JP5250729B2 - Underground consolidated body construction method and underground solid body creation device for creating a solid body using the method - Google Patents

Description

  The present invention is a high-pressure injection of a hardening material liquid from a nozzle used for ground stabilization, ground support, tunnel support, structure foundation, structure foundation reinforcement, liquefaction prevention, underground wall for water shielding, groundwater spring prevention, etc. The present invention relates to an underground solid body forming method for forming a solid body and an underground solid body forming apparatus for forming a solid body using the method.

Conventionally, as a method of creating a solidified body by injecting a hardened material liquid into the ground, for example, a boring hole is cut in the ground to be improved, and a rod provided with a monitor at the tip is inserted into the boring hole. The ground improvement material (hardening material liquid) jet is jetted from the nozzle provided in the monitor in the horizontal direction to mix the ground cutting and the improvement material, while mixing the ground cutting and the improvement material, the rod There was something that pulled up to the ground side while rotating. Thereby, it can consist of a mixture of a ground and a ground improvement material, and can form the cylindrical solid body (improvement body) which has a radial direction dimension equal to a jet reach | attainment distance (for example, patent document 1).

JP 2001-115442 A ("Conventional Technology" column)

However, in a construction method for forming a large-diameter solidified body such as a jet grouting method such as a so-called omnidirectional high-pressure injection method, when a boring hole is cut in advance as a pre-drilling hole when inserting an injection rod, There was a problem that the construction time and construction cost for cutting the steel increased. In addition, by inserting the injection rod directly into the ground without cutting the borehole, the construction time and construction cost can be reduced. However, the verticality of the injection rod increases as the solidification depth is increased. As a result, it becomes difficult to secure the solidified body, and a new problem arises that the consolidated body cannot be formed with high accuracy.

In addition, in the jet grouting method including the so-called omnidirectional high-pressure injection method, a drilling bit is attached to the tip of the injection rod, and water is injected from the drilling bit at a low pressure, usually about 30-60 R.PM. Some drill holes while rotating at the same rotational speed, but even when water is ejected from the drill bit while jetting water at a low pressure, the drilling takes a relatively long time and the injection rod is vertical. It was difficult to ensure the performance, and there was a risk of construction interruption due to jamming.

  The present invention has been made in view of the above problems, and it is possible to improve the accuracy of a consolidated body formed in the ground and to form the consolidated body in a short time and at a low cost. It is another object of the present invention to provide an underground solid body forming apparatus for forming a solid body using the construction method.

In order to solve the above problems and achieve the above object, the first aspect of the present invention includes an insertion step of inserting an injection rod provided with a tip nozzle at an end to a predetermined depth of a target ground. In the insertion process, while rotating or swinging the injection rod, the injection injection process of high-pressure injection of the hardener liquid or liquid from the tip nozzle in the direction of the injection rod insertion side, and pulling up the injection rod from the target ground A plurality of tip nozzles provided at the tip portion of the injection rod, and a plurality of tip nozzles provided at the tip portion of the injection rod are provided on the tip peripheral side of the injection rod, A peripheral tip nozzle that injects a curable material liquid or liquid at high pressure in the insertion direction, and a line that is provided inside the peripheral tip nozzles and that is inclined with respect to the injection rod insertion direction and between the peripheral tip nozzles. And having an inner end nozzle for high-pressure injection of curable material liquid or liquid et away direction.

According to this method, since the hardening material liquid or liquid is injected at a high pressure from the tip nozzle toward the insertion rod insertion side by the insertion injection step, the injection rod insertion side of the injection rod is injected by the high pressure injection of the hardening material liquid or liquid. The ground in the direction (opposite to the pull-up side) can be cut, and the ground in the direction of the insertion side can be liquefied (softened). In addition, the ground in the insertion direction of the injection rod is cut by the hardened material liquid or liquid jetted at a high pressure in the insertion direction of the injection rod by the peripheral tip nozzle, and the inclination of the injection direction of the injection rod is inclined by the inner tip nozzle. The ground in the direction in which the injection rod is inserted and inclined is also cut by the hardening material liquid or liquid jetted in a high pressure direction. In this way, the interaction between the peripheral tip nozzle and the inner tip nozzle can actively cut not only the ground in the injection rod insertion direction but also the ground around the injection rod. It becomes easy to insert into the ground, the injection rod is inserted straight into the liquefied ground, and the verticality of the injection rod can be improved. Therefore, the consolidated body can be formed with high accuracy, and the consolidated body can be formed in a short time and at low cost.

