JPH0288884A - Method of closed type pressure shielding construction - Google Patents

Abstract

PURPOSE:To obtain fluidity and cut-off properties by supplying excavated soil and sand sucked into a chamber demarcated on the front side of a shield excavator body with the gel of an amorphous continuous high water-absorbing resin. CONSTITUTION:When a cutter head 12 installed at the nose of a shield excavator body is turned and a face is excavated, the inside of a chamber 16 is filled with excavated soil and sand. Excavated soil and sand in the chamber 16 and the face are fed with the gel A of an amorphous high water-absorbing resin housed in a tank 34 through a supply pipe 32. The gel A is mixed with soil and sand by driving a screw conveyor 28 and the cutter disk 12.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a closed pressure shield construction method.

(Prior art) As is well known, the shield method is a method for constructing tunnels such as subway tunnels, and various construction methods are available, but recently the shield method, which uses a sealed shield excavator, is relatively popular. It is widely used.

In the closed shield construction method, a chamber is usually formed at the front side of the shield excavator, and the chamber is filled with excavated soil to increase the pressure inside the chamber to counteract the face.

Then, the excavated earth and sand filled in the chamber chamber will be discharged to the outside while preventing the face from collapsing as the shield excavator advances. It becomes difficult.

Therefore, in order to impart fluidity and water-stopping properties to excavated soil, a method of adding and mixing spherical super-absorbent resin was developed.
It is disclosed in Japanese Patent No. 211491.

According to the method disclosed in this publication, when a spherical superabsorbent resin is added and mixed with excavated soil, the bearing effect of the resin facilitates the discharge of the excavated soil. In the case of textured soil or gravel ground, there were technical issues explained below.

(Problem to be Solved by the Invention) That is, according to experiments conducted by the present inventors, in the method disclosed in the above publication, when excavated soil is sandy soil or gravel ground, spherical superabsorbent resin is added. It was found that the mixed excavated soil had a large number of pores, allowing moisture to permeate through it, making it impossible to obtain sufficient water-stopping properties.

The inventors of the present invention repeatedly conducted various experiments in order to eliminate such problems, and as a result, they learned that such problems could be eliminated by using a special super absorbent resin, and based on this knowledge, The present invention has been completed, and its purpose is to provide a closed pressurized shield construction method that can impart sufficient fluidity and water-stopping properties to excavated earth and sand taken into a chamber.

(Means for Solving the Problems) In order to achieve the above object, the present invention includes a chamber chamber separated from the front side of the silt excavator main body, and the pressure of the excavated earth and sand filled in the chamber chamber is used to create a face. In the closed pressurized shield construction method in which a shield excavator is propelled while being opposed to the above-mentioned pressure, the method is characterized in that an amorphous continuous superabsorbent resin gel is supplied to the excavated earth and sand taken into the chamber chamber.

(Operations and Effects) According to the shield construction method with the above configuration, since an amorphous continuous superabsorbent resin gel is supplied to the excavated earth and sand, this gel is interposed between the soil particles of the excavated earth and sand. As a result, the fluidity increases, and almost no gaps are formed as seen in spherical superabsorbent resins.

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows an embodiment of the closed pressure shield construction method according to the present invention.

The shield construction method shown in the figure is an example in which the present invention is applied to a Tonosho type shield excavator, and 10 is the main body of the shield excavator.

A cutter head 12 for excavating earth and sand at the face is rotatably installed at the tip of the shield excavator main body 10.
A partition wall 14 is fixedly installed on the back side of the cutter head 12 to separate a chamber 16 filled with earth and sand excavated by the cutter head 12.

18 is a shield jack for moving the shield excavator main body 10 forward by taking a reaction force to the segment 20, and 22 is a drive motor for rotationally driving the cutter head 12.

Reference numeral 24 designates a screw conveyor whose one end opens into the chamber chamber 16 and which discharges the excavated soil taken into the chamber chamber 16 to the outside. Opening/closing M26 to adjust the amount of excavated soil and take it out of the pressurized area while opposing the excavated soil in 16
is the provision.

A belt conveyor 28 is extended below the opening/closing lid 26, and the excavated earth and sand taken out from the screw conveyor 24 is transported to the shield excavator main body 10 by the belt conveyor 28.
is transferred to the rear of the mine, transferred to the Zuritoro 30, and carried outside the mine.

Although the basic structure of the shield tunneling machine as described above is the same as that of the conventional tunneling machine of this type, the tunneling machine used to carry out the present invention is characterized by the following points.

That is, the partition wall 14 and the cutter disk 12 are provided with a supply pipe 3 that supplies gel A of an amorphous super absorbent resin.
2 is provided, and a tank 3 is connected via this supply pipe 32.
4 is supplied to the excavated earth and sand in the chamber 16 and the face by the pump 35.

When the amorphous superabsorbent resin gel A is supplied to the chamber chamber 16 and the face in this way, the gel A is mixed with the earth and sand excavated by the drive of the screw conveyor 28 and the cutter disk 12, and fills between the soil particles. As a result, the fluidity increases and there are almost no gaps formed, so the chamber 1
6. The fluidity and water-stopping properties of the excavated soil taken in are improved.

In the example shown in FIG. 1, when the excavated soil is transferred from the belt conveyor 28 to the Zuritoro 30, a gel dissolving agent B (a metal such as CaCΩ2) is used to dissolve the gel A mixed in the excavated soil. salt) to make it easier to handle.

FIG. 2 shows an experimental device used to confirm the effects of this invention.

