JP6342126B2 - Ground injection method - Google Patents

Description

  The present invention relates to a ground injection method that can be applied to a case where injection material is injected into a ground at a low pressure to reduce the influence on adjacent structures, for example, when it is necessary to pay attention to displacement in a mine or a tunnel.

  For example, underground tunnels are mainly constructed by shield machines, but when the excavation length is long, excavation is performed with two shield machines from both sides of the planned joining point, and the shield machines are joined in the ground. The ground between them is excavated, and excavation for joining is performed manually. In addition, there are cases where a shield tunnel has to be partially widened at a branch of a route or a station.

Conventionally, in order to cope with groundwater springs and subsidence of surrounding ground, these constructions have been carried out after improving the shield surrounding ground by the freezing method or the grout injection method.
Conventionally, in the tunnel face, under conditions where the natural ground is sandy ground and easily collapses, a chemical injection method has been carried out as one of the stable holding methods for the tunnel face.

The chemical solution injection method is constructed by drilling to a predetermined depth using a rock drill, etc., then inserting the injection rod into the hole and sequentially pulling out the injection rod while feeding the chemical solution into the ground ( For example, see Patent Document 1).
However, in the chemical injection method shown in Patent Document 1, when the target ground is made of sandy soil or gravel, for example, the hole wall is very easy to collapse. Immediately after the hole wall collapsed, there was a problem that the injection rod could not be inserted.

Also, in the drilling work using the inner and outer double pipes, by inserting the injection pipe for supplying chemicals into the inner pipe of the double pipe and making the inner pipe also serve as an injection rod, A method of inserting an inner tube at the same time is disclosed (for example, see Patent Document 2).
However, the method of Patent Document 2 is applied to this method because the chemical solution supply injection tube is inserted into the inner tube of the double tube, and the chemical solution supply injection tube is disposed in the hole simultaneously with the drilling. The drilling machine is mainly a rotary boring machine, and a work scaffold has to be temporarily installed according to the height of the drilling site, which is very complicated.

Moreover, in the method of Patent Document 2, it is necessary to place a lock bolt in order to maintain the stability of the top and side walls of the tunnel after excavation is completed. It is common for machines to be installed. Accordingly, when performing chemical injection, it is very complicated in that it is necessary to retract the rock drill to the rear and then carry in and install the rotary boring machine.
It is known that when the collapsible ground is distributed on the planned tunnel route, the collapse of the tunnel top end associated with excavation is prevented (for example, see Patent Document 3).

However, in the method of Patent Document 3, it is possible to form an improved body around the steel pipe, but since the steel pipe is used, the ground in front of the steel pipe remains unmodified. For this reason, when tunnel excavation is carried out after the steel pipe is built, the excavation up to the tip of the steel pipe collapses the soil in the unmodified part, so that the excavation can only be done somewhat before the tip of the steel pipe.
Further, in Patent Document 3, the steel pipe is constructed from the face of the tunnel face, and an injection material such as urethane or cement milk is filled in the ground using the steel pipe, and the improved body continuously around each steel pipe. A method of forming is disclosed.

In addition, in the method of Patent Document 3, since the steel pipe was built and injected in separate procedures, even after trying to improve the ground around the steel pipe by inserting the injection pipe into the steel pipe after the steel pipe was built, There is a problem that the collapsed sand flows from the tip opening of the steel pipe located in the mountain and closes the steel pipe, and the injection pipe cannot be inserted to a predetermined position in the steel pipe.
As described above, when the injection method is used in a mine or a tunnel, an excessive injection pressure acts on the shield segment to cause an influence such as displacement.
There is a double pipe strainer method in the ground injection method generally used, and it is classified into a single-phase type and a multi-phase type. The gel time of the injection material is the instantaneous setting material (about 10 seconds) for the single phase type, and the instantaneous setting material and the intermediate setting material (several tens of seconds to several minutes) for the double phase type.

Japanese Patent Laid-Open No. 11-350869 JP 2002-363966 A JP 2001-20657 A

However, the single-phase type of the double-pipe strainer method uses an instantaneous setting material, but since the instantaneous setting agent hardens in about 10 seconds, a stress is generated in an instant and affects the adjacent structure.
On the other hand, the double-pipe strainer method that does not use an instantaneous setting material has almost no construction record, and even when it is constructed, injection material leaks, and reliable injection cannot be performed.

Moreover, in order to inject from the shield by the conventional double tube strainer method, the injection tube is inserted from the grout hole provided in the shield segment and the chemical solution is injected, but the instantaneous injection material used for the primary injection Will not penetrate into the ground, and will be injected in a pulsatile manner while destroying the structure of the soil skeleton, and stress acts on the shield segment.
Further, in the secondary injection, as the pore water pressure around the injection material increases, the ground causes local shear failure, and stress acts on the shield segment.

If the injection is continued, excessive stress acts on the shield segment, and eventually the shield segment is deformed.
Since it is necessary to stop the injection when the shield segment is deformed, the improvement rate is insufficient. If the improvement rate is insufficient, troubles such as flooding will occur when the shield is widened.
In addition, when reinjection is performed by taking measures such as reinforcing the shield segment, there are problems such as process delay and cost increase.

  The present invention has been made to solve such a conventional problem, and an object of the present invention is to inject an injection material without giving displacement to a neighboring structure, and to provide a solid water stop effect and ground strength. It is to provide an injection method.

In the invention according to claim 1, a predetermined time has elapsed since the first injection step of pulse-injecting a water glass-based solution type organic alkaline intermediate material into the target ground and the first injection step. In response, the second injection step of infiltrating and injecting the intermediate binder into the target ground, and the process of executing each step with the same depth from the ground surface of the target ground, the target repeated a plurality of times while changing the depth from the ground surface of the ground, said first implantation step and the second implantation step, infusion rate based on the stress of the shield segments after injection, the in formation member Alternatively, it is performed while adjusting the injection pressure.
In the invention according to claim 2, a predetermined time has elapsed since the first injection step of pulse-injecting the water glass-based solution type organic alkaline intermediate material into the target ground and the first injection step. In response, the second injection step of infiltrating and injecting the intermediate binder into the target ground, and the process of executing each step with the same depth from the ground surface of the target ground, the target The first injection step and the second injection step are repeated a plurality of times while changing the depth of the ground from the ground surface. The first injection step and the second injection step are based on the displacement of the adjacent structure, and the injection speed or injection pressure of the intermediate binder It is characterized by executing while adjusting.
In the invention according to claim 3, a predetermined time has elapsed since the first injection step of pulse-injecting the water glass-based solution-type organic alkaline intermediate material into the target ground and the first injection step. In response, the second injection step of infiltrating and injecting the intermediate binder into the target ground, and the process of executing each step with the same depth from the ground surface of the target ground, the target Repeated multiple times while changing the depth of the ground from the ground surface, the first injection step and the second injection step are the injection of the intermediate binder based on the pressure and displacement of the earth retaining after injection It is carried out while adjusting the speed or the injection pressure.

