Colorado Tunnel Excavation Analysis

Performed the numerical simulation of the proposed excavation for the construction of below-grade railway lines. The 28-foot deep excavation was proposed to be done in stages and be supported by a row of 2-foot diameter drilled piers spaced at 2.5-feet on center. The piers would be cantilevered, and the purpose was to limit lateral and vertical movement to reduce any impact on an adjacent high-rise building only 15 feet from the excavation. Used the computer program FLAC to model the soil-structure interaction, which would occur during the excavation process. The numerical prediction was confirmed in the field during the actual excavation process, by survey points and installation and measurement of inclinometers. The FLAC prediction was very close to actual measured values and this prediction was used to develop remedial plans to avoid further movement in the field as the excavation took place.