CN106638318A - Method for positioning anchor point of beam end of cable stayed bridge and installation method of cable guide pipe - Google Patents

Abstract

The invention discloses a method for locating anchor points at the ends of cable-stayed bridges and a method for installing cable guides. The direction is the Z axis, and the origin of the three-dimensional coordinate system is the center point of the tower; according to the design drawings, the coordinates of the anchor center point in the three-dimensional coordinate system are (X ₀ , Y ₀ , Z ₀ ) and the centerline of the stay cable and The included angle ɑ between the XY planes is calculated by back-calculating the coordinates of the four corner points at the installation position of the cable-stayed anchor plate. First calculate the spatial coordinates of the four corner points at the installation position of the anchor plate, stake out and measure the four installation position points at the mark on the anchor tooth block formwork, and continuously adjust the installation position points during the installation process of the anchor tooth block formwork The spatial positions of the four corner points until the installation position of the anchor tooth block formwork coincide with the spatial positions of the four corner points, which has the advantages of simple installation and convenient construction.

Description

Positioning method of cable-stayed bridge end anchor point and installation method of cable guide

technical field

The invention relates to the technical field of cable-stayed bridge construction, in particular to a method for locating an anchor point at an end of a cable-stayed bridge and a method for installing a cable guide.

Background technique

Cable-stayed cables are an important part of cable-stayed bridges, and whether the positioning of the cable guides during cable-stayed cable construction is accurate is related to the cable-hanging, tensioning and cable force control of the cable-stayed cables in the later stage. During the construction of wide cable-stayed bridges, it is difficult and inaccurate to locate the anchor point relative to the main tower cable guide due to factors such as the deformation of the hanging basket and the deflection of the cantilever beam. However, in the construction of cable-stayed bridges, the accurate positioning of the anchor points of the cable-stayed beam ends will seriously affect the later hanging, tensioning and adjusting of cables.

Generally, the front fulcrum hanging basket construction technology is adopted, and the cable stays are stretched three times. The positioning of the cable guide at the beam end first fixes the cable guide on the stay cable, installs the stay cable and sets the outlet point of the cable guide for pre-lifting, and finally completes the small Stay cable tensioned. In general, the design only gives the basic parameters of the cable guides in the completed bridge state, but the positioning of the cable guides in each section of the main girder is affected by construction dynamics during construction, such as the deformation of the hanging basket and the deflection of the cantilever beam body. Very difficult. In the traditional process, the cable guide and the stay cable are directly centered or properly pre-lifted according to experience. After the stay cable force is adjusted, the stay cable is often not in the center of the cable guide. The traditional installation method has low precision, poor reliability, and low efficiency. It needs to repeatedly set up the instrument, which takes a long time, requires more personnel, complicated installation, and is easily affected by the weather.

Contents of the invention

Aiming at the defects existing in the prior art, the object of the present invention is to provide a positioning method for the anchor point of a cable-stayed bridge end and a cable conduit installation method, which can accurately calculate the anchor point of the cable-stayed cable, so that the spatial posture of the cable conduit conforms to Design requirements, with the advantages of high precision, convenient installation and high reliability.

For achieving above object, the technical scheme that the present invention takes is:

A method for locating an anchorage point at the end of a cable-stayed bridge, comprising the steps of: constructing a three-dimensional coordinate system, taking the horizontal direction of the cable-stayed bridge as the X axis, the direction along the bridge as the Y axis, and the direction along the bridge as the Z axis, and the three-dimensional coordinate system The origin of is the center point of the tower;

According to the design drawings, it is known that the coordinates of the anchorage center point in the three-dimensional coordinate system are (X ₀ , Y ₀ , Z ₀ ) and the included angle ɑ between the center line of the stay cable and the XY plane,

The coordinates of the four corner points at the installation position of the stay cable anchor plate are calculated by the back-calculation method as (X ₁ , Y ₁ , Z ₁ ), (X ₂ , Y ₂ , Z ₂ ), (X ₃ , Y ₃ , Z ₃ ) and (X ₄ , Y ₄ , Z ₄ ).

On the basis of the above technical scheme, the coordinate calculation formulas of the four corner points at the installation position of the stay cable anchor plate are as follows:

Among them, L is the side length of the anchor plate.

A cable conduit installation method based on the positioning method as claimed in claim 1, the specific steps are as follows:

S1, making the cable guide and anchor tooth block formwork according to the preset scheme, and vertically welding the cable guide and the stay cable anchor plate;

S2, install and adjust the hanging basket to the design position of the hanging basket;

S3, calculate the coordinates of the four corner points at the installation position of the cable-stayed anchor plate according to the positioning method, and obtain the spatial positions of the four corner points at the installation position of the cable-stayed anchor plate. Four installation position points are measured and set out on the anchoring surface of the formwork, and the installation position points correspond to the spatial positions of the four corner points of the stay cable anchor plate, and the anchor tooth block formwork is installed to the design position, and the design position The installation position points coincide with the four corner points of the stay cable anchor plate respectively;

S4, the four corner points of the cable-stayed anchor plate coincide with the four installation points respectively, so that the cable-stayed anchor plate and the anchoring surface are closely attached, and the embedded steel support is set according to the inclination angle of the cable-stayed cable. The pre-embedded steel support supports the fixed cable guide.

On the basis of the above technical scheme, the coordinate calculation formulas of the four corner points at the installation position of the stay cable anchor plate are as follows:

Among them, L is the side length of the anchor plate.

Compared with the prior art, the present invention has the advantages of:

(1) The positioning method of the anchor point of a cable-stayed bridge end of the present invention is by establishing a space coordinate system, and then using the known anchor center point to carry out reverse calculation to calculate the space coordinates of the four corner points at the anchor pad installation position , the interference factors are small, and the positioning is accurate.

(2) cable conduit installation method of the present invention uses the location method of cable-stayed bridge end anchor point to calculate the spatial coordinates of the four corner points at anchor backing plate installation position earlier, by known main girder cable-stayed cable anchor block and Anchor parameter table Stake out and measure the four installation position points at the marks on the anchor tooth block template. The installation position point coincides with the space position of the four corner points, which can accurately install the anchor tooth block formwork, and then fix the anchor plate to realize the precise positioning of the cable guide, which has high accuracy, good reliability, high efficiency, and does not need to be repeated It takes less time to set up the instrument, less staffing, simple installation and convenient construction.

Description of drawings

Fig. 1 is the structural representation after hanging basket is installed in design position in the embodiment of the present invention;

Fig. 2 is a structural schematic diagram of the anchor tooth block formwork installed in the design position in the embodiment of the present invention;

Fig. 3 is a structural schematic diagram of the positioning and installation of the cable guide in the embodiment of the present invention.

In the figure: 1-hanging basket, 2-anchor tooth block template, 3-cable guide, 4-steel support.

detailed description

The present invention will be described in further detail below in conjunction with the accompanying drawings and embodiments.

Referring to Fig. 1, an embodiment of the present invention provides a method for locating an anchor point at the end of a cable-stayed bridge, comprising the following steps: constructing a three-dimensional coordinate system, with the cross-bridge direction of the cable-stayed bridge as the X-axis, the direction along the bridge as the Y-axis, The longitudinal direction of the bridge is the Z axis, and the origin of the three-dimensional coordinate system is the center point of the tower;

According to the design drawings, it is known that the coordinates of the anchorage center point in the three-dimensional coordinate system are (X ₀ , Y ₀ , Z ₀ ) and the included angle ɑ between the center line of the stay cable and the XY plane;

According to the coordinate calculation formula of the four corner points at the installation position of the stay cable anchor plate, the coordinates of the four corner points at the installation position of the stay cable anchor plate are calculated as (X ₁ , Y ₁ , Z ₁ ) , (X ₂ , Y ₂ , Z ₂ ), (X ₃ , Y ₃ , Z ₃ ) and (X ₄ , Y ₄ , Z ₄ ), the formulas are as follows:

Among them, L is the side length of the anchor plate.

A cable conduit 3 installation method is characterized in that the specific steps are as follows:

S1, process and manufacture the cable guide 3 according to the design plan of the cable guide 3 on the design drawing, set the control of the cable guide 3 concentrically with the anchor hole of the anchor backing plate, and weld the cable guide 3 vertically to the cable-stayed anchor backing plate;

Manufacture the anchoring tooth block template 2 according to the design scheme of the anchoring tooth block template 2 of the design drawing, and the anchoring surface of the anchoring tooth block template 2 is provided with a reserved through hole for cable stay;

S2, as shown in Figure 1, install and adjust the hanging basket 1 to the design position of the hanging basket;

S3. First, calculate the coordinates of the four corner points at the installation position of the stay cable anchor plate as (X ₁ , Y ₁ , Z ₁ ), (X ₂ , Y ₂ , Z ₂ ), (X ₃ , Y ₃ , Z ₃ ) and (X ₄ , Y ₄ , Z ₄ ), the calculation process is as follows:

Construct a three-dimensional coordinate system, taking the horizontal direction of the cable-stayed bridge as the X axis, the longitudinal direction as the Y axis, and the longitudinal direction as the Z axis, and the origin of the three-dimensional coordinate system is the center point of the tower;

According to the design drawings, it is known that the coordinates of the anchorage center point in the three-dimensional coordinate system are (X ₀ , Y ₀ , Z ₀ ) and the included angle ɑ between the center line of the stay cable and the XY plane;

According to the coordinate calculation formula of the four corner points at the installation position of the stay cable anchor plate, the coordinates of the four corner points at the installation position of the stay cable anchor plate are calculated as (X ₁ , Y ₁ , Z ₁ ) , (X ₂ , Y ₂ , Z ₂ ), (X ₃ , Y ₃ , Z ₃ ) and (X ₄ , Y ₄ , Z ₄ ), the formulas are as follows:

Wherein, L is the side length of the anchor pad, and the specification of the cable-stayed anchor pad in the present embodiment is LXL;

Obtain the spatial positions of the four corner points at the installation position of the stay cable anchor plate according to the coordinates of the four corner points at the installation position of the stay cable anchor plate;

