CN220665950U - BIM design-based high-pier large-span portal pier prestress bent cap supporting system - Google Patents

Abstract

The utility model provides a BIM design-based high pier large-span portal pier prestressed bent cap support system which comprises triangular brackets, sand boxes, cross beams and Bailey beams, wherein four pairs of socket type triangular brackets are respectively fixed at two opposite sides of the upper parts of two pier bodies in parallel bent cap directions in a opposite manner, the sand boxes are arranged on each triangular bracket, the cross beams are arranged on the sand boxes, and the Bailey beams are respectively erected and fixed on I-steel main cross beams at two sides of the pier bodies along the transverse bridge direction. The method solves the problems of long construction period, high cost, high operation difficulty, insufficient strength of a large-span supporting system and the like of the traditional method. Belonging to the field of road engineering.

Description

BIM design-based high-pier large-span portal pier prestress bent cap supporting system

Technical Field

The utility model relates to a BIM design-based high pier large-span portal pier prestressed bent cap support system, which belongs to the field of road engineering and is particularly suitable for high pier, large span and overweight structures.

Background

When crossing the upper part of the existing road in the expressway construction process, a portal pier and bent cap system is generally adopted for crossing, the steel bent cap is high in manufacturing cost and large in later maintenance workload, so that the large-span cast-in-situ rectangular portal pier and concrete bent cap are in a bridge pier column form, and the pre-stress is applied after cast-in-situ, so that the load holding capacity of the bent cap can be increased. The portal pier capping beam has the problems of large span, pier height, heavy load, large construction risk and difficulty and the like when crossing the existing road.

For the construction of the high pier and large-span portal pier capping beam crossing the existing road, the existing supporting system is constructed by a steel pipe bracket method, a triangular bracket method, a hoop method or a steel bar penetrating method and reinforced bailey beam combination in order not to influence the traffic of the existing road. The steel pipe support method has large occupied area, more steel pipe materials need to be erected for high piers, long construction period and high cost; the triangular bracket method is used for construction, the triangular bracket has various types and is provided with a triangular bracket for transmitting force through hinging, the force transmission is complex, or the anchor boxes are embedded at the upper end and the lower end, the anchor boxes are fixed in an up-down manner, the requirement on the embedded precision of the field construction is high, and the field construction is not facilitated; the steel bar penetrating method has weak bearing capacity, the bearing area of the sand box or the jack and the steel bar is small, the instability is easy, and the safety risk is high; the common sand box has small unloading holes and low unloading speed, and is not beneficial to the disassembly of a later bracket system; the existing support system is not optimized enough, so that material waste is caused, the optimization design of the support system for the capping beam construction is particularly important, and the requirements of safe production and the like in site construction cannot be met in the support systems such as a traditional support lapping method, a hoop method and a steel bar penetrating method aiming at the construction of the existing high-span portal rectangular pier prestressed concrete cast-in-situ capping beam.

Disclosure of Invention

The utility model provides a BIM design-based high pier large-span portal pier prestressed bent cap supporting system, which aims to solve the problems of long construction period, high cost, high operation difficulty, large potential safety hazard and the like of the traditional method.

In order to achieve the above purpose, the high pier large-span portal pier prestress bent cap supporting system based on BIM design is to be adopted, the supporting system comprises triangular brackets which are pre-buried at two opposite sides of the upper part of a pier column and are fixed in a opposite pulling mode, a sand box is installed on the triangular brackets, bailey beams are respectively arranged at two sides of the pier column along the transverse bridge direction, and the bailey beams at two sides are installed on the sand box or are fixed on a main beam at the top of the sand box along the longitudinal bridge direction.

In the construction method, the triangular brackets are socket type triangular brackets, two pairs of triangular brackets are respectively fixed on two adjacent pier columns along the longitudinal bridge direction through split bolts in a pre-buried mode, sand boxes are fixed at the upper ends of the triangular brackets, and reinforced bailey beams at two sides are fixedly installed on the sand boxes.

