structure

Question 1

1. name 5 vertical loads
2. name 2 lateral (sideways) loads
3. whzat type of loads are traffic and wave?
4. what type of load is fire?

Answer 1

1. gravity, snow, people, furniture, equipment
2. wind, earthquake
3. dynamic
4. thermal

Question 2

1. how would you class Self weight of the structure fixtures and finishes, (that is always present)
2. how would you class Imposed floor loads (people, furniture, equipment)
   Snow load
   Wind load
   ( that is not always acting but at various times)

Answer 2

1. permanent (dead loads)
2. Variable (Live loads)
   not always acting but at various times
   Imposed floor loads (people, furniture, equipment)
   Snow load
   Wind load

Question 3

1. what do loads create?

Answer 3

1. internal forces in structural elements

Question 4

1. what are internal forces?

Answer 4

1. stresses developed in the material

Question 5

1. what do stresses do?

Answer 5

1. deform the structural elements

Question 6

1. what is tension?
2. what does tension usually affect?
3. what is compression
4. what does compression usually affect?
5. what is the name of Instability phenomenon associated to axially compressed columns

Answer 6

1. pulled apart
2. Truss elements, diagonal elements used for bracing, Cables, Membranes
3. pushed together
4. Columns, Vertical members holding a weight.
5. column buckling

Question 7

1. what is bending?
2. what does bending usually affect?

Answer 7

1. compression and tension, makes the thing bend, compression top tension bottom
2. Beams, Floor slabs,
   Horizontal elements carrying gravity loads

Question 8

1. what does a roller support look like?
2. what does a pinned support look like?
3. what does a fixed support look like?
4. what does a simple support look like?

Answer 8

1. circle on rectangle, or triangle with circles
2. triangle on rectangle
3. wall and rectangle directly attached
4. rectangle on top of square, like a floor sitting on a wall

Question 9

1. what does a pinned support do?
2. what does a roller support do?
3. what does a fixed support do?

Answer 9

1. restricts vertical and horizontal movement but allows some rotation
2. restricts vertical movement but allows some movement horizontally and some rotation
3. doesnt allow horizontal or vertical movement or rotation

Question 10

1. qualities of pinned connections?
2. qualities of fixed (rigid) connections?

Answer 10

1. Beams free to rotate
   More common
   Easy
   Less expensive

2.Expensive
Laborious
Need Quality Control

Question 11

1. what are 3 types of resistance against lateral loads?
2. what is comstructed Starting from a stable triangular unit , each additional triangle can be formed by adding 2 members and 1 single joint.
3. what are Simple trusses connected together to form?
4. what are 2 assumptions in design of trusses?

Answer 11

1. Diagonal bracing (big cross across the middle connecting all 4 points)
   Rigid connections (little triangles across top left and right corners)
   Infill/shear walls/Cores (whole wall coloured in)
2. trusses
3. compound trusses

4 The members are connected at ends by pinned connections or hinges.
The forces in the members of the truss are purely axial (tension or compression

Question 12

1. what are the 3 different structural systems?

Answer 12

1. Solid Structures
   Semi-Solid Structures
   Filigree/Frame Structures

Question 13

1. which structural system relys on heavy materials to maintain stability, utilizing gravity to keep them compacted. and are like big singular blocks, example materials Concrete,
   Compacted soil,
   Stone with mortar
2. which one uses Panelised Systems/Curved Structures, can withstand loads with minimal thickness due to their three-dimensional geometry, example materials Brick and blocks to make wall panels,
   Reinforced concrete panels,
   Timber panels, like CLT (Cross laminated timber),
3. which one allows Extensive design freedom
   Loadbearing frame and enclosing walls independent of each other, are independent of interior or exterior walls for load-bearing

Answer 13

1. solid structures
2. semi solid structures
3. filigree/frame structures

Question 14

1. name 10 qualities of structural steel building material

Answer 14

1. very strong in both tension and compression

Slenderness of elements

A ductile material that deflects before failure.

Suitable for high-speed construction

Easy construction with smaller workforce.

Its relative light weight

Steel has a high strength/weight ratio

Lack of resistance to corrosion

Adequate fireproofing is needed

More costly to build than other types of structures

Question 15

1. which material gives you the possibility of using hollow or I-sections?
2. which materials are more suitable for solid cross-sections?

