A construction method without jacking for saddle of a cable-stayed and suspension cooperative system bridge

Abstract

The present invention discloses a construction method without jacking for the saddle of a cable-stayed and suspension cooperative system bridge, which is carried out successively according to the following steps: constructing the outer shell of the main tower of the bridge and installing the main saddle; installing some main girder segments and temporarily fixing the main girder segments; tensioning the stay cables of the side span of the cable-stayed bridge section of the bridge to offset the main tower towards the side span. The number of the tensioned stay cables should ensure that when the main cable of the suspension bridge is erected on the existing tower-girder structure, the stress-free length of the side-middle span cable section of the main cable of the suspension bridge is consistent with the design target, and at the same time, the main cable of the suspension bridge does not slip in the saddle groove of the main saddle; installing the main cable of the suspension bridge; calculating the anti-slip safety factor of the main cable of the suspension bridge and installing the main girders of the cable-stayed bridge part and the main girders of the middle span suspension bridge part according to the obtained anti-slip safety factor; casting the composite section of the main tower; completing the installation of the remaining beam segments of the cable-stayed bridge part, the stay cables and the beam segments of the suspension bridge part, releasing the temporary constraints of the main girder, and finally forming the bridge.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge structure design, and particularly relates to a construction method without jacking for the saddle of a cable-stayed suspension cooperative system bridge. Background Art

[0002] A suspension bridge is a bridge that uses cables suspended and anchored at both banks (or both ends of the bridge) through pylons as the main load-bearing members of the superstructure. The cable-stayed suspension cooperative system bridge combines the advantages of a cable-stayed bridge and a suspension bridge, and has better structural stiffness than a suspension bridge. In recent years, it has been increasingly widely used. During the construction of a suspension bridge, the main saddle needs to be pre-offset towards the side span in advance. During the erection of the main girder, continuous jacking construction towards the middle span is carried out to ensure that the main cables on both sides of the main saddle do not slip.

[0003] However, with the increase in the span of the suspension bridge, the pre-offset amount of the saddle will also increase. Since the main saddle bears a large vertical force when approaching the completed bridge state, a large longitudinal jacking force is required, which will lead to great difficulty in implementing the traditional main saddle jacking construction method, and often affect the construction safety and construction period.

[0004] Therefore, there is a need for a method that can solve the above problems now. Summary of the Invention

[0005] The present invention is to solve the above technical problems, utilize the cable-stayed bridge structure of the cable-stayed suspension cooperative system bridge, overcome the defects of complex and difficult saddle jacking in large-span suspension bridges in the prior art, and provide a construction method without jacking for the saddle of the cable-stayed suspension cooperative system bridge.

[0006] The technical solution of the present invention is: a construction method without jacking for the saddle of a cable-stayed suspension cooperative system bridge, characterized in that: the construction method is carried out in the following steps in sequence:

[0007] S1. Build the outer shell of the bridge main tower 2 and install the main saddle 5;

[0008] S2. Install some main girder segments and temporarily fix the main girder segments;

[0009] S3. Tension the side-span stay cables 7 of the cable-stayed bridge section of the bridge to make the main tower 2 deflect towards the side span. The number of tensioned stay cables needs to be ensured so that when the main cable 3 of the suspension bridge is erected on the existing tower-girder structure, the stress-free length of the side-middle span cable section of the main cable 3 of the suspension bridge is consistent with the design target, and at the same time, the main cable 3 of the suspension bridge does not slip in the saddle groove of the main saddle 5;

[0010] S4. Install the main cable 3 of the suspension bridge;

[0011] S5. Calculate the anti-slip safety factor of the main cable 3 of the suspension bridge, and install the main girder 1 of the cable-stayed bridge part and the main girder 1 of the mid-span suspension bridge part according to the obtained anti-slip safety factor.

[0012] S6. Pour the composite section of the main tower 2.

[0013] S7. Complete the installation of the remaining beam segments of the cable-stayed bridge part, stay cables and beam segments of the suspension bridge part, release the temporary constraints of the main girder 1, and finally complete the bridge.

