scholarly journals Investigation on the Positioning of Open-type Debris Flow Check Dam considering Hydraulic Parameters

2018 ◽  
Vol 18 (5) ◽  
pp. 97-103
Author(s):  
Byonghee Jun ◽  
Kyewon Jun
Keyword(s):  
Debris Flow ◽  
Hydraulic Parameters ◽  
Check Dam ◽  
Open Type

scholarly journals Analysis of Debris Flow Reduction Effect of Check Dam Types considering the Mountain Stream Shape: A Case Study of 2016 Debris Flow Hazard in Ulleung-do Island, South Korea

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Man-Il Kim ◽  
Namgyun Kim
Keyword(s):  
South Korea ◽  
Debris Flow ◽  
Observation Point ◽  
Mountain Stream ◽  
Check Dam ◽  
Open Type ◽  
Flow Reduction ◽  
Check Dams ◽  
Closed Type ◽  
Type Check

Ulleung-do is a volcanic island located 130 km east of the Gangwon-do province of South Korea. It is characterized by steep slopes covered with effusive rocks released from multiple volcanic activities. Having accumulated deep colluvium, Ulleung-do Island manifests a high vulnerability to landslides frequently caused by heavy rains or typhoons, debris flow, rockfall, and other disaster hazards in mountainous areas. Therefore, facilities and residential areas located in the lower areas of the island sustain widespread damage. Hence, the installation of check dams designed to reflect the area’s local conditions is required to avoid further damage. In line with that, this study analyzes the disaster cases in Ulleung-do’s mountain areas and the effect of check dams in debris flow reduction for each type using the KANAKO-2D model. At observation point 1, the result shows that the maximum rate of debris flow is reduced by 48.5% with an open-type check dam installed and 62.9% with a closed-type check dam installed from the level without a check dam. For observation point 2, the maximum flow depth decreases by 49.7% with an open-type check dam and 77.4% with a closed-type check dam. Thus, this study suggests that the simple installation of check dams in a mountain stream that has experienced debris flow effectively mitigates damage brought by various disasters.

scholarly journals Method to evaluate the effect of inclination angle of steel open-type check dam on debris flow impact load

2018 ◽  
Vol 10 (1) ◽  
pp. 95-115 ◽  
Author(s):  
Toshiyuki Horiguchi ◽  
Yoshiharu Komatsu
Keyword(s):  
Debris Flow ◽  
Natural Disasters ◽  
Inclination Angle ◽  
Impact Load ◽  
Time History ◽  
Check Dam ◽  
Open Type ◽  
Inclination Angles ◽  
The Impact ◽  
Type Check

Although the latest statistics indicate a decrease in the number of victims of natural disasters in Japan, the number of sediment disasters has increased. A countermeasure against natural disasters is provided by the installation of a steel open-type check dam (hereafter, open Sabo dam). The open Sabo dam is expected to capture boulders (more than 1.0 m in diameter) contained in debris flow of which boulders concentrate in front part. When a debris flow impacts an open Sabo dam, the large impact load on the steel pipes are caused by the impact of boulders under debris flow. Therefore, it is important to evaluate the impact of both boulders and the following soil and small gravels including fluid force of the open Sabo dam from the design point of view. Although an open Sabo dam has various shapes especially, the every open Sabo dams is evaluated by the same design method in Japan. It is necessary to propose the load evaluation method in the experiment scale in contrast with different shape of open Sabo dam. This article presents an experimental approach to determine the effect of the front inclination angle of steel open Sabo dams on the impact load. The debris flow impacts 1/40 scale models of steel open Sabo dams which are set in a flow channel flume, and the debris flow load is measured by using three load cells placed horizontally at the back of the Sabo dam model. Different front inclination angles are set for each Sabo dam models. The time history of the impact load is examined by comparing the loads corresponding to four kinds of dams, which are different from the front inclination angles, and decrease of impact load considering the buffering effect of driftwoods in debris flow.

