JP2012122272A - Injection device for soil improvement - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable avoidance of bending deformation and eccentricity of an injection pipe and a decrease in the strength of the injection pipe, which are caused by a reaction force based on injection pressure, while sufficiently increasing drilling efficiency of a drilled wall surface by a jetted liquid.SOLUTION: A plurality of injection nozzles 10 are provided on an outer peripheral surface of a monitor mechanism 9 in such a manner that an injection port faces on the side of one of areas formed by circumferentially dividing the outer peripheral surface into two parts. The plurality of injection nozzles 10 are disposed in the state of being provided in line in an obliquely vertical direction. A rod centralizer 16 is provided to cover an outer periphery of an injection pipe 1 above the injection nozzle 10.

Description

  The present invention has a monitor mechanism provided with a solidifying material liquid injection nozzle and an air injection nozzle in the lower part, and an injection pipe having a rod centralizer is inserted above the monitor mechanism, and a swivel is provided above the injection pipe. Connected, supplying the solidified material liquid and air from the swivel at high pressure, continuously injecting the solidified material liquid from the solidified material liquid injection nozzle of the monitor mechanism through the injection pipe outward (for example, in the horizontal direction), The surrounding ground is excavated mainly by the injection power of the solidifying material liquid by continuously injecting air from the air injection nozzle around the solidifying material liquid injection nozzle and pulling it up from the ground while rotating the injection pipe. Further, the present invention relates to a ground improvement injecting apparatus for constructing a ground improvement body by injecting and stirring a solidifying material liquid into the excavation area.

  Conventionally, a soft ground improvement method for solidifying and improving a soft ground by high-pressure jet stirring of a solidifying material liquid is well known. In this soft ground improvement method, a swivel is connected to the upper part of the injection pipe having a monitoring mechanism at the lower part, this injection pipe is inserted from the ground to a predetermined depth in the ground, and then the swivel provided at the upper part of the injection pipe is solidified. Supply the solidified material liquid at high pressure from the material liquid supply port, continuously inject the solidified material liquid horizontally from the solidified material liquid injection nozzle of the monitor mechanism at the lower part of the injection tube, and pull it up while rotating the injection tube In this way, the ground around the ground is excavated by the jetting force (jet flow) of the solidified material liquid that is continuously sprayed, and the ground improved body is constructed by injecting and stirring the solidified material liquid into the excavated region.

  In this ground improvement method, injection of a double pipe in which the inner pipe 32 as shown in FIG. 13 becomes a solidified material liquid supply passage 34 and the space between the inner pipe 32 and the outer pipe 33 becomes an air supply passage 35. Tube 31 is used. The injection pipe 31 has a monitor mechanism 39 provided with a solidifying material liquid injection nozzle 41 and an air injection nozzle 42 for injecting air from the periphery of the solidifying material liquid injection nozzle 41 at the bottom. A swivel 36 provided with a solidifying material liquid supply port 37 and an air supply port 38 is connected to the upper portion of the injection pipe 31. The solidified material liquid supplied from the solidified material liquid supply port 37 of the swivel 36 is injected from the solidified material liquid injection nozzle 41 of the monitor mechanism 39 through the solidified material liquid supply passage 34 and simultaneously from the air supply port 38 of the swivel 36. The ground is improved by injecting the high-pressure supplied air from the air injection nozzle 42 around the solidified material liquid injection nozzle 41 through the air supply passage 35.

  Further, as shown in FIG. 14, the inside of the inner tube 32 becomes a supply passage 34 for the solidified material liquid, the water supply passage 43 becomes between the inner tube 32 and the intermediate tube 40, and the air between the intermediate tube 40 and the outer tube 33 becomes air. There is a ground improvement method using a triple-pipe injection pipe 45 serving as a supply passage 35. The injection pipe 45 is disposed at a lower portion of the solidification material liquid injection nozzle 41, an air injection nozzle 42 for injecting air from the periphery of the solidification material liquid injection nozzle 41, and a 180-degree symmetrical position above the solidification material liquid injection nozzle 41. It has a monitor mechanism 39 provided with a provided water jet nozzle 44. A swivel 36 having a solidifying material liquid supply port 37, an air supply port 38, and a water supply port 46 is connected to the upper portion of the injection pipe 45. The solidified material liquid supplied from the solidified material liquid supply port 37 of the swivel 36 is injected from the solidified material liquid injection nozzle 41 of the monitor mechanism 39 through the solidified material liquid supply passage 34 and simultaneously from the air supply port 38 of the swivel 36. Air supplied at high pressure is injected from the air injection nozzle 42 around the solidified material liquid injection nozzle 41 through the air supply passage 35, and water supplied at high pressure from the water supply port 46 of the swivel 36 is injected from the water injection nozzle 44. Thus, the ground is improved (for example, see Patent Document 1).

