JP4762200B2 - Ground strengthening method by simultaneous multi-point injection - Google Patents

Description

  The present invention relates to a ground strengthening method by simultaneous injection of multi-point ground, and plasticity containing, as active ingredients, a silica-based non-hardening powder, or a silica-based non-hardening powder and a calcium-based powder hardening material in the ground. The injection material is simultaneously injected into a plurality of locations, and a certain range of soil is constrained and consolidated by using the time-dependent expansion of the plastic injection material, thereby increasing the density of the soil and attempting to strengthen the ground.

  Conventionally, a method of injecting a cement-based mortar injection solution into the ground as a method of injecting a consolidation material into the ground to strengthen the ground is known, but the mortar injection solution flows in a slurry state. Since it is solidified by hydration reaction, when injected into the ground, the ground is split and injected and easily escapes, causing large breathing, and material separation and precipitation in the ground. There was a problem of solidifying in a vein shape.

  On the other hand, in order to reduce the breathing, it is sufficient to increase the content of cement, but if the amount of cement is increased, the hardening of the cement will be accelerated and it will not be possible to fill a wide area, or the ground will split and it will deviate. There was a problem.

  Furthermore, a method has been proposed in which aluminum or water glass is used as the plastic material for the flowable mortar mainly composed of cement. Such plastic grout is suitable for filling the cavity, but it is pressed into the ground. In this case, there is a problem that the viscosity is so large that it hardens rapidly in the ground and cannot be injected, or it splits easily.

  Therefore, as a method of strengthening the ground by increasing the density by statically injecting the consolidated material into the ground and pushing the earth and sand around it, a non-fluid low slump or almost slump-free injection material has been used. There has been proposed a method of forming a consolidated body in the ground by press-fitting (mortar) into the ground and consolidation strengthening the ground (Patent Document 1).

JP-A-6-108449 JP-A-12-45259 Japanese Patent Laid-Open No. 2003-232020 Japanese Patent Laid-Open No. 9-291526

  However, in the method described in the above-mentioned Patent Document 1, it is possible to compact the earth and sand in a slightly separated area even if the earth and sand in the vicinity of the injected consolidated material can be compacted. In order to make this possible, there is a problem that it is necessary to considerably reduce the injection interval of the binder, which increases costs.

  The present invention has been made to solve the above problems, and simultaneously injects a plurality of plastic injection materials into the ground, and constrains and compacts a certain range of soil with the plastic injection materials injected into the ground. Thus, an object of the present invention is to provide a ground strengthening method by simultaneous injection of multi-point ground so as to increase the ground strength.

The ground strengthening method by simultaneous injection of multi-point ground according to claim 1, wherein a plurality of injection pipes for injecting a plastic injection material into the ground at a plurality of injection points and a liquid feed for connecting the injection pipes to each other A plurality of unit pumps for injecting a plastic injection material into each injection point via the injection tube, and a liquid injection of the plastic injection material to each injection point through the tube and the liquid supply tube; A plurality of flow path switching valves for switching the flow path of the plastic injection material at the point, a flow rate / pressure measurement device for measuring the flow rate and / or pressure of the plastic injection material at each injection point, the unit pump, a central control device for collectively managing the road switching valve and the flow rate and pressure measuring apparatus, feeding of being connected to the central control device to the implantation conditions and the injection point of the plastic injection material at each injection point Such as using the monitoring panel for monitoring the situation,
While operating the unit pump, and controlling the operation of the unit pump and the flow path switching valve by the centralized management device based on information from the flow rate and pressure measuring device,
A multi-point ground that constrains and compacts the soil in a predetermined region by a massive solid body made of a plastic injection material that gradually expands in the ground at the plurality of injection points by simultaneously injecting the plastic injection material into the plurality of injection points. In the ground reinforcement method by simultaneous injection , injection pipes are respectively inserted into a plurality of injection points in the upper area of the ground, and liquid supply pipes are respectively arranged between the injection points so that the injection pipes are in a plane triangle shape or a lattice shape. connection,
Each of the unit pumps includes a power source, and each of the unit pumps is combined with the flow rate / pressure measuring device to constitute an injection device, and is connected to each injection tube via a liquid feeding tube,
By displaying the liquid flow rate and / or pressure data signal of the plastic injection material at each injection point, and the liquid crystal display on the monitoring panel, respectively, the arrangement form of each injection point and the liquid supply pipe laid between the injection points,
While monitoring the injection volume, injection pressure and injection speed of each injection point, the injection state of the injection material at each injection point, and the state of liquid delivery to each injection point, and to the injection tube at each injection point By simultaneously injecting the plastic injection material into a plurality of opposite injection points while switching the injection material flow path, continuing injection of the injection material, stopping, and completing,
Each area surrounded by multiple injection points facing each other pushes groundwater in a certain direction and drains in a certain direction, facilitating the expansion of massive consolidated bodies by the plastic injection material itself at each injection point, and at the same time It is characterized in that the ground strength is increased by constraining and compacting the soil in each ground region between a plurality of injection points by simultaneous press-fitting of a plastic injection material from each injection point.

The ground reinforcement method by simultaneous injection of multiple points according to claim 2 is the ground reinforcement method by simultaneous injection of multiple points of claim 1, wherein the plastic injection material is moved to a plurality of injection points while moving the injection stage in the vertical direction. It is characterized in that it is press-fitted simultaneously .

The ground reinforcement method by simultaneous injection of multipoint ground according to claim 3 is the ground reinforcement method by simultaneous injection of multipoint ground according to claim 1 or 2, wherein the plastic injection material is formed around the injection pipe by repeatedly increasing and decreasing the injection pressure. It is characterized by being press-fitted while continuously impacting the ground .

  In any one of the first to third aspects, the plastic injection material that is simultaneously injected into a plurality of injection points gradually expands in a columnar shape or a spherical shape in the ground and does not cause lateral flow in the soil in a predetermined region. This is a ground strengthening method that strengthens the ground by restraining and compacting.

  In addition, when simultaneously injecting plastic injection material into multiple injection points, the groundwater is strengthened simultaneously with soil compaction by adjusting the injection amount at each injection point so that the groundwater is pushed out in a certain direction by the plastic injection material. It is a ground strengthening method that makes it possible to drain water.

  Among these, the invention described in claim 1 is an invention related to the most basic ground strengthening method of the present invention, and a plurality of injection pipes installed at each injection point and a plastic injection material are fed to each injection point. And a pump for injecting the plastic injection material into each injection point via the injection pipe, and a flow rate / pressure measurement device for measuring the flow rate and / or pressure of the plastic injection material at each injection point, By simultaneously injecting the plastic injection material into the plurality of injection points based on the information from the flow rate and pressure measuring device, the soil in the predetermined region by the plastic injection material gradually expanding in the ground of the plurality of injection points, The ground is strengthened by compacting while suppressing lateral flow.

  Since the present invention can be performed with a simple device, it is suitable for tightening and strengthening partial loosening of the ground around an existing structure or disaster recovery work.

Moreover, in order to solve the above-mentioned problem, a ground injection material that is sent from the injection material storage tank to each injection point via a liquid supply pipe and fed by a unit pump and is injected into the ground at each injection point via the injection pipe. The required amount is simultaneously or selectively injected into each injection point while appropriately switching the flow path of the injection material by a flow path switching valve connected to each injection point of the liquid feeding pipe.

  At that time, a plurality of unit pumps and flow path switching valves are installed, and the operations of the unit pumps and flow path switching valves can be collectively controlled by the centralized management device. As the flow path switching valve, there can be used one that is mechanically operated by an electromagnetic valve, fluid pressure, or the like, or one that is manually operated.

  For this reason, a large number of unit pumps, on the one hand, have the function of optimally injecting injection material into each injection point, while on the other hand, a set of injections that collectively manage injections at a large number of injection points as a whole The device is configured to allow simultaneous injection and simultaneous continuous injection to other injection points.

  Moreover, the space | interval of each injection | pouring point is about 0.5m-4.0m planarly, ie, the permeable consolidation diameter in one injection | pouring point is about 0.5m-4.0m. Moreover, it is about 0.3 m to 4.0 m in the longitudinal section, and one layer may be a consolidated layer depending on the case.

  In the present invention, a plurality of unit pumps simultaneously inject an injection material into a plurality of injection points while managing the injection amount, injection pressure, and injection speed of the injection material, and the unit pump has a plurality of flow path switching valves. It is possible to inject continuously into multiple injection points via the pump, and to understand and manage the injection status at each injection point, and to detect the pressure at each unit pump and the pressure characteristics at each injection point. In addition, it is possible to quickly inject large volumes of soil with one set of large discharge volume and reduce construction time, even though it is a small-scale injection device by arbitrarily selecting the injection point and continuously injecting while switching. The ground can be improved efficiently and reliably.

  In addition, by the simultaneous continuous injection by the operation of the flow path switching valve, the injection material is injected at each injection point so that the ground water is pushed and drained in a certain direction by the injection material, so that the retained portion of the ground water (Groundwater pockets) can be eliminated and uniform ground improvement can be performed.

  Moreover, as shown in a specific example using a plastic injection material, ground improvement can be performed by a massive solidified body made of plastic gel itself while pushing groundwater in a predetermined direction.

  For ground with different ground conditions for each layer, the optimum amount of ground injection material can be simultaneously or selectively applied to each layer, and the injection stage is moved appropriately in the vertical and / or lateral directions. It is also possible to inject vertically and laterally in the ground, and to control arbitrarily the injection to multiple injection points by multiple injection pipes. This can improve the reliability of infiltration into the fine soil layer and shorten the construction period by rapid construction.

  In addition, the direction of the replacement of the injected material with the groundwater is controlled two-dimensionally and three-dimensionally by simultaneously or selectively and continuously injecting a plurality of injection points in the horizontal direction or the vertical direction. Regardless of the injection, the formation of unmodified parts due to the storage of groundwater in the injection region can be prevented, and a reliable injection effect can be expected.

  Furthermore, by controlling the above using a centralized centralized control device, it is possible to effectively inject ground injection material into a large number of injection points using a small number of unit pumps, and the groundwater is confined by the injection material. This prevents the occurrence of unmodified parts, so-called “groundwater pockets”, and provides an injection effect with excellent workability. In addition, it is possible to cope with deformation and destruction associated with an increase in pore water pressure with respect to underground structures.

  For example, in FIG. 2A, when a plastic injection material is continuously injected into each injection point of P1, P2, P3, and P4, the plastic injection material at each injection point is embedded in each injection point of P1 to P4. It is discharged into the ground from the discharge port of each injection tube 1 and gradually expands in a columnar shape or a spherical shape around each injection tube 1 to push the surrounding soil.