In the construction method, the triangular brackets are socket-joint triangular brackets, four pairs of triangular brackets are respectively fixed on two adjacent pier columns in a pre-buried mode through split bolts along the transverse bridge direction, two pairs of triangular brackets are fixed at the same height of the upper end of each pier column in parallel, sand boxes are fixed at the upper ends of the triangular brackets, main beams are fixed above the sand boxes along the longitudinal bridge direction, and the bailey beams are fixed on the main beams.

In the construction method, the upper chord and the bolt of the triangular bracket are I25b I-shaped steel, the diagonal braces and the vertical braces are I18I-shaped steel, the tail part of the triangular bracket is provided with a 16mm rectangular base plate, when the triangular bracket is stressed, the triangular bracket is stressed and sheared mainly through the upper chord and the bolt, when the upper chord is stressed, the inclined braces and the vertical braces are partially stressed and bear, the force is finally transferred to the base plate, the base plate distributes the force to the pier body, 16mm reinforcing rib plates are welded on two sides of the main stress areas of the upper chord and the pier body interpolation pin, two small triangular rib plates are respectively arranged on two sides of the end parts of the reinforcing rib plates, two knocking plates and bolt limiting plates are respectively arranged on two sides of the reinforcing rib plates, a bailey beam safety baffle and lifting hole is arranged at a position 10cm away from the outer side of the upper chord, and the triangular bracket is welded with Q345 steel.

In the construction method, the sand box is a rectangular box body, the box body and the box cover are uniformly made of 16mm steel plates, the sand box bottom support is made of 10mm steel plates, the box cover is left and right two boxes, when the sand box is pressed, the box cover and sand keep relatively balanced and stable states, the sand in the sand box can be conveniently and rapidly drawn out, 4 threaded holes are arranged in the box body, 2 rectangular sand drawing holes are formed in the outer vertical face, a baffle is arranged on the outer vertical face, and the baffle is fixed with the box body by nuts.

In the construction method, when the portal pier is about to be constructed to the pier top, the arrangement elevation position of the triangular bracket is calculated in advance, an anchor box is pre-embedded before the pier body is poured, and the pier body is treated by taking bottom concrete as a reinforcing steel mesh within the range of 40cm from outside to inside;

in the construction method, when the pier body is constructed, and the triangular bracket is installed, the bolt is inserted into the anchor box, the stopper is tightly attached to the pier body in the process of being put into the anchor box, two phi 24 finish rolling threaded rod pull rods are installed for opposite pulling, and the bolt is tightened, so that reliable connection is completed;

in the construction method, the sand box fixes the baffle plate through the nuts and then loads sand, the baffle plate is mounted at a proper position above the triangular bracket, and the triangular bracket is fixed through Sha Xiangde brackets;

in the construction method, the bailey pieces are reinforced bailey pieces, the bailey pieces are arranged at intervals of 22.5cm, one group of three bailey pieces are arranged on two sides of a bent cap, two sides of a supporting node are reinforced by adding double-spliced I10 channel steel, bolt holes are reserved in the channel steel, the length of the channel steel is the distance between the upper chord member and the lower chord member of the reinforced bailey beam, the channel steel is installed through an iron hammer during reinforcement, the channel steel is not welded with the chord member, the double-spliced channel steel is effectively fixed by bolts, the reinforced bailey beam is hoisted to a sand box in a whole group, the bailey beams are arranged according to the scheme, two sides of a U-shaped clamping groove are connected by the channel steel which is also I10, nut holes are reserved above the clamping groove and the channel steel, the U-shaped clamping groove is fixed by adopting nuts or steel bars, the groups are connected together according to 6 meters, and the installation and the dismantling are completed through the nuts.

In the construction method, the bailey pieces are common bailey pieces, the bailey pieces are arranged at intervals of 45cm and are divided into three groups, two sides of the capping beam are respectively provided with one group, the bottom of the capping beam is provided with one group, two sides of the supporting node are additionally provided with double-spliced I10 channel steel for reinforcement, bolt holes are reserved on the channel steel, the length of the channel steel is equal to the interval between the upper chord member and the lower chord member of the reinforced bailey beam, when the reinforced bailey beam is reinforced, the channel steel is installed through an iron hammer and is not welded with the chord member, the double-spliced channel steel is effectively fixed through bolts, the reinforced bailey beam is hoisted to a sand box, the reinforced bailey beam is arranged according to the scheme, the U-shaped clamping grooves are connected with the bailey beams at two sides by the channel steel which are also provided with I10, nut holes are reserved above the channel steel, the U-shaped clamping grooves are fixed through nuts or steel bars, the groups are connected according to 6 meters, and the installation and dismantling are completed through the nuts.

