Week 12 Challenge

1)

AIM:

We need to designisolated footing design using STAAD Foundation for the given data-

size of column: 300mm x 450mm

Axial load = 1500 KN

Moment Mu = 150 KNm(Reversible)

SBC OF soil=200 KN/m^2 at a depth of 1m from the ground level

grade of concrete = m25

grade of steel = Fe415

design is also to be validated through hand/manual calculation

procedure:

Open the staad Foundation and click on General Design to start the design of combined footing.

A new working window will appear.

Now ,we will enter the support coordinates for the isolated footing .let the footing coordinates be at origin.

To place the footing ,go to column position and enter the coordinates as (0,0,0) as shown in below figure.

now ,we will give the column dimensions as given 300 mm x 450mm as shown in below figure.

Now,we will add the load, for that go to load and factors option on the main navigator panel.

Choose the create new load option to create the load cases for dead load and live load ,also add the given load condition of Fy = -1500kn and Mx =150 KNm as shown in figure.

Now we will generate the load combination cases as per indian code.

Now we will create the job info to analyse and design the footing

now ,a job been created for the isolated footing as shown in below figure.

Now we will fill the data for the design of the footing is given.

safe bearing capacity= 200 KNm2 at depth of 1.0 m from ground level.

grade of concrete = M25

GRADE OF STEEL = Fe415

now after entering the data ,click on the design option to analyse and design the footing as shown in below figure.

click on yes to start the design process

design of footing can be done succesfully

2)

AIM:

We need to design comibned footing for given data:

1. Two column C1 & C2 having size 400mm x 400 mm & 300 mm x 500 mm respectively.
2. Service load on C1 is 800kN & on C2 IS 1200 kn
3. Column C1 is flushed with property line
4. C/C distance between columns = 3.0 m
5. SBC of soi = 200 Kn/M2 at a depth of 1.5 m
6. Grade of conrete = M20
7. Steel grade = Fe 415

Procedure:

• Open the staad foundation software ,click on general mode.
• Now we wil enter the support Coordinates to place the columns.
• Column C1 & C2 are placed at a distance of 3m and their dimensions are 400mm x 400mm & 300 mm x 500 mm respectively as shown in below figure.

Two primary load cases as Live load as per given input have been created as shown in below figure.

Assigning load of 800 KN on C1 & 1200 KN on C2 as shown in below figure.

NOW GENERATE LOAD COMBINATION AS SHOWN IN FIGURE.

AFTER assigning the load combination , we will create the job setup

keep the following points ie design code should be indian ,units should be in SI Unit.

edit current job under job set up then create strip footing after selecting both columns as shown in below figure

under the footing we have to assign the following parameters:

• unit weight of concrete
• Max and Min .spacing of bar
• strengthof concrete = M20
• Yield strength of steel = 415 Nmm2
• Min & max bar size
• clear cover pedestrial & footing
• unit weight and safe bearing capacity (SBC) of soil
• Depth of soil above footing
• MIN % of contact area for service load
• Footing geometrysuch as overhang, min width ,max length ,width,max min thickness, length and thickness increament etc. as shown in below figure.

now ,we wil click on design command to obtain the design of the combined footing

RESULT:

DESIGN IS SUCCESFULL WITH FOOTING DIMENSION AS 9.2 M X 7.5 M AND THICKNESS 0.5 M

C-1 COLUMN IS FLUSHED WITH PROPERTY LINE THAT IS LEFT OVER HANG IS 0

MAIN STEEL TOP 8MM DIA BAR@50MM C/C

MAIN STEEL BOTTOM 8MM DIA BAR @ 55 MM C/C

SECONDARY STEEL BOTTOM 12MM DIA @60 MMC/C AND TOP 8 MM DIA 90 MM C/C

DESIGN IS SAFE AGAINST SLIDING ,SINGLE SHEAR PUNCHING SHEAR ,SOIL PRESUURE OVERTURNING

HENCE DESIGN OF CPMBINED FOOTING HAS BEEEN DONE SUCCESFULLY