JP4313773B2 - Ground hardening material injection method and its equipment - Google Patents

Description

  The present invention makes it possible to support the strengthening support of the foundation foundation ground, or the ground hardening material injection method that injects the ground hardening material into the target ground for the purpose of stabilizing the ground or stopping the water, especially the liquefaction prevention ground. The present invention relates to a ground hardening material injection method and its apparatus.

  Conventionally, ground hardener injection for ground lining support, reinforcement support, or hardener layer construction for the purpose of water stoppage has been achieved by extending the reach of the hardener jet as much as possible to form a large diameter hardener layer. Various methods have been devised with ideal creation, and one of them is a method of extending the reach distance by encapsulating and protecting the hardener jet with air using a polymerization injection nozzle consisting of a core nozzle and an annular nozzle surrounding it. (See, for example, Patent Document 1).

  Prior to the hardening material jet, prior improvement by clear water injection is performed, the effective range of the hardening material jet is extended (for example, see Patent Document 2), or surplus slime is sucked by a suction mechanism (for example, see Patent Document 3). Means for improving breathing have been taken.

  Furthermore, as a ground improvement method corresponding to liquefaction prevention, the ground is consolidated to the appropriate depth in the form of a grid, belt, or other appropriate plane to create a composite ground of consolidated and unconsolidated parts (for example, patents) Means for dealing with the liquefaction phenomenon have been proposed.

Further, an injection rod that keeps the balance by mutually injecting in the left and right directions with the injection ports facing away from each other is illustrated in Patent Document 5 and the like.
Japanese Examined Patent Publication No. 7-100931 Japanese Patent No. 2865653 Japanese Patent Publication No. 6-29506 Japanese Patent Laid-Open No. 61-5114 Japanese Patent Publication No. 4-52333

  However, simply injecting ground hardener at the same density to create a hardened layer and increasing the injection density cannot cope with cracks in the hardened layer and liquefaction caused by loads applied from multiple directions such as earthquakes and construction vibrations. is there.

  In addition, if the injection pressure is increased to increase the injection density, it will be dangerous, and it may cause an unnatural load on the ground and cause phenomena such as ground uplift. It becomes necessary and becomes a big burden economically.

  For loads applied from multiple directions, such as earthquakes and construction vibrations, it is proposed in Patent Document 4 to form a composite ground by solidifying the ground into a lattice or band. There is a problem that there is no correspondence in the horizontal direction due to the correspondence by the partition wall in the direction, the unconsolidated portion is natural ground, and the saturation is not necessarily lowered sufficiently.

  Furthermore, since the diameter of the conventional injection rod is the same from the top to the tip, there is no room for clearance between the rod insertion hole of the ground and the outer periphery of the rod. The pressure was consumed more than necessary.

In order to solve this in response to the above-mentioned problem, the present invention inserts an injection rod provided with a pair or a plurality of pairs of superposition jet nozzles set so that the jet ports face each other back to a predetermined depth of the target ground, Forming a plate-like hardener injection layer by raising the high pressure ground hardener from the core of the polymerization jet nozzle at a predetermined depth and raising it to a predetermined position while rotating the injection rod while jetting air from the surrounding portion, From the predetermined position, the rotation operation is stopped, and it is simply raised to the next predetermined position to form a partition-like hardened material injection layer that is partitioned in the vertical direction, and the injection rod is rotated and raised from the next predetermined position. In this way, a continuous cell structure is formed by partition walls that partition the space between the upper and lower plates and the simple ascending section by alternately repeating the rotation and simple ascent.

In other words, by forming the continuous cell structure by the upper and lower panels and the partition walls alternately by alternately rotating and raising the injection tube rod, the composite structure of the ground is formed not only in the vertical direction but also in the horizontal direction. The soil is desaturated with respect to loads applied from multiple directions.

