Prefabricated bracket construction structure for portal pier of elevated station

Abstract

The utility model provides an elevated station gate-type pier prefabricated corbel construction structure which comprises a gate-type pier cross beam, corbels are installed on the two sides of the gate-type pier cross beam, the corbels are prefabricated corbels, the prefabricated corbels are fixedly connected with the gate-type pier cross beam through finish rolling deformed steel bars, and a plurality of finish rolling deformed steel bars are arranged on an upper layer and a lower layer. The utility model has the advantages that: compared with the traditional cast-in-place bracket process, the prefabricated section splicing construction method of prefabricating in a factory and then installing on site is adopted, the construction efficiency is higher. Prefabrication and installation can be carried out in parallel, most of work is completed in a prefabrication factory, the construction period is shortened, the traffic guide and change time is shortened, the influence on the urban traffic environment is reduced, and environmental protection of a construction site is facilitated.

Description

Technical Field

[0001] The utility model relates to the technical field of bracket assembly, in particular to a construction structure of precast brackets of a portal pier for an elevated station. Background Art

[0002] There are many restrictions on the clearance of urban rail transit, and the land for urban elevated stations is in short supply. In order to save the station clearance, non-through box girders are adopted for the layout of the station girders, and the box girder bearings are placed on the brackets of the cross beam of the portal pier, and the box girder surface is flush with the cross beam surface of the portal pier.

[0003] However, the traditional bracket installation adopts the on-site casting process, which affects the operation time and operation environment of urban rail transit and has low construction efficiency. Content of the Utility Model

[0004] The purpose of the utility model is to provide a construction structure of precast brackets of a portal pier for an elevated station, which shortens the construction period, reduces the traffic diversion time, reduces the impact on the urban traffic environment, is beneficial to protecting the construction site environment, and is precast and then installed.

[0005] In order to achieve the above purpose, the utility model is realized through the following technical solutions:

[0006] A construction structure of precast brackets of a portal pier for an elevated station includes a cross beam of the portal pier, brackets are installed on both sides of the cross beam of the portal pier, the brackets are precast brackets, and the precast brackets are connected and fixed to the cross beam of the portal pier through high-strength steel bars with fine threads, and the high-strength steel bars with fine threads are several and are arranged in upper and lower layers.

[0007] Furthermore, the precast bracket is provided with hole pipes for installing high-strength steel bars with fine threads, the hole pipes are grouted after the high-strength steel bars with fine threads are tensioned, and the redundant high-strength steel bars with fine threads at the orifices of the hole pipes are cut off and welded and sealed with anchor-covering steel bars.

[0008] Furthermore, the surface of the precast bracket is evenly coated with an epoxy resin binder with a thickness of 3 mm.

[0009] Furthermore, there are 7 high-strength steel bars with fine threads and they are installed on the upper and lower sides, 5 high-strength steel bars with fine threads are installed on the upper layer, and 2 high-strength steel bars with fine threads are installed on the lower layer.

[0010] Furthermore, the diameter of the high-strength steel bars with fine threads is 50 mm, the strength is 2022 MPa, and the tension control force is 1516 KN.

[0011] Furthermore, a D50 corrugated pipe is embedded in the hole pipe of the precast bracket.

[0012] Furthermore, a D50 corrugated pipe is embedded at the connection position of the cross beam of the portal pier and the precast bracket, and the orifice is filled with a PE rubber strip.

[0013] Compared with the prior art, the utility model has the following advantages:

[0014] A precast corbel construction structure for a gantry pier of an elevated station according to the utility model adopts a precast segment assembly construction method of prefabricating in a factory and then installing on site. Compared with the traditional cast-in-situ corbel process, the construction efficiency is higher. Prefabrication and installation can be carried out in parallel, and most of the work is completed in the prefabrication factory, shortening the construction period, reducing the traffic diversion time, reducing the impact on the urban traffic environment, and being beneficial to the environmental protection at the construction site.

[0015] Specifically, the precast corbels produced in a factory have stable quality and are easier to control than the cast-in-situ pier body; the segments are light in weight and small in size, convenient for transportation, fast in assembly construction speed, and save the construction period; only the corbel installation construction is carried out on site, and the duration is shortened significantly compared with the cast-in-situ process, which is beneficial to the on-site progress control; the construction method of on-site assembly by special equipment can significantly reduce the impact on the normal traffic and environment around the construction site; there are many special-shaped templates for the corbels, and it is difficult to control the geometric shape details. The adoption of the assembled type can reduce the template installation and support difficulty, and the templates can be recycled, which can improve the construction efficiency and reduce the overall energy consumption of the industry; it reduces or avoids the long-term high-altitude operation of workers and reduces the construction safety risk. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a front structural schematic diagram of the precast corbel of the utility model.

