1. VOCATIONAL TRAINING AT
LARSEN & TOUBRO LIMITED
MMH-IC, EDRC-KOLKATA
PROJECT REPORT
ON
TRUSS ANALYSIS
D BY SUBMITTED TO
MITRA SONJIT MALLICK

2. 2014
Submitted by
UDAYAN MITRA
Under the Supervision of
Mr. SONJIT MALLICK .
6th
June to 30th
June 201
In partial fulfillment of the requirements for the award of the degree of
BACHELOR OF ENGINEERING
SCHOOL OF CIVIL ENGINEERING
KIIT UNIVERSITY
BHUBANESWAR
ODISHA-751024

3. 1
Larsen & Toubro Limited, also known as L&T, is an
Indian multinational conglomerate, it is India's largest engineering and
construction company. Considered to be the "bellwether of India's engineering
& construction sector"
L&T Construction has played a prominent role in India’s industrial and
infrastructure development by executing several projects across length and
breadth of the country and abroad. For ease of operations and better project
management, in-depth technology and business development as well as to focus
attention on domestic and international project execution, entire operation of
L&T Construction is structured into different Independent Companies.
More than seven decades of a strong, customer-focused approach and the
continuous quest for world-class quality have enabled it to attain and sustain
leadership in all its major lines of business.
L&T has an international presence, with a global spread of offices.
A thrust on international business has seen overseas earnings grow significantly.
It continues to grow its global footprint, with offices and manufacturing facilities
in multiple countries.
COMPANY
OVERVIEW

4. 1/
ACKNOWLEDGEMENT
I am indebted to Larsen & Toubro Limited (L&T) for giving me an
opportunity to be a part of its Industrial Vocational Training programme
during my Summer Vacation of 2014.
I take this opportunity to express my profound gratitude and deep regards
to Mr. INDRANIL ROY, Mr. BARUNDEB LAHIRI and Mr. SONJIT MALLICK,
EDRC, MMHIC, L&T, Kolkata for his exemplary guidance, monitoring and
constant encouragement throughout the course of this thesis. The blessing,
help and guidance given by him time to time shall carry me a long way in
the journey of life on which I am about to embark.
Also I would like to thank my mentor Mr. SURAJIT DAS and Mrs. SHAYONEE
CHAKRABORTY and Mr. MALLESH N.G, for their excellent supervision and
guidance in providing a sustained environment for learning during the
tenure of the training.

5. INDEX
• INTRODUCTION
1.DEFINITION OF TRUSS 1
2.PLANE AND SPACE TRUSS 2
3.TRUSS ANALYSIS 3
4.SOFTWARE USED 4
• SCOPE OF WORK 5
• BIBLIOGRAPHY 6
• ASSIGNMENT
(a) ARRANGEMENT OF TRUSS 7
(b) CALCULATION OF LOAD 8
 DEAD LOAD CALCULATION 8
 LIVE LOAD CALCULATION 9
 WIND LOAD CALCULATION 11
 LOAD COMBINATIONS 17
CASE 1 19
CASE 2 21
CASE 3 24
CASE 4 27

6. CASE 5 30
CASE 6 33
CASE 7 36
CASE 8 39
CASE 9 41
 CALCULATION OF ANGLES
AND LENGTHS 43
 ANALYSIS OF BEAM FORCES
CASE 1 52
CASE 2 62
 CASE 3 69
STAAD MODEL 76
STAAD INPUT FILE 77
STAAD OUTPUT FILE 78
COMPARISON OF STAAD
AND MANUAL ANALYSIS 90

7. INTRODUCTION
• What is a TRUSS?
A truss is a structure comprising five or more triangular units constructed with straight
members whose ends are connected at joints referred to as nodes. External forces and
reactions to those forces are considered to act only at the nodes and result in forces in the
members which are either tensile or compressive forces. Moments (torques) are explicitly
excluded because, and only because, all the joints in a truss are treated as revolutes.

