A prefabricated assembled concrete guardrail structure design method

Abstract

This invention discloses a design method for precast concrete guardrail structures. The specific design steps are as follows: selecting guardrail materials; designing the structural dimensions of precast concrete walls, steel columns, and connectors according to specifications; calculating whether the main stress-bearing parts of the structure meet the design protection requirements; establishing a three-dimensional model of the guardrail structure, verifying the design structure and connection positions, and forming a preliminary structural scheme; establishing a finite element simulation model, conducting overall structural mechanics analysis and optimizing the connection method; performing computer finite element collision simulation according to evaluation standards to evaluate the safety performance of the structure; and conducting full-scale vehicle collision tests to meet practical engineering applications. This design method combines the ease of installation of beam-column guardrail columns with the impact resistance of precast concrete walls, making on-site construction simpler, realizing a rapid assembly process for precast concrete guardrails, and providing high protection capabilities for the combined structure, thus meeting the need for reusable concrete guardrails.

Description

Technical Field

[0001] This invention belongs to the field of traffic safety protection, and specifically relates to a design method for a prefabricated assembled concrete guardrail structure. Background Technology

[0002] With the rapid growth of my country's economy and the booming development of highway transportation, traffic volume has increased rapidly and vehicle types have become more diverse, directly leading to an increase in the frequency of use and load on highway traffic safety facilities. At present, people are paying more and more attention to traffic safety, so highway guardrails, as the last line of defense for traffic safety, will play a crucial role.

[0003] Concrete guardrails are a common form of highway guardrail protection. Through years of practical application, they have demonstrated advantages in rigidity and a large safety margin. Continuous research by traffic safety research institutions has led to the development of precast concrete guardrails with assembly capabilities. This structure involves prefabricating standard sections in a factory and assembling them on-site using anchors. This method saves time on road surface encroachment and significantly shortens the construction period. However, to ensure protective performance, the existing precast guardrail foundation connections are complex, and the on-site hoisting and anchoring process is extremely difficult, posing significant risks to construction workers. Due to the difficulty in connection and anchoring, the guardrail structure is rarely reused, and dismantling often involves crushing, resulting in substantial resource waste.

[0004] Furthermore, the investigation revealed that beam-column type steel guardrails are widely used on bridges due to their ease of installation. The main structure includes bridge deck anchor bolts, steel columns, crossbeams, and splicing bolts. The steel columns are anchored to the bridge deck with anchor bolts, and the crossbeams are anchored to the steel columns with splicing bolts. The entire system is bolted together, resulting in high construction efficiency. The steel columns are also very rigid and not easily damaged. After an accident vehicle impact, only the crossbeams need to be replaced.

[0005] Based on the above research, combining the ease of installation of beam-column guardrail posts with the impact resistance of precast concrete walls, and optimizing the assembly method, a rapid installation process and high protective capacity can be achieved for the guardrails. This also allows for the reuse of concrete guardrails, making them suitable for both new and reconstructed highways. In recent years, with the development of new materials, ultra-high performance concrete (UHPC) has been used to increase concrete strength, further enabling lightweight precast wall structure design. New composite material reinforcements address the design problem of easy corrosion of reinforced concrete steel bars. In summary, a precast assembled concrete guardrail structure design method is proposed. Summary of the Invention

[0006] The purpose of this invention is to provide a design method for precast concrete guardrail structures, in order to solve the problems of complex foundation assembly, difficult on-site construction, and reusability of current precast concrete guardrail structures, thereby increasing the applicability of concrete guardrails.

[0007] To achieve the above-mentioned technical objectives, the technical solution of the present invention is implemented as follows:

[0008] A design method for a precast concrete guardrail structure, the design concept of which includes using steel columns of a beam-column guardrail and precast concrete walls to form a composite structure, wherein the precast concrete walls are not connected to the bridge slabs or steel columns, realizing a rapid assembly process for the guardrail. The specific design steps are as follows:

[0009] ① Determine the protection level of the precast concrete guardrail, select the concrete and metal materials to be used, and determine the material properties based on the level of protection.

[0010] ②Based on the determination of the above protection level and materials, and in accordance with the relevant design specifications for guardrails, design the structural dimensions of the precast concrete wall, such as slope form, width, length, and height; design the structural dimensions of the steel column, such as height and plate thickness; and design the quantity and grade of connectors.

[0011] ③ The formula calculates whether the main stress-bearing parts of the precast concrete wall, steel column and connector meet the design protection requirements. If not, return to the previous step to design structural reinforcement.

[0012] ④ Establish a three-dimensional model of the guardrail structure, verify the design structure and connection positions, output design drawings, and form a preliminary structural plan;

[0013] ⑤ Based on the design drawings, establish a finite element simulation model, conduct overall structural mechanics analysis, and optimize the connection methods;

[0014] ⑥ Use computer finite element simulation software to perform safety performance analysis, conduct collision simulation according to the evaluation standard requirements, and evaluate the safety performance of the structure. If the evaluation requirements are not met, return to the previous step to continue the design structure optimization.

[0015] ⑦ Conduct a full-scale crash test on a real vehicle based on the design structure evaluated by computer finite element simulation. If the test requirements are met, it can be applied to actual engineering. If not, return to the previous step to continue optimizing the design structure.

[0016] ⑧ The guardrail is manufactured according to the structure that has passed the full-scale collision test of the actual vehicle. The precast concrete wall is made in the factory with embedded splicing bolts. At the same time, the steel columns and longitudinal splicing steel are manufactured and transported to the project with bridge deck for application.

[0017] ⑨ Anchor bolts have been pre-embedded on the bridge deck. After setting out the positioning, the steel columns are installed first. Then, according to the design position, the precast concrete walls are hoisted and fitted to the steel columns. Each precast concrete wall is assembled into a whole by longitudinally splicing the steel columns. Finally, the alignment is adjusted to complete the installation of the precast concrete guardrail.

[0018] ⑩ The precast concrete guardrail design method can achieve seamless conversion between temporary and permanent guardrails. The precast concrete walls, steel columns, longitudinal splicing steel, and splicing bolts can all be reused. Only the position of the anchor bolts on the bridge deck needs to be changed.

[0019] A precast concrete guardrail structure includes a precast concrete wall, steel columns, longitudinally spliced ​​steel sections, splicing bolts, anchor bolts, and a bridge plate. The precast concrete wall is composed of reinforced concrete precast segments with splicing bolts pre-embedded at both ends of the back side. Every two segments of the precast concrete wall are connected and anchored by the splicing bolts through longitudinally spliced ​​steel sections. The steel columns are independent individuals, and several steel columns are spaced apart on the back side of the precast concrete wall. The steel columns are anchored to the bridge plate by anchor bolts, and the front of the steel columns matches the cross-sectional shape of the back of the precast concrete wall.

[0020] Furthermore, the front slope of the precast concrete wall includes an F-shaped slope, a reinforced slope, and a single slope, and the back of the precast concrete wall is provided with a column mounting groove, into which the steel column is embedded.

[0021] Furthermore, the steel column includes a rectangular steel pipe with a flange plate welded to the bottom. The flange plate has through holes for anchor bolts to pass through.

[0022] Furthermore, the anchor bolts are anchored in the bridge deck by pre-embedding or bolt installation.

[0023] Furthermore, the longitudinal splicing steel is a channel steel or a steel pipe, with through holes at both ends for passing through the splicing bolts.

[0024] By adopting the above technical solution, the present invention has the following beneficial effects:

[0025] (1) A design method for prefabricated concrete guardrail structure is provided to promote industry progress and effectively improve driving safety;

[0026] (2) A prefabricated concrete guardrail structure is provided, which combines the characteristics of easy installation of beam-column guardrail posts and the impact resistance of prefabricated concrete walls. On-site construction is easier and the combined structure has high protection capabilities.

[0027] (3) Achieve mass production in factories and realize the rapid assembly construction process of prefabricated concrete guardrails;

[0028] (4) To meet the requirement of reusable concrete guardrails, reduce resource waste and lower project costs;

[0029] (5) If high-performance materials are used, the structural size can be greatly reduced, the bridge load can be reduced, and the safety margin of the main structure of the bridge can be guaranteed. Attached Figure Description

[0030] To more clearly illustrate the technical solution of this invention, the accompanying drawings used in the embodiments will be briefly described below:

[0031] Figure 1 This is an example of a cross-sectional view of a prefabricated assembled concrete guardrail structure according to the present invention;

[0032] Figure 2 This is an example of a front view of a prefabricated assembled concrete guardrail structure according to the present invention;

[0033] Figure 3 This is an example of a cross-sectional view of the precast concrete wall described in this invention;

[0034] Figure 4 This is an example of a front view of the steel column described in this invention;

[0035] Figure 5 This is an example of a front view of the steel column foundation anchorage described in this invention;

[0036] Figure 6 This is a flowchart illustrating the design method for a prefabricated assembled concrete guardrail structure according to the present invention.

