CN110872807A - A kind of construction method of steel stool bridge and steel stool bridge - Google Patents

Abstract

The invention discloses a construction method of a steel temporary bridge and the steel temporary bridge, and relates to the technical field of engineering. One embodiment of the method comprises: pre-burying a top crown beam of a bored pile, and pre-burying bolts for fixing an end frame of a military beam at the upper part of the top crown beam of the bored pile; after confirming that the earthwork in the foundation pit is excavated to the bottom surface elevation of the military beam, erecting according to the axis of each standard triangle of the military beam; installing a whole military beam based on the set frame and the pre-embedded top crown beam of the bored pile, and pouring; wherein the whole military beam consists of more than one standard triangle and two end frameworks; and paving a pavement system on the upper edge of the upper chord of the whole military beam. The method reduces personnel investment and equipment investment, and has the advantages of low cost, short construction period and remarkable economic benefit.

Description

A kind of construction method of steel stool bridge and steel stool bridge

technical field

The invention relates to the technical field of engineering, in particular to a construction method of a steel bridge and a steel bridge.

Background technique

Steel bridges are usually trestle bridges designed to solve temporary traffic problems to facilitate the passage of vehicles and pedestrians. In the prior art, the structure in which the Bailey sheet and the main beam are connected into one body is often used. However, in the process of implementation, it was found that the existing technology has the following problems: because the steel stool bridges are mostly designed and constructed temporarily, the existing technology cannot meet the needs of rapid transportation, splicing and rapid evacuation of the steel stool bridges; The location is very inconvenient.

SUMMARY OF THE INVENTION

In view of this, the embodiments of the present invention provide a construction method of a steel walkway bridge and a steel walkway bridge, which can reduce the investment of personnel and equipment, and have the advantages of low cost, short construction period and significant economic benefits.

In order to achieve the above object, according to an aspect of the embodiments of the present invention, a construction method of a steel bridge is provided.

The construction method of the steel bridge according to the embodiment of the present invention includes: pre-embedding the top crown beam of the bored pile, and pre-embedding the upper part of the top crown beam of the bored pile for fixing the end frame of the military beam; After the earthwork is excavated to the elevation of the bottom surface of the military beam, erection is carried out according to the axis of each standard triangle of the military beam; based on the erection and the pre-buried bored pile top crown beam, the entire military beam is installed and carried out. pouring; wherein, the whole piece of military beam is composed of more than one standard triangle and two end frames; pavement system is laid on the upper edge of the chord of the whole piece of military beam.

Optionally, the step of laying a pavement system on the upper edge of the chord on the whole piece of military beam includes: laying wooden boards, rubber sheets and steel sheets in sequence, wherein the steel sheets are welded as a whole; Skid plate.

Optionally, before installing the whole piece of military beams, the method further includes: placing 10*10cm square wood at the assembling nodes of the military beams in the flat site, and the spacing between the square woods is consistent with the spacing between the assembling nodes of the military beams; Place two square logs side by side at each node, and use a level to level them; place the end frame and standard triangle that need to be assembled on the square log by means of a crane, align the pin holes one by one, and install after the holes are aligned. Steel pin fixing holes; assembling end frame and standard triangle, and installing end chord; assembling standard triangle and installing horizontal chord.

Optionally, based on the erected and pre-buried bored pile top crown beam, the step of installing the whole piece of military beam includes: cleaning up the floating ballast and debris on the surface of the crown beam that has been constructed, and removing all The protective plastic paper on the pre-embedded bolts; excavate the earthwork in the foundation pit to the elevation of the bottom surface of the military beam; use a total station or theodolite to measure the vertical and horizontal axes of the standard triangle of each military beam, and use a level to measure the elevation ; After confirming that the concrete strength of the crown beam and the temporary strip foundation reaches the preset value, set out the axis mileage of each military beam on the crown beam and the temporary strip foundation, and set up accurately according to the axis of the payout; Install the fixed end frame Steel plate; after the military beam is longitudinally installed with a preset length, the connecting channel steel and the horizontal connecting casing bolts at the lower part of the entire military beam are installed.

