Where was the first bridge built? History of bridges of all times

INTRODUCTION

A bridge is an artificial structure erected across a river, lake, ravine, strait or any other physical obstacle. A bridge built across a road is called an overpass, a bridge over a ravine or gorge is called a viaduct.

The bridge is one of the oldest engineering inventions of mankind.

The modern direction in the construction of metal bridges is characterized by the desire to save metal and reduce labor costs in the manufacture and installation of spans. This is achieved by using high-strength steels, using welded structures, effective types of installation connections, and introducing progressive, economical systems and span structures.

One of the progressive structural elements of steel spans, especially road and city bridges, are orthotropic slabs. Such structures simultaneously perform several functions: they are the load-bearing deck of the roadway for the passage of vehicles; fully or partially act as the roller belts of the main beams or trusses; eliminate the need to arrange longitudinal connections of the span at the level of their location.

Many publications and design materials on steel spans with orthotropic slabs are practically inaccessible to students, which significantly complicates course and diploma design.

History of bridges of all times

Primitive bridges, which consisted of a log thrown across a stream, arose in ancient times.

Later, stone was used as a material. The first such bridges began to be built during the era of slave society. Initially, only the supports of the bridge were made of stone, but then its entire structure became stone. The ancient Romans achieved great success in stone bridge construction, using vaulted structures as supports and using cement, the secret of which was lost in the Middle Ages, but then rediscovered. Bridges (more precisely, aqueducts) were used to provide cities with water. The Roman historian Sextus Julius Frontinus wrote that aqueducts are the main witnesses to the greatness of the Roman Empire. Many ancient Roman bridges still serve today.

In the Middle Ages, the growth of cities and the rapid development of trade created a need for a large number of durable bridges. The development of engineering has made it possible to build bridges with wider spans, flat arches and less wide supports. The largest bridges of that time reached a span of more than 70 meters (Fig. 1).

The Slavs use wood instead of stone. The Tale of Bygone Years reports on the construction of a bridge in Ovruch in the 10th century:

Yaropolk went against his brother Oleg in Derevskaya land. And Oleg came out against him, and both sides became angry. And in the battle that began, Yaropolk defeated Oleg. Oleg and his soldiers ran to a city called Ovruch, and a bridge was thrown across the moat to the city gates, and people, crowding on it, pushed each other down. - The Tale of Bygone Years

In the 12th century, a floating bridge across the Dnieper appeared in Kyiv (Fig. 2). At that time, arched wooden bridges were the most common in Rus'.

At the same time, rope bridges, which are the simplest form of suspension bridges, became widespread among the Incas.

In the 16th and 17th centuries, the need arose for even larger bridges that could accommodate large ships. In the 18th century, the height of the bridge span reached more than 100 m. The project of a wooden single-arch bridge across the Nevudlinaya 298 m, drawn up by Ivan Petrovich Kulibin, remained unrealized.

Since the end of the 18th century, metal has been used for construction. The first metal bridge was built in Colebrookdale, Great Britain on the River Severn in 1779 (Figure 3). The height of its span was about 30 m, the ceilings were cast iron arches.

In the 19th century, the advent of railways required the creation of bridges capable of withstanding significant loads, which stimulated the development of bridge construction. Steel and iron are gradually becoming established as the main materials in bridge construction. Gustav Eiffel built a cast iron arch bridge over the Douro River in Portugal in 1877 (Fig. 5). The span height of this bridge was 160 m. The longest bridge in Europe at the end of the 19th century was the bridge across the Volga in Syzran, built according to the design of Nikolai Apollonovich Belelyubsky and was 1443 m in length. In 1900, a medal at the World Exhibition in Paris was awarded to the bridge across the Yenisei in Krasnoyarsk (project of Lavr Dmitrievich Proskuryakov).

In the 20th century, bridges also began to be built from reinforced concrete. This material differs favorably from steel in that it does not require regular painting. Reinforced concrete was used for beam spans up to 50 m, and arched ones up to 250 m. Metal continues to be used - large metal bridges were built in the 20th century - beam bridges across the St. Lawrence River in Canada (span length 549 m), across the Kill Van Strait -Kill in the USA (503.8 m), as well as the Golden Gate Bridge in San Francisco, USA (main span length - 1280 m).

The largest bridges of our time, including the tallest in the world, the Millau Viaduct and the Akashi-Kaikyo Bridge (the length of the main span is 1991 m), are cable-stayed and suspended. Suspended spans allow you to cover the greatest distances.