[0037] Figure label:

[0038] 1. Precast concrete wall; 2. Steel column; 3. Longitudinal spliced ​​steel; 4. Splicing bolt; 5. Anchor bolt; 6. Bridge plate; 7. Mounting groove; 8. Flange plate; 9. Through hole. Detailed Implementation

[0039] The present invention will be further described in detail below with reference to embodiments and specific implementation methods. However, this should not be construed as limiting the scope of the above-described subject matter of the present invention to the following embodiments; any technology implemented based on the content of the present invention falls within the scope of the present invention.

[0040] like Figure 1-2The diagram shown is an example of a precast concrete guardrail structure according to the present invention. It includes a precast concrete wall 1, steel columns 2, longitudinally splicing steel sections 3, splicing bolts 4, anchor bolts 5, and a bridge deck 6. The precast concrete wall 1 is a precast reinforced concrete segment, with splicing bolts 4 pre-embedded at both ends of its back side. Every two segments of the precast concrete wall 1 are connected and anchored by the longitudinally splicing steel sections 3 and the splicing bolts 4. The steel columns 2 are independent units, and several steel columns 2 are spaced apart on the back side of the precast concrete wall 1. The steel columns 2 are anchored to the bridge deck 6 by the anchor bolts 5, and the front and back cross-sections of the steel columns 2 and the precast concrete wall 1 are both straight-walled.

[0041] like Figure 3 The image shown is an example of a cross-sectional view of the precast concrete wall of the present invention. The front slope of the precast concrete wall 1 is an F-shaped slope, and a rectangular mounting groove 7 is provided on the back of the precast concrete wall 1, into which the steel column 2 is embedded.

[0042] like Figure 4 The image shown is an example of a front view of the steel column of the present invention. The steel column 2 includes a rectangular steel pipe, and a flange plate 8 is welded to the bottom. A through hole 9 is provided on the flange plate 8 for passing through the anchor bolt 5.

[0043] like Figure 5 The image shown is an example of a front view of the steel column foundation anchorage of the present invention. The anchor bolts 5 are anchored in the bridge slab 6 by pre-embedding or by rebar bolting, and the steel column 2 and the bridge slab 6 are anchored by the anchor bolts 5.

[0044] like Figure 6 The diagram shown is a flowchart of a precast concrete guardrail structure design method according to the present invention. The design concept of this precast concrete guardrail structure design method includes using the steel columns 2 of the beam-column guardrail and the precast concrete wall 1 to form a combined structure, wherein the precast concrete wall 1 is not connected to the bridge slab 6 or the steel columns 2, thus achieving a rapid guardrail assembly process. The specific design steps are as follows:

[0045] ① Determine the protection level of the precast concrete guardrail, select the concrete and metal materials to be used, and determine the material properties based on the level of protection.

[0046] ②Based on the determination of the above protection level and materials, and in accordance with the relevant design specifications for guardrails, design the structural dimensions of the precast concrete wall 1, such as slope form, width, length, and height; design the structural dimensions of the steel column 2, such as height and plate thickness; and design the quantity and grade of connectors.

[0047] ③ Calculate whether the main stress-bearing parts of the precast concrete wall 1, steel column 2 and connectors meet the design protection requirements. If not, return to the previous step to design structural reinforcement.

[0048] ④ Establish a three-dimensional model of the guardrail structure, verify the design structure and connection positions, output design drawings, and form a preliminary structural plan;

[0049] ⑤ Based on the design drawings, establish a finite element simulation model, conduct overall structural mechanics analysis, and optimize the connection methods;

[0050] ⑥ Use computer finite element simulation software to perform safety performance analysis, conduct collision simulation according to the evaluation standard requirements, and evaluate the safety performance of the structure. If the evaluation requirements are not met, return to the previous step to continue the design structure optimization.

[0051] ⑦ Conduct a full-scale crash test on a real vehicle based on the design structure evaluated by computer finite element simulation. If the test requirements are met, it can be applied to actual engineering. If not, return to the previous step to continue optimizing the design structure.

[0052] ⑧ The guardrail is processed according to the structure that has passed the full-scale collision test of the actual vehicle. The precast concrete wall 1 is prefabricated in the factory, and the splicing bolts 4 are pre-embedded inside. At the same time, the steel column 2 and longitudinal splicing steel 3 are processed and transported to the project with bridge plate 6 for application.

[0053] ⑨ Anchor bolts 5 are pre-embedded on the bridge deck 6. After setting out the positioning, the steel column 2 is installed first. Then, according to the design position, the precast concrete wall 1 is hoisted and attached to the steel column 2. Each precast concrete wall 1 is assembled into a whole by longitudinally splicing the steel 3. Finally, the alignment is adjusted to complete the installation of the precast concrete guardrail.

