Bearing Capacity Failure of an Excavated Footing Prior to Building Moving Operations

An institution of higher education recently decided to relocate and repurpose several of their existing dormitories to allow for construction of new dormitories. The three-story dormitories generally consist of unreinforced hollow masonry foundation walls, with reinforced-concrete footings. The building relocations required excavation beneath each building to provide clearance for the main jacking beams and cross beams to be inserted below the buildings. The building mover successfully transported the first two dormitories. During the third building relocation, the general contractor (GC) found the east foundation wall at one of the dormitories was reinforced concrete, rather than hollow masonry. The GC engaged a saw-cutting contractor to core access holes to insert the cross beams to lift the structure and then saw cut a horizontal separation joint through the east foundation wall of this dormitory above the line of core holes. After saw cutting the reinforced-concrete east foundation wall and excavating immediately adjacent to the east foundation wall footing below the bottom of footing, the east foundation wall at the third dormitory experienced a bearing capacity failure, which required emergency stabilization and shoring of the building. The failure caused differential settlement of the footing along the east side of the third dormitory, and large cracks developed in both the reinforced-concrete foundation wall and the hollow-masonry exterior walls above. This paper provides an overview of the project and discusses the causes of the failure and the emergency building stabilization.