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Home My WebLink About3557; Carlsbad Blvd Las Encinas Creek & Bridge; Carlsbad Blvd Las Encinas Creek & Bridge; 2009-01-08Bridge Inspection Report For City of Carlsbad Picture taken on 12/15/2008 Jack L. Abcarius Nolte Associates, Inc. 1/8/2009 January 12, 2009 Mr. John Cahill City ofCarlsbad Department of Public Works Municipal Projects Manager 1635 Faraday Avenue Carlsbad, CA 92008 SUBJECT: VISUAL INSPECTION of 4) Carlsbad Boulevard Bridge over Las Encinas Creek Bridge No. 57C-0214 City of Carlsbad, California Mr. Cahill: In accordance with our recent Agreement, Nolte performed the first visual inspection of the subject bridge. Although the actual inspection took place on January 6, 2009, we took it upon ourselves to check the site during the recent storms as indicated with our cover photo. Our observations and comments follow. Figure 1 Overview The bridge is located in the City of Carlsbad within San Diego County, Califomia. It crosses Las Encinas Creek carrying southbound traffic along Carlsbad Boulevard approximately 0.6 miles south of Palomar Airport Road, and approximately 1 mile north of Poinsettia Lane. Nolte Associates has recently been contracted to perform regular inspections at three months intervals to monitor the deteriorating condition of the structure. The original inspection and subsequent report for this bridge was performed by Nolte Associates on August 31, 2005. Structure Description: The structure consists of 12 cast-in-place conventionally reinforced concrete T-beam girders simply supported by reinforced concrete closed end cantilever abutments on spread footings. The structure is approximately 24' long and 68' wide. The deck surface carries two lanes of traffic with shoulders. The Bridge Railing consists of the old concrete baluster type. Current Condition of Structure: Concrete Railing - West Side Being closest to the ocean side, this railing showed the most deterioration due to exposure to corrosive environment during our 2005 inspection, and it has weathered even further since then. Several of the vertical members have large chunks of concrete missing that has exposed corroded reinforcement, and there has been additional spalling at several locations since the initial inspection. The abutment wingwalls have also lost a large amount of concrete due to spalling which has exposed corroding reinforcement. West Barrier During Inspection in 2005 West Barrier During Inspection on 1/6/09 Incipient Spall Fallen Piece West Barrier During 2005 Inspection West Barrier During Inspection on 1/6/09 West Barrier During 2005 Inspection West Barrier During Inspection on 1/6/09 Northwest Abutment During 2005 Inspection Northwest Abutment During Inspection on 1/6/09 Concrete Railing - East Side During the original inspection in 2005, the Eastem Barrier was in a relatively pristine condition when compared to the barrier along the Westem edge ofthe Bridge. However, during our current inspection, we found that this railing had sustained some noticeable damage along the top of the rail and at a few of the vertical posts. Some of this damage appears to be the result of vandalism as some reinforcement has been pulled and distorted from its original position in the rail, but the spalling of the concrete can be mostly attributed to natural degradation of the structure. East Barrier During 2005 Inspection East Barrier During Inspection on 1/6/09 East Barrier During 2005 Inspection East Barrier During Inspection on 1/6/09 Girders The girders are identified in numerical order (1 thru 12) from West to East for clarity. During our 2005 inspection, all of the girders were examined very closely. Unfortunately due to a large amount of water flowing undemeath the bridge, close examination of girders 4 thm 12 was impossible during this inspection. The notes from the inspected girders are listed below: Girder # 1 ~ there is a large 5-foot long section, 6.5' from the south abutment face, where the concrete has spalled off This void was present during our 2005 inspection, but the amount of concrete that has spalled has increased slightly over the last 3 years. Girder 1 During 2005 Inspection Girder 1 During Inspection on 1/6/09 6 Girder # 2 ~ the bottom cover of this girder is almost completely gone, exposing the reinforcement 7.5' from the south abutment face all the way to the north abutment. The concrete cover on the west face has completely fallen off since the initial inspection. We took a sounding at several girder locations to determine the integrity of the concrete. The sounding resulted in a hollow sound in many locations which indicates a lack of bonding between the reinforcing steel and the concrete. Sounding was also performed on the exposed rebar in many locations and the corroding steel would flake or fall off in chunks as a result. Girder 2 During 2005 Inspection Girder 2 During Inspection on 1/6/09 Girder # 3 ~ exposed, corroding reinforcement, and evidence of concrete patchwork are still present at this girder, and there has been only slight additional deterioration since the initial inspection. Girder 3 During 2005 Inspection Girder 3 During Inspection on 1/6/09 Girder # 4 ~ the west face cover of the girder has spalled off in several more locations exposing more ofthe severely corroded reinforcing bars. Girder 4 During Original 2005 Inspection Girder 4 During Inspection on 1/6/09 Girder # 12 ~ The East face of girder 12 appears to still be in fine condition. Girder 12 and East Barrier During Inspection on 1/6/09 Deck Surface The deck surface has been overlaid with approximately 6" of new Asphalt Concrete since our original bridge inspection. Therefore, no damage was found on the deck surface, and the concrete bridge deck could not be inspected for stmctural damage. A re-alignment of traffic to the east side of the bridge has been implemented so that the bridge live loads are transmitted more heavily to the eastem bridge girders, which are in a much better condition than the westem counterparts. The roadway has also been posted for lower speeds and a smaller vehicular loading. Bridge Deck During 2005 Inspection Bridge Deck During Inspection on 1/6/09 Summary Clearly the corrosion of the reinforcing bars on this bridge has progressed significantly over the years since our initial inspection. The west side of the bridge is still the part of the stmcture that is of primary concem. Although the eastem barrier has sustained some damage since then, the eastem portion ofthe bridge appears to be in fairly good condition as compared to the west side. The 4 westem most girders were in bad condition during our 2005 inspection, and their condition has worsened noticeably in the last 3 years. Almost all of the concrete cover on these 4 girders has spalled off The corrosion of the exposed bars is significant, and an estimate that only half the tension reinforcement is effective in these girders is reasonable. Additionally, the concrete sounded hollow in many locations along these girders when sounding tests were performed. This is evidence that the concrete has lost its integrity in several locations. During fiiture inspections, we will continue to document additional degradation of the bridge to ensure that the stmctural integrity of the bridge is not compromised. At this point in time, we recommend that the City send out a crew to cut the reinforcing bar that has been intentionally bent on the top of the eastem railing to avoid potential injury to any person. Should you have any questions conceming this letter, please feel free to contact me at (858) 385- 2128. Sincerely, Nolte Associates, Inc Jfick Abcarius, P.E. ngineering Manager