JPH09125863A - Shaft inner wall lining method and device thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to prevent the occurrence of blockade trouble by inhibiting a curing reaction by a set accelerating agent until an earth retaining material is jetted and form a strong lining layer on the wall surface by hardening an earth retaining material quickly. SOLUTION: This invention relates to a shaft inner wall lining method and device where the excavated inner wall of the shaft, which is substantially over- shaped in a cross section, is lined with a cement-based earth retaining material. A set accelerating agent is continuously jetted at the earth retaining material which is in a flowing state being supplied continuously by a screw rotor 4 from a material tank from a nozzle 5. Then, both are roughly mixed with a paddle 6, thereby producing a mixed state wherein the set accelerating agent is diffused into and mixed with the earth retaining material. Then, this mixed material is centrifugally ejected at the excavated inner wall of the shaft with an impeller 7, thereby diffusing the set accelerating agent into the earth retaining material on the wall surface and hardening the earth retaining material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for lining the inner wall of a shaft with a cement-based earth retaining material such as concrete.

[0002]

2. Description of the Related Art In the process of excavating a vertical shaft for constructing deep foundation piles and the like, the work of retaining earth on the inner wall at the stage of excavation to a predetermined depth and proceeding to excavation again is repeated. A steel member such as a liner plate is generally used for this soil retaining. On the other hand, in recent years, a so-called spraying method in which pressurized concrete is sprayed from a nozzle to form a concrete lining layer on an excavated wall surface may be adopted. According to this, there is an advantage that the pile can be formed in close contact with the excavated surface, so that the supporting force is increased, and that the pile can be constructed with an optimum diameter without being restricted by the specifications of the liner plate.

Further, in such a spraying method, work can be easily automated, and various automatic spraying devices have been proposed (Japanese Utility Model Laid-Open No. 62-16195, Japanese Patent Laid-Open No. 5-263525 and Japanese Patent Laid-Open No. 263525). 6-221082
Reference).

By the way, in such a concrete spraying method, in order to form a strong lining layer having a uniform thickness, a quick-setting agent for rapidly setting and hardening the cement component in the concrete is mixed. .

[0005]

However, in order for this quick-setting admixture to work effectively, it is necessary to thoroughly mix the concrete in the mixer prior to injecting it from the nozzle. There is a disadvantage that a curing reaction starts to progress in the course of transportation and solidifies in the mixer or the inner surface of the pipe to obstruct the flow, or the nozzle is blocked, so that stable spraying work cannot be performed. This also applies to the above automatic spraying device.

There are liquid and powdery quick-setting agents, and even liquid quick-setting agents have the property of being easily clogged by crystallization. For this reason, it is convenient to have a diameter as large as possible so as not to block the conduit or the injection nozzle that conveys this. However, the amount mixed in the soil retaining material is small, and there is a limit in increasing the diameter in order to ensure stable injection, and there is currently no effective means for preventing clogging.

[0007] The present invention has been devised to solve such disadvantages of the prior art, and its main objects are as follows.
A vertical shaft inner wall lining method and apparatus capable of preventing a clogging trouble by suppressing a curing reaction by a quick-setting agent until the soil retaining material is sprayed, and rapidly curing the soil retaining material on a wall surface to form a strong lining layer. To provide. A second object of the present invention is to provide a shaft inner wall lining method and apparatus capable of preventing a blocking trouble due to a quick-setting agent.

[0008]

According to the present invention, such an object is a shaft inner wall lining method of lining a cement-based earth retaining material on an excavation inner wall of a shaft having a substantially circular cross section. After continuously injecting the quick-setting agent toward the soil-holding material in a fluid state, the mixture is roughly mixed to make the state where the quick-setting agent is dispersed and mixed in the soil-holding material. Achieved by providing a shaft inner wall lining method characterized by centrifugally projecting toward the excavated wall surface of a shaft to diffuse the quick-setting agent into the earth retaining material and harden the earth retaining material on the wall surface. It

In particular, it is preferable that compressed air is mixed with the quick-setting admixture so as to be ejected toward the earth retaining material and the compressed air is conveyed to the ejection nozzle.

