CN211850367U - A high-ductility and easy-to-repair concrete column foot joint - Google Patents

Abstract

The utility model discloses a concrete column foot joint with high ductility and easy repair, which comprises a concrete column, a core energy dissipation rod, an adjustable steel bar composite joint, a restraint system and a concrete foundation. The core energy dissipating rod is connected with the longitudinal steel bar in the concrete column and the anchoring steel bar in the concrete foundation, one end of which is connected with the longitudinal steel bar in the concrete column through an adjustable steel bar composite joint, and the other end is connected with the anchorage in the concrete foundation through a threaded connector Rebars are connected reliably. The bottom of the concrete column of the utility model is provided with a column bottom reinforcing core column, which can bear the column bottom pressure under earthquake action without damage; the core energy dissipation rod is installed around the column foot node to replace the force at the original position Longitudinal bars and adjustable steel bar composite joints can reliably transmit both pressure and tensile force. The periphery of the core energy-dissipating rod is constrained by the restraint system, and its hysteretic energy is used to dissipate seismic energy during moderate or large earthquakes, and damage will be damaged. control within it.

Description

A high-ductility and easy-to-repair concrete column foot joint

technical field

The utility model relates to the field of civil engineering, in particular to a concrete column foot joint with high ductility and easy repair.

Background technique

(1) Column foot damage under earthquake action

Under the action of earthquake, reinforced concrete columns or bridge pier columns are also subjected to reciprocating horizontal loads while bearing vertical loads. When the bending resistance, shear strength or ductility are insufficient, cracking or damage of the columns will be caused. The column foot is subjected to the combined action of greater pressure and bending moment. Under the action of the bending moment, one side is compressed and the other side is tensioned, and a plastic hinge will be formed earlier. Especially for the column foot of concrete frame structure, the structure of column foot joint is the key to the seismic capacity of concrete structure, and plastic hinge will inevitably appear under strong earthquake. For traditional concrete columns, the ultimate compressive strain provided by the concrete on the compression side at the bottom of the column is very small, and the improvement of the ultimate compressive strain by restraint reinforcement is also very limited. The concrete may be compressed due to fatigue, and the stirrups themselves cannot limit the buckling of the main reinforcement under compression. There are serious concrete crushing and spalling, the outer bulge of the stirrups collapses, and the longitudinally compressed steel bars are unstable, resulting in instantaneous bearing capacity. If it is lowered, the plastic hinge loses its ability to rotate. The crushing of the concrete at the base of the column and the yielding of the compressive reinforcement made post-earthquake repair work very difficult. How to reduce the damage to the bottom of the column under the action of the earthquake and concentrate the damage on the parts that are easy to repair after the earthquake, so as to achieve the goal of controllable damage, is a common concern of researchers.

(2) Post-earthquake repair

After a strong earthquake, the yield part of the structure will be damaged greatly. The damaged engineering structure has weakened ability to withstand loads and actions, deteriorated mechanical performance, and reduced the safety of the structure. Under the action of earthquakes that may occur in the future, it is more likely that the structure will lose its integrity due to the accelerated failure of the damaged parts, and serious collapse may occur, resulting in huge losses of people's lives and properties. However, if the damaged components after the earthquake can be replaced by quick repair work, and the bearing capacity and mechanical performance of the structure can be restored, it will play a vital and beneficial role in post-disaster recovery and reconstruction.

(3) Buckling Restrained Bracing (BRB)

It is a major demand and urgent task in the engineering field to study safe, reliable, economical and applicable structural seismic systems and shock absorption methods to minimize the impact of earthquake disasters. Energy dissipation and shock absorption absorb and dissipate seismic energy through energy dissipation devices, which can effectively reduce the response and damage of the structure and avoid serious damage to the main structure. It is an important means to achieve performance-based seismic resistance.

The metal yielding energy dissipation device utilizes the hysteretic response generated by the plastic deformation of the metal after yielding to dissipate the energy input into the structure, and at the same time utilizes the post-yielding characteristics of the metal to ensure that the main body of the structure is in an elastic state, so as to concentrate the damage of the structure in the earthquake. to the energy-consuming device. In recent years, many structural forms of metal yield energy dissipation devices have been developed, such as shear plate dampers (SPD), angle steel dampers, buckling restrained braces (BRB) and so on. The metal yield energy dissipation device has strong energy dissipation capacity and relatively simple force transmission mechanism, and has been widely favored by engineers in recent years. The rod-type metal yielding energy dissipation device is prone to decrease in energy dissipation capacity due to buckling prior to yielding during the compression process. Therefore, it is necessary to set a buckling restraint device on the rod-type metal yielding energy dissipation device to form an anti-buckling member, thereby To ensure that it can exert excellent energy dissipation capacity in both the tension direction and the compression direction.

Buckling restraint bracing (BRB) is a widely used anti-buckling metal yield energy dissipation device. It uses low yield point high ductility steel as the core energy dissipation component, and sets lateral deformation restraint components around it to prevent the support from buckling instability. , which is widely used in the central support frame structure system. Its basic working principle is as follows: under normal load conditions and small earthquake environments, BRB acts as a side member of the structure to provide lateral stiffness for the frame structure; under moderate and large earthquakes, the core components of BRB enter into yield and wear out. It can dissipate the input energy of the earthquake, so that the main structural components such as beams and columns can maintain the elastic state and ensure the recoverability of the structure after the earthquake.

In frame structures, buckling restraint bracing (BRB) is usually arranged between the diagonal nodes of the frame, and the size of the members is large, which has a certain adverse effect on the space utilization of the frame structure. There are also corner braces set near the outside of the beam-column joint, which saves structural space compared to buckling restrained bracing (BRB), but still has an adverse effect on structural aesthetics and space utilization.

(4) Fiber Reinforced Composites (FRP)

Fiber-reinforced composite material (FRP) is a composite material made of fiber filaments and resins that are cured in a certain proportion or woven in a certain direction. Common FRP materials include carbon fiber (CFRP), glass fiber (GFRP), and aramid fiber (AFRP). In the field of civil engineering, its common product forms are fiber cloth, fiber board, fiber bar, fiber rod, fiber tube and fiber pultrusion profile.

FRP material is a lightweight, high-strength and corrosion-resistant material, which has many advantages that traditional materials cannot match. Due to the high tensile strength and elastic modulus of FRP materials, the use of FRP to reinforce concrete columns can improve the bearing capacity and deformation capacity of the columns, reflecting the technical advantages of high strength and high efficiency. FRP material has excellent corrosion resistance and durability. It can resist the corrosion of acid, alkali and salt commonly found in bridge structures or seaport and wharf projects. It can effectively protect concrete from the influence of the external environment and effectively prolong the concrete structure. service life. FRP material has a similar thermal expansion coefficient to concrete, and will not generate large temperature stress when the ambient temperature changes. FRP fiber cloth is a kind of fabric, which is easy to carry and can be arbitrarily cut with scissors at the construction site according to the needs. It does not require special cutting tools, and the construction is convenient and occupies less space. FRP fiber cloth is a flexible material. After cutting, it can be used for the reinforcement of various structural types, various structural shapes and various structural parts without changing the structural shape or affecting the structural appearance.

Compared with other FRP materials, carbon fiber reinforced plastic (CFRP) has the advantages of light weight, high fatigue strength, high specific strength and specific modulus, corrosion resistance, and excellent thermal properties.

(1) The structure of the column foot joint is the key to the seismic capacity of the concrete structure. The technical problem that the utility model is aimed at is: under the action of strong earthquake, the axial force and bending moment borne by the column foot joints are relatively large, and the joints are prone to crushing of the concrete in the compression zone, buckling of the main reinforcement under compression, and buckling of the stirrups. Drum collapse and other phenomena, resulting in a significant reduction in bearing capacity;

(2) Easy replacement of damaged components is the key to ensuring easy repair of structural performance. At present, easy repair of structural performance is the latest requirement for seismic resistance of engineering structures. Energy-dissipating connections dissipate seismic energy through the plastic hysteretic energy-dissipation capacity of metal materials (such as steel bars), and the development and accumulation of plasticity will bring about the gradual aggravation of structural damage. In order to ensure that the post-earthquake structure has the ability to withstand earthquakes that may be encountered during the subsequent service period, it is the most economical solution to quickly repair the damaged structure after the earthquake, and the replacement of damaged components is the most thorough and perfect means of repairing the structure;

(3) The existing post-earthquake reinforcement and repair technology has certain drawbacks. In the past few decades, post-earthquake repair and reinforcement techniques for structures have emerged in an endless stream, such as surface reinforcement method, slab wall reinforcement method, reinforcement method of adding reinforced concrete columns, reinforcement method of enlarged section, outer steel reinforcement method, bonded steel reinforcement method, etc. . This kind of reinforcement and repair technology can be used to strengthen the earthquake damage of the existing structure, but it often shows the disadvantages of changing the natural vibration period of the structure, leading to aggravation of the non-uniformity of structural stiffness, and in severe cases, it will lead to changes in the overall lateral resistance of the structure. It is difficult to achieve complete equivalence with the original structure, and its safety performance after repair will also show uncertainty. These repair methods also often affect the use space and aesthetics of the structure due to the addition of components. If it can be ensured that the structure can maintain the elasticity of the main part during the earthquake, and the damage of the structure can be concentrated in the replaceable components, the purpose of easy repair of the structure after the earthquake can be achieved. After the earthquake, the structural function and mechanical performance can be effectively restored by simply replacing the replaceable components, thereby improving the repairability of the structure and further ensuring the safety of human life and property. Therefore, the exploration of the performance and structure of the concept of "easy repair after earthquake" will effectively promote the development of earthquake resistance and disaster reduction of civil engineering structures.

