The most ancient bridges. Ancient and unusual bridges of Europe

The ancient Sumerian city of Girsu is located approximately halfway between modern cities Baghdad and Basra in southern Iraq. It is one of the earliest known cities in the world, with a history of at least five thousand years. Girsu was the capital of the kingdom of Lagash, a sacred metropolis in honor of the Sumerian heroic god Ningirsu, and continued to be its religious center after political power shifted to the city of Lagash.


It was in Girsu that evidence of the existence of the Sumerian civilization was first discovered in the form of thousands of cuneiform tablets with registers of economic, administrative and commercial issues cities. Over fifty years of excavation at this mega-archaeological site has revealed some of the most important remains of Sumerian art and architecture, including a 4,000-year-old bridge built of brick that is the oldest bridge discovered in the world to date.


Girsu was first explored by a team of French archaeologists in 1877, before modern excavation and conservation techniques were invented. The French were also not very keen to follow protocol and paid little attention to preserving architectural monuments. Treasure hunters then looted many of the artifacts and sold them to collectors. It is estimated that between 35,000 and 40,000 artifacts were looted from Girsu and subsequently appeared on the market, as opposed to 4,000 official French finds. Without a doubt, this is one of the most unique bridges peace.

The Girsu Bridge was first discovered in the 1920s. At the time it was interpreted as a temple, a dam and a water regulator. Only recently was the structure identified as a bridge over an ancient waterway. Since its excavation nearly a century ago, the bridge has remained open and subject to constant exposure, without any conservation efforts to preserve the landmark.


The modern Arabic name for Girsu is Tello, and the site is currently being used by the British Museum, with funding from the UK government, to train Iraqi archaeologists in cultural heritage management and practical fieldwork skills.

Restoring the 4,000-year-old bridge will be part of the curriculum, according to a recent statement from the museum.

Bridge construction, like nothing else, characterizes the level of development of society, the degree of technical and scientific progress, if you like, more broadly - the level of civilization.

And we have something to be proud of...

Moscow.
The oldest surviving Moscow bridge is the Lefortovo Palace Bridge. Architect - Semyon Yakovlev. Built, according to various sources, in 1777 or 1781-1799.


Lefortovo Bridge. Moscow. Photo late XIX V.

Lefortovo Bridge. Moscow.

In Moscow there is also the Rostokinsky aqueduct across the Yauza River (the so-called “Million Bridge”), which was built in 1780-1805 for water supply. Now it is pedestrian.


Rostokinsky aqueduct. Moscow. Photos from the late 19th - early 20th centuries

Apparently, park bridges should be placed in a separate category.XVIII century in Neskuchny Garden. One of them is three-arched.


Boring Garden. Moscow.

Bridge in Tsaritsyn, Figurny, 1776-1778. The architect is also V.I. Bazhenov.

As part of the complex of buildings summer residence CatherineII included Big Bridge(1778-1774) through the ravine. It is the largest surviving bridge from the 18th century. Architect V.I. Bazhenov.

Tambov.
Derzhavinsky Bridge over the Studenets River, built in 1786-1788. It had three arches (two of them were blocked, one was filled up).

Vologda.

Stone bridge over the Zolotukha River; built in 1789-1791 according to the design of the architect P.T. Bortnikova. Due to its considerable width it is called a “street-bridge”.


Ryazan.
The stone Glebovsky Bridge, built on the site of a wooden one (leads to the Ryazan Kremlin). According to some information, it was built inXVIII century; according to others - at the beginningXIXth.

Kaluga.

The stone bridge over the Berezuevsky ravine is the largest stone viaduct in Russia. It was built in 1785 according to the design of the architect P.R. Nikitina.


For comparison...

Venice. Rialto Bridge, 1588-1591

The famous "Golden Bridge" in Florence, Ponte Vecchio. Built in 1345.

Prague, Charles Bridge, built 1357





Photo of 1884 from the albums of N. A. Naidenov. Trinity Bridge is the oldest surviving stone bridge in Moscow. But for 200 years it has been running not over the waters of the Neglinka River, but over the alley of the Alexander Garden. Built in 1516 according to the design of the architect Aleviz Fryazin (it was originally built probably in the 1360s). Naturally, it was reconstructed more than once.


Photo con. 1900s It's him.


Photo beginning 1850s All Saints (Kamenny; Bolshoy Kamenny) Bridge (built in the 1680s)


Photo 1852 by R. Fenton. He's the same


Photo con. 1860s Stone (All Saints; Bolshoy Kamenny) bridge. The second stone bridge on this site (built in the late 1850s).


Photo from the 1900s. Maly Kamenny Bridge over the Kanavka (Drainage Canal).


Photo beginning 1910s He's the same


Photo con. 1890s - early 1900s Moskvoretsky Bridge


Photo con. 1890s It's him.


Photo con. 1889 - beginning 1890s Bolshoi Ustinsky Bridge (built in 1881 according to the design of engineer V.N. Speyer).


Photo from the 1900s. He's the same


Photo con. 1860 - 1870s On the right in the photo is the Cast Iron Bridge over the Kanavka (built in the 1830s).