8. • Plane & Space Truss-
The simplest form of a truss is one single triangle. This type of truss is seen in
a framed roof consisting of rafters and a ceiling joist, and in other mechanical
structures such as bicycles and aircraft. Because of the stability of this shape
and the methods of analysis used to calculate the forces within it, a truss
composed entirely of triangles is known as a simple truss. The traditional
diamond-shape bicycle frame, which utilizes two conjoined triangles, is an
example of a simple truss.
A planar truss lies in a single plane. Planar trusses are typically used in
parallel to form roofs and bridges.
The depth of a truss, or the height between the upper and lower chords, is
what makes it an efficient structural form. A solid girder or beam of equal
strength would have substantial weight and material cost as compared to a
truss. For a given span, a deeper truss will require less material in the chords
and greater material in the verticals and diagonals. An optimum depth of the
truss will maximize the efficiency.
A space frame truss is a three-dimensional framework of members pinned at
their ends. A tetrahedron shape is the simplest space truss, consisting of six
members which meet at four joints. Large planar structures may be
composed from tetrahedrons with common edges and they are also
employed in the base structures of large free-standing power line pylons

9. • TRUSS ANALYSIS
Because the forces in each of its two main girders are essentially planar, a truss
is usually modeled as a two-dimensional plane frame. If there are significant out-
of-plane forces, the structure must be modeled as a three-dimensional space.
The analysis of trusses often assumes that loads are applied to joints only and
not at intermediate points along the members. The weight of the members is
often insignificant compared to the applied loads and so is often omitted. If
required, half of the weight of each member may be applied to its two end
joints. Provided the members are long and slender, the moments transmitted
through the joints are negligible and they can be treated as "hinges" or 'pin-
joints'. Every member of the truss is then in pure compression or pure tension –
shear, bending moment, and other more complex stresses are all practically
zero. This makes trusses easier to analyze. This also makes trusses physically
stronger than other ways of arranging material – because nearly every material
can hold a much larger load in tension and compression than in shear, bending,
torsion, or other kinds of force.
Structural analysis of trusses of any type can readily be carried out using a matrix
method such as the direct stiffness method, the flexibility method or the finite
element method.

10. • Software Used:- STAAD ProV8i
About the Software :-
STAAD or (STAAD.Pro) is a structural analysis and design computer program
originally developed by Research Engineers International in Yorba Linda, CA.
In late 2005, Research Engineer International was bought by Bentley
Systems.
The commercial version STAAD.Pro is one of the most widely used structural
analysis and design software. It supports several steel, concrete and timber
design codes.
It can make use of various forms of analysis from the traditional 1st order
static analysis, 2nd order p-delta analysis, geometric non linear analysis or
a buckling analysis. It can also make use of various forms of dynamic analysis
from modal extraction to time history and response spectrum analysis.

11. SCOPE OF WORK
• Finalizing the arrangement of TRUSS model.
• Calculation of loads on the TRUSS.
1. Dead load
2. Live load
3. Wind load
• Calculation of Load Combinations :-
1. Dead Load + Live Load (1 case).
2. Dead Load + Live Load + Wind Load (4 cases).
3. Dead Load + Wind Load (4 cases).
• Analyzing of Member Forces by-
1. Method of joints
2. Method of sections
• Modeling of the structure using Software STAAD PRO V8i.
• Applying load, member sections and specifications
according to behavior of the structure.
• Analysis for Dead Load + Live Load Case.
• Comparison between Staad Analysis and Manual Analysis.

