Study on The Effectiveness of Catch Pits by Monitoring and Analysis of Groundwater Level and Slope Displacement and Simulation Test

• Main Authors: YI,TA-CHENG, 易大成
• Other Authors: Jeng,Ching-Jiang
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/c7fxes

碩士 === 華梵大學 === 環境與防災設計學系碩士班 === 107 === In this study, the slopes of the Huafan University campus were used as the test site, and the monitoring data analysis and the laboratory simulation test were carried out respectively. The purpose was to discuss the impact of the catch pits construction project on the slope displacement and groundwater of the campus. Through the comparison of the monitoring data before and after the catch pits construction to understand the impact and effectiveness of the catch pits. Finally, with the catch pits laboratory simulation test, the difference for the slope land when the presence or absence of the catch pits is simulated. In the analysis of monitoring data, the rainfall, groundwater level and the displacement data of the Shape Accel Array (SAA) were analyzed and correlated. The conclusion is that the water level of the W1 water level observation well drops by about 10m after the application of the construction of catch pits, the rainfall threshold of the groundwater level rise increases and the time need to return to the normal water level decreases. Those impacts caused the rainfall threshold value of the slope displacement of SAA11 and SAA20 increases by at least 70%, and the creep of the slope decreases by 1.83. ~2.19mm/year. In the laboratory simulation test, by comparing different rainfalls and with or without the catch pits application, the test results show that the catch pits have less influence in the case of small rainfall, but in the case of heavy rainfall, the catch pits are significantly achieve in draining groundwater water levels and slowing infiltration rates. Finally, the correlation equation of the comprehensive rainfall induced displacement analysis results is used to verify the possible displacement of the slope caused by the rainfall event in 2017, which is close to the actual inclinometer displacement value. This research finally suggest the rainfall warning value of the slopes of Huafan University campus. The potential slide, the semi-accurate slide, the accurate slide and the emergency slide of the rainfall warning value can be set to 280mm, 500mm, 740mm and 1350mm respectively, as a reference for the subsequent slope management