Embedded type wall foot joint of partially-coated steel-concrete composite wall

Abstract

The invention relates to a partially-coated steel-concrete composite wall embedded type wall foot node which comprises a PEC shear wall, a wall foot bottom plate fixedly installed at the bottom of the PEC shear wall and a concrete foundation, and the PEC shear wall comprises end columns located at the two ends and a web wall located between the end columns at the two ends. Downward-inserting end section steel is arranged at the positions, corresponding to the end columns on the two sides, below the wall foot bottom plate, the top of the downward-inserting end section steel is fixed to the wall corner bottom plate, an expansion anchor plate is arranged at the bottom of the downward-inserting end section steel, the cross section of the expansion anchor plate is larger than that of the downward-inserting end section steel, and toggle pins are arranged on the outer wall of the downward-inserting end section steel. Anchor bars are arranged below the wall foot bottom plate and correspond to the area where the web plate wall is located, the anchor bars are perpendicular to the wall foot bottom plate, the tops of the anchor bars are fixed to the wall foot bottom plate, and the wall foot bottom plate, the downwards-inserted end profile steel and the anchor bars are embedded into the concrete foundation. The embedded depth of the wall foot joint can be reduced, the transfer effect of joint force is improved, construction is convenient, and the construction cost can be reduced.

Description

Technical Field

[0001] The invention relates to the field of prefabricated buildings, and in particular to an embedded wall footing node of a partially coated steel-concrete composite wall. Background Art

[0002] Partially enclosed steel-concrete composite wall (PEC shear wall for short) is a new type of steel-concrete composite steel plate wall. Its structure is to use double-layer steel plates to pour concrete inside, and set steel tube concrete columns at both ends to form a lateral force-resistant component. The foot of the PEC shear wall is the key node connecting the upper structure and the underground foundation. The axial force, bending moment and shear force borne by the PEC shear wall are transmitted to the foundation through the foot node. Therefore, if the foot design is too conservative, it will lead to waste of resources and poor economy.

[0003] The current methods of connecting the foot of the PEC shear wall to the foundation are divided into external concrete form and embedded type. The former is based on the method of external column foot in steel structure, which uses external concrete. Through the joint action of the steel bars and concrete in the external concrete, the bottom force of the foot of the wall is transmitted to the foundation. This external structure, with an external concrete thickness of at least 100mm, will cause the cross-section of the component in the basement to be too large, affecting the realization of the building function. In addition, since the steel bars of the external wall need to pass through the steel web, holes need to be reserved on the steel web in advance, resulting in complex process and slow construction speed of this external column foot. The embedded structure has a clear and reliable force transmission path, and the setting of connectors such as bolts can enhance its anchoring effect. The embedded wall footing node method in the prior art is to insert a steel column into the foundation, and transmit the column bottom force by squeezing the concrete foundation with the inserted steel column. According to the embedded wall footing method in the prior art, it is necessary to insert a wall twice the length of the shear wall to meet the buried depth requirement. The general length of the PEC shear wall is 1.5m to 1.8m, so the buried depth will reach more than 3m, which greatly increases the excavation depth and excavation cost of the foundation pit. Therefore, it is difficult to actually implement it in actual projects. Summary of the invention

[0004] The invention discloses an embedded wall foot node of a partially coated steel-concrete composite wall. The wall foot node has a small cross-section, and the embedding depth of the wall foot can be relatively reduced, which is helpful to reduce construction costs and improve construction efficiency.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] The invention discloses an embedded foot node of a partially clad steel-concrete composite wall, comprising a PEC shear wall, a foot plate fixedly installed at the bottom of the PEC shear wall, and a concrete foundation. The PEC shear wall comprises end columns at two ends and a web wall between the end columns at both ends. A lower plug-in end steel section is respectively arranged below the foot plate corresponding to the end columns on each side. The top of the lower plug-in end steel section is fixed on the wall corner bottom plate. An enlarged anchor plate is arranged at the bottom of the lower plug-in end steel section. The cross section of the enlarged anchor plate is larger than the cross section of the lower plug-in end steel section. Bolts are arranged on the outer wall of the lower plug-in end steel section. Anchor bars are arranged below the foot plate corresponding to the area where the web wall is located. The anchor bars are perpendicular to the foot plate and the top of the anchor bars is fixed on the foot plate. The foot plate, the lower plug-in end steel section and the anchor bars are embedded in the concrete foundation.

[0007] Furthermore, steel bars are arranged in the concrete foundation, and the steel bars in the concrete foundation bypass the lower inserted end steel section.

