Author(s): Gerardo Ruiz

Linked Author(s): Gerardo Ruiz

Keywords: Urban drainage; Bifurcation tunnel; Dropshaft; Hydraulic model

Abstract: The unregulated expansion of the Mexico City metropolitan area, combined with the increasing intensity of extreme rainfall events, necessitates urgent improvements in urban drainage infrastructure. The objective is to enhance the system’s capacity to convey increasingly larger volumes of water over short time periods, thereby mitigating the risk of flooding in densely populated areas. In response to this challenge, the National Water Commission (CONAGUA) built the Eastern Drainage Tunnel (Tunel Emisor Oriente – TEO in Spanish), a circular tunnel with a diameter of 7 m and a length of 62 km, with a maximum discharge capacity of 160 m3/s. A critical component of this system is Shaft No. 5 (S5), where two pumping stations (PS), with a total capacity of 40 m3/s, are planned to be installed, connected to the TEO via a bifurcation. This study presents a hydraulic analysis of Shaft S5 based on a physical model at a 1:29 scale. The shaft, with a diameter of 20 meters, incorporates a slight change in the tunnel’s alignment and a connection to a trash screen. Two downstream tunnels convey the flow to a discharge canal through the pumping stations. Experimental results indicate that no significant instabilities or oscillations in water levels were observed along the tunnel under any tested conditions. The flow regime was predominantly subcritical, except at the shaft entrance under maximum discharge conditions, where localized supercritical flow was observed.

DOI: https://doi.org/10.64697/978-90-835589-7-4_41WC-P2065-cd

Year: 2025