A City on Stilts

” GRANDFATHER! The ground is shaking! Is it an earthquake?” Grandfather smiles and tells his teen-age grandson who is vacationing in Amsterdam: “No, Frank, this is not an earthquake. The truck that just rumbled by triggered the ground to shake. The soil in this city is so unsteady that unexpected pressure of weight causes surroundings […]

” GRANDFATHER! The ground is shaking! Is it an earthquake?” Grandfather smiles and tells his teen-age grandson who is vacationing in Amsterdam: “No, Frank, this is not an earthquake. The truck that just rumbled by triggered the ground to shake. The soil in this city is so unsteady that unexpected pressure of weight causes surroundings to tremble.” Frank breathes a sigh of relief: “I never experienced anything like this prior to. I was actually terrified.” “The city authorities, too, have factor for issue, Frank. The rush hour that winds its method through the old city causes tremors. This does much damage to centuries-old structures that simply weren’t developed for this example.”

” The city authorities, too, have factor for concern, Frank. The heavy traffic that winds its way through the old city triggers tremblings. This does much damage to centuries-old structures that just weren’t built for this example.”

After the two walk on for a while, Frank asks: “What I can’t comprehend is, How do the old houses handle to stand right side up when the soil is so miry and soft?” “Stilts, Frank.” “Stilts?” “Well, I confess, a building professional would not utilize that word. Would you like to know something about this approach of structure?”

” Obviously, Grandpa.” “Let’s sit down on this bench. Now, attempt to remove all your houses, apartment, towers, roads, bridges-everything. What do you see?” Frank shuts his eyes and tries to picture that nothing exists. “I, well, I see nothing.” “! That’s the way everything started-a boggy area at the mouth of a river. In time a small group of individuals settled there, some farmers and a merchant or more. For defense against rising tides, a dam was developed across the mouth of the river Amestelle.

Your houses that were constructed in the area, Frank, were nothing like those of today. People were pleased with extremely little. The wooden walls were established on an easy structure of reeds and small branches. On top of these a roofing system of reeds was made and made fireproof by a layer of clay mud. These early houses weighed very little. When a house captured on fire, individuals living next door quickly dismantled their home and moved it to a safer area.

” The ever-present risk of fire in time required structure more significant structures. In the fifteenth century, two significant fires damaged old ‘Amestelledamme.’ The one in 1452 ruined over half of the then-existing numerous homes. Afterwards the officials ruled out wood walls and needed that brick structures be set up.

This created a new problem for the residents. Frank, I presume that you readily see the issue this brought.”” I expect the old structures of reeds and branches might not support brick walls.” “! Much better structures were required. The first step was to drive wood poles, or piles, into the wet ground. In the beginning these were simply short stacks, just about four or 5 feet [1.2 or 1.5 meters] long.

When bigger houses started to be constructed, piles up to twenty-five feet [7.6 meters] long were used. “Still, old Amsterdam’s houses were rather primitive. A number of houses utilized simply one toilet. Sales contracts included provisions stating who was responsible for emptying the toilet containers and through whose home the waste was to be transported. Not up until 1528 did the city’s administrators decree that no home might be built without its own toilet centers.

Ultimately the city grew to be a busy merchant port, and the demand for more stable buildings increased. At the beginning of the seventeenth century, a thick layer of hard-packed sand was found about thirty-six feet [11 meters] beneath the mire of the city. From then on the city authorities required that stacks be driven down all the way to the hardpan.”

” That’s extremely fascinating, Grandpa,” Frank remarks, “however how did they get those long piles into the ground?” “For a very long time the stacks were driven in by hand. Simply a basic whip was utilized. Later, the stack driving was achieved with a much heavier hammer block that was equipped with manages on each side and was heaved up and down by two men.

Still later, the hammer blocks were made to move up and down between two upright guide poles.This hammer would be prepared high by ways of a rope running over a wheel. Lots of strong guys were needed to pull the hammer up and down.”

” How could so many males yank at the rope without tipping over one another?”

” That’s an excellent concern! Those early Amsterdammers had a service. They connected numerous thinner ropes to the main line so that each man might pull his own rope.

Obviously, it was monotonous work. To break the uniformity, unique pile-driving songs were sung to the rhythm of the hammer. The supervisor would sing the songs, and the employees would provide the rhythm. In an effort to speed up the rhythm and the singing, strong drink would be served. But this frequently caused misconduct and rowdiness-and violation of the building regulations.

” For hundreds of years only wood stacks were used. As each of these can carry only eight to twelve loads, many were required under a structure of significant size. Do you remember seeing the Royal Palace recently? Well, it was constructed on 13,659 wooden piles.” “However, Grandpa, do not those wooden stacks ever decay? Don’t they need to be replaced with new stacks?” “It would seem so, Frank, however when the tops of the piles are driven under the water level, they last for hundreds of years.”

” Are wood stacks still utilized?”

” Every now and then for smaller buildings. Typically enhanced concrete piles are used. They do not need to be driven below the water level and can bear much heavier loads than wood ones. Now back to your question about replacing malfunctioning piles. The stacks used for replacement purposes been available in areas of about four feet [1.2 meters] approximately. These sections have a hollow core and are so constructed that one area fits on top of the other one to form a complete pile.

These piles are pressed into the ground by hydraulic power. As an area is pressed in, the soil from its foot is eliminated through the hollow core. When one section is in the ground, the other areas, one at a time, are pressed into the soil until hardpan is reached.

Thereafter the hollow core is filled with concrete, including strength to the sectioned stack and forming a broad foot to provide it good bearing capability. This technique is likewise utilized in the area of structures that would otherwise be damaged by traditional hammering or in the community of health centers and office complex where people would struggle with the sound of a pile chauffeur.”

” Thank you for telling me all of this, Grandpa. When I get house I’m going to have a lot to tell all my friends about my getaway in the Netherlands.”