According to a fourth aspect of the present invention, there is provided an injection method according to any one of the first to third aspects, wherein a step of drilling the target ground to a predetermined depth, and an injection pipe are added to further cut the ground. And a step of perforating.

The invention according to claim 5 is the injection method according to any one of claims 1 to 3 , further comprising a step of drilling the deepest portion of the target ground, and further drilling while pulling out the injection pipe. And further comprising the step of:

The invention according to claim 6 is characterized in that, in the injection method according to claim 4 or claim 5 , the injection pipe uses a double pipe strainer pipe and performs injection in a single phase system.
The invention according to claim 7 is the injection method according to claim 1 , wherein the target ground is a ground whose injection range is directly under the structure .

The invention according to claim 8 is characterized in that, in the pouring method according to claim 3 , the target ground is a ground in which the pouring range can secure a covering thickness of about 1 m or more .
The invention according to claim 9 is the injection method as claimed in any one of claims 8, wherein in the sintered material, gel time 30 seconds to 6 minutes, the predetermined time is 15 seconds to 30 seconds It is characterized by being.

According to the present invention, only the intermediate binder is used as the injection material, and the injection is interrupted in the same step, so that it is possible to expect the rough packing and packing effects, which are the roles of the conventional instantaneous setting material.
According to the present invention, only the intermediate binder is used as the injection material, and the injection is interrupted in the same step, so that the quality of the cured product is remarkably improved.

  According to the present invention, by using a medium binder with a gel time of about 30 seconds to 6 minutes and providing an interval of 15 seconds to 30 seconds at the time of injection, the first half injection is coarsely packed injection (instantaneous connection material). The ratio of penetration of the latter half of the injection can be balanced, so for example, when the injection range is directly under the structure, such as the back of the shield segment or directly under pressure-resistant concrete, or the soil cover thickness is 1m. It can be effectively applied to water stoppages on the back of the retaining ring that can be secured to a certain extent and water stoppages for crossing work under the track.

According to the present invention, when applied to a chemical solution injection method for the purpose of ensuring the safety of the earth retaining and excavated bottom surface, the entire target ground can be reliably improved while preventing deformation of the earth retaining due to the injection.
According to the present invention, when applied to water stoppage measures by chemical injection that prevents subsidence of the face and the sinking of the foundation board directly below the face where the independence of the face cannot be secured, the entire target ground is prevented while preventing the line from rising due to the injection. Can be improved reliably.
According to the present invention, when applied to ground strengthening by chemical solution injection that prevents subsidence of a track where the self-supporting property of the face cannot be ensured, the entire target ground can be reliably improved while preventing the rail from rising due to injection.

It is a figure which shows the earth tub injection | pouring experiment apparatus used in Embodiment 1 of this invention. It is a figure which shows the concrete gauge and displacement meter (CDP type displacement meter) which were arrange | positioned in the mold upper surface in order to monitor the behavior at the time of injection | pouring of FIG. It is a figure which shows each step in CASE1-CASE6 of FIG. It is a figure which shows the control pattern of the injection apparatus in Embodiment 2 of this invention. It is the schematic which shows the apparatus structure of the injection apparatus used for the injection method which concerns on Embodiment 3 of this invention. It is explanatory drawing which shows the main components of the injection apparatus in FIG. It is a figure which shows the construction flow of the injection construction method which concerns on Embodiment 3 of this invention. It is a schematic diagram of the injection | pouring condition in the construction flow of FIG. It is a figure which shows the control flow of FIG. It is a figure which shows the control pattern of the injection apparatus in Embodiment 4 of this invention. It is a figure which shows the control flow of the injection apparatus shown in FIG. It is a figure which shows the construction flow of the injection construction method which concerns on Embodiment 5 of this invention. It is a schematic diagram of the injection | pouring condition in the construction flow of FIG. It is a figure which shows the example applied to the countermeasure against liquefaction just under a structure based on the injection | pouring method of Embodiment 6 of this invention. It is a figure which shows the example applied to the water stop countermeasure of the earth retaining back based on the injection | pouring method of Embodiment 7 of this invention. It is a figure which shows the example applied to the water stop countermeasure of the crossing under a track based on the injection | pouring method of Embodiment 8 of this invention. It is a figure which shows the injection | pouring range of FIG. It is a figure which shows the example applied to the ground reinforcement of the crossing under a track based on the injection | pouring method of Embodiment 6 of this invention. It is a figure which shows the injection | pouring range of FIG.

Hereinafter, the present invention will be described based on embodiments shown in the drawings.
(Embodiment 1)
For example, in the shield widening part, a chemical solution injection method applied as a water stoppage countermeasure at the time of widening inserts an injection tube into the segment grout hole from the inside of the shield. At this time, since there is a concern about the displacement of the shield segment due to the injection pressure, it is necessary to carry out the construction method in consideration of the displacement.

Therefore, the double pipe strainer method (single phase type) is applied as the construction method.
The single-phase type of the double-pipe strainer method uses caking material, so it quickly solidifies and displaces. Since it became difficult to cope with this, the injection material was used as a binder. However, single-phase injection with a binder is a major obstacle to adoption because it has almost no track record in the past and no literature has been confirmed to be safe.
Therefore, in this embodiment, a soil tank experiment simulating sandy soil on the back of the shield segment was performed, and an experiment was performed to confirm the applicability of the injection method and the optimum construction specifications.

  In this embodiment, the test injection is a double-pipe strainer method single-phase type (medium binder), and a method of temporarily stopping the injection in each step (hereinafter referred to as an inching injection method) is adopted. In addition, in order to analyze the test results, one case of a normal double-pipe strainer method double phase was included.

In the present embodiment, as shown in FIG. 1, the following confirmation was performed using a soil tank injection experimental apparatus (Φ56 cm × H80 cm: drum can) 1.
(1) Confirmation of the effect of chemical solution gel time on the improved body shape (2) Confirmation of the effect of construction specifications of the inching injection method on the improved body shape (3) Injection pressure increase and ground surface displacement

In general, the single-phase type of the double-pipe strainer method uses an instantaneous setting material, and the double-phase type uses an instantaneous setting material and an intermediate to mild setting material. In this case, since the instantaneous setting material hardens in a few seconds, stress is generated in an instant and affects the adjacent structure. In addition, the double-pipe strainer method that does not use instantaneous setting material has almost no track record, and even when it is constructed, there is a lot of leakage of the injection material, and reliable injection cannot be performed.
In this embodiment, an inching injection method was proposed as an injection method for solving such a problem, and its workability and injection effect were verified.

