Segmented hollow thin-wall pier column cast-in-place reinforced butt joint structure and construction method thereof
By designing a solid end and beveled edge at the top of the bottom pier, combined with grouting technology, the problems of small joint surface and poor joint sealing of hollow thin-walled piers were solved, achieving a joint effect with good firmness, fast construction, and high safety and efficiency.
Patent Information
- Application Number
- CN202511670136.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-14
- Publication Date
- 2026-01-13
AI Technical Summary
In the existing technology, the upper and lower joints of segmented hollow thin-walled piers have problems such as small solid joint surface, poor sealing of joints, uneven bearing of upper pressure, many cracks at the joint, and poor firmness. Moreover, the construction is difficult, especially the safety is insufficient when working at height.
The design adopts a solid end and beveled edge at the top of the bottom pier column. Grouting is carried out at the joint to form an inverted trapezoidal tenon and mortise interlocking connection, which expands the solid joint surface. The connection is made by horizontal and vertical steel bars to ensure that the grout seals the joint and enhances the firmness.
It achieves expanded solid joint surface, full and crack-free grouting, uniform bearing of upper pressure, good firmness, fast construction speed, high efficiency, low cost, high safety, and excellent construction quality.
Smart Images
Figure CN121321484A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a reinforced joint structure for segmented hollow thin-walled piers, specifically a cast-in-place reinforced joint structure for segmented hollow thin-walled piers and its construction method. Background Technology
[0002] Small-sized hollow piers (usually referring to those with smaller cross-sectional dimensions, less than 2.5×2.5m) are widely used in bridge engineering, commonly found in viaducts, interchanges, and mountainous highways. For example, the G1816 Wuma Expressway Hesai is located in Gannan Tibetan Autonomous Prefecture, at an altitude of 3100-3600m, in a remote and complex mountainous area. Part of the structure of the Laikuhe No. 2 Bridge could only be prefabricated and installed on-site. A total of 94 piers were prefabricated on-site, with dimensions of 1.4×1.4m and 1.6×1.6m, a wall thickness of 32cm, and heights ranging from 24 to 36m to 28m. These piers were constructed by connecting 2-3 sections of prefabricated piers, each 12-14m long, and were all small-sized hollow pier structures.
[0003] Connecting two adjacent precast hollow piers vertically in mid-air presents a construction challenge. Currently, both the upper and lower ends of the two connecting hollow piers are hollow. Several lower ports of connecting sleeves are located on the middle of the lower end wall of the upper precast connecting pier. The upper end of each connecting sleeve connects to the longitudinal reinforcing bars within the corresponding pier. The upper and lower ends of the connecting sleeves are respectively equipped with grouting pipes and overflow pipes, communicating with the corresponding outer surfaces of the pier walls. Several exposed connecting reinforcing bars are located on the middle of the upper end wall of the bottom precast connecting pier, corresponding to the lower ports of the connecting sleeves. During the vertical connection of the adjacent hollow piers, the exposed connecting reinforcing bars in the upper end wall of the bottom precast connecting pier are inserted into the corresponding connecting sleeves on the middle of the lower end wall of the upper precast connecting pier. Cement grout is then injected through the grouting pipes. Grouting is stopped once the injected cement grout overflows from the overflow pipes. The connection of the two adjacent precast hollow piers is completed after the cement grout solidifies. The problems with the connection of adjacent hollow piers are: (1) The upper and lower ends of the hollow piers are actually two adjacent pier walls, the solid connection surface is small, the joint is not sealed tightly, the upper pressure is uneven, there are many cracks at the connection, and the firmness is poor; (2) The connection is a high-altitude operation and is constructed. Summary of the Invention
[0004] The purpose of this invention is to provide a reinforced joint structure for segmented hollow thin-walled piers, a cast-in-place reinforced joint structure for segmented hollow thin-walled piers, and its construction method, to solve the problems mentioned in the background art. It has the advantages of expanding the solid joint surface of two adjacent precast hollow piers, the solid joint surface being tightly interlocked with tenon and mortise joints, the joint being fully sealed with grout without cracks, and good firmness. It also boasts advantages such as high work efficiency, time and labor saving, fast construction speed, good construction quality, good safety, and low cost.
[0005] A reinforced butt joint structure for segmented hollow thin-walled pier columns includes a bottom pier column and a butt joint pier column, wherein: The bottom pier has a solid pier surface at its upper end, forming a precast solid end that is integral with the bottom pier wall. The solid end is provided with several horizontally arranged solid horizontal steel bars that are connected to the corresponding vertical steel bars of the bottom pier wall. The lower part of several middle protruding steel bars is connected to the solid horizontal steel bars, and the upper part of the middle protruding steel bars is exposed on the upper end of the column surface for a certain distance. The upper part of the vertical steel bars of the bottom pier wall is exposed on the upper end of the column surface at the corresponding sleeve position for a certain distance. The upper pier wall of the bottom pier is provided with a clamp to support the steel bar head. The connecting pier column has a beveled edge inside the lower hollow column hole. This beveled edge creates a section of inverted frustum-shaped wall on the inner wall of the hollow column hole near the lower end of the connecting pier column, which gradually thickens towards the column axis. The inner diameter of the lower end of the inverted frustum-shaped wall is smaller than the inner diameter of the hollow column hole. The height of the lower end of the inverted frustum-shaped wall at the lower column hole opening is the same as the length of the sleeve. Several sleeves are located in the middle of the inner wall of the pier column at the lower end of the inverted frustum-shaped wall, corresponding to the exposed upper end of the vertical reinforcement of the bottom pier wall. The upper end of each sleeve... The sleeve is connected to the longitudinal steel bars in the pier column. The upper and lower side walls of the sleeve are respectively equipped with grouting pipes and overflow pipes, which are connected to the outer side of the corresponding pier wall. The space enclosed by the hollow column hole in the middle corresponding to the side wall of the sleeve and the inverted frustum-shaped wall extending to the upper end is the grouting space. One end of the transverse connecting steel bar is fixed on the side wall of each sleeve corresponding to the grouting space. The other end of the transverse connecting steel bar is located in the grouting space. The upper and lower side walls of the grouting space are equipped with grouting pipes and overflow pipes. Steel shims are used to support the space between the bottom pier column and the connecting pier column. They consist of several rectangular steel shims of varying thicknesses and lengths.
