JP4808241B2 - Ground improvement method and ground improvement equipment - Google Patents

Description

  The present invention relates to a ground improvement method and a ground for strengthening a soft ground by compacting the ground so as to push it around the ground by forming a lump gel consolidated body made of a plastic gel injection material while gradually expanding in the ground. With regard to the improved device, it is possible to prevent the injected material from deviating due to the cracking of the surrounding ground, particularly due to the press-fitting of the plastic gel injected material, and the massive gel consolidated body is surely formed and expanded according to the condition of the ground. The surrounding ground can be securely compacted, and can be applied, for example, to the stabilization of ground such as residential land, factory construction sites, or roads, and the strengthening of slopes (slopes). It can be applied to the ground improvement of the existing structure and the seismic reinforcement of the existing structure can be performed.

  As a ground improvement method that increases the strength of soft ground and suppresses ground subsidence and sliding failure, a plastic gel injection material is pressed into the ground, and the plastic gel injection material is gradually expanded into a lump in the ground. The present applicant has already proposed a ground improvement method (plastic gel press-fitting method) in which the surrounding ground is compacted to push it around and the soft ground is strengthened.

  The conventional plastic gel press-in method uses a press-fit pipe inserted into the ground to apply a high-pressure liquid gel injection material into the ground using a high-pressure pump such as a diaphragm pump or a plunger pump. By injecting, a lump gel consolidated body made of a plastic gel injection material was formed around the press-fitting tube while gradually expanding, and the ground was reinforced by pressing the ground around.

  However, in order to form and consolidate a lump solid body without causing the deviation of the injection material corresponding to the soil layer in the complicatedly structured area, it has to be improved steadily.

  There is also known a compaction grout method in which a mixture of non-fluid slump-free aggregate and cement is pressed into the ground to improve the ground.

  However, ground improvement by this method requires a large device to press-fit non-flowable material, and it cannot be applied from narrow distances in urban areas because the material cannot be sent from a distance. .

  Further, it has been difficult to improve the ground from the horizontal direction, the oblique direction, or upward. In addition, there is a problem that the surrounding ground tends to rise due to the press-fitting.

JP 2007-77794 A JP 2007-9194 A

  According to the applicant's research, it is necessary to use a suspension material with fluidity in order to compact a soft ground consisting of complex alluvial soil layers by expanding the bulk gelled material according to the soil layers. I understood it.

  In addition, in order to improve the ground under narrow working conditions in urban areas, fluid materials are used, and from a remote plant, a liquid feed pipe is inserted from a press-fit pipe installed obliquely or horizontally directly under the building. I have to do it.

  However, when a fluid suspension is used, it is difficult to form a solid consolidated body because the injected liquid spreads along the injection tube or in the weak part of the ground, and therefore the solidified body is difficult to form. The effect of compacting the ground around the body cannot be obtained.

  In order to solve this problem, the present applicant has already filed an application for inventing a method of press-fitting a plastic gel into the ground rather than a simple suspension.

  As for the plastic-like gel, the whole liquid mixture is gelled by itself. The gel body will not flow if left standing, and will flow if force is applied. If left standing, it gradually solidifies and loses fluidity. Or if it spin-dry | dehydrates, since the content of the water | moisture content in a gel body will fall, it will lose fluidity and it will solidify.

  The plastic gel press-fitting method is a method in which a plastic gel injection material is continuously pressed into the ground to form a lump gelled product in the ground, and a thin film is formed on the outer periphery by dehydration by pump pressure. The gel-like body expands the thin film and expands to enlarge the mass.

  The lump gel is solidified gradually from the outer periphery and loses its fluidity, and at the same time the surrounding ground is pushed around and compacted, and the ground is strengthened. This is an epoch-making invention that is effectively used.

  The present applicant has further completed the present invention by further researching the plastic gel press-in method, grasping and improving the problems.

  According to the applicant's research, in order to expand the massive gel without deviating from each layer on the alluvial ground consisting of complex soil layers in Japan and to compact without destroying the surrounding ground, The following points were found necessary.

1. In order to expand greatly without deviating from the plastic gel, it is necessary to gradually increase the density without destroying the surrounding ground. Therefore, the optimum press-fitting speed and press-fitting pressure are continuously applied in response to the increase in the degree of compaction. Must be controlled.

  However, in the conventional method, a diaphragm pump or a plunger pump is used for high-pressure injection of the plastic gel injection material, so that the discharge amount of the plastic gel injection material per minute becomes too large or becomes a pulse shape. It is difficult to press-fit by adjusting the press-fitting amount by continuously changing the pressurization or depressurization at a high pressure as much as possible so as not to destroy the ground corresponding to the ground condition.

  In addition, when the press-fitting pressure increases, dehydration occurs in the pump and the material condenses, which may prevent continuous press-fitting, and may cause problems such as idling of the pump, making construction difficult. there were.

2. In the conventional method, because of the pump mechanism, the plastic gel injection material is pressed into the ground simply by being pushed out by one hand, so that it becomes a monotonous load and the compaction effect is not always sufficient.

  This is because if the plastic gel is unilaterally press-fitted, the pore water pressure in the surrounding area will increase, and the ground will be destroyed from the weak part, and the plastic gel will deviate, making it difficult to form a large body of plastic gel. .

  On the other hand, as a deformation characteristic obtained from the triaxial test result of sand, it is known that a large volume change occurs when repeatedly loaded with the same axial strain and when loaded monotonously.

  That is, by repeating the increase and dissipation of the pore water pressure, the surrounding ground is loosened, and the plastic gel is pressed into the loosened portion, so that a large lump gel body is formed. By repeating this process, the lump gel body expands without causing cracks, and the surrounding ground is compacted firmly.