  Further, when the injection pipes 31 and 45 having the swivel 36 at the upper part and the monitor mechanism 39 at the lower part are inserted into the ground, water is supplied from the solidification liquid supply port 37 of the swivel 36 at a high pressure to supply the solidification liquid supply path. There are a case where the ground is drilled and inserted while discharging downward from the opening 47 at the tip of the monitor mechanism 39 via 34, and a case where the ground is drilled by a boring machine or the like and then inserted into this hole.

  And in the conventional monitoring mechanism of the injection pipe for ground improvement, there is one single-port solidified material liquid injection nozzle, and there are two single-port solidified material liquid injection nozzles arranged at 180 ° symmetrical positions. There are one and one single-portion solidifying liquid jet nozzle, and one water jet nozzle is provided on the opposite side of 180 degrees above the solidified liquid jet nozzle.

JP 2000-091026 A

  However, the monitoring mechanism of the conventional ground improvement injecting device is such that the solidifying material liquid is sprayed horizontally and continuously from the solidifying material liquid injection nozzle of the monitoring mechanism at the lower part of the injection tube to the outside of the tube and the injection tube is rotated. The ground is improved by excavating the wall surface of the hole in the ground with the injection pressure of the solidifying material liquid, and the ground is improved by the injection of the solidifying material liquid. There has been a disadvantage of bending deformation and eccentricity due to the reaction force accompanying the injection force. In addition, there is a disadvantage that the magnitude of the reaction force is biased or the strength of the injection tube is deteriorated due to repeated bending deformation.

  On the other hand, in order to avoid bending deformation and eccentricity of the injection tube, the plurality of injection nozzles of the monitoring mechanism are arranged at symmetrical positions in the circumferential direction (for example, two half-circumferences obtained by dividing the circumference by 180 degrees). It is also conceivable that the nozzle diameter and the supply pressure of the solidifying material liquid are appropriately adjusted so that the injection reaction force is approximated at each position in the circumferential direction. However, separately providing the injection nozzles at the symmetric position causes an increase in cost, and further causes a decrease in the injection pressure at each injection nozzle, resulting in inconvenience that the drilling efficiency of the hole wall surface is deteriorated. Moreover, when adjusting the injection nozzle diameter and the supply pressure of the solidifying material liquid for each injection nozzle, the adjustment equipment cost and the maintenance cost become enormous.

  The present invention has been made paying attention to such conventional disadvantages, and the object of the present invention is a position where the injection nozzle is deviated from the center of the injection pipe in spite of the small number of injection nozzles (described above). Even if it is provided in the half-circumferential part), the injection tube is sufficiently deformed and deformed based on the reaction force based on the injection pressure, eccentricity, and further the strength of the injection tube, while sufficiently increasing the drilling efficiency of the hole wall surface by the injection liquid. An object of the present invention is to provide an injection device for ground improvement capable of avoiding deterioration.

  In order to achieve the above-mentioned object, the ground improvement injection device according to the present invention has a monitor mechanism provided with an injection nozzle at the lower part, and the injection nozzle of the monitor mechanism is located at the center of the solidified liquid injection nozzle. In addition, an air injection nozzle is provided concentrically on the outside in the form of a double nozzle, and an injection tube in which air can be simultaneously injected in the same direction around the solidified material liquid injected from the solidified material liquid injection nozzle. The injection nozzle of the monitoring mechanism of the injection tube has a plurality of nozzles arranged in a slanting direction at a predetermined interval on one of the circumferential surfaces divided into two in the circumferential direction. A lot centralizer is provided around the tube to prevent bending and eccentricity of the injection tube due to the reaction force of the injection pressure generated by the injection of the solidified material liquid and air from the injection nozzle.

