Risk assessment of fault water inrush during deep mining Cao, Zhaodan; Gu, Qixiong; Huang, Zhen ...
International journal of mining science and technology,
March 2022, 2022-03-00, 2022-03-01, Letnik:
32, Številka:
2
Journal Article
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With the gradual depletion of shallow coal resources, the Yanzhou mine in China will enter the lower coal seam mining phase. However, as mining depth increases, lower coal seam mining in Yanzhou is ...threatened by water inrush in the Benxi Formation limestone and Ordovician limestone. The existing prediction models for the water burst at the bottom of the coal seam are less accurate than expected owing to various controlling factors and their intrinsic links. By analyzing the hydrogeological exploration data of the Baodian lower seam and combining the results of the water inrush coefficient method and the Yanzhou mine pressure seepage test, an evaluation model of the seepage barrier capacity of the fault was established. The evaluation results show the water of the underlying limestone aquifer in the Baodian mine area mainly threatens the lower coal mining through the fault fracture zone. The security of mining above confined aquifer in the Baodian mine area gradually decreases from southwest to northeast. By comparing the water inrush coefficient method and the evaluation model of fault impermeability, the results show the evaluation model based on seepage barrier conditions is closer to the actual situation when analyzing the water breakout situation at the working face.
Soil moisture‐Precipitation (SM‐P) coupling, especially the causality from SM to P (SM → P), is an important and highly debated topic. The causal inference from observational data provides a ...statistical approach for this issue, where the experimental research is infeasible. Various causal inference methods exist, each assuming distinct underlying systems for the targeted variables: pure stochastic or deterministic dynamic system (DDS), which means that these methods detect different types of causality: separable or non‐separable. Acknowledging the inherent deterministic dynamic nature of SM‐P coupling, this study employs a DDS‐based method: Convergent Cross‐mapping (CCM), to detect their non‐separable causality. Centering around SM‐P coupling, we also detect the causality between SMs in shallow and deeper layers, and the causality between evapotranspiration (ET) and SMs in all layers. Notably, before applying CCM, a preconditional procedure is required: verifying the DDS nature of targeted variables P, SM, and ET. Key findings of this research include: (a) In SM‐P coupling, only SMs in shallow layers but not deeper layers could render causalities toward P, while P renders causalities toward SMs in all layers. (b) The time‐delay of causality from SM1 to P in spring/summer is around 4–6 days, and that from P to SM1 is around 2–4 days. (c) Inside SMs, shallow SMs have obvious causalities downwards to deeper SMs, but deeper SMs seem harder to render causalities upwards to shallow SMs, explaining why they hardly render causalities to P. In summary, this study furnishes an indispensable DDS‐based complement to stochastic‐based methodologies for SM‐P coupling.
Plain Language Summary
This study aims to investigate the causal interaction between soil moisture (SM) and precipitation (P), especially the impact from SM toward P, based on their observational data (i.e., time series), as experimental approaches are impractical given their large‐scale complex physical mechanisms. Many methods exist in the realm of causal detection, either assuming a stochastic underlying system or a deterministic dynamic system (DDS) for the targeted variables. In stochastic systems, causal interactions among variables are separable, whereas they are non‐separable in DDSs. Given that SM‐P coupling seems aligning with the description of a DDS, we employ a DDS‐based method: Convergent Cross‐mapping (CCM), to detect the non‐separable causality between SM and P. Specifically, we explore whether causality exists both from SM to P (SM → P, SM in different layers) and from P to SM (P → SM), and if so, what is the causal response time and how long could the causality last. Meanwhile, the causalities among SMs in different layers, and those between SMs and evapotranspiration (ET), are also detected. Through these inquiries, our findings highlight the DDS nature of SM‐P coupling and their non‐separable causality, underscoring the indispensable role of CCM as a complement to previous stochastic‐based studies for SM‐P coupling.
