HomeMy WebLinkAboutPA2023-0034_20230206_Hetherington Landslide Mitigation Summary 3-29-2021HETHERINGTON ENGINEERING, INC.
SOIL & FOUNDATION ENGINEERIN G• ENGINEERIN G GEOLOGY• HYDROGEOLOGY
Gerson Bakar and Associates
c/o Park Newport Apartments
One Park Newport Drive
Newport Beach, Cali forn ia 92660
Attention: Mr. Jim Diaz
Fae ii iti es 1\lf anagcr
March 29, 2021
Project No. 8564.1
Log No. 21343
Subj ect: GEOTECHNICAL SUMMARY OF PROPOSED LANDSLIDE
MITIGATION
Park Newport Apartments
One Park Newport Drive
Newport Beach, California
Rere rences: Attached
Dear Mr. Diaz:
Tn accordance with your request, Hetherington Engineering, Inc. has prepared this
gcotechnical summary related to geologic conditions, past landslides, and proposed f-t.1ture
mitigation efforts on the west faci ng coastal bluff at the subject site. ln order to keep this
summary relatively brief, attached is a list of references related to the Park Newport
Apartments site that includes most (if not all) of the known geotechnical/geologic
documents. These documents have addressed various aspects oC the coastal bluff slope
geology, landslides, stability, and mitigation efforts.
SITE IIISTORY/SLOPE CONDITIONS
The subject natural slope is a coastal bluff that descends from the west sid e of Park Newport
Apartments to Backbay Drive along the eastern edge of Upper Newport Bay in Newport
Beach, California (see Location Map, Figure I). The slope descends at slope ratios of0.5: l
to 1.5: 1 (horizontal to ve1tical) to locally vertical with a maximum height of approximately
90-feel. This coastal bluff was left in a natural condition at the time of grading/construction
of Park Newport Apartments in 1969. The slope e xposes 10 to 15-feel or silty sand
Quaternary Paralic Deposits (terrace deposits) over diatomaceous shale and siltstone
Miocene Monterey Formation bedrock. Geologic structure of sedimentary bedding wi thin
the siltstone bedrock reportedly consists of a series of east to west trending, west plunging
anticlines and synclines creating locally unfavorable orientations relative to the west facing
slope. Numerous older landslides that ex isl on this slope \Nere identified by LeRoy Crandall
and Associates. The slope is subj ect to on-going erosion, surficial instabili ty, rockfalls, and
landslides.
5365 Avenida Encinas, Suite A • Carlsbad, CA 92008-4369 • (760) 931 -1917 • Fax (760) 931-0545
333 Third Street, Suite 2 •Laguna Beach, CA 92651-2306 • (949) 715-5440 •Fax (760) 931-0545
www. hetheringtonengineering. com
2 - Geotechnical Mitigation Summary
GPO'J'FCl TNIC'/\ [, ;:;llMM/\RY OF l)Roro:mD LAl 41)SLJ J)I-<: IvHTlG/\T[ON
Pro ject No. 85 M . I
Log No. 21343
Ivlarch 29, 2021
Page 2
The altached Geologic Map, Plate 1, depicts lhe geologic conditions on and near lbc slope.
The Park Newporl buildings were graded in l969 and documented fill exists on lhe level
building pads, but has no t been shown on the Geologic Map fo r simplicity.
The fo llowi ng summary of documented slope instability on lhe coastal bluff is not inlendcd
to be a ll inclu sive, bul is inlendccl lo demonstrate lhe performance of lhe slope. Small to
large lanclsliclcs have taken place in 1978, 1993, l 994 , 2000, 2005, and 2020. Rock fa ll s
have occurred in 1998, 2005, 2006, 2009, and 20 16. Sma ll to large surficial slope fa ilures
take place u1 years with long cluralion and/or hi gh intensity rai nfa ll events. Erosion ta kes
place during most rainfa ll evenls. T he asphalt concrete paved Backbay Drive right-of-way
exists along lhe toe o[ the coastal bluff and has been impacted by debris
accumulation/blockage on the roadway clue lo coasta l bluff instability.
Due Lo the height, steep slope ratio, existing landslides, locally adverse geologic structure,
and poor qua Ii ly bedrock exposed on the coastal bluff, factors-of-safety for gross and
smficial slope stabili ty arc less than 1.5. The coastal bluff slope is consid ered grnssly and
surfi cially unstable from an engineering geologic and geotechnical engineering
perspective.