[0006] As a further description of the above technical solution: the thickness of the solid end of the bottom pier is 40-50cm.
[0007] As a further description of the above technical solution: the lower hollow column of the docking pier may have a beveled edge inside the hollow column opening. This beveled edge creates a section of inverted frustum-shaped wall within the hollow column opening at the lower end of the docking pier, which gradually thickens towards the column axis. The inner diameter of the lower end of the inverted frustum-shaped wall is smaller than the inner diameter of the upper hollow column opening. The lower end of the inverted frustum-shaped wall shares the same opening as the lower column opening of the docking pier. The height of the inverted frustum-shaped wall is greater than the length of the sleeve. The inner center of the pier wall at the outer end of the inverted frustum-shaped wall corresponds to the bottom... Several sleeves are installed at the exposed upper ends of the vertical reinforcing bars of the pier wall. The upper end of each sleeve is connected to the longitudinal reinforcing bars in the corresponding pier column. The upper and lower side walls of the sleeves are respectively equipped with grouting pipes and overflow pipes, which are connected to the outer side of the corresponding pier wall. The space enclosed by the inverted frustum-shaped wall corresponding to the side wall of the sleeve is the docking grouting space. One end of the transverse docking reinforcing bar is fixed on the side wall of each sleeve corresponding to the docking grouting space. The other end of the transverse docking reinforcing bar is located in the docking grouting space. The upper and lower side walls of the docking grouting space are equipped with docking grouting pipes and docking overflow pipes.
[0008] As a further description of the above technical solution: the angle between the beveled edge and the axis of the connecting pier column is 30° to 45°.
[0009] As a further description of the above technical solution: the exposed length of the centrally extending reinforcing bar is adapted to the height of the corresponding grouting space.
[0010] A construction method for a segmented hollow thin-walled pier column cast-in-place reinforced butt joint structure includes the following steps: (1) After the construction of the connection between the lower end of the bottom pier and the upper end of the foundation is completed and the grouting material reaches the strength requirements, a climbing ladder is built on the side of the bottom pier, and the upper end of the climbing ladder is located at the upper end of the bottom pier to form a construction platform. (2) A clamp is erected on the upper perimeter wall of the bottom pier, and the lower end of the clamp is supported on the clamp support steel head protruding from the upper outer wall of the bottom pier. Grouting material and grouting equipment are prepared. (3) Roughen the cement surface at the bottom end of the connecting pier and the top end of the bottom pier. Draw alignment lines in the middle of the sides of the bottom pier and the connecting pier. Paste a cross mark 30cm away from the top of the bottom pier. Use a crane to lift the connecting pier until the bottom end of the connecting pier is on the top end of the bottom pier. Insert the exposed part of the upper part of the vertical steel bar of the bottom pier wall into the corresponding sleeve. The exposed part of the upper part of the steel bar in the middle is in the grouting space in the middle of the bottom end of the connecting pier. Set up a total station on the front and side of the connecting pier at the designed position. Adjust the deviation of the connecting pier at any time during the lifting process. (4) The verticality of the docking pier is adjusted by using several corbels and jacks at the lower end of each side of the docking pier. The verticality correction error is 1mm. The corbels are connected to the docking pier by inserting 10.9 grade M20 bolts into the corresponding side sleeve inlet and overflow port. The telescopic rods of each jack rest on the corbel bearing plate, and the lower end of the jack rests on the clamp. The steel shims support the adjustment space between the bottom pier and the docking pier. The diagonal distance of the column corner steel bars is measured to control the installation accuracy of the docking pier. After the pier is installed and finely adjusted, temporary fixing measures are set at the interface of the upper and lower sections. Wind ropes are set around the docking pier to ensure the stability of the docking pier. (5) Install grout-blocking templates on the sidewall between the bottom pier and the connecting pier to seal the outer end face of the joint; (6) Grouting is carried out in each sleeve and grouting is carried out in the docking grouting space. The grouting is carried out at the same time. C100 high-strength non-shrink cement grouting material is used. The mixing equipment is a vertical shaft planetary mixer. The mixing time is 3 minutes. The grout is pressed into the sleeve from the lower grouting pipe until the grout flows out of the upper overflow pipe. Immediately after that, the grouting pipe opening and the grouting pipe opening connected to the sleeve are sealed with plugs. When each sleeve is full of grout and sealed with plugs, the grouting speed from the docking grouting pipe to the docking grouting space is accelerated until the grout flows out of the docking overflow pipe opening at the upper part of the docking grouting space. Then, the grouting is stopped and the docking grouting pipe opening and the docking overflow pipe opening are sealed with plugs. (7) When the strength of the grout to be poured reaches 2.5MPa, the grout-blocking template is removed, the plugs are removed and the pipe openings are sealed with high-strength non-shrink cement grout, and the outer end of the joint is wrapped with curing tarpaulin to cure the grout. Water is periodically sprayed into the hollow column hole at the top of the docking pier to cure the grout in the grouting space. The curing period is 14 to 15 days, and the connection between the docking pier and the bottom pier is completed.
