CN111962374A - A fast-installed space truss long-span light steel pedestrian bridge and its construction method - Google Patents

Abstract

The invention discloses a quickly-installed space truss long-span light steel walking bridge and a construction method thereof, wherein the space truss long-span light steel walking bridge comprises a footpath structure and a handrail structure; the pavement structure comprises a plurality of pavement trusses arranged at intervals; the handrail structure comprises a plurality of handrail trusses, the handrail trusses are arranged on two sides of two adjacent footpath trusses, the handrail trusses comprise XZ plane handrail trusses and YZ plane handrail trusses, and the two XZ plane handrail trusses are arranged in parallel and are respectively perpendicular to the two YZ plane handrail trusses. The handrail truss structure adopts a three-dimensional truss structure, so that the side support of the handrail truss is increased, the cross section sizes of the handrail structure and the footpath structure in the direction perpendicular to the span direction are increased, the vertical rigidity and the lateral rigidity are improved, and the problem of external instability of the handrail structure under the pressure is solved. The invention relates to the technical field of bridge construction.

Description

A fast-installed space truss long-span light steel pedestrian bridge and its construction method

technical field

The invention relates to the technical field of bridge construction, in particular to a fast-installed space truss large-span light steel pedestrian bridge and a construction method thereof.

Background technique

The construction of modern cities is accompanied by indispensable transportation facilities. In densely populated cities, pedestrian bridges and underground passages are usually used to connect both sides of the road, which is convenient for pedestrians to travel. Compared with underground passages built together with road facilities, the setting of pedestrian bridges is more flexible and convenient.

Traditional pedestrian bridges such as concrete bridges and steel box girder bridges have mature technologies, but the construction period is long and the unit cost is high. In recent years, new types of pedestrian bridges, represented by aluminum alloy bridges, have appeared in my country. Such bridges have the following problems: (1) The elastic modulus of aluminum alloys is only 1/3 of steel, and at the same time, it is expensive. The wall thickness of alloy components is usually several centimeters thick, which goes against the trend of developing simpler structures. (2) The connection technology of aluminum alloy structural members is not as proficient as that of steel structure, resulting in an increase in construction cost, and the connection reliability is not as good as that of steel structure.

Cold-formed thin-walled steel is a thin-walled steel with a thickness of usually several millimeters. Due to its light weight, it is called light steel, and the economic cost of light steel structures is not higher than that of traditional hot-rolled steel structures. In addition, bolted connections are mostly used in construction to avoid quality variability caused by welding. However, the light steel structure is widely used in the low-rise residential field, and the recognition that the stiffness of its components is not as good as that of the traditional steel structure hinders the application of light steel in the field of pedestrian bridges.

For the current few light steel pedestrian bridge structures, there are the following shortcomings: (1) The span is limited, and the linear stiffness of light steel members is weaker than that of traditional steel structural members, but light steel members have the advantages of flexible layout and convenient installation at the same time. A case where the structure itself is optimized. (2) At present, in the rare light steel pedestrian bridges, the vertical stiffness of the structure is improved by multiple supports, but this cannot improve the lateral stiffness of the structure, and it is easy to cause the problem of insufficient lateral comfort. (3) Steel structures are prone to instability, and lack of consideration for the instability of components, especially handrail structures susceptible to lateral loads.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the defects and deficiencies of the prior art, and to provide a fast-installed space truss long-span light steel pedestrian bridge with high lateral stiffness and stable handrail structure.

Another object of the present invention is to provide a construction method for a fast-installed space truss large-span light steel pedestrian bridge.

The object of the present invention can be achieved through the following technical solutions: a fast-installed space truss long-span light steel pedestrian bridge, including a walkway structure and a handrail structure; the walkway structure includes a plurality of spaced walkway trusses; the handrail structure includes A plurality of handrail trusses, the handrail trusses are arranged on both sides of two adjacent walkway trusses, and the handrail trusses include an XZ plane handrail truss and a YZ plane handrail truss, and the two XZ plane handrail trusses are arranged in parallel with the two YZ planes respectively. The handrail trusses are vertical.

