Q1. The rock mass and material characteristics of an igneous rock are influenced greatly
by the chemistry of magma and the tectonic setting of which they were formed. Based on the
statement given, answer the following questions.
a) Differentiate the main features (texture) of the volcanic and plutonic igneous
rock?
(2 marks)
b) Discuss how the silica content will influence the chemistry of magma
(4 marks)
c) Explain the differences on typical rock mass characteristics of plutonic and
volcanic igneous rock
(6 marks)
d) Discuss on the suitability of following rock types in terms of the potential
presence of reactive silica (ASR) for it to be used as an aggregate for concreting
purpose
i)
Granite
ii)
Rhyolite
(6 marks)
Q2. It was established during a site investigation that the bedrock is made of limestone.
Based on the given information, answer the following question.
a) What is the essential and dominant mineral in limestone?
(1 marks)
b) Discuss the chemical weathering in limestone area
(4 marks)
c) Due to the weathering effect, discuss the typical subsurface profile in limestone
area.
(5 marks)
d) Discuss suitable methods to overcome the issues in (c) for deep foundation work.
(5 marks)
Q3. The presence of discontinuities is one of great factors influencing properties of a rock
mass.
a) Explain various types of discontinuities that can be found in a sedimentary rock
mass?
(4 marks)
b) Discuss on how the discontinuities orientation and spacing can affect stability
of a rock mass?
(4 marks)