"GRANDPA! The earth is shaking! Is it an earthquake?" The grandfather smiles and says to his teenage grandson, who is on vacation in Amsterdam: “No, Frank, it's not an earthquake. The roaring truck shook the ground. The ground in this city is so unstable that the sudden pressure weighs down. " the environment is shaking. "
Frank breathes a sigh of relief: “I've never experienced anything like this. I was very afraid. ""
"City officials are also a cause for concern, Frank. The heavy traffic passing through the Old City is shaking. This is causing great damage to centuries-old buildings that were not built for such things."
After a while, the two asked Frank, "I can't figure out how long old houses can last when the floor is so comfortable and soft?"
Stilter, Frank.
"Stilts?
"Well, I admit that a construction specialist wouldn't use that word. Would you like to know more about this type of construction?"
“Of course, grandfather.
“Let’s sit on this bench. Now try to remove all houses, condos, towers, streets, bridges, everything. What do you see?
Frank closes his eyes and tries to imagine that there is nothing. "Yes ... I can't see anything."
It started like this: a welcoming hall at the mouth of a river. Over time a small group of people settled there, a few farmers and a trader or two. To protect against rising tides, a dam was built at the mouth of the river. Amstelle. The houses in the neighborhood, Frank, were not as they are today. People were happy with very little. The wooden walls were built on a simple base made of reeds and small branches. Above them was a roof made of sharp, refractory shapes from a single layer. These early houses weighed very little. When a house was lit, the people who lived next door would come down and move to a safer place.
“The increased risk of fire over time made it necessary to build more complete structures. In the 16th century, two major fires devastated the old Amesteltamme. What was destroyed in 1452 destroyed more than half of the hundreds of homes that existed at the time. The authorities therefore excluded the wooden walls and demanded the erection of brick structures. This created a new problem for the citizens. Frank, I guess you can easily spot the problem that caused this. ""
"I think the old foundation and the reed branches couldn't support the brick walls."
“That's right! Better foundations were needed. The first step was to put poles or wooden poles in the wet ground. At first it was just short poles, only four feet or four feet long. When they started, larger houses to build, poles up to 7.6 meters long were used.
“Yet the old houses in Amsterdam were rather primitive. Several houses used only one bathroom. The sales contracts contained clauses indicating who was responsible for emptying the bins and by whom the waste would be transported. It wasn't until 1528 that city administrators decided that a house couldn't be built without its own bathroom. Over time, the city has become a vibrant trading port and the demand for more stable buildings has increased. At the beginning of the 17th century, a thick layer of compacted sand was found about 11 meters below the town's swamp. City officials later requested that the batteries be placed on the hardboard. ""
"It's very interesting, grandpa," said Frank, "but how did you drop those long batteries?"
“The batteries have been inserted manually for a long time. At first, only a simple club was used. Later, the hammering of the bars was done with a heavier block fitted with handles on each side, and lifted and lowered by two men. Still later, the hammer blocks were placed upside down between two vertical guide posts. This hammer will go up with a rope that turns on a wheel. It took a lot of strong men to raise and lower the hammer. ""
"How can so many men pull the rope without falling on top of each other?"
"That's a good question! The early Amsterdam ponds had a solution. They tied many thinner ropes to the main line so that each man could pull his own rope. Obviously it was monotonous work. Breaking the guide. The specials They sang in time with the hammer, the chairman sang the songs and the workers did the beat, to speed up the rhythm and the song was served a strong drink, but this often leads to bad behavior and accidents and violations of building codes.
“For hundreds of years, only wooden poles have been used. Since each of them can only carry eight to twelve tons, much was needed in a large-sized building. Do you remember the other day you saw the Royal Palace? Well, it was built on 13,659 wooden poles.
"But Grandpa, do these piles of wood never fall apart?" Shouldn't they be replaced with new batteries? ""
"It seems so, Frank, but when the tips of the poles are pushed below the water level, they will take hundreds of years.
"Are the wooden posts still in use?"
“Sometimes for small buildings. As a rule, however, reinforced concrete piles are used. They do not need to be placed below the water level and they can withstand much heavier loads than wood. Now, back to your question on how to replace bad bets. The posts used to replace have sections of about 1.2 meters. These sections have a hollow core and are designed so that one section fits over the other to form a complete stack. These posts are driven into the ground with hydraulic power. When a section is withdrawn, the soil is pulled from the base through the hollow core. When one section is on the ground, push the other sections into the ground, one at a time, until they reach the hard shell. The hollow core is then filled with concrete, which strengthens the cut pile and creates a wide base to give it good load-bearing capacity. This method is also used near buildings that would be damaged by traditional hammering or near hospitals and offices where people would hear the sound of a hammer.
"Thank you for telling me all this, Grandpa. When I get home I will be able to tell all my friends a lot about my holiday in Holland. "
