INSTALLATION OF SEISMIC INSTRUMENTATION ON THE … · 2016. 5. 17. · This bridge serves as the main transportation access between Hilo and Kailua-Kona communities [HDOT, 1995]

INSTALLATION OF SEISMIC INSTRUMENTATION

ON THE KEALAKAHA STREAM BRIDGE

Solomone Tauaika

Ian N. Robertson

and

Gaur P. Johnson

Research Report UHM/CEE/13-01

May 2013

Prepared in cooperation with the:

State of Hawaii

Department of Transportation Highways Division

and U.S. Department of Transportation Federal Highway Administration

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Technical Report Documentation Page

1. Report No.

2. Government Accession No.

3. Recipient's Catalog No.

4. Title and Subtitle

INSTALLATION OF SEISMIC INSTRUMENTATION ON THE KEALAKAHA

STREAM BRIDGE

5. Report Date

May 2013

6. Performing Organization Code

7. Author(s)

Tauaika, S., Robertson, I.N., and Johnson, G.P. 8. Performing Organization Report No.

UHM/CEE/13‐01

9. Performing Organization Name and Address Department of Civil and Environmental Engineering University of Hawaii at Manoa 2540 Dole St. Holmes Hall 383 Honolulu, HI 96822

10. Work Unit No. (TRAIS)

11. Contract or Grant No.

48054

12. Sponsoring Agency Name and Address Hawaii Department of Transportation Highways Division 869 Punchbowl Street Honolulu, HI 96813

13. Type of Report and Period Covered

Interim

14. Sponsoring Agency Code

15. Supplementary Notes

Prepared in cooperation with the U.S. Department of Transportation, Federal Highway Administration

16. Abstract In order to advance the present understanding of how structures respond to earthquakes, it is essential to install seismic instrumentation and record the response of structures located in high seismic zones. This report presents the installation of the seismic instrumentation system on the Kealakaha Stream Bridge on the Island of Hawaii for monitoring the structure during ambient traffic and future seismic activity.

The Kealakaha Stream Bridge is the first base isolated structure in the state of Hawaii. As such, it represents an ideal opportunity to monitor the performance of a major bridge structure equipped with base isolation in a region that experiences numerous earthquakes. Although the bridge is not located in the most seismic portion of the island, it will experience significant ground motion during major events elsewhere on the island.

This report provides a description of each type of instrumentation including details of their operation and purpose. The sensor locations and instrumentation layouts are also provided and explained. A companion report (UHM/CEE/13-02) provides a detailed description of the data recording system that monitors the instruments. Future reports will analyze the data recorded during ambient traffic and future seismic events.

17. Key Words

Seismic, Instrumentation, Base Isolation, Sensors, Accelerometers, Data Acquisition

18. Distribution Statement

19. Security Classif. (of this report)

Unclassified 20. Security Classif. (of this page)

Unclassified 21. No. of Pages

22. Price

Form DOT F 1700.7 (8‐72) Reproduction of completed page authorized

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ABSTRACT

In order to advance the present understanding of how structures respond to earthquakes, it is beneficial to install seismic instrumentation and record the response of structures located in high seismic zones. This report presents the installation of the seismic instrumentation system on the Kealakaha Stream Bridge on the Island of Hawaii for monitoring the structure during ambient traffic and future seismic activity.

The Kealakaha Stream Bridge is the first base isolated structure in the state of Hawaii. As such, it represents an ideal opportunity to monitor the performance of a major bridge structure equipped with base isolation in a region that experiences numerous earthquakes. Although the bridge is not located in the most seismic portion of the island, it will experience significant ground motion during major events elsewhere on the island.

This report provides a description of each type of instrumentation including details of their operation and purpose. The sensor locations and instrumentation layouts are also provided and explained. A companion report (UHM/CEE/13-02) provides a detailed description of the data recording system that monitors the instruments. Future reports will analyze the data recorded during ambient traffic and future seismic events and report on the bridge performance.

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ACKNOWLEDGEMENT

The authors wish to thank Mitchell Pinkerton and Austin Rogers for their considerable effort and assistance during the installation of the instrumentation. Assistance during preparation of the instrumentation was provided by Mehdi Ghalambor and Donna Gonzales. The Hilo office of Hawaii Department of Transportation provided considerable assistance with equipment and personnel to access the soffit of the bridge over the river gorge. They also provided brush clearing assistance around the bridge piers and free field sites.

This project was funded by the Federal Highway Administration and Hawaii Department of Transportation Research Branch. This support is gratefully acknowledged. The contents of this report reflect the views of the authors, who are responsible for the facts and accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of the State of Hawaii, Department of Transportation or the Federal Highway Administration. This report does not constitute a standard, specification or regulation.

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TABLE OF CONTENTS

1 INTRODUCTION ................................................................................................................................ 1

2 BRIDGE OVERVIEW AND BACKGROUND ................................................................................... 3

2.1 Bridge Location ............................................................................................................................ 3

2.2 Bridge Background ....................................................................................................................... 3

2.3 Seismic Instrumentation Purpose .................................................................................................. 4

2.4 Bridge Design and Development .................................................................................................. 4

3 SEISMIC INSTRUMENTATION SYSTEM ....................................................................................... 7

3.1 Accelerometers (Tri-axial) Sensors............................................................................................... 8

3.1.1 Description ............................................................................................................................ 8

3.1.2 Layout and Installation ........................................................................................................ 10

3.2 Free Field Site ............................................................................................................................. 10

3.2.1 Description and Layout ....................................................................................................... 10

3.3 Downhole Accelerometers .......................................................................................................... 12

3.3.1 Description .......................................................................................................................... 12


3.4 Accelerometer (Bi-axial) Sensors ............................................................................................... 14

3.4.1 Description .......................................................................................................................... 14


3.5 Accelerometer (Uni-axial) Sensors ............................................................................................. 15

3.5.1 Description .......................................................................................................................... 15


3.6 Rotation Sensor ........................................................................................................................... 16

3.6.1 Description .......................................................................................................................... 16


3.7 Relative displacement or String Pot Sensors. ............................................................................. 18

3.7.1 Description .......................................................................................................................... 18


3.8 General Cable Routing between Abutments and Piers: .............................................................. 24

4 SEISMIC INSTRUMENTATION PREPARATION ......................................................................... 25

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4.1 Instrumentation Testing .............................................................................................................. 25

4.2 Cables .......................................................................................................................................... 25

5 SEISMIC INSTRUMENTATION OVERALL LAYOUT AND CHANNEL ASSIGNMENT ........ 27

5.1 Central Recording System .......................................................................................................... 27

5.2 DAQ Channel Distribution and Sensors Orientation .................................................................. 31

6 SUMMARY AND CONCLUSION .................................................................................................... 37

7 REFERENCES ................................................................................................................................... 39

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TABLE OF FIGURES

Figure 2-1: Horizontal Ground Acceleration (%g) at a 0.2 Second Period With 2% Probability of

Exceedance in 50 Years [USGS] .................................................................................................................. 3

Figure 2-2: Honokaa end span showing the six drop-in girders and abutment 1. ......................................... 5

Figure 2-3: Bridge plan and elevation views ................................................................................................ 6

Figure 3-1: Overall Layout of First Half of the Bridge, Honokaa Side ........................................................ 8

