If the highway guardrail or road intersection breaks, the column spacing can be adjusted as needed. When crossing the river, when the width of both banks is less than 6M, they should be connected as shown in the drawings or with barbed wire; When the width of both banks of the river exceeds 6M, the expressway guardrail shall be provided with closed connection.
When the construction design unit requires that the column, support or anchor head of the guardrail net be buried in the concrete foundation in the drawing, the contractor shall set necessary temporary stay cables or supports to fix the column in a proper position until the concrete hardens. During the 7-day concrete curing period, no materials or components shall be installed or fastened on columns, stay cables and supports. All columns should be buried vertically according to the drawings and linear requirements. Where the high-voltage transmission line passes through the guardrail network, the highway guardrail should be connected to the ground wire according to the regulations of the electric power department. When the conductor is parallel or nearly parallel to the highway guardrail and higher than the highway guardrail, the grounding wire should be buried at both ends or at a distance of not more than 400M, and the grounding resistance value should be less than10Ω (ohm).
Columns should be buried in sections, first at both ends, and then in the middle with stay wires. From the longitudinal perspective, the axis of the column should be in a straight line, and there can be no unevenness; From the height point of view, the top of the column should be smooth and not uneven. The high-speed highway fence whose size and model meet the requirements shall be firmly installed on the hook of the column from the end of the column in the way specified in the drawings; Or install mesh in the frame, and the connection between the frame and the column should be firm. All meshes and steel wires shall be tensioned without deformation, and the installation height shall meet the requirements of the drawings. After the installation of the isolation grid, the column foundation should be finally compacted. Should be installed as shown in the drawings, firmly installed on the column or bracket; The metal mesh should be stretched and tightened, and the whole structure should not be twisted. Guardrail net construction, generally should be set along the terrain. When necessary, earthwork leveling is needed to obtain a clean appearance. In low-lying areas, when the vertical profile of the ground suddenly changes and the specified clear height from the ground cannot be maintained, a long column can be used, and then a barbed wire can be pulled. The vertical gap between barbed wire is equal to or less than150 mm. After excavation or drilling, all columns shall be buried according to the approved method. Generally, diagonal braces are added on both sides of the column every 120M to ensure its stability; If the direction of expressway guardrail changes according to the construction requirements, three-way diagonal braces should be set on the columns.