The aqueduct is ... History, characteristic of aqueducts
In ancient times, the water supply of cities on a territory that is difficult in terms of relief was carried out with the help of complex engineering structures. Aqueduct is one of the options for laying the highway from a high-altitude source to consumers located below. What is the peculiarity of such structures and why did ancient builders prefer them?
Aqueduct: what is it?
In different states they tried to invent the best way to transfer water from the source to consumers. If on the way there were difficulties of the relief, and it was not possible to bypass them or it was expensive, the design engineers usually set up the highway on high-rise supports.
What does "aqueduct" mean? If you translate from Latin, then this is essentially a water line. However, many associate aqueducts only with complex and often beautiful multi-storey structures, similar to stepped bridges. In fact, an aqueduct is a complete system and should be considered comprehensively along the entire length from the source to the final point of consumption.
High-rise construction, of course, plays an important role in the passage of a complex segment of the route. If it is located in the city, close to residential buildings, then the engineers tried to make it pleasing to the eye. But the water conduit consisted not only of beautiful arches and supports. Over the entire length (they could be from several hundred meters to tens of kilometers) there could be underground sections.
A water supply system of this scale was not built for a year or two. It could be used for decades or even centuries. Therefore, the design and construction itself was carried out carefully. Stones for the base and supports were selected and processed separately. Calculations of arches and ceilings should have been flawless. The design was subjected to constant impacts of winds and precipitation. The slightest inaccuracies or omissions in the construction process could negate the tremendous work.
The construction of bridges, overpasses and overpasses was practiced in many ancient states. To put a pipe or an open chute for such a wire on such a structure was tried in Greece and in the East, however, the most widespread water lines of this type were in ancient Rome.Some of them have survived to this day. They are not only monuments of architecture, but also are in operation.
Another question is why they got such distribution. At that time, pressure pipelines for the supply of water already existed in theory and in practice, there were siphon-based systems.
Roman aqueduct - what is it? The ancient designers chose a gravity gravity system for their water supply. Most of these aqueducts were laid on high-rise supports. In some places, their height was up to fifty meters.
Ancient aqueducts were usually built of stone blocks. Small waterways could settle on relatively low wooden supports. Later, with the development of building technologies, engineers used brick and concrete. The heyday of metallurgy made it possible to use steel and cast iron in complex structures.
The device of Roman type aqueducts assumes the presence of an open or closed water cell. This is a kind of channel or chute, constructed of materials resistant to the ravages of the water flow.For this, stone blocks were most often used. The closed channel was covered on top of the vault or plates to eliminate water pollution.
The pipes used in some aqueducts, at that time, could be either ceramic or lead. Ceramics were made from baked clay, but this material was unreliable. Drilling holes in stone blocks was hard. About the dangers of lead to human health at that time was already known. However, this fact was put up. In addition, in places with hard water, the lead walls of the pipes were quickly covered with a dense layer of plaque.
How does an aqueduct work?
In ancient times, a large city consisted of 500 thousand people. In the heyday of empires in the capitals could live up to two million citizens. To provide them with water, a reliable, constantly functioning system was needed. In some cities a dozen aqueducts could work at the same time. The total length of the system was over 400 km. The volume of water supplied per day, according to some estimates, could be up to 1.5 million cubic meters.
Aqueduct is a complex system, and it worked in such a way as to ensure a constant natural flow of water throughout its length under the action of gravitational forces.The calculations were made so that the channel slope was optimal. Not all aqueducts were mostly high-altitude. The share of such complex areas could account for only up to 10% of the total length.
In some cases it was considered expedient to do a hollow in the soil. The rocks were felled. Loose soils laid out the treated blocks, which were covered with arches. The main task was to ensure the constancy of the level. There could be additional tanks in the system. They could be used to defend water, accumulate reserves, create volumes for pressure structures.
Ancient aqueducts and modernity
The ancient aqueduct is the most complex engineering system. Understanding with the device of such water supply systems, experts note that they were designed by real architects. It is necessary to understand that their authors worked real miracles, showing deep knowledge in hydraulics, mechanics, construction.
Some believe that these aqueducts survived only due to the fact that they had a multiple safety margin. However, modern studies and studies of existing systems prove that they meet the requirements of modern water supply systems.It is known that the engineers of those times were able to calculate the load and resistance of materials during construction. However, how they were able to calculate the effect of the tilting forces of the winds and floods remains a mystery. Formulas for calculating the coefficients of gravity plumbing appeared many centuries later. And the system of mathematical calculations operating at that time with the use of pebbles and counting boards was very laborious and inconvenient.
Legends and facts
Despite the grandeur and complexity of the Roman aqueducts, there were no valves in their systems. The water flowed constantly: day and night. Its consumption was huge even by today's standards. But the advantage of such waste was that the sewage system was constantly washed, there were fewer problems with blockages.
The aqueduct is really a grandiose architectural structure. Not without reason, according to one of the legends, authorship of the world-famous arched structure in Segovia is attributed to the devil. It was as if he built a grand structure in exchange for the girl’s mortgaged soul. But she caught herself in time and begged forgiveness from the Most High. He did not let finish the construction. The devil did not have time to put just one stone.The townspeople, together, completed the work and, after consecration, launched the water supply system into action.