Figure 3-2: Overall Layout of Second Half of the Bridge, Hilo Side ........................................................... 8

Figure 3-3: Interior view of Tri-axial Sensor. ............................................................................................... 9

Figure 3-4: Location of Tri-axial Sensors ................................................................................................... 10

Figure 3-5: Free field site at Honokaa side of the bridge. ........................................................................... 11

Figure 3-6: Free field site at Hilo side of the bridge. .................................................................................. 11

Figure 3-7: Shallow Borehole EpiSensor (ES-SB). .................................................................................... 12

Figure 3-8: Location of the Free Field Site and Free Field sensors. ........................................................... 13

Figure 3-9: Free Field Sensor Layout ......................................................................................................... 13

Figure 3-10: Bi-axial EpiSensor (ES-B) ..................................................................................................... 14

Figure 3-11: Uniaxial EpiSensor, ES-U2 .................................................................................................... 15

Figure 3-12: Rotation Sensor. ..................................................................................................................... 17

Figure 3-13: Location of Rotation sensors. ................................................................................................. 17

Figure 3-14: Relative Displacement Sensor. ............................................................................................... 19

Figure 3-15: Displacement sensor layout configuration. ............................................................................ 20

Figure 3-16: Plan view layout of the displacement sensor at the Pier ........................................................ 22

Figure 3-17: General Side view layout of the displacement sensor at the Pier. .......................................... 22

Figure 3-18: Typical locations of displacement sensors at the Abutment #1 and #2 .................................. 23

Figure 3-19: Overall plan view of displacement sensors at Honokaa side ................................................. 24

Figure 4-1: Cable end after being stripped, treated and tagged. ................................................................. 26

Figure 4-2: Cables ready to be shipped to job site. ..................................................................................... 26

Figure 5-1: Central Recording System or Data Recording Unit ................................................................. 28

Figure 5-2: Plan View of the Honokaa Side of the Bridge ......................................................................... 29

Figure 5-3: Plan View of the Hilo Side of the Bridge ................................................................................. 29

Figure 5-4: Overall Bridge Elevation shows all bridge major components. ............................................... 30

Figure 5-5: Typical Local to Global Orientation of a Tri-Axial Sensor. .................................................... 31

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1 INTRODUCTION

The Kealakaha Stream Bridge Replacement is 720ft long and is about 33 miles northwest of Hilo and one mile from the coast on the island of Hawaii (Big Island). This island has a significant seismic hazard, having experienced earthquakes with magnitude 7.2 as recently as 1975 [Stephens, 1996].

Initial development of this seismic instrumentation was based on several instrumentation projects by the California Division of Mines and Geology (CDMG) and the California Department of Transportation (Caltrans) [Pat Hipley, 2005]. The Kealakaha Stream Bridge was selected for instrumentation since it is located in a high seismic zone with frequent earthquake events. According to the USGS there are about a thousand small earthquakes every year underneath Hawaii Island [Clague, 1995].

A digital seismic instrumentation system was installed to monitor the dynamic response of the bridge and its performance during earthquakes and ambient traffic. All instrumentation systems are interconnected and have download capability to various locations including the research center at the University of Hawaii at Manoa (see Figure B1) for data transmission and remote connection. All data that are collected from this instrumentation will be used to identify the structure’s fundamental and most significant frequencies, calculate deck level acceleration amplification functions, investigate soil-structure interaction effects, and compare the design analytical model with the recorded motion of the structure. To determine and obtain accurate displacements and mode shapes of Kealakaha Bridge, numerous sensors were placed on the bridge structure to provide sufficient data to establish response during an earthquake event. This includes monitoring the substructure (foundations) and the superstructure (bridge deck) simultaneously.

This seismic instrumentation plan consists of thirty four accelerometer sensors, sixteen displacement sensors, eleven rotation sensors and two data acquisition units (DAQ) that have been placed on the bridge structure. There are two free-field sites including bore holes at both sides of the bridge at which SBEPI (Shallow Borehole Episensor) Tri-axial accelerometers are deployed at different depths below grade. The instruments will monitor and record the full motion of the structure, including free-field motion, pile cap translation and rotation, deck and abutment accelerations, and joint movement. This report presents detailed figures and documentation of the overall seismic instrumentation installation process.

The bridge consists of 3 spans composed of cast in place 5 cell box girders over the piers and precast drop-in girders. The bridge has three spans with lengths of 180ft, 360ft, and 180ft. The potential for significant damage from seismic events is high. It is the first bridge in the State of Hawaii to have been built with seismic base isolation. Installing seismic instrumentation to record and analyze the response of this bridge will help to validate the original design, and provide data for future bridge designs. The final seismic instrumentation plan has been modified to accommodate the base isolation system.

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2 BRIDGE OVERVIEW AND BACKGROUND

2.1 Bridge Location

The Kealakaha Stream Bridge Replacement Project is located on Hawaii Belt Road approximately 33 miles northwest of Hilo and one mile from the ocean’s shore (Figure 2-1). This bridge serves as the main transportation access between Hilo and Kailua-Kona communities [HDOT, 1995].

Figure 2-1: Horizontal Ground Acceleration (%g) at a 0.2 Second Period With 2% Probability of Exceedance in 50 Years [USGS]

2.2 Bridge Background

The existing bridge over the Kealakaha Stream on the Island of Hawaii is seismically deficient and was scheduled for replacement in 2003. The Kealakaha Stream Bridge Development was originally designed as a single cell box girder throughout the entire length (645 ft) of the structure [Stephens, 1996]. However, it was ultimately redesigned and constructed with five cell box girder over the piers and prestressed drop-in girders (see Figure 2-2, Figure 2-3, Figures B19 and B20). It was designed with two 12 ft wide traffic lanes, and 12 ft shoulder lanes on each side. Its centerline is approximately 120 ft downstream from the existing bridge with a radius of 1800 ft [HDOT, 1995]. The project was estimated at $14.5 million and so will require two separate designs according to federal law, since the cost is greater than $10 million. The value-engineered pre-cast girder system on base isolation resulted in a

Project site

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significant cost saving, and so was preferred over the original single box girder design [HDOT, 1995].

2.3 Seismic Instrumentation Purpose

The new bridge was built as a prestressed concrete structure spanning approximately720 feet, and designed to withstand all anticipated loads, including earthquake ground shaking. Because of the bridge's location on the seismically active island of Hawaii, it represents an ideal opportunity for seismic instrumentation of a major bridge structure in the state. Earthquakes in the future will be monitored to study the response of this structure and compare the response with the analytical model used to design the Kealakaha Stream Bridge Replacement. In addition to seismic monitoring, the instrumentation will provide feedback on the dynamic properties of the structure under ambient traffic load. This information will be used to evaluate changes in the structural response with time so as to identify potential deterioration of the structure.

The project includes:

1. coordinating with the design consultant of the bridge for the instrument installation; 2. procure and install the instruments in the new construction; 3. monitor and maintain the instruments; 4. monitor ambient traffic; 5. process all data collected during any earthquake events; and 6. prepare final technical report at the completion of the study.

This report will focus mainly on the installation phase (1 and 2) of seismic instrumentation system in the new bridge and prepare a technical report based on the final installation of the seismic instruments.

