Preliminary Geotechnical Engineering Report <br />Project No. 18-4986, 177 Day Island Road, Eugene, Oregon <br />NO " <br />engineering specifications. If earthwork is to be performed or fill is to be placed in wet weather or <br />under wet conditions when soil moisture content is difficult to control, the following <br />recommendations should be incorporated into the contract specifications. <br />• Earthwork should be performed in small areas to minimize exposure to wet weather. <br />Excavation or the removal of unsuitable soils should be followed promptly by the placement <br />and compaction of clean engineered fill. The size and type of construction equipment used <br />may have to be limited to prevent soil disturbance. Under some circumstances, it may be <br />necessary to excavate soils with a backhoe to minimize subgrade disturbance caused by <br />equipment traffic; <br />• The ground surface within the construction area should be graded to promote run-off of <br />surface water and to prevent the ponding of water; <br />• Material used as engineered fill should consist of clean, granular soil containing less than 5 <br />percent passing the No. 200 sieve. The fines should be non-plastic. Alternatively, cement <br />treatment of on-site soils may be performed to facilitate wet weather placement; <br />• The ground surface within the construction area should be sealed by a smooth drum <br />vibratory roller, or equivalent, and under no circumstances should be left uncompacted and <br />exposed to moisture. Soils which become too wet for compaction should be removed and <br />replaced with clean granular materials; <br />• Excavation and placement of fill should be observed by the geotechnical engineer to verify <br />that all unsuitable materials are removed, and suitable compaction and site drainage is <br />achieved; and <br />• Geotextile silt fences, straw wattles, and fiber rolls should be strategically located to control <br />erosion. <br />If cement or lime treatment is used to facilitate wet weather construction, GeoPacific should be <br />contacted to provide additional recommendations and field monitoring. <br />Preliminary Recommendations for Structural Foundations <br />At the time of this report, specific structural loadings have not been developed. GeoPacific is not <br />aware of what structures may be proposed on the site. This report is considered preliminary, <br />pending GeoPacific's review of the project plans, when available. <br />Based on the results of our exploration program, native soils are generally anticipated to be <br />encountered within 30 inches of the ground surface. However, loose sand was encountered to a <br />depth of 5 feet in borings B-1 and B-2. As discussed in the section of this report titled Site <br />Preparation, we recommend that this layer of loose sand be removed from the influence zones of <br />proposed structures and other settlement-sensitive improvements. As described in the Site <br />Preparation section of this report, the removal of undocumented fill soils should extend horizontally <br />to include the influence zone of the proposed structure, extending at a 1 H:1V line from the edge of <br />the perimeter footing. The native soils underneath the layer of loose sand are generally medium <br />dense to very dense or stiff to hard and should provide adequate support of the structural loads. <br />18-4986, 177 Day Island Road GRPT 8 GEOPACIFIC ENGINEERING, INC. <br />Version 1, August 27, 2018 <br />