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HomeMy WebLinkAboutX2022-1009 - SoilsGEOCON W E S T, I N C. GEOTECHNICAL ■ ENVIRONMENTAL ■ MATERIALS Project No. A9649-88-26 December 2, 2022 VIA EMAIL Mr. Peter Tauscher, PE Public Works Department City of Newport Beach 100 Civic Center Drive, Bay 2D Newport Beach, California 92660 Subject: REPORT OF OBSERVATION AND TESTING SERVICES DURING PREPARATION OF BUILDING PAD PROPOSED JUNIOR LIFEGUARD FACILITY 901 EAST OCEAN, NEWPORT BEACH, CALIFORNIA GRADING PERMIT NO. X2022-1009 References: Geotechnical Investigation, by Geocon West, Inc., dated February 1, 2022; Addendum to Geotechnical Investigation, by Geocon West, Inc., dated May 9, 2022; Response to Geotechnical Report Review Checklist, by Geocon West, Inc., dated July 11, 2022. Rapid Impact Compaction, Junior Construction Work Plan, prepared by September 16, 2022. Dear Mr. Tauscher: Lifeguard Building, Newport Beach, CA, Advanced GeoSolutions, Inc. (AGI), dated In accordance with your request, we have provided testing and observation services during the preparation of the building pad at the subject site. Our services were performed during the period of October 18 through November 18, 2022. The scope of our services included the following: • Observing the Rapid Impact Compaction (RIC) operations. • Performing additional soil borings to observe the effectiveness of the RIC. • Observing the grading operation to establish the rough pad grade. • Performing in -place density tests on the soil materials placed and compacted. • Performing laboratory tests to aid in evaluating the compaction characteristics of soil types used for fill. • Preparing a Site Plan and this report of observation and testing services. 2807 McGaw Avenue ■ Irvine, CA 92618 ■ Telephone (949) 491-6570. oc@geoconinc.com GENERAL The purpose of the testing and observations was to determine that the specifications required by the City of Newport Beach, the California Building Code and the recommendations of the referenced reports were followed. Grading was performed under City of Newport Beach Grading Permit No. X2022-1009. This work was requested by Public Works Inspector Matt Bullman with the City of Newport Beach. GRADING Earthwork and site preparation consisted of Rapid Impact Compaction (RIC) performed by Advanced GeoSolutions, Inc. (AGI), as well as rough grading to create a roughly level building pad following the ground improvement. RIC was performed by Advanced GeoSolutions, Inc. (AGI) during the period of October 18, 2022 through October 20, 2022. The area treated by the RIC ground improvement is indicated on the Site Plan (Figure 1). Based on the RIC response statistics shared by AGI via email, deflections of less than 22 inches were observed during the RIC process. This is less than the performance criteria outlined in the RIC submittal prepared by AGI. Verification testing consisting of advancing 2 additional borings at the site was performed on October 25, 2022, using a truck -mounted hollow -stem auger drilling machine. The purpose of the additional borings was to observe the effectiveness of the ground improvement. Representative and relatively undisturbed Standard Penetration Test samples were obtained by driving the sampler into the "undisturbed" soil mass with blows from a 140-pound auto -hammer falling 30 inches. Between a depth of 5 feet and 11 feet, unadjusted blow counts equal to or greater than 18 were obtained. Based on the information outlined in the Addendum Report dated May 9, 2022, this is the target criteria for improving the soils to the desired state. Copies of the boring logs are attached to this report. It is the opinion of the undersigned engineer that the ground improvement has achieved the intent of the geotechnical recommendations. Following the completion of the ground improvement, additional fill was placed to achieve a relatively level building pad. Prior to placing any fill, the exposed subgrade was scarified to a depth of 12 inches, moistened as required to achieve optimum moisture content, and compacted to a minimum of 90 percent of the maximum density in accordance with ASTM test method D 1557 (Laboratory Compaction Test). Fill was placed by means of a CAT 415 skip loader, in loose lifts of about 6 to 8 inches, moistened as required to achieve optimum moisture content by means of a fire hose, and compacted by rolling with a single drum vibratory roller (CAT CS-323C). Where failing tests