In the past, mitigation of impacts to Park Newport improvements has been performed. The
following is a sununary of the measures implemented:
1979 -Timber Pile/Wood Lagging Retaining Wall , west side ol Units 4570
through 4640. Eighteen piles 10-feet bedrock embeclment.
1998 -Soldier Pile Wal.l, west side of clubhouse. Twenty-three, 36-inch
diameter, 7-feet on-center, 60-feet deep reinforced concrete caissons.
1998 -Soldier Pile Wall, south,,vest side of Unit 4570. Six, 48-.inch diameter, 8-
feet on-center, 60-feet deep, reinforced concrete caissons.
The approximate location of these structures are noted on the attached Geologic Map, Plate
1.
The June 2020 landslide event resulted in a ve1tical main scarp (lO±feet high) exposing
highly fractured blocky siltstone. This rocldall potential created a hazard to Backbay Drive
localed at the Loe of the coastal bluff. Backbay Drive has been closed lo vehicular traffic
since the landslide event. Park Newport Apartments has recently completed the installation
of a Geobrugg Tecco anchored mesh system to mitigate the rockfall potential (References
107 -114). We understand completion of this work will allow the City ofNewpo1t Beach
to re-open Backbay Drive.
Park Nevvport Apmtments monitors conditions on and near th e Lop of the slope on an annual
basis. Storm drainage systems have been enhanced and storm water flow is directed away
HETHERINGTON ENGINEERING, INC.
GEO J'l~CI JNICA I, SUMMARY OF PROl'OSED LANDSLI 1)1~ MlTICJJ\ I ION
Proj ect No. 8564. I
Log No. 2 11tl3
March 29, 2021
Page 3
from lbc slope in a controlled manner. In addition, portions or the active landslides are
covered using pl astic membranes and sand bags Lo reduce erosion during lhe rai ny season .
PROPOSED IMPROVENrENTS
As a result or ongoin g slope instability, th e fo llowi ng areas arc bei ng evalu ated for
proposed mi ligation measures consisti ng of soldier piles.
o Extending the clt1b house soldier piles to the south past Unit 4830 approximately
150-feel total (approximately 20-solclier pi les).
o lnsla lling soldier piles on the southeast sid e of Building 4, approximately 200-
feel total, where landslide materi als were mapped by Law-Crandal I and
Associates extending under the structure (approximately 28-solclier piles).
Soldier piles are expected to consist of 36 lo 48-inch diameter dri JJecl holes 7 to 8-feel on
center, to depths of 60 lo 70-feet, that wi ll be fill ed with concrete reinforced with steel
rebar "cages". The holes are drilled using conventional drilling equipment, steel cages are
placed into the hole using a crane, concrete is then placed by tremi e method to fill the hole.
These improvements are needed to protect and extend the useful life of the existing
residential structures.
The approximate locations of these areas are indicated on the attached Geologic Map, Plate
l . Analyses and design would be required to provide further details of the proposed
improvements.
This opp01tunity lo be of servi ce is appreciated. If you have any questions, please contact
om office at your convenience.
N ENGINEERING, INC.
Dist.ribulion: 1-via e-mail Jim Diaz (jdiaz@gb-a.com)
1-via e-mail Ken Dressel (Kdressel@gb-a.com)
1-via e-mail Shawna Schaffner (sschaffner@caaplanning.com) .... ,
HETHERINGTON ENGINEERING, INC.
1 too , 11,I I
REFEREJ ICES
i. 'Report of Supplemental Geologic lnve::;ligation, Proposed Arartmenl )evelopment,
Newporl Beach, CA", by Glem1 Brown and Associates, elated November 21, 1968.
2. "Reports of Soil and Foundation Investigalion Phase 1 Proposed Headlands
Apartmenls Promontory Point Area'', by LeRoy Crandall and Associates for Gerson
Bakar & Associates, dated December 26, 1968.
3. "Preliminary Foundation Recmmnendations, Proposed Headlands Aparlments,
Newport Beach, California", by LeRoy Crandall and Associates, dated January l 6,
l 969.
4. "Report of Soil and Foundation Investigation Phase II Proposed Park Newport
Apartrnenls Promontory Point Area", by LeRoy Crandall aocl Associates for Gerson
Bakar and Associates, dated April 4, 1969.
