13. We l e a d
LECTURE OUTCOME
• Audiences will comprehend the various stages
of building construction
• Audiences will be able to distinguish the
various classes of structures
• Audiences will be able to determine the
structural determinancy of a truss structure
• Audiences will be able to perform the
structural analysis of a determinate truss
structure
REG 162- INTRODUCTION OF STRUCTURES
14. We l e a d
WHO ARE WE?
• ARCHITECTS
• URBAN PLANNERS
• BUILDING ENGINEERS
• PROJECT MANAGERS
• BUILDING SURVEYORS
• QUANTITY SURVEYORS
• INTERIOR DESIGNERS
15. We l e a d
WHAT DO WE DO?
• To ensure a structure is erected at the right
location, aesthetically appealing and safe for
occupancy with optimum cost of construction.
REG 163- Theory of Structures I
16. We l e a d
WHAT IS OUR ROLE AS A BUILDING
CONSULTANTS?
• Produce the architectural and engineering layout
of a building.
• Estimation of loads (live, dead and dynamic
loading)
• Analysis of forces, moments and deflection
• Design of structural members with adequate load
bearing capacity
• Monitoring of compliance of site work to
design specification
REG 163- Theory of Structures I
17. We l e a d
MAJOR STAGES IN BUILDING
CONSTRUCTION
PROJECT FEASIBILITY STUDY
PROJECT PLANNING
ENGINEERING ANALYSIS
AND DESIGN
PROJECT TENDER
PROGRESS AND
COMPLIANCE MONITORING
AS-BUILT SURVEY AND
INTEGRITY CHECK
ISSUANCE OF CERTIFICATE
OF FITNESS
REG 163- Theory of Structures I
18. We l e a d
ENGINEERING ANALYSIS AND DESIGN
SELECTION OF
STRUCTURAL
FORM AND CLASS
• Determination of structural form and class according to site
constraints, expected loading condition, load bearing requirements and
cost consideration.
LOAD ESTIMATION
• Consideration on any type, nature and vector of potential load on the
building.
STRUCTURAL
ANALYSIS
• Determination of the vector of axial forces, shear forces, bending
moments and deflection of a structure in response to the projected
loads
STRUCTURAL
DESIGN
• Specifying the dimensions of structural elements and its internal
reinforcements (if any) to yield adequate load bearing capacity.
19. We l e a d
CLASSIFICATION OF STRUCTURES
• Selection of structure element class is the utmost important
consideration for effective transmission of a given load
• There are five basic categories of structural element based on
the type of internal stress induced by the design load.
– Bending Structures
– Shear Structures
– Tension Structures
– Compression Structures
– Trusses
REG 163- Theory of Structures I
20. We l e a d
CLASSIFICATION OF STRUCTURES
• Bending Structures
– Bending structure is a horizontal structural member which is loaded
perpendicular to its longitudinal axis.
– Internal stress on the structure is combination of bending and shear
stress.
– All external design load exerted on bending structures are
transformed into bending and shear stress within the structure.
21. We l e a d
CLASSIFICATION OF STRUCTURES
• Bending Structures
– Suitable and economical for short spanned structures(<8 metres span)
– Quasi homogeneous materials with composite strength properties
(Such as reinforced concrete) is suitable for fabrication of bending
structures.
– Longer span (up to 20 metres) can be achieved using the pre-stress
concrete technology.
22. We l e a d
CLASSIFICATION OF STRUCTURES
• Shear Structures
– Shear structure is a vertical structural member which is loaded
perpendicular to its longitudinal axis.
– Internal stress on the structure is mainly shear with negligible
bending stress.
– All external design load exerted on bending structures are
transformed into shear stress within the structure.
23. We l e a d
CLASSIFICATION OF STRUCTURES
• Shear Structures
– Shear structure is an essential element in tall building structures to
resist lateral load exerted by wind and seismic movement.
– In most tall building, shear walls are fabricated using reinforced
concrete composite.
– Shear walls are also considered as a vertical support for beams and
slabs in the design of reinforced concrete structures.
24. We l e a d
CLASSIFICATION OF STRUCTURES
• Tension Structures
– Internal stress on the structure is pure tension stress.
– All external design load exerted on tension structures are transformed
into tension stress within the tension structure.
