CN102535348A - Method for tensioning stayed cables of hinged tower cable stayed bridge - Google Patents

Abstract

The invention discloses a method for tensioning stayed cables of a hinged tower cable stayed bridge. The cable stayed bridge comprises a beam body, a bridge tower and the stayed cables, wherein the bridge tower consists of a main tower positioned above the beam body and a lower tower column rigidly connected with the beam body; and the main tower is hinged with the lower tower column. The method for tensioning the stayed cables comprises the following steps of: constructing a bridge foundation which comprises a pile foundation, a bearing platform and a pier column, and constructing the lower tower column while erecting the beam body; constructing the main tower hinged with the lower tower column, and hanging the stayed cables positioned on one side of the main tower; and hanging and tensioning the stayed cables positioned on the other side of the main tower. The method for tensioning the stayed cables of the hinged tower cable stayed bridge can be widely applied to the construction of cable stayed bridges of various structure systems, the work efficiency of tensioning the stayed cables can be greatly improved, and construction accuracy is ensured; and enough technical support and theoretical guarantee are provided for the construction of the cable stayed bridges in future, and the method has great practical significance.

Description

A tensioning method for cable-stayed cables of a hinged-tower cable-stayed bridge

technical field

The invention relates to a tensioning method for cable-stayed cables of a cable-stayed bridge, in particular to a tensioning method for cable-stayed cables of a hinged tower cable-stayed bridge.

Background technique

Cable-stayed bridge, also known as cable-stayed bridge, is a bridge in which the girder body is directly pulled on the bridge tower by many cable-stayed cables. a structural system. It can be regarded as a multi-span elastically supported continuous beam with cable-stayed cables instead of buttresses. It can reduce the bending moment in the beam body, reduce the height of the building, reduce the weight of the structure, and save materials.

As a cable system, the cable-stayed bridge has a larger spanning capacity than the girder bridge, and is the most important type of long-span bridge. A cable-stayed bridge consists of a bridge tower, a beam body, and cable-stayed cables. The bridge tower and beam body are used as a bridge deck system for compression, and the cable-stayed cables are used as a support system for tension. A composite bridge structure system. The types of bridge towers are A type, inverted Y type, B type, and single column, and the materials are steel and concrete. There are single cable plane, parallel double cable plane, oblique cable plane and so on for stay cable layout. The main structural systems of cable-stayed bridges are: floating system, semi-floating system, tower-beam consolidation system, rigid frame system, T-frame system, partial ground anchor system, low tower partial cable-stayed bridge system, etc. The cable-stayed cables of cable-stayed bridges are mainly arranged in the following forms: radial, harp-shaped, fan-shaped, etc.

In the construction of cable-stayed bridges, the tensioning method of the cable-stayed cables is mostly based on symmetrical tensioning of the main and auxiliary spans.

At present, the "dead load balance method" is mostly used for the preliminary drafting of the cable forces of the stay cables. The main assumptions of the "dead load balance method" include two aspects: one is that for the main span, the influence of the bending stiffness of the girder is ignored; the other is that for the auxiliary span, the bending stiffness of the bridge tower is ignored. Therefore, the disadvantage of the traditional cable-stayed cable tensioning method is that the cable-stayed cables need to be tensioned symmetrically, that is, the cable-stayed cables of the main span and the cable-stayed cables of the auxiliary span are simultaneously tensioned. The cable-stayed bridge shown in Fig. 1. The bridge tower (including the main tower 2 and the lower tower column 4) and the stay cable 3 are composed. One side of the bridge tower is the main span side, and the other side of the bridge tower is the auxiliary span side. The tensioning mode of the stay cable 3 Tensioning a1 and tensioning the cable b1 on the side of the auxiliary span; then tensioning the cable a2 on the side of the main span and tensioning the cable b2 on the side of the auxiliary span; then tensioning the cable a3 on the side of the main span At the same time, tension the stay cables b3 on the side of the auxiliary span; and so on, stretch all the stay cables. Due to the error of the hydraulic jack used by the stay cables, the main tower 2 rigidly connected to the lower tower column 4 (or the beam body 1) is bent, and the horizontal force of the beam body 1 is unbalanced.