12. BIBLIOGRAPHY
While doing the work assigned to me, I had to study certain documents , books
and codes to get a better knowledge of my work in the assignment. I was also
greatly helped by my mentors. The books and codes which I had taken help from
are given below.
Books Used:-
• DUGGAL S.K. DESIGN OF STEEL STRUCTURES.
Codes Used :-
• IS : 875 Part 1. 1987 – DEAD LOADS-UNIT WEIGHTS OF BUILDING
MATERIALS & STORED MATERIALS.
• IS : 875 Part 2. 1987. – IMPOSED LOADS.
• IS : 875 Part 3. 1987. - WIND LOADS.
• IS: 800 (3rd Revision). 2007. GENERAL CONSTRUCTION IN STEEL - CODE OF
PRACTICE.
• SP-6 (1)-1964 – HANDBOOK FOR STRUCTURAL ENGINEERS.
World Wide Web :-
• https://engineering.purdue.edu/~aprakas/CE297/CE297-Ch6.pdf. Purdue
University Forum. 26 October 2009.

13. ASSIGNMENT

15. CALCULATION
OF
LOADS

16. DEAD LOAD CALCULATION

18. LIVE LOAD CALCULATION

21. WIND LOAD CALCULATION

28. LOAD COMBINATIONS

31. CASE 1

34. CASE 2

38. CASE 3

42. CASE 4

46. CASE 5

50. CASE 6

54. CASE 7

58. CASE 8

61. CASE 9

64. CALCULATION OF ANGLES
AND LENGTHS

74. ANALYZING BEAM FORCES
FOR CASE 1

85. ANALYZING BEAM FORCES
FOR CASE 2

93. ANALYZING BEAM FORCES
FOR CASE 3

101. STAAD MODEL

103. STAAD INPUT FILE

104. STAAD SPACE
START JOB INFORMATION
ENGINEER DATE 26-Jun-14
END JOB INFORMATION
INPUT WIDTH 79
UNIT METER KN
JOINT COORDINATES
1 0 0 0; 2 15 0 0; 4 7.50002 3.00001 0; 5 2.50001 0 0; 6 5.00001 0 0; 7 10 0 0;
8 12.5 0 0; 9 9.00002 2.4 0; 10 10.5 1.8 0; 11 12 1.2 0; 12 13.5 0.600001 0;
13 1.5 0.600001 0; 14 3.00001 1.2 0; 15 4.50001 1.8 0; 16 6.00001 2.4 0;
17 6.25001 1.5 0; 18 8.75002 1.5 0;
MEMBER INCIDENCES
1 1 5; 3 1 13; 4 4 9; 5 5 6; 7 7 8; 8 8 2; 9 9 10; 10 10 11; 11 11 12; 12 12 2;
13 13 14; 14 14 15; 15 15 16; 16 16 4; 17 6 17; 18 4 18; 19 6 14; 20 14 5;
21 5 13; 22 6 15; 23 17 4; 24 18 7; 25 15 17; 26 17 16; 27 18 9; 28 18 10;
29 10 7; 30 7 11; 31 11 8; 32 8 12; 33 6 7;
DEFINE MATERIAL START
ISOTROPIC STEEL
E 1.99947e+008
POISSON 0.3
DENSITY 76.8191
ALPHA 6e-006
DAMP 0.03
TYPE STEEL
STRENGTH FY 248210 FU 399894 RY 1.5 RT 1.2
END DEFINE MATERIAL
MEMBER PROPERTY INDIAN
1 3 TO 5 7 TO 16 33 TABLE LD ISA110X110X10 SP 0.01
17 18 23 24 TABLE LD ISA90X90X6 SP 0.01
19 TO 22 25 TO 32 TABLE LD ISA65X65X6 SP 0.008
CONSTANTS
MATERIAL STEEL ALL
MEMBER RELEASE
1 3 17 18 START MY MZ
8 12 23 24 END MY MZ
SUPPORTS
1 PINNED
2 FIXED BUT FX FZ MX MY MZ
MEMBER TRUSS
19 TO 22 25 TO 32
LOAD 1 LOADTYPE None TITLE DEAD LOAD
SELFWEIGHT Y -1.1
JOINT LOAD
1 2 FY -1.2
4 9 TO 16 FY -1.62
LOAD 2 LOADTYPE None TITLE LIVE LOAD
JOINT LOAD
1 2 FY -2.19
4 9 TO 16 FY -4.16
LOAD COMB 3 DL+LL
1 1.5 2 1.5
PERFORM ANALYSIS
PRINT MEMBER FORCES ALL
PRINT JOINT DISPLACEMENTS ALL
PRINT SUPPORT REACTION ALL