2.4 Bridge Design and Development

During value-engineering of the bridge design, the structure was changed from a single cell box girder to a five cell box girder combined with drop in girders and a base isolation system. These design modifications were developed due to length requirement between piers and the steep terrain below the bridge structure. The bridge has a radius of curvature of 1800ft and it has three spans of lengths180 ft, 360 ft, and 180 ft. It is approximately 48 ft wide and provides two 12ft wide travel lanes and two 10ft wide shoulders. Since it is located in an active seismic zone, it is required to be designed for a ground acceleration of 0.4g [ASPIRE, 2010]. The new replacement bridge is built with both precast and cast in place structural members.

There are three main parts that make up the Kealakaha Stream Bridge. These parts consist of the Superstructure, Substructure, and the Seismic Bearing Base Isolation. Seismic Base Isolation was the main component of the bridge that dramatically changed the foundation design to reduce the number of caissons and remove the need for nail walls to support the slope around the footings.

The superstructure consists of 100-ft long and 205-ft long WSDOT W95PTG precast, prestressed concrete bulb-tee girders and 150-ft long cast-in-place concrete box girders above each pier [ASPIRE, 2010] (Figure B19). The road leading to the project site is unsuitable to transport long precast members due to tight curves. Forty eight 50-ft long segmental precast members were constructed in Washington State with a compressive strength of 9000 psi. These

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50-ft long girders were shipped to the site and spliced together to get each required girder length (Figure B20).

Figure 2-2: Honokaa end span showing the six drop-in girders and abutment 1.

Because of the addition of base isolation between the piers and superstructure, the demand on the foundation was significantly reduced. The pier height could also be reduced to minimize the cost of construction. In addition, the quantity of drilled shafts was reduced by 2226 linear foot. Footing sizes were also reduced by 60 %.

The substructure consists of four total vertical supports, two abutments and two piers as shown in Fig 2.3. Abutment #1 and drop in girders 1 to 6 are numbered as shown in Figure 2.2. The Superstructure and Substructure are connected by eight friction pendulum seismic isolation bearings. Since the dynamic period of the structure was 3 seconds resulting from two 88-in base isolation effective radius of curvature, the two piers required higher stiffness than before. Pier 1 was reduced in height by 28.5 ft and Pier 2 was reduced in height by 21 ft from the original Pier height. This change eliminates the soil nailed walls around the footing, minimized foundation size and drilled shaft length.

North base isolation South base isolation

Creep Block

Beam “A” Beam “B”

56

4 3 2 1

6

Figure 2-3: Bridge plan and elevation views

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3 SEISMIC INSTRUMENTATION SYSTEM

Acceleration recorder systems such as accelerometers have several standard and optional features which set their minimum characteristics required for recording data. The characteristics include timing of the system, storage capacity, variability of recorder threshold range, etc. These features are the minimum characteristic of the acceleration recorders necessary in order to obtain and register the right response from the loads [Stephens, June 1996]. There are 61sensors and cables in total as shown in Figure 3-1 and Figure 3-2. There are 30 Accelerometers; twelve of them are Tri-axial sensors, seven are Bi-axial sensors, and eleven are Uni-axial sensors. Two free field sites were established, one on each side of the river gorge. At each free field site, one SBEPI was installed at 200 ft depth and another SBEPI was installed at 100ft below grade. A Tri-axial accelerometer was installed at the top surface of the slab at each of the two free field sites. The instrumentation also includes eleven inclinometers and sixteen displacement sensors. All of the sensors and the Data Recording Units were tested before they were deployed on the bridge.

Figure 3-1 and Figure 3-2 show the overall layout of all sensors installed in the bridge and at the free field sites. Most of these sensors were installed in the bridge deck level, either within the drop-in girder or within the box girder. Each sensor is colored and each color defines the type of sensor installed (see Figure B2). Most of the sensors were installed in the superstructure which is above the vertical support except a few that are installed at the abutments and pier footings. Displacement sensors were installed between the superstructure bottom surface and abutment footing top surface at both Hilo and Honoka’a abutment. Displacement sensors were also installed between the top of each pier and the superstructure bottom surface (see Figures B7-B8 and B10-B11 for details). Rotation sensors were installed at each transverse beam along the bridge centerline. Accelerometers are in pink (Tri-axial), blue (Bi-axial) and yellow (Uni-axial), and are mostly installed within the superstructure with some on the pier foundations.

There are four Tri-axial and four Uni-axial sensors that are installed at both Piers as indicated by the star symbol. Both Uni-axial (star symbol under cell 1 and 5) and the Tri-axial (star symbol under cell 1) sensors are installed at the Pier footing (see Figure B6). There are also two Tri-axial sensors installed at each abutment footing, directly below the Tri-axial and a rotation sensor at beam “A” on the superstructure (see Figure B7 and B8). There are two free field sites, each containing two SBEPI sensors and one tri-axial accelerometer.

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Figure 3-1: Overall Layout of First Half of the Bridge, Honokaa Side

Figure 3-2: Overall Layout of Second Half of the Bridge, Hilo Side

3.1 Accelerometers (Triaxial) Sensors

3.1.1 Description EpiSensor force balance accelerometer, Model FBA ES-T is a Tri-axial surface package useful for many types of earthquake recording applications. ES-T were used to measure the movement of the bridge’s structural element in three orthogonal directions namely x, y, and z (Figure 3-3).

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After installed each accelerometer they were adjusted to zero out in all major axes through the zero adjustment access hole (see Figure A1). The accelerometers will monitor acceleration during seismic events and ambient traffic on the bridge. Accelerometer output can be used to produce mode shapes and frequencies of the superstructure that help validate the existence computer model and earthquake experience.

Features: ES-T

Low noise

Extended bandwidth -- DC to 200 Hz

User-selectable full-scale range

Calibration coil (standard)

Single-end or differential output (user selectable)

Double-stage transient protection

Figure 3-3: Interior view of Tri-axial Sensor.

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3.1.2 Layout and Installation There are twelve Tri-axial sensors in total. Ten of them were installed on the bridge as shown in Figure 3-4. The other two were installed at the free field sites. All ten Tri-axial sensors at the bridge structure are at the abutments and piers. Abutment #1 is located at the Honoka’a side and has two Tri-axial sensors with serial numbers 3626 and 3627. Tri-axial 3626 is located at Beam A directly above the creep block and Tri-axial 3627 is located on the Abutment. Tri-axial 3634 and 3635 were installed in the same way as Tri-axial 3626 and 3627 but at Abutment #2 at the Hilo end of the bridge. Tri-axial 3635 was installed at Beam A on the centerline of the bridge. Tri-axial 3634 was installed on Abutment #2 directly below the creep block. Both of these Tri-axial sensors were installed vertically aligned with the base line (see Figures B7 and B8). Tri-axial 3628, 3629 and 3630 were installed at Pier #1 at three different vertical elevations. Tri-axial 3628 was installed at Beam P on the centerline of the bridge. Tri-axial 3629 was installed at the top of the Pier #1 and directly below the Beam P and box girder. Tri-axial 3630 was installed at the Pier #1 at the far right hand corner of the footing in the ocean side as shown below. Pier #2 Tri-axial sensors were installed in the same way. Tri-axial 3631 was installed at the Beam P and sensor 3633 was installed at the top of Pier #2 directly below Beam P and box girder. Both Tri-axial 3631 and 3633 are vertically aligned with the bridge centerline. Tri-axial 3632 was installed at the Pier #2 footing at the corner right hand side (see Figures B12 and B13). The installation of each Tri-axial sensors followed the guidelines described in Kinematics Document 301900 Revision D, October 2005. Also refer to Figure A4 for the sensor and DAQ wiring guideline.

