基于几何线形的立交噪声计算方法

为定量评价道路几何线形对立交噪声的影响,研究了基于几何线形计算立交噪声的方法,以车辆行驶速度为切入点,拟合噪声级和车速之间的关系.对于匝道噪声的计算,根据等效声级的定义给出了相对等效声能量的含义及计算方法,采用将匀速运动段与变速运动段噪声能量相加的方法求出总的噪声能量,建立了相对等效声能量与匝道长度之间函数关系,用对匝道长度进行积分的方法,根据等效声级的定义式推导出左、右转匝道的噪声级.根据主线设计速度、噪声级和车速之间的关系推导出主线噪声级计算公式.立交总噪声通过对各条主线和匝道的噪声级叠加求得.通过对黑龙江省鹤大立交的实例分析表明,该方法能够解决立交匝道变速运动段的噪声计算问题,能够将车辆在立交行驶产生的噪声与道路几何线形联系起来.当道路立交的几何设计条件已知,可以根据几何线形参数进行噪声污染计算,为定量评价立交噪声污染程度提供依据.

Calculation method on noise pollution of interchange based on geometric alignment

The method of calculating interchange noise was studied according to geometric alignment.By using vehicle speed as starting point,the relationship was fitted between noise levels and vehicle speed.For the calculation of ramp noise,the thesis defined the concepts and calculation method of relative equivalent sound energy according to the definition of equivalent sound level,determined the total noise energy by using the method of adding noise energy in uniform motion segment to the one in variable motion segment,and established the functional relationship between relative equivalent energy and the length of ramps.Under the definition of equivalent sound level,the noise level of left-turn ramp and right-turn ramp were deduced by the method of ramp length integral operation.For the calculation of the main line noise,the formula of the main line noise level was deduced according to the relationship among the mainline design speed,noise level and vehicle speed.The total interchange noise was obtained by the superposition of noise level in each main line and ramp.Heda interchange in Heilongjiang province was taken for example.The result shows that this method can solve the calculation problem of noise pollution in interchange ramp variable motion segment,and can connect the noise pollution produced by traveling vehicles with the interchange geometric alignment.When the interchange geometric alignment design conditions are known,the noise pollution can be calculated and the results can be used to quantitatively evaluate the degree of interchange noise pollution.