Author(s): Jiachun Liu; Biao Huang; David Z. Zhu

Linked Author(s):

Keywords: Dropshaft; Deep tunnel systems; Rebound flow; Impinging pressure

Abstract: A dropshaft is a critical component in urban deep tunnel systems, designed to channel surface runoff downward effectively. A physical model study was conducted on jet impingement in a plunging dropshaft with different drop heights of 3.38 m and 1.88 m. Horizontal jets impinging on the shaft wall and falling jets impinging on the pool were investigated, and it was found that the impingement pressure on the shaft wall was dominated by the incoming flow rate, and that the average pressure on the shaft wall could be reasonably predicted, taking into account the rebound flow. The impinging pressure at the bottom of the shaft depends mainly on the velocity of the falling jet reaching the pool. The average value can be well estimated using the annular flow and bouncing jet assumptions.

DOI: https://doi.org/10.3850/iahr-hic2483430201-416

Year: 2024