Further, the XZ plane handrail truss includes a handrail upper chord, a handrail upper inclined rod, a handrail single C-shaped steel crossbar, a handrail vertical abdominal rod, a handrail double C-shaped steel crossbar, a handrail lower inclined rod and a handrail lower chord; the handrail; The upper chord, the single C-shaped steel crossbar of the handrail, the double C-shaped steel crossbar of the handrail and the lower chord of the handrail are arranged in parallel and are respectively perpendicular to the two parallel vertical web bars of the handrail; between the bar and the handrail double C-shaped steel cross bars; the handrail lower inclined bar is diagonally arranged between the handrail double C-shaped steel cross bars and the handrail lower chord.

Further, the cross-sectional size of the C-shaped steel used by the vertical web bar of the handrail is larger than the cross-sectional size of the C-shaped steel used by the upper chord of the handrail, the single C-shaped steel crossbar of the handrail, the double C-shaped steel crossbar of the handrail and the lower chord of the handrail; , The cross-sectional size of the C-shaped steel used in the single C-shaped steel crossbar of the handrail, the double C-shaped steel crossbar of the handrail and the lower chord of the handrail is larger than the cross-sectional size of the C-shaped steel used in the upper inclined rod of the handrail and the lower inclined rod of the handrail. Due to the needs of connection, the rods are made of C-shaped steel with different cross-sections, and holes are opened at the position of the web of the larger C-shaped steel rods, and then the rods with smaller sizes are passed through the reserved openings, and finally bolts are used to connect the two. The flange of the root member.

Further, the YZ plane handrail truss includes connecting upper chords, connecting vertical web bars, connecting upper inclined bars, connecting double C-shaped steel cross bars, connecting lower inclined bars and connecting lower chords; the connecting upper chords, connecting double C-shaped steels The horizontal bar and the connecting lower chord are arranged in parallel and are respectively perpendicular to the two connecting vertical web bars; the two connecting upper oblique bars are crossly arranged between the connecting upper chord and the connecting double C-shaped steel horizontal bars; The oblique bars are arranged crosswise between the connecting double C-shaped steel cross bars and the connecting lower chords.

Further, the two connecting upper inclined rods arranged in a cross are two rods with different cross sections, and the two lower inclined rods arranged in a cross are two rods with different cross sections.

Further, the cross-sectional size of the C-shaped steel used for connecting the vertical web bars is larger than the cross-sectional size of the C-shaped steel used for connecting the upper chord, connecting the double C-shaped steel crossbar and connecting the lower chord; connecting the upper chord and connecting the double C-shaped steel crossbar. And the cross-sectional size of the C-shaped steel used to connect the lower chord is larger than the cross-sectional size of the C-shaped steel used to connect the upper inclined rod and the lower inclined rod. Due to the needs of connection, the rods are made of C-shaped steel with different cross-sections, and holes are opened at the position of the web of the larger C-shaped steel rods, and then the rods with smaller sizes are passed through the reserved openings, and finally bolts are used to connect the two. The flange of the root member.

Further, the trail truss includes a trail upper chord, a trail vertical web, a trail inclined rod and a trail bottom chord, the trail top chord and the trail bottom chord are arranged in parallel, and a plurality of trail vertical web bars are vertically arranged on the trail top chord at intervals. , Between the lower chords of the trail, and between every two vertical belly rods of the trail, there is a trail ramp.

Further, the cross-sectional size of the C-shaped steel used in the vertical web bar of the walkway is larger than the cross-sectional size of the C-shaped steel used by the walkway upper chord and the walkway lower chord; the cross-sectional size of the C-shaped steel used by the walkway upper chord and the walkway lower chord The section size of the C-section steel used for the trail ramp. Due to the needs of connection, the rods are made of C-shaped steel with different cross-sections, and holes are opened at the position of the web of the larger C-shaped steel rods, and then the rods with smaller sizes are passed through the reserved openings, and finally bolts are used to connect the two. The flange of the root member.

Further, the walkway structure and the bars in the handrail structure are connected by bolts. The bolt connection method is adopted to improve the assembly rate of the structure.

