79-564: Matlock Bridge also known as Derwent Bridge , is a stone bridge spanning the River Derwent in Matlock town centre, Derbyshire , England. The bridge dates back to the 15th century, and is a Grade II* listed structure. A ford originally crossed the river at this point, and the side became a major crossing point. A settlement developed around the bridge, known as Matlock Bridge, which later became part of modern Matlock. The bridge
158-600: A bridge-restaurant which is a bridge built to serve as a restaurant. Other suspension bridge towers carry transmission antennas. Conservationists use wildlife overpasses to reduce habitat fragmentation and animal-vehicle collisions. The first animal bridges sprung up in France in the 1950s, and these types of bridges are now used worldwide to protect both large and small wildlife. Bridges are subject to unplanned uses as well. The areas underneath some bridges have become makeshift shelters and homes to homeless people, and
237-525: A bridge is to be designed, standards authorities specify simplified notional load models, notably HL-93, intended to give the same load effects as the characteristic maximum values. The Eurocode is an example of a standard for bridge traffic loading that was developed in this way. Most bridge standards are only applicable for short and medium spans - for example, the Eurocode is only applicable for loaded lengths up to 200 m. Longer spans are dealt with on
316-471: A case-by-case basis. It is generally accepted that the intensity of load reduces as span increases because the probability of many trucks being closely spaced and extremely heavy reduces as the number of trucks involved increases. It is also generally assumed that short spans are governed by a small number of trucks traveling at high speed, with an allowance for dynamics. Longer spans on the other hand, are governed by congested traffic and no allowance for dynamics
395-480: A combination of structural health monitoring and testing. This is regulated in country-specific engineer standards and includes an ongoing monitoring every three to six months, a simple test or inspection every two to three years and a major inspection every six to ten years. In Europe, the cost of maintenance is considerable and is higher in some countries than spending on new bridges. The lifetime of welded steel bridges can be significantly extended by aftertreatment of
474-399: A different site, and re-used. They are important in military engineering and are also used to carry traffic while an old bridge is being rebuilt. Movable bridges are designed to move out of the way of boats or other kinds of traffic, which would otherwise be too tall to fit. These are generally electrically powered. The Tank bridge transporter (TBT) has the same cross-country performance as
553-606: A few will predominate. The separation of forces and moments may be quite clear. In a suspension or cable-stayed bridge , the elements in tension are distinct in shape and placement. In other cases the forces may be distributed among a large number of members, as in a truss. The world's longest beam bridge is Lake Pontchartrain Causeway in southern Louisiana in the United States, at 23.83 miles (38.35 km), with individual spans of 56 feet (17 m). Beam bridges are
632-581: A form of boardwalk across marshes ; examples of such bridges include the Sweet Track and the Post Track in England, approximately 6000 years old. Ancient people would also have used log bridges consisting of logs that fell naturally or were intentionally felled or placed across streams. Some of the first human-made bridges with significant span were probably intentionally felled trees. Among
711-666: A former network of roads, designed to accommodate chariots , between the fort of Tiryns and town of Epidauros in the Peloponnese , in southern Greece . Dating to the Greek Bronze Age (13th century BC), it is one of the oldest arch bridges still in existence and use. Several intact, arched stone bridges from the Hellenistic era can be found in the Peloponnese. The greatest bridge builders of antiquity were
790-573: A range of local archaeological activities, and established the economic and geographic significance of various trackways from the third and first millennia BC. The work of John Coles, Bryony Coles , and the Somerset Levels Project was recognised in 1996 when they won the Imperial Chemical Industries (ICI) Award for the best archaeological project offering a major contribution to knowledge, and in 2006 with
869-605: A ridge of high ground at Shapwick close to the River Brue . A group of mounds at Westhay mark the site of prehistoric lake dwellings, which were likely to have been similar to those found in the Iron Age Glastonbury Lake Village near Godney , itself built on a morass on an artificial foundation of timber filled with brushwood, bracken , rubble, and clay . The remains of similar tracks have been uncovered nearby, connecting settlements on