Figure 3-4: Location of Tri-axial Sensors

3.2 Free Field Site

3.2.1 Description and Layout There are two free field sites. One is located at the Honoka’a end of the bridge and on the Mauka side (mountain) (Figure 3-5). The other at the Hilo end is located on the Makai side (ocean) (Figure 3-6). Figure B18 shows the site locations relative to the bridge. The free field sites are located near the bridge structure but far enough away that they should not be influenced by the presence of the bridge during earthquake events. As part of this strong motion instrumentation program, downhole (subsurface) arrays are being placed near the instrumented bridge to observe the soil movement as well as the structural response. Trying to gather real data as to how various soil types respond to the underlying rock motion will advance our knowledge regarding what motions to expect at the bridge structures. Subsurface earthquake data is needed just as much as structural component testing. Stiff and soft soil sites can be thought of as soil

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columns that react uniquely to rock motions. Whether the bridge foundation sits on rock or has 150-foot long piles driven into soft soil makes a big difference in terms of how the structure will react to earthquakes [Hipley, 2005].

Figure 3-5: Free field site at Honokaa side of the bridge.

The Hilo free field site is located 200 ft away from Abutment #2 (see Figure B18).

Figure 3-6: Free field site at Hilo side of the bridge.

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3.3 Downhole Accelerometers

3.3.1 Description SBEPI downhole accelerometers were installed at each free field site (Figure 3-7). One was installed at 150 ft depth and a second was installed at 75 ft depth. Lastly a Tri-axial accelerometer was installed on the surface of the slab at each free field site. According to the Data Sheet and Factory Testing information, the SBEPI with serial numbers 363 and 364 are limited to a cable length of 40m (130ft) and the SBEPI with serial numbers 365 and 366 are limited to a cable length of 110m (360ft). Signal booster boxes were installed at the top of each borehole to amplify the signals prior to transmission through underground conduits to the DAQs located in the bridge. The free field site instrumentation assists in identifying the ground motion during an earthquake. The locations for each SBEPI were determined from the geotechnical profile of the project site, and the depth of the drilled caissons supporting the piers and abutments.

Features: ES-SB (or SBEPI)

Low noise

Fits in 3" diameter hole

Extended bandwidth – DC to 200 Hz

Factory-selectable full-scale range



Double-stage transient protection

Figure 3-7: Shallow Borehole EpiSensor (ES-SB).

3.3.2 Layout and Installation There are a total of four Shallow Borehole EpiSensors and two Tri-axial accelerometers at the two free field sites (Figure 3-8). The four cylindrical shaped sensors go down the boreholes and Tri-axial sensors 4522 and 4523 were installed at the top surface of the slab at the free field sites

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(Figure 3-9). SBEPI 363 and 365 were installed at the Honoka’a side, which is located on the Mauka side of the bridge. At the same free field site (Honoka’a side), Tri-axial sensor 4522 was bolted to the top of the slab-on-grade at the ground level. SBEPI 363 was installed at a depth of 75ft and SBEPI 365 was installed at a depth of 100ft below grade. SBEPI 364 and 366 were installed at the Hilo end of the bridge, located on the ocean side of the roadway. At this free field site (Hilo side), Tri-axial sensor 4523 was installed at the ground level. SBEPI 364 was installed at 75ft depth and SBEPI 366 was installed at 150ft depth below grade. The sensors and the DAQ connections were wired in accordance with Figure A2. All Shallow Borehole EpiSensors were installed using the guidelines in Kinematics Document 301934 Revision B, January 2005.

Figure 3-8: Location of the Free Field Site and Free Field sensors.

Figure 3-9: Free Field Sensor Layout

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3.4 Accelerometer (Biaxial) Sensors

3.4.1 Description ES-B is made up of two ES-U units and has the same features as ES-U (Figure 3-10). Its layout inside the enclosure looks similar to ES-U. Two ES-U are orthogonal to each other on a two dimensional plane. Since they are set up in this manner, it is easy to measure the two directional displacements simultaneously which are 90 degree apart. It records the seismic response during the events similar to Tri-axial and Uni-axial sensors.

Features:

Low noise





Figure 3-10: Bi-axial EpiSensor (ES-B)

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3.4.2 Layout and Installation All the Bi-axial sensors were installed in the deck level at every beam except Beam “A”, Beam “P” and the two adjacent Beams “B” from the center Beam at the mid span of the bridge. The Bi-axial sensors were installed only at the ocean side of the beam as indicated by the blue color in Figure 3-1 and Figure 3-2. The orientations for each Bi-axial sensor are shown in Figures B2-B5. Further details on the installation process can be found on pages 5–11 of the Document 301929 Revision A, January 2005 and Figure A5 shows the connection between a Bi-axial sensor and the DAQ.

3.5 Accelerometer (Uniaxial) Sensors

3.5.1 Description Uni-axial Sensors defined as model FBA ES-U2 were used to measure a single directional acceleration of the structural element. For simplicity this model is referred to as ES-U in most cases. Since the ES-U is extremely low-noise, it can detect motions of the ambient vibration field at most urban sites and civil structures from 1 Hz to 200 Hz.

Figure 3-11: Uniaxial EpiSensor, ES-U2

Features: ES-U2

Low noise





3.5.2 Layout and Installation Uni-axial sensors were located on the opposite side of the deck from the bi-axial sensors. Therefore, all Uni-axial sensors were installed on the Mauka side of the bridge and are indicated

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in yellow in Figure 3-1 and Figure 3-2. Uni-axial sensors were also installed at both Pier footings. There were two Uni-axial sensors at each Pier footing. One Uni-axial sensor was installed on the Mauka side and the other sensor was installed on the ocean side (see Figure B6). All serial numbers can be obtained from Tables 5.5-5.8. Details of the installation process and guidelines can be found on pages 5-11 of Document 301929 Revision A, January 2005. Also refer to figure A6 for sensor and DAQ wiring details.

3.6 Rotation Sensor

3.6.1 Description All rotation sensors were installed along the centerline of the bridge superstructure to monitor bridge deflections [Powelson, 2010]. Assuming small deformations and integrating the curvature gives the rotation:

L

3 2L

Taking the moment of inertia and modulus of elasticity to be constant the above equation can be simplified to:

To complete the rotation equation, 4 known parameters θ and x are needed, therefore the rotation sensors are grouped into segments to cover the full bridge and each segment represents a group of 4 sensors. To calculate exact tilt of the structure at various locations four sensors will be analyzed for structural member tilt before and after the seismic events at each four location.

∆

Having the angle chang at each of the four locations one can determine the mode shape of that specific structural segment. Therefore, we can further obtain the deflection expression below by integrating the rotation equation once [Powelson, 2010]:

4 3 2

The LSO is a high precision gravity referenced servo inclinometer (rotation sensor) that can be used for a wide variety of applications such as bore-hole mapping, dam, rock shifts, seismic and engineering studies (Figure 3-12). The design is well proven with many thousands in use throughout the world in the most demanding of applications. Rotation sensors help us understand the displacement shape of the superstructure just before and immediately after the seismic event. They are also able to determine the displacement shape of the superstructure during traffic loading (static type loading) [Johnson, 2013]. High precision inclinometers are designed to measure horizontal and vertical angular inclination with virtually infinite resolution [Sherborne Sensor].

