阅读说明：本技术 一种可拆卸垫块加强高强螺栓剪力连接件 (Detachable cushion block reinforced high-strength bolt shear connector ) 是由 钟国辉 王宣鼎 刘界鹏 廖岳 周绪红 于 2021-06-01 设计创作，主要内容包括：本发明公开了一种可拆卸垫块加强高强螺栓剪力连接件,包括钢板母材、钢垫块、若干高强螺栓和若干高强螺母。钢板母材和钢垫块上均设置有供高强螺栓穿过的若干通孔,钢垫块为放置在钢板母材上表面的矩形板,钢垫块的长度方向同钢板母材和钢垫块间的剪力方向垂直。若干高强螺栓从上方穿过钢板母材和钢垫块的通孔,每个高强螺栓上均旋入两个高强螺母,一个高强螺母与钢垫块的上表面抵紧,另一个高强螺母与钢板母材的下表面抵紧。本发明的连接件的安装采用的方式是螺栓连接,涉及的所有部件和安装均可在工厂加工完成,这种方式避免了焊缝带来的残余应力,减小了连接件的初始缺陷,提高了连接件的疲劳性能,加强了连接件的抗剪承载力。(The invention discloses a detachable cushion block reinforced high-strength bolt shear connector which comprises a steel plate base material, a steel cushion block, a plurality of high-strength bolts and a plurality of high-strength nuts. The steel plate base material and the steel cushion block are respectively provided with a plurality of through holes for high-strength bolts to penetrate through, the steel cushion block is a rectangular plate placed on the upper surface of the steel plate base material, and the length direction of the steel cushion block is perpendicular to the shearing direction between the steel plate base material and the steel cushion block. And a plurality of high-strength bolts penetrate through the through holes of the steel plate base material and the steel cushion block from the upper part, two high-strength nuts are screwed on each high-strength bolt, one high-strength nut is tightly propped against the upper surface of the steel cushion block, and the other high-strength nut is tightly propped against the lower surface of the steel plate base material. The connecting piece is installed in a bolt connection mode, all related parts and installation can be finished in a factory, and the mode avoids residual stress caused by welding seams, reduces initial defects of the connecting piece, improves fatigue performance of the connecting piece and strengthens shearing-resistant bearing capacity of the connecting piece.)

1. The utility model provides a can dismantle cushion and strengthen bolt shear connector which characterized in that: the steel plate comprises a steel plate base material (1), a steel cushion block (2), a plurality of high-strength bolts (3) and a plurality of high-strength nuts (4);

the steel plate base material (1) and the steel cushion block (2) are respectively provided with a plurality of through holes through which high-strength bolts (3) penetrate, and the steel cushion block (2) is a rectangular plate placed on the upper surface of the steel plate base material (1);

the high-strength bolts (3) penetrate through holes of the steel plate base material (1) and the steel cushion block (2) from the upper side, two high-strength nuts (4) are screwed into each high-strength bolt (3), one high-strength nut (4) abuts against the upper surface of the steel cushion block (2), and the other high-strength nut (4) abuts against the lower surface of the steel plate base material (1).

2. The detachable cushion block reinforced high-strength bolt shear connector as recited in claim 1, wherein: the steel plate base material (1) and the steel cushion block (2) are provided with a through hole, a high-strength bolt (3) penetrates through the steel plate base material (1) and the steel cushion block (2), and the high-strength bolt (3) penetrates through the center of the steel cushion block (2).

3. The detachable cushion block reinforced high-strength bolt shear connector as recited in claim 1, wherein: the steel plate base material (1) and the steel cushion block (2) are provided with M through holes, M high-strength bolts (3) penetrate through the steel plate base material (1) and the steel cushion block (2), the M high-strength bolts (3) are arranged at intervals, the connecting line of the M high-strength bolts (3) is perpendicular to the shearing direction of the steel plate base material (1) and the steel cushion block (2), and M is not less than 2 and not more than 4.

4. The detachable cushion block reinforced high-strength bolt shear connector as recited in claim 1, wherein: the diameter of the high-strength bolt (3) is d, d is more than or equal to 16mm and less than or equal to 40mm, and the strength grade of the high-strength bolt (3) is more than or equal to 4.8 grade and less than or equal to 12.9 grade.

5. The detachable cushion block reinforced high-strength bolt shear connector as recited in claim 4, wherein: the aperture of the through holes in the steel plate base material (1) and the steel cushion block (2) is D, and D +1mm is not less than D and not more than D +6 mm; the length, the width and the height of the steel cushion block (2) are respectively a, b and h, a is more than or equal to 2d, b is more than or equal to 2d and less than or equal to 5d, and h is more than or equal to d and less than or equal to 4 d.

