The construction of deep excavations in the urban environment is a technically challenging problem. Design and construction typically involves many steps including, but not limited to, site characterization, design of excavation support systems, specification of responses to construction difficulties, preconstruction surveys of adjacent properties and utilities, field observations during construction, excavation installation, and structure construction. Adjacent construction may be a nuisance to neighboring property owners (e.g., right of entry agreements, shoring, underpinning, and/or alterations to operations, dust, noise, felt vibrations, traffic congestion). Frequently, adjacent property owners claim construction-induced damage. For deep excavations, this damage may include a combination of building settlement because of a loss of lateral support, loss of use, business interruption, cosmetic finish distress, and structural damage.
Although excavations are regulated by federal, state, and local building codes, problems occur in the process of developing a site due to many factors including, but not limited to, design errors, construction errors, construction accidents, striking unknown utilities, differing site conditions, unforeseen natural events, or delays in completion. These problems occur on many projects; however, in an urban environment, the result is often damage to adjacent properties.
With 40 years of experience in solving complex scientific and engineering problems, Exponent is uniquely qualified to lead deep excavation failure investigations. Because our staff has in-house expertise in the areas of geotechnical engineering, engineering geology, construction management, structural engineering and mechanical engineering, Exponent can provide a multi-disciplinary approach that will solve any deep excavation problem.
Our services include:
- Pre- and post-construction condition surveys
- Emergency response in the event of a failure
- Analysis of the cause(s) of failure
- Analysis of the nature and extent of damage to real property, cost analysis, delay impacts, and acceleration
- Evaluation of differing site conditions claims
- Evaluation of the suitability of temporary shoring and dewatering systems
- Installation and monitoring of geotechnical instrumentation (i.e., peizometers, inclinometers, crack gauges, tiltmeters) and building monitoring devices to measure ground and building deformation
- Analysis of building or ground deformation resulting from a loss of lateral support
- Vibration analysis, including continuous monitoring of construction induced vibrations
- Evaluation of construction activities and response to construction difficulties
- Act as a third party reviewer to communicate technical issues to interested parties (i.e., owners, contractors, insurance adjusters, regulatory agencies) or to review proposed excavation plans