Spatial self-anchored suspension bridge reference strand erection error correction method

Abstract

The invention provides a spatial self-anchored suspension bridge reference strand erection error correction method which comprises the following steps: after a reference strand is erected, calculating a difference value between the reference strand and a design value; according to the tower height of the bridge tower and the deviation of the span of the main beam, the correction amount # imgabs0 # of the reference strand height loss is calculated; temperature sensors are arranged on the reference strand and the main beam, and the reference strand height loss correction # imgabs1 # caused by temperature changes is calculated; calculating the corrected height loss of the reference strand according to the theoretical height loss # imgabs2 # of the reference strand and the height loss correction # imgabs3 # of the three parts, arranging a plurality of temporary slings between the main tower and the splay saddle, pulling the reference strand to move transversely, and pulling the reference strand to a transverse height loss design position. The method has the beneficial effects that the standard strand can be accurately erected under the conditions of large temperature difference and deviation of the height of the main tower and the span of the main beam, the unstressed line shape of the standard strand can be accurately controlled by eliminating correction of the height loss of the standard strand due to the fact that the height of the main tower, the span of the main beam and temperature change are eliminated, and the design requirement is met.

Description

Technical Field

[0001] The invention relates to the technical field of suspension bridges, and in particular to a method for correcting errors in the erection of reference strands of a spatial self-anchored suspension bridge. Background Art

[0002] A suspension bridge is a bridge with cables as the main load-bearing components. There are various types of suspension bridges. According to the main cable anchoring method, it can be divided into ground-anchored suspension bridges and self-anchored suspension bridges. Ground-anchored suspension bridges transmit the tension of the main cable to the foundation through anchors, which is suitable for large-span bridges, while self-anchored suspension bridges directly anchor the main cable to the main beam, which is suitable for areas with poor geological conditions, but the span is usually not too large. Self-anchored suspension bridges are generally built in the "beam first, cable later" manner, and their base strands directly affect the line shape of the main cable and the stress of the bridge structure.

[0003] When the self-anchored suspension bridge is erected with the benchmark strand, it has already been fixed to the main beam. Under the influence of the external environment, the main beam, main tower and benchmark strand will change the line shape of the benchmark strand due to changes in the external environment. During the erection of the benchmark strand of the self-anchored suspension bridge, the external environment not only causes the line shape of the benchmark strand to change, but also causes the length of the main beam to change. Even under the condition of stable temperature at night, due to the slow heat dissipation of the main beam, the main beam fails to lower the minimum temperature for a period of time, and the external environment begins to change again. As a result, it is difficult to erect the benchmark strand according to the theoretical design value, and there is a deviation between the theoretical loss of height of the benchmark strand and the adjusted loss of height. Therefore, it is urgent to propose a technology to overcome the deviation of the benchmark strand loss caused by changes in external environmental factors. Summary of the invention

[0004] The purpose of the present invention is to provide a method for correcting the error of the reference strand erection of a spatial self-anchored suspension bridge, so as to solve the problem that the reference strand erection method of the existing spatial self-anchored suspension bridge is not accurate enough under the adverse influence of large temperature differences.

[0005] A method for correcting errors in the erection of a reference strand of a spatial self-anchored suspension bridge comprises the following steps: S1: After the benchmark is erected, both ends of the benchmark are temporarily anchored; the tower height and main beam span are tested, and the difference between them and the design value is calculated, including the deviation of the tower height and main beam span; S2: Calculate the correction amount for the height loss of the benchmark section based on the deviation of the tower height and the main beam span ; S3: After the benchmark is erected, temperature sensors are placed on the benchmark and main beams to calculate the correction amount of the benchmark height loss caused by temperature changes. ; S4: Losing high according to the benchmark stock theory And the above three parts of height loss correction Superposition , and calculate the revised loss of the benchmark stock. The specific calculation formula is as follows: in It is the adjustment amount for the benchmark stock to lose height; dS is the stress-free cable length adjustment of the reference strand; is the main tower height deviation value; S5: Set up multiple temporary slings between the main tower and the loose cable saddle, use the jack to pull the reference strand to move laterally, and pull the reference strand to the lateral height loss design position.

[0006] As a preferred solution, the correction amount of the main tower height deviation to the benchmark stock is The calculation method is as follows: As a preferred solution, the correction amount of the deviation of the main beam span to the reference strand is The calculation method is as follows: in, is the main beam span; is the stress-free cable length of the reference strand.

[0007] As a preferred solution, the correction amount of the reference stock main temperature change to the reference stock The calculation method is as follows: in, is the main beam span; is the coefficient of thermal expansion.

[0008] As a preferred solution, the temporary sling includes a temporary cable clamp, an anchor and a steel strand. The reference strand is connected to the temporary cable clamp, the temporary cable clamp is connected to the steel strand and the anchor, and the other end of the steel strand is connected to a jack on the bridge deck, and the temporary cable clamp is pulled by the jack.

[0009] The beneficial effects of the present invention are: (1) The present invention realizes accurate installation of reference strands under large temperature differences, deviations in main tower height and main beam span. The method is simple and easy to implement.