  Further, in the conventional method, the discharge of the plastic gel injection material is pulsation injection as shown in FIG. 20, and the press-fitting speed and the press-fitting pressure of the plastic gel injection material fluctuate in accordance with the pulsation. Thus, the surrounding ground is cracked, and the plastic gel is easily deviated, and compaction is insufficient or the diameter of the gel body is reduced, and the compaction effect is reduced. In addition, it is difficult to grasp the true press-fitting speed and press-fitting pressure of the plastic gel injection material and manage the press-fitting amount, and there is a problem that the optimum press-fitting amount and its improvement effect cannot be grasped.

  The present invention was made in order to solve the above-mentioned problems, by press-fitting a plastic gel injection material into the ground, by forming a massive gel consolidated body composed of the injection material while gradually expanding, A ground improvement method and ground improvement that can effectively and economically strengthen the ground by pressing the thin film continuously to the extent that the ground does not break and preventing the injection of vein cracks and compacting the ground around it. An object is to provide an apparatus.

The ground improvement construction method according to claim 1 is formed by gradually expanding a lump gel consolidated body made of a plastic gel injection material into the ground by press-fitting the plastic gel injection material, and pushing the ground around. In the ground improvement method of compacting, a press-fit pipe inserted into the ground and a press-fit pipe connected to the press-fit pipe , a cylinder and a piston for sucking and press-fitting a plastic gel injection material, a jack for operating the piston, and the piston The displacement and the moving speed of the piston in the cylinder are measured by the displacement meter by a press-fitting device having a displacement meter for measuring the moving amount and moving speed in the cylinder, and the piston is moved based on the measurement result. By repeating the suction and press-fitting of the plastic gel injection material, it is necessary to expand the massive gel consolidated body so that the ground does not break. , Is characterized in that the compacting by adjusting injection pressure of the plasticized gel injection material, a press-fitting velocity, and press-fitting amount.

  The present invention keeps the discharge amount, press-fitting pressure and press-fitting speed of the plastic gel injection material constant, and continuously presses the plastic gel injection material into the ground, thereby preventing cracks in the ground and deviation of the injection material. Preventing or continuously controlling the increase, decrease and dissipation of pore water pressure to form a massive gel consolidated body consisting of plastic gel injection material in the ground while gradually expanding it, thereby surrounding the ground The ground will be strengthened by compaction.

  According to the present invention, even in soft ground, the plastic gel injection material is continuously pressed into the ground at a low discharge rate, low pressure and low speed, thereby preventing cracks in the ground and deviation of the injected material. It is possible to continuously increase, decrease and dissipate pore water pressure, and strengthen the ground by forming a massive gel consolidated body consisting of plastic gel injection material in the ground while gradually expanding. be able to.

The ground improvement construction method according to claim 2 is the ground improvement construction method according to claim 1, wherein the ground pressure is changed by switching the press-fitting pressure, press-fitting speed and press-fitting point of the plastic gel injection material based on the measurement result by the ground displacement meter. In order to prevent the displacement from becoming excessive, it is characterized by adjusting the press-fitting pressure, press-fitting speed, and the press-fitting amount for each soil layer so as to be within the allowable ground displacement limit in real time corresponding to the ground displacement. It is.

  According to the present invention, by continuously adjusting the discharge amount, press-fitting pressure, and press-fitting speed of the plastic gel injection material according to the soil layer of the ground, constant, increase and decrease, according to the condition of the ground It is possible to prevent cracks and deviation of the injected material, and by gradually controlling the increase, decrease and dissipation of the pore water pressure, the bulk gel consolidated body made of plastic gel injected material is gradually expanded in the ground. By forming it, the ground can be strengthened very efficiently.

  For example, when the ground is a soft soil layer, it is possible to prevent the surrounding ground from being destroyed by press-fitting the plastic gel injection material at a low discharge rate and low pressure in the initial press-fitting, and the solid gel consolidation As the body grows larger, the periphery is tightened, and correspondingly, the discharge speed is increased to increase the press-fitting pressure, whereby the expansion of the massive gel consolidated body and the compaction of the surrounding soil layer can be advanced. And if compaction of the surrounding soil of a lump gel consolidation progresses, even if a press-fit pressure increases further, press-fit and compaction can be advanced, without producing a pulse-like deviation to a soil layer.

The ground improvement method according to claim 3 is the ground improvement method according to claim 1 or 2, wherein the press-fitting pressure of the plastic gel injection material is measured by a pressure gauge attached to the conduit in the cylinder or to the press-fitting pipe. It is characterized by.

  As the jack, for example, a hydraulic jack, a screw jack, or a jack operated by water pressure or pressurized air can be used. This is because the jack can continuously control the magnitude of the pressure and the increase and decrease of the pressure by continuously moving the piston and the loading plate in the cylinder up and down. Accordingly, the plastic gel injection material in the cylinder can be pushed into the ground with a jack according to the degree of compaction of the ground to increase the lump gel.

  For example, it can be applied to the stabilization of ground and slopes (slopes) of residential land, factory construction sites, roads, etc., and it can be applied directly under existing buildings and structures for earthquake resistance reinforcement. it can.

  In addition, by forming the massive gel consolidated body while gradually expanding in the ground, the surrounding ground is compacted so that it is pushed around by the massive gel consolidated body. It can also be applied to ground improvement of the ground.

  In addition, when a plastic gel injection material is press-fitted from the deformation characteristics obtained from the triaxial test results of sand, a larger compaction effect due to volume strain (dilatancy) is exhibited by obtaining a process like repeated loading. However, according to the present invention, by using a screw jack or a hydraulic jack as a driving source of the piston, it is possible to easily realize the process of repeated loading by appropriately reciprocating the piston. Since it is possible, volume distortion (dilatancy) can be easily generated, and a larger ground compaction effect can be obtained.

In addition, when the plastic gel injection material is press-fitted at a fixed interval rather than monotonously press-fitting, the volumetric strain (dilatency) of the ground is more easily generated, and the compacting effect is further increased. (See FIGS. 19A and 19B)
In addition, according to the present invention, the plastic gel injection material can be efficiently injected by press-fitting the plastic gel injection material while applying a change in the injection pressure due to the injection and suction to the ground.