[0011] As a further description of the above technical solution: the temporary fixing measures set at the interface between the upper and lower sections are to use threaded rods made of ф25 precision rolled threaded steel to fix the brackets at the lower end of the connecting pier column and the hoops around the upper end of the bottom pier column, so that the compressive stress between the segments of the threaded rods is not less than 0.3MPa.
[0012] As a further description of the above technical solution: the outer edge of the steel gasket is located 2cm inside the side wall joint of the mating pier column.
[0013] As a further description of the above technical solution: the plug is a rubber plug or a wooden plug, and the plug is truncated cone-shaped.
[0014] As a further description of the above technical solution: when the height of the docking pier is less than 8m, two brackets and two jacks are set on one side of the docking pier; when the height of the docking pier is greater than or equal to 8m, four brackets and four jacks are set on one side of the docking pier.
[0015] A bridge pier abutment-tunnel connection structure and its construction method include the following steps: (1) Complete the construction of the bridge piers adjacent to the tunnel entrance; (2) The tunnel exits in the opposite direction, and the tunnel entrance is opened. The entrance is located on the edge of the cliff, and the adjacent tunnel wall is the design location for the initial masonry and inverted arch construction. (3) Detect the state of the rock strata under the tunnel surface within 15 to 25 m from the tunnel entrance, classify the rock hardness and bearing capacity, and select the hard rock strata within this range as the location of the bridge pier based on the detection results, and mark the perimeter of the bridge pier location with white and gray lines. (4) The invert arch and the upper initial and secondary masonry are constructed inside the tunnel entrance. The invert arch is constructed outside the perimeter of the bridge pier. The invert arch reserves a bridge pier construction hole at the perimeter of the bridge pier. The thickness of the invert arch within 1m around the bridge pier construction hole is greater than the design thickness of the invert arch, forming a reinforced invert arch ring beam. (5) Excavate the tunnel rock strata in the reserved bridge pier abutment construction hole downwards to 1.5 to 2m below the horizontal plane of the lower end of the inverted arch to form the bridge pier abutment foundation hole; If the bottom rock layer here is a hard rock layer, then flatten the bottom surface; If the bottom rock layer is loose rock layer, drill holes for the bottom pier columns on both sides of the bottom surface to the hard rock layer, or drill holes for the loose bottom rock layer and grout to reinforce it. (6) Install a steel mesh frame for the pier abutment in the foundation hole of the pier abutment; or install a steel cage in the bottom pier column hole, pour concrete mortar into the bottom pier column hole, install a steel mesh frame for the pier abutment in the foundation hole of the pier abutment, the upper rear part of the steel mesh frame is a back wall steel mesh frame, and the lower end of the corresponding pier abutment steel mesh frame at the upper end of the steel cage is connected to the steel bars at the upper end of the steel cage. (7) Install upper side formwork with a thickness of 1 to 1.5 cm on the inner side of the reinforcing invert arch ring beam of the invert arch. The height of the upper end of the upper side formwork is 20 to 25 cm greater than the height of the upper end of the surrounding invert arch. The upper rear part of the upper side formwork is the back wall formwork. The upper end of the back wall formwork is flush with the upper end of the designed surrounding roadbed. Pour concrete mortar into the pier foundation hole and the back wall formwork. When the strength of the poured concrete reaches 2.5 MPa, remove the formwork and use curing tarpaulin to cure the poured concrete for 14 to 15 days. After demolding, the inner side of the reinforced arch ring beam maintains a gap of 1 to 1.5 cm with the corresponding side of the pier abutment; (8) A pier support is provided on the upper surface of the pier platform at the front end of the back wall, and a road base is laid on the inverted arch at the rear end of the back wall. A 1-1.5cm thick asphalt interlayer is provided between the side of the road base and the corresponding side of the back wall. The upper surface of the road base is flush with the upper surface of the back wall. (9) A precast bridge is erected between the pier support of the bridge pier outside the tunnel entrance and the pier support on the upper surface of the pier platform. The upper surface of the precast bridge is on the same plane as the upper surface of the road base and the upper surface of the back wall. (10) A 2cm thick uniform force steel plate is laid on the upper surface of the precast bridge and road base within a 1.5m radius from the upper surface of the back wall. The road surface layer is laid on the upper surface of the precast bridge and road base and on the uniform force steel plate to complete the construction of the bridge pier and tunnel connection.
[0016] As a further description of the above technical solution: the diameter of the bottom pier column hole is the same as the bottom width.
[0017] As a further description of the above technical solution: the peripheral drilling around the grouting hole has an elevation angle of 15° to 25° and a drilling length of 10 to 15m.
[0018] As a further description of the above technical solution: the road surface layer with a thickness of 20cm is 50m inside the tunnel entrance. The road surface layer is divided into a lower layer, a middle layer and an upper layer. The lower layer is 9cm thick AC-25 asphalt concrete, the middle layer is 6cm thick AC-20 asphalt concrete, and the upper layer is 5cm thick SMA-13 fine-grained asphalt concrete.
