Geotechnical Investigation <br />Capital Hill PUD <br />Eugene, Oregon <br />Based on our field observations, subsurface explorations, and data analyses, we conclude that the site is geologic and <br />geotechnically suitable for the proposed development provided that the recommendations of this report are incorporated <br />into the design and construction of the project. The primary challenge will be establishing and maintaining stable slope <br />conditions for access roads and building pads constructed outside of the Capital Drive/loop area (steeper lots) through <br />proper construction practices and drainage considerations. Following our initial site reconnaissance and our geologic <br />reconnaissance of the site a line delineating an area of the site labeled "Area of recommended exclusion for proposed <br />construction of public roadways and zone of special consideration for the design and construction of residential <br />foundations" is shown on Figure-1 and reflects our observations of the steep topography present on the and the site <br />irregularities described in Section 3.3. <br />Items for consideration in project design and construction are: <br />• Proper construction of cut and fill slopes as described below in coordination with review of plans and <br />observation of site conditions during construction by the geotechnical engineer of record or designated <br />representative(s). <br />• Prior to construction of roadways, driveways, or residential foundations within the area delineated on Figure- <br />1 as "Area of recommended exclusion for proposed construction of public or private streets and zone of special <br />consideration for the design and construction of residential foundations" specific plans should be reviewed by <br />a qualified professional to ensure that the proposed work is feasible given the topographic constraints of the <br />site. <br />5.0 RECOMMENDATIONS <br />The following sections present site specific recommendations for site preparation, drainage, foundations, retaining <br />walls, and utility excavations. General material and construction specifications for the items discussed herein are <br />provided in Appendix B. <br />5.1 Site Preparation and Subgrade Requirements <br />The subsurface conditions observed in our site investigation borin4s are generally consistent; however, the borin4s only <br />represent a very small portion of the site. Should soft or unsuitable soils extend to a depth greater than that described <br />herein, or areas of distinct soil variation be discovered, this office shall be notified to perform site observation and <br />additional excavation may be required. <br />Prior to the placement of structural fill, or during the construction of permanent cut slopes soft, near surface topsoil, <br />organics, and existing vegetation shall be removed from the site or reserved for landscaping in relatively flat areas. The <br />depth to suitable subgrade is anticipated to be up to 30-inches BGS. <br />Areas of Public Street Improvements <br />As described above suitable subgrade shall be free of organics, existing vegetation, and soft, near surface topsoil. The <br />depth to suitable subgrade is expected to range from 12- to 30-inches BGS. Fill slopes and cut slopes are anticipated <br />to be required for the proposed project. Prior to placing or embanking fill material the base of the fill shall be stripped <br />of overlying material to suitable subgrade and keyways shall be constructed to properly retain fill material. We <br />recommend that all fill material be approved prior to placement by the geotechnical engineer of record. <br />Branch Engineering, Inc. <br />