Based on the existing research results and field survey data, this paper analyses and evaluates the rule of land deterioration and ecological environment problems caused by mining subsidence. Besides, the author puts forward the corresponding control measures for the effective exploitation of underground resources, land resources and ecologic environment protection.
In order to explore the deformation characteristics of layered slate tunnels under different dip angles of rock formations, a numerical simulation research method for optimization of large deformation control parameters of layered slate tunnels is proposed. The plane deviation, plane deformation, and DP parameters of the structure are obtained through the calculation mode. When studying the effect of overlapping rock masses on the stability of thick tunnels, the incidence angle of the rock structure is assumed to be zero. The estimated thicknesses of the dolomite limestone surrounding the tunnel are 0.3 m, 0.4 m, 0.5 m, 0.6 m, 0.7 m, 0.8 m, and 0.9 m, respectively. Select the vertical displacement to be analyzed as the result of the calculation. In order to study the influence of the structural slope on the tunnel stability, the thickness of the rock layer was 0.6 m, and the structural slopes of 5°, 15°, 30°, 45°, 60°, 75°, and 85° were used for simulation calculations. During on-site construction, focus on monitoring the tunnel section deformation before the secondary lining construction. Every 10-20 m, when the surrounding rock changes, the observation section of the enclosure convergence and vault settlement is arranged, and the peripheral displacement rate and the vault settlement rate are calculated according to the observed deformation. The results show that the vertical displacement of the top of the tunnel is generally in a “V” shape, that is, the maximum settlement in the tunnel; when the layer thickness is 0.3 m, the maximum vertical displacement of the rock layer is 7.2 mm, and the total settlement in the lining support tunnel is 8.23 mm. When the layer thickness is 0.9 m, the vertical displacement of the rock layer is 5.14 mm, and the total settlement in the lining support tunnel is 5.22 mm2; when the layer thickness was changed from 0.9 m to 0.3 m, the maximum vertical displacement of the rock layer increased by 140%, and the settlement at the vault increased by 158%. At this time, the focus of tunnel support is on both sides of the lining structure and the vault with large vertical settlement. The phenomenon that the section of YK51+032 first decreases and then increases due to the sudden appearance of mud in the surrounding YK51+040, resulting in increased short-term deformation. Only the ZK49+356 section at the entrance of the left line has a large deformation due to the thin overlying stratum, and other sections are relatively consistent, indicating the reliability of the calculation results.
In order to investigate the potential of sequencing batch biofilm reactor (SBBR) technology of two-sludge system for denitrifying dephosphatation (A2ON process),we build a tab-scale experiment .Then find that the simultaneous removal of phosphorus and nitrogen in the two sludge system is possible .By the control of COD/TN ratio ,highly effective simultaneous nitrification and denitrification is achieved in the A2ON system.And the ratio of denitrification is 85%, the ratio of dephosphatation is 87%.It also demonstrates that the process is stable ,at the same time decrease the effect of dephosphorization and denitrification by the limited carbon source.
In order to study the influence of nonlinear numerical simulation on the optimal control of the tunnel rock deformation parameters, the author proposes a numerical simulation study of the deformation characteristics of the layered rock tunnel, and determines the calculation model according to the thickness of the rock mass. The estimated thicknesses of the dolomite limestone surrounding the tunnel are 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, and 0.9 m. Select the vertical displacement to analyze as a result of the calculation. In order to study the influence of the structural slope on the tunnel stability, the thickness of the rock layer was 0.6 m, and the structural slopes of 5°, 15°, 30°, 45°, 60°, 75°, and 85° were used for simulation calculations. During on-site construction, focus on monitoring the tunnel section deformation before the construction of the secondary lining. Every 10–20 m and at the change of the surrounding rock, the observation section of the surrounding convergence and vault settlement shall be arranged, according to the observed deformation, the peripheral displacement rate and the vault subsidence rate are calculated. The results show that the vertical displacement of the top of the tunnel is generally in a “V” shape, that is, the maximum settlement in the tunnel; when the layer thickness is 0.3 m, the maximum vertical displacement of the rock layer is 7.2 mm, and the total settlement in the lining support tunnel is 8.23 mm. When the layer thickness is 0.9 m, the vertical displacement of the rock layer is 5.14 mm, and the total settlement in the lining support tunnel is 5.22 mm. When the layer thickness is from 0.9 to 0.3 m, the maximum vertical displacement of the rock layer increases by 140%, and the settlement at the vault increases by 158%. The focus of tunnel support at this time is the two sides of the lining structure and the vault with large vertical settlement. For the YK51 + 032 section, the phenomenon of first decreasing and then increasing is due to the sudden mud on the surrounding YK51 + 040, which causes the short-term deformation to increase. Only the ZK49 + 356 sections at the entrance of the spider has very good deformation due to the thin overlying stratum, and other sections are similar, which shows the reliability of the calculation results.
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