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#1732781142645948-593: A span of 552 m (1,811 ft). The bridge was opened 29 April 2009, in Chongqing , China. The longest suspension bridge in the world is the 4,608 m (15,118 ft) 1915 Çanakkale Bridge in Turkey. The longest cable-stayed bridge since 2012 is the 1,104 m (3,622 ft) Russky Bridge in Vladivostok , Russia. Some Engineers sub-divide 'beam' bridges into slab, beam-and-slab and box girder on
1027-749: A stream. Often in palaces, a bridge will be built over an artificial waterway as symbolic of a passage to an important place or state of mind. A set of five bridges cross a sinuous waterway in an important courtyard of the Forbidden City in Beijing, China. The central bridge was reserved exclusively for the use of the Emperor and Empress, with their attendants. The estimated life of bridges varies between 25 and 80 years depending on location and material. Bridges may age hundred years with proper maintenance and rehabilitation. Bridge maintenance consisting of
1106-489: A tank even when fully loaded. It can deploy, drop off and load bridges independently, but it cannot recover them. Double-decked (or double-decker) bridges have two levels, such as the George Washington Bridge , connecting New York City to Bergen County , New Jersey , US, as the world's busiest bridge, carrying 102 million vehicles annually; truss work between the roadway levels provided stiffness to
1185-675: A water pumping and distribution system to maintain the wood in its damp condition. Some of the track is stored at the British Museum and at the Museum of Somerset in Taunton. A reconstruction has been made on which visitors can walk, on the same line as the original, in Shapwick Heath National Nature Reserve . In the early fourth millennium BC the track was built between an island at Westhay and
1264-462: Is a bridge that carries water, resembling a viaduct, which is a bridge that connects points of equal height. A road-rail bridge carries both road and rail traffic. Overway is a term for a bridge that separates incompatible intersecting traffic, especially road and rail. Some bridges accommodate other purposes, such as the tower of Nový Most Bridge in Bratislava , which features a restaurant, or
1343-470: Is also historically significant as it is the world's oldest open-spandrel stone segmental arch bridge. European segmental arch bridges date back to at least the Alconétar Bridge (approximately 2nd century AD), while the enormous Roman era Trajan's Bridge (105 AD) featured open-spandrel segmental arches in wooden construction. Rope bridges , a simple type of suspension bridge , were used by
1422-588: Is an early example of a double-decked bridge. The upper level carries a railway, and the lower level is used for road traffic. Other examples include Britannia Bridge over the Menai Strait and Craigavon Bridge in Derry, Northern Ireland. The Oresund Bridge between Copenhagen and Malmö consists of a four-lane highway on the upper level and a pair of railway tracks at the lower level. Tower Bridge in London
1501-496: Is different example of a double-decked bridge, with the central section consisting of a low-level bascule span and a high-level footbridge . A viaduct is made up of multiple bridges connected into one longer structure. The longest and some of the highest bridges are viaducts, such as the Lake Pontchartrain Causeway and Millau Viaduct . A multi-way bridge has three or more separate spans which meet near
1580-511: Is filled with at least 2 metres (6.6 ft) of detritus mud. The two Meare Lake Villages within Meare Pool appear to originate from a collection of structures erected on the surface of the dried peat, such as tents, windbreaks and animal folds. Clay was later spread over the peat, providing raised stands for occupation, industry and movement, and in some areas thicker clay spreads accommodated hearths built of clay or stone. The track
1659-417: Is led by architects, bridges are usually designed by engineers. This follows from the importance of the engineering requirements; namely spanning the obstacle and having the durability to survive, with minimal maintenance, in an aggressive outdoor environment. Bridges are first analysed; the bending moment and shear force distributions are calculated due to the applied loads. For this, the finite element method
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#17327811426451738-540: Is needed. Calculating the loading due to congested traffic remains a challenge as there is a paucity of data on inter-vehicle gaps, both within-lane and inter-lane, in congested conditions. Weigh-in-Motion (WIM) systems provide data on inter-vehicle gaps but only operate well in free flowing traffic conditions. Some authors have used cameras to measure gaps and vehicle lengths in jammed situations and have inferred weights from lengths using WIM data. Others have used microsimulation to generate typical clusters of vehicles on
1817-645: Is stained brown by tannins dissolved in the acidic water, and represents an early stage of fossilisation . The age of the track prompted large-scale excavations in 1973, funded by the Department of the Environment . In 1973 a jadeitite axehead was found alongside the track; it is thought to have been placed there as an offering. One of over 100 similar axe heads found in Britain and Ireland, its good condition and its precious material suggest that it
