Soil throwing device, ground improvement device, ground improvement method

Abstract

To provide a soil gathering device which can exhibit a soil gathering action without a soil discharging blade, does not require an excessive torque in drilling and pulling up, and can improve construction efficiency of a high pressure injection-agitation method.SOLUTION: A soil gathering device 1 plays a role of gathering an original soil in a soil discharging direction by a high pressure injection-agitation method using a rod 3. The soil gathering device 1 has: a pump type soil gathering mechanism 20 configured to repeatedly suck and discharge the original soil; and a push-in member 50 for operating the pump type soil gathering mechanism 20. The push-in member 50 is provided on a peripheral surface of the rod 3, and operates the pump type soil gathering mechanism 20 so as to repeat suction and discharge with the rotation of the rod 3. Using the soil gathering device 1 in the high pressure injection-agitation method enables production of a rise soil flow in the ground and gathering of the original soil in the soil discharging direction without depending on the conventional soil discharging blade.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a pump-type soil lifting device that can be used in a high-pressure jet mixing method, a ground improvement device equipped with the same, and a ground improvement method (high-pressure jet mixing method) using the ground improvement device. [Background technology]

[0002] A ground improvement device that can be used in a high-pressure jet mixing method, which is one type of ground improvement method, is disclosed in Patent Document 1. The ground improvement device disclosed in Patent Document 1 is shown in FIG.

[0003] The conventional ground improvement equipment 8 shown in Fig. 7 is equipped with a soil discharge wing 81 consisting of a screw auger that performs soil lifting function, and an improvement material injection part 82 with mixing wing (special monitor with mixing wing) that injects the improvement material and mixes the ground and the improvement material, and is configured so that it can be attached to the tip of a rod. The high-pressure injection mixing method using this conventional ground improvement equipment 8 is shown in Fig. 8.

[0004] In the conventional high-pressure injection mixing method using a conventional ground improvement device 8, a boring machine (not shown) is used to spray ground improvement material (solidification material slurry) horizontally at an ultra-high pressure discharge flow rate from the improvement material injection section 82 with mixing blades of the ground improvement device 8 attached to the tip of a rod while rotating and pulling up, and by combining mechanical mixing at the central mixing blade section and high-pressure injection mixing at the outer periphery, a cylindrical ground improvement body (column) is created in the ground.

[0005] Specifically, the construction is carried out in the following steps (a) to (f), which correspond to steps (a) to (f) shown in Figure 8. (a) The ground improvement device 8 attached to the tip of the rod is set at the core of the pile. (b) The boring machine is operated to drill holes. In this drilling process, the ground improvement device 8 is inserted to a target depth. (c) The soil improvement device 8 that has penetrated to the target depth is pulled up once, and soil is discharged during the process. During the process of pulling up the soil improvement device 8 while rotating, the soil discharge wing 81 consisting of a screw auger performs the soil lifting function and discharges soil. (d) The boring machine is operated to drill holes again. In this re-drilling step, the soil improvement device 8 is inserted to the target depth in the same manner as in step (b). (e) The soil improvement equipment 8 is rotated and pulled up while the soil improvement material is sprayed horizontally from the improvement material spraying section 82 with agitator blades of the soil improvement equipment 8 at an ultra-high pressure discharge flow rate. During the process of rotating and pulling up the soil improvement equipment 8, mechanical stirring by the agitator blades and high-pressure jet stirring on the outer periphery proceed simultaneously in parallel. (f) By continuing the above step (e) while rotating and pulling up the ground improvement device 8, a cylindrical ground improvement body (column) is created in the ground.

[0006] The soil improvement equipment equipped with the above-mentioned soil discharge blades does not require the use of air, and can carry out high-pressure injection mixing construction by injecting only soil improvement materials such as cement milk (slurry). Therefore, there is no risk of water pollution due to air blowing during underwater construction in rivers or harbors. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 3453351 Summary of the Invention [Problem to be solved by the invention]

[0008] The above-mentioned ground improvement device equipped with the soil discharge wings is equipped with the soil discharge wings as soil lifting means, so that soil discharge is possible even in construction where soil lifting action by air lift cannot be expected.

