EVALUATION AND DESIGN OF NOISE BARRIERS

Abstract

In all mega cities of India transport development is taking place in a big way. Due to rapid urbanization, growing population, rising number of vehicles and transport development the traffic noise pollution has become a challenging problem for present and future generation. In Delhi like metro city the prime source of noise pollution is vehicular traffic. In Urban areas mostly dwelling units and a large number of people are exposed to a noise level which is much higher than the level of human tolerance i.e. 45 dB (A),In Delhi it is found that the ambient noise level (Leq) is exceeding the standard permissible value at all the locations. The average equivalent sound level (Leq) in day time at Rithala, Panchsheel and New Friends Colony has been found 75.63 dB,78.59 dB and73.95dB respectively whereas standard permissible value of Leq in day time as prescribed by Central Pollution Control Board (CPCB), Delhi is 55 dB (A). Even this average equivalent sound level (Leq) in day time at Gurudwara (Roorkee) has been found as 83.35 dB which is exceeding the standard permissible limit. In Urbanized areas the most effective reduction of traffic noise disturbances would be obtained by provision of noise barriers or enclosures. In the present study, an attempt has been made to develop spread sheets for prediction of noise based on FHWA and CORTN procedures. Spread sheets are also developed for evaluating effectiveness of existing boundary walls abutting houses in mitigating noise, redesigning them as noise barriers. Study was also carried out to examine the changes in noise level due to designed noise barrier by using both models FHWA and CORTN respectively. The thesis is mainly focused towards the measurement of noise pollution at various urban locations and assessing effectiveness of existing boundary walls in reducing noise and suggesting additional height of wall required so that noise levels are within prescribed limits.