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Figure 3-12: Rotation Sensor.

3.6.2 Layout and Installation Rotation sensors are located along the centerline of the bridge superstructure at each transverse beam to measure the rotation of the superstructure throughout the longitudinal direction. Figure A7 provides details of the wiring between the rotation sensor and the DAQ.

Rotation sensors 1 and 11 are located right below the Tri-axial 3626 and Tri-axial 3635 respectively at the center of Beam “A” (see Figure B7 and B8). Rotation sensors 2 and 10 are both located at Beams “B”. Rotation sensors 3 and 9 are located at the center of Beams “C”. Rotation sensors 5 and 7 are located at the center of Beam D1 and Beam D3 respectively. Rotation sensors 4 and 8 are located at the center of Beams “P” right below Tri-axial 3628 and Tri-axial 3631 respectively (see Figure B12 and B13) and finally Rotation sensor 6 is located at the center of the Beam “B” at midspan.

According to the layout in Figure 3-13, five rotation sensors (4, 5, 9, 10, and 11) were installed at the left side of the Beam element of the superstructure. The other six inclinometers (1, 2, 3, 6, 7, and 8) were installed at the right side of the Beam element. The intent was to locate the rotation sensors as close as possible to the ideal locations determined by Powelson [2010].

Figure 3-13: Location of Rotation sensors.

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3.7 Relative displacement or String Pot Sensors.

3.7.1 Description String pot style relative displacement sensors are used to measure the movement across the base isolation system (Figure 3-14). The displacement sensors monitor the relative movement between the bridge deck and the vertical supports (Piers and Abutments). There are a total of 16 relative displacement sensors deployed on the bridge. Two displacement sensors are located at each Abutment, one on the Mauka side and the other on the ocean side (see Figure B7 and B8). The other 12 displacement sensors were installed between the top of the Piers and the bottom of the bridge superstructure as shown in Figure B10 and B11. The cable routing details and exact location are shown in Figures B15-B17.

In order to record the relative displacements in three directions, each bearing isolation on the piers has three displacement sensors installed as shown in Figure 3-15. In this case, each displacement sensor measures their change in radius with respect to their own sphere. These changes can be used to determine the relative displacement between the superstructure and the vertical support [Johnson, 2010]. In order to ensure good results and time synchronization, all of the relative displacement sensors must be compatible with the Recording Unit System [Stephens, 1996].

Features: Round About Guide (key feature).

First Mark Control

85 inch maximum travel.

Choice of FlexSignal Analog and Digital Output Signals (Factory Set)

AccuTrak Threaded Drum For Enhanced Repeatability

DirectConnect Sensor-To-Drum Technology = Zero Backlash, No Torsion Springs or Clutches

NEMA 4 / IP 66 Environmental Protection

Flexible Mounting Bases

Industrial Operating Temperature Ranges

Electrical Terminations: DIN 45326

19

Figure 3-14: Relative Displacement Sensor.

3.7.2 Layout and Installation The displacement sensors were installed to track the relative position of an object using three position transducers mounted at known points “r”, “s”, and “t” (Figure 3-15). The transducers measure the radius of three intersecting spheres.

The typical layout for the relative displacement sensors at the piers is shown in Figure 3-16, Figure 3-17 and Figure B10. The displacements sensors are located so as not to interfere with future jacking operations if a seismic pendulum isolation bearing needs to be replaced. The displacement sensors were installed on the bottom of beam “P” at location “r”, “s”, and “t” and the pull wires were anchored at a single point on the top of the Pier next to the seismic bearing (Figure 3-17 and Figure 3-18).

The two displacement sensors at each abutment were installed to measure longitudinal movement of the superstructure relative to the abutment. Creep blocks are provided to prevent transverse movement at the piers, and vertical movement will only be due to the curvature of the base isolation bearing (Figure 3-18).

20

Figure 3-15: Displacement sensor layout configuration.

The following equations are used to determine the position of point P after movement has taken place. P is located relative to point R by P = (R sin α cosβ) i + (R sin α sin β) j + (R cosα) k = Pxi + Pyj + Pzk after the event.

Positive is an extension of the string pot. The direction of the displacement sensors were assigned as 1, 2, and 3. Direction 1 means increasing or decreasing in length of the string pot in the Honoka’a direction. Direction 2 indicated the transverse direction either increasing or decreasing of the string pot. Direction 3 is allocated for the Hilo direction.

Rsz

SszR

2cos

222

Rsz

SszRα2

1sin222 2

)(sin2

])cos([sincos

22222

txR

RtzTtxR

21

RszSszR

txR

RszSszR

RtzTtxRsz

SszRR

21)(2

221

222 2

2222

22222 2

2

1sin

2

Where:

tz = 24’’

tx = 24”

sz = 48’’

22

Figure 3-16: Plan view layout of the displacement sensor at the Pier

Figure 3-17: General Side view layout of the displacement sensor at the Pier.

Two (D) Sensors

One (D) Sensors

Pier Beam Above

24”

24” 24”

23

Figure 3-18: Typical locations of displacement sensors at the Abutment #1 and #2

Because of the concrete Creep Block at each abutment (Figure 3-18), transverse movement is not possible. Therefore one displacement sensor was installed at each side of beam “A” on the bottom surface facing toward the abutment wall which is connected to the footing. The wire transducer from each of these two displacement sensors were pulled and secured directly against the wall behind it. This set up was developed to measure the longitudinal displacement of the super-structure in relation to the abutment.

24

Figure 3-19: Overall plan view of displacement sensors at Honokaa side

The Honokaa half of the bridge with displacement sensor layout is shown in Figure 3-19 and the other half can be found in Figure B10. Figure A3 provides details of the wiring between each displacement sensor and the DAQ.

3.8 General Cable Routing between Abutments and Piers:

The cables from all sensors in the free field sites and abutments are routed to the DAQ along the bottom flange of Drop-in-Girder 3 or 4. They pass through an 8” diameter hole in Beam “C” and into the center cell of the Box Girder at Pier #1 and #2. They then pass through 3” diameter holes in webs 4 and 5 to reach the DAQs (Figure 3-19).

25

4 SEISMIC INSTRUMENTATION PREPARATION

This section describes the preparation of instrumentation for installation in the Kealakaha Stream Bridge.

4.1 Instrumentation Testing

All sensors were tested to ensure proper operation prior to shipping to the project site. All DAQs were tested to make sure they were functioning properly. All the Tri-axial, Bi-axial and Uni-axial accelerometers were labeled with their serial number on the outside cover. This helped to avoid confusion during installation. Both the Tri-axial and Uni-axial sensors were labeled with one serial number (four digits), while the Bi-axial sensors were labeled with two serial numbers representing the two Uni-axial accelerometers making up the Bi-axial sensor.

4.2 Cables

Two types of cable were used to connect the sensors to the DAQs, namely Belden 9874 and Belden 8723 as found in Kinemetrics Document 301900 Revision D [October 2005]. Belden 9874 is about 0.5in diameter and it is used for connecting the accelerometers (Uni-axial, Bi-axial and Tri-axial) to the Data Recording Units. Belden 8723 is about 0.25in diameter and is used for connecting the relative displacement and inclinometer sensors. Each cable length was determined using the bridge plan with an assumption that each cable will be routed along the supporting members. After all measurements were finalized, a 15% extra length was added to ensure the cables were not too short. The cables were cut from eleven rolls of Belden 9874 and ten rolls of Belden 9723, each 1000 ft long in such a way as to optimize cable usage.