  In addition, by operating the piston in the cylinder using a jack and press-fitting the plastic gel injection material, while grasping the ground condition and the press-fitting condition, the optimum press-fitting speed, press-fitting amount, It is possible to increase the lump gel aggregate while making the ground loose while applying the improvement status and the change of the press-fitting pressure into the ground.

  In addition, by using a press-fit pipe having a drainage function, it becomes possible to drain pore water simultaneously with the compaction of the ground, and compaction can be performed very efficiently.

  In addition, by fixing a metal press-fit pipe having a drain function to an unstable slope ground with a plastic gel consolidated body, a drain pipe with the press-fit pipe as a reinforcing material is installed in the ground, and drainage and reinforcement are performed simultaneously. It can be used for ground reinforcement. It can also be used as a foundation pile reinforcement to dissipate excess pore water pressure during an earthquake (see Fig. 6).

  Furthermore, since it is possible to press-fit the plastic gel injection material with a constant press-fitting pressure and a constant discharge amount (see FIGS. 19 (a) and (b)), the plastic gel pouring material varies in the press-fitting pressure. Because there is no, it is possible to manage the injection speed and injection pressure of the plastic gel injection material in real time, grasp the optimal injection amount from the injection pressure of the plastic gel injection material, and confirm the effect, The ground can be improved efficiently and economically by press-fitting an optimal amount of the plastic gel injection material into the ground (see FIGS. 2 and 11).

  The press-fitting amount and press-fitting pressure of the plastic gel injection material can be easily measured by using a displacement gauge and a pressure gauge, and these measured data can be managed by a control device (PC). it can.

  In addition to the single tube rod type (see Figs. 4 and 5), the single packer type (see Fig. 6) and double packer type (in addition to the single tube rod type for the press-in tube for press-fitting the plastic gel injection material into the ground (see Fig. 4 and 5) (See FIG. 7) ', and in a two-component system, injection can be performed using a double-tube lot. Furthermore, in the two-component type (see FIG. 3), the blending ratio can be controlled by changing the extrusion speed of the A and B solutions.

  The plastic gel injection material used in the present invention comprises a silica-based non-curable powder and water, or a silica-based non-curable powder, a calcium-based powder hardening material, and water as active ingredients. Fluidization occurs when pressure is applied, but fluidity is lost when pump pressurization is stopped, and fluidity is restored when pressure is applied, but the outer peripheral surface is dehydrated to reduce the water content and lose fluidity to the surface. Since a thin film is formed and the thin film is pushed and spread by the internal fluid plastic gel, the gelled product gradually expands in the ground and compresses and compacts the surrounding ground.

  The plastic gel injection material according to the present invention has fluidity, and does not deviate in the ground, but forms a lump gel, and the surface forms a membrane with dehydration, while the fluidity is increased and fluidized inside. Need. For this purpose, it is preferable to have the following characteristics.

  The plastic gel injection material contains the following (1) and (3) or (1), (2) and (3) as active ingredients, and the table flow during press-fitting is 12 cm or more and / or slump during press-fitting It is desirable that the injection material is larger than 5 cm or / and the flow through the cylinder is larger than 8 cm and reaches the plastic gel before or during the press-fitting into the ground.

(1) Silica-based non-curable powder (F material)
(2) Calcium-based powder hardening material (C material)
(3) Water (W material)

  The plastic gel injection material reaches the plastic gel with a dehydration rate of 30% or less, and the plastic gel injection material does not require the use of calcium-based powder hardening agents such as clay, bentonite, and fly ash slag fluidized soil. It may be one that loses fluidity by dehydration in the ground to form a lump and exhibits strength equal to or higher than that of the surrounding ground.

  Further, the non-curable powder (F material) is a material selected from the group of fly ash, slag, incinerated ash, clay, earth and sand, and silica sand.

  The calcium-based powdery hardening material (C material) is a material 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.

  The curing agent is 1 to 40 weight percent. However, the ratio of cured material = C / (F + C) × 100 (%), and F, C, and W all represent weight.

  The water powder ratio is 20-200 weight percent. However, the water powder ratio = W / (F + C) × 100 (%), and F, C, and W all represent weight.

  Plastic gel injection material is used as additives from gelling accelerators such as water glass and aluminum salt, thickeners, peptizers such as surfactants, foaming agents such as aluminum powder, and fluidizing materials such as clay. One or more fluidity modifiers selected from the group consisting of:

  The ground improvement construction method according to claim 4 is the ground improvement construction method according to claim 3, wherein the jack is a hydraulic jack, a screw jack, or a jack that is operated by water pressure or pressure.

  The ground improvement construction method according to claim 5 is the ground improvement construction method according to any one of claims 1 to 4, wherein the plastic gel injection material is press-fitted into a plurality of points selected in a row shape or a lattice shape. It is a feature.

  The ground improvement construction method according to claim 6 is characterized in that, in the ground improvement construction method according to any one of claims 1 to 5, the plastic gel injection material is pressed into a plurality of points simultaneously or sequentially. .

  According to the present invention, the compaction action at each injection point exerts a restraining effect on each other, and more effective compaction is possible. In this case, a large compaction effect can be obtained by simultaneously high-pressure injection of the plastic gel injection material at least at three points (see FIGS. 12A and 12B).

  The ground improvement construction method according to claim 7 is the ground improvement construction method according to any one of claims 1 to 6, wherein the plastic gel injection material is press-fitted at a certain interval. The plastic gel injection material is more likely to cause volumetric distortion (dilatency) of the ground when it is pressed continuously at regular intervals than when it is pressed in monotonously. Is obtained (see FIG. 19).

The ground improvement construction method according to claim 8 is the ground improvement construction method according to any one of claims 1 to 7, wherein a drain material is installed in the ground to promote dehydration in the ground, or a press fit having a water absorption port. The plastic gel injection material is press-fitted through a pipe, and the water in the gel and the soil water are dehydrated from the drain material or the water inlet by the press-fitting of the plastic gel injection material.

  According to the present invention, by installing a drain material such as a paper drain or a drain pipe in the ground, or by using a press-fit pipe having a water inlet in the press-fit pipe, the plastic gel injection material is press-fitted into the ground. The ground gel can be drained through the drain material or the press-fitting pipe and the ground improvement can be efficiently performed while simultaneously forming the massive gel consolidated body while compacting the ground to be pushed around.

  The ground improvement construction method according to claim 9 is the ground improvement construction method according to any one of claims 1 to 7, wherein a press-fit pipe having a tensile resistance force or a press-fit pipe is inserted into the ground together with a tensile resistance member. Is compressed to increase the density, and at the same time, the tensile force of the press-fit pipe or the tensile resistance member is applied to the ground. In this case, a steel pipe can be used as the press-fit pipe, and a reinforcing bar, a steel material, or the like can be used as the tensile resistance member.

  The ground improvement construction method according to claim 10 is the ground improvement construction method according to any one of claims 1 to 9, wherein the injection pipe is installed in a curved shape or diagonally or horizontally in the ground below the building. It is characterized in that a plastic gel injection material is press-fitted into the ground via a press-fit pipe to strengthen the ground below the building.

  The ground improvement construction method according to claim 11 is the ground improvement construction method according to any one of claims 1 to 10, comprising a pressure gauge and a flow meter for measuring a press-fitting amount and a press-fitting pressure of the plastic gel injection material, and It has a displacement meter for measuring the displacement of the ground and a control device for receiving these and adjusting the injection and the injection point.

The ground improvement device according to claim 12 is formed by gradually expanding a lump gel consolidated body made of a plastic gel injection material in the ground by press-fitting the plastic gel injection material, and pushing the ground around. In a ground improvement device for compacting, a press-fit pipe inserted into the ground and a cylinder and a piston connected to the press-fit pipe for sucking and press-fitting a plastic gel injection material, a jack for operating the piston, and a cylinder of the piston It is characterized by comprising a press-fitting device provided with a displacement meter for measuring the amount of movement and the moving speed inside .

  A ground improvement device according to a thirteenth aspect is the ground improvement device according to the twelfth aspect, characterized in that the jack is a hydraulic jack screw jack or a jack operated by water pressure or pressure.

  According to the first aspect of the present invention, the crack of the ground is obtained by continuously pressing the plastic gel injection material into the ground while keeping the discharge amount, press-fitting pressure and press-fitting speed of the plastic gel injection material constant. Or by gradually controlling the increase / decrease / dissipation of pore water pressure to form a massive gel consolidated body made of plastic gel injection material in the ground. Thus, the ground can be strengthened by compacting the ground so as to push it around.

  For example, even in soft ground, the plastic gel injection material can be continuously pressed into the ground at a low discharge rate, low pressure and low speed to prevent cracks in the ground and deviation of the injected material. The increase, decrease, and dissipation of water pressure can be controlled continuously, and the ground can be strengthened by forming a massive gel consolidated body made of a plastic gel injection material in the ground while gradually expanding.

  According to the second aspect of the present invention, by continuously adjusting the discharge amount, press-fitting pressure and press-fitting speed of the plastic gel injecting material according to the soil layer of the ground constant, increasing and decreasing, Correspondingly, it is possible to prevent cracking of the ground and deviation of the injected material, and by continuously controlling the increase, decrease and dissipation of the pore water pressure, the bulk gel consolidated body consisting of plastic gel injected material in the ground The ground can be strengthened very efficiently by forming while gradually expanding.

  For example, when the ground is a soft soil layer, it is possible to prevent the surrounding ground from being destroyed by press-fitting the plastic gel injection material at a low discharge rate and low pressure in the initial press-fitting, and the solid gel consolidation As the body grows larger, the periphery is tightened, and correspondingly, the discharge speed is increased to increase the press-fitting pressure, whereby the expansion of the massive gel consolidated body and the compaction of the surrounding soil layer can be advanced. And if compaction of the surrounding soil of a lump gel consolidation progresses, even if a press-fit pressure increases further, press-fit and compaction can be advanced, without producing a pulse-like deviation to a soil layer.

  According to the invention described in claim 3, by using a screw jack or a hydraulic jack as a drive source for operating the piston, it is possible to inject a high pressure even with a low discharge amount of a plastic gel injection material. It can form a gel consolidated body and solidify and strengthen the ground.For example, it stabilizes the ground such as residential land, factory construction site or road, strengthens the slope (slope), and even existing buildings and There is an effect that can be used as a countermeasure against liquefaction on the ground directly under the structure.

  In addition, by forming the massive gel consolidated body while gradually expanding in the ground, the surrounding ground is compacted so that it is pushed around by the massive gel consolidated body. There is also an effect that can be applied to the ground improvement of the ground.

  1 to 3 show an embodiment of the ground improvement device of the present invention, respectively. In the figure, reference numeral 1 denotes a press-fitting pipe for press-fitting a plastic gel injection material (hereinafter referred to as “injection material”) into the ground. Is a press-fitting device for injecting an injection material into the ground via the press-in pipe 1, and 3 is an injection material production plant for producing an injection material to be injected into the ground.

  Reference numeral 4 is arranged between the press-fitting device 2 and the press-fitting pipe 1, and between the press-fitting device 2 and the injection material manufacturing plant 3, and from the injection material manufacturing plant 3 to the press-fitting device 2 and from the press-fitting device 2 to the press-fitting pipe 1. A pressure feed pipe 5 for pressure-feeding the injected material 5 is a three-way switching valve for switching the pressure feed path of the injected material from the injected material manufacturing plant 3 to the press-fitting device 2, and from the press-fitting device 2 to the press-fitted pipe 1. A control device (PC) that manages and controls the entire system.

  Reference numeral 7 denotes a ground displacement meter that measures the displacement (mainly uplift) of the ground surface due to the press-fitting of the injection material, and information related to the measurement result is transmitted to the control device 6.

