Disclosure of Invention
The invention overcomes the defects of the prior art, provides the installation method of the suspension bridge steel trusses, and particularly has the characteristics of simple connection sequence of the suspension bridge steel trusses, less overhead rigid connection workload and low safety risk.
The technical problem solved by the invention can be realized by adopting the following technical scheme:
a method for installing a steel truss girder of a suspension bridge comprises the following steps:
the method comprises the following steps: respectively building main towers at two opposite sides of a mountain, and then installing cable cranes;
step two: hoisting the beam section and the bridge deck of the bridge through a cable crane;
step three: when the beam section of the bridge is installed through the cable crane, firstly installing the beam section No. 1 of the secondary middle beam section at the central line position of the bridge, and then installing the beam section No. 0 of the middle beam section;
step four: on the basis of the third step, symmetrically hoisting the rest beam sections from the central line position of the bridge to two banks in sequence, and hinging the corresponding beam sections;
step five: inserting and hoisting steel bridge deck plates in the hoisting process of the beam sections, and performing rigid connection between corresponding beam sections when the local linear type of the hoisted beam sections reaches a bridge linear type bridge section in the hoisting process;
step six: repeating the step five, and continuing to finish hoisting the beam section and the bridge deck of the bridge;
step seven: and on the basis of the sixth step, the bridge deck is symmetrically welded and bolted from the midspan of the whole bridge to the main towers on both sides.
The beam sections are steel trusses, the structure of each steel truss is a rectangular frame structure consisting of a closed section and an open section, and the beam section No. 1 and the beam section No. 0 in the step III are both steel trusses.
In the first step, after the main towers on two sides are built, the cable crane is installed, the cable crane is debugged and tried to be hung, and then the sling and the cable clamp are installed.
And in the second step, before the girder section and the bridge deck of the bridge are hoisted, the girder section and the bridge deck assembly field is leveled, and the girder section and the bridge deck are assembled in advance.
And in the fourth step, when the beam sections are symmetrically hoisted from the central line position of the bridge to the two banks in sequence, after the beam sections are hoisted for a certain number of times, the two No. 1 beam sections, close to the main towers at the two banks, of the whole bridge are hoisted in advance in a swinging manner, and then the rest beam sections and the bridge decks are hoisted symmetrically to the two banks in sequence.
Two No. 1 beam sections close to the two-bank main tower are lifted with the integral beam section closure section in the middle in an oscillating mode, then the whole beam section is lifted, and finally the rest bridge decks are lifted.
Two No. 1 beam sections close to the two-bank main tower and the integral beam section closure section at the middle part can also be subjected to pre-deflection closure and vertical hoisting, then the hoisting of the whole beam section is completed, and finally the rest bridge deck is hoisted.
And in the fourth step, when the rest beam sections are symmetrically hoisted, the beam sections of the large bridge are hoisted firstly, then the bridge deck on the closed joint is hoisted symmetrically by utilizing the vacant time of hoisting the beam sections, the rigid connection part reaches the beam sections in the bridge line shape, and the newly formed closed joint is hoisted after rigid connection.
The mounting method of the steel truss girder of the suspension bridge, wherein the girder section comprises two main cross girders, the two main cross girders comprise a first main cross girder and a second main cross girder, when the girder section is hoisted, four hoisting points are arranged on the girder section, the four hoisting points comprise a first hoisting point, a second hoisting point, a third hoisting point and a fourth hoisting point, the first hoisting point and the second hoisting point are arranged on the first main cross girder, and the third hoisting point and the fourth hoisting point are arranged on the second main cross girder.
The invention has the beneficial effects that:
compared with the prior art, the rigid connection construction of the hoisting beam sections is gradually carried out along with the hoisting, the traditional method requires integral rigid connection after the hoisting is completely finished, a large amount of rigid connection construction is carried out simultaneously, the personnel and equipment (resource) input amount is large, the construction cost is high, the rigid connection operation occupies the main line construction period, and the construction period of the whole bridge is prolonged. The method has the characteristics of simple installation and connection sequence of the suspension bridge plate girder and the girder, less overhead rigid connection workload and low safety risk, simultaneously avoids the second-stage constant-load equal-generation load weight construction in the prior method, saves resources, adjusts the hoisting sequence of the steel truss, hoists the end girder section in advance, avoids pier-side supports in the prior method, adopts non-end girder sections in the closure section, optimizes the construction process and saves resources.