Further, there is provided a shaft inner wall lining device for lining a cement-based earth retaining material on an excavated inner wall of a shaft having a substantially circular cross section. The earth retaining material in a fluid state is suspended in the vertical shaft so as to be vertically movable. A material tank for accommodating and a material supply means which is internally provided in a flow-down cylinder provided in the lower part of the material tank, and which continuously introduces the earth retaining material in the material tank into the flow-down cylinder, and the material supply means. An injection nozzle for continuously injecting a quick-setting agent into the earth retaining material introduced into the flow-down cylinder by means of an injection nozzle, and a earth-retaining material internally provided in the flow-down tube and descending in the flow-down cylinder with the quick-setting agent. A material mixing means for rough mixing, an impeller provided on the lower side of the downflow tube, and an impeller for centrifugally projecting the earth retaining material, which descends from the downflow tube and is introduced into the central portion, toward the excavated wall surface of the shaft, Containing compressed air in the binder It is achieved by providing a pit inner wall lining apparatus characterized by having a suppressor.

In particular, the material supplying means is a screw rotor provided inside the straight flow-down cylinder, and the material mixing means is a paddle radially protruding from a shaft portion of the screw rotor. Therefore, it is preferable to dispose the injection nozzle with the injection hole facing the lower end of the screw blade of the screw rotor above the paddle.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The structure of the present invention will be described in detail below with reference to the embodiments shown in the accompanying drawings.

FIG. 1 shows a schematic structure of a shaft inner wall lining device according to the present invention. This shaft inner wall lining device 1 is for forming a concrete retaining lining layer on the inner wall surface of a shaft excavated in the construction of deep foundation piles, and is a material tank for storing concrete in a fluid state as soil retaining material. 2, a screw rotor 4 for continuously feeding concrete into a downflow cylinder 3 provided at a lower portion of the material tank 2, and the screw rotor 4
Nozzle 5 for injecting a liquid quick-setting agent into the concrete sent into the down-flow tube 3 by means of, a sloping paddle 6 for shear-mixing the concrete mixed with the quick-setting agent and descending in the down-flow tube 3, and a down-flow tube 3 and an impeller 7 for centrifugally projecting concrete introduced from the lower end to the center.

The material tank 2 has a cylindrical shape with a straight top.
A lower portion is composed of a body portion 2a formed in a funnel shape and a top plate 2b covering the upper end of the body portion. A water tank 8 for storing cleaning water is arranged on a side periphery of an upper portion of the body portion 2a. ing. The top plate 2b of the material tank 2 is provided with a concrete inlet 9 and a feeder driving motor 10
A quick-setting agent tank 11 for storing a liquid quick-setting agent, a pump 12 for pressurizing the quick-setting agent or cleaning water, and the pump 12
A compressor 13 that mixes compressed air into the quick-setting admixture or cleaning water discharged from the device is installed.

The output shaft of the feeder driving motor 10 is connected to a shaft 14 arranged at the center line position of the body 2a of the material tank 2 via a speed change mechanism, and the screw rotor 4 connected to the lower end thereof. It is designed to rotate forward and backward.

The suction side of the pump 12 is connected to the quick-setting admixture tank 11 and the water tank 8 via a three-way valve 15. By switching the three-way valve 15, either the quick-setting admixture or the washing water is supplied. One is supplied to the pump 12. On the other hand, the discharge side is connected to the nozzle 5 of the flow-down cylinder 3 via the conduit 16, and the quick-setting agent during the lining construction,
Cleaning water is sent during cleaning after construction.

An air supply pipe from the compressor 13 is joined to the conduit 16, and compressed air is mixed with the quick-setting admixture or the wash water which is pressure-fed from the pump 12 here. When compressed air is mixed with the quick-setting admixture and conveyed as described above, the flow rate in the conduit 16 or the nozzle 5 increases as a whole, so that stable injection is achieved even if the diameter of the conduit 16 or the nozzle 5 is large. It is possible to secure the above, and it is possible to make it difficult to block. In addition, the wiping action of transporting the liquid quick-setting agent in a gas-liquid mixed state can be expected to have an effect of suppressing solidification on the inner surface of the conduit 5 due to crystallization.

In addition, a plurality of connecting members 17 are fixed to the top plate 2b of the material tank 2 at equal intervals.
The suspension line 18 is fastened here. As shown in FIG. 2, the suspension line 18 is connected to a translational actuator C suspended from a crane vehicle B outside the shaft A to suspend the shaft inner wall lining device 1. . When the translational actuator C is expanded or contracted, the vertical shaft inner wall lining device 1 is moved up and down, and the projection position of the concrete onto the inner wall surface of the vertical shaft A by the impeller 7 can be displaced to form a concrete lining layer having a uniform thickness in the height direction. It can be formed smoothly and efficiently.

