Author(s): Shangtuo Qian; Fei Ma; Weichen Ren; Jianhua Wu; Hui Xu

Linked Author(s):

Keywords: Deep tunnel storage and drainage system; Energy dissipation; Flow regime; Overflow capacity; Stepped dropshaft; Ventilation

Abstract: Dropshafts are an important part of deep tunnel storage and drainage systems, which need to operate safely and efficiently under high head and high flow conditions. For the deep tunnel storage and drainage systems in China, we have designed a stepped shaft, which mainly consists of a central ventilation pipe with air holes and a succession of spiral steps. A series of studies were carried out on the hydraulic characteristics of stepped dropshafts, demonstrating their advantages over traditional dropshaft designs. The flow classification was made and the expressions for predicting the thresholds of the flow regimes were established. The shock wave characteristics were clarified and the expression for the maximum overflow capacity was established. Expressions for the outflow residual energy and ventilation characteristics were also established, and the main influencing factors and their specific roles were clarified. The conclusions support the engineering application of stepped dropshafts and suggest further structural optimization.

DOI: https://doi.org/10.3850/iahr-hic2483430201-410

Year: 2024