Advance Foundation Engineering (ppt- list)

Here is the list of the students with topics to be presented.
Note:
1.All students must be present on the date's given below as it would be considered as normal classes.
2.If you failed to attend the class then you would be marked absent for that concerned date.
3.The student who give their ppt would be given marks as a single that means each member in a team should give their presentation or they will loose marks.
4.There would be gift prize for the best presentation.
                                         If u have any comments regarding, then you are welcome.
                                                                   ALL THE BEST

S.no:	Role no:	Topic	Date
1	113, 116,148	Caissons foundation, types of caissons	23-09-2013	Including pictures
2	117,118,153	Well foundation,diff. shapes of wells, advantages of well foundations	23-09-2013	Including pictures
3	121,122,151	Components of well foundations in detail	23-09-2013	Including pictures
4	126,128,156	Functions and designs of well foundation	23-09-2013	Including pictures
5	132,131,142	Sinking of wells, shifts and tilts	24-09-2013	Including pictures
6	135,136,L-101	Design criteria of well foundation	24-09-2013	Including pictures
7	137,140,L-107	Lateral stability of well foundations by terzaghi’s analysis	24-09-2013	Including pictures
8	146,150	Lateral earth pressures-introduction.	24-09-2013	Including pictures
9	102,125,119	Rankines theory-including active and passive for cohesion and cohessionless soils	25-09-2013	Including pictures
10	104,101,139	Coulomb’s wedge theory- including active and passive for cohesion and cohessionless soils	25-09-2013	Including pictures
11	L-104,158,134	Graphical method to find out lateral earth pressures	30-09-2013	Including pictures
12	115,141	Stability of cantilever retaining wall	30-09-2013	Including pictures
13	120,130,145	Stability of counterfort retaining wall	30-09-2013	Including pictures
14	159,124,144	Reinforced earth-retaining walls including design	30-09-2013	Including pictures
15	103,027,111	Methods of soil exploration, plate load test and bore log	01-10-2013	Including pictures
16	106,L-010	Laterally loaded pile and under reamed piles	01-10-2013	Including pictures
17	133,L-103,149	Alignment of canal and its hydraulic components	01-10-2013	Including pictures
18	114,143,147	Slope stability, stability  analysis by Swedish arc method	01-10-2013	Including pictures
19	108,155,138	Principles of effective stress including total, neutral and eff.stress and seepage through soils	01-10-2013	Including pictures
20	L-011,110,152	Types of pile and load carrying capacity of piles based on static formulae.	07-10-2013	Including pictures
21	105,157,09-130	Field compaction equipments and mechanisam of compaction	07-10-2013	Including pictures
22	123,160,L-112	Newmark’s influence chart for irregular areas	07-10-2013	Including pictures
23	L-109,154,L-102	Index properties of soils.	07-10-2013	Including pictures

SOIL FORMATION AND SOIL TYPES

Soils are the fundamental resource supporting agriculture and forestry, as well as contributing to the aesthetics of a green planet. They are also a base from which minerals are extracted and to which solid wastes are disposed. In addition, soils act as a medium and filter for collection and movement of water. By supporting plant growth, soil becomes a major determinant of atmospheric composition and therefore earth’s climate.

ORIGIN OF SOILS

Soils are formed by weathering of rocks due to mechanical disintegration or chemical decomposition. When a rock surface gets exposed to atmosphere for an appreciable time, it disintegrates or decomposes into small particles and thus the soils are formed.

FORMATION OF SOILS

Soils are formed either by (A) Physical Disintegration or (B) Chemical decomposition of rocks.

A. PHYSICAL DISINTEGRATION

Physical disintegration or mechanical weathering of rocks occurs due to the following physical processes:

1. Temperature changes

Different minerals of rocks have different coefficients of thermal expansion. Unequal expansion and contraction of these minerals occur due to temperature changes. When the stresses induced due to such changes are repeated many times, the particles get detached from the rocks and the soils are formed.

2. Wedging action of ice

Water in the pores and minute cracks of rocks gets frozen in very cold climates. As the volume of ice formed is more than that of water, expansion occurs. Rocks get broken into pieces when large stresses develop in the cracks due to wedging action of the ice formed.

3. Spreading of roots of plants

As the roots of trees and shrubs grow in the cracks and fissures of the rocks, forces act on the rocks. The segments of the rock are forced apart and disintegration of rocks occurs.

4. Abrasion

As water, wind and glaciers move over the surface of rock, abrasion and scouring takes place. It results in the formation of soils.

Note: In all the processes of physical disintegration, there is no change in the chemical composition. The soil formed has the properties of the parent rock. Coarse grained soils, such as gravel and sand, are formed by the process of physical disintegration.

B. CHEMICAL DECOMPOSITION

When chemical decomposition or chemical weathering of rocks takes place, original rock minerals are transformed into new minerals by chemical reactions. The soils formed do not have the properties of the parent rock. The following chemical processes generally occur in nature:

1. Hydration

In hydration, water combines with rock minerals and results in the formation of a new chemical compound. The chemical reaction causes a change in volume and decomposition of rock into small particles.

An example of hydration reaction that is taking place in soils is the hydrolysis of SiO₂

 SiO₂+ 2H₂O Si(OH)₄

2. Carbonation

It is a type of chemical decomposition in which carbon dioxide in the atmosphere combines with water to form carbonic acid. The carbonic acid reacts chemically with rocks and causes their decomposition.

The example for this type of is, that is taking place in sedimentary rocks which contain calcium carbonate.

3. Oxidation

Oxidation occurs when oxygen ions combine with minerals in rock. Oxidation results in decomposition of rocks. Oxidation of rocks is somewhat similar to rusting of steel.

4. Solution

Some of the rock minerals form a solution with water when they get dissolved in water. Chemical reaction takes place in the solution and the soils are formed.

5. Hydrolysis

It is a chemical process in which water gets dissociated into H⁺ and OH^- ions. The hydrogen cations replace the metallic ions such as calcium, sodium and potassium in rock minerals and soils are formed with a new chemical composition.

Note: Chemical decomposition of rocks result in the formation of clay minerals. The clay minerals impart plastic properties of soils. Clayey soils are formed by chemical decomposition.

TRANSPORTATION OF SOILS

The soils formed at a place may be transported to other places by agents of transportation, such as water, ice, wind and gravity.

1. Water transported soils

Flowing water is one of the most important agents of transportation of soils. the size of the soil particles carried by water depends upon the velocity. The swift water can carry the particles of large size such as boulders and gravels. With a decrease in velocity, the coarser particles get deposited. The finer particles are carried further downstream and deposited when the velocity reduces. A delta is formed when the velocity slows down to almost zero at the confluence with a receiving body of still water such as lake, a sea or an ocean.

All types of soils carried and deposited by water are known as alluvial deposits. Deposits made in lakes are called lacustrine deposits. Marine deposits are formed when the following water carries soils to ocean or sea.

2. Wind transported soils

Soil particles are transported by winds. the particle size of the soil depends on the velocity of wind. The finer particles are carried far away from the place of the formation. Soil deposits by wind are known as Aeolian deposits.

Large sand dunes are formed by winds. Sand dunes occur in arid regions and on the lee ward side of the sea with sandy beaches.

Loess is a silt deposit made by wind. These deposits have low density and high compressibility. The bearing capacity of such soils is very low. The permeability in vertical direction is large.

Glaciers are large masses of ice formed by the compaction of snow. As the glaciers grow and move, they carry with them soils varying in size from fine grained to huge boulders. Soils get mixed with ice and are transported far away from their original position.