5. "Supplementary Information, Park Newport Apartments, Newport Beach, CA", by
LeRoy Crandall and Associates, dated August 21, 1969.
6. "Requirements for Drilled Pile Foundations, Townhouses Adjacent to Buildings 4, 5
and 6, Proposed Park Newp01i Apartments, Jamboree Road and San Joaquin Ilills
Road, Newport Beach, CA", by LeRoy Crandall and Associates, dated July 8, 1970.
7. "Estimated Tip Elevations -Drilled Piles, Building Nq. 4, Park Newpmt, Jamboree
Road near San Joaquin Hills Road, Newport Beach, California", by LeRoy Crandall
Associates, dated January 21, 1971.
8. "Repmt of Soil Investigation Proposed Extension of San Joaquin Hills Road -San
Joaquin Hil ls Road to Back.bay Drive Newport Beach, California", by LeRoy Crandall
and Associates, for Park Newport, Ltd., dated July 16, 1971.
9. "Preliminary Observations, Bluff Erosion and Sloughing, Park Newport Apartments,
Newport Beach, California", by LeRoy Crandall and Associates, dated March 10,
1978.
10. "Suggestions for Slope Repairs Existing Slope West of Buildings 32, 35, 36 and 37,
Park Newport Apartments, Newpo1t Beach, CA", by LeRoy Crandall and Associates,
elated July 19, 1978.
11. "Soil and Foundation Inspection, Building 41 (Apartment 3170) Park Newporl
Apartments, Jamboree and San Joaquin Hills Road, Newport Beach, CA", by LeRoy
Crandall and Associates, dated August 10, 1978.
12. "Conference Summary, Erosion Control Retaining Wall Adjacent to Building 35 Park
Newp01t Apartments'', by LeRoy Crandall and Associates, for Gerson Bakar &
Associates, dated November 2, 1978.
·HETHERINGTON ENGINEERING, INC.
Project No. 8564.1
Log No. 21343
•' o 1 JI I
R~1'T~RENCES
13. "Report of Slope Stability Study Wesl Facing Slope Adjacent to Building 4 Park
Newpo1t Aparlmenls", by LeRoy Crandall and Associates for Gerson-Bakar &
Associates, dated June 28, 1979.
14. "Review of Foundation Underpitming, Design NWC B uilding 41(Apartment3170),
Park Newport Apartments, Newport Beach, CA", by LeRoy Crandall and Associates,
dated October 18, 1979.
15. "Verification of Drilled Pile Inspection, and Inspeclion and Testing of Compacted Fill,
Proposed Underpim1ing of Building No. 41, Park Newporl Apartments, One Park
Newport Drive", by LeRoy Crandall and Associates for City ofNewporl Beach, dated
July 31 , 1980.
16. "Inspection of Site Conditions, Existing Park Newport Apartments, San Joaquin Hills
Road, Newpo1t Beach, CA", by LeRoy Crandall and Associates, for Qerson Bakar &
Associates, dated December 3, 1984.
17. "Summary of Observations Site Visit -March 22, 1988 Park Newpo11 Apartments",
by LeRoy Crandall and Associates, for Gerson Bakar & Associates, dated May 26,
1988.
18. "Report of Geologic Evaluation of Slope Below Building 4 Newpmt Beach, California
for Park Newport Apartments", by LeRoy Crandall and Associates, for Park Newport
Apaitments, dated April 30, 1991.
19. "Consultation Regarding Existing Slope Failure on the Promontory Point Area Park
Newport Apartments", by Law Crandall, Inc. fo r Mr. Ken Adelson, dated June 22,
1993.
20. "Maintenance Program Slope Facing Backbay Drive Park Newport Apa.rtments'', by
Law Crandall, Inc. for Gerson, Bakar & Associates, dated August 29, 1994.
2 1. "Monitoring Program Slope Facing Backbay Drive Park Newport Apartments", by
Law Crandall, Inc. for Gerson Bakar & Associates, dated September 1, 1994.
22. "Geotechnical Consultation, Slope Distress Near Units 3160 and 3170, Park Newport
Apartments, One Park Place, Newport Beach, CA", by Law/Crandall, dated December
15, 1994.
23. "Addendum to Geotechnical Consultation Observation of Erosion Control Measures
Park Newport Apartments", by Law Crandall, Inc., for Park Newport Apartments,
dated February 16, 1995.
