CN219410523U - Large-diameter steel bar self-locking anchorage device pre-buried in bearing platform and prefabricated pier - Google Patents

Abstract

The utility model relates to a self-locking anchorage of large-diameter steel bars pre-buried in the bearing platform. The lower end of the large-diameter steel bar is anchored, and the lower end of the large-diameter steel bar is sleeved with a steel backing plate. The self-locking anchorage includes an annular frame, bayonets, springs, and protective covers; the circular inner wall of the annular frame is provided with a plurality of retreat grooves arranged in the circumferential direction, and the retreat grooves, springs, and bayonet pins are set in one-to-one correspondence; The groove bottoms of the retraction grooves are connected, and the bayonet slides radially along the retraction groove, and retreats into the retraction groove under the action of an external force for the steel backing plate to pass through, and stretches out to the self-locking state under the action of the spring force to prevent the steel backing plate from being pulled out; the ring frame is arranged in the protective cover. Prefabricated piers are also involved. The utility model has the advantages of simple structure and convenient operation, and belongs to the technical field of prefabricated bridge piers.

Description

Large-diameter self-locking anchors and prefabricated bridge piers embedded in caps

technical field

The utility model relates to the technology of prefabricated bridge piers, in particular to a large-diameter steel bar self-locking anchor which is pre-buried in the bearing platform, and also relates to a prefabricated bridge pier adopting the self-locking anchor.

Background technique

The traditional bridge pier construction mostly adopts the method of on-site integral pouring, which has a long construction period and is likely to cause traffic congestion and environmental pollution on the site. In recent years, due to the guaranteed quality of prefabricated components, on-site construction operations are reduced, and the impact on the environment is small. It meets the development planning requirements of my country's "double carbon" goal of the construction industry, and has broad application prospects in bridge construction.

The prefabricated bridge pier is formed by dividing the whole pier (mainly including the cap, pier body, and cover beam) into several components, which are prefabricated separately and then spliced on site. The connection between components is the most critical factor affecting the overall stress and seismic performance of prefabricated piers. At present, the most commonly used method in engineering is grouting sleeve connection. The sleeve is pre-embedded inside the pier column, and the steel bars of each component are inserted into the sleeve during splicing, and then grouting is performed from the reserved nozzle. In actual engineering, the number of longitudinal steel bars in the pier column is large, and the accuracy of the alignment with the sleeve is high, so the construction is difficult; the steel bars between the components are not connected, and the force transmission is completed by the bonding force between the grouting material and the steel bar. However, the sleeve is a concealed project. If the grout leaks or the grouting is not enough, it is likely to cause safety hazards.

Some scholars have proposed to use prestressed tendons for the connection of prefabricated piers. The prestressed connection method can increase the self-resetting ability of the pier, which is very beneficial to the seismic performance of the pier. However, the anchorage of prestressed tendons is a technical difficulty. The traditional prestressed anchors need to use clips and apply mechanical force for anchoring, which is difficult to implement in prefabricated piers. Therefore, convenient and reliable anchoring devices suitable for prefabricated piers are in urgent need of research and development.

Utility model content

Aiming at the technical problems existing in the prior art, the purpose of this utility model is to provide a self-locking anchorage for large-diameter steel bars pre-buried in the cap, which can be used for anchoring steel bars connecting assembled bridge piers.

Another purpose of the utility model is to provide a prefabricated bridge pier, which is connected by large-diameter steel bars on the basis of self-locking anchors, which is easy to assemble and has better overall stress performance.

In order to achieve the above object, the utility model adopts the following technical solutions:

The self-locking anchorage of large-diameter steel bar embedded in the platform cap anchors the lower end of the large-diameter steel bar, and the lower end of the large-diameter steel bar is sleeved with a steel backing plate; the self-locking anchorage includes a ring frame, a bayonet, a spring, and a protective cover; the circular inner wall of the ring frame is provided with a plurality of retreat grooves arranged in the circumferential direction, and the retreat grooves, springs, and bayonet pins are set in one-to-one correspondence; the inner side of the upper end of the bayonet is provided with an inclined part that withstands external forces, and the slope is inclined from the inner bottom to the outer top; the outer side of the bayonet passes through the spring and the back groove The bottom of the groove is connected, the bayonet slides radially along the retraction groove, retreats into the retraction groove under the action of external force for the steel backing plate to pass through, and stretches out to the self-locking state under the action of the spring force to prevent the steel backing plate from being pulled out; the ring frame is set in the protective cover.