Answer 15

1. steel
2. timber and concrete

Question 16

1. name 7 qualities of concrete (i think usually reinforced concrete ) building material

Answer 16

1. Good compressive strength

Its tensile strength can be less than 1/10 of its compressive strength - good Reinforcement

Can be produced to any shape and form

Its strength/ weight ratio is low

Superior durability

Reinforced concrete suitable for short-span, low-rise and high-rise

Prestressed concrete suitable for long-spans

Question 17

1, name 6 qualities of timber building material

Answer 17

1. Good in compression and tension

Can be laminated and curved, large thicknesses
can be manufactured to accommodate large spans

Can be shaped into both long/linear elements and panels

Has low embodied carbon

Its strength/ weight ratio is high

vulnerable to moisture

Question 18

1. what does a tensile structure do?
2. how is the load bearing capacity achiveved tensile structures?
3. 4 examples of tensile structures?

Answer 18

1. A Tensile Structure carries Pure Tension in most of its Individual Elements
2. The load bearing capacity is achieved through tension stress in the majority of components, such as cables, and fabrics, or truss elements.
3. Cable-stayed / Cable nets
   Stretching a net of cable woven to a specific shape and fixing it by masts, cables and ground anchors.

Membranes (fabric structures)
Stretching fabric to a specific shape and fixing it by masts, or cables and ground anchors.

Trussed / Space Frame Structures
Normally made of thin steel bars in triangulated forms
Pneumatic structures
Protective membranes supported by means of air pressure.

Question 19

1. what is a form active structure?
2. what is the amount of force or the amount of stress that material can carry before being ruptured, for example the maximum amount of tension that a cable can carry before being pulled apart?
3. what are Tensile form-active structures?
4. compressive?

Answer 19

1. The form of structure actively participate in load carrying.

A axial force over the cross section

The most efficient use of material as the whole cross section is stressed to its limit

2. stress limit
3. cable structures
4. arches

Question 20

1. what are concentrated loads cable forms?
2. what are distributed loads cable forms

Answer 20

1. loads at various asymmetrical points
2. loads at consistent measured points

Question 21

1. what is pre- tensioning (cable structures) and why is it needed?
2. what is the word meaning meaning tightening or fastening more than enough for just carrying the gravity load of the structure. ?

Answer 21

1. extra tightening of the cables at the end points to reduce potential unwanted deformations.
2. prestressing

Question 22

1. name 6 advantages of using tensile structures

Answer 22

1. Lightweight
   Providing wide column-free spans
   Various geometries and shapes
   Easy to disassemble and reuse
   Cost-effective
   Prefabricated

Question 23

1. name 7 components of a frame structure

Answer 23

1. Foundations (Footings)
   Columns (Posts)
   Primary Beams (Girders)
   Secondary Beams (Joists)
   Floor panels
   Roof panels
   Bracing elements

Question 24

1. what is a structural grid?
2. name 6 important things about structural grid

Answer 24

1. This defines on plan two sets of grid lines which are normally perpendicular.
   The structural grid is defined principally by column positions and the main beams spanning between them.
2. For simple structures, two sets of grid lines are normally defined on plan.

Ideally grid lines should be orthogonal (at right angles)

For circular buildings radial and circumferential grids are often used.

A column should normally be positioned at intersection of two grid lines.

Main beams or Load bearing walls should normally be positioned along grid lines.

A repetitive and regular grid is preferred to reduce fabrication costs and erection time.

Question 25

1. what is the standard type of beam? 2. column? 3. what is a secondary beam?

Answer 25

1. universal I beam 2. universal H column 3. Secondary beamsupported at mid-point of primarybeam

Question 26

1. what bracing method is not suitable for a concrete frame? 2. what is the Rule of thumb for estimating the cross section area of columns in a concrete frame?

Answer 26

1. diagonal bracing 2. Estimated cross-section area of a column in mm2 = area supported in m2 x 1000

Question 27

1. what are the differences/advantages of engineered timber, for timber products for construction compared to sawed section from tree? 2. 4 moisture protections for timber structures?

Answer 27

1. Engineered timber (Laminated Timber, Glulam, CLT, …) - Increased size (Longer elements, Bigger sections) - Enhanced strength (reduced variability) 2. Do not embed timber below concrete floor level Do not place timber in direct contact with masonry or concrete Avoid moisture entrapment in connections The foot of a timber column: at least 150mm above external finished ground level

Question 28

1. what is That part of a structure which is in contact with the ground and transmits the loads from structure to the ground? 2. 5 types of foundation?