[0014] When performing the installation step of the main girder 1 of the cable-stayed bridge part in S5, the bridge structural state should meet the following requirements: After installing the mid-span main girder segment of the cable-stayed bridge part on the existing tower-beam structure, the anti-slip safety factor of the main cable 3 of the suspension bridge meets the requirements, and the main cable 3 of the suspension bridge will not slip towards the side span in the saddle groove of the main saddle 5.

[0015] When performing the installation step of the main girder 1 of the cable-stayed bridge part in S5, the bridge structural state should meet the following requirements: After installing the side-span main girder segment of the cable-stayed bridge part on the existing tower-beam structure, the anti-slip safety factor of the main cable 3 of the suspension bridge meets the requirements, and the main cable 3 of the suspension bridge will not slip towards the mid-span in the saddle groove of the main saddle 5.

[0016] When performing the installation step of hoisting the main girder 1 of the mid-span suspension bridge part in S5, the bridge structural state should meet the following requirements: After hoisting the mid-span main girder segment of the suspension bridge part on the existing tower-beam structure, the anti-slip safety factor of the main cable 3 of the suspension bridge meets the requirements, and the main cable 3 of the suspension bridge will not slip towards the mid-span in the saddle groove of the main saddle 5.

[0017] When performing the installation step of the main girder 1 of the cable-stayed bridge part in S5, the bridge structural state should meet the following requirements: When installing the mid-span main girder segment and the side-span main girder segment of the cable-stayed bridge part on the existing tower-beam structure at the same time, the anti-slip safety factor of the main cable 3 of the suspension bridge meets the requirements, and the main cable 3 of the suspension bridge will not slip towards the side span or the mid-span in the saddle groove of the main saddle 5.

[0018] When performing the installation steps of the main girder 1 of the cable-stayed bridge part and the main girder of the mid-span suspension bridge part in S5, the bridge structural state should meet the following requirements: When installing the mid-span main girder segment of the cable-stayed bridge part and hoisting the mid-span main girder segment of the suspension bridge part on the existing tower-beam structure at the same time, the anti-slip safety factor of the main cable 3 of the suspension bridge meets the requirements, and the main cable 3 of the suspension bridge will not slip towards the side span or the mid-span in the saddle groove of the main saddle 5.

[0019] The installation of the partial main girder segments in S2 consists of the following steps: Erect a temporary support 10 or bracket in the foundation area near the main tower 2, and hoist the main girder segments in the area without stay cables.

[0020] The installation of the main girder segments in S2 consists of the following steps: erect temporary scaffolds or brackets in the foundation area near the main tower 2, erect temporary scaffolds in the side span area, hoist the main girder segments in the area without stay cables and the side span main girder segments, and after connecting them section by section, push them into place towards the side span direction.

[0021] In step S3, the tensioning of the side span stay cables 7 of the cable-stayed bridge section of the bridge consists of the following steps: repeatedly perform the operations of "hoisting the side span beam segment and connecting it to the existing beam segment, and then tensioning the stay cable" until the deviation of the main tower 2 meets the bridge structural state described in step S3.

[0022] In step S3, the tensioning of the side span stay cables 7 of the cable-stayed bridge section of the bridge consists of the following steps: tension the stay cables of the side span beam segments one by one until the deviation of the main tower 2 meets the bridge structural state described in step S3.

[0023] In step S1, shear keys are arranged inside the outer shell of the bridge main tower 2 to enable the outer shell of the main tower 2 to jointly bear force with the main tower composite section of S6.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] The saddle-free jacking construction method of a cable-stayed and suspension cooperative system bridge of the present invention relies on the structural characteristics of the cable-stayed and suspension system bridge. By changing the conventional construction sequence of the cable-stayed and suspension cooperative system bridge, with the help of the asymmetric installation and tensioning of the main girder in the cable-stayed bridge section, the horizontal forces of the main cable in the side and middle spans are balanced through the deformation of the main tower during construction, and the jacking process of the saddle is cancelled, thus simplifying the construction of the suspension bridge and improving the operation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figures 1 to 7 It is a schematic diagram of steps S1 to S7 of Embodiment 1 of the present invention.

