exterior design competition of central –wan chai bypass east vent shaft background .
中环湾仔绕道东面排风口外观设计比赛。
the following three schemes were analyzed: ① no vent shaft was set up along sewage pipe;
对三个方案进行了分析:①污水管道沿程都不设通气井;
variable frequency converse fans were adopted for the running tunnels and for the air exhaust of the station, with only one piston vent shaft set at the station end.