Of the present invention, the second aspect is the underground consolidated body construction method according to the first aspect, and can change the injection pressure of the curable material liquid or the liquid injected from the tip nozzle at a high pressure. Is.

According to this method, since the injection pressure of the hardened material liquid or liquid injected from the tip nozzle can be changed, the size of the hole to be drilled can be adjusted, the hardness of the ground, the construction site The size of the hole to be drilled can be adjusted according to the size of the hole. Thereby, when the injection rod can be sufficiently inserted with a small hole, the curing material liquid or the liquid can be ejected at a slightly lower pressure in the high pressure ejection, and the cost can be reduced.

In addition, even when there is stone or the like in the insertion direction of the injection rod, for example, by slightly lifting the injection rod and then spraying a hardener liquid or liquid at high pressure, such as gravel and cobblestone existing in the ground Can be shifted out of the insertion direction of the injection rod. Thereby, the injection rod can be reliably inserted into the ground.

The thing which concerns on a 3rd aspect among this invention is the underground solid body formation apparatus which produces | generates a solid body using the underground solid body construction method which concerns on a 1st or 2nd aspect.

According to this configuration, there is an effect similar to the effect of either the first or second aspect of the present invention described above.

  As described above, according to the underground consolidated body construction method of the present invention, in the insertion and injection process, the hardener liquid or liquid is injected at a high pressure from the tip nozzle to the insertion side of the injection rod. The accuracy of the solidified body can be increased, and the solidified body can be formed in a relatively short time and at a low cost.

Hereinafter, an embodiment of the underground consolidated body construction method of the present invention will be described with reference to the drawings. Drawing 1 is a figure showing the construction situation of the underground solid body construction method in one embodiment of the present invention.

As shown in FIG. 1, tip nozzles 101 to 104 ( circumferential tip nozzles 101 and 102, inner tip nozzles 103 and 104) provided at the tip of the injection rod 1 and an air injection port 105 are passed through the inside of the injection rod 1. Water (liquid) and air supplied are injected, and cement milk (hardening material liquid) supplied via the injection rod 1 is injected from the injection nozzle 13 provided on the side surface of the injection rod 1. Is done. In the present embodiment, water (liquid) is jetted from the tip nozzles 101 to 104, but the present invention is not limited to this, and cement milk may be jetted.

The work machine 2 is a machine that supports the injection rod 1 and moves the injection rod 1 up and down. Thereby, the injection rod 1 can be rotated not only by the working machine 2 but also by the working machine 2.

As described above, the injection rod 1 is provided with nozzles at the end and side surfaces, and the swivel 3 is attached to the rear end. The injection rod 1 is provided with a cement milk flow path 10, an air flow path 11, and a water flow path 12 for supplying cement milk, air, and water (liquid) to nozzles described later.

The swivel 3 is connected to water, air, and cement milk supply pipes 7, 8, and 9 (hose) supplied from a water supply source 4, an air supply source 5, and a cement milk supply source 6, respectively. In addition, water, air, and cement milk are supplied to a water channel 12, an air channel 11, and a cement milk channel 10, which will be described later, provided in the injection rod 1. In this way, the cement milk, air, and water supplied from the water supply source 4, the air supply source 5, and the cement milk (hardening material liquid) supply source 6 are respectively supplied to the supply pipes 7 to 9 → The swivel 3 is ejected from a nozzle or the like through the flow paths 10 to 12. In the present embodiment, for convenience of explanation, the water supply source of the tip nozzles 101 to 104, the air injection port 105, and the injection nozzle 13 is one, and the supply sources 4, 5, 6 Although it has been described that water, air, and cement milk are supplied from the above, actually, a supply source, a supply pipe, and a flow path are provided corresponding to each nozzle and injection port.