(4) There are some deficiencies in the existing post-earthquake repairable concrete column foot joints. In recent decades, with the in-depth research of ductile materials and inelastic structural systems, a variety of energy-dissipating devices that are easily replaceable after earthquakes have been proposed and applied to the design of new structures and the reinforcement of existing buildings. (Repair), the concept of "easy to repair the structure after earthquake" is effectively realized. In the methods of installing post-earthquake replaceable energy-consuming connectors at concrete column foot nodes that have been proposed so far, replaceable steel plates or replaceable steel rods are mostly used as the main energy-consuming components, but in the case of replaceable steel plates or replaceable steel rods The lack of an effective buckling restraint device on the side can easily lead to buckling under large earthquakes, it is difficult to achieve full cross-section yielding, and it cannot exert its hysteretic energy dissipation capacity well. For example, Chinese utility model patent CN 105888058 B proposes a damage-repairable prefabricated composite column foot, which uses replaceable steel plates as energy-consuming components to be placed on the left and right sides of the column foot, and withstands tensile and compressive yield energy dissipation under horizontal earthquake action. However, under the action of a large earthquake, the replaceable steel plate is prone to buckling when it is compressed. In addition, in the existing utility model, the replaceable steel plate or the replaceable steel rod is mostly connected with the concrete column body and the concrete foundation by bolts. Contrasted with the existing construction accuracy level of civil engineering, it is easy to cause difficulty in component installation due to component processing errors or construction errors, and the workload of post-earthquake repair is large.

(5) There are some defects in the connection method of existing steel bars and energy-consuming connectors. The ductile connection (DDC) set in the beam-column joint proposed by American Dywidag Company is a typical representative. The assembly transmits the axial force between the energy-dissipating steel rods and the longitudinal reinforcement of the beam through a transfer block. The conversion block is provided with a through hole at the position corresponding to the energy-consuming steel rod, a countersunk hole with internal thread is provided at the position corresponding to the longitudinal reinforcement of the beam, and the outer end of the energy-consuming steel rod is a sleeve with internal thread. When connecting, screw the longitudinal steel bar into the countersunk hole of the conversion block first, then pass the bolt through the oversized hole in the conversion block and tighten the sleeve at the end of the energy-consuming steel rod. The ductile connection is simple in structure, convenient in manufacture and installation, good in energy consumption and relatively low in cost, and has been applied in developed countries and regions such as the United States. However, the small gap between the end threads of the energy-dissipating connecting rod/beam longitudinal bars and the inner threads of the sleeve in the DDC assembly can cause the connecting assembly to slip when transmitting axial loads. This slippage will reduce the stiffness of the connection under force, which is very unfavorable for the energy-dissipating connection that is mainly subjected to axial force. In addition, this slippage will also make the hysteresis curve of the component not full enough, and the energy dissipation capacity will be reduced; at the same time, the DDC component mainly relies on the conversion block to transmit the axial force between the longitudinal reinforcement in the beam and the energy dissipation connecting rod, and the force transmission is not direct enough for To ensure the force transmission, it is necessary to use larger cross-section conversion blocks and bolts, and the cost is high; in addition, since the DDC components have extra-large holes in the conversion blocks for easy installation and connection, the DDC components have a higher demand for the cross-sectional size (width). big.

Utility model content

In view of the above technical problems, the present utility model provides a high-ductility and easy-to-repair concrete column foot joint, which uses a high-ductility and easy-to-replace core energy-consuming rod as an energy-consuming component under earthquake action, so as to meet the requirements of reasonable stress and convenient construction at the same time. , The requirements of strong energy dissipation and shock absorption ability and easy repair after earthquake.

In order to realize the above-mentioned technical purpose, the utility model adopts the following technical scheme:

A concrete column foot node with high ductility and easy to repair, which is arranged at the bottom of a concrete structural column, comprising:

The foundation concrete block, located at the bottom of the entire concrete column foot joint, is used to carry the concrete structural column part;

The bottom of the concrete structure column is provided with a column bottom reinforcement core column coaxially arranged with the concrete structure column, the bottom of the column bottom reinforcement core column is connected with the upper surface of the foundation concrete block, and the column bottom reinforcement core column is The cross-section of the concrete column is smaller than the cross-section of the concrete column body to form an annular reserved space between the upper surface of the foundation concrete block and the bottom of the concrete structural column;

a horizontal limiting mechanism for limiting the displacement in the horizontal direction between the reinforcing core column at the bottom of the column and the foundation concrete block, including a foundation anchoring unit pre-embedded inside the foundation concrete block and fixedly connected to the foundation anchoring unit, and extending out of the convex limit block arranged on the upper surface of the foundation concrete block, the convex limit block and the bottom side of the column bottom reinforcing core column are closely connected to each other;

A plurality of longitudinal energy dissipation units with the same structure are arranged between the foundation concrete blocks and the concrete structural columns, and are evenly arranged along the annular reserved space, and each longitudinal energy dissipation unit includes:

Longitudinal reinforcement bars in the column are arranged inside the concrete structural column and have an extension part exposing the bottom of the concrete structural column;

The foundation longitudinal anchoring steel bars are pre-embedded and arranged inside the foundation concrete blocks, and are on the same line as the longitudinal steel bars in the column;

One end of the core energy-consuming rod is connected with the longitudinal steel bar in the concrete column through an adjustable steel bar composite joint, and the other end of the core energy-consuming rod is connected with the anchoring steel bar in the concrete foundation through a threaded connector;

A restraint system to limit the lateral buckling of the core energy dissipating rods;

The axial tensile yield bearing capacity of the core energy dissipating rod is smaller than the axial tensile bearing capacity of the longitudinal reinforcement bars in the column and the foundation longitudinal anchoring reinforcement, and is also smaller than the connection bearing capacity of the adjustable steel bar composite joint.

The core energy dissipation rod includes a column-direction connecting section connected with the concrete structural column, a foundation-direction connecting section connected with the concrete foundation, and a middle energy-consuming section connected between the column-direction connecting section and the foundation-direction connecting section;

The cross-sectional area of the column-direction connection section and the foundation-direction connection section is larger than the cross-sectional area of the energy dissipation section;

The core energy dissipating rods, the adjustable steel bar composite joints and the threaded connectors are all made of ductile metal materials.

The core energy-dissipating rod is a solid core energy-dissipating rod at both ends, and the surfaces of the column-direction connection section and the foundation-direction connection section are engraved with external threads; the adjustable steel bar composite joint includes an outer sleeve, a first inner sleeve The cylinder, the second inner sleeve and the column-direction locking nut; one end of the outer sleeve is provided with an equal-diameter constriction with a diameter larger than the nominal diameter of the longitudinal steel bar in the column, and the inner wall of the other end section is provided with an internal thread;

The outer diameter of the first inner sleeve is larger than the diameter of the equal-diameter constriction of the outer sleeve but smaller than the inner diameter of the outer sleeve. One end of the first inner sleeve is provided with a central countersunk hole, and the inner wall of the central countersunk hole is processed with an internal thread. The other end of the inner sleeve is provided with a guide head, and the guide head is set in a hemispherical or conical shape;

The center hole of the second inner sleeve is a through hole, and the diameter of the through hole is slightly larger than the maximum diameter of the guide head. The inner wall of the through hole is provided with an inner thread, and one end of the second inner sleeve has an outer thread on the cylinder wall. The end of the external thread is pressed against the end of the first inner sleeve;

The column direction locking nut has a central through hole, and the inner wall of the central through hole is provided with an inner thread;

The lower end of the longitudinal steel bar in the connected column is provided with an external thread, the lower end of which passes through the equal-diameter constriction, and the external thread is matched and screwed with the internal thread of the counterbore hole of the first inner sleeve;

The inner thread of the outer sleeve is screwed together with the outer thread arranged on the wall of the second inner sleeve;

The outer thread of the column-direction connecting section is screwed together with the inner thread of the inner wall of the second inner sleeve;

The inner thread of the column-direction locking nut is screwed together with the outer thread of the column-direction connecting section, and the column-direction locking nut is pressed against the end of the second inner sleeve;

The threaded connector is a straight threaded sleeve or a tapered threaded sleeve;

A reserved space for installing the sleeve connection is reserved near the upper end of the foundation anchoring steel bar.

