UHPC (Ultra High Performance Concrete) movable guardrail for zoning in highway airport runway

Abstract

The invention discloses a UHPC (Ultra High Performance Concrete) movable guardrail for zoning in a road airport runway, which is formed by splicing a plurality of UHPC movable guardrail sections through stainless steel round pipes, and a hydraulic lifting cylinder controls the UHPC movable guardrail sections to lift. Each UHPC movable guardrail section is composed of a prefabricated shell and internal filling concrete. A movable guardrail system is constructed through the connecting pieces and the moving devices, it is guaranteed that a common road guardrail prevents vehicles from crossing, the out-of-control vehicles are blocked, buffered and guided, and the requirements for rapid dismounting and transferring of zoning guardrails in a road airport runway can be met. Through splicing of the connecting pieces and lifting adjustment of the moving device, a movable guardrail semi-automatic system is formed, potential safety hazards in the guardrail transferring process are avoided, and the construction efficiency is effectively improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of highway guardrails, and particularly relates to a UHPC mobile guardrail for the median strip of highway airport runways. Background Art

[0002] Highway airport runways are special facilities that combine the functions of highways and airports. Usually used as ordinary highways, they play roles such as emergency takeoff and landing, temporary parking, fuel loading, or weapon and equipment loading in specific situations. On highway airport runways, qualified median strip guardrails not only need to prevent vehicles from crossing, and play functions of blocking, buffering, and guiding out-of-control vehicles, but also need to be quickly demolished and transferred. Currently, the median strip guardrails on highway airport runways are mainly composed of combined traditional concrete guardrails and corrugated beam guardrails. After long-term service, there are potential hidden dangers such as corrosion, rust, deformation, bending, loosening or missing of connectors, etc., which cause the guardrails to lose their good combat state. Summary of the Invention

[0003] In view of the above problems, the present invention designs a UHPC mobile guardrail for the median strip of highway airport runways. The present invention can not only give full play to the advantages of UHPC precast guardrails such as low carbon and environmental protection, convenient construction, and long service life, but also meet the requirements of quickly demolishing and transferring the median strip guardrails on highway airport runways.

[0004] The UHPC mobile guardrail for the median strip of highway airport runways is formed by splicing a plurality of UHPC mobile guardrail segments with stainless steel round tubes, and a hydraulic lifting cylinder controls the lifting of the UHPC mobile guardrail segments.

[0005] The UHPC mobile guardrail segment is composed of a precast outer shell and internally filled concrete. The precast outer shell is a UHPC thin-walled structure with a length of 4m, a thickness of not less than 2.5cm, a compressive strength of not less than 120MPa, a tensile strength of not less than 5Mpa, and the internally filled concrete has a compressive strength of not less than 20MPa.

[0006] The internally filled concrete is ordinary concrete or solid waste-based concrete.

[0007] The construction method of the UHPC movable guardrail for the median strip of highway airport runways is as follows: Excavate a plurality of foundation pits at intervals of 20 cm on the line where the guardrail is to be installed. The hydraulic lifting cylinder is buried below the bottom of the foundation pit, and the top is coplanar with the bottom of the foundation pit. Vertically pre-embed screw rods on both sides of the foundation pit to the bottom of the foundation pit, and then pour UHPC concrete. The support plate is horizontally placed on the bottom of the foundation pit, and the hydraulic lifting cylinder jacks up the support plate to the highway pavement. The precast shell is horizontally placed on the support plate. Connecting plates are provided on both sides of the precast shell, and the connecting plates and the screw rods are fixedly connected by splicing nuts. Near the precast shell, the support plate and the connecting plate are fastened by bolts. Three groups of PVC pipes are arranged in the precast shell, and then concrete is poured. After curing, stainless steel round pipes are inserted into the PVC pipes to connect the UHPC movable guardrail segments.

[0008] The bolt for connecting the support plate and the connecting plate is M16×180mm.

[0009] The diameter of the screw rod is 40mm.

[0010] The wall thickness of the stainless steel round pipe is not less than 5mm, and the single-section length = 2×the length of the UHPC movable guardrail segment + 2×the foundation pit interval.

[0011] The bottom surface of the support plate is the same size as that of the foundation pit.

[0012] The technical advantages achieved by the present invention: 1. The present invention designs a UHPC movable guardrail for the median strip of highway airport runways. By constructing a movable guardrail system through connecting parts and moving devices, it not only ensures that ordinary highway guardrails prevent vehicles from crossing, playing a role in blocking, buffering and guiding out-of-control vehicles, but also can meet the requirements of rapid removal and transfer of guardrails in the median strip of highway airport runways.

[0013] 2. Through the splicing of connecting parts and the lifting adjustment of moving devices, the present invention forms a semi-automatic system for movable guardrails, avoiding potential safety hazards during the transfer of guardrails and effectively improving construction efficiency. Description of the Drawings

[0014] Figure 1 It is a three-dimensional view of the precast shell of the UHPC movable guardrail segment in Embodiment 1.

[0015] Figure 2 It is a schematic cross-sectional view of the UHPC movable guardrail used as a highway guardrail in Embodiment 1.

[0016] Figure 3 It is a partial three-dimensional view of the UHPC movable guardrail used as a highway guardrail in Embodiment 1.

[0017] Figure 4 It is a schematic cross-sectional view of the final state of the removal and transfer of the UHPC movable guardrail in Embodiment 1.