Photo beginning 1880s He's the same


Photo from 1908. Komissariatsky Bridge on Kanavka. It was located downstream than the current one, which is a continuation of the Ustinsky Bridge. The photo was taken after the Easter flood of 1908.


Photo beginning 1890s Babiegorodskaya Dam


Photo 1934 Crimean Bridge


Photo beginning 1930s He's the same


Photo 1907 Krasnokholmsky Bridge


Photo from 1908. Krasnokholmskaya Dam


Photo from 1934. Bolshoi Krasnokholmsky Bridge.


Photo from the 1900s. Novospassky Bridge


Photo con. 1900s All Saints pontoon bridge near the Simonov Monastery. I wrote a lot about this bridge at one time (see the tag “mysterious All Saints Bridge”).


Photos from 1910 - 1920s. He's the same


Photo from 1907. Alekseevsky (Kozhukhovsky, now Danilovsky) bridge.


Photo from 1907. The same one.


Photo 1908 Dorogomilovsky (Borodinsky) Bridge


Photo from 1911. Demolition of the old Borodino Bridge


Photo con. 1900 - 1910s Krasnoluzhsky (Nikolaevsky; Nicholas II) bridge. Railroad bridge across the Moscow River. Built in 1905-1907, according to the design of engineer L. D. Proskuryakov and architect A. N. Pomerantsev. In 2000 it was moved 2 km. Nowadays it is the Bohdan Khmelnitsky pedestrian bridge.


Photo con. 1900 - 1910s He's the same


Photo from the 1910s. He's the same


Photo from 1905. Temporary railway wooden bridge of the engineer system. Lembke - the forerunner of the St. Andrew's (Sergievsky) Bridge


Photo 1904-1905 He's the same


Photo from 1908. Andreevsky (Sergievsky) Bridge. Railway bridge over the Moscow River. Built in 1905-1907, according to the design of engineer L. D. Proskuryakov and architect A. N. Pomerantsev. Now, moved downstream and reconstructed, there is the pedestrian Pushkinsky Bridge.

Bridges over the Yauza


Photo from the 1930s. Old Yauzsky (Astakhovsky) Bridge (built in 1876 on the supports of the 1805 bridge).


Photo 1938 by B. Ignatovich. He's in the middle ground. It will be dismantled in 1940, and in its place will be built new bridge, still in effect today.


Photo from 1929. Bridge over the Yauza at Serebryanichesky Lane


Photo from 1902. Vysoko-Yauzsky (High) bridge.


Photo of 1887 from the albums of N. A. Naidenov. He's the same


Photo 1935 Kostomarovsky Bridge


Photo from the 1870s. Colorized photo. Andronikov Viaduct - railway bridge


Photo 1888. Aka


Photo from the 1890s. He's the same


Photo from the 1900s. Palace (Lefortovo) Bridge. The oldest of all operating Moscow bridges (and is located over the river). Built in the 1770-1790s. Although, of course, it was later reconstructed, but without demolition.


Photo 1919. Aka


Photo 1907 Hospital Bridge


Photo from the 1930s. Hospital Bridge


Photo from the 1930s. Sailor's Bridge


Photo from the 1930s. Rubtsovsky (Pokrovsky; now Elektrozavodsky) bridge


Photo from 1896. Bridge of the Moscow-Kazan Railway (now here is the Elektrozavodsky railway bridge)

The history of wooden bridge construction in our country has not yet been the subject of special study. Only the briefest mentions and simple listings of monuments in general works and popular essays devoted to the history of bridge construction in general and Russian wooden architecture are devoted to this topic. This article makes an attempt to systematize Russian wooden bridges of historically established and currently existing types.

Short story. The art of building bridges has been highly developed since ancient times. The main building material was pine due to the straightness and evenness of the trunk, good mechanical properties of the wood and resistance to decay, as well as its wide distribution. Ancient bridges, like other structures, were chopped and processed with an ax: grooves and sockets were cut out when connecting beams; even the manufacture of planks was carried out by splitting logs lengthwise into several pieces using wedges. Therefore, chroniclers, speaking about the construction of wooden buildings or structures, used the word “cut down” instead of the word “build”: they cut down huts, mansions, bridges, etc.

The first mentions of bridges in Russian chronicles date back to the end of the 10th century. The improvement of the art of construction gave rise to the emergence of a special kind of specialist - builders of bridges and crossings, called “bridge builders”. The first bridges were trees thrown from bank to bank, on big rivers raft ferries were arranged. Several interconnected rafts, on top of which a log flooring was laid, formed a “living” floating bridge. They were common on large rivers.

In 1115, under Vladimir Monomakh, a floating bridge across the Dnieper was built in Kyiv. Since floating bridges were quickly built and easily dismantled, they played a large role in military operations. Two such bridges across the Volga are known, mentioned in reports of the siege of Tver under Dmitry Donskoy, another bridge for crossing the Don during the battle with the Tatars in 1380. The first bridges in Moscow were “alive”: Moskvoretsky, Krymsky, etc. It should be noted that that floating bridges were widely used in Russia until the end of the 19th century. The main reason for this was the significant width and depth of the rivers, as well as strong ice flow; under such conditions, floating bridges without permanent supports seemed to be the most appropriate, simple and inexpensive structures.