The core energy dissipation rod is a core energy dissipation rod with central blind holes at both ends, and the outer surface of the column connecting section with the central blind hole is engraved with external threads;

The adjustable steel bar combination joint includes an outer sleeve and a first inner sleeve sleeved inside the outer sleeve; one end of the outer sleeve is set as an equal diameter shrinkage with a diameter larger than the nominal diameter of the longitudinal steel bars in the column , the inner wall of the other end section is provided with an inner thread, which is screwed together with the outer thread of the end section of the column connection section on the core energy dissipation rod;

The outer diameter of the first inner sleeve is larger than the diameter of the equal-diameter neck of the outer sleeve but smaller than the inner diameter of the outer sleeve. One end of the first inner sleeve is provided with a central countersunk hole, and the inner wall of the central countersunk hole is machined with an inner diameter. Thread, the other end of the first inner sleeve is provided with a guide head, the guide head is set in a hemispherical or conical shape, the maximum diameter of the guide head is smaller than the diameter of the central blind hole at the end of the upper column connecting section of the core energy dissipation rod, and the height of the guide head less than the depth of the central blind hole at the end of the column connection section on the core energy dissipation rod;

The lower end of the longitudinal steel bar in the connected column is provided with an external thread, the lower end of which passes through the equal-diameter constriction, and the external thread is matched and screwed with the internal thread of the counterbore hole of the first inner sleeve;

The threaded connector is a basic locking nut;

The connection between the core energy-dissipating rod and the foundation longitudinal anchoring steel bar is screwed together with the end thread of the foundation longitudinal anchoring steel bar through the blind hole inner thread of the foundation-to-connection section, and is fastened with the foundation-toward locking nut;

The foundation direction locking nut is provided with a central through hole, the inner wall of the through hole is provided with an inner thread, and the inner thread is screwed together with the end thread of the foundation longitudinal anchoring steel bar;

The foundation-direction locking nut is pressed against the end of the foundation-direction connecting section on the core energy dissipation rod;

A space is reserved for the vertical screwing of the foundation-to-connection section of the core energy-consuming rod and the foundation-toward locking nut near the upper end of the foundation anchoring steel bar.

When the cross-section of the concrete column is circular, the restraint system at least includes:

Filling concrete and multi-layer carbon fiber cloth, wherein the filling concrete is used to fill the remaining part of the annular reserved space in the column bottom area;

The multi-layer carbon fiber cloth is bonded to the outside of the bottom area of the concrete column.

When the cross-section of the concrete column is circular, the restraint system further includes: an arc-shaped restraint cover plate located on the outer side of the core energy dissipation rod, that is, on the side away from the centroid of the cross-section of the concrete column, and a pre-buried in the reinforcing core column at the bottom of the column. Buried bolts, nuts used to fix the relative position of the arc-shaped constraining cover plate and the reinforcing core column at the bottom of the column;

The length of the arc-shaped constraining cover plate covers the energy-consuming section of the core energy-dissipating rod, the arc-shaped constraining cover plate is provided with a groove matching the outer contour of the covered core energy-dissipating rod section, and the core energy-dissipating rod is connected to the core energy-dissipating rod. There is a gap of 1mm to 2mm between the groove walls;

The arc-shaped constraining cover plate is provided with bolt holes which are convenient for pre-embedded bolts to align and pass through.

When the cross-section of the concrete column is rectangular, the restraint system includes:

The rectangular constraining cover plate located on the outside of the core energy dissipating rod, i.e. away from the centroid of the concrete column section, the right-angle constraining cover plate located at the corner of the rectangular concrete column section, the L-shape close to the right-angle constraining cover plate and the outside of the rectangular constraining cover plate Additional restraint plate, pre-embedded bolts embedded in the column bottom reinforcing core column, nuts used to fix the relative position of the L-shaped additional restraint plate and the column bottom strengthening core column;

The lengths of the right-angle constraining cover plate and the rectangular constraining cover plate cover the energy dissipation section of the core energy-dissipating rod, and the right-angle constraining cover plate and the rectangular constraining cover plate are provided with a matching outer contour of the covered core energy-dissipating rod section. groove, there is a gap of 1mm~2mm between the core energy dissipation rod and the groove wall”

The inner side of the L-shaped additional restraint plate is in close contact with the outer sides of the right-angle restraint cover plate and the rectangular restraint cover plate adjacent to the corresponding position;

The L-shaped additional restraint plate is provided with bolt holes which are convenient for pre-embedded bolts to align and pass through.

Beneficial effects:

Compared with the prior art, the utility model has the following advantages:

1) The division of labor in the structure is clear, and the force transmission system is reasonable. In the utility model, each component of the concrete column foot joint has a clear division of force. The reinforced core column at the bottom of the concrete column bears the pressure of the column bottom under the action of earthquake. Even if the axial pressure of the column is relatively large, the reinforced core column at the bottom of the column will not be damaged, avoiding the occurrence of the bending moment of the concrete in the compression area at the bottom of the traditional concrete column. Crushed when larger. The reinforcing core column at the bottom of the column is placed in the center of the top surface of the foundation concrete block, and can swing freely under the action of earthquake. Sliding on the column can effectively resist the shear force at the bottom of the column. The position of the high ductility core energy dissipation rod is on the same line with the corresponding longitudinal reinforcement in the concrete column and the corresponding longitudinal anchoring reinforcement of the foundation on each side of the concrete foundation, which is convenient to form a direct and reasonable vertical force transmission system. The core energy-dissipating rod can replace the longitudinal reinforcement at the original position of the column foot joint to provide the flexural bearing capacity for the column foot joint.

2) The structural damage is concentrated and the energy consumption performance is good. In the present utility model, the column bottom area is made of concrete-filled steel tubular structure, high-strength concrete structure or composite steel structure. In the present invention, since the core energy-dissipating rods that are easy to yield are installed around the column bottom, the plastic behavior under earthquake action is concentrated at the column foot, while the upper concrete column body is far away from the bottom plastic hinge area, and the The tensile bearing capacity of the longitudinal reinforcement in the column, the longitudinal anchoring reinforcement of the foundation in the concrete foundation, and the connection bearing capacity of the adjustable steel bar composite joint and the threaded connection are all greater than the tensile bearing capacity of the core energy dissipation rod, so that the damage of the column is concentrated. in the core energy dissipating rod at the bottom of the column. The core energy dissipation rod adopts a similar construction principle as the core plate in the buckling restraint brace, yielding will only occur in the middle energy dissipation section of the core energy dissipation rod, and the plastic strain distribution after yielding is uniform. The plastic strain of the bar is small, and it can exert excellent ductility and low cycle fatigue ability.

3) The structure is easy to repair after earthquake. Under the action of the earthquake, the damage of the concrete column foot joint in the utility model is concentrated in the core energy dissipation rod at the bottom of the column, while other main components do not suffer obvious damage, and the repeated use of components such as columns and foundations is not affected. Replacing the core energy stick restores the functionality of the structure. The maintenance scope is small, the maintenance process is relatively simple, and it does not affect the normal use of the longitudinal reinforcement in the column and the longitudinal anchor reinforcement of the foundation during the design life period.

4) It is easy to install and can reliably transmit tension and pressure. The core energy-dissipating rod is like the fuse of a concrete column, which yields first under the action of a strong earthquake and protects other parts of the column. In order to make this concentrated damaged part easy to replace, the utility model designs it to be separated from the longitudinal steel bars in the column, and can be installed after the rest of the structure is installed. The rear-mounted part must have good tolerance adaptability. If the size of the energy-consuming connection assembly is larger than or exactly equal to the size of the component installation space, it will cause the components to collide and block each other, and the installation cannot be implemented. Therefore, in order to facilitate the installation of the components, the size of the energy-consuming connection assembly should be slightly smaller than the size of the installation space of the components, so that there may be gaps between the components after the installation is completed. The traditional threaded sleeve connection can eliminate the gap between the components, but the small gap between the core energy dissipation rod and the thread at the end of the steel bar may still cause slippage during longitudinal force transmission. This kind of slip causes the stiffness of the connection to decrease when it is under stress, which is very unfavorable for the column foot joint that bears the combined action of axial force and bending moment.

In the utility model, when the core energy-consuming rods are solid core energy-consuming rods at both ends, one end of the core energy-consuming rods can be connected with the foundation longitudinal anchoring steel bars by a straight-threaded sleeve. The end of the energy dissipating rod is pressed against the longitudinal anchoring steel bar of the foundation to eliminate the gap between the two, or the taper thread sleeve is used for connection, and the gap can also be eliminated by the deformation of the thread itself; the other end is connected by an adjustable combined steel bar joint The sleeve connects the core energy-dissipating rod with the longitudinal reinforcement in the column, which is convenient to adjust the gap between the core energy-dissipating rod and the steel reinforcement, and through the telescopic characteristics of the sleeve itself during the installation process, the column and the foundation are connected. Organically connected as a whole; after the installation of the adjustable combined steel bar joint is completed and the threads of each part are tightened, the second inner sleeve and the first inner sleeve guide head side end are pressed tightly, and the equal diameter shrinking step of the outer sleeve is connected to the first inner sleeve. The side end of the countersunk head hole of the inner sleeve is pressed tightly, so that the thread at the end of the anchoring longitudinal rib in the column and the thread of the inner thread of the first inner sleeve abut on one side, and the thread of the inner thread of the outer sleeve is in contact with the thread of the second inner thread of the inner sleeve. The thread of the outer thread of the inner sleeve is in contact with the other side; at the same time, the end of the second inner sleeve is pressed against the locking nut by the column, and the thread of the inner thread of the second inner sleeve is connected to the column of the core energy dissipation rod. The thread of the external thread of the connecting section abuts on one side, and the thread of the internal thread of the column-directed locking nut and the thread of the external thread of the column-to-connecting section of the core energy dissipating rod abut on the other side.