Optionally, the top and crown beams of the bored piles are L-shaped.

Optionally, the military beam is a single-layer 64-type military beam, and the end frame is a 2m end frame.

Optionally, after the pavement system is laid on the upper edge of the upper chord of the whole piece of military beam, the method further includes: arranging a monitoring point for monitoring, and installing a surface strain gauge at the monitoring point; The initial data and the real-time data read, the strain value P is indeed obtained:

P=K(F _i -F ₀ )+b(T _i -T ₀ )

Among them, P is the strain value, positive value means tension, negative value means compression; K is the calibration coefficient; F ₀ is the initial frequency modulus; F _i is the frequency modulus during measurement and reading; b is the temperature correction value; T ₀ is room temperature; _Ti is the temperature measured.

Optionally, the monitoring points include settlement monitoring points and internal force monitoring points.

In order to achieve the above object, according to an aspect of the embodiments of the present invention, a steel stool bridge is provided.

The construction method of the steel bridge according to the embodiment of the present invention includes: the two ends of the military beam are end frames, and more than one standard triangle is connected between the end frames at both ends in turn; and, the military beam passes through the end frames at both ends of the military beam. It is fixed with the top crown beam of the bored cast-in-place pile; a pavement system is arranged on the upper chord of the military beam, and the pavement system is sequentially laid with wooden boards, rubber plates and steel plates from bottom to top, wherein the military beam There are 5 internal force monitoring points arranged on the upper part, which are respectively arranged on the vertical pressure rod, upper chord rod, inclined abdominal rod, middle vertical rod and lower chord rod of the military beam.

Optionally, the top crown beam of the bored pile is L-shaped, and the upper part of the top crown beam of the bored pile is pre-embedded with bolts for fixing the end frame of the military beam, and the military beam is a single-layer type. The six-four-type military beam, and the end frame is a 2m end frame.

One embodiment of the above invention has the following advantages or beneficial effects: the military beam is used as the main component for bearing the load of the road vehicle, which has the characteristics of light structure, quick assembly, and strong adaptability. Furthermore, the embodiment of the present invention solves the problem that the prior art cannot meet the requirements of rapid transportation, splicing and rapid evacuation of the steel bridge. Moreover, it is convenient to transport the steel side bridge to the job site. At the same time, the construction process is convenient, the input of personnel and equipment is reduced, and the cost is low, the construction period is short, and the economic benefits are significant.

Further effects of the above non-conventional alternatives will be described below in conjunction with specific embodiments.

Description of drawings

The accompanying drawings are used for better understanding of the present invention and do not constitute an improper limitation of the present invention. in:

Fig. 1 is the schematic diagram of the main flow of the construction method of the steel bridge according to the embodiment of the present invention;

2 is a schematic structural diagram of a military beam according to an embodiment of the present invention;

3 is a schematic diagram of an internal force monitoring point according to an embodiment of the present invention;

4 is a schematic diagram of an L-shaped crown beam according to an embodiment of the present invention;

5 is a schematic structural diagram of a steel stool bridge according to an embodiment of the present invention;

6 is a schematic diagram of a standard triangle according to an embodiment of the present invention;

In the figure,

1-end frame; 2-standard triangle; 3-transverse casing bolt; 4-end frame connection; 5-end chord; 6-oblique web connection; 7-lower chord connection; 8-standard chord Rod; 9- Transverse casing bolt; 10- End chord; 11a, 11b, 11c, 11d, 11e- Surface strain gauge; 12- Pavement system; 13- Bored pile top crown beam; 14- Standard section rectangle Crown beam.

Detailed ways

Exemplary embodiments of the present invention are described below with reference to the accompanying drawings, which include various details of the embodiments of the present invention to facilitate understanding and should be considered as exemplary only. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. Also, descriptions of well-known functions and constructions are omitted from the following description for clarity and conciseness.

