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npr anchorage

Date: October 1, 2020 Author: Categories: Uncategorized

At present, a series of numerical methods such as finite difference method and finite volume method for different types of sliding bodies have been developed.

The NPR anchor cable model was constructed by FLAC3D software, as shown in Figure 15. The parameters of the NPR anchor cable model were determined by the coordinates of the monitoring points of the deep sliding force and buried depth of the NPR anchor cable: inclination angle, 30°; length, 75 m; preload force, 40 kN; and constant resistance value, 85 kN. 2019C03104) and the Fundamental Research Funds for the Central Universities, SCUT (No. “16-1101 landslide” instability displacement contour. The sign of the stability of the slope is that the subsidence curve does not change, but the calculation is continued. (1)Tensile properties and constant resistance characteristics of the constant resistance and large deformation anchor cables Figure 4 shows the static tensile test curve of the test piece anchor cable, indicating the following:(a)From the beginning of the tension to the failure of the anchor cable, it has an average elongation of 1960 mm, showing an extraordinarily large deformation capacity. The constant resistance value of the NPR anchor cable is related to the material size of the constant resistance body and the external load.

The axial force changes in the NPR anchor cables were monitored by FLAC3D and 3DEC software. The key to affecting the reliability and authenticity of forecasting results is to timely and accurately monitor and simulate the data. The orebody is a monoclinic structure. The characteristic cracks are relatively consistent, and the trend of landslide also coincides. Stage 4 (16-1101 landslide facing slip warning): the sliding surface completely losses its stability and sends out early warning information. On November 1st, 2016, at 3:40, the monitoring system reported the occurrence of the landslide, producing a loud noise. (3)After the slope slides (Figure 12(c)): controlling the sliding body In the case of large deformation, the elastic energy is released, the deformation energy inside the slope is less than the design constant resistance P of the resistor, the axial force F of the anchor cable is less than the friction force, and the soil body reaches a new equilibrium and stable state. The numerical analysis model of the NPR anchor cable was constructed by Fish language in numerical simulation software. (2) Analysis of Simulation Results(i)Numerical simulation analysis of the old landslide (Figure 18) Principles of simulation:(a)When the maximum unbalance force F is <1e − 5, the software determines the landslide as stable. Nanfen open-pit iron mine (Figure 7) of the Benxi Steel Group is located 25 km south of Benxi City, Liaoning Province. The maximum tensile force is 2,000 kN; the resolution of the tensile force is 3.3 × 10−6; and the strain rate and tension are in the ranges 0–200 mm/min and 30–5000 mm, respectively. Comparison of numerical simulation curve and monitoring curve. Nanfen open-pit iron mine is the largest single open-pit mine in Asia. The NPR anchor reinforcement unit is generally defined by geometric parameters, material parameters, and anchorage agent characteristics. Therefore, in practical calculation, the strength of the contact surface (sliding surface) should be weakened to decrease the rock mass instability.

There are also anchored piers, poles, and other equipment. The numerical simulation calculation of the whole process monitoring and early warning target of 16-1101 landslide in Nanfen open-pit iron mine was realized, indicating that the model can be used in Nanfen open-pit mine. (1) Insertion of the NPR Anchor Cable Model. Caribou, waterfowl, shorebirds and other wildlife are dependent on specific undeveloped habitats that have been protected under the 2013 plan.

The constant resistance body is the core part of the constant resistance and large deformation anchor cable, and its structure is shown in Figure 2 [18]. Figure 3 shows the schematic diagram of the static stretching system. Send submissions shorter than 200 words to letters@adn.com or click here to submit via any web browser.

proposed that “sliding force is greater than the shear strength, and it is the necessary and sufficient condition for landslide generation.” Based on this, they constructed the mechanical model of “sliding force monitoring” and developed an NPR anchor cable with constant resistance characteristics, which can adapt to landslide monitoring in deep deformation conditions [18–21]. The development of the 2013 plan, on which I participated, included substantial public outreach and input — more than 400,000 public comments were received in support of the final 2013 plan. Maihemuti et al. The slope failure simulated by 3DEC is in close agreement to the field investigation parameters: “16-1101 landslide” has an actual settlement of 3.5 m at the top; the slope of the middle part is broken, and the crack zone appears; the sinking amount is 12 m; a compression deformation zone is formed at the bottom, and a settlement is in the range 2-3 m. It is accumulated at a height of 430 m platform at the bottom. Calibration of model boundary and elevation: the maximum width of the old landslide body and “16-1101 landslide body” is 50 m, and the elevation limits are in the ranges 502–550 m and 430–502 m. Because the width of the model boundary is 2.5 times larger than the width of the target body, the height range of the model is 277–634 m, and the strike direction length is 200 m. In order to simulate the spatial relationship between the upper and lower sliding bodies and the interface characteristics of the sliding body during the start-up process, setting the interface elements between the sliding body and the rock foundation is necessary.
This alternative would open nearly 19 million acres — 82% of the Reserve — to oil and gas leasing, more than the area proposed in any of the alternatives analyzed in the draft plan and EIS.

