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HomeMy WebLinkAbout20170130_Seawall Repair_12-14-2016~~. WILLIAM SIMPSON & ASSOCIATES, INC. S CONSULTING STRUCTURAL ENGINEERS 23 ORCHARD. SUITE 250 PH. (949) 206-9929 LAKE FOREST, CA 92630 FAX (949) 206-9955 www.w5a5e.com e-m a i I : m a i I@ w 5 a 5 e . com December 14, 2016 Ian Harrison 3535 east Coast Hwy #301 Corona Del Mar, CA 92625 RE: SEA WALL REPAIR/REINFORCING 2772 Bayshore Drive Newport Beach, CA 92663 WSA Job #7084 Dear Mr. Harrison, Pursuant to your request and authorization, William Simpson & Associates, Inc., (WSA) is pleased to provide this report regarding questions typically asked by California Coastal Commission related to the current status of existing seawalls. QUESTION: What is the visual appearance status ofthe seawall? ANSWER: The exposed elements of the seawall assembly, concrete coping and panels, seem to be in a good condition for a concrete structure of this vintage. QUESTION: Will the seawall last for the economic life normally taken to be 75 to 100 years) of the associated structure (single-family residence)? ANSWER: From structural engineering stand point the existing seawall should last for the economic life of the associated structure (single-family residence). QUESTION: How will the effects of sea level rise impact the seawall? ANSWER: While sea levels have been rising for decades, higher rates of raise are forecast for the coming century as a consequence of climate change. Increases can be attributed to warmer temperatures, which cause water to expand, as well more liquid mass caused by melting of ice caps. Current estimates of future sea level rise generally fall in the range of 1-3 ft for the year 2100. A United States Environmental Protection Agency study puts these figures in a probabilistic perspective, suggesting there was a 50% chance that sea level rise would exceed 0.4, 0.7 and 1.5 ft by 2025, 2050 and 2100, respectively, and a 10% chance that sea level rise would exceed 0.6, 1.1 and 2.9 ft by 2025,2050 and 2100, respectively. On August 12,2015, California Coastal Commission unanimously adopted Sea Level Rise Policy Guidance: Interpretive Guidelines for Addressing Sea Level Rise in Local Coastal Programs and Coastal Development Permits. According to this Document, considered The Best Available Science and Consequences of Sea Level f PA2017-019 Rise, the sea-level rise projections for California (NRC 2012) are 1, 2 and 5.5 ft by 2030, 2050 and 2100 respectively. The current Highest High Water level in Newport Beach is +7.8'MLL W. If sea level rises by 5.5' by year 2100, Highest High Water level will become +13.3'MLLW, which will be higher than the top of the existing/reinforced seawall of=+ 12.68'NAVD88=+ 12.86'MLLW. In such a case, the existing seawall will have to be raised in a manner similar to the one reflected on the enclosed STD-60 1-L in order to accommodate the actual see level at that time. QUESTION: What work on the seawall is anticipated to occur to deal with sea level rise? ANSWER: If sea level rises by 5.5' by year 2100, Highest High Water level will become + 13.3 'MLL W, which will be higher than the top of the existing/reinforced seawall of=+ 12.68'NAVD88=+ 12.86'MLL W. In such a case, the existing seawall will have to be raised in a manner similar to the one reflected on the enclosed STD-60 1- L in order to accommodate the actual see level at that time. QUESTION: When approximately will the seawall need to be repaired or replaced? ANSWER: As a part of the proposed development on the lot, the seawall wall will be repaired/reinforced in accordance with the enclosed drawings S-0, S-1 & S-2, in order to comply with the City of Newport Beach Building Department requirements. All work shall