In this experiment, a spherical superabsorbent resin a (product name A-m)
and two types of super absorbent resin b that form an amorphous continuous gel.
(Product name D-2350) and c (Product name S-100) were prepared, and the pressure retention and water stop properties when these were added and mixed with earth and sand were investigated.

As an experimental device, a sample soil tank 10 containing sample soil is used.
0 (inner diameter 300φ x height 500mm) and this tank 10
0 and a water tank 103 connected via cocks 101 and 102, a pressure gauge 104 and an open cock 106 are attached to the upper end of the sample soil tank 100, and the tank 100
A pipe 108 having a solenoid valve 107 was connected to the lower end of the pipe.

An open cock 109 and a compressed air supply pipe 110 were attached to the upper end of the water tank 103.

As the earth and sand material to which the superabsorbent resins a, b, and c were added, pea gravel with a diameter of 51 IIl and having an extremely uniform particle size distribution was prepared.

This pea gravel was drained before being mixed with super absorbent resins a, b, and c so that its saturation degree was S -100% and the unit pile weight was γt -1.94 gr/caI.

Gels of superabsorbent resins a, b, and c and sample soil were prepared in the following manner.

(2) Preparation of Gel 1 kg (IN) of tap water was absorbed into the powder weight Wc (g) of super absorbent resins a, b, and c, and the gel was left to stand for 24 hours.

The gel concentration CG (%) at this time is C (%) WG/1000x100 Attachment I　W　c Let us express it as

■Preparation of sample soil For 10g of gravel after draining, add 4g of gel prepared in ■.
They were added at a ratio of 1,000 ml, mixed well, and placed on the sample.

Each of the sample soils obtained as described above was divided into three layers into the sample soil tank 100, and was filled in the sample soil to a height of about 45 cm while being lightly tamped with a protrusion rod.

Next, the cock 101 and the solenoid valve 107 are opened,
The cock 102 was opened to inject water above the sample soil, and at the same time the open cock 106 was opened to vent air.

Then, the solenoid valve 107 was closed when water permeated into the sample soil and began to flow out from the pipe 108.

As described above, when the air in the sample soil tank 100 and the water penetration into the sample soil are completed, each cock 1
06 and 107 were closed and cocks 101 and 102 were opened, water was supplied and pressurized to the sample soil.

The set pressure in the sample soil tank 100 due to this water supply pressurization is 0.5.1.0.1.5, 2. Set to okgr/C-,
Once these predetermined pressures are set, the cock 101 is closed and the pressure inside the sample soil tank 100 is maintained at that state.

Then, the electromagnetic valve 107 was opened for 10 seconds, and the pressure maintained state in the sample soil tank 100 during that time was constantly recorded at 11F1 via the pressure gauge 104 every 0°005 seconds.

Additionally, during this period, the amount of water flowing out from the pipe 108 was also measured using the beaker 111.

3 to 6 show the measurement results obtained in the pressure holding test described above.

FIG. 3 shows the constant results when no superabsorbent resin gel is added. The pressure inside the sample soil tank 100 becomes atmospheric pressure 0.7 seconds after the electromagnetic valve 107 is opened, and then Since water continues to flow out, the pressure becomes negative.

Naturally, the higher the set pressure in the sample soil tank 100, the greater the amount of water flowing out.

FIG. 4 shows a case where a gel of spherical superabsorbent resin a is used, and in this case, openings 6 to 7 of the solenoid valve 107 are
After a few seconds, the pressure inside the sample soil tank 100 became atmospheric pressure.

During this period, the amount of water flowing out from the electromagnetic valve 107 increased by approximately twice as much as in the case where no gel was added, as the pressure retention property was improved.

Note that the gel concentration was C6-1.2%.

FIG. 5 and FIG. 6 show the case of using superabsorbent resins S and C that form an amorphous continuous gel according to the present invention.

Figure 5 shows the case where D2350 is used as the superabsorbent resin, and as is clear from comparison with Figure 4, even if the gel concentration CG is half (0.6%), the solenoid valve 107 is opened. In some cases, the pressure reaches atmospheric pressure after 10 seconds, and pressure retention is improved with a smaller amount added than super absorbent resin a.

As described above, the pressure retention property is improved, and at the same time, the amount of water flowing out is reduced to about 20% of that of the super absorbent resin a, and the water stop property is also improved.

Figure 6 shows the case where S-100 is used as super absorbent resin C, and the pressure retention property when the gel concentration is C6-0.6% is higher than that of other super absorbent resins a and b. The pressure inside the sample soil tank 100 is very good, and the pressure inside the sample soil tank 100 is controlled by the solenoid valve 10.
Even after 10 seconds of opening No. 7, there is very little variation.

In addition, the amount of water flowing out was reduced to less than 50% of that of super absorbent resin a, and about 1/2 of that of super absorbent resin a, indicating extremely good water stopping properties.

[Brief Description of the Drawings] Figure 1 is an explanatory diagram showing an example of the implementation state of the method of the present invention, Figure 2 is an explanatory diagram of the experimental equipment used to confirm the effects of the present invention, and Figure 3 FIG. 6 is a graph showing the results of a pressure holding test conducted using the same experimental device.

Claims (1)

[Claims] (1) In the closed pressurized shield construction method, a chamber is separated on the front side of the main body of the shield excavator, and the shield excavator is propelled by the pressure of the excavated earth and sand filled in the chamber against the face. A closed pressure shield construction method characterized by supplying an irregularly shaped continuous super absorbent resin gel to the excavated earth and sand taken into the chamber.