Detailed Description
Example 1:
referring to fig. 2 and 3, a method for installing a steel girder of a suspension bridge includes the steps of:
the method comprises the following steps: respectively building main towers at two opposite sides of a mountain, and then installing cable cranes;
step two: hoisting the beam section and the bridge deck of the bridge through a cable crane;
step three: when the beam section of the bridge is installed through the cable crane, firstly installing the beam section No. 1 of the secondary middle beam section at the central line position of the bridge, and then installing the beam section No. 0 of the middle beam section;
step four: on the basis of the third step, symmetrically hoisting the rest beam sections from the central line position of the bridge to two banks in sequence, and hinging the corresponding beam sections;
step five: inserting and hoisting steel bridge deck plates in the hoisting process of the beam sections, and performing rigid connection between corresponding beam sections when the local linear type of the hoisted beam sections reaches a bridge linear type bridge section in the hoisting process;
step six: repeating the step five, and continuing to finish hoisting the beam section and the bridge deck of the bridge;
step seven: and on the basis of the sixth step, the bridge deck is symmetrically welded and bolted from the midspan of the whole bridge to the main towers on both sides.
Wherein the installation order of conventional No. 1 roof beam section and No. 0 roof beam section in step three is for installing No. 0 earlier, and No. 1 is installed afterwards, advantage and principle: in the implementation case, the beam section No. 1 is a 4-sling beam section which is stable after installation, and the beam section No. 0 is a double-sling beam section which needs to be provided with temporary slings to keep stability. Then, the No. 1 beam section is installed firstly, then the No. 0 beam section is hoisted, and the No. 0 beam section is hinged with the No. 1 beam section, so that temporary slings are saved, construction steps are saved, and construction time is shortened.
And seventhly, after the bridge deck plates are symmetrically welded and bolted from the midspan of the whole bridge to the main towers at two ends, bridge deck systems and accessory facilities need to be installed, and the cable crane is dismantled to complete the whole construction traffic engineering.
The method is used for hoisting the beam sections in the rigid connection and subsection manner, the aerial full-hinged operation of the hoisting and subsection is realized, the overhead rigid connection operation amount is reduced by 50%, the safety risk is reduced, the steel bridge deck is hoisted in the hoisting process of the beam sections in an inserting manner, the local linear type of the beam sections can reach the bridge linear type in the hoisting process, the working condition that the local linear type of the beam sections can reach the bridge linear type is obtained through software calculation, the calculation method is that the basic information of a constructed large bridge is input into corresponding data calculated by software 'super-large span suspension bridge construction control analysis system 1.0', the length that the local linear type of the beam sections can reach the bridge linear type is determined, the second-stage constant load of the bridge refers to the weight of the bridge deck structure and the accessory facilities, the design linear type of the steel truss girder is consistent with the linear type finished by second-stage constant load construction, the second-stage constant load construction with the pressure weight is carried out after the hoisting of the beam sections is finished, so that the linear type of the beam sections can reach the design linear type, the internal stress can be reduced by rigid connection, is advantageous for the structure. The rigid connection construction of the steel truss girder can be completed without carrying out secondary constant load equal-generation load pressure construction by adopting the method of the invention, and the principle is as follows: the steel bridge deck is hoisted in an inserting mode in the hoisting process of the steel truss, the local linear type of the beam section can reach the bridge linear type in the hoisting process, and the local steel truss beam is just connected, so that the construction cost is reduced, the construction period is saved, wherein software 'extra-large span suspension bridge construction control analysis system 1.0' is the prior art, and the copyright registration number is 2009SR 054376.
The rigid connection construction of the hoisting beam sections is gradually carried out along with the hoisting, the traditional method requires integral rigid connection after the hoisting is completely finished, a large amount of rigid connection construction is carried out simultaneously, the input amount of personnel and equipment resources is large, the construction cost is high, the rigid connection operation occupies the main line construction period, and the construction period of the whole bridge is prolonged. The method reduces the investment of rigid connection construction resources, shortens the construction period of the bridge, and has the characteristics of simple installation and connection sequence of the suspension bridge plate girder and girder combination beam, less overhead rigid connection workload and low safety risk.
