Attachment_3B_-_2014_LCYA0048_UWRpt.pdf

U.S. Department of the Interior Bureau of Reclamation Lower Colorado Region Engineering Services Office Boulder City, Nevada December 2014

Inaccessible Feature Review

Underwater Inspection of Bridges along the All-American Canal

Boulder Canyon Project Lower Colorado Region

Sensitive - For Official Use Only

Mission Statements

The mission of the Department of the Interior is to protect and provide access to our Nation’s natural and cultural heritage and honor our trust responsibilities to Indian Tribes and our commitments to island communities.

The mission of the Bureau of Reclamation is to manage, develop, and protect water and related resources in an environmentally and economically sound manner in the interest of the American public.

Underwater Inspection of Bridges on the All-American Canal

Table of Contents

Page

I. Inspection Report A. Inspection Period B. Location Visited C. Purpose of Inspection D. Synopsis of Inspection E. Background F. Inspection Notes

Senator Wash Bridge-NBI Struc #0304-0044 Mission Wash Bridge-NBI Struc #0304-0052 No-Name Wash Bridge-NBI Struc #0304-0055 Picacho Wash Bridge-NBI Struc #0304-0094 Los Algodones Bridge-NBI Struc #0304-0098

G. Conclusions and Recommendations II. Photos

I. Inspection Report

A. Inspection Period

December 16 and 17, 2014

B. Location Visited

All-American Canal (AAC) in southern California near Yuma, AZ.

C. Purpose of Inspection

The purpose of the inspection was to perform an underwater inspection of bridges along the AAC. The AAC flows year-round and outages are extremely rare.

Therefore, inspections of the portions of the bridges that are underwater are not performed regularly. Additionally, a Federal Highway Administration audit recommended the bridges be removed from regular underwater inspections as the new lining limits the likelihood of scour. The bridges would still be inspected underwater when lower flows permit, i.e., the mid-December holiday season is considered an optimum time to inspect the canal.

Most of the bridges sit directly upstream of siphon or check structure, making dive inspections unsafe; therefore, a Remotely Operated Vehicle (ROV) was used to perform the inspections. Even though they are not coded for underwater inspection, it is recommended that ROV inspections be done on these bridges every five years.

D. Synopsis of Inspection

On December 16, 2014, Lower Colorado Regional Dive Team members Nathaniel Gee, James Burke, Corey Dickson and Caireen Ulepic traveled to the AAC and met up with William Hipp and Keshaw Mallick from Reclamation’s Yuma Area Office and personnel from Imperial Irrigation District (IID) to conduct the ROV inspection of several bridges that cross the AAC.

The first day’s inspection began at Senator Wash Bridge, followed by Mission Wash Bridge, Unnamed Wash Bridge, and Picacho Wash Bridge. On the 17th, the group completed the inspection with the Algodones Road Bridge. High flows in the AAC limited the extent of the ROV inspection as maneuverability was difficult; however, this review of the bridges’ condition is considered sufficient for the next five-year inspection cycle.

All bridges were in satisfactory condition and should be examined again in

FY2019.

E. Background

Constructed between 1934 and 1939, the AAC delivers Colorado River water for irrigation and domestic use to the Imperial and Coachella Valleys in southern California, and to the Yuma Project area in both California and Arizona.

Several bridges that span the AAC are open to public traffic. These structures are considered type I bridges since they are over 20 feet long and are open for public use. Several of these, including Unnamed Wash, Mission Wash and Picacho Wash Bridges, are located directly upstream of wash overchutes that allow local runoff from washes to flow over the canal. Since these bridges are directly upstream of siphons, it is unsafe to complete dive inspections on the underwater portions and therefore an ROV is used.

The canal has an original design capacity of 15,155 cfs; however, IID currently maintains a maximum flow restriction of 12,000 cfs to limit seepage loss. The canal rarely has flows below 500 cfs and it is unknown if the canal has had a full outage in recent history. The infrequency of outages and the large flows in the AAC make underwater inspection of these structures difficult.