[0017] Figure 2 is a side structural schematic diagram of the precast corbel of the utility model.

[0018] Figure 3 is a three-dimensional layout schematic diagram of the construction structure of the utility model.

[0019] Figure 4 is a side layout schematic diagram of the construction structure of the utility model.

[0020] Figure 5 is a schematic diagram (one) of the construction platform erection of the utility model.

[0021] Figure 6 is a schematic diagram (two) of the construction platform erection of the utility model.

[0022] Figure 7a is a schematic diagram (one) of the precast corbel hoisting of the utility model.

[0023] Figure 7b is a schematic diagram (two) of the precast corbel hoisting of the utility model.

[0024] Figure 8a is a schematic diagram (one) of the installation and tensioning of the unilateral precast corbel of the utility model.

[0025] Figure 8b It is the schematic diagram (II) of the installation and tensioning of the single-sided precast bracket of the present utility model.

[0026] Figure 9a It is the schematic diagram (I) of the installation and tensioning of the double-sided precast bracket of the present utility model.

[0027] Figure 9b It is the schematic diagram (II) of the installation and tensioning of the double-sided precast bracket of the present utility model. Specific implementation manners

[0028] The embodiments of the present utility model will be further described in detail below in conjunction with the accompanying drawings.

[0029] As Figures 1 - 4 shown, a construction structure of precast brackets for a gantry pier of an elevated station includes a gantry pier cross beam, and brackets are installed on both sides of the gantry pier cross beam. D50 corrugated pipes are embedded at the connection positions of the gantry pier cross beam and the precast brackets, and the pipe orifices are filled with PE rubber strips. The brackets are precast brackets, and the precast brackets are connected and fixed to the gantry pier cross beam through fine-threaded deformed steel bars. The fine-threaded deformed steel bars are several and are arranged in upper and lower layers. Preferably, there are 7 fine-threaded deformed steel bars, which are installed on the upper and lower sides, 5 fine-threaded deformed steel bars are installed on the upper layer, and 2 fine-threaded deformed steel bars are installed on the lower layer. The diameter of the fine-threaded deformed steel bars is 50 mm, the strength is 2022 MPa, and the tension control force is 1516 KN.

[0030] Holes for installing fine-threaded deformed steel bars are preset in the precast brackets, D50 corrugated pipes are embedded in the holes, and the holes are grouted after the fine-threaded deformed steel bars are tensioned. The redundant fine-threaded deformed steel bars at the orifices of the holes are cut off and welded and sealed with anchor-sealing steel bars.

[0031] The surface of the precast bracket is evenly coated with an epoxy resin binder with a thickness of 3 mm.

[0032] As Figure 5 shown in FIGS. 8 to 9, the construction steps of the present utility model are as follows:

[0033] Step S1) Construction of the gantry pier cross beam of the elevated station

[0034] Since the fine-threaded deformed steel bars (steel bars) of the precast brackets need to pass through the gantry pier cross beam, two rows of D50 corrugated pipes need to be embedded in advance at the connection parts of the gantry pier cross beam and the brackets, and the pipe orifices are filled with PE rubber strips to prevent slurry leakage during concrete pouring, resulting in pipeline blockage. At the same time, the connection surface of the brackets is roughened.

[0035] Step S2) Prefabrication of brackets

[0036] According to the surveying and mapping data of the construction site, the precast corbels are made of C50 concrete. Two rows of holes for high-strength threaded steel bars (rebars) are reserved according to the drawings, and two rows of D50 corrugated pipes are embedded. At the same time, attention should be paid to the linear control of the precast corbels and the treatment of the mating surface (shear key); they are numbered and marked in the order of the left and right precast segments. After the precast and curing are completed, the precast corbels are lifted and loaded onto the truck by the gantry crane in the beam yard. Before hoisting, they are loaded onto the truck according to the installation sequence of the corbels on the pier shaft. The truck and the left and right blocks of the precast corbels are numbered for easy on-site installation and to reduce secondary handling. During transportation, pay attention to wrapping the edges and corners of the precast blocks to prevent bumps and scratches. They are transported to the site one by one by the flatbed truck according to the assembly sequence of the pier shaft; after the precast blocks are transported to the site, check and clean the butt joints of the precast blocks and make records.

[0037] Step S3) Set up the construction platform

[0038] Before installing the precast corbels, an I-beam construction platform needs to be set up. Four I-beam crossbeams form a framework, which is symmetrically arranged and firmly anchored on the crossbeam of the gantry pier. The construction platform is well enclosed.

