Deeds Point & Triangle Park Sanitary Sewer Siphon Improvements

Overview

Ribway was selected as the prime consultant to provide professional engineering services for the rehabilitation of two sanitary siphons crossing the Great Miami River in Dayton, Ohio. Constructed in the late 1940s, these siphons were deteriorating and required comprehensive rehabilitation.

Project Scope

The project involved the following key elements:

• Siphon Crossings:
  • Deeds Point: Three 480-linear-foot (lf) cast iron pipe barrels (two 30″ and one 36″ diameter).
  • Triangle Park: Two 400-linear-foot cast iron pipe barrels (30″ and 36″ diameter).
• Flow Control Chambers: Buried upstream and downstream concrete chambers associated with the siphons.

Engineering Services

Ribway’s responsibilities included:

1. Field Investigations:
   • Condition assessment of the concrete siphon chambers.
   • Sonar investigations of siphon barrels.
   • Field surveys and geotechnical investigations.
2. Hydraulic Analyses:
   • Evaluation of existing siphon crossings.
   • Determination of bypass pumping flow requirements (10.5 MGD at Triangle Park and 14.8 MGD at Deeds Point).
   • Analysis of river flood elevations.
3. Rehabilitation Design:
   • Evaluation of rehabilitation alternatives for the siphons and concrete materials.
   • Plans for sedimentation and erosion control.
   • Replacement of top slabs of all four siphon chambers with cast-in-place construction.
   • Rehabilitation of interior concrete surfaces, including removal of stop plate guides, manhole steps, and abandonment of clean-out chambers.
   • New access openings with sealed covers in the slabs.
   • Cleaning, CCTV inspections, and CIPP lining of siphon barrels with a pre-liner applied prior to final lining.
4. Contingency Items:
   • Mechanical and CIPP pipe repair sleeves.
   • Cementitious chemical grouting of structures.

Design Coordination

The siphons are located within the 100-year floodplain of the Great Miami River. Ribway coordinated with the Miami Conservancy District to minimize disruption to recreational paths and flood control embankments during construction.

Timeline

• Design Completion: May 2015.
• Construction Completion: January 2016.

Results

The rehabilitation restored the structural integrity of the siphons, improved operational reliability, and minimized environmental and recreational disruptions in the area.