Week 3 Challenge

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

The primary load cases to be considered for design are

• Dead load
• Live load
• Wind load
• Seismic load

2. What is One – Way slab?

In one way slab the ratio of longer span to the shorter span is greater than two.

Ly/Lx > 2

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

For structural steel the unit weight is 7840 kg/m3

For soil the unit weight is 18 kN/m3

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

Circular

Rectangle

Trapezoidal section

Tee section

Tapered section etc.

5. Define Primary Beams?

The beams that connecting columns for transforming loads of a structure directly to the columns are known as primary beams. They are generally simply supported structures. Primary beams depth is always greater than secondary beams.

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

The factors and parameters that influence the design pressure are

• K1= probability factor (risk coefficient)
• K2= terrain, height, and structure size.
• K3= topography factor
• Pz= design wind pressure

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

The load is first transferred on slab> beams(primary and secondary)> column> foundation.

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

In one way slab the ratio of longer span to the shorter span is greater than two.

Ly/Lx > 2

The reinforcement is provided along the longer span.

In two way slab the ratio of longer span to the shorter span is less or equal than two.

Ly/Lx <= 2

Reinforcement is provided on both the sides.

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

The beams which are connecting to the primary beams for transferring the loads are known as secondary beams. Secondary beams are provided to provide support and reduce the deflection.

3. Mention the Primary load cases.
   a. State the Indian Standards for each load case

• Dead load – IS 875 part 1
• Live load – IS 875 part 2
• Wind load – IS 875 part 3
• Seismic load – IS 1893

1. Detail the parameters of each load case

- selfweight

- member load

- concentrated load

- floor load

- plate loads etc

1. Brief each load case

- a load case can be of different types like dead load, live load, seismic load etc which can be applied on the member. Furthermore this load case can be defined as point load, udl, etc.

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

• Go to property section
• Select define.
• Select rectangular and define yz and zd values.
• And assign it to the member.
• To add support goto support.
• Select create.
• Choose the required pinned, fixed,etc support.
• Assign it to the model.

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

• Create a simple 5,5,5 model.
• 
• Select the beam through which secondary beam is to be attached.
• Right click>insert node select mid point or particular distance.
• 
• Similarly do it on the opposite side.
• Add the beam through the nodes.
• 
• Since it is secondary beams we need to release moment.
• Go to specification select beam and edit to release the Fx and Mz.
• 
• Assign it to the secondary beam.
• 

Aim- To calculate the wind pressure for the given building.

Procedure-

• Given data –

1. Building Dimension : 20m x 30m x 20m height RCC
   b. Building usage : Hospital block in city centre
   c. Location : Darjeeling

• Design wind speed Vz= Vb.k1.k2.k3
• Vb wind speed = 47 m/sec as per annex in IS 875 part 3.
• K1 risk coefficient = 1.07 as it is hospital building (as per table 1)
• K2 = 1.05 (table 2 category 2 class b)
• K3 = 1
• Therefore, Vz= 47x1.07x1.05x1 = 52.80 m/sec
• Now, design wind pressure Pz = 0.6(Vz)^2
• Pz= 0.6(52.80)^2
• Pz= 1672 N/m2

Result –

• The wind pressure for the given building is 1672 N/m2

Aim – To calculate the dead load and live load for the given building as IS refernces.

Procedure-

• 20m in length and 30m in width and 20 m in height.
• Total 5 floors of 3.5m.
• Dead load = 5 kN/m2
• Super imposed dead laod = 4kN/m2
• Live loads = 3kN/m2
• Live loads in corridors =4kN/m2

Results –

Loads are applied in sttad.pro and results are obtained.