STRUCTURAL DESIGN AND COMPUTER MODELLING · concrete • cross frames resist well to the wind...
Transcript of STRUCTURAL DESIGN AND COMPUTER MODELLING · concrete • cross frames resist well to the wind...
STRUCTURAL DESIGN AND
COMPUTER MODELLING
Ing. Jan Koláček, Ph.D.
Basic structural members
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Basic structural members
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Type of structures
Air view of district Brno-Kohoutovice
• Building structures
• Engineering structures
• Bridges
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Type of structures
• Building structures
• Engineering structures
• Bridges
Oil tanks in Loukov 5
Type of structures
• Building structures
• Engineering structures
• Bridges
Willamette river Bridge in Oregon, USA 6
1. Building structures
• housing
• commercial
• administrative
• manufactural
• agricultural
• stocking, etc.
distinguished according to their purpose:
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1. Building structures are formed:
• by load bearing structures – transform actions imposed on the structures
• by non-load bearing structures – additional function
Load bearing structures:
• vertical members – walls, columns, piers
• horizontal members – roofs, ceilings
• other members – stairs, arches
• hall structures
• multi-storey buildings
Building structures:
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1. Building structures Hall structures
• mostly of one storey (possibly in-built storey)
• used as manufactural, storing, sports, exhibitory, etc.
• one or multi tracts, purlin/non-purlin system
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1. Building structures Hall structure – non-purlin system
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1. Building structures Multi-storey buildings
Structural systems:
• wall
• skeleton
• combined
• special
According to the orientation of vertical structures they are divided into:
• longitudinal
• transversal
• two-ways
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1. Building structures Multi-storey buildings – wall systems
• principal member is a wall
• masonry, precast or cast in-situ concrete
• span of tracts is mostly 3-6 m (restrain disposition)
• transversal system (suitable for housing), longitudinal system
(administrative buildings)
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1. Building structures Multi-storey buildings – skeleton system
• developed from wall system
• principal members are pier or column (reduction of walls)
• due to wind effect have to be supplied by shear walls or cores
• skeleton system has lower stiffness compared to wall system
• better variability of arrangement
Basic division of skeleton system:
• framed
• non-framed
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1. Building structures Multi-storey buildings – skeleton system - framed
• columns are jointed with horizontal beams supporting floor slab
• recommended material is cast in-situ, precast or prestressed
concrete
• cross frames resist well to the wind (higher stiffness) – for high-rise
buildings
• longitudinal frames – for common buildings only
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1. Building structures Multi-storey buildings – skeleton system – non framed
• slab with column head
• flat slab
• combined
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1. Building structures Multi-storey buildings – skeleton system – non framed
Column heads skeleton system
• better safety against punching
• shorter span of slabs
• with high load bearing capacity – manufacturing and storing
halls
Flat slab skeleton system
• shall be more reinforced around columns (punching)
• flat ceiling
• suitable for common houses
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1. Building structures Multi-storey buildings – combined
• combination of wall and skeleton systems
• many variants – longitudinal wall system combined with skeleton
system, two-ways skeleton system with core, etc.
• suitable for high-rise buildings (skyscraper), undermined areas and
seismic active area
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2. Engineering structures
• underground
• water
• technological
• towers, masts and chimneys
• special
Special structures (difficult static and structural solution):
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2. Engineering structures
• foundation structures
• various underground structures
Underground structures
• shallow foundation – spread footings, combined footings and mat
foundations
Foundation structures are:
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2. Engineering structures
• foundation structures
• various underground structures
Underground structures
• deep foundation – piles, micropiles, wells and caissons
Foundation structures are:
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2. Engineering structures
• for transport (railway, traffic, pedestrian, etc.)
• for water service (water supplies, etc.)
• for energetic (telecommunication, cables, collector, etc.)
• halls (hydroelectric power station, gas reservoirs, water tank,
sewerage plants, etc.)