Key Points
Soil moisture‐Precipitation (SM‐P) coupling is detected by Convergent Cross‐mapping (CCM) to investigate their non‐separable causality
The deterministic dynamic system nature of SM‐P coupling is verified, as a precondition for applying CCM to detect their causality
While P could causally impact SMs in all layers; in turn, however, only shallow SMs but not deeper SMs could causally impact P
A deeper understanding of the mechanisms by which geological factors (depositional environment and tectonic evolution) control the occurrence of coalbed methane (CBM) is important for the utilization ...of CBM resources via surface-drilled wells and the elimination of coal-methane outbursts, the latter of which is a key issue for coal mine safety. Based on drill core data, high-pressure isothermal adsorption experiments, scanning electron microscopy experiments, mercury intrusion porosimetry, and X-ray diffraction experiments, the impact of the depositional environment and tectonic evolution on CBM occurrence of the II-1 coal seam of the Shanxi Formation in West Henan was analyzed. Results showed that the depositional environment led to the epigenetic erosion of tidal flat coal-accumulating structures by shallow-delta distributary channel strata. This resulted in the replacement of the original mudstone-sandy mudstone coal seam immediate roof with fine-to-medium grained sandstones, reducing methane storage capacity. Epigenetic erosion by the depositional environment also increased coal body ash content (from 6.9% to 21.4%) and mineral content, filling the cleat system and reducing porosity, reducing methane storage capacity. The maximum methane adsorption capacity of the coal body reduced from 35.7 cm3/g to 30.30 cm3/g, and Langmuir pressure decreased from 1.39 MPa to 0.909 MPa. Hence, the methane adsorption capacity of the coal body decreased while its capacity for methane desorption increased. Owing to the tectonic evolution of West Henan, tectonically deformed coal is common; as it evolves from primary cataclastic coal to granulitic coal, the angle of the diffraction peak increases, d002 decreases, and La, Lc, and Nc increase; these traits are generally consistent with dynamic metamorphism. This is accompanied by increases in the total pore volume and specific surface area of the coal body, further increasing the capacity for methane storage. Increases in micropore volume and specific surface area also increase the ability of the coal body to adsorb methane.
The stability of the reservoir bank landslide is affected by a variety of external factors, and the fluctuation of reservoir water level is one of the important influencing factors. The Erdaohe ...landslide is a typically colluvial landslide in the Three Gorges Reservoir area with periodic reservoir water level fluctuations. According to landslide displacement data, the displacement of the Erdaohe landslide exhibits the significantly stepwise feature. Its failure mechanism was analyzed using strength reduction method by the FLAC3D package in the case of reservoir water level changes. The results indicate that the hydrodynamic pressure has an important impact on the initialization of the landslide failure. When reservoir water level rises rapidly or maintains constant at the lower level, the landslide stability would be higher. When the reservoir water level decreases rapidly or maintains constant at the higher level, the landslide stability will be smaller. When the reservoir water level was in the lowest elevation, the factor of safety (FS) reached the minimum value of 1.11. Findings in this paper can provide guidelines for the risk assessment of colluvial landslides.
Signaling through its widely distributed cell surface receptor, interleukin (IL)-17 enhances the transcription of genes encoding proinflammatory molecules. Although it has been well documented that ...IL-17 activates the transcription factor nuclear factor (NF)-kappaB and c-Jun NH(2)-terminal kinase (JNK), the upstream signaling events are largely unknown. Here we report the requirement of tumor necrosis factor receptor-associated factor (TRAF)6 in IL-17-induced NF-kappaB and JNK activation. In embryonic fibroblasts (EFs) derived from TRAF6 knockout mice, IL-17 failed to activate the IkappaB kinases (IKKs) and JNK. Consequently, IL-17-induced IL-6 and intercellular adhesion molecule 1 expression in the TRAF6-deficient cells was abolished. Lack of TRAF6 appeared to be the sole defect responsible for the observed failure to respond to IL-17, because transient transfection of TRAF6 expression plasmid into the TRAF6-deficient cells restored IL-17-induced NF-kappaB activation in a luciferase reporter assay. Furthermore, the levels of IL-17 receptor (IL-17R) on the TRAF6-deficient EFs were comparable to those on the wild-type control cells. Defect in IL-17 response was not observed in TRAF2-deficient EFs. Moreover, when TRAF6 and IL-17R were coexpressed in 293 cells, TRAF6 coimmunoprecipitated with IL-17R. Together, these results indicate that TRAF6, but not TRAF2, is a crucial component in the IL-17 signaling pathway leading to proinflammatory responses.
Activation of the transcription factor NF-κ B by inflammatory cytokines involves the successive action of NF-κ B-inducing kinase (NIK) and two Iκ B kinases, IKK-α and IKK-β . Here we show that NIK ...preferentially phosphorylates IKK-α over IKK-β , leading to the activation of IKK-α kinase activity. This phosphorylation of IKK-α occurs specifically on Ser-176 in the activation loop between kinase subdomains VII and VIII. A mutant form of IKK-α containing alanine at residue 176 cannot be phosphorylated or activated by NIK and acts as a dominant negative inhibitor of interleukin 1- and tumor necrosis factor-induced NF-κ B activation. Conversely, a mutant form of IKK-α containing glutamic acid at residue 176 is constitutively active. Thus, the phosphorylation of IKK-α on Ser-176 by NIK may be required for cytokine-mediated NF-κ B activation.
