Concerning the project for the drainage tunnels of the city of Lisbon, LNEC carried out a physical model hydraulic study of the entrance works that will be built in Monsanto/Campolide for diverting the pluvial flows from the existing Alcântara tunnel into to the future Monsanto-Sta. Apolónia. The entrance works were conceived to integrate an anti-pollution basin allowing for most rainfall events a pre-treatment of the unitary flood flows prior to the discharge into the Tagus River. As the operating modes and flow ranges involved for this project work are complex and involve unconventional hydraulic structures, the simulation of the main hydraulic operating scenarios on a reduced model, at scale 1:30, was an important tool to validate the project solution.
The scale model was made by means of digital design and fabrication (3D Cad, 3D printing and CNC machining) considering a light and modular design. Comparing with the traditional methods of model construction, this option, innovative at LNEC, made it possible to speed up the construction, improve the geometrical accuracy and simplify the introduction of alternative geometries.
The physical model showed that, in general, the hydraulic operation is adequate for the entire range of flood flow operation foreseen in the project. In addition, it also allowed the identification of various details that can be improved in the final design of the work.
Physical model modular
conception
Assembling the physical
model modules
Some details of the flow during the
physical model tests
Plot of the velocity field at flow surface
base on model measurements
Institutions and Work Teams:
LISBON CITY COUNCIL
ÁGUAS DO TEJO ATLÂNTICO, S.A.
HIDRA – HIDRÁULICA E AMBIENTE, Lda.
Team: Ricardo Jónatas, Nuno Aido Pereira and Maria José Henriques (Senior Technicians)