Large -span steel longeron top pushes away uses steel nose girder

Technical Field

The utility model relates to a steel for liang Dingtuithe steel leads Liang, in particular to a large SPAN for liang Dingtuithe steel leads Liang steel, suitable for pushing the bridge construction, ensure that the bridge during the jacking process, and mound smooth docking, improving the safety of the structure.

Background Art

At present, steel truss girder an increasing number of applied to the bridge structure, the world has completed, such as several of the large SPAN steel truss girder bridge, the present foreign top pushing of achieving maximum SPAN is 171m, bridge for both highway and railway Zhengzhou the yellow river in the most large-SPAN top pushes is 168m for the most successful examples. Without the pillar goes against pushes construction of the SPAN directly determine the maximum cantilever length, with the increase of the length of the cantilever construction design the difficulty of the increase of the geometric series, the structure stress into a square relationship between the length of the cantilever, the cantilever deflection of the four power relationship is more length, so that the manufacturing large-SPAN steel truss liang Dingtuithe steel leads Liang exist for the technical difficulty.

Content of the invention

In order to overcome the above-mentioned shortcomings, realize the large-SPAN (nose girder 120m, the main bridge steel truss girder 40m, to achieve the maximum net cantilever 160m, the maximum SPAN 180m mound of), the utility model relates to a steel for large SPAN the steel leads Liangliang Dingtui.

The utility model to solve the technical problems, the invention adopts the technical scheme is:

A large SPAN for liang Dingtuithe steel leads Liang steel, comprises a guiding nose body, guiding nose body comprises two joist sheets unit, joist sheets unit includes the upper chord member, the upper chord and a plurality of diagonal rods, a plurality of diagonal rods on the upper chord member, the upper chord is in a "W" shape is set, the 1st states leads Liang main body comprises a front end of the conductive segment, the rear end of the roof guide 2nd, 2nd 1st guiding nose section and between the guiding nose section is connected with the guiding nose section through the 3rd, the 3rd is highly gradual change of the roof, the roof guiding 1st, 2nd guiding nose section are composed of a plurality of segments, the distance between the sections forming the internode length, the 1st guide beam segment guiding nose height and the internode length is equal to the ratio of 2nd guide beam segment guiding nose height than the internode length, and the 1st guide beam segment guiding nose height is less than 2nd guide beam segment guiding nose height.

The front end of the nose a relatively small rigidity, unity to the height of the high front-stage structure, and weak cross-section, which is easy to cause jitter and vibration of the structure, need to be properly reduced internode overall size. Large SPAN of the utility model is used for steel truss liang Dingtuithe steel leads Liang 1st guiding nose section and the internode length is less than the height of the roof guide 2nd, and the guiding nose height and festival than the sum of the length of same, can obtain the greater net cantilever, realize the large SPAN over oleandic.

The utility model preparing 180m for large SPAN steel truss liang Dingtuithe steel leads Liang, but technical scheme of "large-SPAN" means in relatively large SPAN, the technical scheme of this application relative to the conventional technology can achieve relatively large SPAN.

Furthermore, according to the embodiment of the utility model for large SPAN steel truss liang Dingtuithe steel leads Liang may also have the following additional technical characteristics:

Preferably, the height and the internode length states leads Liang a ratio of 9:5.

Preferably, the roof guiding 1st 2nd the guiding nose height is the height of the guiding nose of the guide beam segment 1/2.

Preferably, the guide 2nd 1st guiding nose section and the upper and lower roof connects to parallel place same bar connecting structure.

Preferably, the up-and-down by two connects to parallel placeeven link rod member is in accordance with the cross-hairs transposition.

Preferred, the 3rd guiding nose section has two segments.

Preferred, also includes a plurality of shearing force brace, the shear are arranged in corresponding states two clothes rack pieces unit between the diagonal, and the joist sheets on the unit interval of the diagonal is the same as the inclination direction of the shear support.

