Overview

Waterford School District added 55,000 square feet to Waterford Mott High School, including a new gymnasium and auditorium. Unsuitable soils made construction of conventional shallow foundations difficult. G2 Consulting Group reviewed a number of alternatives to identify the best approach. G2 assisted during construction to confirm that design intent was followed in the field.

Prior to construction, G2 performed a geotechnical investigation including soil borings and test pits to define soil and groundwater conditions and developed recommendations for foundation design and construction. During construction, G2 performed all QC/QA testing, including auger-cast pile installation and static load testing.

Challenges/Solutions:

• Unsuitable soil conditions consisting of fill and organic matter were found on site to depths of up to nine feet. G2 considered several foundation alternatives to address variable soil conditions and recommended extending strip and spread footings through the unsuitable material, widening existing foundations to support the adjacent loads, and using a tangent force auger cast retaining/foundation system.
• When the construction team was in the process of removing unsuitable soils near existing foundations to accommodate widening, the team realized that organic matter extended below the existing foundations as well. G2 quickly evaluated the situation on site and designed and installed an auger cast pile foundation in one day.
• G2 observed construction operations and performed tests during all phases of construction to verify design intent: earthwork operations; auger cast pile installation and subsequent load tests, excavation and backfill of utilities and foundations, concrete placement for foundations and floor slabs, construction of an MSE wall in the auditorium area, grout and mortar testing for masonry construction, steel erection and pavement construction.