A Vertical Joint Spacing Calculation Method for UDEC Modeling of Large-Scale Strata and Its Influence on Mining-Induced Surface Subsidence

Abstract

While universal discrete element code (UDEC) is widely used for understanding the mechanism of large-scale strata movement and the effects of mining subsidence on the environment, the fundamental knowledge of how to set vertical joint spacing (VJS) in UDEC is still not fully understood. To address the knowledge gap, we first present a novel VJS calculation method, then conduct UDEC experiments, and finally compare the predictions of UDEC models with field subsidence observation. The results suggest the following: (1) when compared to the conventional VJS setting (1× to 3× bed thickness), the maximum surface subsidence (MSS) prediction via UDEC models based on our proposed VJS setting method is closer to field observation; (2) a smaller but varying VJS setting can also have the effect of a larger VJS setting; and (3) with the increase in VJS, MSS first drops, then rises, and reaches the minimum when VJS is set at approximately 7× bed thickness. This paper provides an explanation of the VJS setting in UDEC and establishes a bridge between the KS theory and VJS, which is helpful for the sustainable development of such an UDEC modeling strategy and for a better understanding of the influences of mining subsidence on the environment in mining-affected areas.

Research on reasonable layout parameters of working faces based on the concept of harmonic extraction to reduce the damage of coal seam waiting for upward mining

“…Due to limitations in the size of similar simulation experiments, it is impossible to simulate the movement of overlying strata after large-scale coal seam mining. Using the UDEC numerical calculation software 19 – 21 , six comparative experiments were established to verify the rationality of the working face layout parameters and calculation methods of the No.6 and 7 coal seams obtained above, as listed in Table 4 .…”

Application and Optimization of the Parameters of the High-Level Boreholes in Lateral High Drainage Roadway

“…A numerical model was constructed according to the geological conditions of the 2-603 working face. The model parameters are shown in [17,27,28]. The distribution characteristics and extent of the mining overburden fissures after excavation of the 2-603 working face were simulated.…”

Numerical Study on the Surface Movement Regularity of Deep Mining Underlying the Super-Thick and Weak Cementation Overburden: A Case Study in Western China

“…It should be mentioned that some of these monitoring points have been damaged or flooded, and in the end, the measurement data of 70 points is reliable and complete, which It should be mentioned that some of these monitoring points have been damaged or flooded, and in the end, the measurement data of 70 points is reliable and complete, which is further used for comparison in this study. The comprehensive borehole log and more details can be found in our previous studies [1,22,23].…”

“…Underground coal mining induces strata movement and in turn causes ground surface subsidence or cracking [1]. As a consequence, farmland, foundations, various buildings and infrastructure will be affected to varying degrees in terms of geomining conditions, which poses a huge challenge to the sustainable development of the coal industry [2,3].…”