JPH0328630B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a propulsion method for laying a small diameter pipe while avoiding underground obstacles.

[Conventional technology]

Most of the construction work for laying pipes for city gas, water, sewerage, etc. is carried out by the cut-and-cover method, but there are many cases in which pipes are laid, such as crossing roads in busy urban areas, crossing under railway tracks, crossing rivers and waterways, and burying existing pipes. When there are objects (for example, buried pipes, culverts, and building substructures), trenchless construction using the propulsion method is generally used.

For this propulsion method, dozens of methods have been developed for small-diameter pipes (pipes that are too large for people to enter). These conventional construction methods are used depending on the site situation, etc., but as shown in Figure 7, all of these conventional construction methods are used when crossing obstacles 1 (for example, agricultural water, sewage, etc. culverts, buried pipes, foundations of structures, etc.) Build large shafts 2a and 2b deeper than the obstacle 1 (for example, 4 to 5 m) on both sides of the obstacle 1, and propel the propulsion pipe 3 horizontally between the shafts 2a and 2b below the obstacle 1. It is designed to allow main pipe 4 to pass through.

However, with the above-mentioned propulsion method, the cost required to construct the shafts 2a and 2b is extremely high, and especially in sites where the groundwater level is high, auxiliary methods such as chemical injection or well points are required, so it costs even more money. It costs money. Furthermore, the current situation is that construction work in urban areas is becoming increasingly difficult due to the lack of space for building vertical shafts due to obstacles such as existing buried objects, and environmental pollution problems. Furthermore, in this type of propulsion method, the construction period required for shaft construction is long, and in short-distance small diameter pipe construction work, the shaft construction period may be longer.

In view of these problems with conventional propulsion methods, we have recently published Japanese Patent Application Laid-Open Nos. 57-6096 and 161291.
No., JP-A-57-161294, JP-A-58-13898,
JP-A-59-13774, JP-A-59-15190, JP-A-Sho
The arc-shaped propulsion method disclosed in Japanese Patent Laid-Open No. 59-15191 and Japanese Patent Application Laid-Open No. 59-15196 has come into use.

In this propulsion method, as shown in FIG.
A semicircular propulsion pipe 6 is propelled from one shaft 5a to the other shaft 5b, and the main pipe 4 is passed through the propulsion pipe 6.

[Problem that the invention seeks to solve]

Although the arc propulsion method described above has many advantages over conventional construction methods, it also has the following problems.

(1) Since the construction method involves laying semicircular propulsion pipes, the depth is too deep compared to the span.

(2) The range of suitable soil types is narrow, and it is particularly sensitive to gravel.

(3) The span is short, currently at a maximum of 11m. Therefore, it cannot be applied to wide obstacles.

(4) Because the propulsion tube is arc-shaped, power transmission is not smooth and requires extra thrust. Therefore, a large propulsion device is required.

(5) Because the propulsion tube is arc-shaped, it is inconvenient to store, transport, and handle.

[Means to solve the problem]

The present invention was made in order to solve the above-mentioned problems, and the present invention has been made in order to solve the above-mentioned problems. A space is formed between the tips of the two propulsion tubes, a flexible main tube with a bellows tube connected to the tip is inserted into one of the propulsion tubes, the bellows tube is pulled up to the other propulsion tube, and the flexible main tube is connected to both of the propulsion tubes. Provided is a small-diameter pipe propulsion construction method in which the space between the main pipe and the bellows pipe and the gap is filled with mortar, sand, etc., the flexible main pipe and the bellows pipe are connected to the main pipe, respectively, and the shaft is backfilled. It is something.

[Operation] Propulsion tubes are propelled downward from the obstacle from vertical shafts provided on both sides of the obstacle, and a flexible main tube and a bellows tube are inserted into both propulsion tubes to form a V-shaped tube. Both ends of the pipe are connected to the main pipe, and the space formed by the V-shaped pipe and the propulsion pipe is filled with mortar, sand, etc. to backfill the shaft.

[Embodiments of the invention]

FIG. 1 is a completed sectional view of the propulsion method (hereinafter referred to as the V-shaped propulsion method) according to the present invention. In the figure, 11a and 11b are shafts 12a and 12 that are shallower and smaller than obstacle 1 built on both sides of obstacle 1.
Reference numeral b denotes a propulsion tube (sheath tube) that is arranged to be inclined from the vertical shafts 11a and 11b toward the bottom of the obstacle 1, and a gap 13 is formed between the tips of both the propulsion tubes 12a and 12b. Reference numeral 14 denotes a flexible main pipe, and a bellows pipe 15 is connected to the tip thereof, both of which are disposed within the propulsion pipes 12a and 12b, and both ends are connected to the main pipes 4a and 4b via connecting pipes 17a and 17b, respectively. It is connected. Reference numeral 16 denotes mortar, sand, or the like filled between the propulsion pipes 12a and 12b, the flexible main pipe 14, and the bellows pipe 15, and in the gap 13.

Next, the construction order of the V-shaped propulsion construction method according to the present invention will be explained.

(1) Before construction, conduct a soil survey and consider whether it is possible to maintain the voids (13 in Figure 1). If it is difficult to maintain the voids, improve the ground by injecting chemicals in advance.

(2) As shown in Figure 1, vertical shafts 11a and 11b are constructed on both sides of obstacle 1. This shaft 11a,
11b is approximately the same size as the burying groove used when burying the main pipes 4a and 4b by the cut-and-cut method.

