ASSIGNMENT 2 Weighting: 20% (200 marks out of 1000) Due date: 24 April 2017
A
B
A TYPICAL FLOOR PLAN
SECTION Z-Z
X
X
4500 4500 4500 4500 4500
22500
180
1500 1500 1500 Z
Z
3200
3200
X X
3200
2X
300
9600 180 0
600
C A
C
2 3 4 5 6 1
B
DESIGN BRIEF
The figures above show a typical floor plan and section elevation of a three-storied reinforced concrete office building to be constructed in Townsville. Drawing is not to scale. All units are in mm. This is a framed reinforced concrete building (to be cast monolithically) with the beams along the grids A, B and C supporting the RC floor at all levels. Beams along grids 1 and 6 are of 250 mm width x 600 mm deep support the brick walls and the slab. This beam and the brick wall on top are flushed with the outer surface of the column. Assume that the thickness of the floor slabs and the roof slab are the same and, are shown in the Table below. There are no beams along grids 2, 3, 4 and 5. Because of the space issues and to eliminate the differential settlement, combined footings are to be designed for the columns as appropriate. All columns are rigidly connected to the footings. Slope of the inaccessible roof (except for maintenance) can be ignored and can be considered as flat.
Because of the difference in elevation between the ground level where the building will be constructed and the adjacent area, a suitable retaining wall is to be designed to accommodate the step change. The retaining wall is parallel to grid 1 and is only on the left side of the building (not shown in fig.). The soil it will retain is only on one side, i.e. the side of the building. Because the wall is close to the building, assume that a part of the building load is to be carried by the retaining wall. In the absence of exact calculations, assume that the building loads up to Grid 3 will be carried by the retaining wall and this load can be considered as a surcharge acting on the retaining wall. The height of the wall is the difference between the GL of the building and the GL of the bottom level of the wall, which is provided. In reality, the calculation is more complicated, things are simplified for the assignment purpose. If you want to do precise calculation, proceed without any problem. Assume data not supplied, however, explain the reasons of the assumed values.
PROBLEM STATEMENT
1) Design the following structural elements for the strength and serviceability requirements and draw the reinforcement detailing clearly: a) Column C1 at the ground floor level. b) Combined footing for columns C1 and B1. Ensure that the soil pressure distribution below the footing is uniform. Assume B1 column has the same dimension as C1, however, calculate the loading on B1. Note: no need to design column B1.
2) Design a RC cantilever retaining wall for the stability and strength requirements for the height given in the Table above. Draw a sketch of the wall showing the forces acting on it. Neglect the effect of wind and seismic load (if any). The soil is clay deposit with the properties: 8c kPa, 19 ,30 o kN/m3. Note: a) Ignore the effect of wind load in design. b) Use approximate methods for the design forces and moments (based on codes) for appropriate load combinations. c) Ignore secondary effects. d) Mention all the relevant clauses of the code at the left/right margin throughout the design so that they can be checked.
DESIGN DATA Glass windows are of 1500x1800x10 mm, unit weight, = 2600 kg/m3. The brick masonry wall is 180 mm thick. Concrete characteristic strength, f'c = Y in MPa Yield strength of reinforcing steel, fy = 500 MPa. Density of RCC, = 2500 kg/m3. Allowable bearing capacity of soil qa = 300 kPa.
All design and detailing should be in accordance with AS3600 2009 and loading should be in accordance with AS1170.
X (mm)
Y (MPa)
Slab thickness (mm)
Beam sizes (along grids A & C) (mm)
Beam size (along grid B) (mm)
Height of the retaining wall (m)
4500 40 100 300 x 300 300 x 450 4
The report should contain one set of safe design for all structural elements showing all the necessary steps and all your trial designs should go in the Appendix in proper sequence. Marks will be given for systematic design with comments.
ASSESSMENT
Design Task Marking scheme 1) Design & detail of column C1 55 2) Design & detail of the combined footing for B1 & C1 70 3) Design the retaining wall 75 TOTAL 200