  With this configuration, a synergistic effect of the drilling and stirring function of the ground (hole drilling wall surface) by the jet fluid jetted from each jet nozzle can be obtained, and the monitor can be used when the jet fluid is jetted by rotating the injection pipe. Since the injection from the injection port below the mechanism precedes the injection from the upper injection port that is delayed in the rotation direction, the injection fluid excavates the hole surface of the ground efficiently and sequentially with a time difference. In order to agitate the earth and sand, the efficiency of agitation of the solidifying material liquid and earth and sand is improved, and for example, it is possible to cope with the use of an injection pipe having a small diameter rather than the case where the injection nozzles are arranged in the circumferential direction.

  A plurality of the injection nozzles are not provided on the entire peripheral surface of the monitor mechanism, but are provided on one of the substantially half peripheral surfaces of the monitor mechanism divided into two in the circumferential direction, so that the number of nozzles for injection can be reduced. The diameter can be increased and the injection distance can be increased, which allows the injection fluid with the desired high injection pressure or high injection flow rate to be concentrated on the hole surface, and the drilling efficiency of the hole surface In addition, the stirring efficiency of excavated earth and sand can be increased. Furthermore, by arranging the injection ports of the injection nozzle intensively on one side (half circumferential surface) of the monitor mechanism, the gun barrel of the injection nozzle can be lengthened, and the flow of the injection fluid can be smoothed and stabilized. Further, the oblique arrangement of each injection nozzle makes it easy for the excavated earth and sand flow to escape into the solidified material liquid opposite to the direction of rotation of the injection pipe, thereby improving the excavation efficiency by injection.

  On the other hand, the lot centralizer provided immediately above the monitor mechanism is close to or in contact with the wall surface of the drilling hole in the ground where the outer periphery is excavated. For this reason, even if the injection tube receives jetting reaction force when jetting the solidified material liquid from the jet nozzle at a position deviated in the circumferential direction, the amount touched by the lot centralizer is affected by the drilling wall. Since the amount is restricted, the injection tube is slightly deformed and is not deformed or decentered.

In the ground improvement injection device according to the present invention, a plurality of injection nozzles arranged in a diagonal direction at predetermined intervals on the monitor mechanism are provided so that the central axes of the injection directions are parallel to each other. Features.
With this configuration, the jet fluid can be applied uniformly to a predetermined region of the hole wall surface, and the efficiency of excavation of the hole wall surface and stirring of the excavated earth and sand can be improved.

Further, in the ground improvement injection device according to the present invention, the plurality of injection nozzles arranged in the oblique direction at predetermined intervals on the monitor mechanism are inclined in the range of 45 to 70 degrees upward from the direction orthogonal to the injection pipe. It is characterized by being arranged in line.
With this configuration, it is possible to optimize the excavation efficiency with respect to the jet fluid drilling wall surface, and to avoid a significant decrease in excavation efficiency that occurs in the range of 0 to 45 degrees or 70 to 90 degrees.

The ground improvement injection device according to the present invention is characterized in that the plurality of injection nozzles arranged in the diagonal direction at predetermined intervals on the monitor mechanism are provided with the injection angle obliquely downward from the horizontal direction. To do.
With this configuration, there is an effect of directing the flow of the excavated waste mud downwards after the excavation, and the recirculation of the fluid in the drilling hole is smoothed to further improve the excavation efficiency. Further, it is possible to avoid that the excavated earth and sand smoothly escape downward by fluid injection from a plurality of injection positions, and the excavated earth and sand prevent the injection of the injection fluid from other injection nozzles.

The ground improvement injecting apparatus according to the present invention is characterized in that the lot centralizer is rotatably provided to the injecting tube.
With this configuration, the reaction force received by the injection pipe with the injection pressure of the injection fluid from the injection nozzle is received by the lot centralizer that is in contact with the inner wall of the drilling hole, thereby preventing the injection pipe from being bent and deformed and eccentric. Can do. In this case, since the lot centralizer is rotatable around the injection tube, the lot centralizer does not follow the rotation of the injection tube. For this reason, when the lot centralizer is pulled up as the injection tube rotates and rises, it is possible to suppress the occurrence of miso-scrubbing movement of the lot centralizer, and thereby drilling holes due to interference with the lot centralizer. Wall damage can be avoided.