[0008] Furthermore, the lower inserted end steel is H-shaped steel, and the bolts are arranged on both side flanges of the H-shaped steel at intervals along the longitudinal direction.

[0009] Furthermore, the thickness of the wall footing plate is greater than the diameter of the anchor bar, and the thickness of the wall footing plate is ≥25 mm.

[0010] Furthermore, the thickness of the wall base plate must also satisfy the following formula:

[0011]

[0012] In the above formula, t is the thickness of the wall base plate, M is the design value of the bending moment of the wall base plate, the unit is N·mm, and f is the design value of the tensile strength of the wall base plate, the unit is N / mm 2 .

[0013] In the wall foot node designed by the present invention, the PEC shear wall is not directly inserted into the concrete foundation, but a wall foot plate is arranged at the bottom of the PEC shear wall, and down-inserted end steel sections are arranged at the two ends of the lower part of the wall foot plate corresponding to the end columns of the PEC shear wall, anchor bars are arranged in the area between the down-inserted end steel sections, and bolts are arranged on the outer wall of the down-inserted end steel sections. The wall foot plate and the lower anchor bars and down-inserted end steel sections are buried in the concrete foundation. After such design, the down-inserted end steel sections at both ends form a pair of force couples through tension at one end of the whole section and compression at the other end of the whole section. The bending moment of the PEC shear wall is balanced by the pair of force couples formed by the down-inserted end steel sections at both ends. The axial force of the PEC shear wall is vertically transmitted downward, the axial force of the web wall grid is transmitted to the concrete foundation through the wall foot plate, and the axial force of the end column is transmitted to the concrete at the bottom of the enlarged anchor plate through the down-inserted end steel sections, so that the shear force of the PEC shear wall and the friction force generated by the axial force are balanced. The studs and the enlarged anchor plates can increase the pull-out bearing capacity of the inserted end steel in the concrete foundation, which helps to reduce the embedding depth of the embedded wall foot node and reduce the construction cost. The anchor bars can improve the bending and shear bearing capacity of the embedded wall foot, ensure the transmission of the internal force of the PEC shear wall, and facilitate the passage of the steel bars in the concrete foundation. The concrete in the end column and the web wall of the PEC shear wall is pre-cast in the factory. After the foot of the PEC shear wall is inserted into the concrete foundation, the steel bars are set in the concrete foundation, and then the concrete is poured on site to form the concrete foundation. The inserted end steel in the foundation can effectively reduce the area of ​​the concrete foundation, which can increase the construction speed and reduce the construction cost. At the same time, according to the calculation, through the joint action of reinforced concrete and steel, the studs also further form a tie effect, making the mechanical properties of the wall foot node more obvious, which is also conducive to further structural optimization and cost reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Schematic diagram of embedded footing node of PEC shear wall in the embodiment;

[0015] Figure 2 for Figure 1 Middle AA section;

[0016] Figure 3 for Figure 1 Middle BB section;

[0017] Figure 4 for Figure 1 Middle CC section.

[0018] Reference numerals:

[0019] 1. PEC shear wall; 11. end column; 12. web wall; 2. wall footing plate; 3. concrete foundation; 4. lower end steel section; 5. studs; 6. expanded anchor plate; 7. anchor bars. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0021] This embodiment discloses a partially covered steel-concrete composite wall embedded wall footing node, such as Figures 1 to 4 As shown, it mainly includes a PEC shear wall 1, a wall footing plate 2 fixedly installed at the bottom of the PEC shear wall 1, and a concrete foundation 3. The two ends of the PEC shear wall 1 are end columns 11, and the web wall 12 is between the end columns 11 at both ends. The web wall 12 is composed of double-layer steel plates or single-layer steel plates. The end columns 11 can be made of H-shaped steel or rectangular steel pipes. The concrete pouring is completed in the area where the end columns 11 and the web wall 12 are located during prefabrication in the factory, thereby forming the PEC shear wall 1. A wall footing plate 2 is welded at the bottom end of the PEC shear wall 1. The transverse section of the wall footing plate 2 is larger than the transverse section of the PEC shear wall 1. The wall footing plate 2 can be pre-welded to the bottom of the PEC shear wall 1 in the factory. Below the wall footing plate 2, corresponding to each side end column 11, a lower plug-in end steel 4 is provided. In this embodiment, the lower plug-in end steel 4 is H-shaped steel. The lower plug-in end steel 4 is arranged perpendicular to the wall footing plate 2, and the top of the lower plug-in end steel 4 is welded to the bottom surface of the wall corner plate 2. An enlarged anchor plate 6 is welded to the bottom of the lower plug-in end steel 4. The enlarged anchor plate 6 is arranged parallel to the wall footing plate 2, and the cross section of the enlarged anchor plate 6 is larger than the cross section of the lower plug-in end steel 4. Studs 5 are welded longitudinally at intervals on the outer surface of the flanges on both sides of the lower plug-in end steel 4. Below the wall footing plate 2, corresponding to the area where the web wall 12 is located, anchor bars 7 are arranged at intervals. The anchor bars 7 are perpendicular to the wall footing plate 2, and the tops of the anchor bars 7 are welded to the bottom surface of the wall footing plate 2.