The inching injection method uses only the intermediate binder, and interrupts the injection in the same step, so that the rough packing / packing effect that is the role of the conventional instant binder is expected.
Here, the inching injection method is basically a step-down method, and the chemical solution gel time is standard (ten dozen seconds to several minutes) as a standard.
For example, after drilling, 1st injection is performed, the pump is stopped, 2nd injection is performed, then re-drilling is performed, 1st injection is performed, the pump is stopped, 2nd injection is performed, and re-drilling is performed. 1st injection is performed, the pump is stopped, and the step of performing 2nd injection is repeated.

The soil layer experiment apparatus 1 shown in FIG. 1 uses a cylindrical mold (drum can) 2. A gravel drainage layer 3 was provided in the lowermost layer, experimental sand 4 was filled on the drainage layer 3, and four drain pipes 5 were installed on the side surface. The drain pipe 5 was used for water injection at the time of saturation and for drainage at the time of injection. The experimental sand 4 was solidified to a state of 80% Dr and divided into a plurality of layers to a layer thickness of 74 cm. A lid 6 was provided with a mortar having a thickness of 5 cm at the top of the mold, and water was sent from the drain pipe 5 at an injection pressure of about 50 kPa or less to saturate the sample. The uniaxial compressive strength of the mortar was 46.5 N / mm ² .

  Further, in order to monitor the behavior at the time of pouring, as shown in FIG. 2, concrete gauges 7 are arranged in two directions (0 °, 90 °) × 3 places = 6 points on the upper surface of the mold 2. C0-1, C0-2, and C0-3 were arranged in the 0 ° direction, and C90-1, C90-2, and C90-3 were arranged in the 90 ° direction. The concrete gauge 7 includes, for example, a steel gauge, a foil gauge based on polyester resin used for measurement of surface strain of concrete, mortar, and short-term measurement of wood.

Displacement meters (CDP displacement meters) 8 were arranged in two directions (0 °, 90 °) × 3 locations = 6 points. H0-1, H0-2, and H0-3 were arranged in the 0 ° direction, and H90-1, H90-2, and H90-3 were installed in the 90 ° direction.
In this embodiment, the injection material and the injection specification were set to 6 types. Table 1 shows the experimental conditions in each case.

CASE 1 and 5 were a general double-pipe strainer double-phase type, CASE 2 was a double-pipe strainer single-phase type, and CASE 3 and 4 and 6 were inching injection methods (intermediate binders). In this experiment, the injection interval time was set to 0 to 30 seconds in consideration of economy and workability.
The experimental method was a step-down method in which a double tube rod 9 was inserted while feeding water while simulating a drilling hole in the execution work, and drilling / injection was repeated every step, and the number of steps was 3 steps per lCASE.

Assuming that the diameter of the improved body is 46 cm and the porosity is 40% (filling rate 90%), the injection amount is 18 L per step.
The injection completion standard was quantitative injection, and the maximum injection pressure (initial pressure + 0.5 Mpa) was determined, but all were quantitative injections. At the time of injection, the injection speed, pressure, strain and displacement were measured.
After curing, the mold (drum can) 2 was disassembled, and water was poured to dig out the solidified body to confirm the improved body shape. In addition, representative improvements were submitted to the soil test site to confirm strength and water permeability.

CASE1
As shown in FIG. 3A, CASE 1 injects 18 L in one step, 18 L injection in 2 steps, and instantaneous binding material with a gel time of 10 seconds and medium binding material with a gel time of 8 minutes. 18L was injected in steps. The total injection volume was 54L.
In CASE 1, the stress of the shield segment reaches 6 N / mm ² immediately after the start of injection, and displacement occurs simultaneously.
The displacement has reached about 7 mm.
The instantaneous setting material hardens, and the stress is generated in an instant, so that the displacement occurs immediately.

CASE2
As shown in FIG. 3B, CASE 2 injected 18L in 2 steps, 18L injection in 2 steps, and 18L injection in 3 steps, with an interruption time of 0 seconds, a medium binder having a gel time of 6 minutes. The total injection volume was 54L.
In CASE 2, the stress of the shield segment is as low as about ² N / mm ^{2 at} maximum, but the displacement gradually increases with the progress of injection.
It is presumed that the injected material does not penetrate the ground and flows into the back surface of the shield segment.

CASE3
As shown in FIG. 3 (C), CASE 3 has a suspension time of 15 seconds for a medium time with a gel time of 6 minutes, 1st injection in 1 step, 2nd injection after 15 seconds of interruption time, total 18L injection, 2 steps Then, after the 1st injection, 2nd injection was performed 15 seconds after the interruption time, and a total of 18 L was injected. In 3 steps, after the 1st injection, 2nd injection was performed 15 seconds after the interruption time, and a total of 18 L was injected. The total injection volume was 54L.
In CASE3, the stress of the shield segment is about 1 N / mm ^{2 at} the maximum, and changes at a low value.
There is no displacement.
The improved body is slightly smaller, and the chemical solution is out of the improved range.

CASE4
As shown in FIG. 3 (D), CASE 4 has a suspension time of 30 seconds for a medium time with a gel time of 6 minutes, 1st injection in 1 step, 2nd injection after 30 seconds of interruption time, and a total of 18L injection. Then, after the 1st injection, 2nd injection was performed 30 seconds after the interruption time, and a total of 18 L was injected. In 3 steps, after the 1st injection, 2nd injection was performed 30 seconds after the interruption time, and a total of 18 L was injected. The total injection volume was 54L.
In CASE4, the stress of the shield segment of 1 to 2 steps is about 1.5 N / mm ^{2 at} the maximum, and is changing at a low numerical value, and no displacement occurs.
In the third step, the stress of the shield segment reaches about ^2.5 N / mm ² , causing displacement.
The water permeability coefficient of the improved soil is the lowest and the water stop performance is high.

CASE5
As shown in FIG. 3 (E), CASE 5 was prepared by injecting 18 L in 1 step, 18 L in 2 steps, and 18 L in 3 steps, with an interruption time of 0 seconds, a medium binder having a gel time of 30 seconds. The total injection volume was 54L.
In CASE5, in the first step, the stress of the shield segment is within ² N / mm ² and no displacement occurs.
In the second step, the stress of the shield segment reaches 3 N / mm ² , and displacement occurs at that stage.
The displacement finally reaches about 50 mm.
It is presumed that the injection material flows into the back surface of the shield segment without penetrating the ground, and the injection pressure directly acts on the shield segment.

