国产精品日本无码久久一老A,人妻互换HDF中文,色婷婷AV一区二区三区之红樱桃,少妇大叫又粗又大太爽A片,艳肉乱痕1一12章,脔到她哭H粗话H上司1V1,4399少妇做受免费A片,国产精品一区二区亚瑟不卡,日本爽爽爽爽爽爽免费视频

Sichuan - chongqing third channel 500 kv project noise control

Time:2018-11-19
shared:


Project introduction: due to the large amount of traffic flow on the channel, the vehicles cause huge noise when passing, which has a great impact on the normal life and office of nearby residents.


Treatment measures: set up sound barrier, the vertical column adopts plastic h-shaped steel, the sound absorption body adopts porous plastic spraying aluminum plate, centrifugal glass wool board, glass fiber cloth, acoustic cavity, plastic spraying panel mixed sound barrier. The top adopts arc reflector plate.

Governance effect: after installing the sound barrier, the sound insulation amount is greater than 20dB (A).