Loading...
R-2017-34, RM-2017-38 Plan Set.pdfSTERN AVENUE5' X 2'-3", 4" THICK CONCRETE SLABON SAND SETTING BED, 12-INCHJOINT FILLED WITH BLACK MEXICANBEACH BEBBLES BETWEEN SLABS,TYP.2'-8"PAVERS BY CALSTONE ORAPPROVED EQUAL, TYPCONTRACTOR TO WORK WITHOWNER TO SELECT PAVER TYPE,PATTERN AND COLORLANDSCAPE HEADER, TYP.16"X16" PRECASTCONCRETE SLAB, TYPEQEQEQEQ3'-0"3'-0"5'-7"R6'-6"6'-6"3'-0"BLACK MEXICANBEACH BEBBLES , TYP18'-6"1'-0"5'-0"18'-0"20'-0"3'-0"3'-0" 9'-8"12'-8" 3'-10"SHEET NO.SHEET TITLE:LICENSE STAMPS AND SIGNATUREDescriptionNo.ISSUEDDateSCALE:DRAWN:DATE:JOB:YH10365 STERN AVENUECUPERTINO, CALANDSCAPE DESIGN3357 SAINT MICHAEL CTPALO ALTO, CA 94306TEL: (415) 694-0800HANRESIDENCEyhNLANDSCAPE DESIGN NOTES1.FIELD LOCATE ALL PLANT MATERIALS PRIOR TOINSTALLATION.2.FINISH PLANTING AREA GRADES ADJACENT TOPAVING SHALL BE 3" BELOW FINISH PAVINGGRADES.3.PLACE A 3-INCH LAYER OF MULCH AS SPECIFIEDON ALL PLANTED AREAS EXCEPT NOTED AREASON THE PLAN.4.AT LEAST 4 CUBIC YARDS OF COMPOST, SIX (6)INCHES DEEP, SHALL BE APPLIED PER 1000SQUARE FEET OF LANDSCAPE AREA BYLANDSCAPE CONTRACTOR5.QUANTITIES SHOWN ON PLAN AND PLANTSCHEDULE ARE FOR CONTRACTOR'SCONVENIENCE, CONTRACTOR TO CONFIRM ALLPLANT QUANTITIES.6.I HAVE COMPLIED WITH THE CRITERIA OF THEMODEL WATER EFFICIENT LANDSCAPEORDINANCE AND HAVE APPLIED THEM FOR THEEFFICIENT USE OF WATER IN THE LANDSCAPEDESIGN PLAN.L-1WATER-EFFICIENTCHECKLIST&LANDSCAPE PLANNOVEMBER 10, 2017 HAND-SHAPE A TOPSOIL OR BACKFILLWATERING BASIN AROUND THE BASEOF EACH PLANTGROUNDCOVER, ANNUAL, ORPERENNIAL3" MIN. MULCH. REMOVE MULCH FROMBASE OF PLANT DO NOT COVERFOLIAGE OR PLANT PARTSFIELD VERIFY A MIN. DEPTH OF 12"BACKFILL MIXEXCAVATE TO 2" BELOW DEPTH OFPLANT CONTAINERUNDISTURBED OR COMPACTEDIMPORTED TOPSOILROTATE AND STRAIGHTEN SHRUBSET TOP OF ROOT BALL 1" ABOVEFINISHED GRADEPLANT-PIT BACKFILL MIXUNDISTURBED OR COMPACTEDIMPORTED TOPSOILCOMPACTED PLANT-PIT BACKBACK FILL MIX3" MIN. MULCHROOTBALLWATERING BASINFIELD VERIFY A MIN. DEPTH OF 12"AMENDED TOPSOIL BACKFILL2 X ROOT BALLMIN.DIA.1'-6"12"MIN.ROOT BALLDIA.12"MIN.PROVIDE 2'-0" DIA. CIRCLE WITH 3"LAYER OF FIR BARK MULCHSET CROWN OF ROOT BALL 1" ABOVE FINIWSHGRADEBACKFILL MIX @ PLANT PITUNDISTURBED SOIL OR COMPACTEDSUBGRADE BELOW & SIDES OF PLANT PIT2'-0"CLEAR1', MIN.3'-0", TYP.1. ALL BOXED TREES SHALL BE SELECTED ATNURSERY BY OWNER OR APPROVED BY OWNER.2. TREE STAKES TO BE LOCATED PREVAILING WINDSIDE WHEN TREE IS IN LEAF.3. DO NOT STAKE THROUGH