1. Moskvoretsky “live” - floating bridge. Engraving by Picard from the 17th century. (Photo library of GNIMA named after Shchusev)

2. Single-span bridge in Yeniseisk towards the 19th century.

3. Cantilever-beam bridge with an arched span on the river. This Arkhangelsk region. (photograph from 1920, Photo library of the Shchusev State National Research Institute)

Floating bridges could also be drawbridges; To allow ships to pass, one part of the bridge (the raft) was moved to the side. A 17th-century engraving by Picard gives an idea of ​​the floating Moskvoretsky drawbridge, which already existed in 1498. (Fig. 1) and a figurative description by Pavel Aleppo: “There are several bridges on the Moscow River, most of which are built on wooden piles. The bridge near the Kremlin, opposite the gate of the second city wall, arouses great surprise: it is level, made of large wooden beams, fitted one to the other and tied with thick ropes of linden bark, the ends of which are attached to the towers and to the opposite bank of the river. When the water rises, the bridge rises, because it is not supported by pillars, but consists of boards lying on the water, and when the water decreases, the bridge also lowers. When a ship with supplies for the palace arrives from the Kazan and Astrakhan regions... from Kolomna... to the bridges approved (on stilts), they lower its mast and guide the ship under one of the spans; when they approach the mentioned bridge, then one of related parts it is freed from the ropes and taken away from the path of the ship, and when it passes to the Kremlin side, then that part (of the bridge) is again brought to its place. There are always many ships docked here, bringing all kinds of supplies to Moscow... On this bridge there are shops where brisk trade takes place; there is a lot of traffic on it; we always go there for a walk...troops constantly move back and forth along it. All the city maids, servants and commoners come to this bridge to wash their clothes in the river, because the water here is high, level with the bridge.” The Moskvoretsky “living” bridge was located opposite the Water Gate of the Kitay-Gorod wall; in the second half of the 18th century. it was replaced with a wooden bridge on stilts.

Drawbridges were used in fortifications. The first chronicle indications of their structure date back to 1229: “...and the erection bridge and the zheravets vozhgosha...”, reports the Ipatiev Chronicle. The span adjacent to the city wall was made liftable and called an overhead bridge. The mechanism that set the bridge deck in motion consisted of a rocker arm rotating between the pillars (jeraves) and chains. In the 16th century The Kremlin bridges - Konstantino-Eleninsky, Spassky, Nikolsky - were connected to a lock system that regulated the filling of the ditch with water from the Neglinnaya River, and had a wooden lifting structure adopted for fortresses. In the 17th century Trinity Bridge had a lifting part.

Strengthening bridges. In the middle there are additional abutments. Below - the appropriate direction of the load using wheel guards (1 and 2) and reinforcement of the flooring (3 and 4).

The types of bridges described above are classified as movable bridges in their design. A fundamentally different type were permanent bridges. Depending on the number of supports on which the spans rested, they were classified as single-span or multi-span. Rowing bridges belong to the ancient type of single-span bridges; the first mention of them dates back to 977: in Vručia “rowing bridge”. Rowing took place in wide floodplains of rivers and was like a dirt road. In the middle part, a slot was left for the construction of a single-span bridge, the abutments of which were log supports filled with earth and stone. It is likely that the rows could also consist of solid log buildings with a slot in the middle part. At the end of the 19th century. L. F. Nikolai, analyzing the drawings of wooden bridges measured on the Arkhangelsk Highway in 1795, came to the conclusion: “A similar method of crossing wide floodplains of rivers is still used today...”. The bridges of the late 19th - early 20th centuries had a similar design. in the city of Yeniseisk (Fig. 2) and on the river. This is in the Arkhangelsk region (Fig. 3). The successive protruding logs of the bank abutments formed an almost arched structure. To prevent the bridge from floating up during floods, cobblestones were laid along the edges of the deck.

In the case when several holes were left in the log house for the entire height of the fence, a multi-span bridge was obtained with supports in the form of cages or gorodny (Subsequently, such supports began to be called ryazhi or bulls). To ensure the necessary degree of immobility and non-floatability, log houses-gorodni were, as a rule, filled with stones. Purlins made of logs were laid on top of the gorodnya in the longitudinal direction, and in turn, a continuous ramp of logs was laid on them in the transverse direction - the flooring of the roadway. The carpenters were required to create a strong support for the roadway, which at the same time could withstand the rapid flow of water during the spring flood. These tasks were complicated by the fact that the bridges reached significant sizes.

The people of Novgorod were famous for their skill as woodworkers. The famous Great Bridge across the river. Volkhov had supports in the form of towns and was built obliquely across the river (the width of Volkhov near Novgorod is about 250 m). Under 1133, the Novgorod First Chronicle reports: “In the same summer, the bridge across the Volkhovo was renewed and destroyed.” Since this date, chronicles have systematically reported damage to the city bridge by floods, storms, and ice drifts. There is a miniature from the Nikon Facial Chronicle of the 16th century, which depicts the Great Bridge, where the Strigolniks were executed in 1375.

