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Mr Matt Woodruff, P.E. <br />October I5, 20111 <br />Page 2 oj4 <br />The condition of the existing bridge is generally consistent with the Ramsey <br />County inspection reports. The structure is load posted and has oniy about 1/3 <br />the normal capacity of a typical bridge design loading. <br />The bridge consists <br />of a concrete slab <br />span supported by <br />concrete abutments <br />on spread footings. <br />No design loading <br />is provided on the <br />plans. According to <br />the bridge inventory <br />report, the most <br />recent ioad rating <br />for the structure <br />was conducted in <br />1981 but was not <br />able to be obtained <br />at the time this <br />memo was written. <br />Kimiey-Horn did Figure 1: 8ridge 4627 <br />not perform a <br />structural analysis or rating of the existing bridge. <br />The concrete deck is covered with a bituminous overlay, which prevents direct <br />visual observation of the top of the slab. �he bottom of the concrete slab is <br />visible from below and is generally in fair condition except for a large spall at <br />mid-span on the west side of the bridge. The reinforcing bars are exposed and <br />have significant corrosion. There is also spalling around the deck tlrains. Based <br />upon field measurements compared to the plans, there may be up to 8-inches of <br />bituminous overlay on the structure. <br />The abuhnents are cast-in-place and supported by spread footings. The <br />abutments are in fair condition, with minor surface spalling or cracking. The <br />wingwalls extend at a 45-degree angle from the front face of the abutments and <br />on the shared spread footing ihat extends to the ends of these walls. The <br />wingwalls also have minor spalling and degradation. <br />Evaluation of the Existing Structure <br />The existing bridge has 84 years of service and is showing its age. While leaving <br />the bridge does provide a less expensive project and would not require changes to <br />the flood insurance maps, we contend the disadvantages of leaving the bridge in <br />place outweigh these considerations. <br />The bridge is load posted, meaning that it does not have the capacity to support <br />normal roadway loads. For the structure to remain in service, it will require <br />continued load posting since strengthening of the structure is not feasible. The <br />