6. The utility model provides a can dismantle cushion and strengthen bolt shear connector which characterized in that: comprises a steel plate base material (1), a steel cushion block (2), a plurality of high-strength screws (5) and a plurality of high-strength nuts (4);

the steel plate base material (1) and the steel cushion block (2) are respectively provided with a plurality of through holes through which high-strength screws (5) penetrate, and the steel cushion block (2) is a rectangular plate placed on the upper surface of the steel plate base material (1);

the middle section of each high-strength screw rod (5) is a smooth section (10), the high-strength screw rods (5) penetrate through holes of the steel plate base material (1) and the steel cushion block (2), the smooth section (10) of each high-strength bolt (3) penetrates through the contact surface of the steel plate base material (1) and the steel cushion block (2), the upper end of each smooth section (10) is located in the through hole of the steel cushion block (2), and the lower end of each smooth section (10) is located in the through hole of the steel plate base material (1);

three high-strength nuts (4) are screwed into each high-strength screw (5), the first high-strength nut (4) is close to the upper end of the high-strength screw (5), the second high-strength nut (4) is tightly propped against the upper surface of the steel cushion block (2), and the third high-strength nut (4) is tightly propped against the lower surface of the steel plate base material (1).

7. The detachable cushion block reinforced high-strength bolt shear connector as recited in claim 6, wherein: the steel plate base material (1) and the steel cushion block (2) are both provided with a through hole, a high-strength screw rod (5) penetrates through the steel plate base material (1) and the steel cushion block (2), and the high-strength screw rod (5) penetrates through the center of the steel cushion block (2).

8. The detachable cushion block reinforced high-strength bolt shear connector as recited in claim 6, wherein: the steel plate base material (1) and the steel cushion block (2) are provided with M through holes, M high-strength screws (5) penetrate through the steel plate base material (1) and the steel cushion block (2), the M high-strength screws (5) are arranged at intervals, the connecting line of the M high-strength screws (5) is perpendicular to the shearing direction of the steel plate base material (1) and the steel cushion block (2), and M is not less than 2 and not more than 4.

9. The detachable cushion block reinforced high-strength bolt shear connector as recited in claim 6, wherein: the diameter of the high-strength screw rod (5) is d, d is more than or equal to 16mm and less than or equal to 40mm, and the strength grade of the high-strength screw rod (5) is more than or equal to 4.8 grade and less than or equal to 12.9 grade; the distances from the lower end and the upper end of the smooth section (10) to the upper surface of the steel plate base material (1) are more than or equal to half of the thickness of the steel plate base material (1).

10. The detachable cushion block reinforced high-strength bolt shear connector as recited in claim 9, wherein: the aperture of the through holes in the steel plate base material (1) and the steel cushion block (2) is D, and D +1mm is not less than D and not more than D +6 mm; the length, the width and the height of the steel cushion block (2) are respectively a, b and h, a is more than or equal to 2d, b is more than or equal to 2d and less than or equal to 5d, and h is more than or equal to d and less than or equal to 4 d; the distance between the center of the through hole in the steel plate base material (1) and the edge of the steel cushion block (2) is larger than or equal to d.

Technical Field

The invention relates to the field of civil engineering, in particular to a detachable cushion block reinforced high-strength bolt shear connector.

Background

The steel-concrete composite beam is widely applied to bridge structures and building structures due to the advantages of small height, light dead weight, good ductility and the like. The shear connector is a key component in the steel-concrete composite beam, and has the functions of ensuring the combined action of the composite beam, resisting the sliding between the steel beam and the concrete wing plate and preventing the lifting.

The cylindrical head welding nail is used as a representative flexible connecting piece, and is widely applied to engineering due to stable shearing resistance and high construction standardization degree; but also has the defects of low shearing resistance and bearing capacity, dense arrangement, large welding quantity and the like of a single stud. In contrast, the welding rigid shear part has higher shear strength, and the number of the shear parts can be effectively reduced; however, the defects of poor ductility and low fatigue strength cause that the rigid shear part is less applied to structures with requirements on earthquake resistance and fatigue. In addition, the combined beam adopting the traditional shear connector has the advantages that the steel beam and the concrete slab are not detachable after construction, and the structure is not convenient to replace, repair and reinforce.

