Industry Experience
As Geotechnical Engineer/Project Manager, responsible for analysis, field and laboratory testing, design, and project management of over a dozen projects involving analysis, design, and retrofitting of dams and reservoirs, lined water storage facilities, and canals. Descriptions of selected projects are as follows:
Design of a 140 ft high earth dam for Parker Water and Sanitation District, Parker, Colorado: Field investigation, laboratory test program, determination of residual shear strength of claystone foundation bedrock, slope stability analysis, seepage analysis, drainage system design, liquefaction potential analysis, settlement analysis using conventional and finite element (program PLAXIS) methods, permanent seismic deformation analysis using conventional methods, SHAKE analysis and finite element program PLAXIS, static and seismic analysis of outlet works tower embedded in the upstream slope and outlet works conduits using PLAXIS.
Determination of strength of about 75 ft thick alluvium in the foundation of a 230 ft high existing dam to evaluate seismic stability (name of the project to remain confidential): Coordinated, supervised and analyzed field investigation program conducted at the downstream toe of the dam. Investigation included Becker hammer testing (BPT), standard penetration testing (SPT), and spectral analysis of surface waves (SASW) measurements. Hammer efficiency measurements were made during BPT and SPT measurements. Based on this data, liquefaction potential analysis was conducted. Undrained steady state strength of the foundation alluvium was estimated to evaluate post-earthquake stability of the dam.
Evaluation of mine-induced seismicity on Bruce Park Dam and adjacent existing landslide, Trinidad, Colorado: Back analysis of the existing landslide near the dam abutment. Material properties determination from field and laboratory investigation. Determination of the magnitude and nature of expected mine-induced seismic activity. SHAKE analysis. Eastimated permanent deformations of the dam and landslide.
Design of a relief well system to reduce pressures in the foundation of 70 ft high North Lake Dam, Trinidad, Colorado: There exists a highly weathered and fractured layer of bedrock, about 8 to 12 feet thick, in the foundation of the dam underneath about 40 feet thick clayey alluvium. The layer is perceived to be hydraulically connected to the reservoir. Field investigation indicated that piezometric heads in this layer at the downstream toe of the dam and below the crest of the dam were up to 30 feet higher than the elevation of the downstream toe. Factors of safety against critical gradient, toe upheaval (blowout), and downstream slope stability are unacceptable. Seepage analysis of the dam was conducted for existing and with relief wells conditions. The model for the existing conditions was compared with measured seepage. A relief well system consitsing of a total of 22, 2 ft diameter, and about 50 ft deep wells was designed. The project will soon go under construction. Relief in foundation pressures will be monitored using piezometers.