Professional Cable Tray Manufacturer

1. The position of the support and hanger is determined according to the straight-through position of the curved and variable diameter of the bridge, and then the position of the support and hanger of the straight line section is determined. 
The supports and hangers on the straight line should be evenly spaced. 
two。. 
The distance between supports and hangers shall be in accordance with the design regulations. 
If the design is not specified, according to the principle that the relative deflection under uniformly distributed load should not be greater than 1 stroke 200, according to the fact that the calculated actual uniformly distributed load is not greater than the maximum uniformly distributed load and deformation diagram of "maximum allowable uniformly distributed load and deformation under different spans" in the product specification of the bridge manufacturer, the distance between support and hanger is 1.5m, 2m or 2.5m. 
2.When the filling rate of large bridge and laying power cable is close to 30%, the distance between support and hanger is 1.5m. 
In the case where the additional concentrated load can be ignored and the specification of the bridge is small, the distance between supports and hangers can be relaxed to 2.5m. 
The calculation method is shown in Appendix B. 
The distance between supports and hangers (3m~6m) of long-span bridges should be calculated according to the corresponding allowable uniformly distributed load and deformation diagram. 
3. On the straight line of the bridge, hoists and brackets should be installed at the distance of 300m and 600m at the connection between the straight line and the non-straight line (bend and variable diameter). 
When the bending radius is greater than 300mm, a support and hanger should be added in the middle of the non-straight section. 
Supports and hangers shall be installed at the front and rear 200mm of the compensation device at the distance from the terminal 200~300mm, before and after the expansion joint, and at the front and rear 200mm of the compensation device where the straight line segment exceeds 30m. 
4. There are many types of supports and hangers of the bridge: columns and arms, columns made of I-beam, T-shaped steel, channel steel and angle steel, as well as special-shaped columns made of thin steel plates, which are generally provided by the bridge manufacturer and the bridge. 
In many occasions, non-stereotyped one-shaped, L-shaped and door-shaped hangers are used, the one-shaped and L-shaped supports can be made of channel steel and angle steel, and the door-shaped hangers can be made of channel steel, angle steel and C-shaped steel. The hanger of the portal hanger can be made of garden steel. 
The surface anti-corrosion of the support and hanger should be consistent with that of the bridge. 
The material selection and manufacture of non-stereotyped supports and hangers should be determined according to the uniformly distributed load and weight of the bridge, and at the same time, it should be decided whether the additional concentrated load should be counted. 
The selection of columns should be adapted to the distance between the layers of the bridge frame, the number of layers and the total load. 
It can be selected correctly according to the product specification provided by the bridge manufacturer. 
5. Supports and hangers welded to embedded parts and steel structures that are allowed to be welded must have no less than two sides and must be firm. 
The welding joint should remove the welding slag and repaint in time. 
Special-shaped columns made of thin steel plates shall not be fixed by direct welding. 
The base plate should be fixed by welding first, and then the column should be connected and fixed on the bottom plate with galvanized bolts. 
6. Before fixing the hanger, it is necessary to know the strength of the wall, building (flat) roof and steel frame itself, whether it can bear the weight of bridges, cables and wires and concentrated additional loads. 
On the brick wall where metal expansion bolts can not be used, different fixing methods should be adopted according to the walls of different materials and different types of clay brick walls (solid, porous, hollow). 
Solid and porous clay brick walls should be fixed with dovetail bolts, and the embedding depth should not be less than 100mm. 
Hollow clay bricks and lightweight bricks should be fixed in the form of long bolts through the wall and splints. 
7. When installing the support and hanger introduced into the indoor bridge outside, the height of the support and hanger should meet the slope of the bridge with a slope of 2100 from the inside to the outside, so as to prevent Rain Water from flowing into the room along the bridge. 
8. The support and hanger shall be horizontal, horizontal and vertical, and the surface contact with the bottom of the bridge shall be maintained. 
The upper and lower, left and right deviations of the hanger in the straight line should ensure the horizontal and vertical of the bridge. The allowable deviation is required in Section 4.5 F. 
1. The connectors between the straight segments of the bridge frame and between the straight line segment and the bend and variable diameter straight-through shall be matched by the bridge frame manufacturer. 
The thickness of the thin steel plate of the connector should not be less than that of the bridge frame. 
The interface should be flat, free of distortion, bulge and depression, and the half-round head galvanized bolt for connection should be on the inside of the bridge frame. The bolt length should be appropriate. After tightening, the exposed length should be 2-5 teeth. 
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2. For the horizontally installed bridge, the connector of its straight segment should be set at about 1max 4 between the two supports and hangers as far as possible. 
3. Under normal circumstances, bridges are not made at the construction site. 
When necessary due to special reasons, the existing bridge can be reformed into non-standard bend and variable diameter straight-through. 
When reforming and cutting off the straight-line bridge, gas or electric welding shall not be used and special cutting tools shall be used. 
The reformed bridge must be flat and repainted in time, and the color of the topcoat should be similar to that of other bridges. 
4. Where the bridge crosses the expansion joints of the building, according to GB50168 regulations, expansion joints should be set up to ensure that the bridge and the cables laid in the bridge can stretch freely and not be damaged when the expansion of the building does not endanger its own safety. 
Because in new buildings, the installation of bridges is usually carried out months or even a year after the completion of the concrete structure project, and the shrinkage of concrete decreases gradually. 
The amount of expansion generally does not exceed the width of the building expansion joint L. 
If it is found or learned from the civil engineering unit that the expansion joint of the building is likely to exceed L, the expansion treatment should be done according to the actual situation. 
a. 
At least one side of the bridge to cross the expansion joint has a long straight line segment, which should be more than 30m, or the straight line segments on both sides of the expansion joint add up to 30m, and there is no horizontal or vertical bend in the middle. 
In order to leave the expansion margin of the cable (or wire) in the bridge tray, this margin should be greater than the expansion joint width L.