Next, the injection rod will be described with reference to FIGS. FIG. 2 is a side view of an injection rod used in the underground consolidated body construction method in one embodiment of the present invention, and FIG. 3 is a view showing an end portion of the injection rod. FIG. 4 is a perspective view of the injection rod.

As shown in FIG. 2, the injection rod 1 is provided with an injection nozzle 13 (approximately 4.0 mm in diameter) for injecting cement milk and air on the side surface, and as shown in FIG. Tip nozzles 101 to 104 (approximately 4.0 mm in diameter) for ejecting water (liquid) and an air ejection port 105 for ejecting air are provided.

Note that, as described above, in the present embodiment, description will be made by using water (liquid) ejected from the tip nozzles 101 to 104. However, the present invention is not limited to this, and from some or all of the tip nozzles 101 to 104. It may be such that cement milk is jetted. In the present embodiment, four tip nozzles are provided at the tip of the injection rod 1, but the number is not limited to four , and five or more nozzles may be provided.

As shown in FIG. 2, the injection nozzle 13 includes a material liquid injection nozzle 14 for injecting cement milk and an air injection port 17 for injecting compressed air. Specifically, the material liquid injection nozzle 14 is provided on the inner tube of the injection nozzle 13, and the air injection port 17 is provided on the outer tube. In this way, when cement milk and compressed air are jetted from the jet nozzle 13 at a high pressure, cement milk is jetted from the inside of the jet nozzle 13, compressed air is jetted from the outside (outer peripheral portion), and the cement milk jet By forming a compressed air layer coating around, it is possible to increase the injection reach compared to the case where there is no compressed air layer coating.

As shown in FIG. 3, the front end nozzles 101 to 104 are attached to a front end nozzle mounting plate 106 having a square shape, and peripheral side front end nozzles 101 and 102 are arranged in the vicinity of each vertex on the diagonal of the square. Inner tip nozzles 103 and 104 are provided. That is, peripheral tip nozzles 101 and 102 are provided on the peripheral side of the tip of the injection rod 1, and inner tip nozzles 103 and 104 are provided inside the peripheral tip nozzles 101 and 102. An air injection port 105 for injecting air is provided in the vicinity of the center of the tip nozzle mounting plate 106. As will be described later, water (liquid) is ejected from the circumferential tip nozzles 101 and 102 in the insertion direction of the injection rod 1, and the injection rod 1 is inserted from the inner tip nozzles 103 and 104. Water (liquid) is injected at a high pressure in a direction having an inclination of about 20 degrees outward. This inclination is given in the direction away from the line connecting the peripheral tip nozzles 101 and 102.

Further, as shown in FIG. 4, the inlets of the cement milk flow path 10, the air flow path 11, and the water flow path 12 described above are provided on the upper surface of the injection rod 1. Cement milk, air, and water are introduced from these inlets, and are jetted from the nozzles through the cement milk flow path 10, the air flow path 11, and the water flow path 12. Note that, as described above, in this embodiment, for convenience of explanation, there are one flow path for water, air, and cement milk in the tip nozzles 101 to 104, the air injection port 105, the injection nozzle 13, and the flow path. Although described so that water, air, and cement milk may be supplied from 10, 11, and 12, actually, it has a flow path corresponding to each nozzle and injection port.

The injection rod 1 of this embodiment has a circular cross section with a diameter of about 10 cm to 20 cm (for example, 14.2 cm), and a passage (for example, cement milk, compressed air, water, a wiring tube for a measurement sensor, a hydraulic pipe, etc.) A porous tube having a flow path) is used. Then, these injection rods 1 are sequentially connected while adjusting the positions of the respective passages and inserted into the ground. In the present embodiment, the injection rod 1 having a circular cross section with a diameter of about 10 cm to 20 cm is used. However, the present invention is not limited thereto, and an injection rod 1 having a square cross section with a side of about 10 cm to 18 cm may be used.

Next, a situation where water (liquid) is ejected from the tip nozzles 101 to 104 provided at the tip of the injection rod 1 will be described. FIG. 5 is a view showing the injection direction of the tip nozzle provided at the end of the injection rod used in the underground consolidated body construction method in one embodiment of the present invention, and FIG. 6 shows water from the tip nozzle. It is a figure which shows the condition currently injected. FIG. 5 corresponds to a view of FIG. 2 viewed from a position rotated 90 degrees.