Contents of the invention

Aiming at the above-mentioned prior art, the present invention provides a kind of tensioning method of the cable-stayed cables of the hinged pylon cable-stayed bridge, which is suitable for cable-stayed bridges in which the main and auxiliary spans are arranged with cable-stayed cables. Only the stay cables on one side of the bridge pylon need to be stretched, while the stay cables on the other side do not need to be stretched, which not only simplifies the tensioning process of the stay cables, but also eliminates the tension caused by the tension of the stay cables on both sides of the bridge pylon. The defect of bridge tower bending due to balance.

In order to solve the above-mentioned technical problems, the technical scheme realized by the tensioning method of the cable-stayed cables of a hinged-tower cable-stayed bridge in the present invention is: wherein the cable-stayed bridge includes a girder body, a bridge tower and a cable-stayed cable, and the bridge tower is located at The main tower above the beam body and the lower tower column rigidly connected with the beam body are formed, and the main tower and the lower tower column are hinged; the tensioning method of the stay cable includes the following steps:

Step 1, construction bridge foundation, described bridge foundation comprises pile foundation, cap and pier column, finishes the construction of lower tower column while erecting beam body;

Step 2. Construction of the main tower hinged with the lower tower column, and completion of the hanging cables located on one side of the main tower;

Step 3, completing the hanging and tensioning of the stay cables on the other side of the main tower.

Further, in the above step 1, the position of the lower tower coincides with the position of one of the piers of the bridge.

Also, in step 2 and step 3, the order of hanging cables is to hang cables outwards successively from the stay cables at the nearest hinge point.

In addition, step 3 includes one of the following two situations: after all the stay cables on this side are hung in sequence, then tensioning is carried out sequentially or after each stay cable is hung, the stay cable is then pulled The cable is stretched. During the tensioning process of the stay cable in step 3, it is determined whether to adjust the cable force of the stay cable according to the monitoring result of the stay cable force.

Compared with prior art, the beneficial effect of the present invention is:

(1) Reduce the number of stretches. Only the stay cables on one side of the bridge tower are stretched, and the number of stretches is 50% of the traditional stretching process, which greatly shortens the stretching time and saves the construction period.

(2) Reduce the tension error. Due to the error of the jack used in tensioning the cable stay, there will be an error every time the cable is stretched, and only the cable on one side of the bridge tower is stretched, and the cable on the other side can be determined by calculation. The corresponding cable force of the cable, the use coefficient of the jack is 50% of the traditional tensioning process, thereby reducing the error of the cable tension caused by the error of the jack itself.

A cable tensioning method of a hinged tower cable-stayed bridge according to the present invention can be widely used in the construction of various cable-stayed bridges in which cable-stayed cables are arranged on the main and auxiliary spans, and can not only greatly improve the tensioning work of the cable-stayed cables Efficiency, but also to ensure the accuracy of construction. It has very important practical significance to provide sufficient technical support and theoretical guarantee for the construction of cable-stayed bridges in the future.

Description of drawings

Fig. 1 is a schematic diagram of a cable tensioning method for a cable-stayed bridge rigidly connected to a bridge tower and a beam body in the prior art;

Fig. 2 is a schematic diagram of the stretching method of the cable-stayed cables of a hinged tower cable-stayed bridge of the present invention;

Fig. 3-1 to Fig. 3-5 are the schematic diagrams of the tensioning method embodiment of the cable-stayed cable of hinged tower cable-stayed bridge of the present invention;

Among them: Figure 3-1 is a schematic diagram after step 1 is completed,

Figure 3-2 is a schematic diagram of completing step 2.

Figure 3-3 is a schematic diagram of the first stay cable hanging cable tensioning completed in step 3,

Figure 3-4 is a schematic diagram after completing all stay cable hanging and tensioning.

Fig. 3-5 adopts the schematic diagram of the cable-stayed bridge that the stretching method of hinged tower cable-stayed bridge cable-stayed cable of the present invention completes;

Detailed ways

The present invention will be further described in detail below in combination with specific embodiments.