As a preference, the number of bayonet pins is at least four, and the circumference is evenly distributed on the plane; the steel backing plate is a circular steel backing plate, which is welded or screwed in and fixed on the lower end of the large-diameter steel bar.

As a preference, the protective cover wraps the entire bottom and the entire side of the annular frame, wraps the top outside of the annular frame, and an opening is provided on the inner side of the upper end of the protective cover, and the position of the opening corresponds to the position of the annular inner wall of the annular frame.

Prefabricated bridge piers include caps, prefabricated pier bodies, prefabricated cap beams, ordinary steel bars, grouting materials, and ordinary steel bars are arranged in prefabricated pier bodies; prefabricated bridge piers also include large-diameter steel bars, steel backing plates, nuts, bellows and self-locking anchors; bellows include diameters of D₁The bellows I and the diameter D₂Bellows II, D₂greater than D₁The corrugated pipe I is set in the prefabricated pier body and prefabricated cap beam, and the corrugated pipe II is arranged in the cap; the self-locking anchorage is buried under the corrugated pipe II in the cap; the large-diameter steel bar passes through the cap, the prefabricated pier body, and the bellows in the prefabricated cap beam to connect the cap, the prefabricated pier body and the prefabricated cap beam, and the upper end of the large-diameter steel bar is connected with a nut to anchor the upper end of the large-diameter steel bar; the grouting material is filled in the bellows.

As a preference, the outer diameter of the steel backing plate is smaller than D ₂ , so that the steel backing plate can pass through the bellows II.

As a preference, the lower end of the bellows II is in contact with the opening of the protective cover, and the seam connection is sealed.

As a preference, there are multiple large-diameter steel bars arranged around the prefabricated pier body, and at least one large-diameter steel bar is arranged at each corner of the prefabricated pier body.

As a preference, the prefabricated pier body adopts one-section prefabrication or segmental prefabrication; during segmental prefabrication, bellows I are arranged in each prefabricated pier body, and large-diameter steel bars pass through each segment of bellows I to connect each segment of the prefabricated pier body.

As a preference, the large-diameter steel bar is a one-stage structure or a multi-stage structure; when a multi-stage structure is adopted, each large-diameter steel bar is connected by a sleeve connector, and threaded sections are arranged at both ends of each large-diameter steel bar.

As a preference, shallow grooves are arranged on the top of the prefabricated cover beam, and the nuts are located in the shallow grooves.

The principle of this practical new type is: the self -locking anchor fixture designed in Chengtai, which is convenient to operate, and realizes the anchor of the large diameter reinforced end. Under the premise of using a self -locking anchor, the large diameter steel bars can be used to connect the prefabricated pier body and the prefabricated cover beam to form a overall force of each component of the assembly pier; apply prestressed stress on the large diameter steel bars to increase the pier pier Seismic performance of the column; use the high strength and large area of large diameter steel bars to reduce the number of holes reserved for stitching in the components for easy construction.

The utility model has the following advantages:

1. The self-locking anchor has a simple structure and is easy to operate. It is pre-buried behind the cap and is suitable for fabricated bridge piers, providing the possibility to use large-diameter steel bars for connection.

2. Large-diameter steel bars are used to run through the entire bridge pier structure, and the independently produced caps, pier columns and cover beams are connected into a system to achieve the purpose of overall force bearing.

3. Utilizing the high strength and large area of large-diameter steel bars, compared with ordinary stressed steel bars, the number of steel bars is reduced under the same stress, thereby reducing the number of preset holes in each component, and the splicing construction is simple and fast.

4. Use self-locking anchors to achieve anchorage to the ends of large-diameter steel bars; apply prestress to large-diameter steel bars to improve the crack resistance of bridge piers, enhance the self-resetting ability of pier tops, and improve the seismic performance of pier columns.

