High-speed guardrail plate collision columns in the installation of what need to pay attention to places

Release time:

2016-10-21


I. Installation of anti-resistance block, waveform beam and end end

(a) After adjusting the column, the bracket (anti-resistance block) can be installed. The bracket (block) is fixed between the waveform beam and the column by connecting bolts. Before tightening the connecting bolts, the bracket (block) should be adjusted so that it is accurately seated.

(b) Waveform beams are spliced with each other through splicing bolts and fixed to brackets (block) by connecting bolts. The lap direction of the roadbed guardrail and waveform beam is the key to installation, and it is installed strictly according to the drawings. Lap direction should be consistent with the direction of travel. Waveform beams should be continuously adjusted during installation. Therefore, its connecting bolts and splicing bolts should not be tightened prematurely so that the long round holes of the waveform beams can be used to make timely adjustments during the installation process, so as to form a smooth line and avoid local concavities and convexities. When the line of the guardrail is considered more satisfactory, the bolts can be tightened at last. The connecting bolts between the bracket (block) and the waveform beam should not be tightened too tightly, so as to use the long round hole to adjust the temperature stress.

(c) The end beam is spliced with the standard section guardrail through the splicing bolt. The construction method of end beam is basically the same as that of waveform beam. After the construction is completed in sections, self-check and report to the supervising engineer for acceptance.

Second, the columns are set by driving-in method.

(a) Considering the impact of guardrail structure on landscape and driver's sight inducing, the verticality, position and elevation should be checked immediately after the columns are installed in place. Verticality checking adopts ruler to check one by one. Position check, spacing check straight line using a steel ruler test, curve section using the declination method using a latitude and longitude detection; lateral position check using a ruler to measure the road centre line and the lateral spacing of the column. Elevation check to the inside of the kerbstone road surface as a reference, using self-made mould or level meter check one by one. Its horizontal and vertical directions should form a smooth line. Installation of gradient section and end columns is the part to be paid attention to during construction, and the position and height of columns should be strictly controlled and parabolic shape should be paid attention to during construction.

(b) If it is difficult to drive in, the column can be installed by drilling method or excavation method. When the column installation is carried out by drilling method, the column should be backfilled with the same material as the roadbed after positioning and compacted by tamping in layers, so as to have a compactness not lower than that of the adjacent in-situ soil. When the excavation method is used for construction and the columns are buried, the backfill shall be made of good and identical materials and compacted in layers (each layer shall not be thicker than 15cm), and the compaction of the backfill shall not be less than that of the adjacent in-situ soil. Column piles in rock should be backfilled with granular material and tamped.

(c) For setting columns by the driving-in method, the position determined by the steel brazier shall be strictly followed, and the homemade guides shall be placed first, and then the columns shall be driven in along the guiding holes to ensure the verticality. Columns should be driven into the soil to the design depth, when driven too deep, the column shall not be partially pulled out to correct, but must be pulled out, until the foundation is compacted and re-driven. Column installation should be consistent with the design drawings. The columns should be firmly buried in the soil to reach the design depth and be perpendicular to the road surface.

Precautions:

(1) The anti-block shall not have obvious twisting. The end cuts shall be straight and burrs must be removed. The weld shall be smooth and even, and the weld position shall be located on any plane without screw holes.

(2) The end shall not have obvious torsion. The cut shall be vertical and the end burrs must be removed. The curved part shall be rounded and smooth.

(3) After the guardrail is installed, a smooth line shall be formed in the horizontal and vertical directions. It should have a good induction of landscape and driver's sight.

(4) The waveform beam steel guardrail of the highway set on the side of the road should not allow the guardrail surface to intrude within the highway construction boundary.

(5) The waveform beam plate shall generally be formed by continuous roll forming. The bolt holes on the waveform beam must be accurately positioned, and all the spliced bolt holes at each end section should be punched at one time.

(6) During the period from the completion of column installation to the installation of column cap, the column should be prevented from dropping sundries into it.

(7) The connecting bolts and splices of waveform beams should not be tightened too early.

(8) Before tightening the connecting bolts should be adjusted bracket (block) accurate in place.

(9) Guardrail, end, column length and width direction does not allow welding, members should not appear cracks.

(10) Columns shall not have obvious torsion, no welding lengthening, end burrs must be removed. Column sampling should be based on the control points on the highway, according to the amount of distance between the column spacing for appropriate adjustments; column installation should be consistent with the design drawings, and coordinated with the road line; columns must be firmly buried in the soil, and the depth of burial must be up to the depth of the design specified, and perpendicular to the ground plane.