Field Test Study Of Ventilation Results In Long Highway Tunnel Using Longitudinal Ventilation Technology

According to《Specifications for Design of Ventilation and Lighting of Highway tunnel》, the applicable length of using the jet-fan longitudinal ventilation mode in one-way traffic tunnel is 2500m. Because longitudinal ventilation mode has lower costs of construction and operating, more simple technical and implemented in phases, At present, more and more over the length of the standardized proposed value of the long tunnel used fan-jet longitudinal ventilation. So generally empirical or code values about the basis of ventilation parameters is inconsistent with the practical projects in highway tunnels ventilation computation, and whether the effects of ventilation with regulations is not clear. Therefore, it is necessary to test the basal information and data for tunnel ventilation computation in situ in long highway tunnels which have been built.This paper is based on the Beibei Tunnel in YU-HE Expressway practical projects, plentiful field test have been made in the operating tunnel over the length of 4000m interiorly for the first time. Beibei tunnel is a long highway tunnel for one-way and two-lane with a length of 4025m in YU-HE Expressway which have been built, it adopted the longitudinal ventilation mode which is formed by jet fans-booster. Precis of field test was draw up before testing, and the instrument was prepared according to the precis.This testing selected the left Beibei tunnel which is an ascent tunnel to test.Plentiful field test have been made on tunnel ventilation parameters, traffic flow field survey. Then testing date were processed and analysed, the ventilation operating results of the tunnel which was over the length of 4000m and adopted the longitudinal ventilation mode by jet fans-booster under the existing traffic flow conditions was validated. The paper carried out computer numerical simulation study to simulate the jet-fan field in the tunnel. And the tunnel's ventilation operating results at a middle and a specified future date were evaluated by the field test data. It offers the field test data and evidence, accumulates experiences for the jet-fan longitudinal ventilation design in long highway tunnels, and the long highway tunnel ventilation design tends to be more reasonable and economical.