So, In the last article, we went through the important questions of Soil Mechanics. Soil Mechanics and Foundation Mechanics ruled the question paper like always. Here, I am putting up the marking scheme of Foundation Mechanics. It becomes easier to study the weight age pattern.
|1 Mark Questions||6||6||4||5||3||3||4||5||5||5||4||8|
|2 Mark Questions||11||10||10||8||10||11||6||6||5||5||6||9|
So, Foundation Mechanics Engineering would have questions from the following topics :
Sub-surface investigations-scope, drilling bore holes, sampling, penetration tests, plate load test. Also, Earth pressure theories, effect of water table, layered soils. Stability of slopes-infinite slopes, finite slopes. Foundation types-foundation design requirements. Shallow foundations-bearing capacity, effect of shape, water table and other factors, stress distribution, settlement analysis in sands and clay. Deep foundation – pile types, dynamic and static formulas, load capacity of piles in sands and clay, negative skin friction.
The questions are as follows-
A ) Two different soil types (Soil 1 and Soil 2) are used as back fill behind a retaining wall as shown in the figure, here, γtγt is total unit weight, and c’ and ϕϕ ‘ are effective cohesion and effective angle of shearing resistance. So, The resultant active earth force per unit length (in kN/m) acting on the wall is: (2004)
C ) A smooth rigid retaining wall moves as shown in the sketch causing the back fill material to fail. Hence, The back fill material is homogeneous and isotropic, and obeys the Mohr-Coulomb failure criterion. Threfore,the major principal stress is (2004)
- face acting upwards
D ) A homogeneous gravity retaining wall supporting a cohesion less back fill is shown in the figure. FURTHERMORE,The lateral active earth pressure at the bottom of the wall is 40 k Pa.So, The minimum weight of the wall required to prevent it from overturning about its toe (Point P) is (1997)
Foundation Mechanics Engineering
E ) Here, strip footing is resting on the surface of a purely clayey soil deposit. If the width of the footing is doubled, the ultimate bearing capacity of the soil (2003)
F) The soil profile at a site consists of a 5 m thick sand layer underlain by a C−ϕC−ϕ soil as shown in figure. The water table is found 1 m below the ground level. Hence, The entire soil mass is retained by a concrete retaining wall and is in the active state. Also, The back of the wall is smooth and vertical. The total active earth pressure (expressed in kN/m2) at point A as per Rankine’s theory is _________ (2013)
G ) The action of negative skin friction on the pile is (2008)
- increase the ultimate load on the pi
- reduce the settlement of the pile
H ) Group I contains representative load-settlement curves for different modes of bearing capacity failures of sandy soil also, Group II enlists the various failure characteristics. So,Match the load-settlement curves with the corresponding failure characteristics. (2007)
|Group I||Group II|
|P. Curve J||1. No apparent heaving of soil around the footing|
|Q. Curve K||2. Rankine’s passive zone develops imperfectly|
|R. Curve L||3. Well defined slip surface extends to ground surface|
J ) Examine the test arrangement and the soil properties given below: (2014)
So, The maximum pressure that can be applied with a factor of safety of 3 through the concrete block, ensuring no bearing capacity failure in soil using Terzaghi’s bearing capacity equation without considering the shape factor, So the depth factor and inclination factor is
Here, the key answers for Foundation Mechanics are given.
A – 31.5
B – PASSIVE EARTH PRESSURE
C – normal to the wall face
D – 120
E – SAME AS ABOVE
F – 69.0 : 70.5
G – reduce the allowable load on the pile
H – P-1,Q-3,R-2
I – 8.83 m
So, In every year’s civil Engineering GATE exam, foundation Engineering and Soil Mechanics comprises of 7 marks . Hence, is a very important topic and comes out as the first thing to do for the GATE prep.
For more information , you can go through practice tests to evolve more into the subject.
So,the video I have posted here is on the FOUNDATION ENGINEERING chapter. Also, Hope you find it useful. so, If you have any queries with regards to this, you can write back to me in the comments section.