CN104775515A - Hidden beam reinforcement method for improving torsional property of Z-shaped column nodes - Google Patents

Abstract

A concealed beam reinforcement method for improving the torsional performance of a Z-shaped column joint, including a Z-shaped column 2 and a frame beam, the Z-shaped column includes a web and two flanges, the flanges are located at the end of the web, and are arranged inside the flanges The flange longitudinal reinforcement and the flange horizontal stirrup, the flange horizontal stirrup is arranged outside the flange longitudinal reinforcement, the web longitudinal reinforcement and the web horizontal stirrup are arranged inside the web, and the web horizontal stirrup is arranged on the web longitudinal reinforcement The outer side of the web, the flange longitudinal reinforcement and the web longitudinal reinforcement at the intersection of the web and the flange are common, and the hidden beam is set in the web horizontal stirrup. The hidden beam includes the hidden beam longitudinal reinforcement and the hidden beam closed stirrup. The hidden beam longitudinal reinforcement is arranged at the four inner corners of the closed stirrup, the hidden beam longitudinal reinforcement is arranged parallel to the web horizontal stirrup, and the end of the hidden beam longitudinal reinforcement is connected with the web longitudinal reinforcement at the intersection of the web and the flange. The invention effectively improves the torsional performance of the web part, has larger torsion bearing capacity, and has better safety and reliability.

Description

A Concealed Beam Reinforcement Method for Improving the Torsional Performance of Z-shaped Column Joints

technical field

The invention belongs to the technical field of reinforced concrete building structures, and relates to a beam-column node of a cast-in-place common reinforced concrete special-shaped column frame structure.

Background technique

The special-shaped column structure system is a new type of structure system and has become one of the main structure systems in residential construction. With the continuous advancement of my country's urbanization process, higher requirements are put forward for the rationality, flexibility and convenience of residential buildings. The special-shaped column refers to the column whose cross-sectional limb height to limb thickness ratio is less than or equal to 4, and the cross-sectional geometric shape is "ten", "T", "L" and "Z". The formed structure is called special-shaped column frame structure; in the special-shaped column frame structure, T-shaped, L-shaped, cross-shaped and Z-shaped cross-section columns are used to replace the rectangular columns in the general frame structure, usually the corner columns are L-shaped cross-sections, and the side columns are T-shaped The section and center column are cross-shaped. When the axis of the column network deviates, the Z-shaped section column is usually used as the conversion column. The Z-shaped section column has been widely used in multi-story and high-rise residential buildings. After the 1970s, the special-shaped column structure system has achieved good economic, social and environmental benefits in the practice of residential engineering, and has a good development prospect.

For cross-section column frame joints, it is beneficial to the structural stress under the negative bending moment at the beam end, while for the web of Z-shaped cross-section frame joints, under the negative bending moment at the beam end, torque will be generated, which is beneficial to Structural force is very unfavorable. Therefore, the problem that Z-shaped column joints are susceptible to torsional damage under the negative bending moment at the beam end has become an urgent problem to be solved in high-rise residential buildings with many reinforced concrete structures. There is no domestic and foreign literature on the research and application of adding hidden beams to the web of the core area of reinforced concrete Z-shaped column joints to enhance the torsional performance of Z-shaped column-beam-column joints.

Contents of the invention

In order to overcome the deficiencies of the existing reinforced concrete Z-shaped column joints, such as poor torsional performance, small torsional bearing capacity, and poor safety and reliability of the web part, the present invention provides a method for effectively improving the torsional performance of the web part, A concealed beam reinforcement method for improving the torsional performance of Z-shaped column joints with large torsional bearing capacity and good safety and reliability.

The technical solution adopted by the present invention to solve its technical problems is:

A concealed beam reinforcement method for improving the torsional performance of a Z-shaped column joint, the Z-shaped column joint includes a Z-shaped column and a frame beam, the Z-shaped column includes a web and two flanges, and the flange is located The end of the web, the flange longitudinal ribs and flange horizontal stirrups are arranged inside the flange, the flange horizontal stirrups are arranged outside the flange longitudinal ribs, and the web longitudinal ribs are arranged inside the web ribs and web horizontal stirrups, the web horizontal stirrups are arranged on the outside of the web longitudinal ribs, the flange longitudinal ribs and web longitudinal ribs at the intersection of the web and the flange are common, and the The hidden beams are arranged in the horizontal stirrups of the web, and the hidden beams include the longitudinal bars of the hidden beams and the closed stirrups of the hidden beams. The beam longitudinal reinforcement is arranged parallel to the horizontal stirrup of the web, and the end of the concealed beam longitudinal reinforcement is connected with the web longitudinal reinforcement at the intersection of the web and the flange.

