structures important for civil protection remain operational.
The random nature of the seismic events and the limited resources available to counter their effects are such as to make the attainment of these goals only partially possible and only measurable in probabilistic terms. The extent of the protection that can be provided to different categories of buildings, which is only measurable in probabilistic terms, is a matter of optimal allocation of resources and is therefore expected to vary from country to country, depending on the relative importance of the seismic risk with respect to risks of other origin and on the global economic resources.
Special structures, such as nuclear power plants, offshore structures and large dams, are beyond the scope of EN 1998. EN 1998 contains only those provisions that, in addition to the provisions of the other relevant Eurocodes, must be observed for the design of structures in seismic regions. It complements in this respect the other EN Eurocodes.
Eurocode 8 comprises several documents, grouped in six parts numbered from EN 1998-1 to EN 1998-6.
Part 1: General rules, seismic actions and rules for buildings
EN 1998-1 applies to the design of buildings and civil engineering works in seismic regions. It is subdivided in 10 Sections, some of which are specifically devoted to the design of buildings.
Section 1 of EN 1998-1 contains the scope, normative references, assumptions, principles and application rules, terms and definitions, symbols and units.
Section 2 of EN 1998-1 contains the basic performance requirements and compliance criteria applicable to buildings and civil engineering works in seismic regions.
Section 3 of EN 1998-1 gives the rules for the representation of seismic actions and for their combination with other actions. Certain types of structures, dealt with in EN 1998-2 to EN 1998-6, need complementing rules which are given in those Parts.
Section 4 of EN 1998-1 contains general design rules relevant specifically to buildings.
Sections 5 to 9 of EN 1998-1 contain specific rules for various structural materials and elements, relevant specifically to buildings as follows:
Section 5: Specific rules for concrete buildings;
Section 6: Specific rules for steel buildings;
Section 7: Specific rules for composite steel-concrete buildings;
Section 8: Specific rules for timber buildings;
Section 9: Specific rules for masonry buildings.
Section 10 contains the fundamental requirements and other relevant aspects of design and safety related to base isolation of structures and specifically to base isolation of buildings.
EN 1998-2 covers the seismic design of bridges in which the horizontal seismic actions are mainly resisted through bending of the piers or at the abutments; i.e. of bridges composed of vertical or nearly vertical pier systems supporting the traffic deck superstructure. It is also applicable to the seismic design of cable-stayed and arched bridges, although its provisions should not be considered as fully covering these cases.
Part 3: Assessment and retrofitting of buildings
The scope of EN 1998-3 is defined as follows:
To provide criteria for the evaluation of the seismic performance of existing individual building structures.
To describe the approach in selecting necessary corrective measures
To set forth criteria for the design of retrofitting measures (i.e. conception, structural analysis including intervention measures, final dimensioning of structural parts and their connections to existing structural elements).
Part 4: Silos, tanks and pipelines
In EN 1998-4, principles and application rules for the seismic design of the structural aspects of facilities composed of above-ground and buried pipeline systems and of storage tanks of different types and uses, as well as for independent items, such as for example single water towers serving a specific purpose or groups of silos enclosing granular materials are addressed.
Part 5: Foundations, retaining structures and geotechnical aspects
EN 1998-5 establishes the requirements, criteria, and rules for the siting and foundation soil of structures for earthquake resistance. It covers the design of different foundation systems, the design of earth retaining structures and soil-structure interaction under seismic actions.
Part 6: Towers, masts and chimneys
EN 1998-6 establishes requirements, criteria, and rules for the design of tall slender structures: towers, including bell-towers, intake towers, radio and TV-towers, masts, chimneys (including free-standing industrial chimneys) and lighthouses.
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.
A building code is a set of rules that specify the standards for constructed objects such as buildings and non-building structures. Buildings must conform to the code to obtain planning permission, usually from a local council. The main purpose of building codes is to protect public health, safety and general welfare as they relate to the construction and occupancy of buildings and structures — for example, the building codes in many countries require engineers to consider the effects of soil liquefaction in the design of new buildings. The building code becomes law of a particular jurisdiction when formally enacted by the appropriate governmental or private authority.
Seismic analysis is a subset of structural analysis and is the calculation of the response of a building structure to earthquakes. It is part of the process of structural design, earthquake engineering or structural assessment and retrofit in regions where earthquakes are prevalent.
Earthquake engineering is an interdisciplinary branch of engineering that designs and analyzes structures, such as buildings and bridges, with earthquakes in mind. Its overall goal is to make such structures more resistant to earthquakes. An earthquake engineer aims to construct structures that will not be damaged in minor shaking and will avoid serious damage or collapse in a major earthquake. A properly engineered structure does not necessarily have to be extremely strong or expensive. It has to be properly designed to withstand the seismic effects while sustaining an acceptable level of damage.
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 Standardization upon the request of the European Commission.
A structural load or structural action is a force, deformation, or acceleration applied to structural elements. A load causes stress, deformation, and displacement in a structure. Structural analysis, a discipline in engineering, analyzes the effects of loads on structures and structural elements. Excess load may cause structural failure, so this should be considered and controlled during the design of a structure. Particular mechanical structures—such as aircraft, satellites, rockets, space stations, ships, and submarines—are subject to their own particular structural loads and actions. Engineers often evaluate structural loads based upon published regulations, contracts, or specifications. Accepted technical standards are used for acceptance testing and inspection.
