Site work for a bridge / tunnel in Portland, Oregon. Completed plans call for site work for a bridge / tunnel.

The Tryon Creek at Boones Ferry Road Culvert Replacement involves the New Construction of a Vehicular Bridge along the following street: SW Boones Ferry Road near the intersection with SW Arnold Street. This work consists of all surveying activities necessary to control the many phases of work required to construct the Project to the lines and grades as shown, specified, or established. Make all supporting computations and field notes required for control of the work and as necessary to establish the exact position, orientation, and elevation of the work from control stations, including furnishing and setting construction stakes and marks, reference marks, and additional control stations. Plans, specifications and other data necessary to lay out the work will be available for inspection at the Project Manager's office. The project is located on SW Boones Ferry Road north of the intersection with SW Arnold Street. The existing 60-in.-diameter, approximately 140 ft-long corrugated metal pipe (CMP) culvert that carries Tryon Creek under SW Boones Ferry Road will be replaced with a single-span 125.5-ft-long by approximately 56- ft-wide steel girder bridge with concrete deck. The existing culvert has an invert about 40 ft below the roadway centerline, and the stream channel will be re-established beneath the bridge by excavating up to about 40 ft through the existing roadway embankment. The locations of the proposed improvements are shown on Figure 2. The elevation of the centerline of the roadway will remain the same, and the width of the top of the embankment will be increased to approximately 61 ft. Due to right-of-way considerations and the location of the existing creek, retaining walls with exposed wall heights up to about 12 ft will be required to support the roadway widening along both sides of the north and south approaches to the proposed bridge. The embankment fill will be graded to a maximum of 2H:1V (Horizontal to Vertical) slope below the retaining walls. The project includes a new recreational trail that extends down from the east side of the south bridge approach, crosses beneath the bridge, then extends west to Arnold Creek, where a bridge will be constructed across the creek as part of a separate project. The trail will include a flight of cast-in-place concrete stairs established on the embankment slope to the east ofthe road.