(1) Basic methods for mine contact measurement
1. Contact the basic content of measurement work
The measurement that transfers the ground plane coordinate system and elevation system of the mine to the well is called contact measurement. Plane contact measurement refers to orientation, and elevation contact measurement is referred to as import elevation.
Mine orientation is divided into two categories, one is geometric orientation and the other is physical orientation.
The geometric orientation has a geometric orientation of a flat or inclined well, oriented through one vertical shaft (one well orientation) or through two vertical shafts (two well orientations).
Physical orientation is precision magnetic instrument orientation and gyro theodolite orientation.
The method of introducing the elevation is divided into a flat introduction high elevation, an inclined well introduction elevation, and a vertical well introduction elevation depending on the development method.
2. Contact the basic requirements of measurement work (emphasis)
(1) The contact measurement shall be performed at least twice independently. When the mutual difference does not exceed the tolerance, the weighted average or arithmetic mean is used as the measurement result.
(2) Before the contact measurement work, the near well point, the elevation base point and the continuous test lead point must be established near the wellhead, and no less than four permanent conductor points are buried in the stable rock or the body of the bottom hole yard and Three elevation base points (the permanent wire points can also be used as the elevation base point).
(3) Measurements by oblique or flat contact can be made from the near-well point on the ground, using theodolite wires (including photoelectric distance and gauge distance), triangular elevation or leveling.
(4) Use gyro theodolite orientation as much as possible, and allow geometric orientation if no conditions are met.
(5) The difference between two independent import elevations shall not exceed 1/8000 of the well depth.
(6) In principle, all kinds of wells leading to the ground should be contacted and measured.
(7) Before conducting the contact measurement work, the test plan and technical measures shall be prepared and submitted to the Geological Survey Department (or the chief engineer) of the Mining Bureau for approval. When conducting measurements, there should be a full command of the person in charge of the measurement.
(2) Near well network and near well point and wellhead elevation control point
1, the basic concept
The near well network is the mine measurement control network, and the near well point and the wellhead elevation base point are the reference points for mine measurement.
2. Near-well point and wellhead elevation base point layout requirements (emphasis)
(1) It should be buried in a place that is easy to observe, preserve and not affected by mining; the number of continuous test leads near the well point to the wellhead should not exceed three; the elevation base point should be no less than two (the near well point can be used as the elevation) Base point). (2)
(3) As far as possible, each near well point is located in the same plane control network, and the near well point of the adjacent wellhead constitutes one edge in the control network or the number of sides to be spaced apart is the least.
(4) The elevation accuracy of the wellhead elevation base point should meet the requirements for the main roadway penetration between two adjacent wellheads.
(5) The depth of the burial point of the near-well point and the wellhead level base point should not be less than 0.6m in the non-frozen area, and the height between the top surface of the boulder and the freezing line in the frozen soil area should be not less than 0.3m. In order to protect the near well point and the wellhead level from damage, protective piles and fences or gill nets should be placed around the points. Above the stone, piles of gravel with a height of not less than 0.5 m should be stacked.
Filter Element
Cartridge Filters,High Flow Filter Cartridge,Pp Spun Filter Cartridge,Washable Dust Cartridge Filter
Jinan Moland Environmental Tech Co.,Ltd , https://www.sdmoland.com