  Therefore, by simultaneously and continuously injecting the plastic injection material into each of the injection points P1 to P4, the plastic injection material is gradually expanded in a columnar shape or a spherical shape at each of the injection points P1, P2, P3 and P4. Therefore, the soil strength is increased by the soil in a certain range surrounded by the plastic injection material being constrained and compacted by the surrounding plastic injection material gradually expanding in a columnar shape or spherical shape.

  In addition, when injecting the plastic injection material to each injection point, the plastic injection material can be efficiently injected by the injection pressure and the impact of the pump if the plastic injection material is injected while giving a pulsating motion or impact. The plastic injection material can be efficiently expanded in the ground.

  Considering the direction of groundwater drainage, by simultaneously injecting plastic injection material at each injection point of P1, P2, P3, and P4, the groundwater is pushed in a certain direction by the plastic injection material that gradually expands in a columnar shape or spherical shape. Therefore, groundwater can be drained in a certain direction simultaneously with the simultaneous injection of the plastic injection material.

  For example, as shown in FIG. 2B, the diameter of the plastic injection material expanding in a columnar shape or spherical shape at the injection point P1 is larger than the diameter of the plastic injection material expanding in a columnar shape or spherical shape at the injection points P2, P3, and P4. By injecting the plastic injection material while adjusting the injection amount at each injection point so that the plastic injection material at each injection point gradually expands in a small state, the groundwater is injected between the injection points P1 and P2, and P1. And P4 can be drained.

  A larger number of injection points of plastic injection material can effectively compact a wide range of soil, and a narrower injection point interval can more effectively and reliably compact soil in a certain area. The number and interval of injection points may be determined in consideration of the performance and economics of the unit pump.

  In general, it is desirable that the interval between the injection pipes is appropriately set in a range of about 0.5 m to 4.0 m according to the properties of the ground. Further, if there are two injection points (positions of the injection pipe) of the plastic injection material, it is possible to compact the soil in a predetermined region with both sides of the plastic injection material. In order to more reliably restrain and compact the soil in the predetermined region, it is desirable to provide the injection points at at least three places as shown in FIG.

  The interval and the number of installation points of the plastic injection material can be determined as appropriate according to the properties of the ground to be constructed as described above.In the case of soft ground or relatively good quality ground, two injection points may be used, The installation interval may be wide.

  Also, when the construction target ground is fairly wide, the first ground injection is performed with a relatively wide interval between the injection points, and the subsequent ground injection is performed between the injection point where the ground injection was first performed and the injection point. If the plastic injection material is injected while narrowing the injection interval in this manner, the ground can be injected very efficiently using a small number of injection pipes and the ground can be compacted.

  The plastic injection material has fluidity during injection and gradually expands into a columnar or spherical shape, but after injection, it loses fluidity in the ground with the passage of time or due to dehydration and loses its fluidity due to dehydration. A plastic injection material capable of forming a ligation, for example, a silica-based non-curable powder, or a plastic gel injection material containing a silica-based non-curable powder and a calcium-based powder cured material as active ingredients Can be used.

  Cement-based mortar injection material is slurry-like, fluid, and solidifies by hydration reaction. If such fluid injection material is injected into the ground, it will split the ground. It was easy to deviate, and it had the problem of causing large breathing, causing material separation in the ground, and precipitating and solidifying in a vein shape. However, the above-mentioned plastic injection material causes splitting in the ground. In order to form a columnar or spherical solid body without causing it, it is possible to strengthen the ground by compacting the soil in a predetermined region by simultaneous injection to a plurality of points.

  In addition, ground consolidation injection material for strengthening or stopping water such as soft ground, industrial waste, injection material for solidification of pollutants, water stop to prevent leakage of harmful substances from pollutants A solidified material for forming a layer, an injectable material containing a chemical substance for detoxifying pollutants, or a heavy metal fixing material that chemically inactivates heavy metals can be used as an injectant. It is possible to select an arbitrary injection material according to the ground situation for each injection point.

According to a third aspect of the present invention, in the process of injecting the plastic injection material into the ground using an injection tube, the injection pressure is continuously increased and decreased while the plastic injection material is press-fitted into the ground. By continuously impacting the injection pressure and the ground around the injection pipe, a negative dilatancy is generated in the ground around the injection pipe, and the soil particles are rearranged by the rearrangement of the soil particles caused by this negative dilatency. At the same time, the plastic injection material injected into the space is filled and the space is replaced with the plastic injection material.

  Thus, by continuously injecting the plastic injection material, a space is generated in the ground around the injection tube by impact or pulsation, and the plastic injection material is columnar around the injection tube by filling the space with the plastic injection material. Or it is spherical and gradually and surely expands.

  In addition, impact is applied to the soil particles around the consolidated body through the massive gel consolidated body of the plastic grout, the surrounding ground density increases, and the massive gel consolidated body expands to compress the surrounding ground. The ground strength is increased.

  This phenomenon is likely to occur when the target ground is loose sand ground, and plastic injection material is injected using its properties, but if the ground is soft and viscous soil, by repeatedly giving impact, Furthermore, the surrounding clay soil where the impact acts is softened, and a region where the plastic injection material is easily injected is formed.

  During the process of injecting the plastic injection material, usually the injection pressure is gradually increased, gradually increased, or the plastic injection material is injected while repeatedly feeding or interrupting the plastic injection material at intervals. Has been proposed by the applicant, but in the present invention, by continuously increasing and decreasing the injection pressure of the plastic injection material, a constant impact is continuously applied to the ground around the injection tube. The plastic injection material can be efficiently injected into the ground, and the plastic injection material injected into the ground can be reliably expanded.