Preferably, the length of the lower chord body states leads Liang 120m, the upper chord total length 125m, to the width of the body of lug bosses 11m; 1st guide beam segment length is 40m, guiding nose height is 9m, internode length is 10m, 2nd conductive segment of a length of 60m, guiding nose height is 18m, internode length of 20m, the 3rd the length of the lower chord element 20m, 3rd upper chord length of the guide beam segment 25m;

Preferably, the main body close to states leads Liang to be mounted on the steel truss chord at least a section of short length, so as to realize the guiding nose body (the front section of the guiding nose section 1st) pre-raising. Preferably, the three upper chord (m9m10, m10 m11, m11m12) short length 30 mm, the front end of the nose is realized raises in advance 500 mm.

The 2nd conductive roof member box cross-section of the two joist sheets, the remaining member is H-shaped cross-section;

The guiding nose body member Q370qD steel.

The utility model Patent against the maximum net cantilever 160m, SPAN 180m pushing construction, the first time at home and abroad.

The utility model has the additional aspects and advantages of the will be given below in the description of the part, from the lower part of the become apparent in the description of, or by the utility model to the practice of.

Description of drawings

The utility model of the above-mentioned and/or additional aspects and advantages of the from the combination of the embodiment of the Figure will become in the description a clear and easy to understand, wherein:

Figure 1 is the whole chart of steel for large SPAN of the steel leads Liangliang Dingtui of the present utility model;

Figure 2 is the integral guide beam girders of Figure 1;

Figure 3 is the integral guiding nose the lower girders of Figure 1;

Figure 4 of the guiding nose sections shearing force value ;

Figure 5 the guiding nose the upright post section;

Figure 6 is a 1st shear support structure chart;

Fig. 7 plan for 2nd shear support structure.

The Figure mark note:

Upper chord g1; the upper chord g2; diagonal g3; of the guiding nose 1st d1; 2nd guiding nose section d2; 3rd conductive segment d3; h steel truss beam.

Mode of execution

The following detailed description of the embodiment of the utility model, the same or similar labels throughout that the same or similar element or with the same or similar functions of the component. By reference to Figure of the described embodiment is exemplary, for the purpose of explanation of the utility model, and can not be understood as limited to the present utility model.

In the description of the utility model, is required, the term "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom" "inner", "outer" position or position of those instructions shown in the Figure is based on relations of relations position or position, is only to facilitate describing the utility model and simplification of the description, and is not directed or imply that the device or element referred to must have a particular orientation, the position of the specific structure and operation, therefore, can not be understood as limited to the present utility model.

Furthermore, the term "1st", "2nd" for description purposes only, and cannot be interpreted as instructions or imply relative importance or implied specified in the technical characteristics of the number of instructions. Therefore, defining a "1st", "2nd" of the feature can be express or implicitely include one or more the feature. In the description of the utility model, the meaning of "a plurality of" is at least two, for example two, three, etc., unless otherwise specifically limited.

In accordance with a below described with reference to the embodiment of the utility model is used for the large-SPAN steel truss liang Dingtuithe steel leads Liang. Figure 1-Figure 3 in particular shows the embodiment for a large-SPAN steel truss liang Dingtuithe steel leads Liang, which comprises a nose body, guiding nose body comprises two joist sheets unit, joist sheets unit includes the upper chord g1, the upper chord g2 and a plurality of diagonal rods, a plurality of diagonal rods in upper chord g1, the upper chord g2 between is a "W" shape. The front end of the main body includes a guiding section guiding nose 1st d1, the rear end of the nose section 2nd d2, of guiding nose 1st d1 and 2nd guiding nose section d2 between the 3rd through the variable cross-section of beam d3 are connected together, the guide beam segment 3rd d3 abacus is highly gradually, is composed of two segments. 1st guiding nose section d1,2nd guiding nose section d2 are composed of a plurality of segments, the distance between the sections forming the internode length. 1st guiding nose section d1 and 2nd guiding nose section d2 connects to parallel place up and down of the same bar connecting structure. 1st guiding nose section d1 the guiding nose height and the internode length is equal to the ratio of the guiding nose 2nd d2 guiding nose of the ratio of the height and the internode length, are 9:5, and of guiding nose 1st d1 the guiding nose height is 2nd guiding nose section d2 the height of the guiding nose of 1/2.

