scholarly journals Study for Analyzing Travel Time and Runout Distance of the Debris Flow

2020 ◽  
Vol 20 (3) ◽  
pp. 51-59
Author(s):  
Sanghyun Jun ◽  
Joonsik Choi ◽  
Hyukjae Kwon ◽  
Byungsoo Park
Keyword(s):  
Debris Flow ◽  
Travel Time ◽  
Rainfall Intensity ◽  
Experimental Results ◽  
Experimental Result ◽  
Slope Length ◽  
Runout Distance ◽  
Model Experiments ◽  
Failure Initiation ◽  
Channel Slope

In this study, model experiments in laboratory were performed to analyze the behavior of debris flow that included the travel time and deposit area according to the change in topographic conditions and rainfall intensity. According to the experimental results, the travel time at failure initiation was shortened owing to the increased channel slope and rainfall intensity. Similarly, runout distance of the debris flow increased when the length of slope and thickness of the soil increased. Further, deposit area of the debris flow was increased as the channel slope, length of slope, and thickness of soil increased, and the analysis on deposit area was related to the increase in the amount of debris flow. According to the experimental result of the various topographical conditions, the deposit area was increased linearly as the travel time increased. Moreover, increase in the rainfall intensity resulted in decreased travel time and increased debris amount.

A Study of Debris Flow Behaviors According to Rheometer Properties: Focused on the Hwangnyeong Mt. and Umyeon Mt.

2020 ◽  
Author(s):  
Hyeong-Jin Kim ◽  
Dae-Ho Yun ◽  
Yun-Tae Kim
Keyword(s):  
Debris Flow ◽  
Rheological Properties ◽  
Yield Stress ◽  
Flow Behavior ◽  
Front Velocity ◽  
Experimental Results ◽  
Small Scale ◽  
Water Mixture ◽  
Runout Distance ◽  
Two Samples

<p>A debris flow, a mass movement of soil and water mixture, is generally occurred by heavy rainfall during the rainy season in Korea. Because of climate change, the amount and frequency of rainfall has continually increased these days. Populated areas located in debris flow-prone mountainous areas are commonly subject to debris flow hazards. For this reason, it is necessary to analyze the characteristics of the debris flow behavior for the hazard mitigation. In this study, for two samples from Hwangnyeong Mt. and Umyeon Mt. in Korea, the vane-type rheometer test were performed to estimate the rheological property such as viscosity and yield stress and small-scale flume experiment was carried out to evaluate the characteristics of debris flow behaviors such as front velocity, runout distance and deposition volume. From the experimental results, rheological properties decrease with decreasing volumetric sediment concentration, and debris flow behavior gradually increased with decreasing rheological properties in the experiment. Additionally, in case of Hwangnyeong Mt. which has a high silt and clay fraction, the experimental results show that the amount of the front velocity, runout distance and deposition volume tend to increase higher than Umyeon Mt. as viscosity and yield stress decreased.</p>

scholarly journals Laboratory Analysis of Debris Flow Characteristics and Berm Performance

Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2223
Author(s):  
Kukhyun Ryou ◽  
Hyungjoon Chang ◽  
Hojin Lee
Keyword(s):  
Debris Flow ◽  
Flow Velocity ◽  
Flow Characteristics ◽  
Flow Depth ◽  
Volumetric Concentration ◽  
Runout Distance ◽  
Deposition Area ◽  
Lateral Width ◽  
Channel Slope ◽  
Study Laboratory

In this study, laboratory tests were used to determine the deposition characteristics (runout distance, lateral width, and deposition area) of debris flow and their relationships with the flow characteristics (flow velocity and flow depth) according to the presence of a berm. An experimental flume 1.3 to 1.9 m long, 0.15 m wide, and 0.3 m high was employed to investigate the effects of channel slope and volumetric concentration of sediment with and without the berm. The runout distance (0.201–1.423 m), lateral width (0.045–0.519 m), and deposition area (0.008–0.519 m2) increased as the channel slope increased and as the volumetric concentration of sediment decreased. These quantities also increased with the flow velocity and flow depth. In addition, the maximum reductions in the runout distance, lateral width, and deposition area were 69.1%, 65.9%, and 93%, respectively, upon berm installation. The results of this study illustrate general debris flow characteristics according to berm installation; the reported relationship magnitudes are specific to the experimental conditions described herein. However, the results of this study contribute to the design of site-specific berms in the future by providing data describing the utility and function of berms in mitigating debris flow.

