JP3439341B2 - Propulsion method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a propulsion method, and more particularly, to a semi-shield method for constructing a pipeline underground.
The present invention relates to a propulsion method that reduces frictional resistance during propulsion and enables ultra-long-distance propulsion at low cost. 2. Description of the Related Art A semi-shield method is employed as a propulsion method for constructing a pipeline for storing sewage facilities and various underground objects underground. [0003] The semi-shield method is as shown in FIG.
A jack 5 and a reaction force support plate 5a are installed in the starting shaft 1,
The semi-shield excavator 2 and the propulsion pipe 3, which is a fume pipe, are driven into the ground by pressing with a jack 5, and the excavation by the excavator 2 and the replenishment and pushing of the propulsion pipe 3 are repeated, and the excavation proceeds to the reaching shaft. By taking out the machine, a pipeline is constructed underground. [0004] In the semi-shield method, for example, in order to realize ultra-long-distance propulsion with a span of 1000 m class, it is most important to reduce frictional resistance generated between the propulsion pipe and the ground. The straight line in FIG. 5 shows the relationship between the progress of propulsion and the frictional resistance in soil with a substantially uniform range of propulsion length,
It can be seen that the frictional resistance increases in proportion to the progress of the propulsion length, and that a longer propulsion length requires a larger propulsion force. In the conventional semi-shield method, a method of reducing frictional resistance between a propulsion pipe and a ground is to propell a shield excavator and a propulsion pipe 3 following the shield excavator into the ground as shown in FIGS. At this time, the tail void 6 which is an overcut portion is excavated on the outer periphery of the propulsion pipe by excavating about 50 mm by an excavator, and the mud layer B (also called a mud film layer) is formed on the outer peripheral portion of the tail void 6 in the excavation portion. Is formed, and a concrete pipe,
The tail void pressurizing agent A supplied from the injection hole 9 provided in the porous tube 4 is injected into the tail void 6, and the lubricating tail void pressurizing agent A is incorporated.
Thus, the tail void 6 is secured to reduce the frictional resistance between the propulsion pipe 3 and the ground during propulsion. Here, in order to secure the tail void 6 with the tail void pressurizing agent A, as shown in FIG. 4, a well-known mud film formed on the entire periphery of the tail void 6 and formed on the ground excavation surface is used. Creation and maintenance of layer B is essential.
This mud layer B is made of a tail void pressurizing agent A under pressure.
In the ground of the ground. When the shield machine 2 excavates, the mud layer B is formed by mixing a mud forming member supplied to the excavated portion with excavated soil, and the mud layer B is formed by contact of the tail void pressurizing agent with the ground. Formed in the area where [0007] Incidentally, in securing the tail void 6, there is a close relationship between the nature of the soil and the formation of the mud layer B. For example, when the soil is a gravel layer or an anhydrous layer, The efficiency of the formation of the mud layer B is poor, and it takes a long time to produce the mud layer B. In addition, the mud layer B is broken down due to infiltration into the ground and deterioration over time, making it difficult to maintain for a long time. For this reason, the tail void pressurizing agent A permeates into the soil of the ground, making it very difficult to secure the tail void 6, increasing the frictional resistance and making propulsion impossible, making long distance propulsion impossible. There is a problem. Accordingly, an object of the present invention is to provide a propulsion method capable of performing ultra-long-distance propulsion by reliably securing a tail void over the entire length of a propulsion pipe for a long time and effectively reducing frictional resistance during propulsion. To provide. SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an excavator having an overcut function and a propulsion pipe following the excavator, so that the excavator can be used by the excavator. In the propulsion method of forming a tail void around the propulsion pipe by digging, a mud layer generated at the excavation part is formed on the periphery of the tail void, and a plurality of perforated pipes connected in the middle of the propulsion pipe are provided in the circumferential direction. From the lubricant injection hole to the tail void at the same time , there is a clogging effect between soil particles
Press in the tail void lubricant and apply the tail void lubricant.
And the inside of the mud layer between the soil particles
By creating a mud film layer with the clogging effect,
In this embodiment, a mud film layer having a double structure including a dough film layer and a mud film layer is formed, and the tail void lubricant is held around the propulsion pipe by the mud film layer having the double structure. [0010] As described above, on the outer peripheral portion of the tail void,
By forming a mud film layer with a double structure,
Even if the mud layer on the side deteriorates over time, the inner mud filter
The tail layer can hold the tail void lubricant,
Long-distance propulsion by long-term reduction of drag
To An embodiment of the present invention will be described below with reference to the drawings. The semi-shield construction method is as shown in FIG. 3, and an excavator 2 having an overcut function is provided from a starting shaft 1 to the ground, and a propulsion pipe connected to a rear portion of a casing 2a of the excavator 2. 3 and a perforated pipe 4 to be incorporated into the propulsion pipe 3 at a predetermined interval.
The excavator 2 is made to penetrate into the ground by the excavating action of the cutter 2b. The excavator 2 forms a tail void 6 of about 50 mm by over-digging by an overcut function, and the lubricant supply device 7 on the ground connects the lubricant supply pipe 8 to the lubricant supply pipe 8. Lubricant A1
Is fed from each lubricant injection hole 9 of the porous tube 4 to the lubricant A1.
Is simultaneously injected into the tail void 6, and the tail void 6 is secured to reduce the resistance of propulsion. FIG. 1 shows a cross-sectional structure of a perforated pipe 4 incorporated in a connected state between the propulsion pipes 3, and a lubricant injection hole 9 is provided on a peripheral wall at predetermined intervals so as to penetrate inside and outside. Distribution pipes 10 arranged on the circumference are connected to each lubricant injection hole 9,
A lubricant supply pipe 8 is connected to the distribution pipe 10 via an electromagnetic valve 11, and by opening the electromagnetic valve 11, the lubricant A 1 supplied from the lubricant supply device 7 on the ground is supplied from each lubricant injection hole 9 to the tail void 6. It is designed to be injected at the same time. Here, the lubricant A1 is mainly composed of sodium polyacrylate and a spherical water-absorbing swelling agent, which is a white powdery food additive and a light yellow sphere sanitary article. Is converted into a transparent spherical viscous material of PH7 and used in a fluid state. The lubricant A1 exerts a clogging effect between the soil particles without any pollution to the human body, animals and plants, and the earth, and forms a mud film layer B1 inside the mud layer B on the outer peripheral surface of the tail void 6. Can be performed instantaneously and has a function to maintain the hydraulic pressure. By using the above-mentioned lubricant A 1, FIG.
As shown in the figure, when excavating by the shield excavator, the lubricant A1 pressed into the tail void 6 is applied to the mud layer B formed by mixing the excavated soil with the mud forming member supplied to the excavated portion. A new mud film layer B1 is generated inside the film layer B, and the mud film layer becomes a mud film layer B and a mud film layer B1.
Even when the outer mud film layer B deteriorates with time or is not sufficiently formed due to soil properties, the inner mud film layer B1 is surely formed, and this mud film layer B1 is pressed into the tail void 6. The lubricant A1 is held so as not to penetrate into the ground, the hydraulic pressure of the lubricant A1 is maintained for a long time over the entire length during propulsion, and as shown in FIG. Enables ultra-long-distance propulsion. According to the present invention, when the propulsion pipe is propelled in the construction of the semi-shield method as described above, the tail void 5 is formed.
The mud film layer B formed by the excavated portion and the mud film layer B by the lubricant A1 pressed into the tail void 6
1 to form a mud film layer, thereby keeping the lubricant A1 pressed into the tail void 6 so as not to penetrate into the ground, securing the tail void 6 over the entire length of the propulsion pipe, and prolonging the propulsion resistance. Ultra-long-distance propulsion is realized by the reduction. As described above, according to the present invention, in a propulsion method using an excavator having an overcut function, a mud film layer and a mud film are formed on the inner peripheral surface of a tail void when a propulsion pipe is propelled. Two mud film layers are formed so that the tail void lubricant, which has been pressed into the tail void, is kept from penetrating into the ground, secures the tail void over the entire length of the propulsion pipe, and reduces propulsion resistance over time. Thereby, super long distance propulsion can be realized.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view of a perforated pipe used in a propulsion method according to the present invention. FIG. 2 is an explanatory view showing formation of a mud film layer of a tail void. FIG. FIG. 4 is an explanatory view showing the formation of a mud film layer of a conventional tail void. FIG. 5 is an explanatory view showing the relationship of frictional resistance on the outer periphery of a propulsion pipe. [Description of symbols] 2 excavator 3 propulsion pipe 4 perforated pipe 6 Tail void lubricant B Mud layer B1 Mud film layer

Claims (1)

(57) [Claims] (Claim 1) A propulsion machine in which an excavator having an overcut function and a propulsion pipe following the excavator are propelled into the ground, and a tail void is formed around the propulsion pipe by excavation by the excavator. In the construction method, a mud layer formed at the excavated portion is formed on the peripheral surface of the tail void, and simultaneously a plurality of lubricant injection holes provided in the circumferential direction of the perforated pipe connected in the middle of the propulsion pipe to the tail void at the same time to the tail void, between soil particles. Tailbo with clogging effect
Press-fit lubricant, and the tail void lubricant
The clogging effect between the soil particles of the mud layer inside the mud layer
By generating a mud film layer, this mud film
A propulsion method comprising forming a double-layer mud film layer consisting of a rubber layer and a mud layer , and holding a tail void lubricant around a propulsion pipe with the double-layer mud film layer.