坡度对跨座式单轨隧道临界风速的影响

为研究不同坡度隧道在大功率火源情况下的烟气运动，采用1∶20的缩尺隧道模型，通过试验对不同坡度情况下(-6%,-3%,0%,3%,6%)的大火源功率火灾(20,50 MW)时的隧道纵向通风临界风速进行研究。结果表明:0%坡度时，20 MW和50 MW的临界风速相差不大；有坡度时，逆坡送风的临界风速大于顺坡送风的临界风速。根据试验结果拟合得出大火源功率(20,50 MW)条件下坡度为-6%至6%时的临界风速与坡度的关系，并对前人提出的坡度与临界风速的关系式进行修正。

Influence of slope on critical wind velocity of straddle monorail tunnel

In order to study the smoke movement in the tunnel with different slopes under large fire source power,a 1/20 reduced scale tunnel model was adopted to study the critical wind velocity of longitudinal ventilation in the tunnel with different slopes (-6%,-3%,0%,3%,6 %) under large fire source powers (20MW,50MW) through the experiments.The results showed that when the slope was 0%,the critical wind velocities under 20 MW and 50 MW were close.When the tunnel had a slope,the critical wind velocity with uphill air supply was greater than that with downhill air supply.According to the fitted experimental results,the relationship between the critical wind velocity and the tunnel slope ranging from -6% to 6% under large fire source powers (20MW,50MW) was obtained,and the relationship formula between the slope and the critical wind velocity proposed by the predecessors was revised.