Anti-slip hybrid high-strength bolt connection joint and its construction method

Abstract

The present invention provides an anti-slip hybrid high-strength bolt connection joint and its construction method. The joint includes a steel joint plate with a number of bolt holes, and high-strength bolts are inserted into the bolt holes. It is characterized in that: the high-strength bolts include bearing-type bolts and friction-type bolts. The bearing-type bolts are arranged on the outside of the bolt group, and the friction-type bolts are arranged inside. Among them, the diameter of the bearing-type bolts is close to the diameter of the bolt holes to achieve bearing-type force; the diameter of the friction-type bolts is smaller than the diameter of the bolt holes to achieve friction-type force. After selecting the distribution method of the high-strength bolts according to the use requirements, a certain pre-tightening force is first applied to the bearing-type bolts, and then a higher pre-tightening force is applied to the friction-type bolts. By setting some bearing-type bolts in the traditional friction-type bolt connection joint, the present invention takes into account both the construction feasibility and convenience, thereby obtaining ideal anti-slip performance, fatigue performance and comprehensive economic indicators, and has the advantages of good anti-slip performance, reasonable force, convenient construction and high economic benefits.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge structures, and specifically to an anti-slip hybrid high-strength bolt connection node and its construction method. Background Art

[0002] High-strength bolts are divided into two categories: friction-type and bearing-type. Friction-type bolt connections do not allow relative slip between the bolts and the gusset plates, and the occurrence of slip is taken as the limit state. While bearing-type bolt connections allow slip between the bolts and the gusset plates, and the limit state is reached when the bolts reach the shear strength or the bolts and the gusset plates reach the bearing strength.

[0003] Steel truss bridges mostly adopt friction-type bolt connection nodes. For such nodes, when the loads borne do not exceed their design bearing capacities, the slip of the bolts is not significant. However, a large number of engineering accidents have shown that the phenomenon of bolt slip deformation is very common in the failure of steel structures and needs to be taken seriously. Research shows that the fatigue failure of steel truss bridge nodes often starts from the slip of high-strength bolts, and slip will reduce the fatigue life of the nodes.

[0004] In order to improve the anti-slip bearing capacity of traditional friction-type bolt connection nodes of steel truss bridges, methods such as increasing the number of bolts and increasing the bolt pre-tightening force are often adopted in engineering. Increasing the number of bolts will increase the workload of steel structure installation, and the assembly working hours will also increase significantly; engineering practice and research have shown that excessive bolt pre-tightening force will instead reduce the fatigue life of the nodes. Therefore, it is necessary to seek a more convenient, fast and economical method to improve the anti-slip ability of the nodes. Summary of the Invention

[0005] In order to solve the problems of the prior art, the present invention provides an anti-slip hybrid high-strength bolt connection node and its construction method. By setting some bearing-type bolts in the traditional friction-type bolt connection node, while taking into account the construction feasibility and convenience, ideal anti-slip performance, fatigue performance and comprehensive economic indicators are obtained, and it has the advantages of good anti-slip performance, reasonable force, convenient construction and high economic benefits.

[0006] The present invention provides an anti-slip hybrid high-strength bolt connection node, which includes a steel gusset plate with a number of bolt holes, and high-strength bolts are inserted into the bolt holes. The high-strength bolts include bearing-type bolts and friction-type bolts. The bearing-type bolts are arranged on the outside of the bolt group, and the friction-type bolts are arranged inside. Among them, the diameter of the bearing-type bolts is close to the diameter of the bolt holes to achieve bearing-type force; the diameter of the friction-type bolts is smaller than the diameter of the bolt holes to achieve friction-type force.

[0007] The distribution methods of the high-strength bolts include type b, type c, and type d. Among them, for type b, bearing-type bolts are arranged on both sides of the end in the force direction, and friction-type bolts are arranged in the remaining bolt holes; for type c, bearing-type bolts are arranged on one side of the end in the force direction, and friction-type bolts are arranged in the remaining bolt holes; for type d, bearing-type bolts are arranged around the perimeter, and friction-type bolts are arranged in the remaining bolt holes.

