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UDC 621.644.2

Orlov V. А., Averkeyev I. A., Khrenov K. E.

Modeling strength properties of inner pipe protective linings

Summary

Lately polymeric spray applied protective linings have been widely used for rehabilitation of old water supply pipelines. Investigations of physical and mechanical properties of Scotchkote™ 169HB polymeric lining spray applied on the inner surface of old water pipes were carried out. In the process of experimental studies Instron 3345 electromechanical tensile testing machine and Ansys software package of finite element analysis were used. In the process of testing a stress model of two-layer pipe structure based on steel pipeline and polymeric lining the following results were drawn: maximum tensile strength of lining 14.95 MPa; flexural yield stress 13.92 MPa; maximum breaking extension 25.57 mm (~ 13%). The strength properties of a steel pipeline with perforation damage were investigated in the process of trenchless rehabilitation with the use of Scotchkote™ 169HB inner lining within the operation range of 0–50 years at 20 °С. With hole diameter enlargement over time to 20 mm the system strength criterion has the value more than 1; herewith the two-layer structure will be age-resistant while providing for the required strength properties for 50 year operation. If the hole diameter is more than 20 mm the strength criterion values less than 1 will be observed which does not ensure the required strength properties of the two-layer pipe structure. The relationships for calculating pipeline strength after the lining application as well as the model itself constructed in the system of Ansys finite element analysis are suggested. This will provide for predicting the behavior of «pipe + Scotchkote™ 169HB protective lining» two-layer structure for various pipeline opera­ting conditions.

Key words

pipeline , trenchless renovation , polymeric lining , physical-mechanical property , computer modeling