In the construction method, after the construction of the bent cap is completed, sand in the sand box is rapidly drawn out through the baffle plate of the sand box, the height of the supporting system is reduced, the supporting system is separated from the bent cap, the dismantling work of the bailey beam is completed, and then the sand box and the triangular bracket are dismantled, and the next utilization is performed.

Compared with the prior art, the utility model utilizes BIM technology to design the capping beam supporting system, reduces material waste to the maximum extent under the premise of ensuring construction safety, reduces construction operation difficulty and quickens construction progress, the novel triangular bracket is transmitted to the base plate after being pressed, and forces are back-pressed to the pier body through the base plate, so that the bearing capacity of the triangular bracket is reduced, and small-sized steel can be adopted to process the triangular bracket and reduce material consumption during design; for structures such as high piers, large spans and overweight structures, compared with the method 1, the method 2 provided by the utility model adjusts the direction of the triangular bracket, so that the socket type triangular bracket is arranged along the direction parallel to the bent cap, the span center distance of the bailey pieces is reduced, the problems that the bridge center disturbance degree of the bailey beams is too large, the internal force of the bridge members of the bailey beams does not meet the stress requirement and the like are solved, the stress requirement can be met by adopting the standard reinforced bailey beams, and the space between the I-shaped steel distribution beams can be enlarged or changed into square timber for use because the bottom of the bent cap is not suspended any more, the use of the profile steel of the distribution beams is reduced, and the stress is more definite and uniform; the detachable 100T-level standard socket type triangular bracket and the novel sand box designed on the basis of the utility model optimize the overall stability measure of the reinforced bailey beam, can greatly reduce the construction difficulty, improve the construction efficiency, and can recycle the support system after the construction is completed, thereby greatly reducing the construction cost and having great significance for the construction of expressway construction.

Drawings

FIG. 1 is a schematic view showing the structure of embodiment 1 of the present utility model in use;

FIG. 2 is a schematic diagram showing the front view structure of embodiment 1 of the present utility model;

FIG. 3 is a side view of embodiment 1 of the present utility model;

FIG. 4 is a schematic perspective view of a triangular bracket;

FIG. 5 is a front view of the triangular bracket;

FIG. 6 is a schematic perspective view of a flask;

fig. 7 is a schematic perspective view of embodiment 2;

fig. 8 is a partial enlarged view in embodiment 2;

fig. 9 is a schematic diagram of the front view structure of embodiment 2;

fig. 10 is a side view of example 2.

Detailed Description

For the purpose of promoting an understanding of the principles of the utility model, reference will now be made in detail to the embodiments described herein, including examples, illustrated in the accompanying drawings.

Example 1

The method mainly comprises the steps of improving a portal pier prestressed bent cap supporting system, and particularly implementing the system, as shown in fig. 1-6, by utilizing a BIM technology to carry out three-dimensional modeling on the portal pier bent cap to obtain three-dimensional space relation and load distribution, when the bent cap is poured, carrying out three-dimensional design on a supporting system on the basis of a bent cap three-dimensional model to obtain a preliminary technical scheme, wherein the whole scheme adopts a triangular bracket 1, a sand box 2 and a reinforced bailey beam 3 as supporting systems, the triangular bracket 1 is a socket type triangular bracket, the socket type triangular bracket is oppositely pulled and fixed on two opposite sides of the upper part of a pier body along the direction perpendicular to a road, the sand box 2 is arranged on the triangular brackets 1 on the two sides, the reinforced bailey beam 3 is respectively erected and fixed on the sand boxes 2 on the triangular brackets 1 on the two sides of the pier body along the arrangement direction of the pier, the preliminarily designed bent cap three-dimensional supporting system model is guided into finite element structure inspection analysis software to carry out stress inspection, and the material consumption is reduced when the requirements are met through continuous optimization, and construction cost is reduced.