Name tags were developed from the combination of structural member code, sensor type and the associated DAQ (see Table B1). After cutting each cable, a name tag was attached to each end as shown in Figure 4-1. The name tag identifies the sensor location, associated DAQ (G10, G20, G30 or G40) and the corresponding physical channel in the DAQ.

26

Figure 4-1: Cable end after being stripped, treated and tagged.

One end of each cable was stripped and prepared for connection to the sensor, while the other end was prepared for connection to the DAQ. In order to assure protection from the atmosphere and to make sure that the stripped wires have good conductivity and quality transmission of data, they were treated with flux then dipped in Plato model SP-500T solder. The cables were then prepared for shipping to the project site (Figure 4-2).

Figure 4-2: Cables ready to be shipped to job site.

27

5 SEISMIC INSTRUMENTATION OVERALL LAYOUT AND CHANNEL ASSIGNMENT

5.1 Central Recording System

The Kinemetrics Dolomite Data Acquisition System is a highly flexible, full-featured Central Recording System populated with IP based Granite Data Acquisition units and accessories to support up to 36 channels, triggered or continuous recording, and sampling rates up to 2000 sps. There are four Central Recording System (DAQ) which each DAQ represented by “Code Name” (Table 5-1) namely G10 (36 channel), G20 (24 channel), G30 (36 channel), and G40 (24 channel) that are installed within the bridge in order to securely record all instrument output. The letter G stands for Granite and the last two digits are obtained from the last two digit of the DAQ unit IP address (Table 5-1).

Two of the Central Recording System (G10 and G20) are installed on the wall in cell number 5 of the box girder near Pier 1 (Figure 5-1 and Figure 5-2). The other two Central Recording Systems (G30 and G40) were installed in the same procedure in cell 5 of the box girder 2 near Pier 2 (Figure 5-3). The location of the DAQs was determined based on the ease of access after construction.

Table 5-2 shows two options for distributing the four channel block within the Data Recording Unit. The option with one Tri-axial and one Uni-axial sensor per block was selected because of the number of Tri-axial sensors. The global direction coordinates are designated as vertical (Z), North (N) and East (E). Each accelerometer sensor has its own local direction (x, y, and z). The global directions corresponding to each accelerometer sensor were recorded in Table 5-5 to Table 5-8. For displacement sensors refer to the Figure B17for general locations and details.

Table 5-1: DAQ system information and Code Name

DAQ Unit IP ID Code Name

192.168.1.10 G203 G10

192.168.1.20 G213 G20

192.168.1.30 G202 G30

192.168.1.40 G293 G40

28

Table 5-2: Channel distribution for 24/36 physical channel with four channel block

Figure 5-1: Central Recording System or Data Recording Unit

29

Figure 5-2: Plan View of the Honokaa Side of the Bridge

Figure 5-3: Plan View of the Hilo Side of the Bridge

30

Figure 5-4: Overall Bridge Elevation shows all bridge major components.

The DAQ locations are shown in the bridge elevation view in Figure 5-4. Abutment 1 and Pier 1 are on the Honoka’a side and Abutment 2 and Pier 2 are on the Hilo side of the bridge. The sensors connected to each DAQ are described below and in Table 5-3 and Table 5-4.

For DAQ @ PIER #1 – Honoka’a

Abut.#1 – All sensors on the Abutments 1, Beam B, Beam C and Free Field.

FTG#1 – All sensors on the Footing 1, Pier 1, and Beam P right above Pier only.

Midspan – All sensors on Beam D1 and Beam B at mid span.

For DAQ @ PIER #2 – Hilo

Abut.#2 – All sensors on the Abutments 2, Beam B, Beam C and Free Field.

FTG#2 – All sensors on the Footing 2, Pier 2, and Beam P right above Pier only.

Midspan – All sensors on Beam D3 only.

Table 5-3: Sensor Counts and Channel Allocation for Honoka’a DAQ

DAQ @ PIER #1 - Honoka'a Available 60 Total 48 Spare 12

Abut. # 1 26 FTG #1 18 Midspan 8

Sensor Type Channels Sensor Type Channels Sensor Type Channels

FF 9 FF 0 FF 0 T 6 T 9 T 0 B 4 B 0 B 4 U 2 U 2 U 2 D 2 D 6 D 0 R 3 R 1 R 2

Honokaa DAQ Hilo DAQ

31

Table 5-4: Sensor Counts and Channel Allocation for Hilo DAQ

DAQ @ PIER #2 - Hilo Available 60 Total 44 Spare 16

Midspan 4 FTG #2 18 Abut. # 2 26

Sensor Type Channels Sensor Type Channels Sensor Type Channels

FF 0 FF 0 FF 9 T 0 T 9 T 6 B 2 B 0 B 4 U 1 U 2 U 2 D 0 D 6 D 2 R 1 R 1 R 3

5.2 DAQ Channel Distribution and Sensors Orientation

Each Sensor has a local direction, for instance, EpiSensor type ES-T, ES-B and ES-U2 have (x, y, z), (x, y), and (x) local directions respectively (Figure 5-5). These local axes are shown on the cover of the sensor enclosure. Table 5-5 to Table 5-8 show the relationship between each local axis and the corresponding global direction. Each of these sensors was connected to the Data Recording Unit through assigned cable as shows in column 2 of the above tables.

Figure 5-5: Typical Local to Global Orientation of a Tri-Axial Sensor.

32

Table 5-5: Sensors and Cable Assignment with Sensor Orientation (CH 36 Honoka’a)

Sensor Serial Number Cable Label

Physical Channel No.

Virtual Channel No.

Sensor/Global direction

365 1-TFf1D61-G10 3 V3 X+/E+ 2 V2 Y+/N+ 1 V1 Z+/V+

12028745 7-DAb1NBrg-G10 4 V4 1

363 2-TFf1D30-G10 7 V7 X+/E+ 6 V6 Y+/N+ 5 V5 Z+/V+

Empty 8

4522 3-TFf1D00-G10 11 V11 X+/E+ 10 V10 Y+/N+ 9 V9 Z+/V+

Empty 12

3627 4-TAb1Ftg-G10 13 V13 X+/V- 14 V14 Y+/N+ 15 V15 Z+/E+

6-RAb1BmA-G10 16 V16

3626 5-TAb1BmA-G10 17 V17 X+/V- 18 V18 Y+/N+ 19 V19 Z+/E+

10-R1CnBmB-G10 20 V20 12028746 11-DAb1SBrg-G10 21 V21 1

Empty 22 Empty 23 Empty 24

2583(X) 15-B1G1BmB-G10

25 V25 X+/V- 2584(Y) 26 V26 Y+/N+

2595 16-U1G6BmB-G10 27 V27 X+/V- 17-R1CnBmC-G10 28 V28

2585(X) 18-B1G1BmC-G10

29 V29 X+/V- 2586(Y) 30 V30 Y+/N+

2596 19-U1G6BmC-G10 31 V31 X+/V- Empty 32

3628 21-TPr1BmP-G10 33 V33 X+/V- 34 V34 Y+/N- 35 V35 Z+/E-

22-RPr1BmP-G10 36 V36

33

Table 5-6: Sensors and Cable Assignment with Sensor Orientation (CH 24 Honoka’a)



Virtual Channel No.


