Materials Engineering and Testing Services

Office of Roadway Materials Testing
Instrumentation Services Branch

The photo album contains a sample of pictures from current and past instrumentation projects.  Click on the thumbnail of interest to see the full-size picture, then use your Web browser's Back button to return to this page.

Construction & Maintenance Support

 

Vincent Thomas Bridge (2012)

String potentiometers were mounted on bridge dampers to monitor linear displacement under traffic load.

Measuring Movement Relative to the Tower	String Pot on Upper South Damper	Sting Pot on Lower North Main Damper	Data Logger in Case

Feather River Bridge -- 10th Street (2011)

Installed and monitored 12 thermocouples to obtain a temperature profile of a newly poured concrete pile cap for the 10th Stree Bridge in Marysville. In four stategic locations, four sets of thermocouples installed on a length of rebar were lowered and attached to the matrix of rebar in the pile cap. The temperature profile was developed from temperatures measured at the bottom, middle, and top of the pile cap to ensure that the installed cooling system was functioning properly.

Unrolling Thermocouple Wire	Attaching Thermocouple Wire to Rebar	Lowering Instrumented Rebar	Installed Thermocouple Viewed from the Top of the Pile Cap

SFOBB SAS Tower Pull-Back (2011)

Installed strain gage rosettes on tower beam webs and flanges at levels 99 and 109.  Gages were monitored using strain indicators during a 0.5-meter tower pull-back operation.

Tower Under Construction	Tower Pull-Back Cables	Three-Element Rectangular Strain Gage Rosette	Strain Indicators

Pavement Rehabilitation -- I-680 in Dublin (2011)

Instrumentation Services installed strain gages and thermocouples on pre-fabricated pavement slabs and collected strain and temperature data after installation of the slabs on the roadbed near the Alcosta Blvd offramp in Dublin. The effect of post-tensioning, shrinkage, loading, and temperature were studied from the data.

Strain Gages Installed on Top Slab	Installing Slab on Roadbed	Gages Wired to Multiplexers and Datalogger	Collecting and Reviewing Data

SFOBB Cable Wrapping Weld Test (2011)

Instrumentation Services provided themocouple welding and temperature monitoring equipment to support engineers monitoring construction of the SAS (self-anchored suspension) span of the Bay Bridge. Experiments were performed using exothermic welds on the S-wire cable wrapping wire for the suspension cable. The maximum temperature beneath the weld was monitored using thermocouples welded to the S-wire.

Setting Up Welding Equipment	Welding onto S-Wire	Welding Thermocouple onto S-Wire

San Mateo-Hayward Bridge Wishbone Beam Monitoring (2010-2012)

Instrumentation Services installed strain gages, a displacement monitoring device, and an accelerometer on the repaired wishbone-shaped beam under the westbound lanes of the bridge. A a high speed data acquisition scanner was connected to the sensors to monitor the behavior of the wishbone under traffic load.

Working from the Walkway and Scaffolding	Magnet Securing Gage During Epoxy Curing Process	Two Strain Gages Attached to the Wishbone	Welded Strain Gage on Member

 

Installing Strain Gages on Wishbone	Installed Strain Gages on Wishbone	Measuring Vertical Displacement Using String Pot	Accelerometer Attached to Wishbone

SFOBB Eyebar Repair (2009)

During the repair and retrofit of the broken eyebar, Instrumentation Services installed strain gages and monitoring equipment to measure the strain on the rods as they were tensioned.  After the repair was in place, Instrumentation installed a high speed data acquisition scanner to continue monitoring the strain gages under traffic load.

Installing Strain Gages on Tension Rods	Installed Jacks and Tension Rods on Eyebars	P3 Strain Gage Indicators	Instrumentation Cabinet with Data Logger

SFOBB SAS Temperature Monitoring (2009-2010)

Installed thermocouples to measure the temperature of the metal at various locations inside the bridge cell on the Self-Anchored Suspension (SAS) transition section.  The purpose is to determine the amount of thermal expansion as a result of solar and seasonal change.

