Prototype Wedge Shaped Block Spillway

The PABLO project has been carried out by a Consortium formed by PREHORQUI S.A., OFITECO, SERPA Group (UPM) and CIMNE, and has been developed thanks to funding from FEDER/Ministry of Science, Innovation and Universities – State Research Agency/Project RTC-2017-6196-5.

Previously, the consortium formed by the company PREHORQUI S.A., CIMNE, and the UPM had long been committed to wedge-shaped block spillways. In 2011, research began with the ACUÑA project ‘Development of a wedge-shaped block prototype and the methodology for its use as protection against erosion in embankment dams or reservoirs’ (IPT-2011-0997-020000), in 2014 with the DIABLO project ‘Development of an optimal design code for wedge-shaped block spillways’ (RTC-2014-2081-5) and, finally, in 2017 with the PABLO project ‘Wedge-shaped Block Spillway Prototype’ (RTC-2017-6196-5). The aim is to improve safety conditions against overtopping in dams, reservoirs, and river levees of earth and earth-rock materials, to increase the hydrological safety of these infrastructures, facing extreme episodes that are occurring more and more frequently due to climate change.

As a result of the ACUÑA and DIABLO projects, the patent “Precast concrete block with drainage and aeration system for protection against erosion by water flows” (ES 2595852 B2) was developed, published in the Official Industrial Property Gazette of 8 May 2017, which incorporates improvements over other models of this type of wedge-shaped block.

With all these elements available, the company PREHORQUI S.A. continues its commitment by launching the PABLO project for the experimental validation on a prototype scale, i.e. in real operating conditions, of the patented blocks and their design methodology, for which it has been necessary to build a unique test facility and manufacture three different sizes of blocks. This facility, called the ‘Luis Ruano Hydraulic Experimentation Facility’, is located in the Inlet Channel of the Laverné Reservoir, in Ejea de los Caballeros (Zaragoza, Spain), and basically consists of three elements: a 38 m section of pressure conduit with a rectangular section of 4 x 3.5 m, followed by a 9 m high tower with a 4×4 m cross section, from which a 16 m long and 2.5 m high test chute starts. The channel slope can be changed, and, at the same time, it has been designed so that the position of one of its pockets can be changed, so that 2, 1.5, 1 and 0.5 m widths are available. In total, almost 1000 blocks have been manufactured for testing: 568 small blocks (520 whole and 47 half blocks on each side), 250 medium blocks (219 whole and 31 half blocks on each side), and 141 large blocks (118 whole and 23 half blocks on each side).

The flows available at the facility exceed 10 m3/s and come from the Acequia de Sora, which belongs to the Bardenas Canal, which transports water from the Yesa Dam reservoir. These infrastructures and resources were made available for the PABLO project thanks to the authorization of the Confederación Hidrográfica del Ebro (CHE) as owner, and in agreement with Aguas de las Cuencas de España (ACUAES), as operator, and with the Comunidad General de Regantes del Canal de Bardenas, as user.

As a result of the research carried out in the project, the article “Quasi-Prototype Size Testing of Wedge-Shaped Block for Armoring Embankment Dams and Levees” has been accepted for publication in the journal Water, where the scientific results of the project are reported.



This R&D project has been funded by: