- Rehabilitation of brick-lined sewer located beneath a busy multi-lane urban roadway
- Two sweeping 90 degree bends with tight radii and cracks in the tunnel crown posed challenges
- Structural rehab was required
- Dry weather flows required by-pass pumping
Rehabilitation of this 1890 vintage, 114-in diameter circular brick sewer about 35-ft beneath a busy four-lane urban roadway was the choice of Kansas City Water Services. However, dry weather flow levels averaging 10- to 14-in required implementation of by-pass pumping to allow rehabilitation to occur. Additionally, wet weather storm surcharging, soil characteristics, slope, limited access and two sweeping 90-degree bends with tight radii, and the development of a crack in the tunnel crown were all challenges to be considered during the assessment of each technology.
Brierley Associates was retained by SAK Construction to complete an engineering design submittal for the use of Sekisui Spiral Wound Pipe Rehabilitation (SPR TM) as the means to structurally rehab the sewer. The Sekisui process uses a PVC-based material that is spirally wound into an existing pipeline. Successive wraps of the profile are locked together and the annular space between the wound profile and host pipe is grouted. The result is a strong composite pipe integrated with the existing pipeline.
The design called for the installation of a 100-in ID SPR TM 102SRW liner with steel ribs that are integrated within the profile. The primary reason behind using the 100-in. ID liner was due to internal dimensions of the brick-lined host varying from 109- to 114-in with a significant deflection at the 4 o’clock and 7 o’clock positions in the crown of the pipe and to allow for grout placement between the host and the new SPR TM liner. The dimensions were verified by SAK using laser profiling equipment taken every 4-feet. By using the SPR TM process, the cross-sectional loss still increased existing flow capacity, while also providing a fully structural 50-year solution.
Although summer wet weather storm events required the evacuation of the tunnel during the performance of the work, the project was completed on time and on budget.
Photos courtesy of Benjamin Media.