[0009] However, there is a problem in that the soil discharge blades consisting of the screw auger are prone to adhesion of the raw soil to be discharged, which reduces the soil lifting function.

[0010] In addition, because the surface area of ​​the soil-removal blades (the area of ​​contact with the soil) is large, excessive torque is required when drilling and pulling up the hole, which places a large burden on the equipment. Related to this, there is also the problem that the soil-removal blades are prone to breakage.

[0011] Furthermore, in addition to drilling and pulling up for constructing the ground improvement body (steps d to f in Fig. 8), drilling and pulling up must be performed just for the purpose of removing soil (steps b and c in Fig. 8), which results in poor construction efficiency.

[0012] In view of the above-mentioned problems, the object of the present invention is to provide a soil lifting device and ground improvement device that can be used with the high-pressure jet mixing method, which can exert soil lifting functions equivalent to those of soil discharge blades, does not require excessive torque when drilling and lifting, and enables improvement in the construction efficiency of the high-pressure jet mixing method. Another object of the present invention is to provide a high-pressure jet mixing method which can perform soil lifting function without the use of soil discharge blades (screw augers), does not require excessive torque when drilling and pulling up, and enables improved construction efficiency. [Means for solving the problem]

[0013] The above-mentioned object is to provide a soil lifting device for lifting raw soil in a soil discharge direction in a high-pressure injection mixing method using a rod, A pump-type soil lifting means configured to repeatedly suck and discharge the raw soil; and a pump operating means for operating the pump type soil lifting means, The pump operating means is provided on the rod, and this is achieved by operating the pump-type soil lifting means so as to repeatedly suck in and discharge as the rod rotates.

[0014] In the above soil lifting device, The pump type soil lifting means may, for example, A pump chamber that is separated by an elastic membrane and can suck and discharge the original soil, A suction port that allows the original soil to be sucked into the pump chamber; and a discharge port for allowing discharge of the raw soil from the pump chamber, The pump actuation means may, for example, It is configured as a pushing member that protrudes from the outer circumferential surface of the rotating rod and pushes in the elastic membrane of the pump-type soil lifting means.

[0015] Furthermore, the above-mentioned objectives are A rod for pumping the ground improvement material toward the ground to be improved; A mixing blade provided on the rod for mixing and mixing the soil improvement material and the ground; A lifting device having the above characteristics provided on the rod; This is achieved by a ground improvement device having the following structure.

[0016] The above-mentioned object is to provide a high-pressure injection mixing method using a ground improvement device having the above-mentioned characteristics, (a) penetrating the soil improvement device to a target depth while drilling a hole, and during the penetration process, lifting up the original soil; (b) constructing a ground improvement body while withdrawing the ground improvement device that has reached the target depth, and lifting up the original soil during the penetration process; This is achieved by using a ground improvement method (high-pressure jet mixing method) that includes the following. Effect of the Invention

[0017] By using this invention in the high pressure jet mixing method, it is possible to create an upward soil flow in the ground and lift up the original soil in the soil discharge direction without relying on the conventional soil discharge blade (screw auger). Therefore, it is possible to solve problems such as a decrease in soil lifting function caused by the structure of the soil discharge blade (screw auger) and excessive torque during drilling and lifting.

[0018] In addition, in the present invention, the rotation of the rod is used to continuously operate the pump type soil lifting means. Therefore, a dedicated power source is not required to operate the pump type soil lifting means. In addition, since it can be retrofitted to an existing rod, it can be widely used.