  Based on the measurement results of the ground displacement meter 7, in order to prevent the ground displacement from becoming excessive by switching the injection amount of the injected material, the flow pressure, the pressure speed and the pressure point, etc. The compaction density can be increased by adjusting the press-fitting pressure, the press-fitting speed, and the press-fitting amount for each soil layer so as to be within the allowable ground displacement limit.

  In FIG. 2, reference numeral 18 denotes a switching valve for switching the injection material feed path to each press-fit pipe 1.

  For the press-fit pipe 1, a single pipe rod type, single packer type or double packer type press-fit pipe is used for the one-liquid composition, and a double pipe multi-phase type or multi-packer type press-fit pipe is used for the two-liquid composition. .

  In the case of the single tube rod system, a press-fit tube 1 having an injection material discharge port at the tip is used. For example, as shown in FIGS. 4 (a) to (d), the press-fit tube 1 is inserted into the ground, By gradually pulling out the press-fit tube 1 while injecting an injection material into the ground through the press-fit tube 1, a massive gel consolidated body A continuous in a columnar shape can be formed.

  At that time, for example, as shown in FIGS. 5A to 5D, the ground can be strengthened by inserting a tensile resistance member 8 made of a reinforcing bar or the like into the massive gel consolidated body A. The tensile resistance member 8 can be installed by being inserted into the ground together with the press-fit pipe 1.

  In the case of the single packer system, for example, as shown in FIG. 6, a press-fit outer tube 9 having a plurality of injection material discharge ports 9a and a valve 9b made of a rubber sleeve for opening and closing the injection material discharge port 9a on the side wall; A press-fit inner tube 10 having an injection material discharge port 10a at the tip and a packer 10b positioned above the injection material discharge port 10a is used.

  Then, as shown in the figure, the press-fit outer tube 9 is inserted into the ground, the press-fit inner tube 10 is inserted into the press-fit outer tube 9, and the packer 10 b is expanded to fill the inside of the press-fit outer tube 9 with the injection material discharge port. After sealing on the upper side of 9a, the aggregated gel consolidated body A can be formed in the ground by press-fitting the injected material into the ground through the injection inner tube 10. A columnar continuous gel aggregate A can be formed integrally with the press-fit outer tube 9 by gradually pulling out the press-fit inner tube 10 while performing this operation at the position of each injection material discharge port 9a.

  In the case of the double packer method, for example, as shown in FIG. 7, the same press-fitting outer tube as the single packer method is used for the press-fitting outer tube 9, and the press-fitting inner tube 10 has an injection material discharge port 10a and the injection material discharge at the tip. A press-fit inner pipe having two packers 10b and 10b located on the upper side and the lower side of the outlet 10a is used.

  Then, the press-fit outer tube 9 is inserted into the ground, the press-fit inner tube 10 is inserted into the press-fit outer tube 9, and the packers 10b and 10b are expanded so that the inside of the press-fit outer tube 9 is above and below the injection material discharge port 9a. After sealing between the two, a spherical massive gel-consolidated body A can be formed in the ground by press-fitting the injected material into the ground through the inner pipe 10.

  A columnar continuous gel aggregate A can be formed integrally with the press-fit outer tube 9 by gradually pulling out the press-fit inner tube 10 while performing this operation at the position of each injection material discharge port 9a.

  Further, in particular, as shown in the figure, the injection material is pressed into every one or a plurality of injection material discharge ports 9a, whereby the drain holes 10c formed of the injection material discharge ports 9a and the massive gel consolidated body A are connected to the injection outer tube. Nine axial directions can be formed alternately.

  Further, in the two-component blending, it can be injected using a double tube rod, and at that time, the blending ratio can be controlled by changing the extrusion speed of the liquid A and liquid B (see FIG. 3).

  The press-fitting device 2 sucks the cylinder 11 and the injection material manufactured in the injection material manufacturing plant 3 into the cylinder 11, pushes out the injection material sucked into the cylinder 11, and presses the injection material 1 through the pressure-feed pipe 4. And a screw jack or a hydraulic jack 13 for operating the piston 12 (see, for example, FIG. 1).

  In FIG. 1, when the injection material manufactured in the injection material manufacturing plant 3 is sucked into the cylinder 11, a path between the press-fitting device 2 and the injection material manufacturing plant 3 is secured in the three-way switching valve 5, and a screw jack or hydraulic pressure is secured. The jack 113 is actuated to retract the piston 12 (moved upward in the drawing) to generate suction in the cylinder 11. Then, the injection material manufactured in the injection material manufacturing plant 3 by the negative pressure in the cylinder 11 is sucked into the cylinder 11.

  On the other hand, when the injection material sucked into the cylinder 11 is press-fitted into the ground, a path between the press-in pipe 1 and the press-in device 2 is secured in the three-way switching valve 5 and the jack 13 is operated to advance the piston 12. Then, the injection material is pushed out of the cylinder 11 by the loading plate 14 attached to the tip of the piston 12.

  Then, the injected material is pumped into the press-fit pipe 1 through the press-pipe 4 and is press-fitted into the ground from the press-fit pipe 1. At that time, by gradually pulling up the press-fitting tube 1, a massive gel consolidated body A made of a plastic gel injection material can be formed in a columnar shape in the ground as shown in FIG. 1.

  In this case, the inhalation process and the press-fitting process of the injection material, and the speed, the press-fitting amount, the press-fitting speed, the press-fitting pressure, and the like of these processes are managed by the control device 6 by remote operation.

  Further, the press-fitting amount and press-fitting pressure at the time of press-fitting the plastic gel injection material are measured by a pressure gauge 15 attached in the cylinder 11 and a displacement meter 16 attached to the loading plate 14, and are managed by the control device 6. (See FIG. 2).

  In more detail in FIG. 1, when the valves 5 a and 5 b of the three-way switching valve 5 are opened, the valve 5 c is closed, and the piston 12 is pulled up by the jack 13, the injected material is sucked into the cylinder 11.