In addition, a plurality of injection rods set at adjacent positions simultaneously perform injection that alternately repeats a rotational rise and a simple rise, and the adjacent upper and lower plates and the tips of the partition walls cross each other to form an enclosed cell structure. In addition, the amount of jet air was increased during simple ascending injection so that air was enclosed in the enclosed cell structure to increase the degree of unsaturation of the ground.

For the injection tube rod, the injection port of the polymerization injection nozzle that superimposes the injection port that communicates with the air pressure storage part set in the air supply path and the injection port that communicates with the curing material flow channel is opposed to the side wall of the injection rod. A pair or a plurality of pairs are set, and the disc body is formed by rotational injection, and the partition wall is formed by simple ascending injection.

In addition, a rectangular outer shell is set on the outer surface of the injection rod at predetermined intervals, and the outer surface of a plurality of set outer shells is configured to form a prismatic rod as a whole. A clearance is generated between the hole and the outer periphery of the rod, and at the time of switching to simple ascent, the angle position at which the injection tube rods mutually cross-join with the tip of the partition wall formed by the injection tube rod at the adjacent position can be confirmed. I did it.

  Embodiments of the present invention will be described below with reference to the drawings. An injection rod 1 is composed of a triple tube as a whole, and includes a pair of polymerization injection nozzles 2 and 3 set with injection ports facing each other on the side wall of the tip, and another pair of polymerization injection nozzles 2a and 3a. The injection port is opened in a radial cross shape around the rod. Moreover, the fresh water injection nozzle 4 is provided in the upper part of these superposition | polymerization injection nozzles at predetermined intervals.

  The superposition spray nozzles 2, 3 and 2a, 3a surround the core nozzles 21 and 31, respectively, in the center and the surrounding nozzles 22 and 32 open, and each communicates with the spray material tank via the swivel 11. It communicates with a separated flow path in the rod.

  The setting of the superposition jet nozzles 2, 3 and 2a, 3a and the fresh water jet nozzle 4 is performed on the monitor portion A which forms the tip of the rod through the tapered base E and incorporates the injection mechanism, and the outer diameter is square. It is formed in a shape and is configured to have a larger diameter than the outer diameter of the upper rod main pipe B, and a clearance is formed between the inner wall of the rod main pipe B and the insertion hole C by insertion excavation of the monitor portion.

  Further, the injection rod 1 is provided with a rectangular outer shell body 16 having the same outer diameter as that of the monitor portion A at predetermined intervals on the outer surface portion thereof, and the outer surfaces of the set outer shell bodies are entirely arranged. As a prismatic rod. Note that the outer diameter of the monitor part A does not necessarily have to be a square shape.

  As described above, the rod 1 is composed of a triple tube as a whole, an air supply path 12 at the center thereof, an annular hardener flow path 13 at the outer periphery thereof, and a fresh water flow path 14 at the outer periphery thereof. An air pressure storage unit 5 such as a receiver tank is set at a terminal of the air supply path 12 via a check valve 51.

  The air pressure storage unit 5 is provided with air flow passages 52 communicating with the surrounding nozzles 22 and 32 that open to the nozzles 2, 3, 2 a, and 3 a, respectively, and each is provided with a check valve 53. Backflow from the peripheral nozzles 22 and 32 is prevented.

  By configuring the air accumulator 5 in this way, air corresponding to the accumulated pressure in the accumulator tank is uniformly supplied without flowing back into the flow path 52, so that injection efficiency close to atmospheric pressure can be obtained. A smooth airlift effect can also be obtained for the lifting of slime.

  The fresh water flow path 14 is configured with an outermost clearance and opens to the fresh water injection nozzle 4 in the middle, but passes through the opening of the hardened material flow path 13 and the outer gap of the air pressure storage section 5 and the tip of the rod 1. The differential pressure valve 51 set in the ejection hole 15 is opened and closed by adjusting the fresh water supply pressure.

  The differential pressure valve 51 is urged upward by a spring 42 and normally opens the ejection hole 15, so that the drilling water is ejected from the ejection hole 15 while being drilled down, and when a predetermined depth is reached, the fresh water supply pressure is increased. When the pressure rises above a certain level, the pressure drops against the urging force of the spring 42 and closes the ejection hole 15.