The 100T socket type triangular bracket is designed, wherein the triangular bracket 1 is made of Q345 steel, the model size of a rod piece is calculated by simple wool calculation according to construction experience, an upper chord and a bolt are made of I25b I-steel, the diagonal braces 11 and the vertical braces 12 are both I18I-steel, a 16mm rectangular base plate 13 is arranged at the tail part of the triangular bracket 1, the traditional lower bolt structure is replaced, the bearing area of the base plate is large, and the effect is good; when the triangular bracket 1 is stressed, the upper chord member 14 is stressed and sheared, when the upper chord member 14 is stressed, partial stress bearing is carried out through the diagonal brace 11 and the vertical brace 12, the partial stress bearing is finally transmitted to the base plate 13, the force is dispersed to the pier body through the base plate 13, the condition that the stress concentration of the pier body is overlarge by the traditional bolt and concrete is destroyed is reduced, small-sized steel can be adopted in design, the bracket is manufactured, the material consumption is reduced, the triangular bracket 1 can bear 100T-level load, 16mm reinforcing rib plates 15 are welded at two sides of the main stress area of the upper chord member 14 and the pier body interpolation pin, two small triangular rib plates are respectively arranged at two sides of the end part of the reinforcing rib plates 15 and used for limiting the later stage finish rolling of the deformed steel bars, two additional knocking plate and bolt limiting plates 16 are arranged at two sides of the reinforcing rib plates, a lifting hole 17 is formed at 10cm from the outer side of the upper chord member 14, the triangular bracket 1 is required to be processed in a specialized manner by factories, and the Q345 welding seam is adopted to ensure that the triangular bracket 1 is welded in a specialized manner.

The sand box 2 is designed by a rectangular box body, the box body 21 and the box cover 22 are uniformly made of 16mm steel plates, the Sha Xiangde support 23 is made of 10mm steel plates, the box cover is left and right two boxes, when the sand box is pressed, the box cover and sand keep relatively balanced and stable state, sand in the sand box 2 can be conveniently and rapidly drawn out, 4 threaded holes 25,2 rectangular sand drawing holes 26 are arranged on the box body 21, a baffle 24 is arranged on the outer vertical surface, and the baffle 24 is fixed with the box body 21 by nuts.

When the portal pier is about to be constructed to the pier top, the arranging elevation position of the triangular bracket is calculated in advance, an anchor box is pre-embedded before the pier body 4 is poured, the bottom concrete of the pier body 4 is used as a reinforcing steel mesh for treatment within the range of 40cm from outside to inside, and the pier body concrete is prevented from being damaged when the triangular bracket 1 is pressed; when the pier body 4 is constructed and the triangular bracket 1 is installed, inserting a bolt into the anchor box, if the bolt is not smooth, knocking a limiter by using an iron hammer until the limiter is tightly attached to the pier body 4, installing two phi 24 finish rolling threaded rod pull rods for opposite pulling, and tightening bolts to complete reliable connection; the sand box 2 fixes the baffle plate through nuts, then sand is filled, the baffle plate is installed at a proper position above the triangular bracket 1, and the triangular bracket 1 is fixed through Sha Xiangde brackets; the bailey pieces are reinforced bailey pieces, the bailey pieces are arranged at intervals of 45cm, a group of three bailey pieces and a group of cover beams are arranged on two sides of a supporting node, double-spliced I8 channel steel is added on two sides of the supporting node to strengthen the bailey pieces, the channel steel length is equal to the distance between the upper chord member and the lower chord member of the reinforced bailey beam 3, the channel steel is installed through an iron hammer and is not welded with the chord member, the reinforced bailey beam 3 is prevented from being damaged, phi 20 steel bars are adopted between the double-spliced channel steel to carry out welding fixation, the reinforced bailey beam 3 is hoisted to a sand box 2 in a whole group, the arrangement is carried out according to the scheme position, I8 channel steel is adopted to design into a U-shaped clamping groove, the two groups of reinforced bailey beams 3 are fixed, a nut hole is reserved above the clamping groove, the left and right connection is carried out through the I8 channel steel, the installation and the dismantling are completed through nuts, the construction of the cover beams is completed, sand in the sand box 2 is rapidly removed through the baffle 24 of the dismantling the sand box 2, the height of the supporting system is reduced, the sand is separated from the cover beam, the dismantling the reinforced bailey beam 3 is completed, and then the sand box 2 and the triangular bracket 1 is reused.

