JP3632959B2 - Improvement method for soft ground - Google Patents

Description

[0001]
[Industrial application fields]
The disclosed technology belongs to a technical field in which the strength of the ground is improved through the consolidation of the ground by improving the strength of the ground such as the soft ground.
[0002]
[Prior art]
As is well known, the improvement of civil society is known to be based on the rise of various industries, but facilities such as factories are indispensable for the various industries. Ensuring sufficient strength of the ground is extremely important.
[0003]
However, it is directly effective for the construction of the above facilities in the land with a narrow land and many mountain forests, and in a special land condition where the inland is close to a long and complicated coastline. The land that can be used is extremely limited in terms of area. Therefore, various technologies have been researched and developed for the effective reuse of land through construction of soft ground improvement works, and some of them have not been put to practical use. It is being planned.
[0004]
Traditionally, the sand drain method, sand compaction method, cement injection method, etc. have been used to improve the soft ground.However, these methods require large construction machines and are expensive, and in addition to urban civil engineering. However, it is inconvenient in operation, and even if an injection method is used, it cannot be injected into the viscosity layer, easily deviates, and the strength is weak, so that the construction effect cannot be achieved sufficiently.
[0005]
In addition to the above, when the chemical solution is injected, the surface of the ground is raised and the structure is changed, and the surface of the ground is raised and the shape of the building is easily changed.
[0006]
And although it is desired that the uplift phenomenon of the ground surface that constructs the building should not occur essentially, the technology etc. that prevents the uplift of the ground surface along with the chemical injection method, For example, there is a technique as shown in the invention described in Japanese Patent Laid-Open No. 10-18282.
[0007]
However, when the grout used in the chemical solution injection technique generally used is an instantaneous grouting grout and injection is performed at a time on a predetermined zone, the instantaneous grouting 1 as shown in FIG. 13 is split. Or when the injected grout runs away in the ground, or even if it is injected into the bag, the bag breaks or breaks down and sandy, etc. There was a demerit that was not desirable in terms of design, such as causing split penetration 2 to the surface.
[0008]
In addition, when a grout is injected into the ground, the reverse of the phenomenon that the ground is raised and the use of a technique for restoring the tilt of the constructed structure due to an earthquake or the like is disclosed in, for example, The invention of 8-260500 and the invention of Japanese Patent Laid-Open No. 9-25642 have been developed and become practical.
[0009]
Thus, although the technology to restore the inclination of the building constructed on the ground due to the liquefaction phenomenon of the ground is used as an effective utilization technology, it is essentially the ground of the ground when constructing the construction A technique for improving the strength of soft ground or the like is that, as shown in the technique of the invention of Japanese Patent Laid-Open No. 10-18282, the injected grout is instantaneously connected. Is low and easy to penetrate, but due to its low viscosity, if it escapes in the ground or stops pumping of the instantaneous grouting, it immediately polymerizes and solidifies, and the grout to be injected subsequently is Since the solidified part is broken and a split part is generated further, and the ground is raised while splitting in the ground direction where resistance is weak, and the ground is raised, it is impossible to increase the strength of the part that has not penetrated. There is a drawback.
[0010]
OBJECT OF THE INVENTION
The object of the invention of this application is to reverse use of the technology for preventing the above-mentioned liquefaction phenomenon and the like and restoring the tilted state of the building constructed on the ground, and the grout injected into the ground in the axial direction of the drilling hole. Step up at a predetermined timing, step down, or if there is fluidity at the time of pumping into the injection pipe inserted into a drilling hole formed in a predetermined number in a predetermined area, and when the pumping press injection is stopped The injection order is repeated at a predetermined timing for a plurality of drill holes in which a suspension type plastic grout having the property of rapidly increasing the viscosity and stopping the fluidity is arranged in the axial direction or the horizontal direction of the hole. By the interval method, the injected plastic gel grout has fluidity during repeated plastic grout injection, loses fluidity when the injection is interrupted, and loses moisture to solidify and subsequently injects. The plastic grout is pressed in the transverse direction, the injection is stopped before splitting occurs, the consolidation phenomenon is repeated, and it does not rise upward in the axial direction of the drilling hole. Bumping of the ground due to the injection of plastic grout of the mold is avoided, and it is possible to repeat the consolidation only on the side, so that the ground strength is increased, and the excellent ground that is beneficial to the field of civil engineering application in the construction industry We will provide a strengthening method.