  In addition, air is supplied to the air pressure storage unit 5 during downhole drilling and drilled while injecting air from the surrounding nozzles 22 and 32, thereby protecting the nozzle 22 nozzle and improving the surrounding soil in advance. Can contribute.

  The fresh water in the fresh water flow path 14 is accumulated by the blockage of the ejection holes 15, and is injected as a high-pressure jet from the fresh water injection nozzle 4 to cut and agitate the surrounding soil, and from the polymerization injection nozzles 2, 3 and 2a, 3a set at the lower part. In addition to extending the reach of the hardener jet, the mixing of the hardener and the surrounding soil is promoted to create a foundation for the formation of a homogeneous hardener injection layer.

  The rear end of the injection rod 1 is a swivel mechanism 11, which is connected to a corresponding portion of each flow path in the rod and a hose 8 connected to the injection material tank and is operated on the base 6. Supported by mechanism 7.

  The hardened layer forming apparatus configured as described above first supplies lubricating fresh water to the flow path 14 and discharges it from the injection nozzle 4 and the tip injection hole 15, and advances with respect to the injection rod 1 by the injection rod operating mechanism 7. An operation such as rotation is applied, and the injection rod is inserted into the target ground G by the rotation of the excavating blade 9 of the rod crown D and the injection rod 1.

  In this way, the injection rod 1 is propelled and inserted toward the target ground G, and when the predetermined depth is reached, the fresh water supply pressure to the flow path 14 is increased and the differential pressure valve 41 is lowered to close the tip ejection hole 15; Injected from the nozzle 4 as a high-pressure jet having a discharge amount of 50 to 80 liters per minute.

  Furthermore, cement milk as a ground hardening material is pumped to the flow path 13 at a discharge rate of 220 liters per minute at a pressure of about 400 Kg / square centimeter, respectively, and the polymerization nozzles 2 and 2a, the core nozzle 21 and the polymerization nozzle 3 3a is ejected from the nuclear nozzle 31.

  The air supplied to the air supply path 12 as described above is accumulated in the air pressure accumulating section 5 and supplied from the air flow path 52 to the surrounding nozzles 22 and 32 above, respectively, and injected as a composite jet fluid of the hardener jet. Is done.

  In this way, by supplying the spray material to each nozzle and by stepping up and moving backward in 15 minutes per meter in the removal direction while rotating or reciprocatingly rotating the injection rod 1 by a predetermined angle, each high pressure jet is The surrounding ground is drilled and cut, and the soil particles are crushed, and the base body X is formed on the target ground G in a cylindrical shape by the hardened material injection layer along the drive locus of the injection rod 1.

When the injection tube rod is turned to the predetermined position, the rotation of the injection tube rod is stopped, and the injection rod is simply raised as it is, so that the hardening material jets from the superposition injection nozzles 2, 3 and 2a, 3a are each in the vertical direction. A hardened material injection layer Y for partitioning the space of the simple ascending section into a partition shape by drilling and cutting the ground is created.

At that time, by increasing the internal pressure of the air pressure storage unit 5, the air injection amount from the surrounding nozzles 22 and 32 is increased, and air is stored in the cell space R formed surrounded by the partition wall layer Y, The degree of saturation in the cell space can be reduced.

  When the injection rod reaches a predetermined position by simple ascent, the injection rod 1 is raised again while rotating or reciprocatingly rotated by a predetermined angle to form a plate-like hardened material injection layer X, and this is used as the upper and lower plates for the cell space. R is formed, and a continuous cell structure is formed by alternately repeating simple ascent and rotational ascent.

Next, an injection rod is set at the adjacent position, and injection is repeated in the same manner, alternately rotating and raising, and the adjacent upper and lower panels and the tips of the partition walls are cross-joined to form an enclosed cell structure. And a predetermined cell structure ground hardening layer is formed by making it adjoin one after another and arranging in parallel in a predetermined shape.