As shown in FIGS. 5 and 6, water (liquid) is jetted from the circumferential tip nozzles 101 and 102 in a substantially inserting direction of the injection rod 1, and the injection rod 1 is inserted from the inner tip nozzles 103 and 104. Water (liquid) is injected at a high pressure in a direction having an inclination of about 20 degrees. In other words, the tip nozzles 101 to 104 are arranged in such a manner that the tip end nozzles 101 and 102 that inject water (liquid) at a high pressure in the substantially inserting direction of the injection rod 1 and the water (liquid) in a direction inclined with respect to the insertion direction of the injection rod 1. ) And the inner tip nozzles 103 and 104 for high-pressure injection. Air is ejected from the air ejection port 105. In the present embodiment, high pressure water (liquid) is jetted from the circumferential tip nozzles 101 and 102 in a substantially inserting direction of the injection rod 1, and from the inner tip nozzles 103 and 104, about 20 in the insertion direction of the injection rod 1. Although water (liquid) is jetted at a high pressure in a direction having a degree of inclination, the water (liquid) is not limited to this, and water (from the tip nozzles 101 to 104 to the insertion rod 1 on the insertion side (opposite to the pulling side)) Any other direction may be used as long as the liquid) is jetted at a high pressure.

  As a result, as shown in FIG. 6, the ground in the direction of the insertion side of the injection rod 1 is cut by water (liquid) jetted from the tip nozzles 101 to 104 at a high pressure, and the ground in the direction of the insertion side is positively removed. It can be liquefied (softened), and compressed air is injected from the air injection port 105, so that water (liquid) injected from the tip nozzles 101 to 104 and the ground (such as soil and stone) are mixed. The effect of draining the discharged mud can be increased (the mud is not clogged in the ground).

  Next, the construction procedure by the underground consolidated body construction method in one Embodiment of this invention is demonstrated using FIG. FIG. 7 is a flowchart showing a construction procedure of the underground consolidated body construction method in one embodiment of the present invention.

  First, in S1, the injection rod 1 is positioned at a position to be excavated. Specifically, the injection rod 1 is suspended by a crane, and the injection rod 1 is positioned at a position to be excavated. Then, when the injection rod 1 is positioned at a predetermined position to be excavated, the process proceeds to S2.

In S <b> 2, water (liquid) is ejected from the tip nozzles 101 to 104 of the injection rod 1 at a high pressure and air is ejected from the air ejection port 105. When the end of the injection rod 1 comes to the vicinity of the grip 18 (see FIG. 1) of the work implement 2 while water and air are being jetted, the end of the injection rod 1 is gripped by the grip 18 of the work implement 2. The end portion (the other end portion) of the same kind of injection rod 1 is connected to the end portion of the injection rod 1 held by the holding portion 18 of the work machine 2 with a bolt, and the injection rod 1 connected with the bolt is also used. Similarly, it is suspended by a crane and inserted into the ground. By repeating this, the injection rod 1 having a length corresponding to the depth of the hole 15 is inserted into the ground. Then, in S3, it is determined whether the injection rod 1 has been inserted to a predetermined depth. If it is determined that the injection rod 1 has been inserted to a predetermined depth, the process proceeds to S4. Note that the water injection from the tip nozzles 101 to 104 and the air injection from the air injection port 105 executed in S2 are performed by the operator by a liquid injection pressure setting switch (not shown) and an air injection pressure setting switch (not shown). Starts when abbreviation is operated. Specifically, it starts when the operator operates the injection pressure of the liquid injection pressure setting switch (not shown) and the air injection pressure setting switch (not shown) to change from “0” to a desired injection pressure. To do.

Thus, since water is injected at a high pressure forward from the tip nozzles 101 to 104 in the insertion direction of the injection rod 1, the ground in the insertion direction of the injection rod 1 is cut by the water injected at the high pressure, The ground can be liquefied (softened). Thereby, the injection rod 1 can be easily inserted into the ground, and the verticality of the injection rod 1 can be secured.