CASE6
As shown in FIG. 3 (F), CASE 6 has a suspension time of 15 seconds for a medium time of 30 seconds with a gel time of 30 seconds, 1st injection in 1 step, 2nd injection after 15 seconds of interruption time, and a total of 18L injection. Then, after the 1st injection, 2nd injection was performed 15 seconds after the interruption time, and a total of 18 L was injected. In 3 steps, after the 1st injection, 2nd injection was performed 15 seconds after the interruption time, and a total of 18 L was injected. The total injection volume was 54L.
In CASE6, the stress of the shield segment is about 1.5 N / mm ^{2 at} the maximum, and is changing at a low value.
There is no displacement.
The shape of the improved body is distorted, and the improvement effect is not uniform.

Summary of CASE1-CASE6:
A summary of CASE 1 to CASE 6 is shown in Table 2.
Here, the surface stress F when a displacement of 1 mm occurs is defined as an allowable surface stress Fb.
Further, F _30% = Fb × 0.3, F _50% = Fb × 0.5, and F _70% = Fb × 0.7.
However, CASE 3 and 6 whose displacement does not reach 1 mm are values that reach the surface stress F _max .
As shown in Table 2, the double pipe strainer single phase type / double phase type of CASE 5, 2, 1 has an injection improvement rate (progress rate) of 14% when the surface stress F reaches the allowable surface stress Fb. 44%.

On the other hand, the inching injection method of CASE 3, 6 and 4 has an injection improvement rate (progress rate) at the time when the surface stress F reaches the allowable surface stress Fb or F _max , resulting in displacement. Almost a predetermined amount of injection could be performed without causing this.
From the above, as shown in the present embodiment, it was confirmed that according to the inching injection method, it is possible to inject the chemical solution while reducing the displacement of the shield segment due to the injection pressure.

(Embodiment 2)
In the present embodiment, for CASE1 to CASE6 in the first embodiment, injection at each step is performed based on the control pattern shown in FIG. The control pattern shown in FIG. 4 is first injected at an injection rate of 100%, and when the stress that increases with the injection reaches the primary control value (F _30% ), the injection rate is reduced to 75% and injected. When the stress that increases with the injection reaches the secondary control value (F _50% ), the injection rate is reduced to 50%, and when the stress that increases with the injection reaches the tertiary control value (F _70% ), injection occurs. The injection is performed by reducing the rate to 25%, and the injection rate is reduced to 0% when the stress that increases with the injection reaches the allowable value Fb (F _max ).

The results are shown in Table 3.
The experimental conditions in each case are the same as in Table 1.
The allowable surface stress Fb is 1.5 N / mm ² from the first embodiment.
Moreover, the injection improvement rate (progress rate) was confirmed at each stage of F _30% = Fb × 0.3, F _50% = Fb × 0.5, and F _70% = Fb × 0.7.
However, CASE 3, 6, and 4 where the displacement does not reach 1 mm are numerical values with respect to the surface stress F _max .

The injection progress rate of the CASE 1, 2, 5 double tube strainer method was improved 1.9 to 3.7 times, but reached the allowable surface stress Fb, and the injection was interrupted.
The injection progress rate of the inching injection method of CASE 3, 4 and 6 achieved 100% at F _70% .
As described above, in CASE 3, 4 and 6, when the control pattern of FIG. 4 is applied, the injection rate is reduced according to the surface stress value generated in the concrete, thereby suppressing the displacement and ensuring the injection progress rate of 100%. I was able to confirm that it was possible.
In addition, it was confirmed that by applying the control pattern shown in FIG. 4 to the apparatus for reducing the injection speed, a certain displacement suppression effect can be obtained even in the double pipe strainer system.

(Embodiment 3)
5 to 9 show an injection method according to this embodiment.
First, based on FIG. 5, FIG. 6, the injection apparatus A for implementing the injection method which concerns on this embodiment is demonstrated.
The injection device A controls the operation of the rotary boring machine 11 that drills the double tube rod 12 in the target ground 13. As in the conventional case, the double tube rod 12 is provided with a swivel 16 at the head and a grout monitor 14 and a bit 15 at the tip. An injection hose 17 and an injection hose 18 are connected to the swivel 16. Water is injected into the injection hose 17 at the time of drilling, and liquid A is injected at the time of injection. The injection hose 18 is injected with water at the time of drilling and liquid B at the time of injection.

In the present embodiment, the rotary boring machine 11 is used as a drilling device for drilling the double tube rod 12 into the soil. However, the present invention is not limited to this, and for example, a rotary percussion drill and a hand auger are used. It may be used.
As shown in FIGS. 5 and 6, the infusion device A includes a dynamic management device 24 that restricts the number of rotations of the infusion pump 20 according to behavior such as stress and displacement, and determines a stop instruction. A dynamic management device system configured by local area connections 31 and 32 connected via a network is used.

The injection hose 17 and the injection hose 18 are connected to a flow rate / detector 19 that measures pressure, instantaneous flow rate, and integrated flow rate.
The flow rate / detector 19 communicates with the injection management device 22 via the LAN. The injection management device 22 communicates with the injection pump 20 via the inverter panel 23 by inverter communication. Infusion pump 20 communicates with grout mixer 21.
The infusion management device 22 communicates with the dynamic management device 24 via the LAN, and displays and records the pressure, instantaneous flow rate, and integrated flow rate, determines the rotation speed of the infusion pump 20 according to the flow rate, and performs multiphase control. The dynamic management device 24 communicates with the observation data recording PC 25, and the observation data recording PC 25 communicates with the measuring device 26 arranged on the shield segment 27 provided on the target ground 13.

The behavior management device 24 performs the limitation of the rotation speed of the infusion pump 20 and the stop instruction determination according to the behavior such as stress and displacement. Local area connections 31 and 32 are connected to the activity management device 24 via a LAN.
The local area connection 31 sends displacement data from measuring instruments 26 such as a plurality of strain gauges to the dynamic management device 24 via the LAN, and the local area connection 32 is a limit / stop instruction signal (multiplication of the rotation speed of the infusion pump 20). Rate) is sent from the activity management device 24 via the LAN.

