JPS609179B2 - Large diameter pipe buried turning method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a construction method for burying an Oyo pipe that prevents the Oyo pipe immediately after being buried from floating up due to a rise in the underground water table.

If a large-diameter pipe with a diameter of 3 or 4 pipes is buried underground, if the water table rises due to heavy rain immediately after the pipe is buried, the empty pipe before use will be destroyed. Accidents such as surfacing occur.

To prevent this, it is possible to bury large-diameter pipes deeply and use vertical mounds of buried soil to prevent the pipes from floating, but this method requires a large amount of excavation of the pipe burying trench, which increases construction costs. Not only was it bulky, but there were also many problems in construction, such as removing underground water that had flowed up. Therefore, in order to bury the Daiyo tube shallowly and prevent it from floating up, there are methods such as installing a weight on the Daiyo tube, or fixing a fin plate by extending it from the side of the Daiyo tube. Conventionally, a method has been used in which a buried large pipe is prevented from surfacing by applying a load of earth and sand to the surface, but the former weight method requires a weight made of a large concrete block and is very heavy. Not only does it take time and effort to handle the concrete blocks, but if the ground is soft, underground pipes may sink, and since the car bell is suspended using ropes, a concentrated load is applied to the pipes, causing excess stress on the pipe walls. There are problems such as stress being applied.On the other hand,
In the case of the latter fin plate method known as No. 2, the fin plate is extended and fixed in advance to the large distortion pipe, or the fin plate is installed in the large distortion pipe after the large distortion pipe is laid in the excavation groove. Since the plates are fixed by means such as welding, it takes time and effort to attach the fin plates, especially when the fin plates are attached in advance.
This obstructs the transportation of large-diameter pipes, and is extremely inconvenient because it is necessary to align the fin plates to a predetermined position when joining the pipes in the groove.

In addition, when attaching fin plates after installing a large pipe in an excavated area, the installation work in a narrow area is labor-intensive, and the construction period is lengthened accordingly.

In addition, if a rigid fin plate is installed on the large-diameter pipe with the fin plate projecting out to the side, there is a high possibility that a void filled with earth and sand will form under the fin plate, making it impossible to do so. Not only is it difficult to backfill with earth and sand, but it is even more difficult to fill in the voids that have already been created. This invention has been made to eliminate the above-mentioned drawbacks of the conventional method, particularly the drawbacks of the fin plate method, and a specific construction method thereof will be explained below with reference to the drawings.

In other words, ``The method of replacing a large ridge according to the present invention is to first drive sheet piles 1 into the ground at a predetermined distance apart, then excavate a relatively shallow trench 2 between the sheet piles for burying a pipe, and insert a large-diameter pipe into this trench. Install pipe 3.

(the condition shown in Fig. 1), then, after backfilling the trench 2 with earth and sand 4 to a height Ht that fills approximately the lower half of the large diameter pipe 3 as shown in Fig. 2, A bendable load-bearing sheet 5 such as a vinyl chloride seal is applied to cover the exposed upper half of the large tube 3 and is bent on both sides of the sheet so that both sides of the sheet rise upward along both sides of the groove. Lay down.
At this time, both ends of the sheet are pulled up so that they slightly extend upward from the upper end of the sheet pile 1, as shown in FIG. Once the load carrying sheet 5 is covered in this manner, the sheet 5 is then filled with earth and sand 6 as shown in FIG. 4 to completely backfill the pipe laying groove 2. Note that the initial height (Ht) of the burrower 4 is determined by the vertical pressure increment due to the sheet 5 and the distance B between the pipe 3 and the sheet pile furnace. For example, when the tube D is 3.6 and the interval B is 0.6,
Assuming that the depth from the ground surface to Dairyukae 3 is H = 0.9 skin,
Ht=D'2 (1.8). The following phenomena occur when the groundwater table rises close to the ground surface. First, when the groundwater table rises and reaches the ground surface, the empty Oyo Pipe 3 before use tries to float up due to its buoyancy. Since a load-bearing sheet 5 supported by is prevented.

When the groundwater level rises for the second time, the pipes 3 do not move because the burrowers 4 and 6 have been rearranged and are solidified. The load-bearing sheet 5 needs to be continuous in the direction perpendicular to the tube axis in the width direction of the groove 2, and also needs to have strength.

However, they do not necessarily need to be continuous in the tube axis direction, and may be provided at appropriate intervals depending on the quality of the tube. In addition, even when continuous in the tube axis direction, several lengths can be wrapped at both ends to be continuous. Holes (not shown) with a diameter of about 5 to 10 skins are provided at appropriate intervals in the direction of the pipe axis in the parts 7 and 7' on both sides where the sheet 5 bends the most, so that holes that accumulate in the sheet after the groundwater level rises are made. It is a good idea to allow water to drain easily.

This hole is also effective in the sense that it does not create a gap filled with earth and sand under the sheet. The service life of the sheet 5 is sufficient as long as it lasts for a minimum period from when the pipe 3 is buried until it is used (water, oil, etc. are passed through the pipe). Once the water is in the pipe,
This is because if oil or the like is passed through it, the weight of the oil will prevent the tube 3 from floating up. As mentioned above, when burying a large pipe in a pipe burying yard, this invention provides a bendable load-carrying device that transfers the weight of the buried soil above the pipe and the backfill soil on both sides of the pipe to the pipe. Because it is characterized by a sheet, the soil buried on top of the sheet can prevent the Oyo Pipe from floating up, which eliminates the need to dig deep trenches for management construction, making management construction work easier. can be done efficiently and at low cost.

Moreover, the prevention of levitation by this sheet is different from that of conventional fixation of fin plates, and does not require fixation to the Oyo tube.
Moreover, it is easy to handle, and construction can be performed extremely simply and efficiently. Not only that, but the cost of the sheet is very low, and unlike the rigid structure of the fin plate, the sheet has flexibility, so if earth and sand are buried on the sheet,
It blends well with the soil surface below, and there is no problem of large voids forming under the sheet. Moreover, the load-bearing sheet covers the upper half of the large-diameter pipe and is bent on both sides of the pipe so that both sides of the sheet rise upward along both sides of the groove. It has the effect of effectively transmitting the entire weight of the backfilled earth and sand to the pipe, and has the effect of reliably blocking the floating force of the pipe even with a large carrying load.

[Brief explanation of the drawing]

FIGS. 1 to 4 are explanatory diagrams showing one embodiment of the construction method of the present invention in the order of steps. 2... Groove for burying the pipe, 3... Large diameter pipe, 4...
・・Lower burrower, 6・・・Load bearing seat, 6・・
・Top backfill soil. Fins 1 Jinblin 3 Figures Scales 8 Kyoumanzu Figures

Claims (1)

[Claims] 1. A large diameter pipe 3 is installed in a pipe burying trench 2 excavated in the ground, and then soil 4 is backfilled into the trench 2 to a height Ht that fills approximately the lower half of this large diameter pipe 3, and then the A bendable load-bearing sheet 5 having a width wider than the groove width covers the exposed upper half of the large diameter pipe 3 and is bent on both sides thereof so that both sides of the sheet rise upward along both sides of the groove. This large-diameter pipe burying construction method is characterized in that the load-bearing sheet 5 is then covered with earth and sand 6 to completely backfill the pipe laying groove 2.