The URL can be used to link to this page

Home My WebLink AboutCT 02-13; FARBER; GEOTECHNICAL RECONNASSSANCE; 1998-09-14(FRi)10 6 2000 1~O/ST.13:20/NO. 5500000510 P 1 • 4», d-£4-1/8 b ttr6'T C • Geotechnfcal ., GeologIc • Environmental 5741 Pil!mtr Way • catlsba9. Callkwnia 92008 • (780) 438-3155 '. FAX (760) 931-0915 September 14,1998 W.O. 2543-A-SC orO~rs . 'Jordan Pacific, 'nc.. 4142 ~tonebridge Lane ' , Rancho, santa fe. C~ltomla 9~1. Attention: Mr. Curt Farber Subject: Geotechnical Reconnalssance. 1100 Las Flores Drive. City Of Carlsbad, CaHfomia ' Dear SIr.: In accordance with yoUr raquNt, 1h1s rePort'has been prepared, by G,oSoUs, Inc. (GS,) in, order to present a summary of 'our visual reconnaissance 'and,literature reylew regarding , geotechnical condiUon~ at #)e subject she. ' , . , Sm; OESiRlfDON ' '" ! The site 18 an rectangular sl1aped ptoperty located northeast of· the inte~(m of las 'FIOreS Drive and Jefferson 'Street in the CIty of Carlsbad,' California., The aJte la bounded on the north. by an·;adJ.Cent"~denti4l'propertyt the _ by·a·vacant property,.1h8'south by Las Floree Drive· and ~ the west by Jeffenson Str"t. The stt_ coi'l8ists of a'relatfveiY flat lying pad area bounded by graded slop" located along,the west and aoutl:16ides of . . the pad. that descend from to Jeffaraon Street and Las Flores' ·Drlve, respectively. . Maximwn aJope height appears to be on the orderof 19 feet with .'o~ gradients' on: the . order Qf 1.5:1 .(h:V). ~g lmprov~ents to'the property OOflslst of '8 single floor residential ab'1JCture Jocatod within the pad area. It is our und8ritandlng that thIS structure Is approximately 40 years Old. Other Improvements consist of ~ cfrlvew8y·accees to Las Flores DrIve. 'a.smalJ 0-than 3 'feet high) ~etaln;ng wan «long' the eastem property line and a daiveway ~ from Jefferson Street to the adjacent property north of the eite. A . fourfoot high retaining waif rslocated along the east slda. of this driveway. Landaoaplng onalte appt.-s typical for sfmllar re~idenUai strUCtures In the vfc:fnlty •. Slope areas were observed to support a dense growth of Ivy. . EVfdence of 81gnl1leant dls'trees to the exlating residential structure was not obselYed during our site reconnaissance. nlting of the small retaining wall located alOng the eastem property line 'was obserVed. The'tllting app~ to be directed away from th~ wall backfill with the greatest lateraJ displacement at the top of the wall. . (, FROM EfjQINEEBING GEOLOGY earth Materl." Earth materials 'onaite pred~nii;,antJy consist of Quaternary-age terrace deposits. These deposits typically consists of silty sand and' are-generally stritabfe for 8tIppOt"t of-fiHa-and' structures. In areas of the property where natural ground surfaces are located, a relatively loose zone of soil (colluvium and weathered terrace deposits) i, typically developed in 1h8: terrace 'deposits to an apprOximate depth of 2 to 4 feet below' existing grades. The topographic configuration of the property ,suggests 1hat the lot may be a cut lot, or a 1ransition lot with perimeter ftlls located along the. west and south sIdes of the property. Fill materials onslte are likely derived from the onslte native soil. Distress indicative of a structure spanning a cutIflll transition was not obselVed. : ' GrouOCIWIt,r S'ased on the relatively high topographic ~itfon of the sit, and our e)(petience in the vicinity, It'8 antIcJpated.that groundwater should not affect site development. However, perched groundwater conditions could develop In the future due to over il'!'igation, storm runoff and/or broken utilities. Thijs potential is considered to be no greater than 'for other similar project in the Vicinity; Enalni.dnq GeQlgglc H.prdl Sued on a review of available pUbiicati~ns and our experience In the vicinity, geologic hazards (lIqu.factlon, ~It ruptu~, !endslldes, etc.) are not antIclpated to tlgnlftcantly. Impact this slte. The presence of faulting onsite was not Indicated from a review' of . available literature. EYbIrI' aitllgSUD.rit.J cgOlldtgiloUI Grading:· . . ", . '. . . . Grading ·could likely be performed with convantionaJ g~rng equipment Remedial earthwork anticipated orwite wUl Include, but may not be limited. to removal and racompaction of colluvfal topsoils and eXIStIng fill, and over excavation of transition Pads or cut·pads.exposing bedrock transitions ~r expansive soil. Buttresses and/or Stabilization fills do not appear to be necessary at "this. time. . , Removal depths on the order of 2 to .4 'feet ~Uy deeper) below existing grades t:nay be antlcfpated at this time. However, these depths should be . verified with subsurface ~~~oo. . . Jordan Ptome, Inc:. 1100 lu FIol1lS Drive FIle: .:\Wp7\2SOO\ 2543a.ar . c. ... , .. , Ju. W.O.~A-SC Septemb.r 14,1998 Pagl2 >{)::t ~;. " ::. _I' FROM (FR I) 10 6 2000 1,22/8T. 13: ZO/NO. 5500000510 P 3 Site soils observed at the surface were observed to be relatively sandy and are anticipated to be relatively low in expansive potential. However, the presence of expansive sOils·shOuld not be preofuded from occurring onsite. .. Slope.: . , ' Graded slopes constructed with elte soils should perform ade~uately, assuming proper ., construction. However. these solis would bo considered erosive are mitigative measures Q.e". jute. hydroseed, etc.) ShoUld be ,considered and likely recommended. The existing graded slo~ appear to be relatively stable. HoweVer, slope gradients appear to be steeper than the typical 2: 1 gradient constnJcted In accordanQe With current standards of practice. Any future development in the vicinity of these stopes should ' consider the . stabilitY of the slopes and a appropriate setback applied. The existing structure appearl tO'be setback, no less th~ approximately 10 feet from the top of slopes. . . '. . Foundations: " Post·tension~d and/or conventional foundation systems may be considered for this 'site. Foundations should be designed and Constructed in accordance with ,criteria presented . in the l)niform Building Code. . " paa.M'HABY CONCLUSIONS A"D BECOMMENDADOlfS easGd on the age of the struc:ture and relative absenCe ',of ,slgnmcant distress to the , structure's exterior, It can be assumed that 11. foun~ation and structure have performed adequately. DistreSs to the 8111811 retalnlng wall is HkGly due io a Inadequate foundation syetem and/or the apparent lack, of a, wall drain to relieve hydrOstatic pressure.. ' , , . Future development of this site appear$ to be feasible from ~ geotechnical viewpoint. I~ 'Is recommended ,.t a preUmfnary geotechnical evaluation of the ~ite Is CQmpteted, wHh emphaSis on, but not n~1y limited to, the following:' , • • .. • Stability of, existing' slopet. . .site seismicity.' , Earthwork reCOmmendations • Foundation design and co!')struCtfon. Jardin PacIfIo, Inc. 1100 las FIoree Drtve file: t:\wp~ 254SLgr 0. ...... , Inc. W.O.2543-A-$C September 14. 1_ P~g'3 ! ; , .J .' ~ I I '> FRO~ . (FRI)10 6 2000 i22/ST. 13: 20/NO. 550000~,~:;\~~~: '"'}~''' ..... ~>.~:,*-~ LIMITATIONS Since. our ~tudy is based upon visual observation and a review of available publlcation.s, the conclusion and recommendatfons presented are professional opinlons.-ThelSe opinions have been de~ed in accordance with current standards of practice and no warranty Is 'eKpresSed-or impffed. standards of·p~e·stlbject to· charlge-with time. Get assumes no responsibility or liability for work. testing or recommendations performed or provided by others. The opportunity to be ot service Is greatly appreciated. If you have any questions concerning this report or if we may be of further assistance, please do not hesJtat, to conta~ any of the Undersigned. RespectfUUy sUbnlitted, GtoSolls, Inc. 4-{1;.,.~ Robert G. Crisman En·glneeiin.g Geologist, CEG.1 . RGC;/ARKiJPF/mo .... Distribution:' (4) Addr~sse9 :iOrdan P4ICHIc, Ino; 1100 l.8s Flores Drive PIle: ,:\wp'1'\25(n 2543a.gr Revi~wed by, ." " W.O.2&43-A-SC September 14. 1996 Page 4 . '<::~:i:>l . :':::.~ .. .: .