Quantitative investigation of sediment regulation performance of slot-check dam on viscous debris flow

2021 ◽  
Vol 14 (14) ◽  
Author(s):  
Jinfeng Liu ◽  
Huaquan Yang ◽  
Wenbing Zhou ◽  
Yong You ◽  
Hao Sun ◽  
...  
Keyword(s):  
Debris Flow ◽  
Check Dam ◽  
Quantitative Investigation ◽  
Viscous Debris Flow

scholarly journals Prevention and Mitigation of Debris Flow Hazards by Using Steel Open-Type Sabo Dams

2016 ◽  
Vol 9 (3) ◽  
pp. 135-144 ◽  
Author(s):  
Joji SHIMA ◽  
Hiroshi MORIYAMA ◽  
Hiroshi KOKURYO ◽  
Nobutaka ISHIKAWA ◽  
Takahisa MIZUYAMA
Keyword(s):  
Debris Flow ◽  
Open Type

scholarly journals Effects of Y-type spillway lateral contraction ratios on debris flow patterns and scour features behind a check dam

2016 ◽  
Author(s):  
Huayong Chen ◽  
Jinfeng Liu ◽  
Wanyu Zhao
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Flow Patterns ◽  
Check Dam ◽  
Mountainous Areas ◽  
Dimensionless Analysis ◽  
Lateral Contraction ◽  
Contraction Ratio ◽  
New Type ◽  
Good Agreement

Abstract. Debris flows often cause devastating damage to property and can injure or kill residents in mountainous areas. The construction of check dams in debris flow valleys is considered a useful strategy for mitigating the damages downstream. In this paper, a new type of spillway structure with lateral contraction was proposed to distribute debris flows after the check dam storage filled up. Four different lateral contraction ratios of the spillway were considered in experiments that investigated debris flow patterns, scour characteristics, and energy dissipation rates when debris flows passed through the spillway. The results indicated that lateral contraction considerably influenced the extension of debris flow nappes. The drop length of the nappe at η = 0.7 (η means lateral contraction ratio) was approximately 1.4 times larger than at η = 0.4. The collision, friction, and mixing forces between the debris flow nappes and debris flows in downstream plunge pools dissipated much of the debris flow kinetic energy, ranging from 42.03 % to 78.08 % at different contraction ratios. Additionally, based on a dimensionless analysis, an empirical model was proposed to predict the maximum scour depth behind the check dam. It indicated that the results calculated by the model exhibited good agreement with the experimental results.

Evaluation and Governance Design of Risk Factor of Debris Flow on Gunmaling

2011 ◽  
Vol 90-93 ◽  
pp. 3151-3154
Author(s):  
Lei Nie ◽  
Li Na Xu ◽  
Yan Xin Yu
Keyword(s):  
Debris Flow ◽  
Correlation Method ◽  
Mature Stage ◽  
Check Dam ◽  
Effect Measure ◽  
Gray Correlation ◽  
Medium Risk ◽  
Reduce Risk ◽  
Total Capacity ◽  
Set Up

Abstract: It is analyzed and obtained the result that the debris flow is currently in mature stage with medium risk and high occurrence through the gray correlation method of fractal research and effect measure of debris flow gully. Therefore, it is necessary to take corresponding governance measures. In this article, check dam is used as main preventive engineering measures to set up two check dams in the passing area of debris flow, with total capacity about 2800m3 and design reservoir capacity of flood once per 50 years. Construction of the check dam will effectively reduce risk of debris flow.

Sediment-trapping effectiveness of check dams with multiple debris-flow surges: Experimental study

2021 ◽  
Author(s):  
Jiangang Chen ◽  
Xi'an Wang ◽  
Huayong Chen
Keyword(s):  
Debris Flow ◽  
Field Investigation ◽  
Sediment Deposition ◽  
Disaster Mitigation ◽  
Check Dam ◽  
Sediment Trapping ◽  
Check Dams ◽  
The Relationship ◽  
Debris Flow Hazard ◽  
Deposition Morphology

<p>A series of check dams were constructed for debris-flow hazard mitigation in China. Based on the results of field investigation, check dam has a significant impact on the geomorphology of debris flow gully, especially the upstream and downstream of a check dam. According to the relationship between the sediment deposition thickness and the check dam height, the running status of a check dam can be divided into three states: without sediment deposition, half of the storage capacity with sediment deposition, and full of sediment deposition. With the accumulation of sediment transport, the running state of a check dam gradually changed and the sediment-trapping effect of check dams has gradually weakened, leading to the loss of part of the disaster mitigation effect, increasing the risk of downstream infrastructure and human security. Therefore, experiments with multi-surges of debris flows were carried out to study the geomorphic and sediment-trapping effectiveness of check dams. The results showed that with the increase of the sediment amount with multi-surges, the deposition slope in the downstream dam approached or even exceeded that of upstream dam. For one surge, deposition morphology has slightly difference in the cascade dams. At last, a method for calculating the reduction coefficient of deposition slope considering the check dam height and sediment amount with multi-surges is proposed.</p>

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