Socket and spigot type disc buckle type full framing construction method suitable for elevated station

Abstract

The invention provides a construction method of a socket and spigot type disc buckle type full framing suitable for an elevated station, and particularly introduces a series of key construction methods of framing, bracket pre-pressing, reinforcing steel bar manufacturing and mounting, bracket erecting construction precautions and the like in the socket and spigot type disc buckle type full framing suitable for the elevated station. According to the socket type disc buckle type full framing construction method, the safety use of a cast-in-place construction formwork and a cast-in-place support structure of an elevated station main body structure and the safety of construction machinery and operating personnel can be effectively guaranteed, and compared with a same-type full framing lap joint method, the socket type disc buckle type full framing construction method has the advantages that the construction efficiency is improved; the construction period of the full framing can be greatly shortened, and the production efficiency is further improved.

Description

Technical Field

[0001] The invention belongs to the field of station construction, and in particular relates to a construction method of a socket-type disc-locked full-bridge bracket suitable for an elevated station. Background Art

[0002] An elevated station is a railway station where platform and other station facilities are built on an elevated structure with a certain height difference from the ground. An elevated station is a railway track that is elevated or a station built at a high altitude to eliminate the elevation difference in mountainous areas. It is a station system used by monorail or passenger rapid transit systems. The span of the elevated station project is large, and there are many reserved holes in many parts such as the pump room and the substation mezzanine. The structure is relatively complex. Therefore, the main construction adopts a socket-type disc-type bracket solution to jointly construct a support system to meet the construction needs.

[0003] Cast-in-place concrete has various cross-sectional forms, high overall performance requirements, long construction period and complex process, which requires the support system in the construction process of cast-in-place box girders to withstand multi-directional loads. The high stability and high bearing capacity of the socket-type disc-type support make its feasibility and reliability in elevated station projects increasingly increasing. The present invention elaborates on the layout form, support erection, support pre-compression, support removal, support structure verification and optimization of the socket-type disc-type steel pipe support suitable for elevated stations, in order to provide reference for similar engineering support schemes. Summary of the invention

[0004] The purpose of the present invention is to provide a construction method of a socket-and-spigot-type disc-type full-floor bracket suitable for elevated stations, which is convenient to construct, has a higher safety and stability coefficient and is easy to dismantle. The bracket system as a whole has the trend of being light, high-strength, low-cost, easy to operate and diversified in functions. The present invention mainly describes the process of the socket-and-spigot-type disc-type full-floor bracket in the elevated station, summarizes each process, and provides experience for subsequent projects.

[0005] The present invention provides an ultra-long pile foundation internal force monitoring method based on an optical fiber Bragg sensor, and the materials required for the implementation include: a 1.5 cm thick square wood bamboo plywood composite template, a 10 cm × 5 cm square wood, a double-jointed Ф48 mm × 3.5 mm ordinary steel pipe, a Q345B material Ф60 × 3.2 mm steel pipe, a Q235B material Ф48 × 2.5 mm steel pipe, a Q235B material Ф33 × 2.3 mm steel pipe, an M18 tension bolt, a single Ф48 mm × 3.5 mm steel pipe, a Q235B material Ф33 × 2.3 mm steel pipe, etc.

[0006] The cast-in-place formwork adopts a combination of square wood and bamboo plywood, with a thickness of 1.5 cm. The secondary keel of the formwork adopts 10 cm × 5 cm square wood. The main keel of the formwork adopts double-jointed Ф48 mm × 3.5 mm ordinary steel pipes. According to the different pressures of the formwork in different parts, the spacing and laying methods of the main and secondary keels are designed separately. The secondary purlins of the underground structure side wall formwork are laid vertically with a spacing of 30cm; the main purlins are laid longitudinally and transversely with a spacing of 60cm; the side wall is cast-in-place with single-sided formwork closed, the bamboo plywood and square timber are connected with iron nails to form a whole, the main purlins are tied together by tension bolts, and the tension bolts are welded to the main reinforcement on the outside of the side wall; the side wall formwork is mainly stabilized by the top support of the bracing pipe, the bracing pipe is made of Ф48mm×3.5mm steel pipe, and the spacing is 60cm vertically and 50cm vertically. It is connected to the horizontal rod of the full-floor bracket by a cross fastener to constrain the free length to ensure that the radial axial force of the rod does not cause bending deformation.

