Attachment_8_-_Template_Underwater_Inspection_Plan_0001.docx

2024 San Luis Canal MP 79.23 Canyon Road Underwater Inspection Plan

Underside of bridge looking upstream.

Bridge Name: 2024 San Luis Canal MP 79.23 Canyon Road Bridge

NBI #: 39C0260

U.S. Department of the Interior December 2024

Background The structure is a four span precast prestressed concrete bridge carrying Canyon Road in Merced County, CA over the San Luis Canal. The bridge is supported by reinforced concrete abutment walls and four “I” girders on reinforced concrete pier walls. The deck is 27.6 feet wide, and the length is 308.1 feet. For this inspection, the bridge is documented from right to left looking downstream.

The San Luis Canal has a regularly scheduled one-week annual outage for the pumping plant that results in zero flows in the canal. This is the ideal time to preform these inspections. Low flow conditions in the canal still result in unacceptable flow velocity conditions at the bottom of the canal.

Inspection Staff Required

· Team Lead – Plan and lead bridge inspection. Team lead must be present at the bridge during all inspection activities.

· Dive Team Supervisor – Responsible for all underwater activities and emergency rescue procedures.

· Underwater Bridge Inspectors – Perform visual and tactile inspection of normally underwater features. Underwater bridge inspectors must have completed an FHWA-approved comprehensive bridge inspection training course or other FHWA-approved underwater bridge inspection training course.

· State of California Department of Water Resources – Maintain communication with operations.

Access Equipment Required

· Dive equipment for surface supplied dive operations.

· Fall protection equipment for access down the canal embankment to the water line.

· Down line connected to a truck is the minimum for diver to control decent with tender on the bank.

· Preferable to have a progress capture system to control decent of the diver by a rope connected to the harness. A haul system can be connected to the progress capture to assist with diver exit from the water and return to the bank.

List of Underwater Members and Details

· Left, center, and right pier from bast to highwater line (32.8 ft)

· Concrete floor and channel lining from 10 ft upstream of the upstream pier nose to 10 ft downstream of the downstream pier nose.

Inspection Levels A routine underwater bridge inspection normally includes a 100% Level I inspection and a 10% Level II inspection. It may also include additional Level II inspections and Level III inspections if necessary to determine the structural condition of the submerged substructure elements with certainty.

· Level I : Visual, tactile inspection

· Level II : Detailed inspection with partial cleaning

· Level III : Highly detailed inspection with Non-Destructive Testing (NDT) or Partially Destructive Testing (PDT) Procedure Inspection procedures will generally follow the guidelines established in the Bridge Inspection Reference Manual (BIRM).

· Diver will be prepared for dive using surface supplied air.

· Dive supervisor will notify on-site district representative the diver is ready to deploy.

· District representative will report to DWR control that diver is entering the water.

· Diver will enter canal downstream of bridge structure.

· Diver will move upstream to Span 1 inspecting channel floor, right pier.

· Diver will move to Span 2 inspecting channel floor center pier.

· Diver will move to Span 3 inspecting channel floor left pier.

· Diver will move to Span 4 inspecting channel floor.

· Diver will return to canal bank and exit canal.

· Dive supervisor will notify district representative the diver is out of the water and operations can resume.

Safety A dive hazard analysis (DHA) will be prepared by the dive team supervisor and shared with the inspection team members and facility prior to the inspection. Hazards for the inspection include but are not limited to hazards, steep slopes, entanglement, and debris.

Dive operations will be supported from the O&M Road which is closed to the public. Traffic control measures are not necessary.

Follow-up Procedures In the event of a Critical Finding, the Team Lead will follow the notification procedures outline in Reclamation’s Directive and Standard FAC 07-01. The Area Manager, Regional Bridge Program Manager (RBPM), and Bridge Program Manager (BPM) must be notified within 48 hours of discovery. Additionally, the finding will be discussed with representatives from the area office and water district prior to leaving the site.

Reference Drawings

· 805-D-1420 Canyon Road Bridge – Design No. 2 Plan – Elevation - Sections image1.png image2.JPG