Geotechnical Instrumentation Report White Point Landslide San Pedro District Los Angeles, California August 21, 2014 Submitted To: Mr. Craig Kunesh City of Los Angeles Department of Public Works Bureau of Engineering 1149 S. Broadway, Suite 120 Los Angeles, CA 90015 By: Shannon & Wilson, Inc. 664 West Broadway Glendale, CA 91204 51-1-10079-033 / 51-1-10111-001
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Geotechnical Instrumentation Report White Point Landslide
San Pedro District Los Angeles, California
August 21, 2014
Submitted To: Mr. Craig Kunesh
City of Los Angeles Department of Public Works
Bureau of Engineering 1149 S. Broadway, Suite 120
Los Angeles, CA 90015
By: Shannon & Wilson, Inc.
664 West Broadway Glendale, CA 91204
51-1-10079-033 / 51-1-10111-001
51-1-10079-033-R1/wp/ady 51-1-10111-001
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TABLE OF CONTENTS
Page
1.0 GENERAL .............................................................................................................................1
2.2 Location and Details ...................................................................................................2 2.3 Data Collection ...........................................................................................................4 2.4 Data Reduction .........................................................................................................11 2.5 Monitoring and Reporting Recommendations .........................................................12
3.2 Location and Details .................................................................................................13 3.3 Data Collection .........................................................................................................13
6.1 LogView Installation ................................................................................................19 6.2 Data Collection .........................................................................................................20
6.3 Battery and Desiccant Pack Maintenance ................................................................21 6.4 Data Reduction .........................................................................................................23
7.0 DYNA FORCE SYSTEM ....................................................................................................24 7.1 General .....................................................................................................................24 7.2 Data Collection .........................................................................................................24
On many occasions during construction and service life of the structure, it is crucial to know the force in the post-tensioning system. Although there are many methods to measure the tendon force, most of them are cumbersome, expensive, and the accuracy differs depending on the method used. DYWIDAG has been involved in the development, testing and execution of DYNA Force™ to measure the force in the tendon. DYNA Force™ is being used in cable stay bridges, cable system testing and building structure to measure the force during stressing and to monitor forces during the service life of the structure. DYNA Force™ can be used for bare, epoxy-coated and greased-sheathed steel.
DYNA Force™ is manufactured based on the theory that the permeability of steel to a magnetic field changes with the stress level in the steel. By measuring the change in a magnetic field the magnitude of the stress in the steel element can be obtained. The DYNA Force™ does not alter the characteristics of the tendon other than its magnetization. The permeability is a function of temperature and magneti zation, and a calibration process eliminates the impact of these variables. The program takes into consideration the temperature change effect auto matically. A portable Power Stress unit is attached to wire leads from the DYNA Force™. This unit will create the magnetic field and then measure the residual value
and then convert it to a direct force reading. The accuracy of the force measurement is within 1%.DYNA Force™ system is robust, requires no maintenance and has no moving parts. It is composed of sensors and Power Stress unit (read-out box). DYNA Force™ is installed over the strand or bar during construction and a zero reading is taken before applying any post- tensioning force. It is expected to have a similar service life as the bridge/building structure. This will allow the owner to regularly monitor the forces in the post-tensioning system in minutes as a part of their inspection procedures without the need for lift-off equipment or other special expensive techniques. This will also avoid the inaccuracies and risks often associated with lift-off readings. One person can do this job.
Bar DYNA Force™
Strand DYNA Force™Power-Stress Unit
DYNA Force™ Dimensions
DYNA Force™ Type Strand/Bar DYNA Force™ Dimensions ID OD Length
[in] [in] [in]
Strand DYNA Force™ 0.5“ 0.71 1.50 5.1
0.6“ 0.78 1.50 5.1
Bar DYNA Force™ 1-1/4“ & 1-3/8“ 1.70 2.80 6.7
1-3/4“ 2.10 3.90 8.3
2-1/2“ 2.85 6.20 12
Note: Dimensions for 2-1/2“ bar are preliminary
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Quality Assurance
All DYNA Force™ sensors are professionally made in a quality controlled facility. Furthermore, each DYNA Force™ is tested and individually packed and numbered at the DSI facility before sending to the job site. Although many tests have been conducted in the development
of the DYNA Force™, DSI conducted additional tests to simulate the performance of the system when places within the anchorage zone of stay cables. In these tests DYNA Force™ sensors were placed near the center and on the outside of the strand bun dle. The loads were applied using
a stressing jack and the force was monitored using a very accurate load cell. The load cell readings were compared to the results from the Power Stress unit and very good correlation was obtained.
