Tutorial Chap 2 Complete Version

8/18/2019 Tutorial Chap 2 Complete Version

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WORK OOK

hallow foundations

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1 page

Define the following terms:

(a) Foundation;

(b) Base of the foundation;

(c) Embedment depth;

(d) Shallow foundation;(e) Ultimate bearing

capacity;

(f) Allowable bearing

capacity;

(g) Factor of safety.

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2 page

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3 page

What are the ultimate net

bearing capacity and the

allowable bearing capacity

of shallow footings? and

How do I determine theallowablebearing capacity

for shallow footings?

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4 page

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5 page

What are the assumptions

made in bearing capacity

analyses?

What soil parametersare

needed to calculate itsbearing capacity?

What effects do

groundwater and eccentric

loads have on bearing

capacity?

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6 page

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7 page

What are the assumptions

made in the derivation of

Terzhagi’s bearing

capacity theory?

Write the equation for theultimate bearing capacity

in local shear is

determined?

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8 page

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9 page

Differentiate between the

general shearfailure and

the local shear failure. How

the ultimate bearing

capacity in local shear isdetermined?

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10 page

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11 page

Discuss the effect of water

table on the bearing

capacity of thesoil.

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13 page

Discuss Meyerhof’s

bearing capacity theory.

How does it differ from

Terzhagi’s theory.

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14 page

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15 page

To obtain a higher bearing

capacity, either width of

the footing could be

increased or the depth of

foundation can beincreased. Discuss

critically the relative merits

and demerits.

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16 page

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17 page

Discuss the various factors

that affect the bearing

capacity of a shallow

footing. Write brief critical

notes on settlement of foundations. How do you

ascertain whether a

foundation soil is likely to

fail in local shear or in

general shear?

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18 page

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19 page

Discuss the various types

of foundations and their

selection with respect to

differentsituations.

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20 page

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21 page

Discuss the effect of

shape on the bearing

capacity. Differentiate

between safe bearing

capacity and allowable soilpressure.

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22 page

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23 page

Bring out clearly the effect

of ground water table on

the safe bearing capacity.

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24 page

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25 page

Describe the procedure of

determining the safe

bearing capacity based on

the standard penetration

test.

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26 page

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27 page

Explain the recommended

constructionpractices to

avoid detrimental

differential settlement in

large structures.

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28 page

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29 page

What is meant by bearing

capacity of soil? How will

you determine it in the

field? Describe the

procedure bringing out itslimitations.

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30 page

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31 page

Write brief critical notes

on:

(i) Standard Penetration

test

(ii) General shear failureand local shear failure of

shallow foundations.

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32 page

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33 page

Give the algebraic

equations showing the

variation of safe bearing

capacity of soil (for clay

and sand to be givenseparately) inshallow

foundation with:

(i) depth of foundation; (ii)

width of foundation; and

(iii) position of water table.

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34 page

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35 page

For the following cases,

determine the allowable

gross vertical load-bearing

capacity of the foundation.

Use Terzaghi’s equationand assume general shear

failure in soil. Use FS =

4.00.

Part B

(m)Df

(m) φ’

(a) 1.22 0.91 25

(b) 2 1 30

(c) 3 2 30

Part c ’(kN/m2)

γ (kN/m3)

(a) 28.75 17.29

(b) 0 17

(c) 0 16.5

Use continuous type for (a)

and (b), and square typefor (c).

(Answer: (a): 252.6 kN/m2;

(b) 176.8 kN/m2; (c) 280

kN/m2)

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36 page

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37 page

A square column

foundation has to carry a

gross allowable load of

1805 kN (FS = 3.0). Given:

D f = 1.5 m, γ = 15.9kN/m3, φ’ = 34°, and c ’ =

0. Use Terzaghi’s equation

to determine the size of

the foundation (B ).

Assume general

shear failure.

(Answer:B = 2 m)

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38 page

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39 page

Use the general bearing

capacity equation to solve

C1 question.

(Answer: (a): 267.6 kN/m2;

(b) 184.7 kN/m2;(c) 368.8 kN/m2)

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40 page

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41 page

The applied load on a

shallow square foundation

makes an angle of with the

vertical. Given:B = 1.83

m,D f = 0.9 m,γ

= 18.08kN/m3, φ’ = 25°, and c ’ =

23.96 kN/m3. Use FS =

4.0 anddetermine the

gross allowable load. Use

Meyerhof’s method.

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42 page

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43 page

A column foundation,

showed below, is in plan.

Given:B = 3 m, L = 2 m,

D f = 1.5 m,D 1 = 1 m,D 2 =

0.5 m, φ’ = 25°, and c ’ =70 kN/m3. γ 1 = 17 kN/m3,

γ 2 = 19.5 kN/m3. Use FS

= 3.0 and determine the

net allowable load the

foundation could carry.

Use Meyerhof’s method.(Answer: 5760 kN)

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44 page

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45 page

For a square foundation

that isB xB in plan,

vertical gross allowable

load,Q all = 3330 kN, D f =

2 m,γ

= 16.5 kN/m3

, φ’ =30°, andc ’ = 0 kN/m3, FS

= 4.0. Determine the size

of the foundation. Use

Meyerhof’s method.

(Answer:B ≈ 3 m)

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46 page

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47 page

An eccentrically loaded

foundation is shown in

figure down below. UseFS

of 4 and determine the

maximum allowable loadthat the foundation can

carry. Use Meyerhof’s

effective

area method.

(Answer: 377.8 kN)

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48 page

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49 page

Repeat C7 using Prakash

and Saran’s method.

