Semi-flange connection node structure of concrete-filled steel tube arch frame

Abstract

The utility model provides a concrete filled steel tube arch frame semi-flange connection node structure. The concrete filled steel tube arch frame semi-flange connection node structure structurally comprises a concrete filled steel tube arch frame, a semi-flange plate connection part, a screw rod, a nut, a waterproof layer and CFRP fiber cloth, the half flange plate connecting part is a half flange plate provided with a groove, and the lower half part of the connecting joint of the outer steel pipe is placed in the groove of the half flange plate and is welded with the half flange plate; waterproof layers are laid on the outer side and the periphery of the top of the connecting joint, and the waterproof layers of the connecting joint and the half flange plate connecting part are integrally bundled through CFRP fiber cloth. According to the structure, the problem of stress concentration on the contact surface of a traditional full-flange connection structure and surrounding rock can be effectively solved while the advantages of a traditional flange connection node are reserved. In tunnel engineering under the high-stress surrounding rock condition, the node structure can adapt to the large-deformation working condition of the surrounding rock, and a good choice is provided for supporting design of the concrete-filled steel tube tunnel under the complex geological condition.

Description

Technical Field

[0001] This utility model relates to the field of tunnel lining support technology, specifically to a novel steel-concrete arch frame semi-flange connection node structure. Background Technology

[0002] In high-stress surrounding rock tunnel engineering, the steel-concrete composite arch support system is widely used due to its excellent load-bearing performance. At this time, the arch structure is subjected to strong compressive and bending stress for a long time under the load of the surrounding rock. The nodes, as the connecting parts between the arch sections, are the weakest and most vulnerable parts of the entire arch structure. Their force transmission mechanism has a significant impact on the internal force distribution and failure mode of the structure. The reliability of the connection method of the arch nodes is an important link in the stability of the tunnel arch support performance and safe production.

[0003] Sleeve connection is the primary connection method for arch frame joints in practical engineering. A sleeve joint is a type of joint that uses an empty steel pipe to connect two sections of constrained concrete arch frame, widely used for strengthening and protecting arch frame joints. However, sleeve connections reduce the axial load-bearing capacity, bending resistance, and combined bending resistance of the arch frame. Furthermore, the greater the load eccentricity, the greater the impact of the sleeve on the axial load-bearing capacity of the arch frame, and the heavier the load borne by the sleeve. Consequently, this connection method easily causes localized stress concentration in the steel-concrete composite member and the sleeve at the sleeve opening, leading to strength failure of the sleeve joint. In recent years, some scholars have proposed using flange joints; however, the protruding structure at the contact point between the flange structure and the surrounding rock at the tunnel roof can cause significant stress concentration, severely affecting the durability and safety of the structure under high-stress surrounding rock loads.

[0004] Based on the aforementioned technical deficiencies, there is an urgent need to develop a novel method for connecting steel-concrete composite arch frames. This technical solution should simultaneously possess rapid construction characteristics and stress optimization capabilities. The semi-flange connection node structure for steel-concrete composite arch frames proposed in this invention, through innovative structural design, not only ensures the load-bearing capacity advantages of traditional flange connection nodes and the overall integrity of the steel-concrete composite arch frame, but also significantly improves the stress distribution at the contact surface between the traditional flange connection node and the surrounding rock, thereby comprehensively enhancing the load-bearing performance of the arch frame structure. This technical solution provides a superior technical solution for tunnel support engineering in high-stress surrounding rock. Summary of the Invention

[0005] To overcome the defects such as stress concentration caused by flange connection nodes in steel-concrete composite arch supports in existing tunnel engineering, this utility model provides a semi-flange connection node structure for steel-concrete composite arch supports, offering a better option for high-stress surrounding rock tunnel engineering.

[0006] The objective of this utility model is mainly achieved through the following technical solutions:

[0007] This utility model provides a steel-concrete composite arch frame semi-flange connection node structure, which consists of a steel-concrete composite arch frame, a semi-flange connection part, bolts, nuts, a waterproof layer, and CFRP fiber cloth (carbon fiber reinforced composite material). The steel-concrete composite arch frame is composed of an outer steel pipe and core concrete poured inside the outer steel pipe. The semi-flange connection part is a semi-flange with a groove. The lower half of the connection node of the outer steel pipe is placed in the groove of the semi-flange and welded to the semi-flange. The semi-flange connection parts of the two steel-concrete composite arch frames are connected by bolts and nuts. A waterproof layer is laid on the top outer side and around the connection node of the two steel-concrete composite arch frames, and CFRP fiber cloth is used to bind the waterproof layer and the semi-flange connection part of the connection node as a whole.