Further, as shown in FIG. 1, the flow-down cylinder 3 provided below the body 2a of the material tank 2 is arranged concentrically with the body 2a, and the screw rotor 4 is disposed inside thereof.
Are arranged concentrically. The upper end of the shaft portion 4a of the screw rotor 4 is coaxially connected to the shaft 14, and the rotational driving force of the feeder driving motor 10 is transmitted. On the other hand, the lower end of the shaft portion 4a of the screw rotor 4 is
It is supported by a dispersion unit 19 provided at the center of an impeller 7 rotatably attached to the lower end of the flow-down cylinder 3.

The screw rotor 4 has screw blades 20 at the connecting portion between the body 2a of the material tank 2 and the downflow cylinder 3, and when the screw rotor 4 is normally rotated by the feeder driving motor 10, the screw rotor 4 is stored in the material tank 2. A certain amount of the contained concrete is continuously sent out, and when it is reversed, the concrete in the material tank 2 can be prevented from falling to the impeller 7 below.

Screw blades 20 of the screw rotor 4
Above the above, there is a stirring rod 21 for loosening the concrete deposited on the funnel-shaped portion of the body 2a of the material tank 2,
Four protrusions are arranged at equal intervals in the axial direction while sequentially changing the protrusion angle by 90 degrees. On the other hand, screw blade 2
The inclined paddles 6 provided below 0 are formed in the shape of a strip plate, and the pair of diametrically projecting shaft portions 4a projecting from the shaft portion 4a are alternately arranged at equal intervals in the axial direction. 4 pairs are provided. The tilt paddle 6 is attached, for example, at a predetermined tilt angle with respect to the axis of the shaft portion 4a so as to have a feeding performance.

A pedestal 22 is horizontally fixed to the outer circumference of the flow-down cylinder 3, and a pair of impeller driving motors 23 are mounted on the pedestal 22 on both sides of the flow-down cylinder 3. The impeller drive motor 23 rotationally drives the cylinder shaft 26 of the impeller 7 via a drive pulley 24 connected to the output shaft on the lower surface side of the pedestal 22 and a V belt 25 attached to the drive pulley 24. However, if necessary, the impeller driving motor 23 may be configured to be capable of shifting and rotating in the reverse direction so that the rotation of the impeller 7 can be appropriately controlled. The drive pulley 24, the V belt 25, and the cylinder shaft 26 are
It is covered with a cover 27 in order to prevent the splash of concrete sprayed from the impeller 7 from adhering.

The nozzle 5 for injecting the quick-setting agent or cleaning water is
It is provided in the portion of the falling pipe 3 facing the lower end of the screw blade 20, and as shown in FIG. 3, four injection pipes are arranged in the center of the falling pipe 3 at equal intervals. A mixture of quick-setting agent or water and compressed air sent from the pump 12 and the compressor 13 via the conduit 16 is injected into the inside of the downflow tube 3.

As shown in FIG. 1, the impeller 7 includes a disc-shaped upper plate portion 28 and a disc-shaped lower plate portion 29 which are arranged to face each other.
And a plurality of radially arranged blades 3 that connect the two
The cylinder shaft 26 fixed to the upper surface of the upper plate portion 28 is externally fitted to the downflow cylinder 3 and is held so as to be relatively rotatable. Further, at the center of the inner surface of the lower plate portion 29, a conical dispersion portion body 19 whose diameter is expanded downward is fixed.
The lower end of the shaft portion 4a of the screw rotor 4 is supported in a relatively rotatable state.

The feeder driving motor 10, the pump 12, the compressor 13 and the impeller driving motor 2
The drive type of 3 may be either electric or hydraulic, and in the case of the electric drive type, it is connected to the drive control device outside the mine via a control cable or, in the case of the hydraulic drive type, via a hydraulic conduit, respectively. Operated remotely.

Here, the procedure for constructing the concrete lining by the shaft inner wall lining device 1 will be described.

First, before starting the lining,
As shown in FIG. 2, a concrete mixed with a predetermined water / Selund ratio and a slump value is required in the material tank 2 from the input port 9 of the shaft inner wall lining device 1 received on the installation platform D outside the mine. Add the amount. The concrete put in here is screw blade 2 of screw rotor 4.
Reversal of 0 prevents the fall. In addition, the quick-setting agent tank 11 is loaded with the quick-setting agent.

[0028] When it is possible to dig down to a predetermined depth through a series of excavation steps such as rock drilling and blasting to remove the ground and carry the earth and sand out of the mine, the shaft lining device 1 is used to move the shaft inner wall lining device 1 into the shaft A. Suspend and lower it along the center line of the shaft A and position it at the lining start position.