24. "Park Newp01t Monitoring Survey'', by RBF, dated October 10, 1995, December 6,
1995, February 12, 1996.
' I • j
HETHERINGTON ENGINEERING, INC.
Project No. 8564.1
Log No. 21343
REFERENCE!i
25. "Park Newport Monitoring Survey", by Robert Bein, William Frost, & Associates, ror
Law Crand all, dated February 21, 1996.
26. "Park Newport Monitoring Survey", by Robert Bein, William Frost & Associates, for
Law Crandall, dated April 8, 1996.
27. "Bi-Monthly Monitoring Program S lope Facing Backbay Drive Park Newport
Apartments'', by Law Crandall for Gerson Bakar & Associates, dated May 14, 1996.
28. "Report of Geolcchnica l Investigation Existing Landslide", by Law/Crandall for
Gerson, Bakar & Associates, dated May 31, 1996.
29. "1995-1996 Annual Slope Monitoring Program Slope Facing Backbay Drive'', by Law
Crandall for Gerson, Bakar & Associates, dated June 24, 1996.
30. "Memo-3 160 Landsli de Area", by Linda Gunther of Park Newpmt Apartments fo r
Andy Dodge, Maintenance Supervisor, dated October 3 l, 1996.
31. "Supplemental Geolechnical Investi gation for a Slope Wall'', by Bagahi Engineering
for Gerson, Bakar & Associates, daled November 14, 1996.
32. "Email Summaries -Park Newport Slide Area'', from Gerson, Bakar and Associates,
dated June 29, 1995 tlu·ough October 21, 1996.
33. "Geotechnical Consultation Observation of Asphaltic Distress Near Building 4", by
Law Crandall for Gerson, Bakar & Associates, dated March 18 , 1997.
34. "Park Newport Monitoring Survey, Newpo1t Beach", by Robert Bein, Will iam Frost
& As.sociates for Gerson, Bakar & Associates, dated April 2, 1997.
35. "1996-97 Annual Monitoring Program Slope Facing Backbay Drive", by Law
Crandall for Gerson, Bakar and Associates, dated May 13, 1997.
36. "Landslide Mitigation Action -Park Newport Apaitments", by Bagahi Engineering
for California Civil Inc., dated July 25, 1997.
37. "Response to Coastal Commission -Park Newport Slope Repair'', by Bagahi
Engineering for Gerson, Bakar & Associates, dated August 4, 1997.
3 8. "Park N ewpmt Apartments' Slope Rehab Project", by Gerson, Bakar & Associates for
Eric Buress of P F & G, dated September 9, 1997.
39. "Retaining Wall Calculations -Park Newpo1t Apatiments", by Stample Engineering
for Park Newport Apartments, dated October 9, 1997.
HETHERINGTON ENGINEERING, INC.
Project No. 8564.1
Log No. 2 l343
REFERENCES
40. 'Special I11spection Report Park Newport Retaiuing Wall", by Gary Rutherford Cor
Cily of Newport Beach, dated October 14, 1997.
41. "Sile Reconnaissance Slope Facing Backbay Drive", by Law Crandall for Gerson,
Bakar & Associates, dated October 22, 1997.
42. "Progress Report -Park Newport Slope Wall", by Bagahi Engineering for Gerson,
Bakar & Associates, dated October 23, 1997.
43. "Progress Report -Park Newporl Slope Wall", by Bagahi Engineering for Gerson,
Bakar & Associates, dated December 5, l 997.
44. "Fine Grade Compaction Report -Park Newporl Apartments Slope Wall", by Bagahi
Engineering for Gerson, Bakar and Associates, dated December 8, 1997.
45. "Park Newport Apartment Drain Revegetation", by LSA Associales, Inc. for Park
Newport Apartments, dated February 25, 1998.
46. "Review of Slope Mitigation Options, Park Newport Apaitments, One Park Newport,
Newport Beach, CA", by Law Crandall for Gerson Bak.ar & Associates, dated
April 13, 1998.
47. "Final Slope Improvement Options Report", by Law Crandall for Gerson, Bakar, and
Associates, dated April 14, 1998.
48. "Report of Slope Stability Evaluation", by Law Crandall for Gerson, Bakar &
Associates, dated May 1, 1998.