[0011]
Thus, the above-mentioned plastic grout is cement bentonite, or the one in which a small amount of water glass is added to cement bentonite, or a small amount of water glass is added to cement bentonite, or slaked lime is added to the slag. In addition, bentonite and a small amount of water glass are added, bentonite is added to cement, and additives such as slaked lime are added, and fillers such as fly ash and clay are added, and aluminum powder is added. It may be foamed or air may be mixed.
[0012]
In other words, plastic grout is fluid when pump pressure is applied, but pump pressure Stop Then the grout that loses fluidity Plasticity This is called grout.
[0013]
Plasticity As grout, there are one-part and two-part. One component Plasticity As grout, cement bentonite is used as the main material, and slag, fly ash, soil removal, etc. are added to it as an extender, and a small amount of lime, water glass, etc. is added to adjust the plasticity, or a foaming agent is added. Adjust the liquidity. Two-component Plasticity As grout, cement bentonite is added to the A liquid, and further, an extender and a foaming agent are added, and a water glass liquid is used as the B liquid to form a grout that exhibits plasticity when the A liquid and the B liquid are merged. . In addition, a plastic grout that hardly causes breathing may be formed by combining the cement A bentonite liquid with the liquid A and the bentonite liquid with the liquid B. In addition, animal protein and surfactants are added as foaming agents to cement bentonite as liquid A, and lime and aluminum salts such as aluminum sulfate and aluminum chloride are combined as liquid B and combined to produce aluminum hydroxide. It may be made to give plasticity.
[0014]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the structure of the invention of the present application, which is summarized in the scope of the above-mentioned claims along the above-mentioned purpose, is configured such that a grout is formed in the ground via an injection pipe. Injecting and improving the strength of the ground, in the soft ground improvement method, the grout is the above-mentioned plastic grout, or a grout with a short gelation time, and repeatedly press-fitted into the ground by the interval method to surround the soil particles. Based on the principle of pushing and compacting to strengthen the ground, therefore, in the above injection, a bag body is arranged at a predetermined position of the injection pipe to form a packer, and grout is pressed into the ground from the discharge port. In order to suppress the bulge of the ground and increase the density of the surrounding soil, depending on the soil layer, the penetration method between the soil particles and the plastic grout, or the grout interval with a short gel time In addition, a bag is disposed in the axial direction of the injection tube, and a plastic grout or a grout with a short gelation time is press-fitted into the bag by an interval method. A bag packer is disposed at a predetermined pitch in the axial direction of the bag, a hardener is pressed into the bag packer to form a packer, and a plastic grout or gelation time is formed from an inlet of an injection tube provided between the packers. The short grout is pressed into the ground by the interval method, and further, the drain material is arranged in the soft ground improvement method, and the plastic grout or the grout interval method having a short gelation time is used. At the time of injection, it is possible to measure the displacement of the ground while measuring the displacement of the ground, plastic grout, or gelation time. It is also possible to carry out by the interval method while selecting or adjusting the injection depth of the short grout, the injection amount, and in the soft ground improvement construction method, in the soil layer, the penetration injection between the particles and the plastic grout, Alternatively, a technical means is adopted in which repeated injection by a grout interval method with a short gel time is also used.
