A STUDY OF THE LONG-TERM APPLICATIONS
OF VINYL SHEET PILES
PIYUSH K. DUTTA AND UDAY VAIDYA
1
INTRODUCTION
Many field engineers in the U.S. Army Corps of Engineers have found that replacing heavy
steel sheet piling by lightweight PVC or FRP composite sheet piling can reduce the installation
cost by 3050% per job. This is a significant saving, considering that many millions of dollars are
spent by Corps Districts each year in installing new sheet piles and replacing old corroded steel
sheet piles. However, concerns have been raised recently in Engineering and Construction
Bulletin (ECB) No. 2002-31 (CECW-EWS 28 October 2002) about the integrity, durability,
impact damage, construction standards, and allowable design of commercially available PVC
sheet piles.
This report, written for the Corps of Engineers, summarizes the results of a brief investigation
of the long-term application of vinyl sheet piles to address some of the concerns raised in a recent
Engineering and Construction Bulletin about the integrity, durability, impact damage,
construction standards, and allowable design of commercially available PVC sheet piles. The data
used in this investigation were available from existing literature, technical organizational
databases, (e.g. the Vinyl Institute), manufacturers' input, input from the technical experts on
vinyl, and a few limited laboratory tests. The comments apply primarily to generic PVC and not
to the specific PVC material of any manufacturer. The performance of an individual
manufacturer's PVC sheet pile may vary from what has been generally reported here.
We observed that while material degradation generally may not be a factor in long-term
performance, the selection of sheet pile design and installation must consider the impact of the
low modulus of elasticity. We did not consider design issues in this short study, as it was outside
the scope. But we note that because of the visco-elastic nature of the PVC, degradation of the
modulus occurs over time; as a result, excessive deformation may occur over the long term under
a given load without any failure. Such excessive deformation may be unacceptable, and this
progressive deformation under load must be taken into consideration at the material selection and
design stage. Manufacturers of PVC sheet pile must have the creep modulus degradation data
available to allow appropriate selection and design. With a predictable creep modulus with time
and a known load, the deformation can be calculated over the lifetime of the sheet pile. A
criterion based on the maximum allowable deflection rather than the maximum allowable stress
should be considered for using such visco-elastic plastic materials.
Section 2 of this report gives a general background of PVC as a material as used in
manufacturing sheet piles. Section 3 discusses several examples of applications to prepare the