If you fly over the sea between India and Sri Lanka (Ceylon), then at some point you will notice a strange sandbank located literally at the very surface, which, slightly curving, connects the island and the continent. Muslims call this sandbank Adam's Bridge, and Hindus call it Rama's Bridge.

Strange Shoal

The Muslim name is due to the fact that followers of this religion believe that Adam, expelled from paradise, descended to earth in Ceylon. And to the continent, to India, he crossed over this strange sandbank, so similar to a bridge.

Hindus even believe that this is truly a man-made bridge, built in ancient times by order of Emperor Rama by an army of monkeys led by Hanuman. According to the Ramayana, Nala, the son of the legendary divine architect Vishvakarman, supervised the construction, and over this bridge Rama’s troops crossed to Sri Lanka to fight its ruler, the demon Ravana, who kidnapped Rama’s beloved Sita.

On Arab medieval maps it is marked as a real bridge rising above the water, over which anyone could cross from India to Ceylon. The situation changed in 1480, when, as a result of a strong earthquake and subsequent severe storm, the bridge sank and was partially destroyed. However, the Portuguese and British still marked it on maps as an artificial structure, a dam or a bridge.

The length of the bridge is almost 50 kilometers, its width ranges from approximately 1.5 to 4 kilometers, and the depth of the seabed around the structure is 10-12 meters. Most of it is hidden by water, sometimes at a depth of more than a meter. So even now it is quite possible to walk along it from beginning to end, sometimes wandering along a stone surface in knee-deep water, sometimes going deeper to the waist or more.

The only serious obstacle is the so-called Pambas Pass between Rameswar Island and Ramnad Point, accessible to the traffic of small merchant ships. The few travelers who decide to make such a transition have to use all their swimming skills here. For those who are not good at this, it is better not to walk on the bridge at all - the strong current through Pambas strives to carry daredevils into the open sea.

Damn channel

Large ships are still forced to sail around Sri Lanka, which takes an extra 800 kilometers, which is 30 hours of travel. To solve this problem, back in 1850, the English commander Taylor proposed to build a canal through the Rama Bridge. In 1955, Jawaharlal Nehru wanted to implement this plan. Since it is somehow unethical to destroy the sacred places of one’s own people, the government of the country stated in the Supreme Court of India that there is no historical evidence of the construction of the bridge by Rama. The Ramayana, although a holy book, somehow does not count.

But real passions regarding the construction of the canal flared up already in the 21st century, when the Setusa Mudram corporation was formed for this purpose. She even began construction work on the site of the future canal, but for unknown reasons, some of the dredgers were returned to the port due to breakdowns, including the teeth of the buckets. An unexpected storm scattered the vessels involved in the construction and prevented work from continuing. Hindu believers immediately declared that it was the monkey king Hanuman who was protecting his creation.

On March 27, 2007, just on Rama's birthday, a group of international public organizations launched the Save Ram Sethu campaign. Since for Hindus the Rama Bridge is living proof of their ancient history, the construction that began touched the feelings of millions of believers. Campaigners also said the destruction of the bridge would destroy the entire local ecosystem. After all, to the northeast of the bridge there is the stormy and dangerous Polk Strait with its storms and cyclones, and to the southwest is the calm Manara Bay with clear emerald-colored water.

The Rama Bridge separates them and mitigates the terrible effects of cyclones and tsunamis. Thus, according to scientists, the tsunami that hit India in 2004 and claimed tens of thousands of lives was significantly weakened by the Rama Bridge. Without this ancient “dam,” there could have been much more casualties. Thousands of people have signed the Save Ram Sethu appeal. Defenders of the bridge are proposing an alternative project: digging a canal along a large sandbank near the village of Mandapam. Whether they will be heard by the Indian government remains to be seen.

Facts show: the bridge is man-made

In many ways, we have become accustomed to the fact that behind legends and myths reality and long-overturned pages of our planet’s past are often hidden. However, the images that NASA released several years ago surprised even the residents of Sri Lanka and India.

On them, with all the clarity that modern photographic equipment provides, a real bridge between the continent and Ceylon is visible. After the publication of NASA images, the Indian newspaper Hindustan Times reported that the images obtained by American satellites serve as proof of the reality of Indian legends, and that the events described in the Ramayana, including the construction of the Rama Bridge, really took place.

However, NASA chose to distance itself from any specific statements. Yes, satellite photographs clearly show the amazing geomorphology of the area. But, NASA says, "orbital remote sensing images alone cannot provide specific information about the origin or age of an island chain and cannot determine human involvement in the origin of a given object."

