Challenge

Project 1

SSruthi Krishnan2 Jan 2023

Aim: To Model & Design a Proposed Coil Centre, Chennai using STAAD. Pro for following input from Client

Design only a Main Frame with Lean (Grid 2) & Gable Frame without Lean (Grid 15)

Introduction:

The portal frame structure is mainly composed of steel columns and roof beams, and the frame is a plane loading system. To ensure longitudinal stability, which column bracing and roof bracing will arrange.

The portal frame divided into several forms, 1. Typical portal steel frame. 2. Steel frame with the crane. 3. Steel frame with mezzanine structure.

Bracing Structure

The portal frame, purlin Bracing system and the metal cladding rely on each other through reliable connection and support.

The main structure of the portal frame load-bearing structure divided into two types according to the kind of the rigid frame: the clear span structure without interior columns and the multi-span continuous structure with interior columns.According to the specific project, it can also be used in single and multiple slopes, as well as in different spans and heights.

The main functions of the bracing system are:

1) The strut beam transmits the longitudinal horizontal force.

2) The horizontal bracing resists the horizontal force transmitted between the columns and roof beams.

3)Flange Bracing use to keep the stability of the outer plane

4) All bracing systems, together with purlin or wall girt and portal frames, which form a space system, which ensures the overall function of the space of the structure, bear, and transfer horizontal loads, and ensure the stability and convenience during the installation.T

Purlin and Wall Girt

The main component types of purlins and wall girt are C-type or Z-type steel, and the size of the cross-section needs to determine through the load calculation. Compared with the Z-section, the mechanical properties of the C-section are quite different, C section steel connects to the portal frame bolted.

The different types of loads that are to be considered

Dead load
Live load
Wind load
Earthquake load

Dead Loads (D): The PIP Structural Design Criteria prescribes specific dead loads for pipe racks. Pipe racks and their foundations should be designed to support these loads applied on all available rack space, unless other criteria is provided by the client.

Structure dead load (Ds): The weight of materials forming the structure and all permanently attached appurtenances. This includes the weight of fire protection material, but does not include the weight of piping, cable trays, process equipment and vessels.

Operating dead load (Do): The operating dead load is the weight of piping, piping insulation, cable tray, process equipment and vessels plus their contents (fluid load). The piping and cable tray loads may be based on actual loads or approximated by using uniform loads.

Empty dead load (De): The empty weight of piping, piping insulation, cable tray, process equipment and vessels. When using approximate uniform loads, 60% of the operating dead load for piping levels is typically used. Engineering judgment should be used for cable tray levels.

Test dead load (Dt): The empty weight of the pipes plus the weight of the test medium.

Live load: Live load is one of the gravity load imposed by liquid or viscous materials in pipes during the operation along with which the human load is also added to it. Live load is defines as the load which is produced by the use and the occupancy of the structure thus not including any kind of construction or the environmental loads. Live load generally comes around the platform area, staircase and at the places where the access for the maintenance is provided.

Wind Load: Transverse wind load on structural members, piping, electrical trays, equipment, platforms, and ladders should be determined in accordance with project approved design code. Longitudinal wind should typically be applied to structural framing, cable tray vertical drop (if any), large dia pipes vertical drop (if any) and equipment only. The effects of longitudinal wind on piping and trays running parallel to the wind direction should be neglected.

Earthquake Loads: Earthquake loads in the vertical, transverse, and longitudinal directions should be determined in accordance with the project design criteria. Vertical, transverse, and longitudinal seismic forces generated by the pipes, raceways, supported equipment, and the pipe rack structure should be considered and should be based on their operating weights. Pipes must be evaluated for seismic loads under both full and empty conditions and then combined with the corresponding gravity loads.