The ground reinforcement method by simultaneous injection of multipoint ground according to claim 4 is the ground reinforcement method by simultaneous injection of multipoint ground according to any one of claims 1 to 3, in a region surrounded by a plurality of injection pipes. It is characterized by installing drainage drains in the ground . Simultaneously with the compaction of the ground, groundwater in the ground can be efficiently drained to the ground via the drainage drain. As the drainage drain, a paper drain, a sand drain or the like can be used.

The ground reinforcement method by simultaneous injection of multipoint ground according to claim 5 is the ground reinforcement method by simultaneous injection of multipoint ground according to any one of claims 1 to 4 , wherein each unit pump is supplied to each injection point. It is characterized by including a speed change mechanism for adjusting the flow rate and / or pressure of the ground injection material to be liquefied.

The ground strengthening method by multi-point ground simultaneous injection according to claim 6 is the ground strengthening method by multi-point ground simultaneous injection according to any one of claims 1 to 5, wherein the discharge ports of the plurality of injection pipes are in a planar direction. Are installed at different injection points and / or different injection points in the vertical direction.

Ground reinforcement method according to multi-point ground coinjection of claim 7, wherein, in the ground reinforcement process according multipoint ground coinjected according to any one of claims 1 to 6, plastic injection material, a silica-based non-curable powder Containing solid and water, or silica-based non-curable powder and water and calcium-based powder-curing material as active ingredients, and loses fluidity due to the passage of time or dehydration to form a massive solid body It is characterized by manufacturing as follows.

  For example, silica-based non-hardening powders such as fly ash (coal ash), slag, incineration ash, clay, earth and sand, silica sand, calcium-based powder hardening material such as cement, lime, gypsum and water are active ingredients. In the case of using a plastic injection material prepared by blending an appropriate amount of these, it can be efficiently injected by producing a slurry having a specific gravity of 2.0 or less, and the plastic injection material is gradually injected after the injection. It can be solidified to reach a predetermined strength, and a massive gel consolidated body having a predetermined strength can be formed.

  It should be noted that the solidification rate can be adjusted by adding a solidification promoting material or a solidification delay material according to the construction situation. Further, the flow value and the slump value when the plastic injection material is injected may be 12 cm or more and 15 cm or more, respectively.

  As other specific components, there are slaked lime, gypsum, bentonite, slag, foaming agent, aluminum powder, sulfate band (aluminum sulfate, solidification promoter), etc., for example, sulfate band is a gelation accelerator, When added to a flowable mortar composed of ash and mortar, it rapidly gels and can be immediately plasticized. However, if the amount added is large, the expression of long-term strength tends to decrease, so 0.1 to 1.0% is appropriate.

  Cement is a hardened material and a fly ash plasticizer. Fly ash alone does not gel and does not become a self-hardening / plastic solidifying material, but it causes a pozzolanic reaction by mixing cement to obtain consolidation strength. However, as the amount of cement increases, the properties as a plastic injection material deteriorate. When the blending amount of cement exceeds 50%, the plastic holding time is shortened, the breathing rate is increased, the time until plasticizing is shortened, and the fluidity and workability are lowered.

  Accordingly, the blending amount of the cement is less than 50%, preferably 20% or less, more preferably 10% or less, so that the plastic holding time is long, the breathing rate and the initial viscosity are both low, fluidity and workability. Both are good.

  Moreover, since the breathing rate can be lowered, settlement after solidification can be minimized. In this case, ordinary Portland cement can be used as the cement.

  On the other hand, when the water powder ratio is less than 30%, the viscosity after blending is extremely high, and the fluidity and workability in the pump injection tube become difficult. In general, as the water-powder ratio decreases, both the gel time and the plastic holding time are shorter, the breathing rate is lower, the viscosity is higher, and the strength is higher. In general, the water / powder ratio is suitably 30 to 130%, preferably 30 to 70%, more preferably 35 to 50% in view of workability. If it exceeds this, since it takes time to become plastic, the breathing rate increases, and the settlement after solidification also increases.

  In addition, a two-component plastic injection material can be used as another injection material. The two-part plastic injection material exhibits plasticity by adding cement bentonite to the A liquid, further an extender and a foaming agent, and combining the A liquid and the B liquid at the injection point using a water glass liquid as the B liquid. It is an injection material. In addition, a cement bentonite liquid may be combined with the A liquid, and a bentonite liquid may be combined with the B liquid to form a plastic injection material that hardly causes breathing. Furthermore, animal protein or a surfactant is added as a foaming agent to cement bentonite as liquid A, and lime and aluminum salts such as aluminum sulfate and aluminum chloride are combined as liquid B, and combined to produce aluminum hydroxide. Plasticity may be imparted.

The ground strengthening method by simultaneous injection of multipoint ground according to claim 8 is the ground reinforcing method by simultaneous injection of multipoint ground according to claim 7, wherein the non-hardening powder is fly ash, slag, incinerated ash, clay, earth and sand. And selected from the group of silica sands.

The ground strengthening method by simultaneous injection of multi-point ground according to claim 9 is the ground strengthening method by simultaneous injection of multi-point ground according to claim 7 or 8, wherein the calcium-based powder hardened material is cement, lime, gypsum and slag. It is characterized by selecting from a group. However, slag is excluded from a hardening expression material, when a non-hardening powdery body is slag.

