The Evaluation And Countermeasure Study On Noise Annoyance Of High-speed Railways

With the late-years’rapid development of high-speed railway in China, the country has become one holding the world’s longest mileage in terms of high-speed railways in operation or under construction. High-speed railways in China are mainly distributed in the central and eastern regions, with the noise pollution being the most notable among other environmental impacts, directly or indirectly threatening the physical and mental health of people living along the railway lines and hence affecting their normal work and life. The current research of high-speed railway noise attenuation and distribution is not adequate and the high-speed railway noise environment management policies are mostly formulated according to those of ordinary railways. Since the influences of high-speed railway noises on crowds are underestimated, people living along the already-built and the proposed railway lines are coming with rising antipathies against noises, signing potential social problems. Therefore, studying on the attenuation and distribution characteristics of the high-speed railway noise, establishing a proper assessment and regulation system for noise annoyance impacts, are of great significance for our high-speed railway environmental management, and for the public health.Based on the analysis of China’s high-speed railway construction cases, as well as the technology demands for crowd noise annoyance evaluation management, according to the attenuation and distribution characteristics of high speed railway, the noise annoyance assessing and controlling system is then composed.After the completion of the assessing and controlling system above-mentioned, the largest-scaled, longest-occupied Beijing-Shanghai high-speed railway is selected, with Anhui section being specialized on, the noise attenuation and distribution, noise disturbances towards population, noise annoyance assessment, and noise manipulating strategies are respectively studied..Firstly, the noise characteristics of high-speed railway are discussed, and research results show that:High-speed Rail noises are frequent, in short duration, with higher source intensity, greater instantaneous effect, and wider affecting spheres; The observed high-speed Rail noise has higher source intensity amount than what’s recommended in current domestic standards, which confirmed the under-estimated influence of the noise; the exposed noise levels of bridge sections are higher than that of cutting sections and the noise levels of low-bridge sections are higher than that of tall-bridge sections; with the increasing of bridge and roadbed distances, the gradual exposure levels tend to be in consistence; the exposure levels will double when the distances increase, and the attenuation quantity is around3.8-6.6dB.Secondly,3S technology is adopted in this study to interpret the satellite remote images, the distribution data of residents living by are extracted, hence the chi square test results show that residents are distributed evenly along the Beijing-Shanghai high-speed railways, and no particular avoidance is taken in the railroad selection process. Data of sample characteristics, physical and mental health, subjective feelings on high-speed rail noise, sleep disturbances, daily behavior disturbances and field measurement are acquired via682valid questionnaires in the population noise annoyance evaluation. The study analyzed on impacting degrees of the living environment for residents living by after two years of railway’s operation, people’s subjective feelings, their sleep and daily conduct interference effects in these two years, moreover, univariate test helps to select the relative significant factors in each indicator. The results indicate that86.2%of the samples are exposed to the noise exposure level above70dB;81.4%of the living environment has been interfered by high-speed noise,32.1%of which has reached a serious or rather serious degree. Significant differences exist in terms of the variety in age, hearing status, body health, building sound insulation effect and exposure sound level;35.8%samples rise earlier,35.3%samples prolong sleep,49.6%awaken more during nights,35.3%are severely disturbed in sleeping, the running traffic between8pm to8am producing great disturbances onto sleep quality of residents along; The significant difference boundary lies in300-400meters, so the influence scope of200meters prescribed in present technical specification is unrepresentative.Thirdly, according to the population noise evaluation conclusion, an index Ka≤3for environmental management critical value is proposed from the perspective of basic environmental right. The statistics show that the residents along the Beijing-Shanghai high-speed railways arise with apparent annoyed feelings from the running noise; High-speed Rail management should take further steps to ease and control noises. People under the age of18are within mild annoyance while the Ka value exceeds the critical point for all ages above30. Four items, namely the building sound insulation effect, the physical and mental health status, hearing status and the noise exposure level, are significantly associated with Ka index. The better the hearing and the body state, the lower the exposure level, the more effective the insulation effect, the farther the distance, then the lower the sample’s annoyance index. The judging model of high-speed noise annoyance index is explanatorily constructed; the application concepts are lodged, and the Anhui section in Beijing-Shanghai high-speed rails is exemplified, with3typical states selected to render the LAE-Ka state line.Finally, the regulation study of population noise disturbing verified the fact that the disturbing value of residents along the Beijing-Shanghai High-speed Rail has exceeded the critical level, and the annoyance effect intervention is bound to carry out. The typical state being the limited conditions, it’s identified that the key intervention management boundary signifies disturbed people with exposure level more than79dB and Ka greater than3. Moreover, concrete control and manage measures are put forward from several specific key points, namely the pollution sources controlling, the exposure routes blocking, the receptor protecting, etc..