Characteristics and functions of steel pipe car stopper

1. Guardrail construction plan and method:

The construction of corrugated steel guardrails is to prevent uncontrolled vehicles from crossing the median or rushing out of the roadbed on dangerous road sections, so as not to cause secondary accidents; In order to absorb energy, reduce the degree of accidents and damage to vehicles and personnel, and induce vision and beautify roads.

(1) Construction plan

① Strictly select materials according to the requirements of the bidding documents, and all steel materials must have material quality certificates as required by the bidding documents.

The steel components used in the waveform beam steel guardrail are all treated with hot-dip galvanizing for metal corrosion prevention. After hot-dip galvanizing, the connection surface of high-strength bolts should be coated with butter and lubricated with phosphating. They should be sealed and packaged at the factory to prevent rust or dirt during transportation and storage.

② The overall construction sequence is to first install single-sided guardrails and then double-sided guardrails, install anti glare facilities, adopt segmented construction, connect each section, self check each section, implement full process quality control, and ensure the completion of the entire line.

③ The construction team consists of two pile driving teams, two installation teams, one measurement team, one maintenance team, and one transportation team, totaling 15 people. We plan to equip 2 DY300 pile drivers, 2 AC welding machines, and 1 heavy-duty truck.

(2) Construction method a: Column installation

(a) Use the driving method to set up the columns. The installation of columns using the driving method should strictly follow the position determined by the steel drill. First, place the self-made guide, and then drive the columns along the guide holes to ensure verticality. The column should be driven into the soil to the design depth. When it is driven too deep, the column should not be partially pulled out for correction, but must be completely pulled out and re driven after the foundation is compacted. The installation of columns should be consistent with the design drawings. And coordinated with the road alignment, the columns should be firmly buried in the soil to the design depth and perpendicular to the road surface.

(b) When it is difficult to drive in, drilling or excavation methods can be used to install columns. When using the drilling method for column installation, the column should be backfilled with the same material as the roadbed after positioning, and compacted in layers to achieve a density not lower than that of the adjacent undisturbed soil. When using excavation method for construction and burying columns, the backfill material should be of good quality and compacted in layers (each layer should not exceed 15cm in thickness), and the compaction degree of the backfill soil should not be less than that of the adjacent undisturbed soil. Columns and piles in rocks should be backfilled with granular materials and compacted.

(c)

Considering the impact of guardrail structure on the landscape and driver's line of sight guidance, after the installation of the columns, the verticality, position, and elevation should be checked immediately. The verticality inspection is carried out by using a ruler to check each one. Position and spacing checks are conducted using a steel ruler for straight lines, and using a theodolite for curved sections using the deflection angle method; The horizontal position inspection uses a ruler to measure the horizontal distance between the road centerline and the columns. Elevation inspection, based on the inner surface of the curbstone, using self-made molds or level gauges to inspect each one. The horizontal and vertical directions should form a smooth linear shape. The installation of the transition section and end columns is a key point to pay attention to during construction. During construction, the position and height of the columns should be strictly controlled, and attention should be paid to the parabolic shape. Installation of anti blocking blocks, waveform beams, and ends

(a) After adjusting the column, the bracket (anti blocking block) can be installed. The bracket (anti blocking block) is fixed between the corrugated beam and the column by connecting bolts. Before tightening the connecting bolts, adjust the bracket (anti blocking block) to ensure accurate positioning.

(b) The waveform beams are connected to each other by splicing bolts and fixed to the bracket (anti blocking block) by connecting bolts. The overlapping direction of roadbed guardrails and corrugated beams is the key to installation, and installation should be strictly carried out according to the drawings. The overlapping direction should be consistent with the driving direction. The waveform beam should be continuously adjusted during the installation process. Therefore, the connecting bolts and splicing bolts should not be tightened too early, so that the long circular holes of the corrugated beam can be adjusted in a timely manner during installation to form a smooth line shape and avoid local unevenness. When the linearity of the guardrail is considered satisfactory, the bolts can be tightened finally. The connecting bolts between the bracket (anti blocking block) and the corrugated beam should not be tightened too tightly, in order to adjust the temperature stress with a long circular hole.

(c) The end beam is connected to the standard section guardrail through splicing bolts. The construction method of end beams is basically the same as that of corrugated beams. After the segmented construction is completed, self inspection is qualified and reported to the supervising engineer for acceptance.

Attention:

(1) The column must not have obvious twisting, welding elongation is not allowed, and burrs at the ends must be removed. The layout of columns should be based on the control points on the highway, and the spacing between columns should be adjusted appropriately according to the distance measurement; The installation of columns should be consistent with the design drawings and coordinated with the road alignment; The column must be firmly buried in the soil, and the burial depth must reach the depth specified in the design, and be perpendicular to the ground plane.

(2) Regardless of the method used to install the guardrail, the contractor should try to avoid damaging the pipes buried under the road surface as much as possible

If the line facilities are damaged, the contractor shall be responsible for repairing them, and the repair costs after the damage shall be borne by the contractor.

(3) After the installation of the guardrail, a smooth line should be formed in both horizontal and vertical directions. Good guidance for landscape and driver's line of sight.

(4) The waveform beam guardrail set on the roadside should not allow the guardrail surface to intrude into the boundary of the highway building.

(5) Waveform beams and slabs should generally be formed by continuous rolling. The bolt holes on the waveform beam must be accurately positioned,