  According to the present invention, by simultaneously and continuously injecting a plastic injection material into a plurality of injection points, the injected plastic injection material gradually expands in a columnar shape or a spherical shape in the ground to restrain the soil in a predetermined region. By compacting, the ground can be strengthened reliably and efficiently.

  In addition, when simultaneously injecting plastic injection material into multiple injection points, the amount of injection at each injection point is adjusted so that the groundwater is pushed in a certain direction by the plastic injection material. Can also be performed.

  In addition, by switching the flow path of the plastic injection material using the path switching valve, it is possible to inject the required amount of injection material simultaneously or selectively into multiple injection points, so that the wide ground can be securely tightened in fixed areas. The whole ground can be strengthened efficiently and reliably.

  A plurality of unit pumps simultaneously inject the injection material into a plurality of injection points while controlling the injection amount, injection pressure, and injection speed of the injection material, and at least one unit pump switches a plurality of flow paths. Since it is possible to inject continuously into multiple injection points via a valve, and to understand and manage the injection status at each injection point, it is possible to detect the pressure at each unit pump and the pressure characteristics at each injection point Because the injection point can be selected arbitrarily and the flow path of the injection material can be arbitrarily switched, a large-capacity soil can be rapidly injected with a large amount of injection in one set even though it is a small-scale injection device. Injection is possible, construction time is shortened, and the ground can be improved efficiently and reliably.

  1 to 3 are conceptual diagrams showing an example of a ground strengthening method by simultaneous injection of multiple points according to the present invention. In the figure, reference numeral 1 denotes an injection pipe installed at each injection point (injection point) of the target ground in order to inject a plastic injection material into the ground.

    As shown in the drawing, the injection tube 1 has, for example, each horizontal axis X1 when assuming a grid having a plurality of horizontal axes X1, X2, X3,... And vertical axes Y1, Y2, Y3,. , X2, X3,... And the vertical axes Y1, Y2, Y3,.

  The injection tube 1 has a single tube structure or double tube structure with a plastic injection material discharge port at the tip, or a double packer or multi-packer (3 pieces) on an outer tube having one or more discharge ports. A double-tube structure constructed by inserting an inner tube having the above-mentioned packer), a bundle of a plurality of narrow tubes having discharge ports at different positions in the axial direction, or an outer peripheral portion of the outer tube A plurality of bag packers arranged in the axial direction of the outer tube and a plurality of discharge ports provided between the bag packers can be used.

  For example, in order to inject the plastic injection material into the ground using the injection pipe 1 provided with a plurality of bag packers and discharge ports in the outer pipe, the bag packer is solidified into the bag packer in the ground. After the material is supplied from the ground and expanded, the plastic injection material is continuously supplied into the injection pipe 1 from the ground.

  Then, as illustrated in FIG. 2A, the plastic injection material is discharged into the ground from the discharge port of each injection pipe 1 embedded at each injection point P <b> 1 to P <b> 4, and is columnar around each injection pipe 1. Or it gradually expands in a spherical shape and spreads the surrounding soil.

  Therefore, by simultaneously and continuously injecting the plastic injection material into each of the injection points P1 to P4, the plastic injection material is gradually expanded in a columnar shape or a spherical shape at each of the injection points P1, P2, P3 and P4. Therefore, the soil strength is increased by the soil in a certain range surrounded by the plastic injection material being constrained and compacted by the surrounding plastic injection material gradually expanding in a columnar shape or spherical shape.

  Considering the direction of groundwater drainage, by simultaneously injecting plastic injection material at each injection point of P1, P2, P3, and P4, the groundwater is pushed in a certain direction by the plastic injection material that gradually expands in a columnar shape or spherical shape. Therefore, groundwater is drained in a certain direction simultaneously with the simultaneous injection of the plastic injection material.

  For example, as shown in FIG. 2B, the diameter of the plastic injection material expanding in a columnar shape or spherical shape at the injection point P1 is larger than the diameter of the plastic injection material expanding in a columnar shape or spherical shape at the injection points P2, P3, and P4. By injecting the plastic injection material while adjusting the injection amount at each injection point so that the plastic injection material at each injection point gradually expands in a small state, the groundwater is pushed to the injection point P1 side and drained, At the same time, the soil surrounded by the injection points of P1, P2, P3 and P4 is compacted to increase the ground strength. In this case, since the bag packer is inflated laterally at the upper and lower side portions of the discharge port of each injection tube 1, the plastic injection material does not escape upward and downward of the injection tube 1.

  It should be noted that there are many injection points, and narrower intervals between injection points can efficiently and reliably compact a predetermined range of soil, but the number and intervals of injection points should be set in consideration of the properties and economics of the target ground. Can be determined. Usually, it is desirable to set the interval between the injection tubes as appropriate in the range of about 0.5 m to 4.0 m according to the properties of the ground. However, in order to constrain and compact the soil in a predetermined region, it is desirable to provide injection points at at least three places as shown in FIG.

  Reference numeral 2 denotes an injection material storage tank in which a plastic injection material to be injected into the ground at each injection point is stored, and reference numerals 3 and 4 denote liquid injection of the plastic injection material from the injection material storage tank 2 to the injection pipe 1 at each injection point. A liquid feeding tube 3 is laid between the injection points along the Y-axis direction, and a liquid feeding tube 4 is laid between the injection points along the X-axis direction, Therefore, the liquid feeding pipe 3 and the liquid feeding pipe 4 are laid in a lattice shape in the X-axis direction and the Y-axis direction.

