GEOTECHNICAL & STRUCTURAL INSTRUMENTATION

Geotechnical Instrumentation: ASC provides high quality geotechnical instrumentation design, installation, monitoring and data management services for a wide range of structure and foundation applications; from tunnels, dams and bridges, to buildings, roadways and unique structures. We have planned and implemented geotechnical instrumentation installation during construction and operation for some of the major recent tunneling projects in California. Instrumentation for monitoring performance commonly include measurement of load, deformation, strain, temperature, pore pressure, earth pressure, or ground vibration. Our services include industry standard instrumentation programs and innovative solutions developed to meet the needs of our clients. Our designs may include manually monitored instruments and automated systems with web based interfaces.

We integrate sensor technology: including fiber optics, precision GPS and software – with consultation services to achieve clarity through monitoring and risk-assessment solutions for construction-related activity or other unforeseen events. For monitoring systems, we use state-of-the-art instruments to measure tilt, settlement, strain, stress, displacement, deformation, pore pressure, vibration, and noise.

Structural Instrumentation: Our approach is to develop customized monitoring solutions for our clients from the ground up. We provide turnkey structural health monitoring systems for buildings, historical structures and bridges; including steel truss, segmental box girder, cable-stay, and composite-type structures; for use in construction monitoring and long-term performance evaluation, and as maintenance tools for damage detection.  Our systems continuously monitor large, multi-sensor arrays (including fiber optics) to provide engineers and contractors with immediate feedback on structural performance and condition assessment.

ASC personnel also have experience with other unique structures, such as wind towers; we monitor foundation movements of wind towers to determine frequency response of the structure over time.  We also provide verification of the structural response of retractable roof systems to earthquakes; and structural element component testing.

The project installed 4,000 linear feet of concrete tunnel, from Harney Way to Talbert Street, via Sunnydale Avenue.  Three distinct excavation methods were used in the construction of the tunnel – Earth Pressure Balance TBM; Micro-tunneling; Pipe Jacking and Jet Grouting.

Internally-Braced Excavations: Three internally-braced excavations were constructed on the project: the first excavation was used to launch the TBM; the second excavation was used to retrieve the TBM and launch the Micro-tunnel; and the third excavation was used to retrieve the Micro-tunnel.

ASC was the Construction Tunnel/Geotechnical Instrumentation Engineer for the Contractor.  We provided Geotechnical & Tunnel Instrumentation, including instrumentation of the three excavations on the project; Railroad Instrumentation; Noise & Vibration Monitoring; and Pre-construction and Post-construction Surveys.

The Transbay Transit Center Project in downtown San Francisco will transform transportation in California by creating the “Grand Central of the West.”  The $4 billion program will replace the current Transbay Terminal with a modern regional transit hub connecting eight Bay Area counties and the State of California through nine transit systems – AC Transit,  BART, Caltrain, Golden Gate Transit, Greyhound, MUNI, SamTrans, WestCAT and future High Speed Rail from San Francisco to Los Angeles.

ASC provided services on three separate contracts – for Balfour-Beatty; Shimmick Construction; and Skanska USA Civil.  Our scope items included: Pre- and Post-construction Surveys; Real-time Geotechnical Instrumentation; Noise Monitoring; and Vibration Monitoring.  We provided services on the Excavation Contract, the BEP Contract and the Superstructure Contract.

This $1.5 billion project creates a spectacular regional gateway between the iconic Golden Gate Bridge and the City of San Francisco.  It has been designed to be context sensitive, and to improve access to the Presidio of San Francisco; it includes the unique features of a parkway, rather than a freeway.

ASC provided Real-time Instrumentation and Monitoring of the construction and existing structures at the site.  Our scope included: Pre-construction and Post-construction Surveys; Structural Health Monitoring of historical Presidio Trust Properties; Noise Monitoring; and Vibration Monitoring.

The Traffic Operations Center in Hawaii includes an underground Vehicle Turn-around at 40 ft below the surface, which was supported with a soil-nailed wall through the native sensitive Saprolite.  The excavation abutted an existing building with expensive, sensitive equipment.  The Project was implemented as part of the conversion of the Exploratory Tunnel of the H3 Tunnel into a Maintenance Tunnel.

A cast-in-place concrete tunnel lining was constructed for the existing 5,400-foot-long Exploratory Tunnel and the existing cross-passages of the main highway tunnels.

Dr. Oyenuga, as Task Manager, provided: Design; and Design Support during construction to Kiewit Pacific Co.; as well as Excavation Instrumentation / Monitoring.

The “Crenshaw/LAX Transit Corridor” is Metro construction from the Metro Green Line to Crenshaw Boulevard where it would travel north within the middle of the Crenshaw Boulevard right-of-way to the Exposition/Crenshaw Station, adjacent to the Metro Exposition Line.  The Project Route is 8.5 miles.

ASC is the Project Acoustic Engineer, responsible for control, monitoring and mitigation of Construction-induced Noise and Vibration on the project.  Monitoring at the site is being provided with Real time, automated instrumentation linked to our Web-based Central Server.

The “Bay Bridge Demolition Project” involves: i) Removal of the Cantilever Bridge Superstructure; ii) Removal of Pier E1 to approximately elevation 45; iii) Removal of Bypass Structure; and iv) Completion of the Eastbound On-ramp, the bike path, the bike path landing and Southgate Road.

Dr. Oyenuga has been ASC’s Project Manager and Principal-in-Charge since November of 2012, and is responsible for control and monitoring of Construction-induced Vibration on the project.  Monitoring at the site is being provided with automated instrumentation linked to our Web-based Central Server.