In S4, the water injection from the tip nozzles 101 to 104 and the air injection from the air injection port 105 are terminated, and the process proceeds to S5. Note that the water injection from the tip nozzles 101 to 104 and the air injection from the air injection port 105 executed in S2 are performed by the operator by a liquid injection pressure setting switch (not shown) and an air injection pressure setting switch (not shown). Ends by operating (omitted). Specifically, the operation is terminated when the operator operates the injection pressures of the liquid injection pressure setting switch (not shown) and the air injection pressure setting switch (not shown) to be “0”.

By S5, cement milk and compressed air are injected from the injection nozzle 13 while the injection rod 1 is swung. Specifically, when the injection rod 1 is rotated 30 degrees (predetermined angle) while cement milk (pressure of about 40 MPa) is jetted from the injection nozzle 13 together with compressed air (pressure of about 1 MPa), A fan-shaped consolidated body is formed. The cement milk injection and air injection from the injection nozzle 13 executed in S5 are performed by a worker operating a cement milk injection pressure setting switch (not shown) and an air injection pressure setting switch (not shown). Start by. Specifically, the operator operates the cement milk injection pressure setting switch (not shown) and the air injection pressure setting switch (not shown) to change the injection pressure from “0” to a desired injection pressure. Start. In this embodiment, the injection rod 1 is swung. However, the present invention is not limited to this, and the injection rod 1 may be rotated in one direction (right rotation or left rotation is possible).

Thus, cement milk and compressed air are jetted from the jet nozzle 13 at a high pressure, so that the jet action region in the ground can be increased by vortex and cavitation generated by the jet jetted from the jet nozzle 13. Further, in the case where a fan-shaped solid body is formed by high-pressure jetting of cement milk from the injection nozzle 13 while the injection rod 1 is swung, the thickness of the solidified body in the vicinity of the injection nozzle 13 is usually reduced. According to the present invention, since the ground around the injection rod 1 is also liquefied, the cement milk jetted from the injection nozzle 13 is mixed with the liquefied ground, and the width of the solidified body around the injection rod 1 is mixed. Can be made thicker. Since the waste mud mixed with the ground (soil, stone, etc.) and cement milk crushed by the jet flow jetted from the jet nozzle 13 is always discharged from between the injection rod 1 and the hole 15, the waste mud is It is sucked and processed directly by a vacuum car.

In the present embodiment, the pressure of the cement milk sprayed from the spray nozzle 13 is 40 MPa, but is not limited thereto, and is 20-50 MPa.
You may make it eject with the pressure of. Further, the injection rod 1 is swung by 30 degrees to form a fan-shaped solid body in the ground. However, the present invention is not limited to this, and a wall-like rotary body may be formed without rotating the injection rod 1. The fan-shaped solid body may be formed by rotating the angle. Alternatively, the injection rod 1 may be rotated 360 degrees to form a circular solid body in the ground.

  In S6, the injection rod 1 is pulled up by a predetermined length (for example, 10 cm or less (preferably 5 cm)) in a state where the injection rod 1 is swung by 30 degrees in S5. Specifically, the injection rod 1 is pulled up by a predetermined length by moving the holding portion 18 (upper holding portion 18) of the working machine 2 holding the injection rod 1 upward. When the injection rod 1 is pulled up by a predetermined length, the process proceeds to S7. Here, one process of S5 and S6 is combined to constitute “one step”.