[0008] Furthermore, the outer steel pipe is a round steel pipe; the semi-flange connection part is a semi-circular flange, and the groove opened on the semi-circular flange is a semi-circular groove; when the outer steel pipe is a round steel pipe, the semi-flange connection part adopts a semi-circular flange, the lower half of the connection node of the round steel pipe is placed in the semi-circular groove of the semi-circular flange, and welded to the semi-circular flange.

[0009] Furthermore, the outer steel pipe is a rectangular steel pipe; the half-flange connection part is a rectangular flange, and the groove opened on the rectangular flange is a rectangular groove; when the outer steel pipe is a rectangular steel pipe, the half-flange connection part adopts a rectangular flange, the lower half of the connection node of the rectangular steel pipe is placed in the rectangular groove of the rectangular flange and welded to the rectangular flange.

[0010] Compared with the prior art, the present invention has the following beneficial effects:

[0011] 1) Compared with the traditional full flange connection node, the novel semi-flange connection structure proposed in this utility model effectively eliminates the stress concentration problem in the contact surface between the flange and the surrounding rock in the traditional full flange connection node structure, and improves the load-bearing performance of the arch frame structure.

[0012] 2) Compared with traditional sleeve connection nodes, the structure proposed in this utility model has the advantages of greater stiffness, better integrity, clearer force transmission path, and more reliable stress performance.

[0013] 3) By using CFRP fiber cloth integral binding technology, the stress distribution of nodes was optimized, which significantly improved the fatigue resistance and structural durability of the nodes.

[0014] In summary, the steel-concrete composite arch frame semi-flange connection node structure proposed in this utility model retains the advantages of traditional flange connection nodes while effectively eliminating the stress concentration problem at the contact surface with the surrounding rock in traditional full flange connections, thus fully utilizing the material properties of steel-concrete composite. In tunnel engineering under high-stress surrounding rock conditions, this node structure can adapt to large deformation conditions of the surrounding rock, providing a better option for the support design of steel-concrete composite tunnels under complex geological conditions. Attached Figure Description

[0015] Figure 1 This is a front view of the structure of this utility model without the waterproof layer and CFRP fiber cloth.

[0016] Figure 2 This is a cross-sectional view of the connection node structure when the outer steel pipe is a round steel pipe and the semi-circular flange connection part is a semi-circular flange, without the arrangement of a waterproof layer and CFRP fiber cloth.

[0017] Figure 3 This is a cross-sectional view of the connection node structure when the outer steel pipe is a rectangular steel pipe and the half-flange connection part is a rectangular flange, without the arrangement of a waterproof layer and CFRP fiber cloth.

[0018] Figure 4 This is a front view of the structure of this utility model after the waterproof layer and CFRP fiber cloth are arranged.

[0019] Figure 5 This is a cross-sectional view of the connection node structure after arranging a waterproof layer and CFRP fiber cloth when the outer steel pipe is a round steel pipe and the semi-circular flange connection part is a semi-circular flange.

[0020] The markings in the diagram are as follows: 1-Steel pipe concrete arch frame, 101-Outer steel pipe, 102-Core concrete, 2-Half flange connection, 3-Threaded rod, 4-Nut, 5-Waterproof layer, 6-CFRP fiber cloth. Detailed Implementation

[0021] To further explain the features of this utility model, the following embodiments are provided, and detailed descriptions are given in conjunction with the accompanying drawings.

