|
Integral Bridge
An integral bridge contains no expansion joints to accommodate enlargement due to increased temperature. Horizontal (axial) movements due to thermal expansion and braking loads are instead transferred to the fill adjacent to the abutment. The omission of the expansion joint removes a pathway for the penetration of chloride-bearing road salts to the bridge's sub-structure. In the United Kingdom there is a presumption that most new short to medium length bridges will be of the integral type. An early example of an integral bridge is masonry arch bridge. Some of the earliest examples of integral bridges in reinforced concrete were constructed as part of the United Kingdom's M1 motorway in 1959. Description An integral bridge contains no expansion joints, spanning monolithically from abutment to abutment. Movement due to thermal expansion and contraction or braking loads is accommodated by the end walls or abutments. Where intermediate supports are specified (e.g. bridge p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Expansion Joint
An expansion joint, or movement joint, is an assembly designed to hold parts together while safely absorbing temperature-induced expansion and contraction of building materials, and vibration, or to allow movement due to ground settlement or seismic activity. They are commonly found between sections of buildings, bridges, sidewalks, railway tracks, piping systems, ships, and other structures. Building faces, concrete slabs, and pipelines expand and contract due to warming and cooling from seasonal variation, or due to other heat sources. Before expansion joint gaps were built into these structures, they would crack under the stress induced. Bridge expansion joints Bridge expansion joints are designed to allow for continuous traffic between structures while accommodating movement, shrinkage, and temperature variations on reinforced and prestressed concrete, composite, and steel structures. They stop the bridge from bending out of place in extreme conditions, and also allow eno ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arch Bridge
An arch bridge is a bridge with abutments at each end shaped as a curved arch. Arch bridges work by transferring the weight of the bridge and its loads partially into a horizontal thrust restrained by the abutments at either side. A viaduct (a long bridge) may be made from a series of arches, although other more economical structures are typically used today. History Possibly the oldest existing arch bridge is the Mycenaean Arkadiko Bridge in Greece from about 1300 BC. The stone corbel arch bridge is still used by the local populace. The well-preserved Hellenistic Eleutherna Bridge has a triangular corbel arch. The 4th century BC Rhodes Footbridge rests on an early voussoir arch. Although true arches were already known by the Etruscans and ancient Greeks, the Romans were – as with the vault and the dome – the first to fully realize the potential of arches for bridge construction. A list of Roman bridges compiled by the engineer Colin O'Connor featur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
M1 Motorway
The M1 motorway connects London to Leeds, where it joins the A1(M) near Aberford, to connect to Newcastle. It was the first inter-urban motorway to be completed in the UK; the first motorway in the country was the Preston By-pass, which later became part of the M6. The motorway is long and was constructed in four phases. Most of the motorway was opened between 1959 and 1968. The southern end was extended in 1977 and the northern end was extended in 1999. History There had been plans before the Second World War for a motorway network in the United Kingdom. Lord Montagu formed a company to build a 'motorway like road' from London to Birmingham in 1923, but it was a further 26 years before the Special Roads Act 1949 was passed, which allowed for the construction of roads limited to specific vehicle classifications, and in the 1950s, the country's first motorways were given the government go-ahead. The first section of motorway was the Preston Bypass in Lancashire, now par ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monolithic Architecture
Monolithic architecture describes buildings which are carved, cast or excavated from a single piece of material, historically from rock. The most basic form of monolithic architecture is a rock-cut building, such as the monolithic churches of Ethiopia built by the Zagwe dynasty, or the Pancha Rathas in India. These are cut out of solid rock, to which they remain attached at the base. In most cases this is evident from the remaining surrounding rock, but sometimes a building is cut from an outcrop, as in the Shore Temple in southern India, and only inspection at close quarters reveals that the building is monolithic. The terms ''monolith'' and '' monolithic column'' are normally used for objects made from a single large piece of rock which is detached from the ground. They may have been moved a considerable distance, as with several ancient Egyptian obelisks, which have been moved around the world. Buildings with a structural material that is poured into place, most commonly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abutment
An abutment is the substructure at the ends of a bridge span or dam supporting its superstructure. Single-span bridges have abutments at each end which provide vertical and lateral support for the span, as well as acting as retaining walls to resist lateral movement of the earthen fill of the bridge approach. Multi-span bridges require piers to support ends of spans unsupported by abutments. Dam abutments are generally the sides of a valley or gorge, but may be artificial in order to support arch dams such as Kurobe Dam in Japan. The civil engineering term may also refer to the structure supporting one side of an arch, or masonry used to resist the lateral forces of a vault.Pevsner, N. (1970) ''Cornwall''; 2nd ed. Harmondsworth: Penguin; p. 245 The impost or abacus of a column in classical architecture may also serve as an abutment to an arch. The word derives from the verb "abut", meaning to "touch by means of a mutual border". Use in engineering An abutment may be us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Road Salt
