Influence of soil permeability on rainfall-induced flowslides in laboratory flume tests

2007 ◽  
Vol 44 (9) ◽  
pp. 1128-1136 ◽  
Author(s):  
Fawu Wang ◽  
Hiroki Shibata
Keyword(s):  
Significant Influence ◽  
Rainfall Intensity ◽  
Soil Permeability ◽  
Artificial Rainfall ◽  
Flume Tests ◽  
Laboratory Flume ◽  
Slope Condition ◽  
Model Slope ◽  
Different Soils

The mobility of flowslides is influenced by various factors. In this paper, laboratory flume tests were used to evaluate the influence of soil permeability using different soils with different permeabilities in a model slope, while keeping the slope condition and artificial rainfall intensity constant. It was found that the permeability of soil has a significant influence on the initialization of flowslides and that there is an optimal soil permeability existing for the mobility of flowslides when rainfall intensity is kept constant.

Subgrade Stability Analysis with Rainfall Infiltration

2012 ◽  
Vol 204-208 ◽  
pp. 284-288
Author(s):  
Li Jin Zhou
Keyword(s):  
Stability Analysis ◽  
Rainfall Intensity ◽  
Limit Equilibrium ◽  
Limit Equilibrium Method ◽  
Matric Suction ◽  
Rainfall Infiltration ◽  
Soil Permeability ◽  
Safety Coefficient ◽  
Equilibrium Method

Based on limit equilibrium method, the subgrade stability formula under rainfall infiltration is derived and the influence of matric suction on subgrade stability is analyzed using the safety coefficient formula. What’s more, the affection of rainfall intensity, duration and soil permeability on subgrade stability is studied and the influences is obtained. The presented research provides the theory basis to controlling of rainfall infiltration.

scholarly journals Uji Laboratorium Pengaruh Kemiringan Lereng Terhadap Kejadian Longsoran Aliran Debris Pasir Merapi

2020 ◽  
Vol 16 (1) ◽  
pp. 23-34
Author(s):  
Bayu Seto Waseso Utomo ◽  
Jati Iswardoyo ◽  
Ruzardi Ruzardi
Keyword(s):  
Debris Flow ◽  
Laboratory Test ◽  
Early Warning ◽  
Debris Flows ◽  
Rainfall Intensity ◽  
Laboratory Scale ◽  
Artificial Rainfall ◽  
Rain Simulator

The debris flow that happen on the of Mount Merapi is really hard to be seen, therefore, it is necessary to conduct laboratory-scale simulations to know when debris flows will happen as regard to rainfall intensity and the slope of Mount of Merapi. This research examines the correlation between the slope and the potential for debris flow at 25 mm/h rainfall intensity. This will be a reference for early warning of landslides on Mount of Merapi. This research uses a tool such as flume that sized 3 x 5 x 0,15 m as a model of slope of Mount of Merapi, and artificial rainfall apparatus as the rain simulator. The simulation is conducted using five years rainfall intensity of 25 mm/h in combination of slope i.e. 15, 20, 25, 30 and 35 degrees whereas the material used to represent the sediment is in form of sand taken from Gendol River upstream with 4,75 mm passing mesh sieves. The result of this simulation is the steeper the slope is, the faster the duration for the rain to cause debris flow. This research can be continued with change variation of rainfall intensity to understand the debris flows behavior. Keywords: Debris flow, Mount of Merapi, laboratory test, rainfall intensity, flume model

scholarly journals Determining the susceptibility of soils materials to erosion by rain-impacted flows

2016 ◽  
Author(s):  
P. I. A. Kinnell
Keyword(s):  
Drop Size ◽  
Rainfall Intensity ◽  
Rainfall Erosivity ◽  
Soil Erodibility ◽  
Flow Depth ◽  
Empirical Coefficient ◽  
Artificial Rainfall ◽  
Spatial Uniformity ◽  
Absolute Measure ◽  
The Relationship

