1505 INDUSTRY ST 2018-01-01 MF Import

01/E;/',7903 U6:1F, `t13?74`_f9`il !'A!I!1TTONL �3JLFM1YJT CO PGS[ 13 GEOTECHNICAL ENGINEERING S'�UDY Panattoni Development Company, LLC f-10134-1 October 2, 2002 Pege 8 If design a�ainst earthquake londing is desired, a rectanquler pressure distribution equal to six times the woll height (6H) should be added to the a6ovc latcral earth pressure vnlues. In order to reduce the potential for hydrostatic forcos building up b �^�d the walis, tho walis should bo provided with a perforated drainpipe nnd backfilled � h a free-draining material. 7he free-draininc� material should contorm to ihe WSDO�f pecificatior.s for gravel backfill (or walls IWSDUT 9-03.1212�1 and extend at least eiy, een I18) inches .- bahind the full haight a( the wall. The remainder of the bar.kfill should consist cf slructurul till. !1 typical retainin� wall detaii is provide.d ns Plate 3. - Seiamic Dasign Considcratians The Pugct Lowland is classified as a Seismic Zone 3 in the 1937 Uniform Duilding Gode � (U[3Cy. [aRhquakes occur in the Pupet Lowland with reqularity, however, tha mPjority of these evc�nts are of s�mh low magnitude they are not telt without instruments. � Larc�e earthquakes do oceur, as indicnted 6y the 1949, 7.2 magnitude earthyuake in � the Olympin urcu and the 1965, 6.5 magniwde earthquake in the Midwsy aree and the 2001, 6.8 ma�nitude earthquake in the Nisqually ares. 'fhere are three potential c�eologic hnzArds associated with a strong motion seismic �jvont at this site: pround rupture, liquefaction, and ground irwtion response. Gruund Rupturc: The strongest earthquakes in the Pugot Lowlend nre wid�spread, subcrustal events, rengin{7 in dopth (rom thlrty (30) to tifty-fivc (55) miles. Surfacc faulting from thesc deep events has not been documented to date. Thergfore, it is our opinion, that the risk of t�round rupturo at this site durinp a stronp motion seismic event is negligible. Liquefactlon: Liquefection is a phenor,ienon in which soils lose all shear strength for sl�ort poriods oi tima durinfl an aerthqunke. Groundshakinp of sufficient duration results in the loss of yrain-to-grain contact and rapid incrcase in pore water prossure, causing the soil to behave as a fluid. To have a potential �or liquelaction, a soil must be cohesionless with a grsin size distribution of a soecitied range (generally sand and silt�; it must be loose; it must be below the groundwater table; and it must be subject � to sufficient magr.itude and durntion of groundshnkinp. Tho oHects of liqusfaction may be large total and/or diffcrential settlemr.nt (or struclures tounded in the liquetying i soils. 1, e.�m c��n.,,�F.i,,,