rehabilitation methods for approximately 50,000 LF of sewers and 325
manholes in the City of Houston Southwest Wastewater Treatment Plant
Service Area. The sewers ranged in size from 6 to 48 inches in diameter.
Slip lining, pipe bursting, remove and replace and cured-in-place were the
rehabilitation methods available.
subconsultant, RBI was responsible for all of the rehab design.
The RBI design effort began with a thorough review of all available
physical inspection tests and reports, including all manhole inspection
reports and all television inspection videotapes and reports, for all
sewers in the areas proposed for rehabilitation. Also included in this
effort was the review of the hydraulic modeling results for these sewers.
As a result of this preliminary design effort a recommendation was made
and approved, that allowed for the television inspection of adjacent
mainline sections which had not been internally inspected previously and,
if found to be in poor structural condition and in need of rehabilitation,
to allow these sewers to be included in our rehabilitation design effort.
This additional and subsequent television inspection effort resulted in a
more comprehensive and thorough sewer rehabilitation effort in the
target neighborhoods to reduce and minimize future disruptions and
inconvenience to the area residents, allow for continuity of the
contractor’s work effort and provide the benefit of “economy of scale” to
the contractor and in turn savings to the City. Our rehabilitation
design was tailored to follow all City of Houston guidelines and
procedures established for sanitary sewer rehabilitation and selected
the most appropriate rehabilitation method available for the least
design engineering effort resulted in the recommendation to
rehabilitate approximately 26,000 linear feet of sewer by pipebursting,
10,000 linear feet of sewer by the cured-in-place method,
approximately 8,000 linear feet of sewer by sliplining and
approximately 2,000 linear feet of sewer by removal and
replacement. Additionally, 300 existing manholes were proposed
for rehabilitation by either removal and replacement or
wall sealing. Also included in rehabilitation design for manholes was
the installation of inflow protectors beneath the covers of manholes
located in ponding areas, cover and/or cover frame replacement and chimney
seals between the manhole corbel and cover frame.