[0007] The secondary purlin of the beam formwork is laid longitudinally with a spacing of 30cm; the main purlin is laid vertically and horizontally with a spacing of 60cm; the beam body is cast in three sides and the formwork is closed, the bamboo plywood and square wood are connected with iron nails to form a whole, the main purlins on both sides are tied together by tension bolts, and the spacing of the tension bolts is 60cm×60cm, and the main purlin at the bottom of the beam is laid on the top support of the full-floor bracket rod.

[0008] Furthermore, the secondary purlins of the column formwork are laid vertically with a horizontal center spacing of 10cm; the main purlins are made of Ф48×3.5mm steel pipes with a vertical center spacing of 60cm, and the tension rods between the main purlins are made of M18 tension bolts; the secondary purlins of the cast-in-place formwork of the structural slab are laid longitudinally with a spacing of 30cm; the main purlins under the slab are laid on the top support of the full-floor bracket rods, and the spacing is adjusted accordingly based on the bracket spacing. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a process flow chart of cast-in-place construction of station main structure brackets of a socket-type disc-locked full-chamber bracket construction method applicable to elevated stations; DETAILED DESCRIPTION

[0013] The method in the present invention will be described clearly, completely and in detail below in conjunction with the drawings in the present invention.

[0014] See also Figure 1 This is a process flow chart of the cast-in-place construction of the station main structure support of the patented socket-type disc-locked full-floor support construction method suitable for elevated stations. Figure 1 As shown, the construction process mainly includes four steps: erection of the socket-type disc-type full-span bracket, bracket pre-compression, and steel bar production and installation.

[0015] During the scaffolding erection, the size of the foundation construction site is determined according to the specific size of the beam and slab structure required for the main body of the station, and a foundation site of corresponding size is arranged; at the same time, construction preparations are carried out, the scaffolding force is calculated according to the size of the beam and slab structure, and the size of the scaffold and the amount of materials are determined.

[0016] After determining the ground elevation, the work of setting up the bracket is carried out. According to the specification, the vertical diagonal bars need to be arranged on each layer of all spans, and the step distance of the horizontal diagonal bars is within 1.5m. In the height direction, it is necessary to design a reinforcement diagonal bar or a steel pipe scissor brace every 5 steps. When there are stable structures or structures around the bracket, the cross bar can be used to connect it with the bracket. When the beam, slab and column are cast together, the bracket needs to be erected around the column and connected to the column formwork through the "fastener-type steel pipe + base" and the horizontal bar of the disc buckle frame to form a reliable top support connection to form a column holding effect. The distance of the adjustable bracket of the formwork bracket hanging out of the horizontal bar shall not be greater than 65cm, and the un-lapped distance of the screw rod shall not be greater than 40cm. The length of the adjustable bracket inserted into the vertical pole is strictly prohibited to be less than 15cm. The step distance of the bottom horizontal bar is set according to the standard step distance, that is, the step distance of the bottom horizontal bar is 150cm, and the bottom is set with vertical diagonal bars.

[0017] The support preloading material is steel bar preloading, and the load test is carried out. The maximum construction load of the support preloading construction is 1.5 times the deadweight of reinforced concrete (3.9kN / m 2 ), considering the loads of construction personnel, materials and construction equipment (take 0.1kN / m 2 ), the pre-compressed material is piled on the completed formwork system without considering the formwork load.