Another object of the present invention can be achieved through the following technical solutions: a construction method for a fast-installed space truss large-span light steel pedestrian bridge, comprising the following steps:

Complete the size and screw hole processing of C-shaped steel rods;

Use C-shaped steel rods to assemble to form trail truss, XZ plane handrail truss and YZ plane handrail truss;

Two XZ plane handrail trusses are arranged in parallel, and respectively form a handrail truss vertically with two YZ plane handrail trusses;

A plurality of walkway trusses are arranged at intervals, and the handrail trusses are arranged on both sides of two adjacent walkway trusses.

Compared with the prior art, the present invention has the following advantages and beneficial effects:

1. The present invention adopts a three-dimensional space truss structure, increases the side support of the handrail truss, increases the cross-sectional size of the handrail structure and the walkway structure perpendicular to the span direction, improves the vertical and lateral stiffness, and solves the problem of the handrail structure. The problem of out-of-plane instability.

2. Compared with the traditional steel structure and concrete pedestrian bridge, the structure is light and easy to be decorated. At the same time, on-site welding construction is avoided to avoid the uncertainty of quality caused by welding, and the lighter structure further reduces the cost of foundation construction.

3. The adoption of a large number of bolted connection methods improves the assembly rate of the structure, making the construction model of factory processing and on-site assembly a reality, greatly shortening the construction period, and making green and civilized construction easier to achieve.

4. Compared with aluminum alloy bridges, the advantages of steel elastic modulus are used to make the rod wall thin and light. Compared with aluminum alloy materials, it has obvious price advantages and mechanical performance advantages, and the structure is simple and the connection is reliable.

5. The overall structure is made of prefabricated components in the factory, and then transported to the construction site for assembly, which effectively reduces the difficulty of on-site construction and the uncertainty of on-site construction. .

Description of drawings

Fig. 1 is the side structure schematic diagram of light steel pedestrian bridge in the embodiment of the present invention;

2 is a mid-span sectional view of a light steel pedestrian bridge in an embodiment of the present invention;

3 is a cross-sectional view of a light steel pedestrian bridge in an embodiment of the present invention;

4 is a mid-span top view of a light steel pedestrian bridge in an embodiment of the present invention;

5 is a cross-sectional view of a C-shaped steel in an embodiment of the present invention;

6 is a schematic structural diagram of an XZ plane handrail truss in an embodiment of the present invention;

FIG. 7 is a schematic structural diagram of a YZ plane handrail truss in an embodiment of the present invention;

FIG. 8 is a schematic diagram of the structure of a walkway truss in an embodiment of the present invention.

Among them: 1: Main span, 2: Stairs, 3: Walkway structure, 4: Handrail structure, 5: YZ plane handrail truss, 6: XZ plane handrail truss, 7: Walkway truss, 8: C-section steel, 11: Handrail top chord , 12: Handrail up inclined bar, 13: Handrail single C-shaped steel cross bar, 14: Handrail vertical web bar, 15: Handrail double C-shaped steel cross bar, 16: Handrail down inclined bar, 17: Handrail lower chord, 18: Connected top chord Rod, 19: Connect vertical web bar, 20: Connect upper slant bar, 21: Connect upper slant bar, 22: Connect double C-shaped steel cross bar, 23: Connect lower slant bar, 24: Connect lower slant bar, 25: Connect lower chord Rod, 26: Trail top chord, 27: Trail ramp, 28: Trail vertical web, 29: Trail ramp, 30: Trail bottom chord, a: C-section web length, b: C-section flange length , c: flange width of C-section steel.

Detailed ways

The present invention will be described in further detail below with reference to the embodiments and the accompanying drawings, but the embodiments of the present invention are not limited thereto.

As shown in Figure 1, a fast-installed space truss long-span light steel pedestrian bridge includes a main span 1 with a length of 40 meters, stairs 2 on both sides and approach bridges. The main span 1 adopts a variable section design, and the section height is the largest at the mid-span position and the smallest at the side span position.

FIG. 2 is a cross-sectional view of FIG. 1 at A-A, that is, a cross-sectional view of the main span 1 at the mid-span position. The main span 1 includes a walkway structure 3 and a handrail structure 4, both of which are space truss structures composed of multiple plane trusses. The trail structure 3 has a width of 4 meters and a height of 1 meter, and is composed of a plurality of trail trusses 7 arranged at intervals of 1 meter. After the completion of the construction of the pedestrian bridge, the pavement panels will be laid on the pavement structure 3 to form the pavement of the pedestrian bridge. The pavement structure 3 can transmit the bridge deck load to the handrail structures 4 on both sides.

