Segmental box girder socket type shear key device and construction method thereof

Abstract

The invention belongs to the technical field of segment splicing type bridges, and particularly relates to a segment box girder socket type shear key device and a construction method thereof. The shear key device structurally comprises a prismatic table convex key and a concave key groove body which are arranged at the two ends of a box girder body respectively, and further comprises a steel column body which is arranged on the box girder body and the prismatic table convex key and extends out of the end face of the prismatic table convex key. The positioning groove is formed in the inner side of the concave key groove body and used for installing the steel column body, and the positioning pipe body is arranged on the positioning groove and used for clamping the steel column body. The shear key device at least has the beneficial effects that after the shear key device is combined with the steel column body at the prismatic table convex key, the shear key device has the compression resistance advantage of a concrete material and the tensile resistance advantage of a steel material, so that the prismatic table convex key is not easy to break and fall off on the box girder main body, and the relatively high structural strength at the joint of the segmental box girder is ensured.

Description

Technical Field

[0001] This application belongs to the technical field of segmentally spliced bridges, and particularly relates to a segmental box girder socket shear key device and its construction method. Background Art

[0002] Compared with the existing common cast-in-situ bridges, the advantages of segmentally spliced bridges mainly include: controllable quality, short cycle, small environmental impact, and high flexibility.

[0003] On the other hand, the structural components of segmentally spliced bridges mainly include: segmental beams, shear convex keys, and shear concave keys. Among them, a common existing segmental beam is the above-mentioned segmental box girder, the shear convex key is generally the protruding concrete part on the end face of the segmental beam, and the shear concave key is generally the reserved groove part on the other end face.

[0004] Generally, the above-mentioned shear convex key and shear concave key together can be called a shear key device or shear key facility.

[0005] For example, the Chinese utility model patent with the authorization announcement number CN214219334U and the authorization announcement date of September 17, 2021, discloses a box girder segment with shear keys, and its structural components mainly include: web, top plate, bottom plate, web shear key, top plate shear key, bottom plate shear key, top plate glue outlet groove, bottom plate glue outlet groove, joint area shear key, joint area glue outlet groove, and shear concave key.

[0006] The advantages of the box girder segment in this utility model patent are mainly: both the shear convex key and the shear concave key are set as frustum-shaped, which facilitates the alignment and splicing during the construction of segmental bridges.

[0007] However, in the actual use process of this box girder segment, there are at least the following problems with relatively low structural strength and splicing accuracy, specifically manifested as: its shear key structure is easy to break and fall off on the end face of the box girder segment, and it is difficult to provide a relatively high-precision plugging effect between the shear key and the shear concave key, resulting in the box girder segment being prone to vertical and horizontal misalignment at the joint even without large loads. Summary of the Invention

[0008] This application provides a segmental box girder socket shear key device, and the technical problem to be solved is: how to enable the segmental box girder to have relatively high structural strength and splicing accuracy at the joint.

[0009] At the same time, this application also provides a construction method for the above-mentioned shear key device.

[0010] The technical solution adopted by this application to solve the above problems is as follows: A segmental box girder socket shear key device, the structure of which includes a frustum convex key and a concave key groove body respectively arranged at both ends of the box girder main body, and also includes a steel column body arranged on the box girder main body and the frustum convex key and protruding from the end face of the frustum convex key, a positioning groove arranged inside the concave key groove body and used for installing the steel column body, and a positioning pipe body arranged on the positioning groove and used for clamping the steel column body.

[0011] A further preferred technical solution lies in: It also includes a sealing end plate arranged on the inner end face of the positioning pipe body and used for blocking concrete.

[0012] A further preferred technical solution lies in: It also includes an adhesive layer arranged between the frustum convex key and the concave key groove body, and between the positioning pipe body and the steel column body.

[0013] A further preferred technical solution lies in: Before the frustum convex key and the concave key groove body are inserted, the adhesive is arranged inside the positioning pipe body.

[0014] A further preferred technical solution lies in: It also includes an axial groove arranged on the exposed section of the steel column body and used for draining the adhesive towards the concave key groove body.

[0015] A further preferred technical solution lies in: There is a reserved distance L1 between the end face of the axial groove close to the frustum convex key and the end face of the frustum convex key.

[0016] A further preferred technical solution lies in: The exposed end face of the positioning pipe body has an indented distance L2 on the end face of the concave key groove body, and the indented distance L2 ≥ the reserved distance L1.

[0017] A further preferred technical solution lies in: The positioning groove is also provided with an annular flared groove located at the indented distance L2 and used for accommodating the concrete fragments at the end face of the positioning pipe body.

[0018] A further preferred technical solution lies in: The adhesive layer forms a thickened layer at the annular flared groove to avoid the concrete fragments at the end face of the positioning pipe body from wearing and breaking the adhesive layer.

[0019] A construction method of a segmental box girder socket shear key device, the overall notch formed by the combination of the concave key groove body, the annular flared groove and the positioning groove is formed by a combined formwork. The structural composition of the combined formwork includes: a formwork main body, a frustum block, a circular block, and a cylinder. The diameter of the circular block is larger than the outer diameter of the positioning pipe body, and the end face of the positioning pipe body abuts against the circular block, and the concrete fragments at the end face of the positioning pipe body are formed at the abutting gap.

[0020] The beneficial effects of this application include at least the following five points.

[0021] First, after the shear key device combines with the steel column at the frustum convex key, it combines the compressive strength advantages of concrete materials and the tensile strength advantages of steel, making the frustum convex key not easy to break and fall off the main body of the box girder, ensuring that the joint of the segmental box girder has greater structural strength.

[0022] Second, compared with the frustum convex key and the concave key groove, a relatively higher dimensional accuracy can be provided between the steel column and the positioning pipe. When there is no large load on the segmental box girder, this precise insertion relationship can prevent misalignment in the vertical and horizontal directions at the joint.

[0023] Third, a binder layer is provided at the joint, making the connection strength of the segmental box girder at the joint greater, especially the connection strength in the longitudinal bridge direction.

[0024] Fourth, the binder layer itself has the advantage of a large effective connection area, which can fully connect the frustum convex key and the concave key groove, as well as the steel column and the positioning pipe.

[0025] Fifth, the binder layer reserves a thickened layer at the inevitable concrete fragments at the end face of the positioning pipe, preventing the former from wearing and breaking the latter, and ensuring the long-term effectiveness of the above-mentioned binder strengthening connection function. Brief Description of the Drawings

[0026] Figure 1 It is a schematic position diagram of this application.

[0027] Figure 2 It is a schematic shape diagram of the concave key groove in this application.

[0028] Figure 3 It is a schematic position and shape diagram of the positioning pipe in this application.

[0029] Figure 4 It is a first schematic structural diagram of the combined formwork in this application.

[0030] Figure 5 It is a schematic diagram of the filling method of the binder in the positioning pipe in this application, and the shaded part is the binder.

[0031] Figure 6 It is a schematic position and shape diagram of the binder layer in this application.

[0032] Figure 7 It is a schematic position diagram of the indentation distance and the reserved distance in this application.

[0033] Figure 8 It is a schematic diagram of the function of the indentation distance and the reserved distance in this application.

[0034] Figure 9In this application, under the requirement of the drainage binder, there is only a schematic diagram of the invalid state with the reserved distance.

[0035] Figure 10 In this application, under the requirement of the drainage binder, there is a schematic diagram of the valid state where neither the indentation distance nor the reserved distance exists.

[0036] Figure 11 In this application, when the reserved distance does not exist, there is a schematic diagram of the harmful way that concrete will leak between the convex key template and the axial slot.

[0037] Figure 12 In this application, there is a schematic diagram of the formation position of the concrete fragments at the end face of the positioning pipe body.

[0038] Figure 13 In this application, there is a schematic diagram of the safe use method of the convex key template.

[0039] Figure 14 In this application, there is a schematic diagram of the position of the concrete fragments at the end face of the positioning pipe body.

[0040] Figure 15 In this application, there is a schematic diagram of the function of the annular flared groove.

[0041] In the figure, the meanings of the respective marks are as follows.

[0042] Box girder main body a, concrete fragments b at the end face of the positioning pipe body, template main body c, frustum block d, circular block e, cylinder f, fragment formation position g, convex key template h, concrete pouring position k, concrete amorphous block p, reserved distance L1, indentation distance L2; Frustum convex key 11, concave key groove body 12; Steel column 1, positioning groove 2, positioning pipe body 3, sealing end plate 4, binder layer 5, axial slot 6, annular flared groove 7. Detailed implementation manners

[0043] The following is only a preferred embodiment of this application, and does not limit the scope of this application.

[0044] As Figures 1 - 15 shown, a segment box girder socket shear key device has a structure including a frustum convex key 11 and a concave key groove body 12 respectively arranged at both ends of the box girder main body a, and further includes a steel column 1 arranged on the box girder main body a and the frustum convex key 11 and protruding from the end face of the frustum convex key 11, a positioning groove 2 arranged inside the concave key groove body 12 and used for installing the steel column 1, and a positioning pipe body 3 arranged on the positioning groove 2 and used for engaging the steel column 1.

[0045] In this embodiment, the box girder main body a includes a top plate, a web plate, and a bottom plate, and shear key devices can be provided on all of the above three components.

[0046] The above-mentioned "socket type" refers to the plug-in relationship between the steel column 1 and the positioning pipe body 3, which can be regarded as a plug-in type pipeline connection method in a broad sense. This plug-in relationship has the characteristics of sufficient connection and relatively high sealing degree.

[0047] Among them, the frustum convex key 11 and the concave key groove body 12 are made of concrete, and the steel column 1 and the positioning pipe body 3 are made of high-strength steel. Due to the limitations of the material itself and the construction process, the width of the gap between the former two is generally only 4.0 - 5.0 mm, and the width of the gap between the latter two is generally ≤ 1.5 mm. Correspondingly, the plug-in relationship between the former two provides the main shear strength, and the latter two can only provide relatively small shear strength. However, the splicing accuracy at the joint is mainly provided by the latter two, so that when there is no large load on the segment box girder, the joint is not likely to be misaligned vertically and horizontally.

[0048] On the other hand, the steel column 1 is formed and fixed together with the box girder main body a and the frustum convex key 11, so that the frustum convex key 11 has the advantages of a steel-concrete structure, and thus can provide relatively large shear resistance performance, making it not easy to break and fall off the box girder main body a.

[0049] In addition, the position of the concave key groove body 12 on the end face of the box girder main body a corresponds to that of the frustum convex key 11, and their shapes and sizes also correspond, ensuring that the plug-in relationship between the frustum convex key 11 and the concave key groove body 12 has a basic and existing effective shear resistance and convenient docking function.

[0050] Finally, the larger rectangular end face of the frustum convex key 11 is arranged on the box girder main body a, the steel column 1 extends from its smaller rectangular end face, the shape of the steel column 1 is cylindrical, its diameter is smaller than the width of the above smaller rectangular end face, and it is centered. Correspondingly, the positioning pipe body 3 is a circular pipe, and the positioning groove 2 is formed by the positioning pipe body 3. The combined formwork composed of the formwork main body c, the frustum block d, and the cylinder f is removed after the segment box girder is prefabricated, but the positioning pipe body 3 is left on the box girder main body a, and thus the positioning groove 2 is formed passively.

[0051] The shear key device further includes a sealing end plate 4 which is arranged on the inner end face of the positioning pipe body 3 and is used to block concrete.

[0052] In this embodiment, the inner area of the positioning pipe body 3 is the plug-in installation area of the steel column 1, and there should be no concrete at this position. The above concrete removal method can be: First, the length of the cylinder f ≥ the length of the positioning tube body 3. The cylinder f first occupies the inner area, and then withdraws, leaving the insertion and installation area. Second, the positioning tube body 3 and the sealing end plate 4 are integrally formed, which can prevent concrete from entering the inner area.

[0053] The main advantage of the first method is that the sealing end plate 4 can be omitted, while the main advantage of the second method is that concrete can be almost completely prevented from entering the inner area, and the length limit of the cylinder f is also removed. For details, please refer to the appendix Figure 4 Either of the above two methods can be selected.

[0054] It should be noted that the exposed length of the steel column body 1 can be relatively short and does not need to touch the sealing end plate 4, because the source of the necessary precise insertion between the steel column body 1 and the positioning tube body 3 is the relatively small gap between their annular surfaces.

[0055] In addition, another function of the sealing end plate 4 is to reinforce the positioning tube body 3 to prevent the latter from being easily deformed or cracked by the steel column body 1.

[0056] The shear key device further includes an adhesive layer 5 provided between the frustum convex key 11 and the concave key groove body 12, and between the positioning tube body 3 and the steel column body 1.

[0057] In this embodiment, the adhesive is any one of epoxy resin, polyurethane, and acrylate. The specific shape of the adhesive layer 5 is indefinite, and its area is relatively large, covering all the inner ring surfaces of the positioning tube body 3, the concave key groove body 12, and most of the end face area of the box girder main body a.

[0058] Before the frustum convex key 11 and the concave key groove body 12 are inserted, the adhesive is provided in the positioning tube body 3.

[0059] In this embodiment, in order to relatively conveniently dock the frustum convex key 11 at the concave key groove body 12, the transverse and vertical cross-sectional shapes of the former are both isosceles trapezoids. Therefore, if the adhesive is filled at the concave key groove body 12, it is relatively easy to flow out and fall off. On the contrary, the positioning tube body 3 is horizontally arranged, and after the adhesive is filled therein, the outflow speed is relatively small, so that the frustum convex key 11 does not need to be immediately spliced and installed, which is very practical.

[0060] On the other hand, if the binder is filled on the concave key groove body 12, the amount of binder required in the positioning tube body 3 can only be brought in by the insertion action of the steel column body 1, and this amount is relatively small and it is difficult to coat the inner ring surface of the positioning tube body 3 completely. On the contrary, this is the advantage of the above-mentioned binder filling method, which can ensure that the amount of binder at the gap between the steel column body 1 and the positioning tube body 3 is sufficient, appropriate, and completely coated.

[0061] The shear key device further includes an axially grooved portion 6 provided on the exposed section of the steel column body 1 and used for draining the binder towards the concave key groove body 12.

[0062] In this embodiment, the axially grooved portion 6 is a straight two-sided groove, one end of which is the insertion end of the steel column body 1, and its main notch position is provided on the annular surface of the steel column body 1.

[0063] In a cross-section perpendicular to the length direction of the steel column body 1, the general cross-sectional shape of the axially grooved portion 6 can be rectangular, circular, or fan-shaped, and its cross-sectional shape size is relatively small compared to the end face size of the steel column body 1, so as to avoid the opening of the axially grooved portion 6 significantly reducing the structural strength of the steel column body 1.

[0064] Among them, the main function of the axially grooved portion 6 is that during the insertion process of the steel column body 1, the binder originally between the sealing end plate 4 and the end face of the steel column body 1 can flow through the axially grooved portion 6 and be squeezed to flow between the frustum convex key 11 and the concave key groove body 12 and between the end faces of the joints.

[0065] Correspondingly, the flow resistance of the binder at the relatively precise and narrow gap between the steel column body 1 and the positioning tube body 3 is relatively large, while it can flow and be extruded quickly between the frustum convex key 11 and the concave key groove body 12.

[0066] A reserved distance L1 is provided between the end face of the axially grooved portion 6 close to the frustum convex key 11 and the end face of the frustum convex key 11.

[0067] In this embodiment, the reserved distance L1 means that the length of the axially grooved portion 6 is less than the length of the exposed section of the steel column body 1. The advantage of this setting method is that it can avoid the formation of the above-mentioned concrete amorphous block p, and specific reference can be made to the appendix Figure 11 and 13 .

[0068] The size of the amorphous concrete block p is much larger than that of the concrete fragments b at the end face of the positioning pipe body, and the former will seriously block the docking distance of the main box girder a at the joint. Under normal circumstances, the above docking distance is generally slightly larger than the distance of 4.0 - 5.0 mm between the frustum convex key 11 and the concave key groove body 12, for example, about 1.0 cm, while the size of the amorphous concrete block p can reach 5 - 10 cm. Therefore, this needs to be avoided, which is also the necessity of the above reserved distance L1.

[0069] The exposed end face of the positioning pipe body 3 has an indentation distance L2 on the end face of the concave key groove body 12 of the main box girder a, and the indentation distance L2 ≥ reserved distance L1.

[0070] In this embodiment, if the above reserved distance L1 is not used in combination with the indentation distance L2, then as shown in the appendix Figure 9 It is shown that it is difficult for the binder to pass through the area on the circumferential surface of the steel column body 1 where the axial slot 6 is not provided. Although the binder can finally be extruded from the positioning pipe body 3, the extrusion action is not continuous, smooth, and gentle enough, and it is easy to form binder spraying at the joint, and even it is easy to spray outside the joint, and finally drop and be lost.

[0071] On the contrary, this is the function of the indentation distance L2, and its size ≥ reserved distance L1, ensuring that there is no position where the inner circumferential surface of the positioning pipe body 3 and the circumferential surface of the steel column body 1 are all precisely engaged in any circumferential direction. Specifically, reference can be made to the appendix Figure 8 .

[0072] In addition, the axial slot 6 can be located above, below, or on the side in the circumferential direction of the steel column body 1.

[0073] The positioning groove 2 is also provided with an annular flared groove 7 located at the indentation distance L2 and used to accommodate the concrete fragments b at the end face of the positioning pipe body.

[0074] In this embodiment, as shown in the appendix Figure 13 It is shown that the convex key template h is provided with a circular hole passing through the steel column body 1. In principle, concrete will also leak at this circular hole, but when the circular hole is opened, its size can be set to be large enough to engage the circumferential surface of the steel column body 1. Therefore, the degree of concrete leakage at this place is relatively small and can be ignored.

[0075] However, the difference is that as shown in the appendix Figure 4 and 12As shown, when the box girder main body a is precast, the positioning pipe body 3 can only abut against the frustum block d and the circular block e, and it is impossible to have high dimensional accuracy at this place. Moreover, after the box girder main body a is precast, both the frustum block d and the circular block e need to be separated from the positioning pipe body 3, and it is impossible to avoid the formation of the concrete fragments b at the end face of the positioning pipe body by means such as using glue.

[0076] Therefore, the fragment formation position g must exist, and the concrete fragments b at the end face of the positioning pipe body will also surely remain. Its remaining position on the end face of the positioning pipe body is uncertain, and its own size is uncertain. However, its size is much smaller than that of the concrete amorphous block p because there is a cylinder f inside the positioning pipe body 3, and the gap between the two can be set to be relatively small, and it can be set that no concrete block will remain at this gap.

[0077] On the other hand, if the binder is not used, the concrete fragments b at the end face of the positioning pipe body are instead harmless. During the long-term use of this segment of the box girder, the frustum convex key 11 can slowly grind it into pieces and make it fall out. However, due to the use and formation of the binder layer 5, the concrete fragments b at the end face of the positioning pipe body are squeezed and rubbed and then fall off, remaining in the binder layer 5 and continuing to be squeezed and rubbed by the frustum convex key 11, and finally will wear and break the binder layer 5. This is the reason for setting the annular flared groove 7.

[0078] At this time, the binder layer 5 forms a thickened layer around at the annular flared groove 7, for example, with a thickness of ≥1.0 cm, so that even if it contains the concrete fragments b at the end face of the positioning pipe body, the frustum convex key 11 is not easy to wear it, so that even if the concrete fragments b at the end face of the positioning pipe body fall off, they will remain at the position of this thickened layer, and the binder layer 5 is not easy to break at this place. For details, please refer to the appendix Figure 15 .

[0079] The binder layer 5 forms a thickened layer at the annular flared groove 7 to prevent the concrete fragments b at the end face of the positioning pipe body from wearing and breaking the binder layer 5.

[0080] In this embodiment, the amount of the concrete fragments b at the end face of the positioning pipe body is relatively small compared to the size of the annular flared groove 7 and will not block the outward extrusion channel of the binder.

[0081] The binder layer 5 can accommodate the concrete fragments b squeezed off by the frustum convex key 11 during and after curing, and the latter is difficult to crush or crack the relatively thick binder layer at this place.

[0082] A construction method of a socket shear key device for a segmental box girder. The overall notch formed by the concave key groove 12, the annular flared groove 7 and the positioning groove 2 is formed by a combined formwork. The structural composition of the combined formwork includes: a formwork main body c, a frustum block d, a circular block e, and a cylinder f. The diameter of the circular block e is larger than the outer diameter of the positioning pipe body 3. The end face of the positioning pipe body 3 abuts against the circular block e, and the concrete fragments b at the end face of the positioning pipe body are formed at the abutting gap.

[0083] In this embodiment, the diameter of the circular block e is larger than the outer diameter of the positioning pipe body 3, and a release agent is provided between the cylinder f and the positioning pipe body 3.

[0084] The embodiments of the present application have been described in detail above in conjunction with the accompanying drawings. However, the present application is not limited to the above embodiments. Within the scope of knowledge possessed by those of ordinary skill in the art, various modifications can be made without departing from the purpose of the present application. These are all non-creative modifications and are protected by the Patent Law as long as they are within the scope of the claims of the present application.

Claims

1. A segment box girder socket shear key device, the structure of which includes a frustum convex key (11) and a concave key groove body (12) respectively arranged at both ends of the box girder main body (a), and is characterized in that: It further includes a steel column body (1) disposed on the box girder main body (a) and the frustum convex key (11) and protruding from the end surface of the frustum convex key (11), a positioning groove (2) disposed inside the concave key groove body (12) and used for installing the steel column body (1), and a positioning pipe body (3) disposed on the positioning groove (2) and used for clamping the steel column body (1).

2. The socket shear key device for segmental box girders according to claim 1, characterized in that: It further includes a sealing end plate (4) disposed on the inner end surface of the positioning pipe body (3) and used for blocking concrete.

3. The segment box girder socket shear key device according to claim 1, characterized in that: It further includes an adhesive layer (5) disposed between the frustum convex key (11) and the concave key groove body (12), and between the positioning pipe body (3) and the steel column body (1).

4. The socket shear key device for segmental box girders according to claim 3, characterized in that: Before the frustum convex key (11) and the concave key groove body (12) are inserted, the adhesive is disposed inside the positioning pipe body (3).

5. The segment box girder socket shear key device according to claim 4, characterized in that: It further includes an axial slotted groove (6) disposed on the exposed section of the steel column body (1) and used for draining the adhesive to the concave key groove body (12).

6. The segment box girder socket shear key device according to claim 5, characterized in that: There is a reserved distance L1 between the end surface of the axial slotted groove (6) close to the frustum convex key (11) and the end surface of the frustum convex key (11).

7. The socket shear key device for segmental box girder according to claim 6, characterized in that: The exposed end surface of the positioning pipe body (3) has an indented distance L2 on the end surface of the concave key groove body (12), and the indented distance L2 ≥ the reserved distance L1.

8. A segmental box girder socket shear key device according to claim 7, characterized in that: The positioning groove (2) is further provided with an annular flared groove (7) located at the indented distance L2 and used for accommodating the concrete debris (b) on the end surface of the positioning pipe body.

9. The segment box girder socket shear key device according to claim 8, characterized in that: The adhesive layer (5) forms a thickened layer at the annular flared groove (7) to prevent the concrete debris (b) on the end surface of the positioning pipe body from wearing and breaking the adhesive layer (5).

10. A construction method of the segment box girder socket shear key device as described in claim 8, characterized in that The overall notch formed by the concave key groove body (12), the annular flared groove (7) and the positioning groove (2) is formed by a combined formwork. The structural composition of the combined formwork includes: a formwork main body (c), a frustum block (d), a circular block body (e), and a cylinder (f). The diameter of the circular block body (e) is larger than the outer diameter of the positioning pipe body (3). The end surface of the positioning pipe body (3) abuts against the circular block body (e), and the concrete debris (b) on the end surface of the positioning pipe body is formed at the abutting gap.

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