105. STAAD OUTPUT FILE

106. ****************************************************
* *
* STAAD.Pro V8i SELECTseries2 *
* Version 20.07.07.32 *
* Proprietary Program of *
* Bentley Systems, Inc. *
* Date= JUN 30, 2014 *
* Time= 10:45:43 *
* *
* USER ID: LNT ECC DIV *
****************************************************
1. STAAD SPACE
INPUT FILE: Udayan Truss.STD
2. START JOB INFORMATION
3. ENGINEER DATE 26-JUN-14
4. END JOB INFORMATION
5. INPUT WIDTH 79
6. UNIT METER KN
7. JOINT COORDINATES
8. 1 0 0 0; 2 15 0 0; 4 7.50002 3.00001 0; 5 2.50001 0 0; 6 5.00001 0 0; 7 10 0
0
9. 8 12.5 0 0; 9 9.00002 2.4 0; 10 10.5 1.8 0; 11 12 1.2 0; 12 13.5 0.600001 0
10. 13 1.5 0.600001 0; 14 3.00001 1.2 0; 15 4.50001 1.8 0; 16 6.00001 2.4 0
11. 17 6.25001 1.5 0; 18 8.75002 1.5 0
12. MEMBER INCIDENCES
13. 1 1 5; 3 1 13; 4 4 9; 5 5 6; 7 7 8; 8 8 2; 9 9 10; 10 10 11; 11 11 12; 12 12
2
14. 13 13 14; 14 14 15; 15 15 16; 16 16 4; 17 6 17; 18 4 18; 19 6 14; 20 14 5
15. 21 5 13; 22 6 15; 23 17 4; 24 18 7; 25 15 17; 26 17 16; 27 18 9; 28 18 10
16. 29 10 7; 30 7 11; 31 11 8; 32 8 12; 33 6 7
17. DEFINE MATERIAL START
18. ISOTROPIC STEEL
19. E 1.99947E+008
20. POISSON 0.3
21. DENSITY 76.8191
22. ALPHA 6E-006
23. DAMP 0.03
24. TYPE STEEL
25. STRENGTH FY 248210 FU 399894 RY 1.5 RT 1.2
26. END DEFINE MATERIAL
27. MEMBER PROPERTY INDIAN
28. 1 3 TO 5 7 TO 16 33 TABLE LD ISA110X110X10 SP 0.01
29. 17 18 23 24 TABLE LD ISA90X90X6 SP 0.01
30. 19 TO 22 25 TO 32 TABLE LD ISA65X65X6 SP 0.008
31. CONSTANTS
32. MATERIAL STEEL ALL
33. MEMBER RELEASE
34. 1 3 17 18 START MY MZ
35. 8 12 23 24 END MY MZ
36. SUPPORTS
37. 1 PINNED
38. 2 FIXED BUT FX FZ MX MY MZ
39. MEMBER TRUSS
40. 19 TO 22 25 TO 32