Then, when the feeder driving motor 10 is normally rotated at a predetermined number of revolutions by remote control by a drive control device (not shown) outside the mine, the concrete inside the material tank 2 is stirred by the stirring rod 21 of the screw rotor 4. At the same time, the material is continuously pushed into the flow-down cylinder 3 from the funnel-shaped portion of the material tank 2 at a speed proportional to the number of rotations of the screw blade 20 in a fixed amount.

The concrete pushed into the flow-down cylinder 3 has a proper amount of the quick-setting agent continuously injected from the nozzle 5 in the vicinity of the lower end of the screw blade 20, and then descends the flow-down cylinder 3 to incline the paddle 6. The mixture is shear mixed by and is put into the central portion of the impeller 7 that is rotating. By roughly mixing the concrete in this way, the quick-setting admixture is in the form of particles having a relatively large diameter and is appropriately dispersed and mixed in the concrete. In this state, the contact area between the quick-setting agent and the concrete is small, and the portion where the hardening reaction occurs is limited, so that the concrete as a whole is smoothly sent to the impeller 7 without hardening being accelerated. In this way, a clogging trouble due to the solidification of the soil retaining material in the device is avoided.

The concrete poured into the central portion of the impeller 7 is converted into four directions by the dispersion portion body 19 at the central portion of the impeller 7 in a direction orthogonal to the axis and then dispersed by centrifugal force. It is emitted in a substantially tangential direction through between 30.

The discharged concrete is scattered into a wide area as small lumps, and uniformly collides with and adheres to the excavation wall surface of the vertical shaft A having a substantially circular cross section to spread in a thin film form. To form a concrete lining layer. At this time, the concrete is violently shaken by the impact of collision and convectively mixed, and as the small clumps of concrete spread and spread on the wall surface in a thin layer, the granular quick-setting agent inside also becomes thin and the concrete Spread quickly inside. In this way, the hardening reaction proceeds all at once on the inner wall surface of the pit A, the concrete is rapidly hardened, and a lining layer having a strong and uniform thickness is formed on the entire peripheral surface of the inner wall of the pit A.

At the same time as concrete is centrifugally projected in this manner, the shaft inner wall lining device 1 is repeatedly moved up and down in the axial direction of the shaft A at a predetermined speed by the expansion and contraction operation of the translational actuator C. Therefore, the concrete lining layer is formed to have a uniform thickness even in the depth direction. At this time, the lining layer having a uniform thickness with a desired thickness can be obtained by appropriately controlling the number of repetitions of the expansion / contraction operation of the translational actuator C, the rotation speed and rotation direction of the impeller driving motor 23, and the rotation speed of the feeder driving motor 10. Can be installed.

In order to clean the inside of the flow-down cylinder 3 after finishing the lining work, the three-way valve 15 is operated to supply the cleaning water in the water tank 8 to the pump 12, and the cleaning water pressurized here is supplied. , Jetted from the nozzle 5 into the flow-down cylinder 3 via the conduit 16,
The concrete and the quick-setting agent adhering to the inner surface of the falling pipe 3 and the screw blades 20 are washed away. Also, after stopping the supply of the quick-setting admixture and cleaning water by the pump 12, the compressor 1
By operating 3 to send only compressed air, it is possible to wipe off the deposits on the inner surfaces of the conduit 16 and the nozzle 5.

In this embodiment, the plurality of nozzles 5 are arranged on the same circumference of the flow-down cylinder 3, but they may be arranged in a plurality of stages in the height direction. Further, although the nozzle 5 is arranged in a region near the lower end of the screw blade 20, the present invention is not limited to this.
You may make it provide in the position corresponding to an inclined paddle above or below this. Further, the injection holes may be arranged at positions displaced from the center of the flow-down cylinder 3. Further, although the liquid quick-setting agent is used in the present embodiment, the present invention is not limited to this, and a powdered or other solid quick-setting agent is similarly applicable.

[0036]

As described above, according to the present invention, even if the earth retaining material and the quick-setting admixture are not sufficiently mixed in the apparatus, the quick-setting admixture can be dispersed in the earth-holding adhering material on the wall of the shaft projected by centrifugal projection. It is possible to diffuse quickly to rapidly harden the soil retaining material, form a strong and uniform lining layer, and avoid clogging troubles due to curing of the soil retaining material.