(3) As shown in FIG. 2, the excavation device 20 is installed inside the shaft 11a. The guide frame 22 on which the excavator 21 is mounted is configured to be able to adjust the inclination angle θ ₁ by a stay 23 made of, for example, a hydraulic cylinder, and is adjusted as appropriate depending on the depth of the obstacle 1. A carbide bit is attached to the tip of the propulsion tube 12a, and is driven by the excavator 21 to rotate while digging. The auger 24 disposed within the propulsion tube 12a is composed of a screw 25 and an auger head 26 provided at its tip, and the screw 25 discharges excavated earth and sand.

(4) When the propulsion tube 12a propels the predetermined length,
Advance only the auger head 26 and dig ahead.
A void (13 in FIG. 1) is formed. When the formation of the void is completed, the propulsion tube 12a remains as it is,
Pull out the auger 24.

(5) As shown in Figure 3, the excavation device 20 is
After moving to the b side and propelling the propulsion tube 12b in the same manner as above, the auger head 26 is used to dig ahead.
The voids 13 are connected. In this case, the inclination angle θ ₂ of the guide frame 22 may be different from the inclination angle θ ₁ in the case of the vertical shaft 11a.

In addition, the preliminary excavation from the shaft 11a side and the shaft 1
When connecting the voids 13 by pre-excavation from the 1b side, the work is controlled by observing using a fiberscope or the like.

When the work from the shaft 11b side is finished,
Pull out the auger 24. The state at this time is shown in FIG.

(6) As shown in Fig. 5, a flexible main pipe 14 to which a bellows pipe 15 with a ring 18 at the tip is connected
is supported by a truck 30, etc., and the vertical shaft 11a is
It is charged into the propulsion tube 12 from the side. Note that the flexible main pipe 17 refers to a resin pipe, a high-pressure hose, a bellows pipe, or the like.

On the other hand, from the shaft 11b side, a drawing rod 27 having a hook or the like 28 at the tip and mounted on the excavation device 20 is inserted, and while observing with a fiberscope or the like, the hook or the like 28 is hooked onto the ring 18. The excavation device 20 pulls up the bellows pipe 15 toward the propulsion pipe 12b, and pushes the flexible main pipe 14 into the shaft 11a. FIG. 6 shows the state after this work is completed.

(7) Propulsion pipes 12a, 12b and flexible main pipe 1
4 and the bellows pipe 15 and the gap 13 are filled with mortar, sand, etc. 16, and then the connecting pipe 17a,
17b connects the flexible main pipe 14 and the bellows pipe 15 to the main pipes 4a and 4b, respectively (see FIG. 1).

(8) Finally, backfill the shafts 11a and 11b to complete the work.

In addition, in the above embodiment, the propulsion pipes 12a, 12b
was 250φ, and main pipes 4a and 4b were 150φ.

In the above explanation, one propulsion device 20 is
1a and 11b are installed sequentially, but 2
A platform propulsion device may be prepared and installed in both shafts 11a and 11b at the same time, or excavation and propulsion may be started simultaneously from the shaft 11a side and the shaft 11b side. Further, in pulling up the bellows tube 15, a case is shown in which the ring 18 is provided at the tip of the bellows tube 15 and the hook 28 is provided at the tip of the pulling rod 27, but other mechanisms may be used.

〔Effect of the invention〕

As is clear from the above description, the V-shaped propulsion method according to the present invention can bring about the following remarkable effects.

(1) In the above-mentioned circular arc propulsion method, there is a certain relationship between span and depth, and there is a limit to the length of the span, but according to the present invention, the propulsion angle of the propulsion pipe can be selected appropriately. By doing so, the span length can be significantly expanded.

(2) Since the span can be made longer, construction is possible even when the width of the obstacle is wide.

(3) Since the propulsion pipe is propelled by an auger, construction can be carried out even in gravel layers, and there are almost no restrictions due to soil quality.

(4) The shaft can be as large as a trench for burying the main pipe and need only be shallow, making construction of the shaft easy and eliminating the need for groundwater countermeasures.

(5) Since the propulsion tube is propelled in a straight line, power transmission is performed smoothly, and therefore it can be constructed using a small propulsion device.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing the state of construction using the V-shaped propulsion method according to the present invention, Figs. 2 to 6 are explanatory diagrams showing the construction procedure of the present invention, and Figs. 7 and 8 are conventional It is an explanatory diagram showing an example of the propulsion construction method. 1: Obstacle, 4a, 4b: Main, 11a, 11
b: Vertical shaft, 12a, 12b: Propulsion pipe, 13: Gap, 14: Flexible main pipe, 15: Bellows pipe, 1
6: mortar, sand, etc., 17a, 17b: connecting pipe,
18: ring, 20: excavation device, 24: auger, 2
7: Retractable rod, 28: Hook.

Claims (1)

[Claims] 1 Propulsion tubes are propelled downward from the obstacle from shallow shafts provided on both sides of the obstacle to form a gap between the tips of both propulsion tubes, and a gap is formed between the tips of the two propulsion tubes. A flexible main pipe formed by connecting bellows pipes is inserted, and the bellows pipe is pulled up to the other propulsion pipe, and both the propulsion pipes and the flexible main pipe are connected.
A small diameter pipe propulsion construction method comprising filling mortar, sand, etc. between the bellows pipe and the gap, connecting the flexible main pipe and the bellows pipe to the main pipe, and backfilling the shaft.