60" Cast-in-Place Concrete Pipe

1. Project Location: Residential area of Houston, Texas. Pipe actually forms a foot bridge over a small river.

2. Diameter of line, sewer pipe material (RCP, MCIP, brick, etc.), length of rehab portion: 60", Cast-in-place concrete pipe, 1106 linear feet.

3. When was it constructed and how long has it been in service: Unknown age, but severely corroded in upper 2/3 of pipe.

4. Rehab method used: Danby Panel Lok III with full annulus grouting with cementitious grout with minimum compressive strength of 5000 psi.

5. Cleaning method used (if required) and who cleaned the line: High pressure (10,000 psi) water blasting performed by the Danby licensee (Kinsel Industries, Inc.).

6. Method of flow bypass or diversion, if used: Flows 100% pumped via 3 Godwin pumps (100% over capacity) and temporary HDPE fusion welded pipe.

7. Depth of pipe: 0 -10 feet to crown.

8. Depth of ground water: No ground water above pipe invert.

9. Ventilation and odor control used: Fresh air pumped into pipe at upstream manhole, and suction fan at downstream manhole to provide adequate ventilation during the work periods.

10. Construction cost (total amount and cost per foot): $540,000 ($8.14/ID in-ft).

11. Month and year of start-up and end of construction: June 22 - July 24, 1998.

12. Problems encountered during construction: Due to construction method used in building this pipe, variations in alignments (both horizontal and vertical) and in wall thickness were severe enough so that 54" Hobas slipliner (original choice for rehab) could not be installed. The Danby liner installed was 55" ID with alignment adjustments at discrete location as required.

13. Problems encountered after construction: None.

14. Health and safety: Used conventional confined space entry program.

15. Has any re-inspection been performed? What was the condition of the pipe? No.


Mac Bakri, P.E.

City of Houston

Telephone: 713-646-5609

Project: 4250-98R (GFS #R1040-06-03)