500 LAUREL DR 2016-01-01 MF Import

Geotechni�al Engineering Study Page 1�3 00-2267 Ti�ree Story Addition - 500 Laurel Street, Everett January 31, 2001 intercept any surface water runoff from the stockpile and to help prevent it from potentially transferring soil fines from the stockpile to the site. Overexcavation: It currently appears that overexcavation and removal of up to about three or four feet may be required along the western end of the proposzd addition where the yard area currently slopes up around the comer of the building. P.dditionally, overexcav2tion of about two feet for foundation installation, and about six feet for utility installation, will probably be required. In any excavation in excess of four feet in depth that is not shored the excavation side slopes must be laid back at an appropriate gradient in conformance with the current local and OSHA safety standards (discussed later in this report). This should be expected to increase the amount of material that must be excavated, stockpiled and either replaced or reuserl as backfiil. All overexcavated material not removed from the site and disposed should be stockoiled. Stockpiled material should, where possible, be protected against the elements. As with the topsoil, this can be accomplished by covering the stockpile(s) with a pegged or sandbagged in-place visqueen sheeting. We recommend all stockpiles be set back at least fifteen (15) feet from any excavation or at least twenty (20) feet from the crest of the westem bluff slope. Only the reusable soils should be stockpiled. Any unsuitable soils should be removed from the site and disposed in accordance with the appropriate local regulations. We recommend the installation of either a shallow swale, a low earthen berm, or a silt fence along the downgrade perimeter of the stockpile to help prevent surface flow from the stockpile transporting soil fines to the excavated building area of the site, or beyond. Proofrolling: Wherever possible the existing ground surface where foundation or floor area subgrades are e>;posed should be proofrolled under our representative's observation. Depending on the time of construction, the aroofrolling can be accomplished with a vibratory steel wheel or sheep's foot, roller if the soil is dry. If moist, we recommend the use of only the roller's dead weight. In wet weather, proofrolling should be discontinued to avoid the risk of purr�ping moisture up into the surficial soil and, thereby, creating an unacceptable condition that might require re-excavation and replacement of the wetted and purnping soil. As another option, proofrolling can be accomplished by the use of a fully loaded O