HomeMy WebLinkAbout3557; Carlsbad Blvd Las Encinas Creek & Bridge; Carlsbad Blvd Las Encinas Creek & Bridge; 2014-04-161
2014
Jack L. Abcarius
Nolte Associates, Inc.
April 16, 2014
Bridge Elevation – 4/14/2014
Bridge Revetment Monitoring Report
for the City of Carlsbad and the
California Coastal Commission
Las Encinas Creek Bridge
Br. No. 57C-0790L
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April 16, 2014
State of California – The Natural Resources Agency
California Coastal Commission
San Diego Area
7575 Metropolitan Drive, Suite 103
San Diego, CA 92108-4421
SUBJECT: 2014 Bridge Revetment Monitoring Report
Las Encinas Creek Bridge along Southbound Carlsbad Boulevard
Bridge No. 57C-0790L
City of Carlsbad, California
In accordance with Special Condition No. 2 set by the California Coastal Commission to approve
the City of Carlsbad’s Application No. 6-09-051, Nolte Associates, Inc., an NV5 company, is
submitting this final report for the Revetment Monitoring Program for Las Encinas Creek Bridge,
Br. No. 57C-0790L. This special condition states that “the monitoring report shall be submitted to
the Executive Director and City of Carlsbad Engineering Department yearly after each winter
storm season but prior to the 1st of May starting with May 1, 2010”. This report is the final report
of the five-year monitoring program which started in May of 2010.
Condition of Revetment
The rip-rap along the west edge of southbound Carlsbad Boulevard starts at Station 104+20.00 to
105+37.50 and 105+81.00 to 110+08.00. The stationing is measured along the centerline of
southbound Carlsbad Boulevard, and runs from north to south. Bridge construction and rip-rap
placement was completed on May 28, 2010. In order to control the location of the toe of slope on
the beach side during construction, the contractor placed sheet piles located 51′-10″± from the
centerline roadway prior to the installation of the rip-rap. This dimension coincided with the High
Tide Contour Line of 4.77′ (NGVD29) which was equivalent to 7.65′ (MLLW) as surveyed in
2009 during the design phase of this project.
The fifth High Definition Scanning was performed on March 20 of 2014. For ease of comparison,
the original monuments installed in 2010 were surveyed and results are shown in a tabular format
in this report (Appendix A). The results of our survey showed very little evidence of movement,
although some of the rocks at the toe have clearly moved westward, as shown in our recent photos.
It should be noted that this beach area is highly dynamic due to the constant wave action that
deposits and removes small sized cobbles and/or sand along the length of this project. At the time
of this report the beach area was absent of cobbles and consisted of a uniform sand layer except
that there was more sand deposits along the south face of the arch culvert as shown in the attached
photos.
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Following are some photos taken on April 14 of 2014 showing the current condition of the rip-rap.
These photos are used for comparison to the baseline condition post construction of 2010. We’ve
also included new scanned images to compare against the scanned images developed in 2010.
View looking North (2010)
View Looking North (2014)
Rip-Rap Looking Northeast (2010)
Looking Northeast (2014)
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Rip-Rap Looking South (2010) Looking South (2014)
Rip-Rap Looking South,
Past the Bridge (2010)
Looking South, Past the Bridge (2014)
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For the 5 year rip-rap monitoring plan, a control system was established and an initial survey was made
on June 10-11, 2010. Control was established by GPS based on CCS83, Epoch 1991.35 coordinates per
City of Carlsbad Survey Control, ROS 17271. The Benchmark is OC-147 (ROS 17271 point #1433),
having a NGVD 29 elevation of 50.56′. Five control points were set in the project vicinity, but outside
of the rip-rap for future surveys, including a 1″ brass disc mounted on the bridge, identified as M-5.
Additionally, six brass caps were set into boulders of the rip-rap and surveyed both horizontally and
vertically for future monitoring. These are identified as M-1, 2, 3, 4, 6, and 7. All these monuments are
clearly shown on the “Key Map to Control and Check Points” drawing included in this report
(Appendix B). The control points were documented photographically as well as surveyed for future
use. It was noted during our recent survey that the brass cap of monument M-2 has been removed.
Bridge Elevation View Looking North-East (2010)
(April 2014)
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High Definition Scan Model - Section Key (See 2010 – 2014 Profile Sections as an insert at end of this
report)
Summary
This report concludes our five-year monitoring program for this project. In general, we found
that the 4-ton and 2-ton rock rip rap has performed well over the years, although there are
instances where the rocks at the toe of slope have moved, and will most likely continue to
move. Such movement however, is not expected to jeopardize the integrity of the roadway
and/or bridge, but will, at some point in time, need to be placed back in order to maintain a
clear beach area.
On a separate matter, we noticed during our investigation, that the southernmost base plate of
the west bridge railing is beginning to show signs of rusting due to a metal chain that has been
placed around it. It appears that this chain has been there for quite some time, and is causing
both the base plate and rail post to start rusting. We recommend that the City cut/remove this
chain as soon as possible, clean the anodized plate and post to prevent the rust from spreading
further.
Should you have any questions concerning this letter report, please feel free to contact me at
(858) 385-2128.
Sincerely,
Nolte Associates, Inc.
______________________
Jack Abcarius, P.E.