Further, the height of the concealed beam is the same as that of the frame beam.

Furthermore, the reinforcement ratio of the web longitudinal reinforcement on the upper and lower edges of the concealed beam should not be less than 0.15%, and the diameter of the web reinforcement should not be less than 12 mm, and not less than 2.

The longitudinal reinforcement of the hidden beam is anchored in the longitudinal reinforcement of the web at the intersection of the web and the flange, and the anchorage length is greater than or equal to the threshold _la ; The end of the closed stirrup is made into a 135° hook, and the length of the straight section at the end of the hook is greater than or equal to 10d, where d is the diameter of the closed stirrup of the concealed beam.

Tie bars are arranged between two web longitudinal bars opposite to each other on both sides of at least one group of Z-shaped centerlines. One set of tie bars can be set as required, or multiple sets.

The beneficial effects of the present invention are mainly manifested in: the hidden beam is added to the core area of the web plate of the Z-shaped column-beam-column joint, which has a good strengthening effect on the Z-shaped column joint, can improve the torsional performance of the Z-shaped column joint, and can effectively Improve the torsional bearing capacity of Z-shaped column joints.

Description of drawings

Figure 1 is a structural side view of a Z-shaped column node. .

Fig. 2 is an enlarged top view of section A-A in Fig. 1 .

Fig. 3 is an enlarged top view of section B-B in Fig. 1 .

Fig. 4 is a side view of the beam end of the concrete Z-shaped column joint frame.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings.

Referring to Figures 1 to 4, a concealed beam reinforcement method for improving the torsional performance of a Z-shaped column joint, the Z-shaped column joint includes a Z-shaped column 2 and a frame beam 3, and the Z-shaped column 2 includes a web and two a flange, the flange is located at the end of the web, and the flange longitudinal reinforcement and the flange horizontal stirrup 10 are arranged in the flange, and the flange horizontal stirrup 10 is arranged on the flange longitudinal Outside the ribs, the web longitudinal ribs 6 and web horizontal stirrups 8 are arranged in the web, and the web horizontal stirrups 8 are arranged on the outside of the web longitudinal ribs 6, between the web and the flange The flange longitudinal reinforcement at the intersection and the web longitudinal reinforcement 6 are common, and a concealed beam is arranged in the web horizontal stirrup 8, and the concealed beam includes a concealed beam longitudinal reinforcement 4 and a concealed beam closed stirrup 5, and the concealed beam The concealed beam longitudinal reinforcement 4 is arranged at the four inner corners of the closed beam stirrup 5, the concealed beam longitudinal reinforcement 4 is arranged parallel to the web horizontal stirrup 8, and the end of the concealed beam longitudinal reinforcement 4 is connected to the web It is connected with the web longitudinal reinforcement 6 at the intersection of the flange.

Further, the height of the concealed beam is the same as that of the frame beam 3 .

Furthermore, the reinforcement ratio of the web longitudinal reinforcement 6 on one side of the upper and lower edges of the concealed beam should not be less than 0.15%, and the diameter of the web reinforcement 6 should not be less than 12 mm, and not less than 2.

The longitudinal reinforcement 4 of the hidden beam is anchored in the longitudinal reinforcement 6 of the web at the intersection of the web and the flange, and the anchorage length is greater than or equal to the threshold _la ; the diameter of the closed stirrup of the hidden beam is the same as that of the horizontal stirrup of the web, and the spacing is less than or equal to 100mm. The end of the closed stirrup of the hidden beam is made into a 135° hook, and the length of the straight section at the end of the hook is greater than or equal to 10d, where d is the diameter of the closed stirrup of the hidden beam.

Tie bars 7 are arranged between two web longitudinal bars 6 opposite to each other on both sides of at least one group of Z-shaped centerlines. One set of tie bars can be set as required, or multiple sets.

In Figure 1, 1 is the core area of the Z-shaped column joint, 2 is the Z-shaped column, 3 is the frame beam, and 7 is the tie bar; referring to Figure 4, 9 is the longitudinal reinforcement (bottom bar) of the frame beam, and 11 is the longitudinal frame beam Reinforcement bar (top bar), 12 is the frame beam node stirrup.