F. Inspection Notes

Senator Wash Bridge-NBI Struc #0304-0044 The bridge is located in Imperial County, California, approximately 15.2 miles northeast of Yuma, AZ on the AAC. The bridge is a 2-way, 2-lane structure that carries traffic on the Senator Wash Road over the AAC. The 38-foot-wide bridge deck is a cast-in-place concrete slab with a curb-to-curb width of 32.5 feet, and a total structure length of 272.9 feet. The bridge deck has 4-foot-wide shoulders and a 4-foot-wide raised concrete sidewalk along the south side of the bridge. The bridge guardrail (on both sides of the bridge) consists of two steel horizontal rails supported by steel posts bolted to a concrete parapet wall. The bridge has two types of expansion joint devices at the abutment ends. An elastomeric expansion device (transflex model) is installed at the west abutment end and a steel compression joint seal device is at the east abutment end. Both extend the full width of the deck. The structure is a three span bridge with the intermediate span having a length of 103 feet and end spans of 84 feet. The superstructure consists of four continuous steel W36 x 230 girders with intermediate MC18 x 42.7 diaphragms evenly spaced through the structure length. The four steel girders are intermediately supported by two pile bents consisting of 12 precast prestressed concrete piles and cap. The steel girders are set on the pile bent caps on preformed fabric bearing pads. The abutments are the open type. On the west abutment the girders are set on preformed bearing pads (pin end), and on the east the girders are set on roller type of bearing device. The abutment structures are supported by concrete spread footings set on load bearing material. The approach roadway is paved with asphalt.

The canal is earthen lined under the bridge structure and the only portions of the bridge that are underwater are the canal bank and the pile bents. Only the left downstream pile bents were inspected as the high velocity of the water did not allow sufficient control of the ROV to inspect all sections. However, the pile bents that were inspected appeared to be in satisfactory condition; there were minor abrasion losses (Photo 1) and therefore the bridge would be rated a 6. The canal did not have any noticeable scour upstream or downstream of the pile bents inspected but did have some very minor debris buildup of mostly dead quagga mussels (Photo 2).

Mission Wash Bridge-NBI Struc #0304-0052 The bridge spans the AAC in Imperial County, California approximately 10.6 miles northeast of the city of Yuma, AZ. The bridge is considered a one-lane two-way traffic structure. The bridge connects the O&M roads on each side of the AAC and is open to traffic. The bridge deck is a concrete slab, intermediate structure supported by four pier walls and at the abutment ends, all on spread footing on load bearing material. There are four expansion joints along the 200-foot length of the bridge and the deck is 14.5 feet in width, with an 11.5-foot width curb-to-curb. The deck has 18-inch wide, 10-inch high concrete curbs at both sides of the bridge. The approach guardrails are constructed of timber. The abutments are described as stub abutments. The channel under the bridge structure is concrete lined. Adjacent to the bridge structure on the downstream side is an overchute that carries the Mission Wash over the All-American Canal.

Most of the pier walls are underwater year-round and the foundation of the pier walls is below the concrete lining. As at other bridges, the high velocity of water flow limited the ROV’s maneuverability so only limited underwater portions of the bridge could be seen; however, enough was inspected to consider this inspection complete for the next 5 years. The pier wall has some cracking that was noted (Photo 3). However, this cracking is not significant, so the pier wall would be given a 6 rating. The pier walls did have significant amount of grass debris on the upstream side (Photo 4). There is grass debris from the top all the way down to the invert of the canal. The largest portion, however, is near the surface and can be viewed from topside. The routine review should determine the need to clean off the piers. It is likely that the piers may need to be cleared of debris occasionally.

The concrete lining begins directly upstream of the bridge and ends downstream of the siphon. The ROV traveled along the lining and determined that there was minimal to no scour upstream of the concrete lining, and the contact area between the pier wall and the concrete lining showed no signs of erosion or scour.