Specifically, in the ground improvement injection device according to the present invention, a swivel is connected to an upper portion of the injection pipe, and the injection pipe is a double pipe of an inner pipe and an outer pipe. The solidified material liquid supply passage, between the inner tube and the outer tube is an air supply passage. The solidified material liquid supply passage communicates with the solidification material liquid injection nozzle of the monitor mechanism, and the air supply passage communicates with the air injection nozzle. The solidified material liquid and air supplied from the shiw swivel are supplied to the spray nozzles through the respective supply passages.
With this configuration, the solidifying material liquid and the air can be ejected by a single injection tube and a monitoring mechanism.

  According to the present invention, the drilling efficiency of the drilling wall surface by the jet fluid from the jet nozzle can be greatly improved, and the reaction force generated based on the jet pressure of the jet fluid bends, deforms, and decenters the injection pipe. Therefore, it is possible to effectively prevent the deterioration of the strength of the injection tube.

  The present invention has been briefly described above. Further, the best mode for carrying out the invention described below will be described in detail with reference to the accompanying drawings.

It is a longitudinal cross-sectional view which shows the injection apparatus for ground improvement by embodiment of this invention. It is the sectional view on the AA line in FIG. It is explanatory drawing which shows the monitor mechanism in this invention. It is explanatory drawing which shows another monitor mechanism in this invention. It is explanatory drawing which shows the example of arrangement | positioning of the injection nozzle installed in the monitor mechanism in this invention. It is explanatory drawing which shows the excavation condition of the hole wall surface by the monitor mechanism of the injection apparatus for ground improvement by this invention. It is sectional drawing which shows the lot centralizer in FIG. It is sectional drawing which shows another lot centralizer in FIG. It is explanatory drawing which shows the reaction force support effect | action of the lot centralizer in FIG. It is the perspective view (a) which shows another lot centralizer, and its fragmentary sectional view (b). It is a perspective view which shows another lot centralizer. It is explanatory drawing which shows the execution procedure of the ground improvement by the injection apparatus for ground improvement in this invention. It is sectional drawing which shows the conventional injection pipe for ground improvement. It is sectional drawing which shows the injection pipe for other conventional ground improvement.

  Hereinafter, an injection device for ground improvement according to an embodiment of the present invention will be described with reference to FIGS. 1 to 9.

FIG. 1 shows a ground improvement injection pipe 1 (sometimes simply referred to as an injection pipe) having a swivel 6 connected to the upper part and a monitor mechanism 9 on the lower part. The ground improvement injection pipe 1 is formed of a double pipe of an inner pipe 2 and an outer pipe 3, the inside pipe 2 serves as a supply passage 4 for the solidified material liquid, and the space between the inner pipe 2 and the outer pipe 3 is air. A supply passage 5 is provided.
The swivel 6 includes a solidification material liquid supply port 7 and an air supply port 8. The solidification material liquid supply port 7 communicates with the solidification material liquid supply passage 4 of the injection pipe 1 through a passage 7 a, and is supplied with air. The supply port 8 communicates with the air supply passage 5 of the injection pipe 1 through the passage 8a.

  The monitor mechanism 9 is provided with an injection nozzle 10. The injection nozzle 10 of the monitor mechanism 9 has a solidifying material liquid injection nozzle 11 located at the center, and an air injection nozzle 12 is provided concentrically in the form of a double nozzle on the outside thereof, and is injected from the solidification material liquid injection nozzle 11. The air can be simultaneously jetted around the solidifying material liquid in the same direction. The solidified material liquid injection nozzle 11 communicates with the solidified material liquid supply passage 4 of the injection tube 1, and the air injection nozzle 12 communicates with the air supply passage 5 of the injection tube 1 through the solidified material liquid supply port 7 of the swivel 6. The solidified material liquid supplied at high pressure can be injected from the solidified material liquid injection nozzle 11 through the solidified material liquid supply passage 4 of the injection tube 1, and the air supplied at high pressure from the air supply port 8 of the swivel 6 is supplied to the injection tube 1. The air can be jetted from the air jet nozzle 12 through the air supply passage 5.