The local area connection 31 includes a measuring device 26 such as a plurality of strain meters, a switch box 28 connected to the measuring device 26 such as a plurality of strain meters, a data logger 29 connected to the switch box 28, and an observation data recording PC 25 connected to the data logger 29. And a router or hub 30 connected to the observation data recording PC 25 via a LAN. Displacement data is sent to the activity management device 24 via the LAN.
The local area connection 32 includes an injection management device 22 that performs display and recording of flow pressure, instantaneous flow rate, integrated flow rate, determination of the number of rotations of the infusion pump 20 according to the flow rate, and multiphase control. Are connected.

The injection management device 22 is connected to a plurality of flow rate / detectors 19 that measure flow rate pressure, instantaneous flow rate, and integrated flow rate via a LAN, and inputs a measured value of flow rate pressure. Further, power is supplied to the plurality of flow rate / detectors 19.
The injection management device 22 is connected to a plurality of injection pumps 20 via the inverter panel 23. An ON / OFF of the injection pump 20 and a frequency control signal are sent to the inverter board 23 from the injection management device 22 through inverter communication, and the inverter board 23 outputs an inverter to the plurality of injection pumps 20.

The dynamic management device 22 compares the regulation value and the measured data sequentially. When the displacement data exceeds the regulation value, the injection management device 22 is instructed to regulate the decreasing rate between 0 and 99%. The multiplication factor can be changed for each infusion pump 20.
The injection management device 22 adjusts the number of rotations of the injection pump 20 so as to maintain the set flow rate. However, when there is a restriction instruction, the injection management device 22 adjusts the amount by a numerical value obtained by multiplying the set flow rate by a multiplication factor.
In the injection method according to the present embodiment, a double-pipe strainer method single-phase method (intermediate material) was adopted, and a method of temporarily stopping injection at each step (hereinafter referred to as inching injection method) was adopted.

In the present embodiment, as shown in FIG. 5, a descending type (forward type) is adopted. The descending method (advancing method) is a method in which injection is started from the mouth side of the injection port, and is sequentially injected in the direction of the deepest part while adding the injection tube, and is also called a step-down method.
In the inching injection method, the injection method is basically a step-down method, and the single-phase method is used, and the chemical solution gel time is standardized (ten times to several minutes). As the injection material, it is standard to use a water glass solution type, but it is also possible to use an ultrafine particle spherical silica injection material having excellent permeability.

In this embodiment, using the injection apparatus A and the rotary boring machine 11 shown in FIG. 5, the dynamic management system shown in FIG. 6 is used to inject the back surface of the shield segment 27 as shown in FIGS. An example will be described.
First, the double tube rod 12 is drilled into the soil by the rotary boring machine 11 (step S1).

Next, the main agent and the curing agent are simultaneously pumped from the outer tube and the inner tube of the double tube rod 12, respectively, and the 1st injection in which the chemical solution mixed by the grout monitor 14 at the tip penetrates into the soil is performed (step S2).
Next, the infusion pump 20 for supplying the chemical solution is stopped for about ten seconds to several minutes (step S3).
Next, the main agent and the curing agent are simultaneously pumped from the outer tube and the inner tube of the double tube rod 12, respectively, and 2nd injection is performed so that the chemical solution mixed by the grout monitor 14 at the tip penetrates into the soil (step S4).

Next, re-drilling is performed to drill the double-pipe rod 12 into the soil by the rotary boring machine 11 (step S5).
Next, the 1st injection | pouring which the chemical | medical solution mixed by the grout monitor 14 of the front-end | tip mix | blends with the main agent and hardening | curing agent simultaneously from the outer tube | pipe and the inner tube | pipe of the double tube rod 12 infiltrates in soil is performed (step S6).

Next, the infusion pump 20 for supplying the chemical solution is stopped for about ten seconds to several minutes (step S7).
Next, the main agent and the curing agent are simultaneously pumped from the outer tube and the inner tube of the double tube rod 12, respectively, and 2nd injection is performed so that the chemical solution mixed by the grout monitor 14 at the tip penetrates into the soil (step S8).
Next, it returns to step S5 and repeats the step which performs step S6, step S7, and step S8.
When the predetermined injection is completed, the process ends (step S9).

In this step, the behavior management device 24 performs the control operation shown in FIG. 9 based on the control pattern shown in FIG. Table 4 shows a list of setting values.
First, the dynamic management device 24 outputs a command to start injection in the 1st injection in Step S2 in FIG. 7 and FIG. 8, the 2nd injection in Step S4, the 1st injection in Step S6, and the 2nd injection in Step S8. (Step S21).
Next, in the local area connection 31, the measurement value from the measuring device 26 arranged on the shield segment 27 is sent to the observation data recording PC 25 via the switch box 28 and the data logger 29 connected to this, and the router connected via the LAN. Alternatively, the measurement data is sent from the hub 30 to the dynamic management device 24 via the LAN (step S22).

Next, the behavior management device 24 determines whether or not the measured values from the local area connection 31 and the local area connection 32 are within a primary management value that is 100% of the set value (step S23).
Next, when the movement management device 24 determines in step S23 that the measurement value is within the primary management value, it maintains and recovers the injection rate of 100% (step S24), and returns to step S22.
Next, when the movement management device 24 determines in step S23 that the measurement value is not within the primary management value, the movement management device 24 decelerates the injection rate to 75% (step S25), and then continues the injection at the injection rate of 75% (step S25). S26).

Next, the behavior management device 24 determines whether or not the measurement values from the local area connection 31 and the local area connection 32 are secondary management values that are 70% of the set value (step S27).
Next, when determining that the measured value is within the secondary management value in step S27, the behavior management device 24 maintains and recovers the injection rate of 75% (step S28), and returns to step S22.
Next, when the movement management device 24 determines in step S27 that the measured value is not within the secondary management value, the movement management device 24 decelerates the injection rate to 50% (step S29), and then continues the injection at the injection rate of 50% (step S29). Step S30).

Next, the behavior management device 24 determines whether or not the measured values from the local area connection 31 and the local area connection 32 are within a tertiary management value that is 50% of the set value (step S31).
Next, when the movement management device 24 determines that the measured value is within the tertiary management value in step S31, it maintains and recovers the injection rate of 50% (step S32), and returns to step S22.
Next, when the movement management device 24 determines that the measured value is not within the tertiary management value in step S31, the movement management device 24 decelerates the injection rate to 10% (step S33), and then continues the injection at the injection rate of 10% (step S33). S34).

Next, when the behavior management device 24 determines in step S35 that the measured value is within the allowable value, the behavior management device 24 returns to step S22.
Next, when it is determined in step S35 that the measured value is not within the allowable value, the behavior management device 24 issues an injection interruption or an injection interruption warning (step S36).