The construction process of the concealed beam reinforcement method for improving the torsional performance of Z-shaped column joints in this embodiment is as follows:

1) Bind the Z-shaped column web horizontal stirrups 8 and flange horizontal stirrups 10 below the bottom surface of the beam. The hooks of the stirrups in the Z-shaped column shall be set at the corners of the column and shall be arranged staggered in the vertical direction, and all the stirrups shall be perpendicular to the longitudinal reinforcement of the column;

2) Install column formwork;

3) Pouring column concrete (pay attention to the anchorage position of the beam reinforcement at the edge of the column on the top floor);

4) Remove the column formwork;

5) Install the bottom mold of the frame beam, and pay attention to reserve the thickness of the protective layer;

6) Place the longitudinal reinforcement of the frame beam (bottom reinforcement 9);

7) Binding node beam stirrups 12;

8) Bind the Z-shaped column web hidden beam longitudinal reinforcement 4 and hidden beam closed stirrup 5, the hidden beam longitudinal reinforcement is anchored on the inner side of the longitudinal reinforcement at the column ends on both sides of the core area, the anchorage length is greater than or equal to the threshold _la , and the hidden beam is closed The stirrups should be made into a closed type with the same diameter as the horizontal stirrups at the nodes, and the spacing should be less than or equal to 100mm. The ends of the stirrups should be made into 135° hooks. 4 times, the length of the straight section at the end of the hook is greater than or equal to 10d, where d is the diameter of the stirrup;

9) binding web horizontal stirrups 8 and flange horizontal stirrups 10;

10) binding frame beam longitudinal reinforcement (top reinforcement 11);

11) Install the joint area formwork, including the side formwork of the frame beam and the bottom formwork of the floor slab;

12) Pouring node concrete, vibrating and compacting;

14) Remove the formwork to obtain Z-shaped column nodes reinforced by hidden beams.

In the construction process, a concealed beam reinforcement method to improve the torsional performance of Z-shaped column joints is basically the same as the construction technology of ordinary special-shaped column joints, and only concealed beams are arranged at the web of reinforced concrete Z-shaped column joints.

Claims (5)

1. one kind is improved the dark beam Enhancement Method of Z-shaped Column border node torsional property, described Z-shaped Column border node comprises Z-shaped post and Vierendeel girder, described Z-shaped post comprises web and two edges of a wing, the described edge of a wing is positioned at the end of described web, arrange in the described edge of a wing that muscle and edge of a wing horizontal hoop are indulged in the edge of a wing, described edge of a wing horizontal hoop is arranged on the described edge of a wing and indulges outside muscle, arrange in described web that web indulges muscle and web horizontal hoop, described web horizontal hoop is arranged on the outside that muscle indulged by described web, muscle is indulged on the edge of a wing of described web and intersection, the edge of a wing, it is public that muscle indulged by web, it is characterized in that: in described web horizontal hoop, dark beam is set, described dark beam comprises dark beam and indulges muscle and dark beam closed stirrup, four interior angle places of described dark beam closed stirrup arrange that described dark beam indulges muscle, described dark beam indulges muscle and described web horizontal hoop be arranged in parallel, described dark beam is indulged muscle end and is indulged muscle with web with the web of intersection, the edge of a wing and be connected.

2. a kind of dark beam Enhancement Method improving Z-shaped Column border node torsional property as claimed in claim 1, is characterized in that: described dark depth of beam is identical with described framework depth of beam.

3. a kind of dark beam Enhancement Method improving Z-shaped Column border node torsional property as claimed in claim 1 or 2, it is characterized in that: the reinforcement ratio that muscle indulged by the one-sided web in the described upper and lower edge of dark beam should not be less than 0.15%, the diameter of web reinforcement should not be less than 12mm, and is no less than 2.

4. a kind of dark beam Enhancement Method improving Z-shaped Column border node torsional property as claimed in claim 1 or 2, is characterized in that: dark beam is indulged the web that muscle is anchored at web and intersection, the edge of a wing and indulged in muscle, and anchorage length is more than or equal to threshold value l _a; The diameter of dark beam closed stirrup is identical with web horizontal hoop, and spacing is less than or equal to 100mm, and the end of dark beam closed stirrup makes 135 ° of crotches, and crotch termination flat segments length is more than or equal to 10d, and d is the diameter of dark beam closed stirrup.

5. a kind of dark beam Enhancement Method improving Z-shaped Column border node torsional property as claimed in claim 1 or 2, is characterized in that: the two piece webs relative at least one group of Z-shaped center line both sides are indulged between muscle and arranged tension rib.