scholarly journals The Estimation of Angular Misalignments for Ultra Short Baseline Navigation Systems. Part II: Experimental Results

2013 ◽  
Vol 66 (5) ◽  
pp. 773-787 ◽  
Author(s):  
Hsin-Hung Chen
Keyword(s):  
Trial Data ◽  
Experimental Results ◽  
Experimental Result ◽  
Alignment Error ◽  
Navigation Systems ◽  
Analytical Prediction ◽  
Short Baseline ◽  
Sea Trial ◽  
Alignment Errors ◽  
Cross Track

An algorithm of alignment calibration for Ultra Short Baseline (USBL) navigation systems was presented in the companion work (Part I). In this part (Part II) of the paper, this algorithm is tested on the sea trial data collected from USBL line surveys. In particular, the solutions to two practical problems referred to as heading deviation and cross-track error in the USBL line survey are presented. A field experiment running eight line surveys was conducted to collect USBL positioning data. The numerical results for the sea trial data demonstrated that the proposed algorithm could robustly and effectively estimate the alignment errors. Comparisons of the experimental result with the analytical prediction of roll misalignment estimation in Part I is drawn, showing good agreement. The experimental results also show that an inappropriate estimation of roll alignment error will significantly degrade the quality of estimations of heading and pitch alignment errors.

scholarly journals Modelling Effects of Rainfall Patterns on Runoff Generation and Soil Erosion Processes on Slopes

Water ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2221
Author(s):  
Qihua Ran ◽  
Feng Wang ◽  
Jihui Gao
Keyword(s):  
Soil Erosion ◽  
Rainfall Intensity ◽  
Temporal Patterns ◽  
Runoff Generation ◽  
Slope Length ◽  
Erosion Processes ◽  
Total Runoff ◽  
Wide Range ◽  
Critical Slope ◽  
Rainfall Patterns

Rainfall patterns and landform characteristics are controlling factors in runoff and soil erosion processes. At a hillslope scale, there is still a lack of understanding of how rainfall temporal patterns affect these processes, especially on slopes with a wide range of gradients and length scales. Using a physically-based distributed hydrological model (InHM), these processes under different rainfall temporal patterns were simulated to illustrate this issue. Five rainfall patterns (constant, increasing, decreasing, rising-falling and falling-rising) were applied to slopes, whose gradients range from 5° to 40° and projective slope lengths range from 25 m to 200 m. The rising-falling rainfall generally had the largest total runoff and soil erosion amount; while the constant rainfall had the lowest ones when the projective slope length was less than 100 m. The critical slope of total runoff was 15°, which was independent of rainfall pattern and slope length. However, the critical slope of soil erosion amount decreased from 35° to 25° with increasing projective slope length. The increasing rainfall had the highest peak discharge and erosion rate just at the end of the peak rainfall intensity. The peak value discharges and erosion rates of decreasing and rising-falling rainfalls were several minutes later than the peak rainfall intensity.

Numerical Simulation of Cutting Force in High Speed Machining of Inconel 718

2020 ◽  
Vol 856 ◽  
pp. 43-49
Author(s):  
Santosh Kumar Tamang ◽  
Nabam Teyi ◽  
Rinchin Tashi Tsumkhapa
Keyword(s):  
Cutting Force ◽  
Inconel 718 ◽  
High Speed ◽  
Experimental Results ◽  
Machining Process ◽  
Experimental Result ◽  
Work Piece ◽  
High Speed Machining ◽  
Numerical Result ◽  
3D Software

Machining is one of the major manufacturing processes that converts a raw work piece of arbitrary size into a finished product of definite shape of predetermined size by suitably controlling the relative motion between the tool and the work. Lately, machining process is shifting towards high speed machining (HSM) from conventional machining to improve and efficiently increase production, and towards dry machining from excessive coolant used wet machining to improve economy of production. And the tools used are mostly hardened alloys to facilitate HSM. The work piece materials are continually improving their properties by emergence and development of newer and high resistive super alloys (HRSA). In this paper an attempt has been made to validate an experimental result of cutting force obtained by performing HSM on an HRSA Inconel 718, by comparing it with the numerical result obtained by simulating the same setting using DEFORM 3D software. Based on the comparison it is found that the simulated results exhibit close proximity with the experimental results validating the experimental results and the effectiveness of the software.