In the utility model, when the core energy-consuming rods are selected as core energy-consuming rods with blind holes at both ends, the column-to-column connecting section of the core energy-consuming rods is connected with the longitudinal steel bars in the column by an adjustable combined joint, and the adjustable combined joint is installed After completing and tightening each part of the thread, the end of the column connecting section of the core energy dissipation rod is in contact with the end of the guide head side of the first inner sleeve of the adjustable combined joint, and the outer sleeve of the adjustable combined joint is equal in diameter. The side end of the countersunk head hole of the first inner sleeve is tightly pressed, and the outer thread of the longitudinal steel bar in the column and the thread of the inner thread of the first inner sleeve are abutted on one side, and the thread of the inner thread of the outer sleeve and the core dissipate energy. The thread of the external thread of the rod-to-column connection section is in contact on the other side; the foundation-to-connection section of the core energy dissipation rod is connected to the external thread of the end of the longitudinal anchoring steel bar of the foundation through the blind hole internal thread of the end section, and The foundation direction lock nut is used for fastening. After the installation is completed and the threads of each part are tightened, the foundation direction lock nut is pressed against the end of the foundation connection section of the core energy dissipation rod, and the end section of the foundation direction connection section is blinded. The thread of the inner thread of the hole and the thread of the end thread of the longitudinal anchoring steel bar of the foundation abut on one side, and the thread of the inner thread of the foundation lock nut and the thread of the end thread of the longitudinal anchoring steel bar of the foundation abut on the other side.

The inter-engagement relationship between the above-mentioned threads enables the tension and pressure of the core energy-dissipating rod to be transmitted through the tightly offset pressure surfaces between the components, and the connection does not slip during the transmission of tension and pressure, eliminating the thread gap for force transmission. Influence, to ensure the validity and reliability of the node force transmission system.

5) It has strong adaptability to the installation tolerance between components. An adjustable combined steel bar joint is used to connect the longitudinal stressed steel bar and the core energy-dissipating rod. The short sleeve joint does not affect the installation of stirrups, and the small size does not affect the concrete protective layer. The length and eccentricity of the steel bars can be adjusted appropriately. During the construction process, the steel bar joints can be rotated for fine adjustment to improve the construction accuracy and ensure reliable and stable connection quality.

Description of drawings

Figure 1a is a circular concrete column foot node, the core energy-dissipating rods are solid core energy-dissipating rods at both ends, and the restraint system only includes multiple layers of carbon fiber cloth;

Among them, 1 is the concrete column; 2 is the core energy dissipation rod; 3 is the adjustable steel bar composite joint; 4 is the restraint system; 5 is the concrete foundation;

Figure 1b is a circular concrete column foot node, the core energy dissipation rods are solid core energy dissipation rods at both ends, and the restraint system includes restraint cover plates, embedded bolts, nuts and multi-layer carbon fiber cloth;

Figure 1c is a rectangular concrete column foot node. The core energy dissipation rods are solid core energy dissipation rods at both ends. The restraint system includes restraint cover plates, L-shaped additional restraint plates, embedded bolts, nuts and multi-layer carbon fiber cloth;

Figure 1d is a circular concrete column foot node, the core energy dissipation rods are core energy dissipation rods with blind holes at both ends, and the restraint system only includes multiple layers of carbon fiber cloth;

Figure 1e is a circular concrete column foot node. The core energy dissipation rods are core energy dissipation rods with blind holes at both ends. The restraint system includes restraint cover plates, embedded bolts, nuts and multi-layer carbon fiber cloth;

Figure 1f is a rectangular concrete column foot node. The core energy dissipation rods are core energy dissipation rods with blind holes at both ends. The restraint system includes restraint cover plates, L-shaped additional restraint plates, embedded bolts, nuts and multi-layer carbon fiber cloth;

Figure 2a is a circular concrete column foot node, the core energy-dissipating rods are solid core energy-dissipating rods at both ends, and the restraint system only includes multiple layers of carbon fiber cloth;

Figure 2b is a circular concrete column foot node, the core energy dissipation rods are solid core energy dissipation rods at both ends, and the restraint system includes restraint cover plates, embedded bolts, nuts and multi-layer carbon fiber cloth;

Figure 2c is a rectangular concrete column foot node. The core energy-dissipating rods are solid core energy-dissipating rods at both ends. The restraint system includes restraint cover plates, L-shaped additional restraint plates, embedded bolts, nuts and multi-layer carbon fiber cloth;

Figure 2d is a circular concrete column foot node, the core energy dissipation rods are core energy dissipation rods with blind holes at both ends, and the restraint system only includes multiple layers of carbon fiber cloth;

Figure 2e is a circular concrete column foot node. The core energy dissipation rods are core energy dissipation rods with blind holes at both ends. The restraint system includes restraint cover plates, embedded bolts, nuts and multi-layer carbon fiber cloth;

Figure 2f is a rectangular concrete column foot node. The core energy-dissipating rods are core energy-dissipating rods with blind holes at both ends. The restraint system includes a restraint cover plate, an L-shaped additional restraint plate, embedded bolts, nuts and multiple layers of carbon fiber cloth;

Fig. 3 is the front view of the structure of the utility model;

Among them, 46 is multi-layer carbon fiber cloth;

Figure 4a is a circular concrete column foot node, the core energy dissipation rods are solid core energy dissipation rods at both ends, and the restraint system only includes multiple layers of carbon fiber cloth;

Among them, 11 is the concrete column body; 12 is the reinforced core column at the bottom of the column; 13 is the longitudinal steel bar in the column; 31 is the adjustable steel bar composite joint; 53 is the foundation embedded steel block; 54 is the foundation longitudinal anchoring steel bar; 55 is the foundation additional anchoring steel bar;

Figure 4b is a circular concrete column foot node, the core energy dissipation rods are solid core energy dissipation rods at both ends, and the restraint system includes restraint cover plates, embedded bolts, nuts and multi-layer carbon fiber cloth;

Among them, 41 is an arc-shaped restraint cover plate; 42 is an L-shaped additional restraint plate; 43 is a pre-embedded bolt; 44 is a nut;

Figure 4c is a rectangular concrete column foot node. The core energy dissipation rods are solid core energy dissipation rods at both ends. The restraint system includes a restraint cover plate, an L-shaped additional restraint plate, embedded bolts, nuts and multiple layers of carbon fiber cloth;

Figure 4d is a circular concrete column foot node, the core energy dissipation rods are core energy dissipation rods with blind holes at both ends, and the restraint system only includes multiple layers of carbon fiber cloth;

Among them, 322 is the basic lock nut;

Figure 4e is a circular concrete column foot node. The core energy dissipation rods are core energy dissipation rods with blind holes at both ends. The restraint system includes restraint cover plates, embedded bolts, nuts and multi-layer carbon fiber cloth;

Figure 4f is a rectangular concrete column foot node. The core energy dissipation rods are core energy dissipation rods with blind holes at both ends. The restraint system includes restraint cover plates, L-shaped additional restraint plates, embedded bolts, nuts and multi-layer carbon fiber cloth;

Figure 5a is a solid core energy dissipation rod at both ends;

Among them, 21 is the column connecting section; 22 is the energy consumption section; 23 is the foundation connecting section;

Figure 5b is a core energy dissipating rod with blind holes open at both ends;

Among them, 211 is the blind hole in the center of the column connection section; 231 is the blind hole in the center of the connection section in the foundation direction;

In Figure 6a, the core energy-dissipating rods are solid core energy-dissipating rods at both ends;

311 is the outer sleeve; 312 is the first inner sleeve; 313 is the second inner sleeve; 314 is the column locking nut; Head hole; 3122 is the guide head;

In Figure 6b, the core energy-dissipating rod is selected as the core energy-dissipating rod with blind holes at both ends;

Figure 7a is a schematic diagram of the structure of the arc-shaped restraining cover plate in the circular concrete column foot joint;

Wherein, 41 is an arc-shaped constraining cover plate; 412 is a bolt hole; 411 is an inner groove of the arc-shaped constraining cover plate;

Figure 7b is a schematic structural diagram of a right-angle restraint cover plate corresponding to a corner core energy dissipation rod in a rectangular concrete column foot node;

Wherein, 47 is the right-angle restraint cover plate; 471 is the inner groove of the right-angle restraint cover plate;

Figure 7c is a schematic structural diagram of a rectangular confinement cover plate corresponding to a non-corner core energy dissipation rod in a rectangular concrete column foot node;

48 is a rectangular constraining cover plate; 481 is an inner groove of the rectangular constraining cover plate;

Fig. 8 is the schematic diagram of the L-shaped additional restraint plate in the restraint system;

Among them, 421 is the bolt hole.

Detailed ways

Below in conjunction with accompanying drawing and embodiment, the utility model is further described:

As shown in Figures 1 to 3, the utility model is a concrete column foot joint with high ductility and easy repair. The concrete column foot joint is arranged at the bottom of the concrete structure column, including a concrete column 1, a core energy dissipation rod 2, and adjustable steel bars. Composite joint 3, restraint system 4 and concrete foundation 5. The core energy dissipating rod 2 is connected to the longitudinal steel bar in the concrete column 1 and the anchoring steel bar in the concrete foundation, and its two ends are respectively connected with the longitudinal steel bar in the concrete column and the anchoring steel bar in the concrete foundation through the adjustable steel bar composite joint 3 respectively. The steel bar combination joint 3 can reliably transmit both pressure and tension, and the periphery of the core energy-consuming rod 2 is constrained by a restraint system.