No-Name Wash Bridge-NBI Struc #0304-0055 The bridge is located 8.3 miles northeast of the city of Yuma, Arizona in California’s Imperial County. The bridge carries traffic across the AAC from one side to the O&M service road on the other side. On the downstream side adjacent to the bridge is the No-Name Wash overchute structure that passes over the AAC.

The bridge dimensions are 200 feet in length, a deck width of 14.6 feet out-to-out, and a curb-to-curb width of 11.6 feet. The structure is a one-lane bridge carrying traffic traveling in both directions. The bridge deck is a concrete cast-in-place type supported by four pier walls throughout the length of the bridge and at both abutment ends. The abutments foundations are concrete piers. The bridge guardrails are constructed of 3-inch diameter steel pipe, with posts embedded in concrete along the curbs, and approach guardrails constructed from timber.

This bridge had conditions similar to those noted at Mission Wash Bridge. There was no cracking noted in the pier wall and the pier wall rating would be a 7 or ‘in good condition’, given the portions that were viewed. As at the other bridges, the high velocity flows restricted a full inspection, but the underwater portions of the bridge were sufficiently inspected, and will not require another inspection for five years.

The most significant issue at this location is the amount of debris buildup. Grass covered the water surface at several of the bridge spans and at the pier nose (Photo 5), and could cause significant blockage of the water below the bridge and siphon. The buildup was reduced at lower levels, and most of the pier wall down to the last two feet of the invert (Photo 6) did not have debris. A recommendation should be made during the next routine bridge inspection to remove debris if the debris has not been removed or if flows have not washed it downstream.

The contact area between the concrete lining and the pier wall were in satisfactory condition (Photo 7) with no sign of scour or erosion. The concrete was covered with algae and therefore, the condition was difficult to note. However, no defects such as large spalls were noted. The concrete lining had sediment and minor debris but no significant debris along the invert of the canal.

Picacho Wash Bridge-NBI Struc #0304-0094 This bridge has the same design as No-Name Wash Bridge. It has an overall width of 21 feet and an overall length of 206 feet, and consists of three 39.71-feet and two 36.44-feet spans. The bridge deck’s cross-section provides an 18-foot clear road, and curb/guardrail at both sides takes a 3-foot width. The superstructure section consists of a cast-in-place reinforced concrete beam monolithically connected to the concrete deck. The siphon headwall provides continuous support to the opposite side of the bridge. The beam is 24-inches wide spaced at 12-feet center-to-center, and the deck slab is 10 to 10.5 inches thick.

The bridge guardrail consists of two horizontal rails supported on evenly spaced post, all constructed of 3-inch diameter steel pipe. The steel pipe bridge guardrail posts are embedded in the bridge concrete curbs on both sides. The bridge structure carries traffic from the AAC’s O&M roads across the canal.

The findings for the Picacho Wash Bridge were similar to those for the other wash bridges that were inspected. The pier walls did not show any significant signs of deterioration. There was no noted scour or erosion at the connection point of the lined canal invert and the pier walls. There was no erosion or scour upstream of the lined portion of the canal. There was minimal debris on the canal invert with only sediment and small debris. The most significant finding was the grass debris that has built up on both the water surface and at the pier walls and at the invert of the canal at the pier walls (Photo 8).

Los Algodones Bridge-NBI Struc #0304-0098 Los Algodones Bridge across the AAC is a continuous concrete, 3-span structure with intermediate supporting pier walls. The span between each of the pier walls has a length of 20 feet for a total structure length of 140.1 feet. The deck width is

32.2 feet edge-to-edge which includes the width of the gate control deck along the west face of the bridge. The deck design is considered a slab and is a concrete cast in place type. The concrete curbs are 8-inches high and 18-inches wide along both edges of the bridge. The bridge guardrails have a top and mid rail constructed of 3-inch diameter steel pipe and are 25-inches high set on top of the concrete curbs.

