1. A method for erecting a last-span trimming beam at a point where a high-speed railway platform line merges into a turnout beam is characterized by comprising the following steps of: the method comprises the following steps:

firstly, determining the position of a fulcrum of a front supporting leg according to the equipment parameters of a bridge girder erection machine, and marking on the surface of a turnout beam;

secondly, constructing a supporting mechanism between the turnout beam flange plate and the pier top at the marked position, then paving coarse sand on the turnout beam surface at one side of the mark, leveling, and paving a steel plate above a coarse sand leveling layer;

thirdly, the bridge girder erection machine is put in place, the front and the rear hangers are transversely moved to the side of the rear-span trimming beam at the side of the trimming beam by S1, and the transverse moving distance S1 is determined according to the gravity center position of the trimming beam;

fourthly, adjusting the position of a fulcrum of the beam transporting vehicle to enable the beam transporting vehicle to transversely move towards the side, which is not trimmed, of the trimming beam S2, wherein the transverse movement distance S2 is determined according to the position of the center of gravity of the trimming beam, and then the end-span trimming beam is placed on the beam transporting vehicle for transportation;

fifthly, mounting the end-span trimming beam on front and rear hangers for feeding the beam, when the beam falling position is reached, firstly transversely moving the front and rear hangers to the non-trimming side of the end-span trimming beam by S1, then carrying out beam falling operation, and after the end-span trimming beam is in place, rechecking the direction and position of a support and then carrying out support grouting;

and sixthly, after the bridge girder erection machine is transferred, detaching the supporting mechanism, recovering the appearance of the lower part of the turnout beam flange plate and finishing construction.

2. The method for end-span edge-cutting beam erection where a high-speed railway platform line merges into a switch beam according to claim 1, characterized in that:

the supporting mechanism in the second step comprises a supporting column, a lower end plate connected with a pier top is arranged at the bottom of the supporting column, an upper end plate is arranged at the top of the supporting column, a cast-in-situ supporting cushion block is arranged between the upper end plate and a turnout beam flange plate, and a first shear steel bar and a second shear steel bar are arranged in the cast-in-situ supporting cushion block;

the construction steps of the supporting mechanism comprise:

firstly, prefabricating a support column with an upper end plate and a lower end plate, and welding a first shear steel bar on the upper end plate;

secondly, placing the support column between the turnout beam flange plate and the pier top at the marked position, connecting the lower end plate and the pier top by adopting an expansion bolt, installing a steel template between the upper end plate and the turnout beam flange plate, and tightly sealing by using foam rubber;

and thirdly, drilling grouting holes in the turnout beam flange plates, grouting into the steel template through the grouting holes, inserting second shear steel bars extending to the upper end plate into the grouting holes, and forming cast-in-situ supporting cushion blocks after the grouting is solidified to complete construction of the supporting mechanism.

3. The method for end-span edge-cutting beam erection where a high-speed railway platform line merges into a switch beam according to claim 2, characterized in that: the first shear steel bars are divided into a plurality of groups, the heights of the first shear steel bars in the same group are consistent, and the heights of the first shear steel bars in the adjacent groups are increased along with the linear change of the lower surface of the turnout beam flange plate.

4. The method for end-span edge-cutting beam erection where a high-speed railway platform line merges into a switch beam according to claim 2, characterized in that: the aperture of the grouting hole is 80mm, and the strength of the cast-in-place supporting cushion block is 40 Mpa.

5. The method for end-span edge-cutting beam erection where a high-speed railway platform line merges into a switch beam according to claim 1, characterized in that: the thickness of the steel plate in the second step is 10 mm.

6. The method for end-span edge-cutting beam erection where a high-speed railway platform line merges into a switch beam according to claim 1, characterized in that: when the distance between the gravity center of the trimming beam and the longitudinal center line of the box beam of the trimming beam is 20cm, the transverse moving distance S1 is 30cm, and the transverse moving distance S2 is 20 cm.

7. The method for end-span edge-cutting beam erection where a high-speed railway platform line merges into a switch beam according to claim 1, characterized in that: and the speed of the girder transporting vehicle in the fourth step is 2 km/h.

8. The method for end-span edge-cutting beam erection where a high-speed railway platform line merges into a switch beam according to claim 1, characterized in that: in the fifth step, the beam feeding speed is 2m/min, and the beam falling speed is 0.5 m/min.