[0019] As a further description of the above technical solution: the length of the cast-in-place box girder entering the tunnel is greater than 10m.
[0020] As a further description of the above technical solution: the tunnel invert arch and upper lining, and the secondary masonry are constructed before the bridge piers and abutments. A gap of 1 to 1.5 cm is left between the bridge piers and the corresponding tunnel invert arch and lining, so that the force and load on the bridge piers and abutments are directly transferred to the rock strata of the mountain at the lower end of the tunnel, thus avoiding disturbance and damage to the tunnel invert arch and upper lining and secondary masonry structure caused by the bridge load.
[0021] As a further description of the above technical solution: the two ends of the uniform force steel plate are provided with anti-slip texture, which consists of several points protruding or recessed from the end face.
[0022] As a further description of the above technical solution: the thickness of the inverted arch within 1m around the construction hole of the bridge pier is greater than the design thickness of the inverted arch, which means that the thickness of the reinforcing inverted arch ring beam is at least more than 1 times the thickness of the inverted arch, and the upper end face of the reinforcing inverted arch ring beam is flush with the upper end face of the inverted arch, and the lower end face of the reinforcing inverted arch ring beam extends downward.
[0023] As a further description of the above technical solution: the steel mesh frame of the bridge pier and the steel mesh frame of the back wall are an integrated steel mesh frame structure.
[0024] As a further description of the above technical solution: the inner side of the reinforced arch ring beam maintains a gap of 1 to 1.5 cm with the corresponding side of the pier abutment, and the gap can be filled with rubber particles or sand.
[0025] The present invention has the following beneficial effects: 1. This invention solves the problems of small solid joint surface, poor sealing of joint joint, uneven bearing pressure, numerous cracks at the joint, and poor firmness in the current jointing of two precast hollow piers. In this invention, the upper end face of the bottom pier is a solid pier surface, forming a solid joint end precast integrally with the bottom pier wall. A beveled edge is provided in the hollow column hole at the bottom of the joint pier. The beveled edge gives the inner wall of the hollow column hole near the bottom column hole of the joint pier a section of inverted frustum-shaped wall that gradually thickens towards the column axis. After the joint is completed, grouting is performed in the sleeves and the joint grouting space. The grout seals the joint joint between the joint pier and the bottom pier, the sleeves, and the joint grouting space, so that the joint pier and the bottom pier form a cast-in-place inverted trapezoidal tenon-and-mortise interlocking connection. This invention expands the solid joint surface of two adjacent precast hollow piers, with the solid joint surface being interlocked and tightly secured by mortise and tenon joints, and the joint is fully sealed with grout without cracks, providing advantages such as uniform and firm support under upper pressure.
[0026] 2. This invention has low operating costs, convenient construction, and requires few construction personnel. The process of this invention is simple and easy to master. This invention has good usage effects and has the advantages of saving labor and effort during construction, simple construction, fast speed, saving materials, high efficiency and strong practicality. Attached Figure Description
[0027] Figure 1 This is a schematic diagram of the lower end structure of the docking pier column of the present invention; Figure 2 This is a schematic diagram of another structure at the lower end of the docking pier of the present invention; Figure 3 This is a schematic diagram of the upper structure of the bottom pier column of the present invention; Figure 4 This is a schematic diagram of the structure when the connecting pier column and the bottom pier column of the present invention are connected; Figure 5 This is a schematic diagram of the structure after the connecting pier column and the bottom pier column of the present invention have been connected and cast. Figure 6 This is a schematic diagram of the structure when the docking pier and the bottom pier are docked and supported. Figure 7 for Figure 6 A schematic diagram of the other side of the structure. Detailed Implementation
[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. To facilitate understanding of the technical means, creative features, and achieved objectives and effects of the present invention, the present invention will be further elaborated below with reference to specific embodiments. However, the following embodiments are merely preferred embodiments of the present invention and not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments without creative effort are all within the protection scope of the present invention. Unless otherwise specified, the construction methods in the following embodiments are conventional methods. Unless otherwise specified, the materials, devices, equipment, etc., used in the following embodiments can be obtained commercially.
[0029] This invention only relates to the aerial vertical connection of two precast adjacent hollow piers, that is, the connection between the connecting pier and the bottom pier, and does not involve the connection between the lower end of the bottom pier and the foundation or the connection between the upper end of the connecting pier and the cap beam.
[0030] Example 1: As Figures 1 to 3 As shown, a reinforced butt joint structure for segmented hollow thin-walled piers includes a bottom pier 2 and a butt joint pier 1, wherein: like Figure 3 As shown, the upper surface of the bottom pier 2 is a solid pier surface, forming a prefabricated butt joint solid end 25 integrally formed with the bottom pier wall 24. The butt joint solid end closes the upper part of the column hole 26 of the bottom pier. The thickness of the butt joint solid end of the bottom pier is 40-50cm to increase the strength of the solid butt joint surface. Several transverse solid reinforcing bars 23, which are integrally formed with the corresponding vertical reinforcing bars 27 of the bottom pier wall, are arranged inside the butt joint solid end 25. The lower parts of several protruding reinforcing bars 21 are connected to the solid transverse reinforcing bars 23, and the upper parts of the protruding reinforcing bars 21 are exposed beyond the upper column surface for a certain distance. The exposed length of the protruding reinforcing bars 21 is adapted to the height of the corresponding butt joint grouting space so that after butt jointing, the protruding reinforcing bars in the middle of the bottom pier can extend into the butt joint grouting space at the lower end of the butt joint pier, forming a reinforced concrete structure with the grouted cement mortar. The upper part 22 of the vertical reinforcing bars of the bottom pier wall is exposed beyond the upper column surface for a certain distance at the corresponding sleeve position. The upper part of the bottom pier column is equipped with a clamp support steel bar head 28, which is used to support the lower end of the clamp.