[0027] Figures 8 to 14 It is a schematic diagram of steps S1 to S7 of Embodiment 2 of the present invention.

[0028] Main girder 1, main tower 2, main cable 3 of the suspension bridge, hanger 4, main saddle 5, anchor and cable spreader saddle 6, side span stay cable 7, middle span stay cable 8, side pier 9, temporary scaffold 10. DETAILED DESCRIPTION OF THE INVENTION

[0029] The following will describe the specific embodiments of the present invention in conjunction with the drawings. As Figure 1 shown: A saddle-free jacking construction method of a cable-stayed and suspension cooperative system bridge is carried out in sequence according to the following steps:

[0030] S1. Build the outer shell of the bridge main tower 2 and install the main saddle 5;

[0031] S2. Install some main girder segments and temporarily fix the main girder segments.

[0032] S3. Tension the side-span stay cables 7 of the cable-stayed bridge section of the bridge to deflect the main tower 2 towards the side-span. The number of tensioned stay cables should be ensured so that when the main cable 3 of the suspension bridge is erected on the existing tower-girder structure, the stress-free length of the side-span and mid-span cable segments of the main cable 3 of the suspension bridge is consistent with the design target, and at the same time, the main cable 3 of the suspension bridge does not slip in the saddle groove of the main saddle 5.

[0033] S4. Install the main cable 3 of the suspension bridge.

[0034] S5. Calculate the anti-slip safety factor of the main cable 3 of the suspension bridge, and install the main girder 1 of the cable-stayed bridge part and the main girder 1 of the mid-span suspension bridge part according to the obtained anti-slip safety factor.

[0035] S6. Pour the composite section of the main tower 2.

[0036] S7. Complete the installation of the remaining beam segments of the cable-stayed bridge part, stay cables and beam segments of the suspension bridge part, release the temporary restraint of the main girder 1, and finally complete the bridge.

[0037] In step S3, the specific measures to ensure that the main cable 3 of the suspension bridge does not slip in the saddle groove of the main saddle 5 are as follows: Try to tension several pairs of side-span stay cables 7 to obtain the structural state after the tension of the side-span stay cables 7; Activate the main cable 3 of the suspension bridge on the structure after the tension of the side-span stay cables 7, and fix the main cable 3 of the suspension bridge to the main tower 2 to obtain the wrap angle of the main cable 3 on the saddle groove, the tension of the tight side of the main cable, and the tension of the slack side of the main cable; Calculate whether the anti-slip safety factor K of the main cable in the saddle groove meets the requirements according to the provisions of the "Design Code for Highway Suspension Bridges" (JTG / T D65-05-2015). When the anti-slip coefficient meets the requirements, it means that the selected number of tensioned pairs of side-span stay cables 7 is appropriate; When the anti-slip coefficient does not meet the requirements and the side-span main cable tension is greater, it means that the number of tensioned pairs of side-span stay cables 7 should be increased; When the anti-slip coefficient does not meet the requirements and the mid-span main cable tension is greater, it means that the number of tensioned pairs of side-span stay cables 7 should be reduced.

[0038] In step S5, after installing the mid-span main girder cable-stayed bridge segment and tensioning the stay cables, the main tower 2 will deflect towards the mid-span, the mid-span main cable will relax, and the side-span main cable will be tensioned. The main cable has a tendency to slip towards the side-span in the saddle groove of the main saddle 5. The anti-slip requirement should be met, that is, the bridge structural state should meet the following requirements: After installing the mid-span main girder segment of the cable-stayed bridge part on the existing tower-girder structure, calculate the wrap angle of the main cable on the saddle groove, the tension of the tight side of the main cable, and the tension of the slack side of the main cable. Calculate that the anti-slip safety factor K of the main cable in the saddle groove meets the requirements according to the provisions of the "Design Code for Highway Suspension Bridges" (JTG / T D65-05-2015), and the main cable will not slip towards the side-span in the saddle groove of the main saddle 5. Mark this requirement as A.