The handrail structure 4 is a variable-section structure, and the height at the mid-span position is 3.2 meters, of which the upper surface of the walkway structure 3 is 1 meter above and 1.2 meters below. FIG. 3 is a cross-sectional view at B-B of FIG. 1 , that is, a cross-sectional view of the main span 1 at the side span position. The height of the handrail structure 4 at this position is 2.2 meters, of which the upper surface of the walkway structure 3 is 1 meter above and 0.2 meters below. The handrail structure 4 includes 80 handrail trusses, and the 80 handrail trusses are equally divided into two columns, which are respectively arranged on both sides of the walkway structure. Every two handrail trusses are arranged on both sides of two adjacent walkway trusses. Each handrail truss includes a YZ plane handrail truss 5 and an XZ plane handrail truss 6 . The two XZ plane handrail trusses are arranged in parallel and are respectively perpendicular to the two YZ plane handrail trusses. For the convenience of description, a three-dimensional coordinate system can be established. The span direction along the main span 1 is the X axis, the vertical direction to the X axis is the Z axis, and the vertical direction to the X axis to the width direction of the walkway structure 3 is the Y axis.

As shown in Figure 4, the top view of the pedestrian bridge with a length of 2 meters in the mid-span area is taken to further illustrate the structural composition of the pedestrian bridge. The trail trusses 7 are arranged at intervals of 1 meter and connect the handrail trusses on both sides. Each handrail truss includes 2 XZ plane handrail trusses 6 and 2 YZ plane handrail trusses 5, the distance between the 2 XZ plane handrail trusses 6 is 0.5 meters, and the distance between the 2 YZ plane handrail trusses 5 is 1 meter. Since the adjacent handrail trusses are connected to each other, the YZ plane handrail trusses 5 at the connection are shared with each other. The handrail trusses arranged on both sides of the walkway truss can bear the load transmitted by the walkway truss.

As shown in Figure 5, the pedestrian bridge adopts cold-formed thin-walled C-shaped steels with 4 cross-sectional sizes, and the C-shaped steels of different sizes are connected by M12 bolts. The dimensions of the four C-shaped steels are: the web length a of the first C-shaped steel is 100 mm, the flange length b is 50 mm, and the width c is 2 mm; the web length a of the second C-shaped steel is 96 mm, and the flange length b is 96 mm. is 48mm, and the width c is 2mm; the web length a of the third C-shaped steel is 92mm, the flange length b is 46mm, and the width c is 2mm; the web length a of the fourth C-shaped steel is 88mm, and the flange length b is 88mm. is 44mm, and the width c is 2mm. The sizes of the four C-shaped steels are gradually reduced, and the smaller-sized C-shaped steels can be nested between the flanges of the large-sized C-shaped steels to realize the connection of components. In the case of cross-members, the web of the large-sized C-section steel shall be opened, and the flanges on both sides of the large-sized C-section steel shall be bolted at the intersection point.

As shown in FIG. 6 , the XZ plane handrail truss 6 with a length of 2 meters in the mid-span area is taken for illustration. The XZ plane handrail truss 6 can be divided into the following rods from top to bottom: handrail upper chord 11, handrail upper inclined rod 12, handrail single C-shaped steel crossbar 13, handrail vertical web rod 14, handrail double C-shaped steel crossbar 15, handrail Down sloping bar 16 and armrest lower chord 17. Among them, the vertical web bar 14 of the handrail adopts the first type of C-shaped steel; the upper chord 11 of the handrail, the single C-shaped steel crossbar 13 of the handrail, the double C-shaped steel crossbar 15 of the handrail and the lower chord 17 of the handrail use the second type of C-shaped steel; 12 and the handrail sloping bar 16 use the third C-shaped steel. The handrail double C-shaped steel cross bar 15 is obtained by bolting two symmetrical C-shaped steel bars at the web position. Since two adjacent XZ plane handrail trusses 6 are connected to each other, the handrail vertical web bars 14 at the connection are shared with each other.