[0008] The present invention also provides a construction method for an anti-slip hybrid high-strength bolt connection joint, which includes the following steps:

[0009] 1) Prefabricate the steel gusset plate in the factory and drill bolt holes of the same size. Improve the friction coefficient on the surface of the steel gusset plate by means such as sandblasting.

[0010] 2) Select the distribution method of the high-strength bolts according to the usage requirements.

[0011] The hybrid bolt joints are divided into type b, type c, and type d according to the arrangement method of the bearing-type bolts. Among them, for type b, bearing-type bolts are arranged on both sides of the end in the force direction; for type c, bearing-type bolts are arranged on one side of the end in the force direction; for type d, bearing-type bolts are arranged around the perimeter. For medium-number high-strength bolt joints, in order to obtain better anti-slip effect, type b, type c, or type d joints can be adopted. For large-number high-strength bolt joints, in order to obtain better anti-slip effect, type b or type d joints are adopted.

[0012] 3) For the bolt holes where the bearing-type bolts are arranged, install high-strength bolts with large diameter and fine machining to achieve bearing-type force. The specific method is to select bolts close to the size of the bolt holes. For example, for a 22mm bolt hole, a bolt with a diameter of 21mm is used, and high-strength bolts with fine machining are adopted to achieve bearing-type force.

[0013] 4) For the bolt holes where the friction-type bolts are arranged, install high-strength bolts with a diameter smaller than the bolt holes. The specific method is to select bolts smaller than the size of the bolt holes. For example, for a 22mm bolt hole diameter, a bolt with a diameter of 20mm is used, and a pre-tightening force is applied to the bolts to achieve friction-type force.

[0014] 5) First apply a certain pre-tightening force to the bearing-type bolts, and then apply a higher pre-tightening force to the friction-type bolts. By different tightening sequences and pre-tightening forces, ensure that the bearing-type bolts are under bearing-type force, and ensure that the friction-type bolts bear a greater pre-tightening force and are under friction-type force.

[0015] The beneficial effects of the present invention are as follows:

[0016] (1) When the friction coefficient and the bolt pre-tightening force are kept unchanged, by adopting the method of arranging bearing-type bolts on both sides or arranging bearing-type bolts around the perimeter, compared with only arranging friction-type bolts, the sliding distance of the nuts can be effectively reduced.

[0017] (2) When the friction coefficient and the bolt pre-tightening force are kept unchanged, adopting the measure of arranging bearing-type bolts around can effectively improve the fatigue life of the gusset plate and the bolt group compared with only arranging friction-type bolts. Description of the Drawings

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0019] Figure 1 It is a schematic diagram of a hybrid high-strength bolt connection joint.

[0020] Figure 2 It is a schematic diagram of the bolt holes opened on the steel gusset plate.

[0021] Figure 3 It is a plan view of a type-b hybrid joint.

[0022] Figure 4 It is a plan view of a type-c hybrid joint.

[0023] Figure 5 It is a plan view of a type-d hybrid joint.

[0024] Figure 6 It is the maximum slip of a 4×8 joint of a type-a traditional friction-type joint.

[0025] Figure 7 It is the maximum slip of a 4×8 joint of a type-b hybrid joint.

[0026] Figure 8 It is the maximum slip of a 4×8 joint of a type-c hybrid joint.

[0027] Figure 9 It is the maximum slip of a 4×8 joint of a type-d hybrid joint.

[0028] Figure 10 It is the maximum slip of an 8×13 joint of a type-a traditional friction-type joint.

[0029] Figure 11 It is the maximum slip of an 8×13 joint of a type-b hybrid joint.

[0030] Figure 12 It is the maximum slip of an 8×13 joint of a type-c hybrid joint.

[0031] Figure 13 It is the maximum slip of an 8×13 joint of a type-d hybrid joint.

[0032] Figure 14Schematic diagram of the influence of bolt arrangement on the maximum slip of different types of joints.

[0033] Figure 15 Influence of bolt arrangement of traditional friction-type joints of type A on the fatigue life of 4×8 joints.

[0034] Figure 16 Influence of bolt arrangement of hybrid joints of type B on the fatigue life of 4×8 joints.