Fig. 1 is the schematic diagram of the main flow of the construction method of the steel stool bridge according to the embodiment of the present invention, as shown in Fig. 1, the construction method of the steel stool bridge of the embodiment of the present invention mainly includes:

Step S101 : pre-embedding the top and crown beams of the bored cast-in-place piles, and pre-embedding bolts for fixing the end frames of the military beams in the upper part of the top and top beams of the bored cast-in-place piles. The military beam is a single-layer six-four-type military beam, and the end frame is a 2m end frame. Military girder is a disassembled upper-bearing steel truss girder of all-welded frame, pinned assembly, single-layer or double-layer multi-piece, open bridge deck system. The embodiment of the present invention adopts a single-layer structure, and selects a reinforced single-layer six-four-type military beam (composed of a reinforced tripod and an auxiliary end frame). The main truss of the 64-type railway military beam (code: 102-1) includes standard triangle (code ①), end frame (code ②), standard chord (code ③), end chord (code ④), and inclined chord It is composed of six basic components such as rod (code ⑤) and strut (code ⑥) and two types of joints such as steel pin and support pin bolt, which can be assembled into railways that meet the national standard (GB904-65) and vary by 4 meters Single or double deck girders of standard span. The reinforced six-four-type railway military beam (code: 102-2) is only the main truss with the reinforcement triangle (code 21) and the reinforcement chord (code 23) two components to replace the standard triangle (code ①) and standard chord (code 1) respectively. Code ③), the rest of the components and joints are exactly the same as the military beams of the 64-type railway, which are mainly used to adapt to larger spans.

FIG. 2 is a schematic structural diagram of a military beam according to an embodiment of the present invention. As shown in FIG. 2 , the military beam according to the embodiment of the present invention mainly includes: an end frame 1, a standard triangle 2, a horizontal sleeve bolt 3, an end frame connection 4. End chord 5, oblique web connection 6, lower chord connection 7, standard chord 8, transverse casing bolt 9, end chord 10. The accessories of military beams are universal, and there are eleven kinds in total. It is divided into four categories according to the purpose: the component connecting pins include steel pins and support rod pins; the connecting accessories include horizontal casing bolts, connecting channel steel, No. 2 U-bolts and No. 3 U-bolts; The bridge deck accessories include four types: panel, No. 1 U-bolt, pressure plate, and pressure plate bolt; for supports, each set of supports includes pre-embedded positioning bolts, positioning steel pressure plates and connecting bolts; steel pins are used for upper and lower main chord members For node connection, transverse casing bolts are mainly used for chord connection between each main truss, and the connection channel steel is mainly plane and section connection members. No. 1 U-bolt connects the panel with the upper chord of the main truss, and No. 2 U-bolt connects the channel steel with the lower chord and strut of the main truss. No. 3 U-bolt connection connects the channel steel and the web rod (including the strut).

The assembly of military beams is carried out in the stacking site. First, level the site and place 10*10cm square wood at the joints of the military beam assembly. The distance between the square wood is the same as that of each node of the military beam, and two square woods are placed side by side at each node. , and use a level for leveling to ensure that the elevation of the square wood is consistent and the deviation is controlled within 3mm. Place the 2m end frame and two standard triangles that need to be assembled on the square wood by crane, and align the pin holes one by one. After the holes are aligned, install the steel pins to fix the holes. First install the end frame and standard triangle, then install the end chord, then install the standard triangle, and finally install the horizontal chord, and the single-piece military beam is assembled. Review the axis and level of the assembled military beams. After the assembly errors meet the requirements of the specification, they can be transported to the site for installation. Specifically, at the assembly nodes of the military beams in the flat site, place 10*10cm square wood. The spacing of square wood is the same as that of military beam assembly nodes. Then, place two square logs side by side at each node and level them with a level. And, the end frame and standard triangle to be assembled are placed on the square wood by a crane, and the pin holes are aligned one by one. After the holes are aligned, the steel pins are installed to fix the holes. Assembled end frame and standard triangle, and installed end chord. Also, assemble standard triangles and install horizontal chords. Combined with the six-four beam structure, the plane structure is analyzed, and the PKPM software steel structure module is used to calculate the single-story six-four beam plane structure. In the embodiment of the present invention, if the self-weight system of the six-four beams is automatically calculated, the dead weight of the bridge deck is 1.0KN/m according to half of the aforementioned load, and the truck load is 7 pieces of six-four beam width according to the passing width of one truck. The model load is 1000/14=71KN, and the load is applied to three nodes of the six-four beam element in the mid-span. Considering a certain safety factor, the load applied to each node is 28KN.