The abutment between the ends of the hardener injection layer Y that partitions the space of the simple ascending section into a partition shape is performed by setting the angle of the reciprocating rotation of the injection rod 1 or by adjusting the angle of the symbol marked on the surface of the rectangular outer shell body 16. Can be performed. Rotating or reciprocating at a predetermined angle, stepping up in 15 minutes per meter in the removal direction and moving backward, each high-pressure jet perforates and cuts the surrounding ground, crushing the soil particles, and the target ground G Next, a disk body X made of a hardened material injection layer is formed in a cylindrical shape along the drive locus of the injection rod 1.

Since the present invention is configured as described above, it can cope with loads applied from multiple directions such as earthquakes and construction vibrations, and enables the creation of a continuous cell structure effective in preventing fluidization. is there.

The main part expansion perspective view of the injection | pouring rod which shows the injection | pouring condition of continuous cell structure formation by the Example of this invention, a board | substrate, and a partition partition wall injection layer FIG. 3 is a plan view of an injection rod and a continuous cell structure showing an injection locus according to an embodiment of the present invention The longitudinal cross-section side view which abbreviate | omits one part and shows the principal part structure of the injection | rod rod tip monitor part by the Example of this invention Similarly, the nozzle setting part enlarged side view of the injection rod showing the appearance of the polymerization injection nozzle from the front The side view of the whole of the injection apparatus and the ground showing the construction status of continuous cell structure creation according to an embodiment of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Injection rod 11 Swivel mechanism 12 Air supply path 13 Hardening material flow path 14 Fresh water flow path 15 Fresh water ejection hole 16 of rod end 16 Square-shaped outer shell body 2 Polymerization injection nozzle 21 Concentric nozzle 22 Enclosed peripheral nozzle 3 Backward polymerization Injection nozzle 31 Co-nuclear nozzle 32 Encircling nozzle 4 Fresh water injection nozzle 41 Differential pressure valve of fresh water injection hole 42 Energizing spring of fresh water injection hole differential pressure valve 5 Air storage section 51 Check valve 52 of air supply path terminal 52 Air storage pressure Air flow path from the nozzle to the surrounding nozzle 53 Air pressure check section Air flow check valve 6 Base 7 Injection rod operating mechanism 8 Hose connected to the injection material tank A Rod monitor section B Rod-Main pipe C Rod insertion Hole E Rod monitor taper diameter expansion part D Rod crown G Target ground R Cell space X Plate body injection layer Y Partition bulkhead injection layer

Claims (3)

Insert an injection rod provided with one or more pairs of superposition jet nozzles set with the jet ports facing each other up to a predetermined depth of the target ground, and at a predetermined depth from the core of the superposition jet nozzle, high pressure ground hardening material, surrounding A step of rotating and raising the injection rod while injecting air from the section to create a disk-shaped hardener injection layer, and a high-pressure ground hardening material in which the amount of injection air is increased by stopping the rotation of the rod It is possible to create a continuous cell structure in which air is enclosed by alternately raising and lowering the rod while spraying to form a partition-like hardener injection layer and injecting air into the partition enclosure. Characterized ground hardening material injection method A plurality of injection rods set at adjacent positions simultaneously perform injection that alternately repeats rotation and rotation stop air increase , and the adjacent upper and lower plates and the tip of the partition wall are cross-joined to enclose the air. The ground hardening material injection method according to claim 1, wherein the sealed cell structure is constructed. A pair or a plurality of pairs of injection nozzles, which are formed by superposing the injection ports communicating with the air pressure storage section set in the air supply path and the injection ports communicating with the curing material flow path, face each other against the side wall of the injection rod. A rectangular outer shell body is set at predetermined intervals on the outer surface portion of the injection rod, and the outer surface of the plurality of outer shell bodies set as a whole forms a prismatic rod. Ground hardener injection device used for the ground hardener injection method described