Given :

Building Parameters
1	Building Width	30000.00 mm	Client	Out to Out of Steel
2	Width Module	Clear Span	Client
3	Building Length	140000.00 mm	Client	Center to Center of Steel Column
4	Building Height	11100.00 mm	Client	Clear Height from FFL
5	Roof Slope	1:10	Client
6	Column Base	Fixed Base	Assumed	To control Deflection
7	Bay Spacing (in mm) Main frame with Rafters	14@10000	Client	Center to Center of Steel Column
8	Roof Bracing	Diagonal Angle Bracing	Client
9	Wall Bracing	Portal Bracing and above Angle Bracing	Client	Up to 6.5m Portal Bracing
10	End Wall Typea`	Rigid Frame	Assumed

GENERAL PARAMETERS
Loads & Design
1	Dead Load	0.14 KN/m2	Assumed
2	Coll Load	0.15 KN/m2	Client	False ceiling load for Roof extension alone
3	Live Load	0.75 KN/m2	Code	IS 875 (Part 2) -2015

Sl.No	Parameter	Value		Data From	Remark
4	Wind Load	*Wind Speed*	180 KMPH	Code	IS 875 (Part 3) - 2015
		*K1 =*	1.00	Code	IS 875 (50 years of mean probable design life
		*K2 =*	0.94	Code	IS 875 (Terrain Category 3)
		*K3 =*	1.00	Code	IS 875 (Upwind slope is less than 3°)
		*K4 =*	1.15	Code	IS 875 (Cyclone Zone)
		*Building Condition*	Medium Permeability	Code	IS 875 (Part 3) - 2015
		*Wind co-efficients calculated as per*		Code	IS 875 (Part 3) - 2015
5	Seismic Zone	Zone III		Code	IS 1893-2015 (Part 4)
6	Loads applied as per	IS 875 - 2015		Client
7	Primary Member design	IS 800 : 2007		Client
8	Cold Form Design	AISI 2001		Assumed

Procedure:

Open STAAD and units for the loads and the distance are setup .

The coordinates are added in order to model the structure.

Beams are connected from node to node to frame a frame.

The supports like fixed or pinned are defined with the help of the support definition.

The end and the start moment for the bracings and the truss members are released so that they take up only the axial forces.

member properties are assigned to the beams

The L.L and D.L that are acting on the structure are added by defining the D.L and L.l cases.

The wind load and the EQ load are defined

Then the design load and EQ load are defined

Then the design parameters for the steel as well as concrete members are defined.

Structure is analysed and then checked for any failure members

Section view of the model

For main frame and gable frame

For area 1-30m width

Roof slope =1/10=0.1

Height of roof inn top level =1.5m

Add walls and add wall sheeting and roof sheeting

Go to properties and section database and add and assign section to the structure

3D view of the entire structure

Section view of one bay

Go to support and create support and add and assign support for fixed and pinned base.

Defining of the member property and support

Load calculation:

Wind load

Basic wing speed (Vb)=50m/s

Total length of the industrial building for area 1 = 140m

Width of the industrial building for area 1 = 30m

Height of the industrial building for area 1 = 11.1 m

Risk factor,K1=1(designed for 50 year life span of structure)(table 1 of IS 875part 3)

Terrain category in this project is category 3.

K2 for 7m height =0.94

K3 the topography factor as per IS code is 1

K4 the cyclone factor =115

Design wind speed (vz)=Vb*K1k2*k3*k4

=50*1*0.94*1*1.15

=54.05m/s

Deisgn wind intensity(Pz) = 0.6*(Vz^2)

=0.6*54.05^2

= 1.75KN/m^2

Wind load calculation with the internal pressure and succession

WL+X+CIP = 1.75*11.1+0.5-0.9=19.025KN/m

WL-X-CIP = 1.75*11.1-0.5-0.9=18.025kN/m

WL+Z+CIP=1.75*11.1+0.5-0.8=19.125kN/m

WL+Z-CIP=1.75*11.1-0.5-0.8=18.125KN/m

Seismic load

EQ+X

EQ-x

EQ+z

EQ-z

Go to laod combinations and add as per stength design and servicebility criteria

Go to edit combination load

Go to design and add parameters using IS 800:2007

After run analysis and check deflection and section safe results.

For Gable frame and gable frame

Go to STAAD and define nodes and beams

Go to translation assign bay

For gable frame we analysis and design for one frame

For area 1-30m width
Roof slope =1/10=0.1
Height of roof inn top level =1.5m
Add walls and add wall sheeting and roof sheeting