A method for controlling alignment of pre-fabricated segmental beams based on a short-line matching method

Abstract

The invention relates to the technical field of alignment control of pre-assembled segmental beams in bridge engineering, in particular to a method for controlling alignment of pre-fabricated segmental beams based on a short-line matching method. The method comprises the following steps: S1, performing on-site data measurement; S2, establishing a local global coordinate conversion system; S3, n-1# block 6 control point measured local coordinates are converted into measured global coordinates data; S4, deviation analysis is performed on the -1 # block; S5, determining the coupling angle of n-1 #two end axis and performing decoupling; S6, calculating the correction coordinates of the I end of the n # block; S7, judging whether the adjustment is made to the n + 1 # block; S8, judging whether there is deviation in the construction of the n # block, and if so, adjusting the positioning point of the I end section of the n + 1 # block; S9, obtaining the local coordinate data of the six control points when the n # block is used as the matching block to prefabricate the n + 1 # block through the global-local coordinate conversion, which has the beneficial effect that the real beam block axis deviation angle can be obtained, and the calculation accuracy of the corrected coordinate of the prefabricated beam block is improved.

Description

technical field [0001] The invention relates to the technical field of alignment control of segmental beam prefabrication in bridge engineering, in particular to a method for controlling the alignment of segmental beam prefabrication based on a short-line matching method. Background technique [0002] 1. Common control methods for segmental beam prefabrication in the field of bridge engineering: [0003] The short-line matching method is a construction technique that divides the bridge girder into several short segments and pours them segment by segment. During prefabrication, the coordinates of the geometric linear control points in the overall coordinate system of the bridge are converted into coordinates in the on-site prefabricated coordinate system, and used as the basis for linear control, starting from the initial beam segment (block 0#) of each span, and the previous block The poured beam sections (block 0# is the movable end formwork) are used as the rear end match...

AI Technical Summary

Problems solved by technology

[0130] (1) The calculation accuracy of the correction coordinate value of n# block I is not enough

[0131] Reason: The corrected coordinate value is obtained by first rotating the horizontal plane according to the horizontal deviation angle, and then performing vertical elevation rotation according to the vertical deviation angle (see formulas 1-9~1-11), but it is not considered in the plane rotation The impact on the coordinate z (that is, the z coordinate is considered as a constant value), and the influence on the x, y coordinates is not considered when the facade is rotated (that is, the x, y coordinates are considered as a constant value)

[0132] (2) There may be errors in the deviation angle analysis results in the local coordinate system

[0134] (3) The angle coupling problem is not considered, resulting in errors in the deviation angle analysis

[0138] (4) The included angle problem between the control point connection line and the axis of the prefabricated section is not considered, resulting in a deviation in the calculation

If the construction unit can bury the control points in accordance with the requirements parallel to the axis during the construction of each block, then the error caused by this approximate consideration may not be very large, but when there is a large angle between the control point connection line and the axis (see Figure 10 ), this approximate consideration will cause a large error. In the construction of short-line matching, which requires millimeter precision as the requirement, this error is likely to cause great trouble to the subsequent line shape control.

[0143] (5) The I end of the next prefabricated beam (n+1# block) is not adjusted, so that the axis of the beam block is no longer perpendicular to the fixed end formwork

[0144] In short-line matching construction, it is necessary to ensure that the axis of each prefabricated beam is perpendicular to the fixed end (see figure 1 ), but due to construction errors, the section at the I end of the prefabricated block n# will deviate from the theoretical design, such as Figure 11 shown, resulting in It is no longer perpendicular to the fixed end, and the fixed end mold is fixed, so if you want to keep the axis of the n+1# block perpendicular to the fixed end mold to ensure the construction accuracy, you need to fix the positioning point of the I end of the n+1# block (I point, K point, V point) to make adjustments

At present, prior art 1 (including prior art 2 and prior art 3) does not take this problem into account

[0145] (6) The deviation angle correction method is not flexible enough, and the practical application is not convenient enough

In fact, this part of the V-xyz local coordinate system is unnecessary and involves angle orientation problems, and it is easy to cause calculation errors due to the increased system conversion

[0150] (2) The angle coupling problem is not considered

[0152] (3) The angle between the control point line and the axis of the prefabricated section is not considered

[0154] (4) There is no measure to ensure that the axis of the next prefabricated beam is perpendicular to the fixed end form

We know that a plane can be determined by selecting three points, but it is difficult to ensure that the remaining three points are also on the same plane during actual construction, which will cause difficulties in system conversion calculations, even if the least squares It is also difficult to guarantee the accuracy of the multiplication solution, and it is easy to cause such a result: the prediction result of some points is very good, but other points may have a large deviation

[0159] (2) The angle coupling problem is not considered

[0161] (3) The angle between the control point line and the axis of the prefabricated section is not considered

[0163] (4) There is no measure to ensure that the axis of the next prefabricated beam is perpendicular to the fixed end form

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