Engineering Manager
Rusting Base Plate
Adjacent Base Plate
Approx. Sta. 104+20
~Sta. 105+37.50 ~Sta. 105+81 ~Sta. 110+08
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APPENDIX A
COMPARISON TABLE
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Mon. No.North East Elevation North East Elevation Variation North Variation East Variation Elevation
M-1 1987170.037 6232576.644 14.893 1987170.029 6232576.643 14.882 -0.008 -0.001 -0.011
M-2 1987189.332 6232558.688 8.516 1987189.332 6232558.694 8.499 0.000 0.006 -0.017
M-3 1987278.205 6232540.045 15.696 1987278.196 6232540.040 15.680 -0.009 -0.005 -0.016
M-4 1987333.538 6232508.076 8.588 1987333.536 6232508.071 8.570 -0.002 -0.005 -0.018
M-5 1987425.621 6232501.512 15.913 1987425.609 6232501.507 15.911 -0.012 -0.005 -0.002
M-6 1987555.970 6232428.560 6.990 1987555.970 6232428.538 6.994 0.000 -0.022 0.004
M-7 1987585.650 6232423.510 9.645 1987585.639 6232423.454 9.634 -0.011 -0.056 -0.011
4" B.D.1 N/A N/A N/A 1987231.984 6232553.516 14.141 #VALUE!#VALUE!#VALUE!
L.S. 79901 N/A N/A N/A 1987487.706 6232476.664 16.160 #VALUE!#VALUE!#VALUE!
1 Monuments placed by others; Nolte does not have the 2010 coordinates and elevations to compare against.
Highlighted cells represent the largest values measured.
Mon. No.North East Elevation North East Elevation Variation North Variation East Variation Elevation
M-1 1987170.037 6232576.644 14.893 1987170.005 6232576.653 14.914 -0.032 0.009 0.021
M-2 1987189.332 6232558.688 8.516 1987189.363 6232558.685 8.521 0.031 -0.003 0.005
M-3 1987278.205 6232540.045 15.696 1987278.194 6232540.048 15.659 -0.011 0.003 -0.037
M-4 1987333.538 6232508.076 8.588 1987333.545 6232508.084 8.577 0.007 0.008 -0.011
M-5 1987425.621 6232501.512 15.913 1987425.592 6232501.516 15.916 -0.029 0.004 0.003
M-6 1987555.970 6232428.560 6.990 N/A3 N/A3 N/A3 #VALUE!#VALUE!#VALUE!
M-7 1987585.650 6232423.510 9.645 1987585.690 6232423.507 9.630 0.040 -0.003 -0.015
4" B.D.2 1987231.984 6232553.516 14.141 1987231.985 6232553.505 14.135 0.001 -0.011 -0.006
L.S. 79902 1987487.706 6232476.664 16.160 1987487.713 6232476.717 16.159 0.007 0.053 -0.001
2 Coordinates and elevations shown under 2010 are based on Nolte's 2011 Survey.
3 Monument M-6 was buried with cobbles
Highlighted cells represent the largest values measured; Less than a 1/2" vertically and 3/4" horizontally.
Mon. No.North East Elevation North East Elevation Variation North Variation East Variation Elevation
M-1 1987170.037 6232576.644 14.893 1987170.043 6232576.625 14.895 0.006 -0.019 0.002
M-2 1987189.332 6232558.688 8.516 1987189.366 6232558.699 8.509 0.034 0.011 -0.007
M-3 1987278.205 6232540.045 15.696 1987278.203 6232540.044 15.692 -0.002 -0.001 -0.004
M-4 1987333.538 6232508.076 8.588 1987333.572 6232508.105 8.590 0.034 0.029 0.002
M-5 1987425.621 6232501.512 15.913 1987425.641 6232501.557 15.936 0.020 0.045 0.023
M-6 1987555.970 6232428.560 6.990 1987555.997 6232428.591 6.987 0.027 0.031 -0.003
M-7 1987585.650 6232423.510 9.645 1987585.676 6232423.527 9.648 0.026 0.017 0.003
4" B.D.2 1987231.984 6232553.516 14.141 1987232.003 6232553.528 14.151 0.019 0.012 0.01
L.S. 79902 1987487.706 6232476.664 16.160 1987487.734 6232476.709 16.186 0.028 0.045 0.026
2 Coordinates and elevations shown under 2010 are based on Nolte's 2011 Survey.
Highlighted cells represent the largest values measured; Less than 1/2" vertically and 3/4" horizontally.
Mon. No.North East Elevation North East Elevation Variation North Variation East Variation Elevation
M-1 1987170.037 6232576.644 14.893 1987170.027 6232576.639 14.884 -0.010 -0.005 -0.009
M-23 1987189.332 6232558.688 8.516 1987189.360 6232558.697 8.4913 0.028 0.009 -0.025
M-3 1987278.205 6232540.045 15.696 1987278.185 6232540.029 15.667 -0.020 -0.016 -0.029
M-4 1987333.538 6232508.076 8.588 1987333.540 6232508.086 8.583 0.002 0.010 -0.005
M-5 1987425.621 6232501.512 15.913 1987425.592 6232501.516 15.916 -0.029 0.004 0.003
M-6 1987555.970 6232428.560 6.990 1987555.960 6232428.543 6.985 -0.010 -0.017 -0.005
M-7 1987585.650 6232423.510 9.645 1987585.643 6232423.482 9.646 -0.007 -0.028 0.001
4" B.D.2 1987231.984 6232553.516 14.141 1987231.997 6232553.507 14.135 0.013 -0.009 -0.006
L.S. 79902 1987487.706 6232476.664 16.160 1987487.710 6232476.678 16.177 0.004 0.014 0.017
2 Coordinates and elevations shown under 2010 are based on Nolte's 2011 Survey.
3 Brass disc of Monument M-2 has been removed/destroyed.
Highlighted cells represent the largest values measured; Less than 1/2" vertically and 1/2" horizontally.
2010 2013 Difference From 2010 / 2011 (Feet)
2010 2014 Difference From 2010 / 2011 (Feet)
2010 2011 Difference From 2010 (Feet)
2010 2012 Difference From 2010 / 2011 (Feet)
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APPENDIX B
KEY MAP TO CONTROL AND
CHECK POINTS
+
PROFILE SECTIONS
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