[0015]
[Action]
In the above configuration, in order to significantly improve the strength of soft ground etc., if an excessive amount of plastic grout is injected at a time, the surface of the ground will rise, or the ground will be destroyed and deviated laterally. However, the strength of the ground does not improve as designed, but due to the characteristics of the plastic grout, fluidity is present during the injection, and when the injection is stopped, the fluidity stops and a solidified state appears. Therefore, by solidification by repeatedly injecting into the target injecting soil layer by an interval method, the injected ground is compacted without breaking, and the excluded water is dispersed among the surrounding soil particles, to the side of the ground Consolidate and dehydrate, or use grouts with short gel times and use a grout with a certain time lag to inject in the vertical direction. And repeatedly press-fitting the plastic grout into the plastic grout previously injected, and press-fitting the plastic grout repeatedly without splitting the ground. By using the interval method and repeatedly injecting over a predetermined time lag, consolidation dehydration is performed on the side of the ground, the ground is strengthened, or a predetermined number of grindings are applied to a predetermined area of the ground. A hole is formed, and for each drilling hole, the plastic grout is divided into several parts so that the plastic grout is not injected all at once in a single place through a predetermined time lag. The plastic grout of the drilling hole is injected by the interval method for each soil layer or each stage through a predetermined time lag with each other, and the plastic grout previously injected consolidates the surrounding ground, or The plastic grout injected into the predetermined number of drilling holes by the repeated injection by itself or by dehydration of the injection solution by itself will cause each soil layer or each For each stage, the dewatering action is performed on the sides in the same way, increasing the strength, suppressing the displacement overall, and increasing the strength of the ground in the predetermined area. One or a plurality of bag bodies are provided in the injection pipe to be inserted into the drilling hole in the axial direction at a predetermined pitch, and plastic grout is injected into the bag bodies at intervals to cause a compacting and dehydrating action through the bag body. In addition, the bag body is prevented from being damaged by injecting a predetermined amount at a time to destroy the surrounding ground, and the upward movement is prevented by gradually expanding within the volume range of the bag body, By injecting the injection solution to the side, While increasing the density of the surrounding ground while suppressing the ground uplift, the ground strength is improved in the same manner as described above, and the bag body is set at a predetermined pitch in the injection tube to be inserted into the drilling hole. The suspension grout is press-fitted to form a bag packer, and the bag packer is pressed against the soil layer around the drilling hole, thereby substantially increasing the size of the packer to form the bag packer. By pressing the plastic grout from below the bag packer, there is no overcoming of the plastic grout on the bag packer, there is no displacement of the ground uplift due to the restraining effect by the bag packer, and the strength due to the ground dewatering action is overall In addition, drainage drainage materials are provided so that the strength can be improved over the entire area, and in addition, in order to eliminate moisture in the soil when plastic grout is injected into the ground. Accelerate the side consolidation dehydration effect due to intermittent drainage effect, or install drainage pipe to drain groundwater, improve the speed due to the consolidation, and measure changes such as ground uplift Therefore, by measuring the change in real time with a sensor such as a laser and grasping the amount of compression of the ground, or when the change is abnormal in design, immediately adjust the injection of plastic grout, Or, via the control device of the injection device, automatically adjust the injection amount, injection depth, specific gravity, injection amount, interval time, etc., and move to another stage before exceeding the predetermined displacement, The strength of the ground can be reliably improved by compaction dehydration as designed, and the displacement of the ground can be measured for the ground uplift on the ground surface, or the Stranger It is possible to know the displacement of the part of the ground in the measurement direction by setting a measuring rod with a tension in the ground, and to install a pore water pressure meter in the ground so that the consolidation dehydration status can be grasped It is a thing.
[0016]
BACKGROUND OF THE INVENTION
Thus, in the invention of this application, when a suspension type plastic grout is press-fitted from the injection pipe into the soft ground at a low speed, there is fluidity in the vicinity of the injection pipe outlet from the supply pipe to the injection pipe. While adding water, the flow range is maintained and the injection range is expanded, or in the advanced part of the injection grout in the ground, the water content of the grout is reduced by dehydration to the surrounding soil particles due to the injection pressure, and the fluidity is lost. . For this reason, if the press-fitting is continued further, the soil particles outside the injection tube are pushed to the periphery, and the plastic grout is replaced, so the density of the soil between the injection holes increases, the strength of the ground increases, and subsequently By pressing the flexible grout, it pushes to the periphery without destroying the surrounding soil and increases the density, thereby strengthening the ground.
[0017]
In other words, the improved ground is injected through the injection hole, and if a large amount of plastic grout is injected into a predetermined area at once, the surrounding soil will be destroyed before it is consolidated. Then, because it is plastic, the flow stops due to interruption of injection, and it is held in that position, the surrounding soil is consolidated and dewatered and strengthened, and the columnar consolidated body and its columnar consolidated body by the central plastic grout The present invention has been found out that it becomes a composite ground of soil particles with increased density.
[0018]
Furthermore, the invention of this application has been completed by obtaining the following technique in order to ensure an increase in the density of soil around the injected material in soft ground.
1. Using an injectable material that is difficult to flow, push the infusate without infiltrating the soil particles without splitting the surrounding soil,
2. To prevent the ground surface from rising as much as possible, and to prevent an increase in the displacement of the ground in the axial direction of the injection pipe,
3. The injected material splits the surrounding ground and does not cause cracks, forming solid pillars of a predetermined diameter by the injected material at each depth to give strength by the consolidated body and the surrounding soil particles in the lateral direction To increase the density,
4). Furthermore, the tensile strength of the injection pipe is given to the ground,
5. Enables construction management that can grasp the increase in consolidation diameter and density at each depth
6). This makes it possible to design ground improvement effects.
