A steel truss railway bridge hanging formwork system and construction method thereof

Abstract

The present invention discloses a steel truss railway bridge hanging formwork system and a construction method thereof, comprising double-jointed channel steels, wherein two channel steels of the double-jointed channel steels are connected by channel steel clamps, and multiple groups of double-jointed channel steels are fixed on each two crossbeams of each bridge deck of the steel truss railway bridge by channel steel clamps; multiple support rods are evenly arranged on the double-jointed channel steels, and the bottom ends of the support rods are provided with bottom support clamps, and the bottom support clamps are connected to the double-jointed channel steels; the top ends of the support rods are provided with top support clamps, and the inner sides of the top support clamps are connected to horizontal double-jointed I-beams, and the horizontal double-jointed I-beams are arranged parallel to the double-jointed channel steels; multiple longitudinal I-beams are evenly arranged above the horizontal double-jointed I-beams, and the upper surfaces of the longitudinal I-beams are tightly paved with a rubber plate bottom formwork. The hanging formwork is simple and convenient to install and will not cause damage to the paint surface of the outer surface of the steel truss railway bridge. At the same time, the hanging formwork system can be constructed within the height of the lower chord of the steel truss railway bridge and will not affect the normal operation of the waterway.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge construction, in particular to a steel truss railway bridge hanging formwork system and a construction method thereof. Background Art

[0002] In modern railway construction, steel truss railway bridges are widely used due to their large spans and excellent structural performance. However, during the construction of steel truss railway bridges, particularly during the concrete pouring phase, formwork support and installation have always been a technical challenge. Traditional formwork support systems often suffer from insufficient stability. During construction, due to the complexity of bridge structures and the variability of the construction environment, formwork is easily affected by external forces, causing deformation or displacement, which can affect the quality of the concrete pour. Consequently, a number of suspended formwork structures for bridge construction have emerged on the market.

[0003] For example, a Chinese patent with publication number CN112064510A discloses a cast-in-place bridge deck assembled hanging formwork structure, including a support base fixedly connected to a box beam, a connecting piece detachably connected to the support base, a hanging beam provided on the connecting piece, at least two hangers provided on the hanging beam, and a formwork combination hung on the hanger, the formwork combination is located between adjacent box beams or at the cantilevered end of the box beam. The hanging formwork structure is applicable not only to the assembled hanging formwork of the middle span bridge deck but also to the assembled hanging formwork of the cantilevered end bridge deck. The support base can be welded on the steel box beam, which is convenient, reliable and can provide stable support. The connecting piece is detachably connected to the support base, which is convenient for segmented construction and the support base can be directly cast in the bridge deck layer after the hanging formwork is completed without the need for laborious disassembly.

[0004] The hanging formwork structure provided by the above patent is convenient for segmented construction, but it is not convenient for the construction of steel truss railway bridges. During the construction of steel truss railway bridges, most of the steel trusses have been painted, and the formwork construction needs to avoid contact and collision with the steel trusses as much as possible to prevent damage to the paint. There is a navigable canal under the bridge, and the hanging formwork cannot encroach on the navigation height in terms of elevation. Construction can only be carried out within the height of the lower chord of the bridge, which makes the existing hanging formwork structure unable to be installed quickly and effectively. Therefore, there is a need for a hanging formwork system suitable for the construction of steel truss railway bridges, and the hanging formwork system needs to be simple and easy to dismantle, shortening the time of dismantling the formwork in the river channel to reduce the impact on normal shipping. Summary of the Invention

[0005] The purpose of the present invention is to provide a steel truss railway bridge formwork system and a construction method thereof, which are suitable for the construction of steel truss railway bridges. The formwork system is simple and easy to dismantle, takes less time to dismantle the formwork in the river channel, and can effectively reduce the impact on normal shipping.

[0006] The present invention is achieved in that:

[0007] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, the present invention provides a steel truss railway bridge hanging formwork system, including double-jointed channel steels, the two channel steels of the double-jointed channel steels are connected by channel steel clamps, and multiple groups of double-jointed channel steels are fixed on every two cross beams of each bridge deck of the steel truss railway bridge by channel steel clamps; a plurality of support rods are evenly arranged on the double-jointed channel steels, the bottom ends of the support rods are provided with bottom support clamps, and the bottom support clamps are connected to the double-jointed channel steels; the top ends of the support rods are provided with top support clamps, and the inner side of the top support clamps is connected to a horizontal double-jointed I-beam, and the horizontal double-jointed I-beam is arranged parallel to the double-jointed channel steel; a plurality of longitudinal I-beams are evenly arranged above the horizontal double-jointed I-beams, and the upper surfaces of the longitudinal I-beams are tightly covered with a rubber plate bottom formwork.

[0008] Furthermore, the parts where the two ends of the double-jointed channel steel contact the crossbeams of the steel truss railway bridge are wrapped with geotextile to protect the paint surface of the steel truss railway bridge and avoid friction between the two ends of the double-jointed channel steel and the crossbeams of the steel truss railway bridge, which may cause damage to the paint surface.

[0009] Furthermore, the adjacent support rods are connected by diagonal rods, and the diagonal rods and the support rods are detachably connected; this is used to ensure the stability of the entire hanging formwork system and also facilitate the subsequent dismantling of the hanging formwork system.