ROOTBALL, TAKECARE TO AVOID DAMAGE TO ROOTBALL.90% COMPACTED PLANT-PIT BACK FILLVERTICAL DRAIN: 6" DIA. X 4'-0" DEEPPERF. PVC PIPE FILLED WITH 3/4"ØUNIFORM DRAIN ROCK (1, TYP.)2" DIA. LODGEPOLE PINE TREE STAKES,LOCATE OUTSIDE OF ROOT BALL, (3) PER TREE7'-0" MIN. ABOVE FINISH GRADELOCATE TREE TIES 4"BELOW TOP OF STAKECORDED RUBBER TREE TIE HELD INPLACE W/ 1 1/4" GALV. ROOF NAILS,(3) PER TREE, TYP.NOTES:ROOT BALLTEMPORARY WATERING BASINSHEET NO.SHEET TITLE:LICENSE STAMPS AND SIGNATUREDescriptionNo.ISSUEDDateSCALE:DRAWN:DATE:JOB:YH703 JOSINA AVENUEPALO ALTO, CALANDSCAPE DESIGN3357 SAINT MICHAEL CTPALO ALTO, CA 94306TEL: (415) 694-0800NEWRESIDENCEyhAS SHOWNPLANTING DETAILS& SCHEDULEL-2SCALE:FILE NAME:2TYPICAL SHRUB PLANTINGN.T.S.D-SHRUB.DWGSCALE:FILE NAME:3TYPICAL GROUND COVER PLANTINGN.T.S.D-GCOVER.DWGSCALE:FILE NAME:1TYPICAL TREE PLANTINGN.T.S.D-TREE.DWGNOVEMBER 10, 2017SYM.BOTANICAL NAMECOMMON NAMEQUAN.SIZESPACINGSHRUBSPLANT SCHEDULEFestuca glauca 'Elijah Blue''Elijah Blue' FescueFeGlPERENNIAL and GROUNDCOVERWUCOLS*L* WUCOLS WATER USAGE LEVEL: H - HIGH, M - MODERATE, L - LOW AND VL - VERY LOW15 gal.Lavandula angustifoliaEnglish Lavander2' O.C.LPhormium 'Firebird''Firebird' New Zealand FlaxL15 gal.PhFiLaAnAgAtAgave attenuataFox Tail AgaveL15 gal.5' O.C.5' O.C.Senecio MandrailscaeBlue Chalk SticksSeMa5 gal.18" O.C.Nandina domestica 'Nana Purpurea'Dwarf Sacred BambooNaNaM3' O.C.15 gal.TREE24" boxAcer buergeianumTrident MapleAs ShownAcBuM15gal.Asparagus densiflorusFoxtail FernAsDeM3' O.C.15 gal.LFraxinus americana (Area C Themed Street Tree)Autumn Purple American AshFrAm **M1As Shown15 gal.Polystichum munitumWestern Sword FernPoMuM5' O.C.24" box-------Sod LawnH230 SF24711057818" O.C.Pittosporum eugenoidesTarataPiEuL15 gal.5' O.C.1324" boxMagnolia grandifloraSouthern MagnoliaMaGrM315' O.C.VINE5 gal.Ficus pumilaCreeping FigFiPuM4' O.C.715 gal.EuChEuphorbia characias 'wulfenii 'LEuphorbia34' O.C.AnBiAnigozanthos 'Big Red'L'Big Red 'Kangaroo Paw42' O.C.15 gal.** NEW STREET TREE TO BE INSTALLED BY CITY UPON PROJECT COMPLETION. OWNER SHALL CONTACT CTI @ 408.777.3269 TO ARRANGE FOR INSTALLATION STERN AVENUEZ2Z1Z3HYDROZONE 1:AREA COVERED BYSTATIONS 2 & 3230 SFHYDROZONE 2:AREA COVERED BYDRIP ZONES 1 & 2816 SFHYDROZONE 3:AREA COVERED BYDRIP ZONE 3606 SFWATERMETERSHEET NO.SHEET TITLE:LICENSE STAMPS AND SIGNATUREDescriptionNo.ISSUEDDateSCALE:DRAWN:DATE:JOB:YH10365 STERN AVENUECUPERTINO, CALANDSCAPE DESIGN3357 SAINT