1, Engineering Overview
Mayor Qi Irrigation District is located in Guangxi Fangchenggang most southern Shiwandashan southern foot. Irrigation jurisdiction Fangchenggang anti-urban and port areas were nine townships, with a total area of 1433km2, accounting for anti-urban areas, the port area a total area of 51.45%, the total irrigated area of arable land 17.47km2. Irrigation District main canal of the current design flow 12m3 / s, total length of 10.08km. Left trunk design flow 8.4m3 / s, total length of 66.6km, the right trunk design flow 3.6m3 / s, total length of 21.78km. canal system after 20 years of running the building, siltation, leakage, collapse of the more common, subsidiary buildings and equipment seriously damaged, especially the aqueduct, bucket gate damage to more prominent. To improve irrigation efficiency of irrigation and water supply for the qisha Industrial Park, Linhai Industrial Park, the development of economic, Fangchenggang city government decided to length of about 98km trunk main channel and carry out remediation construction of impervious reinforcement expansion. The engineering survey mission is to carry out irrigation trunk topographic mapping, and for the design of flat band topographic maps, as well as vertical and horizontal cross-section.
2, vertical and horizontal cross-section measurement of the working methods of
Optimization of the working methods of channel cross-section measurements in the field along the channel central axis with the tape Measure the channel mileage, starting from 0 +000 Stake every 20 meters marked with a cross-section of Stake, there are important channels for water facilities, or terrain changes in the subsidiary a larger increase in cross-section of local Stake. With the water level measured from the first-stage control point elevation to the sections cited in the pile, thereby finishing the pile mileage and elevation mapping will be entitled to channel vertical section diagram. And then cross-sectional measurements, usually there are two ways to cross-sectional measurements, the first one is the field measurement method, the pile began to cross-section from both sides of the vertical ruler with two intersecting lines of planning based on expenditure to the various points of spacing and elevation difference, collate the data plotted cross-section, this approach requires testing facilities must reach the cross-section on each feature point. Since the mid-seventies Nagaki irrigation in operation since the state of disrepair for many years, landslides have occurred, the steep slope channels of the two sides and there is no rule, measure each section will have to pay a high price, simply using this method will waste a lot of The human and material resources; The second method is measuring the field with total station measurements, easy-to-walk in the flat areas based on field measurement method, used elsewhere in Total Station measurements, the advantage of saving time and resources to address the high-side Shi slope measured cross-section of staff can not be measured, we opted for this method. Channels found in the work of some areas, such as the irrigation main channel 6 +500 to 7 +510 section, channels on both sides of high slope are rocky slope, slope exceeds 60 degrees and no change in the law, subject to conditions, Shi test personnel hard to reach the middle of feature points on the slope mining point, if a simple point and top of the hill slope with the slope-point connected to draw the cross-section does not match with the field, resulting in the amount of engineering and engineering estimates accuracy unreasonable deviation. To solve this problem, we have adopted a non-prism Total Station Leica TPS1200 measurements.
3, non-prism measurement techniques Introduction and application conditions
About 3.1 Non-prism measurement technology is based on non-prism measurement principle of phase-based method, issued a very narrow laser beam, can be very accurately hit the target to ensure high-precision distance measurement. Measurements are compared with the prism, its advantage is that as long as the measuring point of the reflective medium in line with non-prism measurement conditions, do not need to be placed at the measuring point on the prism, you can measure the three-dimensional coordinates of the point. Within the scope of this technology around the world has been widely used, it has good technical specifications: high-precision (3mm + 2ppm), large-scale (using the standard Kodak gray cards, which range up to 180 meters [1]), with a visible red laser spot, as well as a small beam diameter. In order to achieve excellent standards, using 3R-level visible laser, and using non-prism distance measuring technology phase-based method. As for the International Laser standards, 3R laser class is relatively is relatively new, it is often a class 3B laser mix to use. Class 3R laser laser is a relatively new standard, its safety classes ranging from two lasers and laser class 3B between the guide contains fewer security restrictions. From this perspective, 'R' is used to indicate "requirements to simplify." Class 3R laser non-reflecting prisms ranging in their application can be measured in scope than the Class 2 laser with a fold increase for the surveyors to improve operational efficiency is beneficial. In accordance with international laser safety standards, 3R type laser operators should be careful not to make people look directly at a laser beam eyes. To trigger a measurement when the measurement of key personnel, the laser can be activated to measure completed its been closed. When you open a laser pointer, when, 3R type lasers can also be activated. The human eye exposed to laser lines such as, naturally, some of the reactions (for example: pupil narrowing, strabismus, eye transfer) will be more or less harm reduction, so that the human eye in the laser beam because of the more unintentionally a long time the possibility of injury caused negligible in.
3.2 Non-prism measurement techniques applicable conditions for each measurement device has its own characteristics and scope of practice found in non-prism measurement techniques applicable to the following conditions:
(1) applies to pass, as the conditions are good, reflecting the media's good points, in the reflective medium dark, smoking was too light, reflected poor conditions in places like inappropriate use of non-prism measurements.
(2) Non-prism measurement technique suitable for measurement of reflective surfaces exposed to the measuring point elevation, such as rocks, housing, roads, etc., and within sight of the topography, surface features point of elevation.
(3) non-prism measurement for line of sight no obstacle to measuring the topography of surface features, if there are any obstacles between the measured coordinates of the obstacles, elevation. To measure the terrain outside the 400-meter point, if there is a place in the 200 meters line of sight leaves block will be measured is the foliage of the coordinates, elevation.
(4) non-prism measurement consumes a larger power supply, outside the industry will be ready to meet the power, if necessary, equipped with an external power supply.
(5) Be careful not to mirror the surface like a laser beam fired.
(6) Shi measured during the process of observing a long time through the eyepiece the subject matter in order to avoid the eye a long time where the laser beam caused injuries.
(7) No prism measurement is difficult for officers is difficult to reach, reflecting the media a good terrain measurement, such as cliffs, valleys, traffic major highway, there are highly toxic and other surface features.
4, Leica TPS1200 characteristics and Shi testing process
4.1 TPS1200 Leica TPS1200 is characterized by a long measuring range, ultra-high precision with a variety of functions and easy to use total stations. Intuitive menu-based operating system, clear, able to guide users to complete the work required independently, users can set up their own operations as needed, display and output. TPS1200 offers many on-board programs, such as measurement, set up stations, lofting, coordinate geometry, you can use G eoC + + procedures for the preparation of a dedicated airborne. Coaxial measuring principle is the visible red laser phase measurement, non-prism measurement range of 500m, while measuring accuracy 2mm +2 ppm / typ, angle measuring accuracy of 2 〃
4.2 Shi test process
4.2.1 Control of measuring channels, water diversion project a very high elevation accuracy requirements, due to channel length, the error accumulation of more channels, the error is too large will affect the water flow, water, or even give rise to channel the water back flow phenomenon, affecting the water supply effects. Therefore, we use the Pentax and SOKKIA LEVEL simultaneous operation of two operating groups, the first-stage elevation control points from the GPS measurement cited to various sections, the elevation difference closure are to meet the specifications. In the section line pass as the selected conditions are good, easy to set up stations where prism tripod to do with the TPS1200, and wires, encryption map the root points to the cross-section.