In recent years, the bolt shear connector is applied to a bridge structure to a certain extent due to the advantages of easy installation, detachability, excellent fatigue performance and the like. However, the initial slippage of the bolt shearing part is large, the shear strength cannot be fully exerted, and when the large-diameter bolt is adopted, the steel beam flange is obviously weakened, and the application range is narrow.

Disclosure of Invention

The invention aims to provide a detachable cushion block reinforced high-strength bolt shear connector to overcome the defects of the traditional bolt shear connector.

The technical scheme adopted for achieving the purpose of the invention is that the detachable cushion block reinforced high-strength bolt shear connector comprises a steel plate base material, a steel cushion block, a plurality of high-strength bolts and a plurality of high-strength nuts.

The steel plate base material and the steel cushion block are respectively provided with a plurality of through holes for high-strength bolts to pass through, and the steel cushion block is a rectangular plate placed on the upper surface of the steel plate base material.

And a plurality of high-strength bolts penetrate through the through holes of the steel plate base material and the steel cushion block from the upper part, two high-strength nuts are screwed into each high-strength bolt, one high-strength nut is tightly propped against the upper surface of the steel cushion block, and the other high-strength nut is tightly propped against the lower surface of the steel plate base material.

Furthermore, a through hole is formed in each of the steel plate base material and the steel cushion block, a high-strength bolt penetrates through the steel plate base material and the steel cushion block, and the high-strength bolt penetrates through the center of the steel cushion block.

Furthermore, M through holes are formed in the steel plate base material and the steel cushion block, M high-strength bolts penetrate through the steel plate base material and the steel cushion block and are arranged at intervals, the connecting line of the M high-strength bolts is perpendicular to the shearing direction of the steel plate base material and the steel cushion block, and M is larger than or equal to 2 and smaller than or equal to 4.

Furthermore, the diameter of the high-strength bolt is d, d is more than or equal to 16mm and less than or equal to 40mm, and the strength grade of the high-strength bolt is more than or equal to 4.8 grade and less than or equal to 12.9 grade.

Furthermore, the aperture of the through holes in the steel plate base material and the steel cushion block is D, and D +1mm is not less than D and not more than D +6 mm. The length, the width and the height of the steel cushion block are respectively a, b and h, a is more than or equal to 2d, b is more than or equal to 2d and less than or equal to 5d, and h is more than or equal to d and less than or equal to 4 d.

A detachable cushion block reinforced high-strength bolt shear connector comprises a steel plate base material, a steel cushion block, a plurality of high-strength screws and a plurality of high-strength nuts.

The steel plate base material and the steel cushion block are respectively provided with a plurality of through holes for the high-strength screws to penetrate through, and the steel cushion block is a rectangular plate placed on the upper surface of the steel plate base material.

The middle section of the high-strength screw rod is a smooth section, the high-strength screw rods penetrate through holes of the steel plate base material and the steel cushion block, the smooth section of each high-strength bolt penetrates through the contact surface of the steel plate base material and the steel cushion block, the upper end of the smooth section is located in the through hole of the steel cushion block, and the lower end of the smooth section is located in the through hole of the steel plate base material.

Three high-strength nuts are screwed into each high-strength screw rod, the first high-strength nut is close to the upper end of each high-strength screw rod, the second high-strength nut abuts against the upper surface of the steel cushion block, and the third high-strength nut abuts against the lower surface of the steel plate base material.

Furthermore, a through hole is formed in each of the steel plate base material and the steel cushion block, a high-strength screw rod penetrates through the steel plate base material and the steel cushion block, and the high-strength screw rod penetrates through the center of the steel cushion block.

Furthermore, M through holes are formed in the steel plate base material and the steel cushion block, M high-strength screws penetrate through the steel plate base material and the steel cushion block, the M high-strength screws are arranged at intervals, the connecting line of the M high-strength screws is perpendicular to the shearing direction of the steel plate base material and the steel cushion block, and M is larger than or equal to 2 and smaller than or equal to 4.

Furthermore, the diameter of the high-strength screw is d, d is more than or equal to 16mm and less than or equal to 40mm, and the strength grade of the high-strength screw is more than or equal to 4.8 grade and less than or equal to 12.9 grade. And the distances from the lower end and the upper end of the smooth section to the upper surface of the steel plate base metal are more than or equal to half of the thickness of the steel plate base metal.

