Measuring and estimating the impact pressure of debris flows on bridge piers based on large-scale laboratory experiments
After the 2008 Wenchuan earthquake, mountainous areas in SW China are recognized as a region with highly active and perilous landslides and debris flows. The frequent impacts of debris flow are a major threat to bridge piers located in debris flow gullies. It is an important issue for guaranteeing the safety of railway bridges in areas prone to hazardous debris flows. Previous research has achieved significant results characterizing the initiation and mechanisms for debris flow, and their interactions with some structures. However, there has been little research on the dynamic pressure of debris flow on bridge pier caused by different debris flows. In this study, the measurement and estimation of the impact pressure and dynamic behavior of debris flows on scaled bridge piers were conducted. Nine pressure sensors were used to measure the impact pressure of debris flows. Flow velocities and flow depths were determined at the end of a flume using a high-speed camera. The results show that the impact pressure differed between different types of debris flows. The distribution of impact pressures from high-viscosity debris flows indicated three layers, with different features in individual event. In comparison, a layered structure was not observed in low-viscosity debris flows. Based on dimensional analyses, the impact pressure depended on Froude number (Fr) and Reynolds number (Re). For low-viscosity debris flows, the dimensionless impact pressures were power functions of Fr, while for high-viscosity debris flows, the dimensionless impact pressures were power functions of both Re and Fr. The impact frequencies of low-viscosity and high-viscosity debris flows showed considerable differences based on spectral analysis. Compared to high-viscosity debris flows, low-viscosity debris flows were characterized by relatively high velocity, strong striking pressure, and high impact frequency.
KeywordsDebris flows Bridge pier Impact pressure Laboratory experiments
This work was carried out in collaboration between all the authors. Dongpo Wang and Siming He defined the research theme. Dongpo Wang and Yang Liu designed the experiment methods. Zheng Chen, Yang Liu, and Hao Tang carried out the laboratory experiments, analyzed the data, interpreted the results, and wrote the paper. Siming He co-designed experiments, discussed analyses, interpretation, and presentation. All the authors have contributed to this work and have seen and approved this manuscript.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no competing interests.
- Hákonardóttir KM, Hogg AJ, Batey J, Woods AW (2003) Flying avalanches. Geophys Res Lett 30(23):2191. https://doi.org/10.1029/2003GL018172
- Huang HP, Yang KC, Lai SW (2007) Impact pressure of debris flow on filter dam. Momentum 9:2Google Scholar
- Hübl J, Suda J, Proske D (2009) Debris flow impact estimation steep slopes. In Proceedings of the 11th International Symposium on Water Management and Hydraulic Engineering, Ohrid, Macedonia, 1-5Google Scholar
- Lichtenhahn C (1973) Die berechnung von sperren in beton und eisenbeton. Kolloquium uber Wildbachsperren, Mitteilungen der Forstlichen Bundesanstalt Wien 102:91–127Google Scholar
- Lien HP (2003) Design of slit dams for controlling stony debris flows. Int J Sediment Res 18:74–87Google Scholar
- Mineo C (2009) Mathematical models for geophysical mass flows. University of Catania, CataniaGoogle Scholar
- Scotton P, Deganutti AM (1997) Phreatic line and dynamic impact in laboratory debris flow experiments. Debris-Flow Hazards Mitigation 1997:777–786Google Scholar
- Tang C, Asch TWJV, Chang M, Chen GQ, Zhao XH, Huang XC (2012) Catastrophic debris flows on 13 August 2010 in the Qingping area, southwestern China: the combined effects of a strong earthquake and subsequent rainstorms. Geomorphology 139:559–576. https://doi.org/10.1016/j.geomorph.2011.12.021
- Watanabe M, Ikeya H (1981) Investigation and analysis of volcanic mud flows on Mt Sakurajima, Japan. Erosion and Sediment Trans Meas 133:245–256Google Scholar