FIG. 4 is a schematic diagram of an L-shaped crown beam according to an embodiment of the present invention. As shown in FIG. 4 , the top crown beam of the bored pile is L-shaped. The reinforced concrete continuous beam set at the top of the supporting (enclosure) structure (mostly piles and walls) around the foundation pit, one of its functions is to connect all the pile foundations together (such as bored piles, rotary excavation piles, etc. ), to prevent the top edge of the foundation pit (shaft) from collapsing, and the second is to bear the horizontal pressing force and vertical shear force of the steel support (or reinforced concrete support) through the corbel. pulp etc.

Step S102: After confirming that the earthwork in the foundation pit is excavated to the elevation of the bottom surface of the military beam, erect the frame according to the axis of each standard triangle of the military beam.

Step S103: Based on the erected and pre-buried bored cast-in-place pile top and crown beams, install a whole piece of military beams, and perform pouring. Among them, the whole military beam is composed of more than one standard triangle and two end frames. Specifically, clean up the floating ballast and debris on the surface of the crown beam that has been constructed, and remove the protective plastic paper on the embedded bolts; excavate the earthwork in the foundation pit to the elevation of the bottom surface of the military beam; use a total station or theodolite to carry out For the measurement and design of the vertical and horizontal axes of the standard triangle of each piece of military beam, use a level to measure and set the elevation; after confirming that the concrete strength of the crown beam and the temporary strip foundation reaches the preset value, stake out each piece of military beam on the crown beam and the temporary strip foundation. Install the fixed steel plate of the end frame; after the military beam is longitudinally installed with a preset length, install the connecting channel steel and horizontal casing bolts at the lower part of the entire military beam.

It can be seen from the above that the installation process of military beams mainly includes on-site cleaning, measuring and laying out and installation. During the on-site cleaning, the floating ballast and debris on the surface of the crown beam that has been constructed are cleaned up, and the protective plastic paper on the embedded bolts is removed. , to facilitate the installation of military beams. And, the earthwork in the foundation pit is excavated to the elevation of the bottom surface of the military beam. In the process of measuring and laying out the line, the survey team uses a total station or theodolite to measure and design the longitudinal and horizontal axes of each military beam, and use a level to measure and design the elevation. In the installation process of the embodiment of the present invention, after the concrete strength of the crown beam and the temporary strip foundation reaches 85%, the axis mileage of each military beam is set out on the crown beam and the temporary strip foundation, and the erection is carried out accurately according to the axis of the payout. Install the fixed steel plate of the end frame to fix the position of the entire military beam. The lower part of the military beam is connected to the channel steel and the horizontal casing bolts are installed after a certain length of longitudinal installation of the military beam. Then, the strip concrete is poured. In this process, the crown beam post-cast strip concrete is poured before the cover plate is installed. After the concrete pouring is completed, the upper part is backfilled with earthwork to the military beams for maintenance.

Step S104: Lay a pavement system on the upper edge of the chord on the entire piece of military beam. Specifically, a wooden board, a rubber board and a steel plate are laid in sequence, wherein the steel plate is a welded whole; a welded anti-skid plate is laid on the steel plate. Both ends of the pavement system are placed on the upper edge of the upper chord of the military beam. When the pavement deck is paved, the elevation of the slab and the slab are the same, the splicing is tight and flush, and there should be no staggered phenomenon. In the embodiment of the present invention, in the process of laying the pavement system on the upper part of the military beam, firstly lay 5cm thick wooden boards, then lay 10mm thick rubber sheets, then lay 20mm thick steel plates and weld them as a whole, and finally lay 0.4mm thick patterns on the top. The steel plates are reliably welded between the steel plates to form a whole.