  FIG. 3 shows a case where three injection nozzles 10 including a solidifying material liquid injection nozzle 11 and an air injection nozzle 12 are juxtaposed in the circumferential direction of the monitor mechanism 9. Specifically, the injection nozzle 10 is provided so that the injection port faces one area side of an area where the outer peripheral surface of the monitor mechanism 9 is divided into two in the circumferential direction. Three spray nozzles 10 are arranged in an oblique direction on the outer peripheral surface of the one region at a predetermined interval. Here, since the injection port is provided so as to face the one region side, the injection nozzle 10 can be extended to the opposite side of the injection port as shown in FIG. Thereby, the injection of the solidifying material liquid can be stabilized or the injection distance can be extended as will be described later.

  FIG. 4 shows a case where four injection nozzles 10 including the solidifying material liquid injection nozzle 11 and the air injection nozzle 12 are arranged in parallel in the circumferential direction of the monitor mechanism 9. Specifically, the injection nozzle 10 is provided so that the injection port faces one area side of an area where the outer peripheral surface of the monitor mechanism 9 is divided into two in the circumferential direction. Four spray nozzles 10 are arranged in an oblique direction on the outer peripheral surface of the one region at a predetermined interval. The three or four injection nozzles 10 shown in FIG. 3 and FIG. 4 inject the solidifying material liquid and air injected from different height positions in the circumferential direction of the injection pipe 1 onto the ground wall surface. By doing so, the area | region of the predetermined width according to the number of injection nozzles can be excavated efficiently.

  Thus, the injection nozzle 10 installed so that the injection port faces one area of the monitor mechanism 9 is arranged obliquely in the vertical direction, thereby reducing the number of injection nozzles 10 with respect to the monitor mechanism 9. Therefore, the solidified material liquid and the air jet fluid can be made to act strongly on the hole wall surface with a small jetting loss even though the same pumping capacity is used. Further, for example, the drilling wall surface can be efficiently excavated using “the number of injection ports−1” of the injection nozzle 10 as an excavation surface.

  Further, the injection nozzle 10 composed of the solidifying material liquid injection nozzle 11 and the air injection nozzle 12 is arranged such that the injection port faces one side of the area where the outer peripheral surface of the monitor mechanism 9 is divided into two in the circumferential direction. In the case where it is provided, the diameter of the injection nozzle 10 can be increased as compared with the case where the injection port is provided so as to face both of the two divided areas, and the solidified liquid and air injection effective distance can be increased. Can be stretched. In addition, for example, four small-size solidifying material liquid injection nozzles 11 and four air injection nozzles 12 are provided, and three large-diameter solidifying material liquid injection nozzles 11 and three air injection nozzles 12 are provided. In some cases, each solidifying material liquid and each air can be sprayed to the same amount.

  Although the injection nozzles 10 are spaced at regular intervals, they are arranged obliquely in the axial direction (vertical direction) of the injection tube 1 and from the injection nozzle 10 at the lowest position in the rotation direction of the injection tube 1. Since the jetting fluid is jetted from the jet nozzles 10 obliquely above the jetting hole 10 in order of jetting of the jetting fluid in advance, the jetting fluid is jetted from the lower side to the upper side of the borehole wall surface. Will go. Therefore, the excavated earth and sand and the solidified material liquid can be excavated without affecting the jet flow of the jet fluid.

  In this case, the earth and sand mixed by the excavating fluid composed of the solidified material liquid and air by excavation easily settles on the bottom side of the drilling hole, and the sand particles in the excess liquid rising to the ground can be reduced. In addition, as shown in FIG. 5A, as the inclined arrangement of the injection nozzles 10 in the monitor mechanism 9, a line L1 connecting the centers of, for example, three injection nozzles 10 arranged in an inclination form an imaginary horizontal line L2. The angle is set to 60 degrees, as shown in FIG. 5B, the vertical interval L3 and the diameter of each of the injection nozzles 10 are increased, and as shown in FIG. It is conceivable that the angle formed by the line L4 connecting the centers with the imaginary horizontal line L5 is 45 degrees and the vertical distance and diameter of the injection nozzle 10 are further increased.