3630 1-TPr1FT1-G20(Ocean)

3 V3 X+/E+ 2 V2 Y+/N+ 1 V1 Z+/V+

2598 6-UPr1FT1-G20

(Ocean) 4 V4 X+/V-

3629 2-TPr1PR1-G20 7 V7 X+/E- 6 V6 Y+/N- 5 V5 Z+/V+

2599 7-UPr1FT1-G20

(Mauna Kea) 8 V8 X+/V- 12028747 3-DPr1NBrg-G20 9 V9 1 12028748 4-DPr1NBrg-G20 10 V10 2 12028749 5-DPr1NBrg-G20 11 V11 3

8-R2CnBmD1-G20 12 V12 2589(X)

9-B2G1BmD1-G20 13 V13 X+/V-

2590(Y) 14 V14 Y+/N- 2600 10-U2G6BmD1-G20 15 V15 X+/V-

Empty 16 12028750 12-DPr1SBrg-G20 17 V17 1 12028751 13-DPr1SBrg-G20 18 V18 2 12028752 14-DPr1SBrg-G20 19 V19 3

15-R2CnMidBmB-

G20 20 V20 2591(X) 16-B2G1MidBmB-

G20 21 V21 X+/V-

2592(Y) 22 V22 Y+/N-

2601 17-U2G6MidBmB-

G20 23 V23 X+/V- Empty 24

34

Table 5-7: Sensors and Cable Assignment with Sensor Orientation (CH 36 Hilo)



Virtual Channel No.


366 1-TFf2D61-G30 3 V3 X+/E+ 2 V2 Y+/N+ 1 V1 Z+/V+

12028753 7-DAb2NBrg-G30 4 V4 1

364 2-TFf2D30-G30 7 V7 X+/E+ 6 V6 Y+/N+ 5 V5 Z+/V+

Empty 8

4523 3-TFf2D00-G30 11 V11 X+/E+ 10 V10 Y+/N+ 9 V9 Z+/V+

Empty 12

3634 4-TAb2Ftg-G30 13 V13 X+/V- 14 V14 Y+/N- 15 V15 Z+/E-

6-RAb2BmA-G30 16 V16

3635 5-TAb2BmA-G30 17 V17 X+/V- 18 V18 Y+/N- 19 V19 Z+/E-

10-R3CnBmB-G30 20 V20 12028754 11-DAb2SBrg-G30 21 V21 1

Empty 22 Empty 23 Empty 24

2581(X) 15-B3G1BmB-G30

25 V25 X+/V- 2582(Y) 26 V26 Y+/N-

2597 16-U3G6BmB-G30 27 V27 X+/V- 17-R3CnBmC-G30 28 V28

2587(X) 18-B3G1BmC-G30

29 V29 X+/V- 2588(Y) 30 V30 Y+/N-

2605 19-U3G6BmC-G30 31 V31 X+/V- Empty 32

3631 21-TPr2BmP-G30 33 V33 X+/V- 34 V34 Y+/N+ 35 V35 Z+/E+

22-RPr2BmP-G30 36 V36

35

Table 5-8: Channel, Sensors and Cable Assignment with Sensor Orientation (CH 24 Hilo)



Virtual Channel No.


3632 1-TPr2FT2-G40

(Ocean)

3 V3 X+/E+ 2 V2 Y+/N+ 1 V1 Z+/V+

2603 6-UPr2FT2-G40

(Ocean) 4 V4 X+/V-

3633 2-TPr2PR2-G40 7 V7 X+/E+ 6 V6 Y+/N+ 5 V5 Z+/V+

2604 7-UPr2FT2-G40

(Mauna Kea) 8 V8 X+/V- 12028755 3-DPr2NBrg-G40 9 V9 1 12028756 4-DPr2NBrg-G40 10 V10 2 12028757 5-DPr2NBrg-G40 11 V11 3

8-R2CnBmD3-G40 12 V12 2593(X)

9-B2G1BmD3-G40 13 V13 X+/V-

2594(Y) 14 V14 Y+/N+ 2602 10-U2G6BmD3-G40 15 V15 X+/V-

Empty 16 12028758 12-DPr2SBrg-G40 17 V17 1 12028759 13-DPr2SBrg-G40 18 V18 2 12028760 14-DPr2SBrg-G40 19 V19 3

36

37

6 SUMMARY AND CONCLUSION

The objective of this project was to design and install a seismic instrument system for the Kealakaha Stream Bridge on the Island of Hawaii. The system consists of accelerometers, rotation sensors and displacement sensors to monitor bridge response during future earthquakes and ambient traffic flow. The sensors are monitored continuously at 200 Hz and data is stored whenever a triggering event occurs. The stored data are transferred to UH Manoa via a satellite connection for processing.

This report provides a description of each type of instrumentation including details of their operation and purpose. The sensor locations and instrumentation layouts are also provided and explained. A companion report (UHM/CEE/13-02) provides a detailed description of the data recording system that monitors the instruments. Future reports will analyze the data recorded during ambient traffic and future seismic events and report on the bridge performance.

The following items were achieved during this project:

Correctly install all sensors forming part of the seismic instrumentation to provide important information on the dynamic properties of the structure under ambient traffic load and future earthquakes. This information will be used to evaluate the performance of the base isolation system and to evaluate changes in the structural response with time so as to identify potential deterioration of the structure.

A total of 61 sensors and 4 data recording units were installed in the bridge.

This report provides details of the installation of seismic instruments in the Kealakaha Stream Bridge. Locations, orientation, and connectivity to the data acquisition system are given for all sensors.

38

39

7 REFERENCES

Clague, D., (1995, March), Geological Hazards In Hawaii, Hawaii Volcano Observatory, U.S. Geological Survey.

Fujiwara, D., Hamada, H., Matsumoto, E., Iwamoto, G., Robertson, I., (2010), Kealakaha Stream Bridge Replacement, ASPIRE, The Concrete Bridge Magazine, Summer Edition.

Firstmark Controls website, http://www.firstmarkcontrols.com/

Ghalambor, M., Robertson, I.N. and Johnson, G.P. (2013), Acquisition of Data From Seismic Instrumentation of The Kealakaha Bridge, Research Report UHM/CEE/13-02, University of Hawaii at Manoa, Honolulu HI. HDOT, (1995, September), Draft Environmental Assessment For Kealakaha Stream Bridge Replacement Project No. BR-019-2(26), Hawaii Department of Transportation, Honolulu, HI.

Hipley, P., Shakal, A., and Huang, M., (2005, September), Status of the Caltrans/GCS Bridge Strong Motion Instrumentation Project, California Department of Transportation, Strong Motion Instrumentation and Geological Survey, Sacramento, California.

Kinemetrics Manufacturing and Design website, http://www.kmi.com

Lee, A., and Robertson, I., (1995), Instrumentation And Long-Term Monitoring Of The North Halawa Valley Viaduct, Report UHM/CEE/95-08, Honolulu, Hawaii.

Powelson, N., and Robertson, I., (2010), Seismic Instrumentation Of The Kealakaha Bridge, Research Report UHM/CEE/10-05, University of Hawaii, Honolulu, Hawaii.

