EFFECT ' OF SWELLING SOIL IN THE FOUNDATION OF RIVER VALLEY STRUCTURES

Abstract

The safety of any River Valley Structure is of major concern. This safety becomes of paramount importance if the structure is required to be built on expansive/swelling soils and ubiquity of the BLACK COTTON SOILS (which contain predominance of mineral MONTMORILLONITE responsible for its high shrinkage and swelling characteristics) in various parts of our country. It may not be possible to avoid construction of WRD structure on them. The swelling and abnormal volume changes occur in expansive soils due to variation in moisture content, make the behavior complicated and sometimes disastrous failure of structure founded in/on such soils may occur. These problematic soils are encountered mostly in Central & Southern part of India. Instability of structure constructed on swelling soils are essentially due to volume expansion and contraction in the soil mass on saturation and drying during rainy and summer season respectively. The structure founded on swelling soils undergoes undesirable large-scale movement, due to resulting variation in strength & compressibility characteristics of the soils. This paper is an attempt to study the general problems associated with swelling soils both as support material for foundation and also as construction material. This paper also presents the possible remedial measure for swelling soils. Soils samples having swelling characteristics were tested to know their index and engineering properties and to evaluate swelling pressure