[0019] Furthermore, according to the present invention, the pump-type soil lifting means always operates as long as the rod is rotating. In other words, by rotating the rod when drilling and lifting, the original soil is continuously sucked and discharged, which creates an upward soil flow, making it possible to lift the original soil. This eliminates the need for drilling and lifting just for the purpose of soil removal, and allows drilling and lifting to be done once each (i.e., re-drilling is not necessary), making it possible to improve the efficiency of construction and shorten the construction period. [Brief description of the drawings]

[0020] [Figure 1] FIG. 2 is a side view showing a ground improvement device equipped with a lifting device. [Diagram 2] 2 is a top view, a side view (see-through view), and a bottom view showing a soil lifting device provided in the ground improvement device of FIG. 1. [Diagram 3] FIG. 2 is a side view (perspective view) showing a schematic internal structure of the soil lifting device. [Figure 4] 1A and 1B are a plan view and a side view (perspective view) showing the state when a pump-type soil lifting mechanism (pump-type soil lifting means) equipped in the soil lifting device sucks raw soil to be lifted into a pump chamber. [Diagram 5] 1A and 1B are a plan view and a side view (perspective view) showing a state in which a pump-type soil lifting mechanism (pump-type soil lifting means) provided in the soil lifting device discharges raw soil to be lifted from a pump chamber. [Figure 6] This is a process diagram showing a high-pressure jet mixing method using a ground improvement device equipped with a soil lifting device. [Figure 7] FIG. 1 is a side view showing a conventional ground improvement device. [Figure 8] FIG. 1 is a process diagram showing a high-pressure jet mixing method using a conventional ground improvement device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] (Configuration of the soil lifting device) First, the configuration of a soil lifting device that can be used in the high-pressure jet mixing method will be described with reference to Figs. 1 to 5.

[0022] The soil lifting device 1 of this embodiment is used to generate an upward soil flow and lift up raw soil in a high-pressure jet mixing method using a rod and a soil improvement device attached to the tip of the rod. This soil lifting device 1 has a pump-type soil lifting mechanism 20 (pump-type soil lifting means) that generates the soil lifting action by repeatedly suctioning and discharging the raw soil, and a pushing member 50 (pump operating means) that continuously operates the pump-type soil lifting mechanism to perform the soil lifting action.

[0023] The pump type soil lifting mechanism 20 (pump type soil lifting means) A top plate 21 and a bottom plate 22 each having a circular opening 23 through which the rod 3 can be inserted; A pump chamber 30 located between the top plate 21 and the bottom plate 22 and capable of sucking and discharging soil from within the ground; A suction port 31 that allows the raw soil to flow into the pump chamber 30; An open / close check valve 32 that closes the suction port 31; an outlet 33 allowing the discharge of the raw soil from the pump chamber 30; A check valve 34 that closes the exhaust port 33 is provided. It has.

[0024] The pump type soil lifting mechanism 20 of the soil lifting device 1 is rotatably attached to the rod 3 during construction. The pump type soil lifting mechanism 20 attached to the rod 3 is supported by the soil lifting device support member 5 so as not to move up and down, but can rotate freely as there is nothing to restrict movement in the rotational direction. Therefore, during construction, while the rod 3 rotates within the ground, the pump type soil lifting mechanism 20 receives resistance from the ground and maintains a non-rotating state.

[0025] The top plate 21 and the bottom plate 22 each have a circular opening 23 through which the rod 3 can be inserted. The circular opening 23 is formed to have a diameter slightly larger than the outer diameter of the rod 3. A plurality of bearings 25 are provided in this circular opening 23. The rod 3 contacts the top plate 21 and the bottom plate 22 via the plurality of bearings 25, allowing the rod 3 to rotate freely relative to them (even when the pump type soil lifting mechanism 20 is stationary in the ground).

[0026] The pump chamber 30 is partially partitioned by an elastic membrane 35 and functions as a discharged soil intake chamber. The elastic membrane 35 is made of, for example, rubber. The original soil to be pumped is temporarily taken into the pump chamber 30.

[0027] As shown in Fig. 4, the elastic membrane 35 of the pump chamber 30 maintains an approximately hemispherically bulged state in its original form, and in the process of compressing and depressing the elastic membrane 35 from the outside, the volume of its internal space decreases. On the other hand, when the compression of the elastic membrane 35 is released, the elastic membrane returns to its original approximately hemispherically bulged state, and in the process, the volume of the internal space increases. Therefore, by repeatedly compressing and releasing the approximately hemispherical elastic membrane 35, the pump chamber 30, which is the discharge soil intake chamber, repeatedly expands and contracts.

