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May 18, 2022, Lérida, Spain |

The Catalan Water Agency awards OFITECO, in a joint venture, the rehabilitation ‎works of the La Llosa del Cavall dam, in Lleida

The works, which will last 10 months, will consist of improving the dam safety by rehabilitating the drainage network and the monitoring system.

Presa de La Llosa del Cavall

As a result of the ordinary operation of the dam, the Catalan Water Agency has carried out various studies and safety reviews, recommending maintenance actions, especially focused on the existing leaks and underpressures in the dam foundation.

The works will consist of:

Improvement of the drainage system: the existing drainage network will be rehabilitated and it will be expanded by drilling new drains in the foundation. Additionally, to ensure the stability and behavior of the foundation in specific areas, the injection of resins will be carried out prior to the rehabilitation of the drainage network.

Improvement of the dam monitoring system: action will be taken on the instrumentation and on the extension of the automation of readings. For this, the data acquisition system will be updated, which will be processed and analyzed with the DAMDATA application, developed by OFITECO, guaranteeing the obtaining and processing of results for the interpretation of auscultation series in situ without the need to connect to no network. At the same time, the current monitoring system will be improved by adding the following elements:

 

  • Topographic monitoring: external references, crest, downstream slope and contact with the ground.
  • Acquisition of topographic total station.
  • Vibrating wire piezometers in each of the dam blocks and provided  with automated reading.
  • Two rod extensometers on the right bank to control the abutments (with automated reading).
  • Automation of external joint gauges associated with the Self-protection Plan.
  • Seismic monitoring with the installation of 3 seismographs.
  • Gauge with automated reading in the gallery of the counter-dam.
  • Gauge with automated reading on the left bank.
  • Gauge with manual reading in gallery 714 block 6 to measure the filtrations of the existing extensometer.
  • Modification of the gauges on the left bank to be automated.

Regarding automation, work will be done on:

  • The sensors used to change the Emergency Plan scenarios.
  • Gauge in the diversion tunnel.
  • Gauges in the access gallery to the stilling basin on the right bank.
  • All rod extensometers.
  • The currently existing piezometers will be upgraded with vibrating wire sensors and will be installed again, all of them with an automated reading system.
  • The pendulums at their ends (lower in the case of the direct ones and higher in the case of the inverse ones).
  • Renewal of the manual reading plates of all the pendulums.

As these are works that aim to rehabilitate the drainage network and improve the monitoring system within the dam intake, these have particularities that make them interrelated and require total technical coordination for their implementation.

OFITECO once again demonstrates its solvency for the execution of contracts that require the maximum guarantee for dam operators.