7/2024 - Cemetery expansion with CRB retaining walls in Spain

La Almudena Cemetery, Madrid, Spain

In the reclamation of a plot previously filled with waste, retaining walls were necessary to create new horizontal platforms and garden areas for the La Almudena Cemetery in Madrid, Spain.

Initially, the plan involved the construction of poured concrete walls. However, the presence of extremely soft soils led the project team to seek alternatives, as the foundations required for the concrete walls would have been prohibitively expensive.

In total 10 500 Terraforce L12 blocks were installed at the cemetery, resulting in visually striking rock face finish walls. — In total 10 500 Terraforce L12 blocks were installed at the cemetery, resulting in visually striking rock face finish walls

Geotechnical surveys and investigations

Says Miguel Seller, civil engineer, ORBE Técnicas y Medioambiente: “Following the initial engineering study conducted by ORBE, we recommended the installation of green reinforced soil walls (Green Walls) in certain areas of the plot to be reclaimed, and segmental walls in other sections of the project. The segmental walls, designed by ORBE, feature Terraforce L12 rock face blocks, which are manufactured by Prensagra Prefabricados near Madrid as prefabricated elements for the visible surface.”

The supporting soil was very soft to great depths, as confirmed by our penetration tests. — The supporting soil was very soft to great depths, as confirmed by our penetration tests

Setting out the corners and placement of geogrids every second row of Terraforce blocks

Due to soft soil, ORBE proposed reinforcing the foundation beneath the segmented wall with geogrids and improved soil

Compaction of backfill in process behind the wall and a precise ninety-degree corner

Miguel explains how in-depth geotechnical testing helped formulate the best design for the site: “The project is not particularly notable in terms of wall height, with the walls being only 3m maximum height, whereas ORBE has previously constructed walls up to 10m with Terraforce blocks. However, it is especially significant that the supporting soil was very soft to great depths, as confirmed by our penetration tests.

“Internal stability was analysed as usual using Terraforce’s Maxiwall Pro software, this analysis was subsequently compared with other software owned by ORBE, along with a global stability assessment. Based on these studies, we proposed reinforcing the foundation beneath the segmented wall with geogrids and improved soil.”

Visual Appeal

The Terraforce walls also accommodate gently sloping access ramps a — The Terraforce walls also accommodate gently sloping access ramps

Steps, corners and garden features with Terraforce blocks

To finish of the overall linear look, straight-lined steel rails were set into blocks - filled with concrete for that purpose - and sharp-edged concrete caps set along the top rows of blocks — To finish of the overall linear look, straight-lined steel rails were set into blocks – filled with concrete for that purpose

Sharp-edged concrete caps set along the top rows of blocks finish off the walls

In total 10 500 Terraforce L12 blocks were installed at the cemetery, resulting in visually striking rock face finish walls. Reinforced with geogrids every second row and stepped outwards at intervals with precise ninety-degree corners, the walls also accommodate gently sloping access ramps and rectangular garden features. To finish of the overall linear look, straight-lined steel rails were set into blocks – filled with concrete for that purpose – and sharp-edged concrete caps set along the top rows of blocks.