After the pavement system is laid on the upper edge of the upper chord of the entire military beam, it also includes: arranging monitoring points for monitoring, and installing surface strain gauges at the monitoring points. Moreover, the monitoring points include settlement monitoring points and internal force monitoring points. Based on the initial data of the surface strain gauge and the real-time data read, the strain value P is determined:

P=K(F _i -F ₀ )+b(T _i -T ₀ )

Among them, P is the strain value, positive value means tension, negative value means compression; K is the calibration coefficient; F ₀ is the initial frequency modulus; F _i is the frequency modulus during measurement and reading; b is the temperature correction value; T ₀ is room temperature; _Ti is the temperature measured.

Military beams are the main components that bear the load of road vehicles. In order to ensure the normal passage of vehicles and the stability of the foundation pit, and ensure the normal construction of the main structure, the military beams are specially monitored to verify the structural design and revise the structural design and construction plan. Provide feedback. The monitoring content mainly includes military beam settlement monitoring and internal force monitoring. The required testing instruments mainly include: precision level, Inwa ruler, EBJ-57 surface strain gauge, and vibrating wire frequency receiver.

For settlement monitoring, settlement observation points can be arranged along the base end of the temporary strip of the military beam to observe the settlement of the military beam under the action of the vehicle load, and at the same time grasp the settlement of the temporary strip foundation.

FIG. 3 is a schematic diagram of an internal force monitoring point according to an embodiment of the present invention. A total of two monitoring sections were selected for internal force monitoring, namely, two military beams were selected for internal force monitoring. According to the stress characteristics of the military beam structure, the single military beam is regarded as a truss structure. In the embodiment of the present invention, each beam is arranged with 5 internal force monitoring points, which are respectively arranged on the upper chord, the lower chord, the middle vertical rod, the vertical pressure rod and the inclined web rod of the military beam. As shown in Figure 3, the surface strain gauges 11a, 11b, 11c, 11d, and 11e are installed on the five internal force monitoring points, that is, the surface strain gauges 11a, 11b, 11c, 11d, and 11e are respectively arranged on the vertical pressure rod, the upper chord, On the oblique abdominal rod, the middle vertical rod of the reinforced triangle and the lower chord rod.

In the process of installing the surface strain gauge: ① Put on the standard mandrel during installation, the outer sides of both ends must be flush with the outer side of the mounting frame, and then tighten the two M10 screws with a wrench. ② Paste the mounting frame with the standard mandrel on the steel support surface with high-strength special glue. When pasting, first of all, the base surface of the general beam should be derusted and cleaned. The strain gauge must be parallel to the support axis, preferably coincident. ③ Loosen the two M10 screws, take out the standard mandrel from one end, and then put the standard mandrel into the other mounting frame to continue the installation of the next one. ④ After the mounting frame and the steel support are firmly attached, the formal installation of the strain gauge can be carried out. When installing, slowly push the strain gauge into the mounting frame from one end, and then tighten the two M10 screws in place. ⑤ Note down the zero frequency value and the temperature value at the time of installation.

And, when pushing the strain gauge into the mounting frame, it is strictly forbidden to bend the strain gauge and push it in smoothly; it is strictly forbidden to twist the strain gauge and push it in a free state; after the strain gauge is in place, it must be in contact with the two ends of the mounting frame. Outer sides are flush. When tightening the M10 screw, connect the frequency reading instrument and measure the frequency value (f1) once before tightening; when tightening the M10 screw, the frequency value (f2) of the strain gauge must be observed, at this time, the frequency should be controlled within the range of f2=f1±100Hz Inside, the two screws should be screwed in slowly until they are tightened, and it is strictly forbidden to tighten one and then screw the other.

For the embodiment of the present invention, the military beam is used as the main component that bears the load of the road vehicle, which has the characteristics of light structure, quick assembly, and strong adaptability. Furthermore, the embodiment of the present invention solves the problem that the prior art cannot meet the requirements of rapid transportation, splicing and rapid evacuation of the steel bridge. Moreover, it is convenient to transport the steel side bridge to the job site. At the same time, the construction process is convenient, the input of personnel and equipment is reduced, and the cost is low, the construction period is short, and the economic benefits are significant.

