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Gary. Rayor, P.E. December 6, 2004 <br /> OBEC Consulting Engineers <br /> 920 Country Club Road, Suite 100B <br /> Eugene, Oregon 97401 Q <br /> o <br /> Amazon Park Pedestrian Bridge Proposal 041200 <br /> Proposal for Geotechnical Services <br /> Eugene, Oregon <br /> Dear Mr. Rayor: <br /> Please consider this letter as our proposa{ to provide the requested geotechnical <br /> services for the proposed Amazon Park Pedestrian Bridge in Eugene, Oregon. Details <br /> of our proposed scope of work, estimated costs and schedule are summarized below. <br /> BACKGROUND <br /> The City of Eugene plans to build a pedestrian bridge in Amazon Park crossing <br /> Amazon Creek. The bridge will connect the bark mulch-surfaced path west of the <br /> creek to a concrete-paved path east of the creek. The bridge will be a 5-span, wood <br /> structure with relatively short (3 to 18-foot) spans. Driven pile foundations are <br /> anticipated to support the new bridge. <br /> PROPOSED SCOPE OF WORK <br /> Subsurface /nvesti4ation. We propose to drill one exploratory borehole on the west <br /> side of the crossing using struck-mounted drill rig. It is assumed that the drill rig will <br /> access the site from the south along the bark mulch-surfaced path. It should be <br /> understood that the proposed equipment will likely result in some rutting and surface <br /> disturbance. We wi{I attempt to minimize the disturbance, but have not included <br /> costs for restoration of the site. Therefore, we have assumed that, if required, this <br /> work would be conducted by others. <br /> Based on our previous explorations at the Roosevelt Middle School, located northeast <br /> of the site, we anticipate the subsurface conditions will include medium to high <br /> plasticity clay underlain by highly weathered sandstone within f20 feet of the ground <br /> surface. <br /> We have assumed that the borehole wilt extend to a maximum depth of ~i0 feet. <br /> However, the actual depth may be adjusted in the field depending on the subsurface <br /> conditions. We anticipate sampling at 2 %rfoot intervals to a depth of about t15 feet - <br /> and at 5-foot intervals thereafter. Disturbed soil samples will be taken with asplit- <br /> spoon as part of the Standard Penetration Test (SPT). Undisturbed specimens may <br /> <br /> be obtained with thin-walled Shelby tubes. No coring is planned. The samples wilt <br /> <br />