[0028] The suction port 31 is located on the bottom side of the pump type soil lifting mechanism 20, and functions as an inlet to the pump chamber 30. The raw soil to be lifted is sucked in through the suction port 31 and taken into the pump chamber 30. The suction port 31 is provided with a check valve 32 consisting of an openable and closable lid. As shown in Fig. 4, this check valve 32 opens only in the direction in which the raw soil is sucked in (upper side of the drawing), and does not open in the direction in which the raw soil is discharged (lower side of the drawing). Therefore, the suction port 31 does not function as a discharge port.

[0029] The discharge port 33 is located on the upper side of the pump type soil lifting mechanism 20, and functions as an outlet from the pump chamber 30. The raw soil to be lifted, which is taken into the pump chamber 30 from the suction port 31, is discharged from the discharge port 33. The discharge port 33 is provided with a check valve 34 consisting of an openable and closable lid. As shown in Fig. 5, this check valve 34 opens only in the discharge direction of the raw soil (upper side of the drawing) and does not open in the suction direction (lower side of the drawing). Therefore, the discharge port 33 does not function as a suction port.

[0030] The pushing member 50, which is a pump operating means, plays a role of pushing in the elastic membrane 35 of the pump type soil lifting mechanism. The pushing member 50 is fixed to the rotating rod 3 so as to protrude horizontally from the outer circumferential surface of the rod 3 and to rotate integrally with the rod 3. The pushing member 50 is also fixed to the rod 3 between the soil lifting device support members 5, 5. This pushing member 50 operates the pump type soil lifting mechanism 20 so as to continuously repeat suction and discharge as the rod 3 rotates.

[0031] (Principle of soil lifting by soil lifting equipment) Next, the principle of soil lifting by the soil lifting device 1 will be described mainly with reference to Figs.

[0032] The pump type soil lifting mechanism 20 attached to the rod 3 is supported by the soil lifting device support members 5, 5 so as not to move vertically. In this state, the rod 3 rotates in the ground, and the pump type soil lifting mechanism 20 maintains a nearly non-rotating state due to the resistance of the original soil in the ground. In other words, the rod 3 rotates relative to the non-rotating pump type soil lifting mechanism 20 in the ground.

[0033] When the rod 3 rotates in the ground, the pushing member 50 fixed to the rod 3 also rotates integrally. That is, the pushing member 50 protruding horizontally from the outer circumferential surface of the rod 3 rotates integrally with the rod 3. In the process in which the rod 3 rotates and the pushing member 50 rotates, the pushing member 50 repeatedly presses (FIG. 5) and releases (FIG. 4) the elastic membrane body 35.

[0034] In the push-released state shown in Figure 4, the push-in member 50 separates from the elastic membrane 35 (which had been forcibly pushed in until just before), and as a result, the elastic membrane 35 returns to its original shape of a roughly hemispherical bulge. This causes the capacity of the pump chamber 30 to return to its original capacity, generating negative pressure, and the original soil is sucked into the pump chamber from the suction port 31 in one go. At this time, the check valve 34 of the discharge port 33 remains closed, while the check valve 32 of the suction port 31 automatically opens in response to the negative pressure caused by the elastic membrane 35 returning to its original shape.

[0035] 5, the pushing member 50 forcibly pushes the substantially hemispherical elastic membrane 35, which elastically deforms into a concave state. This causes the volume of the pump chamber 30 to suddenly shrink, generating pressure, and the raw soil contained therein is discharged all at once from the discharge port 33. At this time, the check valve 32 of the suction port 31 remains closed, while the check valve 34 of the discharge port 33 automatically opens in response to the discharge pressure caused by the elastic deformation of the elastic membrane 35.