Various underground structures are used:
• foundation structures
• various underground structures
Underground structures
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2. Engineering structures
• dams
• weirs
• lock chambers
• hydro power stations
• pumped-storage hydro power station
Water structures
• dominant material is plain concrete, reinforced concrete and steel
For example :
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2. Engineering structures
• blast furnace
• coking plants
• petroleum refinery
• cooling towers
Technological structures
For example:
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2. Engineering structures
• fixed supported freestanding
towers
• transmission masts
• etc.
Towers, masts and chimneys
For example
• tall slim structures
• suitable material is steel (towers, masts) or concrete (chimneys)
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2. Engineering structures Special structures
• tanks
• reservoirs
• silos
• pools
• etc.
Oil tanks in Loukov 25
3. Bridges Bridge structures
• are structures built to span physical obstacles (such as a body
water, valley or road)
They can divided into three types:
• bridges (clear span greater than 2,0 m)
• culverts (clear span less than 2,0 m)
• pedestrian bridges (serve pedestrians or bicyclists)
Bridge across the Swiss Bay of Vranov Lake 26
3. Bridges Bridge components:
• superstructure
• substructure
• foundation
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3. Bridges Substructure
• abutments – (external support) a wall supporting the ends of
a bridge including footing, etc.
• piers – (internal support) columns, pier shaft, web wall, etc.
• wingwalls
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3. Bridges Substructure
• abutments – (external support) a wall supporting the ends of a
bridge including footing, etc.
• piers – (internal support) columns, pier shaft, web wall, etc.
• wingwalls
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3. Bridges Superstructure
• a part of bridges which transfer the action (reaction) of loads to
substructure
Bridge deck
• a part of superstructure which is on the top of a bridge
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Main structure
• is supporting system of the bridge
3. Bridges Type of superstructure (span type):
• slab
• beam
• arch
• vault
• cable-stayed
• suspension
• rigid frame
• etc.
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3. Bridges Type of superstructure (span type):
• slab
• beam
• arch
• vault
• cable-stayed
• suspension
• rigid frame
• etc.
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3. Bridges Type of superstructure (span type):
• slab
• beam
• arch
• vault
• cable-stayed
• suspension
• rigid frame
• etc.
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3. Bridges Type of superstructure (span type):
• slab
• beam
• arch
• vault
• cable-stayed
• suspension
• rigid frame
• etc.
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3. Bridges
Pylon
Stays Type of superstructure (span type):
• slab
• beam
• arch
• vault
• cable-stayed
• suspension
• rigid frame
• etc.
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3. Bridges
Bridge deck
Type of superstructure (span type):
• slab
• beam
• arch
• vault
• cable-stayed
• suspension
• rigid frame
• etc.
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3. Bridges Next classification of bridges
• railroad (railway, tram, funicular, etc.)
• vehicular (road, highway, etc.)
• pedestrian
• material handling
• migration (migration of animal)
function:
• masonry
• concrete
• steel
• timber
• composite
structure materials:
• others
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Design process:
• definition of geometry of the structure,
• definition of the connecting joints (mutual connection of individual
members),
• design of material characteristics,
• design of cross sections of individual members,
• determination of loads and load combinations,
• calculation (computing) of the structure,
• dimensioning of members and connecting joints,
• design (construction drawings) of the structure,
• production of members and blocks of the structure,
• assembly of the structure,
• construction drawings of the structure as built
Calculation models of structures
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can be defined as a model that simulates the behaviour of the real
structure.
Special notice shall be taken to the following definitions:
• geometry
• method of supporting
• materials of used members
• dimensioning of members
• action of loads
Based on this model it is
possible to perform analysis.
Calculation models of structures
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Four fundamental type of elements are used
• bar elements
• surface element
• brick elements
Bar elements
• are idealized by its centre line
• suitable for columns, arches, ties and beams
• the span is not less than 3 times the overall section depth and
width.