In this way, assuming that the soil volume in the predetermined injection target ground is V1, the volume of the injected consolidated material is V2, and the ground uplift is V3, the decrease in the gap of the ground V1 in the predetermined area is V2 − V3, which is an increase in density, that is, an increase in strength or bearing capacity. Furthermore, it is possible to obtain an increase in strength as a composite ground in consideration of an increase in sand density, the strength of consolidated columns, and the respective planar area ratios.
[0019]
For this purpose, plastic grouting or instantaneous grouting is used (especially plastic grouting is excellent) to prevent the surface from rising as much as possible and to increase the axial displacement of the injection pipe in the axial direction. Prevention Repeatedly move to another injection stage before the predetermined ground uplift, or before the surrounding soil breaks up, in an interval manner, or dehydrate and compact the consolidated material and the surrounding ground. Wait and repeat injection again.
[0020]
Alternatively, after a small amount of plastic grout that does not deviate to a predetermined area is injected, the stage is moved repeatedly.
[0021]
Alternatively, the injected material does not split and crack in the surrounding ground, forming a solid pillar of a predetermined diameter by the injected material at every depth to give sufficient strength by the consolidated body and surrounding soil particles Was pushed laterally to increase the ground density, and using an injection tube with a bag body that became a packer in the axial direction of the injection tube, a consolidated column was pressed into the bag body and the injection tube was inserted into the ground. The plastic grout is press-fitted from the discharge port located above the bag body. As a result, even if the plastic grout having fluidity is injected near the ground surface, the injected material tends to move upward or the ground does not rise, and the solidified matter is likely to be stored in a predetermined region. For this reason, an injection material comes to be injected by the side direction for every predetermined soil layer.
[0022]
In addition, the tensile strength of the injection pipe is further imparted to the ground, and the drainage material is used together to promote consolidation dehydration, or the drain pipe is installed in the ground to achieve the above-mentioned purpose. The invention of this application has been achieved.
[0023]
If the volume of the injected material V, the volume V1 ′ after dehydration and the amount of ground uplift V2 are used in the soft ground improvement method, the amount of decrease in the gap in the ground injection is V1′−V2, and the density increases, that is, the strength increases. The support force can be increased.
[0024]
Aspects of the Principle of the Invention
The invention of this application employs the following construction method as the ground improvement technology that enables soft ground improvement by an injection method. The principle aspect of the invention of this application will be described below.
FIG. 1 shows a ground strengthening model by plastic grout press-fitting in soft ground improvement according to the invention of this application. In FIG. 1 (a), the soil capacity of the ground to be improved is V0, and a solid column made of plastic grout. Assuming that the capacity of each is Vi and n is formed, and the amount of occurrence when n is formed is ΣΔVi (i = 1 to n), the amount of compression of the voids between the soil particles of the ground to be improved Total is V = ΣVi−ΣΔVi. That is, in FIG. 1 (b), the improvement area per injection is S0i, the consolidation pillar area is S1i, and the compressed soil area is S2i in the improvement target ground. Then, S0i The ground strength is a composite strength composed of the strength of the consolidated pillar of S1i and the strength of S2i of the compressed soil.
[0025]
FIG. 2 shows a case where an injection tube 9 having a bag packer A attached to an injection tube 4 having tensile strength (or a reinforcing material obtained by tying a tensile material to the injection tube) is installed on the ground and a plastic grout B is press-fitted. Fig. 2 illustrates the ground reinforcement model. As shown in FIG. 2 (c), the ground is drilled, the injection pipe 4 with the bag body 8 is buried, the suspension grout is press-fitted into the bag body 8, and the bag body is expanded to the surrounding ground. By forming the packer A of 8, the surrounding soil is compressed and a larger soil anchor than the actual bag body 8 is formed. The injection pipe 4 having tensile strength is fixed on the ground by the soil anchor. Even in this state alone, if the ground is displaced, the tensile body is stretched and tensile strength is imparted to the ground. Next, as shown in (2) of FIG. 2, when the plastic grout B is pressed into the bag 4 packer A from the discharge port of the injection tube 9, the surrounding soil is compressed and the region G having a high density is compressed. Form. Since the plastic grout B is restrained from moving up and down by the bag packer A and the larger packer E in the soil, the plastic grout B has no choice but to spread the lateral soil layer. For this reason, a region G having a high density in which the soil particle interval is reduced is formed around the periphery. Furthermore, as shown in FIG. 2 (e), the press-in of the plastic grout B tends to expand up and down between the bag packers A and E, so that a force for extending the injection tube (tensile material) acts. This expresses the tensile strength of the injection tube 4 and imparts tensile strength to the ground. Further, due to the restraining effect of the bag packers A and E, the ground uplift due to the injection pressure at each injection stage is suppressed. This effectively increases the density of the ground and at the same time reliably improves every predetermined soil layer, so that it is possible to design a strength increase corresponding to the injection amount for each layer.