In particular, when the quick-setting agent is mixed in the soil retaining material, if compressed air is mixed in the quick-setting agent and conveyed to the nozzle, the flow rate in the conduit or the nozzle as a whole increases, so that the conduit becomes It is possible to increase the diameter of the nozzle and the nozzle, and it is possible to make it difficult to close the nozzle. In addition, the effect of wiping the liquid quick-setting agent in a gas-liquid mixed state to suppress the solidification on the inner surface of the conduit due to crystallization can be expected. Further, it is possible to stop the supply of the quick-setting admixture after completion of the work and send only compressed air to remove the deposits on the inner surface of the conduit or nozzle.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view showing a shaft inner wall lining device constructed according to the present invention.

FIG. 2 is a schematic diagram showing a construction situation by the shaft inner wall lining device shown in FIG.

FIG. 3 is a conceptual diagram showing a mechanism for supplying a quick-setting admixture.

[Explanation of symbols]

 1 Vertical shaft inner wall lining device 2 Material tank 2a Body part 2b Top plate 3 Falling tube 4 Screw rotor 4a Shaft part 5 Nozzle 6 Inclined paddle 7 Impeller 8 Water tank 9 Feed port 10 Feeder drive motor 11 Rapid binder tank 12 Pump 13 Compressor 14 Shaft 15 Three-way Valve 16 Conduit 17 Connection Tool 18 Suspension Line 19 Dispersion Body 20 Screw Blade 21 Stirring Rod 22 Frame 23 Impeller Drive Motor 24 Drive Pulley 25 V Belt 26 Cylindrical Shaft 27 Cover 28 Upper Plate 29 Lower Plate 30 Blade A A Vertical shaft B Mobile crane C Translational actuator D Installation stand

Front Page Continuation (72) Inventor Yasuo Ugada 4-1, Egasaki-cho, Tsurumi-ku, Yokohama-shi, Kanagawa TEPCO Electric Power Technology Laboratory (72) Inventor Sakae Nakai 518-1, Komagaki, Nagareyama-shi, Chiba Mitsui (72) Inventor Masataka Uozumi 518-1 Komagaki, Nagareyama-shi, Chiba Mitsui Construction Co., Ltd. (72) Inventor Tatsuo Ito 518-1 Komagaki, Nagareyama-shi, Chiba Mitsui Construction Co., Ltd. In the laboratory

Claims (4)

[Claims] 1. A vertical shaft inner wall lining method for lining a cement-based earth retaining material on an excavated inner wall of a vertical shaft having a substantially circular cross-section, which is rapidly connected to a continuously supplied fluid retaining material. After continuously injecting the agent, the mixture is roughly mixed so that the quick-setting agent is dispersed and mixed in the earth retaining material, and then this is centrifugally projected toward the excavated wall surface of the vertical shaft, and on that wall surface. A method for lining an inner wall of a shaft, which comprises hardening an earth retaining material by diffusing a quick-setting agent into the earth retaining material. 2. The shaft inner wall lining method according to claim 1, wherein compressed air is mixed with the quick-setting admixture to be jetted toward the earth retaining material and the compressed air is conveyed to the jet nozzle. 3. A shaft inner wall lining device for lining a cement-based earth retaining material on an excavated inner wall of a shaft having a substantially circular cross section, the earth retaining material being suspended in a vertical shaft and being in a fluid state. A material tank for accommodating and a material supply means which is internally provided in a flow-down cylinder provided in the lower part of the material tank, and which continuously introduces the earth retaining material in the material tank into the flow-down cylinder, and the material supply means. An injection nozzle for continuously injecting a quick-setting agent into the earth retaining material introduced into the flow-down cylinder by means of an injection nozzle, and a earth-retaining material internally provided in the flow-down tube and descending in the flow-down cylinder with the quick-setting agent. A material mixing means for rough mixing, an impeller provided on the lower side of the downflow tube, and an impeller for centrifugally projecting the earth retaining material, which descends from the downflow tube and is introduced into the central portion, toward the excavated wall surface of the shaft, A compressor that mixes compressed air with the binder. Pit inner wall lining system characterized in that it comprises a support. 4. The material supply means is a screw rotor provided inside the flow-down cylinder having a straight cylindrical shape,
The material mixing means is a paddle that radially projects from the shaft portion of the screw rotor, and the injection nozzle is disposed so as to face an injection hole near the lower end of the screw blade of the screw rotor above the paddle. The shaft inner wall lining device according to claim 3, wherein