Its specific structural characteristics are as follows:

The design requirements: the main bridge steel truss girder h40m, design guiding nose 120m achieve maximum net cantilever 160m, the maximum SPAN 180m mound of.

Structural characteristics:

1, the front end of the steel girder h the steel leads Liang design, according to the width of the steel girder h, in accordance with the distance between the central line 11m the steel leads Liang design. The design length the steel leads Liang 120m, reduce the dead weight of the nose at the front end of the, height variation a, front end 40m guiding nose height is 9m, internode length is 10m; the 40 [...] 60m internode the gradual change of the height of the nose, the back end 60m guiding nose height is 18m, internode length of 20m, nose girder structural uses the proximity equilateral triangle truss. The guiding nose transverse connection of the I-shaped cross-section, according to cross transposition connection. To the torsion resistance of the a number of ring, and set up in the corresponding two joist sheets unit of the same plane of the diagonal, and the joist sheets on the unit interval of the diagonal is the same as the inclination direction of the shear support.

Height 9m leads Liang Zhuheng and a variable cross-section the front end of the two diagonal rod and the middle of the H-shaped cross-section are high and low connects to parallel, the rest are box-shaped cross-section.

Specifically, the size of the main body structure of the nose of the: nose girder body the lower chord length is 120m, the upper chord total length 125m, to the width of the body of lug bosses 11m; of the guiding nose 1st d1 the length of 40m, guiding nose height is 9m, internode length is 10m, 2nd guiding nose section d2 of a length of 60m, guiding nose height is 18m, internode length of 20m, 3rd conductive segment d3 the lower chord length of 20m, 3rd conductive segment d3 upper chord length 25 m.

Nose girder adopts three sections of an upper chord g1 short length 30 mm, the front end of the nose is realized raises in advance 500 mm.

As shown in Figure 1-3, Figure numbering 1-49 for guiding nose bar, 50 for the steel truss beam chord g1,51 of the lower chord for the steel truss g2,52 the diagonal for the steel truss, 54 of the vertical rod for steel truss beam. Figure number M1-M12 for guiding nose upper chord, a node number, N1-N12 to freely lower chord node number, A1-A3 main steel truss upper chord of a node number, E0-E3 steel as the number of nodes of the lower chord.

2, the optimization choice of the angle between the. The upper, the lower chord g1, g2 main bear bending moment, mainly bear of the diagonal shear, the angle between the chord and of the diagonal directly determines the size of the shear transfer efficiency, the greater the angle the higher the shear the efficiency of the transmission, the larger the density of the bar at the same time, the greater the number, the greater the weight of; the smaller the angle, the lower the shear transfer efficiency, the lower the density of the rods, the weight of light. At the same time the the steel leads Liang Q370qD steel, high-strength material with weight reducing guiding nose structure.

Nose girder condition complex, in particular node plates, repeated tensile stress concentrated on the node board, the jitter of the node board is mainly in the form of guiding nose damage, the entire nose of the most thin soft part. Is the angle of the diagonal is reasonable, in-depth technical decision node plate and the overall length of the inner size of the node board, outside the node directly determine the rigidity of the plate. The node board member from the end of the smaller centre distance, the more can ensure the rigidity of the outer-plane of the node board, to ensure stability of the node board. According to the applicant's study, two of the diagonal of the node board with the upper, the lower chord g1, g2 arrangement angle θ is the most reasonable arctan9/5=60.9 °  [...] 61 °, can be selected in the range of 60° - 62 °, approximately equal to the triangle. An in-depth of the diagonal of the mutual interference of the node board the minimum, the most close to the end of the diagonal center of the node board. Therefore, steel truss liang Dingtui the most reasonable construction guiding nose of the diagonal angle of 61°.

The equilateral triangle in the near future is not a substantial increase in weight of the structure, but also the rod shear efficient transfer, the node board at the same time reasonable and compact design. Give consideration to structural size and follow-up construction is convenient, the actual selection of the diagonal angle with the chord to 61°.