49. "Shoring Plan, Park Newport Apartments, Slope Stabilization -Clubhouse Area and
Rockfall Area, One Park Newport, Newport Beach, CA", by Gerald Leluner
Associates, dated May 5, 1998. and August 11, 1998 (Sheets SH-1 tlu·ough SH-4).
50. "Grading Plan Review-Temporary Erosion Repair, Po1tions of the West Facing Slope,
Park Newport Apartments, Newport Beach, CA", by Hetherington Engineering, Inc.,
dated August 25, 1998.
51. "Alternatives to Temporary Erosion Repair, Portions of the West Facing Slope, Park
Newpo1t Apartments, Newpo11 Beach, CA'', by Hetherington Engineering, Inc., dated
September 10, 1998.
52. "Additional Geo technical Comments, Proposed Repairs to Portions of the West Facing
Slope, Areas 2 and 3, Park Newport Apartments, Newport Beach, CA", by
Hetherington Engineering, Inc., dated September 21, 1998.
HETHERINGTON ENGINEERING, INC.
Project No. 8564.1
Log No. 21343
REl,.ERENCES
53 . "Review of Project Special Provisions, Park Newport Sites A and B, Park Newport
Apartments, Newport Beach, Ca", by Hetheri11gton Engineering, dated Seplernber 24,
1998.
54. "1997 -l 998 Ammal Monitoring Program, Slope Facing Backbay Drive'', by Law
Crandall, dated October 14, 1998.
55. "Review of Site Conditions, Portions of the West Facing Slope Adj acent to the
Clubhouse, Park Newpott Apartments, Newpo1t Beach, CA", by Iletherington
Engineering, Inc. daled December 15, 1998.
56. "Temporary Erosion Repair, Portions of the West Facing Slope, Park Newpmt
Apartments, Newport Beach, CA", by Hetherington Engineering, Inc., dated
December 22, 1998.
57. "Response to Draft Submittal Letter for CDP Application to the Coastal Commission,
Park Newport Apartments, Slope Stability Repairing Work (Siles 2 and 3), Newport
Beach, CA", by Hetherington Engineering, Inc., dated January 19, 1999.
58. "Geolechnical Review -Temporary Erosion Repairs, West Facing Slope, Areas 2 and
3, Park Newport Apartments, Newpmt Beach, California", by Hetherington
Engil1eering, Inc., dated Pebruary 18, 1999.
59. "1998 -1999 Annual Monitoring, Backbay Drive Slope, Park Newport Apa1tments,
One Park Place, Newport Beach, CA ... ", by Hetheril1gton Engil1eering, Inc., dated
October 22, 1999.
60. "Morutoring Report for Slope and Parking Garage ... ", prepared by RBF Consulting,
dated December 27, 2000.
61. "1999 -2000 Annual Monitoring Program, Backbay Drive Slope and Adjacent Areas,
Park Newport Apartments, One Park Newport Drive, Newport Beach, California'', by
Hetherington Engineering, Inc., dated Januruy 5, 2001.
62. "Park Newp01t Apartments, Slope Monitoring Project. .. ", prepared by RBF
Consultil1g, dated January 28, 2002.
63. "2000 -2001 Annual Monitoring Progrrun, Backbay Drive Slope and Adjacent Area,
Park Newpo1t Apartments, One Park Newport Drive, Newport Beach, California", by
Hetherington Engineering, Inc., dated February 20, 2002.
64. "Pmk Newp01t Apartments, Slope Monitoring ... ", prepared by RBF Consulting, dated
December 26, 2002.
HETHERINGTON ENGINEERING, INC.
Project No. 8564.1
Log No. 21343
REFERENCES
65. "2001 -2002 Annual Monjtoring Program, Backbay Drive Slope and Adjacenl Areas,
Park Newport Apartmenls, One Park Newport Drive, Newporl Beach, California", by
Hetherington Engineering, Inc., dated January 27, 2003.
66. "Park Newp01t Apartments, Slope and Parking Structure Monitoring Project",
prepared by RBF Consulting, daled Pebruary 18, 2004.
67. "2002 -2003 Annual Monitoring Program, Backbay Drive Slope and Adjacent Areas,
Park Newport Apartments, One Park Newport Drive, Newport Beach, Californ ia ... ",
by Hetherington Engineering, Inc., dated March J 2, 2004.
68. "Am1ual Monitoring/Slope Area Drainage System, Update on Condition of Surface
Drainage Devices, Park Newport Apartments ... ", by Hetherington Engineering, Inc.,
elated October 29, 2004.