[0036] Therefore, by rotating the rod 3 in the ground, the pushing member 50 simultaneously rotates, and this rotational motion repeatedly sucks the raw soil into the pump chamber 30 of the soil lifting device 1 and discharges the raw soil from the pump chamber 30. In other words, the pushing member 50 repeatedly pushes and releases the elastic membrane 35, causing the elastic membrane 35 to continuously repeat reciprocating motion, thereby allowing the pump-type soil lifting mechanism 20 to perform its pumping function. As a result, an upward soil flow (soil lifting action) is generated in the ground, facilitating soil removal.

[0037] (Configuration of the ground improvement device equipped with the soil lifting device) Next, the configuration of the ground improvement device equipped with the above-mentioned soil lifting device will be described mainly with reference to FIG.

[0038] The ground improvement device 7 of this embodiment is A rod 3 for pumping the ground improvement material toward the ground to be improved; - An improvement material injection section 9 with an agitator blade (special monitor with an agitator blade) provided on the rod 3; A lifting device 1 provided on the rod; -Soil lifting device support member 5 It has.

[0039] The rod 3 has an internal flow path for pumping the ground improvement material (solidification material slurry) toward the improvement material jetting section 9 with agitating blades. In this application, the ground improvement material will be abbreviated to "improvement material" as necessary.

[0040] The improvement material jetting unit with agitator 9 integrally comprises an agitator 91 and an improvement material jetting unit 93. A drilling bit 95 is provided on the bottom side of the agitator 91. The improvement material (solidification material slurry) pumped through the flow path in the rod is jetted horizontally from the improvement material jetting unit 93.

[0041] The soil lifting device 1 has the above-mentioned configuration and is provided so as to be located above the improvement material jetting section with agitating blades 9. In this embodiment, the ground improvement device 7 is provided with one soil lifting device 1, but soil lifting devices may be provided in multiple stages along the rod.

[0042] The soil lifting device support member 5 is composed of a step portion fixed to the rod 3. The soil lifting device support member 5 supports the pump type soil lifting mechanism 20 so that the pump type soil lifting mechanism 20 does not move in the vertical direction and so that the rod 3 can freely rotate relative to the pump type soil lifting mechanism 20.

[0043] (High-pressure jet mixing method using soil improvement equipment equipped with soil lifting equipment) Next, a high-pressure jet mixing method using the above-mentioned ground improvement device 7 will be described with reference to FIG.

[0044] In the high-pressure jet mixing method using the ground improvement device 7, a boring machine (not shown) is used to spray the improvement material (solidification material slurry) horizontally at an ultra-high pressure discharge flow rate from the improvement material injection section 9 with mixing blades of the ground improvement device 7 attached to the tip of a rod while rotating and pulling up, and by combining mechanical mixing at the central mixing blade section and high-pressure jet mixing at the outer periphery, an approximately cylindrical ground improvement body (pillar-shaped column) is created in the ground.

[0045] Specifically, construction is carried out in the following steps (a) to (d). The following steps (a) to (d) correspond to steps (a) to (d) shown in Fig. 6. For the configuration of the ground improvement device 7, refer to Fig. 1 as necessary.

[0046] (a) The ground improvement device 7 attached to the tip of the rod is set at the core of the pile.

[0047] (b) The boring machine is operated to drill holes. In this drilling process, the rod 3 is rotated to penetrate the soil improvement device 7 to the target depth. During the penetration process, the pushing member 50 protruding horizontally from the outer periphery of the rod 3 rotates together with the rod 3, so that the pump-type soil lifting mechanism 20, which is almost non-rotating, continuously performs its pumping function. As a result, in the drilling process, soil lifting action occurs from the bottom up in the ground, facilitating soil removal.