[0010] According to a second aspect of the present invention, the present invention provides a construction method for a steel truss railway bridge hanging formwork system, the specific steps of the construction method are as follows:

[0011] S100, assembling the railway bridge at the jacking position of the steel truss railway bridge, and calculating the jacking force of the steel truss railway bridge, wherein the deadweight of the hanging formwork system is substituted into the jacking calculation process when calculating the jacking force of the steel truss railway bridge;

[0012] S200, directly install the hanging formwork system at the top-pushing position of the steel truss railway bridge. First, splice the double-jointed channel steels with channel steel clamps according to the distance between every two crossbeams of each bridge deck of the steel truss railway bridge to ensure that the double-jointed channel steels meet the use requirements;

[0013] S300, hoisting the assembled double-jointed channel steels to the two crossbeams of each bridge deck of the steel truss railway bridge; and the double-jointed channel steels should be arranged at equal distances;

[0014] S400, connecting the support rod to the top support fixture and the bottom support fixture, and evenly fixing the support rod to the double-jointed channel steel through the bottom support fixture;

[0015] S500, a transverse double-jointed I-beam is erected parallel to each set of double-jointed channel steels, and each set of transverse double-jointed I-beams is connected to the top support fixtures of the top support rods of each set of double-jointed channel steels;

[0016] S600, after the installation of the horizontal double I-beams, install the vertical I-beams at equal distances on top of them; and lay the rubber sheet bottom formwork on the upper surface of the vertical I-beams. After the rubber sheet bottom formwork is laid, all kinds of fasteners must be installed in place.

[0017] S700. Install a jacking system to jack the steel truss railway bridge to install it to the predetermined position and further secure the steel truss railway bridge.

[0018] After the S800 steel truss railway bridge is installed, the steel mesh is tied on the bridge deck, and the embedded parts that need to be embedded are installed in the designated positions, and then concrete is poured to complete the bridge deck construction.

[0019] Furthermore, in step S100, a mechanical model of the jacking process is established when calculating the jacking force of the steel truss railway bridge. The jacking force is:

[0020]

[0021] Among them, F p (t) is the top thrust,

[0022] M b (t) is the weight of the bridge,

[0023] M f (t) is the mass of the hanging formwork system,

[0024] ∑M a (t) is the additional mass,

[0025] g is the acceleration due to gravity,

[0026] F f (t) is the friction force,

[0027] F w (t) is the wind load,

[0028] F t (t) is the additional force caused by temperature change.

[0029] Furthermore, in step S200, the bearing capacity of the double-jointed channel steel needs to be calculated before installing and assembling the double-jointed channel steel to ensure that the bearing capacity of the double-jointed channel steel meets the use requirements. The bearing capacity is:

[0030]

[0031] Among them, F c (x, t) is the bearing capacity of the double channel steel at position x and time t,

[0032] σ y (x, t) is the yield strength of the double channel steel at position x and time t,

[0033] A c (x, t) is the cross-sectional area of ​​the double-jointed channel steel at position x and time t,

[0034] γ F (x, t) is the safety factor at position x and time t,

[0035] is the integral of the load density function at position x′ and time t,

[0036] ΔF a (t) is the loss of bearing capacity, which is caused by material aging.

[0037] Furthermore, in step S300, before installing the double-jointed channel steel, geotextile is used to wrap the contact position between the double-jointed channel steel and the crossbeam of the steel truss railway bridge to avoid the problem of the double-jointed channel steel causing damage to the surface paint of the steel truss railway bridge.

[0038] Furthermore, in step S800, the deformation of the entire formwork system is estimated before pouring concrete to ensure that the deformation is within the error range, specifically:

[0039]

[0040] Among them, δ c (x, t) is the deformation caused by the concrete load at position x and time t,

[0041] P c (y, t) is the concrete pressure at position x and time t,

[0042] E(y, t) is the elastic modulus at position x and time t,

[0043] I(y, t) is the moment of inertia at position x and time t,

[0044] δ fl (t) is the deformation caused by the fluidity of concrete.

[0045] Furthermore, in step S500, before installing the horizontal double-jointed I-beams, adjacent support rods are connected using diagonal rods to generate interaction forces between the support rods to ensure the stability of the entire hanging formwork system.

[0046] Furthermore, after completing step S800, the formwork needs to be removed after the concrete solidification strength reaches the standard for formwork removal. When dismantling the hanging formwork system, the formwork needs to be removed from the bottom of the steel truss railway bridge. When dismantling the formwork, the hanging formwork system is dismantled in sections. First, the bottom support clamps are removed from the double-jointed channel steel, and then the channel steel clamps on the double-jointed channel steel are removed with the assistance of the auxiliary support device. After the channel steel clamps are removed, the double-jointed channel steel is removed in a safe environment, and then the support rods, top support clamps, horizontal double-jointed I-beams, longitudinal I-beams and rubber plate bottom formwork above the double-jointed channel steel are removed; in this way, the next group of double-jointed channel steels and the various components installed on their top are removed until the entire hanging formwork system is completely dismantled.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] 1. The hanging formwork system provided by the present invention is simple and convenient to install, and will not cause damage to the paint surface of the outer surface of the steel truss railway bridge. At the same time, the hanging formwork system can be constructed within the height of the lower chord of the steel truss railway bridge, and will not affect the normal operation of the waterway. At the same time, the hanging formwork system is easy to assemble and disassemble, which is convenient for the staff to remove the hanging formwork efficiently and quickly, shortening the waterway time occupied by the formwork removal.

[0049] 2. The support rods of the present invention are connected to each other by diagonal rods, which can ensure the stability of the entire hanging formwork system and avoid the problem of shaking or collapse of the hanging formwork system during the construction process.

[0050] 3. The present invention uses channel steel clips and top support clips to enable quick disassembly and assembly between double-jointed channel steels and horizontal double-jointed I-beams, which facilitates the quick installation and disassembly of the entire hanging formwork device and greatly facilitates the use of the entire hanging formwork device.