As described above, according to the present embodiment, only the intermediate binder is used as the injection material, and the injection is interrupted in the same step, so that the role of the conventional quick setting material is roughly packed, packing Expect the effect.
This embodiment is suitable for construction from inside a tunnel or tunnel because the injection method is a descending type (step down).
According to the present embodiment, the stress generated in the shield segment 27 is measured by the measuring device 26, and is interlocked with the injection management device 22, so that the injection speed is automatically set when the stress rises before the displacement occurs. The influence on the shield segment 27 can be reduced by controlling.

In Table 4, the allowable surface stress Fb is 1.5 N / mm ² which is the minimum value of the first embodiment.
Further, F _30% = Fb × 0.3, F _50% = Fb × 0.5, and F _70% = Fb × 0.7.
Primary control value: F _30% , secondary control value: F _50% , tertiary control value: F _70% , allowable value: Fb.
The initial setting value of the injection rate was 6 L / min.

In the present embodiment, the behavior management device 24 is operated according to the control operation shown in FIG. 9 so as to obtain the control pattern shown in FIG. 4, and the injection management standard is the primary management value 100% and the secondary management value 75%. The third management value was explained as 50%, but the standard of these management values was obtained based on the experiment described later.
Moreover, in this embodiment, although the dynamic management apparatus 24 demonstrated the case where a strain meter was used for the measuring device 26 in order to obtain | require the regulation value with respect to injection | pouring speed, this invention is not limited to this, For example, besides stress Structure displacement, pore water pressure, earth pressure can be used.

(Embodiment 4)
In this embodiment, using the injection device A and the rotary boring machine 11 shown in FIG. 5, the dynamic management device 24 in the injection process shown in FIG. 7 and FIG. 11 is different from the third embodiment in that the control operation shown in FIG. 11 is performed based on the control pattern shown in FIG.
First, the dynamic management device 24 outputs a command to start injection in the 1st injection in Step S2 in FIG. 7 and FIG. 8, the 2nd injection in Step S4, the 1st injection in Step S6, and the 2nd injection in Step S8. (Step S41).

Next, in the local area connection 31, the measurement value from the measuring device 26 arranged on the shield segment 27 is sent to the observation data recording PC 25 via the switch box 28 and the data logger 29 connected to the measuring device 26, and connected via the LAN. Measurement data is sent from the router or hub 30 to the activity management device 24 via the LAN (step S42).
Next, the behavior management device 24 determines whether or not the measured values from the local area connection 31 and the local area connection 32 are within a primary management value that is 100% of the set value (step S43).

Next, when determining that the measured value is within the primary management value in step S43, the behavior management device 24 maintains and recovers the injection rate of 100% (step S44), and returns to step S42.
Next, when the movement management device 24 determines that the measured value is not within the primary management value in step S43, the movement management device 24 decelerates the injection rate to 60% (step S45), and then continues the injection at the injection rate of 60% (step S45). S46).
Next, the activity management device 24 determines whether or not the measured values from the local area connection 31 and the local area connection 32 are within the secondary management value that is 60% of the set value (step S47).

Next, when the movement management device 24 determines that the measured value is within the secondary management value in step S47, it maintains and recovers the injection rate of 60% (step S48), and returns to step S42.
Next, when the movement management device 24 determines in step S47 that the measured value is not within the secondary management value, the movement management device 24 decelerates the injection rate to 10% (step S49), and then continues the injection at the injection rate of 10% (step S49). Step S50).
Next, the behavior management device 24 determines whether or not the measured values from the local area connection 31 and the local area connection 32 are within allowable values (step S51).

Next, when the behavior management device 24 determines in step S51 that the measured value is within the allowable value, the behavior management device 24 returns to step S42.
Next, when it is determined in step S51 that the measured value is not within the allowable value, the behavior management device 24 issues an injection interruption or an injection interruption warning (step S52).
Also in this embodiment, the same effect as Embodiment 3 can be produced.
In the present embodiment, the behavior management device 24 is operated according to the control operation shown in FIG. 10 based on the control pattern shown in FIG. 9, and the injection management standard is the primary management value 100% and the secondary management value 60%. However, the standard of these control values was obtained based on experiments described later.

(Embodiment 5)
The present embodiment is different from the third embodiment in that an ascending type (retracting type) is adopted.
The ascending method (retracting method) is a method in which injection starts from the direction of the deepest part and is sequentially injected toward the mouth side of the injection hole while pulling out the injection tube, and is also called a step-up method.
In the present embodiment, an example will be described in which the injection device shown in FIG. 5 is used to inject the back surface of the shield segment 27 as shown in FIGS. 12 and 13 by the dynamic management device system shown in FIG.

First, the double tube rod 12 is drilled to the deepest part in the soil by the rotary boring machine 11 (step S11).
Next, the 1st injection | pouring which the chemical | medical solution mixed by the grout monitor 14 of the front-end | tip mix | blends with the main agent and hardening | curing agent simultaneously from the outer tube | pipe and the inner tube | pipe of the double tube | pipe rod 12 osmose | permeates in soil is performed.
Next, the infusion pump 20 for supplying the chemical solution is stopped for about several tens of seconds to several minutes (step S13).

Next, the main agent and the curing agent are simultaneously pumped from the outer tube and the inner tube of the double tube rod 12, respectively, and 2nd injection is performed so that the chemical solution mixed by the grout monitor 14 at the tip penetrates into the soil (step S14).
Next, re-drilling is performed to drill the double-pipe rod 12 while pulling out the double-pipe rod 12 from the deepest part of the soil by a predetermined length by the rotary boring machine 11 (step S15).

Next, the 1st injection | pouring which the chemical | medical solution mixed by the grout monitor 14 of the front-end | tip mix | blends with the main agent and the hardening | curing agent simultaneously from the outer tube | pipe and the inner tube | pipe of the double tube | pipe rod 12 osmose | permeates in soil is performed.
Next, the infusion pump 20 for supplying the chemical solution is stopped for about several tens of seconds to several minutes (step S17).

Next, the main agent and the curing agent are simultaneously pumped from the outer tube and the inner tube of the double tube rod 12, respectively, and 2nd injection is performed so that the chemical solution mixed by the grout monitor 14 at the tip penetrates into the soil (step S18).
Next, it returns to step S15 and repeats the step which performs step S16, step S17, and step S18.
When the predetermined injection is completed, the process ends (step S19).
Also in this embodiment, the same effect as Embodiment 1 can be produced.