  The codes U1 to 6 feed the plastic injection material from the injection material storage tank 2 to each injection point through the liquid supply pipe 3 and the liquid supply pipe 4 and also through the injection pipe 1 into the ground of each injection point. A unit pump 5 for injecting the plastic injection material is a power source for driving the unit pumps U1 to U6.

  Each of the unit pumps U1 to U6 includes a power source 5 and is controlled by a controller 6a of a centralized management device 6 to be described later, and sends a necessary amount of plastic injection material to each injection point. It is connected to the liquid feeding pipe 3 so that a necessary amount of plastic injection material can be continuously injected into the ground at each injection point.

  Reference numeral 7 denotes a flow rate / pressure measuring device connected to each liquid feeding pipe 3 for measuring the injection amount and injection pressure of the plastic injection material at each injection point. The flow rate / pressure measuring device 7 is a concentration which will be described later. Controlled by the controller 6b of the management device 6, the injection amount, injection pressure and injection speed of the plastic injection material injected into the ground at each injection point can be measured in real time.

  The unit pumps U 1 to 6, the power source 5 that drives the unit pumps U 1 to 6, and the flow rate / pressure measuring device 7 are combined to form one system (one set) of injection devices. The apparatus is connected to the injection material storage tank 2 and the injection pipe 1 at each injection point via liquid feeding pipes 3 and 4.

  Therefore, even if a trouble occurs in some unit pumps during the injection of the plastic injection material and the operation becomes impossible, the plastic injection material can be continuously fed from other injection systems.

  Reference numeral 8 is a flow path switching valve for switching the flow path of the plastic injection material sent from the injection material storage tank 2 to each injection point by the liquid supply pipe 3 and the liquid supply pipe 4 at each injection point. The path switching valve 8 is connected to a connection portion between the liquid feeding pipe 3 and the liquid feeding pipe 4 at each injection point.

  The plastic injection material sent from the injection material storage tank 2 to each injection point is switched in flow path by the flow path switching valve 8, for example, through the injection pipe 1 to which the flow path switching valve 8 is connected. The liquid is injected into the ground, or is supplied to another injection point via the liquid supply pipe 3 or 4.

  Further, the flow path switching valve 8 at each injection point is controlled by a controller 6c of the centralized management device 6 described later so that the flow path of the injection material can be freely switched for each injection point or for each of a plurality of injection points. It has become.

  Reference numeral 6 denotes a centralized management device for centrally controlling the unit pumps U1 to U6, the power source 5, the flow rate / pressure measuring device 7 and the flow path switching valve 8, and each unit pump U1 to U6 and its power A controller 6 a for controlling the source 5, a controller 6 b for controlling each pressure / flow rate measuring device 7, and a controller 6 c for controlling each flow path switching valve 8 are provided.

  For example, when the controller 6b obtains information on the flow rate and / or pressure of the injection material at a certain injection point from the flow rate / pressure measurement device 7, the controller 6b is plastic at the injection point within a predetermined pressure range and injection rate range. The unit pumps U1 to U6 and the power source 5 are controlled so as to feed the injection material (the rotational speed is changed by a rotation irregular mechanism, etc.).

  When the injection amount of the injection material at the injection point reaches a predetermined amount, information to that effect is transmitted to the controller 6c, and then the controller 6c operates the flow path switching valve 8 at the injection point to move to the next injection point. Information is transmitted to the controller 6b so that the injection solution is fed into the injection tube. By such control, a necessary amount of plastic injection material can be continuously and simultaneously sent from the injection material storage tank 2 to each injection point or a plurality of injection points.

  Reference numeral 9 is a monitoring panel for monitoring the injection point of the plastic injection material, the injection state of the plastic injection material at each injection point, and the liquid supply state of the injection material to each injection point. It is connected. The monitoring panel 9 displays the actual injection points and the arrangement of the liquid supply pipes 3 and the liquid supply pipes 4 laid between the injection points by a liquid crystal display method or the like.

  The monitoring board 9 displays the injection point of the plastic injection material, the injection state of the injection material at each injection point, and the liquid supply path to each injection point so that it can be confirmed by the human eye. Furthermore, while looking at the monitoring board 9, the injection point, the flow path of the injection material to the injection point, etc. can be freely set and changed.

  In such a configuration, the plastic injection material fed from the injection material storage tank 2 to each injection point via the liquid supply pipes 3 and 4 was controlled by the controller 6a via the injection pipe 1 for each injection point. It is injected into the ground at each injection point by unit pumps U1-6.

  At that time, an optimum injection amount and / or injection pressure is set for each injection point by the flow rate / pressure measuring device 7 controlled by the controller 6b, and an optimum amount of the plastic injection material is determined according to the ground properties at each injection point. Injected.

  Further, the flow path switching valve 8 at each injection point is controlled by the controller 6b and is operated for each injection tube 1 or for each of the plurality of injection tubes 1 so that the injection material is for each injection point or for each of the plurality of injection points. Is injected into the ground through the injection tube 1.

  Further, the injection amount, injection pressure, and injection speed of the injection material at each injection point are measured by the flow rate / pressure measurement device 7, and the information is transmitted to the controller 6 in real time.