Testing and Calibration of DYNA Force™
6
Practical Applications
DYNA Force™ in Cable Stay Anchor, Waldo, Maine, USA
When a DYNA Force™ is installed on a strand/bar, the force in it may be obtained directly by merely attaching the leads from DYNA Force™ to a portable Power Stress unit. No other equipment is needed. DYNA Force™ sensors have been used in many bridge and building structures for the past several years.
DSI supplied two hundred forty sensors for Waldo cable stay bridge, Maine, USA. Each cable had six sensors and the cable forces at each stage of construction were monitored using these sensors. Periodic lift-off operations were made on the strands with sensors. A good correlation was observed. The bridge is now open to traffic and the forces in any cable can be monitored anytime using these DYNA Force™ sensors without any disruption to traffic.
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Practical Applications
DSI used DYNA Force™ sensors in a fatigue testing of 41-strand cable stay system. Force in each 0.6” dia epoxy coated strand was monitored at various loading stages during two-million fatigue cycles.
DYNA Force™ in Fatigue Test of Cable Stay System
DYNA Force™ sensors were used in moment resisting frames in a City Office building, California. The tendons
DYNA Force™ for Seismic Evaluation of Building Structure, California, USA
were 0.5“ diameter greased and sheathed un-bonded strands. DYNA Force™ was used to measure the force
during stressing and will be used to monitor the forces in each loop tendon especially after earthquake takes place.
A U S T R I A
A R G E N T I N A
A U S T R A L I A
B E L G I U M
B O S N I A A N D H E R Z E G O V I N A
B R A Z I L
C A N A D A
C H I L E
C O L O M B I A
C O S T A R I C A
C R O A T I A
C Z E C H R E P U B L I C
D E N M A R K
E G Y P T
E S T O N I A
F I N L A N D
F R A N C E
G E R M A N Y
G R E E C E
G U A T E M A L A
H O N D U R A S
H O N G K O N G
I N D O N E S I A
I R A N
I T A L Y
J A P A N
K O R E A
L E B A N O N
L U X E M B O U R G
M A L A Y S I A
M E X I C O
N E T H E R L A N D S
N O R W A Y
O M A N
P A N A M A
P A R A G U A Y
P E R U
P O L A N D
P O R T U G A L
Q A T A R
S A U D I A R A B I A
S I N G A P O R E
S O U T H A F R I C A
S P A I N
S W E D E N
S W I T Z E R L A N D
T A I W A N
T H A I L A N D
T U R K E Y
U N I T E D A R A B E M I R A T E S
U N I T E D K I N G D O M
U R U G U A Y
U S A
V E N E Z U E L A
w w w . d s i a m e r i c a . c o mw w w . d s i c a n a d a . c a 04
Western Division19433 96th Av.Suite 103Surrey, BC V4N4C4Phone: (604) 888-8818Fax: (604) 888-5008E-Mail: [email protected]
Calgary Office2816-21 Street N.E., Suite 204Calgary, Alberta T2E 6 Z2Phone: (403) 291-4414Fax: (403) 250-5221E-Mail: [email protected]
Please note:This brochure serves basic information purposes only. Technical data and information provided herein shall be considered non-binding and may be subject to change without notice. We do not assume any liability For losses or damages attributed to the use of this technical data and any improper use of our products. Should you require further information on particular products, please do not hesitate to contact us.