The bridge guardrails’ vertical posts are embedded in the concrete curb along the edges of the bridge. The concrete deck has a bituminous overlay wear surface.

The concrete deck is intermediately supported by 6 equally spaced pier walls and at both abutment ends. On the west face of the bridge, a 7 radial gate check structure is a part of the bridge. The section of the AAC where the bridge is located is concrete lined.

The IID personnel were able to operate the radial gates at the site to reduce flows that allowed the ROV to access all the pier walls. The pier walls do not have large debris buildup as seen on other AAC bridges. There is a small amount of algae growth, but overall the pier walls look clean (Photo 9). The contact between the pier wall and the concrete lining does not show any signs of deterioration, but there is very minor honeycombing likely left from poor consolidation during construction (Photo 10).

The invert of the canal or canal lining is mostly clear of debris or sediment; there is some minor debris (Photo 11). There were small patches of what appeared to be delamination (Photo 12) in the concrete lining; however, this is minor and covered less than 1% of the lining inspected. There is also some joint material that has been pushed up out of the joint (Photo 13) which was only noted at one of the joints during the inspection. The wingwall upstream of the right abutment had significant spalling and exposed rebar above the water line; this should be examined and recommended to be fixed as part of the RO&M inspection on the AAC since it is not directly part of the bridge. The ROV examined the wall below the water line and did not note similar conditions; therefore, the concrete is considered to be in satisfactory condition.

The ROV also examined the upstream side of the check gates. They were in satisfactory condition. Several of the gates did not seal completely at the bottom when closed (Photo 14); however, this is not a significant concern at this time.

G. Conclusions and Recommendations

The overall condition of the bridges was satisfactory. The pier bents and pier walls for the bridges show only minor deterioration. No scour was noted at the pier bents, walls or along the lining of the canal.

The only significant finding was grass debris on the upstream side of the pier walls on Mission Wash, Unnamed Wash, and Picacho Wash Bridges. This may be carried away downstream, but could also cause blockage and increased force on the piers. If it has not been removed by the next routine inspection, a recommendation should be made to remove the debris.

The inspection was impaired by the high water velocity which did not allow the ROV to inspect each individual underwater feature; however, the ROV inspection offered a representative sample of the bridge elements and therefore, additional underwater inspection is not required until FY 2020. It is recommended that if there is an outage or very low flow period below 500 cfs on the AAC during the next five years that the opportunity to do a more extensive inspection of these underwater features should be completed.

II. Photos

Photo 1: Close-up view of the pier bent showing abrasion deterioration on Senator Wash Bridge.

Photo 2: Pile of dead quagga mussels on the pier of Senator Wash Bridge.

Photo 3: Crack on the left-most pier wall on Mission Wash Bridge.

Photo 4: Large amount of grass debris buildup on the upstream side of the pier wall of Mission Wash Bridge.

Photo 5: Grass near the water surface on the pier nose of No-Name Wash Bridge.

Photo 6: Debris at the bottom of a pier wall on No-Name Wash Bridge.

Photo 7: View of contact area between the pier wall and concrete lining on No- Name Wash Bridge.

Photo 8: Debris at the invert of the canal along a Picacho Wash Bridge pier wall.

Photo 9: Algae growth on the upstream side of the pier wall at Los Algodones

Photo 10: View of the contact of the pier wall and the lining of the canal along the invert of Los Algodones Bridge. No erosion or scour was evident, but there did appear to be small honeycombing likely caused by poor consolidation during construction.

Photo 11: Example of minor debris along the canal lining near Los Algodones

Photo 12: Delamination along the invert of the canal near the Los Algodones

Photo 13: Joint material that is being pushed out of the joint near the Los Algodones Bridge.

Photo 14: Seal below the Los Algodones Bridge check gate showing daylight on the other side.