The comparison between the numerical simulation results and the field measurement results shows good agreement between the simulation monitoring curve and the field monitoring curve and proves that this model can be used to monitor the landslide model of Nanfen open-pit mine. After the appearance of “16-1101 landslide,” the old landslide body “resurrected” and then slipped, and the 502 m step appeared staggered. The axial force variation in the NPR anchor cables located at 478 m steps in the landslide body is also divided into four stages, as shown in Figure 20. When the slope is about to slip or begin to slip, the original mechanical equilibrium state between the slope and NPR anchor cable will be destroyed, causing slip. In recent years, satellite remote sensing technology monitoring methods (SAR, INSAR, and D-INSAR) have been widely used in landslide monitoring leading to significant results [13–16]. Wildlife in the Reserve require large areas for their health and survival as their ranges and habitats are dynamic, varying with conditions year-to-year. For the template on this page, that currently evaluates to autocollapse. KNBA - Anchorage, AK - Listen to free internet radio, news, sports, music, and podcasts. Before excavation, the slope is in equilibrium.
Author: Pat Pourchot | Opinion.

The anchor cables are numbered as “MS-01-01,” “MS-01-02,” and “MS-01-03,” and their physical parameters are listed in Table 1. Reducing the casualties and property losses caused by landslides and forecasting them have been a research hotspot. Comparison of the axial force variation curve of the NPR anchor cable. It would dramatically increase the areas open to oil and gas leasing by seven million acres, as well as the areas allowing surface developments by 4.3 million acres. Stage 3 (relative displacement of 16-1101 slip surface): the slope has reached the safety threshold because of the shovel excavation, microcracks appear in the rock mass, relative displacement of the slip surface begins to appear, and the axial force of the NPR anchor cable increases suddenly.

Stream live CNN, FOX News Radio, and MSNBC. However, the NPR anchor cable monitoring, numerical modeling, and simulation analysis in the whole process of landslides are rarely investigated.

Figure 1 shows the structural composition of the NPR anchor cable, mainly including mechanical sensors, anchor cables (steel strands), constant resistance bodies, constant resistance bushings, top covers, backing plates, filling new materials, and other equipment. The results of this study indicate that the stress monitoring curves and failure characteristics of the NPR anchor cables in the whole process of landslide by the two numerical simulation methods are basically consistent with the field measurement results, providing a theoretical and practical basis for the mechanistic analysis and numerical simulation of other similar slopes. combined the finite element method suitable for the analysis of continuous problems with the discrete element method suitable for transient, contact detection, contact interaction, and other discrete problems [33]. The numerical simulation monitoring curve of the anchor cable force shows four times of rise and one time of decline, coinciding with the field monitoring curve. The speed and deformation of the old landslide body set to zero to fully consider the effect of the accumulated load caused by the old landslide body. Comparison of displacement distribution contour after the landslide instability process. When the relative displacement of the sliding surface reaches 2.54 m, the sliding surface completely losses stability, the anchor cable fails, the axial force suddenly drops to 18 kN, and the anchor cable extends to 1.45 m, eventually sending out warning information. When the sliding surface passes through, the software determines the sliding surface instability and stops calculation. (2)Slope sliding (Figure 12(b)): energy absorption process of the “NPR structure” When the slope is about to slip or begin to slip, the original mechanical equilibrium state between the slope and NPR anchor cable will be destroyed, causing slip. Monitoring curve of 16-1101 landslide by 3DEC software: (a) anchor cable force; (b) anchor cable elongation; (c) vertical relative displacement of monitoring point 1; (d) vertical relative displacement of monitoring point 2. Sun, and L. Gao, “Effective evaluation of pressure relief drilling for reducing rock bursts and its application in underground coal mines,”, W. Sun, H. Du, F. Zhou, and J. Shao, “Experimental study of crack propagation of rock-like specimens containing conjugate fractures,”, X. J. Yang, C. W. Hu, M. C. He et al., “Study on presplitting blasting the roof strata of adjacent roadway to control roadway deformation,”, T. Kamai, “Monitoring the process of ground failure in repeated landslides and associated stability assessments,”, R. Ohbayashi, Y. Nakajima, H. Nishikado, and S. Takayama, “Monitoring system for landslide disaster by wireless Sensing node network,” in, G. Puglisi, A. Bonaccorso, M. Mattia et al., “New integrated geodetic monitoring system at Stromboli volcano (Italy),”, B. The double-sliding model is shown below (Figure. In the present extrusion failure mode, tension fracture occurs in the middle and rear edges. He et al. Based on the monitoring data and the engineering geological conditions of “2016-1101 landslide,” in this study, we established the NPR anchor cable numerical calculation model and carried out numerical simulation on the monitoring of “2016-1101 landslide” through the Fish language in FLAC3D and 3DEC software. The static tensile mechanical properties. This new plan would supersede the current plan finalized in 2013.

These areas of special conditions are clearly geographically designed to accommodate and promote oil development, not to protect key areas utilized by the Teshekpuk Lake caribou or other wildlife resources.

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