The concrete column 1 includes a concrete column body 11, a reinforcing core column 12 at the bottom of the column, and a longitudinal steel bar 13 in the column. , the first structure is a concrete block bounded by steel plates on the sides and bottom, the second structure is a block made of high-strength materials such as high-strength grouting material and ultra-high-performance concrete, and the third structure is made of multiple steel plates Formed steel blocks made by fixed connections.

There is an abrupt change of section area between the concrete column body 11 and the column bottom reinforcing core column 12, the cross section of the column bottom strengthening core column 12 is smaller than that of the concrete column body 11 to form a reserved space, and the section center of the column bottom strengthening core column 12 is the same as the one of the concrete column body 11. The center of the section of the concrete column body 11 is vertically aligned.

The concrete foundation 5 includes a foundation concrete block 51 , a raised limit block 52 , a foundation embedded steel block 53 , a foundation longitudinal anchoring steel bar 54 and a foundation additional anchoring steel bar 55 , and the foundation embedded steel block 53 is anchored on the top surface of the foundation concrete block 51 . And it is located at the periphery of the column bottom reinforcing core column 12, the column bottom reinforcing core column 12 is placed in the center of the top surface of the foundation concrete block 51, and the convex limit block 52 is in close contact with the bottom side of the column bottom reinforcing core column 12. The position block 52 is fixedly connected with the foundation embedded steel block 53, the bottom surface of the foundation embedded steel block 53 is fixedly connected with the foundation additional anchoring steel bar 55, and the foundation longitudinal anchoring steel bar 54 and the foundation additional anchoring steel bar are embedded in the corresponding position of the foundation concrete block 51. 55. The longitudinal anchoring steel bar 54 of the foundation is on the same line as the longitudinal steel bar 13 in the column corresponding to the top; when the core energy dissipation rod 2 is a solid core energy dissipation rod at both ends, a sleeve is set aside near the upper end of the longitudinal anchoring reinforcement bar 54 of the foundation. The reserved space required for the connection of the cylinder; when the core energy dissipation rod 2 is a core energy dissipation rod with blind holes at both ends, a foundation for the core energy dissipation rod 2 is reserved near the upper end of the longitudinal anchoring steel bar 54 of the foundation. The space where the connection section 23 and the foundation are vertically screwed to the lock nut 322 . The raised limit block 52 can also be replaced with a raised limit steel bar and a raised limit steel bar, but it is not limited to these three structures, and the functions are all to resist the shear force at the bottom of the column.

As shown in Figures 4 and 5, the core energy dissipation rod 2 is arranged around the reinforcing core column 12 at the bottom of the column; the two ends of the core energy dissipation rod 2 are respectively provided with a column connection section 21 and a foundation connection section 23, and the middle part is the energy dissipation rod Section 22; the cross-sectional area of the column-direction connecting section 21 and the foundation-direction connecting section 23 is greater than the cross-sectional area of the energy-consuming section 22; The longitudinal reinforcement bars 13 in the inner column are reliably connected, and the foundation energy dissipation section 23 is reliably connected with the foundation longitudinal anchoring reinforcement bars 54 in the concrete foundation through the threaded connectors 32 in the adjustable steel bar composite joint 3 to form a continuous force transmission system; The core energy-consuming rod 2, the adjustable steel bar combination joint 31 and the threaded connector 32 are all made of metal materials, which can be steel or other ductile metals; Center blind hole core energy dissipation rod.

The solid core energy-dissipating rods at both ends have external threads engraved on the surfaces of the column connecting section 21 and the foundation connecting section 23; the corresponding threaded connector 32 in the adjustable steel bar composite joint 3 is a straight threaded sleeve or Tapered Thread Sleeve.

The core energy dissipation rod with central blind holes at both ends has an external thread engraved on the surface of the column connecting section 21, the end section is provided with a central blind hole 211, and the base is provided with a central blind hole in the end section of the connecting section 23 231, and an internal thread is engraved on the inner wall of the blind hole; the threaded connector 32 in the corresponding adjustable steel bar composite joint 3 is the basic locking nut 322; the blind hole type core energy-consuming rod with central blind holes at both ends is longitudinally anchored to the foundation The connection between the reinforcement bars 54 is screwed together with the inner thread of the blind hole of the foundation connection section 23 and the end thread of the foundation longitudinal anchoring steel bar 54, and is fastened by the foundation direction lock nut 322; the foundation direction lock nut 322 has The central through hole, the inner wall of the through hole is provided with an internal thread, and the internal thread is screwed with the end of the foundation longitudinal anchoring steel bar 54; .

As shown in FIG. 6 , when the core energy-dissipating rods 2 use solid core energy-dissipating rods at both ends, the adjustable steel bar combination joint 31 in the adjustable steel bar combination joint 3 includes an outer sleeve 311, a first inner sleeve 312, The second inner sleeve 313 and the column locking nut 314; one end of the outer sleeve 311 is provided with an equal diameter constriction 3111 with a diameter larger than the nominal diameter of the longitudinal steel bar 13 in the column, and the inner wall of the other end section is provided with an internal thread; The outer diameter of the inner sleeve 312 is larger than the diameter of the equal diameter constriction 3111 of the outer sleeve 311 but smaller than the inner diameter of the outer sleeve 311. One end of the first inner sleeve 312 is provided with a central countersunk hole 3121, and the inner wall of the central countersunk hole 3121 is processed There is an internal thread, the other end of the first inner sleeve 312 is provided with a guide head 3122, and the guide head 3122 may be set in the form of a hemisphere, a cone, etc.; the center hole of the second inner sleeve 313 is a through hole, and the diameter of the through hole is slightly Larger than the maximum diameter of the guide head 3123 of the first inner sleeve 312, the inner wall of the through hole is provided with an inner thread, one end of the second inner sleeve 313 has an outer thread on the cylinder wall, and the end of the outer thread of the second inner sleeve 313 is pressed against At the end of the first inner sleeve 312; the column direction locking nut 314 has a central through hole, and the inner wall of the central through hole is provided with an inner thread; Through the equal diameter necking 3111, the outer thread is screwed with the inner thread of the countersunk hole 3121 of the first inner sleeve 312; the inner thread of the outer sleeve 311 is matched with the outer thread provided on the cylinder wall of the second inner sleeve 313 Screw connection; the external thread of the column connection section 21 of the connected core energy dissipating rod 2 is screwed together with the inner thread of the inner wall of the second inner sleeve 313; The post is screwed together with the external thread of the connecting section 21 , and the post lock nut 314 is pressed against the end of the second inner sleeve 313 .

When the core energy-dissipating rods 2 are core energy-dissipating rods with blind holes open at both ends, the adjustable steel bar combination joint 31 in the adjustable steel bar combination joint 3 includes an outer sleeve 311 and a first sleeve sleeved inside the outer sleeve 311. An inner sleeve 312; one end of the outer sleeve 311 is set as an equal diameter constriction 3111 with a diameter larger than the nominal diameter of the longitudinal steel bar 13 in the column, and the inner wall of the other end section is provided with an internal thread, which is connected with the column of the core energy dissipation rod 2 Fitted and screwed to the outer thread of the end section of the connecting section 21; the outer diameter of the first inner sleeve 312 is larger than the equal diameter necking diameter 3111 of the outer sleeve 311 but smaller than the inner diameter of the outer sleeve 311, one end of the first inner sleeve 312 There is a central countersunk hole 3121, the inner wall of the central countersunk hole 3121 is processed with internal threads, the other end of the first inner sleeve 312 is provided with a guide head 3122, and the guide head 3122 may be set in the form of a hemisphere, a cone, etc. The maximum diameter is smaller than the diameter of the central blind hole 211 at the end of the column connecting section 21 of the core energy dissipation rod 2, and its height is smaller than the depth of the central blind hole 211 at the end of the column connecting section 21 of the core energy dissipation rod 2; the connected The lower end of the longitudinal steel bar 13 in the column is provided with an external thread, the lower end of which passes through the equal diameter constriction 3111, and the external thread is screwed together with the internal thread of the counterbore hole 3121 of the first inner sleeve 312.

As shown in Fig. 4, Fig. 7 and Fig. 8, when the cross-section of the concrete column 1 is circular, the restraint system 4 includes the inner side of the arc-shaped restraint cover plate on the outside of the core energy dissipation rod, that is, on the side away from the centroid of the cross-section of the concrete column. The arc-shaped constraining cover plate 41 of the groove 411, the pre-embedded bolts 43 pre-buried in the column bottom reinforcing core column, the nut 44 for fixing the relative position of the constraining cover plate and the column bottom strengthening core column, and the pre-filled column bottom area. Filled concrete 45 with space left and multi-layer carbon fiber cloth 46 reliably bonded to the outside of the bottom area of the concrete column; the length of the arc-shaped constraining cover plate 41 covers all the energy-dissipating sections 22 of the core energy-dissipating rods 2 and part of the column-to-connecting section 21 And part of the foundation to the connecting section 23, a certain gap needs to be left between the upper end of the arc-shaped constraining cover plate 41 and the adjustable steel bar composite joint 31, and a certain gap needs to be left between the lower end of the arc-shaped constraining cover plate 41 and the foundation concrete block 51. Clearance, at the intersection of the energy-consuming section 22 of the core energy-consuming rod 2 and the column-direction connecting section 21 and the intersection of the energy-consuming section 22 and the foundation-direction energy-consuming section 23, the arc-shaped constraining cover plate 41 and the core energy-consuming rod 2 are in the vertical direction. A certain gap should be left in the direction to prevent the arc-shaped restraint cover plate 41 from contacting with the adjustable steel bar composite joint 31, the foundation concrete block 51 or the core energy-dissipating rod 2 when the core energy-dissipating rod 2 is axially deformed; The position and shape of the grooves 411 on the inner side of the arc-shaped restraint cover plate 41 match with the outer contour of the covered core energy dissipation rod 2 section, and the inner grooves 411 of the arc-shaped restraint cover plate are located at various positions along the radial direction. The size of the column is slightly larger than the size of the corresponding position of the core energy dissipation rod 2; the arc-shaped restraint cover plate 41 is provided with bolt holes 412 that facilitate the alignment and passage of the embedded bolts 43; when the cross-section of the concrete column 1 is circular, the restraint system 4 It is also possible to include only filled concrete 45 and multiple layers of carbon fiber cloth 46 , but not include the arc-shaped restraint cover plate 41 , the embedded bolts 43 and the nuts 44 .

