2710 WETMORE AVE 2018-01-01 MF Import

i`�,��;�, ;� EarthpCon�sultants,.[nc' September 22, 1992 E-5343-1 SDL Corporation , P.O. Box 1685 Bellewe, Washington 98009 Attendon: Mr. John Akre Subject: Temporary Excovation for Electrical Vault Everett Community Theater Everett,Washington Reference: Farth Consultanu, Inc. Geotechnical Engineering Study E-5343, October 28, 1991 Dear Mr. AIQe: In acoordance with your request, we have reviewed the referenced report for the purpose of evaluating the planned method of excavation su�port for the electrical vaulG It is our understandiag that the excavadon will be located on the northwest corner of the site and will by ten feet by fourteen feet in plan and ten feet deep. It is our understanding the current plan is to construct a concrete"box"around the excavation limit,prior to beginning the main excavatioa 'Ibe"box"would be consWcted by excavating a one foot wide uench around the limit of the planned excavadon and filling t6e uench with concrete. The information contained in the referenced report indicates the soils expected to be exposed by the excavadon wnsist of dense to very dense silry sand (glacial till). Based on this information, ow calculadons indicate adequate support for a temp�,rary excavation would be provided by the ooncrete "box" system. The conerete shouid have a minimum 28 day strength of 2000 psi and the excavadon inside the"box"should begin no sooner than three days after placement of the rnncrete. Excavadon of the uench should be observed by a representative of ECI in order to confirm that the soil conditions are as anticipated. In addition, as the excavation inside the "box" is made, the concrete walls should be observed for indications of distress. If necessary, cross bracing could then be installed. 1805�S36th PWce N.E.,Suite 1D7,Bellevue,Washinglon 98005 222 E.26Ih Stieel,Suee 101,Tacoma,N"ashington 98421�9998 Belle�ue(206)6433780 Seatlle(206)464�1584 FAX(206)746-0860 Tacoma(206)272 6608