[0039] Similarly, in step S5, after installing the side-span main girder cable-stayed bridge section and tensioning the stay cables, the main tower 2 will deflect towards the side span, the side-span main cable will relax, and the mid-span main cable will be tensioned. The main cable has a tendency to slide towards the mid-span in the saddle groove of the main cable saddle 5, and the anti-sliding requirement should be met, that is, the bridge structure state should meet the following requirements: After installing the side-span main girder beam sections of the cable-stayed bridge on the existing tower-beam structure, calculate the wrap angle of the main cable on the saddle groove, the tension of the tight side of the main cable, and the tension of the loose side of the main cable. According to the provisions of the "Design Code for Highway Suspension Bridges" (JTG / T D65-05-2015), calculate that the anti-sliding safety factor K of the main cable in the saddle groove meets the requirements, and the main cable will not slide towards the mid-span in the saddle groove of the main cable saddle 5. Mark this requirement as B;

[0040] Similarly, in step S5, after hoisting the mid-span main girder suspension bridge section, the mid-span main cable will be tensioned, the side-span main cable will relax, and the main cable has a tendency to slide towards the mid-span in the saddle groove of the main cable saddle 5. The anti-sliding requirement should be met, that is, the bridge structure state should meet the following requirements: After hoisting the mid-span main girder beam sections of the suspension bridge on the existing tower-beam structure, calculate the wrap angle of the main cable on the saddle groove, the tension of the tight side of the main cable, and the tension of the loose side of the main cable. According to the provisions of the "Design Code for Highway Suspension Bridges" (JTG / T D65-05-2015), calculate that the anti-sliding safety factor K of the main cable in the saddle groove meets the requirements, and the main cable will not slide towards the mid-span in the saddle groove of the main cable saddle 5. Mark this requirement as C;

[0041] When performing the main girder installation step of the cable-stayed bridge part in S5, the bridge structure state should meet the following requirements: When installing the mid-span and side-span main girder beam sections of the cable-stayed bridge on the existing tower-beam structure at the same time, calculate the wrap angle of the main cable on the saddle groove, the tension of the tight side of the main cable, and the tension of the loose side of the main cable. According to the provisions of the "Design Code for Highway Suspension Bridges" (JTG / T D65-05-2015), calculate that the anti-sliding safety factor K of the main cable in the saddle groove meets the requirements, and the main cable will not slide towards the side span or the mid-span in the saddle groove of the main cable saddle 5.

[0042] When performing the main girder installation step of the cable-stayed bridge part in S5, the bridge structure state should meet the following requirements: When installing the mid-span main girder beam sections of the cable-stayed bridge and the mid-span main girder beam sections of the suspension bridge on the existing tower-beam structure at the same time, calculate the wrap angle of the main cable on the saddle groove, the tension of the tight side of the main cable, and the tension of the loose side of the main cable. According to the provisions of the "Design Code for Highway Suspension Bridges" (JTG / T D65-05-2015), calculate that the anti-sliding safety factor K of the main cable in the saddle groove meets the requirements, and the main cable will not slide towards the side span or the mid-span in the saddle groove of the main cable saddle 5.

[0043] When performing the steps of S5, first calculate the anti-slip safety factor of the main cable of the suspension bridge, and install the main girders of the cable-stayed bridge part and the main girders of the mid-span suspension bridge part according to the obtained anti-slip safety factor; that is to say, when the individual requirements A, B, and C can be met, any action corresponding to one of the requirements A, B, and C can be selected, and when the individual requirements A, B, and C cannot be met, the actions corresponding to requirements A and C can be combined and carried out simultaneously, or the actions corresponding to requirements B and C can be combined and carried out simultaneously.

[0044] That is to say, performing steps such as installing the main cable of the suspension bridge, installing the cable-stayed bridge section of the main girder, and installing the suspension bridge section of the main girder will all cause changes in the wrap angle of the main cable on the saddle groove, the tension of the tight side of the main cable, and the tension of the slack side of the main cable. The anti-slip safety factor K of the main cable in the saddle groove calculated according to the provisions of the "Design Code for Highway Suspension Bridges" (JTG / T D65-05-2015) will also change. Before and after performing the operations of S5 steps, the anti-slip safety factor of the main cable should meet the requirements to ensure the normal and safe progress of subsequent construction.