Water shortage and soil salinization are the key limiting factors in agricultural production of arid and semi-arid regions. Located in western Inner Mongolia of China, the Hetao Irrigation District ...(HID) is one of the top three largest irrigation districts in China. Irrigation water overuse and high level of soil salinity have curbed the agricultural productivity, adversely affected farmers’ revenues, and threatened long-term sustainability of irrigated farming in the HID. Nevertheless, opportunities still exist to improve the situation. Irrigation water allocation, salt accumulation and leaching, crop productivity and farming decisions are intrinsically connected and thus require taking a holistic approach to investigate into the interactions among all those factors and devise appropriate technological, management and policy interventions. Towards this goal, we develop an integrated hydro-agro-economic optimization model to reconcile agricultural net revenue, irrigation practices, and environmental sustainability in the HID. Positive Mathematical Programming is used for model calibration to ensure the model can replicate the base year observations of crop acreage, making the model suitable for evaluating alternative scenarios. Scenario analyses are conducted to analyze the effects of water supply reduction, reducing winter irrigation, water-saving irrigation, and crop commodity price change on optimal agricultural water management practices. Results show that water supply reduction without complementary measures increases land fallow, exacerbates soil salinization, and reduces net benefits. Winter irrigation can conserve soil moisture and increase the net salt leaching in the root zone, and a reduction in winter irrigation will incur a benefit loss to the HID. Water-saving irrigation can stabilize planting areas under water shortage but exacerbate soil salinization. Price increase of a cash crop, if it has a large area share, tends to “crowd out” grain crops growing in the same season. These results provide a holistic perspective and useful insights for water management and policy in the HID.
•A hydro-agro-economic model is developed for the Hetao Irrigation District in China.•Winter irrigation reduction will incur a benefit loss for the farmers.•Water-saving irrigation is beneficial only when considerable water shortage exists.
Many cytokines signal through different cell-surface receptors to activate the transcription factor NF-kappaB. Members of the TRAF protein family have been implicated in the activation of NF-kappaB ...by the tumour-necrosis factor (TNF)-receptor superfamily. Here we report the identification of a new TRAF family member, designated TRAF6. When overexpressed in human 293 cells, TRAF6 activates NF-kappaB. A dominant-negative mutant of TRAF6 inhibits NF-kappaB activation signalled by interleukin-1 (IL-1) but not by TNF. IL-1 treatment of 293 cells induces the association of TRAF6 with IRAK, a serine/threonine kinase that is rapidly recruited to the IL-1 receptor after IL-1 induction. These findings indicate that TRAF proteins may function as signal transducers for distinct receptor families and that TRAF6 participates in IL-1 signalling.
The interleukin-1 receptor-associated kinase (IRAK) was first described as a signal transducer for interleukin-1 (IL-1) and
has later been implicated in signal transduction of other members of the ...Toll/IL-1 receptor family. We now report the identification
and characterization of a novel IRAK-like molecule. In contrast to the ubiquitously expressed IRAK and IRAK-2, this new IRAK-like
molecule is found mainly in cells of monomyeloic origin and is, therefore, designated IRAK-M. Although IRAK-M and IRAK-2 exhibit
only a negligible autophosphorylation activity, they can reconstitute the IL-1 response in a 293 mutant cell line lacking
IRAK. In addition, we show for the first time that members of the IRAK family are indispensable elements of lipopolysaccharide
signal transduction. The discovery of IRAK-M adds another level of complexity to our understanding of signaling by members
of the Toll/IL-1 receptor family.
•Nonlinear Dynamic System (NDS) in phase domain is applied in drought propagation.•Nonlinear information about drought propagation can be detected by NDS.•The propagation time and rate between two ...types of drought can be calculated by NDS.
Current approaches for calculating propagation time and rate from meteorological to hydrological drought mainly focus on the time series of SPI and SRI, and most of these methods are conducted in time domain (e.g., correlation analysis) and frequency domain (e.g., wavelet analysis), which are regarded as linear statistic methods. Inaccuracy could emerge when the complexity and nonlinearity of drought propagation is addressed by such linear methods. In light of this problem, this research adopts Nonlinear Dynamic System (NDS) conducted in phase domain, which provides a nonlinear and systematic perspective on drought propagation. NDS may conditionally generate chaos (commonly known as “butterfly” phenomenon), which was not covered by previous studies on drought propagation. Assuming an underlying NDS for drought events, we demonstrate the NDS of drought propagation could generate chaos, and the nonlinear information about the propagation from meteorological to hydrological droughts can be detected within such chaotic NDS. The propagation time of 1–5 months and the propagation rate of 0.686 were found in the Pearl River Basin. In addition, the propagation time of 3, 7 and 11 months was also found in the Wei River Basin, to prove the broad applicability of our method. The results for these two basins are verified by previous studies.
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