Experiment on water bank instability under rainfall
- Article
- Figures
- Metrics
- Preview PDF
- Reference
- Related
- Cited by
- Materials
Abstract:
Bank slope instability is a common geological hazard,which extremely threatens people′s property and life in China.Rainfall is an important cause of bank slope instability,and the slope angle and the slope material directly control the stability of the bank slope.Therefore,it is meaningful to study the influence of slope angle and slope material on bank slope stability under rainfall conditions. To explore the influence of slope angle and slope material on the instability of water banks under heavy rainfall,5 model tests were carried out by taking different slope angles,slope materials and the deformation characteristics of bank slope were observed at different times.The change of pore water pressure and earth pressure in different positions of the slope were monitored by a pore water pressure gauge and earth pressure gauge. By comparing the failure process of 5 model tests at different times,the results showed that heavy rainfall had a significant effect on the stability of the slope surface structure.Under the action of rainfall,the surface structure rapidly saturated,the shear strength was greatly reduced and the stability deteriorates.However,the internal structure was less affected because the water was difficult to penetrate.At 60° slope angle,there were obvious cracks in the bank slope after 10 minutes of rainfall,and the cracks became larger as the rainfall time increased.After 2 hours of rainfall,the slope angle changed from 60° to 47°,and there were many obvious cracks on the surface of the bank slope.When the slope angle was 30° and 45°,there was no obvious damage on the bank slopes.The change in bank slope with different slope materials was also significantly different.There was little obvious damage to the clay slope during the whole test.When the sand content was 20%,the bank slope had erosion damage after 40 minutes of rainfall,and as the rainfall time increased,the damage gradually increased,Eventually,a collapse occurred on the surface of the bank slope when the sand content was 40%,and it was also noted that the bank slope had obvious cracks after 5 minutes of rainfall.About 70 minutes,there was a scour groove in the middle of the bank slope,which gradually widened with the increase of rainfall time. Under the rainfall,the bank slope became heavier and the sliding force increased.Moreover,with the increase of the water content of the bank slope,the shear strength decreased sharply,then induced bank slope instability.The slope angle had a great influence on bank stability.The bigger the slope angle,the deeper the rain seep,and the sliding force and infiltration force become stronger,which was not conducive to the stability of the bank slope,the influence was 60°＞45°＞30°,respectively.The slope material affected the bank slope stability directly,and different materials had different permeability.When the sand content was 40%,the permeability was best,and bank slope was damaged at 5 minutes and the response of pore water pressure was fast,the instability probability was higher with the worst permeability.When the bank slope was pure clay,and no damage obviously,and the response of pore water pressure was slow,the impact of rainfall on bank slope stability was low relatively.
Keywords:
Project Supported:
Clc Number:
Mobile website
® 2024 All Rights Reserved
冀公网安备13010502002656号
冀公网安备13010502002656号