[0031] like Figure 1As shown, the lower hollow column hole 11 of the connecting pier column 1 is provided with a beveled edge 12. The beveled edge 12 creates a section of inverted frustum-shaped wall that gradually thickens towards the column axis on the inner wall of the hollow column hole near the lower end of the connecting pier column. The inner diameter of the lower end of the inverted frustum-shaped wall is smaller than the inner diameter of the hollow column hole. The height of the lower end of the inverted frustum-shaped wall at the lower end of the column hole is the same as the length of the sleeve. The angle between the beveled edge and the axis of the connecting pier column is 30° to 45°. The connecting pier column wall is provided with a reinforcing cage composed of several longitudinal reinforcing bars and transverse ring bars 10. Several sleeves 14 are provided in the middle of the pier column wall 16 at the lower end of the truncated cone-shaped wall, corresponding to the exposed upper end of the vertical steel bar 22 of the bottom pier wall. The upper end of each sleeve 14 is connected to each longitudinal steel bar 13 in the pier column. The upper and lower side walls of the sleeves are respectively provided with grouting pipes 19 and overflow pipes 17, which are connected to the corresponding outer side of the pier wall. The space enclosed by the hollow column hole in the middle corresponding to the side wall of the sleeve and the truncated cone-shaped wall extending to the upper end is the grouting space 111. One end of the transverse connecting steel bar 110 is fixed on the side wall of each sleeve corresponding to the grouting space 111. The other end of the transverse connecting steel bar 110 is located in the grouting space. The upper and lower side walls of the grouting space are provided with grouting pipes 18 and overflow pipes 15.
[0032] Steel shims are used to support the space between the bottom pier column and the connecting pier column. They consist of several rectangular steel shims of varying thicknesses and lengths.
[0033] like Figures 1 to 7 As shown, a construction method for a segmented hollow thin-walled pier column cast-in-place reinforced butt joint structure includes the following steps: (1) After the bottom pier 2 is connected to the top of the foundation, and the grouting material reaches the required strength, a ladder frame is built on the side of the bottom pier. The upper end of the ladder frame is located at the top of the bottom pier to form a construction platform.
[0034] (2) A clamp 6 with lifting lugs 8 is erected on the upper perimeter wall of the bottom pier. The lower end of the clamp 6 is supported on the clamp support steel head 28 protruding from the outer wall of the bottom pier. The grouting material and grouting equipment are prepared. The grouting material is C100 high-strength non-shrink cement grouting material 3. The grouting equipment is a vertical shaft planetary mixer with a mixing time of 3 minutes.
[0035] (3) Roughen the cement surface of the lower end of the connecting pier 1 and the upper end of the bottom pier. Draw alignment lines in the middle of the sides of the bottom pier and the connecting pier. Affix a cross mark 30cm from the top of the bottom pier. Use a crane to lift the connecting pier until the lower end of the connecting pier is on the upper end of the bottom pier. Insert the upper exposed part of the vertical reinforcing bar 22 of the bottom pier wall into the corresponding sleeve 14, and place the upper exposed part of the middle protruding reinforcing bar 21 into the grouting space 111 in the middle of the lower end of the connecting pier. Set up a total station on the front and side of the connecting pier at the designed position. Adjust the deviation of the connecting pier during the lifting process. Make the alignment lines in the middle of the sides of the bottom pier and the connecting pier on the same side on the same straight line, and the midpoint of the cross mark at the designed midpoint position.
[0036] (4) The verticality of the connecting pier is adjusted by using several corbels 4 and several jacks 9 installed at the lower end of each side of the connecting pier. The verticality correction error is 1mm. The corbels are made of welded steel plates with reinforcing ribs on both sides and corbel bearing plates on the lower outer side. The corbels are connected to the connecting pier by inserting 10.9 grade M20 bolts into the corresponding side sleeve inlet and overflow port. The telescopic rods of each jack rest on the corbel bearing plate, and the lower end of the jack rests on the clamp. The clamp serves as a platform for the reaction force of the jack. After adjustment, the space between the bottom pier and the connecting pier is adjusted by using steel shims. The outer edge of the steel shim is located 2cm inside the side wall joint of the connecting pier so that the grout after grouting at the joint will cover the steel shim and form an integrated structure. The diagonal distance of the column corner reinforcement is measured to control the installation accuracy of the connecting pier. After the pier is finely adjusted, temporary fixing measures are set at the interface of the upper and lower sections, and guy ropes are set around the connecting pier to ensure the stability of the connecting pier. When the height of the connecting pier is less than 8m, two brackets and two jacks are installed on one side of the connecting pier. When the height of the connecting pier is greater than or equal to 8m, four brackets and four jacks are installed on one side of the connecting pier to ensure sufficient adjustment force.
[0037] Temporary fixing measures are set at the interface between the upper and lower sections by using 5 tie rods made of ф25 fine rolled threaded steel to fix the lower end of the pier column to the bracket and the upper perimeter of the bottom pier column, so that the compressive stress between the tie rod segments is not less than 0.3MPa.
