JPH0651969B2 - Grouting device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a grouting device that blows a powdered grout material together with a compressed gas into a hole formed in a place to be improved, and particularly, an air passage is compressed by the compressed gas. The present invention relates to a grouting device which is formed around the air passage and injects a powdered grout material into the air passage together with a compressed gas.

(Prior Art) A grouting method is used for improving soft ground such as a sand layer, a gravel layer, a silt layer, and a soft rock layer.

As one of the grouting methods of this kind, a spout pipe is arranged in a hole formed in the ground by a boring machine, and a grout material in which a hardening agent and a liquid are mixed is spouted from the spout pipe into the hole, There is a method of press-fitting grout material. However, in this method, since the viscosity of the liquid is larger than that of the gas, in the case of the ground having a low hydraulic conductivity, the grout material only penetrates into the region near the hole formed in the ground, and the grouting is performed. Effect is small.

As another grouting method, there is a method using a grout material in the form of gas or powder. In this method, compressed air is blown into a hole formed in the ground to form an air passage around the hole, and then a gas or powder grout material is blown into the hole together with the compressed air. Thus, the grout material is injected into the wide area around the hole through the air passage.

The air passage is a space through which a gas such as air can pass by expanding the gap between the ground particles and / or removing the pore water existing in the gap by the compressed air blown into the hole. Say.

However, in the conventional grouting apparatus for carrying out such a grouting method, it is necessary to accurately predict the state of the airway, the deformed state of the ground, the injection range of the grout material, etc. It requires many years of experience and skill.

(Object of the Invention) It is an object of the present invention to provide a grouting apparatus that can easily and correctly predict the state of the airway, the deformed state of the ground, the injection range of the grout material, and the like.

(Structure of the Invention) The grouting apparatus of the present invention comprises a means for generating compressed gas,
A guide pipe for guiding the compressed gas to a hole for grouting, a means for supplying a powdered grout material to the guide pipe, a means for measuring the pressure of the compressed gas blown into the hole, and a means for blowing the compressed gas into the hole. Means for measuring the flow rate of the compressed gas, means for measuring the blowing amount of the grout material supplied to the guide pipe from the grout material supplying means, and the grout material supply via the blowing quantity measuring means. Means for supporting the means.

The grout material supply means is a hopper that is supported by the support means via the blowing amount measurement means and that stores the grout material, and a grout material discharger that is disposed at a grout material discharge port of the hopper. A grout material discharger that sends the grout material in the hopper toward the guide pipe, and a valve that is arranged at a communication portion between the grout material discharger and the guide pipe and that opens and closes a powder outlet of the grout material discharger. And a mechanism.

(Operation and effect of the invention) When the valve mechanism of the grout material supply means is closed,
Since the powder outlet of the grout material discharger is closed by the valve mechanism, the grout material in the hopper is not discharged to the guide pipe, but compressed gas such as compressed air enters the hole for grouting through the guide pipe. Supplied.

On the other hand, if the valve mechanism of the grout material supply means is opened while the grout material discharger is operating, the powder outlet of the grout material discharger is opened by the valve mechanism, so the grout material in the hopper is opened. Is supplied to the hole for grouting together with the compressed gas supplied to the guide pipe.

When a compressed gas is blown into the hole for grouting with the valve mechanism closed, the compressed gas expands the gap between the ground particles around the hole and the pore water existing in the gap. Is eliminated, an air passage through which a gas can pass is formed over a wide area around the hole.

Until the air passage is formed, the pressure in the guide pipe gradually decreases, and the rate of increase in the flow rate of the compressed gas blown into the hole gradually increases. On the other hand, when the air passage is formed, the pressure in the guide pipe sharply decreases, and the rate of increase in the flow rate of the compressed gas blown into the hole sharply increases. As a result, the state of the airway and the state of deformation of the ground can be known based on both measured values.

When the air passage is formed, the grout material discharger is operated and the valve mechanism is opened, so that the grout material is blown into the hole together with the compressed gas supplied to the guide pipe. The grout material enters the inside of the air passage by compressed gas and sequentially closes the air passage from the inner part thereof.

Until the air passage is completely closed, the pressure in the guide pipe gradually increases, and the rate of increase in the flow rate of the compressed gas blown into the hole gradually decreases. As a result, the state of the airway and the state of deformation of the ground can be known based on both measured values.

The amount of the grout material blown into the hole changes in proportion to the length of the air passage, that is, the blowing range. Thereby, the injection range of the grout material can be known from the blowing amount of the grout material.