Abstract. Conceptually, rain has a capacity to cause erosion (rainfall erosivity) and soils have a susceptibility to erosion by rainfall (soil erodibility) but no absolute measure of rainfall erosivity exists. Consequently, soil erodibility is nothing more than an empirical coefficient in the relationship between an index of rainfall erosivity and soil loss. Erosion by rain-impacted flow is influenced by the size, velocity and impact frequency of the raindrops but also flow depth and velocity. Experiments with artificial rainfall falling on sloping surfaces in the field usually do not enable flow depth and velocity to be well measured or controlled. Also, sprays produce artificial rainfall where the spatial uniformity in rainfall intensity, drop size and frequency is often less than desirable. Artificial rainfall produced by pendant drop formers can produce rainfall that has better spatial uniformity. Equipment for controlling flow depth and velocity over eroding surfaces has been developed and used to calibrate the effect of flow depth on the discharge of sediment by rain-impacted flow using artificial rainfall having a uniform drop-size distribution under laboratory conditions. Once calibrated, laboratory experiments can be conducted to rank soils according to their susceptibility to erosion under the flows impacted by the artificial rainfall under conditions where the erosive stress applied to the eroding surface is well controlled.

Laboratory tests to study hydraulic fill

1992 ◽  
Vol 29 (3) ◽  
pp. 405-417 ◽  
Author(s):  
Angela A. G. Küpper ◽  
Norbert R. Morgenstern ◽  
David C. Sego
Keyword(s):  
Grain Size ◽  
Laboratory Tests ◽  
Constant Composition ◽  
Hydraulic Fill ◽  
Flume Tests ◽  
Experimental Apparatus ◽  
Mean Grain Size ◽  
Laboratory Flume ◽  
The Mean ◽  
Physical Phenomena

Laboratory flume deposition tests were carried out to study the physical phenomena associated with the deposition of a sand slurry to form a hydraulic fill. The experimental apparatus was carefully designed to minimize flume-wall effects on the flow and to allow discharge of slurry of constant composition for an indefinite period of time. Slurry concentration and flow rate were varied independently to study their effects on characteristics of the fill such as geometry, grain-size distribution, and density. Three different sands were used to evaluate the influence of the mean grain size. Key words : hydraulic fill, flume tests, sand, profile, slope, density.

Enhancing the spatial rainfall uniformity of pressurized nozzle simulators

2017 ◽  
Vol 28 (1) ◽  
pp. 17-31 ◽  
Author(s):  
Alexandre Silveira ◽  
Jorge M.G.P. Isidoro ◽  
Fábio P. de Deus ◽  
Simone Siqueira dos Reis ◽  
Antônio Marciano da Silva ◽  
...  
Keyword(s):  
Urban Areas ◽  
Rainfall Intensity ◽  
Physical Models ◽  
Variation Coefficient ◽  
Rainfall Simulation ◽  
Operating Pressure ◽  
Content Type ◽  
Artificial Rainfall ◽  
Average Rainfall

Purpose Rainfall simulators are used on experimental hydrology, in areas such as, e.g., urban drainage and soil erosion, with important timesaving when compared to real scale hydrological monitoring. The purpose of this paper is to contribute to increase the quality of rainfall simulation, namely, for its use with scaled physical models. Design/methodology/approach Two pressurized rainfall simulators are considered. M1 uses three HH-W 1/4 FullJet nozzles under an operating pressure of 166.76 kPa and was tested over a 4.00 m length by 2.00 m width V-shaped surface. M2 was prepared to produce artificial rainfall over an area of 10.00 m length by 10.00 m width. The spatial distribution of rainfall produced from a single nozzle was characterized in order to theoretically find the best positioning for nozzles to cover the full 100 m2 area with the best possible rainfall uniformity. Findings Experiments with M1 led to an average rainfall intensity of 76.77-82.25 mm h−1 with a 24.88 per cent variation coefficient and a Christiansen Uniformity Coefficient (CUC) of 78.86 per cent. The best result with M2 was an average rainfall intensity of 75.12-76.83 mm h−1 with a 21.23 per cent variation coefficient and a CUC of 83.05 per cent. Practical implications This study contributes to increase the quality of artificial rainfall produced by pressurized rainfall simulators. Originality/value M2 is the largest rainfall simulator known by the authors worldwide. Its use on rainfall-runoff studies (e.g. urban areas, erosion, pollutant transport) will allow for a better understanding of complex surface hydrology processes.

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