(Embodiment 6)
As shown in FIG. 14, the present embodiment shows an example in which the present invention is applied to a liquefaction countermeasure directly under a structure based on the injection method described in the third embodiment.
In FIG. 14, the injection range 51 of the building 50 is directly below the pressure plate concrete 52.
A reflecting prism 53 is attached to the pillar 50a of the building 50. The relative displacement angle was measured by the reflecting prism 53 and monitored so as to be within an allowable value of 2.0 × 10 ⁻³ rad. For example, in FIG. 6, the relative displacement angle measured by the reflecting prism 53 is the same as the measuring device 26 of the local area connection 31, and the measured value (relative displacement angle) from the reflecting prism 53 is set to the switch box 28 and the data logger 29. The measurement data is sent to the observation data recording PC 25 via the LAN, and the measurement data is sent from the router or hub 30 connected via the LAN to the behavior management device 24 via the LAN, so that the behavior management device 24 can make a determination.

Moreover, the injection method by the hand auger 54 can also be used for the drilling of the double tube rod 12.
In this embodiment, the behavior at the time of construction is measured according to the construction flow shown in FIGS. 7 and 8 by the dynamic management system shown in FIG. 6 using the infusion apparatus shown in FIG. 20 was controlled.
Here, the injection management criteria were an allowable injection pressure (initial pressure + 0.2 MPa) and a discharge amount (5.0 L / min).
The results are shown in Table 5.
As a result, liquefaction countermeasures directly under the structure became possible.

(Embodiment 7)
Since this embodiment can secure a covering thickness of about 1 m or more, as shown in FIG. 15, an example in which the present embodiment is applied to water stoppage measures on the back of the earth retaining wall based on the injection method described in the third embodiment is shown.
In the present embodiment, in order to measure the displacement of the injection range 60, a measuring device 26 such as a strain gauge and a displacement meter and an earth pressure gauge 62 are arranged on the earth retaining 61, and the pressure measured by the earth pressure gauge 62 is, for example, 6, the measured value from the earth pressure gauge 62 is sent to the observation data recording PC 25 via the switch box 28 and the data logger 29 together with the measuring device 26 of the local area connection 31, and the LAN or the router 30 or the hub 30 connects to the LAN. The measurement data is sent to the dynamic management device 24 via the network, and the dynamic management device 24 can make a determination.

At the time of excavation, the chemical injection method is used for the purpose of ensuring the safety of the sediment and the bottom surface of the excavation. However, in the conventional method, it has been a problem to cause excessive stress and displacement in the sediment due to the injection pressure. .
In the present embodiment, by using the inching injection method based on the third embodiment, the entire target ground can be reliably improved while preventing the deformation of the earth retaining 61 due to the injection.

  On the other hand, in the conventional double tube strainer method, in order to take measures against water stoppage on the backside of the retaining wall, a hole is drilled from the ground part on the backside of the retaining wall, and the chemical solution is injected. The injected material does not penetrate into the ground, and is injected in a vein shape while destroying the structure of the soil skeleton, and stress acts on the soil retaining. In the conventional double pipe strainer method, it is standard to use an instantaneous injection material together. It is necessary to select an injection method that does not use instantaneous injection material.

Further, in the secondary injection, as the pore water pressure around the injection material increases, the ground causes local shear failure, and stress acts on the soil retaining.
If the injection is further continued, excessive stress acts on the soil retaining wall, and eventually the soil retaining deformation occurs. In the injection of the low earth covering, the surrounding ground rises.

In addition, in order to prevent the deformation of the earth retaining and the displacement of the surrounding ground, it is necessary to reduce the injection rate so that local shear failure due to the increase in pore water pressure of the ground does not occur.
However, since it is necessary to stop the injection when the earth retaining deformation or the surrounding ground displacement occurs, the improvement rate is insufficient. When the improvement rate is insufficient, troubles such as boiling occur during earth retaining excavation. In addition, when reinjection is performed by taking measures such as reinforcing earth retaining, there are problems such as process delay and cost increase.

(Embodiment 8)
As shown in FIG. 16, the present embodiment shows an example in which the present invention is applied to a water stoppage measure for a crossing under the track based on the injection method described in the third embodiment.
In the present embodiment, description will be made on the assumption that the track 70 is constituted by a track 71 and a roadbed 72 that are paths through which a railway vehicle travels. FIG. 17 shows an injection range 75 in the present embodiment.
In the front-rear direction (left-right direction in the figure) of the roadbed 72, a soil retaining 73 is provided. A measuring instrument 26 such as a strain gauge or a displacement gauge is disposed on the earth retaining 73, and an inclinometer 76 is disposed between the earth retaining 73.

A displacement meter 74 such as a reflecting prism is disposed on the track 71.
The inclination angle measured by the inclinometer 76 and the displacement meter 74 such as the reflecting prism is measured by the displacement meter 74 such as the inclinometer 76 and the reflecting prism in FIG. Is sent to the observation data recording PC 25 via the switch box 28 and the data logger 29, and the measurement data is sent from the router or hub 30 connected via the LAN to the dynamic management device 24 via the LAN so that the dynamic management device 24 can make a judgment. Configure.

In non-open-cut track crossing work, if the water stoppage of the face cannot be ensured, there is a concern about the sinking of the track or the sinking of the direct underlaying of the track. The problem was to raise the rails by pressure.
In the present embodiment, by using the inching injection method based on the third embodiment, the entire target ground can be reliably improved while preventing the line from being raised due to the injection.

  On the other hand, in order to prevent water crossing under the railroad crossing work and strengthen the ground by the conventional double pipe strainer method, the chemical solution is injected by drilling horizontally or radially from the vertical shaft on the side under the railroad crossing. The instantaneous injection material used for the primary injection does not penetrate into the ground, but is injected in a pulse shape while destroying the structure of the soil skeleton, and stress acts on the track base board. In the conventional double pipe strainer method, it is standard to use an instantaneous injection material together. It is necessary to select an injection method that does not use instantaneous injection material.

Further, in the secondary injection, with the increase of the pore water pressure around the injection material, the ground causes local shear failure, and the stress acts on the track base foundation.
If the injection is further continued, excessive stress acts on the base board directly on the line, and eventually the line is raised. If the track rises, it will take time to maintain the track, which will lead to disruption of the train schedule and suspension of operation. In order to prevent uplift of the track and surrounding ground, it is necessary to reduce the injection rate so that local shear failure due to the increase in pore water pressure in the ground does not occur.

Moreover, since it is necessary to stop the injection at the time when the line is raised, the improvement rate is insufficient. If the improvement rate is insufficient, the track crossing work will not be able to secure the independence and water stoppage of the face, causing the subsidence of the track and the subsidence of the track base. If time is required for restoration, the train schedule will be disrupted and suspended, which will have a significant impact.
In addition, when reinjection is performed after taking measures such as track maintenance, there are problems such as process delay and cost increase.