1896-737: Is the most popular. The analysis can be one-, two-, or three-dimensional. For the majority of bridges, a two-dimensional plate model (often with stiffening beams) is sufficient or an upstand finite element model. On completion of the analysis, the bridge is designed to resist the applied bending moments and shear forces, section sizes are selected with sufficient capacity to resist the stresses. Many bridges are made of prestressed concrete which has good durability properties, either by pre-tensioning of beams prior to installation or post-tensioning on site. In most countries, bridges, like other structures, are designed according to Load and Resistance Factor Design (LRFD) principles. In simple terms, this means that
1975-510: The Inca civilization in the Andes mountains of South America, just prior to European colonization in the 16th century. The Ashanti built bridges over streams and rivers . They were constructed by pounding four large forked tree trunks into the stream bed, placing beams along these forked pillars, then positioning cross-beams that were finally covered with four to six inches of dirt. During
2054-486: The National Heritage Memorial Fund , and installation of a water pumping and distribution system along a 500-metre (1,600 ft) section, several hundred metres of the track's length are now being actively conserved. This method of preserving wetland archaeological remains (maintaining a high water table and saturating the site) is rare. A 500-metre (1,600 ft) section, which lies within
2133-497: The River Trent and a submerged forest at Stolford enabled a fuller mapping of the rings, and their relationship with the climate of the period. The wood used to build the track is now classed as bog-wood , the name given to wood (of any source) that for long periods (sometimes hundreds of thousands of years) has been buried in peat bogs, and kept from decaying by the acidic and anaerobic bog conditions. Bog-wood usually
2212-552: The Roman era , as the technology for cement was lost (then later rediscovered). In India, the Arthashastra treatise by Kautilya mentions the construction of dams and bridges. A Mauryan bridge near Girnar was surveyed by James Princep . The bridge was swept away during a flood, and later repaired by Puspagupta, the chief architect of emperor Chandragupta I . The use of stronger bridges using plaited bamboo and iron chain
2291-864: The University of Minnesota ). Likewise, in Toronto , the Prince Edward Viaduct has five lanes of motor traffic, bicycle lanes, and sidewalks on its upper deck; and a pair of tracks for the Bloor–Danforth subway line on its lower deck. The western span of the San Francisco–Oakland Bay Bridge also has two levels. Robert Stephenson 's High Level Bridge across the River Tyne in Newcastle upon Tyne , completed in 1849,
2370-608: The ancient Romans . The Romans built arch bridges and aqueducts that could stand in conditions that would damage or destroy earlier designs, some of which still stand today. An example is the Alcántara Bridge , built over the river Tagus , in Spain. The Romans also used cement, which reduced the variation of strength found in natural stone. One type of cement, called pozzolana , consisted of water, lime , sand, and volcanic rock . Brick and mortar bridges were built after
2449-594: The peat bog ; they include the Honeygore, Abbotts Way, Bells, Bakers, Westhay, and Nidons trackways. Sites such as the nearby Meare Pool provide evidence that the purpose of these structures was to enable easier travel between the settlements. Investigation of the Meare Pool indicates that it was formed by the encroachment of raised peat bogs around it, particularly during the Subatlantic climatic period (1st millennium BC), and core sampling demonstrates that it
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2528-504: The river Severn . With the Industrial Revolution in the 19th century, truss systems of wrought iron were developed for larger bridges, but iron does not have the tensile strength to support large loads. With the advent of steel, which has a high tensile strength, much larger bridges were built, many using the ideas of Gustave Eiffel . In Canada and the United States, numerous timber covered bridges were built in
2607-523: The 18th century, there were many innovations in the design of timber bridges by Hans Ulrich Grubenmann , Johannes Grubenmann , as well as others. The first book on bridge engineering was written by Hubert Gautier in 1716. A major breakthrough in bridge technology came with the erection of the Iron Bridge in Shropshire, England in 1779. It used cast iron for the first time as arches to cross
2686-594: The A6 road expected to be re-opened in September. 53°08′16″N 1°33′22″W / 53.1379°N 1.5561°W / 53.1379; -1.5561 This article about a bridge in the United Kingdom is a stub . You can help Misplaced Pages by expanding it . Bridge A bridge is a structure built to span a physical obstacle (such as a body of water , valley , road, or railway) without blocking