When the cross-section of the concrete column 1 is rectangular, the restraint system 4 includes a right-angle constraining cover plate 47 located at the corner of the cross-section of the rectangular concrete column and having a groove 471 on the inner side of the right-angle constraining cover plate. A rectangular constraining cover 48 with a groove 481 on the inner side of the rectangular constraining cover on one side of the centroid of the column section, an L-shaped additional constraining plate 42 close to the right-angle constraining cover 47 and the outer side of the rectangular constraining cover 48, embedded in the Pre-embedded bolts 43 in the reinforcing core column at the bottom of the column, nuts 44 for fixing the relative position of the additional restraint plate and the reinforcing core column at the bottom of the column, filling concrete 45 for filling the reserved space at the bottom of the column, and reliable bonding to the bottom of the concrete column The multi-layer carbon fiber cloth 46 on the outside of the area; the length of the right-angle constraining cover plate 47 and the rectangular constraining cover plate 48 covers all the energy-dissipating sections 22 of the core energy-dissipating rod 2, part of the column-direction connecting section 21 and part of the foundation-direction connecting section 23, right angle A certain gap should be left between the upper ends of the restraint cover plate 47 and the upper end of the rectangular restraint cover plate 48 and the adjustable steel bar composite joint 31 , and a gap should be left between the lower ends of the right angle restraint cover plate 47 and the lower end of the rectangular restraint cover plate 48 and the foundation concrete block 51 . With a certain gap, at the intersection of the energy-consuming section 22 of the core energy-consuming rod 2 and the column-direction connecting section 21 and the intersection of the energy-consuming section 22 and the foundation-direction energy-consuming section 23, the right-angle constraining cover plate 47 and the rectangular constraining cover plate 48 are connected to the core. The energy-dissipating rod 2 also needs to have a certain gap in the vertical direction to prevent the right-angle constraining cover plate 47 and the rectangular constraining cover plate 48 and the adjustable steel bar combination joint 31 and the foundation concrete block when the core energy-dissipating rod 2 is axially deformed. 51 or the core energy dissipation rod 2 is in contact; the right-angle constraining cover plate 47 and the rectangular constraining cover plate 48 are opened on the right-angle constraining cover plate inner groove groove 471 and the rectangular constraining cover plate inner groove 481 The position and shape of the covered core The outer contours of the energy-dissipating rod 2 sections are matched, and the size of the inner groove groove 471 of the right-angle constraining cover plate and the inner groove 481 of the rectangular constraining cover plate along the radial direction is slightly larger than the size of the corresponding position of the core energy-dissipating rod 2, There is a gap of 1mm~2mm between the core energy dissipation rod 2 and the groove wall of the inner groove groove 471 of the right-angle restraint cover plate and the inner groove 481 of the rectangular restraint cover plate; the inner side of the L-shaped additional restraint plate 42 is adjacent to the corresponding position. The outer side of the restraint cover plate is tightly attached; the L-shaped additional restraint plate is provided with bolt holes 421 which facilitate the alignment and passage of the embedded bolts.

The utility model is characterized in that the structural division of labor is clear, the force transmission path is direct, the core energy dissipation rod can exert stable ductility and energy dissipation capacity, and even if the axial pressure of the concrete column is relatively large, the damage of the column bottom can only be concentrated in the core. The damaged core energy-consuming rod can be easily replaced after a strong earthquake, so as to quickly restore the structural function.

The adjustable steel bar composite joint used in the utility model is used in the construction of the mutual connection of two sections of steel bars in a concrete structure, which can realize the non-slip and reliable connection of two sections of steel bars in the same section axis, and is suitable for various occasions. The connection of steel bars of different diameters has a wide range of applications; its characteristics are that the sleeve joints are short, which does not affect the installation of stirrups; the size of the sleeves is small, which does not affect the concrete protective layer; the length and eccentricity of the steel bars can be adjusted appropriately; During installation, the steel bar joint can be rotated for fine adjustment to adapt to the installation accuracy of the component; the connection quality is reliable and stable; the joint connection can realize no gap slippage when the steel bar is under compression and tension, and the force is reliable, which can meet the requirements of the first-class joint.

An important reason for the failure of concrete columns is the insufficient lateral restraint of the columns under the action of earthquakes, which causes shear failure, anchor failure and peeling failure of the concrete protective layer. Covering the concrete column with carbon fiber cloth can effectively improve the bearing capacity and ductility of the eccentrically compressed concrete column, limit the development of oblique cracks, and significantly improve the shear bearing capacity of the column. The bending failure of the normal section has a harbinger before the failure. Unlike ordinary reinforced concrete columns, the stirrups only have a constraining effect on the core concrete, and the carbon fiber cloth is used to constrain the concrete, which constrains the concrete of the entire column. In this way, the number of stirrups in the column can be effectively reduced, and it is convenient to explore the reinforcement method of replacing or changing a large number of stirrups in the conventional column. By increasing the number of wrapping layers of carbon fiber cloth, the bearing capacity and lateral deformation capacity of the eccentrically compressed concrete column are also continuously increased. For concrete columns with large shear-span ratio, it is only necessary to wrap carbon fiber cloth within a certain range at the root of the column during seismic reinforcement, and the carbon fiber cloth far from the root of the column has a weak reinforcement effect. Generally, the carbon fiber cloth can be pasted within the range of twice the height of the column section in the potential plastic hinge area of the column to meet the requirements.

The reinforcement effect of carbon fiber cloth on the circular section concrete column is better, and the improvement of the column bearing capacity and ductility is better than that of the rectangular section concrete column. When carbon fiber cloth is used to restrain a circular section concrete column, it can provide uniform restraint force around the column; when a rectangular cross section concrete column is restrained with carbon fiber cloth, the restraint force provided by it is not uniform, and the concrete at the edge of the middle of the side of the column is affected. The constraint is small and negligible, and only the core concrete in the middle part is effectively constrained. The ratio of the corner radius of the concrete column to the column diameter (side length) has a significant impact on the restraint effect. Increasing the corner radius will improve the seismic performance of the carbon fiber cloth restrained concrete column.

The use method of this utility model:

1) Component production

The concrete column 1 and the concrete foundation 5 are respectively processed and manufactured according to the design size, and a reserved space is set in the node area of the column foot for the installation of the core energy dissipation rod 2, the adjustable steel bar composite joint 3 and the restraint system 4;

According to the design size, the core energy-consuming rod 2, the adjustable steel bar composite joint 3, and the various components in the restraint system 4 are processed and manufactured respectively;

The foundation longitudinal anchoring steel bar 54 and the foundation additional anchoring steel bar 55 are pre-buried in the corresponding position in the concrete foundation 1; the upper end of the foundation longitudinal anchoring steel bar 54 does not protrude from the top surface of the foundation concrete block 51, and its upper end section has an end thread section, and the foundation The cross-sectional centroid of the longitudinal anchoring steel bar 54 and the cross-sectional centroid of the longitudinal steel bar 13 in the column to be connected are located on the same axis; The space required for the pre-embedded connection sleeve shall be reserved near the upper end; when the core energy dissipation rod 2 is a core energy dissipation rod with blind holes at both ends, a space for the core shall be reserved near the upper end of the longitudinal anchoring steel bar 54 of the foundation. The space where the foundation connection section 23 of the energy dissipation rod 2 and the foundation lock nut 322 are screwed vertically, and the reserved space is separated from the surrounding foundation concrete with plastic sheets to ensure the end of the foundation longitudinal anchoring steel bar 54 Thread segments clean.

