Week 3 Challenge

Week 3 Challenge.

Question 1:

1. State the primary load cases to be considered for design.

Answer:

• Dead Load
• Live load / Imposed load
• Wind load
• Earth Quake load

2. What is One – Way slab?

Answer:

• One-way slab
• The ratio of the longer span to the shorter span is greater than 2 is known as one-way slab.
• Where Ly/Lx is greater than 2

3. What is the value of unit weight of structural steel and soil?

Answer:

• The unit weight of structural steel and soil is given in IS 875 part 1
• The unit weight of soil is 18 KN/cub.m

4. Name few sections that can be defined using Properties tab in STAAD Pro.

Answer:

• Circular section
• Rectangular section
• Trapezoidal section
• Tee section
• General section
• Tapered I
• Tapered Tube.

5. Define Primary Beams.

Answer:

• Primary beams are the beam located at the exterior of the structural elements
• The beam cannot have much load on the exterior beams or primary beams.
• Secondary beam are laid on the primary beam.

Question 2:

1. State the factors and parameters that influence the design pressure intensity of a high-rise building.

Answer:

The Factors that influence the design pressure intensity of a high-rise building are;

• K1 = probability factor (risk co-efficient)
• K2 = Terrain, height and structure size
• K3 = Topography factor

Design wind pressure – The design wind pressure at any height above mean ground level shall be obtained by the following relationship b/w wind pressure & wind velocity

Pz = 0.6`Vz^2`

2. Mention the load transfer process of a Reinforced Concrete Building.

Answer:

The load transfer process of a reinforced concrete building is;

• Slab
• Secondary beam
• Primary beam
• Columns
• Foundation

Question 3:

1. Differentiate One-Way and Two way slabs. Elaborate each slab type.

Answer:

One-way slab:

• The ratio of the longer span to the shorter span is greater than 2 is known as one-way slab.
• Where Ly/Lx is greater than 2

Two-way slab:

• The ratio of the longer span to the shorter span is less than 2 is known as one-way slab.
• Where Ly/Lx is less than 2

2. Explain the concept of secondary beams with proper sketch.

Answer:

• Beam resting on the main beam or on the wall is called secondary beam.
• Secondary beam are the internal beam that are restrained on the primary beam.
• They are the simply supported beam.
• In secondary beam the moment is zero at the end of the beam.

3. Mention the Primary load cases.
a. State the Indian Standards for each load case
b. Detail the parameters of each load case
c. Brief each load case

Answer:

A). State the Indian standards for each load cases:

• Dead Load = IS 875 par 1
• Live Load = IS 875 part 2
• Wind Load = IS 875 part 3
• Seismic Load = IS 13927

B). Detail the parameters of each load cases:

• The parameter of dead load are;

1. Unit weight
2. Volume of the section that may be rectangular section, circular section etc.,

• The parameter of live load are depend on the building type residential building, commercial building, industrial building, area type room, toilet room, corridor, roof, balcony etc.,

C). Brief each load cases:

• A load case is a combination of different types of loads with safety factors applied to them.
• A Structure is checked for strength and serviceability against all the load cases it is likely to experience during its lifetime.

4. Detail the steps involved in assigning Properties and Support to a model using STAAD Pro sequentially.

Answer:

• Go to Property section
• Click on define material
• Select the section, rectangular section, circular section etc.,
• Select the material type concrete, steel, aluminum
• For rectangular section enter YD & ZD in the column below
• Click add & close
• Select the material type & assign to the selected view.

For the Support;

• Click on the support
• Click on the create
• Select the type of support do we want to assign the section
• Click on add close.

5. Brief the steps to be followed to create and assign secondary beams in STAAD Pro

Answer:

• First create a simple model by using the node in staad pro
• Click on the screen beam option and create a beam in the direction of X & Z-axis
• Click on any primary beam in the section
• Right click and add new node in the beam section a node will be added
• Again click on the create beam.

PRACTICAL

1. Calculate the wind pressure for the given building
a. Building Dimension : 20m x 30m x 20m height RCC
b. Building usage : Hospital block in city centre
c. Location : Darjeeling.

Answer:

Wind Pressure, Pz = 0.6`Vz^2`

Wind speed at Darjelling location = 47 m/s

Probability factor for hospital for 100 yrs = 1.07 m/s

K1 = 1.07

K2 = 1.12 (Class A)

K3 = 1.0

Vz = 47 x 1.07 x 1.12 x 1

Vz = 56

Pz = 0.6`56^2`

= 1903.49

Pz = 1.9 KN

2. Calculate the Dead load and Live load for the above building with reference to IS standards ( assume suitable sections )

Answer:

Dead Load:

Dead Load of the section = Unit weight x volume of the section

Unit weight of concrete = 25 KN/m

Volume of the section = 0.5 x 0.23 x 1

= 0.115`m^3`

Therefore, Dead Load = 25 x 0.115 = 2.875 KN/m

Live Load:

a. Building Dimension : 20m x 30m x 20m height RCC
b. Building usage : Hospital block in city centre

RESULT:

• Wind Design & Wind Pressure is calculated Successfully.
• Dead Load & Live Load is calculated Successfully.