2765-712: The European Archaeological Heritage Prize. Dendrochronology (tree-ring dating) of the timbers has enabled precise dating of the track, showing it was built in 3807 BC. This dating led to claims that the Sweet Track was the oldest roadway in the world, until the discovery in 2009 of a 6,000-year-old trackway built in 4100 BC, in Plumstead , near Belmarsh prison . Analysis of the Sweet Track's timbers has aided research into Neolithic Era dendrochronology; comparisons with wood from
2844-463: The River Derwent would mean the bridge returning to two-way traffic for a temporary period. Additionally, the bridge's superstructure was altered to include installation of a safety vehicle restraint system , a run of fabricated steel side-barriers to protect pedestrians and the bridge fabric from any damage from passing traffic. With no direct access to the repair-site, a major contributor to
2923-662: The Shapwick Heath Nature Reserve involves the Nature Conservancy Council, the Department for Environment, Food and Rural Affairs , and the Somerset Levels Project. Although the wood recovered from the Levels was visually intact, it was extremely degraded and very soft. Where possible, pieces of wood in good condition, or the worked ends of pegs, were taken away and conserved for later analysis. The conservation process involved keeping
3002-412: The X shapes to form the walkway. In some places a second rail was placed on top of the first one to bring the plank above it level with the rest of the walkway. Some of the planks were then stabilised with slender, vertical wooden pegs driven through holes cut near the end of the planks and into the peat, and sometimes the clay, beneath. At the southern end of the construction smaller trees were used, and
3081-624: The appearance of the bridge can have great importance. Often, this is the case with a large bridge that serves as an entrance to a city, or crosses over a main harbor entrance. These are sometimes known as signature bridges. Designers of bridges in parks and along parkways often place more importance on aesthetics, as well. Examples include the stone-faced bridges along the Taconic State Parkway in New York. Bridges are typically more aesthetically pleasing if they are simple in shape,
3160-716: The area) was donated to the British Museum in London. Although this short section can be assembled for display purposes, it is currently kept in store, off site, and under controlled conditions. A reconstructed section was displayed at the Peat Moors Centre near Glastonbury . The centre was run by the Somerset Historic Environment Service, but was closed in October 2009 as a result of budget cuts imposed by Somerset County Council . The main exhibits are extant, but future public access
3239-643: The attention of the general public in the 1990s by the novel, movie and play The Bridges of Madison County . In 1927, welding pioneer Stefan Bryła designed the first welded road bridge in the world, the Maurzyce Bridge which was later built across the river Słudwia at Maurzyce near Łowicz , Poland in 1929. In 1995, the American Welding Society presented the Historic Welded Structure Award for
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3318-596: The basis of their cross-section. A slab can be solid or voided (though this is no longer favored for inspectability reasons) while beam-and-slab consists of concrete or steel girders connected by a concrete slab. A box-girder cross-section consists of a single-cell or multi-cellular box. In recent years, integral bridge construction has also become popular. Most bridges are fixed bridges, meaning they have no moving parts and stay in one place until they fail or are demolished. Temporary bridges, such as Bailey bridges , are designed to be assembled, taken apart, transported to
3397-432: The bridge is constructed and anchored, the material used to make it, and the funds available to build it. The earliest bridges were likely made with fallen trees and stepping stones . The Neolithic people built boardwalk bridges across marshland. The Arkadiko Bridge , dating from the 13th century BC, in the Peloponnese is one of the oldest arch bridges in existence and use. The Oxford English Dictionary traces
3476-437: The bridge to Poland. Bridges can be categorized in several different ways. Common categories include the type of structural elements used, by what they carry, whether they are fixed or movable, and by the materials used. Bridges may be classified by how the actions of tension , compression , bending , torsion and shear are distributed through their structure. Most bridges will employ all of these to some degree, but only
3555-584: The bridge. Sweet Track The Sweet Track is an ancient trackway , or causeway , in the Somerset Levels , England, named after its finder, Ray Sweet. It was built in 3807 BC (determined using dendrochronology - Tree-ring dating) and is the second-oldest timber trackway discovered in the British Isles, dating to the Neolithic . The Sweet Track was predominantly built along
