11731 AIRPORT RD Geotech Report 2018-01-02 MF Import

08/18l2005 15:27 4257478561 GE�TE�I PA'CE 0� Lucia Oevefcpment, LLC JN 05233 August 18.2005 Page G not be appropriate. We recommend a safety factor of et least 1.5 tor the foundation's resistanee to laterel loading, when using the above ultimate pessive value. PERMANENT FOUNOA770N AND RETA/N/NQ WALLS Retaining walls baekfiiled �n only one side should be designed to resist the iaterel eafth pressures imposed by the soil they retain. The tollowing recommended parameters are for walls that restrain level ba�ll: Active Earth Preuure' 35 pcf Sa7 Unit Weight 125 pcf WMn: (p pe1 Ie pwnda per cuac (oet, ,nd (M7 aetive eartfi preasur�s�n canPuOed W in9 the eQUlvaleM fluld precswq. •Fa a realralnsd wall tlw!qnnot Mfleq at baet o.004 tlmss Ite ryNght,�wHoem IaMal pnssun equal to 10{at Hm�s iM hNpht d the wall 9hoWd W�ddW to fhe ahow�cWe pufvaNnt fluld pressure. The values given abo�e are to be used lo dasign pertnanent foundation and retaining wails only. It ia not appropriate to back-ea�culate soil strength parameters from the earth pressures and sal unit weights presented in the table. We recommend a safety faetor of at least 1.5 for overtuming and sliding, when using the above values to desig� the walls. Restrained wall Soil parameters should be util'vxd for a distance of 1.5 times the wall heigM from comers or bends in the walis. This is irrtanded to reduce the amount of crecking that can occur where a wall is resuained by a comer. The design values given above do not include the effeds of any hyd�ostatiG pressures behind the walls and assume that no sutCharges, such as those caused by slopes, vehicles, or adjacent foundations will be exeRed on the walls. If these eonditio�s exist, those pressures should be ad�d to the above lateral sal pressures. Whare sloping backf'dl is desired behind the walls,we will need to be given the wall dimensions and the slope of the backfill in order to provide the appropriate design earth pressures. the surcharge due to treffic loads behind a wall can typically be aecounted for by adding a unifomt pressure equai to 2 feet multiplied by the above active flaid de�sity. Heavy construdion equipmerrt should not be opefaied behind retaining and foundation walls within a distance equal to the height ot a wall, unless �he walls are designed for the additicnaf fateral pressures resulting from the equipment. The wall design criteria assume that the backfill will be well-compaeted in I'rfts no thicker than 12 inChes. The wmpaction of baelcflll near the waAs should be accomplished with hand-operated equipment to preverrt the walls from being overbaded by the higher soil forces that occur during compaction. Retainino Wall Baakfill and Wafernroofina Backfill placed behind retaining or foundation walls should be coarse, iree�raining structural fill corRaining no organics. This backfill should coMain no more than 5 percent silt or clay partiCles and have no grevel greater than 4 inches in diameter. The percentage of particles passing the No. 4 sieve should be between 25 and 70 percent. The on-stte soils GEOTECH CONSULTANTS,INC.