BS 5400 was a British Standard code of practice for the design and construction of steel, concrete and composite bridges. It was applicable to highway, railway and pedestrian bridges. It has now been replaced by the European standard, BS EN 1991-2_2003 [1] and other Eurocodes for the design of steel and concrete structures.
British Standards (BS) are the standards produced by the BSI Group which is incorporated under a Royal Charter. The BSI Group produces British Standards under the authority of the Charter, which lays down as one of the BSI's objectives to:
(2) Set up standards of quality for goods and services, and prepare and promote the general adoption of British Standards and schedules in connection therewith and from time to time to revise, alter and amend such standards and schedules as experience and circumstances require
The Steel Bridge is a through truss, double-deck vertical-lift bridge across the Willamette River in Portland, Oregon, United States, opened in 1912. Its lower deck carries railroad and bicycle/pedestrian traffic, while the upper deck carries road traffic, and light rail (MAX), making the bridge one of the most multimodal in the world. It is the only double-deck bridge with independent lifts in the world and the second oldest vertical-lift bridge in North America, after the nearby Hawthorne Bridge. The bridge links the Rose Quarter and Lloyd District in the east to Old Town Chinatown neighborhood in the west.
Concrete, usually Portland cement concrete, is a composite material composed of fine and coarse aggregate bonded together with a fluid cement that hardens over time—most frequently a lime-based cement binder, such as Portland cement, but sometimes with other hydraulic cements, such as a calcium aluminate cement. It is distinguished from other, non-cementitious types of concrete all binding some form of aggregate together, including asphalt concrete with a bitumen binder, which is frequently used for road surfaces, and polymer concretes that use polymers as a binder.
Contents
The standard specifies the requirements and the code of practice [2] [3] on design of steel, [2] concrete (reinforced, prestressed or composite) [3] and composite bridges that use steel sections (rolled or fabricated, cased or uncased) [4] as well as the materials and workmanship in bridge erection.
Reinforced concrete (RC) (also called reinforced cement concrete or RCC) is a composite material in which concrete's relatively low tensile strength and ductility are counteracted by the inclusion of reinforcement having higher tensile strength or ductility. The reinforcement is usually, though not necessarily, steel reinforcing bars (rebar) and is usually embedded passively in the concrete before the concrete sets. Reinforcing schemes are generally designed to resist tensile stresses in particular regions of the concrete that might cause unacceptable cracking and/or structural failure. Modern reinforced concrete can contain varied reinforcing materials made of steel, polymers or alternate composite material in conjunction with rebar or not. Reinforced concrete may also be permanently stressed, so as to improve the behaviour of the final structure under working loads. In the United States, the most common methods of doing this are known as pre-tensioning and post-tensioning.
Prestressed concrete is a form of concrete used in construction that while under construction is substantially "prestressed" (compressed) in the areas that will be subjected to tensile forces while in service to strengthen it against these forces.
A bridge is a structure built to span physical obstacles without closing the way underneath such as a body of water, valley, or road, for the purpose of providing passage over the obstacle, usually something that can be detrimental to cross otherwise. There are many different designs that each serve a particular purpose and apply to different situations. Designs of bridges vary depending on the function of the bridge, the nature of the terrain where the bridge is constructed and anchored, the material used to make it, and the funds available to build it.
The standard also includes the specification and calculation of standard bridge loads, the application of the limit state principles, [5] analysis, and fatigue load calculation [6] and the reservoir method for fatigue load cycle counting. [6]
Limit state design (LSD), also known as load and resistance factor design (LRFD), refers to a design method used in structural engineering. A limit state is a condition of a structure beyond which it no longer fulfills the relevant design criteria. The condition may refer to a degree of loading or other actions on the structure, while the criteria refer to structural integrity, fitness for use, durability or other design requirements. A structure designed by LSD is proportioned to sustain all actions likely to occur during its design life, and to remain fit for use, with an appropriate level of reliability for each limit state. Building codes based on LSD implicitly define the appropriate levels of reliability by their prescriptions.
In materials science, fatigue is the weakening of a material caused by repeatedly applied loads. It is the progressive and localized structural damage that occurs when a material is subjected to cyclic loading. The nominal maximum stress values that cause such damage may be much less than the strength of the material typically quoted as the ultimate tensile stress limit, or the yield stress limit.
The standard also covers the structural design of bridge foundations [5] and design and requirements on bridge bearings for ordinary and moving bridges. [7] [8]
In engineering, a foundation is the element of a structure which connects it to the ground, and transfers loads from the structure to the ground. Foundations are generally considered either shallow or deep. Foundation engineering is the application of soil mechanics and rock mechanics in the design of foundation elements of structures.
In 2010, BS 5400 was superseded by the Structural Eurocodes for the design of new bridges. However, BS 5400 still forms the basis of assessment standards for existing highway and railway structures. Some of the prescriptive clauses from the old code have been re-cast in a form consistent with the principles of the Eurocodes and presented as advisory material within British Standard Published Documents; these exist as non-contradictory complementary information (NCCI) to the Eurocodes and offer means of compliance with the requirements of the Eurocodes, typically using closed-form solutions familiar to the engineer experienced in the application of BS5400.
The eurocodes are the ten European standards specifying how structural design should be conducted within the European Union (EU). These were developed by the European Committee for Standardisation upon the request of the European Commission.