[0038] (5) Install grout-blocking template 7 on the side wall between the bottom pier and the connecting pier to seal the outer end face of the joint and prevent grout leakage at the joint during grouting.
[0039] (6) Grouting is carried out simultaneously in the sleeves and the grouting space between the two connections. C100 high-strength, non-shrink cement grout is used, and a vertical shaft planetary mixer is used for mixing. The mixing time is 3 minutes. Grout is injected into the sleeves from the lower grouting pipe until grout flows out of the upper overflow pipe. Immediately afterward, the grouting pipe openings and the grouting duct openings connecting the sleeves are sealed with plugs. Simultaneously, the grout fills the joint between the bottom pier and the connecting pier. Once each sleeve is full of grout and sealed with plugs, the grouting speed from the connecting grouting pipe 18 into the grouting space is increased until grout flows out of the upper grouting overflow pipe 15. Grouting is then stopped, and the connecting grouting pipe openings and the connecting overflow pipe openings are sealed with plugs. The plugs are rubber plugs or wooden plugs, and are frustum-shaped.
[0040] (7) When the strength of the grout to be poured reaches 2.5MPa, the grout-blocking template is removed, the plugs are removed, and each pipe opening is sealed with high-strength non-shrink cement grout. The outer end of the joint is wrapped with a curing tarpaulin to cure the grout. Water is periodically sprayed into the hollow column hole at the top of the connecting pier to cure the grout in the grouting space. The curing period is 14-15 days. The connection between the connecting pier and the bottom pier is completed, and then the corbels, clamps, etc. are removed. The grout poured in the grouting space at the middle of the lower end of the connecting pier and the middle protruding steel bar 21 and each transverse connecting steel bar 110 solidify to form a tenon and mortise structure of reinforced concrete interlocking, so that the joint between the two has high compressive and flexural strength.
[0041] Example 2: As Figure 2 As shown, unlike Embodiment 1, another structural feature of the docking pier 1 is that the lower hollow column opening of the docking pier 1 has a beveled edge 12. This beveled edge creates a section of inverted frustum-shaped wall within the hollow column opening at the lower end of the docking pier, which gradually thickens towards the column's axis. The angle between the beveled edge and the axis of the docking pier is 30°–45°. The inner diameter of the lower end of the inverted frustum-shaped wall is smaller than the inner diameter of the upper hollow column opening. The lower end of the inverted frustum-shaped wall shares the same opening as the lower column opening of the docking pier, and the height of the inverted frustum-shaped wall is greater than the length of the sleeve. Several sleeves are provided in the middle of the inner wall of the pier column at the outer end of the inverted truncated cone shape, corresponding to the exposed position of the upper end of the vertical reinforcement of the bottom pier wall. The upper end of each sleeve is connected to the longitudinal reinforcement of the corresponding pier column. The upper and lower side walls of the sleeve are respectively provided with grouting pipes and overflow pipes, which are connected to the outer side of the corresponding pier wall. The space enclosed by the inverted truncated cone shape wall corresponding to the side wall of the sleeve is the docking grouting space 111. One end of the transverse docking reinforcement 110 is fixed on the side wall of each sleeve corresponding to the docking grouting space. The other end of the transverse docking reinforcement 110 is located in the docking grouting space. The upper and lower side walls of the docking grouting space are provided with docking grouting pipes and docking overflow pipes.
[0042] The rest is the same as in Example 1, so it will not be repeated here.
[0043] The simulation experiment comparison data between the method of this invention embodiment and the traditional method are as follows: (1) Test method: Thin-walled hollow columns with dimensions of 24cm×11.5cm×9cm and a central porosity of 40% were fabricated using the same materials and preparation method to simulate the connection of two thin-walled hollow columns using the traditional method. The same connection support column and bottom support column structure of the present invention were fabricated using the same materials and dimensions to simulate the connection of two thin-walled hollow columns using the method of the present invention. A universal testing machine was used for compressive strength testing, with the loading rate controlled within 0.5MPa / s; the flexural strength test was completed using the three-point bending method. The comparative data of the simulation experiments are as follows: Table 1:
[0044] Table 1 shows that all indicators of the embodiments of the present invention are superior to those of the traditional methods. The physical joint area of the present invention is increased by 70% compared with the traditional construction method, the compressive strength is increased by 50%, the flexural strength is doubled, and the construction quality is excellent. The present invention gives the joints of the two objects higher compressive and flexural strength, better construction effect, and has the advantages of saving labor and effort, simple construction, fast speed, high efficiency and strong practicality.
[0045] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.