MICHAEL CTPALO ALTO, CA 94306TEL: (415) 694-0800HANRESIDENCEyhNNOVEMBER 10, 2017IRRIGATION DESIGN NOTES1.I HAVE COMPLIED WITH THE CRITERIA OF THEMODEL WATER EFFICIENT LANDSCAPEORDINANCE AND HAVE APPLIED THEM FOR THEEFFICIENT USE OF WATER IN THE IRRIGATIONDESIGN PLAN.IR-1IRRIGATION PLAN&WATER BUDGETWORKSHEETWATER BUDGET WORKSHEETTOTAL LANDSCAPED AREA (LA) = 1,652 SQ. SF.SPECIAL LANDSCAPE AREA (SLA) = 0 SQ. SF.MAXIMUM APPLIED WATER ALLOWANCE (MAWA)= ETo x 0.62 x (ETAF x LA + (1 - ETAF) x SLA)= 45.3 x 0.62 x (0.55 x 1,652 + 0.45 x 0)= 25,519 GALLONS/YRHYDROZONE # /PLANT WATER USEIRRIGATIONMETHODIRRIGATIONEFFICIENCY(IE)HYDROZONEAREA (HA)(SQ FT)3 / MEDIUM WATER USEDRIP606816230TOTALSESTIMATED TOTAL WATER USE (ETWU)= ETo x 0.62 x ETAF x HA= 45.3 x 0.62 x 715= 20,081 GALLONS/YR* USE WUCOLS TO DETERMINE PF, SEE SHEET L-2 FOR PLANT WATER USAGE LEVELETWU < MAWA , SO PROJECT MEETS WATER EFFICIENT REQUIREMENTSSPRINKLERPLANT FACTOR*(PF)0.40.20.7Reference Evapotrranspiration (ETo): 45.3ETAF(PF/IE)ETAF X HAREGULAR LANDSCAPE AREASSPECIAL LANDSCAPE AREAS2 / LOW WATER USE1 / HIGH WATER USEIRRIGATION CONTROLLER:MOUNT ON WALL OR PEDESTALAT THIS LOCATION AS DIRECTEDBY OWNER. CONNECT TO 120VOLT A.C. ELECTRICAL SERVICEINSTALLED AT THIS LOCATIONUNDER ELECTRICAL CONTRACT.IRRIGATION CONTRACTOR SHALLCOORDINATE LOCATION OFELECTRICAL SERVICE PRIOR TOCONSTRUCTION.TOTALS01,65200.750.490.250.932972042147150.81DRIP0.81 SHEET NO.SHEET TITLE:LICENSE STAMPS AND SIGNATUREDescriptionNo.ISSUEDDateSCALE:DRAWN:DATE:JOB:YH10365 STERN AVENUECUPERTINO, CALANDSCAPE DESIGN3357 SAINT MICHAEL CTPALO ALTO, CA 94306TEL: (415) 694-0800HANRESIDENCEyhIRRIGATION NOTES& SCHEDULEIR-2IRRIGATION PLAN NOTES1.THE INTENT OF THIS IRRIGATION PLAN IS TO PROVIDE THE MINIMUM AMOUNT OF WATER REQUIRED TO SUSTAINGOOD PLANT HEALTH.2.THESE IRRIGATION DRAWINGS ARE DIAGRAMMATIC AND INDICATIVE OF THE WORK TO BE INSTALLED. ALLPIPING, VALVES, AND OTHER IRRIGATION COMPONENTS MAY BE SHOWN WITHIN PAVED AREAS FOR GRAPHICCLARITY ONLY AND ARE TO BE INSTALLED WITHIN PLANTING AREAS. DUE TO THE SCALE OF THE DRAWINGS, ITIS NOT POSSIBLE TO INDICATE ALL OFFSETS, FITTINGS, SLEEVES, CONDUIT, AND OTHER ITEMS WHICH MAY BEREQUIRED. INVESTIGATE THE STRUCTURAL AND FINISHED CONDITION AFFECTING THE CONTRACT WORKINCLUDING OBSTRUCTIONS, GRADE DIFFERENCES OR AREA DIMENSIONAL DIFFERENCES. IN THE EVENT OFFIELD DISCREPANCY WITH CONTRACT DOCUMENTS, PLAN THE INSTALLATION WORK ACCORDINGLY BYNOTIFICATION AND