SEISMIC ZONE V, CHANGING THE ANGLE OF REPOSE DURING EARTH QUAKES AND DISTURBING THE INTENSITY OF SOIL DUE TO INCREASE IN. THE MOISTURE CONTENT

The zone V of the seismic zone of classification of the region based frequency and intensity of earthquakes experiencing more heavy intense rainfall than other areas of the hilly regions. The frequency of flash floods has increased in this zone because of the catchment area profiles and after affects of the organic matters in soil consists of the more or less decomposed remains of plant and animal organisms. It is of open spongy structure, swells or shrinks with increase or decrease of the moisture content and undergoes considerable volume changes under load. In general, dark colours of grey, brown or black indicate organic soils. Whereas brighter colours are usually found with Inorganic soils. Organic soils commonly have a distinctive smell and are undesirable constituent of a soil from engineering point of view. Deposits of silts and clays are often accompanied by a considerable amount of organic matter which makes itself evident by its odour when the deposit is disturbed. Due to pressure of the organic matters the bearing capacity of the soil is generally reduced. In general, the properties of soils composed largely of course materials are primarily controlled by the characteristics of the particles, but for soils composed largely of clays and colloids the properties are primarily controlled by the moisture content. Zone V is the most dangerous zone encompassing regions like the northeastern states particularly the hill states of jammu and Kashmir and Himachal pradesh and these areas are designed as zone V due to their proximity to tectonic plate boundaries, making them highly susceptible to severe seismic activities. These zones are determined by scientific data on the past earthquakes, the tectonic setting, and the potential intensity of future tremors. The soils subjected to the higher normal stresses will have lower moisture contents and higher bulk densities at failure than those subjected to lower normal stresses and the angle of internal friction may thus change. The capillary rise in a soil when wet may equal as much as 4 to 5 times the height of capillary rise in the same soil when dry, wherein the course gravel has no capillary rise. :-- Er Fateh chand Guleria, Director RTI welfare Association registered number HPCD, 3552 , Bilaspur Himachal pradesh phone number 9459334377