[0051] 4. The present invention installs the hanging formwork system before the bridge is pushed, which can avoid the problem of occupying the waterway when installing the hanging formwork system after the pushing is completed, greatly facilitating the assembly and use of the entire hanging formwork system; the pushing is carried out after the hanging formwork system is installed. This operation method allows the steel cage to be tied and concrete to be poured after the bridge is pushed into place, which is beneficial to saving time in bridge deck concrete construction and facilitating the workers to carry out efficient bridge deck concrete construction operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 It is a front view of the present invention as a whole;

[0053] Figure 2 is a side view of the present invention as a whole;

[0054] Figure 3 It is a top view of the present invention as a whole;

[0055] Figure 4It is a flow chart of the construction method of the present invention.

[0056] In the figure: 1. Double-jointed channel steel; 2. Channel steel clamps; 3. Support rods; 4. Top support clamps; 5. Bottom support clamps; 6. Diagonal tie rods; 7. Horizontal double-jointed I-beams; 8. Vertical I-beams; 9. Rubber board bottom formwork. DETAILED DESCRIPTION

[0057] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0058] The following is a further description with reference to the accompanying drawings and specific embodiments:

[0059] Example 1

[0060] like Figure 1 、 Figure 2 and Figure 3 As shown, a steel truss railway bridge hanging formwork system includes a double-jointed channel steel 1, and the two channel steels of the double-jointed channel steel 1 are connected by a channel steel clamp 2. The channel steel clamp 2 is used to splice the two channel steels together to achieve the purpose of stable placement of the entire channel steel. And multiple groups of double-jointed channel steels 1 are fixed by channel steel clamps 2 on every two crossbeams of each bridge deck of the steel truss railway bridge; the multiple groups of double-jointed channel steels 1 mainly serve the purpose of supporting the entire hanging formwork system. A plurality of support rods 3 are evenly arranged on the double-jointed channel steel 1, and a bottom support clamp 5 is provided at the bottom end of the support rod 3, and the bottom support clamp 5 is connected to the double-jointed channel steel 1; the support rod 3 is convenient for connection with the double-jointed channel steel 1, and at the same time achieves the purpose of supporting other components. The top of the support rod 3 is provided with a top supporting fixture 4, and the inner side of the top supporting fixture 4 is connected to a horizontal double-jointed I-beam 7, which is arranged parallel to the double-jointed channel steel 1; the top supporting fixture 4 is used to clamp the horizontal double-jointed I-beam 7, and it is also convenient for the support rod 3 to support the horizontal double-jointed I-beam 7. A plurality of longitudinal I-beams 8 are evenly arranged above the horizontal double-jointed I-beam 7, and the upper surface of the longitudinal I-beam 8 is tightly covered with a rubber plate bottom formwork 9; the horizontal double-jointed I-beam 7 is used to support the longitudinal I-beam 8 to ensure the stability of the longitudinal I-beam 8, and the longitudinal I-beam 8 is used to stably support the rubber plate bottom membrane, and the rubber plate bottom formwork 9 is used to support concrete. Through this structure, the entire hanging formwork system can be directly installed on the steel truss railway bridge, and the hanging formwork system can be used to pour the bridge deck concrete; when disassembling the hanging formwork system, the mechanism is directly disassembled from the bottom of the bridge deck, which is simple and convenient to operate, and facilitates the rapid construction of the entire steel truss railway bridge.

[0061] Example 2

[0062] like Figure 1 、 Figure 2 and Figure 3 As shown, a steel truss railway bridge hanging formwork system includes a double-jointed channel steel 1, and the two channel steels of the double-jointed channel steel 1 are connected by a channel steel clamp 2. The channel steel clamp 2 is used to splice the two channel steels together to achieve the purpose of stable placement of the entire channel steel. And multiple groups of double-jointed channel steels 1 are fixed by channel steel clamps 2 on every two crossbeams of each bridge deck of the steel truss railway bridge; the multiple groups of double-jointed channel steels 1 mainly serve the purpose of supporting the entire hanging formwork system. A plurality of support rods 3 are evenly arranged on the double-jointed channel steel 1, and a bottom support clamp 5 is provided at the bottom end of the support rod 3, and the bottom support clamp 5 is connected to the double-jointed channel steel 1; the support rod 3 is convenient for connection with the double-jointed channel steel 1, and at the same time achieves the purpose of supporting other components. The top of the support rod 3 is provided with a top supporting fixture 4, and the inner side of the top supporting fixture 4 is connected to a horizontal double-jointed I-beam 7, which is arranged parallel to the double-jointed channel steel 1; the top supporting fixture 4 is used to clamp the horizontal double-jointed I-beam 7, and it is also convenient for the support rod 3 to support the horizontal double-jointed I-beam 7. A plurality of longitudinal I-beams 8 are evenly arranged above the horizontal double-jointed I-beam 7, and the upper surface of the longitudinal I-beam 8 is tightly covered with a rubber plate bottom formwork 9; the horizontal double-jointed I-beam 7 is used to support the longitudinal I-beam 8 to ensure the stability of the longitudinal I-beam 8, and the longitudinal I-beam 8 is used to stably support the rubber plate bottom membrane, and the rubber plate bottom formwork 9 is used to support concrete. Through this structure, the entire hanging formwork system can be directly installed on the steel truss railway bridge, and the hanging formwork system can be used to pour the bridge deck concrete; when disassembling the hanging formwork system, the mechanism is directly disassembled from the bottom of the bridge deck, which is simple and convenient to operate, and facilitates the rapid construction of the entire steel truss railway bridge.

[0063] like Figure 1 and Figure 2 As shown, the parts where the two ends of the double-jointed channel steel 1 contact the crossbeam of the steel truss railway bridge are wrapped with geotextile to protect the paint surface of the steel truss railway bridge and avoid friction between the two ends of the double-jointed channel steel 1 and the crossbeam of the steel truss railway bridge, which may cause damage to the paint surface.