3634-439: The center of the bridge. Multi-way bridges with only three spans appear as a "T" or "Y" when viewed from above. Multi-way bridges are extremely rare. The Tridge , Margaret Bridge , and Zanesville Y-Bridge are examples. A bridge can be categorized by what it is designed to carry, such as trains, pedestrian or road traffic ( road bridge ), a pipeline ( Pipe bridge ) or waterway for water transport or barge traffic. An aqueduct
3713-449: The course of an earlier structure, the Post Track . The track extended across the now largely drained marsh between what was then an island at Westhay and a ridge of high ground at Shapwick , a distance close to 1,800 metres (5,900 ft) or around 1.1 mi. The track is one of a network that once crossed the Somerset Levels . Various artifacts and prehistoric finds, including a jadeitite ceremonial axe head, have been found in
3792-467: The deck is thinner in proportion to its span, the lines of the structure are continuous, and the shapes of the structural elements reflect the forces acting on them. To create a beautiful image, some bridges are built much taller than necessary. This type, often found in east-Asian style gardens, is called a Moon bridge , evoking a rising full moon. Other garden bridges may cross only a dry bed of stream-washed pebbles, intended only to convey an impression of
3871-402: The islands in the bog was sufficiently pressing for them to mount the enormous communal activity required for the task of stockpiling the timber and building the trackway, presumably when the waters were at their lowest after a dry period. The work required for the construction of the track demonstrates that they had advanced woodworking skills and suggests some differentiation of occupation among
3950-491: The lake. Between 1358 and 1360, Rudolf IV, Duke of Austria , built a 'new' wooden bridge across the lake that was used until 1878; it was approximately 1,450 metres (4,760 ft) long and 4 metres (13 ft) wide. On 6 April 2001, a reconstruction of the original wooden footbridge was opened; it is also the longest wooden bridge in Switzerland. The Arkadiko Bridge is one of four Mycenaean corbel arch bridges part of
4029-507: The land owned by the Nature Conservancy Council , has been surrounded by a clay bank to prevent drainage into surrounding lower peat fields, and water levels are regularly monitored. The viability of this method is demonstrated by comparing it with the nearby Abbot's Way, which has not had similar treatment, and which in 1996 was found to have become dewatered and desiccated. Evaluation and maintenance of water levels in
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#17327811426454108-781: The late 1700s to the late 1800s, reminiscent of earlier designs in Germany and Switzerland. Some covered bridges were also built in Asia. In later years, some were partly made of stone or metal but the trusses were usually still made of wood; in the United States, there were three styles of trusses, the Queen Post, the Burr Arch and the Town Lattice. Hundreds of these structures still stand in North America. They were brought to
4187-555: The levels were heavily wooded, but local inhabitants began to clear these forests about this time to make way for an economy that was predominately pastoral with small amounts of cultivation. During the winter, the flooded areas of the levels would have provided this fishing, hunting, foraging and farming community with abundant fish and wildfowl; in the summer, the drier areas provided rich, open grassland for grazing cattle and sheep, reeds, wood, and timber for construction, and abundant wild animals, birds, fruit, and seeds. The need to reach
4266-427: The load is factored up by a factor greater than unity, while the resistance or capacity of the structure is factored down, by a factor less than unity. The effect of the factored load (stress, bending moment) should be less than the factored resistance to that effect. Both of these factors allow for uncertainty and are greater when the uncertainty is greater. Most bridges are utilitarian in appearance, but in some cases,
4345-639: The oldest timber bridges is the Holzbrücke Rapperswil-Hurden bridge that crossed upper Lake Zürich in Switzerland; prehistoric timber pilings discovered to the west of the Seedamm causeway date back to 1523 BC. The first wooden footbridge there led across Lake Zürich; it was reconstructed several times through the late 2nd century AD, when the Roman Empire built a 6-metre-wide (20 ft) wooden bridge to carry transport across
4424-495: The origin of the word bridge to an Old English word brycg , of the same meaning. The Oxford English Dictionary also notes that there is some suggestion that the word can be traced directly back to Proto-Indo-European *bʰrēw-. However, they also note that "this poses semantic problems." The origin of the word for the card game of the same name is unknown. The simplest and earliest types of bridges were stepping stones . Neolithic people also built
4503-629: The past, these load models were agreed by standard drafting committees of experts but today, this situation is changing. It is now possible to measure the components of bridge traffic load, to weigh trucks, using weigh-in-motion (WIM) technologies. With extensive WIM databases, it is possible to calculate the maximum expected load effect in the specified return period. This is an active area of research, addressing issues of opposing direction lanes, side-by-side (same direction) lanes, traffic growth, permit/non-permit vehicles and long-span bridges (see below). Rather than repeat this complex process every time