69. "Inspecti on of Slope Area Damages, Park Newport Apartments, Nev,rport Beach ... '',
by Hetherington Engineering, Inc., dated January 31, 2005.
70. "Inspecti on of February 2005 Storm Damages, Park Newport Apaiiments, Newport
Beach ... ", by Hetherington Engineering, Inc., dated February 24, 2005.
71. "Park Newport Monitoring Garage Structure and Slope Monitoring Project", prepared
by RBF Consulting, dated March 23, 2005.
72. "2003 -2004 Annual Monitoring Program, Backbay Drive Slope and Adjacent Areas,
Park Newport Apartments, One Park Newp01t Drive, Newport Beach, California ... '',
by Hetherington Engineering, Inc., dated May 20, 2005.
73. "Notice of Code Violation for Slope Failure at 1 Park Newport Drive ... ", by City of
Newport Beach, dated June 24, 2005.
74. "Rep01t of Findings, Geo technical Evaluation ofTlu·ee Areas Along the Coastal Bluff,
Park Newport Apartments, Newp01t Beach, California", by Hetherington Engineering,
Inc., dated November 11, 2005.
75. "Response to City Letter, Park Newport Apartments, Newport Beach, California'', by
Heth erington Engineering, Inc., dated December 19, 2005.
76. "Park Newp01t Apaitments, Garage Structure and Slope Monitoring Project. .. ", by
RBF Consulting, dated December 29, 2005, revised January 11 , 2006.
77. "Slope Inclinometer Data, Park Newpo.rt Apartments ... ", by Hetherington
Engineering, Inc., dated January 23, 2006.
HETHERINGTON ENGINEERING, INC.
Project No. 8564.1
Log No. 21343
REFEKENCE.~
/8. "2006 Annual Monitoring Program, Backbay .)rive Slope and Adjacent Areas, Park
Newport Apartmenls, One Park Newport Drive, Newport Beach, Californ ia 92660",
by Hetherington Engineering, Inc., dated February 27, 2006.
79. "Slope Rockfall Mitigation, Park Newport Apartments, West of Unit 4570, Newport
Beach, California", by Hetherington Engineering, Inc., elated May 12, 2006.
80. " ... Setllemenl and Deformation Monjtoring Surveying Services at the Park Newport
Apartments ... ", by RBf Consulting, dated Febrnary 23, 2007.
81. "2007 Annual Monitoring Program, Backbay Drive Slope and Adj acent Areas, Park
Newport Apmiments, One Park Newport Drive, Newport Beach, California 92660",
by Hetherington Engineering, Inc., dated June 29, 2007.
82. "Inspection of Top of Coastal Bluff Drainage Conditions, Park Newport Aparlments,
Newport Beach, Califo rnia", by Hetherington Engineering, Inc., dated December 5,
2007.
83. " ... Settlement and Deformation Monitoring Surveying Serv ices at the Park Newport
Apartments ... ", by RBF Consulti ng, dated June 19, 2008.
84. "2008 Annual Monitoring Program, Backbay Drive Slope and Adjacent Areas, Park
Newpo1i Apartments, One Park Newport Drive, Newport Beach, California, 92660",
by Hetherington Engineering, Inc., dated September 3, 2008.
85. "... Settlement and Deformation Monitoring Survey Services at the Park Newport
Apartments ... ", by RB F Consulting, dated June 5, 2009.
86. "2009 Annual Monitoring Program, Backbay Drive Slope and Adjacent Areas, Park
Newport Apartments, One Park Newport Drive, Newport Beach, California", by
Hetherington Engineering, Inc., dated August 18, 2009.
87. "Surficial Slope Failure, Coastal Bluffs Below Building 4, Park Newport Apaiiments,
Newport Beach, Californja", by Hetherington Engineering, Inc., dated January 28 ,
2010.
88 . " ... Settlement and Deformation Monitoring Survey Services ... ", by RBF Consulting,
dated July 7, 20 I 0.
89. "2010 Annual Monitoring Report, Backbay Drive Slopes and Adjacent Areas, Park
Newport Apmiments, One Park Newport Drive, Newport Beach, California'', by
Hetherington Engineering, Inc., dated September 29, 2010.