  Next, when the valves 5a and 5c are opened, the valve 5b is closed and the piston 12 is pushed down, the injected material is press-fitted into the ground. By gradually pulling up the press-fit tube 1 while repeating the above, a massive gel consolidated body A continuous in a columnar shape can be formed in the ground as shown in the figure.

  At that time, if the lowering speed of the piston 12 is decreased according to the hardness of the ground, the ground gel gradually expands without breaking the ground, and as the bulk gel consolidated body A expands, the surrounding ground Is compacted and the ground strength is increased. Therefore, if the press-fitting is continued and the pressurization amount is increased to adjust the press-fitting amount, the massive gel consolidated body A expands without destroying the surrounding ground or deviating in a pulse shape.

  Further, when the piston 12 is pulled up, if the valves 5c and 5a or the valves 5a, 5b, and 5c are opened while the valve 5b is closed, the injected material injected into the ground is drawn back into the press-fit pipe 1. As a result of the movement, negative pressure is applied to the massive gel consolidated body in the ground and the pore water pressure in the surrounding ground is reduced. As a result, the surrounding soil collapses to create a space.

  Then, next, when the valve 5c is closed and the valves 5a and 5b are opened and the injection material is sucked into the cylinder 11, the valve 5b is closed and the valves 5a and 5c are opened to press-fit the injection material. The injected material is pressed into the space.

  In this case, the piston 12 is moved up and down by the jack 13, the valves 5a, 5b and 5c are opened and closed, the moving speed of the piston 12 in the cylinder 11, the pressurizing force, the press-fitting speed and the press-fitting amount of the injection material in each stage, and the ground resistance Information and commands related to the transition of the force and press-fit stage can be managed by the control device 6. Further, the press-fitting operation can be performed based on information from the ground displacement meter 7.

In FIG. 2, the pressure gauge 15 measures the resistance force of the ground at the time of injection of the injected material, that is, the pressure, and the displacement gauge 16 measures the displacement amount, the displacement speed, the pressure amount, and the pressure speed of the piston 12 , respectively. Can be managed in the control device 6.

  That is, in the present invention, the piston 12 in the cylinder 11 is operated by the jack 13 to press-fit the injected material into the ground, and the optimum press-fitting according to the situation while grasping the ground situation and the press-fit situation at that time. While adding the speed, press-in amount, ground improvement status, and press-in pressure change to the ground, it is possible to increase the mass of the solid gel while making the ground loose.

  2 shows a case where a plurality of press-fitting pipes 1 are connected to a single press-fitting device 2, and the press-fitting pipe 4 connecting the press-fitting device 2 and each press-fitting pipe 1 is appropriately switched by opening and closing a switching valve 18. The injection material can be pressed into a plurality of injection points in order, or can be simultaneously injected into a plurality of injection points.

  8 (a) to 8 (c) show a method in which the injection material manufactured in the injection material manufacturing plant 3 is sucked into the cylinder 11 by the injection material pumping pump 17 connected between the injection material manufacturing plant 3 and the cylinder 11. As shown, according to this method, the injection material can be reliably sucked into the cylinder 11 in a short time.

  In this case, when the injection material is sucked into the cylinder 11, the switching valve 18a on the press-fitting pipe side is closed, the switching valve 18b on the injection material manufacturing plant 3 side is opened, and the piston 12 is pulled to make the inside of the cylinder 11 hollow. In this state, the pressure pump 17 is operated.

  When the injection material in the cylinder 11 is pumped to the press-fitting pipe side and press-fitted into the ground through the press-fitting pipe, the switching valve 18a is opened, the switching valve 18b is closed, and the jack is operated to move the piston 12 What is necessary is just to push down on drawing.

  FIG. 9 shows a method of simultaneously performing the step of sucking the injection material manufactured in the injection material manufacturing plant 3 into the cylinder 11 and the step of press-fitting the injection material sucked into the cylinder 11 into the ground. According to this, there is no waste in operation, the injection of the injected material can be performed very efficiently, and the apparatus can be made compact.

  In this case, the two cylinders 11 and 11 are arranged on the same axis at a constant interval, the piston 12 is arranged in each cylinder 11, and the piston rods 12a of the two pistons 12 are on the same axis. It is integrally formed with.

  Each cylinder 11 is provided with a switching valve 18a on the press-fit pipe 1 side and a switching valve 18b on the injection material manufacturing plant 3 side.

  Then, the injection material from the injection material manufacturing plant 3 can be sucked into one cylinder 11 and simultaneously the injection material sucked into the other cylinder 11 can be pressed into the ground via the press-in pipe 1.

  FIG. 10 shows a method in which a plurality of apparatuses shown in FIG. 9 are installed, and injection materials are simultaneously or sequentially injected into a plurality of points via a plurality of press-fitting pipes 1.

  Further, FIG. 11 shows that the capacity of the cylinder 11 is increased and a plurality of press-fitting pipes 4 extending from the press-fitting device 2 to the press-fitting pipe 1 are branched into a plurality of press-fitting pipes 1 and connected thereto. 1 shows a ground improvement device in which injection material can be press-fitted into a plurality of points simultaneously or sequentially.

  According to this embodiment, a large amount of injection material can be pressed into the loosely accumulated ground, while a small amount of injected material can be pressed into the ground that has been compacted to some extent, so that it can be compacted into a uniform deposited state. Note that the press-fitting amount and press-fitting pressure at the time of press-fitting the plastic gel injection material are measured by the pressure gauge 15, and the information is transmitted to the control device 6.

  Also, as shown in FIGS. 12 (a) and 12 (b), by simultaneously injecting the injection material into three or four adjacent injection points, a large restraining effect is exhibited at the center of the injection point, and efficiency is improved. Can be compacted.