But the Geological Survey of India 6SI received data allowing us to judge this. Its specialists examined the entire structure of the Rama Bridge. 100 wells were drilled in and near the bridge, and soil samples from them were carefully studied. Magnetic and bathymetric scanning was carried out. As a result, it was found that a low underwater ridge (bridge) is a clear anomaly, since it appears at the bottom completely unexpectedly.

The ridge is a collection of boulders measuring 1.5 x 2.5 meters of regular shape, consisting of limestone, sand and coral. These boulders lie on sea sand, the thickness of which ranges from 3 to 5 meters. And only under the sand does the hard rocky soil begin. The presence of loose sand below the boulders apparently indicates that the ridge is not a natural formation, but is laid on top of sandy soil. Some of the boulders are so light that they can float on water.

It was also found that these land areas did not rise as a result of any geological processes and rather resemble a dam. A homogeneous material was discovered in the wells - limestone. The straight and orderly nature of the placement also suggests that these boulders were brought by someone and placed in the dam.

What seems strange, of course, is that the bridge is simply too wide for crossing troops, or anything else. But this is by modern standards. Here's what Alexander Volkov, director of the 2009 documentary film “Rama's Bridge,” says:

Legends say that it was built by monkey warriors who were gigantic in stature. And we even tried to illustrate in the film that the height of these giants was - you won’t believe it - 8 meters! But, looking at this bridge, you involuntarily begin to believe in it - it makes no sense for you and me to build such a width. But for people eight meters tall, who also have some kind of weapons, there is probably some logic in the width of this bridge.

In general, there are many questions, of course, many. One such issue is the age of the bridge. Based on the legends, some Hindu theologians say that the Rama Bridge is a million years old, others give a more modest age - 20 thousand years. Western alternative researchers have put forward a truly radical version - 17 million years. Even Indian academic science condescended to solve the problem and proposed its own option - 3500 years, obviously linking the construction with the Aryan conquest of India. However, with many ambiguities, it is obvious that the Rama Bridge is indeed an artificial, man-made structure. Research conducted by GSI, I dare say, has conclusively proven this.

Who built the Brooklyn Bridge in New York?

Records for the length of spans, as a rule, do not belong to stone or concrete bridges, not to beams and arches. All of them give way to the “king of bridges” - the suspension bridge on steel cables. Even 2000 years ago, the Chinese suspended bridges with fairly large spans on wrought iron chains. One of them, the Lu Ding Bridge over the Dadu River in Sichuan Province, for example, has a length of 101 m. However, its roadway sags.

In modern suspension bridges, the roadway is suspended by steel rods or cables of varying lengths, allowing it to remain horizontal. The first such bridge was built back in 1801 in Pennsylvania by American James Finlay. The span was only 21 m long, but it became a model for many of Finlay's followers. One of the longest existing bridges is the road bridge across the Menaean Strait (England) with its 175-meter span. But back in 1826, the first postal carriage solemnly passed along it. The bridge across the Menaean Strait was built by the English engineer Thomas Telford. In his youth he was a shepherd and mastered the art of bridge building on his own.

One of the first wire rope bridges was built across the river. Zane near Friborg (Switzerland). Steel engraving 1850

Supporting cable of the Severinsky Bridge in Cologne. It consists of 34 cores, each of which is spirally twisted from steel wires

Modern suspension bridges do not use chains, but cables woven from thousands of thin steel wires. Such a cable was invented around 1820 by the Swiss Henri Dufort. And in 1834, a bridge on wire ropes was thrown across the valley of the Zane River, not far from the city of Friborg.

However, the longest suspension bridges appeared in America, where especially large spans were required to span numerous wide rivers. The most famous builder of North American bridges was John August Roebling. He was born in Berlin and emigrated to the USA in 1831. There Roebling founded a farming colony, then worked as a surveying engineer on canal construction, finally built a plant for the production of steel cables and began building bridges. By that time, several suspension bridges had already collapsed due to the winds. Therefore, Roebling's main concern was the search for reliable rigid fastenings that would give his structures wind resistance. His first big success was a suspension bridge on the Niagara River, below the world famous falls. The span of the bridge is 246 m, it is two-story - one floor for vehicles, the other for locomotives. Roebling became famous for the Brooklyn Bridge in New York, which connected the urban areas of Brooklyn and Manhattan across the East River. The structure is truly colossal: the span itself of 486 m was incredible for that time, and the portals made of granite blocks, carrying steel cables up to 40 cm thick, are higher than many bell towers of churches and temples.