[0048] (c) The soil improvement device 7 is rotated and pulled up while the soil improvement device 7 is horizontally sprayed with an ultra-high pressure discharge flow rate from the soil improvement device 7 improvement material spray unit 9 with agitator blades. During the process of rotating and pulling up the soil improvement device 7, mechanical stirring by the agitator blades and high-pressure jet stirring on the outer periphery proceed simultaneously in parallel. In addition, during the process of rotating and pulling up the soil improvement device 7, the pushing member 50 protruding horizontally from the outer periphery of the rod 3 rotates together with the rod 3, so that the pump-type soil lifting mechanism 20, which is almost non-rotating, continuously performs its pumping function. As a result, soil lifting action occurs from the bottom up in the ground not only in the drilling process but also in the construction process, promoting soil removal.

[0049] (f) By continuing the above step (c) while rotating and pulling up the ground improvement device 7, a substantially cylindrical ground improvement body (column) is created in the ground.

[0050] As described above, in the high-pressure jet mixing method of this embodiment, there is no need to repeatedly drill holes and pull up the rock as in the conventional technique shown in Fig. 8. In other words, drilling holes and pulling up the rock only need to be done once, which makes it possible to improve the efficiency of construction and shorten the construction period.

[0051] Furthermore, in the high-pressure injection mixing method of this embodiment, soil removal is promoted not only when the ground improvement body is constructed (step f) but also when holes are drilled (step c), so that the volume increase associated with the injection of improvement material when the ground improvement body is constructed (step f) is minimized, and displacement of the surrounding ground caused by ground improvement can be suppressed.

[0052] The above-mentioned high-pressure jet mixing method can be used in high-pressure jet mixing methods in which the air lift effect (soil lifting effect by air lift) cannot be expected because air is not used, for example. [Explanation of symbols]

[0053] 1 Soil lifting device 2. Ground improvement body 3. Rod 5. Soil lifting device support member 7 Ground improvement equipment 8 Ground improvement equipment 9. Improvement material injection section with stirring blades (special monitor with stirring blades) 20 Pump-type soil lifting mechanism (pump-type soil lifting means) 21 Tabletop 22 Bottom plate 23 Circular opening 25 Bearings 30 Pump room (soil discharge intake room) 31 Suction port 32 Suction side check valve 33 Outlet 34 Discharge side check valve 35 Elastic membrane 50 Pushing member (pump operating means) 81 Screw auger 82 Improvement material injection unit with stirring blades (special monitor with stirring blades) 91 Stirring blade 93 Improved material injection part 95 Drilling Bits

Claims

1. A soil lifting device used in a high-pressure injection mixing method using a ground improvement device having a rod with a mixing blade, which lifts up raw soil in the soil discharge direction without using a soil discharge blade as a soil lifting means, A pump-type soil lifting means configured to repeatedly suck and discharge the raw soil; and a pump operating means for operating the pump type soil lifting means, The pump operating means is provided on a rod of the ground improvement device, and is configured to push or release the pump type soil lifting means by rotating the pump operating means, and the pump operating means rotates by rotating the rod within the ground, and the pump type soil lifting means operates to repeatedly suck and discharge the soil. A soil lifting device used in a high-pressure jet mixing method.

2. The pump type soil lifting means is A pump chamber that is separated by an elastic membrane and can suck and discharge the original soil; A suction port that allows the raw soil to be sucked into the pump chamber; and a discharge port for allowing discharge of the raw soil from the pump chamber, The pump actuation means includes: A pushing member is provided to protrude from the outer circumferential surface of the rotating rod and pushes in the elastic membrane of the pump-type soil lifting means. A soil lifting device for use in the high-pressure jet mixing method according to claim 1.

3. A rod for pumping the ground improvement material toward the ground to be improved; A mixing blade provided on the rod for mixing and mixing the soil improvement material and the soil; The soil lifting device according to claim 1 provided on the rod; A ground improvement device for use in a high-pressure jet mixing method, comprising:

4. A high-pressure injection mixing method using the ground improvement device according to claim 3, (a) penetrating the soil improvement device to a target depth while drilling a hole, and during the penetration process, lifting up the original soil; (b) constructing a ground improvement body while withdrawing the ground improvement device that has reached the target depth, and lifting up the original soil during the penetration process; A ground improvement method comprising the steps of:

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