TRANSMITTAL NO, +-BOARD OF

BUILDING AND SAFETYCOMMISSIONERS

VAN AMBATIELOSPRESIDENT

E. FELICIA BRANNONVICE PRESIDENT

JOSELYN GEAGA-ROSENTHALGEORGE HOVAGUIMIAN

JAVIER NUNEZ

CITY OF Los ANGELESCALIFORNIA

ERIC GARCETTIMAYOR

DEPARTMENT OF

BUILDING AND SAFETY201 NORTH FIGUEROA STREET

LOS ANGELES, CA 90012

FRANK BUSHGENERAl MANAGER

SUPERINTENDENT OF BUILDING

OSAMA YOUNAN, P.E.EXECUTIVE OFFICER

GEOLOGY AND SOILS REPORT APPROVAL LETTER

January 17,2017LOG # 94130-01SOILS/GEOLOGY FILE - 2LAN

Loveto, LLC4653 White Oak PI.Encino, CA 91316

TRACT:LOT(S):LOCATION:

9066FR 1 (Arb 6) / FR 1 (Arb 3)13040/ 13050 W. Mulholland Drive

CURRENT REFERENCEREPORT/LETTER(S)Geology/Soils ReportOversized Doc(s).

PREVIOUS REFERENCEREPORT/LETTER(S)Dept. Correction LetterGeology/Soils ReportOversized Doc(5).

REPORTNo.4557

REPORTNo.941304557

DATE(S) OFDOCUMENT12/09/2016

DATE(S) OFDOCUMENT08/18/201606/30/2016

PREPARED BYSubsurface designs, Inc.

PREPARED BYLADBSSubsurface designs, Inc.

The Grading Division ofthe Department ofBuilding and Safety has reviewed the referenced reportthat provides recommendations for two proposed single-family residences. According to thereport, the site consists of two vacant lots situated on a northeast trending ridge with descendingslopes to the southeast and northwest. Driveway access to the residences will be on the northerlyside with a retaining wall constructed between the structures.

The earth materials at the subsurface exploration locations consist of minor fill, natural soil, andcolluvium overlying Modelo Formation bedrock. Bedding within the Modelo Fonnationreportedly dips to the northwest. The consultants recommend to support the proposed structureson conventional and/or drilled-pile foundations bearing on competent bedrock.

The site is located in a designated seismically induced landslide hazard zone as shown on theSeismic Hazard Zones map issued by the State of California. The above report/s include/s anacceptable seismic slope stability analysis and the requirements of the 2014 City of Los AngelesBuilding Code have been satisfied.

LADBS G·5 (Rev 1112312016) AN EQUAL EMPLOYMENT OPPORTUNITY - AFFIRMATIVE ACTION EMPLOYER

Page 213040/13050 W. Mulholland Drive

The referenced reports are acceptable, provided the following conditions are complied with duringsite development:

(Note: Numbers in parenthesis ( ) refer to applicable sections of the 2014 City of LA BuildingCode. PIBC numbers refer the applicable Information Bulletin. Information Bulletins can beaccessed on the internet at LADBS.ORG.)

1. The geologist and soils. engineer shall review and approve the detailed plans prior toissuance of any permits. This approval shall be by signature on the plans that clearlyindicates the geologist and soils engineer have reviewed the plans prepared by the designengineer and that the plans include the recommendations contained in their reports.(7006.1)

2. All recommendations of the report that are in addition to or more restrictive than theconditions contained herein shall be incorporated into the plans.

3. A copy of the subject and appropriate referenced reports and this approval letter shall beattached to the District Office and field set of plans. Submit one copy of the above reportsto the Building Department Plan Checker prior to issuance ofthe permit. (7006.1)

4. A grading pennit shall be obtained for all structural fill and retaining wall backfill.(106.1.2)

5. All man-made flll shall be compacted to a minimum 90 percent of the maximum drydensity ofthe fill material per the latest version ofASTM D 1557. Where cohesionless soilhaving less than 15 percent finer than 0.005 millimeters is used for fill, it shall becompacted to a minimum of95 percent relative compaction based on maximum dry density(D1556). Placement of gravel in lieu of compacted fill is allowed only if complying withSection 91.7011.3 ofthe Code. (7011.3)

6. Existing uncertified fill shall not be used for support of footings, concrete slabs or new fill.(1809.2, 7011.3)

7. Drainage in conformance with the provisions of the Code shall be maintained during andsubsequent to constmction. (7013.12)

8. The applicant is advised that the approval of this report does not waive the requirementsfor excavations contained in the State Construction Safety Orders enforced by the StateDivision of Industrial Safety. (3301.1)

9. Unsurcharged temporary excavations exposing unsupported bedding planes shall betrimmed back along the lowest unsupported plane or shoring and construction ofABC slotcut may be used, as recommended.