[0064] like Figure 1 and Figure 2 As shown, adjacent support rods 3 are connected by diagonal rods 6, and the diagonal rods 6 are detachably connected to the support rods 3; this is used to ensure the stability of the entire hanging formwork system and also facilitate the subsequent dismantling of the hanging formwork system.

[0065] Example 3

[0066] like Figure 4 As shown, a construction method of a steel truss railway bridge hanging formwork system, the specific steps of the construction method are as follows:

[0067] S100. Assemble the steel truss railway bridge at the jacking position and calculate the jacking force of the steel truss railway bridge. When calculating the jacking force of the steel truss railway bridge, the deadweight of the hanging formwork system must be substituted into the jacking calculation process. When calculating the jacking force of the steel truss railway bridge, a mechanical model of the jacking process is established. The jacking force is:

[0068]

[0069] Among them, F p (t) is the top thrust,

[0070] M b (t) is the weight of the bridge,

[0071] M f (t) is the mass of the hanging formwork system,

[0072] ∑M a (t) is the additional mass,

[0073] g is the acceleration due to gravity,

[0074] F f (t) is the friction force,

[0075] F w (t) is the wind load,

[0076] F t (t) is the additional force caused by temperature change.

[0077] S200. Install the formwork system directly at the top-pushing position of the steel truss railway bridge. First, splice the double-jointed channel steel 1 with the channel steel clamp 2 according to the distance between each two crossbeams of each bridge deck of the steel truss railway bridge to ensure that the double-jointed channel steel 1 meets the use requirements. Before installing and assembling the double-jointed channel steel 1, calculate the bearing capacity of the double-jointed channel steel 1 to ensure that the bearing capacity of the double-jointed channel steel 1 meets the use requirements. The bearing capacity is:

[0078]

[0079] Among them, F c (x, t) is the bearing capacity of the double channel steel at position x and time t,

[0080] σ y (x, t) is the yield strength of the double channel steel at position x and time t,

[0081] A c (x, t) is the cross-sectional area of ​​the double-jointed channel steel at position x and time t,

[0082] γF(x, t) is the safety factor at position x and time t,

[0083] is the integral of the load density function at position x′ and time t,

[0084] ΔF a (t) is the loss of bearing capacity, which is caused by material aging.

[0085] S300. The assembled double-jointed channel steel 1 is hoisted onto the two crossbeams of each bridge deck of the steel truss railway bridge; and the double-jointed channel steel 1 is arranged at equal intervals; before installing the double-jointed channel steel 1, the contact position between the double-jointed channel steel 1 and the crossbeam of the steel truss railway bridge is wrapped with geotextile to prevent the double-jointed channel steel 1 from damaging the surface paint of the steel truss railway bridge.

[0086] S400, connecting the support rod 3 with the top support clamp 4 and the bottom support clamp 5, and evenly fixing the support rod 3 on the double-jointed channel steel 1 through the bottom support clamp 5;

[0087] S500, a horizontal double-jointed I-beam 7 is erected parallel to each set of double-jointed channel steels 1, and each set of horizontal double-jointed I-beams 7 is connected to the top supporting fixture 4 of the top support rod 3 of each set of double-jointed channel steels 1;

[0088] S600, after the installation of the horizontal double I-beam 7, install the longitudinal I-beam 8 on top of it at equal distances; and lay the rubber plate bottom formwork 9 on the upper surface of the longitudinal I-beam 8. After the rubber plate bottom formwork 9 is laid, all kinds of fasteners should be installed in place.

[0089] S700. Install a jacking system to jack the steel truss railway bridge to install it to the predetermined position and further secure the steel truss railway bridge.

[0090] After the S800 steel truss railway bridge is installed, the steel mesh is tied to the bridge deck, and the embedded parts that need to be embedded are installed in the designated locations. Then, concrete is poured to complete the bridge deck construction. Before pouring concrete, the deformation of the entire hanging formwork system must be estimated to ensure that the deformation is within the error range. Specifically:

[0091]

[0092] Among them, δ c (x, t) is the deformation caused by the concrete load at position x and time t,

[0093] P c (y, t) is the concrete pressure at position x and time t,

[0094] E(y, t) is the elastic modulus at position x and time t,

[0095] I(y, t) is the moment of inertia at position x and time t,

[0096] δ fl(t) is the deformation caused by the fluidity of concrete.

[0097] In step S300, the deflection of the double-jointed channel steel needs to be dynamically monitored, and the deflection is:

[0098]

[0099] Among them, δ d (x, t) is the deflection of the double channel steel at position x and time t,

[0100] F a (x, t) is the applied force on the double channel at position x and time t,

[0101] L(x, t) is the length of the double channel steel at position x and time t,

[0102] E(x, t) is the elastic modulus of the double-jointed channel steel at position x and time t,

[0103] I(x, t) is the moment of inertia of the double-jointed channel at position x and time t,

[0104] δ th (x, t) is the deformation of the double channel steel due to temperature at position x and time t,

[0105] δ hu (x, t) is the deformation of the double-jointed channel steel due to humidity at position x and time t.

[0106] In step S400, the dynamic load of the support rod needs to be monitored, specifically:

[0107]

[0108] Among them, P t (t) is the total load that changes with time,

[0109] P v (t) is the vertical load that changes with time,

[0110] P h (t) is the horizontal load that changes with time,

[0111] k v (t) is the vertical coefficient that changes with time,

[0112] k h (t) is the time-varying coefficient in the horizontal direction,

[0113] F v (t) is the vertical force that changes with time,

[0114] Fh (t) is the horizontal force that changes with time.