[0039] Step S4) Install the left precast corbel

[0040] After checking the numbers of the precast corbels, use a truck crane to lift the precast corbels and align them with the corbel connection parts of the crossbeam of the gantry pier; the hoisting of the corbels on both sides of the crossbeam of the gantry pier is carried out simultaneously. After the precast corbels on both sides are pre-positioned, the shear keys of the precast corbels are cleaned again, and a 3-mm-thick epoxy resin binder is evenly applied; then the crane slowly moves the precast corbels, and the workers assist in pushing and pulling to make the shear keys and key grooves of the precast blocks completely in close contact; the installation workers install the high-strength threaded steel bars through the reserved holes. The high-strength threaded steel bars connect the corbels on both sides and the crossbeam of the gantry pier and are temporarily locked with nuts. A total of 7 high-strength threaded steel bars are installed, with 5 installed in the upper layer and 2 installed in the lower layer. The high-strength threaded steel bars have a diameter of 50 mm, a strength of 2022 MPa, and a tension control force of 1516 KN; the high-strength threaded steel bars should be tensioned synchronously at both ends and comply with the designed tensioning sequence. During the pre-application of force, the elongation at both ends should be kept basically the same; the prestress value is mainly based on the reading of the oil pressure gauge and is checked with the elongation value of the steel bars. The difference between the actual elongation and the calculated elongation of the steel bars should be within ±6%; the pier shaft tensioning system uses a hydraulic jack. According to the distribution of the high-strength threaded steel bars, first in the middle and then on both sides. During the tensioning process, pay attention to the changes in the beam body, especially the concrete of the corbels, and send special personnel to observe and record. During prestress tensioning control, the tensile stress is the main factor and the elongation is the auxiliary factor; after the high-strength threaded steel bars are tensioned, immediately carry out duct grouting to make the other end of the corrugated pipe full of grout. After the duct is grouted, it should be cured for at least five days; after passing the inspection, use a grinding wheel cutting machine to cut off the excess high-strength threaded steel bars. After cutting, install the end-anchoring steel bars according to the design requirements. The end-anchoring steel bars are welded firmly to the embedded steel bars of the corbels, and the concrete at the end-anchoring part is poured and cured.

[0041] Step S5) Installation of the precast bracket on the right side

[0042] It is the same as the installation of the precast bracket on the left side.

[0043] The above description is only the preferred embodiment of the present utility model. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present utility model, several improvements and refinements can be made, and these improvements and refinements should also be regarded as within the protection scope of the present utility model.

Claims

1. A prefabricated bracket construction structure for a portal pier of an elevated station, comprising a portal pier cross beam, with brackets installed on both sides of the portal pier cross beam, characterized in that: The corbel is a prefabricated corbel, which is connected and fixed to the portal pier crossbeam through precision-rolled threaded steel bars. The precision-rolled threaded steel bars are in multiple numbers and are arranged in upper and lower layers.

2. The prefabricated bracket construction structure of the elevated station portal pier according to claim 1 is characterized by: The prefabricated corbel is pre-installed with a hole tube for installing fine-rolled threaded steel. The hole tube is grouted after the fine-rolled threaded steel is tensioned. The excess fine-rolled threaded steel bars are cut off from the hole tube mouth and are welded and sealed with anchor steel bars.

3. A prefabricated corbel construction structure for portal piers of elevated stations according to claim 1 or 2, characterized in that: The surface of the prefabricated corbel is evenly coated with a 3 mm thick epoxy resin adhesive.

4. A prefabricated corbel construction structure for portal piers of elevated stations according to claim 1 or 2, characterized in that: There are 7 fine-rolled threaded steel bars and they are installed on the upper and lower sides, with 5 fine-rolled threaded steel bars installed on the upper layer and 2 fine-rolled threaded steel bars installed on the lower layer.

5. The prefabricated bracket construction structure of the elevated station portal pier according to claim 4 is characterized by: The diameter of the fine-rolled threaded steel bar is 50 mm, the strength is 2022 MPa, and the tension control force is 1516 KN.

6. The prefabricated bracket construction structure of the elevated station portal pier according to claim 2 is characterized by: A D50 corrugated pipe is pre-buried in the hole tube of the prefabricated corbel.

7. A prefabricated corbel construction structure for portal piers of elevated stations according to claim 1 or 6, characterized in that: The portal pier crossbeam is pre-embedded with a D50 corrugated pipe at the prefabricated corbel connection position, and the pipe opening is filled with PE rubber strips.

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