Guardrail transition section and end post installation work
Guardrail column foundations are excavated using either an excavator or a pit digging machine. The structure of the guardrail manufacturer divides the original guardrail pillars into upper and lower sections. The lower end of the steel pipe of the upper pillar fits into the upper end of the steel pipe of the lower pillar, with bolts crossing through to connect the two sections of the steel pipe. By reinforcing the lower pillar, either through the use of sleeves or other techniques, it prevents deformation of the lower guardrail pillar. Meanwhile, the upper pillar is locally or fully weakened to control the deformation position of the guardrail pillar. Although the lever arm is reduced, the bending modulus of the cross-section is also reduced, ensuring the collision resistance meets or exceeds the original design standard. Highway guardrail nets are produced through specific technical methods to form a mesh product. They are woven from copper wire, stainless steel wire, iron wire, and steel wire, with wire diameters typically ranging from 4 to 0.025 mm. Generally, plain weave, diagonal weave, or mat weave methods are used. Metal wire screens have clear and precise mesh openings, a flat and firm surface, and features such as high-temperature resistance and wear resistance. Stainless steel wire screens are also corrosion-resistant. Therefore, metal wire screens are widely used in powder screening and oil filtering. Sports stadium guardrail nets differ from general mesh products, as they have strict mesh size series and are recognized by the industry, institutions, and standards for their grading and screening of particle objects. The term "mesh count" is not used in wire screens; it is merely a habit of describing screens and is hard to overcome. Unlike general mesh products, wire screens have strict mesh sizes rather than mesh count. These sizes are not isolated; they consist of a series of mesh sizes for grading and screening purposes. The application of wire screens spans industries, agriculture, technology, and national defense. The excavation dimensions for the column foundation are 300×400×300 mm, and for the end inclined support column foundation, they are 400×400×500 mm. After excavation, the foundation should be compacted, leveled, with vertical side walls and a vertical foundation trench. A site supervisor engineer should inspect and approve the foundation before proceeding to the next construction phase.
Firstly, the fence installation should comply with the design and coordinate with the road alignment.
The guardrail installation columns should be securely embedded into the ground to the designed depth and be perpendicular to the road surface.
In the case of general cross-section columns, construction can be carried out at the entrance, with precise positioning essential during the process. If penetration is too deep, the column cannot be pulled out to correct it. It must be withdrawn, reinserted, and then the foundation compacted.
Time cannot be used as a method of construction; it can be buried and excavated. When laying columns, the backfill material should be of good quality and layered, not less than the compactness of the original soil adjacent to it. The column pit should be filled with round stones and compacted.
Five, the installation of guardrails and construction columns can be done using the drilling method. After the pillars are positioned, backfill with materials identical to the subgrade, and compact in layers. When setting pillars on the road surface, fill the桩坑 with 5cm of the same material as the subgrade, extending it up to the surface layer. The remaining portion is backfilled and compacted with materials identical to the road surface.
The rear column has been installed and is now formed into a smooth line in both the horizontal and vertical directions.
Section 8: The installation of guardrails, construction transition sections, and terminal posts should be carried out according to the coordinates specified in the design.