scholarly journals A study of the debris flow activity on the one-stepped channel slope

2016 ◽  
Vol 10 (No. 1) ◽  
pp. 32-39 ◽  
Author(s):  
S. Kim ◽  
H. Lee
Keyword(s):  
Debris Flow ◽  
Channel Slope ◽  
The One ◽  
Flow Activity

scholarly journals Experimental and Numerical Evaluation of Shear Strength of Directly and Indirectly Loaded Flanged Recycled Self-Compacted Reinforced Concrete Deep Beams

2020 ◽  
Vol 2020 ◽  
pp. 1-20
Author(s):  
Thamer Hussein Amer Alhussein ◽  
Jamal Abdul Samad Khudhair
Keyword(s):  
Experimental Data ◽  
Reinforced Concrete ◽  
Ultimate Load ◽  
American Concrete Institute ◽  
Shear Capacity ◽  
Recycled Concrete ◽  
Experimental Results ◽  
Experimental Result ◽  
Deep Beams ◽  
Aashto Lrfd

Experimental and numerical investigations of the behavior of directly and indirectly loaded flanged reinforced concrete (RC) deep beams cast with self-compacted concrete (SCC) containing recycled concrete as coarse aggregate (RCA) were conducted in this research. Seventeen RC deep flanged beams were designed to fail in shear. These beams were divided into three groups: twelve indirectly loaded beams without shear reinforcement; three directly loaded beams without stirrups; and two indirectly loaded beams with vertical stirrups. These beams were also classified according to the RCA ratio and shear span-to-effective depth (a/d) ratio, which will be detailed later. The RCA ranged from 0% to 75%, while the a/d ratio was taken as 1.0, 1.35, and 1.7. Experimental results show that the use of RCA reduces the cracking and ultimate capacities, and this finding complies with the conclusions of several research studies in the literature as will be detailed later. It was observed that beams with higher RCA exhibited higher deflection, strain, and crack width. Furthermore, by increasing the a/d ratio, the ultimate load was decreased due to the lower contribution of arch action shear transfer in the beam. A web reinforcement spaced at 100 mm and 50 mm increases the ultimate load by 35% and 48%, respectively. Strut and tie model (STM) presented by the American Concrete Institute (ACI) 318-14 and the American Association of State Highway and Transportation Officials (AASHTO LRFD 2012) was used to predict the ultimate shear capacity of the beams. STM predicted lower beam capacity than the experimental result. The ultimate strength calculated using ACI318-14 and AASHTO LRFD 2012 was on average 38% and 52% lower than the experimental data, respectively, which reflects the conservative nature of this approach. Finally, 3D finite element models were created to investigate the responses of the beams. The FE results showed very good agreement with the experimental data, where FE-predicted shear capacities were on average 9% higher than the experimental results.

The Effects of Free Space in Mould Cavity on Sandglass Extrusion

2005 ◽  
Vol 475-479 ◽  
pp. 2999-3002
Author(s):  
W.L. Lu ◽  
Y. Wang ◽  
Jin Tao Hai
Keyword(s):  
Grain Size ◽  
Free Space ◽  
Large Strain ◽  
Experimental Results ◽  
Experimental Result ◽  
Ultrafine Grain ◽  
Theory Analysis ◽  
Ultrafine Grain Size ◽  
Mould Cavity

Sandglass extrusion is an ultrafine grain size method. Due to the repetitive and multiple extrusions, large strain will be accumulated and ultafine grain size can be obtained. There are some factors that can affect the experimental result of sandglass extrusion. Among these factors, free space in mould cavity is very important, which can affect the forming of the fold during the extrusion. In this paper, the effects of free space in mould cavity on sandglass extrusion have been discussed and theory analysis and experimental results have been reported.

Debris-flow runout predictions based on the average channel slope (ACS)

2008 ◽  
Vol 98 (1-2) ◽  
pp. 29-40 ◽  
Author(s):  
Adam B. Prochaska ◽  
Paul M. Santi ◽  
Jerry D. Higgins ◽  
Susan H. Cannon
Keyword(s):  
Debris Flow ◽  
Channel Slope
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