As shown in Fig. 2, a kind of tensioning method of the cable-stayed cable of hinge tower cable-stayed bridge of the present invention, wherein cable-stayed bridge comprises girder body 1, bridge tower and cable-stayed cable 3, and described bridge tower is positioned at beam body 1 top The main tower 2 is composed of the lower tower column 4 rigidly connected with the beam body 1, and the main tower 2 and the lower tower column 4 are hinged; According to the proposed principle, when the initial stay cable force is drawn up, the tensioning method of the stay cable 3 comprises the following steps:

Step 1, construction bridge foundation, described bridge foundation comprises pile foundation, cap and pier column, finishes the construction of lower tower column 4 while finishing beam body 1 erection; Wherein the position of lower tower column 4 can be with the bridge's The position of one of the piers coincides.

Step 2, constructing the main tower 2 hinged with the lower tower column 4, and completing the hanging cables positioned at one side of the main tower 2;

Step 3, completing the hanging and tensioning of the stay cables on the other side of the main tower 2 . When tensioning the stay cables, the stay cables on the side can be hung in sequence, and then stretched in sequence; La Zhang. In addition, according to the monitoring result of the cable force of the stay cable, it is determined whether to adjust the cable force of the stay cable.

For the convenience of construction, no matter which side of the bridge tower is located (there is no restriction on the side of the main span or the side of the auxiliary span), the order of the stay cables can be hung outwards from the stay cables closest to the hinge point. , but other orders are not restricted.

According to the principle of the preliminary drafting of the cable force of the "constant load balance method", when the initial cable force of the cable stay is drafted, the present invention adopts a hinged tower (hinged between the main tower 2 and the lower tower column 4) The purpose of ignoring the bending stiffness of the tower is achieved, so as to eliminate the influence of the bending stiffness of the bridge tower during the tensioning process of the stay cables. The present invention is characterized in that: the stay cables on one side of the bridge tower are not stretched, and the cable force of the side stay cables can be determined through numerical calculation. After the stay cable stretching is completed, the hinge of the hinge tower can be consolidated. Therefore, the tensioning method of the cable stay of the present invention is not only applicable to the hinge tower cable-stayed bridge but also can be applied to the stay cables of other structural system cable-stayed bridges. La Zhang.

The following describes the detailed process of the present invention through the examples. The examples are provided for the convenience of understanding, and are not intended to limit the present invention, such as the sequence of tensioning the cables of the stay cables.

Example:

Brief introduction of research materials: As shown in Figure 3-5, a cable-stayed bridge with hinged towers is adopted. The bridge towers are inclined 18° towards the center of the river. The span arrangement is: 45m front auxiliary span + 138m main span + 2x30m rear auxiliary span. The beam body adopts a steel and concrete composite structure, that is, the main span adopts a steel box girder structure, and the auxiliary span adopts a prestressed concrete box girder structure. The anchorage area of the side stay cables of the main span is located in the central dividing zone, with a horizontal spacing of 12m, and the anchorage area of the side stay cables of the auxiliary span is located outside the sidewalk, with a horizontal spacing of 3.75m. The stay cables of the auxiliary span are arranged such that the stay cable anchor point on the girder body closest to the bridge tower corresponds to the highest anchor point on the tower, and so on.

The bridge tower is a hinged tower with a total length of 120m. The position of the lower tower column coincides with the position of the main pier column of the bridge, and the main tower and the lower tower column (also the main pier column of the bridge) are hinged. The hinge that realizes the hinge is composed of upper and lower components, wherein the upper component is connected to the bottom of the main tower, and the lower component is anchored to the top of the lower tower column (that is, a pier column of the bridge foundation) through a fine-rolled threaded steel bar.