Stephens, T., and Robertson, I., (1996), Kealakaha Stream Bridge Replacement Project Seismic Instrumentation Plan, Report UHM/CEE/96-04, Honolulu, Hawaii.

U.S. Geological Survey website, Earthquake Hazards Program, National Seismic Mapping Project 2013, http://www.usgs.gov/

40

41

APPENDIX A: SENSOR WIRING DIRECTION AND CABLE

Figure A1: Tri-axial Sensor

42

Figure A2: Shallow Borehole sensor wiring from the sensor to the DAQ

White

Brown

BlackBrown

Cable from the Sensor

ES‐SBH Sensors

1 2 3

Green

Shield Green

Black Green

1 2 3

Yellow

Black Yellow

Shield Yellow

Black White Shield White

Green Black Green ShieldGreen

Yellow

Black Yellow Shield Yellow

Shield Brown& Blue

White Black White Shield White

Green Black Green Shield Green Yellow

Black Yellow Shield Yellow Brown Black Brown

Shield Brown& Blue & Black Blue & Shield Blue & Shield Red Red

Black ‐ Red

Black Blue Red

Black ‐ Blue

Red

9 1 2 3 4 5 6 7 8 10

White

Black W

hite

Shield W

hite

Brown

Black Brown

Blue

Shield Brown

Shield Red

& Shield Blue

Inside the unit G40

43

Figure A3: Displacement sensor wiring from the sensor to the DAQ

White

Red

Black

Sensor Connector

1 2 3 4 5 6 7 8 9 10

Displacement SensorsWhite

Jumper

Shield Black

Black & Jumper

Red

A

B

C

D

E

F

44

[Document 301923 Revision NC, July 2009]

Figure A4: Tri-axial sensor wiring from the sensor to the DAQ

Yellow

Green

White

Blue

Red

Black Yellow

Black Green

Black White

Black Blue

Brown

Black Brown

Black Red

Inside the Sensor

ES‐T Sensors

9 1 2 3 4 5 6 7 8 10

White

Black W

hite

Shield W

hite

Brown

Black Brown

Blue

Black Blue

Red

Black Red

Shield Br, Blue & Red

1 2 3

Green

Shield Green

Black Green

1 2 3

Yellow

Black Yellow

Shield Yellow

All shields attached to sensor plate

45

Figure A5: Bi-axial wiring guide from sensors to DAQ

Green

White

Blue

Black Brown

Black Red

Black Green

Black White

Brown

Red

Black Blue

Inside the Sensor

1 2 3 4 5 6 7 8 9 10

ES‐B SensorsWhite

Black W

hite

Shield W

hite

Brown

Black Brown

Blue

Black Blue

Red

Black Red

Shield Brown & Shield Blue & Shield Red

1 2 3

Green

Shield Green

Black Green


46

Figure A6: Uni-axial sensor wiring direction

Black White

Black Brown

Black Red

White

Brown

Red

Black Blue

Inside the Sensor

1 2 3 4 5 6 7 8 9 10

ES‐U2 SensorsWhite

Black W

hite

Shield W

hite

Brown

Black Brown

Blue

Black Blue

Red

Black Red

Shield Brown & Shield Blue & Shield red

Blue


47

Figure A7: Rotation sensors with wiring direction

Black

Red

Green

Sensor Connector

1 2 3 4 5 6 7 8 9 10

Rotation SensorsWhite

Green

Red

A

B

C

D

E

F

White

Black

Shield

48

APPENDIX B: SENSORS LOCATION, ORIENTATION AND CABLE ROUTING

Table B1: Sensor Layout and Cable Label

Location CODE Location Description Location Strings

2 digits

1 Center of Abutment 1 Ab1

2 Center of Pier 1 Pr1

3 Center of Pier 2 Pr2

4 Center of Abutment 2 Ab2

5 Span #1 Girder 1 Beam B 1G1BmB


7 Box Girder #1 Web 1 Beam C 1G1BmC


9 Box Girder #1 Web 1 Beam D 2G1BmD1


11 Span #2 Girder 1 Beam B Midspan 2G1Mid

12 Span #2 Girder 6 Beam B Midspan 2G6Mid







F1 Free Field #1 Ff1

F2 Free Field #2 Ff2

Element CODE Structural Element Description

BMX Beam "X" A thru E and P. P is the box girder bearing element over the piers.

ABX Abutment "X" is the footing of at abutments 1 or 2.

PRX Top of Pier "X", 1 or 2 at the lEvel of the bottom of the base isolation bearings.

BGX Box Girder "X", 1 or 2.

FTX Pier Footing "X" the footings which support piers 1 and 2.

DXX Depth of borehole in meters rounded [15 = 15.24m (50ft), 30 = 30.48m (100ft), 46 = 45.72m (150ft), 61 = 60.96m (200ft)]

49

Sensor CODE Sensor Description # Channels Per Sensor

1 Digit

U EpiSensor ES-U2 (Uni-axial) 1

B (2) EpiSensor ES-U2 (Bi-axial) 2

T EpiSensor ES-T (Tri-axial) 3

R Inclinometer Sensor 1

D Displacement Wire Transducers 1

Figure B1: Overall Instrumentation connection diagram

COLOR LEGEND:

YELLOW SENSOR – ES-U

BLUE SENSOR – ES-B

PINK SENSOR– ES-T

RED SENSOR– INCLINOMETER SENSOR

Figure B2: Sensor direction and its corresponding color.

50

Figure B3: Typical beam “B” with Bi-axial at ocean side and Uni-axial at the Mauka side of the bridge with orientation

Figure B4: End section of the box girder 2 (Hilo side) when looking down station.

51

Figure B5: Beam B at Span #3 looking up station

Figure B6: Pier #1 and Pier #2 footing instrumentation detail

52

Figure B7: Instrumentation details and layout for Abutment #1

53

Figure B8: Tri-axials, Displacements, and Rotation sensors layout for Abutment #2.

Figure B9: Accelerometer sensors at Deck level connected to DAQ-G20(24CH) with cable routing Honoka’a Side.

54

Figure B10: Displacement sensors shows on the Pier #2 and Abutment #2 connected to DAQ.

Figure B11: Side view of the displacement sensors at the Piers

55

Figure B12: Tri-axials and a Rotation Sensor with their respective orientation at Pier #1

3630

Y

z

56

Figure B13: Tri-axials and a Rotation Sensor with their respective orientation at Pier #2

3632z

Y

57

Figure B14: Local and Global direction of the Displacement and Tri-axial Sensor at the Abutment.

58

Figure B15: Cable routing the displacement and Tri-axial sensors at the top of Pier #2

59

Figure B16: Cable routing the displacement and Tri-axial sensors at the top of Pier #1

60

Figure B17: Plan view of the exact location of the displacement sensors on top of the Pier#1 and #2

61

Figure B18: Hilo (top) and Honokaa (bottom) free field site locations

Hilo Free Field Site

Honokaa Free Field Site

62

Figure B19: Middle span and Pier #2

Figure B20: Drop-in girders shown in segments prior to connection to form long span beams

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Documents

INSTALLATION OF SEISMIC INSTRUMENTATION ON THE … · 2016. 5. 17. · This bridge serves as the main transportation access between Hilo and Kailua-Kona communities [HDOT, 1995]