Answer 28

1. foundation 2. Strip foundation (mass or reinforced concrete)Good ground Pad foundation (mass or reinforced concrete)Good ground 3) Raft (reinforced concrete) Poor ground 4) Pile (steel or reinforced concrete) Poor ground/heavily loaded 5) Piled Raft (reinforced concrete) Poor ground/heavily loaded

Question 29

1. 3 materials used for compressive structures? 2. what type of elements are columns and walls? 3. what is the slenderness ratio

Answer 29

1. Masonry, brick, block Discrete elements Natural stone Discrete elements Concrete (plain or RC) Continuous elements 2. Vertical compressive elements 3. the ratio between the cross section and the length of the element

Question 30

1. what is the main mode of faiure in an overloaded thick wall? and what causes it 2. same for slender wall? 3. how to increase buckling resistance of a (slender) wall?

Answer 30

1. crushing (compression) (wall cracks in the middle), In-plane strength of the wall is exceeded 2. buckling, Out-of-plane pre-mature failure 3. A lateral support keeps the wall in plane and increases the buckling resistance of the wall, Lateral support to limit slenderness of the wall (horizontal floor or something in middle)

Question 31

1. equation slenderness of wall? 2. how do arches work? 3. what is the keystone arch?

Answer 31

1. Slenderness of the wall = length/ thickness The length in the above equation can be the unsupported height (the storey height) or the height of the wall in between the lateral supports (floors or cross-walls). 2. Carry loads by developing compressive stresses within the arch itself. No bending, Little to no tension 3. A keystone (or capstone) is the wedge-shaped stone at the apex of a masonry arch. It is the final piece placed during construction and locks all the stones into position, allowing the arch or vault to bear weight. The keystone completes the curvature of the arch and locks all the other stones of the arch into position. If you remove the keystone the arch collapses

Question 32

1. what is a flying buttress? 2. what is a barrel vault? 3. how do domes work? 4. what are Continuum/Continuous Structures?

Answer 32

1. Holding or giving support to a main structure It is an arch that extends out from a tall stone wall. The practical purpose of a flying buttress is to help hold the heavy wall up by pushing from the outside. A buttress is a support—but it also serves an aesthetic purpose 2. An extended arch shape in the longitudinal direction, a semi cylinder. 3. Develop compressive strength along the meridians Develop compressive or tensile strength around its hoops In a dome tension hoops and compression hoops both will develop. Reinforcement rings are needed at the lower parts to resist tension at the hoops. Domes are naturally more stable than arches and barrel vaults 4. Shells, dams, domes, …. Made of concrete, clay, …. eg. double curved shells

Question 33

1. what is the line of thrust or line of pressure? 2. what shape does the line of thrust take?

Answer 33

1. line, along which internal forces flow theoretical line which represents the path of the compressive forces 2. inverted catenary curve. A catenary is the curve assumed by a freely suspended chain or flexible cable under the action of gravity

Question 34

1. properties of catenary arches? 2. how many hinges will lead an arch to collapse? 3. what does it mean if If the line of thrust passes the inner or the outer surface of the arch, ?

Answer 34

1. Always the most stable so their thickness can be reduced The line of thrust is centred in the arch only in the case of inverted catenary arches. All the other types of arches can have LT moving in the middle third of the arch thickness, but it will never be centred. Therefore, the non-catenary arches intend to develop tension at some sections which may lead to crack or joint opening (hinges). 2. more than 3 3. it means that section is cracked, and a hinge has formed at that point.

Question 35

1. where should the line of thrust remain in a circular arch To prevent any tension and crack opening? 2. what will happen If the line of thrust does not remain in the middle third? 3. the line of thrust also needs to be in the middle third of the pier (the straight wall bit beneath the arch), and if it not it will collapse. what are 2 ways it not being in the middle third of the pier can be fixed? 4. heavy central load can also cause line of thrust out of middle third and failure what can you fo?

Answer 35

1. the middle third of the arch section and pier. 2. some cracks/hinges may form, but the arch may not collapse. Collapse will happen only when the number of hinges become more than 3 (remember the concept of 3-pin arch is a stable form). 3. Load the haunches of the archto change the angle of the thrust.  (eg build more wall up where the arch is) Increase the width of the pier or,if it is a vault, add regular spaced buttresses.  4. catenary arch keep shape load haunches