In response to necessary educational and programming changes, APS elected to modernize the existing Abingdon Elementary School. APS contracted with Hord Coplan Macht (HCM) to serve as the prime design AE for the project, and HCM subsequently engaged WDP to serve as the project’s geotechnical engineering consultant.
Additions and renovations planned for the project included a single-story gym addition, a 3-story classroom addition, relocated front entry area, reconfigured main parking lot and bus loop, site retaining walls, and several SWM/BMP concepts and facilities for proper stormwater management.
The site’s development history dates back to the late 1940s and as such, WDP was informed that periods of fill placement occurred to create the current site elevations and drainage patterns. No records could be produced documenting the fill materials placed or compaction efforts; from historical research WDP discovered that these undocumented fill soils existed where the new 3-story classroom and main parking lot/bus loop/SWM and BMP facilities were planned. Variable types of uncontrolled fill materials of low strength were encountered in several of WDP’s test borings.
WDP’s geotechnical engineering services resulted in an economically constructible project that met all APS and HCM project criteria. WDP performed geotechnical site characterization using cone penetration testing (CPT) to more reliably determine settlement potential in the 3-story classroom addition area. Due to excessive settlement predictions from loads supported by shallow foundations, WDP recommended auger-cast piles with grade beams to safely support the 3-story addition. This solution was most cost efficient and easier to install without the excessive noise or vibration from driven piles, micropiles, rammed aggregate piers, or drilled piers and thus less disruptive to school operations.
Arlington Public Schools
Arlington, VA