After the design thought is determined, carrying out two-dimensional sketch parameterization design on the basis of a three-dimensional model of the bent cap, driving the size of the supporting system through parameters, giving sketch profile steel models such as a triangular bracket 1, a sand box 2, a reinforced bailey beam 3, a distribution beam and the like in a component environment, completing modeling of a single component model, and then completing the position arrangement of the triangular bracket 1, the sand box 2, the reinforced bailey beam 3 and the distribution beam through an assembly and combination function to obtain a three-dimensional model preliminary design scheme of the bent cap supporting system.

And then performing finite element analysis, namely exporting a capping beam three-dimensional support system model into a STp file format in BIM design software, importing the STp file format into Spacelaim design software, simplifying a bracket model, only reserving main stress rods, then performing shell extraction processing to complete node sharing, obtaining a bracket linear model, starting an Ansys Workbench in the Spacelaim design software, directly transmitting the linear model to the Ansys Workbench finite element analysis software, reducing repeated modeling steps of the finite element analysis, supporting multi-scheme simulation in the finite element analysis software, performing stress analysis on a single component, taking the triangular bracket 1 and the reinforced bailey beam 3 as an example, and performing the detection by adopting a rod system finite element. The whole member of the triangular bracket 1 is meshed according to 25mm, and the total is that: the number of units is 143, the number of nodes is 286, the upper chord bolt is fixedly connected with the bottom of the reinforcing range of the rib plate in the column, the top plate of the diagonal brace 11 is limited to move vertically to the column, other directions are free to move, other parts are connected in a default welding binding mode and the like, bearing capacity is applied, and a detection and analysis result shows that the absolute value of the maximum combined stress is 296.98Mpa < fd=305 Mpa, the maximum combined shear stress is 164.42Mpa < fvd =175 Mpa, the maximum vertical deformation of the middle of the triangular bracket 1 is about 0.85mm and smaller than the standard calculation deformation allowable value 670/400=1.67 mm; the maximum vertical deformation of the cantilever end at the end part of the triangular bracket 1 is about 1.35mm, which is smaller than the standard deformation allowable value 400/200=2mm, the strength and the rigidity of the bracket meet the design requirement, the inspection shows that the inspection value is close to the design allowable value, in order to improve the bearing capacity and the safety of the bracket, 16mm reinforcing rib plates are welded at two sides of the main stress areas of the upper chord member 14 and the interpolation pin of the pier body 4, two small triangular rib plates are respectively arranged at two sides of the end part of the reinforcing rib plates and used for limiting when the later finish rolling screw steel is pulled oppositely, two knocking plates and bolt limiting plates are further arranged at two sides of the reinforcing rib plates, the bailey beam safety baffle and lifting hole is arranged at the position 10cm away from the outer side of the upper chord member 14, the design is completed through the Spacelaim design software, the added design model can be automatically transmitted to the Ansys Workbench without the secondary inspection setting flow, the inspection result is updated, a new inspection report is obtained, the strength calculation value can be further reduced, and the rigidity of the 100T socket type triangular bracket 1 is designed.

