ground improvement 2011
TRANSCRIPT
Professor of Civil Engineering (Retd) VNIT Nagpur, India
A.S.Nene
Introduction - Shilpashashtra
Engineering sciences were very advanced in India in
ancient period (5000 BC to 1500 AD).
More than thousand texts can be mentioned on the
various engineering sciences
Many references are available in ancient Indian
literature (Vedas, Puranas, and Shilpa-Samhitas etc).
Most of the practices mentioned in these references
are scientific and relevant to modern engineering.
The word Shilpa is derived from words
Sheel samadhou ,which mean
“any thing that pleases the mind “
Terms and terminology
. Shilpashashtra - Science which deals with creation of a Shilpa.
. Shilpa Samhita –Compilation (of rules and procedures) related to Shilpashastra.
Sthapati – One who has complete knowledge of Shilpa Samhita (An engineer or architect).
3 Parts- (Khanda)
ADhatu -Materials
BSadhana - Transport
CVastu -Habitat
1.KrushiBiological Sciences
3.KhaniMining & Metallurgy
2.JalaWater Resources
4.RathSurface
5.NauWater
6.AgniyanAir / space
7.VeshmaHousing
9.Nagar RachanaTown Planning
8.PrakarForts/ Castles
10. YantraMachines
Extent of Shilpa
Vidya- Vidya means a particular technique. One musthave both theoretical and practical knowledge of that subject. Kala - Kala means an art which can be acquired by practiceand observation. Even a handicapped person can be expert in a particular art without any theoretical knowledge.
There are 32 Vidyas and 64 Kalas related to Shilpashashtra.
53. Mrudkarm- Soil conditioning
48. Mrudsadhan- Collection of soils for a specific purpose
27. Estikadibhajan- Making of bricks, roof tiles etc
8.Bhasmikaran(Incineration)
KalasVidya
Relevant Vidya & Kalas
As a leather is stretched by driving nails, the ground was stabilized (by Gods) with gravels and boulders.Shatapatha Brahman, Chapter 21
GROUND IMPROVEMENT
“The marshy land was stabilized by gods using sands”Kapisamhita, 6.7
If ground is waterlogged, then the water should be
drained out by digging drains parallel to north-east and
refilling the trenches by brickbats and stones so that
excess water drains out.
SOIL STABILIZATION
Functions of soil plasticizers
• Increase the workability with minimum watercontent
• Increase the water repellent property
• Increase the strength by increasing the density.
• Impart glazing to pottery products.
Ancient plasticizers can be grouped as
Extracts of Herbs, Fruits and tree barksTrifala- Aamla, Hirda and Behada1
Wood apple2, Holy tree fruit3Barks- Khadir4, Arjun trees
Natural fibers
Cotton, coir, wool, silk cotton1 , jute2
Natural polymers
Cow Dung, Jaggaery, Coconut water, Eggs, Green Algae, burnt coconut shell
Brick making
Bricks of Lothal -1500 BC Village Sirpur (chhattisgarh) 5th century AD.
Foundry soils for metal castingThe Dhokra Technique of the tribal artists of Bastar
1. The first layer, the closest to the wax sculpture,is the river bed soil, water and coal powder applied with brush.
2. A paste of red soil with rice husk is applied to first dry solidified layer This is applied with hands.
3.A final coating of rice husk, sand and clay is applied to the entire surface of the piece.
.
Idols - Mud plaster
This constancy is determined by rolling the clay mass on the palms. When the lines of palm are clearly impressed on the clay mass the constancy is proper.
Liquidity index for this consistency (Palm line limit) corresponds to 15 to 20 %
CASE STUDIES
A. Gadhi soils –white soil
The main constituents are local soil, fine sand, cow dung, quick lime,extracts of Belphal , fibers of jute and water for mixing.
The mixture is allowed to mature for a minimum period of 30 days and kneaded everyday.
2. Mud flooring. The floors of Padmanabhapurum palace (1601 A.D) in Kerala were made of a material that is unique blend of burnt coconut shells, quick lime, palm toddy, the whites of eggs and extracts of certain barks of trees and nuts.
Reasons for loss of ancient technical literature
Natural - Limited life of the writing materials,Language – Most of the texts were in Sanskrit. Secrecy – The knowledge was encrypted Foreign aggression Improper interpretation Neglect by modern engineers Religion –misconception Irrelevance Absence of technical data
CONCLUSIONS
1.Ancient Indian engineers and artisans had deep knowledge about ground improvement and stabilization techniques.
2.Many of the ancient Indian techniques may not be relevant as modern methods and materials are more cost effective. But one must appreciate the ancient Indian knowledge which was centauries ahead of that available in rest of the world.
3.There is a need to preserve this treasure of ancient Indian traditions.
This paper is based on references from the vast collection of rare literature on Shilpasamhita, compiled by Late Shri G.G.Joshi, Nagpur