Background

In the throat line changing area of the station for changing two lines into four lines and the like, the tail span of the turnout beam and the platform line shares a pier, and the side line of the platform line is limited by the position, namely the side cutting beam (shown in figure 4) is adopted for the side line of the platform line, namely the single-side flange plate is cut off. When the last span of traditional platform line merges into the switch roof beam, adopt cast-in-place technology or road bed transition more, the operation degree of difficulty is low, and construction convenience, nevertheless construction cost is high, and the construction period is long, and economic benefits is low. With the wide application of bridge girder erection machines, some platform lines are changed into prefabricated erection construction, and the construction period is greatly shortened. However, the self-weight of the bridge girder erection machine is larger, the supporting legs of the bridge girder erection machine are in direct contact with the lower girder surface, and the box girders and the bridge girder erection machine are concentrated on the supporting girder surface by self weight in the girder feeding and falling processes. For the edge-cutting beam, the front support leg of the bridge girder erection machine is positioned on the flange plate of the overhanging structure of the turnout beam and is not superposed with the web plate of the turnout beam, so that the stress of the beam surface of the turnout beam is uneven, and serious potential safety hazards exist under the condition that the existing beam surface structure cannot meet the requirement of upper concentrated load.

Disclosure of Invention

In order to solve the problems, the invention provides a method for erecting a tail-span trimming beam at a point where a high-speed railway platform line merges into a turnout beam, which can specifically adopt the following technical scheme:

the invention relates to a method for erecting a tail-span edge-cutting beam at a point where a high-speed railway platform line is merged into a turnout beam, which comprises the following steps:

firstly, determining the position of a fulcrum of a front supporting leg according to the equipment parameters of a bridge girder erection machine, and marking on the surface of a turnout beam;

secondly, constructing a supporting mechanism between the turnout beam flange plate and the pier top at the marked position, then paving coarse sand on the turnout beam surface at one side of the mark, leveling, and paving a steel plate above a coarse sand leveling layer;

thirdly, the bridge girder erection machine is put in place, the front and the rear hangers are transversely moved to the side of the rear-span trimming beam at the side of the trimming beam by S1, and the transverse moving distance S1 is determined according to the gravity center position of the trimming beam;

fourthly, adjusting the position of a fulcrum of the beam transporting vehicle to enable the beam transporting vehicle to transversely move towards the side, which is not trimmed, of the trimming beam S2, wherein the transverse movement distance S2 is determined according to the position of the center of gravity of the trimming beam, and then the end-span trimming beam is placed on the beam transporting vehicle for transportation;

fifthly, mounting the end-span trimming beam on front and rear hangers for feeding the beam, when the beam falling position is reached, firstly transversely moving the front and rear hangers to the non-trimming side of the end-span trimming beam by S1, then carrying out beam falling operation, and after the end-span trimming beam is in place, rechecking the direction and position of a support and then carrying out support grouting;

and sixthly, after the bridge girder erection machine is transferred, detaching the supporting mechanism, recovering the appearance of the lower part of the turnout beam flange plate and finishing construction.

The supporting mechanism in the second step comprises a supporting column, a lower end plate connected with a pier top is arranged at the bottom of the supporting column, an upper end plate is arranged at the top of the supporting column, a cast-in-situ supporting cushion block is arranged between the upper end plate and a turnout beam flange plate, and a first shear steel bar and a second shear steel bar are arranged in the cast-in-situ supporting cushion block;

the construction steps of the supporting mechanism comprise:

firstly, prefabricating a support column with an upper end plate and a lower end plate, and welding a first shear steel bar on the upper end plate;

secondly, placing the support column between the turnout beam flange plate and the pier top at the marked position, connecting the lower end plate and the pier top by adopting an expansion bolt, installing a steel template between the upper end plate and the turnout beam flange plate, and tightly sealing by using foam rubber;

and thirdly, drilling grouting holes in the turnout beam flange plates, grouting into the steel template through the grouting holes, inserting second shear steel bars extending to the upper end plate into the grouting holes, and forming cast-in-situ supporting cushion blocks after the grouting is solidified to complete construction of the supporting mechanism.

The first shear steel bars are divided into a plurality of groups, the heights of the first shear steel bars in the same group are consistent, and the heights of the first shear steel bars in the adjacent groups are increased along with the linear change of the lower surface of the turnout beam flange plate.

The aperture of the grouting hole is 80mm, and the strength of the cast-in-place supporting cushion block is 40 Mpa.

The thickness of the steel plate in the second step is 10 mm.

When the distance between the gravity center of the trimming beam and the longitudinal center line of the box beam of the trimming beam is 20cm, the transverse moving distance S1 is 30cm, and the transverse moving distance S2 is 20 cm.