[0115] In step S500, the load on the support rod needs to be evaluated, specifically:

[0116] K(t)u(t)=F(t);

[0117] K(t) is the time-varying stiffness matrix,

[0118] u(t) is the displacement vector that changes with time,

[0119] F(t) is the external force vector that changes with time.

[0120] In step S600, the pressure distribution generated during the concrete hardening process needs to be estimated, specifically:

[0121]

[0122] Among them, σ c (x, t) is the pressure of the concrete at position x and time t,

[0123] P c (z, t) is the pressure of the concrete at depth z and time t,

[0124] A co (z, t) is the contact area at depth z and time t,

[0125] σ cu (t) is the internal stress generated during the concrete curing process.

[0126] In step S700, the acceleration during the installation process needs to be controlled, specifically:

[0127]

[0128] Among them, a p (t) is the acceleration at time t,

[0129] F p (t) is the thrust at time t,

[0130] F f (t) is the friction force at time t,

[0131] M t (t) is the total mass at time t,

[0132] a n (t) is the acceleration correction term due to nonlinear effects.

[0133] Example 4

[0134] like Figure 4 As shown, a construction method of a steel truss railway bridge hanging formwork system, the specific steps of the construction method are as follows:

[0135] S100. Assemble the steel truss railway bridge at the jacking position and calculate the jacking force of the steel truss railway bridge. When calculating the jacking force of the steel truss railway bridge, the deadweight of the hanging formwork system must be substituted into the jacking calculation process. When calculating the jacking force of the steel truss railway bridge, a mechanical model of the jacking process is established. The jacking force is:

[0136]

[0137] Among them, F p (t) is the top thrust,

[0138] M b (t) is the weight of the bridge,

[0139] M f (t) is the mass of the hanging formwork system,

[0140] ∑M a (t) is the additional mass,

[0141] g is the acceleration due to gravity,

[0142] F f (t) is the friction force,

[0143] F w (t) is the wind load,

[0144] F t (t) is the additional force caused by temperature change.

[0145] S200. Install the formwork system directly at the top-pushing position of the steel truss railway bridge. First, splice the double-jointed channel steel 1 with the channel steel clamp 2 according to the distance between each two crossbeams of each bridge deck of the steel truss railway bridge to ensure that the double-jointed channel steel 1 meets the use requirements. Before installing and assembling the double-jointed channel steel 1, calculate the bearing capacity of the double-jointed channel steel 1 to ensure that the bearing capacity of the double-jointed channel steel 1 meets the use requirements. The bearing capacity is:

[0146]

[0147] Among them, F c (x, t) is the bearing capacity of the double channel steel at position x and time t,

[0148] σ y (x, t) is the yield strength of the double channel steel at position x and time t,

[0149] A c(x, t) is the cross-sectional area of ​​the double-jointed channel steel at position x and time t,

[0150] γ F (x, t) is the safety factor at position x and time t,

[0151] is the integral of the load density function at position x′ and time t,

[0152] ΔF a (t) is the loss of bearing capacity, which is caused by material aging.

[0153] S300. The assembled double-jointed channel steel 1 is hoisted onto the two crossbeams of each bridge deck of the steel truss railway bridge; and the double-jointed channel steel 1 is arranged at equal intervals; before installing the double-jointed channel steel 1, the contact position between the double-jointed channel steel 1 and the crossbeam of the steel truss railway bridge is wrapped with geotextile to prevent the double-jointed channel steel 1 from damaging the surface paint of the steel truss railway bridge.

[0154] S400, connecting the support rod 3 with the top support clamp 4 and the bottom support clamp 5, and evenly fixing the support rod 3 on the double-jointed channel steel 1 through the bottom support clamp 5;

[0155] S500. A transverse double-jointed I-beam 7 is erected parallel to and directly above each set of double-jointed channel steels 1, and each set of transverse double-jointed I-beams 7 is connected to the top supporting fixture 4 of the top supporting rod 3 of each set of double-jointed channel steels 1; before installing the transverse double-jointed I-beams 7, adjacent supporting rods 3 must be connected using diagonal rods 6 to generate interaction force between the supporting rods 3 to ensure the stability of the entire hanging formwork system.

[0156] S600, after the installation of the horizontal double I-beam 7, install the longitudinal I-beam 8 on top of it at equal distances; and lay the rubber plate bottom formwork 9 on the upper surface of the longitudinal I-beam 8. After the rubber plate bottom formwork 9 is laid, all kinds of fasteners should be installed in place.

[0157] S700. Install a jacking system to jack the steel truss railway bridge to install it to the predetermined position and further secure the steel truss railway bridge.

[0158] After the S800 steel truss railway bridge is installed, the steel mesh is tied to the bridge deck, and the embedded parts that need to be embedded are installed in the designated locations. Then, concrete is poured to complete the bridge deck construction. Before pouring concrete, the deformation of the entire hanging formwork system must be estimated to ensure that the deformation is within the error range. Specifically:

[0159]

[0160] Among them, δ c (x, t) is the deformation caused by the concrete load at position x and time t,

[0161] P c (y, t) is the concrete pressure at position x and time t,

[0162] E(y, t) is the elastic modulus at position x and time t,

[0163] I(y, t) is the moment of inertia at position x and time t,

[0164] δ fl (t) is the deformation caused by the fluidity of concrete.

[0165] In step S300, the deflection of the double-jointed channel steel needs to be dynamically monitored, and the deflection is:

[0166]

[0167] Among them, δ d (x, t) is the deflection of the double channel steel at position x and time t,

[0168] F a (x, t) is the applied force on the double channel at position x and time t,

[0169] L(x, t) is the length of the double channel steel at position x and time t,

[0170] E(x, t) is the elastic modulus of the double-jointed channel steel at position x and time t,

[0171] I(x, t) is the moment of inertia of the double-jointed channel at position x and time t,

[0172] δ th (x, t) is the deformation of the double channel steel due to temperature at position x and time t,

[0173] δ hu (x, t) is the deformation of the double-jointed channel steel due to humidity at position x and time t.

