Using the results of two full-scale tests on a sprayed liner system previously reported, a procedure has been developed to design sprayed cementitious liners considering circumferential bending moments leading to cracking along the crown. The design procedure is presented, considering the contribution of the deteriorated corrugated steel pipe to the liner-host pipe-soil composite, as well as the influence of semi-rigid response where moments are reduced below those that develop in rigid pipes. Comparisons are made to simpler versions of the design procedure that neglect the old corrugated steel pipe, as well as the cracking loads reported from the laboratory tests. The experimental evidence indicates that the modified theory provides design estimates that are much closer to the observed strength, and could be used to provide more realistic and economical choices of liner thickness for those cases where corrugated steel pipe corrosion is arrested by the installation of the cementitious liner.
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