1. The document summarizes the design of a steel intensive toilet block in India under the Swachh Bharat initiative. 2. It includes the design of steel connections and members using STAAD and the types of connections that were designed, which include shear and moment connections. 3. Key structural elements like columns, beams, and beam-columns are discussed along with their potential failure modes.

1. 1. Designing of steel intensive toilet block (An initiative taken by
INSDAG under the “Swach Bharat Aviyaan”, by Govt. of India.
2. Designing of Steel Connections.
3. Designing of Steel Members.
Presented By:
Debarghya Roy Subhasish Roy
4th Year Civil Engg.
Jalpaiguri Govt. Engg. College
Under the guidance of-
Debasish Datta
Arijit Guha
Sajal Ghorai
Nibedita Dey

2. Preparation of Design Basis
 Assumed soil parameters : SBC= 70 KN/m² (at FGL)
 Wind speed: basic wind speed= 47 m/s (K₁=1.0, K₂=1.0, K₃=1.0 )
 Earth quake zone (Zone III)
STAAD.Pro Structures-
Load Calculations
Dead Loads:
Self weight of the structure
Loads on the periphery of the structure: (Translucent sheets with 0.15 KN/m² weight)
Nodal load
Loads on Internal Partitions : (Ferro-cement panels with weight of 0.375 KN/m²) Nodal
Load
Loads on perlins : (weight of roofing sheet 0.15 KN/m²) UDL
Floor Load for Handicap Toilet section : (Load per unit area = 25 x 0.1 = 2.5 KN/m²) Floor
load

3. Live Loads:
Live Loads on perlin : (Inaccessible roofs is 0.75 KN/m²) Member load
Live Load on RCC floor between two toilet blocks : (Total imposed load = 7.31 KN/m²) Floor load.
Wind Load:
Basic wind Speed, = 47 m/s ; Design wind pressure, =0.6X47²/1000=1.32 KN/m²
Earthquake loads :
Z = zone factor= 0.16 (Since zone III) I = Importance factor= 1, under the category of other building;
R = response reduction factor= 5, steel moment resisting frame
Assuming, medium soil sites, SS = 2 Damping ratio = 3% for steel structure (X and Z directions )
Combination Load Cases :
 1.5DL+1.5LL
 1.2DL+1.2LL±1.2WL
 1.5DL±1.5WL
 1.5DL±1.5SL
 0.9DL±1.5SL

4. Member Design: ( Boundary conditions: For Max. BM & Min. Axial load ; Max. Axial load
& Min. BM ; if necessary intermediate cases may be considered for design purpose)
Design of Column
Design of Beam
Design of Perlin
Design of Rafter
the sections SHS 50x50x3.6 mm is found out to be sufficient for every member mentioned
above. Hence it is used as structural steel for whole structure. Total structural steel
take off- 3.2 ton.
Connection: single V butt-weld with 3 mm weld-size for the whole structure.
Base-plate: size 130x130x8mm for all footings
Footing Sizes: i) 450 X 450X150 mm (8 nos. Footings)
ii) 300x300x150 mm (52 nos. Footings)
precast footings and slabs are to be used.
Cost Estimation: total estimated cost of building(including sanitary & plumbing fixtures
and electrical fixtures)- Rs. 7,48,653; total cost- Rs. 960/sq. Ft.

5.  Overview-
i. Connections are the glue that holds a steel structure together.
ii. Historically, most major structural failures have been due to some form of connection
failure.
Connections depend on:
Type of loading
Strength and stiffness
Economy
Difficulty or ease of erection

6. Types of connection-
Different types of fasteners available for making connections are rivets, bolts, pins, and
welds. Today, steel structures are constructed by bolting (ordinary or high-strength
bolts) or welding, or by a combination of both.
According to IS code, based on connection rigidity joints can be defined as-
i)Rigid- develop the full moment capacity of connecting members and retain the original
angle between the members under joint rotation.(i.e. Moment connection)
ii) simple- no moment transfers is assumed between the connecting parts and hence is
assumed as hinged (pinned).(i.e. Shear connection)
iii) Semi-rigid- may not have sufficient rigidity, to hold the original angles between the
members and develop less than full moment capacity of the connected members.
Welded connection Bolted connection
Advantages:
• Eliminates need for punching or drilling.
• Simplifies complicated joints.
Disadvantages:
• Greater level of skill required
for welding than bolting
• More expensive than bolting.
• Weld inspection is required and is
expensive
Advantages:
• Easy method of connecting members on the site.
• Field-bolting is cheaper than field-welding.
Disadvantages:
• Requires drilling or punching through all plies.

7.  Shear Connections:-
 Shear connections are the most prevalent type of connections in a steel frame
building.
 Shear connections are called simple connections – Since they are assumed not to
transfer bending moment, thus allowing end rotation of the member.
 Shear connections may be made to the web of the supported member while the
flanges remain unconnected.(except the seat-angle connection)
Shear Connections transfer load from beam web to column flange. No moment transfer occurs since the flanges
are free to rotate
 There are various types of Shear connections found in steel structures. These are -
i)Seat Angle connection
ii)Web angle connection
iii)Stiffened seat angle connection
iv)Cleat-plate connection, etc.
Designs of these connections are discussed in the training report thoroughly.

8.  Moment Connections:-
 Moment connections are also called rigid connections.
 Moment connections carry a portion or the full moment capacity of the supported
member thus preventing any end-rotation of the member.
 Moment connections are typically designed to also carry the shear component of the
load.
 Relative rotation between the supporting and supported members is negligible.
 The flanges of the supported member are attached to either a connection element or
directly to the supporting member.
 The types of moment resisting connections discussed in the report are-
a) End-plate connection.
b) Welded moment resisting connection.
 The detailing of connection should be simple and be based on repetitive use of
standard practices to facilitate ease of fabrication and erection, thus acquire speed
and economy to the project.
 In reality, all connections will be semi-rigid. However, for convenience we assume
some of them as rigid (Moment connection ; joint rotation<10%) and some as
hinged (Shear connections ; joint rotation>90%).

9. The types of structural members which is generally used, are-
1. Tension Member
2. Compression Member
3. Beam
4. Beam-Column
Tension Member :
A structural member subjected to two pulling (tensile) forces
applied at its end is called a tension member.
Check for Tension Member:
1. Net Section Fracture.
2. Gross Section Yielding.
3. Block shear Failure.
Compression Member:
A compression is a structural member which is straight and subjected to two equal and
opposite compressive forces applied at its ends.
Possible failure modes:
 Local buckling.
 Squashing.
 Overall flexural Buckling.
 Torsional and Flexural- Torsional Buckling.

10. Beams:
A structural member subjected to transverse load (loads perpendicular to its longitudinal
axis) is called a beam.
Types of beams:
 Laterally supported Beams.
 Laterally unsupported Beams.
Beam-Columns:
Most columns are subjected to bending in addition to the axial load. Considerable
care should be taken in a practical situation to load a column under axial load only.
When significant bending is present in addition to the axial load in the member, is
termed as Beam-Column.