Claims
1. A reinforced butt joint structure for segmented hollow thin-walled piers, comprising a bottom pier and a butt joint pier, characterized in that: The bottom pier has a solid pier surface at its upper end, forming a precast solid end that is integral with the bottom pier wall. The solid end is provided with several horizontally arranged solid horizontal steel bars that are connected to the corresponding vertical steel bars of the bottom pier wall. The lower part of several middle protruding steel bars is connected to the solid horizontal steel bars, and the upper part of the middle protruding steel bars is exposed on the upper end of the column surface for a certain distance. The upper part of the vertical steel bars of the bottom pier wall is exposed on the upper end of the column surface at the corresponding sleeve position for a certain distance. The upper pier wall of the bottom pier is provided with a clamp to support the steel bar head. The connecting pier column has a beveled edge inside the lower hollow column hole. This beveled edge creates a section of inverted frustum-shaped wall on the inner wall of the hollow column hole near the lower end of the connecting pier column, which gradually thickens towards the column axis. The inner diameter of the lower end of the inverted frustum-shaped wall is smaller than the inner diameter of the hollow column hole. The height of the lower end of the inverted frustum-shaped wall at the lower column hole opening is the same as the length of the sleeve. Several sleeves are located in the middle of the inner wall of the pier column at the lower end of the inverted frustum-shaped wall, corresponding to the exposed upper end of the vertical reinforcement of the bottom pier wall. The upper end of each sleeve... The sleeve is connected to the longitudinal steel bars in the pier column. The upper and lower side walls of the sleeve are respectively equipped with grouting pipes and overflow pipes, which are connected to the outer side of the corresponding pier wall. The space enclosed by the hollow column hole in the middle corresponding to the side wall of the sleeve and the inverted frustum-shaped wall extending to the upper end is the grouting space. One end of the transverse connecting steel bar is fixed on the side wall of each sleeve corresponding to the grouting space. The other end of the transverse connecting steel bar is located in the grouting space. The upper and lower side walls of the grouting space are equipped with grouting pipes and overflow pipes. Steel shims are used to support the space between the bottom pier column and the connecting pier column. They consist of several rectangular steel shims of varying thicknesses and lengths.
2. The reinforced docking structure according to claim 1, characterized in that: The thickness of the solid end of the bottom pier is 40-50cm.
3. The reinforced docking structure according to claim 1, characterized in that: The aforementioned docking pier, or the lower hollow column opening of the docking pier, has a beveled edge. This beveled edge creates a section of inverted frustum-shaped wall within the hollow column opening at the lower end of the docking pier, which gradually thickens towards the column's axis. The inner diameter of the lower end of this inverted frustum-shaped wall is smaller than the inner diameter of the upper hollow column opening. The lower end of this inverted frustum-shaped wall shares the same opening as the lower column opening of the docking pier. The height of this inverted frustum-shaped wall is greater than the length of the sleeve. Several sleeves are installed in the middle of the inner wall of the pier column at the outer end of the inverted truncated cone shape, corresponding to the exposed position of the upper end of the vertical reinforcement of the bottom pier wall. The upper end of each sleeve is connected to the longitudinal reinforcement of the corresponding pier column. The upper and lower side walls of the sleeve are respectively provided with grouting pipes and overflow pipes, which are connected to the outer side of the corresponding pier wall. The space enclosed by the inverted truncated cone shape wall corresponding to the side wall of the sleeve is the docking grouting space. One end of the transverse docking reinforcement is fixed on the side wall of each sleeve corresponding to the docking grouting space. The other end of the transverse docking reinforcement is located in the docking grouting space. The upper and lower side walls of the docking grouting space are provided with docking grouting pipes and docking overflow pipes.
4. The reinforced docking structure according to claim 1 or 3, characterized in that: The angle between the beveled edge and the axis of the connecting pier column is 30° to 45°.
5. The reinforced docking structure according to claim 1, characterized in that: The exposed length of the centrally extending reinforcing bar is adapted to the height of the corresponding grouting space.
6. A construction method for a reinforced butt joint structure of a segmented hollow thin-walled pier column. The method for constructing a cast-in-place reinforced butt joint structure for a segmented hollow thin-walled pier column is characterized by: Includes the following steps: (1) The lower end of the bottom pier is connected to the upper end of the foundation. After the construction of the bridge pier adjacent to the tunnel entrance is completed and the grouting material reaches the strength requirements, a climbing ladder is built on the side of the bottom pier. The upper end of the climbing ladder is located at the upper end of the bottom pier to form a construction platform. (2) A clamp is erected on the upper perimeter wall of the bottom pier, and the lower end of the clamp is supported on the clamp support steel head protruding from the outer wall of the bottom pier. Grouting material and grouting equipment are prepared. The tunnel exits in the opposite direction, and the tunnel entrance is opened. The entrance is located on the edge of the cliff, and the adjacent tunnel wall is the initial masonry and inverted arch construction design position. (3) Roughen the cement surface of the lower end of the connecting pier and the upper end of the bottom pier. Draw alignment lines in the middle of the side of the bottom pier and the connecting pier. Paste a cross mark 30cm away from the top of the bottom pier. Use a crane to lift the connecting pier until the lower end of the connecting pier is on the upper end of the bottom pier. Insert the upper exposed part of the vertical steel bar of the bottom pier wall into the corresponding sleeve. The upper exposed part of the steel bar in the middle is located in the grouting space in the middle of the lower end of the connecting pier. Set up a total station on the front and side of the connecting pier at the design position. Adjust the deviation of the connecting pier at any time during the lifting process. Detect the state of the rock strata under the tunnel surface within 15-25m from the tunnel entrance. Classify the rock hardness and rock bearing capacity. Based on the detection results, select the hard rock strata within this range as the pier position. Mark the perimeter of