DHARM388 GEOTECHNICAL ENGINEERINGQ uestions and Problems
10.1 State the basic requirements to be satisfied for the validity of Boussinesq equation for stress
distribution. (S.V.U.—B.E., (N.R.)—Sep., 1967)
10.2 (a) State Boussinesq’s equation for vertical stress at a point due to a load on the surface of an
elastic medium.
(b) Using Boussinesq’s expression, derive the expression for vertical stress at depth h under the
centre of a circular area of radius a loaded uniformly with a load q at the surface of the mass
of soil. (S.V.U.—B.E., (R.R.)—Dec., 1968)
10.3 (a) Explain the concept of ‘Pressure Bulb’ in soils.
(b) Derive the principle of construction of Newmark’s chart and explain its use.
(S.V.U.—B.E., (R.R.)—Nov., 1969)
10.4 (a) Explain stress distribution in soils for concentrated loads by Boussinesq’s equation.
(b) What do you understand by ‘Pressure bulb’? Illustrate with sketches.
(S.V.U.—B.E., (R.R.)—May, 1971)
10.5 Write a brief critical note on ‘Newmark’s influence chart’.
(S.V.U.—B.E., (R.R.)—Nov., 1973, May, 1975 & Feb., 1976
Four-year B.Tech.—Dec., 1982
Four-year B.Tech.—Apr., 1983
B.Tech.—(Part-time)—Sept., 1982)
10.6 Write a brief critical note on ‘the concept of pressure bulb and its use in soil engineering prac-
tice’. (S.V.U.—B.E., (R.R.)—Nov., 1974, Nov., 1975)
10.7 What are the basic assumptions in Boussinesq’s theory of stress distribution in soils? Show the
vertical stress distribution on a horizontal plane at a given depth and also the vertical stress
distribution with depth. What is a ‘Pressure Bulb’? (S.V.U.—B.E., (R.R.)—Feb., 1976)
10.8 Explain in detail the construction of Newmark’s chart with an influence value of 0.002.
Explain Boussinesq’s equation for vertical stress within an earth mass.
(S.V.U.—Four-year—B.Tech., Oct., 1982)
10.9 Derive as per Boussinesq’s theory, expressions for vertical stress at any point in a soil mass due
to
(i) line load on the surface, and (ii) strip load on the surface
State the assumptions. (S.V.U.—B.Tech. (Part-Time)—Sept., (1983)
10.10 Find the vertical pressure at a point 4 metres directly below a 20 kN point load acting at a
horizontal ground surface. Use Boussinesq’s equations. (S.V.U.—B.E., (R.R.)—Dec., 1971)
10.11 A 25 kN point load acts on the surface of a horizontal ground. Find the intensity of vertical
pressure at 6 m directly below the load. Use Boussinesq’s equation.
(S.V.U.—B.E., (R.R.)—June, 1972)
10.12 A reinforced concrete water tank of size 6 m × 6 m and resting on ground surface carries a
uniformly distributed load of 200 kN/m^2. Estimate the maximum vertical pressure at a depth of
12 metres vertically below the centre of the base. (S.V.U.—B.E. (Part-time)—Dec., 1971)
10.13 A line load of 90 kN/metre run extends to a long distance. Determine the intensity of vertical
stress at a point 1.5 metres below the surface (i) directly under the line load and (ii) at a distance
1 m perpendicular to the line. Use Boussinesq’s theory.