Integrated effects of combined manhole and sewer pipe countermeasures in liquefied ground using dynamic centrifuge model tests
Integrated effects of combined manhole and sewer pipe countermeasures in liquefied ground using dynamic centrifuge model tests
This study addresses the challenge of manhole and sewer pipe uplift caused by ground liquefaction during earthquakes, which is a critical issue for urban infrastructure resilience. The research aims to evaluate the integrated effectiveness of three seismic countermeasures: the Seismic Retrofitting Joint Manhole (SRM), which enhances flexibility at manhole-pipe connections; the floatless manhole method, which reduces excess pore water pressure using dissipation valves; and the lining pipe method, which internally reinforces aging pipes. Dynamic centrifuge model tests were conducted with various combinations of these methods. Results demonstrated that the floatless manhole method significantly suppressed manhole uplift, while the lining pipe method effectively suppressed pipe joint bending. The SRM method allowed flexible movement at connections, further contributed to uplift suppression. When all three measures were combined, both vertical displacement and bending strain were minimized, confirming their synergistic benefits. These findings provide practical insights for engineers and urban planners to enhance the seismic resilience of sewer systems in liquefaction-prone areas.
Sreng Sokkheang SUZUKI
11th International Conference on Physical Modelling in Geotechnics (ICPMG2026)
Special Session 11: Underground Structures in Liquefiable Ground
https://doi.org/10.53243/ICPMG2026-199