[0035] Figure 17 Influence of bolt arrangement of hybrid joints of type C on the fatigue life of 4×8 joints.

[0036] Figure 18 Influence of bolt arrangement of hybrid joints of type D on the fatigue life of 4×8 joints.

[0037] Figure 19 Influence of bolt arrangement of traditional friction-type joints of type A on the fatigue life of 8×13 joints.

[0038] Figure 20 Influence of bolt arrangement of hybrid joints of type B on the fatigue life of 8×13 joints.

[0039] Figure 21 Influence of bolt arrangement of hybrid joints of type C on the fatigue life of 8×13 joints.

[0040] Figure 22 Influence of bolt arrangement of hybrid joints of type D on the fatigue life of 8×13 joints.

[0041] Figure 23 Influence of bolt arrangement on the gusset plate fatigue life of different types of joints.

[0042] Figure 24 Influence of bolt arrangement on the bolt group fatigue life of different types of joints.

[0043] In the figure, the markings are: 1. steel gusset plate; 2. bolt hole; 3. friction-type bolt; 4. bearing-type bolt. Specific implementation method

[0044] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0045] The anti-slip hybrid high-strength bolt connection joint and its construction method provided by the present invention mainly include a steel gusset plate, 1. bolt hole 2, friction-type bolt 3, and bearing-type bolt 4, asFigure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 as shown.

[0046] Uniform bolt holes 2 of the same size are drilled on the steel gusset plate 1, as Figure 2 shown.

[0047] Friction-type bolts 3 and bearing-type bolts 4 are installed at the bolt holes 2. There are 3 bolt arrangement methods, as Figure 3 , Figure 4 and Figure 5 shown. For medium-number high-strength bolt joints, in order to obtain better anti-slip effect, type b, type c or type d joints as Figure 3 , Figure 4 and Figure 5 shown can be adopted. For large-number high-strength bolt joints, in order to obtain better anti-slip effect, type b or type d joints as Figure 3 or Figure 5 shown are adopted.

[0048] For the bolt holes 2 where bearing-type high-strength bolts 4 are arranged, install bearing-type high-strength bolts 4 with large diameter and precision machining to achieve bearing-type force. The specific method is to select bolts close to the size of the bolt holes. For example, for 22mm bolt holes, bolts with a diameter of 21mm are used, and precision-machined high-strength bolts are adopted to achieve bearing-type force.

[0049] For the bolt holes 4 where friction-type high-strength bolts 3 are arranged, install friction-type high-strength bolts 3 with a diameter smaller than the bolt holes. The specific method is to select bolts smaller than the size of the bolt holes. For example, for 22mm bolt holes, bolts with a diameter of 20mm are used, and pre-tightening force is applied to the bolts to achieve friction-type force.

[0050] First apply a certain pre-tightening force to the bearing-type bolts 4, and then apply a higher pre-tightening force to the friction-type bolts 3. By different pre-tightening forces and tightening sequences, ensure that the friction-type bolts 3 bear a greater pre-tightening force, ensure that the bearing-type bolts 4 are in bearing-type force, and the friction-type bolts 3 are in friction-type force.

[0051] The construction process of the present invention is as follows:

[0052] 1) Prefabricate the steel gusset plate 1 in the factory, and drill bolt holes 2 of the same size according to the design requirements, and increase the friction coefficient of the steel gusset plate 1 by means of sandblasting, etc.;

[0053] 2) Install friction-type bolts 3 and bearing-type bolts 4 at the bolt holes 2. There are 3 bolt arrangement methods. For medium-number high-strength bolt joints, type b, type c or type d joints as Figure 3 , Figure 4 and Figure 5 shown are adopted. For large-number high-strength bolt joints,Figure 3 or Figure 5 the b-type or d-type nodes shown.

[0054] 3) First, apply a certain pre-tightening force to the bearing-type bolt 4, and then apply a higher pre-tightening force to the friction-type bolt 3.

[0055] Through finite element analysis, for two commonly used bolt node specifications in engineering, compare the slip of the traditional friction-type high-strength bolt node (a-type) and the hybrid high-strength bolt node (b-type, c-type, d-type) proposed by the present invention under axial load, as Figures 6 - 13 It can be seen that for these two bolt node specifications, when using the hybrid node, the maximum slip of the bolts is significantly reduced.