[0045] The installation of some main girder segments in S2 consists of the following steps: erect a temporary support 10 or bracket in the area near the main tower foundation, and hoist the main girder segments in the area without stay cables.

[0046] In the S3 step, the tensioning of the side-span stay cables of the cable-stayed bridge section of the bridge consists of the following steps: repeatedly perform the operation of "hoisting the side-span beam segment and connecting it to the existing beam segment, and then tensioning the stay cable" until the deviation of the main tower 2 meets the bridge structural state described in the S3 step.

[0047] The above is the technical solution corresponding to claim 9, that is, Embodiment 1 of the present invention, corresponding to the attached Figure 1 to the attached Figure 7 .

[0048] The installation of some main girder segments in S2 consists of the following steps: erect a temporary support 10 or bracket in the area near the main tower foundation, erect a temporary support in the side-span area, hoist the main girder segments in the area without stay cables and the side-span main girder segments, and push them into place segment by segment and then push them in the direction of the side span after connection.

[0049] In the S3 step, the tensioning of the side-span stay cables of the cable-stayed bridge section of the bridge consists of the following steps: tension the stay cables of the side-span beam segments one by one until the deviation of the main tower meets the bridge structural state described in the S3 step.

[0050] The above is the technical solution corresponding to claim 10, that is, Embodiment 2 of the present invention, corresponding to the attached Figure 8 to the attached Figure 14 ;

[0051] In the step S1, shear keys are arranged inside the outer shell of the bridge main tower 2 to enable the common force bearing of the outer shell of the main tower 2 and the composite section of the main tower 2 in S6.

[0052] In the step S1, the outer shell of the bridge main tower 2 can be made of steel structure or thin-walled high-performance concrete structure. Using steel structure or thin-walled high-performance concrete structure as the outer shell of the main tower 2 enables the structure of the main tower 2 to have both the bearing capacity to meet the early-stage construction of the bridge and good flexibility, so that the displacement that meets the requirement of no jacking for the main cable saddle of the suspension bridge can be generated more conveniently.

[0053] In the step S6, the post-cast composite section of the bridge main tower 2 can be made of concrete structure, which can not only meet the force-bearing requirements in the later stage of the main tower construction stage and the completed bridge state, but also save the construction cost.

Claims

1. A construction method without jacking for the saddle of a cable-stayed and suspension cooperative system bridge, characterized in that: The construction method is carried out successively according to the following steps: S1. Construct the outer shell of the main tower (2) of the bridge and install the main cable saddle (5); S2. Install some main girder segments and temporarily fix the main girder segments; S3. Tension the side-span stay cables (7) of the cable-stayed bridge section of the bridge to offset the main tower (2) towards the side-span side. The number of tensioned stay cables shall be ensured so that when the main cable (3) of the suspension bridge is erected on the existing tower-girder structure, the stress-free length of the side-span and mid-span cable segments of the main cable (3) of the suspension bridge is consistent with the design target, and at the same time, the main cable (3) of the suspension bridge does not slip in the saddle groove of the main cable saddle (5); S4. Install the main cable (3) of the suspension bridge; S5. Calculate the anti-slip safety factor of the main cable (3) of the suspension bridge, and install the main girder (1) of the cable-stayed bridge part and the main girder (1) of the mid-span suspension bridge part according to the obtained anti-slip safety factor; S6. Pour the composite section of the main tower (2); S7. Complete the installation of the remaining beam segments of the cable-stayed bridge part, stay cables and beam segments of the suspension bridge part, and release the temporary restraint of the main girder (1) to finally complete the bridge.

2. The construction method without jacking of the saddle of the cable-stayed and suspension cooperative system bridge according to claim 1, characterized in that: When carrying out the installation step of the main girder (1) of the cable-stayed bridge part in S5, the bridge structural state shall meet the following requirements: after installing the mid-span main girder segment of the cable-stayed bridge part on the existing tower-girder structure, the anti-slip safety factor of the main cable (3) of the suspension bridge meets the requirements, and the main cable (3) of the suspension bridge does not slip towards the side-span in the saddle groove of the main cable saddle (5).

3. The construction method without jacking of the saddle of the cable-stayed and suspension cooperative system bridge according to claim 1, characterized in that: When carrying out the installation step of the main girder (1) of the cable-stayed bridge part in S5, the bridge structural state shall meet the following requirements: after installing the side-span main girder segment of the cable-stayed bridge part on the existing tower-girder structure, the anti-slip safety factor of the main cable (3) of the suspension bridge meets the requirements, and the main cable (3) of the suspension bridge does not slip towards the mid-span in the saddle groove of the main cable saddle (5).

4. The construction method without jacking for the saddle of the cable-stayed and suspension cooperative system bridge according to claim 1, characterized in that: When carrying out the installation step of hoisting the main girder (1) of the mid-span suspension bridge part in S5, the bridge structural state shall meet the following requirements: after hoisting the mid-span main girder segment of the suspension bridge part on the existing tower-girder structure, the anti-slip safety factor of the main cable (3) of the suspension bridge meets the requirements, and the main cable (3) of the suspension bridge does not slip towards the mid-span in the saddle groove of the main cable saddle (5).

5. The construction method without jacking of the saddle of the cable-stayed suspension cooperative system bridge as claimed in claim 1, characterized in that: When carrying out the installation step of the main girder (1) of the cable-stayed bridge part in S5, the bridge structural state shall meet the following requirements: when installing the mid-span main girder segment and the side-span main girder segment of the cable-stayed bridge part on the existing tower-girder structure at the same time, the anti-slip safety factor of the main cable (3) of the suspension bridge meets the requirements, and the main cable (3) of the suspension bridge does not slip towards the side-span or mid-span in the saddle groove of the main cable saddle (5).

6. The construction method without jacking of the saddle of the cable-stayed suspension cooperative system bridge as claimed in claim 1, characterized in that: When carrying out the installation steps of the main girder (1) of the cable-stayed bridge part and the main girder of the mid-span suspension bridge part in S5, the bridge structural state shall meet the following requirements: when installing the mid-span main girder segment of the cable-stayed bridge part and hoisting the mid-span main girder segment of the suspension bridge part on the existing tower-girder structure at the same time, the anti-slip safety factor of the main cable (3) of the suspension bridge meets the requirements, and the main cable (3) of the suspension bridge does not slip towards the side-span or mid-span in the saddle groove of the main cable saddle (5).

7. The construction method without jacking of the saddle of the cable-stayed suspension cooperative system bridge according to claim 1, characterized in that: The part of installing some main girder segments in S2 consists of the following steps: erect a temporary support (10) or bracket in the foundation area near the main tower (2) and hoist the main girder segments in the area without stay cables.

8. The construction method without jacking for the saddle of the cable-stayed suspension cooperative system bridge as claimed in claim 1, characterized in that: The installation of the partial main girder segments in S2 consists of the following steps: erect temporary supports or brackets in the foundation area near the main tower (2), erect temporary supports in the side span area, hoist the main girder segments in the area without stay cables and the side span main girder segments, and after connecting them section by section, push them into place towards the side span direction.

9. The construction method without jacking for the saddle of the cable-stayed and suspension cooperative system bridge as claimed in claim 1 or 7, characterized in that: In step S3, the tensioning of the side span stay cables (7) of the cable-stayed bridge section consists of the following steps: repeatedly perform the operations of "hoisting the side span beam segment and connecting it to the existing beam segment, and then tensioning the stay cable" until the deviation of the main tower (2) meets the bridge structural state described in step S3.

10. The construction method without jacking for the saddle of the cable-stayed and suspension cooperative system bridge according to claim 1 or 8, characterized in that: In step S3, the tensioning of the side span stay cables (7) of the cable-stayed bridge section consists of the following steps: tension the stay cables of the side span beam segments one by one until the deviation of the main tower (2) meets the bridge structural state described in step S3.

11. The construction method without jacking for the saddle of the cable-stayed and suspension cooperative system bridge according to claim 1, characterized in that: In step S1, shear keys are arranged inside the outer shell of the bridge main tower (2) to enable the outer shell of the main tower (2) to jointly bear the load with the main tower composite section of S6.

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