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This post was last edited by hesonchang214 on 2019-1-25 at 22:15. For control surveys during the construction process, when the terrain is flat and buildings and structures are arranged in an orderly manner, it is advisable to set up () as the plant’s planar control network to facilitate construction. A. Elevation control network B. Traverse network C. Building grid network D. Control network 【Correct answer】: C Explanation: This question tests the basic requirements for control surveying during the construction process. Basic requirements for control surveys during the construction process: (1) For the establishment of the control network for construction process control, the existing planimetric and elevation control networks in the area can be utilized; they should be used when they meet the technical requirements for construction surveys. (2) When the terrain is flat and buildings and structures are arranged neatly, a building grid network should be established as much as possible as the plane control network for the plant area, to facilitate construction work. The main technical requirements for the building grid system are established by estimating the precision required to meet the positioning needs of ordinary buildings. Its deployment adopts a scheme of secondary networking encryption. For the primary control of the building grid, the axis method or the grid layout method can be employed. (3) For construction sites larger than 1 km2 or important industrial complexes, a plane control network with accuracy equivalent to that of first-class traverse lines is advisable; for construction sites smaller than 1 km2 or ordinary building areas, a plane control network with accuracy equivalent to that of second- or third-class traverse lines can be established as needed. (4) The control survey of the building shall be carried out in accordance with the design requirements, and the survey points should be selected in locations with good visibility and suitable for long-term preservation. Indicative piles for control network encryption should be installed along the alignment of building rows or in the direction of the centerline of major equipment. Concrete fixed markers should be installed at the main control points and the endpoint of the main equipment center line. (5) The leveling points for controlling the elevation of buildings can be buried separately on the stakes of the building’s planar control network, or existing leveling points near the site can be utilized; the distance between them should be around 200 ram. When level points cannot be preserved during construction, their elevation should be measured relative to a stable building or structure. The accuracy of the surveying shall not be lower than the grade requirements of the original leveling.