[0022] In this embodiment, the PEC shear wall 1 located on the upper part of the wall footing plate 2 is not directly inserted into the concrete foundation 3, but the wall footing plate 2, the lower inserted end steel 4 and the anchor bar 7 are buried in the concrete foundation 3. In this embodiment, the bending moment of the wall footing node is transmitted by the lower inserted end steel 4 through tension or compression. The embedding depth is determined by the pull-out resistance of the lower inserted end steel. The embedding depth of this type of embedded wall footing node is within 1.2m. Compared with the embedded wall footing node in the prior art, its embedding depth is 3m~4m, which significantly reduces the embedding depth. Therefore, the scheme of the present invention has more practical application value. The thickness of the wall footing plate 2 in the scheme given by the present invention must meet certain requirements: the thickness of the wall footing plate 2 must be greater than the diameter of the anchor bar 7, and the thickness of the wall footing plate 2 must be ≥25mm. In addition, the thickness of the wall footing plate 2 must also meet the following formula:

[0023]

[0024] In the above formula, t is the thickness of the wall base plate 2, M is the design value of the bending moment of the wall base plate, in N·mm, which is the maximum bending moment calculated based on the support conditions of the wall base plate 2; f is the design value of the tensile strength of the wall base plate 2, in N / mm 2 .

[0025] After the PEC shear wall 1 has been assembled at its bottom, the assembled structure is inserted into the foundation before the concrete foundation 3 is poured. Steel bars are arranged in the foundation so that the steel bars bypass the lower inserted end steel 4. Then concrete is poured in the foundation so that the top surface of the concrete foundation 3 is flush with the top surface of the wall footing slab 2. The concrete to be cured is integrated with the part buried in the foundation.

[0026] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A partially clad steel-concrete composite wall embedded foot node, comprising a PEC shear wall, a foot plate fixedly installed at the bottom of the PEC shear wall, and a concrete foundation, wherein the PEC shear wall comprises end columns at both ends and a web wall between the end columns at both ends, characterized in that: A lower plug-in end steel section is provided below the wall footing plate corresponding to the end column on each side, the top of the lower plug-in end steel section is fixed to the wall corner plate, an enlarged anchor plate is provided at the bottom of the lower plug-in end steel section, the cross-section of the enlarged anchor plate is larger than the cross-section of the lower plug-in end steel section, studs are provided on the outer wall of the lower plug-in end steel section, anchor bars are provided below the wall footing plate corresponding to the area where the web wall is located, the anchor bars are perpendicular to the wall footing plate and the top of the anchor bars are fixed to the wall footing plate, the wall footing plate, the lower plug-in end steel section and the anchor bars are buried in the concrete foundation.

2. The embedded wall footing node of a partially clad steel-concrete composite wall according to claim 1, characterized in that: The concrete foundation is provided with steel bars, and the steel bars in the concrete foundation bypass the lower inserted end section steel.

3. The embedded wall footing node of a partially clad steel-concrete composite wall according to claim 1, characterized in that: The lower inserted end steel is H-shaped steel, and the bolts are arranged on the flanges of both sides of the H-shaped steel at intervals along the longitudinal direction.

4. The embedded wall footing node of a partially clad steel-concrete composite wall according to claim 1, characterized in that: The thickness of the wall footing plate is greater than the diameter of the anchor bar, and the thickness of the wall footing plate is ≥25mm.

5. The embedded wall footing node of a partially clad steel-concrete composite wall according to claim 4, characterized in that: The thickness of the wall base plate must also satisfy the following formula: In the above formula, t is the thickness of the wall base plate, M is the design value of the bending moment of the wall base plate, the unit is N·mm, and f is the design value of the tensile strength of the wall base plate, the unit is N / mm 2 .

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