5. The self-locking anchorage is pre-embedded in the cap, and the large-diameter steel bar is directly inserted to realize self-locking and reliable anchoring, which reduces the construction difficulty of prestressed tendon penetration and speeds up construction efficiency.

Description of drawings

Fig. 1 is a schematic elevation view of a prefabricated bridge pier connected by self-locking large-diameter steel bars.

Fig. 2 is a sectional view of the prefabricated pier A-A in Fig. 1 .

Fig. 3 is a partially enlarged elevation view of the connection between the self-locking anchorage and the large-diameter steel bar at B in Fig. 1 .

Fig. 4 is a partially enlarged top view of the connection between the self-locking anchorage and the large-diameter steel bar at B in Fig. 3 .

Fig. 5 is a schematic diagram of the components of the prefabricated bridge pier before assembly.

Fig. 6 is a structural elevation view of the self-locking anchor.

Fig. 7 is a top view of the structure of the self-locking anchor in Fig. 6 .

1 is cap, 2 is prefabricated pier body, 3 is prefabricated cover beam, 4 is self-locking anchor, 5 is large-diameter steel bar, 6 is nut, 7 is ordinary steel bar, 8 is bellows I, 9 is bellows II, 10 is grouting material, 11 is grouting hole, 12 is shallow groove, 13 is ring frame, 14 is bayonet pin, 15 is spring, 16 is protective cover, 17 is steel backing plate, 18 is retreat groove, and 19 is inclined part .

Detailed ways

The utility model will be described in further detail below in conjunction with specific embodiments.

Embodiment one

The self-locking anchorage of large-diameter steel bar embedded in the platform cap anchors the lower end of the large-diameter steel bar, and the lower end of the large-diameter steel bar is sleeved with a steel backing plate; the self-locking anchorage includes a ring frame, a bayonet, a spring, and a protective cover; the circular inner wall of the ring frame is provided with a plurality of retreat grooves arranged in the circumferential direction, and the retreat grooves, springs, and bayonet pins are set in one-to-one correspondence; the inner side of the upper end of the bayonet is provided with an inclined part that withstands external forces, and the slope is inclined from the inner bottom to the outer top; the outer side of the bayonet passes through the spring and the back groove The bottom of the groove is connected, the bayonet slides radially along the retraction groove, retreats into the retraction groove under the action of external force for the steel backing plate to pass through, and stretches out to the self-locking state under the action of the spring force to prevent the steel backing plate from being pulled out; the ring frame is set in the protective cover.

The number of bayonet pins is at least four, and the circumference is evenly distributed on the plane; the steel backing plate is a circular steel backing plate, which is welded or screwed in and fixed on the lower end of the large-diameter steel bar. There are four in the present embodiment, and the connection mode is welding.

The protective cover wraps the entire bottom and the entire side of the annular frame, and wraps the top outside of the annular frame. An opening is provided on the inner side of the upper end of the protective cover. The position of the opening corresponds to the position of the annular inner wall of the annular frame. Set up a protective cover to prevent the concrete of the cap from entering the self-locking anchor, which will affect the normal operation of the anchor.

The operation method is as follows:

The large-diameter steel bar and the steel backing plate are inserted into the self-locking anchorage. First, the end of the large-diameter steel bar penetrates between the four bayonet pins. With the downward pressure of the large-diameter steel bar, the steel backing plate presses down on the inclined part of the bayonet pin. Under the action of the inclined part, the downward pressure is transformed into a radially outward force. Anchorage at the lower end of the bar.

Embodiment two

Prefabricated bridge piers include caps, prefabricated pier bodies (also known as prefabricated pier columns), prefabricated cap beams, ordinary steel bars, grouting materials, and ordinary steel bars are set in prefabricated pier bodies; prefabricated bridge piers also include large-diameter steel bars, steel backing plates, nuts, bellows and self-locking anchors; bellows include D₁The bellows I and the diameter D₂Bellows II, D₂greater than D₁The corrugated pipe I is set in the prefabricated pier body and the prefabricated cap beam, and the bellows II is set in the cap; the self-locking anchorage is buried under the corrugated pipe II in the cap; the large-diameter steel bar passes through the cap, the prefabricated pier body, and the bellows in the prefabricated cap beam to connect the cap, the prefabricated pier body and the prefabricated cap beam, and the upper end of the large-diameter steel bar is tensioned by a jack, and the nut is tightened to maintain the applied pre-tightening force; The grouting material is injected upwards to fill the bellows.

