Tuesday, January 7, 2014

51+ MCQs of Geo-Technical and Foundation Engineering you must know

Foundation and geo-technical engineering is a very interesting and useful field of civil engineering. Like the name of the subject it plays a pivotal role in the success or failure of any structure. The portion upon which the load of building or super-structure rests is called a foundation and the lower part of the foundation is footing. The ultimate destiny of any load in the structure is the underneath supporting soil and the mean which we adopt for this transfer is footing.

Geo-technical and foundation engineering MCQS


 Why foundation is necessary? Well a common question but very simple answer could be, how will you stand if you don’t have feet? Obviously you will not be able to stand on your own load, thus to stand the loads of the building along with the live load of persons, machinery etc, footing is needed secondly if we place the column or wall directly over the footing the wall or column will sink easily due to high contact pressure.

Contact pressure is decreased by increasing surface area and this is where the footing plays its role to distribute the load over a larger or wider area. Here is this post I will not be discussing about the whole subject of course because it is out of the scope of the post, below are simple, useful and important questions along with answers which all geo-tech and civil engineers must know;


In SPT, The test uses a thick-walled sample tube, with an outside diameter
A    45 mm
B    50 mm
C    55 mm
D    53 mm
Correct Choice    □ B


2) In SPT, we terminate the test for no of blows which are obtained to drive the required 12-in
    A    70 blows
    B    80 blows
    C    90 blows
    D    100blows
Correct Choice    □ D


3) Gravels are ……………. Lines more previous than clays
    A    10, 000
    B    50, 000
    C    1 million
    D    30,000
Correct Choice    □ C


4)     The design of  ……………………………………………… dams vary much based upon the permeability of soils used:
    A    Concrete dam
    B    Earth Dam
    C    Coffee Dam
    D    Steel Dam
Correct Choice    □ B


5) Units for K (co-efficient of  permeability ) are :
    A        m^3/sec
    B        〖cm〗^2/sec 
    C        m/〖sec〗^2
    D       cm/sec
Correct Choice    □ D


6) Major principle stress is given by  ð1 = 40 KN/m^2   and Minor principle stress is given by ð3 = 20 KN/m^2  , share strength is givin by :
Z = (ð1-ð3)/2
    A    20 KN/m^2
    B    40 KN/m^2
    C    60 KN/m^2
    D    10 KN/m^2
Correct Choice    □ D


7)Unconfined compressive strength is given by 120 KN/m^2  , what  will be the unconfined shear strength or cohesion?
                    C=qu/2                                            
    A    60  KN/m^2
    B    80  KN/m^2
    C    99  KN/( m^2 )
    D    120 KN/m^2
Correct Choice    □ A


8) According to ASTM D2573, in Field Vane Shear test with the vane in position, apply the torque to the vane at a rate which should not exceed ______.
A    1 °/sec
B    4° /sec
C    1 °/min
D    4 °/min
Correct Choice    □ A


9) According to ASTM D2573, Field Vane Shear test in case of very soft clays the time to failure may be as much as ________.
    A    3 – 5 min
    B    5 – 8 min
    C    10 – 15 min
    D    15 – 18 min
Correct Choice    □ C


10) A structure is erected on impervious clay whose thickness is 12m. Drainage is possible both at upper and lower surfaces. Coefficient of consolidation is 0.015 cm2 per minute.For attaining 50% consolidation with a time factor of 0.20, the number of days required??
    A    3123
    B    3333
    C    3233
    D    3313
Correct Choice    □ B


11) A Standard proctor compaction test performed on sample of crushed limestone(Gs=2.70) obtained a maximum dry unit weight of 90 Pcf at OMC.A field compacted sample showed a moisture of 28% and unit weight of 103.7 pcf.Find the relative compaction (RC)=?
    A    70%
    B    80%
    C    90%
    D    100%
Correct Choice    □ C


12)The moist unit weight of a soils is 16.5 KN/m3.Given that the w=15% and Gs=2.70 , Find the porocity n=?
    A    46%
    B    48%
    C    50%
    D    52%
Correct Choice    □ A


13)Number of blows N=32, Find allowable bearing capacity in KPa =? using B<4 by="" ft="" method.="" meyerhof="" p="" s="">
    A    14
    B    12
    C    10
    D    8
Correct Choice    □ D


14) The permissible settlement of a shallow foundation  on a rock evaluation of safe bearing pressure from a plate load test is taken as ………………
    A    12mm
    B    25mm
    C    40mm
    D    50mm
Correct Choice    □ D


15) In loose coarse gravel, the split spoon (SPT)  tends to slide into the ………………. and ………………..resistance is observed.
    A    large voids, low penetration                        
    B    small voids, large penetration
    C    small voids, small penetration                     
    D    large voids, large penetration
Correct Choice    □ A