As shown in Figure 7, take the YZ plane handrail truss 5 with the largest height at the mid-span position for illustration. The handrail truss 5 is composed of the following rods from top to bottom: connecting the upper chord 18, connecting the vertical web rod 19, connecting the upper inclined rod 20 , connect the upper slant bar 21, connect the double C-shaped steel cross bar 22, connect the lower slant bar 23, connect the lower slant bar 24 and connect the lower chord bar 25. Among them, the first type of C-shaped steel is used for the connection of the vertical web bar 19; The third type of C-shaped steel; the fourth type of C-shaped steel is used for the connection of the upper inclined rod 20 and the connection of the lower inclined rod 24 .

As shown in Figure 8, the trail truss is 1 meter high and 4 meters wide, and is composed of the following rods: the trail upper chord 26, the trail diagonal rod 27, the trail vertical web rod 28, the trail diagonal rod 29, and the trail bottom chord 30. The first type of C-shaped steel is used for the vertical web bar 28 of the trail; the second type of C-shaped steel is used for the upper chord 26 and the lower chord 30 of the trail; .

The construction method of a fast-installed space truss long-span light steel pedestrian bridge of the present invention comprises the following steps:

(1) Member level: the handrail double C-shaped steel crossbar 15 and the connecting double C-shaped steel crossbar 22 are obtained by bolting two symmetrical C-shaped steel members at the web position. First, complete the connection processing of the handrail double C-shaped steel cross bar 15 and the connecting double C-shaped steel cross bar 22, as well as the size and screw hole processing of the remaining rods.

(2) Plane truss level: The XZ plane handrail truss 6, the YZ plane handrail truss 5 and the walkway truss 7 are assembled by using the above processed C-shaped steel members. During the assembly process, when the transverse rod crosses with the vertical web rod, a rectangular hole is opened in the web of the vertical web rod, and the transverse rod passes through; Small diagonal bars run through. The total length of the pedestrian bridge is 40 meters, and the XZ plane handrail trusses 6 can be spliced together at the construction site in multiple sections.

(3) Space truss level: The handrail truss is a space truss structure, which is vertically arranged by the XZ plane handrail truss 6 and the YZ plane handrail truss 5. When connecting, use M12 bolts to connect through the screw holes reserved for connecting the web of the vertical web rod 19 and the bolts on the flange of the vertical web rod 14 of the handrail. The YZ plane handrail trusses 5 are arranged at intervals of 1 meter in the span direction, and correspond to the vertical web bars 14 of the handrails 14 arranged in sequence in the XZ plane handrail trusses 6 at intervals of 1 meter.

(4) Overall structure level: the handrail structure 4 is assembled from the handrail truss, and the overall pedestrian bridge is assembled from the handrail structure 4 and the walkway structure 3. During the construction, M12 bolts were used to connect the flange of the vertical web bar 14 of the handrail and the web of the vertical web bar 28 of the walkway. The rods 14 are in one-to-one correspondence.

In this embodiment, the space truss long-span light steel pedestrian bridge is constructed with cold-formed thin-walled steel based on the construction levels of rods, plane trusses, space trusses and the overall structure, which shows good performance. The high lateral stiffness and bidirectional stability ensure the pedestrian comfort of the structure in both vertical and horizontal directions.

The above-mentioned embodiments only represent several embodiments of the present invention, and the descriptions thereof are specific and detailed, but should not be construed as a limitation on the scope of the patent of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can also be made, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims (10)