– Suitable and economical for long spanned structures(>15 metres
span)
– Materials with good tensile strength properties (Such as steel and
fibre reinforced polymers) is suitable for fabrication of tension
structures.
– Tension structures is usually lacking in lateral stiffness and susceptible
to wind-induced oscillation.
25. We l e a d
CLASSIFICATION OF STRUCTURES
• Compression Structures
– Internal stress on the structure is pure compression stress.
– All external design load exerted on compression structures are
transformed into compression stress within the structural members.
– Economical for fabrication of long spanned structures.
– Materials with good compressive strength properties (Such as
concrete and natural rocks) is suitable for fabrication of compression
structures.
– Compression structures is usually lacking in lateral stiffness and
susceptible to buckling failure.
26. We l e a d
CLASSIFICATION OF STRUCTURES
• Trusses
– Trusses are stable structural configuration which composed of
straight members connected at their ends
– Internal stress of an ideal truss system is either pure compression
stress or pure tension.
– All external design load exerted on compression structures are
transformed into either compression stress or tension stress within
the structural members.
27. We l e a d
CLASSIFICATION OF STRUCTURES
• Trusses
– Economical for fabrication of long spanned structures.
– Homogeneous materials with good compressive strength and tension
strength(Such as structural steel) is suitable for fabrication of truss
structures.
– Can be subcategorized into two dimensional and three dimensional
truss system.
– An efficient structural system which is both light weight and high
strength.
– Not suitable for use when headroom is limited.
28. We l e a d
PROJECT BRIEF
• TOTAL GROUP:25
• NUMBER OF STUDENTS PER GROUP:7-8
• NOTE: GROUP LIST CAN BE REFERRED IN THE
ELEARN @ USM (elearning.usm.my) Portal
REG 163- Theory of Structures I
29. We l e a d
PROJECT BRIEF
• PART 1: ASSESSMENT ON BENDING STRUCTURES
1.1 SUPPORT REACTION ASSESSMENT
1.2 SHEAR FORCE ASSESSMENT
1.3 BENDING MOMENT ASSESSMENT
• LABORATORY TECHNICIAN-IN-CHARGE:
PN DIANA ISME ISHAK
• GROUP COORDINATORS NEED TO BOOK THE LAB SCHEDULE
WITH PN DIANA IMMEDIATELY AFTER TODAY CLASS.
• LAB ASSESSMENT WILL COMMENCE ON THE SECOND WEEK
OF THE ACADEMIC SEMESTER
• THREE GROUP PER LAB SESSION
30. We l e a d
PROJECT BRIEF
• PART 2: ASSESSMENT ON THE MECHANICAL PERFORMANCE
OF STEEL REINFORCEMENT
2.1 PREPARATION OF STEEL REBAR AND PHYSICAL PROPERTIES ASSESSMENT
2.2 TENSILE AND YIELD STRENGTH PERFORMANCE
2.3 ASSESSMENT ON YOUNG’S MODULUS
• LABORATORY TECHNICIAN-IN-CHARGE:
PN. DIANA ISME ISHAK
• GROUP COORDINATORS NEED TO BOOK THE LAB SCHEDULE WITH THE
TUTOR
• LAB WORK WILL COMMENCE ON THE SECOND WEEK OF THE ACADEMIC
SEMESTER
• TWO GROUP PER LAB SESSION
31. We l e a d
PROJECT REPORTING FORMAT
• TITLE PAGE (REFER TO STANDARD TEMPLATE
IN E-LEARN)
• ACKNOWLEDGEMENT
• TABLE OF CONTENT
• CHAPTER 1:STRUCTURAL ASSESSMENT
• CHAPTER 2:PROPERTIES OF STEEL
REINFORCEMENT
• CHAPTER 3:CONCLUSIONS
REG 163- Theory of Structures I
32. We l e a d
REPORT SUBMISSION
• REPORT SHALL BE SUBMITTED INDIVIDUALLY
• SUBMISSION DATELINE:10TH MAY 2016
• CHANNEL OF SUBMISSION: E-LEARN SYSTEM
• DOCUMENT SHALL BE IN MS WORD
FORMAT(doc. File)
• File name nomenclature order:
Group No._Student Name_Matric Number
• Severe action will be taken in the event of
plagiarism REG 163- Theory of Structures I
33. We l e a d
ANALYSIS OF PLANE TRUSSES
• Four basic steps involved in the analysis of
truss
Determination of truss
structural condition
Identification of zero-force
members
Determination of support
reaction forces
Determination of internal
forces of truss members
34. We l e a d
ANALYSIS OF PLANE TRUSSES-STEP 1
• There are three basic truss structural conditions namely:
• Where m=number of members
r = number of reactions
j = number of joints
•Structurally unstable and not able to sustain
any load.