(Answer: 287.37 kN)

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50 page

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51 page

Asquare footing is shown

in figure down below. Use

FS = 6 and determine the

size of the footing. Use

Prakash and Saran theory.

(Answer: q u (eccentric )=

936.47 kN/m2,Q u = 1066

kN/m)

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52 page

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53 page

Determine the ultimate

bearing capacity of a

square footing of size 1.2

m if the depth of

foundation is 1 m. Takec ’= 25 kN/m2, γ = 18 kN/m3

and c = 15 kN/m2.

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54 page

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55 page

A circular foundation is of

2.4 m diameter. If the

depth of foundation is 1 m,

determine the net

allowable load. Takeγ =

19 kN/m3, c' = 30kN/m2,

' = 15° and factor of

safety as 3.0. Use

Terzaghi's equation and

assume local shear failure.

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56 page

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57 page

A square column

foundation has to carry a

gross allowable load of

1805 kN (FS = 3.0). Given:

D f = 1.5 m, γ = 15.9kN/m3, φ’ = 34°, and c ’ =

0. Use Terzaghi’s equation

to determine the size of

the foundation (B ).

Assume general

shear failure.

(Answer:B = 2 m)

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58 page

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59 page

A square footing with a

size of 8 ft by 8 ft is to

carry a total load of 40

kips. The depth of the

footing is 5 ftbelow theground surface, and

groundwater is located at

the ground surface. The

subsoil consists of a

uniform deposit of

soft clay, the cohesion of

which is 500 lb/ft2. The

soil’s unit weight is

110 lb/ft3. Compute the

factor of safety against

bearing capacity failure.

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60 page

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61 page

A square footing 0.3 m by

0.3 m is placed on the

surface of a dense

cohesionless sand (unit

weight 18.2 kN/m3

) andsubjected to a load test. If

thefooting fails at a load of

13.8 kN, what is the value

of for the sand?

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62 page

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63 page

A load test is performed

on a 0.3-m by 0.3-m

square footing on a dense

cohesionlesssand (unit

weight 18.0 kN/m3

). Thefooting’s base is located

0.6 m below the ground

surface. If the footing fails

at a load of 82 kN, what is

the failure load per unit

area of the base of asquare footing 2.0 m by

2.0 mloaded with its base

at the samedepth in the

same materials?

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64 page

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65 page

A square footing 2 m by 2

m is to be constructed

1.22 m below the ground

surface, as shown in

figurebelow. Thegroundwater table is

located 1.82 mbelow the

ground surface. The

subsoil consists of a

uniform, medium dense,

cohesionless soil with thefollowing properties:Unit

weight of soil = 18.53

kN/m3; φ = 32°; c = 0 kPa.

Determine the foundation

soil’s allowable bearing

capacity if a factor of

safety of 3 is used.

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66 page

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67 page

A square footing is to be

constructed on a uniform

thick deposit of clay with

anunconfined

compressive strength of 3kips/ft2. The footing will be

located5 ft below the

ground surface and is

designed to carry a total

load of 300 kips. The unit

weight of the supporting

soil is 128 lb/ft3. No

groundwater was

encounteredduring soil

exploration. Considering

general shear, determine

the square footing

dimension, using a factor

of safety of 3.

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69 page

A proposed square footing

carryinga total load of 500

kips is to be constructed

on a uniform thick deposit

of dense cohesionless soil.The soil’s unitweight is

135 lb/ft3, and its angle of

internal friction is38°. The

depth of thefooting is to

be 5 ft. Determine the

dimension of this

proposed footing, using

a factor of safety of 3.

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71 page

A wall footing is to be

constructed on a uniform

deposit of stiff clay, as

shownin figure. The

footing is to support a wallthat imposes 130 kN/m of

wall length. Determine the

required width of the

footing if a factor of safety

of 3 is used.

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72 page

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73 page

Compute and draw soil

pressure diagrams for the

footing shown infigure for

P = 70kips and H = 20

kips.

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74 page

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75 page

Compute and draw soil

pressure diagrams for the

footing shown in figure for

P = 70 kips and H =10

kips.

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76 page

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77 page

Considering general shear,

compute the safetyfactor

against a bearing capacity

failure for each of the two

loadings in Problem 9–14if the bearing soil is

cohesionless, φ = 30°; γ =

110 lb/ft3; and c = 0 kPa.

groundwater is 10 ft below

the base of the footing

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79 page


compute the safety factor




cohesive, φ =0°; γ = 110

lb/ft3; and c =3000lb/ft2.

groundwater is 10 ft below

the base of the footing

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failurefor each of the two


cohesive, φ = 0°; γ = 110

lb/ft3; and c = 3000 lb/ft2.

groundwater is located at

the ground surface.

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cohesionless, φ =30°; γ =

110 lb/ft3; and c =0 lb/ft2.

groundwateris located at

the ground surface.

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85 page

For the footing shown in

figure, the vertical load,

including the column

load, surcharge weight,

and weight of the footing,is 120 kips. The horizontal

load is 10 kips, and a

moment of 50 ft-kips

(clockwise) is also

imposed on the

foundation. 1. Computethe soil contact pressure

and draw the soil contact

pressure diagram. 2.

Compute the shear on

section a–a (Figure 9–47).

3. Compute the moment

on section a–a (Figure 9–

47). 4. Compute the factor

of safety against

overturning. 5. Compute

the factor of safety against

sliding if the coefficient of

friction between the soil

and the base of the footing

is 0.60.

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Tutorial Chap 2 Complete Version

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