Practical Approach to Predict Geyser Occurrence in Stormwater Drainage System

A large volume of entrapped air pressurized by a bore through a pipe can lead to geysering in stormwater drainage system. In this study, the dominant factors for occurrence of geyser are identified with respect to the movement of air through a realistic stromwater drainage system, not through single pipe used in other studies, by conducting relatively simplified computer modeling. The results show that there are 4 significant factors, that determine the strength of geyser, of which the effects are variable depending on other factors. Thus, results are summarized in a unified set of diagram in terms of the two significant factors using Response Surface Methodology (RSM), which represents the relationships between several explanatory variables. The diagram can suggest a way of calculating pressure force pushing upwards against a manhole cover which is useful for the hydraulic engineers to design geyser countermeasures through drainage system.