possible, 70% of the traffic police in Fuzhou City, except those who maintain normal traffic, have gathered in front of the Convention and Exhibition Center to conduct command and handling.

Such a big move even alarmed several Linshi!

Not to mention the convention and exhibition center just around the corner.

A quarter past five.

The sun has set in the west mountain, but the artificial lake in Fuzhou People's Park has not fallen into darkness.

The construction searchlights erected on the embankment emit light that is ten or a hundred times stronger than the burning clouds in the sky. Various large-scale workmanship equipment also turned on the lighting system, making the surroundings of the artificial lake look like daytime amid the rumbling sounds.

The search lights on the safety helmets of many construction unit workers also seemed to turn the artificial lake into a hurriedly flowing galaxy!

The two engineering teams have taken advantage of the time before commercial concrete has arrived to enter the lake bottom and conduct complete mapping and exploration of the lake bottom.

Zhengxin’s two ZXLS-1911s have also turned their booms and pointed them towards the artificial lake. The hose that had gone deep into the lake before was now connected to a simple commercial concrete station temporarily set up by the lake.

On the outskirts of the lake, reporters who had heard the news or had been stationed for a long time were recording the "first aid operation" triggered by a fatal mistake with cameras and microphones;

"Hello, audience friends, I am Wang Yang, a reporter from China Provincial Radio and Television Station. I am currently in the Fuzhou Municipal People's Workers' Park. Seventeen meters below me is what happened this morning. Fuzhou Metro Line 1 with penetration accident..."

"Hello everyone, I am Liu Zhaozhao, a reporter from CCTV Economic Channel. The water seepage accident has occurred for more than nine hours now. It benefited from the two new ultra-high-power pump trucks of Zhengxin Group that came to Fuzhou to participate in the International Industrial Expo. , the lake has been drained and the penetration of underground tunnels has been contained.

But please look behind me, there is still a lively scene. This is the construction site of the emergency response plan of China Railway No. 12 Bureau. I had the honor to interview Director Wang from China Railway just now. Director Wang told me that tonight, they will take advantage of the temperature below the artificial lake to carry out anti-seepage treatment on the pebble layer at the bottom of the lake that is causing leakage..."

"Hey, Everyone! I'm Elizabeth, and I'm representing my company at an industrial expo in China. At the scene, I discovered a super cool, super interesting thing, and now I'm showing it to you through Twitter..."

Although the outdoor temperature is only in the early twenties, there are busy construction units near the artificial lake, reporters around the artificial lake, citizens gathered in a large circle, the traffic police responsible for maintaining order, and the long A fleet of commercial concrete convoys made the entire People's Park emit a heat that was inconsistent with the harsh winter!

Li Fanyu sat in the warm spring-like ZXLS-1911 control room, watching a large group of city leaders and relevant accompanying personnel squatting next to a command vehicle and grabbing lunch boxes, and couldn't help but shudder.

"Tonight is destined to be a sleepless night."

He stuffed a piece of Fuzhou specialty beef jerky into his mouth and murmured. .