16)Expression for  “Q allowable” using Mehyerhoff s equation  in FPS system for B< 4ft  is
    A    N/4 Kd                                               
    B    N/2.5 Kd
    C    N/8 Kd
    D    12NKd
Correct Choice    □A


17)The contact pressure of flexible footing on non-cohesive soils is:
    A    Uniform throughout.
    B    More in the centre than at edges.
    C    Less at the centre than at edges.
    D    Not on the footing.
Correct Choice    □ B


18)In case of lateral loads or moments, the foundation should also be checked to be safe against sliding and overturning The FOS shall not be less than
    A    1.75 against sliding
    B    2.0 against overturning.
    C    3.0 for wind seismic
    D    a,b both
Correct Choice    □D


19)For Strip Spread Footings
- Length (L) to width (B) ratio,
    A    L/B < 10
    B    L/B ≥ 10
    C    L=B
    D     B is very small
Correct Choice    □ B


20) In shallow foundation, the contribution of side shear stress is …….?
    A    Maximum
    B    Minimum
    C    Negligible
    D    Average
Correct Choice    □ C


21) Which of the following statement is correct?
    A    The settlement of rigid footing on cohesion less soil is uniform throughout.
    B    The settlement of flexible footing on cohesive soil is less in the center than at the edges.
    C    The settlement of flexible footing on cohesion less soil is more in the center than at the edges.
    D    The settlement of rigid footing on cohesive soil is uniform throughout.
Correct Choice    □A


22) In shallow foundation if Rw = 1&Rw'  = 0.5 than where the water table lies:
    A    At base of footing  
    B    Below the footing
    C    At the ground level
    D    Any where at the mid
Correct Choice    □ A


23) If Qu = Qs+ Q b where Qs = Shaft resistance,Qb = Bearing resistance
And Qs is greater than Qb the pile is classified as

    a.    skin friction pile
    b.     End bearing pile
    c.    Cast in –situ pile
    d.     Driven pile
Correct Choice    □ A 


24) Which type of pile is used near sea to protect harbor just by absorbing the effect of floating objects
    a.      Anchor piles
    b.      Fender piles
    c.     Batter piles
    d.     Sheet piles  
Correct Choice    □B


25) For over consolidated soil the value of OCR is
    a.    equal to one
    b.     greater than one
    c.    can’t be measured
    d.    smaller than one
Correct Choice    □ B


26) Find the approximately No. of Standard Penetration’s (N)  by using Cone Penetration Resistance (qc) of 20 MPa, if ‘k’ factor is 0.3 and the soil is silty sand; (qc=kN)
    A    66
    B    77
    C    88
    D    99
Correct Choice    □A


27) Max. Overburden pressure (q’) at the tip of the pile can be calculated by;
    A     2γDf
    B     (1/2)γDf
    C     γDf
    D    (3/2) γDf
Correct Choice    □C


28) If the ultimate load carrying capacity(Qu) of certain pile is 500 kips, the shaft resistance (Qs) is 415kips and bearing resistance (Qb) is 40 kips then comment about the nature of the pile;
    A    Cast in situ pile
    B    Driven Pile
    C    Sheet pile
    D    None
Correct Choice    □ B


29) If the shaft resistance Qs = 300,000 lbs  and bearing resistance Qb is equal to 30,000 lbs then ultimate load carrying capacity Qu is equal to;
     A    300 kips
    B    330 kips
    C    310 kips
    D    None
Correct Choice    □ B


30) For clayey soil “Fs” will be equal to
 “where Fs is pile unit surface skin friction”
    A αc+qk tanδ
    B qk tanδ
    C αc
    D none of above  
Correct Choice    □C


31) if a soil is fully saturated having void ratio 0.67 what wil be the porosity?

A 40%
B 42%
C 44%
D 46%
Correct Choice    □ A


32) D60 is 9.6mm,D30 is 2mm and D10 is 0.16mm what is value of Cc (coefficient of curvature)?
a)2.4
b)2.5
c)2.6
d)2.7
Correct Choice    □ C


33)  For construction of an embankment, if max dry unit wt is 120.5lb/ft3, optimum moisture content 13%, dry density 118lb/ft3, actual field moisture content 12.9%, the relative compaction will be?

