摘要

A landslide occurred on September 27, 2020, on the slope of the Taihe open pit iron mine in Xichang, Sichuan, China. The landslide has posed a serious threat to the safety of workers and equipment, as well as the safe operation of the mine. To investigate the failure mechanism of the landslide and propose the corresponding treatment measures, several methods including geotechnical investigations, laboratory tests and numerical simulation have been adopted. The field investigations showed that landslide formation process has close relationship with rainfall, and the lithology where the slope was damaged is mainly diabase. The test results revealed that the diabase in the study area has obvious characteristics of disintegration and softening when exposed to water, and the water has a strong weakening effect on its strength. On this basis, the failure mechanism of the landslide was revealed: that is, the unique lithology of diabase is the material basis in the formation of landslide, and the concentrated rainfall during the rainy season was a triggering factor. According to numerical simulation, prior to treatment, the stability coefficient of the landslide was 1.08 in natural state and 0.97 under concentrated rainfall condition; after landslide treatment, its stability coefficient in natural state increased from 1.08 to 1.28, while increased from 0.97 to 1.20 under concentrated rainfall condition. These results indicated that the simulations agreed very well with the actual field observations, and the treatment measures taken were effective. This study can provide a reference for understanding the mechanism of the landslides induced by complex internal and external factors, as well as guidelines for the treatment of similar open-pit landslides.

  • 单位
    中国科学院