Coal gangue is widely used as a filling material in coal seam mining. During the steeply dipping seam, loading rate, gradation, and speed have an important impact on deformation failure of gangue, further affect bearing overlying strata control surrounding rock movement deformation. Therefore, this article uses self-made steel cylinder to conduct compression test HCT pressure testing machine. T...

Over 800 mud-filled casts of upright lycopsid tree stumps have been documented immediately above the Mahoning coal in an active underground mine located in northwestern Jefferson County, Ohio. The coal body originated as a pod-shaped peat body of ~ 60 km^. Trees are rooted at several levels within a thin (15-40 cm) bone coal directly above the banded coal; they extend upward up to 15 cm into ov...

Aiming at the problem that it is difficult to achieve accurate laying of model and precise excavation roadways in special surrounding rock structure roadway according conventional physical similarity simulation, which reduces reliability experimental results. An method, named “labeling positioning drawing line, presetting model” (LPDLPRM), was proposed. The simulation deformation failure charac...

Four different compression/impression floras are preserved in only 4.32 m of the geologic section in the Early Permian Shanxi Formation of the Wuda District of Inner Mongolia, northwestern China. These floras represent four different plant communities and landscapes that followed each other in time. The oldest flora was rooted in sandy clay and initiated peat accumulation that lead to the forma...