As described above, based on the pressure and flow rate of the blown gas and the blown amount of the grout material, the amount of grout material discharged per unit time is required in order to correctly know the state of the airway and the ground and the injection range of the grout material. Is important to keep constant.

If the amount of grout material discharged per unit time is not constant, the pressure and flow rate of the blown gas and the amount of grout material blown will change temporarily or abruptly every time the amount of grout material discharged changes. Whether or not the air passage was formed or the air passage was blocked by the grout material, each measurement value changed rapidly, and as a result, the state of the air passage and the ground or the injection range of the grout material was correctly known. I can't.

When discharging powdered grout material to the compressed gas flow path, the amount of grout material discharged per unit time is kept constant even if the rotation speed of the motor for the grout material discharger is kept constant. It is extremely difficult to do. This is because the actual discharge amount from the grout material discharger fluctuates due to fluctuations in the pressure difference between the hopper that stores the grout material and the compressed air flow path, and the floating of the grout material in the hopper. Because it does.

In order to solve this problem, in the present invention, a valve mechanism for opening and closing the powder outlet of the grout material discharger is arranged in the communication part between the grout material discharger and the guide pipe, and the grout material in the hopper is discharged from the grout material discharger. I sent it toward the guide pipe. As a result, not only the grout material is continuously discharged, but also the discharge amount of the grout material per unit time becomes constant, and as a result, the pressure and flow rate of the blown gas and the grout caused by the uneven discharge of the grout material. Temporary or sudden changes in the amount of material blown are prevented.

As described above, according to the present invention, since the grout material in the hopper is continuously fed out by a constant amount, the pressure and flow rate of the gas to be blown and the amount of the grout material to be blown are temporarily caused by uneven discharge of the grout material. Or sudden changes can be prevented, and as a result, the condition of the airway, the deformed state of the ground and the injection range of the grout material can be correctly known.

(Example) Hereinafter, the Example of this invention shown in drawing is described.

The grouting device generally indicated by reference numeral 10 in FIG.
A compressed air source 12 such as a compressor, an injection pipe 18 arranged in a hole 16 excavated in the ground 14, a guide pipe 20 for guiding compressed air to the injection pipe 18, and a gas or powder grout material. It includes a grout material supply mechanism 22 for continuously supplying a fixed amount to the pipe 20.

The injection pipe 18 is provided with compressed air and grout material for the holes 16
Has a plurality of slits at the lower end for ejecting into. Around the upper portion of the injection pipe 18, a sealing material 24 that hermetically closes the hole 14 is arranged.

The guide pipe 20 is divided into a primary side portion 20 a between the compressed air source 12 and the grout material supply mechanism 22 and a secondary side portion 20 b between the grout material supply mechanism 22 and the injection pipe 18. Both parts 20 a and 20 b are connected to each other by a nozzle 26 attached to the grout material supply mechanism 22.

On the primary side portion 20a of the guide pipe 20, a manually operated valve 28, a filter 30 for removing dust in compressed air,
Flow meter 32 for measuring the flow rate of compressed air supplied to the hole 16
A pressure reducing valve 34 and a manually operated valve 36 are arranged. In addition, the converter 38 that measures the pressure of compressed air in the primary side 20a, that is, the supply pressure, on each of the upstream side and the downstream side of the pressure reducing valve 34 of the guide pipe 20, and outputs an electric signal proportional to the supply pressure. , 40 are arranged.
On the other hand, a manually operated valve 42 is arranged in the secondary side portion 20b of the guide pipe 20, and the secondary side pressure, that is, the injection pressure is measured upstream of the valve 42 in the secondary side portion 20b. A converter 44 is provided which outputs an electrical signal proportional to the supply pressure.

The primary side portion 20a is connected to the grout material supply mechanism 22 by a branch pipe 46 branched from a portion between the pressure reducing valve 34 and the converter 40. The branch pipe 46 includes a pressure reducing valve 48, a pressure gauge 50 for measuring and displaying the pressure in the branch pipe 46, a flow rate adjusting valve 52 for adjusting the flow rate of the compressed air in the branch pipe 46, and a manually operated valve 54. And are arranged.

The branch pipe 46 is connected to the grout material supply mechanism 22 by a branch pipe 56 branched from a portion between the pressure gauge 50 and the flow rate adjusting valve 52, and a manually operated valve 58 is arranged in the branch pipe. There is.