the pier position with white lime lines. (4) The verticality of the connecting pier is adjusted by using several corbels and jacks at the lower end of each side of the connecting pier. The verticality correction error is 1mm. The corbels are connected to the connecting pier by inserting 10.9 grade M20 bolts into the corresponding side sleeve inlet and overflow port. The telescopic rods of each jack are supported on the corbel bearing plate, and the lower end of the jack is supported on the clamp. The steel shims are used to support the adjustment space between the bottom pier and the connecting pier. The diagonal distance of the column corner steel bars is measured to control the installation accuracy of the connecting pier. After the pier is finely adjusted, temporary fixing measures are set at the interface of the upper and lower sections. Wind ropes are set around the connecting pier to ensure the stability of the connecting pier. The invert arch and the upper initial and secondary masonry are constructed in the tunnel entrance. The invert arch is constructed outside the perimeter of the bridge pier. The bridge pier construction hole is reserved at the perimeter of the bridge pier. The thickness of the invert arch within 1m around the bridge pier construction hole is greater than the design thickness of the invert arch, forming a reinforced invert arch ring beam. (5) Install a grout-blocking template on the side wall between the bottom pier and the connecting pier to seal the joint. The tunnel rock strata reserved in the pier abutment construction hole are excavated downward to 1.5 to 2m below the horizontal plane of the lower end of the inverted arch to form the pier abutment foundation hole. If the bottom rock layer here is a hard rock layer, then flatten the bottom surface; If the bottom rock layer is loose, drill holes for the bridge pier columns on both sides of the bottom surface to the hard rock layer, or drill holes for grouting to reinforce the loose bottom rock. (6) Grouting is carried out simultaneously in the sleeves and the grouting space between the two connections. C100 high-strength non-shrink cement grout is used as the grouting material. A vertical shaft planetary mixer is used for mixing, and the mixing time is 3 minutes. The grout is pressed into the sleeves from the lower grouting pipe until grout flows out of the upper overflow pipe. Immediately after that, the grouting pipe openings and the grouting pipe openings connecting the sleeves are sealed with plugs. After each sleeve is full of grout and sealed with plugs, the grouting from the connecting grouting pipes into the connecting grouting space is accelerated. After the grouting speed reaches the point where grout flows out of the overflow pipe at the top of the grouting space, stop grouting and seal the grouting pipe and overflow pipe with a plug; install a steel mesh frame for the pier abutment in the foundation hole of the pier; or install a steel cage in the bottom pier column hole, pour concrete mortar into the bottom pier column hole, install a steel mesh frame for the pier abutment in the foundation hole of the pier, the upper rear part of the steel mesh frame is the back wall steel mesh frame, and the lower end of the corresponding pier abutment steel mesh frame at the upper end of the steel cage is connected to the steel bars at the upper end of the steel cage; (7) Install upper side formwork with a thickness of 1-1.5cm on the inner side of the reinforcing invert arch ring beam. The height of the upper side formwork's upper end face is 20-25cm greater than the height of the upper end face of the surrounding invert arch. The upper rear part of the upper side formwork is the back wall formwork, and the upper end face of the back wall formwork is flush with the designed upper end face of the surrounding roadbed. Pour concrete mortar into the pier foundation hole and the back wall formwork. When the strength of the poured grout concrete reaches 2.5MPa, remove the grout-blocking formwork, remove the plugs, and seal each pipe opening with high-strength non-shrink cement grout. Wrap the outer end face of the joint with a curing tarpaulin to cure the poured grout. Periodically spray water into the grout in the grouting space through the hollow column hole at the top of the connecting pier column to cure the grout. The curing period is 14-15 days. After demolding, the inner side of the reinforced arch ring beam maintains a gap of 1 to 1.5 cm with the corresponding side of the pier abutment; (8) A pier support is installed on the upper surface of the pier abutment at the front end of the back wall. A road base is laid on the inverted arch at the rear end of the back wall. An asphalt interlayer with a thickness of 1-1.5cm is provided between the side of the road base and the corresponding side of the back wall. The upper surface of the road base is flush with the upper surface of the back wall to complete the connection between the connecting pier and the bottom pier. (9) A precast bridge is erected between the pier support of the bridge pier outside the tunnel entrance and the pier support on the upper surface of the pier platform. The upper surface of the precast bridge is on the same plane as the upper surface of the road base and the upper surface of the back wall. (10) A 2cm thick uniform force steel plate is laid on the upper surface of the precast bridge and road base within a 1.5m radius from the upper surface of the back wall. The road surface layer is laid on the upper surface of the precast bridge and road base and on the uniform force steel plate to complete the construction of the bridge pier and tunnel connection.
7. The method according to claim 1, characterized in that: The temporary fixing measures at the interface between the upper and lower sections are described above. The tie rods made of ф25 precision rolled threaded steel are used to tie the lower end of the pier column to fix the bracket and the upper perimeter of the bottom pier column, so that the compressive stress between the tie rod segments is not less than 0.3MPa and the diameter of the bottom pier column hole is the same as the bottom width.
8. The method according to claim 1, characterized in that: The outer edge of the steel gasket is located 2cm inside the side wall joint of the docking pier. The grouting is carried out around the perimeter of the hole with an elevation angle of 15° to 25° and a drilling length of 10 to 15m.
9. The method according to claim 1, characterized in that: The sealing plug is a rubber plug or a wooden plug. The plug is truncated cone-shaped and enters the tunnel entrance. The road surface layer is 20cm thick and is divided into a lower layer, a middle layer and an upper layer. The lower layer is 9cm thick AC-25 asphalt concrete, the middle layer is 6cm thick AC-20 asphalt concrete, and the upper layer is 5cm thick SMA-13 fine-grained asphalt concrete.
10. The method according to claim 1, characterized in that: When the height of the connecting pier is less than 8m, two brackets and two jacks are installed on one side of the connecting pier. When the height of the connecting pier is greater than or equal to 8m, four brackets and four jacks are installed on one side of the connecting pier.