Repairing the Washington Monument

The newly restored Washington Monument reopened almost three years after the Aug. 23, 2011, earthquake caused enough cracks and breaks to force it to close. See the extent of the damage and how it was fixed:

washington monument
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    No. of damaged slabs: 544

    Spin to explore

    Total height:
    555 feet

    Stainless steel anchor bracket

    Heaviest damage in top

    Stone masonry on all four sides of the National Monument was damaged during the earthquake, but the top section, known as the pyramidion, was most affected.

    Repairing the top

    Spalling or breakage of exterior panel corners, cracking of vertical “rib” supports and shifting of vertical joints must be addressed. Installation of stainless steel
    anchor brackets would
    connect exterior marble
    panels to interior
    marble blocks.

    pyramidion

    Damage to core

    Masonry damage was prevalent along outer corners of the structure. Repairs will involve these four techniques:

    Anchoring

    Loose fragments were secured with adhesive and stainless steel anchors that were drilled in to the backing stone.

    Patching

    A rectangular shape was cut around missing stone and filled with one that matches the space and reinforced with stainless steel rods and mortar.

    Sealing

    Cracks were injected with epoxy-based adhesive until completely filled. Limestone dust was sprinkled on the surface to mask the crack.

    Repointing

    Damaged lime mortar was removed and replaced. The water-permeable material allows moisture to flow off of the structure instead of trapping it in the stones.

    Shallow base

    The base of the monument extends about 35 feet below ground level and sits on several layers of sand and clay.

    Loam, fill and clay

    Sand and clay

    Sand, gravel and clay

    Blue clay

    loam
    sand and clay
    sand, gravel, and clay
    blue clay

    SOURCE: National Park Service. GRAPHIC: Alberto Cuadra, Kathryn Faulkner, Cristina Rivero and Michael E. Ruane - The Washington Post. Published Aug. 23, 2012.

    Repairing the National Cathedral

    National Cathedral

    A team of engineers, masons and stone carvers soon will begin fixing damage from the August 2011 earthquake at the National Cathedral, a delicate process that is expected to cost at least $15 million and take a decade or more.

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