  Further, in the present invention, the total length (cannon) of the injection nozzle 10 can be increased by providing the injection port of the injection nozzle 10 so as to face the half region of the outer periphery of the monitor mechanism 9. As a result, the ejection distance of the ejection fluid can be extended, and the ejection fluid can be rectified and stabilized. In addition, since the number of the injection nozzles 10 is less than the case where the injection nozzles of the injection nozzles 10 are desired on the entire peripheral surface of the monitor mechanism 9, the diameter of the injection nozzles or the injection distances are increased accordingly. In this case, the desired injection pressure can be obtained. If the injection flow rate and the injection distance are not increased, it is possible to reduce the size and capacity of the injection fluid or air supply pump. In this case, the central injection nozzle 10 out of the injection nozzles 10 arranged obliquely below is supported by the injection flow by the injection nozzles obliquely above and obliquely below, so that the reach distance can be further extended, and the excavation efficiency is increased. Can be raised.

  FIG. 6 shows a structure in which a lot centralizer 16 is mounted on the outer periphery of the injection tube 1 so as to be located immediately above the injection monitor 9. The lot centralizer 16 is entered so as to be in contact with the inner peripheral surface of the hole 27 of the ground 26 with a slight gap. In addition, the injection nozzle 10 in the monitor mechanism 9 during the excavation work receives a reaction force generated when the injection fluid is ejected, thereby functioning to prevent the injection tube 1 from being bent and deformed. For example, as shown in FIG. 7, the lot centralizer 16 has a cylindrical shape as a whole, the cylindrical portion 16a, and a fixing portion 16b for fixing the upper end and the lower end of the cylindrical portion 16a to the peripheral surface of the injection tube 1. 16c. The fixed portion 16b has a conical shape, and is provided with a plurality of notches 17 communicating with the inside and outside of the cylindrical portion 16a.

  The fixed portion 16c is also provided with a plurality of notches 18 communicating with the inside and outside of the cylindrical portion 16a. These notches 17, 18 can freely move the solidified material liquid and the excavated earth and sand particles in the ascending / descending direction of the lot centralizer 16 when the injection tube 1 enters the hole 27 and is pulled up to the ground. It is a flow passage. The size and strength of the lot centralizer 16 are designed on the basis of a predetermined size relating to a hole size and a hole wall corresponding to the reaction force.

  When the outer diameter of the injection tube 1 is 90 mm, for example, the outer diameter of the lot centralizer 16 is 150 to 200 mm. When the monitor mechanism 9 has three injection nozzles 10 provided obliquely as described above, the reaction force acting on the injection tube 1 can be suppressed to 60 kg or less, and the lot centralizer 16 Can sufficiently and safely receive this reaction force, and as a result, bending deformation and eccentricity of the injection tube 1 can be avoided.

  FIG. 8 shows another lot centralizer 16A. The lot centralizer 16A is mounted so as to be horizontally rotatable via bearings 19 and 20 mounted at two locations on the upper and lower sides of the outer periphery of the injection tube 1. For this reason, one metal of the bearings 19 and 20 is fixed to the upper and lower two places on the outer periphery of the column fitting pipe 1 by welding or the like, and the other metal is fixed to the fixing portions 16b and 16d at the upper and lower ends of the lot centralizer 16A by welding or the like. Has been. The lot centralizer 16A is supported by the bearings 19 and 20 so as to be rotatable around the injection pipe 1 immediately above the monitor mechanism 9. The fixed portion 16d has a conical shape as a whole like the fixed portion 16b, and a plurality of notches 18 are formed in the conical shape.

  The injection tube 1 having the lot centralizer 16 shown in FIG. 7 receives the injection pressure of the injection fluid from the injection nozzle 10 as shown in FIG. A reaction force in a direction P opposite to the injection direction S of the injection fluid injected from the injection nozzle 10 is received. For this reason, the lower part of the injection tube 1 tends to bend, deform and decenter in the direction of the arrow Q. However, the deformation and eccentricity in the direction of the arrow Q are regulated by the lot centralizer contacting (interfering) with the wall surface of the drilled hole. Therefore, the deformation and eccentricity of the injection tube 1 can be reliably prevented.

  On the other hand, during the rotation of the injection tube 1, there is a case where a subtle taste-entraining movement of the lot centralizer 16 due to the rotation of the injection tube 1 is caused by the bending deformation and eccentricity of the injection tube 1. In this case, as shown in FIG. 8, a rotary centralizer 16 </ b> A that is rotatable around bearings 19 and 20 is attached around the injection tube 1. As a result, the rotary lot centralizer 16A becomes free with respect to the rotation of the injection tube 1, and therefore does not cause rotational friction with the hole wall surface. As a result, the lot centralizer 16A does not perform the taste bud exercise. Further, the lot centralizer 16A is not forcibly rotated together with the injection tube 1.