The longitudinal reinforcement bars 13 in the column are embedded in the concrete column 1, the lower end of which protrudes from the lower surface of the concrete column body for a certain length, and the end of the extension is engraved with external threads; When the core energy dissipation rod is used, the length of the lower end of the longitudinal steel bar 13 in the column should be longer than the length of the outer sleeve 311, so as to ensure that there is space for pushing the outer sleeve 311 upward when installing the core energy dissipation rod 2; if necessary, in the column Pre-embedded bolts 43 are pre-embedded on the side of the bottom reinforcing core column 12;

2) Installation of core energy dissipation rod 2 and adjustable steel bar combination joint 3

When the core energy-dissipating rods 2 are solid core energy-dissipating rods at both ends, the outer sleeve 311 of the adjustable steel bar composite joint 31 is sleeved into the threaded section at the end of the longitudinal steel bar 13 in the column. Screw the column locking nut 314 and the second inner sleeve 313 of the adjustable steel bar combination joint 31 into the outer thread of the column connecting section 21 of the core energy dissipating rod 2 in sequence. Connect the foundation connection section 23 of the core energy dissipation rod 2 with the threaded section of the foundation longitudinal anchoring steel bar 54 through the threaded connector 32 and fasten and fix it through the thread on the surface of the component, and ensure that the foundation connection section 23 of the core energy dissipation rod 2 The ends abut against the ends of the threaded segments of the longitudinal anchor reinforcement bars 54 of the foundation. Screw the first inner sleeve 312 into the threaded section at the end of the longitudinal steel bar 13 in the column and press it tightly. Screw the second inner sleeve 313 to the first inner sleeve 312 and push it tightly. When there is a slight error in the axis of the longitudinal steel bar 13 in the column and the longitudinal anchoring steel bar 54 of the foundation, due to the difference between the guide head 3122 and the second inner sleeve 313 The guiding effect between the longitudinal bars 13 in the column or the core energy dissipating rods 2 will produce slight bending to adapt to the error; the outer sleeve 311 is pulled down, and the inner thread of the outer sleeve is screwed into the outer thread of the second inner sleeve 313 , to ensure that the equal diameter constriction 3111 of the outer sleeve 311 catches the end of the first inner sleeve 312 and tightens it tightly; rotate the column lock nut 314 to the second inner sleeve 313 and tighten.

When the core energy-dissipating rod 2 is a core energy-dissipating rod with blind holes at both ends, the outer sleeve 311 of the adjustable steel bar composite joint 31 is sleeved into the end threaded section of the longitudinal steel bar 13 in the column. Thread foundation lock nut 322 into the end male thread of foundation longitudinal anchor bar 54 and screw down. Screw the foundation of the core energy-dissipating rod 2 into the connecting section 23 of the foundation longitudinal anchoring steel bar 54 and screw it down, and push the outer sleeve 311 up until the column-oriented connecting section of the core energy-dissipating rod 2 A space that can be put into the first inner sleeve 312 is left between 21 and the threaded section at the end of the longitudinal steel bar 13 in the column. The first inner sleeve 312 is screwed into the end threaded section of the longitudinal steel bar 13 in the column and abutted tightly. The core energy dissipating rod 2 is reversely screwed so that the end of the column connecting section 21 abuts the end of the first inner sleeve 312 on the side of the guide head 3123 . When there is a slight error in the axis of the longitudinal reinforcement 13 in the column and the longitudinal anchoring reinforcement 54 of the foundation, due to the guiding effect between the guide head 3122 and the column connecting section 21 of the core energy dissipation rod 2, the longitudinal reinforcement in the column 13 or the core energy dissipation rod 2 will produce a slight bend to accommodate the error. Pull the outer sleeve 311 down, and screw its inner thread into the outer thread of the end section of the column-to-connecting section 21 of the core energy dissipating rod 2, until the step of the equal-diameter constriction 3111 of the outer sleeve 311 abuts against the first A central countersunk hole 3121 side end of an inner sleeve 312 . Rotate the basic locking nut 322 upward until its end abuts against the end of the column connecting section 21 of the core energy dissipating rod 2 .

3) Installation of restraint system 4

When the cross-section of the concrete column is circular, the remaining part of the reserved space in the node area of the column foot can be directly filled with filled concrete 45 and cured.

When the cross-section of the concrete column is circular, install the arc-shaped constraining cover plate 41, insert the embedded bolts 43 in the bolt holes 412, between the core energy dissipation rod 2 and the groove wall of the inner groove 411 of the arc-shaped constraining cover plate, Leave a gap of 1mm~2mm to ensure the effective performance of the low cycle fatigue performance and yield energy dissipation capacity of the core energy dissipation rod 2; screw the nut 44 into the end of the embedded bolt 43 and tighten it with a wrench to fix it; after completing the above work, put the The remaining part of the reserved space in the node area of the column foot is filled with filled concrete 45 and cured.

When the cross-section of the concrete column is rectangular, install the right-angle restraint cover plate 47 and the rectangular restraint cover plate 48 to ensure that the inner side of the right-angle restraint cover plate 47 and the inner side groove groove 471 of the right-angle restraint cover plate 47 and the inner side of the rectangular restraint cover plate 48 are rectangular The inner groove 481 of the constraining cover plate fastens the core energy dissipation rod 2 and covers the energy dissipation section 22 thereof. There is a gap of 1mm~2mm between them to ensure the effective performance of the low cycle fatigue performance and yield energy dissipation capacity of the core energy dissipation rod 2; the L-shaped additional restraint plate 42 is attached to the adjacent arc restraint cover plate 41 at the corresponding position; Insert embedded bolts 43 into the bolt holes of the L-shaped additional restraint plate 42, screw nuts 44 at the ends of the embedded bolts 43 and tighten them with a wrench; Filling concrete 45 is filled and cured.

After the filled concrete 45 reaches the strength, the multi-layer carbon fiber cloth 46 is reliably pasted to the outside of the bottom area of the concrete column. The specific process is as follows: cutting carbon fiber cloth, it is required to be neatly cut without missing corners, burrs, etc. Polish the concrete surface to the area where the carbon fiber cloth needs to be attached, remove the laitance and oil stains on the surface, remove the surface concrete floating dust with a high-pressure water gun, and then use a absorbent cotton cloth dipped in acetone or pure alcohol solution to wipe the surface clean and air dry after it is completely dry. . When the cross-section of the concrete column is rectangular, the area to be pasted with carbon fiber cloth should be chamfered first to prevent the carbon fiber cloth from breaking prematurely due to excessive concentrated force under the action of earthquake. Configure the repair glue as a leveling material to repair and fill the honeycomb, pockmarked and concave parts of the concrete surface to ensure that the carbon fiber cloth is in full contact with the concrete surface when pasting, and it is cured until it is dry to the touch. After configuring the primer and mixing well, apply it evenly to the concrete surface with a brush. Configure the impregnating glue in a certain proportion, apply it evenly to the concrete surface with a brush, align the carbon fiber tightly and paste it on, and at the same time use a roller to compact the wrapped column surface in the same direction until the glue seeps out and air bubbles are driven out , to ensure a tight bond between the carbon fiber cloth and the concrete, the fiber cloth should be fully infiltrated by the impregnating glue, and kept straight and flat. In the overlapping part of each layer of carbon fiber cloth, roll repeatedly with rollers to ensure good overlapping of carbon fiber cloth. Repeat the above steps to paste multiple layers of carbon fiber cloth. The surface of the upper layer of carbon fiber cloth needs to be dry to the touch before pasting the next layer of carbon fiber cloth. After the outermost layer of carbon fiber cloth is pasted, it is still necessary to apply dipping glue evenly on the surface for protection.

4) Replacement of damaged core energy-consuming rod 2 after earthquake

After a major earthquake, the multi-layer carbon fiber cloth 46 wrapped around the bottom of the concrete column is released, and part of the concrete around the joint at the foot of the column is chiseled. If the restraint system includes the arc-shaped restraint cover plate 41, the L-shaped additional restraint plate 42 and other components, the arc-shaped restraint cover plate 41, the L-shaped additional restraint plate 42, etc. need to be removed according to the reverse procedure of the installation process.

When the core energy-dissipating rod 2 is made of solid core energy-dissipating rods at both ends, loosen the column-oriented locking nut 314 and the second inner sleeve 313 of the adjustable steel bar combination joint 31 in turn and follow the core energy-dissipating rod 2. Screw down to the external thread of the connecting section 21. Loosen the threaded connector 32 , and screw the basic connecting section 23 of the core energy dissipating rod 2 upward along the inner thread of the threaded connector 32 until the core energy dissipating rod 2 is disengaged from the threaded connector 32 .

When the core energy-dissipating rod 2 is a core energy-dissipating rod with blind holes at both ends, unscrew the outer sleeve 311 of the adjustable steel bar combination joint 31 and follow the column of the core energy-dissipating rod 2 to the end of the connecting section 21 The external thread of the segment is screwed upwards. Remove part of the concrete near the end of the foundation longitudinal anchoring steel bar 54, and screw the foundation-to-base locking nut 322 and the foundation-to-connecting section 23 of the core energy dissipation rod 2 along the outer thread of the end of the foundation longitudinal anchoring steel bar 54 until the core The space left between the column connecting section 21 of the energy dissipation rod 2 and the end of the longitudinal steel bar 13 in the column is sufficient to take out the first inner sleeve 312 . The first inner sleeve 312 is screwed out of the end threaded section of the longitudinal reinforcement bar 13 in the column and taken out. Screw the foundation of the core energy dissipating rod 2 to the connecting section 23 along the external thread of the end of the longitudinal anchoring steel bar 54 of the foundation, until the core energy dissipating rod 2 can be taken out.

After taking out the damaged core energy-dissipating rod 2, re-install it according to the installation methods of the core energy-dissipating rod 2, the adjustable steel bar composite joint 3 and the restraint system 4 in steps 2 and 3, so that the seismic performance of the structure can be restored.