•m+r<2j
Statically
unstable truss
•Structurally stable and the forces in members
can be determined with consideration on
equilibrium of planar forces
•m+r=2j
Statically
determinate
truss
•Structurally stable but the forces in members
cannot be determined with consideration only
on equilibrium of planar forces
•m+r>2j
Statically
indeterminate
truss
35. We l e a d
ANALYSIS OF PLANE TRUSSES
• m=17, j=10, r= 2
REG 163- Theory of Structures I
36. We l e a d
ANALYSIS OF PLANE TRUSSES
• m=17, j=10, r= 3
REG 163- Theory of Structures I
37. We l e a d
ANALYSIS OF PLANE TRUSSES
• m=21, j=10, r= 3
REG 163- Theory of Structures I
38. We l e a d
ANALYSIS OF PLANE TRUSSES-STEP 2
• Identification of zero force members:
– Performed to expedite the analysis of forces of
members in a truss system.
– There is only two conditions that a member of
truss will have zero force.
REG 163- Theory of Structures I
39. We l e a d
ANALYSIS OF PLANE TRUSSES-STEP 2
• Condition 1: If only two non-colinear member
are connected to a joint that has no external
loads or reactions applied to it. Then forces in
both members are zero.
REG 163- Theory of Structures I
40. We l e a d
ANALYSIS OF PLANE TRUSSES-STEP 2
• Condition 2: If three members, two of which
are co-linear, are connected to a joint that has
no external loads or reaction applied to it. The
force in the member that is not co-linear is
zero.
REG 163- Theory of Structures I
41. We l e a d
ANALYSIS OF PLANE TRUSSES-STEP 3
• Determination of support reactions
• Conditions which can be employed are:
𝐹𝑦 = 0
𝐹𝑥 = 0
𝑀 𝑃𝐼𝑁 𝑆𝑈𝑃𝑃𝑂𝑅𝑇 = 0
REG 163- Theory of Structures I
42. We l e a d
ANALYSIS OF PLANE TRUSSES-STEP 4
• Determination of member forces
• Conditions which can be employed are:
𝑓𝑦 = 0
𝑓𝑥 = 0
REG 163- Theory of Structures I
43. We l e a d
ANALYSIS OF PLANE TRUSSES-METHOD OF
JOINTS
• Example 1:
What is the
structural
condition?
REG 163- Theory of Structures I
𝑚 = 5
𝑟 = 3
𝑗 = 4
𝑚 + 𝑟 = 8
2𝑗 = 8
𝑚 + 𝑟 = 2𝑗
Statically Determinate
44. We l e a d
ANALYSIS OF PLANE TRUSSES-METHOD OF
JOINTS
• Example 1:
Which one is zero
force member?