A check mechanism 60 that monitors whether or not the grout material is injected is connected to the secondary side portion 20b. The check mechanism 60 includes a branch pipe 62 branched from a portion between the valve 42 and the injection pipe 18. Branch pipe 6
2, a manually operated valve 64, a filter 66, and a flow meter 6 for measuring the amount of compressed air moving in the branch pipe 62.
8 is arranged, and the tip of the branch pipe 62 is connected to the suction pump 70. Filter 66, flow meter 68
The suction pump 70 is a filter paper holder, a flow meter, and a suction pump defined by Japanese Industrial Standard "Welding Fume Concentration Measuring Method" (Z 3950).

The air flow rate measured by the flow meter 32 is displayed on the air flow rate indicator 72, the supply pressure measured by the converter 38 is displayed on the supply pressure indicator 74, and the injection pressure measured by the converter 44 is injected. It is displayed on the pressure indicator 76. Although the converter 40 is a pressure gauge in the illustrated example, the converter 38 may be a pressure gauge, and instead, the measured pressure of the converter 40 may be displayed on the supply pressure indicator 74.

The grout material supply mechanism 22 is a powder discharge mechanism in the illustrated example, and as will be described later, a hopper 78 having a funnel-shaped lower portion for accommodating the powder grout material and agitating the grout material in the hopper. Stirrer 80 and hopper 78 for grout material
From a plurality of support columns 88 via a plurality of load detection mechanisms 86 for measuring the discharge amount of the grout material, including a discharger 82 for continuously discharging from the hopper 78 and a pressure gauge 84 for measuring the pressure in the hopper 78. Supported by.

A cylinder 90 that defines a grout material charging port is welded to the upper part of the hopper 78, and the grout material charging port of the cylinder is a lid 92 that is detachably attached to the cylinder 90 by a plurality of bolts. Is blocked by. At the lower end of the hopper 78, the nozzle 26 that connects the primary side portion 20a, the secondary side portion 20b of the guide pipe 20 and the hopper 78 to each other is attached.

The branch pipe 46 communicates with the lower part of the hopper 78, and the branch pipe 56 communicates with the upper part of the hopper 78.

The load detection mechanism 86 is a mechanism for measuring the weight of the entire grout material supply mechanism 22 with a load cell, and the measured load is displayed on the load indicator 94.

During operation of the grouting device 10, the compressed air from the compressed air source 12 is adjusted to a predetermined pressure by the pressure reducing valve 34,
The pipe 18 in the hole 16 is continuously supplied. As a result, the gap between the ground particles around the hole 16 is gradually expanded by the compressed air, and the pore water existing in the gap is gradually removed by the compressed air.
An airway is formed in a wide area around the.

While compressed air is being blown into the holes 16, the supply pressure measured by the converter 38 is displayed on the supply pressure indicator 74, the injection pressure measured by the converter 44 is displayed on the injection pressure indicator 76, The compressed air supply amount measured by the flow meter 32 is displayed on the air flow rate indicator 72.

The gap between the ground particles around the hole 16 is gradually expanded, and the pore water existing in the gap is gradually eliminated, so that the injection pressure indicated by the injection pressure indicator 76 is gradually decreased. However, the rate of increase in the flow rate displayed on the air flow rate indicator 72 increases. When the air passage is formed, the injection pressure displayed on the injection pressure indicator 76 rapidly decreases, and the rate of increase in the flow rate displayed on the air flow rate indicator 72 rapidly increases. Therefore, the formation of the air passage can be known by confirming the values displayed on the injection pressure indicator 76 and the air flow rate indicator 72 and the rapid changes thereof.

When the air passage is formed, the grout material supply mechanism 22 then operates to continuously discharge the grout material in the hopper 78 through the nozzle 26 to the secondary side portion 20b of the guide pipe 20 in a fixed amount. As a result, the grout material is blown into the hole 16 together with the compressed air, enters the inside of the air passage by the compressed air, and sequentially closes the air passage from the inner portion thereof.

As the grouting material sequentially closes the air passage from its inner portion, the injection pressure displayed on the injection pressure indicator 76 gradually increases, and the increase in the supply air amount displayed on the air flow rate indicator 72 is proportionally increased. Gradually decreases. When the value displayed on the load indicator 94 reaches a predetermined value, all valves are closed and the grouting is completed.

While the grout material supply mechanism 22 is operated, the valve 64 is opened and the suction pump 70 is operated. As a result, part of the grout material and compressed air to be supplied to the hole 16 is sucked by the suction pump 70, so that the grout material adheres to the filter paper of the filter 66. Therefore, the amount of the grouting material supplied can be predicted from the concentration of the grouting material attached to the filter paper when the grouting is completed.

Next, examples of the grout material supply mechanism 22 and the load detection mechanism 86 shown in FIGS. 2 to 5 will be described.