Secondly, referring to Fig. 2, according to the known main girder stay cable anchor block and anchor parameter table, four installation position points are measured and staked out on the anchor surface of the anchor tooth block formwork 2, and the installation position points are consistent with the stay cable The spatial positions of the four corner points of the anchor pad correspond one by one;

Again, during the installation process of the anchor tooth block formwork 2, the spatial positions of the four installation points and the four intersection points are continuously adjusted until the anchor tooth block formwork 2 is installed to the design position, and the installation position points at the design position are respectively connected to the cable-stayed The four corners of the cable anchor plate coincide;

S5, as shown in Figure 3, the four corner points of the cable-stayed anchor plate coincide with the four installation points respectively, so that the cable-stayed anchor plate and the anchoring surface are closely attached, according to the inclination angle of the cable-stayed cable A pre-embedded steel bar support 4 is set, and the pre-embedded steel bar support 4 supports the fixed cable conduit 3 .

The present invention is not limited to the above-mentioned embodiments. For those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications are also considered protection of the present invention. within range. The content not described in detail in this specification belongs to the prior art known to those skilled in the art.

Claims (4)

1. a kind of localization method of cable-stayed bridge beam-ends anchor point, it is characterised in that comprise the steps：Build three-dimensional system of coordinate, With cable-stayed bridge direction across bridge as X-axis, along bridge to as Y-axis, vertical bridge to as Z axis, and the origin of three-dimensional system of coordinate is tower central point；

The coordinate of the anchoring central point according to known to design drawing in three-dimensional system of coordinate is (X₀, Y₀, Z₀) and suspension cable center line Angle ɑ between X/Y plane,

The coordinate that four angle points of suspension cable anchor plate installed position are calculated by anti-pushing manipulation is respectively (X₁, Y₁, Z₁)、(X₂, Y₂, Z₂)、(X₃, Y₃, Z₃) and (X₄, Y₄, Z₄)。

2. a kind of localization method of cable-stayed bridge beam-ends anchor point as claimed in claim 1, it is characterised in that：Suspension cable anchor plate The coordinate computing formula of four angle points of installed position is as follows：

$X_1=X_0+\frac{L}{2},Y_1=Y_0+\frac{Lsin\mathrm{\α}}{2},Z_1=Z_0+\frac{Lcos\mathrm{\α}}{2};$

$X_2=X_0-\frac{L}{2},Y_2=Y_0+\frac{Lsin\mathrm{\α}}{2},Z_2=Z_0+\frac{Lcos\mathrm{\α}}{2};$

$X_3=X_0-\frac{L}{2},Y_3=Y_0-\frac{Lsin\mathrm{\α}}{2},Z_3=Z_0-\frac{Lcos\mathrm{\α}}{2};$

$X_4=X_0+\frac{L}{2},Y_4=Y_0-\frac{Lsin\mathrm{\α}}{2},Z_4=Z_0-\frac{Lcos\mathrm{\α}}{2};$

Wherein, L is the length of side of anchor plate.

3. a kind of cable guide pipe installation method based on localization method as claimed in claim 1, it is characterised in that concrete steps are such as Under：

S1, according to presupposed solution cable guide pipe and anchoring tooth block template are made, and by cable guide pipe and suspension cable anchor plate vertical welding；

S2, installs and adjusts Hanging Basket to Hanging Basket design attitude；

S3, the coordinate of four angle points of suspension cable anchor plate installed position is calculated according to the localization method, is obtained tiltedly The locus of four angle points of drag-line anchor plate installed position, surveying and locating goes out four on the anchoring face of anchoring tooth block template Individual installation site point, and installation site point and the locus one-to-one corresponding of four angle points of suspension cable anchor plate, will anchor tooth Block model sheetinstallat is to design attitude, and installation site point overlaps respectively with four angle points of suspension cable anchor plate at design attitude；

S4, four angle points of suspension cable anchor plate is overlapped respectively with four installation site points so that suspension cable anchor plate and anchor Gu face is brought into close contact, embedded bar support is arranged according to the angle of inclination of suspension cable, embedded bar support holds fixed cable guide pipe.

4. cable guide pipe installation method as claimed in claim 3, it is characterised in that：

The coordinate computing formula of four angle points of suspension cable anchor plate installed position is as follows：

$X_1=X_0+\frac{L}{2},Y_1=Y_0+\frac{Lsin\mathrm{\α}}{2},Z_1=Z_0+\frac{Lcos\mathrm{\α}}{2};$

$X_2=X_0-\frac{L}{2},Y_2=Y_0+\frac{Lsin\mathrm{\α}}{2},Z_2=Z_0+\frac{Lcos\mathrm{\α}}{2};$

$X_3=X_0-\frac{L}{2},Y_3=Y_0-\frac{Lsin\mathrm{\α}}{2},Z_3=Z_0-\frac{Lcos\mathrm{\α}}{2};$

$X_4=X_0+\frac{L}{2},Y_4=Y_0-\frac{Lsin\mathrm{\α}}{2},Z_4=Z_0-\frac{Lcos\mathrm{\α}}{2};$

Wherein, L is the length of side of anchor plate.