Designing a polygonometric path and preliminary calculation of its accuracy when creating a geodetic base Plan



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Designing a polygonometric path and preliminary calculation of its accuracy when creating a geodetic base
Plan
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1. Natural-geographic characteristics of the project area
2. Design principles, goals and methods
3. Designing the project
Summary


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The purpose of this coursework is to design and perform preliminary calculation of the accuracy of the base bounding (fruit) network in the form of 4th grade polygonometry.
Tasks to be solved in the process of designing course work: strengthening and expanding special knowledge, mastering design experience, summarizing conclusions and independent recommendations based on completed calculations.
The project is created in the area bounded by the 1:10000 card trapezium frame. Designing is carried out in accordance with the requirements for the construction of state geodetic networks specified in the "Rules for the construction of state geodetic networks".
Polygonometric path is made between the triangulation points on the map, taking into account the topography of the area. The road is designed in the most convenient places for line and angle measurements. The road is designed in an elongated shape, which allows the use of simple formulas for the initial calculation of the accuracy of the road to be built. The work consists of an explanatory text and an appendix showing the graphic part. The graphic shows the following:
- a copy of the topographic map showing the route project and the geodetic base used;
- scheme - copy the road from the map to the map, showing the calculated angles and lengths, the coordinates of the base points and the projected signs;
- longitudinal profile of the place to determine the visibility between waypoints;
- solving inverse geodesic problems;
- the road scheme made to calculate the road shape setting characteristics;
- polygonometry tayanch belgilarini joylashtirish markazlarining sxemasi.
Natural-geographic characteristics of the project area


The project area is an undulating plain separated by river valleys. Water separators are slightly rounded and flat. There is one hill with a height of 128.9 m. The average height of the project area is 80-100 m. The main form of relief is plain.
The design area of the base and border network crosses two rivers. River valleys are crossed at a height of 70-80 meters.
The vegetation consists of row trees, meadows, young branches and broad-leaved trees.
Not far from the project area are the cities of Elsen, the city of Molaison; settlements - Klein-Woltersdorf, Seedorf. The highway to Lanburg passes through this area.
A design district is an undeveloped area.


Design principles, goals and methods


The main task of designing is to choose the option of polygonometric roads and networks from all possible options, which corresponds to the tasks from the point of view of accuracy and requires minimum labor and financial costs for implementation.
The design of class 4 polygonometric roads and networks is carried out taking into account the scale and method of future surveys, the requirements of the guidelines for the construction of state geodetic networks. Before designing, the boundaries of the working area should be determined; collecting information about working conditions in it: information about communication methods and means, meteorological data, physical-geographical and geomorphological descriptions, hydrological research data, etc.; 1: 25000 and larger scale topographic maps, previously performed triangulation
and collecting schemes of polygonometric networks, determining the availability and suitability of starting points (topographic and geodetic survey). In addition, before starting work, it is necessary to clarify the necessary density of geodetic points, as well as the accuracy of determining the location of points, direction angles and line lengths, taking into account the prospects for the development of areas in accordance with the master plan and land development plan. . Polygonometric paths are designed as separate open paths based on two starting points. Polygonometric networks are designed to provide large areas with geodetic points. It should be taken into account that roads and networks of the 4th class must be based on triangulation points and polygonometry points of the higher class.
When drawing up the project, first of all, the most appropriate scheme of network construction, the accuracy of measuring angles and lines are determined, and the expected errors are calculated. If the expected accuracy does not meet the requirements, then the construction scheme is changed and the calculation is repeated. Detailed design of polygonometric roads of the 4th class is carried out on topographic maps on a scale of 1: 25,000 for the undeveloped area and on a scale of 1: 10,000 for the settlement. On the maps, first of all, the starting points are drawn on the territory of the object and neighboring areas, after which the directions of individual roads are determined in accordance with the adopted scheme of network development. Roads are marked where they can be used with maximum efficiency, but taking into account both the character of the area and the available instruments for line measurements. Roads should be laid in places where it is most convenient to perform angle and line measurements.
Accordingly, polygonometric roads are determined along or near communication roads, along river valleys, along existing forest roads, bypassing swamps.
After determining the direction of individual roads, the position of individual points is chosen by observing the maximum and minimum lengths of the lines. It should not be forgotten that in order to set polygonometric symbols
designated places should ensure their long-term storage. Signs should not be installed in cultivated fields, swamps, landslides, etc.
After the project is developed, the volume of work is calculated, the need for tools, materials, transportation, technicians and labor is determined. Based on this, a cost estimate and work organization plan will be drawn up. Later, all these documents are determined based on reconnaissance data.




Creating a project
The design and creation of polygonometric roads is carried out in several stages: drawing up the project, reconnaissance of the route, setting signs and centers, measuring angles, measuring lines, connecting to DGT point, processing the results of field measurements, assessment of the accuracy of preliminary calculations and field measurements, assessment of the accuracy of equalization calculations and obtained results, compilation of a catalog and technical report.
Designing is carried out taking into account the requirements of "Instructions for topographic surveying on the scale 1:5000, 1:2000, 1:1000, 1:500".
When drawing up the project, the expected accuracy of the road is preliminarily calculated. [s] is taken from the card, combinable L, number of lines n, number of angles n+1, maximum and minimum sides, ssr.
The educational map on which the design of the basic boundary network in the form of 4th grade polygonometry is carried out is a topographic map on a scale of 1:50,000. - 6004295.00, along the ordinate axis - 2407695.00 - 2415235.00.
In the 2-4th class polygonometry networks, it is necessary to ensure a mutual view along the line: a sighting target (retracement) - a place for installing an angle measuring device and/or a dalnumer.
When searching for a polygonal road construction option, the following considerations should be followed:
the location and construction of signs must ensure their minimum height;
the location of the points should be approximately the same, using the column height of the place for them;
the location of the points should ensure the long-term preservation of the centers, the safety and convenience of conducting observations;
points should be selected on solid ground, away from railways and highways, all types of buildings, telephone lines, at a distance not closer (further) than twice the height of the sign;nuqtalarning yuqori kuchlanishli tok chizig‘idan uzoqligi kamida 120 m bo‘lishi kerak.
The height of the characters can be calculated analytically and graphically.
If there are several obstacles in the plot between the points, then the required sign heights are calculated separately for each obstacle and those that require the maximum sign heights are selected.
After calculating the height of the characters in all directions, the most useful combination of them is selected for each pair of points. The most economically useful elevation of a pair of points is the pair with the smallest sum of elevations.






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