Laserfiche WebLink
_ . _ <br /> � I <br /> pPR-T:�99 08�49 FROM�EVEREST PLANNINC DEP'I' ID�4262678742 PAGE 1/3 <br /> � '� I <br /> SENVICES�INC. <br /> �t�..�..wo����e wiuo swa��mw.a� . <br /> )<S Marin�prtve•BeUingh�m,WA 98225•I�one 360.733.7318•Fax 360.733.7618.�.moil qeotat@nu.com <br /> April 14, 1999 - <br /> Job No. G9093 ' <br /> ` � I�,��n <br /> Trepanier Engineering !/ � /� <br /> 1420 Hewitt Avenue q pR ���� ! <br /> Everett, Washingwn 98201 �IT 2 � Jgy9 '�� <br /> Attn: Ted Trcpanier ���9�k`��. <br /> ePL � <br /> Re: Rock�ry Design ._ -- ...— _—. —.,— <br /> Northshore 1C6urch p�,n•Fax N�e 7g�� wr,� p,� o► <br /> Seaway,I.ot 3 � � <br /> Bvcretc, Washington �''� <br /> �, co. <br /> aMna r hana r <br /> Refw�ence: Seaway Center,i,ot 3 <br /> Preliminary Geotechnical Report � • <br /> by Associated Earth Sciences <br /> dated January I998,Projeet No. G95103A <br /> Dear Mr.Trepanier, , <br /> As rcquested, we have reviewed the referenced report in ordcr to pmvide a design for <br /> construction of nu►forceri earth rockeries along Powder Mill Crcek and an assessment of <br /> potential im}�.cts of the creek on fill placement and rockery construction. <br /> In our opinioa; the pmposed mckeries along the top of the East Fork Powder Mill Creek ravine <br /> may be consUvcted as proposed provided our recoaunendations are incorporated into the final <br /> design and constnudon specifications. It sMuld be noud that rocl:eries aze not iatended as <br /> retaining structures but rather as erosion wntrol facings for soil that would otherwise stand near <br /> vertical. Therefore, since these rockeries will be facing a Sll with a backfill slope of 2H:1 V, the <br /> smictural fill must be reinforced with a geosynthetic such as Miragcid 7T. <br /> Rockery construcuon is dependent largely upon the skill and expericna of the coetractor. As <br /> such it is not entirely controllable by enginaring design due to tLe variebility of rock sius and <br /> shapes. Specific guidelines for rockery constrnction are tttat each rock should be supported by at <br /> least 2 rocks beneath, rxks should be att�+ilau in shape and a minimum 12 inches of dreinage <br /> matcrial should be provided betund the n�kery facing with a drainpipe at the bau. <br /> As noud on the attached plate,the structural fill should be reinforoM with ten foot lonQ Miragrid <br /> 7T, or equivalent, with the first layer placed one foot from the base of the fill. The subsoquent <br /> three layers should be evenly spaced at 1.75 foot inten+als. Ends of the geo�rid should be <br /> ,�.,....4,,._......�.-..M..,.....,r... Psje ! of 2 ' <br />