C E1152 Pages: 2

Reg No: Name:
APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY
V SEMESTER B.TECH DEGREE EXAMINATION(S), MAY 2019
Course Code: CE305
Course Name: GEOTECHNICAL ENGINEERING - II
Max. Marks: 100 Duration: 3 Hours

PARTA
Answer any two full questions, each carries 15 marks. Marks

1 9) Determine the depth at which vertical stress reduces to 10% of the applied (7%)
pressure on a circular footing.

b) A retaining wall supports a two layered backfill having the following properties: (7%)
Upper layer: angle of internal friction=30°; unit weight=16KN/m* ; thickness=3m
Lower layer: angle of internal friction=45°; unit weight=20KN/m*; thickness=2m
Determine the total passive earth pressure.

2 a) State any 4 major limitations in Boussinesq’s theory. Why is the theory still in (714)
use in spite of limitations?

0) A retaining wall [height=5m] supports a granular backfill [angle of internal (7%)
friction=36°; unit weight above WT=16KN/m*; unit weight below WT
=19KN/m*] WT table is at a depth of 2m beneath the backfill surface. Determine
the total active earth pressure..

3 9) A uniform pressure acts on a rectangular footing having coordinates [in metres] (712)
of corners (0,10), (8,10), (8,0), and (0,0). Find the (m,n) combinations which are
to be used for determination of vertical stress [using Fadum’s chart] at a depth of
8m vertically beneath the point having coordinates (8,12).
b) State the assumptions in Rankine’s theory. (712)

PART ந
Answer any two full questions, each carries 15 marks.

4 9) What are the soil types for which local shear failure can be expected? Draw the (71൭)
typical pressure versus settlement curve for such a failure.

b) Design a rectangular combined footing for two columns, each of size (7%)
250mmX250mm, the magnitude of column loads being 85010 and 1050KN. c/c
distance between columns is 3.8m and a clear spacing of 0.125m only is
available beyond the outer face of 850111 column. Take SBC of subsoil as
202kPa.

5 ച Two footings A and 8, both having length of 22m, are placed on the surface of 8 (7൭)
dry, purely granular soil. Widths of footings A and B are 2.5m and 1.5m
respectively. Determine the ratio of their net safe bearing capacities.

b) Suggest any three methods (with neat sketches) for rectification of tilts in a well (716)
foundation.

6 a) Define Gross ultimate bearing capacity, Net ultimate bearing capacity, Net safe (712)
bearing capacity and Allowable bearing capacity.

b) What are the situations where raft foundations are preferred? What is meant by (7%)
floating foundation?

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