occurred, additional compaction effort was applied utilizing the above mentioned compaction equipment until passing tests were achieved. Approximate limits and depths of engineered fill are indicated on the enclosed Site Plan (see Figure 1). Geocon Project No. A9649-88-26 -2- December 2, 2022 In -place density tests were performed in conformance with ASTM Test Method D1556 (Sand Cone), and ASTM Test Method D6938 (Nuclear Density Gauge) for soil. The results of the in -place dry density and moisture content tests for soil are summarized on Table 1. In general, the in -place density test results indicate that the earth materials placed have achieved a relative compaction of at least 90 percent in accordance with ASTM test method D 1557 (Laboratory Compaction Test). The approximate locations of all in -place density tests are indicated on the Site Plan (Figure 1). Laboratory tests were performed on the materials used as engineered fill to evaluate moisture -density relationships, optimum moisture content and maximum dry density. The results of the laboratory tests are summarized in Table 2. Fill soils were derived from onsite excavations and consist primarily of silty sand and clayey sand with gravel. CONCLUSIONS AND RECOMMENDATIONS 1. GENERAL 1.1 Based on observations and test results, it is the opinion of Geocon West, Inc. that the grading and placement of engineered materials has been performed in substantial conformance with the requirements of the City of Newport Beach, the California Building Code and the recommendations of the referenced reports. 2. Expansive Soils 2.1 The soils exposed at the subgrade elevation are in the "very low" expansion range. Special considerations for expansive soils are not required. 3. Mat Foundation Design 3.1 A reinforced concrete mat foundation deriving support on the improved soils may utilize an allowable soil bearing value of 3,500 pounds per square foot. The thickness of and reinforcement for the mat foundation should be designed by the project structural engineer. 3.2 All foundation excavations should be observed by a representative of Geocon West, Inc. to verify penetration into the recommended bearing materials. Foundations should be deepened if necessary to extend into satisfactory earth materials. Foundation excavations should be cleaned of all loose soils prior to placing steel and concrete. Any required foundation backfill should be mechanically compacted, flooding is not permitted. 3.3 Resistance to lateral loading may be provided by friction acting at the base of foundations and by passive earth pressure. An allowable coefficient of friction of 0.4 may be used with the dead load forces. Geocon Project No. A9649-88-26 - 3 - December 2, 2022 3.4 Passive earth pressure for the sides of foundations poured against newly placed engineered fill may be computed as an equivalent fluid having a density of 280 pounds per cubic foot with a maximum earth pressure of 2,800 pounds per square foot. When combining passive and friction for lateral resistance, the passive component should be reduced by one-third. A one- third increase in the passive value may be used for wind or seismic loads. 3.5 The RIC design was recommended to be designed based on settlement criteria of a maximum combined static and seismic differential settlement of I inch over a distance of 40 feet with an allowable bearing pressure of 3,500 pounds per square foot (psf). 4. Future Grading 4.1 Any additional grading performed at the site should be accomplished in conjunction with our observation and compaction testing services. This office should be notified at least 24 hours prior to commencing additional grading or fill placement operations. 5. Drainage 5.1 Proper surface drainage is critical to the future performance of the project. Uncontrolled infiltration of irrigation excess and storm runoff into the supporting soils can adversely affect the performance of the planned improvements. Saturation of a soil can cause it to lose internal shear strength and increase its compressibility, resulting in a change in the original designed engineering properties. Proper drainage should be maintained at all times. 