Bridges, in addition to their main purpose - crossing over any obstacle, were used as street markets. There were benches on the Moskvoretsky Bridge, mentioned above. Resurrection Bridge on the river. Neglinke was a multi-span brick structure covered with a wooden pavement, and was built on both sides with two rows of chopped wooden trading benches. It was located at the Resurrection Gate of Kitay-Gorod and provided access from the city to Red Square near the present Historical Museum.

Stone-wooden bridges were logical in the system of defensive structures of the Kremlin. To prevent enemies from crossing the bridge, it was enough to dismantle or even burn the wooden decking of the bridge. Then he recovered easily.

Changes in the country's economy caused by the transformations of Peter I had a positive impact on the development of bridge construction. The construction of the capital at the mouth of the Neva required the construction of a large number of crossings in a relatively a short time. The first bridge of the new city, built in 1705, was floating. Instead of rafts, barges were used there. Such bridges were built in St. Petersburg throughout the 18th and 19th centuries, the most notable of them being St. Isaac's. Simultaneously with the floating ones, permanent bridges on pile supports were built across the canals. It is interesting to note the fact that at this time wooden bridges were often built according to “samples”, i.e. standard standard drawings. By 1748, there were about 40 wooden bridges in St. Petersburg, about half of which had drawbridges. On the river In Fontanka, according to the design of V.V. Rastrelli, an aqueduct was built, which, using a special machine, supplied water to the fountains of the Summer Garden.

An outstanding achievement of Russian technical thought of the 18th century. was a project by I.P. Kulibin. It was proposed to block the Neva with a huge wooden arch with a span of 294 m.

The most important and complex engineering structure among bridges are dam bridges, which are functionally connected to an entire system of hydraulic structures. From the end of the 17th century. the construction of waterways of national importance began, such as the Vyshne-Volotsk, Tikhvin, and Mariinsk systems. All hydraulic structures of these systems were wooden. In Vytegorsky local history museum types of dams and bridges of the Mariinsky system have been preserved. The St. Paul Dam (at the same time it served as a bridge), located on the river. Vytegra near the village. Devyatina, had a red-colored stepped drain, the difference in heights of the pool marks (the pool is a section of the river between two neighboring dams on the river) was 8.5 m. The Anninsky swing bridge on the river was of significant interest. Kovzha, it existed from 1810 to 1896. The middle support of the bridge had a rotating mechanism that could rotate along with the bridge spans by 90°, allowing oncoming ships free passage on both sides. In the city of Vytegra, there was a drawbridge on the connecting canal until 1961. It was built on pile supports. The middle part of the bridge had two lifting spans of different sizes. With the introduction of the Volga-Baltic waterway, the Mariinsky system was reconstructed with the replacement of wooden hydraulic structures with concrete ones.

Widespread construction of highways, and then railways in the 19th century led to the rise of bridge construction. Appeared big variety structural systems of span structures: braced, arched, trusses, etc. Issues of engineering construction in Russia of this period are beyond the scope of this article and deserve special consideration. With the introduction of new building materials (cast iron, concrete, steel, etc.), wooden bridges are gradually being replaced, and then in the central part of the USSR they almost completely disappear.

Modern timber bridge construction. In the North of the USSR, wooden bridge construction received the most striking and multifaceted development. Sustainability northern life contributed to the transfer from generation to generation of the construction skills of folk architects, which is why examples of wooden bridges have been preserved here to this day various types. What are the types of bridges that have survived and are currently under construction, what are their technical and design features?

Wooden bridges experience great physical and atmospheric influences, therefore, more often than other structures, they are subject to overhaul or replacement of individual parts, but at the same time, the original forms and structural basis remain the same, formed from the river regime and operating conditions. Thanks to these features, bridges, unlike other structures, retain their original shapes, which date back to ancient times.

The simplest way to communicate between banks is ferry crossings. They are used with low traffic intensity. A raft, or pontoon, ferry moves manually along a rope thrown from bank to bank along the river bottom or over the water. For example, in the Arkhangelsk region, on the Onega and Moshe rivers, ancient ferry crossings have been preserved, which are currently in use. In cases where the construction of a bridge on permanent supports is expensive and cannot be justified by the cargo turnover, floating bridges are used. When the water horizon is high, all the rafts of such a bridge are afloat; when the water horizon is low, some of the rafts near the shore rest on the river bottom. With the onset of winter, these raft bridges have to be dismantled and put into backwaters, protected from floods and ice drift. In this case, communication between banks on winter period happens on ice. In Kargopol across the river. A pontoon bridge was thrown across Onega. In more remote areas, raft floating bridges have been preserved - in the village. Korovino on the river Kene and village Ust-Pocha in the Plesetsk district of the Arkhangelsk region.