Engineer John August Roebling's first big bridge: a two-tier suspension road-railway bridge across the river. Niagara

Roebling himself died in an accident in 1869, shortly after work began. However, all his calculations and plans were implemented by his son Washington. Unfortunately, Roebling's heir also suffered a tragic fate. To install the supports, he used a caisson method, which was new at that time: a sealed, but open at the bottom, wooden chamber, somewhat reminiscent of a bell, was lowered to the bottom, and water was forced out of it by the force of compressed air; workers entered the caisson through a special transition chamber with an airlock. They had to work under the light of kerosene lamps and high atmospheric pressure, and this was unsafe. They suffered from shortness of breath if they finished locking too quickly. They experienced throat and nose bleeding, many lost consciousness, and others were even paralyzed. Some died from the then unknown decompression sickness. Washington Roebling himself became a victim of it: at the age of 35 he was paralyzed. Confined to a wheelchair, he nevertheless continued to supervise the construction, observing the work through a telescope from the windows of his house. His wife served as a "liaison" between him and the construction site, relaying her husband's instructions. Washington Roebling's will to live was amazing. And after 14 years of construction, in 1883, the US President inaugurated the bridge. For 20 years, the hanging Brooklyn Bridge remained the longest in the world and was considered almost the eighth wonder of the world.

Powerful supports hold the wire ropes on which the Brooklyn Bridge hangs

The over 100-year-old Brooklyn Suspension Bridge over the East River with New York skyscrapers in the background

"King of Bridges" - the suspension bridge - in different guises: on the left - the Golden Gate Bridge in San Francisco, on the top right- bridge across the Bosphorus, under it - the George Washington Bridge across the river. Hudson in New York

Caisson in section. Through a vertical shaft with a transition airlock, workers enter the pressurized room

The USA soon became the country of suspension bridges. In 1931, the George Washington Bridge was built in New York, the span of which was already more than a kilometer. In 1937, a bridge across the Golden Gate with four-stage steel frame pylons 210 m high was erected in San Francisco. Many consider it the most beautiful bridge in the world. The Bosphorus Bridge, built in 1973, is not as huge as these suspension structures, but it is the first such connection between Europe and Asia. The record for the longest span since 1981 belongs to the bridge over the Humber River in the east of England - its length is 1410 m, height 162 m.

Work is already underway on the construction of a bridge that in 1998 will connect the Japanese islands of Honshu and Shikoku. Its span will be 1990 m.

If you fly over the sea between India and Sri Lanka (Ceylon), then at some point you will notice a strange sandbank located literally at the very surface, which, slightly curving, connects the island and the continent. Muslims call this sandbank Adam's Bridge., and Hindus - the Rama Bridge.

Strange Shoal

Damn channel

On March 27, 2007, just on Rama's birthday, a group of international public organizations launched the Save Ram Sethu campaign. Since for Hindus the Rama Bridge is living proof of their ancient history, the construction that began touched the feelings of millions of believers. Campaigners also said the destruction of the bridge would destroy the entire local ecosystem. After all, to the northeast of the bridge there is the stormy and dangerous Polk Strait with its storms and cyclones, and to the southwest there is the calm Manara Bay with clear emerald-colored water.

Facts show: the bridge is man-made

The ridge is a collection of boulders measuring 1.5x2.5 meters of regular shape, consisting of limestone, sand and coral. These boulders lie on sea sand, the thickness of which ranges from 3 to 5 meters. And only under the sand does the hard rocky soil begin. The presence of loose sand below the boulders apparently indicates that the ridge is not a natural formation, but is laid on top of sandy soil. Some of the boulders are so light that they can float on water.

— Legends say that it was built by monkey warriors who were gigantic in stature. And we even tried to illustrate in the film that the height of these giants was - you won’t believe it - 8 meters! But, looking at this bridge, you involuntarily begin to believe in it - it makes no sense for you and me to build such a width. But for people eight meters tall, who also have some kind of weapons, there is probably some logic in the width of this bridge.

In general, there are many questions, of course, many. One such issue is the age of the bridge. Based on legends, some Hindu theologians say that the Rama Bridge is a million years old, others give a more modest age - 20 thousand years. Western alternative researchers have put forward a truly radical version - 17 million years. Even Indian academic science condescended to solve the problem and proposed its own option - 3500 years, obviously linking the construction with the Aryan conquest of India. However, with many ambiguities, it is obvious that the Rama Bridge is indeed an artificial, man-made structure. Research conducted by GSI, I dare say, has conclusively proven this.