Materials Specifications and Dimensions
EM Sensor
Measurement Range Absolute stress 1770 MPa Temperature sensor 3000 ohm @25˚C Temperature accuracy 0.5˚C , in the range of -20˚C to +80˚C Operating Temperature Range -20˚C to +80˚C Primary Coil Resistance 16 ohm to 25 ohm Secondary Coil Resistance 5 ohm to 25 ohm Standard lead Length 2m Maximum lend Length 250m Extension Cord AWG 16 to 14, 6 contacts, twisted Dimensions: ID x OD x L (mm) 19 x 36 x 130 mm Weight Approx. 0.5 kg
Extension Cable
Conductors 3 pairs (1 pair of AWG16 and 2 pairs of AWG 20) Shield Individually & Overall Alum/Mylar & TC drain wire Tape Overall Clear Mylar Wrap Jacket .050” Sunlight Resistant Black PVC Jacket Voltage Rating 300 V Temperature Rating 105 C Dimensions: Dia. (mm) 11 mm
Multiplexer Board
Number of Channels 8 CH Dimensions: W x L x H (mm) 160 x 100 x 30 mm
Number of Channels 4 CH Dimensions: W x L x H (mm) 187 x 66 x 30 mm
Control Panel (Modem)
Dimensions: W x L x H (mm) 187 x 66 x 30 mm
Read-out Unit
Number of Channel (s) 1 Measurement Range 1 to 95% Yielding Stress Accuracy 0.5% F.S. (Dependent upon the size of an EM sensor) Operating Temperature Range -20˚C to +80˚C Maximum Discharge Voltage 450 V Charging time 7 second (Max) Sample Rate higher than 0.1Hz Interface RS485/RS232C LCD Display Graphic LCD 128 X 64 Pixels Protection Lightning protector, Power Surge protector Power Supply AC 90-246, 60/50 Hz, 150W Cover NEMA4X/IP68 Enclosure (Option) Dimensions: W x L x H (mm) 183.5x111x300 mm
Enclosure Box
Materials 16-ga. steel with concealed steel hinges Protection NEMA4/IP66 Enclosure Cover Polyurethane-foam gasket and a 1/4-turn coin-slot latch Color Gray Inner Panel Steel Dimensions: W x L x H (inch) 24”x20”x8”
51-1-10079-033
APPENDIX B
IMPORTANT INFORMATION ABOUT YOUR
GEOTECHNICAL/ENVIRONMENTAL REPORT
1/2010
SHANNON & WILSON, INC. Geotechnical and Environmental Consultants
Dated:
Attachment to and part of Report 51-1-10079-033
Date: August 21, 2014
To: City of Los Angeles
Bureau of Engineering Attn: Mr. Craig Kunesh
Important Information About Your Geotechnical/Environmental Report
CONSULTING SERVICES ARE PERFORMED FOR SPECIFIC PURPOSES AND FOR SPECIFIC CLIENTS.
Consultants prepare reports to meet the specific needs of specific individuals. A report prepared for a civil engineer may not be
adequate for a construction contractor or even another civil engineer. Unless indicated otherwise, your consultant prepared your report
expressly for you and expressly for the purposes you indicated. No one other than you should apply this report for its intended
purpose without first conferring with the consultant. No party should apply this report for any purpose other than that originally
contemplated without first conferring with the consultant.
THE CONSULTANT'S REPORT IS BASED ON PROJECT-SPECIFIC FACTORS.
A geotechnical/environmental report is based on a subsurface exploration plan designed to consider a unique set of project-specific
factors. Depending on the project, these may include the general nature of the structure and property involved; its size and
configuration; its historical use and practice; the location of the structure on the site and its orientation; other improvements such as
access roads, parking lots, and underground utilities; and the additional risk created by scope-of-service limitations imposed by the
client. To help avoid costly problems, ask the consultant to evaluate how any factors that change subsequent to the date of the report
may affect the recommendations. Unless your consultant indicates otherwise, your report should not be used: (1) when the nature of
the proposed project is changed (for example, if an office building will be erected instead of a parking garage, or if a refrigerated
warehouse will be built instead of an unrefrigerated one, or chemicals are discovered on or near the site); (2) when the size, elevation,
or configuration of the proposed project is altered; (3) when the location or orientation of the proposed project is modified; (4) when
there is a change of ownership; or (5) for application to an adjacent site. Consultants cannot accept responsibility for problems that
may occur if they are not consulted after factors, which were considered in the development of the report, have changed.
SUBSURFACE CONDITIONS CAN CHANGE.
Subsurface conditions may be affected as a result of natural processes or human activity. Because a geotechnical/environmental report
is based on conditions that existed at the time of subsurface exploration, construction decisions should not be based on a report whose
adequacy may have been affected by time. Ask the consultant to advise if additional tests are desirable before construction starts; for
example, groundwater conditions commonly vary seasonally.