  As shown in FIG. 13, a large number of press-fitting devices 2 are connected to one injection material manufacturing plant 3, and a press-fitting pipe 1 is connected to each press-fitting device 2, and these injection material manufacturing plant 3, press-fitting device 2, and By controlling the press-fitting pipe 1 with a single control device 6, it is possible to press-fit the injection material simultaneously or sequentially into a plurality of injection points via the multiple press-fitting pipes 1.

  In addition, by injecting the injection material under the arrangement as shown in FIGS. 12A and 12B, it is possible to press-in while constraining a certain range of soil by the solidified body (FIG. 12). 12).

  Further, as shown in FIG. 14, by pressing the injection material in rows at a plurality of points, even if the massive gel consolidated bodies A are not directly connected, the gap is within the range of influence of compaction. Since the density of the ground in the meantime increases and the ground strength increases, the same effect as that of the bulk gel consolidated body A is expected.

  Furthermore, as illustrated in FIG. 15, it is possible to form a massive gel consolidated body that is continuous in a planar lattice shape so as to completely surround the ground for each predetermined range. In this way, even in the event of an earthquake, the consolidated wall composed of the consolidated body A blocks repeated shearing forces such as earthquakes by the massive gel consolidated body A and the compaction zone therebetween, and is surrounded by the consolidated wall. Further, the increase in excess pore water pressure inside can be suppressed and liquefaction can be suppressed.

  In addition, when the consolidated body is a concrete body, the density of the surrounding ground does not become dense, but when the plastic gel injection material is press-fitted, the density of the surrounding area also increases and the wall As a whole, the seismic structure makes it difficult for the wall itself to be destroyed by seismic motion and absorbs it.

  In addition, as shown in FIG. 16, the side of the massive gel consolidated body A continuous in a columnar shape is uneven, so that the ground between the massive gel consolidated bodies A and A is stepwise relative to each other. Since the surface only undergoes a gentle displacement without displacement, there is an advantage that the upper structure (not shown) remains broken so that it can be easily recovered without being completely damaged.

  Further, by using a member having a drain function in the press-fitting pipe, it becomes possible to drain pore water simultaneously with the compaction of the ground, and compaction can be performed very efficiently.

  Further, by installing a press-fit pipe having a drainage function and a reinforcement function in the ground, drainage of underground water and reinforcement of the ground can be performed simultaneously. In this case, a steel pipe (such as a perforated steel pipe) can be used as the press-fit pipe.

  Furthermore, the press-fit pipe in which one or a plurality of massive gel consolidated bodies A are integrally formed in this way can also be used as a foundation pile reinforcing pile that dissipates excess pore water pressure during an earthquake (see FIG. 6).

  17 and 18 show an example in which the present invention is applied mainly to the ground directly under an existing building or structure such as a building or a storage tank for the purpose of ground improvement, liquefaction prevention or cavity filling. It is.

  The construction method will be described. In FIGS. 17A and 17B, a press-fit pipe 20 having a drain function (drainage function) is provided below the existing structure 19 in the ground directly under the existing structure 19 such as a storage tank. A plurality of them are laid in parallel so as to straddle, and both ends 20a, 20b are projected to the ground surface.

  Further, the plastic gel injection material is press-fitted into the ground just below the existing structure 19 from one end side 20a of the press-fit pipe 20, and a plurality of massive gel consolidated bodies A are gradually expanded on the outer peripheral portion of each press-fit pipe 20. Form.

  Then, the ground around the consolidated body A is compacted so that the massive gel consolidated body A gradually expands and is pushed to the surroundings to strengthen the ground. At that time, the pore water generated by compacting the ground is drained to the ground from the opposite end 20b of the press-fit pipe 20 through the press-fit pipe 20 having a drain function.

  In addition, the bore hole for laying the press-fit pipe 20 may be drilled first, and the press-fit pipe 20 may be inserted into the bore hole later. The press-fit pipe 20 has a drain function semipermanently even after the ground improvement is completed.

  18 (a) and 18 (b), a plurality of press-fit pipes 20 having a boring function in a ground directly under an existing structure 19 such as a storage tank are arranged in parallel and in multiple stages so as to straddle the lower side of the existing structure 19. Laying and projecting one end side 20a to the ground.

  Further, the plastic gel injection material is press-fitted into the ground just below the existing structure 19 from one end side 20a of the press-fit pipe 20, and a plurality of massive gel consolidated bodies A are gradually expanded on the outer peripheral portion of each press-fit pipe 20. Form.

  Then, the ground around the consolidated body A is compacted so that the massive gel consolidated body A gradually expands and is pushed to the surroundings to strengthen the ground.

  The press-fitting pipe 20 is provided with an apparatus capable of confirming the position of the tip of the press-fitting pipe 20 from a plurality of position confirmation systems, such as an electromagnetic induction method, an insertion type gyro, a method using an inclining / azimuth meter and a wireless communication system. Performed by free boring.

  Alternatively, the boring hole may be first drilled by free boring, and then the press-fit tube 20 may be inserted into the boring hole to form the massive gel consolidated body A.

  FIGS. 19 (a) and 19 (b) show the effects of the present invention confirmed by experiments. In the experiment, four times using a press-fitting device equipped with a cylinder having a plastic gel injection material suction amount of 20 liters. In the injection process, four massive gel consolidated bodies A were formed in the ground (see FIG. 1).

  FIG. 19A shows the relationship between the press-fitting time and the press-fitting amount of the plastic gel injection material, and FIG. 19B shows the relationship between the press-fitting amount and the press-fitting pressure of the plastic gel injection material. You can see that it has changed. Thereby, since the press-fitting pressure of the plastic gel injection material can be managed in real time and the optimum press-fitting amount can be grasped, the ground improvement can be performed efficiently and economically.

  The present invention can efficiently and reliably strengthen the ground by compacting the ground by forming the massive gel consolidated body made of the plastic gel injection material in the ground while gradually expanding.

