SPAIN | CIVIL ENG. AND CONSTRUCTION
Structural and hydraulic parameter monitoring system
Udalaitz Tunnel
PROJECT OBJECTIVE
Structural monitoring
The project is based on the development of the Udalaitz tunnel, located between KP 1+215 and 4+406 of the section, with a total length of 3185m, of which 1020m cross the Udalaitz hydrogeological subunit corresponding to a karstic aquifer. Almost the entire tunnel has been excavated in mine, using the New Austrian Method (NATM).
The supports considered (designated as ST-I to ST-V) consist of gunite and bolts (supports ST-I to ST-III); gunite, bolts and trusses (ST-IV); and micropile umbrellas, gunite, gable bolts and trusses (ST-V).
The section near the Vitoria mouth of the tunnel, 1020 m long, crosses the Udalaitz karst aquifer. In this section it adapts a watertight type section in order to avoid filtrations inside the tunnel.
Date of execution:
2017
Location:
Udalaitz, Spain.
Sector:
Civil Engineering and Construction
Client:
How we made it happen
Load testing
Grupo Álava provides the hydraulic load test protocol, the installation of the sensors and acquisition system, as well as the data representation software.
The purpose of this load test is to ensure that the water pressures that may act on the tunnel lining are below the structurally permissible values. For this purpose, thresholds are set for the measured values. A complete solution is also provided, including all the services required to carry out the project: revision of the original project, drafting of the hydraulic load test protocol, installation of structural sensors (240 vibrating wire extensometers distributed in 20 sections), installation of the distributed acquisition system (32 distributed sections) and integration of the hydraulic control sensors (22 pressure sensors, 22 flow sensors and 5 solenoid valves).
OUR CONTRIBUTION
Some of our products and services applied to this project
Service
Technology consulting
We advise on the best technological solution to apply according to the needs of each project. Learn more about our technology consulting.
Service
Infrastructure process monitoring
We obtained a continuous monitoring system for structural and hydraulic parameters. Learn more about our monitoring service.
RESULTS AND ACHIEVEMENTS
Reliable system
A system for continuous monitoring of structural and hydraulic parameters during the different load states was obtained, with visualization of the data recorded in comparison with the pre-calculated thresholds and the possibility of acting on the solenoid valves.
In this way it is possible to regulate the water table acting on the lining. It has proved to be a reliable system to control all the parameters and even act on the loads during the load test. It has served to validate the design calculations in the extreme case that the tunnel drainage system stops working.
7
states of variation of the water table
50m
above the tunnel key
OUR EXPERIENCE