[0018] Reference numerals: 1 - precast housing, 2 - concrete, 3 - PVC pipe, 4 - stainless steel round pipe, 5 - splicing nut, 6 - screw rod, 7 - bolt, 8 - connecting plate, 9 - support plate, 10 - hydraulic lifting cylinder, 11 - UHPC concrete, 12 - road surface. Detailed implementation mode

[0019] The following further details a UHPC mobile guardrail for the median strip of highway airport runways according to the present invention in conjunction with the accompanying drawings and specific embodiments: Embodiment 1

[0020] Dig a plurality of foundation pits at intervals of 20 cm on the line for installing the guardrail. The size of the foundation pit is 4.2 m × 1.5 m × 1.3 m. The hydraulic lifting cylinder is buried below the bottom of the foundation pit, and the top is coplanar with the bottom of the foundation pit. Vertical screw rods are pre-buried on both sides of the foundation pit to the bottom of the foundation pit. The diameter of the screw rod is 4 cm, and the interval is 25 cm. Then, pour 10 cm thick UHPC concrete; horizontally place a support plate with a length of 4 m, a width of 1 m, and a thickness of 4 cm on the bottom of the foundation pit, and use the hydraulic lifting cylinder to raise the support plate to the road surface; horizontally place the precast housing on the support plate, and the bottom of the precast housing is closely attached to the connecting plate; connecting plates are provided on both sides of the precast housing, and the connecting plate and the screw rod are fixedly connected by an M16 mm splicing nut. The threaded rod of the connecting part of the screw rod and the connecting plate is 10 cm long and 1.6 cm in diameter. Near the precast housing, the support plate and the connecting plate are fastened and connected by an M16×180 mm bolt; 3 groups of PVC pipes with an inner diameter of 10 cm are arranged in the precast housing. The 3 groups of PVC pipes are fixed by a steel frame. The center of the bottom PVC pipe is coplanar with the upper edge line of the vertical plate at the bottom end of the precast housing, and the distance between the centers of the PVC pipes is 35 cm. Pour concrete into the precast housing. The cross-sectional view is as Figure 2 shown, and the segment interval is 20 cm. After curing, a stainless steel round pipe with a length of 8.4 m, an outer diameter of 10 cm, and a thickness of 5 mm is inserted into the PVC pipe to connect the UHPC mobile guardrail segments.

[0021] For Figure 3 the guardrail structure in, a full-vehicle SB-level collision simulation test is carried out. Vehicles of three types do not cross, climb over, or straddle the test guardrail. The vehicles do not roll over after the collision and all drive away from the test site along a trajectory parallel to the guardrail. The stainless steel pipe and the UHPC housing do not break or fail after the collision. The designed UHPC mobile guardrail for the median strip of highway airport runways meets the safety performance requirements of the SB protection level.

[0022] When the guardrail needs to be disassembled and transferred, pull out the stainless steel round pipe, remove the splicing bolts used to connect the connecting plate and the support plate, and use the hydraulic lifting cylinder to lower the UHPC guardrail segment into the foundation pit. Horizontally place a connecting plate with a length of 4 m, a width of 1 m, and a thickness of 2 cm on the top of the guardrail segment. The cross-sectional view of the final state of the guardrail disassembly and transfer is as Figure 4 shown.

[0023] The present invention has been described in detail in conjunction with the embodiments. The materials and structures involved in the present invention are not limited to the above examples. Various changes made without departing from the gist of the present invention shall be regarded as falling within the protection scope of the present invention.

Claims

1. A UHPC mobile guardrail for the median strip of highway airport runways, characterized in that, The guardrail is formed by splicing multiple UHPC mobile guardrail segments with stainless steel round tubes, and a hydraulic lifting cylinder controls the lifting of the UHPC mobile guardrail segments.

2. The UHPC mobile guardrail for the median strip of highway airport runways according to claim 1, characterized in that, The UHPC mobile guardrail segment is composed of a precast outer shell and internally filled concrete. The precast outer shell is a UHPC thin-walled structure with a length of 4m, a thickness of not less than 2.5cm, a compressive strength of not less than 120MPa, a tensile strength of not less than 5Mpa, and the internally filled concrete has a compressive strength of not less than 20MPa.

3. The UHPC mobile guardrail for the median strip of highway airport runways according to claim 2, characterized in that, The internally filled concrete is ordinary concrete or solid waste-based concrete.

4. The construction method of the UHPC mobile guardrail for the median strip of highway airport runways according to any one of claims 1-3, characterized in that, The specific operation of the construction method is as follows: Excavate multiple foundation pits at intervals of 20cm on the line where the guardrail is installed. The hydraulic lifting cylinder is buried below the bottom of the foundation pit, and the top is coplanar with the bottom of the foundation pit; Vertical pre-embedded screws are installed on both sides of the foundation pit to the bottom of the foundation pit, and then UHPC concrete is poured; The support plate is horizontally placed at the bottom of the foundation pit, and the hydraulic lifting cylinder jacks up the support plate to the road surface; The precast outer shell is horizontally placed on the support plate. Connection plates are provided on both sides of the precast outer shell, and the connection plates and the screws are fixedly connected by splicing nuts. Near the precast outer shell, the support plate and the connection plate are tightly connected by bolts; 3 groups of PVC pipes are arranged in the precast outer shell, and then concrete is poured. After curing, the stainless steel round tube is inserted into the PVC pipe to connect the UHPC mobile guardrail segments.

5. The construction method according to claim 4, characterized in that, The bolt connecting the support plate and the connection plate is M16×180mm.

6. The construction method according to claim 4, characterized in that, The diameter of the screw is 40mm.

7. The construction method according to claim 4, characterized in that, The wall thickness of the stainless steel round tube is not less than 5mm, and the single-section length = 2×UHPC mobile guardrail segment length + 2×foundation pit interval.

8. The construction method according to claim 4, characterized in that, The bottom surface of the support plate is the same size as the foundation pit.

Images