107. 41. LOAD 1 LOADTYPE NONE TITLE DEAD LOAD
42. SELFWEIGHT Y -1.1
43. JOINT LOAD
44. 1 2 FY -1.2
45. 4 9 TO 16 FY -1.62
46. LOAD 2 LOADTYPE NONE TITLE LIVE LOAD
47. JOINT LOAD
48. 1 2 FY -2.19
49. 4 9 TO 16 FY -4.16
50. LOAD COMB 3 DL+LL
51. 1 1.5 2 1.5
52. PERFORM ANALYSIS
P R O B L E M S T A T I S T I C S
-----------------------------------
NUMBER OF JOINTS/MEMBER+ELEMENTS/SUPPORTS = 17/ 31/ 2
SOLVER USED IS THE OUT-OF-CORE BASIC SOLVER
ORIGINAL/FINAL BAND-WIDTH= 14/ 4/ 30 DOF
TOTAL PRIMARY LOAD CASES = 2, TOTAL DEGREES OF FREEDOM = 98
SIZE OF STIFFNESS MATRIX = 3 DOUBLE KILO-WORDS
REQRD/AVAIL. DISK SPACE = 12.1/ 22331.4 MB
ZERO STIFFNESS IN DIRECTION 6 AT JOINT 2 EQN.NO. 95
LOADS APPLIED OR DISTRIBUTED HERE FROM ELEMENTS WILL BE IGNORED.
THIS MAY BE DUE TO ALL MEMBERS AT THIS JOINT BEING RELEASED OR
EFFECTIVELY RELEASED IN THIS DIRECTION.
ZERO STIFFNESS IN DIRECTION 6 AT JOINT 1 EQN.NO. 98
***WARNING - INSTABILITY AT JOINT 1 DIRECTION = MX
PROBABLE CAUSE SINGULAR-ADDING WEAK SPRING
K-MATRIX DIAG= 8.9387320E+01 L-MATRIX DIAG= -7.2759576E-12 EQN NO 96
***NOTE - VERY WEAK SPRING ADDED FOR STABILITY
**NOTE** STAAD DETECTS INSTABILITIES AS EXCESSIVE LOSS OF SIGNIFICANT
DIGITS
DURING DECOMPOSITION. WHEN A DECOMPOSED DIAGONAL IS LESS THAN THE
BUILT-IN REDUCTION FACTOR TIMES THE ORIGINAL STIFFNESS MATRIX DIAGONAL,
STAAD PRINTS A SINGULARITY NOTICE. THE BUILT-IN REDUCTION FACTOR
IS 1.000E-09
THE ABOVE CONDITIONS COULD ALSO BE CAUSED BY VERY STIFF OR VERY WEAK
ELEMENTS AS WELL AS TRUE SINGULARITIES.
***WARNING - INSTABILITY AT JOINT 1 DIRECTION = MY
PROBABLE CAUSE SINGULAR-ADDING WEAK SPRING
K-MATRIX DIAG= 8.1743928E+00 L-MATRIX DIAG= -2.2580728E-09 EQN NO 97
***NOTE - VERY WEAK SPRING ADDED FOR STABILITY
53. PRINT MEMBER FORCES ALL

116. COMPARISON OF STAAD ANALYSIS
TO MANUAL ANALYSIS

118. MANUAL CALCULATIONS STAAD-PRO
CALCULATIONS
Member
Mark
Force
in
(kN)
Beam
No.
from
Staad
File
Axial
Force in
(kN)
AB 105.0
4 (T)
3 130.643 (T)
AO 97.52
(C)
1 120.643 (C)
BO 10.05
(T)
21 9.994 (T)
BC 95.8
(T)
13 120.743 (T)
OC 5.68
(C)
20 6.538 (C)
OP 86.73
(T)
5 109.651 (T)
CP 15.14
(T)
19 17.711 (T)
CD 78.94
(T)
14 101.910 (T)
PT 54.29
(C)
33 69.468 (C)
PD 12.23
(T)
22 13.990 (T)
PQ 25.47
(C)
17 33.148 (C)
DQ 7.76 (C) 25 6.855 (C)
EQ 8.43 (T) 26 6.805 (T)
EF 80.05 (T) 16 102.733 (T)
DE 83.79 (T) 15 105.571 (T)

119. The differences in manual and staad analysis is caused
as the self weight of the truss was not added to the
dead load calculation of the truss.