Bir üniversite kampus alanında gürültü haritasının çıkarılması : İTÜ Maslak kampusü örneği

Abstract

Gürültü, tüm diğer çevresel kirlilikler gibi ciddiye alınması gereken, gerekli tedbirlerin alınmasını ve kontrol edilmeyi gerektiren bir unsurdur. Gerek iç gerekse dış mekanlarda gürültü oluşturan birçok kaynak mevcuttur. Gürültünün kontrol edilmemesi durumunda günlük hayatımızın her alanında karşılaşacağımız ve sürekli rahatsızlık verecek bir etken haline gelir. Bu da uzun ya da kısa vadede sürekli veya anlık birçok sağlık sorunu meydana getirir. Gürültünün kontrol edilmesi aşamasında gürültü haritalarının rolü büyüktür. Gürültü haritalarının oluşturulması, seçilen bölgede gürültü düzeylerinin belirlenmesini, izin verilebilir değerlerin aşılıp aşılmadığının gözlenmesini, eğer limit değerler aşılıyorsa ne kadarlık bir nüfusun bu yüksek değerlere maruz kaldığını, ne kadarlık bir azaltım sağlanması gerektiğini ve bu azaltımı sağlayacak önlemlerin neler olabileceğini değerlendirme imkanı verir. İTÜ Maslak Kampüsü için gürültü haritasının hazırlanması amacıyla yapılan bu çalışmanın en temel amacı, çevre mühendislerinin de çevresel bir kirlilik olan gürültünün kontrolü konusunda görev ve sorumluluğu olduğunu hatırlatmaktır. Tez metni içerisinde, gürültü ve gürültü kontrolünün daha iyi anlaşılabilmesini sağlamak için detaylı literatür bilgisine de yer verilmiştir. Tez için çalışma alanı olarak üniversite kampüsünün seçilmesinin amacı, kampüs bünyesinde eğitim, idari, sosyal ve konut amaçlı kullanılan binaların birlikte yer almasıdır. Tüm bu yapılar mevzuatta gürültüye hassas alanlar olarak nitelendirilmiştir. Kampüs çevresinde ciddi bir trafik yükü bulunan anayolların bu binalara olumsuz etkide bulunup bulunmadığının belirlenmesi ve gerekiyorsa önlem alınması adına bir gürültü haritasının oluşturulması gerekmektedir. Bu amaçla, İTÜ Maslak kampüsü için SoundPLAN programı aracılığıyla ızgaralı gürültü haritası hazırlanmıştır. Haritada gürültü kaynağı olarak Büyükdere Caddesi ve İstinye Bayırı Caddesi ele alınmış, bu yolların trafik verileri ve yol özellikleri programda veri olarak girilmiştir. Ayrıca, gürültü haritasında hesaplamayla bulunan sonuçların doğruluğunu belirleyebilmek amacıyla altısı cadde üzerinde dördü kampüs içinde olmak üzere on noktada Brüjel&Kjaer- Tip 2250 gürültü düzeyi ölçerle ölçümler yapılmıştır. Ölçüm sonuçları ve harita sonuçları birbirleriyle kıyaslanarak harita sonuçlarının doğruluğu gösterilmiş ve yine haritada elde edilen gürültü seviyelerine göre kampüsün gürültü açısından değerlendirilmesi yapılmıştır. Sonuç olarak, kampus genelinde 55-60 dBA aralığında gürültü seviyesinin hakim olduğu, bu değerlerin anayollara yaklaştıkça 5-10 dBA artış gösterdiği ve maksimum değerlere Büyükdere Caddesi boyunca ulaşıldığı gözlenmiştir. SoundPLAN programıyla yapılan hesaplamalar ve Brüel&Kjaer-Tip 2250 ses düzeyi ölçer ile yapılan ölçüm sonuçları, kampus alanının anayol civarında artan gürültü düzeyine rağmen sessiz alan olarak nitelendirilebileceğini göstermektedir.