4. Bridges in the village. Purnema, Arkhangelsk region. a - new bridge (1969), the solid structure of the bridge is not extended to the slope of the ravine; b - the ancient bridge (1927) has a solid log structure with logs laid “in the dir”

5. Cantilever-beam single-span bridge made of timber in the village. Gridino, Karelia

6. An ancient bridge with supports made of rectangular logs in the village of Verkhovskaya, Komi Republic (Photo by I. N. Shurgin)

7. Bridge with two triangular log houses in the village. Stupino Arch. region

Narrow obstacles, such as ravines and rivers, are covered by solid bridges. They consist of end-to-end rows of log buildings (ryazhevoy log house), connected in the transverse direction by the same rows of logs, forming a monolithic structure. This design, for example, has been preserved in the Arkhangelsk region on Kenozero in the village of Tarasovo. Ancient Bridge in the village Purnema in the Arkhangelsk region (Fig. 4, b) is built through a deep ravine (8 m); its flooring lies on a solid timber frame, filling the ditch to the very bottom. This method of cutting “in the dir” (It is necessary to distinguish the concept of a ryazhe log house or a ryazhe support from the felling “in the dir.” Ryazh is the accepted name for the construction of a bridge support. “Rezh” is a method of laying logs with gaps) protects the bridge from rotting and allows free let spring waters through. A hole is left in the middle part for free passage of water. The bridge has already fallen into disrepair, its edges have settled, since the bank of the slope is sandy. In 1969, next to the old bridge, a new one was built, similar in design, but the ryazhe frame was not completed to the end of the ditch (Fig. 4, a). The new wooden bridge is also of significant interest.

The most common type of bridge for small rivers is single-span beam bridges, such as in Ust-Tsilma of the Komi Autonomous Soviet Socialist Republic. To increase the span between supports, a cantilever-beam structure is used - successively protruding logs of coastal abutments. Such a bridge in the village. Gridino of the Karelian Autonomous Soviet Socialist Republic (Fig. 5) was built across a stormy, rocky river, its foundations are littered with boulders.

On wider rivers, multi-span bridges are built; this is achieved by introducing intermediate supports: piles, ryazhevyh. In case of rocky or muddy soil, ryazhe supports are arranged, having different log shapes: three-, four-, five-sided and more complex.

Simple and more ancient supports are rectangular log houses. In the Komi ASSR, in the village of Verkhovskaya (Ust-Tsilmsky district), a bridge was built across the Domashny stream (Fig. 6), the flooring of which, without a fence, lies on four rectangular bull cages. The logs of the log houses are processed with an ax, laid “in the cut” and have large outlets.

In the Arkhangelsk region, in the village of Stupino (Nyandoma district), in 1967 a bridge was measured, the intermediate abutments of which have a triangular shape (Fig. 7), and the frame of the bulls is placed at an angle towards the river flow.

On rivers with ice drift, pentagonal-shaped ridges are arranged. A triangular appendage is cut into the rectangular frame of the bull, acting as an ice cutter. Wooden bridges with this type of frame are the most widespread and can reach significant sizes. In the village Shueretskoe Karelian Autonomous Soviet Socialist Republic (Fig. 8) the bridge has eleven bulls, and its length is 150 m. In the village. Ryagovo (Kargopolye) with a bridge length of more than 100 m, the height of the ridge reaches 8 m (Fig. 9). (Today, a new concrete bridge has been built nearby.)

As a rule, ryazhe bridges have the original foundation of log houses, since wood survives in water for centuries. When replacing or rebuilding the top of the supports, their shapes are repeated. There are many similar bridges in the Arkhangelsk region in the direction Krechetovo-Kargopol-Oshevensk on the rivers Ukhta, Tikhmanga, Lekshma, Churiega. With the same design solutions, each of them has its own unique architectural and artistic image (Fig. 10).

8. The longest surviving wooden bridge (150 m) in the village. Shueretskoye, Karelia

9. Ryazhevoy bull of the bridge in the village. Ryagovo reaches a height of 8 m. (Arch. region)

North of Oshevensk, in the place where the river. Churiega flows into the river. Ken, in the 15th century. The Kenoretsky monastery was founded, which reached its heyday at the end of the 17th - beginning of the 18th century. Large land acquisitions on both sides of the river date back to this time. Kens. In 1764 the monastery was abolished, and in 1800 a fire destroyed its buildings. The only witnesses of that time are two ryazhe bridges: in the village of Leshino (now the village of Kenoretskaya) (Fig. 11) and three kilometers downstream of the river, in the village of Pelyugino.

According to the ancient Russian tradition, at the entrance to the Pelyuginsky Bridge, on the elevated bank, there was a chapel on the basement, with a hipped belfry above the entrance, surrounded by a gallery (now transported to the Arkhangelsk Museum of Wooden Architecture "Little Karelia").

Back in 1946, an expedition from the Institute of History and Theory of Architecture of the USSR Academy of Architecture explored Kargopolye. One of the most important results of her work was the measurements of the Ken bridges made by A.V. Opolovnikov. In 1982, the author of the article carried out repeated surveys and measurements, which showed that, despite the almost complete replacement of building materials, the shape and design of the bridges had not changed. Honed over centuries, these forms have proven to be very stable.

The structural basis of Ken bridges is the same. The five-span bridge near the village of Leshino has a length of 114 m, the four-span bridge near the village of Pelyugino has a length of 84 m. Their design is unique, each middle ridge consists of a rectangular frame with triangular and trapezoidal cuts protruding from its lower part; so that the entire outline of the plan resembles the shape of a boat. The bottom here is rocky, the river flow is very fast, so the frame of the ryazh is littered with boulders. To eliminate the resulting thrust and to uniformly fill the bull with boulders in the transverse and longitudinal directions at different levels, the log houses have ligated crowns, forming a system of internal triangular “pockets.” The upper tetrahedral base of the bull forms rolls on the log outlets, which makes it possible to increase the spans to 15 m.