10. The soils engineer shall review and approve the shoring plans prior to issuance of thepermit. (3307.3.2)

11. Prior to the issuance of the permits, the soils engineer and/or the structural designer shallevaluate the surcharge loads used in the report calculations for the design of the retainingwalls and shoring. If the surcharge loads used in the calculations do not conform to theactual surcharge loads, the soil engineer shall submit a supplementary report with revisedrecommendations to the Department for approval.

Page 313040/ 13050 W. Mulholland Drive

12. Temporary excavations that remove lateral support to the public way, adjacent property, oradjacent structures shall be supported by shoring or constructed using ABC slot cuts. Note:Lateral support shall be considered to be removed when the excavation extends below aplane projected downward at an angle of 45 degrees from the bottom of a footing of anexisting structure, from the edge of the public way or an adjacent property. (3307.3.1)

13. Prior to the issuance ofany pennit which authorizes an excavation where the excavation isto be of a greater depth than are the walls or foundation of any adjoining building orstructure and located closer to the property line than the depth of the excavation, the ownerof the subject site shall provide the Department with evidence that the adjacent propertyowner has been given a 30-day written notice of such intent to make an excavation.(3307.1)

14. Unsurcharged temporary excavations over 5 feet exposing soil, colluvium and fill shall betrimmed back at a gradient not exceeding 1:1, as recommended.

15. Unsurcharged temporary excavations in bedrock with favorably oriented bedrock may becut vertical up to 10 feet. Excavations over 10 feet shall be trimmed back at a uniformgradient not exceeding 1:1 (horizontal to vertical), from top to bottom of excavation, asrecommended.]

16. Shoring shall be designed for a minimum EFP of20 PCF, as specified in the section titled"Excavations" starting on page 23 ofthe report dated 06/30/2016; all surcharge loads shallbe included into the desi~ as recommended. Total lateral load on shoring piles shall bedetermined by multiplying the recommended EFP by the pile spacing.

17. Ifthe shoring is to be used for permanent structure ofthe retaining wall, it shall be designedfor the lateral earth pressures specified in the section titled "Retaining Wallsu starting onpage 25 of the report; all surcharge loads shall be included into the design. Total lateralload on shoring piles shall be detennined by multiplying the recommended EFP by the pilespacmg.

18. A shoring monitoring program shall be implemented to the satisfaction of the soilsengineer.

19. A-B-C slot-cut method may be used for temporary excavations with each slot notexceeding 12 feet in height and not exceeding 8 feet in width, as recommended. The soilsengineer shall verify in the field ,if the existing earth materials are stable in the slot cutexcavation. Each slot shall be inspected by the soils engineer and approved in writing priorto any worker access.

20. All foundations shall derive entire support from competent bedrock, as recommended (andapproved by the geologist and soils engineer by inspection).

21. Foundations adjacent to a descending slope steeper than 3:1 (H:V) in gradient shall be aminimum distance ofone-third the vertical height ofthe slope but need not exceed 40 feetmeasured horizontally from the footing bottom to the face of the slope (1808.7.2).

22. Pile caisson and/or isolated foundation ties are required by Code Sections 1809.13 and/or1810.3.13. Exceptions and modification to this requirement are provided in InformationBulletin P/BC 2014-030.

Page 413040/13050 W. Mulholland Drive

23. Pile and/or caisson shafts shall be designed for a lateral load of 1000 pounds per linear footofshaft exposed to fill, soil and weathered bedrock. (pIBC 2014-050)

24. The design passive pressure shall be neglected for a portion of the pile with a setbackdistance (horizontal set back) less than five feet from fill, soil or weathered bedrock contactplane with bedrock.

25. When water over 3 inches in depth is present in drilled pile holes, a concrete mix with astrength of 1000 p.s.i. over the design p.s.i. shall be tremied from the bottom up; anadmixture that reduces the problem ofsegregation ofpaste/aggregates and dilution ofpasteshall be included. (1808.8.3)

26. Existing uncertified fill shall not be used for lateral support ofdeep foundation. (1810.2.1)

27. The Code requires analysis for the group effects on lateral behavior where the center-to­center spacing ofdeep foundation elements in the direction oflateral force is less than eighttimes the least horizontal dimension ofan element. The Code also requires analysis for thegroup effects on axial behavior where the center-to-center spacing of deep foundationelements is less than three times the least horizontal dimension of an element. Where thisoccurs for the [existing and/or] proposed pile layout, a supplemental report shall besubmitted that contains said analysis and recommendations for reduction factors asappropriate. (1810.2.5)

28. The seismic design shall be based on a Site Class C as recommended. All other seismicdesign parameters shall be reviewed by LADBS building plan check.