A-94%

B-96%

C-98%

D-100%
Correct Choice    □ C


34)The total weight to be arranged for a pile load test in compression should be:
    A    equal to the anticipated maximum test load
    B     at least 100% greater than the anticipated maximum test load
    C     at least 50% greater than the anticipated maximum test load
    D     at least 10% greater than the anticipated maximum test load
Correct Choice    □ D


35) A plate (0.3 x 0.3 m plate size) load test performed on clayey soil gives ultimate settlement of 2.2 mm. The ultimate settlement of 2 x 2 m isolated footing will be:
    A    18.65 mm
    B     12.50 mm
    C     14.67 mm
    D    16.39 mm
Correct Choice    □C


36) Usually for driven piles, the value of lateral earth pressure co-efficient “K” is
    A    ≥1
    B    ≤1
    C    1.75
    D    zero   
Correct Choice    □ A


37) For very hard-clay ,value of cohesion reduction factor “α” is
    A    1
    B    0.3
    C    0.4
    D    3
Correct Choice    □C


38) In vane shear test if  ( 0.6 < Id < 1.8 )  than the soil type will be:
    A    Sand      
    B    Silt
    C    Clay
    D    Gravely soil
Correct Choice    □ B


39) In vane shear test initially  ΔA, ΔB (before inserting the blade) must be in the Ranges:
    A    ΔA= 15 to 30 kpa         ΔB= 15 to 80 kPa
    B       ΔA= 5 to 30 kips           ΔB= 5 to 80 kips
    C      ΔA= 5 to 30 kpa            ΔB= 5 to 80 kPa
    D      ΔA= 20 to 30 kpa         ΔB= 20 to 80 kPa
Correct Choice    □C


40) Foundation on loess in situ dry densities range from?
    A    10 to 14.6kN/m3
    B    10 to 15.5KN/m3
    C    10 to 16.5KN/m3
    D    10 to 17.5KN/m3
Correct Choice    □C


41) When footings are to be placed adjacent to an existing structure, the line from the base of the new footing to the bottom edge of the existing footing should be
    A    30 degree
    B    45 degree
    C    60 degree
    D    90 degree
Correct Choice    □ B


42) The vane head should be turned five complete rotations at a speed of approximately ________seconds per rotation, and steps 3.6 to 3.8 repeated
    A      10
    B      30
    C      60
    D      5
Correct Choice    □ A


43) The backfill used in Reinforced earth structures should contain less than _____ fines content as required by the AASHTO Specifications for Highway Bridges.
    A    15 %
    B    18%
    C    25%
    D    28%
Correct Choice    □ A


44) In CPT test, the rate at which we push the instrumented con tip into the ground is
    A    2 centimeters/second
    B     4 centimeters/second
    C     5 centimeters/second
    D     3 centimeters/second
Correct Choice    □ A


45) In Case of  SPT , the graph between Depth of influence and Breadth has behavior
    A        Inversly propertional
    B        Constant line
    C        Directly proportional
    D        Non unfiorm behviour
Correct Choice    □C


46)Geotechnical investigation of soil resulted in SPT value of N=30. If square footing dimensions are confined to be 5 feet. Suggest allowable bearing capacity for permissible settlement of 1 inch using Teng Method.
    A    6 K/ft2
    B    7 K/ft2
    C    9 K/ft2
    D    8 K/ft2
Correct Choice    □ B


47)Geotechnical investigation of soil resulted in spt value N=25, allowable bearing capacity of soil was found to be 6k/ft2. Suggest suitable dimensions of square footing using Meyerhof Method for (B>4feet)?
    A    5 feet
    B    6 feet
    C    7 feet
    D    8 feeta
Correct Choice    □A


48)Geotechnical investigation of soil resulted in SPT value of N=30. If square footing dimensions are confined to be 5 feet. Suggest allowable bearing capacity for permissible settlement of 1 inch using Teng Method.
    A    6 K/ft2
    B    7 K/ft2
    C    9 K/ft2
    D    8 K/ft2
Correct Choice    □ B


49)The un-drained shear strength  of cohesive soil and SPT N  is controlled by
    A    Plasticity
    B    Sensitivity
    C    Fissuring
    D    All of  Above
Correct Choice    □D


50)Black cotton soils are:
    A    Residual Soils
    B    Organic  Soils
    C    Expansive Soils
    D    Ash Soils
Correct Choice    □ B


51)The expansion of soil due to shear at a constant value of pressure is called…….
    A    Apparent cohesion
    B    Dilatancy
    C     true cohesion
    D    Consistency
Correct Choice    □ B


52)Inorganic clays of high plasticity and having high inherent swelling capacity have liquid limit exceeding…………. % and plastic index over …………..
    A    20%   ,    10              
    B    40%  ,  30              
    C    30%    ,    20
    D     50%  ,  30
Correct Choice    □D


53)The best way to avoid damage from expansive soils is :
    A    To give a shallow foundation
    B    To give a  pile foundation
    C    To give foundation beneath the water zone
    D    To use of cobbles
Correct Choice    □ C


54)Which of the following is deep foundation
    A    Mat foundation
    B    Strip Footing
    C    Rock Anchor
    D    Cassion
Correct Choice    □D

From Editors Desk

These simple Multiple Choice question of foundation engineering is to help civil engineers and geo-technical engineers to enhance and fresh their knowledge, if you have found any error or you want to add any question in it you can comment below or you can send me at admin@iamcivilengineer.com. 
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