According to the following table 1,2 (Figure 4, Figure 5) enveloping table the bending moment, in 0m-120m mound is control, 120m-160m is cantilever state control, that is, freely by the mound control, the main beam by the maximum cantilever control. And 0-60m bending moment is about 160m one quarter of the bending moment at the, beam w bending section modulus of the beam is proportional to the square of high, therefore the former 60m freely the height of the half of the main beam is set high, can meet the demands.

Because the optimum of the diagonal angle of 61 °, consistent and requires guiding nose the step size, full-bridge within the range of a can at the same time slide block goes against but actually, of the slide block the coordinated each spot but actually, freely variable cross-section of the internode length should be one half of the length of the internode of the main beam, one-third, which is also the height corresponding to one half of the main beam, one-third, is determined according to the envelope diagram of the height of the guiding nose with variable cross-section for the original half of the height of the most reasonable.

Through practice of the applicant, of guiding nose 1st d1 guiding nose of the ratio of height and the internode length 9 ; 5, and equal to that of the guiding nose 2nd d2 the internode length of the guiding nose of the ratio of the height of 9:10,9 ; 8 and 9:4, other parameters are the same as processing 120m three sets of guiding nose, can not achieve the maximum net cantilever 160m and maximum SPAN 180m through oleandic. Diagonal angle is 55° and 65 °, the same as other parameters are respectively processed 120m two groups of freely, can not be realized as the maximum net cantilever 160m and maximum SPAN 180m through oleandic. Furthermore, 1st guiding nose section d1 the guiding nose height is 2nd guiding nose section d2 the height of the guiding nose of 1/3 and 2/3, other parameters are the same as processing 120m two sets of guiding nose, the same can not achieve the maximum net cantilever 160m and maximum SPAN 180m through oleandic.

3, the selected section.

According to the guiding nose overall stress, the cantilever state is triangle bending moment envelope diagram of structure, during the mound cross-sectional bending envelope diagram is the trapezoid, the integrated guiding, bending envelope diagram of the final select for the trapezoidal, according to the approximate trapezoidal change freely rigidity.

Table 1 bending moment shear SUMMARY

In order to facilitate to stress than the guiding nose and the front end of the main beam, in order to freely force so as to 10 position as the base mound 1, compared with the position of the stress, and the stress of the air conduction beam to increase in length. The ratio as 2 the column:

Table 2 bending moment bending force magnification relationship table

4, overall rigidity the steel leads Liang gentlely transition. The front end of the nose a relatively small rigidity, unity to the height of the front end structure is high, and weak cross-section, which is easy to cause jitter and vibration of the structure. Reduced internode overall size is not the second selection, to adjust the overall compatibility, the height and the internode length can be reduced to half at the rear end, that is, the height of the back end 18m, internode length 20m, change to clothes rack high 9m, node length 10m, if freely between the two section 10m to change, the rapid change of section of member bar, greater rigidity is abruptly, is easy to cause stress concentration, adverse the overall structure, long-nose top chord clothes rack 25 m. EI overall structural rigidity, the elastic modulus is steel E, inertia I≈AR², the neutral axis of the square relationship between a, is proportional to the cross section of a single member.

5, the choice of the transverse rigidity of the nose. H and guiding nose the steel truss beam affected by the weight of, the vertical-direction rigidity of the truss as the main control, but at the same time large wind in coastal areas, instantaneous wind up to 12 level, the transverse rigidity of the nose that is required is very large, in that the lateral stability, the use of the cross section of the main girder and reasonable resistance to lateral bending, horizontal high-to-width ratio is selected as the Golden section point, the nose width 18m × 0.618=11.124m, the rounding width 11 m.