12. Ryazhevoy bridge with a triangular shape on the river. Keme (Vologda region) Combination folk traditions and engineering techniques (Photo Sevan O. G.)

Unlike civil structures, bridges do not have a shell - walls, ceilings that hide the supporting structure. Therefore, the structural system of the bridges remains open and forms the basis of the architectural composition. Bridges are rarely subjected to artistic treatment; their architectural expressiveness is achieved by the boldness of constructive solutions, the originality of spatial composition and various wood processing techniques. The most interesting engineering and architectural structure is the bridge across the river. Kema in the Vytegorsky district of the Vologda region. Its distinctive feature - a triangular log truss - significantly enriches the volumetric composition: it is arranged “in space” in the deeper part of the river, which allows increasing the span length (Fig. 12). Another example is the bridge in the village. Umba Murmansk region. Its bright artistic expressiveness is achieved by the log struts of the spans and the X-shaped frame of the bridge handrails (Fig. 13).

Any wooden bridge, having its own special artistic image, is also part of the environment: landscape or residential development. In the Oshevensky complex of villages located along the Churyega and Khaluy rivers, wooden bridges are an important element of the planning structure and, together with unique religious, residential and utility buildings, form a harmonious whole.

The city of Belomorsk (formerly the village of Soroka) can be considered a kind of “reserve” of wooden bridges. Old part The city is built of wood and does not have unique architectural monuments, but nature itself has made it unusually picturesque. When it flows into the White Sea, the Vyg River overcomes many rapids and, spilling over several kilometers, forms about forty islands, on which the village of Soroka was once located. In these natural conditions bridges have become a necessary element of intracity communication. On a relatively small old territory There are about twenty of them in the city (Fig. 14). Unfortunately, several bridges have been lost; the longest among them (more than 300 m) was replaced with a concrete one. But all the existing bridges, merging with the space of the river, and the buildings along with the rapids created a unique image of this city.

The idea of ​​wooden bridge construction at the present time would be incomplete without noting some surviving types of purely “engineering” bridges, among which beam bridges with pile supports of various combinations with frame and strut systems are the most widely used. Multi-span beam bridge on the river. Tartas in Novosibirsk region(50s of the XX century) has a two- and four-row system of pile supports (Fig. 15). In the transverse direction, the pillars of the support frame have diagonal contractions, and the entire structure of the supports is secured with steel bolts and pins. The purlins are laid on the supports, and in turn, the roadway deck is laid on them. The length of the bridge is 66 m. Ice cutters 11 m long are installed in front of the middle supports.

An important component of a bridge with piles and frame supports are wooden ice cutters. To protect supports and spans from shocks when struck by ice floes, ice cutters are not connected to the bridge supports. Narrow supports are protected by flat ice cutters having one or two rows of piles. For wide supports, tent ice cutters are used, consisting of several rows of piles. Ice floes approaching the ice cutter, under the influence of inertial forces and water pressure, rise along it and break under the influence of their own weight.

There are still wooden bridges with trusses, which were widely used since the mid-19th century. Gau-Zhuravsky truss spans are the most common design of wooden bridges. This bridge was built in 1967 on the river. Moshe in the Arkhangelsk region (Fig. 16). The channel spans of the bridge are blocked by spans with trusses with a ride on the bottom (design span 31.5 m). The outer spans are covered with spans of a simple beam system with two-tier purlins. The length of the bridge is 146 m. ​​The channel pile supports are protected by free-standing tent ice cutters.

Another type is bridges with a braced system. In the Plesetsk district of the Arkhangelsk region there is a wooden overpass (a bridge designed to pass one road over another), built in 1939 on the Plesetsk-Kargopol highway, which passes over the railway local significance, forming an oblique intersection of 42°. The three-span bridge has frame supports on a support base (Fig. 17). The two middle supports are completed with a combined braced system, which made it possible to create a middle span. The design of the overpass is typical for bridge structures of the 19th - early 20th centuries. and now practically never occurs. Although the bridge is in good condition, it is in danger of being destroyed.

Currently, there is another type of single-span bridges - suspension bridges, found in the Arkhangelsk region. The bridge in the village of Papinskaya, Konosha district (Fig. 18) has the following structure: on both banks of the river there are two log houses with passage gates at the upper level, metal cables are stretched along the top and bottom of the openings of the log house, secured to the ground using metal crutches. Along the entire length of the bridge, the upper and lower cables are connected to each other by wooden blocks (acting as hangers); wooden flooring is laid on the lower cables. On both sides of the log houses there are boardwalks. On the river Emtse in the village. Emtsa, Arkhangelsk region, the suspension bridge of the hydrometeorological service was built in 1928 (see side 4 of the cover). The simple design creates a beautiful silhouette against the background of the river, giving lightness to the entire structure. Suspension bridges, widely used since the mid-19th century, are now rare.

