Road guardrails are generally divided into flexible guardrails, semi-rigid guardrails and rigid guardrails. Flexible guardrails generally refer to cable guardrails, rigid guardrails generally refer to cement concrete guardrails, and semi-rigid guardrails generally refer to beam guardrails. Beam fence guardrails are a beam structure fixed with pillars, relying on the bending deformation and tension of the guardrail to resist vehicle collisions. Beam guardrails have certain rigidity and toughness, and absorb collision energy through the deformation of the crossbeam. Its damaged parts are easy to replace, have a certain visual induction effect, can be coordinated with the road line shape, and have a beautiful appearance. Among them, the corrugated beam guardrail is the most widely used at home and abroad in recent years. For the wide range.
1. Principles of setting roadside guardrails
Roadside guardrails are mainly divided into two types: embankment guardrails and obstacle guardrails. The minimum setting length of the roadside is 70 meters. When the distance between two sections of guardrails is less than 100 meters, it is advisable to set them continuously between the two sections. The fence guardrail is sandwiched between two filling sections. The excavation section with a length of less than 100 meters should be continuous with the guardrails of the filling sections at both ends. In the design of roadside guardrails, guardrails must be set if any of the following conditions are met:
A. Sections where the road slope i and the embankment height h are within the shaded range of Figure 1.
B. Sections intersecting with railways and highways, where vehicles have Sections where the vehicle may fall onto the intersecting railway or other roads.
C. Sections where there are rivers, lakes, seas, swamps and other waters within 1.0 meters from the foot of the roadbed on expressways or first-class roads for automobiles, and where vehicles may be extremely dangerous if they fall into them.
D. The triangular area of the entrance and exit ramps of the interchange of expressways and the outside of the small radius curves of the ramps.
2. Road guardrails should be installed in any of the following situations:
A. Sections where the road slope i and the embankment height h are above the dotted line in Figure 1.
B. Sections where the road slope i and the embankment height h are within 1.0 meters from the edge of the earth shoulder on expressways or first-class roads for automobiles Shanghai epoxy floor, when there are structures such as gantry structures, emergency telephones, piers or abutments of overpasses.
C. Parallel to railways and highways, where vehicles may break into adjacent railways or other highways.
D. Gradual sections where the width of the roadbed changes.
E. Sections where the curve radius is less than the minimum radius.
F. Speed change lane sections at service areas, parking areas or bus stops, and sections included in the triangular areas where fences and guardrails divide and merge traffic.
G. The connection between the ends of large, medium and small bridges or the ends of elevated structures and the roadbed.
H. Where it is considered necessary to set guardrails at diversion islands and separation islands.
Post time: Aug-12-2024