  In FIG. 1, six unit pumps U <b> 1 to U <b> 6 are arranged, each of which includes a power source 5, and each of the injection material storage tank 2 through the liquid supply pipe 3 and the liquid supply pipe 4. It is connected to an injection tube 1 at each injection point. In addition, six injection tubes 1 are connected to each liquid supply tube 3 arranged along each of the Y1 to 6 axes via a flow path switching valve 8.

  Accordingly, since 6 unit pumps U1 to U6 make a total of 6 × 6 = 36 injection pipes 1, simultaneous and continuous injection of the plastic injection material becomes possible under the collective management by the centralized control device 6, so that the weight of the device is reduced. And dramatic improvement in workability.

  Further, by continuously operating the flow path switching valve 8 at each injection point, selective and continuous liquid feeding to any injection pipe 1 on each of the Y1 to 6 axes becomes possible.

  Further, a plurality of liquid feeding pipes 3 in each Y-axis direction and liquid feeding pipes 4 in each X-axis direction are arranged in a planar lattice shape, and an injection pipe 1 is provided at each intersection of the liquid feeding pipe 3 and the liquid feeding pipe 4. By installing, the injection pipe 1 can be arbitrarily selected, so that it is possible to inject an injection material corresponding to the ground or considering the existence of underground structures, and perform a precise ground improvement. be able to.

  Next, the ground strengthening method by simultaneous injection of the multipoint ground according to the present invention will be described with reference to FIGS. In FIG. 4, in order to strengthen the ground of the S1 region portion (portion indicated by mesh hatching), first, P1, P2, and P3 of the flow path switching valves 8 connected to the injection points on the Y1 axis. The flow path switching valve 8 is switched so as to open only on the injection point P4 side on the Y2 axis.

  Further, among the flow path switching valves 8 connected to each injection point on the Y5 axis, the flow path switching valves P5, P6 and P7 are switched so as to open only on the injection point P8 side on the Y4 axis. Furthermore, the flow path switching valves 8 at the injection points P4, P8, P9 and P10 are switched so as to open only on the side of the injection pipe 1 embedded at the injection point.

  Then, the unit pumps U1, U2, U4, U5 on the Y1, Y2, Y4, and Y5 axes are operated to feed the plastic injection material to the injection points P4, P8, P9, and P10. The plastic injection material is simultaneously injected through the injection tube 1 connected to each injection point.

  At that time, the flow rate and pressure measuring devices 7 on the Y1, Y2, Y4, and Y5 axes measure the injection amount, injection pressure, and injection rate of the injection material for each of the injection points P4, P8, P9, and P10. An optimal amount of plastic injection material is delivered to each injection point.

  Thus, the plastic injection material injected into each injection point P4, P8, P9, and P10 gradually expands in a columnar shape or a spherical shape around each injection tube 1 and pushes the surrounding soil. Furthermore, since the plastic injection material forms a columnar shape or a spherical shape at the injection points P4, P8, P9, and P10 and gradually expands simultaneously, the soil in the predetermined region S1 surrounded by the plastic injection material becomes the surrounding plastic injection material. The ground strength is increased by being constrained and compacted.

  In addition, the plastic injection material is injected into each injection point of P4, P8, P9 and P10 in consideration of the direction of groundwater drainage, so that the groundwater is pushed in a certain direction by the plastic injection material. At the same time, groundwater can be drained.

  Next, in FIG. 5, in order to strengthen the ground of the S2 region portion (the portion indicated by hatching of the mesh), all of the flow path switching valves 8 that are first connected to the injection points on the Y2 axis are connected to the Y2 axis. It changes so that it may open only to the upper injection | pouring point P1 side, and it switches so that all the flow-path switching valves connected to each injection | pouring point on Y6 axis may open only to the injection | pouring point P2 side on Y4 axis.

  Further, among the flow path switching valves connected to each injection point on the Y3 axis, the flow path switching valves 8 of P3, P4 and P5 are switched so as to open only on the injection point P6 side on the same Y3 axis, and the Y5 axis Of the flow path switching valves connected to the above injection points, the flow path switching valves P7, P8 and P9 are switched so as to open only to the injection point P10 side on the same Y5 axis.

  Further, the flow path switching valve 8 at the injection points P1, P2, P6, and P10 is switched so as to open only on the side of the injection pipe 1 embedded at the injection point.

  Then, the unit pumps U2, U3, U5, and U6 on the Y2, Y3, Y5, and Y6 axes are operated to send the plastic injection material to the injection points P1, P2, P6, and P10. The plastic injection material is simultaneously injected through the injection pipe 1 connected to the injection points P1, P2, P6 and P10.

  At that time, the flow rate and pressure measuring devices 7 on the Y2 axis, Y3 axis, Y5 axis, and Y6 axis measure the injection amount, injection pressure, and injection rate of the injection material for each injection point P1, P2, P6, and P10. An optimal amount of plastic injection material is delivered to each injection point.

  Thus, the plastic injection material injected into each injection point gradually expands in a columnar shape or a spherical shape around each injection tube 1 and pushes the surrounding soil. Furthermore, since the plastic injection material gradually expands in a columnar shape or a spherical shape at the injection points P1, P2, P6 and P10, the soil in the predetermined region S2 surrounded by the plastic injection material is restrained by the surrounding plastic injection material. The ground strength is increased by being compacted.

  In addition, by simultaneously injecting plastic injection material to multiple injection points in consideration of the direction of groundwater drainage, the groundwater is pushed in a certain direction by the plastic injection material. Push in the direction and drain.