[0174] In step S400, the dynamic load of the support rod needs to be monitored, specifically:

[0175]

[0176] Among them, P t (t) is the total load that changes with time,

[0177] P v (t) is the vertical load that changes with time,

[0178] P h (t) is the horizontal load that changes with time,

[0179] kv (t) is the vertical coefficient that changes with time,

[0180] k h (t) is the time-varying coefficient in the horizontal direction,

[0181] F v (t) is the vertical force that changes with time,

[0182] F h (t) is the horizontal force that changes with time.

[0183] In step S500, the load on the support rod needs to be evaluated, specifically:

[0184] K(t)u(t)=F(t);

[0185] K(t) is the time-varying stiffness matrix,

[0186] u(t) is the displacement vector that changes with time,

[0187] F(t) is the external force vector that changes with time.

[0188] In step S600, the pressure distribution generated during the concrete hardening process needs to be estimated, specifically:

[0189]

[0190] Among them, σ c (x, t) is the pressure of the concrete at position x and time t,

[0191] P c (z, t) is the pressure of the concrete at depth z and time t,

[0192] A co (z, tt) is the contact area at depth z and time t,

[0193] σ cu (t) is the internal stress generated during the concrete curing process.

[0194] In step S700, the acceleration during the installation process needs to be controlled, specifically:

[0195]

[0196] Among them, a p (t) is the acceleration at time t,

[0197] F p (t) is the thrust at time t,

[0198] Ff (t) is the friction force at time t,

[0199] M t (t) is the total mass at time t,

[0200] a n (t) is the acceleration correction term due to nonlinear effects.

[0201] Example 5

[0202] like Figure 4 As shown, a construction method of a steel truss railway bridge hanging formwork system, the specific steps of the construction method are as follows:

[0203] S100. Assemble the steel truss railway bridge at the jacking position and calculate the jacking force of the steel truss railway bridge. When calculating the jacking force of the steel truss railway bridge, the deadweight of the hanging formwork system must be substituted into the jacking calculation process. When calculating the jacking force of the steel truss railway bridge, a mechanical model of the jacking process is established. The jacking force is:

[0204]

[0205] Among them, F p (t) is the top thrust,

[0206] M b (t) is the weight of the bridge,

[0207] M f (t) is the mass of the hanging formwork system,

[0208] ∑M a (t) is the additional mass,

[0209] g is the acceleration due to gravity,

[0210] F f (t) is the friction force,

[0211] F w (t) is the wind load,

[0212] F t (t) is the additional force caused by temperature change.

[0213] S200. Install the formwork system directly at the top-pushing position of the steel truss railway bridge. First, splice the double-jointed channel steel 1 with the channel steel clamp 2 according to the distance between each two crossbeams of each bridge deck of the steel truss railway bridge to ensure that the double-jointed channel steel 1 meets the use requirements. Before installing and assembling the double-jointed channel steel 1, calculate the bearing capacity of the double-jointed channel steel 1 to ensure that the bearing capacity of the double-jointed channel steel 1 meets the use requirements. The bearing capacity is:

[0214]

[0215] Among them, F c (x, t) is the bearing capacity of the double channel steel at position x and time t,

[0216] σ y (x, t) is the yield strength of the double channel steel at position x and time t,

[0217] A c (x, t) is the cross-sectional area of ​​the double-jointed channel steel at position x and time t,

[0218] γ F (x, t) is the safety factor at position x and time t,

[0219] is the integral of the load density function at position x′ and time t,

[0220] ΔF a (t) is the loss of bearing capacity, which is caused by material aging.

[0221] S300. The assembled double-jointed channel steel 1 is hoisted onto the two crossbeams of each bridge deck of the steel truss railway bridge; and the double-jointed channel steel 1 is arranged at equal intervals; before installing the double-jointed channel steel 1, the contact position between the double-jointed channel steel 1 and the crossbeam of the steel truss railway bridge is wrapped with geotextile to prevent the double-jointed channel steel 1 from damaging the surface paint of the steel truss railway bridge.

[0222] S400, connecting the support rod 3 with the top support clamp 4 and the bottom support clamp 5, and evenly fixing the support rod 3 on the double-jointed channel steel 1 through the bottom support clamp 5;

[0223] S500. A transverse double-jointed I-beam 7 is erected parallel to and directly above each set of double-jointed channel steels 1, and each set of transverse double-jointed I-beams 7 is connected to the top supporting fixture 4 of the top supporting rod 3 of each set of double-jointed channel steels 1; before installing the transverse double-jointed I-beams 7, adjacent supporting rods 3 must be connected using diagonal rods 6 to generate interaction force between the supporting rods 3 to ensure the stability of the entire hanging formwork system.

[0224] S600, after the installation of the horizontal double I-beam 7, install the longitudinal I-beam 8 on top of it at equal distances; and lay the rubber plate bottom formwork 9 on the upper surface of the longitudinal I-beam 8. After the rubber plate bottom formwork 9 is laid, all kinds of fasteners should be installed in place.

[0225] S700. Install a jacking system to jack the steel truss railway bridge to install it to the predetermined position and further secure the steel truss railway bridge.

[0226] After the S800 steel truss railway bridge is installed, the steel mesh is tied to the bridge deck, and the embedded parts that need to be embedded are installed in the designated locations. Then, concrete is poured to complete the bridge deck construction. Before pouring concrete, the deformation of the entire hanging formwork system must be estimated to ensure that the deformation is within the error range. Specifically:

[0227]

[0228] Among them, δ c (x, t) is the deformation caused by the concrete load at position x and time t,

[0229] P c (y, t) is the concrete pressure at position x and time t,

[0230] E(y, t) is the elastic modulus at position x and time t,

[0231] I(y, t) is the moment of inertia at position x and time t,

[0232] δ fl (t) is the deformation caused by the fluidity of concrete.

