Distribution Characteristics and Formation Mechanism of Surface Crack Induced by Extrathick Near Horizontal Seam Mining: An Example from the Datong Coal Field, China

Research on Electrical Characteristics of Water Conducted Crack Zone in the Coal Seam

Water disaster is one of the five natural disasters in coal mines, and it badly threats the lives safety of miners. As well known, the main reason of evoked flooding is water conducted fractured zone in the coal seam. Based on the Maxwell equation, we try to study the relationship between apparent resistivity and stratigraphic dip as well as strata direction. The numerical results show that the...

Characteristics of Horizontal and Vertical Near-Field Ground Motions and Investigation of Their Effects on the Dynamic Response of Bridges

Recently, concerning failure of structures due to earthquakes, special investigations of near fault ground motions have been noticed. Hence, in this paper, characteristics of near field ground motions have been considered in horizontal and vertical directions. In this consideration, the record averages have been compared with Uniform Building Code and Eurocode8 spectra in two levels. In additio...

Measuring seam/crack formation in interconnect metallization

Low cost processes, in both GaAs and Silicon, often use non-planar interconnect metals. While very efficient in simplifying processes, seam (more commonly called ‘‘crack’’) formation due to inter-level dielectric topologies can (1) cause significant thinning in the metallization, impacting the reliability and (2) act as process defects that reduces circuit yield. To better understand and monito...

Reduction of Stress Acting on a Thick, Deep Coal Seam by Protective-Seam Mining

Aiming to reduce the high mining stress observed in large-space roof structures during mechanized mining of thick coal seams, a control technique based on protective-seam mining is proposed. This technique was used to investigate the 8108 working face of the No. 3–5 thick coal seam of the Tashan mine located in the Datong area of Shanxi, China, by means of simulations and field measurements. Th...

Seam Wave Characteristics in an Eastern U.S. Coal