(Embodiment 9)
As shown in FIG. 18, the present embodiment shows an example in which the present invention is applied to ground reinforcement for crossing under a track based on the third embodiment.
In the present embodiment, a description will be given on the assumption that a track 80 is constituted by a track 81 and a roadbed 82 which are paths through which a railway vehicle travels. FIG. 19 shows the injection range 85 in the present embodiment.
A soil retaining ring 83 is provided in the front-rear direction (left-right direction in the figure) of the roadbed 82. A measuring instrument 26 such as a strain gauge or a displacement gauge is disposed on the earth retaining 83, and an inclinometer 86 is disposed between the earth retaining 83.

A displacement meter 84 such as a reflecting prism is disposed on the track 81.
The tilt angle measured by the displacement meter 84 such as the inclinometer 86 and the reflecting prism is measured by the displacement meter 84 such as the inclinometer 86 and the reflecting prism in FIG. Is sent to the observation data recording PC 25 via the switch box 28 and the data logger 29, and the measurement data is sent from the router or hub 30 connected via the LAN to the dynamic management device 24 via the LAN so that the dynamic management device 24 can make a judgment. Configure.

In non-open-cut track crossing, if the water stoppage of the face cannot be secured, there is a concern about the sinking of the track or the sinking of the direct base of the track, so water stop measures are taken by chemical injection, but the conventional method is The problem was to raise the rails by the injection pressure.
In the present embodiment, by using the inching injection method based on the third embodiment, it is possible to reliably improve the entire target ground while preventing the line from being raised due to the injection.

  On the other hand, in order to take measures against liquefaction directly under the structure with the conventional double pipe strainer method, drill holes from the first floor or underground of the structure and inject chemical into the liquefied layer directly under the pressure plate. However, the instantaneous injection material used for the primary injection does not penetrate into the ground, and is injected in a pulse shape while destroying the structure of the soil skeleton, and stress acts on the pressure plate. In the conventional double pipe strainer method, it is standard to use an instantaneous injection material together. It is necessary to select an injection method that does not use instantaneous injection material.

Further, in the secondary injection, as the pore water pressure around the injection material increases, the ground causes local shear failure, and stress acts on the pressure plate.
If the injection is further continued, excessive stress acts on the pressure plate, and eventually the pressure plate is raised and deformed. When the pressure plate is raised or deformed, the structure is inclined and cracks are generated on the floor, walls, columns, and the like. In order to prevent the pressure plate from rising and deforming, it is necessary to reduce the injection rate so that local shear failure due to the increase in pore water pressure in the ground does not occur.

Moreover, since it is necessary to stop the injection when the pressure plate is raised or deformed, the improvement rate is insufficient. If the improvement rate is insufficient, liquefaction and land subsidence will occur during an earthquake, which greatly affects the operation of the structure.
In addition, when the subsidence of the structure is corrected and reinjected, there are problems such as a delay in the process and an increase in cost.

1 Soil layer experiment equipment 2 Cylindrical mold (drum can)
3 Drainage layer 4 Experimental sand 5 Drain pipe 6 Lid 7 Concrete gauge 8 Displacement meter (CDP displacement meter)
9, 12 Double tube rod 11 Rotary boring machine 13 Target ground 14 Grout monitor 15 Bit 16 Swivel 17, 18 Injection hose 19 Flow rate / detector 20 Injection pump 21 Grout mixer 22 Injection management device 23 Inverter panel 24 Dynamic management device 25 Observation Data recording PC
26 Measuring instrument 27 Shield segment 28 Switch box 29 Data logger 30 Router or hub 31, 32 Local area connection 50 Building 50a Pillar 51, 60, 75, 85 Injection range 52 Pressure plate concrete 53 Reflecting prism 54 Hand augers 61, 73, 83 Earth retaining 62 Earth pressure gauge 70, 80 Track 71, 81 Track 72, 82 Subbase 74, 84 Displacement meter 76, 86 Inclinometer

Claims (9)

A first injection step of injecting a water glass solution type organic alkaline intermediate binder into the target ground in a pulsed manner;
In response to the fact that a predetermined time has elapsed since the completion of the first injection step, a second injection step of infiltrating and injecting the intermediate binder into the target ground;
The process of executing each step of the above from the ground surface of the target ground at the same depth is repeated a plurality of times while changing the depth from the ground surface of the target ground,
The first implantation step and the second implantation step, based on the stress of the shield segments after injection, injection method, characterized by executing while adjusting the infusion rate or injection pressure in said sintered material . A first injection step of injecting a water glass-based solution-type organic alkaline binder into the target ground in a pulsed manner ;
In response to the fact that a predetermined time has elapsed since the completion of the first injection step, a second injection step of infiltrating and injecting the intermediate binder into the target ground ;
The process of executing each step of the above from the ground surface of the target ground at the same depth is repeated a plurality of times while changing the depth from the ground surface of the target ground,
The first injection step and the second injection step are performed while adjusting the injection speed or injection pressure of the intermediate binder based on the displacement of the adjacent structure . A first injection step of injecting a water glass-based solution-type organic alkaline binder into the target ground in a pulsed manner;
In response to the fact that a predetermined time has elapsed since the completion of the first injection step, a second injection step of infiltrating and injecting the intermediate binder into the target ground;
The process of executing each step of the above from the ground surface of the target ground at the same depth is repeated a plurality of times while changing the depth from the ground surface of the target ground,
The first injection step and the second injection step are executed while adjusting the injection speed or injection pressure of the intermediate binder based on the pressure and displacement of the earth retaining after injection.
Injection method, wherein a call. In the injection method according to any one of claims 1 to 3 ,
Drilling the target ground to a predetermined depth ;
Adding the injection pipe and further drilling holes;
An injection method characterized by further comprising: In the injection method according to any one of claims 1 to 3 ,
For the target ground, a step of drilling to the deepest part,
A process of further drilling while pulling out the injection tube;
An injection method characterized by further comprising: In the injection method according to claim 4 or claim 5 ,
The injection method is a single phase injection method using a double strainer tube. In the injection method according to claim 1,
The target ground is a ground whose injection range is directly under the structure . In the injection method according to claim 3,
  The said target ground is a ground which can ensure the injection | pouring range about 1 m or more of covering thickness, The injection method characterized by the above-mentioned. In the injection method according to any one of claims 1 to 8,
  The intermediate binding material has a gel time of 30 seconds to 6 minutes, and the predetermined time is 15 seconds to 30 seconds.

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