[0233] After completing step S800, the formwork needs to be removed after the concrete solidification strength reaches the standard for formwork removal. When dismantling the hanging formwork system, the formwork needs to be removed from the bottom of the steel truss railway bridge. When dismantling the formwork, the hanging formwork system is dismantled in sections. First, the bottom support clamp 5 is removed from the double-jointed channel steel 1, and then the channel steel clamp 2 on the double-jointed channel steel 1 is removed with the assistance of the auxiliary support device. After the channel steel clamp 2 is removed, the double-jointed channel steel 1 is removed in a safe environment, and then the support rod 3, top support clamp 4, horizontal double-jointed I-beam 7, longitudinal I-beam 8 and rubber plate bottom formwork 9 above the double-jointed channel steel 1 are removed; in this way, the next group of double-jointed channel steels 1 and the various components installed on the top thereof are removed until the entire hanging formwork system is completely dismantled.

[0234] In step S300, the deflection of the double-jointed channel steel needs to be dynamically monitored, and the deflection is:

[0235]

[0236] Among them, δ d (x, t) is the deflection of the double channel steel at position x and time t,

[0237] F a (x, t) is the applied force on the double channel at position x and time t,

[0238] L(x, t) is the length of the double channel steel at position x and time t,

[0239] E(x, t) is the elastic modulus of the double-jointed channel steel at position x and time t,

[0240] I(x, t) is the moment of inertia of the double-jointed channel at position x and time t,

[0241] δ th (x, t) is the deformation of the double channel steel due to temperature at position x and time t,

[0242] δ hu (x, t) is the deformation of the double-jointed channel steel due to humidity at position x and time t.

[0243] In step S400, the dynamic load of the support rod needs to be monitored, specifically:

[0244]

[0245] Among them, P t (t) is the total load that changes with time,

[0246] P v (t) is the vertical load that changes with time,

[0247] P h (t) is the horizontal load that changes with time,

[0248] k v (t) is the vertical coefficient that changes with time,

[0249] k h (t) is the time-varying coefficient in the horizontal direction,

[0250] F v (t) is the vertical force that changes with time,

[0251] F h (t) is the horizontal force that changes with time.

[0252] In step S500, the load on the support rod needs to be evaluated, specifically:

[0253] K(t)u(t)=F(t);

[0254] K(t) is the time-varying stiffness matrix,

[0255] u(t) is the displacement vector that changes with time,

[0256] F(t) is the external force vector that changes with time.

[0257] In step S600, the pressure distribution generated during the concrete hardening process needs to be estimated, specifically:

[0258]

[0259] Among them, σ c (x, t) is the pressure of the concrete at position x and time t,

[0260] P c (z, t) is the pressure of the concrete at depth z and time t,

[0261] A co (z, t) is the contact area at depth z and time t,

[0262] σ cu (t) is the internal stress generated during the concrete curing process.

[0263] In step S700, the acceleration during the installation process needs to be controlled, specifically:

[0264]

[0265] Among them, a p (t) is the acceleration at time t,

[0266] F p (t) is the thrust at time t,

[0267] F f (t) is the friction force at time t,

[0268] M t (t) is the total mass at time t,

[0269] a n (t) is the acceleration correction term due to nonlinear effects.

[0270] In summary, compared with the prior art, the present application installs the hanging formwork system before the bridge is pushed. This method can avoid the problem of occupying the waterway when installing the hanging formwork system after the pushing is completed, which greatly facilitates the assembly and use of the entire hanging formwork system. After the hanging formwork system is installed, the pushing is carried out. This operation method allows the steel cage to be tied and the concrete to be poured after the bridge is pushed into place, which is conducive to saving time for bridge deck concrete construction and facilitating efficient bridge deck concrete construction operations for workers. The hanging formwork system is simple and convenient to install and will not cause damage to the paint surface of the outer surface of the steel truss railway bridge. At the same time, the hanging formwork system can be constructed within the height of the lower chord of the steel truss railway bridge and will not affect the normal operation of the waterway. At the same time, the hanging formwork system is easy to assemble and disassemble, which is convenient for workers to remove the hanging formwork efficiently and quickly, shortening the waterway time occupied by the formwork removal. The support rods are connected to each other by diagonal rods, which can ensure the stability of the entire hanging formwork system and avoid the problem of shaking or collapse of the hanging formwork system during construction. Through the channel steel clips and the top support clips, the double-piece channel steel and the horizontal double-piece I-beam can be quickly disassembled and assembled, which is convenient for the rapid installation and disassembly of the entire hanging formwork device and greatly facilitates the use of the entire hanging formwork device.