[0026]
That is, it is possible to calculate the increase in density due to the formation of a consolidated column having a diameter corresponding to the injection amount for each soil layer and the decrease in soil volume (ΔV) in consideration of the consolidated volume and ground uplift amount ΣΔVi. .
[0027]
That is, ΔV = ΣAi + ΣBi−ΣΔVi = decrease in gap = increase in density.
[0028]
Further, as shown in FIG. 3 (h), the strength of the composite ground can be calculated from the strength of the consolidated column B, the increased density of the increased density region G, and the respective area ratios. And by measuring the gap and strength of the ground before pouring and setting the pouring amount of the plastic grout for each soil layer, the ground improvement effect can be designed systematically and realized reliably.
(G) and (H) in FIG. 3 show a reinforcement model of a building foundation based on the above ground strengthening principle. FIG. 4 shows a ground strengthening model by plastic grout injection and dehydration or water absorption. H is a drain material or a drain pipe. Generally, when these dehydration or drainage is used together in ground injection, the streamline concentrates on that portion, so that the injected material flows into the drain material or the drain pipe H and is not effective. However, in the case of plastic grout, since the consolidated column is gradually expanded without causing cracks in the ground and flowing out, pore water around the consolidated column is dehydrated through these drain materials or drain pipes H. Therefore, there is an effect that the density of the surrounding soil is reliably and rapidly increased.
[0029]
DETAILED DESCRIPTION OF THE INVENTION
Next, the mode of the invention of this application will be described as an embodiment according to the interval method according to FIGS.
[0030]
In addition, the same aspect part as FIG. 13 shall be demonstrated using the same code | symbol.
[0031]
The embodiment shown in FIG. 5 shows an aspect of the basic example of the interval system, and the predetermined holes are formed in the lateral direction with a predetermined pitch in the same manner as in the conventional soft ground 3, similarly to the conventional mode. At a depth, a normal injection tube 9 (not shown) is inserted into the drilling hole 4, and a suspension type plastic grout from an injection device (not shown) on the ground is inserted into the injection pipe 9 by a predetermined time lag at a predetermined pitch, As shown in (i), the injection is repeated through a predetermined step-up or step-down, and the injection is repeated for each zone of 6, 7, 8 and the ground 3 in a chasing manner.
[0032]
In this case, the injection of the plastic grout in each cycle can be smoothly injected while draining the ground 3 in order to maintain fluidity in the initial stage of injection, but after a predetermined timing, When the pumping is stopped, the fluidity is lost and solidifies with time as described above, and the plastic grout to be injected later pushes the previously injected plastic grout from the inside to the side and escapes to the upper ground direction. Instead, it is injected in a laterally overlapping manner, and the side ground is consolidated and dehydrated, and the injection site is dehydrated to increase the strength of the injected plastic grout, and the post-injected plastic grout is The strength increases with each cycle, and the ground strength increases with each cycle through the overlapping consolidation action.
[0033]
For this reason, the injection pressure produces a consolidation action in the lateral direction rather than acting on the ground uplift.
[0034]
In addition, due to the function of the plastic grout that is injected at a predetermined time lag in the axial direction upward of the drilling hole 4, the displacement is more likely to occur in the horizontal direction than in the vertical direction, and thus the uplift of the ground 3 is avoided.
[0035]
The injection mode of the plastic grout in the basic interval system through the time lag is as shown in FIG. 5 (i), but in the mode shown in (nu), the ground of the plastic grout in the same zone By changing the injection time lag to a predetermined value, the lateral multiple integral of the plastic grout that has solidified over time is cycled 5 ', 6', 7 'and the ground is consolidated to improve its strength. It shows the way to go.