Installing Thermocouples to Wall	Installing Thermocouples to Ceiling	Installed Thermocouples on the Floor	Thermocouples Connected to Data Logging System

Richmond-San Rafael Bridge Galvanic Cathodic Protection System (2009)

Instrumentation Services retrofitted terminal boxes on the piers for electrical reference cell potential measurements for the galvanic cathodic protection system.

Karim Cutting Conduit	Installed Terminal Box without Cover	Lowering Reference Cell into the Water	Measuring Potential with Respect to the Reference Cell

SFOBB Yerba Buena Island Transition Structure (2009)

Setup and measured the temperature of a concrete mass pour for Pier W7R footing using integrated logger and thermister package as well as thermocouples.

Installing Temperature Sensors	Installed Temperature Sensors	Karim next to installed Terminal Box and Thermocouple Data Logger

Yuba Pass Overhead Antenna Relocation (2008)

Instrumentation Services performed an extensive field evaluation of cellular phone service coverage when its customer reported difficulty downloading data from a cathodic protection system data logger. A Yagi antenna was mounted on a weather tower in the vicinity which afforded a more direct view of the cellular phone tower and provided greater signal strength

Cathodic Protection Cabinet	Feeding Antenna Cable in Pull Box	Mounting Antenna to Tower	Mounted Antenna on Tower

SFOBB West Approach Replacement (2007-2008)

Displacement sensors were installed at different bridge frames to measure concrete shrinkage during and after post-tensioning.

Instrumentation	Data Logger Setup	Installation	Tensioning Jack

SFOBB Yerba Buena Island Upper Roadway Deck Section Replacement (2007)

Strain gages were installed in various locations on the rebar and on the concrete surface to monitor deflections during the rolling in of a replacement upper deck section during the Labor Day weekend. An approximately 300-ft pre-cast section was jacked up from temporary columns and rolled into place and onto new columns.

Surface Preparation	Strain Gaged Rebar	Jack Setup	Moving Structure

SFOBB Yerba Buena Island Detour (2007)

String potentiometers were installed to assess prestress bar slippage during cutting operations on a demolition project at the approach to the Yerba Buena Island tunnel.

Installing String Pot	Installed String Pot	Cut Bar	Readout Box

SFOBB Skyway (2007)

The service platform attached to the side of the Skyway structure was instrumented and the platform was load tested to 65 kips for 12 hours. Strain gages were attached to the mounting plates, stubs, and concrete. Inclinometers were attached to the plates. LVDTs were attached to selected bolt heads.

Platform	Installing Strain Gages	Installed Sensors	Data Loggers	Test Load

Benicia-Martinez Bridge (2005 to 2007)

Thermocouples were installed to monitor concrete curing temperatures for deck and soffit pours for the construction of the new Benicia-Martinez Bridge.  Crack monitors were also installed to measure changes in width of hairline cracks during construction. String potentiometers measured the displacement change prior to hinge installation.

Benicia Span	Soffit Pour	Group Photo	Thermocouple Installation

 

Crack Monitor Installation	Crack Monitor	Soffit Displacement Measurements	Deck Displacement Measurements

Highway 149 Pile Testing (2006)

Instrumentation Services assisted the Geotechnical Services Foundation Testing Branch in setting up data logging programs to collect pile load test data at the construction of interchanges on SR 149/SR 99 and SR 149/SR 70 near Oroville.  This was a research project to evaluate fiber optic, vibrating wire, and resistive strain gage technology from various manufacturers. 

Pile Test Beam	Monitoring Pile Test Operations	Connecting Fiber Optic Sensors	Connecting Vibrating Wire Sensors

Feather River Bridge (2006)

Strain gages and inclinometers were installed to measure rotation of a sidewalk expansion channel as well as the bend, stress and displacement of the adjacent fascia beam before, during, and after the concrete pour for a section of the new sidewalk on the south side of the Highway 20 Feather River Bridge between Yuba City and Marysville.