Cold-formed steel (CFS) is the common term for steel products shaped by cold-working processes carried out near room temperature, such as rolling, pressing, stamping, bending, etc. Stock bars and sheets of cold-rolled steel (CRS) are commonly used in all areas of manufacturing. The terms are opposed to hot-formed steel and hot-rolled steel.
In the Eurocode series of European standards (EN) related to construction, Eurocode 2: Design of concrete structures specifies technical rules for the design of concrete, reinforced concrete and prestressed concrete structures, using the limit state design philosophy. It was approved by the European Committee for Standardization (CEN) on 16 April 2004 to enable designers across Europe to practice in any country that adopts the code.
In the Eurocode series of European standards (EN) related to construction, Eurocode 3: Design of steel structures describes how to design steel structures, using the limit state design philosophy.
In the Eurocode series of European standards (EN) related to construction, Eurocode: Basis of structural design establishes the basis that sets out the way to use Eurocodes for structural design. Eurocode 0 establishes Principles and requirements for the safety, serviceability and durability of structures, describes the basis for their design and verification and gives guidelines for related aspects of structural reliability. Eurocode 0 is intended to be used in conjunction with EN 1991 to EN 1999 for the structural design of buildings and civil engineering works, including geotechnical aspects, structural fire design, situations involving earthquakes, execution and temporary structures.
STAAD or (STAAD.Pro) is a structural analysis and design software application originally developed by Research Engineers International(REI) in 1997. In late 2005, Research Engineers International was bought by Bentley Systems. STAAD stands for STructural Analysis And Design.
In the Eurocode series of European standards (EN) related to construction, Eurocode 1: Actions on structures describes how to design load-bearing structures. It includes characteristic values for various types of loads and densities for all materials which are likely to be used in construction.
Performance-Based Building Design is an approach to the design of any complexity of building, from single-detached homes up to and including high-rise apartments and office buildings. A building constructed in this way is required to meet certain measurable or predictable performance requirements, such as energy efficiency or seismic load, without a specific prescribed method by which to attain those requirements. This is in contrast to traditional prescribed building codes, which mandate specific construction practises, such as stud size and distance between studs in wooden frame construction. Such an approach provides the freedom to develop tools and methods to evaluate the entire life cycle of the building process, from the business dealings, to procurement, through construction and the evaluation of results.
In the Eurocode series of European standards (EN) related to construction, Eurocode 4: Design of composite steel and concrete structures describes how to design of composite structures, using the limit state design philosophy. It was approved by the European Committee for Standardization (CEN) on 4 November 2004. Eurocode 4 is divided in two parts EN 1994-1 and EN 1994-2.
In the Eurocode series of European standards (EN) related to construction, Eurocode 9: Design of aluminium structures describes how to design aluminium alloy structures. It complies with the principles and requirements for the safety and serviceability of structures, the basis of their design and verification that are given in EN 1990 – Basis of structural design. It sets requirements for structural integrity, including strength, serviceability, durability and fire resistance.
In the Eurocode series of European standards (EN) related to construction, Eurocode 5: Design of timber structures describes how to design buildings and civil engineering works in timber, using the limit state design philosophy. It was approved by the European Committee for Standardization (CEN) on 16 April 2004. It applies for civil engineering works from solid timber, sawn, planned or in pole form, glued laminated timber or wood-based structural products, or wood-based panels jointed together with adhesives or mechanical fasteners and is divided into the following parts.
Robustness is the ability of a structure to withstand events like fire, explosions, impact or the consequences of human error, without being damaged to an extent disproportionate to the original cause – as defined in EN 1991-1-7 of the Accidental Actions Eurocode.
Seismic codes or earthquake codes are building codes designed to protect property and life in buildings in case of earthquakes. The need for such codes is reflected in the saying, "Earthquakes don't kill people—buildings do." Or in expanded version, “Earthquakes do not injure or kill people. Poorly built manmade structures injure and kill people.”
The infill wall is the supported wall that closes the perimeter of a building constructed with a three-dimensional framework structure. Therefore, the structural frame ensures the bearing function, whereas the infill wall serves to separate inner and outer space, filling up the boxes of the outer frames. The infill wall has the unique static function to bear its own weight. The infill wall is an external vertical opaque type of closure. With respect to other categories of wall, the infill wall differs from the partition that serves to separate two interior spaces, yet also non-load bearing, and from the load bearing wall. The latter performs the same functions of the infill wall, hygro-thermically and acoustically, but performs static functions too.
Earthquake rotational loading indicates the excitation of structures due to the torsional and rocking components of seismic actions. Nathan M. Newmark was the first researcher who showed that this type of loading may result in unexpected failure of structures, and its influence should be considered in design codes. There are various phenomena that may lead to the earthquake rotational loading of structures, such as propagation of body wave, surface wave, special rotational wave, block rotation, topographic effect, and soil structure interaction.
This page is based on this Wikipedia article Text is available under the CC BY-SA 4.0 license; additional terms may apply. Images, videos and audio are available under their respective licenses.