  In the same manner, the entire target ground can be efficiently and reliably strengthened by compacting the soil for each predetermined range in the same manner. At that time, the injection point of plastic injection material, the number of injection points, and the injection interval are determined according to the properties of the target ground, and the plastic injection material route to each injection point can be sent at the shortest distance. Thus, it is determined by switching the flow path switching valve 8 at each injection point.

  The present invention can increase the density of the soil and strengthen the ground by simultaneously injecting a plurality of plastic injection materials into the ground and constraining and compacting the soil in a predetermined region.

It is a conceptual diagram which shows the ground reinforcement | strengthening method by the multipoint ground simultaneous injection | pouring of this invention. (A), (b) is an enlarged view of an injection | pouring point. It is an enlarged view of an injection | pouring point. It is a conceptual diagram which shows the construction method of this invention. It is a conceptual diagram which shows the construction method of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Injection pipe 2 Injection material storage tank 3 Liquid supply pipe 4 Liquid supply pipe 5 Power source of unit pump 6 Centralized control device 7 Flow volume / pressure measuring device 8 Flow path switching valve 9 Monitoring board U1-U6 Unit pump P Injection point (point) )

Claims (9)

A plurality of injection pipes for injecting a plastic injection material into the ground at a plurality of injection points, a liquid supply pipe for connecting the injection pipes to each other, and a plastic injection to each injection point via the liquid supply pipe A plurality of unit pumps for injecting the plastic injection material into each injection point via the injection pipe, and a plurality of flow channels for switching the flow path of the plastic injection material at each injection point A switching valve, a flow rate / pressure measuring device for measuring the flow rate and / or pressure of the plastic injection material at each injection point, and a centralized point for collectively managing the unit pump, the flow path switching valve and the flow rate / pressure measuring device. Using the monitoring device for monitoring the injection status of the plastic injection material at each injection point and the liquid feeding status to each injection point connected to the central control device and the management device ,
While operating the unit pump, and controlling the operation of the unit pump and the flow path switching valve by the centralized management device based on information from the flow rate and pressure measuring device,
A multi-point ground that constrains and compacts the soil in a predetermined region by a massive solid body made of a plastic injection material that gradually expands in the ground at the plurality of injection points by simultaneously injecting the plastic injection material into the plurality of injection points. In the ground reinforcement method by simultaneous injection , injection pipes are respectively inserted into a plurality of injection points in the upper area of the ground, and liquid supply pipes are respectively arranged between the injection points so that the injection pipes are in a plane triangle shape or a lattice shape. Each of the unit pumps is equipped with a power source, and each of the unit pumps is combined with the flow rate / pressure measuring device to constitute an injection device, and is connected to each injection tube via a liquid feeding tube,
By displaying the liquid flow rate and / or pressure data signal of the plastic injection material at each injection point, and the liquid crystal display on the monitoring panel, respectively, the arrangement form of each injection point and the liquid supply pipe laid between the injection points,
While monitoring the injection volume, injection pressure and injection speed of each injection point, the injection state of the injection material at each injection point, and the state of liquid delivery to each injection point, and to the injection tube at each injection point By simultaneously injecting the plastic injection material into a plurality of opposite injection points while switching the injection material flow path, continuing injection of the injection material, stopping, and completing,
Each area surrounded by multiple injection points facing each other pushes groundwater in a certain direction and drains in a certain direction, facilitating the expansion of massive consolidated bodies by the plastic injection material itself at each injection point, and at the same time A ground strengthening method by simultaneous injection of multiple points, characterized by increasing the ground strength by constraining and compacting the soil for each ground region between multiple injection points by simultaneous injection of plastic injection material from each injection point . The plastic injection material, multi-point ground coinjected ground strengthening method according to claim 1, wherein the simultaneously pressed into a plurality of injection points while moving the injection stage in the vertical direction. 3. The ground reinforcement method according to claim 1 or 2 , wherein the plastic injection material is press-fitted while continuously impacting the ground around the injection pipe by repeatedly increasing and decreasing the injection pressure . The ground strengthening method by simultaneous multipoint ground injection according to any one of claims 1 to 3 , wherein a drainage drain is installed in the ground in an area surrounded by a plurality of injection pipes . Each unit pump is provided with the speed change mechanism for adjusting the flow volume and / or pressure of the ground injection material sent to each injection | pouring point, The any one of Claims 1-4 characterized by the above-mentioned. Ground strengthening method by simultaneous injection of multiple points. The discharge port of the plurality of injection tubes, multi-point ground simultaneously according to any one of claims 1 to 5, characterized by being installed in different injection points and / or the vertical direction different injection point of the plane direction Ground strengthening method by injection. The plastic injection material contains silica-based non-curable powder and water, or silica-based non-curable powder and water and calcium-based cured material as active ingredients. It manufactures so that a fluidity may be lost and a massive solid body may be formed, The ground reinforcement method by simultaneous injection | pouring of the multipoint ground as described in any one of Claims 1-6 characterized by the above-mentioned. Non-hardening powdery body fly ash, slag, ash, clay, sand and silica sand multipoint ground coinjected ground strengthening method according to claim 7, wherein the selected from the group of. The ground strengthening method by simultaneous injection of multipoint ground according to claim 7 or 8, wherein the calcium-based powdery hardening material is selected from the group of cement, lime, gypsum and slag. However, slag is excluded from a hardening expression material, when a non-hardening powdery body is slag.

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