The tensioning process of the cable-stayed cables of the hinged tower cable-stayed bridge corresponding to the above research materials is as follows:

Step 1. Construction of the bridge foundation (pile foundation, cap and pier column), complete the erection of the beam body and the construction of the lower tower column at the same time, including the steel beam assembled by the bracket, and pour the front and rear auxiliary span concrete beam sections on the full hall bracket at the same time , the prestressed concrete beam section is prestressed, and the connection of the steel box girder of the main span and the prestressed concrete box girder of the auxiliary span is completed. After the beam body is connected, the support of the auxiliary span is removed, as shown in Figure 3-1;

Step 2: After constructing the main tower hinged with the lower tower column, install the stay cables on the side of the rear auxiliary span as shown in Figure 3-2, and complete the hanging cables in sequence from A9 stay cables to A1 stay cables The hanging cable of the stay cable on one side of the rear auxiliary span, and the main tower support is removed after the main tower reaches the predetermined position;

Step 3. Complete the hanging cables of the stay cables on one side of the main span in sequence. As shown in Figure 3-3, hang the cables from the stay cable B1 closest to the hinge point to the outside in sequence (that is, according to B1, B2, B3, B4, The order of B5, B6, B7, B8, B9), each time a stay cable is connected, then the stay cable is stretched, and the steel box girder bracket corresponding to the stay cable is removed after the design cable force is reached, until the completion of the main Hanging cable-tensioning of all stay cables on one side, as shown in Figure 3-4. During this process, all the stay cables A1, A2, A3, A4, A5, A6, A7, A8 and A9 on one side of the rear auxiliary span need not be stretched.

During the tensioning process of the stay cable in Step 3, according to the monitoring results of the stay cable force, it is determined whether to adjust the cable force of the stay cable, namely: compare the measured cable force value with the target cable force value to adjust the main Cable forces across side stays. For example, in this embodiment, for the stay cables on one side of the main span, follow the sequence of B9, B8, B7, B6, B5, B4, B3, B2, and B1 shown in Figure 3-4 to carry out supplementary cable adjustment. .

To sum up, according to the above steps, the cable-stayed cables of the cable-stayed bridge provided by the research materials can be stretched, which can save the tension of nine pairs of eighteen cables in the auxiliary span side cable-stayed cables A1-A9, and greatly reduce the tension caused by The force error of the cable-stayed cables caused by the tension has obvious advantages compared with the traditional cable-stayed cable tensioning construction technology of the cable-stayed bridge.

Although the present invention has been described above in conjunction with the drawings, the present invention is not limited to the above-mentioned specific embodiments, and the above-mentioned specific embodiments are only illustrative, rather than restrictive. Under the inspiration, many modifications can be made without departing from the gist of the present invention, and these all belong to the protection of the present invention.

Claims (5)

1. a kind of stretching method of cable-stayed cable of hinged tower cable-stayed bridge, wherein cable-stayed bridge comprises beam body (1), bridge tower and stay cable (3), and described bridge tower is positioned at beam body (1) top The main tower (2) of the main tower (2) and the lower tower column (4) that is rigidly connected with the beam body are composed of, and a hinge is used between the main tower (2) and the lower tower column (4); it is characterized in that: the The stretching method of stay cable (3) comprises the following steps: Step 1, construction bridge foundation, described bridge foundation comprises pile foundation, cap and pier column, finishes the construction of lower tower column (4) while finishing beam body (1) erection; Step 2, constructing the main tower (2) hinged with the lower tower column (4), and completing the suspension cables positioned at one side of the main tower (2); Step 3, completing the hanging and tensioning of the stay cables on the other side of the main tower (2). 2. the tensioning method of the cable-stayed cable-stayed bridge of hinged tower cable-stayed bridge according to claim 1 is characterized in that: in step 1, the position of the lower tower column (4) and the position of one of the pier columns of the bridge coincide. 3. the tensioning method of the cable-stayed cable of hinged tower cable-stayed bridge according to claim 1, is characterized in that: in step 2 and step 3, the order of hanging cables is to start successively from the cable-stayed cable at hinge point nearest place Hang the rope outward. 4. the tensioning method of the cable-stayed bridge of hinged tower cable-stayed bridge according to claim 1, is characterized in that: comprise one of following two situations in step 3: (1) After all the stay cables on this side are hung in turn, they are stretched in sequence; (2) After each stay cable is hung, the stay cable is tensioned immediately. 5. the tensioning method of the cable-stayed cable of hinged tower cable-stayed bridge according to claim 1, is characterized in that: in the cable-stayed tensioning process of step 3, according to the monitoring result to cable force of cable-stayed cable, determine whether Adjust the cable force of the stay cable.

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