It is a general view which shows the outline | summary of a ground improvement apparatus. It is a general view which shows the outline | summary of a ground improvement apparatus. It is a figure which shows a partial outline | summary of a ground improvement apparatus. (A)-(d) is a figure which shows a construction procedure. (A)-(d) is a figure which shows a construction procedure. It is a figure which shows a construction procedure. It is a figure which shows a construction procedure. (A)-(c) is a figure which shows the outline | summary of a press-fit apparatus. It is a figure which shows the outline | summary of a press-fitting apparatus. It is a figure which shows the outline | summary of a press-fitting apparatus. It is a general view which shows the outline | summary of a ground improvement construction method. (A), (b) is a top view which shows the example of arrangement | positioning of the press injection pipe at the time of carrying out simultaneous injection | pouring to multiple points, or press-fitting in order. It is a figure which shows the outline | summary of the press-fitting apparatus which press-fits in several places simultaneously or in order. It is a top view which shows the example of arrangement | positioning of the press-fit pipe | tube at the time of carrying out the press-fitting to several points simultaneously or in order. It is a top view which shows the example of arrangement | positioning of a block-shaped gel solid body. It is a longitudinal cross-sectional view of FIG. The example which applied the ground improvement construction method of the present invention to the ground just under an existing structure is shown, (a) is a longitudinal section and (b) is a top view. The example which applied the ground improvement construction method of the present invention to the ground just under an existing structure is shown, (a) is a longitudinal section and (b) is a top view. The effect of the present invention is shown by experiment, (a) is a graph showing the relationship between the injection time of the injection material and the injection amount, and (b) is a graph showing the relationship between the injection amount of the injection material and the injection pressure. is there. It is a graph which shows the relationship between the press-fitting time, press-fit speed | velocity | rate, and pressure when injecting high-pressure injection material using the conventional high-pressure injection pumps, such as a diaphragm pump.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Press-in pipe 2 Press-in apparatus 3 Injection material manufacturing plant 4 Pressure feed pipe 5 Three-way switching valve 6 Control apparatus (PC)
7 Ground displacement meter 8 Tensile resistance member 9 Press-fit outer tube 10 Press-fit inner tube 11 Cylinder 12 Piston 13 Jack 14 Loading plate 15 Pressure gauge 16 Displacement meter 17 Injection material feed pump 18 Switching valve 18a Switching valve 18b Switching valve 19 Existing structure 20 Press-fit pipe

Claims (13)

In the ground improvement method in which a massive gel consolidated body made of plastic gel injection material is gradually expanded in the ground by press-fitting of the plastic gel injection material, and the ground is compacted so as to push the ground around. A cylinder and a piston connected to the inserted press-fit pipe and the press-fit pipe for sucking and press-fitting the plastic gel injection material, a jack for operating the piston, and a moving amount and a moving speed of the piston in the cylinder are measured. The displacement and the moving speed of the piston in the cylinder are measured by the displacement meter, and the piston is operated based on the measurement result to suck in the plastic gel injection material. By repeating the press-fitting, the press-fitting pressure and pressure of the plastic gel injection material are expanded while expanding the massive gel consolidated body so that the ground does not break. Speed, and ground improvement method, wherein the compacting by adjusting the press-fitting amount. Based on the measurement result of the ground displacement meter, the displacement of the plastic gel injection material is allowed in real time according to the ground displacement so that the ground displacement does not become excessive by switching the press-fitting pressure, press-fitting speed and press-fitting point. 2. The ground improvement method according to claim 1 , wherein the press-fitting pressure, the press-fitting speed, and the press-fitting amount for each soil layer are adjusted so as to be within the limits, and then compacted . The ground improvement method according to claim 1 or 2, wherein the press-fitting pressure of the plastic gel injection material is measured by a pressure gauge attached to a pipe leading to the press-fitting pipe in the cylinder .   The ground improvement method according to any one of claims 1 to 3, wherein the jack is a hydraulic jack, a screw jack, or a jack that is operated by water pressure or pressure.   The ground improvement method according to any one of claims 1 to 4, wherein the plastic gel injection material is press-fitted into a plurality of points selected in a row or lattice form from a plurality of injection points.   The ground improvement method according to any one of claims 1 to 5, wherein the plastic gel injection material is pressed into a plurality of points simultaneously or sequentially.   The ground improvement method according to any one of claims 1 to 6, wherein the plastic gel injection material is press-fitted at a constant interval. A drain material is installed in the ground to promote dehydration in the ground, or a plastic gel injection material is pressed through a press-fit pipe having a water absorption port. The ground improvement method according to any one of claims 1 to 7, wherein the soil water is dehydrated from a drain material or a water inlet.   A press-fit pipe having a tensile resistance force in the ground, or a press-fit pipe is inserted together with a tensile resistance member, and compressing the ground to increase the density and simultaneously applying the tensile force of the press-fit pipe or the tensile resistance member to the ground The ground improvement construction method according to any one of claims 1 to 8.   It is characterized in that a press-fit pipe is inserted into the ground below the building in a curved shape, diagonally or horizontally, and a plastic gel injection material is pressed into the ground through the press-fit pipe to strengthen the ground below the structure. The ground improvement construction method according to any one of claims 1 to 9.   Based on the flow rate meter that measures the amount of plastic gel injection, the pressure meter that measures the pressure of plastic gel injection, the displacement meter that measures the displacement of the ground, and the measurement values obtained from these instruments The ground improvement method according to any one of claims 1 to 10, further comprising a control device for adjusting an injection amount and an injection point of the plastic gel injection material. In the ground improvement device that forms a lump gel consolidated body made of plastic gel injection material in the ground by gradually injecting the plastic gel injection material, and compacts the ground so as to push it around. Cylinder and piston connected to the inserted press-fit pipe and the press-fit pipe for sucking and press-fitting the plastic gel injection material, a jack for operating the piston, and measuring the moving amount and moving speed of the piston in the cylinder A ground improvement device comprising a press-fitting device provided with a displacement meter for the purpose .   The ground improvement device according to claim 12, wherein the jack is a hydraulic jack, a screw jack, or a jack that is operated by water pressure or pressure air.

Images