• according to behaviour in the structure as follows:
• truss – compressive and tensile normal
forces are dominantly
• beam – is loaded dominantly by the
loads which act predominantly
perpendicular to the centre line
Bar elements model in software IDEA StatiCa
Types of elements
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Walls
• are loaded dominantly in the centre line
• usually serve as bracing members of multi-story
buildings
• section depth exceed 4x its width and the height
is more than 3x the overall section depth Slabs
• are loaded dominantly perpendicular to the
central plane
• minimum dimension is not less than 5x the
overall slab thickness
• act as one-way, two-way of flat slabs (supported
locally by columns)
Types of elements Surface elements – are idealized by their central surface that
are either flat (plates) or curved (shells). Plate elements are
slabs and walls.
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Shells
• are thin-walled spatial structure supported at all edges
• loaded mostly by uniform load acting in the direction
approximately perpendicular to the surface
• we distinguish simple curvature and double curvature
Types of elements Surface elements – are idealized by their central surface that
are either flat (plates) or curved (shells). Plate elements are
slabs and walls.
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Brick elements
• in cases where there are dimensions of the elements of all
direction comparable
• difficult computing
Types of elements
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Elements are usually supported as following:
• roller - are free to rotate and translate along the surface upon
which the roller rest,
• pinned - can resist both vertical and horizontal forces but not a
moment - they will allow the structural member to rotate, but not
to translate in any direction,
• fixed - can resist vertical and horizontal forces as well as a
moment - they restrain both rotation and translation.
Production of calculation models
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Elements are usually connected with each other. We distinguish
• pin connections - has allowed rotation around a distinct axis,
and prevented translation in two direction
• fixed connections - due to the fact that can resist vertical and
lateral loads as well as develop a resistance to moment
• combined connections
Pin and fixed connections are very common
Production of calculation models
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Examples of connection checking by method
CBFEM
Production of calculation models
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• calculation models made from beam elements
are used for steel and timber structures
• in addition to beam elements surface elements
(slabs, walls and shells) are used for concrete
structures
• brick elements are suitable for detailed
calculation models
Production of calculation models
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• exact manual solution – usage at basic tasks
• numerical computer calculation – in practise only this is used –
enables interconnection with drawings, assessments, etc.
Numerical calculations - in building practice they are based on the
finite element method (FEM).
Solution and computing
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Willamette river bridge in Oregon, USA
Examples of FEM models
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Model test of cable supported bridge
Examples of FEM models
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Examples of FEM models
51 Oil tanks in Loukov
Examples of FEM models
52 Construction work on the pedestrian bridge in Kroměříž
Examples of FEM models
53 Pedestrian bridge over the Elbe river in Hradec Králové - competition
Examples of FEM models
54 Tower for strap testing, Dolní Loučky
2008 Summer Olympic games - The Beijing National Stadium (The bird‘s nest)
Examples of FEM models
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Burj Khalifa -Scyscraper in Dubai
Examples of FEM models
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References
• Procházka, J., Štemberk, P.: Concrete structures 1, Nakladatelství
ČVUT, Praha, 2007
• Procházka, J., Štemberk, P.: Design procedures for reinforced
concrete structures, Nakladatelství ČVUT, Praha, 2009
• Gartner, O., Kuda, R., Procházka, M.: Betonové konstrukce VI –
Zásady pro navrhování betonových konstrukcí, VUT Brno, Brno,
1985.
• Bajer, M., Pilgr, M., Veselka, M.: Konstrukce a dopravní stavby,
Moduly BO01-MO1, Studíjní opory VUT v Brně
• Karmazínová, M., Sýkora, K., Šmak, M.: Konstrukce a dopravní
stavby, Moduly BO01-MO2, Studíjní opory VUT v Brně
• Nečas, R., Koláček, J., Panáček, J.: BL12 - Betonové mosty I –
zásady navrhování, VUT v Brně, Brno, 2014
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WE BUILT TOO MANY WALLS
AND NOT ENOUGH BRIDGES. ISAAC NEWTON
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