Wooden engineering bridges were the predecessors of steel and concrete structures and played a certain historical role in their time. It seemed that with the development of professional engineering bridge construction, with the introduction of various new structural systems - strutted, arched, suspended, etc. - they were supposed to finally replace ryazhe, folk bridges, displace them. However, this did not happen.

Folk wooden bridges, having a long history, are examples of the stability of architectural form, which have been precisely worked out by many generations of builders, carpenters, and folk architects.

In our age of technological progress, the widespread replacement of wooden bridges with modern steel and concrete ones leads to the disappearance in some places of this type of structure. At the same time, in the North of the USSR and in Siberia, where wood is the main building material, wooden bridges continue to be built, especially since wood is a cheap building material that can be quickly harvested and processed, allowing construction to be carried out in the most short time. Wooden bridge structures, reflecting the ancient culture of the Russian people, connect times and generations; They still have practical significance today and are a most valuable contribution to the cultural heritage of our Motherland.

8. Laskovsky F. F. Materials for the history of engineering art in Russia. St. Petersburg, 1858. Part 1.

9. Novgorod first chronicle of the older and younger editions of M.; L., 1950.

10. Punin A.L. The Tale of Leningrad Bridges. L., 1971.

11. Zabella S. Kargopol expedition. - In the book: Architectural heritage. M., 1955, No. 5.

An article about a pedestrian wooden bridge over the Fosha Canal in Trogir. The span structure consists of two oak double-hinged arches with a span of 25 meters with the possibility of simple dismantling. All elements are made of solid oak and are connected with conventional joinery joints. All this was done to fit the bridge into the atmosphere of the ancient city.

Trogir is a small historical Croatian city on the Adriatic coast. Approximately 20 km west of Split. Due to its rich architectural and cultural heritage, the historical center of the city is included in the register of the world cultural heritage UNESCO. The historical center of the city is located at small island, about 400 m long and 200 m wide, connected to the mainland by a small stone arch bridge on the north side. The southern side is connected by a steel-reinforced concrete drawbridge to the island of Ciovo.
A new wooden bridge spans the Forsa Canal and connects Old city Trogir with parking on the mainland. It is located 600 m west of the existing stone bridge.
The assignment required a wooden bridge in a traditional style with a removable span that would allow small vessels to pass under the bridge. To harmonize with the architecture of the old town, only natural wood elements and traditional joinery were allowed to be used.

The arched bridge design was chosen as one of the oldest natural load-bearing systems in the history of construction. In addition, the arch allows small ships to navigate the canal and looks elegant.
The span structure consists of two branches of double-hinged arches 480x680 with a constant radius of 21.7 m, a span of 25 meters. The branches of the arches are located on the sides of the section, and are connected to each other by wooden transverse beams every 0.8 m with a two-layer plank flooring.


The selected double-hinged design of the arched span is not susceptible to foundation settlement. The massive reinforced concrete foundations are hidden under the entrance staircase. The hinges between the arches and the foundation are made of sheet steel.
The arrow of the arches is 4 m, which provided a navigable clearance of 4.5 m. This arrow was chosen based on the balance of aesthetic, pedestrian, navigation and technical requirements.
The width of the passage is 3 m, the total width of the bridge is 4.16 m. The clear distance between the branches of the arches is 3.2 m. The load-bearing elements are made of solid oak with traditional joints. The steel railings with oak handrails are made as transparent as possible.


Each branch of the arch consists of 4 oak beams 240x340 mm, assembled into a section of 480x680 mm. The connection of the branch section is made with stainless steel bolts and tenons. Cross beams act as dowels between the beams. Bolts made of steel with a strength of 360 MPa: horizontal - 20 mm, vertical - 24 mm. The bolts are installed in drilled holes with epoxy resin, the contact surfaces of the oak beams are also coated with epoxy resin. Epoxy resin with fillers is immune to changes in wood moisture content and weather conditions. The bolts are tightened to 12 kN for 20 mm and 15 kN for 24 mm. When calculating the composite section of the arch, only bolts, tenons and cross beams acted as dowels were taken; epoxy resin was not taken into account.
In the longitudinal direction, the beams of the arch are connected by an oblique joint over a length of 1 m. Fig. 5 s. Transmission of longitudinal force is ensured by stainless steel spikes. The joints are spaced along the length, with only one joint in each section. The transverse beam is attached to the arch in the middle of the longitudinal joint of the beams. The axial distance between the joints of the beams in the semi-arch is 3.2 m, i.e. 1.6 m in the arch as a whole.


To avoid bending of straight timbers, great effort was spent searching for oak trees with a natural curvature. Small deviations of the curvature from the design were accepted so that the correction of the initial curvature of the beam would have as little effect as possible on reducing the load-bearing capacity of the arch branches and the span of the structure as a whole. Most of the beams are 7.4 m long and only two beams are 8.5 m long. The curved handrail was also made from naturally curved oak trees.
The overall rigidity of the span is provided by 220x220 mm transverse beams together with a two-layer cross plank deck. They are pinched along the axis of the branches of the arches and cantileverly protrude 0.25 m beyond the plane of the arches (Fig. 5b). The cross-section of the cross beam in the connection is reduced to 120x140 mm, the connection between the cross beam and the arch branch is secured with screws. The net cross-beam cross-section is capable of transmitting bending, torsional and lateral forces. The arrangement of the transverse beams along the axis makes it possible for the branches of the arches to serve as a border for the pedestrian passage.