1. A space truss long-span light steel pedestrian bridge for quick installation, characterized in that it comprises a walkway structure and a handrail structure; the walkway structure comprises a plurality of spaced-apart walkway trusses; the handrail structure comprises a plurality of handrail trusses, The handrail trusses are arranged on both sides of two adjacent walkway trusses. The handrail trusses include an XZ plane handrail truss and a YZ plane handrail truss. The two XZ plane handrail trusses are arranged in parallel and are respectively perpendicular to the two YZ plane handrail trusses. 2. A space truss large-span light steel pedestrian bridge for quick installation according to claim 1, wherein the XZ plane handrail truss comprises a handrail upper chord, a handrail upper inclined bar, a handrail single C-shaped steel cross bar, The handrail vertical web bar, the handrail double C-shaped steel crossbar, the handrail lower inclined bar and the handrail lower chord; the handrail upper chord, the handrail single C-shaped steel crossbar, the handrail double C-shaped steel crossbar and the handrail lower chord are arranged in parallel and are respectively Two parallelly arranged vertical web bars of the handrail are vertical; the diagonal line of the upper inclined rod of the handrail is set between the upper chord of the handrail and the double C-shaped steel cross bar of the handrail; the diagonal line of the lower inclined rod of the handrail is set to the double C-shaped steel of the handrail Between the crossbar and the lower chord of the armrest. 3. The space truss large-span light-steel pedestrian bridge for quick installation according to claim 2, wherein the cross-sectional size of the C-shaped steel used in the vertical web bar of the handrail is larger than that of the upper chord of the handrail and the single C-shaped steel cross-section of the handrail. Cross-sectional dimensions of the C-shaped steel used for the rod, handrail double C-shaped steel crossbar and handrail lower chord; cross-sectional size of the C-shaped steel used for the handrail upper chord, handrail single C-shaped steel crossbar, handrail double C-shaped steel crossbar and handrail lower chord It is larger than the cross-sectional size of the C-shaped steel used for the upper inclined rod of the handrail and the lower inclined rod of the handrail. 4. A space truss large-span light steel pedestrian bridge for quick installation according to claim 1, wherein the YZ plane handrail truss comprises a connecting upper chord, a connecting vertical The C-shaped steel cross bar, the connecting lower inclined bar and the connecting lower chord; the connecting upper chord, the connecting double C-shaped steel horizontal bar and the connecting lower chord are arranged in parallel and are respectively perpendicular to the two connecting vertical web bars; The inclined rods are arranged crosswise between the connecting upper chords and the connecting double C-shaped steel cross rods; the two connecting lower inclined rods are crossed and arranged between the connecting double C-shaped steel cross rods and the connecting lower chords. 5. A kind of space truss large-span light steel pedestrian bridge for quick installation according to claim 4, characterized in that, the two connecting upper inclined rods arranged in the cross are two rods with different cross-sections, and the crossing The two downward inclined rods provided are two rods with different cross-sections. 6. The space truss long-span light-steel pedestrian bridge for quick installation according to claim 5, characterized in that, the cross-sectional size of the C-shaped steel used for connecting the vertical web bars is larger than that for connecting the upper chord and connecting the double C-shaped steel horizontal bars. The cross-sectional dimensions of the rod and the C-shaped steel used to connect the lower chord; the cross-sectional size of the C-shaped steel used to connect the upper chord, the double C-shaped steel crossbar and the lower chord is larger than the C-shaped steel used to connect the upper inclined rod and the lower inclined rod. Section size of the steel. 7. A fast-installed space truss long-span light-steel pedestrian bridge according to claim 1, wherein the walkway truss comprises a walkway upper chord, a walkway vertical web, a walkway oblique rod and a walkway lower chord, so The trail upper chord and the trail lower chord are arranged in parallel, a plurality of trail vertical web bars are vertically arranged between the trail top chord and the trail bottom chord at intervals, and a trail sloping bar is crossed between every two trail vertical web bars. 8. A space truss long-span light steel pedestrian bridge for quick installation according to claim 7, characterized in that, the cross-sectional size of the C-shaped steel used for the vertical web bar of the walkway is larger than the size of the upper chord of the walkway and the lower chord of the walkway. The cross-sectional size of the C-shaped steel used; the cross-sectional size of the C-shaped steel used for the upper chord and the lower chord of the walkway is larger than that of the C-shaped steel used for the inclined rod of the walkway. 9 . The fast-installed space truss long-span light steel pedestrian bridge according to any one of claims 1 to 8 , wherein the walkway structure and the bars in the handrail structure are connected by bolts. 10 . 10. A construction method of a space truss large-span light steel pedestrian bridge for quick installation, characterized in that, comprising the steps: Complete the size and screw hole processing of C-shaped steel rods; Use C-shaped steel rods to assemble to form trail truss, XZ plane handrail truss and YZ plane handrail truss; Two XZ plane handrail trusses are arranged in parallel, and respectively form a handrail truss vertically with two YZ plane handrail trusses; A plurality of walkway trusses are arranged at intervals, and the handrail trusses are arranged on both sides of two adjacent walkway trusses.

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