What types of bridges are there?
There are about a dozen types of bridge structures, the most common of which are beam, beam-cantilever, arch, suspension and cable-stayed. Arch and suspension bridges are the most ancient types of bridges.

Are arch bridges always semicircular in shape?
No not always. The Chinese engineer, who was the first to realize that an arched bridge does not have to be semicircular, but can be flat, made a real revolution in bridge construction. Let's imagine a giant circle buried in the ground so that only its top is visible on the surface. This segment forms a gentle arch. Such bridges are stronger than semicircular ones, and their construction requires less materials. This discovery was made in China in the 7th century.

When were the first bridges built?
The first capital bridges, which were not afraid of floods or other elements, began to be built back in ancient times. Bridge construction became most widespread during the era of the Roman Empire. The Romans crossed the rivers along the way with magnificent arched stone bridges, which have survived in many places. Even today, a highway passes over the bridge that lies between Carthage and Hippo Diorite. Also still in use is a bridge in Rimini (Italy, early 1st century AD), built from marble-like Dalmatian limestone. The appearance of the bridge in Rimini is distinguished by strict, severe proportions, noble restraint and simplicity of decoration. The famous Italian architect Palladio, who sensitively perceived the beauty of ancient architecture, considered it the best Roman bridge.
In Spain, near the Portuguese border, in a harsh mountainous area, there is the Alcantara Bridge, thrown across the Tagus River at the turn of the 1st-2nd centuries. architect Guy Latzer. Not far from the bridge on the bank of the river in ancient times there was a temple, near the ruins of which they found an inscription on a marble slab: “The bridge that will always remain in the centuries of constant peace, Latzer erected over the river, famous for his art.” In total, about three hundred Roman bridges have survived in Europe.

Are ancient bridges preserved only in Europe?
In the Chinese province of Hebei, a single-span stone bridge has survived to this day. For thirteen centuries, this building continues to serve people. Its creator, Li Jun, is the founder of an entire school of construction, whose influence on Chinese construction technology has persisted for many centuries. The first of its bridges, built in 610, survives today and is still in use. The Great Stone Bridge (as it was called) spanned the Jiao River in the Zhaoxian region in the foothills of Shanxi, on the edge of the Great Plain of China. The length of the Great Stone Bridge is 37.5 m.
The design of the bridge used four small through arches, the world's first arched anthrovolts - an innovation that was of great importance in construction. Li Jun found that by placing them on both sides of the bridge, several problems can be solved simultaneously: the passage of flood waters reduces the risk of bridge destruction during a sudden flood, the overall weight of the structure is reduced, which reduces the likelihood of it sinking into the river banks, and a significant amount of materials is saved.

What are the largest bridges of antiquity that have survived to this day?
The largest surviving ancient Roman arch bridge (St. Martin's Bridge near Aosta, Italy) has a span of 35.5 m, while a typical Roman arch bridge has a span of 18 to 25 m. The most famous arch bridge in China, often called "Marco's Bridge" Polo" was built in 1189 across the Yunding River near the city of Lugouqiao, west of Beijing. It consists of 11 gentle arches, the span of each of them is on average 19 m, and the total length of the bridge is 213 m. Today, a stream of modern trucks and buses moves across this bridge, which Marco Polo considered “the most remarkable in the world” .

Where can you see ancient suspension bridges today?
If ancient suspension bridges have been preserved anywhere, it is only in Peru. Built during the Inca era, these bold engineering structures spanning chasms have earned the admiration of those who have seen them. Local residents used them back in the 19th century. The Spanish chronicler Garey Laso de la Vega left a detailed description of the Incas' construction of these huge structures. From three unusually thick ropes they wove a cable - krisneha, which was thicker than the human body. Then they pulled the ends of these grandiose ropes to the other side of the river and there they firmly strengthened them on both sides on two high supports carved into powerful rocks. If there were no suitable cliffs nearby, they were erected from hewn blocks of stone, their strength not inferior to the rocks.

Which suspension bridge was the largest?
The largest of these bridges was the 45-meter suspension bridge over the Apurimac River in Peru, built during the Inca Empire. American scientist Victor Hagen, who studied the Incan road network for many years, described this bridge as “undoubtedly the most significant technical achievement of the indigenous population of the Americas.” The traveler and geographer J. Squire visited these places more than a century ago and sketched the bridge over the Apurimac, which existed in the middle of the 19th century. Unfortunately, this bridge has not survived to this day; it collapsed in 1880 along with the people passing through it.