Page 18 - Trenchless Technology Piping Installation and Inspection

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and specifications, submittals, quality control/quality assurance issues,
construction considerations, and safety considerations. The last sec-
tion of this chapter is devoted to pipe load calculations, to provide a
simplified approach for better understanding of forces encountered
in the field. While this chapter is mainly focused on HDPE, which is
product of choice for pipe bursting, the same concept can be applied
to other pipe materials.
Chapter 7 concentrates on Cured-in-Place Pipe (CIPP) technology,
which is the most common method for renewal of deteriorated exist-
ing pipes. The chapter covers full description of CIPP technology, and
continues with site compatibility and applications, effects of existing
pipe defects, and installation methods. Due to a large number of fac-
tors influencing quality installation of CIPP, there have been a num-
ber of issues regarding final inspection and acceptance by owners.
Therefore, this chapter provides a section on inspecting installation
of CIPP, and covers possible CIPP defects and causes, accepted
tolerances, repair types, and possible monetary penalties. While
throughout this book, partnering among owners, design and consult-
ing engineers and contractors/installers are emphasized, there might
be situations that owners may have to correct a defective CIPP instal-
lation, and contractors may offer a deduction in order for owners to
be able to accept the installation and pay the balance of payment to
the contractor. Therefore, these suggested guidelines can be used as
bases for considerations that are mutually accepted to both parties. It
should be noted that including harsh language in the bid documents
and/or unacceptable and unreasonable tolerances in the contract
and specifications will result in contractors submitting higher bids
(with more contingencies) or not submitting bids at all.
Chapter 8 is dedicated on quality assurance/quality control con-
siderations for trenchless installation and replacement methods. The
idea for this chapter came around the concept that most trenchless
installations are conducted in urban settings and “under a road,
street, or pavement.” So basically, the trenchless installation must be
safe for the general public, road embankment and the operational use.
This chapter provides suggested guidelines for the “road authority”
or the “transportation agency” to evaluate requests for trenchless
installations (such as road crossings), issue permit, and inspect the
installation. It provides simple charts and checklists for the inspec-
tors to observe compliance with the main parameters of permit, to
ensure a safe and quality installation is completed. This chapter is
written in such a way that provides a standalone presentation of
trenchless installation methods (microtunneling, horizontal direc-
tional drilling, horizontal auger boring, pipe ramming, conventional
pipe jacking, pilot-tube microtunneling, and pipe replacement) with
introduction, pipe material, and construction considerations. For
each method, it presents a simple inspection guide, which includes
preinspection plan review and construction inspection.