  The lot centralizer is not limited to the above embodiment. The injection nozzle 10 is provided so that the injection port faces one area side of the area where the outer peripheral surface of the monitor mechanism 9 is divided into two in the circumferential direction. When liquid and air) are injected, the injection tube 1 is bent and deformed by the reaction force of the injection pressure, or the injection tube 1 is eccentric with respect to the drilling hole. The lot centralizer prevents such deformation and eccentricity of the injection tube 1. Therefore, the lot centralizer may be configured to prevent the deformation and eccentricity of the injection tube 1 due to the reaction force of the injection pressure generated by the injection of the solidified material liquid and air from the injection nozzle 10. For example, a reaction force receiver fixed in the other region other than one region where the cylindrical ring 16B as shown in FIGS. 10 (a) and 10 (b) and the injection nozzle 10 as shown in FIG. 11 are provided. The board 16C etc. can be illustrated. The cylindrical ring 16B may be fixed or rotating with respect to the injection tube 1, but it is preferable that the cylindrical ring 16B is rotatable as shown in FIG. 10B.

  Further, as described above, the plurality of injection nozzles arranged in the oblique direction at a predetermined interval on the peripheral surface of the monitor mechanism, the direction of the injection ports (injection angle) is set from the horizontal direction as indicated by an arrow R in FIG. It can also be directed diagonally downward. In this case, the excavation surface is inclined, so that the excavated soil and the solidified material liquid flow downward and the flow after excavation becomes smooth. In addition, sand having a high specific gravity among the earth and sand mixed with the solidified material liquid after excavation is likely to settle at the bottom of the drilling hole, and the earth and sand particles in the excess liquid rising to the ground part can be reduced.

Next, a procedure for improving the ground using the injection tube 1 according to the embodiment will be described with reference to FIG.
First, an example of the construction device 22 used in this ground improvement method will be described. The construction apparatus 22 includes a leader 23. A slide plate 24 is slidable (movable forward and backward) along the reader 23, and a drill head 25 is fixed to the slide plate 24. A feeding device (not shown) is connected to 24 so that it can move forward and backward along the reader 23. A ground improvement injection pipe 1 having a monitor mechanism 9 in the lower part is attached to a drill head 25, and the injection pipe 1 can be rotated by driving the drill head 25. Since the head 25 is fixed, the injection tube 1 can be advanced and retracted together with the drill head 25 by advancing and retracting the slide plate 24 along the leader 23 with a feeding device (not shown). Examples of the feeding device include a cylinder or a chain that is suspended and driven by sprockets provided at the upper end or the lower end of the leader 23.

  Therefore, first, as shown in FIG. 12A, the injection pipe 1 is attached to the drill head 25 of the construction apparatus 22, and the construction apparatus 22 is set at a position where the ground is improved. A swivel 6 is connected to the upper portion of the injection tube 1 at this time. Next, as shown in FIG. 12 (b), the injection tube 1 is inserted up to a predetermined depth of the ground at a position where the ground is improved. The injection tube 1 is inserted into the ground by supplying high-pressure water from the solidifying material liquid supply port 7 of the swivel 6 and discharging it downward from the opening 13 at the tip of the monitor mechanism 9 through the solidifying material liquid supply passage 4. Drill the ground and insert it, or drill in advance with a boring machine and insert it into the hole. When the injection tube 1 is inserted by the former method, after reaching a predetermined depth, the ball 15 is introduced from the solidified material liquid supply passage 4 to close the opening 13 (see FIG. 1). Reference numeral 14 denotes a check valve.