The longitudinal reinforcement of prefabricated pier columns includes two parts: large-diameter steel bars and ordinary steel bars, with diameters d ₁ and d ₂ respectively. Among them, large-diameter steel bars are arranged around the pier column. The number depends on the force of the pier column. At least one piece is arranged at the corner of the pier column; large-diameter steel bars should be high-strength steel bars above HRB500, or finish-rolled rebar, and the diameter d ₁ is 32 ~ 50mm; , when the multi-section structure is adopted, the large-diameter steel bars of each section are connected by sleeve connectors. In order to facilitate the connection, threaded sections are set at both ends of each large-diameter steel bar.

When the pier column is prefabricated, a bellows I with a diameter of D ₁ is pre-embedded at the position of the large-diameter steel bar, and the bellows at the bottom of the pier column protrude to a certain length (L≥100mm), so as to be socketed with the bellows of the cap. Ordinary longitudinal reinforcements are evenly arranged around the pier columns, mainly for crack resistance. The grade should be HRB400, and the diameter d ₂ ≤ 25mm. The design and fabrication requirements of the ordinary longitudinal reinforcement and stirrup of the pier column are the same as those of the conventional pier column. The prefabricated pier body adopts one-section prefabrication or segmental prefabrication; when the pier column is high, when segmental prefabrication is adopted, bellows I are installed in each prefabricated pier body, and large-diameter steel bars pass through each segment of bellows I to connect each segment of the prefabricated pier body.

When the cap is poured, the corrugated pipe II corresponding to the large-diameter steel bar of the pier column and the self-locking anchorage are pre-embedded inside the cap, and the self-locking anchorage is located at the bottom of the bellows II. The diameter _D2 of the bellows II in the cap is larger than the diameter _D1 of the bellows I in the pier column. In order to prevent blockage caused by the inflow of cement slurry during concrete pouring of the cap, the top surface of the bellows is higher than the surface of the cap, and the nozzle is temporarily closed; the lower end of the bellows II is connected to the protective cover, and the joint joints are sealed to prevent blockage caused by the inflow of grout during concrete pouring of the cap.

When the cover beam is prefabricated, the bellows I corresponding to the large-diameter steel bar of the pier column are pre-embedded, and the bellows I run through the cover beam, and the diameter of the bellows I is D ₁ . The top of the prefabricated cap beam is provided with a shallow groove, and the nut is located in the shallow groove, and the nut is tightened after the large-diameter steel bar is tensioned to maintain the applied pre-tightening force.

The number of pre-embedded bellows in caps, prefabricated pier columns, and prefabricated cap beams is the same as the number of large-diameter steel bars, and the positions are one-to _{- one} correspondence. Among them, the prefabricated cap beam is the same as the bellows I in the prefabricated pier columns.

钢垫板套接固定在大直径钢筋的下端，钢垫板的外径小于D ₂ ；自锁式锚具包括环形框架、卡销、弹簧、保护罩，环形框架的圆环形内壁设有多个周向排列的、容纳卡销的回退槽；回退槽、弹簧、卡销一一对应设置；卡销通过弹簧连接在回退槽中，卡销在弹簧的作用下从回退槽中伸出，在外力的作用下回退入回退槽；卡销的内侧上端设置从内下方往外上方倾斜的倾斜部，倾斜部作为承受钢垫板下压力的受力面；环形框架设置在保护罩内。 There are four bayonet pins arranged in a cross shape on a plane. Pass the large-diameter steel bar through the pre-embedded corrugated pipe Ⅰ in the pier column, protrude from the bottom of the pier column, install the circular steel backing plate, insert it into the anchorage along the pre-embedded bellows Ⅱ in the cap, and lock the steel backing plate at the end of the steel bar through the spring clip to achieve the purpose of self-locking; when prestress is applied to the top of the large-diameter steel bar, no upward displacement will occur to achieve the anchoring effect. The working mechanism of the self-locking prestressed anchor is that as the large-diameter steel bar is inserted, the circular steel backing plate at the end pushes the bayonet pin, and the spring inside the anchor retracts, and the bayonet pin also retracts with the spring, so that the steel backing plate and the steel bar can pass through smoothly. After the steel bar passes through the anchor, the spring drives the bayonet pin to reset, and the bayonet pin plays the role of anchoring the large-diameter steel bar after being reset. The size of the self-locking anchor needs to be determined according to the prestress applied to the large-diameter steel bar, so as to ensure that the steel backing plate can be stuck and not pulled out during the prestressing process.