Installing Sensors	Inclinometer	Displacement Measured with LVDT	Shear Gage

Pit River Bridge (2006)

Accelerometers were used to measure bridge vibration due to train and vehicular traffic on the bridge.  The purpose was to determine whether vibration had any effect on the distribution of aggregates on freshly poured concrete.  Concrete was poured into forms placed on the deck surface.  Accelerometer data were recorded for 8 hours.  The concrete slabs were later removed and shipped to the laboratory in Sacramento for further testing.  

Accelerometer	Setting Up Scanner	Setting Up Scanner	Concrete Pour

Noyo River Bridge (2004)

Strain gages were used to measure the resonant frequency of the old Noyo River bridge in Fort Bragg.  They were also installed at strategic locations on the bridge to monitor changes in strain during bridge dismantling.  This was conducted to verify the bridge models. An accelerometer was used to measure the frequency of the new bridge.

Surface Preparation	Applying Adhesive	DAQ Setup on Deck	Accelerometer

New Benicia-Martinez Bridge Toll Plaza (2003)

Instrumentation Services installed strain gages on concrete and string potentiometers in order to determine the amount of strain and displacement on the bent cap and column with a 90-kip load at the end of the structure.  A cable attached to the cap running through a pulley to a crane provided the necessary load. Pulling force was measured with a 120-kip capacity load cell.  

Loading the Structure	Data Logger Inside Van	Strain Gage	String Potentiometers

New Carquinez Bridge (2003)

With assistance from Geotechnical Instrumentation, Instrumentation Services strain gaged the tension rods on the suspender ropes as orthotropic box girder sections were hoisted and connected to suspender links.  This was done to ensure that the tension in the suspender ropes was within design limits.

Zhenhua	Deck Lifting	Linking Suspender Ropes	Strain Gages

Seismic Retrofit Support  (2000 to present)

Seismic Joint Test (2005)Instrumentation Services instrumented a seismic joint at a test bed in the eastbound lanes of I-80 approaching the Carquinez Bridge.  Deflection measurements are used to verify joint design parameters.

Trench Forms and Rebar	Installing Seismic Plate	Sensor Installation	Data Logger

San Francisco Oakland Bay Bridge 4th Street Ramp (2004)

Instrumentation Services, along with the Geotechnical Services' Geotechnical Design Branch and Foundation Testing Branch, instrumented two piles for the San Francisco-Oakland Bay Bridge 4th Street Off Ramp project.  Site C is a 80-foot long soil-cement pile and Site B is a 120-foot Tubex pile.  The reinforcing cage for both piles were instrumented with strain gaged sister bars to determine the strain on the pile during pile load testing.

Installing Piped Cable	Lifting the Cage	View of Cage in Hole with Sister Bars	Telltale Instrumentation

San Francisco Oakland Bay Bridge (2001-2003) 

Instrumentation Services installed instrumentation to monitor tongue prestress plate expansion, temperature and stress during the heating process. 

Heating the Prestress Plate		Inserting Bolts	Data Acquisition Setup

Instrumentation Services monitored the motion of the suspension cable relative to the deck cord prior to installation of cable ties.  String potentiometers measured displacement and thermocouples measured air and cable temperature

Cable String Pot	Setting Up Data Acquisition Recorder	Tower String Pot

Vincent Thomas Bridge (2001-2002)

String potentiometers and strain gages were mounted on bridge dampers to monitor linear displacement and stresses under traffic load.

Installing Strain Gages	String Pot Installation

Strain gages and instrumentation were installed to monitor stresses on bridge members during jacking operations on the San Francisco Oakland Bay Bridge and the Carquinez Bridge.

San Francisco Oakland Bay Bridge  (2000-2001)

Data Acquisition Setup	Gaged Member	Installed Bearing

Carquinez Bridge (2000-2001)

Gage Installation	Installed Isolation Pads