Next, as shown in FIG. 12 (c), the solidified material liquid and air are supplied from the swivel 6 at a high pressure, and the solidified material liquid and air are injected from the solidified material liquid injection nozzle 11 and the air injection nozzle 12 of the monitor mechanism 9 at the lower end of the injection pipe 1. While injecting air, the injection tube 1 is rotated and pulled up. Then, the injection force of the solidified material liquid and air collides with the hole wall surface of the surrounding ground, excavates the surrounding ground, the excavation area is filled with the injected solidified material liquid, and the ground improvement body 21 is built. Accordingly, as shown in FIGS. 12C to 12D, the ground improvement body 21 is constructed from the lower side to the upper side as the injection pipe 1 is pulled up. FIG.12 (d) has shown a mode that the injection pipe 1 was pulled up on the ground and the ground improvement body 21 was built in the predetermined area of the ground.

  As for the supply of the solidified material liquid and the air, the construction device 22 includes pumps (not shown) for supplying the solidified material liquid and the air, and each pump is connected to the solidified material liquid supply port 7 of the swivel 6 and the air by a pipe. It is connected to the supply port 8. Accordingly, the solidified material liquid is supplied at a high pressure from the solidified material liquid supply port 7 of the swivel 6, and is injected from the solidified material liquid injection nozzle 11 through the passage 7 a and the solidified material liquid supply passage 4, and the air is supplied to the swivel 6. High pressure is supplied from the port 8, and the air is injected from the air injection nozzle 12 through the passage 8 a and the air supply passage 5.

  As described above, in the present embodiment, a plurality of injection nozzles 10 are provided on the outer peripheral surface of the monitor mechanism 9 so that the injection ports face one side of the region obtained by dividing the outer peripheral surface into two in the circumferential direction. The plurality of injection nozzles 10 are arranged so as to be arranged in an oblique vertical direction, and the lot centralizer 16 is provided so as to cover the outer periphery of the injection pipe 1 above the injection nozzle 10, thereby reducing the number of injection nozzles. In spite of being ten, even if the injection nozzle 10 is provided at a position deviating from the center of the injection tube 1 (the half-circumferential portion), the hole cutting efficiency of the hole wall surface by the injection liquid can be greatly improved. The bending deformation of the injection tube 1 based on the reaction force generated by the injection pressure can be prevented, and thus the strength of the injection tube can be deteriorated.

  The present invention can greatly improve the drilling efficiency of the drilling wall surface by the jet fluid from the jet nozzle, and can prevent the reaction force generated based on the jet pressure of the jet fluid from bending and deforming the injection pipe. It is useful when excavating the wall surface of the hole with the injection force of the solidifying material liquid, and injecting and stirring the solidifying material liquid into the excavation basin to build a ground improvement body.

DESCRIPTION OF SYMBOLS 1 Injection pipe 2 Inner pipe 3 Outer pipe 6 Swivel 9 Monitor mechanism 10 Injection nozzle 11 Solidification material liquid injection valve 12 Air injection valve 16, 16A, 16B, 16C Lot Centralizer

Claims (5)

It has a monitor mechanism provided with an injection nozzle at the bottom, the injection nozzle of the monitor mechanism is located at the center of the solidified material liquid injection nozzle, and the air injection nozzle is concentrically provided in the form of a double nozzle outside. , An injection pipe in which air can be jetted simultaneously in the same direction around the solidified liquid jetted from the solidified liquid jet
The injection nozzles of the injection pipe monitoring mechanism are arranged in a slanting direction at a predetermined interval on one of the half circumferential surfaces of which the circumferential surface is divided into two in the circumferential direction, and the injection nozzles above the injection nozzles An injection device for ground improvement is provided with a lot centralizer for preventing bending and eccentricity of the injection tube due to the reaction force of the injection pressure generated by injection of the solidified material liquid and air from the injection nozzle. .   2. The ground improvement injection device according to claim 1, wherein a plurality of injection nozzles arranged in an oblique direction at predetermined intervals on the monitor mechanism are provided such that central axes in the injection direction are parallel to each other.   The plurality of injection nozzles arranged in an oblique direction at predetermined intervals on the monitor mechanism are arranged obliquely in a range of 45 to 70 degrees upward from a direction orthogonal to the injection pipe. The injection device for ground improvement according to 1 or 2.   4. A plurality of spray nozzles arranged in a diagonal direction at a predetermined interval on a peripheral surface of the monitor mechanism are provided with a spray angle obliquely downward from a horizontal direction. An injection device for ground improvement as described in 1.   2. The ground improvement injection device according to claim 1, wherein the lot centralizer is provided so as to be rotatable with respect to the injection pipe.

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