Walker Jones School
“The Walker Jones campus brings together all the public facilities you need to build a strong community,” Mayor Fenty announced at the project unveiling in 2009. The DC public project consisted of the demolition of two existing schools and the construction of a new 100,000-sf K-8 school, a 5,000-sf public library and a 20,000-sf public recreation center. All three parts are incorporated in a four-story U-shaped building, with a playground nestled in the middle.
Fill material blanked the site, followed by a mix of soft and organic soils present more than 35 ft below the FFE, consisting of low/highly plastic clays and peat. Organic soils are problematic for foundation support due to their susceptible to large amounts of settlement and posed the main challenge for this project. Soil conditions below bottom of footing consist of 0 to 5 ft of very stiff clay fill underlain by stiff to very stiff clay underlain by loose to medium dense silty sand, underlain by very stiff clay. A couple of borings encountered very stiff peat and very soft organic silt. Groundwater was encountered as high as 1 to 4 ft below bottom of footing.
Grouted Impact Pier elements were a perfect fit for the site, which initially was to be supported by a costly mat foundation. Grouted impact piers not only handled the high ground water on site (some borings as high as 1 to 4 ft below the bottom of footing) but also prevent excessive settlement by allowing the building loads to span the soft and organic layers into a denser soil.
GeoConstructors installed 628, 20-inch Grouted Impact Pier elements from 14 to 37 ft. Column loads for the building ranged from 48 to 300 Kips, mat foundations from 924-2299 Kips and walls from 0.75-18 KLF (42klf for a retaining wall).
District of Columbia Office of the Deputy Mayor for Planning and Economic Development - Washington, DC
Forrester Construction Company - Rockville, MD
Hord Coplan Macht, LLC - Baltimore, MD
Simpson Gumpertz & Heger, Inc - Rockville, MD
ECS Mid-Atlantic, LLC - Chantilly, VA