[0010] (2) When the reference strand is erected, the present invention temporarily fixes both ends of the reference strand, thereby eliminating the influence of the main beam on the linear shape of the reference strand due to temperature changes.

[0011] (3) By eliminating the correction of the height loss of the reference strand caused by the main tower height, main beam span and temperature changes, the stress-free linear shape of the reference strand can be precisely controlled, meeting the design requirements. DETAILED DESCRIPTION

[0012] To illustrate the features of the present invention, the present invention will be further described below in conjunction with embodiments.

[0013] Embodiment 1: The embodiment of the present invention is a span arrangement of (50+350+350+50)=800m, using a single-tower space cable self-anchored suspension bridge. In the designed bridge state, the theoretical sag of the main cable mid-span is 27.32m, the rise-span ratio is 1 / 12.81, and the bridge tower is a column-type bridge tower structure consisting of a tower column, a lower crossbeam, and a saddle room. The main cable adopts a parallel steel wire prefabricated cable skeleton method.

[0014] This embodiment provides a method for correcting errors in the installation of a reference strand of a spatial self-anchored suspension bridge, comprising the following steps: S1: After the benchmark strand is erected, both ends of the benchmark strand are temporarily anchored; the tower height and main beam span are tested. The length of the benchmark strand is 774.934m, and the tower height and span deviations are 2cm and 5cm respectively; S2: Calculate the correction amount for the height loss of the benchmark section based on the deviation of the tower height and the main beam span ,in , ; in is the main tower height deviation value; S3: After the benchmark is erected, temperature sensors are placed on the benchmark and main beams to calculate the correction amount of the benchmark height loss caused by temperature changes. ; S4: Losing high according to the benchmark stock theory And the above three parts of height loss correction Superposition , and calculate the revised loss of the benchmark stock. The specific calculation formula is as follows: , the adjustment amount of the benchmark stock can be obtained as in It is the adjustment amount for the benchmark stock to lose height; dS is the stress-free cable length adjustment of the reference strand; S5: Set up 7 temporary slings between the main tower and the loose cable saddle, use the jack to pull the reference strand to move laterally, and pull the reference strand to the lateral height loss design position.

[0015] The actual measured value and theoretical value after the adjustment of the benchmark stock are shown in the following table: Measured value and theoretical value after adjustment of benchmark stock installation (unit: m) The temporary sling used in this embodiment includes a temporary cable clamp, an anchor and a steel strand. The reference strand is connected to the temporary cable clamp, the temporary cable clamp is connected to the steel strand and the anchor, and the other end of the steel strand is connected to the jack on the bridge deck, and the temporary cable clamp is pulled by the jack.

[0016] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the present invention. The present invention is described in detail with reference to the preferred embodiments. It should be understood by those skilled in the art that any changes, modifications, additions or substitutions made by those skilled in the art within the essential scope of the present invention do not deviate from the purpose of the present invention and should also fall within the scope of the claims of the present invention. Other related technical structures not fully disclosed in the present invention are prior art in the art.

Claims

1. A method for correcting the error of erecting a reference strand of a spatial self-anchored suspension bridge, characterized in that: The following steps are involved: S1: After the benchmark strand is erected, both ends of the benchmark strand are temporarily anchored; Test the bridge tower height and main beam span, and calculate the difference between them and the design value, including the deviation of the bridge tower height and main beam span; S2: Calculate the correction amount for the height loss of the benchmark section based on the deviation of the tower height and the main beam span ; S3: After the benchmark is erected, temperature sensors are placed on the benchmark and main beams to calculate the correction amount of the benchmark height loss caused by temperature changes. ; S4: Losing high according to the benchmark stock theory And the above three parts of height loss correction Superposition , and calculate the revised loss of the benchmark stock. The specific calculation formula is as follows: ， in It is the adjustment amount for the benchmark stock to lose height; dS is the length of the base stock; is the main tower height deviation value; is the main beam span; S5: Set up multiple temporary slings between the main tower and the loose cable saddle, use the jack to pull the reference strand to move laterally, and pull the reference strand to the lateral height loss design position.

2. A method for correcting errors in erecting a reference strand of a spatial self-anchored suspension bridge according to claim 1, characterized in that: The correction amount for the benchmark stock due to the deviation of the main tower height The calculation method is as follows: 。 3. The method for correcting the error of erecting a reference strand of a spatial self-anchored suspension bridge according to claim 1 is characterized in that: The correction amount of the deviation of the main beam span to the reference stock The calculation method is as follows: ， in, is the stress-free cable length of the reference strand.

4. The method for correcting the error of erecting a reference strand of a spatial self-anchored suspension bridge according to claim 1 is characterized in that: The correction amount of the reference stock main temperature change to the reference stock The calculation method is as follows: ， in, is the coefficient of thermal expansion.

5. The method for correcting the error of erecting a reference strand of a spatial self-anchored suspension bridge according to claim 1 is characterized by: The temporary sling includes a temporary cable clamp, an anchor and a steel strand. The reference strand is connected to the temporary cable clamp, the temporary cable clamp is connected to the steel strand and the anchor, and the other end of the steel strand is connected to a jack at the bridge deck, and the temporary cable clamp is pulled by the jack.

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