Example 2:
referring to fig. 1, the present embodiment is different from embodiment 1 in that: the beam section is a steel truss 1, the structure of the steel truss is a rectangular frame structure consisting of a closed joint 11 and an open joint 12, and the beam section 1 and the beam section 0 in the third step are both the steel truss 1.
In actual use: the steel truss 1 is hoisted once in the hoisting process, and the bridge is installed on the steel truss which is hoisted in the prior art and has a rectangular frame structure with an opening section.
The side face of a rectangular frame structure between the open sections is of an Contraband-shaped structure, the rectangular frame structure is assembled and hoisted in sections according to rigid connection, the side face of the hoisting steel truss 1 is of an opening + Contraband-shaped interface, the structure is more stable, and deformation in the installation process is avoided.
Example 3:
referring to fig. 2, the present embodiment is different from embodiment 1 in that: and in the first step, after the main towers on two sides are built, the cable crane is installed, the cable crane is debugged and tried to be hung, and then the sling and the cable clamp are installed, so that the hoisting construction can be normally carried out.
Example 4:
the present embodiment is different from embodiment 1 in that: and in the second step, before the beam section and the bridge deck of the bridge are hoisted, leveling the beam section and the bridge deck assembly field, assembling the beam section and the bridge deck in advance, and preparing early hoisting for hoisting construction.
Example 5:
referring to fig. 4, 6 and 7, the present embodiment is different from embodiment 1 in that: and in the fourth step, when the beam sections are symmetrically hoisted from the central line position of the bridge to the two banks in sequence, after the beam sections are hoisted for a certain number of times, the two No. 1 beam sections, close to the main towers at the two banks, of the whole bridge are hoisted in advance in a swinging manner, and then the rest beam sections and the bridge decks are hoisted symmetrically to the two banks in sequence.
Two No. 1 beam sections close to the two-bank main tower are lifted with the integral beam section closure section in the middle in an oscillating mode, then the whole beam section is lifted, and finally the rest bridge decks are lifted.
In actual use: when beam sections are symmetrically hoisted from the center line position of a bridge to two banks in sequence, after the beam sections are hoisted for a certain number of times, the certain number of hoisting times is obtained through software calculation, the calculation method is that basic information of the constructed bridge is input into corresponding data calculated by software 'super-span suspension bridge construction control analysis system 1.0', the number of times of hoisting the beam sections is determined, then two No. 1 beam sections of the whole bridge close to main towers at two banks are hoisted in an oscillating mode, the end beam sections are hoisted in advance, the end beam sections are used as bridge deck hoisting platforms, pier side brackets in the traditional method are replaced, the construction steps are simplified, the construction period is shortened, the software 'super-span suspension bridge construction control analysis system 1.0' is the prior art, and the copyright registration number is 2009SR 054376.
Example 6:
referring to fig. 8, this embodiment is different from embodiment 5 in that: two No. 1 beam sections close to the two-bank main tower and the integral beam section closure section at the middle part can also be subjected to pre-deflection closure and vertical hoisting, then the hoisting of the whole beam section is completed, and finally the rest bridge deck is hoisted.
The method for vertically hoisting the closure section of the pre-biased closure comprises the following steps:
take the construction of Jinan Jinshajiang river bridge pre-biased closure as an example.
The method comprises the following steps:
the cable crane sling is connected with a No. 31 beam section;
2 windlasses 8t are arranged in the beam yard, the closed beam section is reversely pulled towards the main span side, the reverse pulling point is arranged at the end part of the lower chord of the truss beam, and the reverse pulling force is about 7 t;
and the cable crane hoisting cable keeps a relaxed state, and the trolley is pulled to the approach bridge side, so that the trolley at the small pile number side is about 17m away from the center line of the cable tower.
Step two:
after the closure beam section is lifted for 1.5m, the reverse-pull winch is released to enable the cable crane hoisting cable to keep a vertical state;
the connection between the winch and the closure section is released;
at the moment, the distance between the small pile number side roadster and the center line of the tower is about 19m, and the clear distance between the closure section and the bearing platform is about 1.0 m.
