Characteristics and mechanism of loess surface disasters under coal-mining: a case study in Lüliang, China

Abstract

Loess has unique physical, hydrodynamic and mechanical properties, which are influenced by both internal and external geological processes, as well as human engineering activities. Consequently, surface disasters are especially prevalent in the Loess region of China. The study area is situated in the middle part of Lüliang Mountain in the middle part of the Loess Plateau, which is characterised by a typical loess landform with a complex system of gullies and hill ridges. According to current theory, the cracking boundary of the goaf profile is a straight line. However, these surface disasters are actually caused by the shear action of the deep rock layer and the original vertical joint structure of the loess. By analysing the cracking process of the ‘Goaf-Overburden-Loess’ section in the study area, it can be found that the boundary of the movement basin section presents a broken line shape, which has important implications for the accurate estimation of the area affected by loess-type surface subsidence.

Keywords

• Goaf
• coal mining subsidence
• loess collapse
• movement basin
• ground fissure