90. "Geotechnical Investigation, Proposed Rockfall Netting Slope Protection System,
Coastal Bluff Below Unit 4570, Building No. 35, Pai·k Newport Apartments, One Pmk
HETHERINGTON ENGINEERING, INC.
Project No. 8564.1
Log No. 21343
REFERENCES
Newporl Drive, Newport Beach, California", by Hetherington Engineering, Inc., dated
January 5, 20 l l.
91. " ... Settlement and Defonnalion Monitoring Survey Services ... ", by RBF Consulting,
dated June 14, 2011.
92. "2011 Annual Monitoring Report, Backbay Drive Slope and Adj acent Areas, Park
Newport Apartments, One Park Newport Drive, Newpo1t Beach, California", by
Hetherington Engineering, Inc., dated August 26, 20 11.
93. "2012 A1urnal Moniloring Report, Backbay Dri ve Slope and Adjacent Areas, Park
Newport Apartments, One Park Newport Drive, Newport Beach, California", by
Hetherington Engineering, Inc., dated October 12, 2012.
94. "2013 Arurnal Monitoring Report, Backbay Drive Slope and Adjacent Areas, Park
Newport Apmtments, One Park Newporl Drive, Newporl Beach, California", by
Hetherington Engineering, Inc., elated September 25, 2013.
95. "2014 Annual Monitoring Report, Backbay Dri ve Slope and Adjacent Areas, Park
Newport Apartments, One Park Newport Drive, Newport Beach, California", by
Hetherington Engineering, Inc., dated October 15, 2014.
96. "2015 An11ual Monitoring Report, Backbay Drive Slope and Adjacent Areas, Park
Newport Apaitments, One Park Newport Drive, Newport Beach, California", by
Hetherington Engineering, Inc., dated October 5, 2015.
97. "2016 Annual Monitoring Report, Backbay Drive Slope and Adjacent Areas, Park
Newp01t Apartments, One Park Newport Drive, Nevvport Beach, California", by
Hetherington Engineering, Inc., dated December 14, 2016.
98. "Geoteclmical Investigation, Damaged Retaining Wall, Pai·k Newport Aparlments,
Building la, Newport Beach, California", by Hetherington Engineering, Inc., dated
April ·19, 2017.
99. "Addendum to Geotechnical lnvestigation, Damaged Retaining Wal.I, Park Newport
Apaitments, Building la, Newport Beach, California", by Hetherington Engineering,
Inc., dated October 19, 2017.
100. "2017 Annual Monitoring Report, Backbay Drive Slope and Adjacent Areas, Park
Newport Apartments, One Park Newport Drive, Newport Beach, California'', by
Hetherington Engineering, Inc., dated December 29, 2017.
101. "2018 Annual Monitoring Report, Back bay Drive Slope and Adjacent Areas, Park
Newport Aprutments, One Park Newp01t Drive, Newport Beach, California", by
Hetherington Engineering, Inc., dated November 5, 2018.
HETHERINGTON ENGINEERING, INC.
Project No. 8564.1
Log No. 21343
REFERENCES
102."Emcrgency Storm Drain Repair, North of Building 41 (Units 3150 through 3220),
Park Newport A partments, One Park Newport Drive, Newport Beach, Californ.ia", by
Hetherington Engineering, Inc., elated March 5, 20 l9.
103."Park Newpo1t Apartments, l Park Newport Drive, 24-inch St01m Drain
Rehabilitati on Plan'', by BFK Engineers, dated October 23, 2019 (2 Sheets).
104. "Geo technical Report Review Checklist, Repair Rear Drainage Pipe, 1 Park Newport
Drive ... ", by City of Newport Beach, dated November 12, 201 9.
105. "20 l 9 Annual Monitoring Program, Back bay Drive Slope and Adjacent Areas, Park
Newport Apartments, One Park Newport Drive, Newpoli Beach, California", by
Hetherington Engineering, Inc., dated December 18, 2019.
106. "Geotechni cal Sununary of Proposed Storm Drain Rehabilitation, North of Building
41 (Un i ts 3160 and 3 l 70), Park Newport Apartments, One Park Newport Drive,
Newport Beach, California", by Hetherington Engineering, Inc., dated December 20,
2019.
107."Geoteclm.ical Summary of Landslide Mitigation, West of Unit 4830, Park Newport
Apartments, One Park Ncwpo1t Drive, Newport Beach, Ca lifornia", by Hetherington
Engineering, Inc., dated July 21, 2020.