[0054] ⑩ The precast concrete guardrail design method can realize the functional conversion between temporary guardrails and permanent guardrails. The precast concrete wall 1, steel column 2, longitudinal splicing steel 3, and splicing bolt 4 can all be reused. Only the position of the anchor bolt 5 on the bridge plate 6 needs to be changed.

[0055] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A design method for a precast concrete guardrail structure, characterized in that: The design concept includes using the steel columns (2) of the beam-column guardrail and the precast concrete wall (1) to form a combined structure. The precast concrete wall (1) is not connected to the bridge slab (6) or the steel columns (2), thus realizing the rapid assembly process of the guardrail. The specific design steps are as follows: ① Determine the protection level of the precast concrete guardrail, select the concrete and metal materials to be used, and determine the material properties based on the level of protection. ②Based on the determination of the above protection level and materials, and in accordance with the requirements of the guardrail design specifications, design the slope form, width, length and height of the precast concrete wall (1), the height and thickness of the steel column (2), and the quantity and grade of the connectors. ③ Calculate whether the main stress-bearing parts of the precast concrete wall (1), steel column (2) and connectors meet the design protection requirements. If not, return to the previous step to design structural reinforcement. ④ Establish a three-dimensional model of the guardrail structure, verify the design structure and connection positions, output design drawings, and form a preliminary structural plan; ⑤ Based on the design drawings, establish a finite element simulation model, conduct overall structural mechanics analysis, and optimize the connection methods; ⑥ Use computer finite element simulation software to perform safety performance analysis, conduct collision simulation according to the evaluation standard requirements, and evaluate the safety performance of the structure. If the evaluation requirements are not met, return to the previous step to continue the design structure optimization. ⑦ Conduct a full-scale crash test on a real vehicle based on the design structure evaluated by computer finite element simulation. If the test requirements are met, it can be applied to actual engineering. If not, return to the previous step to continue optimizing the design structure. ⑧ The guardrail is processed according to the structure that has passed the full-scale collision test of the actual vehicle. The precast concrete wall (1) is prefabricated in the factory, and the splicing bolts (4) are pre-embedded inside. At the same time, the steel column (2) and longitudinal splicing steel (3) are processed and transported to the project with bridge plate (6) for application. ⑨ Anchor bolts (5) have been pre-embedded on the bridge deck (6). Lay out the positioning, install the steel column (2) first, then hoist the precast concrete wall (1) according to the design position and fit it with the steel column (2). Assemble each precast concrete wall (1) into a whole by longitudinally splicing the steel (3). Finally, adjust the line shape and complete the installation of the precast concrete guardrail. ⑩ The design method of precast concrete guardrail can realize the functional conversion between temporary guardrail and permanent guardrail. The precast concrete wall (1), steel column (2), longitudinal splicing steel (3), and splicing bolt (4) can all be reused. Only the position of the anchor bolt (5) on the bridge plate (6) needs to be changed. The precast concrete guardrail structure includes a precast concrete wall (1), steel columns (2), longitudinal splicing steel (3), splicing bolts (4), anchor bolts (5), and a bridge plate (6). The precast concrete wall (1) is a precast reinforced concrete segment with splicing bolts (4) pre-embedded at both ends of the back side. Every two segments of the precast concrete wall (1) are connected and anchored by the splicing bolts (4) through the longitudinal splicing steel (3). The steel columns (2) are independent individuals, and several steel columns (2) are spaced apart on the back side of the precast concrete wall (1). The steel columns (2) are anchored to the bridge plate (6) through the anchor bolts (5), and the front of the steel columns (2) matches the cross-sectional shape of the back of the precast concrete wall (1). The precast concrete wall (1) has a column mounting groove (7) on its back, and the steel column (2) is embedded in the mounting groove (7).

2. The design method for a precast concrete guardrail structure according to claim 1, characterized in that: The front slope of the precast concrete wall (1) includes F-type slope, reinforced slope and single slope.

3. The design method for a precast assembled concrete guardrail structure according to claim 1, characterized in that: The steel column (2) includes a rectangular steel pipe and a flange plate (8) welded to the bottom. A through hole (9) is provided on the flange plate (8) for passing through the anchor bolt (5).

4. The design method for a precast concrete guardrail structure according to claim 1, characterized in that: The anchor bolts (5) are anchored in the bridge slab (6) by pre-embedding or bolting.

5. The design method for a precast concrete guardrail structure according to claim 1, characterized in that: The longitudinal splicing steel (3) is a channel steel or steel pipe with through holes (9) at both ends, which are used to pass through the splicing bolts (4).

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