Original ResearchExperimental study on blocking and self-cleaning behaviors of beam dam in debris flow hazard mitigation
Introduction
Debris flows are geomorphic processes or violent natural disasters of multiphase movement due to gravity in mountainous areas (Fei and Shu, 2004, Iverson, 1997). Check dams, which are one of the most effective counter measures for debris flow hazard mitigation, can be distinguished as closed-type and open-type. The former is commonly used to stabilize the gully bed and bank slopes, whereas the latter is mainly used to trap and regulate sediment of debris flows (Fei and Shu, 2004, Li, 1997). Some open-type check dams, such as beam dams (Chen et al., 2006, Cui, 2005, Cui et al., 2007), slot-check dam (Chen et al., 2014, Zou et al., 2014, Zou and Chen, 2015) have performed well in Wenchuan earthquake area and scenic spots. There have also been successful precedents in debris flows mitigation along railways ( Fei & Shu, 2004; Li, 1997; Shen & Wang, 1996). At present some linear projects still pass through areas where mountainous hazards frequently occur: e.g., there are thousands debris flow gullies along the Sichuan-Tibet Highway (Zhao, 1993). Further, the Sichuan-Tibet railway project which is under construction, also facing with increasingly serious issues of mountainous hazards. Thus, open-type check dams will frequently be applied in these areas. To meet design requirements, some qualitative and quantitative experimental and numerical research (Itoh et al., 2013, Lin et al., 2011, Michele and Arrmanini, 2000, Mizuno et al., 2001, Takahashi et al., 2010, Watanbe et al., 1980, Zou and Chen, 2015) have been done for various open-type check dams. Additionally, D'Agostino et al. (2000), Wu and Chang (2002), Nakatani et al., 2007, Nakatani et al., 2008, Maricar and Hashimoto (2014), and Schwindt et al. (2015) did a series of researches which focused on other aspects of a check dam, such as the trapping of driftwood with an open-type check dam.
A blockade forms when trapping debris flow with an open-type check dam. The blockade forms in opening of the check dam due to the deposition large gravel particles in the debris flow, and the subsequently transported sediment deposits upstream. Self-cleaning is a phenomenon in which sediment deposited upstream of a check dam is eroded by perennial flow or post-debris-flow floods whereby storage capacity is recovered automatically. A considerable number of studies have been done to investigate blocking behavior at open-type check dams using experimental, numerical and mathematical methods (Han, 2007, Maricar, 2012, Michele et al., 2005, Mizuyama et al., 1995, Satofuka and Mizuyama, 2006, Shibuya et al., 2012, Takahashi et al., 2001, You, 2001, Zhao, 2013), however, few studies have paid attention to self-cleaning (Piton and Recking, 2015, Shrestha et al., 2008, Wu and Chang, 2002).
To demonstrate the blocking and self-cleaning behaviors of beam dams, an experimental study was done at the Key Laboratory of Mountain Hazards and Earth Surface Process (KLMHESP), Chinese Academy of Sciences (CAS). According to the available research methods, the characteristics of blocking and self-cleaning of beam dams were analyzed, including the critical blocking criterion and the self-cleaning performance for different blocking-types under erosion from post-debris-flow floods (PDFF). These experimental results may provide a technological basis for an optimal design of a beam dam so that it will provide a better service for disaster prevention and mitigation.
Section snippets
Test setup
A series of flume experiments were done in KLMHESP, CAS, to investigate blocking and self-cleaning behaviors of beam dams. The experimental setup consists of a hopper (60 cm × 60 cm × 80 cm), a rectangular channel (400 cm × 30 cm × 40 cm, with an adjustable gradient of 0–36%), a beam dam model, and a tail water pool. A beam dam made of wood and steel was placed 1 m from the end of the rectangular channel. Fig. 1 is a schematic sketch of the experimental facility. Both sides of the flume were
Blocking and self-cleaning process
Fig. 3, Fig. 4 show the blocking and self-cleaning process in the flume experiments at different times. As the sluice of the hopper was opened, the debris surged into the flume rapidly. When debris flow passed through beam dam, it was blocked gradually by large boulders in the debris flow from the bottom up. Subsequently transported sediment deposited upstream of the beam dam. The velocity and discharge of the debris flow were reduced dramatically. After the debris flow passed the blockade was
Discussion and suggestions about the optimal design of a beam dam
Owing to its simple structure, material savings and little effect on the environment (Cui et al., 2005, Cui et al., 2007, Shen and Wang, 1996), beam dams have good potential in term of debris flow hazard mitigation in Wenchuan Earthquake area; for protection of railways, highways and pipelines; and in scenic areas. The opening of a beam dam is blocked by one or more large boulders in a debris flow, and the subsequently transported sediment deposit upstream of the beam dam. Both practical
Conclusions
In this study, an experimental investigation was done to clarify the behavior and characteristics of blocking and self-cleaning of beam dams under different conditions. The following preliminary conclusions are draw from the results and analysis of the investigation.
- (1)
A new critical criterion (F) of the blocking performance of beam dam that considers the interaction of multiple factors is proposed. The beam dam performs as total-blocking when , partial-blocking when , and
Acknowledgments
This study is supported by the National Natural Science Foundation of China (Grant no. 41772343), West Light Foundation (Class A) of the CAS, and the 135 Strategic Program of the Institute of Mountain Hazards and Environment, CAS (No. SDS-135-1701). The authors thank three anonymous reviewers and the editors for their comments.
References (45)
- et al.
Hydraulic model tests for evaluating sediment control function with a grid-type Sabo dam in mountainous torrents
International Journal of Sediment Research
(2013) - et al.
Study on debris flow control – hydraulic function of grid type open dam
Annuals of Disaster Prevention Research Institute, Kyoto University
(1980) - et al.
Civil engineering techniques for debris flow control in national parks
The Chinese Journal of Geological Hazard and Control
(2006) - et al.
Engineering measures for debris flow hazard mitigation in the Wenchuan earthquake area
Engineering Geology
(2014) Debris flow study and prevention in national park
(2005)- et al.
Techniques of debris flow prevention in national parks
Earth Science Frontiers
(2007) - et al.
Research and prevention of debris flow in national parks
(2005) - et al.
Experimental investigation on open check dams for coarse woody debris control
Quaderni di Idronomia Montana
(2000) - et al.
Debris flow kinematic mechanism and disaster prevention
(2004) - Fukawa, G., Katsuki, S., Ishikawa N., & Yamada, T. (2002). Simulation and stochastic evaluation of open type steel...
Fundamental study on intercepting sediment capability of silt dam in preventing debris flow (Ph.D. dissertation)
The physics of debris flows
Rev Geophysics
Study on effect of variance of rock diameter on capturing probability for Grid check dam
Kozo Kogaku Ronbunshu A
Theory and practice of debris flow disaster mitigation
Design of slit dams for controlling stony debris flows
International Journal of Sediment Research
Retaining function of open-type sabo dams
Debris flow control by open type check dam (Ph.D. dissertation)
Case study: Efficiency of slit-check dams in the mountain region of versilia basin
Journal of Hydraulic Engineering
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