108. "Park Ncwpmt Apartments, Back Bay Drive, Rockfall Assessment Letter, Newport
Beach, California'', by Kane Geotech, Inc., dated August 20, 2020.
109. "Park Newport Apartments, Surficial Slope Stabilization and Rockfall Mitigation,
Engineering Design Calculation Report, Newport Beach, California'', by Kane
Geotech, Inc., dated August 20, 2020 (Sheets l tlu·ough 5). '
110. "Park Newport Apmtments, Surficial Slope Stabilization and Rockfall Mitigation
(Project Specifications), Newport Beach, Californ.ia", by Km1e Geotech, Inc., dated
August 20, 2020.
111. "Proposed Rockfall Mitigation, West of Unit 4830, Park Newport Apattments, One
Park Newport, Newport Beach, California", by Hetherington Engineering, Inc., dated
September 4, 2020.
1 12. "Response to Geotechnical Repo1t Review Checklist, Proposed Rockfall Mitigation,
West of Unit 4830, One Park Newport Drive, Newport Beach, California, Plan Check
No. 1636-2020", by Hetherington Engineering, Inc., dated December 18, 2020.
113 ."Response to Plan Check Correction List, Proposed Rockfall M itigation, West of Un.it
4830, One Park Newport Drive, Newport Beach, California, Plan Check No. 1636-
2020", by Hetherington Engineering, Inc., dated December 18, 2020.
HETHERINGTON ENGINEERING, INC.
Project No. 8564.1
Log No. 21343
IlliFERENCES
114.''Proposcd Emergency Rockfall Mitigation, West of Unit 4830, One Park Newport
Drive, Newport Beach, California,,, by Hetherington Engineering, Inc., dated January
6, 202 1.
HETHERINGTON ENGINEERING, INC.
Project No. 8564.1
Log No. 21343
PLATE NO.PROJECT NO.PROJECT NO.
GEOLOGIC MAP
0 1 2
0 30 60 90 120
N
SCALE: 1" = 60'EXPLANATION
BORING BY LEROY CRANDALL & ASSOCIATES (1978)
GEOLOGIC CONTACT
APPROXIMATE LOCATION OF EXISTING PILES: TIMBER/WOOD LAGGING
RETAINING WALL, PILES 10 FEET INTO BEDROCK (1979)
APPROXIMATE LOCATION OF EXISTING PILES: CLUBHOUSE SOLDIER PILE WALL,
23 PILES, 36-INCH DIAMETER, 7-FEET ON CENTER, 60 FEET DEEP (1998)
APPROXIMATE LOCATION OF EXISTING PILES: SOLDIER PILE WALL, 6 PILES,
48-INCH DIAMETER, 8-FEET ON-CENTER, 60-FEET DEEP (1998)
1
2
3
B-7
APPROXIMATE LOCATION OF POSSIBLE SOLDIER PILE WALL:EXTEND CLUBHOUSE PILES SOUTH ABOVE JUNE 2021 LANDSLIDE
BUILDING 45APPROXIMATE LOCATION OF POSSIBLE SOLDIER PILE WALL:
(1978)
BORING BY LEROY CRANDALL & ASSOCIATES (1968)B-7
(1968)4
(1968)
B-4
(1968)
B-5(1978)
B-1
(1978)
B-6(1968)
LANDSLIDE
FORMATIONMONTEREY
DEPOSITSTERRACE
DEPOSITSTERRACE
FORMATIONMONTEREY FORMATIONMONTEREY
FORMATIONMONTEREY
DEPOSITSTERRACE
FORMATIONMONTEREY
FORMATIONMONTEREY
LANDSLIDE
MARCH 1978(ACTIVE)
JUNE 2020
(ACTIVE)
1998(ACTIVE)JANUARY 1993
(ACTIVE)
JANUARY 1993
(ACTIVE)
DECEMBER 1994
(ACTIVE)
(ACTIVE)NOVEMBER 1978
DEPOSITSTERRACE
B-3
Park Newport Apartments
Newport Beach, California
1
1
SURFICIAL FAILURES / EROSION
ROCKFALL(PERIODIC ACTIVITY)
4
B-5(1968)
2
3
5
B-7(1978)
B-6
(1978)
B-7
(1968)
B-2
(1978)
B-4
(1978)B-3
(1978)