Furthermore, the aperture of the through holes in the steel plate base material and the steel cushion block is D, and D +1mm is not less than D and not more than D +6 mm. The length, the width and the height of the steel cushion block are respectively a, b and h, a is more than or equal to 2d, b is more than or equal to 2d and less than or equal to 5d, and h is more than or equal to d and less than or equal to 4 d. And the distance between the center of the through hole in the steel plate base material and the edge of the steel cushion block is more than or equal to d.

The invention has the beneficial effects that:

1. the detachable cushion block is used for reinforcing the high-strength bolt shear connector, so that the connector and the steel plate base metal can be assembled in a factory, welding operation is not needed, and the development concept of energy conservation and environmental protection is met;

2. the detachable cushion block is used for reinforcing the high-strength bolt shear connector, so that the structure can be conveniently detached when damaged or needs to be maintained and reinforced, and the sustainable development concept is met;

3. the detachable cushion block is used for reinforcing the high-strength bolt shear connecting piece, no welding seam exists between the connecting piece and the steel plate base material, and the high-strength bolt shear connecting piece has better fatigue performance;

4. the perforated steel cushion block can increase the stress area between the connecting piece and the steel plate base metal and reduce the stress concentration of the connecting piece on the steel plate base metal; the perforated steel cushion block can increase the stress area of the bolt root and the concrete slab and improve the local compression performance of the concrete slab.

5. The high-strength screw without local screw threads can avoid weakening of the section caused by the screw threads, and has higher shear bearing capacity than a full-thread high-strength screw.

Drawings

FIG. 1 is a schematic view of a joint member described in example 1;

FIG. 2 is a cross-sectional view of FIG. 1;

FIG. 3 is a schematic view of the joint member described in embodiment 2;

FIG. 4 is a schematic view of a high-strength bolt;

FIG. 5 is a schematic view of the joint member described in embodiment 3;

FIG. 6 is a cross-sectional view of FIG. 5;

FIG. 7 is a schematic view of the joint member according to embodiment 4;

FIG. 8 is a schematic view of a high tensile screw.

In the figure: the steel plate comprises a steel plate base material 1, a steel cushion block 2, a high-strength bolt 3, a high-strength nut 4, a high-strength screw rod 5 and a smooth section 10.

Detailed Description

The present invention is further illustrated by the following examples, but it should not be construed that the scope of the above-described subject matter is limited to the following examples. Various substitutions and alterations can be made without departing from the technical idea of the invention and the scope of the invention is covered by the present invention according to the common technical knowledge and the conventional means in the field.

Example 1:

the embodiment discloses a detachable cushion block reinforced high-strength bolt shear connector which comprises a steel plate base material 1, a steel cushion block 2, a high-strength bolt 3 and a high-strength nut 4. The steel plate base material 1 is made of Q460 grade steel, and the steel cushion block 2 is made of Q235 grade steel.

All be provided with the through-hole that high-strength bolt 3 passed on steel sheet parent metal 1 and the steel cushion 2, steel cushion 2 is the rectangular plate of placing at 1 upper surface of steel sheet parent metal, and the length direction of steel cushion 2 is perpendicular with the shear force direction between steel sheet parent metal 1 and steel cushion 2.

The high-strength bolts 3 penetrate through holes of the steel plate base material 1 and the steel cushion block 2 from the upper side, two high-strength nuts 4 are screwed into each high-strength bolt 3, one high-strength nut 4 abuts against the upper surface of the steel cushion block 2, and the other high-strength nut 4 abuts against the lower surface of the steel plate base material 1.

Referring to fig. 1 or 2, in the present embodiment, a through hole is formed in each of the steel plate base material 1 and the steel pad 2, and the through holes of the two are aligned, a high-strength bolt 3 passes through the steel plate base material 1 and the steel pad 2, and the high-strength bolt 3 passes through the center of the steel pad 2.

Referring to fig. 4, which is a schematic view of the high-strength bolt 3, the diameter of the high-strength bolt 3 is d, d is greater than or equal to 16mm and less than or equal to 40mm, and the strength grade of the high-strength bolt 3 is greater than or equal to 4.8 grade and less than or equal to 12.9 grade. The aperture of the through holes in the steel plate base material 1 and the steel cushion block 2 is D, and D +1mm is less than or equal to D and less than or equal to D +6 mm. The length, the width and the height of the steel cushion block 2 are respectively a, b and h, a is more than or equal to 2d, b is more than or equal to 2d and less than or equal to 5d, and h is more than or equal to d and less than or equal to 4 d. And the distance between the center of the through hole on the steel plate base material 1 and the edge of the steel cushion block 2 is more than or equal to d. In this embodiment, D is 16mm, the strength of the high-strength bolt 3 is rated at 4.8, D +1mm is 17mm, a is 2D is 32mm, b is 2D is 32mm, and h is 16 mm.