The single reinforced bailey beam 3 is designed and calculated by adopting the same method, and the bailey beam components are divided into grids according to 30mm, and the total is that: 5148 units and 10220 nodes. Maximum combined stress 259.44Mpa < fd=273 Mpa; the maximum combined shear stress is 279.8Mpa > fvd =208 Mpa, the maximum vertical deformation of the bailey beam member in the span is about 35.6mm, and the maximum vertical deformation is smaller than the standard calculation deformation allowable value 16000/400=40 mm; the maximum vertical deformation of the left cantilever end of the end part is 13.5mm respectively, the maximum vertical deformation of the right cantilever end of the end part is 6.7mm respectively and smaller than the standard cantilever end deformation allowable value 4500/200=22.5 mm, the maximum vertical deformation of the right cantilever end of the end part is smaller than the standard cantilever end deformation allowable value 1500/200=7.5 mm, the rigidity meets the requirement, the strength shearing force exceeds the standard, the overstandard part is obtained by analysis and is positioned at the supporting node of the bailey beam and the sandbox, the reinforcing design is carried out on the node, double-spliced I10 channel steels are added on two sides of the supporting node to strengthen the node, the channel steel length is the distance between the upper chord member and the lower chord member of the bailey beam, the recheck is carried out, and the strength and the rigidity meet. The best beam chord axial force is 415.02kN < F tolerance=560 kN, the best beam axial force is 240.21kN > F tolerance=171.5kN, and the best beam axial force is 277.96kN > F tolerance=210 kN, which does not meet the requirement. At the moment, in order to meet the axial force requirement, the detection, calculation and analysis show that the construction safety requirement can be met only by 4 pieces of bailey beams on two sides of the pier column. At this moment, this braced system adopts 4 bailey pieces to arrange, will lead to bailey beam whole group width to increase to 67.5cm from 45cm, and the sand box 2 that forms a complete set of use needs to use 2, and chord length, bracing length all need to increase on the triangle bracket 1, and in this set of scheme, left side cantilever end need pour 3.3 meters long bent cap, for satisfying later stage construction demand, this side bailey beam cantilever length of growing up 5.25 meters, though examine to satisfy the requirement, there is the deformation too big, the relatively poor risk of security. Therefore, on the basis of the first scheme, continuous optimization is required, and when the safety specification requirement is met, the material consumption is reduced, and the construction cost is reduced.

According to the detection analysis, the factors influencing the strength, the rigidity and the axial force of the Bailey beam are load, the net distance between two support nodes of the Bailey beam and the like, so that the distance between the support nodes of the Bailey beam is shortened under the condition of unchanged total load, and the problem that the detection index of the detection part of the Bailey beam is not met is solved.

Example 2

Based on the above embodiment 1, a second construction method is designed, and referring to fig. 4-10, the construction requirement is satisfied by checking, and the difference between the embodiment and the embodiment 1 is that: 4 pairs of socket type triangular brackets 1 are embedded along the transverse bridge direction of a pier body 4, a sand box 2 is installed (the triangular brackets 1 on two sides are oppositely pulled through 4 finish rolling screw steels with the diameter of 24mm, the sand box 2 is used for elevation adjustment and serves as a landing block), 2I 45I steel girders 5 are installed on the longitudinal bridge direction, 2 pieces of 27 m ordinary type bailey girder pieces are respectively placed on two sides of a capping beam pier column, the distance is 45cm, 4 pieces of 16.5 m ordinary type bailey girder pieces are placed on the bottom of the capping beam, the distance is 45cm, 10x10cm square lumber is placed again, and 80cm is used as a distribution beam. And finally, paving a shaping steel mould on the square timber, and then constructing the bent cap. Compared with the embodiment 1, in the embodiment 2, the triangular bracket 1 is embedded in the inner side of the bent cap, and the bailey beam supports are arranged under the bent cap, so that the distance between the nodes of the bailey beam supports is shortened from 18 meters to 16.5 meters, the problems that the middle-span disturbance degree of the bailey beam is too large, the internal force of the bailey beam rod part does not meet the stress requirement and the like are solved; secondly, the length of the 4-piece bailey beams below the cover beam is shortened from 27 meters to 16.5 meters, and the reinforced structure is optimized to be a common structure, so that the material consumption is reduced; thirdly, because the bottom of the capping beam is not suspended any more, the space between the I-shaped steel distribution beams can be enlarged or changed into square timber for use, the use of the distribution beam profile steel is reduced, and the stress is also more definite and uniform.