APPROVAL OF OWNER OR THE OWNER'S AUTHORIZED REPRESENTATIVE AND ACCORDINGTO THE CONTRACT SPECIFICATIONS. NOTIFY AND COORDINATE IRRIGATION CONTRACT WORK WITHAPPLICABLE CONTRACTORS FOR THE LOCATION AND INSTALLATION OF PIPE, CONDUIT OR SLEEVES THROUGHOR UNDER WALLS, ROADWAYS, PAVING AND STRUCTURES BEFORE CONSTRUCTION. IN THE EVENT THESENOTIFICATIONS ARE NOT PERFORMED, THE CONTRACTOR ASSUMES FULL RESPONSIBILITY FOR REQUIREDREVISIONS.3.FOR COMPLETE PERFORMANCE AND TECHNICAL SPECIFICATIONS, IRRIGATION CONTRACTOR TO VISITSPECIFIED LANDSCAPE PRODUCTS CATALOG, VISIT THE PRODUCTS WEBSITE OR CONTACT THEREPRESENTATIVES OF THE IRRIGATION PRODUCTS\ MANUFACTURERS.4.IRRIGATION PIPE AND WIRE CROSSING BENEATH HARDSCAPE SURFACES SHALL BE CONTAINED WITHINSLEEVING OR SCHEDULE 40 PVC CONDUIT. SLEEVING SIZE SHALL BE A MINIMUM OF TWO TIMES THEAGGREGATE DIAMETER OF ALL PIPES CONTAINED WITHIN SLEEVE. PROVIDE VERTICAL SWEEP FOR ALLELECTRICAL CONDUIT ON EACH SIDE OF HARDSCAPE AND TERMINATE ENDS AT 12" MINIMUM DEPTH AND 12"FROM HARDSCAPE SURFACE.5.IT IS THE RESPONSIBILITY OF THE MAINTENANCE CONTRACTOR AND/OR OWNER TO PROGRAM THE IRRIGATIONCONTROLLER(S) TO PROVIDE THE MINIMUM AMOUNT OF WATER NEEDED TO SUSTAIN GOOD PLANT HEALTH.THIS INCLUDES MAKING ADJUSTMENTS TO THE PROGRAM FOR SEASONAL WEATHER CHANGES, PLANTMATERIAL, WATER REQUIREMENTS, MOUNDS, SLOPES, SUN, SHADE AND WIND EXPOSURE.6.INSTALL REMOTE CONTROL VALVE BOXES 12" FROM WALK, CURB, HEADER BOARD, BUILDING, OR LANDSCAPEFEATURE. AT MULTIPLE VALVE BOX GROUPS, INSTALL EACH BOX 12" FROM THE WALK, CURB, HEADER BOARD,BUILDING, OR LANDSCAPE FEATURE AND INSTALL EACH BOX 12" APART.7.INSTALL A GATE VALVE TO ISOLATE EACH REMOTE CONTROL VALVE OR GROUP OF RCV'S LOCATED TOGETHER.GATE VALVE SIZE SHALL BE SAME AS THE LARGEST REMOTE CONTROL VALVE IN MANIFOLD.8.IT IS THE RESPONSIBILTY OF A LICENSED ELECTRICAL CONTRACTOR TO PROVIDE 120 VOLT A.C. (2.5 AMPDEMAND PER CONTROLLER) ELECTRICAL SERVICE TO THE CONTROLLER LOCATION(S). IT IS THE RESPOSIBILITYOF THE IRRIGATION CONTRACTOR TO COORDINATE THE ELECTRICAL SERVICE STUB-OUT TO THECONTROLLER(S). PROVIDE PROPER GROUNDING PER CONTROLLER MANUFACTURER'S INSTRUCTIONS ANDINACCORDANCE WITH LOCAL CODES.9.PROVIDE EACH CONTROLLER WITH ITS OWN GROUND ROD. SEPARATE THE GROUND RODS BY A MINIMUM OFEIGHT FEET. THE GROUND ROD SHALL BE AN EIGHT FOOT LONG BY 5/8" DIAMETER U.L. APPROVED COPPERCLAD ROD. INSTALL NO MORE THAN 6" OF THE GROUND ROD ABOVE FINISH GRADE. CONNECT #6 GAUGE WIREWITH A U.L. APPROVED GROUND ROD CLAMP TO ROD AND BACK TO GROUND SCREW AT BASE OF CONTROLLERWITH APPROPRIATE CONNECTOR. MAKE THIS WIRE AS SHORT AS POSSIBLE, AVOIDING KINKS OR BENDING.10.PROVIDE EACH IRRIGATION CONTROLLER WITH ITS OWN IDEPENDENT LOW VOLTAGE COMMON GROUND WIRE.11.INSTALL NEW BATTERIES IN THE IRRIGAITON CONTROLLER(S) TO RETAIN PROGRAM IN MEMORY DURINGTEMPORARY POWER FAILURES. ISE QUANTITY, TYPE AND SIZE REQUIRED AS PER CONTROLLERMANUFACTURER'S INSTRUCTIONS.12.THE IRRIGATION CONTRACTOR SHALL BE RESPONSIBLE FOR MINOR CHANGES IN THE IRRIGATION LAYOUT DUETO OBSTRUCTIONS NOT SHOWN ON THE IRRIGATION DRAWINGS SUCH AS LIGHTS, UTILITY BOXES, ELECTRICALENCLOSURES, ETC13.NOTIFY LOCAL JURISDICTIONS FOR INSPECTION AND TESTING OF INSTALLED BACKFLOW PREVENTION DEVICE.14.PIPE THREAD SEALANT COMPOUND SHALL BE RECTOR SEAL #5.15.NSTALL GREEN PLASTIC VALVE BOXES WITH BOLT DOWN, NON HINGED COVER MARKED "IRRIGATION". BOXBODY SHALL HAVE KNOCK OUTS. ACCEPTABLE VALVE BOX MANUFACTURER'S INCLUDE NDS, CARSON ORAPPROVED EQUAL.16.INSTALL A GATE VALVE TO ISOLATE EACH REMOTE CONTROL VALVE OR GROUP OF RCV'S LOCATED TOGETHER.GATE VALVE SIZE SHALL BE SAME AS THE LARGEST REMOTE CONTROL VALVE IN MANIFOLD.17.IRRIGATION CONTROL WIRES: SOLID COPPER WITH U.L. APPROVAL FOR DIRECT BURIAL IN GROUND. CONTROLWIRE SERVICING REMOTE CONTROL VALVES: SIZE #14-1 WIRE WITH A UNIQUE COLOR INSULATING JACKET FOREACH CONTROLLER. COMMON GROUND WIRE: SIZE #12-1 WIRE WITH A WHITE I INSULATING JACKET AND ASTRIPE OF COLOR WHICH MATCH'S THE CONTROL WIRE COLOR CHOICE FOR SPECIFIC CONTROLLER. SPAREWIRE: #14-1 WIRE WITH BLACK INSULATION JACKET. SPLICES SHALL BE MADE WITH 3M-DBY SEAL PACKS ORAPPROVED EQUAL.18.INSTALL TWO SPARE CONTROL WIRES OF A DIFFERENT COLOR ALONG THE ENTIRE MAIN LINE. LOOP 36" EXCESSWIRE INTO EACH SINGLE VALVE BOX AND INTO ONE VALVE BOX IN EACH GROUP OF VALVES.19.SPLICING OF LOW VOLTAGE WIRES IS PERMITTED IN VALVE BOXES ONLY. LEAVE A 36" LONG, 1" DIAMETER COILOF EXCESS WIRE AT EACH SPLICE AND A 36" LONG EXPANSION LOOP EVERY 100 FEET ALONG WIRE RUN. TAPEWIRES TOGETHER EVERY TEN FEET. DO NOT TAPE WIRES TOGETHER WHERE CONTAINED WITHIN SLEEVING ORCONDUIT.20.SCHEDULE A MEETING WHICH INCLUDES REPRESENTATIVES OF THE IRRIGATION CONTROLLERMANUFACTURER, THE OWNER AND THE IRRIGATION CONTRACTOR AT THE SITE FOR INSTRUCTION ON THEPROPER PROGRAMMING AND OPERATION OF THE IRRIGATION CONTROLLER.12345CLEAN BACKFILL MATERIALFINISH GRADELATERAL LINEMAIN LINELOW VOLTAGE CONTROL WIRESYMBOLMANUFACTURERMODEL NO.DESCRIPTIONRAIN BIRD975XLSEU-1"1120-CL. 200 PVC PLASTIC PIPE. COVER TO BEAS INDICATED ABOVE FOR PIPE DEPTH OFCOVER.1" SIZE:CLASS 315 PVC PLASTIC PIPE WITH SCHEDULE40 PVC SOLVENT WELD FITTINGS. 