The above-mentioned embodiment is the preferred implementation of the present utility model, but the implementation of the present utility model is not limited by the above-mentioned embodiment, and any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present utility model, all should be equivalent replacement methods, and are all included within the protection scope of the present utility model.

Claims (10)

1. The large-diameter steel self-locking anchorage embedded in the cap, anchors the lower end of the large-diameter steel bar, and the lower end of the large-diameter steel bar is sleeved with a steel backing plate. It is characterized in that: the self-locking anchor includes a ring frame, a bayonet pin, a spring, and a protective cover; the circular inner wall of the ring frame is provided with a plurality of circumferentially arranged retraction grooves, and the retraction grooves, springs, and bayonet pins are set in one-to-one correspondence; The spring is connected to the groove bottom of the retraction groove, and the bayonet slides radially along the retraction groove. Under the action of external force, it retreats into the retraction groove for the steel backing plate to pass through. 2. The large-diameter self-locking anchorage pre-embedded in the cap according to claim 1, characterized in that: the number of bayonet pins is at least four, and the circumference is evenly distributed on the plane; the steel backing plate is a circular steel backing plate, which is welded or screwed in and fixed on the lower end of the large-diameter steel bar. 3. The large-diameter self-locking steel anchor pre-embedded in the cap according to claim 1, characterized in that: the protective cover wraps the entire bottom and the entire side of the annular frame, wraps the top outside of the annular frame, and an opening is provided on the inner side of the upper end of the protective cover, and the position of the opening corresponds to the position of the circular inner wall of the annular frame. 4. Prefabricated bridge piers, including caps, prefabricated pier bodies, prefabricated cap beams, ordinary steel bars, and grouting materials, and ordinary steel bars are arranged in the prefabricated pier bodies.₁The bellows I and the diameter D₂Bellows II, D₂greater than D₁The corrugated pipe I is set in the prefabricated pier body and the prefabricated cap beam, and the bellows II is set in the cap; the self-locking anchorage is buried under the bellows II in the cap; the large-diameter steel bar passes through the cap, the prefabricated pier body, and the bellows in the prefabricated cap beam to connect the cap, the prefabricated pier body and the prefabricated cap beam, and the upper end of the large-diameter steel bar is connected with a nut to anchor the upper end of the large-diameter steel bar; the grouting material is filled in the bellows. 5. The prefabricated bridge pier according to claim 4, wherein the outer diameter of the steel backing plate is smaller than D ₂ , so that the steel backing plate can pass through the bellows II. 6. The prefabricated bridge pier according to claim 4, characterized in that: the lower end of the bellows II is in contact with the opening of the protective cover, and the seam connection is sealed. 7. The prefabricated bridge pier according to claim 4, characterized in that there are multiple large-diameter steel bars arranged around the prefabricated pier body, and at least one large-diameter steel bar is arranged at each corner of the prefabricated pier body. 8. The prefabricated bridge pier according to claim 4, characterized in that: the prefabricated pier body adopts one-section prefabrication or prefabricated in sections; when prefabricated in sections, each section of the prefabricated pier body is provided with bellows I, and the large-diameter steel bars pass through the corrugated pipes I of each section to connect each section of the prefabricated pier body. 9. The prefabricated bridge pier according to claim 4, characterized in that: the large-diameter steel bar is a one-stage structure or a multi-stage structure; when a multi-stage structure is adopted, each large-diameter steel bar is connected by a sleeve connector, and threaded sections are arranged at both ends of each large-diameter steel bar. 10. The prefabricated bridge pier according to claim 4, wherein a shallow groove is arranged on the top of the prefabricated cap beam, and the nut is located in the shallow groove.