FIG. 5 is a schematic structural diagram of a steel stool bridge according to an embodiment of the present invention, and FIG. 6 is a schematic diagram of a standard triangle according to an embodiment of the present invention. As shown in FIGS. 5 and 6 , the steel bridge of the embodiment of the present invention mainly includes: a top crown beam 13 of bored piles, a military beam and a pavement system 12; the two ends of the military beam are end frames 1, and the end frames 1 at both ends are There are more than one standard triangle 2 connected in turn. And, the military beam is fixed by the end frame 1 and the top crown beam 13 of the bored pile at both ends thereof. A standard section rectangular crown beam 14 is embedded under the top crown beam 13 of the bored pile. A pavement system 12 is provided on the upper chord of the military beam. The steel access bridge of the embodiment of the present invention spans the main foundation pit, and the system is mainly composed of a top crown beam of bored cast-in-place piles, a reinforced 64-type railway military beam, a pavement system, and the like. Reinforced 64-type railway military beam (referred to as military beam) is the main component that bears the load of road vehicles. It has the characteristics of light structure, fast assembly and strong adaptability. As shown in FIG. 5 , the total length of the steel stool bridge of the embodiment of the present invention is 24.48m, including 5 standard triangles, 2 end frames and their accessories. The main engineering materials include reinforced 64-type military beams, C25 concrete and Q235 steel. And, in the six main truss members of the 64-type military beam, all the members and the node plates are all 16 manganese low-alloy steel. Among the six main truss members of the reinforced 64-type railway military beam, except that the upper chord and the reinforced chord of the reinforced triangle and the pinned joint sheet are made of 15 manganese vanadium nitrogen low alloy steel, the other rods in these two members are made of 15 manganese vanadium nitrogen low alloy steel The parts and the other four components are all 16 manganese low alloy steel. All members and node plates of the auxiliary end frame are made of 16 manganese low alloy steel. The main truss members are all welded structures. The main truss joints (steel pins and strut pins) are made of 35 silicon-manganese alloy structural steel and are quenched and tempered. Used in conjunction with the standard set, the 2m-long end frame ② in the standard set is used to adjust the span length as an auxiliary component. And, the design basic allowable stress of the weld metal welded with steel and the above welding consumables is as follows:

The embodiment of the present invention provides a steel bridge, as shown in FIGS. 2-6 , which mainly includes: a crown beam 13 of bored piles, a military beam and a pavement system 12; the two ends of the military beam are end frames 1, and two More than one standard triangle 2 is sequentially connected between the end frames 1 at the ends; and the military beam is fixed by the end frames 1 at both ends and the top crown beam 13 of the bored pile. And, a standard section rectangular crown beam 14 is embedded under the top crown beam 13 of the bored pile. A pavement system 12 is arranged on the upper chord of the military beam, and the pavement system 12 is sequentially laid with wooden boards, rubber sheets and steel plates from bottom to top. The military beam is a single-layer six-four-type military beam, and the end frame 1 is a 2m end frame. The top crown beam 13 of the bored pile is L-shaped, which improves the stability of the structure. And, bolts for fixing the end frame of the military beam are embedded in the upper part of the top crown beam 13 of the bored pile. And, a welded skid plate is laid on the steel plate. The thickness of wood board, rubber board and steel plate are 50mm, 10mm and 20mm respectively, and the thickness of skid plate is 4mm. Internal force monitoring points 11a, 11b, 11c, 11d, and 11e are respectively set on the vertical pressure rod, upper chord rod, inclined web rod, reinforced triangle middle vertical rod and lower chord rod of the military beam.

The steel toilet bridge of the embodiment of the present invention has the advantages of light structure, quick assembly and strong adaptability, which can reduce the investment of personnel and equipment in the construction process, and has the advantages of low cost, short construction period and significant economic benefits.

