Presentation Title

How Safety Margin of a Slope Changes With Duration of Rainfall

Faculty Mentor

Binod Tiwari Ph.D

Start Date

23-11-2019 1:00 PM

End Date

23-11-2019 1:15 PM

Location

Markstein 105

Session

oral 3

Type of Presentation

Oral Talk

Subject Area

engineering_computer_science

Abstract

How Safety Margin of a Slope Changes With Duration of Rainfall

When analyzing the potential causes of a landslide, one of the main factors is rainfall. Before rainfall, the slope has less of a moisture content and higher strength. That is precisely why in our study our objective was to evaluate how the safety margin drops with the duration of rainfall. In our experiment, we designed three 45-degree angle slopes with 2% moisture and varying densities of vegetation. We then applied a rain simulator system which released 0.5 mm of water per minute until the slope was fully saturated. After that, we recorded the coordinates of the wetting front lines after every 30-minutes of rainfall. As the moisture content increased, the soil lost its strength due to the decreasing cohesion and friction angle values. With more vegetation, the rainfall pours into the sand at a faster rate. The results showed that over time, the safety margin dropped and the seepage velocity increased therefore creating a higher risk of a landslide. Based on the results, we observed that the stability of slopes decreases with a high intensity of rain or a long duration of it.

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Nov 23rd, 1:00 PM Nov 23rd, 1:15 PM

How Safety Margin of a Slope Changes With Duration of Rainfall

Markstein 105

How Safety Margin of a Slope Changes With Duration of Rainfall

When analyzing the potential causes of a landslide, one of the main factors is rainfall. Before rainfall, the slope has less of a moisture content and higher strength. That is precisely why in our study our objective was to evaluate how the safety margin drops with the duration of rainfall. In our experiment, we designed three 45-degree angle slopes with 2% moisture and varying densities of vegetation. We then applied a rain simulator system which released 0.5 mm of water per minute until the slope was fully saturated. After that, we recorded the coordinates of the wetting front lines after every 30-minutes of rainfall. As the moisture content increased, the soil lost its strength due to the decreasing cohesion and friction angle values. With more vegetation, the rainfall pours into the sand at a faster rate. The results showed that over time, the safety margin dropped and the seepage velocity increased therefore creating a higher risk of a landslide. Based on the results, we observed that the stability of slopes decreases with a high intensity of rain or a long duration of it.