It is worth to be noted that, because the installation of the connecting piece of the embodiment adopts the mode of bolt connection, all the related parts and installation can be processed and finished in factories, the mode avoids residual stress caused by welding seams, reduces the initial defect of the connecting piece, improves the fatigue performance of the connecting piece, and strengthens the shear-resistant bearing capacity of the connecting piece.

Example 2:

the embodiment discloses a detachable cushion block reinforced high-strength bolt shear connector which comprises a steel plate base material 1, a steel cushion block 2, a plurality of high-strength bolts 3 and a plurality of high-strength nuts 4.

The steel plate base material 1 and the steel cushion block 2 are provided with M through holes through which high-strength bolts 3 penetrate, the steel cushion block 2 is a rectangular plate placed on the upper surface of the steel plate base material 1, the length direction of the steel cushion block 2 is perpendicular to the shearing force direction between the steel plate base material 1 and the steel cushion block 2, and M is larger than or equal to 2 and smaller than or equal to 4.

M high-strength bolts 3 penetrate through holes of the steel plate base material 1 and the steel cushion block 2 from the upper side, two high-strength nuts 4 are screwed into each high-strength bolt 3, one high-strength nut 4 abuts against the upper surface of the steel cushion block 2, and the other high-strength nut 4 abuts against the lower surface of the steel plate base material 1. Referring to fig. 3, in the present embodiment, M is 2, and two high-strength bolts 3 are arranged at intervals along the length direction of the steel shim block 2.

Referring to fig. 4, which is a schematic view of the high-strength bolt 3, the diameter of the high-strength bolt 3 is d, d is greater than or equal to 16mm and less than or equal to 40mm, and the strength grade of the high-strength bolt 3 is greater than or equal to 4.8 grade and less than or equal to 12.9 grade. The aperture of the through holes in the steel plate base material 1 and the steel cushion block 2 is D, and D +1mm is less than or equal to D and less than or equal to D +6 mm. The length, the width and the height of the steel cushion block 2 are respectively a, b and h, a is more than or equal to 2d, b is more than or equal to 2d and less than or equal to 5d, and h is more than or equal to d and less than or equal to 4 d. The distance between the center of the through hole in the steel plate base material 1 and the edge of the steel cushion block 2 is larger than or equal to d, and the distance between the two through holes in the steel plate base material 1 is larger than or equal to 2 d. In this embodiment, D is 40mm, the strength of the high-strength bolt 3 is 12.9, D +6mm is 46mm, a is 3D 120mm, b is 5D 200mm, h is 4D 160mm, and the distance between two through holes in the steel plate base material 1 is 2D 80 mm.

Example 3:

the embodiment discloses a detachable cushion block reinforced high-strength bolt shear connector which comprises a steel plate base material 1, a steel cushion block 2, a high-strength screw rod 5 and a high-strength nut 4.

All be provided with the through-hole that high-strength screw 5 passed on steel sheet base metal 1 and the steel cushion 2, steel cushion 2 is the rectangular plate of placing at 1 upper surface of steel sheet base metal, and the length direction of steel cushion 2 is perpendicular with the shear force direction between steel sheet base metal 1 and steel cushion 2.

Referring to fig. 8, the middle section of the high-strength screw 5 is a smooth section 10, the high-strength screw 5 penetrates through holes of the steel plate base material 1 and the steel cushion block 2, referring to fig. 6, the smooth section 10 of each high-strength bolt 3 penetrates through the contact surface of the steel plate base material 1 and the steel cushion block 2, the upper end of the smooth section 10 is located in the through hole of the steel cushion block 2, the lower end of the smooth section 10 is located in the through hole of the steel plate base material 1, the smooth section 10 can be designed to avoid cross section weakening and stress concentration caused by threads, and the high-strength screw has higher shear bearing capacity than a full-thread high-strength screw.

Three high-strength nuts 4 are screwed into each high-strength screw rod 5, the first high-strength nut 4 is close to the upper end of the high-strength screw rod 5, the second high-strength nut 4 is abutted against the upper surface of the steel cushion block 2, and the third high-strength nut 4 is abutted against the lower surface of the steel plate base material 1.

Referring to fig. 5, in the present embodiment, a through hole is formed in each of the steel plate base material 1 and the steel pad 2, the through holes of the two are aligned, a high-strength screw 5 penetrates through the steel plate base material 1 and the steel pad 2, and the high-strength screw 5 penetrates through the center of the steel pad 2.

