Monitoring of structure performance via instrumentation is a significant component of D’Appolonia’s work related to dams, hydraulic structures, slope and fill construction, and foundations for rotating machinery. Instrumentation systems typically comprise in-situ gages, either surface mounted or installed in borings, that provide information about specific aspects of structure behavior and environmental conditions. Instrumentation systems provide data regarding structure loading, deformation, and internal and external water pressures. In general, instrumentation systems are either manually read or automatically monitored. Manually read systems are economical for short-term projects where only infrequent data collection is required and/or when project personnel are frequently on site. Automated systems are employed for long-term monitoring where frequent data collection is required, particularly at remote sites. Automated systems also allow for rapid data distribution to large numbers of individuals, if necessary, and allow for the automatic triggering of alarms if pre-established threshold limits are exceeded.

Instrumented caisson reinforcement being installed at dam and lock structure on Monongahela River and typical instrumentation panel for automatic data acquisition.

Descriptions of some D'Appolonia projects involving instrumentation installation and monitoring are provided in the following:


Instrumentation for Construction of Abutments for New Dam

D’Appolonia was retained by the prime contractor for abutment construction at the new Braddock Dam near Pittsburgh, Pennsylvania to design, install, and monitor an instrumentation system for verifying that the abutments performed as intended in the design.

Instrumentation and Monitoring for Cofferdam System

D’Appolonia was retained to install an extensive instrumentation and data acquisition system for monitoring the response associated with construction of a lock wall and sheetpile cofferdam cells at the Point Marion Lock and Dam located on the Mongahela River near the Pennsylvania-West Virgina border.

Rehabilitation of Fossil-Fuel Power Plant Infrastructure

D'Appolonia designed and installed an instrumentation system to evaluate the effects of foundation heave from expansive soils on a turbine generator foundation. It was determined that the foundation movement had ceased and repairs were limited to realigning pipes and installing new pipe supports, resulting in a major cost savings to the owner.

Airport Runway Embankment Settlement Monitoring

D’Appolonia was retained to install and monitor instruments for a 60-foot-high fill constructed over a layer of compressible peat. The instrumentation included pneumatic settlement gages, settlement plates, pneumatic piezometers, and inclinometers. Once the compression of the peat was essentially complete, additional fill was placed to bring the fill surface to the desired grade.