California Department of Transportation
Coronado Bridge Carquinez Bridge San Francisco/Oakland Bay Bridge Richmond San Rafael Bridge

Materials Engineering and Testing Services

Office of Roadway Materials Testing
Instrumentation Services Branch

Photo Album

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.

String Pot Attached to Tower
String Pot Attached to South Damper
String Pot Attached ot North Damper
Yellow Case Containing Data Logger
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 from Spools
Technicians Attaching Thermocouple Wire to Rebar
Technicians Installing Thermocouples on Rebar to the Rebar Matrix
Installed Thermocouple Viewed from Top of the Pile Cap
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 Viewed from the East
Pull-Back Cables Attached to Tower
Rectangular Rosette Strain Gages Installed on Beam
Strain Indicators Set Up at Level 99
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.

Installed gages on upper slab
Installing pavement slab in roadbed
Gages wires terminated to datalogger cabinet
Installing gages on wishbone from snooper
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.

Installing gages on wishbone from snooper
Welding onto S-wire
Welding thermocouple onto S-Wire with thermocouple welder
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.

Two workers Working from the Scaffolding
Magnet Applying Pressure to Gage in Epoxy Curing Process
Two Strain Gages Attached to the Wishbone Beam
Welded Strain Gage on Member
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 gages on wishbone from snooper
Installed gages on wishbone
String pot attached to beam as reference for vertical displacement measurement
Accelerometer attached to the wishbone
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.

Installed tensioning jacks and rods on eyebar

P3 strain gage indicators

Data Logger and cabinet mounted on bridge
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.

Eric installing thermocouples on wall
Eric installing thermocouples on ceiling

Installed thermocouples in bridge cell floor

Karim with data logger and computer
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
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.

Technicians installing temperature sensors
Installed temperature loggers and thermocouples
Karim next to installed terminal box
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 at the Yuba Pass Overhead Antenna

Mounting the antenna to the tower for the Yuba Pass overhead antenna relocation

 The mounted antenna on the tower at the Yuba Pass overhead antenna relocation
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.

connecting instrumentation encased in plywood enclosure
Data Logger Setup in the field

String pot spanning the joint in a plywood enclosure

 Hydraulic jack pulling tensioning strands
Data Logger Setup
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.

Grinding concrete surface
Completed installation of a strain gaged rebar

Setup of lifting jacks

Moving a deck section supported by jacks along rails on the ground

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.

Attaching astring pot
Completed installation of a String Pot

A cut bar

P3 read out box

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.

Crew working from platform on the side of the bridge
Installed Sensors
Three data loggers and two battries
65-kip test load on service 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-Martinez bridge span under construction
Crew pouring concrete in bridge soffit. Cooling pipes in the background

Group photo of Ed, Fred, Karim, And Eric inside of soffit

Thermocouple Installed on rebar and cooling pipe.

Benicia Span

Soffit Pour
Group Photo
Thermocouple Installation


Installing crack monitor
Closeup of crack monitor

String pot connected for soffit displacement measurement

String pot connected across gap for deck displacement measurement.

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. 

Two jacks on pile pushing against the pile test beam
Monitoring pile test operation with notebook computers
Connecting fiber optic cables to the data logger
Connedting vibrating wire cables to the data logger
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 beneath the bridge deck

Close up of inclinometer

Deflection measurement using an LVDT mounted to a reference beam

Shear gage mounted to the bridge structure

Installing Sensors


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.  

Seismic accelrometers mounted to an aluminum block measuring two axes

Setting up data acquisition scanner for vibration measurements

Instrumentation setup

Concrete poured onto test forms on the bridge deck


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.

Prearing bridge steel surface using a protable grinder
Applying load adhesive to glue strain gage
Fred with data acquisition scanner and notebook PC on the bridge deck at night
Seismic accelerometer on the bridge deck
Surface Preparation
Applying Adhesive
DAQ Setup on Deck

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.  

Applying load on the bent cap using a crane and pulley setup. Force measured with a load cell suspended below the bent cap
Data acquisition scanner and notebook PC inside the instrumentation van
Strain gage mounted to concrete
String pot anchored to cable spool is measuring bent cap displacement
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.

The Zhenhua cargo ship loaded with bridge sections
A bridge section is lifted into position from the ship below
Construction worker linking suspender ropes to the bridge section
Strain gages mounted to glass in preparation for installation
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 installed in the roadway
Installing seismic plate over the trench
LVDT (left), Strain gages (center), and LVDTs (background) measure deflection
Data loggers in cabinet mounted on the road shoulder
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.

Feeding PVC pipe encased cabling mounted on plywood into the rebar cage
Lifting rebar cage with a crane
Rebar cage with sister bars attached and set in the pile hole
Telltale instrumentation comprised of LVDTs mounted on reference beams
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. 

Constuction workers heating the prestress plate
Constuction workers heating the prestress plate
Workers inserting and tightening bolts in the expanded plate
Data acquisition setup comprised of a notebook computer and scanner
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

String pot mounted on a bracket attached to suspension cable
Stting up data acquisition recorder
String pot monitoring the motion of the bridge tower
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 on the bridge damper
String pot installation monitoring the movement of the damper
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 - Signal conditioning amplifier and laptop computer
Strain gage installed on bridge structure
Installed bridge bearing
Data Acquisition Setup
Gaged Member
Installed Bearing

Carquinez Bridge (2000-2001)

Installing strain gage on bridge member
Installing isolation pad
Gage Installation
Installed Isolation Pads