Claims (7)

1. The utility model provides an easy prosthetic concrete column foot node of high ductility, sets up in concrete structure column bottom, its characterized in that: the method comprises the following steps:

the foundation concrete block is positioned at the bottommost part of the whole concrete column foot node and is used for bearing the concrete structure column part;

the bottom of the concrete structure column is provided with a column bottom reinforcing core column which is coaxial with the concrete structure column, the bottom of the column bottom reinforcing core column is connected with the upper surface of the foundation concrete block, and the section of the column bottom reinforcing core column is smaller than the cross section of the concrete column body, so that an annular reserved space is formed between the upper surface of the foundation concrete block and the bottom of the concrete structure column;

the horizontal limiting mechanism is used for limiting the displacement between the column bottom reinforcing core column and the foundation concrete block in the horizontal direction, and comprises a foundation anchoring unit which is pre-embedded in the foundation concrete block and a protruding limiting block which is fixedly connected with the foundation anchoring unit and extends out of the upper surface of the foundation concrete block, and the protruding limiting block and the bottom side surface of the column bottom reinforcing core column are mutually attached and connected;

the vertical energy consumption units with the same structure are arranged between the foundation concrete block and the concrete structure column and are uniformly arranged along the annular reserved space, and each vertical energy consumption unit comprises:

a column-inside longitudinal steel bar disposed inside the concrete structure column and having an extension portion exposed to the bottom of the concrete structure column;

the foundation longitudinal anchoring steel bars are pre-buried in the foundation concrete block and are in the same straight line with the longitudinal steel bars in the columns;

one end of the core energy dissipation rod is connected with longitudinal steel bars in the concrete column through an adjustable steel bar combined joint, and the other end of the core energy dissipation rod is connected with anchoring steel bars in the concrete foundation through a threaded connecting piece;

a restraint system for limiting lateral buckling of the core energy dissipating bar;

the axial tensile yielding bearing capacity of the core energy dissipation bar is smaller than the axial tensile bearing capacity of the longitudinal steel bar in the column and the longitudinal foundation anchoring steel bar, and is also smaller than the connection bearing capacity of the adjustable steel bar combined joint.

2. A high ductility easy repair concrete column foot node according to claim 1, characterized in that:

the core energy consumption rod comprises a columnar connecting section connected with the concrete structure column, a foundation connecting section connected with the concrete foundation and a middle energy consumption section connected between the columnar connecting section and the foundation connecting section;

the sectional areas of the column direction connecting section and the foundation direction connecting section are larger than the sectional area of the energy consumption section;

the core energy consumption bar, the adjustable steel bar combined joint and the threaded connecting piece are all made of ductile metal materials.

3. A high ductility easy repair concrete column foot node according to claim 2, characterized in that: the core energy dissipation bar is a solid core energy dissipation bar with two ends, and external threads are engraved on the surfaces of the columnar connecting section and the foundation connecting section; the adjustable steel bar combined joint comprises an outer sleeve, a first inner sleeve, a second inner sleeve and a column-direction locking nut; one end of the outer sleeve is provided with an equal-diameter reducing opening with the diameter larger than the nominal diameter of the longitudinal steel bar in the column, and the inner wall of the section at the other end is provided with an internal thread;

the outer diameter of the first inner sleeve is larger than the diameter of the constant-diameter reducing opening of the outer sleeve but smaller than the inner diameter of the outer sleeve, a central countersunk hole is formed in one end of the first inner sleeve, internal threads are machined in the inner wall of the central countersunk hole, a guide head is arranged at the other end of the first inner sleeve, and the guide head is hemispherical or conical;

the central hole of the second inner sleeve is a through hole, the diameter of the through hole is slightly larger than the maximum diameter of the guide head, the inner wall of the through hole is provided with an internal thread, the cylinder wall of one end of the second inner sleeve is provided with an external thread, and the end part of the external thread of the second inner sleeve is abutted against the end part of the first inner sleeve;

the column-direction locking nut is provided with a central through hole, and the inner wall of the central through hole is provided with internal threads;

the lower end of the longitudinal steel bar in the connected column is provided with an external thread, the lower end of the longitudinal steel bar passes through the constant-diameter reducing opening, and the external thread is matched and screwed with the internal thread of the countersunk hole of the first inner sleeve;

the internal thread of the outer sleeve is matched and screwed with the external thread arranged on the wall of the second inner sleeve;

the external thread of the columnar connecting section is matched and screwed with the internal thread of the inner wall of the second inner sleeve;

the internal thread of the column-direction locking nut is matched and screwed with the external thread of the column-direction connecting section, and the column-direction locking nut abuts against the tail end of the second inner sleeve;

the threaded connecting piece is a straight threaded sleeve or a conical threaded sleeve;

a reserved space required by the connection of the installation sleeve is reserved near the upper end of the foundation anchoring steel bar.

4. A high ductility easy repair concrete column foot node according to claim 2, characterized in that: the core energy consumption rod is a core energy consumption rod with central blind holes at two ends, and external threads are engraved on the outer surface of the columnar connecting section provided with the central blind hole;

the adjustable steel bar combined joint comprises an outer sleeve and a first inner sleeve sleeved in the outer sleeve; the end part of one end of the outer sleeve is provided with an equal-diameter reducing opening with the diameter larger than the nominal diameter of the longitudinal steel bar in the column, and the inner wall of the section at the other end is provided with internal threads which are matched and screwed with external threads of the end section of the column-direction connecting section on the core energy consumption rod;

the outer diameter of the first inner sleeve is larger than the diameter of the isodiametric reducing opening of the outer sleeve but smaller than the inner diameter of the outer sleeve, a central countersunk hole is formed in one end of the first inner sleeve, internal threads are machined in the inner wall of the central countersunk hole, a guide head is arranged at the other end of the first inner sleeve and is hemispherical or conical, the maximum diameter of the guide head is smaller than the diameter of a central blind hole in the end part of the upper column of the core energy consumption rod towards the connecting section, and the height of the guide head is smaller than the depth of the upper column of the core energy consumption rod towards;

the lower end of the longitudinal steel bar in the connected column is provided with an external thread, the lower end of the longitudinal steel bar passes through the constant-diameter reducing opening, and the external thread is matched and screwed with the internal thread of the countersunk hole of the first inner sleeve;

the threaded connecting piece is a base locking nut;

the connection between the core energy consumption bar and the foundation longitudinal anchoring steel bar is screwed with the end part thread of the foundation longitudinal anchoring steel bar through the blind hole internal thread of the foundation direction connecting section in a matching way, and the foundation direction locking nut is used for fastening;

the foundation-direction locking nut is provided with a central through hole, the inner wall of the through hole is provided with internal threads, and the internal threads are matched and screwed with the end threads of the foundation longitudinal anchoring steel bar;

the foundation direction locking nut is tightly propped against the end part of the foundation direction connecting section on the core energy consumption rod;

and spaces for vertically screwing the foundation of the core energy consumption bar to the connecting section and the foundation to the locking nut are reserved near the upper end of the foundation anchoring steel bar.

5. A high ductility easy repair concrete column foot node according to claim 1, characterized in that: the concrete column cross-section is circular, the restraint system includes at least:

filling concrete and a plurality of layers of carbon fiber cloth, wherein the filling concrete is used for filling the rest part of the annular reserved space in the column bottom area;

the multi-layer carbon fiber cloth is bonded to the outer side of the bottom area of the concrete column.

6. A high ductility easy-repair concrete column foot node according to claim 5, characterized in that: the constraint system further comprises: the concrete column comprises an arc-shaped constraint cover plate, an embedded bolt and a nut, wherein the arc-shaped constraint cover plate is positioned on the outer side of a core energy consumption rod, namely on one side far away from the centroid of the section of the concrete column;

the length of the arc-shaped constraint cover plate covers an energy consumption section of the core energy consumption rod, a groove matched with the outer contour of the covered section of the core energy consumption rod is arranged on the arc-shaped constraint cover plate, and a gap of 1 mm-2 mm is formed between the core energy consumption rod and the groove wall of the groove;

and the arc-shaped constraint cover plate is provided with bolt holes which are convenient for the alignment and the penetration of the embedded bolts.

7. A high ductility easy-repair concrete column foot node according to claim 5, characterized in that: when the concrete column cross-section is the rectangle, restraint system includes:

the device comprises a right-angle constraint cover plate positioned at a corner of the section of the rectangular concrete column, a rectangular constraint cover plate positioned on the outer side of a core energy consumption rod, namely one side far away from the section centroid of the concrete column, an L-shaped additional constraint plate tightly attached to the outer sides of the right-angle constraint cover plate and the rectangular constraint cover plate, an embedded bolt embedded in a column bottom reinforcing core column, and a nut used for fixing the relative positions of the L-shaped additional constraint plate and the column bottom reinforcing core column;

the length of the right-angle constraint cover plate and the length of the rectangular constraint cover plate cover the energy consumption section of the core energy consumption rod, grooves matched with the outer contour of the covered section of the core energy consumption rod are arranged on the right-angle constraint cover plate and the rectangular constraint cover plate, and a gap of 1 mm-2 mm is formed between the core energy consumption rod and the groove wall of each groove;

the inner side of the L-shaped additional constraint plate is tightly attached to the right-angle constraint cover plate and the outer side of the rectangular constraint cover plate which are close to the corresponding positions;

and the L-shaped additional constraint plate is provided with bolt holes which are convenient for the alignment and the penetration of the embedded bolts.

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