6, leads Liang Kangniu design

Pushing in the process of construction, the height difference and each pivot to freely create distortions, in the guiding nose structure, additional torsional shear knife support, the stability of the overall structure is increased. Freely in the diagonal n1m1, n3 m3, n5m5, n7m7, n9 m9 web member surface the torsion of the shearing knife support, the change clothes rack high, in order to improve the guiding nose different torsion-resistance capacity of the structure, after the variable height adjust the torsional door frame, the actual use of two scissors support. As shown in Figure 6,7 illustrated, structure form n1m1, n3 m3, n5m5 1st guiding nose section is d1 the use of torsional 1st cutter support, n7m7, n9 m9 2nd guiding nose section is d2 the use of torsional 2nd cutter support, is shown in the Figure, 1st shear support for a set of X-shaped rod is connected to the two joist sheets corresponding to the two oblique rod, the upper chord g1, g2 between the cross point. 2nd in the same diagonal shear support provided with an upper and a lower position, are respectively connected to two corresponding to the middle of the diagonal and upper chord g1 and the middle part of the cross-point between the lower chord g2 between the cross point. 2nd shear supports place the two pairs is connected with the middle of the diagonal has should be. When the wind force is larger, the guiding nose section 2nd d2 complex stress state, and the bearing is relatively large. Shear are arranged in and 2nd n7m7, n9 m9 or interval is set up. The original structure of a 2nd shear support rigidity, torsional effect is great, when the local large wind, 2nd guiding nose section d2 bear on the torque to be transferred to the not provided with the segments of shear 2nd, 2nd shear support is not set by the segments bear larger torque, reduced stability. Therefore, as this embodiment is a preferred example, the shear support at the upper end of the middle part of the 2nd position of the cross points close to the upper chord g1,2nd shear support the middle part of the lower end of the cross connection point position close to the lower chord g2. Tests prove that, its torsion is diminishing, increase the torsion-resistance capacity of the whole guiding nose.

7, the strengthening of the node board.

Guiding nose each rod stress and alternating, the upper, the lower chord g1, g2 whole node plate is forced to very complex. In the design stage, the upper, the lower chord g1, g2 the plate are each node measures partial thickening, diagonal partition of the node board is connected with the web plate and, at the same time take into account problems of construction and operation, is arranged in the middle hole, the two wings of the baffle extends downwards to the top chord member, the guiding nose to the Provisional component, high-strength bolt construction in very small pre-tightening force relaxation possibility, manhole does not need to be left as the other observation reinforced channel, therefore, the has been completed a preset hole gusset plate closed, the high-strength bolt has been completed on the based of the steel plate for the manhole, resume its strength and stiffness, the out-of-plane stability of the node board. Can also strengthen the board internal to the node, the node of the node board has been completed the inner side of the of welding steel plate; the node board can also be no bolts to the outside of the welding part of the steel plate. Through the above-mentioned method can remarkably improve the stability of the node plate.

8, the front end is pre-crown

Use of guiding nose upper chord g1m9m10, m10m11, m11 m12 the three in the processing, processing of short length 30 mm, the length and the splice plate unchanged, the guiding nose foremost 500 mm pre-crown of, smooth support to the next effect of the pillar slides block.

The utility model embodiment of the preparation of the steel truss beam the steel leads h40m, design guiding nose 120m achieve maximum net cantilever 160m, the maximum SPAN 180m mound of. By optimizing the angle of the various rods, using approximate equilateral triangle with the optimal angle for the light, the requirement that large rigidity, the rigidity of the cross section of the stress change of state of the different parts of the prominent contradictions.

Weight demand to solve the contradiction between the requirements and the rigidity, using Q370qE the characteristics of high strength steel to reduce the weight of the structure itself, using the whole cross-section and a bar section size becomes high to realize the guiding nose with rigidity of the structure is large and small change, between the two subsections clothes rack high change the whole, the overall rigidity of the gentle transition.

The item guiding nose for re-distribution of the back rod piece clothes rack high changes in adjustment, internode length adaptive clothes rack high, full use of the bar of the axle, and the integrated capacity. Comprehensive consider beam longitudinal rigidity and lateral stability, high-to-width ratio is selected as the Golden section point ratio.

For coastal areas lichin, large wind during construction, a height of the construction structure 34m, the maximum momentary wind up to 12 level, high requirement for rigidity of the horizontal structure. In accordance with the interval internode set up torsional shear knife support, improving overall stability the steel leads Liang.

Although have already shown and described the embodiment of the utility model; the ordinary technical personnel in this field can be understood: without departing from the principle of the utility model and purposes of these examples of the many changes, modification, replacement and modification; the utility model by the scope of the claim and its equivalent limits.