This application claims priority to Chinese Patent Application No. 201110033983.5, filed on Jan. 31, 2011, entitled “Universal Precise Leveling Measuring Device and Measurement Method thereof”, which is hereby incorporated by reference in its entirety.
The present invention relates to measurement technology, and more particularly to a universal precise leveling measuring device and a measurement method thereof for measuring levelness of various foundations of a wind power generator set.
According to prior art, a steel tower and a foundation of a wind power generator set are generally connected securely in two modes including a foundation ring mode and an anchor bolt mode. Since the wind power generator set is a high-rise structure subjecting to a larger horizontal load, a higher levelness is required for the connection structure within the foundation no matter which mode is used to securely connect the wind power generator set and the foundation. In the construction of the foundation of the wind power generator set, the levelness of the connection structure of the foundation ring or the anchor bolt is calibrated by adjusting three or more leveling supports below the foundation ring or the anchor bolt. In prior art, the levelness of the connection structure of the foundation ring or the anchor bolt is measured by a scale and a level. After the foundation ring or the anchor bolt is in place by putting an anchor ring, reinforcing bars are bound and then concrete is poured. During the curing of the concrete and before hoisting of the tower, a levelness of a flange on the foundation is measured by the following steps:
1. determining the number of measuring control points (generally a multiple of 3 and no less than 6), and marking these points on the flange (or the anchor ring) by equidistant points;
2. determining the position of the level (generally on the edge of foundation pit), then putting and leveling the level;
3. holding and controlling, by one person, the scale in perpendicular to the flange or anchor ring at the measuring control points marked in step 1;
4. reading, by another person, a reading (which is the height value in relation to the flange) of the scale from the level at the location of level, thus finishing the height measurement of one measuring control point;
5. repeating steps 3˜4 to finish the height measurement of remaining measuring control points; and
6. taking the maximum and minimum height valves of all measuring control points and obtaining their difference, which is the final data required for the level measurement.
It can be seen from the aforementioned measurement steps that the measurement method of prior art has the following shortcomings: since the scale is held manually in perpendicular to the flange or anchor ring at the measuring control point, the verticality of the scale cannot be assured, and thus the measurement accuracy is insufficient and susceptible to human factors. The measured reading is the height value of the measuring control point, so a desired level offset value can only be obtained through cumbersome multiple measurement for multiple points and conversion, thus affecting the accuracy of the final data. At least 2 persons shall be required to conduct the measurement collaboratively, and one level offset value can be obtained by measuring at least 6 points, which results in a heavy workload. In the case where the levelness of the connection structure of the foundation ring or the anchor bolt is found unacceptable, the leveling supports set below the flange or anchor ring shall be required for leveling and then the measurement is repeated; if it's still unacceptable, it's required to repeat leveling and measurement, causing higher time consumption and lower efficiency.
Moreover, with the successful development of high-power wind power generator set in our country, there is a growing demand on the height and bottom diameter of the tower. Thanks to the advantages of anchor bolts such as more convenient fabrication and transportation, lower cost, better integrity and more reasonable structural stress, the anchor bolt type foundation in large-sized generator set will become a major trend in the near future. Of which, the upper and lower flanges as well as the template flange in the anchor bolt foundation need to be leveled, meanwhile more workload on level measurement will be required. Thus, a common concern is raised to conduct an accurate, convenient, efficient and economical level measurement in the foundation construction of large-sized wind power generator set.
One aspect of the present invention provides a universal precise leveling measuring device and a measurement method thereof, with its purpose of solving the shortcomings in prior art and realizing an accurate, convenient, efficient and economical level measurement in the foundation construction of large-sized wind power generator set.
A universal precise leveling measuring device according to an embodiment of the present invention comprise a plate-shaped horizontal base, a round bubble level set at the center of an upper surface of the base, and three outriggers set on the base. At least one through-hole is set at one end of each of the outriggers far from the base, and a point contact bolt is set in the through-hole. The three outriggers are extended in different directions and in the same plane parallel to the base, and included angle of two adjacent outriggers is smaller than 180°.
With the universal precise leveling measuring device of the present invention, the prior art manual levelness measurement of foundation flange of wind power generator carried out by using a scale and a level is modified into the dynamic measurement carried out only by using the universal precise leveling measuring device, thus increasing the measurement precision, simplifying the measurement procedures, reducing the workload of the operator, and further guaranteeing the construction quality and performance of various foundations of the wind power generator set.
The technical solutions of the present invention are further described with reference to the drawings and embodiments.
In the present embodiment, the foundation levelness of the wind power generator set is measured by the universal precise leveling measuring device in the following steps:
1. cleaning up an upper surface of a flange (or anchor ring) preset in the foundation, and then marking a center position of the flange by a red pen;
2. putting the point contact bolts 34 into the suitable through-holes 33 on respective outriggers 3 depending on the size of the flange;
3. placing the universal precise leveling measuring device of the present embodiment on the flange using the point contact bolts 34 in such a way that the round bubble level 2 is set correspondingly to the center position of the flange marked by the red pen; and then marking the positions of the point contact bolts 34 on the flange by the red pen;
4. observing a reading of the round bubble level 2; if a levelness offset exceeds a threshold, adjusting leveling bolts set below the flange or anchor ring while observing a bubble position of the round bubble level 2; finishing a first sampling measurement after the reading of the round bubble level 2 is within the threshold; and
5. rotating the universal precise leveling measuring device by a certain angle with respect to a center position thereof, and then repeating the above steps 2˜4 to finish a second and more sampling measurements.
Generally, the number of measuring control points is a multiple of 3 and no less than 6, namely, at least two sampling measurements are required to meet the actual engineering demands. It can be seen from the aforementioned steps that, the universal precise leveling measuring device of the present invention can be used easily, helping to eliminate the human errors arising from manual holding and reading in prior art, and also guaranteeing the measurement accuracy. Moreover, the flange is leveled in tune with the reading of the round bubble level, thus enabling to realize dynamic measurement, simplifying greatly the measurement process, shortening the measurement time and improving the construction efficiency of foundations of the wind power generator set.
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Finally, it should be noted that the above examples are merely provided for describing the technical solutions of the present invention, but not intended to limit the present invention. It should be understood by the ordinary skill in the art that although the present invention is described in detail with reference to the foregoing embodiments, modifications can be made to the technical solutions described in the foregoing embodiments, or equivalent replacements can be made to some technical features in the technical solutions, without the essence of corresponding technical solutions departing from the spirit and scope of the embodiments of the present invention.
Number | Date | Country | Kind |
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201110033983.5 | Jan 2011 | CN | national |