And carrying out stress detection and calculation on the BIM design model in simulation analysis software, and adjusting and optimizing a supporting system according to a detection and calculation result to finally obtain the construction supporting system suitable for the high pier large-span portal pier bent cap. The method comprises the steps of exporting a final finalized bent cap support system model in space eClaim design software, importing the model into CATIA compound software in a stp file format, manufacturing a three-dimensional processing design drawing and a three-dimensional intersection, marking the dimensions on the three-dimensional model, marking labels, and summarizing BOM quantity tables to finally form an exe executable program, and directly opening the three-dimensional intersection executable program by a processing manufacturer and a construction operator without installing other BIM modeling software by only having a computer end to check the model, thereby knowing design information and being beneficial to guiding construction.

The field construction implementation requirements are as follows:

(1) The socket type triangular bracket is uniformly processed by manufacturers, so that full welding of welding seams is ensured, and the materials can be used after the inspection of the welding seams; when the portal pier is about to be constructed to the pier top, the arrangement elevation position of the bracket is calculated in advance, a bracket hole is reserved, and a layer of anti-cracking reinforcing steel meshes with the diameter of HRB400 and the spacing of 12mm and 100mm are respectively added above and below the reserved hole within the range of 40cm from outside to inside of the pier body; and then pre-burying an anchor box, wherein the anchor box is made of a 0.5-thick Q235 steel plate and welded into a cuboid with one non-closed side, the size of the cuboid is 620 multiplied by 250 multiplied by 120mm, a round hole with the diameter of 100mm is formed in the center of the other non-closed side, and the two steel boxes are welded and connected by utilizing a steel pipe with the diameter of 100 mm. The steel pipe penetrates into the steel box for 10mm, so that concrete is prevented from leaking into the steel box during concrete pouring. The steel box utilizes the reinforcing bar to connect firmly with pier stud reinforcing bar, and four steel boxes guarantee in same horizontal plane, and utilize geotechnique cloth to fill closely knit in the steel box after pre-buried completion, avoid concrete placement in-process, the concrete flows into in the steel box.

(2) After the pier body is constructed, the bracket is hoisted in place by adopting a crane and is manually matched and installed. Before the bracket is hoisted, the bracket is inspected, and the bracket can be installed after the inspection is qualified. When the bracket is installed, the bolt is inserted into the anchor box, the bracket is initially fixed by utilizing 2 phi 24 prestress finish rolling screw steels, and then the bracket is screwed by using an iron hammer to knock down a limiter to be matched with a screwing nut, wherein the pretightening force is not less than 65KN. The gap between the chord member I-steel reinforcing rib plate and the reserved hole is tightly plugged and fixed by a thin steel plate, so that the bracket is prevented from moving up and down, and the diagonal bracing base plate wraps the geotechnical close pier body.

(3) The sand box 2 is uniformly processed and manufactured by factories, so that full welding of welding seams is ensured; the cavity of the upper member in the sand box 2 is not filled with concrete, the appearance, the size and the weld quality of the sand box 2 are checked and accepted one by one after the sand box 2 enters the field, and after the check is qualified, 2 pieces of the sand box are arbitrarily extracted to carry out bearing capacity tests, wherein the bearing capacity value is not smaller than 800KN. After the bracket is installed, a sand box and a 2I 45I-shaped steel main beam are installed, a Bailey beam limiter is arranged on the main beam, preliminary elevation adjustment is carried out, and after the elevation adjustment of the I-shaped steel main beam is completed, the Bailey beam is ready to be installed.