29. Retaining walls shall be designed for the lateral earth pressures specified in the sectiontitled "Retaining Walls" starting on page 25 of the report. All surcharge loads shall beincluded into the design.

30. Retaining walls higher than 6 feet shall be designed for lateral earth pressure due toearthquake motions as specified on page 28 of the 06/30/2016 report (1803.5.12).

31. Retaining walls at the base of ascending slopes shall be provided with a minimumfreeboard of 12 inches, as recommended.

32. The recommended equivalent fluid pressure (EFP) for the proposed retaining wall shallapply from the top ofthe freeboard to the bottom ofthe wall footing.

33. All retaining walls shall be provided with a standard surface backdrain system and alldrainage shall be conducted to the street in an acceptable manner and in a non-erosivedevice. (7013.11)

34. With the exception ofretaining walls designed for hydrostatic pressure, all retaining wallsshall be provided with a subdrain system to prevent possible hydrostatic pressure behindthe wall. Prior to issuance ofany permit, the retaining wall subdrain system recommendedin the soil report shall be incorporated into the foundation plan which shall be reviewedand approved by the soils engineer ofrecord. (1805.4)

35. Installation of the subdrain system shall be inspected and approved by the soils engineerof record and the City grading/building inspector. (108.9)

• PageS13040/ 13050 W. Mulholland Drive

36. Basement walls and floors shall be waterproofed/damp-proofed with an L.A. City approved"Below-grade" waterproofmg/damp-proofing material with a research report number.(104.2.6)

37. Prefabricated drainage composites (Miradrain) (Geotextiles) may be only used in additionto traditionally accepted methods of draining retained earth.

38. The structure shall be connected to the public sewer system. (PIBC 2014-027)

39. All roof and pad drainage shall be conducted to the street in an acceptable manner; watershall not be dispersed on to descending slopes without specific approval from the GradingDivision and the consulting geologist and soils engineer. (7013.10)

40. All concentrated drainage shall be conducted in an approved device and disposed of in amanner approved by the LADBS. (7013.10)

41. Any recommendations prepared by the geologist and/or the soils engineer for correction ofgeological hazards found during grading shall be submitted to the Grading Division oftheDepartment for approval prior to utilization in the field. (7008.2, 7008.3)

42. The geologist and soils engineer shall inspect all excavations to determine that conditionsanticipated in the report have been encountered and to provide recommendations for thecorrection ofhazards found during grading. (7008 & 1705.6)

43. All friction pile or caisson drilling and installation shall be performed under the inspectionand approval of the geologist and soils engineer. The geologist shall indicate the distancethat friction piles or caissons penetrate into competent bedrock in a written fieldmemorandum. (1803.5.5, 1704.9)

44. Prior to the pouring of concrete, a representative of the consulting soils engineer shallinspect and approve the footing excavations. He/She shall post a notice on the job site forthe LADBS Building Inspector and the Contractor stating that the work so inspected meetsthe conditions of the report, but that no concrete shall be poured until the City BuildingInspector has also inspected and approved the footing excavations. A written certificationto this effect shall be filed with the Grading Division of the Department upon completionof the work. (108.9 & 7008.2)

45. Prior to excavation, an initial inspection shall be called with LADBS Inspector at whichtime sequence of construction, shoring, ABC slot cuts, pile installation, protection fencesand dust and traffic control will be scheduled. (108.9.1)

46. Installation of shoring, slot cutting excavations and/or pile installation shall be performedunder the inspection and approval of the soils engineer and deputy grading inspector.(1705.6)

47. Prior to the placing of compacted fill, a representative of the soils engineer shall inspectand approve the bottom excavations. He/She shall post a notice on the job site for the CityGrading Inspector and the Contractor stating that the soil inspected meets the conditions ofthe report, but that no fill shall be placed until the LADBS Grading Inspector has alsoinspected and approved the bottom excavations. A written certification to this effect shallbe included in the final compaction report filed with the Grading Division of theDepartment. All fill shall be placed under the inspection and approval ofthe soils engineer.

Page 613040/ 13050 W. Mulholland Drive

A compaction report together with the approved soil report and Department approval lettershall be submitted to the Grading Division of the Department upon completion of thecompaction. In addition, an Engineer's Certilicate of Compliance with the legaldescription as indicated in the grading pennit and the permit number shall be included.(7011.3)

DANIEL C. SCHNEIDEREITEngineering Geologist II

DCS/DLS:dcs/dlsLog No. 94130-01213-482-0480

~(M\,~_DAN L. STOICAGeotechnical Engineer I

cc: Joseph Ahdoot, ApplicantSubsurface designs, Inc., Project ConsultantLA District Office