Sodium chloride , commonly known as salt (although sea salt also contains other chemical salts), is an ionic compound with the chemical formula NaCl, representing a 1:1 ratio of sodium and chloride ions. With molar masses of 22.99 and 35.45 g/mol respectively, 100 g of NaCl contains 39.34 g Na and 60.66 g Cl. Sodium chloride is the salt most responsible for the salinity of seawater and of the extracellular fluid of many multicellular organisms. In its edible form, salt (also known as ''table salt'') is commonly used as a condiment and food preservative. Large quantities of sodium chloride are used in many industrial processes, and it is a major source of sodium and chlorine compounds used as feedstocks for further chemical syntheses. Another major application of sodium chloride is de-icing of roadways in sub-freezing weather. Uses In addition to the familiar domestic uses of salt, more dominant applications of the approximately 250 million tonnes per year production (2008 da ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chloride Attack
The chloride ion is the anion (negatively charged ion) Cl−. It is formed when the element chlorine (a halogen) gains an electron or when a compound such as hydrogen chloride is dissolved in water or other polar solvents. Chloride salts such as sodium chloride are often very soluble in water.Green, John, and Sadru Damji. "Chapter 3." ''Chemistry''. Camberwell, Vic.: IBID, 2001. Print. It is an essential electrolyte located in all body fluids responsible for maintaining acid/base balance, transmitting nerve impulses and regulating liquid flow in and out of cells. Less frequently, the word ''chloride'' may also form part of the "common" name of chemical compounds in which one or more chlorine atoms are covalently bonded. For example, methyl chloride, with the standard name chloromethane (see IUPAC books) is an organic compound with a covalent C−Cl bond in which the chlorine is not an anion. Electronic properties A chloride ion (diameter 167 pm) is much larger than ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Highways England
National Highways, formerly the Highways Agency and later Highways England, is a government-owned company charged with operating, maintaining and improving motorways and major A roads in England. It also sets highways standards used by all four UK administrations, through the Design Manual for Roads and Bridges. Within England, it operates information services through the provision of on-road signage and its Traffic England website, provides traffic officers to deal with incidents on its network, and manages the delivery of improvement schemes to the network. Founded as an executive agency, it was converted into a government-owned company, Highways England, on 1 April 2015. As part of this transition, the UK government set out its vision for the future of the English strategic road network in its Road Investment Strategy. A second Road Investment Strategy was published in March 2020, with the company set to invest £27 billion between 2020 and 2025 to improve the network as d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bridge Bearing
A bridge bearing is a component of a bridge which typically provides a resting surface between bridge piers and the bridge deck. The purpose of a bearing is to allow controlled movement and thereby reduce the stresses involved. Possible causes of movement are thermal expansion and contraction, creep, shrinkage, or fatigue due to the properties of the material used for the bearing. External sources of movement include the settlement of the ground below, thermal expansion, and seismic activity. There are several different types of bridge bearings which are used depending on a number of different factors including the bridge span, loading conditions, and performance specifications. The oldest form of bridge bearing is simply two plates resting on top of each other. A common form of modern bridge bearing is the elastomeric bridge bearing. Another type of bridge bearing is the mechanical bridge bearing. There are several types of mechanical bridge bearing, such as the pinned bearing, whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Design Manual For Roads And Bridges
The Design Manual for Roads and Bridges (DMRB) is a series of 15 volumes that provide standards, advice notes and other documents relating to the design, assessment and operation of trunk roads, including motorways in the United Kingdom, and, with some amendments, the Republic of Ireland. It also forms the basis of the road design standards used in many other countries. DMRB volumes form part of a suite of technical documents produced by National Highways, which comprises: * Design Manual for Roads and Bridges (DMRB) * Manual of Contract Documents for Highway Works (MCHW) * Asset Maintenance and Operation Requirements (AMOR) which supersedes the Network Maintenance Manual and Routine and Winter Service Codes, and its predecessor the Trunk Road Maintenance Manual Overview The volumes within the Design Manual for Roads and Bridges are: Volume 0 – Introduction and General requirements Volume 1 – Highway Structures: Approval Procedures and General Design Volume 2 – ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skew Lines
In three-dimensional geometry, skew lines are two lines that do not intersect and are not parallel. A simple example of a pair of skew lines is the pair of lines through opposite edges of a regular tetrahedron. Two lines that both lie in the same plane must either cross each other or be parallel, so skew lines can exist only in three or more dimensions. Two lines are skew if and only if they are not coplanar. General position If four points are chosen at random uniformly within a unit cube, they will almost surely define a pair of skew lines. After the first three points have been chosen, the fourth point will define a non-skew line if, and only if, it is coplanar with the first three points. However, the plane through the first three points forms a subset of measure zero of the cube, and the probability that the fourth point lies on this plane is zero. If it does not, the lines defined by the points will be skew. Similarly, in three-dimensional space a very small perturbati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
_map.svg "Click for more on -> M1 Motorway")