And the speed of the girder transporting vehicle in the fourth step is 2 km/h.

In the fifth step, the beam feeding speed is 2m/min, and the beam falling speed is 0.5 m/min.

The method for erecting the end-span trimming beam merged into the turnout beam of the high-speed railway platform line provided by the invention has the advantages that the site construction risk is practically reduced, the operation procedure is simplified, the construction period is long, the operation efficiency is improved, and compared with the prior art, the comprehensive construction cost is saved by about 8.9 percent by means of adding the reinforcing and supporting structure at the flange plate of the turnout beam overhanging structure where the front supporting leg of the bridge erecting machine is positioned, and adjusting the gravity center of the box beam in the processes of beam feeding and beam falling.

Drawings

Fig. 1 is a schematic view of the positional relationship between the platform line and the turnout beam in the present invention.

FIG. 2 is a schematic illustration of a feed beam for an edge slitting beam in an embodiment of the present invention.

FIG. 3 is a schematic view of a drop beam of the trimming beam in an embodiment of the present invention.

Fig. 4 is a schematic diagram of the position relationship of the trimming beam on the girder transporting vehicle in the embodiment of the invention.

Fig. 5 is an enlarged view taken along line a-a in fig. 2.

Fig. 6 is an enlarged view from B-B in fig. 3.

Fig. 7 is an enlarged view of the bifurcated beam portion of fig. 5.

Detailed Description

The following describes embodiments of the present invention in detail with reference to the drawings, and the embodiments are implemented on the premise of the technical solution of the present invention, and detailed embodiments and specific construction processes are given, but the scope of the present invention is not limited to the following embodiments.

As shown in fig. 1-7, in a high-speed railway line, a main line and left and right tie lines are merged into a turnout beam 1 and then introduced into a station, wherein the left line is an edge-cutting beam 2, the weight of a single span beam is 450t, and the eccentric distance is 20cm, namely, the distance between the line m of the center of gravity of the edge-cutting beam 2 and the longitudinal center line n of a box beam of the edge-cutting beam 2 is 20cm, the method for erecting the last span of the edge-cutting beam 2 adopts the method for erecting the last-span edge-cutting beam at the position where the high-speed railway platform line is merged into the turnout beam, and specifically comprises the following:

firstly, selecting a JQXD32m-550 type bridge girder erection machine 3, determining the fulcrum position of a front supporting leg 301 according to equipment parameters of the bridge girder erection machine 3, and marking on the beam surface of a turnout beam 1;

secondly, constructing a supporting mechanism 5 between a flange plate of a turnout beam 1 and a pier top 4 at a marked position, then paving coarse sand 6 on a beam surface of the turnout beam 1 at one side of the mark, leveling 2% of a herringbone slope on the beam surface, paving a steel plate 7 with the thickness of 10mm above a coarse sand leveling layer, and checking the flatness of the steel plate by using a horizontal ruler, thereby ensuring the transverse level of a front supporting leg 301 of the bridge girder erection machine 3;

thirdly, the bridge girder erection machine 3 is in place, specifically, a lower cross beam of a front supporting leg 301 of the bridge girder erection machine 3 is placed above a leveling steel plate 7 of the beam surface of the turnout beam 1 and is supported in place, the state of the whole bridge girder erection machine is adjusted to ensure that the front is high and the rear is low, and the height difference between the main beam of the front supporting leg 301 and the main beam of the middle supporting leg 302 is not more than 100 mm; then, the front hanger 303 and the rear hanger 304 of the bridge girder erection machine 3 are respectively transversely moved towards the trimming side of the non-span trimming beam 2 by S1 (see fig. 5), namely, the central line L of the lifting appliance of the front hanger 303 and the rear hanger 304 is transversely moved towards the trimming side of the non-span trimming beam 2 by S1, so that the distance between the central line L of the lifting appliance and the line m of the center of gravity of the trimming beam 2 is S1, the acting point of the front leg 301 of the bridge girder erection machine 3 is far away from the flange plate support of the turnout beam 1, and the vertical load of the flange plate is reduced; considering that the center of gravity of the trimming beam 2 is shifted by 20cm, and the traverse strokes of the front and rear hangers of the bridge girder erection machine 3 are 45cm and 70cm, respectively, and other equipment parameters of the bridge girder erection machine 3 are combined, the traverse distance S1 is determined to be 30 cm.