Construction operations at or adjacent to the site and natural events such as floods, earthquakes, or groundwater fluctuations may also
affect subsurface conditions and, thus, the continuing adequacy of a geotechnical/environmental report. The consultant should be kept
apprised of any such events, and should be consulted to determine if additional tests are necessary.
MOST RECOMMENDATIONS ARE PROFESSIONAL JUDGMENTS.
Site exploration and testing identifies actual surface and subsurface conditions only at those points where samples are taken. The data
were extrapolated by your consultant, who then applied judgment to render an opinion about overall subsurface conditions. The actual
interface between materials may be far more gradual or abrupt than your report indicates. Actual conditions in areas not sampled may
differ from those predicted in your report. While nothing can be done to prevent such situations, you and your consultant can work
together to help reduce their impacts. Retaining your consultant to observe subsurface construction operations can be particularly
beneficial in this respect.
1/2010
A REPORT'S CONCLUSIONS ARE PRELIMINARY.
The conclusions contained in your consultant's report are preliminary because they must be based on the assumption that conditions
revealed through selective exploratory sampling are indicative of actual conditions throughout a site. Actual subsurface conditions can
be discerned only during earthwork; therefore, you should retain your consultant to observe actual conditions and to provide
conclusions. Only the consultant who prepared the report is fully familiar with the background information needed to determine
whether or not the report's recommendations based on those conclusions are valid and whether or not the contractor is abiding by
applicable recommendations. The consultant who developed your report cannot assume responsibility or liability for the adequacy of
the report's recommendations if another party is retained to observe construction.
THE CONSULTANT'S REPORT IS SUBJECT TO MISINTERPRETATION.
Costly problems can occur when other design professionals develop their plans based on misinterpretation of a
geotechnical/environmental report. To help avoid these problems, the consultant should be retained to work with other project design
professionals to explain relevant geotechnical, geological, hydrogeological, and environmental findings, and to review the adequacy of
their plans and specifications relative to these issues.
BORING LOGS AND/OR MONITORING WELL DATA SHOULD NOT BE SEPARATED FROM THE REPORT.
Final boring logs developed by the consultant are based on interpretation of field logs (assembled by site personnel), field test results,
and laboratory and/or office evaluation of field samples and data. Only final boring logs and data are customarily included in
geotechnical/environmental reports. These final logs should not, under any circumstances, be redrawn for inclusion in architectural or
other design drawings, because drafters may commit errors or omissions in the transfer process.
To reduce the likelihood of boring log or monitoring well misinterpretation, contractors should be given ready access to the complete
geotechnical engineering/environmental report prepared or authorized for their use. If access is provided only to the report prepared
for you, you should advise contractors of the report's limitations, assuming that a contractor was not one of the specific persons for
whom the report was prepared, and that developing construction cost estimates was not one of the specific purposes for which it was
prepared. While a contractor may gain important knowledge from a report prepared for another party, the contractor should discuss the
report with your consultant and perform the additional or alternative work believed necessary to obtain the data specifically
appropriate for construction cost estimating purposes. Some clients hold the mistaken impression that simply disclaiming
responsibility for the accuracy of subsurface information always insulates them from attendant liability. Providing the best available
information to contractors helps prevent costly construction problems and the adversarial attitudes that aggravate them to a
disproportionate scale.
READ RESPONSIBILITY CLAUSES CLOSELY.
Because geotechnical/environmental engineering is based extensively on judgment and opinion, it is far less exact than other design
disciplines. This situation has resulted in wholly unwarranted claims being lodged against consultants. To help prevent this problem,
consultants have developed a number of clauses for use in their contracts, reports and other documents. These responsibility clauses
are not exculpatory clauses designed to transfer the consultant's liabilities to other parties; rather, they are definitive clauses that
identify where the consultant's responsibilities begin and end. Their use helps all parties involved recognize their individual
responsibilities and take appropriate action. Some of these definitive clauses are likely to appear in your report, and you are
encouraged to read them closely. Your consultant will be pleased to give full and frank answers to your questions.
The preceding paragraphs are based on information provided by the
ASFE/Association of Engineering Firms Practicing in the Geosciences, Silver Spring, Maryland