1. According to IS codes, the maximum differential settlements should not exceed ___________ in the foundation on clayey soil.
a) 25 mm
b) 100 mm
c) 25 mm
d) 40 mm
Explanation: According to IS: 2950-1965 code of practice, the maximum settlement should not exceed 40 mm in the foundation on clayey soils and 25 mm in foundations on clayey soils.
2. The possible method adopted for designing of raft foundation is ___________
a) Conventional method
b) Elastic method
c) Soil line method
d) All of the mentioned
Explanation: The behavior of a raft foundation being complicated, a number of simplifying assumption has to be made in design. There are two approaches for design-conventional method and the elastic method or the soil line method
3. The conventional method for designing raft foundation is based on which of the following assumptions?
a) Foundation is infinitely rigid and Soil pressure is assumed to be planar
b) Overburden pressure is assumed as zero
c) None of the mentioned
d) All of the mentioned
Explanation: The conventional method is based on the following two basic assumptions:
i) The foundation is infinitely rigid and therefore, the actual deflection of the raft does not influence the pressure distribution below the shaft.
ii) The soil pressure is assumed to be planar such that the centroid of the soil pressure coincides with the line of action of the resultant force of all the loads acting on the foundation.
4. The actual reinforcement provided should be ___________ of that worked out theoretically by conventional method.
a) Twice
b) Thrice
c) Lesser
d) None of the mentioned
Explanation: The actual reinforcement provided should be twice of that worked out theoretically in the case of design by conventional method.
5. The method that can be used for designing raft, based on elastic method?
a) Simplified elastic foundation and Truly elastic foundation
b) Conventional elastic foundation
c) None of the mentioned
d) All of the mentioned
Explanation: A number of methods have been proposed based primarily on two approaches of a simplified and truly elastic foundation, i) simplified elastic foundation ii) truly elastic foundation.
6. In truly elastic foundation, the soil is assumed to be obey ____________
a) Terzaghi’s theory
b) Hooke’s law
c) Skempton’s theory
d) All of the mentioned
Explanation: The soil in a simplified elastic foundation is assumed to be continuous elastic medium obeying Hooke’s law.
7. Both conventional and flexible method can be used only in the case when _________
a) Foundation is laid on cohesive soil
b) Soil pressure is low
c) Foundation is flexible
d) Load is concentrated on larger area
Explanation: Conventional and flexible methods are to be used in case the foundation is comparatively flexible and the loads tend to concentrate over small areas.
8. The modulus of subgrade reaction is applicable only when the load is applied through _________
a) Plate of size 30 ×30 cm and Beam 30 cm wide on soil area
b) Plate size is 10 × 10 cm
c) None of the mentioned
d) All of the mentioned
Explanation: The modulus of subgrade reaction (Ks) is applicable to the case of load through a plate of size 30 × 30 cm or beam 30 cm wide on soil area.
9. The value of Ks(modulus of subgrade reaction) can be found out, based on the effect of ___________
a) Size and Shape
b) Properties
c) None of the mentioned
d) All of the mentioned
Explanation: The value of Ks can be found corresponding to a different size and shape for both cohesive and cohesionless soils.
10. The effect of shape is based on ____________principal.
a) Principal of superposition
b) System of forces
c) Hooke’s law
d) Principal of center of gravity
Explanation: The effect of shape utilizes the principal of superposition.