Member BD
REG 163- Theory of Structures I
45. We l e a d
EXAMPLE 1
Ax
Ay Cy
𝐹𝑥 = 0; 𝐴 𝑥 − 28 = 0
𝐴 𝑥 = 28𝑘𝑁
+
𝐹𝑦 = 0; 𝐴 𝑦 + 𝐶 𝑦 − 42 = 0
𝐴 𝑦 + 𝐶 𝑦 = 42𝑘𝑁
+
𝑀𝐴 = 0; 𝐶 𝑦 35 − 42 20 + 28 20 = 0+
𝐶 𝑦 = 8𝑘𝑁
𝐴 𝑦 + 8 = 42𝑘𝑁
𝐴 𝑦 = 34𝑘𝑁
REG 163- Theory of Structures I
46. We l e a d
ANALYSIS OF PLANE TRUSSES-METHOD OF
JOINTS
• Consider Point A
Ax=28kN
Ay=34kN
Cy=8kN
Ax=28kN
1
1
√2
Ay=34kN
FAD
FAB
𝑓𝑦 = 0; 34 + 𝐹𝐴𝐷
1
2
= 0
𝐹𝐴𝐷 = −48.08𝑘𝑁 (Compression)
+
𝑓𝑥 = 0; 28 + 𝐹𝐴𝐷
1
2
+ 𝐹𝐴𝐵 = 0
𝐹𝐴𝐵 = 6𝑘𝑁 (Tension)
+
28 + −48.08
1
2
+ 𝐹𝐴𝐵 = 0
47. We l e a d
ANALYSIS OF PLANE TRUSSES-METHOD OF
JOINTS
• Consider Point B
Ax=28kN
Ay=34kN
Cy=8kN
FAB=6kN
FBC
𝑓𝑥 = 0; −6 + 𝐹𝐵𝐶 = 0
𝐹𝐵𝐶 = 6𝑘𝑁 (Tension)
+
48. We l e a d
ANALYSIS OF PLANE TRUSSES-METHOD OF
JOINTS
• Consider Point C
Ax=28kN
Ay=34kN
Cy=8kN
FBC=6kN
4
3
5
Cy=8kN
FDC
𝑓𝑦 = 0; 8 + 𝐹 𝐷𝐶
4
5
= 0
𝐹 𝐷𝐶 = −10.00𝑘𝑁 (Compression)
+
49. We l e a d
ANALYSIS OF PLANE TRUSSES-METHOD OF
JOINTS
• Consider Point D (Checking Answer)
Ax=28kN
Ay=34kN Cy=8kN
28kN
1
1
√2
3
4
5
FAD=48.08kN
FDC=10.00kN
42kN
𝑓𝑦 = 48.08
1
2
+ 10.00
4
5
− 42 = −0.00231 ≈ 0
(OK)
+
𝑓𝑥 = 48.08
1
2
− 28 − 10.00
3
5
= −0 . 00231 ≈ 0
(OK)
+
50. We l e a d
ANALYSIS OF PLANE TRUSSES-METHOD OF
JOINTS
Ax=28kN
Ay=34kN
Cy=8kN
0kN
(ZERO
FORCE
MEMBER)
10kN (COMPRESSSION)
6kN (TENSION) 6kN (TENSION)
48.08kN
(COMPRESSSION)
51. We l e a d
TEST
• DATE:8 MARCH 2016
• DURATION: 1.5 HOURS
• SCOPE:
STRUCTURE CLASSES
TRUSS ANALYSIS
STRUCTURE FORM
REG 163- Theory of Structures I
52. We l e a d
STRUCTURAL FORMS
• Structural form is a complex structural system whereby two
or more structural classes are used in combination.
• The combination of a number of structural classes is often
necessary to maximize the efficiency of load transfer and
mitigation while meeting the architectural requirements
namely:
– Internal space and floor area
– Height of a structure
– Aspect ratios
– Spans between supports
– Geographical location of a project
53. We l e a d
STRUCTURAL FORMS
• The five main structural form of building which can be
found locally are as follows:
– Braced frame structure
– Rigid frame structure
– In-filled frame structure
– Shear walls structure
– Wall-frame structure
54. We l e a d
BRACED FRAME STRUCTURE
• Load mitigation mechanism
– Dead and live gravity load is transferred by the
conventional beam-column structural frames
– The gravity loads are transferred by the beams in the
form of bending and shear stresses.
– Subsequently the load from the beams are transferred
to the foundation by the structural columns in the form
of compression stress.
55. We l e a d
BRACED FRAME STRUCTURE
• Load mitigation mechanism
– Seismic and wind load are sustained by the diagonal
bracing struts of the building structure
– Seismic and wind loading exerted on the building is
converted into tension and compression stresses within
the diagonal struts members
56. We l e a d
BRACED FRAME STRUCTURE
• Advantages of the structural form
– High lateral stiffness and lateral load
mitigation capacity
– Incurs minimum additional material
and highly cost effective
– The sizes of the beams and slabs are
independent of the height of
building. This enable duplication of
design for the beams and slabs for
multiple floors.
