Site surveying Procedures for Construction &Engineering Geology and Soil Mech Document Preview: Requirement of assignment Please provide me with the assignment the following: Summary (a description of...

Requirement of assignment
Please provide me with the assignment the following:
a) Summary (The under mentioned assignment is related to Engineering Geology & Geomechanics wherein the suitability of rock masses as foundation and building structures are analysed. The rocks have been classified based on their origin and their respective strengths have been discussed. The common rock forming minerals and their suitability to use building materials has also been discussed )
) Introduction
Name the commonly occu
ing rock types depending on the way they have been formed?
Ans. Rocks are grouped into three major groups based on the origin- Igneous, Sedimentary and Metamorphic Rocks.
Common Igneous Rocks based on the depth of origin
a. Plutonic – Granite, Granodiorite, Syenite, Diorite, Ga
o
. Hypabyssal – Microgranite, Quartz Porphyry, Microgranodiorite, Microsyenite, microdiorite, Dolerite
c. Volcanic –Rhyolite,Pitchstone,Dacite,Trachyte,Andesite,Basalt
Sedimentary Rocks-
1. Rudaceous – Gravel,Conglomerates , Breccias
2. Arenaceous – Sands,Silts, Sandstones,Siltstones
3. Argillaceous – Mds,Clays,Brick Earth,HardClays,Shales,Mudstones,Fine Clay, Marls
4. Calcareous – Shelly Sands,Coral Reefs,Limestones,Chalk
5. Ca
onaceous – Coals
6. Fe
ugenous – Clay Ironestone, Blackband ironstone
7. Siliceous- Silica Gel, Flint, Chert
Metamorphic Rocks –
e.g- Gneiss, Ma
le or Quartzite, Schist, Slate, Phyllite
Describe the mode of formation for the aforementioned rock types?
Ans. Igneous Rocks are those, which are formed by the solidification of molten magma originating in the interior of the Earth. Magma, which occurs inside the Earth in the fluid state, consists of molten silicates, water vapour and volatiles. If the rocks are formed by the solidification of lava on the surface, the rate of cooling is faster and rapid solidification takes place. In such cases, fine grained materials are formed.
Igneous Rocks, which are formed at depth are known as Plutonic Igneous Rocks and those which are formed from Lava mainly at the surface are known as Volcanic Igneous Rocks. Classification of Igneous Rock depends upon the composition of the parent magma and its textural classification will depend upon the environment in which it is solidifies.
e.g
1. Common Igneous Rocks based on the depth of origin
a. Plutonic – Granite, Granodiorite, Syenite, Diorite, Ga
o
. Hypabyssal – Microgranite, Quartz Porphyry, Microgranodiorite, Microsyenite, microdiorite, Dolerite
c. Volcanic –Rhyolite,Pitchstone,Dacite,Trachyte,Andesite,Basalt
Sedimentary Rocks are derived from weathering and decomposition of earth Crust or from any rock type. When a rock or earth crust is weathered or decomposed and transported and redeposited and subsequently consolidated and cemented partly or fully, the new product formed is known as Sedimentary Rock. The type of sedimentary deposits formed in any area depends upon the nature of sediments ca
ied into the area and the physical environment within the area.
e.g of Sedimentary Rocks-
8. Rudaceous – Gravel,Conglomerates , Breccias
9. Arenaceous – Sands,Silts, Sandstones,Siltstones
10. Argillaceous – Mds,Clays,Brick Earth,HardClays,Shales,Mudstones,Fine Clay, Marls
11. Calcareous – Shelly Sands,Coral Reefs,Limestones,Chalk
12. Ca
onaceous – Coals
13. Fe
ugenous – Clay Ironestone, Blackband ironstone
14. Siliceous- Silica Gel, Flint, Chert
Metamorphic Rocks – Due to high temperature, high pressureand temperature gradings as well as high shearing stresses on existing igneous or sedimentary rock masses , under the earth crust, recrystallization of rocks take place and the resulting complete or incomplete recrystallized mass is known as Metamorphic Rocks.
e.g- Gneiss, Ma
le or Quartzite, Schist, Slate, Phyllite
Produce engineering description and classification for rocks?
Ans. In Engineering Geology and Rock Mechanics, Rocks are classified on the basis of their in-situ properties. The behaviour of rock mass subjected to change in stress due to change in physical conditions due to constructions of some superstructures or excavation of tunnels etc. is governed by mechanical properties of the intact rock mass and number and nature of geological discontinuities present in the mass. .Hence in rock classification, these two items are taken separately .Besides, rocks are also classified sometimes according to their degree of weathering, because this also gives important information...