CHEMICAL GROUTING IN PERVIOUS AND ROCK FOUNDATIONS

Abstract

This dissertation presents the modern practice of chemical grouting in pervious and rock foundation to make them impermeable and to increase the structural strength to a certain extent and also as an aid in construction. A brief history of grouting is given with its development since beginning in 1802. The principle of cement grouting is also given as it is necessary to know it before studying the chemical grouting. The planning for chemical grouting is des-cribed in brief. Scope and objectives of chemical grouting, various types of chemicals with their properties and rheological character-istics are explained. Experimental procedures in laboratory for study of properties of chemicals are given. The selection of chemi-cals is also dealt with. Handling precautions of chemicals, while in field application and transportation are explained in case of toxic chemicals. The mechanism of grout penetration, effect of vis-cosity, granulometry of grout and soil and efficiency of grout curtain - are all treated mathematically. The chemical grouting technique comprising the various methods and equipments, their limitations and proper choice are explained. The -theory of short gel time is dealt in detail. The importance of short gel time and its utility in the case of stratified deposits and deposits with flowing water are ex- plained. The grouting patterns for chemical grouting in stratified deposits and for grout curtains are illustrated. A few examples of chemical grouting application in India as well as in foreign countries are given briefly. At the end, a conclusion is drawn that the chemical grouting is a still developing process even in foreign countries. In India, in very few places, the chemical grout-ing is being applied. There is a great scope in further investiga-tion to introduce more cheap chemn.cals as existing ones are more costly. Much literature is not available about this process as it is being carried out as a "trade secret". Whenever chemical grouting is carried out, the experience during grouting should be published in detail. It Ia also necessary to draw standard specifications to standardise the process.