4582-405: The path underneath. It is constructed for the purpose of providing passage over the obstacle, which is usually something that is otherwise difficult or impossible to cross. There are many different designs of bridges, each serving a particular purpose and applicable to different situations. Designs of bridges vary depending on factors such as the function of the bridge, the nature of the terrain where
4661-451: The peat bogs along its length. Construction was of crossed wooden poles, driven into the waterlogged soil to support a walkway that consisted mainly of planks of oak , laid end-to-end. The track was used for a period of only around ten years and was then abandoned, probably due to rising water levels. Following its discovery in 1970, most of the track has been left in its original location, with active conservation measures taken, including
4740-423: The pegs suggest that they were taken from coppiced woodland. Longitudinal log rails up to 6.1 metres (20 ft) long and 7.6 centimetres (3.0 in) in diameter, made of mostly hazel and alder , were laid down and held in place with the pegs, which were driven at an angle across the rails and into the peat base of the bog. Notches were then cut into the planks to fit the pegs, and the planks were laid along
4819-424: The planks split across the grain to utilise the full diameter of the trunk. Fragments of other tree species including holly , willow , poplar , dogwood , ivy , birch , and apple have also been found. The wetland setting indicates that the track components must have arrived prefabricated , before being assembled on site, although the presence of wood chips and chopped branches indicates that some trimming
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#17327811426454898-472: The principles of Load and Resistance Factor Design . Before factoring to allow for uncertainty, the load effect is generally considered to be the maximum characteristic value in a specified return period . Notably, in Europe, it is the maximum value expected in 1000 years. Bridge standards generally include a load model, deemed to represent the characteristic maximum load to be expected in the return period. In
4977-763: The roadways and reduced movement of the upper level when the lower level was installed three decades after the upper level. The Tsing Ma Bridge and Kap Shui Mun Bridge in Hong Kong have six lanes on their upper decks, and on their lower decks there are two lanes and a pair of tracks for MTR metro trains. Some double-decked bridges only use one level for street traffic; the Washington Avenue Bridge in Minneapolis reserves its lower level for automobile and light rail traffic and its upper level for pedestrian and bicycle traffic (predominantly students at
5056-734: The same year, has the span of 90 m (295 ft) and crosses the valley of the Syrabach River. The difference between the two is that the Solkan Bridge was built from stone blocks, whereas the Friedensbrücke was built from a mixture of crushed stone and cement mortar. The world's largest arch bridge is the Chaotianmen Bridge over the Yangtze River with a length of 1,741 m (5,712 ft) and
5135-573: The scheme was 'Lifty McShifty', an 800- ton crane sited on Derwent Way, a short closed section of the A6 road , used to position plant and materials as needed. The project is expected to be halfway-completed by Christmas 2022 with the cost anticipated to be around £ 5 million. In May 2023, the Environment Agency announced completion of structural repair work to the flood barrier, with cosmetic improvements involving local stone cladding underway and
5214-430: The simplest and oldest type of bridge in use today, and are a popular type. Some cantilever bridges also have a smaller beam connecting the two cantilevers, for extra strength. The largest cantilever bridge is the 549-metre (1,801 ft) Quebec Bridge in Quebec, Canada. With the span of 220 metres (720 ft), the Solkan Bridge over the Soča River at Solkan in Slovenia is the second-largest stone bridge in
5293-644: The undertimbers of bridges all around the world are spots of prevalent graffiti. Some bridges attract people attempting suicide, and become known as suicide bridges . The materials used to build the structure are also used to categorize bridges. Until the end of the 18th century, bridges were made out of timber, stone and masonry. Modern bridges are currently built in concrete, steel, fiber reinforced polymers (FRP), stainless steel or combinations of those materials. Living bridges have been constructed of live plants such as Ficus elastica tree roots in India and wisteria vines in Japan. Unlike buildings whose design
5372-433: The weld transitions . This results in a potential high benefit, using existing bridges far beyond the planned lifetime. While the response of a bridge to the applied loading is well understood, the applied traffic loading itself is still the subject of research. This is a statistical problem as loading is highly variable, particularly for road bridges. Load Effects in bridges (stresses, bending moments) are designed for using