[0056] Influence diagram of bolt arrangement on slip, as Figure 14 shown, it can be seen that in both types of nodes, arranging bearing-type bolts on both sides of the end or arranging bearing-type bolts around can effectively reduce the sliding distance of the nut.

[0057] Through finite element analysis, for two commonly used bolt node specifications in engineering, compare the traditional friction-type high-strength bolt node (a-type) and the hybrid high-strength bolt node (b-type, c-type, d-type) proposed by the present invention, and study the influence of changing the bolt arrangement on the fatigue performance of the node model. The results are as Figures 15 - 22 shown.

[0058] As Figure 23 and 24 , it can be seen that by arranging bearing-type bolts around, for the case of only arranging friction-type bolts, the service lives of the gusset plates and bolt groups of both specifications are increased. In the 4×8 node, the minimum fatigue life of the gusset plate increases from 11983 to 13953, an increase of 16.44%; the minimum fatigue life of the bolt group increases from 66491 to 82848, an increase of 24.60%; in the 8×13 node, the minimum fatigue life of the gusset plate increases from 12514 to 12951, an increase of 3.49%; the minimum fatigue life of the bolt group increases from 15108 to 17892, an increase of 18.43%.

[0059] Each embodiment in this specification is described in a progressive manner. For the same or similar parts among the embodiments, reference can be made to each other. Each embodiment focuses on the differences from other embodiments. In particular, for the device embodiments, the above description is only the preferred implementation manner of the present invention. Since it is basically similar to the method embodiments, the description is relatively simple. For the relevant parts, reference can be made to the partial description of the method embodiments. As described above, this is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. For any person skilled in the art in the technical field disclosed by the present invention, for those of ordinary skill in the technical field, any changes or substitutions that can be easily thought of without departing from the principle of the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A slip-resistant hybrid high-strength bolt connection joint, comprising a steel joint plate with a number of bolt holes, and high-strength bolts inserted into the bolt holes, characterized in that: The high-strength bolts include bearing-type bolts and friction-type bolts. The bearing-type bolts are arranged on the outside of the bolt group, and the friction-type bolts are arranged inside. Among them, the diameter of the bearing-type bolts is close to the diameter of the bolt holes to achieve bearing-type force; the diameter of the friction-type bolts is smaller than the diameter of the bolt holes to achieve friction-type force. The distribution methods of the high-strength bolts include type b, type c, and type d. Among them, for type b, bearing-type bolts are arranged on both sides of the end in the force direction, and friction-type bolts are arranged in the remaining bolt holes; for type c, a bearing-type bolt is arranged on one side of the end in the force direction, and friction-type bolts are arranged in the remaining bolt holes; for type d, bearing-type bolts are arranged around, and friction-type bolts are arranged in the remaining bolt holes.

2. A construction method for an anti-slip hybrid high-strength bolt connection joint, using the anti-slip hybrid high-strength bolt connection joint described in claim 1, characterized in that It includes the following steps: 1) Prefabricate the steel gusset plate in the factory and drill bolt holes of the same size; 2) Select the distribution method of high-strength bolts according to the usage requirements; 3) For the bolt holes where bearing-type bolts are arranged, install large-diameter high-strength bolts with fine machining to achieve bearing-type force; 4) For the bolt holes where friction-type bolts are arranged, install bolts with a diameter smaller than the bolt holes; 5) Apply a certain pre-tightening force to the bearing-type bolts first, and then apply a higher pre-tightening force to the friction-type bolts.

3. The construction method of the anti-slip hybrid high-strength bolt connection node according to claim 2, characterized in that: In step 1), the friction coefficient is increased by sandblasting on the surface of the steel gusset plate.

4. The construction method of the anti-slip hybrid high-strength bolt connection node according to claim 2, characterized in that: In step 2), for high-strength bolt joints with a medium number, type b, type c, or type d joints are adopted; for high-strength bolt joints with a large number, type b or type d joints are adopted.

Images