5.2 Drainage should not be allowed to pond anywhere on the site, and especially not against any foundation or retaining wall. Sealing planters which are located adjacent to foundations should be considered to minimize moisture intrusion into the engineered fill. 5.3 Positive site drainage should be provided away from structures, pavement, and the tops of slopes to swales or other controlled drainage structures. The building pad and pavement areas should be fine graded such that water is not allowed to pond. 5.4 Landscaping planters immediately adjacent to paved areas could be detrimental to the paving due to the potential for surface or irrigation water to infiltrate the pavement's subgrade and base course. Either a subdrain, which collects excess irrigation water and transmits it to drainage structures, or an impervious above -grade planter boxes should be considered. In addition, where landscaping is planned adjacent to the pavement, it is recommended that consideration be given to providing a cutoff wall along the edge of the pavement that extends at least 12 inches below the base material. Geocon Project No. A9649-88-26 - 4 - December 2, 2022 6. Closure 6.1 Fill which is placed beyond the limits shown on the Site Plan should be compacted with suitable equipment and observed by our representative. Geocon West, Inc. assumes no responsibility for compacted fill or earth materials placed beyond the limits shown by test elevations on the Site Plan. Any additional fill which is placed is the responsibility of the contractor to place in accordance with the approved plans and specifications. 6.2 Prior to placing steel or concrete in the footing excavations, a site visit must be made by a representative of Geocon West, Inc. to see that the footings are free of loose and disturbed material and are supported on the properly compacted fill (and/or undisturbed natural soils). A 24-hour notice is requested for a site visit. LIMITATIONS The conclusions and recommendations contained herein apply only to our work with respect to grading, and represent conditions at the date of our final observation, November 18, 2022. Any subsequent work should be done in conjunction with our observation and testing services. As used herein, the term "observation" implies only that we observed the progress of the work with which we agreed to be involved. Our services did not include the evaluation or identification of the potential presence of hazardous or corrosive materials. Our conclusions and opinions as to whether the work essentially complies with the job specifications are based on our observations, experience, and test results. Subsurface conditions, and the accuracy of tests used to measure such conditions, can vary greatly at any time. We make no warranty, express or implied, except that our services were performed in accordance with engineering principles generally accepted at this time and location. We will accept no responsibility for any subsequent changes made to the site by others, by the uncontrolled action of water, or by the failure of others to properly repair damages caused by the uncontrolled action of water. The findings and recommendations of this report may be invalidated wholly or partially by changes outside our control. Therefore, this report is subject to review and should not be relied upon after a period of one year. Geocon Project No. A9649-88-26 - 5 - December 2, 2022 If you have any questions regarding this report, or if we may be of further service, please contact the undersigned at your convenience. Very truly yours, Jelisa Tho____ GE 3092 Enclosures: Figure 1, Site Plan Boring Logs (2 pages) Explanation of Coded Terms Tables 1 and 2 Certification (Email) Addressee Geocon Project No. A9649-88-26 - 6 - December 2, 2022 C N F 5 — v _ w K O z W m c m c �mm Z Q Q W ¢ U m .O a �o ws 0 0 = o z wa. LU Wm r W z gyp' ~ �Q U o m w m p y I.I..I N F p - N O m gae gg do WT�q W z R 0 0 o rc`=w w n U a V3 W„o v ry o 1 1 I � a I m a 'CI nG k oR 9 �• _ 8 kC _ m<�v 8 aMmmrvcm� 1'a• G .. '. °ws� �—kG KC n mf`t 8 E� •� _ G kC kG kC� kG ^k kG RS mmua ry •� . v aew G q A _ ,I�r .a- { - C N a kC' ` .0 r GkCA - ;= L _ — w rwm PROJECT NO. A9649-88-26 w BORING 3 zpm-, DEPTH } ¢ SOIL O ~ Q Q Z u- m D IN SAMPLE NO p 3 z cuss ELEV. (MSL) DATE COMPLETED 10126122 ¢ w y o a Z `� Iu FEET J O (Uses) W W m v O tmf EQUIPMENT HOLLOW STEM AUGER BY: PZ a n: �" o p MATERIAL DESCRIPTION 0 ARTIFICLA.L FILL Sand, poorly graded, medium dense, dry to slightly moist, brown, fine- to - medium -grained, some gavel concrete and asphalt fragments. 2 ALLUVIUM B3@2.5' -_- _- - Sand, poorly graded, loose, slightly moist, fight -brown, fine- to 8 -= medium -grained. 