be done from the land side of the seawall. Once reinforced in accordance with the aforementioned drawings, no additional repair or replacement of the seawall shall be anticipated in the next 7 5 to 1 00 years. The above answers were prepared based on the existing condition, and within the inherent limitations of this study, in accordance with generally acceptable engineering principles and practices. We make no further warranty, either expressed or implied. William Simpson & Associates, Inc. appreciates the opportunity to work with you towards the successful completion of your project. Should you have any questions regarding this report, please contact us. Respectfully submitted, Plamen Petrov, P.E. Senior Project Manager Enclosures: Seawall Reinforcing Drawings S-0, S-1 & S-2 STD-601-L Masoud Jafari, S.E. Principal PA2017-019 ~ WILLIAM SIMPSON & ASSOCIATES, INC. CONSULTING STRUCTURAL ENGlNEERS ~l OROt.o.RO. sun: ao ~ErORE<SI,C.0.916lO I'(U9)106-H:HI , (9•91 106-99~~ m""h•cuec""" 2772 BAYSHORE DRIVE NEWPORT BEACH, CA 92883 STRUCT CENERAL NOTES & \1ClNITY t.4AP OWNER / APPUCANT Mr. Kevin Moriarty 2782 Bayshore Drive Newport Beech, CA 92663 Phone. 19491 300·0310 (/) -4 :a c: () -4 c: :a )> r- G') m z m :a )> r- z 0 -4 m (/) PA2017-019 ID• c .... "" z m ,. 0 m .... m < ,. .... 0 z I I I ~----- 1 I ---+--- 1 I I r----- 1 I I r----- 1 I I r--- 1 I I I r --- 1 I g ---~--+---+---L- < -7084 S-1 1 I I r ----- 1 I I r -------- I en :::j Ill "0 ,.. ,. z o, ~ WILLIAM SIMPSON & ASSOCIATES, INC. CONSUL ~NC STRUCTURAL EN"NEERS 1JOI'I01AR!l.Sl.ITt 1.!4 UO<£rQil(n C4~26l0 P (U9)"X»-H2'J r li•9} 106-ii~~ molha1«.<...., REINFORCING TH! !XIST1NG 81!.\WALL lOCATED .U, 2772 BAYSHORE DRIVE NEWPORT BEACH, CA 92663 SITE PlAN & ELEVA nON D n II II II II II II II II 0.: II -----------~=~========:=-= OWNER I A.PPUCANT Mr. Kevin Moriarty 2782 Bayshore Drive Newport Beach, CA 92663 Phone. 19491 300·0310 N .., .., ~i~ "' ~ -~ Ol " ~~ )> § -~8 -< ~ ~~~ C/) :I: t. ~~3 0 l' :~~~..,"!; ;o : ~~r( "" "a 0 ;o < "" PA2017-019 •· s ! ~ I~ ~ r- I ~ r; r- --;;: - 8 ! ' . : I~ ..... i 11 ~ rmi[~~~------'oli IWiii +-H---,.j ,--- ~~~l ~ ~ ', - ~ ~- ~ -; -", I~ i i '" 1--~~ ! 1]1 ! ' UL WILLIAM SIMPSON I LOCATED'A S • ASSOCIATES, I,_ C. I "".,,;""DRIVE '· Mr. Kevin Moriarty 2782 Bayshore Drive Newport Beach, CA 92663 Phone. 19491 300•0310 ! j I ,_,,,, """' ,,, "'" "" PA2017-019 NOTE: 2-#4 CONT. EPOXY-COATED~----. PER ASTM A934 8" CONCRETE BLOCK WALL ADDED TO TOP OF EXISTING BULKHEAD #5 @ 24" O.C. DRILL AND EPOXY BARS PER~--...... MANUFACTURER'S RECOMMENDATIONS INTO EXISTING COPING TOP OF IMPROVEMENTS ALTERNATE "A" (CONCRETE BLOCK) 11/2" CHAMFER (TYPICAL)----------.. #4 CONT. EPOXY COATED A934 -------...... CONCRETE: f'c = 4,500 PSI (MIN.)---.....,_ W /C RATIO = 0.45 (MAX.) #5 @ 24" O.C. DRILL AND EPOXY BARS PER MANUFACTURER'S RECOMMENDATIONS INTO EXISTING COPING TOP OF IMPROVEMENTS----- ALTERNATE "B" (POURED-IN-PLACE CONCRETE) EPOXY SHALL CONFORM TO ASTM C881 STANDARD AND BE USED IN STRICT ACCORD WITH THE MANUFACTURERS PRINTED INSTRUCTIONS. PROPERTY, BULKHEAD OR OTHER BAYWARD LIMIT ROUGHEN FOR BOND AND APPLY EPOXY EXISTING COPING EXISTING BULKHEAD PROPERTY, BULKHEAD OR OTHER BAYWARD LIMIT ELEVATION + 9.0 M.L.L.W. ROUGHEN FOR BOND AND APPLY EPOXY BONDING AGENT PER MANUFACTURER'S RECOMMENDATIONS. EXISTING COPING 0 REV. 11/07 ~ ~-------------------------------------------,--~--~~~~~~~~~~~~~~~~ APPROVED: e CITY OF NEWPORT BEACH BUILDING DEPARTMENT DETAIL FOR RAISING BULKHEADS ~ :;_' ~----~~B~UI~LD~IN~1G~D~I~~C~T~OR~----~~I y r-~~~~~~---.-----------------1 ] Drawn: R. OKADA "' Date: JULY 2004 Scale: N.T.S. ~ ~--~~~~~--~-----------------1 ffi DRAWING NO. STD-601 -L f ~------------------------------------~--------------------------~ PA2017-019