[0018] Before the steel bar raw materials enter the site, the material management personnel shall check whether there are any bends or damages. There shall be no serious cracks, oily dirt, rust and other traces on the steel bar surface. Before the raw materials enter the site, the steel bar yield strength, tensile strength, elongation, bending performance and weight deviation shall be sampled and checked. Only those that pass the inspection shall be allowed to enter the site, and those that fail the inspection shall not be allowed to enter the site. The relevant requirements for different steel bar connection methods shall be strictly implemented in accordance with the relevant specifications for the same type of construction.

[0019] When longitudinal compressive reinforcement in a member is overlapped, its overlap length shall not be less than 0.8 times the overlap length of longitudinal tensile reinforcement and shall not be less than 200 mm. Reinforcement overlap position: For top plate and beam, middle plate and beam, upper reinforcement is overlapped at mid-span, and lower reinforcement is overlapped at support and 1 / 3 of clear span; for bottom plate and beam, upper reinforcement is overlapped at support and 1 / 3 of clear span, and lower reinforcement is overlapped at mid-span.

[0020] The cast-in-place formwork is removed by combining manual removal and mechanical removal. The cantilever components of each floor must reach 100% strength after the concrete is poured before the support and bottom formwork can be removed, and the component construction load should be ≤2.5KN / m2 During construction, the load on the floor must be strictly controlled to prevent overloading; ensure that the structural edges and corners are intact.

[0021] The above is a preferred implementation of the patent of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the patent of the present invention. These improvements and modifications are also regarded as the protection scope of the patent of the present invention.

Claims

1. A socket-type disc-locked full-height bracket construction method suitable for elevated stations, characterized in that: The following steps are involved: S1. Scaffolding installation: The cast-in-place scaffolding of the main structure of the station adopts socket-type disc-locked full-span scaffolding. The vertical and horizontal spacing of the full-span scaffolding poles and the pitch of the horizontal poles are set according to the distance determined in the scaffolding structure design calculation book using fixed-length rods. S2. Preloading of support: The preloading material of the support adopts steel bar preloading: according to the distribution of preloading load, the whole 12m steel bar raw material (C16 / C 18 / C 20 / C 25 / C 28) is used for preloading, and the preloading method adopts the equivalent load method. After the longitudinal and transverse distribution beams are laid, a layer of bamboo plywood bottom formwork is laid, and the load is piled according to the beam and slab load. The preloading is divided into three levels according to 60%, 100%, and 110% of the maximum construction load. S3. Fabrication and installation of steel bars: After acceptance, they are hoisted to the site for binding and installation. The connection position of the stressed steel bars is determined at the non-stress concentration point. The longitudinal main bars of the underground structure floor, roof, side wall and main structure columns and beams with a diameter of 20mm / 18mm are all mechanically connected; the main bars of columns, beams and slabs with a diameter less than 20mm are welded or overlapped, the length of the single-sided lap weld is not less than 10d, and the lap length of the main bars of the overlapped beam is not less than 35d; the stirrups of columns, beams and the surface bars of the above-ground structure plate are tied with wire. S4. Removal of formwork and support: The removal of cast-in-place formwork is carried out by a combination of manual removal and machinery.

2. A method for constructing a socket-type disc-locked full-height bracket suitable for an elevated station as claimed in claim 1, characterized in that: S1 adopts socket-type disc-lock full-chamber bracket.

3. The method for constructing a socket-type disc-locked full-height bracket suitable for an elevated station as claimed in claim 1, characterized in that: In S1, the bracket erected around the column needs to be horizontally connected to the column formwork through the "fastener-type steel pipe + base" and the horizontal rod of the disc buckle frame to form a reliable top support connection to form a column-holding effect. The preloading method in S2 adopts the equivalent load method.

4. The method for constructing a socket-type disc-locked full-height bracket suitable for an elevated station as claimed in claim 1, characterized in that: The preloading method in S2 adopts the equivalent load method.

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