[0271] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A construction method for a steel truss railway bridge formwork system, using a steel truss railway bridge formwork system, characterized in that: The steel truss railway bridge hanging formwork system comprises a double-jointed channel steel (1), two channel steels of the double-jointed channel steel (1) are connected via a channel steel clamp (2), and multiple groups of double-jointed channel steels (1) are fixed on each two crossbeams of each bridge deck of the steel truss railway bridge via the channel steel clamp (2); multiple support rods (3) are evenly arranged on the double-jointed channel steel (1), and the bottom ends of the support rods (3) are provided with bottom support clamps (5), and the bottom support clamps (5) are connected to the double-jointed channel steel (1); the top ends of the support rods (3) are fixed with a bottom support clamp (5). A top supporting fixture (4) is provided, and a transverse double-jointed I-beam (7) is connected to the inner side of the top supporting fixture (4), and the transverse double-jointed I-beam (7) is arranged in parallel with the double-jointed channel steel (1); a plurality of longitudinal I-beams (8) are evenly arranged above the transverse double-jointed I-beam (7), and a rubber plate bottom mold (9) is tightly laid on the upper surface of the longitudinal I-beam (8); adjacent support rods (3) are connected by an inclined rod (6), and the inclined rod (6) and the support rod (3) are detachably connected; The specific steps of this construction method are as follows: S100, assembling the railway bridge at the jacking position of the steel truss railway bridge, and calculating the jacking force of the steel truss railway bridge, wherein the deadweight of the hanging formwork system is substituted into the jacking calculation process when calculating the jacking force of the steel truss railway bridge; S200, directly installing the hanging formwork system at the top-pushing position of the steel truss railway bridge, firstly splicing the double-jointed channel steel (1) through the channel steel clamp (2) according to the distance between each two crossbeams of each bridge deck of the steel truss railway bridge, to ensure that the double-jointed channel steel (1) meets the use requirements; S300, hoisting the assembled double-jointed channel steels (1) to the two crossbeams of each bridge deck of the steel truss railway bridge; and the double-jointed channel steels (1) are arranged at equal distances; S400, connecting the support rod (3) with the top support clamp (4) and the bottom support clamp (5), and evenly fixing the support rod (3) on the double-jointed channel steel (1) through the bottom support clamp (5); S500, a transverse double-jointed I-beam (7) is erected parallel to and directly above each set of double-jointed channel steels (1), and each set of transverse double-jointed I-beams (7) is connected to a top support fixture (4) of a top support rod (3) of each set of double-jointed channel steels (1); S600, after the installation of the horizontal double-jointed I-beam (7) is completed, the longitudinal I-beam (8) is installed at equal distances on the top thereof; and a rubber plate bottom mold (9) is laid on the upper surface of the longitudinal I-beam (8). After the rubber plate bottom mold (9) is laid, various fasteners are installed in place; S700. Install a jacking system to jack the steel truss railway bridge to install it to the predetermined position and further secure the steel truss railway bridge. After the S800 steel truss railway bridge is installed, the steel mesh is tied on the bridge deck, and the embedded parts that need to be embedded are installed in the designated positions, and then concrete is poured to complete the bridge deck construction.

2. The construction method of a steel truss railway bridge hanging formwork system according to claim 1, characterized in that: The parts where the two ends of the double-jointed channel steel (1) contact the crossbeam of the steel truss railway bridge are wrapped with geotextiles to protect the paint surface of the steel truss railway bridge and avoid friction between the two ends of the double-jointed channel steel (1) and the crossbeam of the steel truss railway bridge, which may cause damage to the paint surface.

3. The construction method of a steel truss railway bridge hanging formwork system according to claim 1, characterized in that: In the step S200, before installing and assembling the double-joined channel steel (1), the bearing capacity of the double-joined channel steel (1) needs to be calculated to ensure that the bearing capacity of the double-joined channel steel (1) meets the use requirements. The bearing capacity is: Among them, F c (x, t) is the bearing capacity of the double channel steel at position x and time t, σ y (x, t) is the yield strength of the double channel steel at position x and time t, A c (x, t) is the cross-sectional area of ​​the double-jointed channel steel at position x and time t, γ F (x,t) is the safety factor at position x and time t, is the integral of the load density function at position x′ and time t, ΔF a (t) is the loss of bearing capacity, which is caused by material aging.

4. The construction method of a steel truss railway bridge hanging formwork system according to claim 1, characterized in that: In the step S300, before installing the double-joined channel steel (1), the contact position between the double-joined channel steel (1) and the crossbeam of the steel truss railway bridge is wrapped with geotextile to avoid the problem of the double-joined channel steel (1) causing damage to the surface paint of the steel truss railway bridge.

5. The construction method of a steel truss railway bridge hanging formwork system according to claim 1, characterized in that: In step S800, the deformation of the entire formwork system is estimated before pouring concrete to ensure that the deformation is within the error range, specifically: Among them, δ c (x,t) is the deformation caused by the concrete load at position x and time t, P c (y,t) is the concrete pressure at position x and time t, E(y,t) is the elastic modulus at position x and time t, I(y, t) is the moment of inertia at position x and time t, δ fl (t) is the deformation caused by the fluidity of concrete.

6. The construction method of a steel truss railway bridge hanging formwork system according to claim 1, characterized in that: In the step S500, before installing the transverse double-jointed I-beam (7), adjacent support rods (3) are connected using diagonal tie rods (6) so that interaction forces are generated between the support rods (3) to ensure the stability of the entire hanging formwork system.

7. The construction method of a steel truss railway bridge hanging formwork system according to claim 1, characterized in that: After completing step S800, the concrete solidification strength reaches the standard for demolding and the demolding operation needs to be carried out. When dismantling the hanging formwork system, the formwork needs to be removed from the bottom of the steel truss railway bridge. When dismantling the formwork, the hanging formwork system is dismantled in sections. First, the bottom support clamp (5) is removed from the double-jointed channel steel (1), and then the channel steel clamp (2) on the double-jointed channel steel (1) is removed with the assistance of the auxiliary support device. After the channel steel clamp (2) is removed, the double-jointed channel steel (1) is removed in a safe environment, and then the support rod (3), the top support clamp (4), the horizontal double-jointed I-beam (7), the longitudinal I-beam (8) and the rubber plate bottom form (9) above the double-jointed channel steel (1) are removed; in this way, the next group of double-jointed channel steels (1) and the various components installed on the top thereof are removed until the entire hanging formwork system is completely dismantled.

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