Fourthly, the YLJ550 tire type girder transporting vehicle 8 is adopted to transport the non-span trimming beam 2, in order to adapt to the actual condition that the gravity center of the trimming beam 2 is not at the original symmetrical center, the fulcrum position of the girder transporting vehicle 8 needs to be adjusted, and the girder transporting vehicle 8 is enabled to transversely move towards the non-trimming side of the trimming beam 2S 2, so that the line m of the gravity center of the trimming beam 2 is enabled to coincide with the fulcrum center line of the girder transporting vehicle 8; the traversing distance S2 is determined according to the gravity center position of the edge cutting beam 2, and in the present embodiment, the traversing distance S2 is 20 cm. When the girder transporting vehicle 8 transports the final-span trimming beam 2, the speed is controlled to be 2km/h, and a specially-assigned person monitors the traveling of the girder transporting vehicle 8 in front of and behind the girder transporting vehicle;

fifthly, mounting the non-straddle trimming beam 2 on a front hanger 303 and a rear hanger 304, feeding the beams at the speed of 2m/min, and keeping the state that the center line L of the lifting appliance deviates 30mm to the trimming side of the non-straddle trimming beam 2; when the beam falling position is reached, firstly, the front hanger 303 and the rear hanger 304 transversely move 30mm to the non-edge cutting side of the end-span edge cutting beam 2, then the normal beam falling operation is carried out at the speed of 0.5m/min, and after the end-span edge cutting beam 2 is in place, the direction and the position of the support are rechecked and the support is grouted;

and sixthly, after the bridge girder erection machine 3 is transferred, the supporting mechanism 5 is detached, the appearance of the lower part of the flange plate of the turnout beam 1 is recovered, and construction is completed.

The supporting mechanism 5 located between the flange plate of the turnout beam 1 and the pier top 4 in the second step comprises a supporting column 501 formed by double-spliced I40I-shaped steel, wherein the top and the bottom of the supporting column 501 are respectively welded with a steel plate, namely an upper end plate 502 and a lower end plate 503, the lower end plate 503 is fixedly connected with the pier top 4 by 8M 16 expansion bolts, a cast-in-situ supporting cushion block 504 is arranged between the upper end plate 502 and the flange plate of the turnout beam 1, and a first shear steel bar 505 and a second shear steel bar 506 are arranged in the cast-in-situ supporting cushion block 504, so that the structure stability of the turnout beam 1 after the flange plate is temporarily supported and loaded is ensured.

The supporting mechanism 5 is constructed according to the following steps:

firstly, prefabricating a supporting column 501 with an upper end plate 503 and a lower end plate 502, welding first shear steel bars 505 on the top surface of the upper end plate 503, wherein the first shear steel bars 505 are 9 bransted 20 shear steel bars and are arranged in three rows, the heights of the first shear steel bars 505 in the same group are consistent, and the heights of the first shear steel bars 505 in adjacent groups are in a linear change increasing trend under the limiting action of the lower surface of the flange plate of the turnout beam 1;

secondly, placing the supporting column 501 between the turnout beam 1 flange plate and the pier top 4 at the marked position, connecting the lower end plate 503 and the pier top 4 by adopting 8M 16 expansion bolts, welding and fixing the steel template 505 between the upper end plate 503 and the turnout beam flange 1 flange plate, and tightly sealing by using foam rubber;

thirdly, a water drill is adopted to cut a grouting hole 507 with the aperture of 80mm on the flange plate of the turnout beam 1, grouting materials are poured into a steel template 508 through the grouting hole 507, then three brans 20 shear-resistant reinforcing steel bars are inserted through the grouting hole 507 to serve as second shear reinforcing steel bars 506, the bottom of the second shear reinforcing steel bars 506 is in contact with an upper end plate 502, the top of the second shear reinforcing steel bars is flush with the top surface of the grouting hole 507, a cast-in-situ supporting cushion block 504 with the strength of 40Mpa is formed after the grouting materials are solidified, and construction of the supporting mechanism is completed.

In order to avoid mixing of scum generated by digging the grouting holes 507 into the grouting material, the holes may be first dug, and the steel form 508 may be welded after the scum is cleaned up. The mix proportion of the bagged grouting material and water in the grouting material is 1:0.12, the construction process is simple, the coagulation is fast, the strength is high, and the close contact and uniform stress between the flange plate of the turnout beam 1 and the supporting structure 5 can be ensured.

It should be noted that in the description of the present invention, terms of orientation or positional relationship such as "front", "rear", "left", "right", "vertical", "horizontal", "inner", "outer", etc., are based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.