Step three:
and (3) vertically lifting the closure section, when the upper chord of the main girder of the closure section is close to the lower chord of the main girder of the 30-32 girder section by about 0.5m, accurately adjusting the longitudinal position of the closure section again, ensuring that the clear distance between the closure section and the 32 girder section is about 12cm and the clear distance between the closure section and the main girder of the No. 30 girder section is about 51cm, and controlling by adopting a plumb-ball method.
Step four:
after the closure section is lifted to the installation height, the closure beam section is pulled to the installation position to the main span side, and a sling is installed;
the closure section is rigidly connected with the No. 30 beam section;
and (4) loosening the end beam section to the mounting position, and rigidly connecting the No. 32 beam section with the closure section.
Example 7:
referring to fig. 5, the present embodiment is different from embodiment 1 in that: and in the fourth step, when the rest beam sections are symmetrically hoisted, the beam sections of the large bridge are hoisted firstly, then the bridge deck on the closed internode 11 is hoisted symmetrically by utilizing the vacant time of hoisting the beam sections, the rigid connection part reaches the bridge section in a bridge line shape, and the newly formed closed internode 11 is hoisted after rigid connection. By adopting the method to separate and hoist the beam section and the bridge deck, the construction resource input amount is reduced, and the construction period of the bridge is shortened.
Example 8:
this embodiment differs from any of embodiments 1-7 in that: the beam section include two main crossbeams, two main crossbeams include first main crossbeam 6 and second main crossbeam 7, when hoist and mount the beam section, set up four hoisting points on the beam section, four hoisting points include first hoisting point 2, second hoisting point 3, third hoisting point 4 and fourth hoisting point 5, first hoisting point 2 and second hoisting point 3 set up on first main crossbeam 6, third hoisting point 4 and fourth hoisting point 5 set up on second main crossbeam 7.
In actual use: the hoisting points are usually arranged on the top surfaces of the steel truss main cross beams with high strength and stable structure when the steel truss is hoisted, if one steel truss is hoisted at one time, the side surfaces of the steel truss are asymmetrical when the steel truss is hoisted at one time, the side surfaces of the steel truss are in an Contraband-shaped structure, the steel truss is easy to deform in the hoisting process, the steel truss is not beneficial to posture control in the hoisting process, and the hoisting is not beneficial.
Example 9:
taking the construction of Jinan Jinshajiang river bridge as an example:
the construction method is adopted, the steel truss is installed in a way of separating plate girders and fully hinging, and the cable crane is hoisted by four-point hoisting, and the steel truss or the bridge deck with 1 beam section is hoisted each time. And (3) inserting and hoisting the bridge deck slab in the hoisting process of the steel truss, symmetrically hoisting from the midspan to two sides, and closing the steel truss at the secondary end beam section. The standard loading weight of the steel truss is 210t, and the hoisting weight of the bridge deck is 55 t.
The end steel truss girder is positioned outside the longitudinal movement range of the cable crane, swinging and lifting are adopted, the swinging and lifting distance is 10m, plate girders are adopted for separate lifting, the weight of the steel truss girder is 190t, and the weight of the bridge deck is 58 t.
And after the end steel truss girder is hoisted, the end girder section is used as a platform to swing and move to hoist other bridge decks by a swing distance of 2m, and the other bridge decks are symmetrically hoisted from midspan to two sides, so that the bridge deck of the closed internode steel truss girder is preferentially hoisted.
By adopting the method, the construction resource input amount is reduced after construction, the bridge construction period is shortened, and the method is suitable for wide popularization in the field.
While the embodiments of the present invention have been described in detail with reference to the drawings, the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention within the knowledge of those skilled in the art, and the scope of the present invention is within the scope of the claims.
It should be noted that all the directional indicators (such as up, down, left, right, front, and rear … …) in the embodiment of the present invention are only used to explain the relative position relationship between the components, the movement situation, etc. in a specific posture (as shown in the drawing), and if the specific posture is changed, the directional indicator is changed accordingly.
Technical solutions between various embodiments may be combined with each other, but must be realized by those skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention.