Dry type steel bar connector suitable for prefabricated assembly type bridge pier

Abstract

According to the dry type steel bar connector suitable for the prefabricated assembly type pier, the top and the bottom of a connector body are in threaded connection with a top connecting sleeve and a bottom connecting sleeve correspondingly, and an inner limiting protrusion and an outer limiting protrusion are arranged in the middle of the connector body inwards and outwards correspondingly; a top anchoring groove and a bottom anchoring groove are formed in the top and the bottom of the connector body respectively and used for anchoring an upper rib material reserved section and a lower rib material reserved section, and a top supporting ring is arranged between the top of the connector body and the upper rib material reserved section. A bottom supporting ring is arranged between the bottom of the connector main body and the lower rib material reserved section; the connector is used for connection between reserved ribs of adjacent prefabricated parts, in the process that the top connecting sleeve and the bottom connecting sleeve are screwed together, the top end and the bottom end of the connector body with gaps can be locked inwards and reset, the holding force of the connector body on the reserved ribs of the prefabricated parts is enhanced, and the connector body is prevented from being damaged. And the fastening connection between the reserved rib material and the top of the connector main body is realized.

Description

TECHNICAL FIELD

[0001] The utility model belongs to prefabricated bridge technical field, especially relate to a dry -type steel bar connector suitable for prefabricated pier. BACKGROUND

[0002] The prefabricated pier system is an effective way and an important means to realize the "good and fast" requirement of bridge construction in the new era. Compared with the traditional cast-in-place concrete pier, the prefabricated pier system can solve the problem of construction interference near the operating line, improve the quality of the pier column, shorten the on-site construction operation amount, save the construction period, improve the green level of engineering construction, and save the resources of the building industry.

[0003] The existing prefabricated pier column connection methods mainly include grouting sleeve connection, grouting corrugated pipe connection, cast-in-place wet joint connection, and post-tensioned prestressed connection. However, the grouting sleeve connection method cannot fully develop the performance of longitudinal reinforcement, which affects the ductility of the pier column and may cause grouting defects, which affects the connection performance. The grouting corrugated pipe connection has the problems of difficult positioning and easy deformation of the corrugated pipe, which cannot provide sufficient strength. The cast-in-place wet joint has a large amount of on-site pouring work and a long construction period, which has a great impact on the surrounding environment. The post-tensioned prestressed connection cannot balance the energy consumption capacity and self-resetting capacity. These connection methods mainly rely on the bonding effect between grouting material and reinforcement to realize bearing, which has a large construction process difficulty and a long construction period, and the connection quality is uneven. In addition, the prefabricated structure cannot move because the reinforcement is usually embedded in the prefabricated component, which limits the application of mechanical connection in prefabricated structures. For example, the patent application CN116377862B discloses a prefabricated component pier column and cap beam joint test method, which mentions that the ductility at the connection node is poor, and the column cross section is weakened, which affects the strength and stiffness of the prefabricated column. Therefore, how to propose a connection structure suitable for prefabricated pier, which can realize rapid and convenient construction under the premise of ensuring connection strength, is an urgent problem to be solved. SUMMARY

[0004] In order to overcome the defects of the above-mentioned prior art, the purpose of the utility model is to provide a dry-type steel bar connector suitable for prefabricated pier, which solves the problems of large construction difficulty and long construction period of the existing prefabricated pier connection section.

[0005] To solve the above problems, the technical scheme adopted by the utility model is:

[0006] A dry type steel bar connector suitable for prefabricated assembly bridge pier, comprising a connector main body 1, a top connector sleeve 2 and a bottom connector sleeve 4 are threadedly connected to the top and bottom of the connector main body 1 respectively, an internal limiting protrusion 1-1 and an external limiting protrusion 1-2 are arranged inward and outward in the middle of the connector main body 1 respectively, a top anchoring groove 1-3 and a bottom anchoring groove 1-4 are arranged on the top and bottom of the connector main body 1 respectively for anchoring an upper bar reserved section 6 and a lower bar reserved section 7, a top supporting ring 3 is arranged between the top of the connector main body 1 and the upper bar reserved section 6, and a bottom supporting ring 5 is arranged between the bottom of the connector main body 1 and the lower bar reserved section 7.

[0007] The top and bottom of the connector main body 1 are provided with external threads, the top connector sleeve 2 and the bottom connector sleeve 4 each include a large-diameter end and a small-diameter end, the large-diameter end is provided with internal threads and is connected to the external threads of the top and bottom of the connector main body 1, and the inner diameter of the small-diameter end is matched with the outer diameter of the upper bar reserved section 6 and the lower bar reserved section 7.

[0008] The depth of the top anchoring groove 1-3 is greater than the anchoring length of the upper bar reserved section 6, and the depth of the bottom anchoring groove 1-4 is greater than the anchoring length of the lower bar reserved section 7.

[0009] The upper bar reserved section 6 and the lower bar reserved section 7 are each made of ordinary steel bars or shape memory alloy materials.

[0010] The top and bottom of the connector main body 1 are each provided with a plurality of non-penetrating axial fine slits 1-5, the inner surfaces of the top end and the bottom end of the connector main body 1 are each outwardly expanded, the top supporting ring 3 and the bottom supporting ring 5 are each hollow and circularly tapered, and the outer surfaces of the top supporting ring 3 and the bottom supporting ring 5 are respectively matched with the inner surfaces of the top end and the bottom end of the connector main body 1.

[0011] The surfaces of the upper bar reserved section 6 and the lower bar reserved section 7 are each provided with an annular groove 11, the inner surfaces of the top supporting ring 3 and the bottom supporting ring 5 are each provided with a protrusion 8 matched with the annular groove 11, and the protrusion 8 is embedded in the annular groove 11; the outer surfaces of the top supporting ring 3 and the bottom supporting ring 5 are each provided with an axial groove 9, and the opposite surface of the axial groove 9 is provided with a broken gap 10.

[0012] The threadedly connected length of the top connector sleeve 2 and the bottom connector sleeve 4 in the connector main body 1 needs to meet:

[0013]

[0014] Wherein,

[0015] A t= 0.785(d - 0.94P) 2

[0016] E s,min = d - 0.65P

[0017] K n,max = d - 1.08P

[0018] In the formula, L an is the anchoring length, d is the diameter of the reinforcement, and P is the thread pitch; A t is the equivalent area corresponding to the thread pitch diameter, E s,min is the elastic modulus of the thread material, K n,max is the thread minor diameter.

[0019] Compared with the prior art, the beneficial effects of the utility model are:

[0020] (1) The plurality of gaps provided at the end of the connector body can ensure that the prefabricated segment with the reserved reinforcement has sufficient error allowance during installation. During the screwing of the top connecting sleeve and the bottom connecting sleeve, the top end and the bottom end of the connector body with the gaps can be tightly returned inward, thereby enhancing the holding force of the reinforcement. Meanwhile, the screwing of the top connecting sleeve and the bottom connecting sleeve also exerts pressure on the support ring, and the wedge-shaped support ring and the reinforcement embedded in the support ring are continuously anchored into the top groove and the bottom groove of the connector body under the pressure, so that the fastening connection between the reserved reinforcement and the top of the connector body is finally realized.

[0021] (2) When connecting the reserved reinforcements of adjacent prefabricated components, the weight of the hoisted upper prefabricated component can be used to provide the force for inserting the reserved reinforcement into the connector, so that the construction is convenient and fast, and the construction efficiency can be greatly improved under the premise of ensuring excellent connection performance.

[0022] In summary, the connector proposed in the utility model can generate sufficient extrusion force in the body to ensure the connection performance of the reinforcement in the connector. The end of the connector body is enlarged, cooperates with the wedge-shaped support ring, and the support ring is embedded and force-transferring with the reinforcement through the protrusion and the groove. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a specific structural schematic view of the reinforcement connector of the utility model.

[0024] Figure 2 is a structural schematic view of the connector body of the utility model.

[0025] Figure 3 is a structural schematic view of the support ring of the utility model.

[0026] Figure 4is the axial pull test of the connector and the corresponding steel bar raw material pull test results schematic diagram.

[0027] Figure 5 is the comparison diagram of the stress-strain relationship curve of the connector calculated according to the theoretical formula and the test value.

[0028] Figure 6 is the finite element analysis stress nephogram of the connector under different groove depths, wherein, Figure 6 (a) in is the connector with a groove depth of 1mm; (b) is the connector with a groove depth of 2mm.

[0029] Figure 7 is the comparison diagram of the stress-strain relationship curve simulation value of the connector under different groove depths.

[0030] Figure 8 is the finite element analysis stress nephogram of the connector under different groove types, wherein, Figure 8 (a) in is the connector with a ring groove type; (b) is the connector with a half groove type.

[0031] Figure 9 is the comparison diagram of the stress-strain relationship curve simulation value of the connector under different groove types.

[0032] In the figure: 1. connector body; 2. top connecting sleeve; 3. top support ring; 4. bottom connecting sleeve; 5. bottom support ring; 6. upper reserved section of reinforcing bar; 7. lower reserved section of reinforcing bar; 8. protrusion; 9. axial groove; 10. disconnection gap; 11. ring groove; 1-1. internal limiting protrusion; 1-2. external limiting protrusion; 1-3. top anchoring groove; 1-4. bottom anchoring groove; 1-5. axial fine slit. DETAILED DESCRIPTION

[0033] The utility model will be explained in detail below in combination with the drawings and specific embodiments.

[0034] As Figure 1As shown, a dry steel bar connector suitable for prefabricated assembly pier, including connector body 1, top connecting sleeve 2, top support ring 3, bottom connecting sleeve 4 and bottom support ring 5, the connector body 1 middle part inward and outward respectively set internal limiting convex 1-1 and external limiting convex 1-2, the connector body 1 top and bottom respectively set top anchoring groove 1-3 and bottom anchoring groove 1-4 for anchoring upper bar reserved section 6 and lower bar reserved section 7, the connector body 1 top and the upper bar reserved section 6 between set the top support ring 3, the connector body 1 bottom and the lower bar reserved section 7 between set the bottom support ring 5;The connector body 1 top and the top connecting sleeve 2, the connector body 1 bottom and the bottom connecting sleeve 4 between using threaded connection, the connector body 1 top and the upper bar reserved section 6, the connector body 1 bottom and the lower bar reserved section 7 respectively through the top support ring 3 and the bottom support ring 5 realize fixed connection.The connector body 1 top and bottom are all set external thread, the top connecting sleeve 2 and the bottom connecting sleeve 4 all contain large diameter end and small diameter end, large diameter end is provided with internal thread, is used for with the connector body 1 top and bottom threaded connection, small diameter end inner diameter is compatible with the upper bar reserved section 6 and the lower bar reserved section 7 outer diameter.The top anchoring groove 1-3 depth is greater than the anchoring length of the upper bar reserved section 6, the bottom anchoring groove 1-4 depth is greater than the anchoring length of the lower bar reserved section 7.The upper bar reserved section 6 and the lower bar reserved section 7 are made of ordinary steel bar and shape memory alloy material.

[0035] As Figure 2 And Figure 3 As shown, the connector body 1 top and bottom are all set several not through axial fine slit 1-5, the connector body 1 top end inner surface and bottom end inner surface are all outwardly expanded, the top support ring 3 and the bottom support ring 5 are all hollow inverted circular table shape, and the top support ring 3 outer surface and the bottom support ring 5 outer surface are respectively matched with the connector body 1 top end inner surface and bottom end inner surface;The upper bar reserved section 6 and the lower bar reserved section 7 surface are all provided with annular groove 11, the top support ring 3 inner surface and the bottom support ring 5 inner surface are all provided with convex 8 matched with the annular groove 11, embedded in the annular groove 11;The top support ring 3 and the bottom support ring 5 outer surface are all provided with axial groove 9, and the opposite surface is provided with broken gap 10.The meshing length calculation formula of the top connecting sleeve 2 and the bottom connecting sleeve 4 in the connector body 1 is as follows:

[0036]

[0037] in,

[0038] A t =0.785(d-0.94P) 2

[0039] E s,min =d-0.65P

[0040] K n,max =d-1.08P

[0041] In the formula, L an d is the anchorage length, d is the diameter of the reinforcing bar, and P is the thread pitch.

[0042] The working principle of this utility model is as follows: This utility model is used for the connection between the reserved reinforcing bars of adjacent precast components, such as... Figure 1 As shown, for anchoring the upper rib reserved section 6 and the lower rib reserved section 7, several non-through axial slits 1-5 are opened at the top and bottom of the connector body 1 to ensure that the upper rib reserved section 6 or the lower rib reserved section 7 has sufficient error margin during installation. During the process of screwing the top connecting sleeve 2 and the bottom connecting sleeve 4, the top and bottom ends of the connector body with gaps can be tightened and returned to their original positions, enhancing its clamping force on the reserved ribs of the prefabricated components. At the same time, the screwed top connecting sleeve and the bottom connecting sleeve will also apply pressure to the support ring. Utilizing the wedge shape of the support ring, the support ring and the ribs embedded with it are continuously anchored into the top and bottom grooves of the connector body under this pressure, ultimately achieving a tight connection between the reserved ribs and the top of the connector body.

[0043] See Figure 4 A comparison of the axial pull-out test results of the connector and the corresponding pull-out test results of the original steel bar shows that, in terms of strength, the yield strength of the connector is slightly higher than that of the original steel bar, while the ultimate strength is comparable to that of the original steel bar. In terms of deformation, since the parts in the connector are in dry contact, there are gaps. In the early stage of tension, oscillations occur as the parts automatically integrate to eliminate the gaps, which also leads to greater slippage of the connector than that of the original steel bar in the early stage of tension. After the connector enters the plastic stage, the deformation is less than that of the original steel bar, and the ductility is slightly inferior to that of the original steel bar.

[0044] A comparison between the connector stress-strain relationship curve calculated using this theoretical formula and the experimental values ​​can be found in [reference needed]. Figure 5 In the elastic stage, the theoretical formula did not consider the displacement caused by the gaps between the connector components, resulting in the theoretical results showing a higher stiffness in the elastic segment than the experimental value, and a lower total displacement than the experimental value. The error value is acceptable. Overall, it can be seen that the theoretical model proposed in this application fits the experimental values ​​well.

[0045] To explore the optimal parameters, finite element calculation and analysis were carried out for 12 mm diameter HRB400 steel and 16 mm diameter HRB400 steel with different groove depths and different groove types, as shown in Figure 6 , Figure 7 , Figure 8 and Figure 9 . The results show that the connector failure occurs on the steel bar and is located outside the groove, because the clamping force generated by the support ring on the steel bar groove part can make up for the weakening effect of the steel bar caused by the groove. Through calculation, it is known that the bearing capacity of 2 mm groove depth is reduced by 11.5% compared with 1 mm groove depth, and the displacement ductility capacity is reduced by 29.1%, so the steel bar groove depth parameter is optimized to 1 mm groove depth; for the two groove forms of ring groove and half groove, the calculation and analysis show that the bearing capacity and deformation capacity of the two are similar, and the half groove form is slightly better than the ring groove form, which is specifically manifested as: the bearing capacity of the half groove form connector is increased by 11.1% compared with the ring groove form connector, and the displacement ductility capacity is increased by 15.2%, so the steel bar groove form parameter is optimized to the half groove form.

Claims

1. A dry bar coupler suitable for use in precast fabricated bridge piers comprising a coupler body (1) characterised in that, The connector body (1) top and bottom are respectively connected with top connecting sleeve (2), bottom connecting sleeve (4) by screw thread connection, the middle part of the connector body (1) is provided with internal limiting protrusion (1-1) and external limiting protrusion (1-2) respectively, the top and bottom of the connector body (1) are provided with top anchoring groove (1-3) and bottom anchoring groove (1-4) respectively for anchoring upper reinforcement reserved section (6) and lower reinforcement reserved section (7), the top of the connector body (1) is provided with top support ring (3) between the upper reinforcement reserved section (6), the bottom of the connector body (1) is provided with bottom support ring (5) between the lower reinforcement reserved section (7).

2. A dry bar coupler for use in a precast segmental bridge pier according to claim 1, wherein The top and bottom of the connector body (1) are provided with external threads, the top connecting sleeve (2) and the bottom connecting sleeve (4) both contain large diameter end and small diameter end, the large diameter end is provided with internal thread, and is connected with the external threads of the top and bottom of the connector body (1); the inner diameter of the small diameter end is matched with the outer diameter of the upper reinforcement reserved section (6) and the lower reinforcement reserved section (7).

3. The dry bar coupler for use in the prefabricated pier according to claim 1, wherein The depth of the top anchoring groove (1-3) is greater than the anchoring length of the upper reinforcement reserved section (6), and the depth of the bottom anchoring groove (1-4) is greater than the anchoring length of the lower reinforcement reserved section (7).

4. The dry bar coupler for use in the prefabricated pier according to claim 1, wherein, The upper reinforcement reserved section (6) and the lower reinforcement reserved section (7) are made of ordinary steel shape memory alloy material.

5. The dry bar coupler for use in the prefabricated pier according to claim 1, wherein The top and bottom of the connector body (1) are provided with several non-through axial fine slits (1-5), the inner surface of the top end of the connector body (1) and the inner surface of the bottom end are both outwardly expanded, the top support ring (3) and the bottom support ring (5) are both hollow inverted circular table, and the outer surface of the top support ring (3) and the outer surface of the bottom support ring (5) are respectively matched with the inner surface of the top end of the connector body (1) and the inner surface of the bottom end.

6. A dry bar coupler for use in a precast segmental bridge pier according to claim 1, wherein The upper reinforcement reserved section (6) and the lower reinforcement reserved section (7) are both provided with annular groove (11), the inner surface of the top support ring (3) and the inner surface of the bottom support ring (5) are both provided with protrusion (8) matched with the annular groove (11), and the protrusion (8) is embedded in the annular groove (11); the outer surface of the top support ring (3) and the bottom support ring (5) are both provided with axial groove (9), and the opposite surface of the axial groove (9) is provided with disconnected gap (10).

7. A dry bar coupler for use in a precast segmental bridge pier according to claim 1, wherein The screw thread connection length of the top connecting sleeve (2) and the bottom connecting sleeve (4) in the connector body (1) needs to meet: Wherein, A t = 0.785(d - 0.94P) 2 E s,min = d - 0.65P K n,max = d - 1.08P In the formula, L an is the anchorage length, d is the diameter of the reinforcement, and P is the thread pitch; A t is the equivalent area corresponding to the thread pitch diameter, E s,min is the elastic modulus of the thread material, and K n,max is the thread minor diameter.

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