Nicholson constructed a soil nail and shotcrete support of excavation system for the new Chinese Embassy in Washington, D.C. The wall consisted of approximately 1,600 soil nails and 50,000 square feet of exposed shotcrete surface. The soil nail wall was selected over more conventional systems because the adjacent embassies would not grant underground easements for tieback anchors to cross their property lines. The close proximity of other structures led to tight excavation requirements, precise wall positions, and shotcrete tolerances. The soil nail wall was irregularly shaped, benched in areas, and reached total heights up to 98 feet. Design challenges included soft soil conditions, inside wall corners, underground utilities, the adjacent critical structures and seismic impacts from blasting.
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