As shown in FIG. 3, the hopper 78 has a funnel-shaped lower portion. A blower port 100 for blowing compressed air from the branch pipe 46 is provided in the lower part of the hopper 78, and a blower port 102 for blowing compressed air from the branch pipe 56 is provided in the upper part. The nozzle 26 is attached to the lower end of the hopper 78 by a plurality of bolts.

The stirrer 80 includes a rotating shaft 104 that traverses the hopper 78,
A blade 106 provided on the rotating shaft and a motor 108 for rotating the rotating shaft 104 are provided. The rotating shaft 104 is rotatably supported by a pair of support frames 110 and 112 attached to the hopper 78 at opposed positions.
8 extends in a horizontal direction at a position spaced from the central axis line OP. The motor 108 is a hydraulic motor, and the support frame 11
It is attached to 0. The motor 108 may be a pneumatic motor or an electric motor. Feather 106
When the rotating shaft 104 is rotated by the motor 108,
The grout material in the hopper 78 is stirred by rotating in a plane perpendicular to the rotating shaft 104.

The ejector 82 supports a rotating shaft 114 extending vertically in the hopper 78, a blade 116 spirally attached to the outer periphery of the lower end of the rotating shaft, and an upper part of the rotating shaft 114 rotatably supported by the hopper 78. The screw conveyor is provided with a support body 118 for rotating and a hydraulic motor 120 supported by the support body for rotating the rotating shaft 114, and feeds the grout material in the hopper 78 downward. The motor 120 may also be a pneumatic motor or an electric motor.

The rotating shaft 114 extends along the central axis line OP of the hopper 78 so as not to overlap the rotating shaft 104 of the stirrer 80.
The blades 116 are provided on the cylindrical portion 122 at the lower end of the hopper 78, as shown in FIG. The tubular portion 122 extends downward in the nozzle 26.

As shown in FIG. 4, the nozzle 26 includes a funnel-shaped connecting portion 124 for receiving the grout material and the compressed air, a guide portion 126 following the lower end of the connecting portion, and a support cylinder 128 welded to the guide portion. , A valve rod 130 that penetrates the support cylinder in the vertical direction and opens and closes the grout material outlet of the cylinder portion 122 of the discharger 82, and is connected to the primary side portion 20 a of the guide pipe 20 to receive compressed air into the connection portion 124. Socket 132.

As shown in FIG. 4, the connecting portion 124 is attached to the flange at the lower end of the hopper 78 by a plurality of bolts. The guide part 126 is welded to the lower end of the connecting part 124 and extends obliquely downward from the lower end of the connecting part 124 and then extends horizontally. The secondary side portion 20 of the guide pipe 20 is provided at an end portion of the guide portion 126 opposite to the connecting portion 124.
b is connected. The support cylinder 128 has a screw hole that extends downward along the extension line of the central axis OP and is screwed with the valve rod 130.

The valve rod 130 has a conical valve 134 at its upper end and a handle 136 at its lower end. The valve 134 is
The lower opening of the cylindrical portion 122 of the hopper 78, that is, the hopper 7
It faces the grout material outlet 138 from 8 and opens and closes it. Therefore, the lower end portion of the tubular portion 122 has a function of a valve seat with which the valve 134 abuts.

When the handle 136 is rotated, the nozzle 26 causes the valve stem 13 to rotate.
0 rotates with respect to the support cylinder 128 and moves in the vertical direction, and the valve 134 opens and closes the grout material outlet 138. The amount of grout material discharged from the hopper 78 can be adjusted by changing the number of rotations of the motor 120 per unit time.

During the operation of the grout material supply mechanism 22, the blades 106 are rotated with the rotation of the motor 108.
The grout material inside is agitated by the blade 106. Therefore, the grout material floats in the hopper 78 and is not consolidated. Therefore, it is not necessary to keep the amount of grout material remaining in the hopper 78 constant.

Further, since the blades 116 are rotated with the rotation of the motor 120, the grout material in the hopper 78 is changed to the blades 116.
Is pushed out to the nozzle 26. In this case, the nozzle 2
Compressed air is supplied to socket 6 from socket 132. The compressed air supplied from the socket 132 to the connecting portion 124 is ejected from the jet nozzle portion which is a gap between the lower end of the tubular portion 122 and the connecting portion 124, and thereby guides the grout material falling from the grout material outlet 138. Part 12
Blow towards 6.