The plank flooring is made of two perpendicular layers of 30 mm planed boards assembled into a groove. The first layer of boards is longitudinal, the second is transverse. The longitudinal boards are nailed to the transverse beams with nails spaced every 2.4 m, so 50% of the boards are nailed in one section. The second layer is connected with nails at the cross beams and short metal clamps between the cross beams. Additionally, two layers of flooring are glued together with epoxy resin.
Longitudinal and transverse forces are transferred from the timber arches to the concrete foundation through galvanized support hinges (Fig. 5e). The upper balancer of the hinge covers the heel of the arch with a metal clip, the lower balancer is fixed in the concrete foundation with 4 rods 32x1400 mm. The support joint balancers are connected through a 50 mm pin.

Proper drying of the wood required special attention and a lot of time. Drying was carried out in a drying installation with continuous monitoring of changes in humidity in the depth of the cross-section of each branch of the arch and regulation of temperature and air humidity. The wood was dried with high quality, only a few cracks appeared on the elements of the completed bridge. Rice. 6 shows changes in humidity along the cross-sectional height of the arch branches during drying. Temperature and humidity changed from 32 to 36°C and from 50 to 56%, respectively.


Since the bridge is subject to weathering, protecting the wooden elements of the structure is very important to ensure operational reliability and durability wooden bridge. Therefore, after adjustment and control assembly, all elements were sandblasted to remove all weak layers of wood. After that, all wooden elements were lowered into a bath with a preservative composition against fungi, insects, humidity and other harmful effects. Impregnation with colorless fungicide was carried out by a single immersion. Then a weather-resistant coating was applied in two dips. The wide cracks were further moistened and filled with liquid mortar and a durable plastic sealant. The last layer of protection, carried out in the workshop, consisted of immersing the elements in a protective matte varnish.
During the final assembly process, all contact wood surfaces were coated with epoxy and all screw holes were filled. The screws and tenons were also dipped in epoxy before installation. After completing the assembly of the bridge, the protective layer was restored in places of damage, and additionally the entire structure was covered with a layer of varnish. In the future, it is planned to cover the wood with at least two layers of protective varnish every two years.


Some calculation provisions
The bridge was calculated and designed in accordance with Eurocodes. The structure was modeled by the spatial elements of arches, cross beams and plank. The deck above the transverse beams was not included in the calculation of the load-bearing capacity of the bridge and thus increases the safety factor. The work of the deck was taken into account only when calculating horizontal displacements by increasing the transverse bending stiffness of the arch.
For the longitudinal joints of the elements of the arch branches, a friction coefficient of 0.6 was adopted when calculating rigidity (displacement) and 0.5 when checking the stress state. All symmetric and asymmetric loading schemes with a pedestrian load of 5 kN/m2 are considered. The wind load is assumed to be a wind speed of 180 km/h in the direction of the bridge axis and vertically. The effect of humidity fluctuations was modeled as a uniform temperature change of ±30 °C along the length of the elements, and a non-uniform change of ±10 °C along the height of the section of the wooden elements.
The horizontal interval of the design elements of the arch is 20 mm. Base acceleration for seismic analysis 0.25 g. Seismic forces are calculated by the superposition method using the first 20 free vibration modes. The accepted value of the work coefficient is 2.0. The ship pile-up is assumed to be 100 kN of static lateral horizontal forces at the crown of the arch. Bending moments, torques, longitudinal and transverse forces of all loads for transverse beams in connection with an arch, net cross-section of the transverse beam 0.12x0.14 m.
The load-bearing capacity of the span is significantly higher because the deck was not included in the calculation. The vertical movements of the arch are small due to its rigidity. There are no problems with vibration under pedestrian load, because the calculated frequency of the first vibration mode of the bridge is 3.5 Hz.


Construction and Conclusion
The base under the foundations was strengthened using the “jet-grouting” technology, injecting liquid binder into the soil under high pressure. The support is concreted “dry” with pumping out of leaked water from the pit.
All wooden structures of the bridge were made at the factory (Fig. 7), and control assembly of the arches and cross beams was carried out (Fig. 8). Then the span was completely assembled on the site near the bridge (Fig. 9). Afterwards, the entire span was placed on supporting hinges using a truck crane (Fig. 10). And finally, stone approach stairs, railings with oak handrails, and other finishing works were built. The completed bridge is shown in
rice. 11 and 12.








Rice. 11. Completed bridge. Facade


Rice. 12. Completed bridge.

Customer: Trogir Administration
Design: Professor Jure Radnic PhD, Radnic d.o.o., Split
Construction:
Superstructure: Naprijed Sinj d.o.o., Sinj
Foundation
And a stone staircase: “Point d.o.o.”, Split
Technical control: Kozina projekt d.o.o., Trilj

Bridge indicators
Oak forest, m3 38.0
Concrete, m3 112.0
Rebar, t 11.2
Cost, thousand EUR 300.0
Delivery date, June 2006

 

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