57. We l e a d
BRACED FRAME STRUCTURE
• Disadvantages of the
structural form
– The presence of diagonal struts
obstruct the planning of the
windows location.
– High cost incurred for
fabrication of diagonal strut
joints.
58. We l e a d
RIGID FRAME STRUCTURE
• Load mitigation mechanism
– Dead and live gravity load is transferred by the
conventional beam-column structural frames
– The gravity loads are transferred by the beams in the
form of bending and shear stresses.
– Subsequently the load from the beams are transferred
to the foundation by the structural columns in the form
of compression stress.
59. We l e a d
RIGID FRAME STRUCTURE
• Load mitigation mechanism
– Seismic and wind load are mitigated by the rigid frame
system which consist of columns and beams joined by
moment resistant connection.
– Seismic and wind loading exerted on the building is
converted into bending stresses at the moment resistant
connection.
– The bending stresses are resisted by the additional
internal reinforcements placed within the moment
resistant connection.
60. We l e a d
RIGID FRAME STRUCTURE
• Advantages
– The open rectangular arrangement of the structural
form ease planning and placement of openings of a
building.
– It is an ideal structural form for reinforced concrete
building due to inherent rigidity of reinforced concrete
joint.
61. We l e a d
RIGID FRAME STRUCTURE
• Disadvantages
– Size of colums and beams are highly dependent on the
height of the building. Hence, the design of floor
members are not repeatable for the upper floors.
– Lateral load resistance capacity is limited, hence, not
suitable for use in areas with active seismic activity.
62. We l e a d
INFILLED FRAME STRUCTURE
• Load mitigation mechanism
– Gravity load transfer mechanism is similar to rigid frame
and braced frame structure form.
– The space in between columns and beams are filled by
concrete blocks instead of normal brick works
– Seismic and wind load are mitigated by the concrete
blocks infills which act like a diagonal compression strut
to brace the frame.
63. We l e a d
INFILLED FRAME STRUCTURE
• Advantages
– Infills which normally serves as external or internal walls
serves additional function of increasing lateral stiffness
to resist lateral loads
• Disadvantages
– Unpredictable infill strength due to complex interaction
behavior of infill and frame.
– Higher cost for placement of concrete blocks instead of
conventional bricks.
64. We l e a d
SHEAR WALL STRUCTURE
• Load mitigation mechanism
– Gravity load transfer mechanism is similar to rigid frame
and braced frame structure form.
– Heavily reinforced concrete columns with high aspect
ratios (>5) called shear walls are placed in the critical
direction of the building
65. We l e a d
SHEAR WALL STRUCTURE
• Load mitigation mechanism
– Shear walls can be designed in a form of planar walls or
non planar assembly (in the form of lift cores)
– Seismic and wind load are transferred by the high
stiffness shear wall system in the form of shear stresses
which are eventually transferred to the foundation
system.
66. We l e a d
SHEAR WALL STRUCTURE
• Advantages
– Higher lateral stiffness and lateral load resistance as
compared to infilled frame and rigid frame structures
– Exceptional seismic load resisting performance.
• Disadvantages
– The presence of large numbers of shear walls impose
restriction on the planning of the internal spaces of a
building.
67. We l e a d
WALL-FRAME STRUCTURE
• Load mitigation mechanism
– The structural form consist of rigid reinforced concrete
walls placed in the critical direction of a building.
– Dead and live gravity load is transferred by the
reinforced concrete walls in the form of compressive
stress to the foundation of the building.
68. We l e a d
WALL-FRAME STRUCTURE
• Load mitigation mechanism
– Seismic and wind load are transferred by the high
stiffness highly elongated reinforced concrete wall
system in the form of shear stresses which are
eventually transferred to the foundation system.
69. We l e a d
WALL-FRAME STRUCTURE
• Advantages
– Very high lateral stiffness and lateral load resistance.
– The dimension of walls and floors are highly uniform.
This allows the use of system form work which greatly
expedite the construction progress.
• Disadvantages
– The presence of large numbers of elongated reinforced
concrete walls impose heavy restriction on the planning
of the internal spaces of a building.
70. Presented by
DR CHEAH CHEE BAN | SENIOR LECTURER, SCHOOL OF HOUSING, BUILDING AND
PLANNING