Since the begginning of twentieth century it is clear that the developing technology brought a considerable amount of innovation for human beings. On the other hand this development rapidly created new sources of pollution. Firstly water sources and after air were polluted. Especially at the end of the twentieth century pollution became global rather than local dimension. Community did not stay unresponsive and initiated environmental movements. As a result of these movements the authorities have engaged in the process of finding solutions to these problems that require many disciplines work together. Legal regulations, initiation of institutional configurations and technical education is one of the results of this process. UK and USA, created new engineering departments within the civil engineering. Movements on a global scale has been reflected in our country, in addition to the regulatory sequence environmental engineering department has been established and education at undergraduate and postgraduate level has been started. This new branch of engineering, primarily dealt with issues such as supply, transmission and treatment of drinking water, but later researchs in water and at least as important as air and soil were done. In addition, studies have been initiated for the management of the waste that the inevitably result of increased consumption. Water, air, soil pollutions and other wastes are excepted as environmental pollution sources that threaten all kind of livings and need to be controlled seriously. The main purpose of existing of environmental engineers is controlling all these environmental pollution sources.Just as the other environmental pollution sources, noise should be under control. Mechanical engineers, acoustic engineers and architects have been working on this subject. However, enviromental engineers has just started to pay attention on this issue. Especially outdoor noise is an environmental problem which environmental engineers should work with other disciplines and be a part of solution of problems. There are several kind of sources such as roads, railways, aircfrafts, industries and construction/demolition activities that cause noise and if they are not controlled they will become an undesirable but inevitable part of the daily life which will cause different types of acute or chronic health problems. The most common health problems caused by noise are hearing loss, insomnia and psychological deteriorations.Noise Directive (2002/49 / EC) has been published by European Parliament and Council on June 25th, 2002 for all EU member states and it is mandatory to be transposed into national law by each member state. In our country, the need to take measures to environmental pollution, including noise is specified in the Constitution of the Republic of Turkey. Therefore, authorities prepared Environmental Act in 1983 and Noise Control Regulation that is related with Act, in 1986. In the accession process to European Union, Noise Control Regulation revised on 01/07/2005 and Assessment and Management of Environmental Noise Regulation has been published. Regulation requires noise maps, acoustic reports and the preparation of environmental noise assessment reports that cover the preparation of the results of the assessment and necessary for noise prevention and action to reduce background which indicate the levels of noise exposure. Noise mapping is the most important part of noise control. By the help of noise mapping, the areas and the amount of population which exposure more noise than regulatory limits can be detected. If it is needed, the ways of noise reduction or control can be estimated. Insulation may be applied or noise barriers may be designed. Noise maps may be done both by mesaurements or simulation programmes. Measurements supply more reliable results but noise mapping by measurement requires a few number of sound level analyzers and experts on noise measuring which increase the costs of projects. Also it takes really long time compared to using simulation programmes. Thus, the method that includes using simulation programmes and after controlling by some measurements is more feasible. Therefore, in this study firstly noise maps are prepared by a simulation programme called SoundPLAN and after some measurements are done by Brüel&Kjaer-Type 2250 sound level analyzer.SoundPLAN is a good tool to create noise maps (grid, facade or meshed noise maps) and also design noise barriers. It is easy to use the programme and get results so it is an user-friendly programme. Both indoor and outdoor simulations can be prepared by this programme. Environmental noise maps for road traffic, railways or aircrafts or any other outdoor source can be simulated and the exposure leves can be detected. Also it can be applied for more than fifty regulations that allows the user work for whichever regulation needed. Due to reasons above SounPLAN is used for noise mapping of ITU Maslak Campus. Brüel&Kjaer-Type 2250 sound level analyzer is an professional and Type 1 analyzer which gives highly reliable results for both laboratory and site studies. It is also an user-friendly equipment that easy to understand and use. It can gives results as frequancy base or sound levels in any desired filter. The reason for choosing this equiepment is being both reliable and useful.The main aim of this thesis that includes noise maps for ITU Maslak Campus is to be a case study for environmental engineering that should be a part of controlling noise pollution which is as important as the other environmental pollutions. Besides, because of that the noise pollution is a new issue for environmental engineers, this thesis includes subtitles for sound, noise and noise maps.In this thesis, the purpose of chosing a campus area for noise mapping is that campus includes different kind of noise sensitive buildings which are used for educational, social purposes or as offices. To detect wheter the sensitive buildings are negatively effected by the main road which has a significant traffic flow or not it is needed to prepare a noise map for the campus. Due to reasons above a grid noise map is made by SoundPLAN simulation programme. The parts of Buyukdere Street and Istinye Street covering campus are selected as noise source and the data of roads are given to simulation programme and emission levels at 1,5 m height are calculated. To compare the accurancy of noise map results, some measurements are made by Brüel&Kjaer-Type 2250 sound level analyzer. Six measurement points are selected besides the road and four measurement points are seleted inside the campus. The points outside are located at the entries of campus for both vehicles and pedestrians. The points inside are on the most used streets and choosed to be descriptive for campus profile. Measurements are done at 1,5 m height and results are in terms of dBA. All the levels that measured or simulated are A weighted which represents hearing capacitiy of human. The reason of having measurement results in terms of dBA is to have an ability to compare both the results of simulation programme and sound level analyzer. Both noise maps and measurments gave noise level data for 1,5 m height and in terms of dBA. Therefore the results of maps and measurements became comperable. By comparing the results of measurements and noise maps, the accurancy of maps are proved and the noise levels among campus boundaries estimated. Noise maps show that the campus area is as silent as it is supposed by regulatory limits. Between working hours (08:30-17:30) most of the builgings inside campus area are exposed to noise level which is lower than 65 dBA, the limit value of day time according to regulations. Very few of buildings inside the campus area are exposed to noise which is higher than 65 dBA. Because the noise levels in any times of day are mostly acceptable according to regulatory limits, taking individual precautions such as insulations for these buildings is feasible. The area where the all student hostels and main library are located is silent enough at any hour of day. Especially at night time the average sound level is between 40-45 dBA which is pretty good level for resting and studying areas. In conclusion, it is clear that there is no need to take any precautions for all campus area. The buildings which are exposed to noise levels higher than regulatory limits may apply individual insulations. By the way the walls surrounding the campus area is getting higher and thicker. So that they will work as noise barriers and the sound levels will be lower than recent levels.