DUE TO EFFECT OF SEASONAL WEATHER CHANGES, GROUND WHICH IS SHRINKABLE WILL EXHIBIT LARGE CRACKS IN THE SURFACE IN DRY WEATHER AND BECOME VERY STICKY DURING THE RAINS

Various systems of classifying soils for civil Engineering purposes have been devised and the use of different systems has led to much confusion. The course grained soils are usually classified mainly on the basis of their particles size distribution and the fine grained soils on the basis of their plasticity characteristics. The two most widely used systems of soil classification is necessary required to separation into several fractions of different grain size and divided into various size groups as, gravels, sands, silts and clays for the particles size analysis which is carried out by combining sieving and sedimentation methods. It is further noticed on the captioned subject of effects of the seasonal weather changes that movements are caused by the clay shrinking beneath the shallow foundations in dry summer seasons and subsequent swelling during the rains. The ground will dry most where it receives the greatest radiation from the sun. The movements associated with these seasonal changes are greatest at the surface and decrease with the depth, but may go upto even 3m below the surface. Foundations on such clays should be placed at a depth at least one metre below the ground level as the shrinkage movements beyond that depth are likely to be small. Adjoining deeper excavation may dry out clays and cause settlement. Ground which is shrinkable will exhibit large cracks in the surface in dry weather and become very stocky during the rains:-- Er Fateh chand Guleria, RTI welfare Association registered number HPCD, 3552 , Bilaspur Himachal Pradesh phone number, 9459334377