Laserfiche WebLink
2009-0'-28 09:30 The Boeing Company 4252947864 » <br />Group Northwes <br />October 30, 2008 <br />Inc. <br />Mr. llavid Gubhels <br />501G Nichols Place <br />Gverett, Nt\ 98203 -�. . _______ <br />-- "� —� <br />Subjcct: GG07'ECHNICAL 1NSPGCTION SUD71ViARY LG1'TCR <br />IC�YSTONC RLTAINING �VALL <br />� 5016 NICHOLS 1'Le10E , <br />EVlRGTT, WASHINGTON <br />Dear Mr. Gubbels: <br />� <br />1 <br />P 2/3 <br />Geotechniwl Engineers, GQolo�ists <br />8 Enviranmenlal Scientists <br />G-2a36 <br />Wc havc prcpared the 1'ollowing Icttcr in ordcr to siunmarize our geotcchnical inspections 1'ur the <br />new keystone retaiuing wall at the subjec[ site. G�O Group Northwes[, Inc., visitcd thc sitc on <br />s���eral occasions, munitored the ��all construceion tmd generated o lield reports witich have been <br />ti�r�varded to the ownrc Please refer to the tield reports for specific dclails. <br />l3ased upon our oUservations, the new Keystone wull subgradc consists of fim� and unyielding <br />site soils or compacted sWctural fills placed un top of the cotnpetent site soils in accordancc <br />with the project pluns. A crushed rock leveling pad was placed on top of the prepared sub�rade <br />prior to stacking oFthe btocks. Tlie new ���all consists of Keystone 5tandard blocks per die <br />pcnnitted plans. 7'hc base of thc wall was verified to h�ve a minimum embcdmcnt depth of ].� <br />fcet in accurdance witl� the project plans. <br />A pourly gruded 3/4-inch cle:tn crushed rock �vas importcd to the projcct site for use as d�e <br />ret�ining wall structural lill, bnsc Icveling pad, and unit fill. GEO Group Nortfivest, Ina, <br />��erilied that tliis materiul is acceptable for die aforementioned uses. The cruslicd rock was <br />placed behind die blocks mid tamped via plate compac[or. <br />Layers uf Syntcen SF 55 geugrid were installed per d�e gcogrid schedule shuwn on tlie project <br />plan,. The prujrct pi:tus rcquircd �4ir.igrid : XTC or eGuivalent. GEO Group Nonhwest, inc., <br />vcrifird tl�at long-tertn design sncneths �vere equivalent for the Syuteen SF �5 grid. "Cherefore, <br />this gcogrid was approvcd for subjc�t �v.dl. <br />�3 <br />