4 B3@5' - moist, medium dense 19 6 1 SP 8 B3@7.5' - - - wet, fine- to coarse -grained, some shell fragments 21 10 133@10' ` - decrease in coarse -grained 25 12 3@12.5' -- 28 14 133@15' - fine- to medium -grained, trace shell fragments 19 16 Total depth of boring: 16 feet. Fill to 1 feet. Groundwater encountered at 7 feet. Backfilled with cement bentonite grout. *Penetration resistance for 140-pound hammer falling 30 inches by auto -hammer. Figure 1, A9549-85-26 BORING LOGS GPJ Log of Boring 3, Page 1 of 1 SAMPLE SYMBOLS ❑ _. SAMPLING UNSUCCESSFUL [] -STANDARD PENETRATION TEST . ..DRIVE SAMPLE (UNDISTURBED) ® _. DISTURBED OR BAG SAMPLE W ... CHUNK SAMPLE i ... WATER TABLE OR SEEPAGE NOTE. THE LOG OF SUBSURFACE CONDNIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND ATTHE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES- GEOCON PROJECT NO. A9649-88-26 ul ul BORING 4 Z DEPTH 17 Q SOIL O 2 LL W e of IN SAMPLE O z CLASS '10125122 Q Q N N Z D- Z W FEET NO. ELEV. (MSL.) DATE COMPLETED In m J Z) (USCS) wwm m of 2O EQUIPMENT HOLLOW STEM AUGER BY: PZ a �- m v MATERIAL DESCRIPTION 0 ARTIFICIAL FILL Sand, poorly graded, medium dense, dry to slightly moist brown, fine- to medium -grained, trace gravel, some concrete fragments. 2 ALLUVIUM - _ Sand, poorly graded, loose, slightly moist, fight -brown, fine- to - medium -grained. 4 B4@5' SP - medium dense, moist, some coarse -grained 18 6 °i 8 B4@7.5' 22 - trace shell fragments 10 B4@10' - -dense 37 Total depth of boring 11 feet. Fill to 1 feet. Groundwater encountered at 7 feet. Backfilled with cement bentonite grout. *Penetration resistance for 140-pound hammer falling 30 inches by auto -hammer. Figure 2, A9649-88-26 BORING LOGS GPJ Log of Boring 4, Page 1 of 1 SAMPLE SYMBOLS [_1 . SAMPLING UNSUCCESSFUL ID...STANDARD PENETRATION MST .._DRIVE SAMPLE (UNDISTURBED) RI .. DISTURBED OR BAG SAMPLE Q ... CHUNK SAMPLE t ... WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDMONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED_ IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. GEOCON k��)�ƒm)\ j\o7\z\)] ns*]a ems $/§ «��\\�])o �(ce)cn EQ �)/ \\�U� LL(D S $ a_) §u 2/ e&« M /deE¥lttJ - a) .2 � § \& gga-0o 4 e0� $ (f )} }) �\ )} §\ }) \} _� }\ \2 )) )) 7) \ \\) 2 \) «g �\ \\ /® ) z z z z z z z z z m 0 0 0 0 0 0 0 0 0 0 W W W W W W W W W W oiQ �firr� r m m r m W m o o m m W m a O m N N N N N N N N m o m m m m m m m m o 0 0 0 o d o 0 0 N a m m m m m m m m m N m m m m m m m m �'y'a It LL LL LL aan. N N N N W W W W D D lLL li 'O "O U U v v m m m m J J N N N N N N N N a a a a a a a a m m m m N N N N N N N N N N N N N N N N N N O N O N N N N N N N N N C C7aaaa a a m a m m m m m m m m m m N W w Ol Q !A E V V V 1. V 401 W E IST, I N C. GEOTECHNICAL ■ ENVIRONMENTAL ■ MATERIALS ENGINEER'S CERTIFICATE OF COMPLIANCE FOR COMPACTED EARTH FILLS LOCATION OF FILL: JOB ADDRESS: SOIL TESTING AGENCY: PROPERTY OWNER'S NAME: OWNER'S ADDRESS: PER REPORTS ON OUR PROJECT NO: DATE WORK STARTED ON PROJECT: DATE FILL WAS COMPLETED: DATE OF THIS CERTIFICATE: TO THE SUPERINTENDENT OF BUILDING: Building Pad (see Site Plan) 901 East Ocean Newport Beach, California Grading Permit No. X2022-1009 Geocon West, Inc. City of Newport Beach 100 Civic Center Drive, Bay 2D Newport Beach, California 92660 A9649-88-26 10/18/2022 11 /18/2022 12/2/2022 I hereby certify that I have personally observed and tested the placing of compacted earth fill on the above described property, and on the basis of these observations and tests, it is my opinion that the same was placed in conformity with the requirements of the City of Newport Beach Building Code and California Building Code.' _^ 2\ JelisarThom G.E. 3092 — 'For the purpose of this Certificate, to "have personally observed and tested" shall include observation and testing performed by any person responsible to the licensed engineer signing this Certificate. Where the inspection and testing of all or part of the work above is delegated, full responsibility shall be assumed by the licensed engineer whose signature is affixed thereon. Business and Professions Code, Ch.229, Sec.3.6735.5. The use of the word "certify" or "certification" by a registered professional engineer in the practice of professional engineering or land surveying constitutes an expression of professional opinion regarding those facts or findings which are the subject of the certification, and does not constitute a warranty or guarantee, either expressed or implied. 2807 McGow Avenue . Irvine, CA 92618 . Telephone (949) 491-6570 ■ oc@geoconinc.com