[0036]
The embodiment shown in FIG. 7 is an embodiment in which plastic grout is injected into each predetermined bag body 81 through an injection tube provided with one or a plurality of bag bodies 81 by an interval method. This is a mode in which the reinforcement of the ground 3 between the holes 41.
[0037]
Thus, the bags 81, 81 ′, 81 ′ provided around the outer tube 9 to be inserted into the hole 4 are initially in a reduced state as shown in FIG. By injecting it by the interval method through a predetermined time lag, as shown by 8 'in FIG. 7 (e), and as shown in FIG. In this aspect, the side ground is expanded and a compressive force is applied to the side ground so as to provide a consolidation action so that the ground can be strengthened.
[0038]
In addition, since injection of more plastic grout of the process adopts an interval method, the surrounding ground does not split and break, so the bag body 81 is not torn. Therefore, the plastic grout can avoid an escape by breaking the bag body 81. . This embodiment is an example of improving the ground by consolidation consolidation of the surrounding ground only by injecting plastic grout into the bag body 81 by the interval method.
[0039]
Thus, in the embodiment of the present embodiment shown in FIG. 5, the injection tube 9 inserted into the drilling hole 4 is passed through a predetermined time lag, through a predetermined step-up or step-down interval method, In the embodiment shown in FIG. 6, a set number of holes 41, 42, 43,... Are formed in a predetermined area of the ground 3 at predetermined intervals in the horizontal direction. Each injection hole is inserted into each drilling hole, and a predetermined time lag is connected to an injection device (not shown) through valves 51, 52, 53, 54... And a pump (not shown), and the plastic grout is connected to a computer. As shown in FIG. 6, the injection timing for the holes 41, 42, 43... Then, the grouts 41, 42, 43,... Formed in parallel in the horizontal direction are injected with plastic grout by an interval method with a predetermined time lag through the valves 51, 52,. Thus, it is possible to perform consolidation dehydration over the entire area of the side ground of the adjacent drilling holes 41, 42, 43..., And as a result, it is possible to improve the strength of the ground over the entire area.
[0040]
Of course, in this aspect, by taking a predetermined interval method, it is possible to return to the initial hole 41 after making a round of all the holes 41, 42, 43. In the plastic grout injection at the interval of the pipe, the injected plastic grout is solidified and maintains a consolidated state with respect to the ground 3.
[0041]
In the invention of this application, the injection of plastic grout by the interval method basically takes the method shown in FIGS. 5 and 6, and the injection pipes 9, 9, 9 ... step up or down, and drilling holes 41, 42, 43 ... adjacent to each other, and the program of the computer 17, the interval method is three-dimensionally in the horizontal direction with a predetermined time lag. By using it, it is possible to avoid uplift of the ground surface and to perform consolidation dehydration of the entire side ground.
[0042]
Next, as shown in FIG. 7, the outer pipes 9, 9 ′, 9 ″ inserted into the hole 4 have a predetermined axial pitch and are made of a permeable bag such as a nonwoven fabric or a synthetic resin. A water-impermeable bag body 8 is inserted in a predetermined folded state, is inserted into the drilling hole 4, and a suspension-type grout such as a plastic grout is injected into the bag body 8 to be inflated. The side 3 is consolidated and dehydrated to improve the strength of the ground 3 as in the above-described embodiment.
[0043]
In this mode, when the bag body 8 is initially in a contracted state as shown in FIG. 7 (e), it is injected over time with a predetermined time lag over time. As shown in FIG. 7 (8), as shown in FIG. 7 (8), and as shown in FIG. 3 (8), it expands as shown in FIG. This is a mode in which an effect is given so that a strengthened ground can be achieved.
[0044]
Thus, in this embodiment, the injected grout is not injected in the vertical direction by the bag body 8, and therefore, it is possible to prevent the ground 3 from being raised or the like. This is a mode in which the action is sufficiently strengthened to surely strengthen the ground.
[0045]
In addition, the unit length of the bag body 10 shown in FIG. 8 and the length in the longitudinal direction are lengthened, the plastic grout is injected and expanded, the area to be crimped to the side wall of the drilling hole 4 is widened, and the compacting action is achieved. It is possible to apply a mode in which the sand layer, the viscosity layer, and the gravel layer are made larger than the entire layer.