18" COVER.SLEEVING:REDUCED PRESSURE BACKFLOW ASSEMBLYREMOTE CONTROL VALVE WITH PRESSURE REGULATOR ANDFILTER FOR DRIP LATERALSIRRIGATION LEGENDRAIN BIRD XFD DRIPLINE FOR ON-SURFACEAPPLICATION. WATER DELIVERY RATE OF 0.6GALLON PER HOUR, WITH EMITTER SPACING 24"APART. DRIPLINE LATERAL SPACING 24" APART.INSTALL PER MANUFACTURER'SRECOMMENDATIONINLINEEMITTER:WILKINSZONE CONTROL VALVE ASSEMBLYMANIFOLD:1" SIZE:CLASS 315 PVC PLASTIC PIPE WITH SCHEDULE40 PVC SOLVENT WELD FITTINGS. 12" COVER.PERMANUFACTURER'SRECOMMENDATIONFLUSH VALVESUPPLY ANDHEADERLINES:DATA INDUSTRIALREFER TOSATELLITE MODELNUMBERFLOW WENSOR/MASTER VALVE, NORMALLY OPEN.AIR RELIEF VALVE ASSEMBLYIRRIGATION CONTROLLER WITH SOLAR SYNC ET SENSORPRO-CHUNTERTEES & ELBOWS FOR ASSEMBLING PIPESTIE-DOWN STAKESXFD- 06 - 24 - 500PVC RISER PIPE FOR BRINGING UNDERGROUND PIPE TO THESURFACE AND RAISED PLANTERS1XFD ON-SURFACE DRIPLINE END FEED LAYOUT QF HEADERXFD Dripline Maximum Lateral Lengths (Feet)Inlet Pressure psi12" Spacing18" Spacing24" SpacingNominal Flow (gph)Nominal Flow (gph)Nominal Flow (gph)0.60.90.60.90.60.9152731553142504243222031816935329450836830360230413350586414403952554654026524745041728552842072048860460290596455780514SEPTEMBER 30, 2017RAIN BIRD2.TRENC`H UNDER HARDSCAPE12"4"REFER TOIRRIGATIONLEGEND123451806-SAM-PRS-10F,H,Q1806-SAM-PRS-12F,H,Q1806-SAM-PRS-5 H,Q1806-SAM-PRS-8 H,Q1806-SAM-PRS-15F,H,Q6" POP-UP SPRAY SPRINKLER6" POP-UP SPRAY SPRINKLER6" POP-UP SPRAY SPRINKLER6" POP-UP SPRAY SPRINKLER6" POP-UP SPRAY SPRINKLER2" AND SMALLER:CLASS 315 PVC PLASTIC PIPE WITH SCHEDULE40 PVC SOLVENT WELD FITTINGS. 18" COVER.MAIN LINE:LATERALLINE:3/4" AND LARGER:1120-SCHEDULE 40 PVC PLASTIC PIPE WITHSCHEDULE 40 PVC SOLVENT WELD FITTINGS.12" COVER.* WHEN RADIUS OF SPRINKLER HEADS, REQUIRED FOR PROPER COVERAGE, IS LESS THAN RADIUS SHOWN ON LEGEND, THE CONTRACTORSHALL EQUIP HEAD WITH A RAIN BIRD "PCS" PRESSURE COMPENSATING SCREEN FOR FLOW AND RADIUS CONTROL. SELECT SCREEN ON PCSNOZZLE SCREEN SELECTION CHART FOR APPROPRIATE RADIUS.2.6,1.3,0.73.7,1.9,1OPERATINGPSINOZZLE GPMOPERATINGRADIUS(FEET)8-100.2,0.1300.5,0.251.6,0.8,0.43030303010-1212-154-56-8REMOTE CONTROL VALVE ASSEMBLY FOR SPRINKLER LATERALS1