Referring to FIG. 8, which is a schematic view of the high-strength screw 5, the diameter of the high-strength screw 5 is d, d is greater than or equal to 16mm and less than or equal to 40mm, and the strength grade of the high-strength screw 5 is greater than or equal to 4.8 grade and less than or equal to 12.9 grade. The distances from the lower end and the upper end of the smooth section 10 to the upper surface of the steel plate base material 1 are more than or equal to half of the thickness of the steel plate base material 1. The aperture of the through holes in the steel plate base material 1 and the steel cushion block 2 is D, and D +1mm is less than or equal to D and less than or equal to D +6 mm. The length, the width and the height of the steel cushion block 2 are respectively a, b and h, a is more than or equal to 2d, b is more than or equal to 2d and less than or equal to 5d, and h is more than or equal to d and less than or equal to 4 d. The distance between the center of the through hole on the steel plate base material 1 and the edge of the steel cushion block 2 is more than or equal to d. In this embodiment, D is 16mm, the strength grade of the high-strength screw 5 is 4.8, the distance from the upper end and the lower end of the smooth section 10 to the upper surface of the steel plate base material 1 is half of the thickness of the steel plate base material 1, D +1mm is 17mm, a is 2D 32mm, b is 2D 32mm, h is 16mm, and the distance between the center of the through hole in the steel plate base material 1 and the edge of the steel pad 2 is 16mm or more.

Example 4:

the embodiment discloses a detachable cushion block reinforced high-strength bolt shear connector which comprises a steel plate base material 1, a steel cushion block 2, a plurality of high-strength screws 5 and a plurality of high-strength nuts 4.

The steel plate base material 1 and the steel cushion block 2 are both provided with M through holes through which the high-strength screw rods 5 penetrate, the steel cushion block 2 is a rectangular plate placed on the upper surface of the steel plate base material 1, the length direction of the steel cushion block 2 is perpendicular to the shearing force direction between the steel plate base material 1 and the steel cushion block 2, and M is larger than or equal to 2 and smaller than or equal to 4.

The middle section of the high-strength screw rod 5 is a smooth section 10, M high-strength screw rods 5 penetrate through holes of a steel plate base material 1 and a steel cushion block 2, the smooth section 10 of each high-strength bolt 3 penetrates through the contact surface of the steel plate base material 1 and the steel cushion block 2, the upper end of the smooth section 10 is located in the through hole of the steel cushion block 2, and the lower end of the smooth section 10 is located in the through hole of the steel plate base material 1. In the embodiment, M is 2, and two high-strength screws 5 are arranged at intervals along the length direction of the steel cushion block 2.

Referring to fig. 7, three high-strength nuts 4 are screwed into each high-strength screw 5, the first high-strength nut 4 is close to the upper end of the high-strength screw 5, the second high-strength nut 4 abuts against the upper surface of the steel cushion block 2, and the third high-strength nut 4 abuts against the lower surface of the steel plate base material 1.

Referring to FIG. 8, which is a schematic view of the high-strength screw 5, the diameter of the high-strength screw 5 is d, d is greater than or equal to 16mm and less than or equal to 40mm, and the strength grade of the high-strength screw 5 is greater than or equal to 4.8 grade and less than or equal to 12.9 grade. The distances from the lower end and the upper end of the smooth section 10 to the upper surface of the steel plate base material 1 are more than or equal to half of the thickness of the steel plate base material 1. The aperture of the through holes in the steel plate base material 1 and the steel cushion block 2 is D, and D +1mm is less than or equal to D and less than or equal to D +6 mm. The length, the width and the height of the steel cushion block 2 are respectively a, b and h, a is more than or equal to 2d, b is more than or equal to 2d and less than or equal to 5d, and h is more than or equal to d and less than or equal to 4 d. And the distance between the center of the through hole on the steel plate base material 1 and the edge of the steel cushion block 2 is more than or equal to d. In this embodiment, D is 40mm, the strength grade of the high-strength screw 5 is 12.9, the distance from the upper end and the lower end of the smooth section 10 to the upper surface of the steel plate parent material 1 is half of the thickness of the steel plate parent material 1, D +6mm is 46mm, a is 3D 120mm, b is 5D 200mm, h is 4D 160mm, and the distance between the center of the through hole in the steel plate parent material 1 and the edge of the steel pad 2 is not less than 16 mm.