(4) After entering the field, the Bailey beams are assembled in an open field, 8 Bailey beams are divided into 3 groups, two outer 2 sheets are taken as 1 group, and the inner 4 sheets are taken as 1 group. The beam is reinforced by adopting double-spliced I10 channel steel at two sides of a support node of the beam, the length of the channel steel is equal to the distance between the upper chord member and the lower chord member of the beam, the channel steel is installed through an iron hammer and is not welded with the chord member during reinforcement, bolts are adopted between double-spliced channel steel for effective fixation, the beam is hoisted in the whole group during installation, the middle group 2 is installed firstly, gaps between two side ends of the beam and pier columns are tightly propped by square lumber, and the beam transverse bridge is prevented from moving towards the pier column. And then the installation and the fixation of the 1 st and the 3 rd groups are carried out. The bailey beam transverse bridge is fixed to a U-shaped clamping groove designed by adopting I10 channel steel, the bailey beams on two sides of the U-shaped clamping groove are connected by using the channel steel which is also I10, nut holes are reserved above the clamping groove and the channel steel, the bailey beam transverse bridge is fixed by adopting nuts or steel bars, and each group is connected according to 6 meters. And after the Bailey beam is installed, controlling the height of the sand box to adjust the elevation of the Bailey beam. And (5) after the elevation adjustment is completed, mounting a subsequent distribution beam and paving a bottom die. After the bracket construction is completed, the bracket supporting system is comprehensively checked and accepted, written records are formed, and after the quality of the bracket is confirmed to be qualified after the checking is completed, the pre-pressing test and the capping beam construction can be carried out.

The foregoing description of the preferred embodiments of the utility model is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the utility model.

Claims (5)

1. High mound long span portal mound prestressing force bent cap braced system based on BIM design, its characterized in that: the support system comprises triangular brackets (1) which are pre-buried at two opposite sides of the upper part of a pier column (4) and fixed in opposite pulling, wherein a sand box (2) is installed on each triangular bracket (1), bailey beams (3) are respectively arranged at two sides of the pier column (4) along the transverse bridge direction, and the bailey beams (3) at two sides are installed on the sand box (2) or are fixed on a main beam (5) at the top of the sand box (2) along the longitudinal bridge direction.

2. The BIM design-based high pier large-span portal pier prestressed bent cap support system of claim 1, wherein: the triangular bracket (1) is a socket type triangular bracket, two pairs of triangular brackets (1) are respectively fixed on two adjacent pier studs (4) along the longitudinal bridge direction through split bolts in a pre-buried mode, sand boxes (2) are fixed at the upper ends of the triangular brackets (1), and reinforced bailey beams (3) on two sides are installed and fixed on the sand boxes (2).

3. The BIM design-based high pier large-span portal pier prestressed bent cap support system of claim 1, wherein: the triangular bracket (1) is a socket type triangular bracket, four pairs of triangular brackets (1) are respectively fixed on two adjacent pier columns (4) along the transverse bridge direction through split bolts in a pre-buried mode, two pairs of triangular brackets (1) are parallelly fixed at the same height of the upper end of each pier column (4), sand boxes (2) are all fixed at the upper ends of the triangular brackets (1), main beams (5) are fixed above the sand boxes (2) along the longitudinal bridge direction, and bailey beams (3) are fixedly installed on the main beams (5).

4. The BIM design-based high pier large-span portal pier prestressed bent cap support system of claim 2, wherein: the upper chord member and the bolt of the triangular bracket (1) are made of I25b I-steel, the inclined strut (11) and the vertical strut (12) are made of I18I-steel, a 16mm rectangular base plate (13) is arranged at the tail of the triangular bracket (1), 16mm reinforcing rib plates (15) are welded at two sides of a main stress area of the upper chord member (14) and the pier body inner bolt, two small triangular rib plates are respectively arranged at two sides of the end part of each reinforcing rib plate (15), two knocking plate and bolt limiting plates (16) are arranged at two sides of each reinforcing rib plate (15), a safety baffle and lifting hole (17) is formed at a position 10cm away from the outer side of the upper chord member (14), Q345 steel is adopted for the triangular bracket (1), and welding seams of the triangular bracket (1) are fully welded.

5. The BIM design-based high pier large-span portal pier prestressed bent cap support system of claim 2, wherein: the sand box (2) is a rectangular box body, the box body (21) and the box cover (22) are uniformly made of steel plates with the thickness of 16mm, the sand box bottom support (23) is made of steel plates with the thickness of 10mm, 4 threaded holes (25) and 2 rectangular sand drawing holes (26) are arranged on the box body (21), a baffle (24) is arranged on the outer vertical face, and the baffle (24) is fixed with the box body (21) by nuts.