The above-mentioned specific embodiments do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions may occur depending on design requirements and other factors. Any modifications, equivalent replacements and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. a construction method of a steel bridge, is characterized in that, comprises: pre-embedded bored pile top crown beam, and the upper part of the bored cast-in-situ pile top crown beam is embedded with bolts for fixing the end frame of the military beam; After confirming that the earthwork in the foundation pit is excavated to the elevation of the bottom surface of the military beam, erect the frame according to the axis of each standard triangle of the military beam; Based on the erected and pre-buried bored pile top crown beams, a whole piece of military beam is installed and poured; wherein, the whole piece of military beam is composed of more than one standard triangle and two end frames; A pavement system is laid on the upper edge of the chord on the whole piece of the military beam. 2. The method according to claim 1, wherein the step of laying a pavement system on the upper edge of the chord on the entire piece of military beam comprises: Lay wooden boards, rubber sheets and steel sheets in sequence, wherein the steel sheets are welded as a whole; A welded skid plate is laid on the steel plate. 3. The method according to claim 1, characterized in that, before installing the whole piece of military beam, further comprising: Place 10*10cm square wood at the assembling nodes of military beams in a flat site, and the spacing between the square woods and the assembling nodes of military beams is the same; Place two square logs side by side at each node and level them with a level; Place the end frame and standard triangle that need to be assembled on the square wood by crane, and align the pin holes one by one. After the holes are aligned, install the steel pins to fix the holes; Assembly end frame and standard triangle, and installation end chord; Assemble standard triangles and install horizontal chords. 4. method according to claim 1, is characterized in that, based on described erection and pre-buried bored pile top crown beam, the step of installing the whole piece of military beam comprises: Clean up the floating ballast and debris on the surface of the crown beam that has been constructed, and remove the protective plastic paper on the embedded bolts; Excavate the earthwork in the foundation pit to the elevation of the bottom surface of the military beam; Use a total station or theodolite to measure and design the vertical and horizontal axes of the standard triangle of each military beam, and use a level to measure and design the elevation; After confirming that the concrete strength of the crown beam and the temporary strip foundation reaches the preset value, the axis mileage of each military beam is set out on the crown beam and the temporary strip foundation, and the erection is carried out accurately according to the axis of the payout; Mounting the fixed steel plate of the end frame; After the military beam is longitudinally installed with a preset length, the connecting channel steel and the transverse connecting casing bolts at the lower part of the entire military beam are installed. 5 . The method according to claim 1 , wherein the top and crown beams of the bored piles are L-shaped. 6 . 6 . The method according to claim 1 , wherein the military beam is a single-layer 64-type military beam, and the end frame is a 2m end frame. 7 . 7. The method according to claim 1, characterized in that, after the pavement system is laid on the upper edge of the upper chord of the whole piece of military beam, the method further comprises: laying out monitoring points for monitoring, and installing surface strain gauges at said monitoring points; Based on the initial data of the surface strain gage and the real-time data read, the strain value P is determined: P=K(F _i -F ₀ )+b(T _i -T ₀ ) Among them, P is the strain value, positive value means tension, negative value means compression; K is the calibration coefficient; F ₀ is the initial frequency modulus; F _i is the frequency modulus during measurement and reading; b is the temperature correction value; T ₀ is room temperature; _Ti is the temperature measured. 8. The method according to claim 7, wherein the monitoring points comprise settlement monitoring points and internal force monitoring points. 9. A steel bridge, characterized in that it comprises a bored pile top crown beam, a military beam and a pavement system; Both ends of the military beam are end frames, and more than one standard triangle is sequentially connected between the end frames at both ends; and, the military beam is fixed by the end frames at both ends and the top crown beam of the bored pile ; A pavement system is arranged on the upper chord of the military beam, and the pavement system is sequentially laid with wooden boards, rubber boards and steel plates from bottom to top. Wherein, five internal force monitoring points are arranged on the military beam, which are respectively arranged on the vertical pressure rod, the upper chord, the inclined abdominal rod, the middle vertical rod and the lower chord of the military beam. 10 . The steel bridge according to claim 9 , wherein the top and crown beams of the bored piles are L-shaped, and the upper parts of the top and crown beams of the bored piles are pre-buried for fixing the end frames of the military beams. 11 . The bolts, the military beam is a single-layer six-four-type military beam, and the end frame is a 2m end frame.

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