The load detection mechanism 86, as shown in FIG.
A support pillar 88 extending upward from the support base 140 shown in FIG.
Is mounted between the slider and the guide 144 by a bolt 142 attached to the base, a guide 144 extending upward from the tip of the mount, a slider 146 vertically movably fitted to the outside of the guide. The compression coil spring 148 that pushes the slider 146 upward with respect to the guide 144.
A shaft 150 penetrating the guide 144 and the slider 146 so as to be vertically movable, and a guide 144 and a slider 14
6 is provided with a bearing 152 and a tension type load cell 154 (see FIG. 3).

The slider 146 is a mounting arm 1 that extends in the horizontal direction.
It is attached to the hopper 78 via 56, and a connecting portion 158 is provided on the upper portion thereof. As shown in FIG.
The connecting portion 158 is connected to the lower portion of the load cell 154, and the upper portion of the load cell is connected to the support arm 160 attached to the support column 88. A nut 161 is screwed onto the upper and lower ends of the shaft 150, and the nut 161 prevents the slider 146 from vibrating with respect to the guide 144.

The entire load of the grout material supply mechanism 22 is applied to the slider 146 via the mounting arm 156. As a result, the slider 146 descends against the force of the spring 148,
A tensile load is applied to the load cell 154, and the load is detected by the load cell 154 as an electric signal. The detection signal of the load cell 154 decreases in proportion to the amount of grout material discharged from the hopper 78. Therefore, the output signal of the load cell 154 is the amount of grout material used,
That is, it is used to calculate the supply amount of grout material. The amount of grout material used is the reduction amount of the total load detected by the load cell 154.

According to the grout material supply mechanism 22, not only the grout material is continuously sent out, but also the amount of grout material discharged per unit time becomes constant. This prevents a temporary or abrupt change in the pressure and flow rate of the blown gas and the blown amount of the grout material due to uneven discharge of the grout material.

If the amount of grout material discharged per unit time becomes constant in this way, the pressure and flow rate of the gas to be blown and the amount of blown grout material caused by uneven discharge of grout material will be prevented from changing temporarily or suddenly. It is possible to correctly know the condition of the airway, the deformed condition of the ground, and the injection range of the grout material.

On the other hand, if the discharge amount of the grout material per unit time is not constant, the pressure and flow rate of the gas to be blown and the blow amount of the grout material change temporarily or abruptly every time the discharge amount of the grout material changes. As a result, even if no air passage is formed or the air passage is not occluded by the grout material, each measurement value changes rapidly, and as a result, the condition of the air passage and the ground, the injection range of the grout material are changed. I can't know correctly.

[Brief description of drawings]

1 is a block diagram showing an embodiment of the grouting apparatus of the present invention, FIG. 2 is a plan view showing an embodiment of a grout material supply mechanism, and FIG. 3 is a view taken along line 3-3 of FIG. FIG. 4 is an enlarged sectional view showing the grout material discharge part of the same grout material supply mechanism, and FIG. 5 is an enlarged sectional view showing the load detection mechanism. 10: Grouting device, 12: Compressed air source, 14: Ground, 16: Hole, 20: Guide pipe, 22: Crout material supply mechanism, 32: Compressed air flow meter, 40: Transducer for measuring supply pressure 44: Transducer for measuring injection pressure, 86: Load detector for measuring amount of grout material supplied.

Claims (3)

[Claims] 1. A means for generating compressed gas, a guide pipe for guiding the compressed gas to a hole for grouting, a means for supplying a powdered grout material to the guide pipe, and the compressed gas blown into the hole. Means for measuring the pressure, means for measuring the flow rate of the compressed gas blown into the hole, means for measuring the blowing amount of the grout material supplied to the guide pipe from the grout material supply means, Means for supporting the grout material supply means via the blowing amount measuring means, wherein the grout material supplying means accommodates the grout material supported by the supporting means via the blowing amount measuring means. A hopper and a grout material discharger disposed at a grout material discharge port of the hopper, the grout material being sent out toward the guide pipe from the grout material in the hopper. A grouting device comprising: a grout material discharging machine; and a valve mechanism which is arranged in a communication portion between the grout material discharging machine and the guide pipe and which opens and closes a powder outlet of the grout material discharging machine. 2. The blow amount measuring means, a guide attached to the supporting means so as to extend upward, a slider fitted to the outside of the guide so as to be vertically movable, and attached to the hopper, A tension type load cell that is connected between the slider and the support means and is arranged between the slider and the guide and pushes the slider upward with respect to the guide, and supports the hopper on the support means. The grouting apparatus according to claim (1), comprising: 3. The blow amount measuring means further comprises a shaft that penetrates the guide and the slider in a vertically movable manner, and a nut screwed to an upper end portion and a lower end portion of the shaft. The grouting apparatus described in the range (2).