Abhishek Prakash Paswan

Safe disposal of coal ash slurry is a primary concern of the environment owing to the bulk generation of ash in industries, especially in any developing country. Generally, it is observed that the generated coal ash waste is disposed of into the ash ponds as slurry. Ash dyke breaches may inundate the surrounding area with toxic ash slurry, thus inducing a high environmental hazard. This article presents a study on the slope stability of ash dyke structures for different geometries, which may be constructed of various materials and are subjected to varied seepage conditions. The present analysis compares different dyke erection methodologies, namely the upstream method, centreline method and downstream method. Numerical analysis is performed using Geostudio Slope/w software. The study found that ash dyke safety increases when the dyke structures are designed with adequate drainage. Further, from this study, it can be concluded that the dyke stability not only depends on the geotechnical properties of the ash material used in its construction but also on the design of the dyke, the method of erection and the seepage through the dyke.

Landslides in northern India are a frequently occurring risk during the rainy season resulting in human, animal, and property losses as well as obstructing transportation facilities. Usually, numerical and analytical approaches are applied to predicting and monitoring landslides, but the unpredictable nature of rainfall-induced landslides limits these methods. Sensor-based monitoring is an accurate and reliable method, and it also collects accurate and site-specific required data for further investigation with a numerical and analytical approach. This study developed a low-cost tilt-based rainfall-induced landslide monitoring system using the economical and precise MEMS sensor to record displacement and volumetric water content. A self-developed direct shear-based testing setup was used to check the system’s operational performance. A physical slope model was also prepared to test the monitoring system in real scenarios. A debris failure occurred at Kotrupi village in the Mandi district of Himachal Pradesh, India, which was chosen for the modelling to investigate the failure mechanism. A rainfall generator was developed to simulate the rainfall, equipped with a flow sensor for better simulation and data recording. The tilt angle records the deviation in terms of angle with a least count of 0.01 degrees, and the moisture content was recorded in terms of percentage with a least count of 1. The results show that the developed system is working properly and is very effective in monitoring the rainfall-induced landslide as it monitors the gradual and sudden movement effectively. This study explains the mechanism behind the landslide, and it can be helpful in monitoring the slope to enable the implementation of preventative actions that will mitigate its impact.