It is generally stipulated that the pipeline shall be laid on the original land base or treated backfill on the land after grooving, and the thickness of the overburden under the roadway is not less than 700mm.

 

Pipeline should be laid in a straight line, the need for flexible interface polyline laying, the pipeline at each of the mouth angle should generally not be greater than 1.5 °.

 

Drainage pipeline works can be constructed with the same groove, but should conform to the general drainage pipe with the same groove laying design, construction of the relevant provisions.

 

Pipeline through the railway, high-grade road embankment and obstacles to the structure, should be set up reinforced concrete, steel, cast iron and other materials made of protective casing, casing diameter should be greater than 200mm outside the outer diameter of the bellows, pipe and casing between the end of the space with add-on.

 

When the buried depth of the pipeline foundation is lower than that of the building foundation, the pipe shall not be laid within the pressure Zone of the foundation diffusion angle under the foundation surface.

 

Where the groundwater level is higher than the elevation of the bottom of the trench groove, measures should be taken to reduce the water level and prevent the groove from stabilizing. The water level drops below the lowest point below the bottom of the trough 300mm~500mm can be installed.

 

 

 

Do not stop lowering the water level during backfilling.

 

1. Grooves

 

The bottom net width of the groove groove should be determined according to the outer diameter of the tube plus 600mm~1000mm, so that the manual operation at the bottom of the groove is appropriate. Excavation grooves shall strictly control the height of the substrate and shall not disturb the base surface. The base design elevation above the 200mm~300mm of the original soil should be retained, the pipe before the manual cleaning to the design elevation.

 

If the local super-excavation or disturbance, do not backfill the soil, can be replaced with 10mm~15mm natural grade of gravel material or medium and coarse sand and leveling and compaction. Rainy season construction, should be as short as possible slotted length, to achieve fast groove, backfill fast, and do a good job of anti-bubble groove measures.

 

Once the bubble groove occurs, water should be removed, the softened soil layer should be removed, the gravel material or medium coarse sand should be replaced, and the basic treatment should be done. When the manual slotted, it is advisable to put the upper part of the groove mixed soil, the bottom of the trough of the good soil stacked separately, in order to backfill. The heap soil shall not affect the stability of the pipe trench. When buried in the bottom of the trough is not easy to remove stone, gravel, bricks and other substances, should be eradicated to the design elevation above 200mm, and then pave the groundwork for natural and sand stone, surface layer spread sand leveling and compaction.

 

 

 

The bottom of the groove shall not be soaked or frozen.

 

2. Basics Pipeline Foundation design, the use of Cushion Foundation. For the general soil area, the substrate only need to lay a layer of sand cushion, its thickness is 100mm, to the Soft soil foundation, the bottom of the trough is below the groundwater level, it is advisable to pave a layer of gravel or gravel, its thickness of 150mm, gravel particles for 5mm~40mm, above the sand cushion (medium and coarse sand) thickness is not less than 50mm,

 

The total thickness of the cushion is not less than 200mm.

 

 

 

After grooving, the groove width, the base cushion thickness, the foundation surface elevation, the drain smooth situation, whether there is muddy in the ditch, debris, the base has no disturbance and other work items, respectively, after the acceptance, qualified to carry out arrangements.

 

3. Pipeline Installation Pipeline installation is generally manual installation can be used. When installing, carry both ends of the pipe to the bottom of the groove construction personnel.

 

Open groove, groove depth greater than 3m or pipe diameter greater than 400mm pipe, when the lower tube can be used non-metallic rope slip pipe, with theodolite review and then stable tube. When installing the interface, you should first confirm the placement of the rubber ring and the depth of the socket, clean the inner wall of the bearing mouth and apply the lubricant. For pipe belt socket, the insertion direction of the socket is generally consistent with the direction of water flow, which is installed sequentially from low to high. When the socket is inserted, the small caliber (nominal diameter <400mm= can be used manpower at the end of the pipe to set up a wooden stall plate, with a crowbar will be installed pipe along the alignment of the axis slowly inserted into the mouth, gradually installed. For large-caliber (nominal diameter >400mm) pipes can be bundled with cables, and then with two fasteners (or gourds) and other tools on both sides of the pipe symmetrical uniform force tightening installation. After the pipe mouth is docked, the pipe elevation and the central axis are reviewed.

 

 

 

For the pipe connected with the sleeve pipe fittings, you can first install a head on the Groove flat, and then slip the pipe into the groove in place, installation, the specific practice is the same.

 

4, Pipeline and inspection well connection Pipeline and inspection Well connection, it is advisable to use flexible interface or socket parts connection, when the requirements are not high, can also be directly inserted into the inspection wall.

 

 

 

In order to ensure that the pipe or pipe fittings and the inspection of the well wall combination of good non-leakage, the connection between the pipe and the inspection well can be used prefabricated concrete coat ring plus rubber ring structure form.

 

5. Pipeline Repair After the pipeline is laid, the pipe wall is partially damaged by unexpected factors, and when the length or width of the damaged part does not exceed 1/12 of the circumference of the tube, the repair measures of the hardy parts can be taken.

 

 

 

If the damaged hole is less than 100mm, you can first use the glue trap in the damaged part, and then the Haji parts are well, evenly tighten the bolts.

 

6, backfill requirements

 

Pipeline installation should be immediately backfilled after acceptance, at least backfill to the top of the tube at a height of pipe diameter. Groove Backfill from the base of the bottom of the pipe to the top of the tube in the 0.5m range, it is necessary to manually backfill.

 

It is strictly forbidden to backfill with mechanical soil.

 

The backfill of the top 0.5m of the tube can be made by mechanical backfill at the same time from both sides of the pipe axis, compaction or milling. In the process of backfill, there should be no standing water in the ditch, not allowed to backfill, not backfill mud, organic matter, backfill should not contain rocks, bricks, frozen soil and other hard objects.

 

Groove Backfill, From the pipeline, inspection wells and other structures at the same time symmetrical backfill, to ensure that the pipeline and structure do not produce displacement, if necessary, can be used limit measures.