7/27/2019 Design of RC Building - Exercise

1/6

Design of Concrete Buildings.

7/27/2019 Design of RC Building - Exercise

2/6

Reinforced concrete.

Requirements.

1. All work is to be in A4 format.

2. Drawings must not be larger than A3 in size and should be bound into yourfinished document in such away that they can be readily folded out.3. Include code references where applicable.4. Design in accordance with EC2.5. Note any assumptions made.

Brief.

An office building is shown in plan (Figures 1 and 2) and section (Section AA). Yourcompany is to undertake a reinforced concrete design using EC2 of the building.

Design :

1. Collector beam (TUDVW) at ground floor level and located above PQRS.(See Sect AA). This design should include for robustness effects . i.e. Youshould consider if this beam is a key element and design it accordingly whichmay in some instances mean surrounding beams and columns needadditional consideration. Surrounding elements should not be designed indetail.

2. Part CD of a typical column which passes from roof to gd. floor. (Sect AA)

Combined office and storage.

A developer requires offices together with integral storage areas. The building isrectangular in shape and the sub-basement and basement (Section AA) are to beused for storage. Above that, namely, ground, first and second floor are offices. Upto ground floor there are four rows of columns, two along the external edge to thebuilding and two internal rows along the length of the building. Above the storagearea i.e from ground floor to roof level, the client requires only one line of internalcolumns. The roof comprises a false mansard which hides the plant for the building.Access to the storage area is via internal lifts as indicated in Figure 1 and 2. Thebuilding will be constructed on a slope as shown in section AA and the earth retainingwall EF (Sect AA) and its foundation have been designed by others. The building isto be clad in cavity masonry walls which comprise 103mm thick brick outer skin(density 1800kg/m 3) and 190mm thick block inner skin (density 1400kg/m 3). Initial

estimates indicate the slabs in the storage area will be 150mm thick whilst thosesupporting office loading may need to be 200mm. Assume all slabs have supportingbeams. In the storage area it is desired the supporting beams be 300 wide x 400mmdeep. The beam includes 150mm of slab and so has a down stand of 250mm. Theoffice loading and span are larger than in the storage zone and 350 wide x 600mmdeep beams should suffice. Again the slab will reduce the actual down stand of thebeam to 400 mm. Collector beams at ground floor are required to transfer the officeloads to the lower columns. These beams may need to be widened but the client isinsistent on maintaining head clearances and the building may not be any taller.

Imposed loadsOffice loading 5.0kN/m 2. Storage 3.0kN/m 2. Roof : Plant - 7.5kN/m 2 and

0.75kN/m2

snow load. Consider the roof as a flat reinforced concrete slab which

7/27/2019 Design of RC Building - Exercise

3/6

carries its self weight and the two variable loads as uniformly distributed over thewhole area. Ignore additional loading from the mansard.

7/27/2019 Design of RC Building - Exercise

4/6

Dead loads.False ceiling and services in offices 1.0kN/m 2.

Foundations.The ground below is able to sustain a pressure of 300kN/m 2 without appreciabledeflection.

Material properties.Concrete strength - C40/50N/mm 2. Reinforcement strength - 500N/mm 2.

Slab A5200

5200

5200

PQ

R S

Liftshaft

A

4800 4800 4800400400400

400

A

520052005200

5200

5200

5200

5200

5200

Figure 1.Layout of building at basement storage level

(Not to scale)

Possible shearwall locations

7/27/2019 Design of RC Building - Exercise

5/6

5200

5200

5200

5200

Slab B

400

Liftshaft

A

7400 7400 400400

A

78007800

5200

5200

5200

5200

Figure 2.Layout of building at Office level

(Not to scale)

7/27/2019 Design of RC Building - Exercise

6/6

E

F Collectorbeam

PQ R S

WVU

A

B

C

D

2nd floor

1st floor

Ground floor

Basement level

Subbasement level

Storage

Officeaccommodation

500

2 0 0 0

4 0 0 0

4 0 0 0

4 0 0 0

3 0 0 0

3 0 0 0

Plant inroof void

Office beams

Storagearea beams

T

SECTION AA(Not to scale)