5451-424: The wood in heated tanks in a solution of polyethylene glycol and, by a process of evaporation, gradually replacing the water in the wood with the wax over a period of about nine months. After this treatment the wood was removed from the tank and wiped clean. As the wax cooled and hardened, the artefact became firm and could be handled freely. A section of the track on land owned by Fisons (who extracted peat from
5530-399: The wood may be influencing the peat's hydrology , causing the loss or collection of minerals within the pore water and peat matrix. The community that constructed the trackway were Neolithic farmers who had colonised the area around 3900 BC, and the evidence suggests that they were, by the time of construction, well organised and settled. Before this human incursion, the uplands surrounding
5609-648: The workers. They also appear to have been managing the surrounding woodland for at least 120 years. Built in 3807 or 3806 BC, the track was a walkway consisting mainly of planks of oak laid end-to-end, supported by crossed pegs of ash , oak, and lime , driven into the underlying peat. The planks, which were up to 40 centimetres (16 in) wide, 3 metres (120 in) long and less than 5 centimetres (2.0 in) thick, were cut from trees up to 400 years old and 1 metre (39 in) in diameter, felled and split using only stone axes, wooden wedges, and mallets. The length, straightness, and lack of forks or branches in
5688-452: The world and the longest railroad stone bridge. It was completed in 1905. Its arch, which was constructed from over 5,000 tonnes (4,900 long tons; 5,500 short tons) of stone blocks in just 18 days, is the second-largest stone arch in the world, surpassed only by the Friedensbrücke (Syratalviadukt) in Plauen , and the largest railroad stone arch. The arch of the Friedensbrücke, which was built in
5767-538: Was a symbolic axe, rather than one used to cut wood. Because of the difficulty of working this material, which was derived from the Alpine area of Europe, all the axe heads of this type found in Great Britain are thought to have been non-utilitarian and to have represented some form of currency or be the products of gift exchange. Radiocarbon dating of the peat in which the axe head was discovered suggests that it
5846-444: Was deposited in about 3200 BC. Wooden artefacts found at the site include paddles, a dish, arrow shafts, parts of four hazel bows, a throwing axe , yew pins, digging sticks, a mattock , a comb, toggles, and a spoon fragment. Finds made from other materials, such as flint flakes, arrowheads, and a chipped flint axe (in mint condition) have also been made. A geophysical survey of the area in 2008 showed unclear magnetometer data;
5925-489: Was discovered in 1970 during peat excavations and is named after its finder, Ray Sweet. The company for which he worked, E. J. Godwin, sent part of a plank from the track to John Coles , an assistant lecturer in archaeology at Cambridge University , who had carried out some excavations on nearby trackways. Coles' interest in the trackways led to the Somerset Levels Project, which ran from 1973 to 1989, funded by various donors including English Heritage . The project undertook
6004-534: Was in daily use as part of the farming life of the community. Since its discovery, it has been determined that parts of the Sweet Track were built along the route of an even earlier track, the Post Track , which was constructed thirty years earlier in 3838 BC. Most of the track remains in its original location, which is now within the Shapwick Heath biological Site of Special Scientific Interest and National Nature Reserve . Following purchase of land by
6083-489: Was made into one-way for vehicles in 2007. Matlock Bridge Conservation Area was established in 1989, but was further widened in 2008 and includes an area on both sides of the river. It contains 283 buildings, of which three are listed structures , including the bridge itself. In May 2022, the Environment Agency announced nearby repair work to failed flood defences close to the bridge and immediately alongside
6162-421: Was performed locally. The track was constructed from about 200,000 kilograms (440,000 lb) of timber, but Coles estimates that once the materials were transported to the site, ten men could have assembled it in one day. The Sweet Track was used only for about ten years; rising water levels may have engulfed it, and therefore curtailed its use. The variety of objects found alongside the track suggest that it
6241-742: Was visible in India by about the 4th century. A number of bridges, both for military and commercial purposes, were constructed by the Mughal administration in India. Although large bridges of wooden construction existed in China at the time of the Warring States period , the oldest surviving stone bridge in China is the Zhaozhou Bridge , built from 595 to 605 AD during the Sui dynasty . This bridge
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