[0022] like Figures 1-5As shown, this utility model provides a novel steel-concrete composite arch frame semi-flange connection node structure, including a steel-concrete composite arch frame 1, a semi-flange connection part 2, a bolt 3, a nut 4, a waterproof layer 5, and CFRP fiber cloth 6 (carbon fiber reinforced composite material). The steel-concrete composite arch frame 1 consists of an outer steel pipe 101 and a core concrete 102 cast inside the outer steel pipe; the outer steel pipe 101 is a round steel pipe or a rectangular steel pipe; the semi-flange connection part 2 is a semi-circular flange or a rectangular flange, the semi-circular flange has a semi-circular groove, and the rectangular flange has a rectangular groove; when the outer steel pipe 101 is a round steel pipe, the semi-flange connection part adopts a semi-circular flange, and the lower half of the connection node of the round steel pipe is placed in the semi-circular groove of the semi-circular flange and connected with the semi-circular flange. Flange welding; when the outer steel pipe is a rectangular steel pipe, the half-flange connection part adopts a rectangular flange. The lower half of the connection node of the rectangular steel pipe is placed in the rectangular groove of the rectangular flange and welded to the rectangular flange. The half-flange connection parts of the two steel pipe concrete arches are connected by bolts 3 and nuts 4. A waterproof layer 5 is laid on the top outer side and around the connection node of the two steel pipe concrete arches, and CFRP fiber cloth 6 is used to bind and protect the waterproof layer 5 and the half-flange connection part 2 of the connection node as a whole.

[0023] Based on the structural characteristics of the newly designed steel-concrete arch frame semi-flange connection node, the construction steps are as follows:

[0024] Step 1: Select the type of outer steel pipe 101 according to the project requirements.

[0025] Step 2: Based on the local surrounding rock load characteristics and structural design, determine the structural shape and thickness of the semi-flange connection part 2 required for the structure.

[0026] Step 3: The designed semi-flange connection part 2 structure is handed over to the factory for prefabrication and welded to the outer steel pipe 101, and then transported to the construction site.

[0027] Step four: On-site workers connect the prefabricated welded outer steel pipe 101 and the semi-flange connection part 2 using screws 3 and tighten nuts 4.

[0028] Step 5: Lay a waterproof layer 5 on the top outer side and around the connection node of the outer steel pipe 101.

[0029] Step 6: Use CFRP fiber cloth 6 to bundle the waterproof layer 5 and the half-flange connection part 2 of the connection node as a whole.

[0030] Step 7: Pour the core concrete 102 and cure it to form a complete steel-concrete composite arch frame 1.

[0031] Compared to traditional full-flange connections, the semi-flange connection proposed in this invention effectively eliminates stress concentration at the contact surface between the traditional full flange and the surrounding rock, thus improving the load-bearing capacity of the arch structure. Compared to traditional sleeve connection nodes, the proposed structure has advantages such as greater stiffness, better integrity, clearer force transmission path, and more reliable stress performance. By applying CFRP fiber cloth integral binding technology, the proposed structure optimizes the stress distribution at the node, significantly improving the node's fatigue resistance and structural durability.

Claims

1. A semi-flange connection node structure for a steel-concrete composite arch frame, characterized in that: The structure comprises a steel-concrete composite arch frame, a half-flange connection, bolts, nuts, a waterproof layer, and CFRP fiber cloth. The steel-concrete composite arch frame consists of an outer steel pipe and a core concrete cast inside the outer steel pipe. The half-flange connection is a half-flange with a groove. The lower half of the connection node of the outer steel pipe is placed in the groove of the half-flange and welded to the half-flange. The half-flange connections of the two steel-concrete composite arch frames are connected by bolts and nuts. A waterproof layer is laid on the top outer side and around the connection node of the two steel-concrete composite arch frames, and CFRP fiber cloth is used to bind the waterproof layer and the half-flange connection of the connection node as a whole.

2. The steel-concrete composite arch frame semi-flange connection node structure according to claim 1, characterized in that: The outer steel pipe is a round steel pipe; the semi-flange connection part is a semi-circular flange, and the groove opened on the semi-circular flange is a semi-circular groove; when the outer steel pipe is a round steel pipe, the semi-flange connection part adopts a semi-circular flange, the lower half of the connection node of the round steel pipe is placed in the semi-circular groove of the semi-circular flange and welded to the semi-circular flange.

3. The steel-concrete composite arch frame semi-flange connection node structure according to claim 1, characterized in that: The outer steel pipe is a rectangular steel pipe; the half-flange connection part is a rectangular flange, and the groove opened on the rectangular flange is a rectangular groove; when the outer steel pipe is a rectangular steel pipe, the half-flange connection part adopts a rectangular flange, the lower half of the connection node of the rectangular steel pipe is placed in the rectangular groove of the rectangular flange and welded to the rectangular flange.

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