In S7, it is determined whether the injection is finished. Specifically, a predetermined step is executed, and it is determined whether cement milk and compressed air are no longer sprayed from the spray nozzle 13. If “NO” is determined in S7, the process proceeds to S5. In S5, cement milk and compressed air are injected from the injection nozzle 13 while the injection rod 1 is swung counterclockwise from the state in which the injection rod 1 is pulled up (the previous state of S6). Then, when the injection rod 1 swings 30 degrees counterclockwise, the process proceeds to S6. Thus, until the injection from the injection nozzle 13 is completed, S5 (clockwise swing injection) → S6 (injection rod pulling up) → S5 (counterclockwise swing injection) → S6 (injection rod pulling up) → S5 (clockwise swinging injection) → S6 (pouring rod pulling up) is repeated. If a predetermined step is executed in S7 and it is determined that the injection is completed, the process proceeds to S8. The cement milk injection and air injection from the injection nozzle 13 executed in S5 are performed by a worker operating a cement milk injection pressure setting switch (not shown) and an air injection pressure setting switch (not shown). To finish. Specifically, the operation is terminated when the operator operates the injection pressure of the cement milk injection pressure setting switch (not shown) and the air injection pressure setting switch (not shown) to be “0”. Here, in the present embodiment, for convenience of explanation, it has been described that the air injection pressure of the air injection port 105 and the injection nozzle 13 is adjusted by one air injection pressure switch. Corresponding to the air injection pressure switch.

  In S <b> 8, the injection rod 1 is pulled up from the hole 15 by a crane (not shown). Specifically, the injection rod 1 inserted into the hole 15 is pulled up by a crane and extracted from the hole 15. By doing in this way, a solidified body as shown in FIG. 8 is formed.

The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

Hereinafter, modifications of the present invention will be described.
(1) In this embodiment, cement milk and compressed air are injected from the injection nozzle 13 at a high pressure. However, the present invention is not limited thereto, and compressed air is not injected from the injection nozzle 13 and only cement milk is injected at a high pressure. May be.

(2) In this embodiment, when the injection rod 1 is oscillated, the injection rod 1 is first oscillated clockwise and then counterclockwise. The rod 1 may be swung counterclockwise and then swung clockwise.

(3) In the present embodiment, each process of S5 and S6 is combined into one step. However, the present invention is not limited to this, and a combination of processes executed by S5 and S6 a plurality of times is combined. It may be “one step”, and when the injection rod 1 is rotated, one rotation may be “1 step”, and a plurality of rotations may be “1 step”.

It is a figure which shows the construction condition of the underground solid body construction method in one Embodiment of this invention. It is a side view of the injection rod used for the underground solid body construction method. It is a figure which shows the front-end | tip part of the injection rod. It is a perspective view of the injection rod. It is a figure which shows the injection direction of the front-end | tip nozzle provided in the edge part of the injection rod. It is a figure which shows the condition where water is injected from the front-end | tip nozzle provided in the edge part of the injection rod. It is a flowchart which shows the construction procedure of the underground solid body construction method in one Embodiment of this invention. It is a figure which shows the construction condition of the underground solid body construction method in one Embodiment of this invention.

DESCRIPTION OF SYMBOLS 1 Injection rod 2 Working machine 3 Swivel 13 Nozzle 15 Drilling hole 14 Material liquid injection nozzle 17 Air injection port 101 peripheral side nozzle
102 Circumferential tip nozzle
103 Inner tip nozzle
104 Inner tip nozzle

Claims (3)

It is an underground solid body construction method of creating a solid body by high-pressure jetting of a curing material liquid from a spray nozzle provided on a side surface of an injection rod,
An insertion step of inserting an injection rod provided with a tip nozzle at the end to a predetermined depth of the target ground; and
An insertion injection step of high-pressure injection of a curing material liquid or liquid from the tip nozzle in the direction of the insertion side of the injection rod while rotating or swinging the injection rod in the insertion step;
A pulling step of pulling up the injection rod from the target ground,
A plurality of tip nozzles are provided at the tip of the injection rod;
A plurality of tip nozzles provided at the tip of the injection rod are provided on the periphery of the tip of the injection rod, and a peripheral tip nozzle that jets a curable material liquid or a liquid at a high pressure in a substantially inserting direction of the injection rod; An inner tip that is provided inside the circumferential tip nozzles and that injects the curable material liquid or liquid at a high pressure in a direction inclined with respect to the insertion direction of the injection rod and away from a line connecting the circumferential tip nozzles. An underground solid body construction method characterized by having a nozzle . Ground consolidation body Construction method of claim 1 Symbol placement can be changed injection pressure of curable material or liquid is high-pressure injection from the tip nozzle. The underground solid body formation apparatus which forms a solid body using the underground solid body construction method of Claim 1 or 2 .

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