The outstanding performance of unplasticized polyvinyl chloride (UPVC) has led to its widespread use in urban underground pipeline systems. However, understanding the effects of high-temperature industrial wastewater on the buried pipes is very complicated. To investigate the influence of industrial wastewater on the safety of pipes, the mechanical properties were tested using the material specimens. The changes in mechanical properties caused by the environmental temperature and heat cycles were experimentally analyzed. Empirical formulas to predict the mechanical parameters of UPVC pipe material were proposed. The ultimate strength of underground urban pipes was numerically studied by the parametric analysis. Results show that the maximum stress and ductility of UPVC pipe material decrease significantly as the ambient temperature and heat cycle increase. The ultimate strength of the underground pipe decreases exponentially with the increase in the ambient temperature. Both the temperature amplitude and the number of heat cycles have significant influences on the performance of the underground pipes.
Chen et al. (Thu,) studied this question.