[0046]
Further, in the embodiment shown in FIG. 8, the injection pipes 91, 92, 93, 94 inserted in the holes 41, 42, 43. .. In such a manner that the bag packers 10, 10..., 10 ′, 10 ′, 10 ′..., 10 ″, 10 ″, 10 ″. Yes, in this embodiment, each of the bag packers 10, 10 ', 10 "is inflated and pressed against the drilling wall to perform a compacting action, so that the bag packers 10, 10', 10" Of the bag packer 10, 10 ', 10 ", 10 adjacent to each other in the axial direction. ⁿ However, the plastic grout to be injected does not escape the plastic grout in the axial direction due to the substantially large size of the bag packer 10, 10 ′, 10 ″. As described above, the deformation of the ground 3 is not reliably deformed, the consolidation dehydration action to the side of the ground 3 is more reliably performed, and the effect that the ground reinforcement is surely performed is obtained.
[0047]
Thus, as described above, in the invention of this application, the plastic grout injected into each drilling hole 4 performs the consolidation dehydration action on the side of the ground 3 to prevent the upward runaway. Although it is unlikely to be raised, a level detection method using a well-known level sensor is used to measure the amount of deformation on the ground surface and between adjacent drilling holes, and a laser beam generator as shown in FIG. 11 'is provided with a laser beam sensor 15 via a laser receiving device 12 provided on the upper portion of the injection tube 9, and via a receiving device, via a computer 17, and by an appropriate injection control device as shown in the figure. No. 9, plastic grout injection amount and interval time specific gravity The receiving device 13 is displaced up and down with respect to the laser beam sensor 15 in which the laser beam generated from the laser beam device 11 ′ is precisely manufactured, and the ground 3 is raised accurately. When detected, an injection control device (not shown) is started and stopped via the computer 17, and injection is performed at the optimal timing and amount for consolidation dehydration of the lateral ground of the plastic grout to be injected intermittently. In this mode, injection is optimally performed while measuring.
[0048]
As shown in FIG. 10, laser beam is used for detection and detection of lateral displacement of the compacted body of injection and ground uplift, and precise measurement in mm is possible because of optical detection. is there.
[0049]
Accordingly, the displacement of the drilling hole 4 and the bulge of the ground 3 can be measured accurately over a wide range, and a minute displacement such as the displacement of the ground 3 can be accurately detected to detect the strength of the ground 3 as designed. Improvements can be made.
[0050]
In this embodiment, a side displacement measuring hole 9 'is formed on the side of the hole 4, and a laser beam half mirror 14 generated by the laser beam device 11' is provided on the upper part to provide the measuring hole. The lateral displacement of the hole 9 ′ is detected by the detection device 13 ′ of the hole 9 ′, and similarly, injection of the plastic grout by an injection control device (not shown) is carried out to perform correction and repair by a predetermined time lag, its injection amount, specific gravity and consolidation. Is adjusted to avoid the displacement of the ground due to the drilling, that is, the injection of the plastic grout, and the strength ground of the ground 3 as designed is intended.
[0051]
Thus, in the above-described embodiment, it is basically possible to improve the strength of the ground 3 through the consolidation and dehydrating action on the side ground 3, but at the injection site of the plastic grout to the ground 3 In order to eliminate potential causes such as liquefaction, etc., the water in 3 may escape to the other and increase the fluidity of other ground 3 parts. As shown in FIG. 9, in order to forcibly dispose the moisture in the ground 3 to be excluded, the drain material 18 such as a well-known paper drain or sand drain inside the drilling hole (the ground layers having different drainage and soil properties) And the bag body 8 or the bag (the technology that has already been developed and put to practical use can be easily used for the technology for inserting and setting the drain material 18 into the drilling hole 4). Accompanying consolidation dehydration due to expansion of packer 10 etc. The water in the panel 3 is pumped up and drained by the paper drain material 18 (not limited to a single unit) or a drain pipe, and the compacting action and the dehydrating action by the plastic grout are carried out intermittently and actively. This is a mode that can be done.
[0052]
Moreover, in the form of the embodiment shown in FIG. 11, the bag body 81 is connected to the injection pipe 9 as an outer pipe in which the bag body 81 is provided only in the upper part in the drilling hole 4 previously formed at a predetermined depth with respect to the ground 3. It has a rubber sleeve 19 '... installed at a predetermined pitch below. From the outlet In this embodiment, plastic grout is injected. In the embodiment, the same effects as those in the above embodiments can be expected by injecting plastic gel grout at predetermined intervals.
[0053]
In the aspect of the embodiment shown in FIG. 11 (ne), bag bodies 81, 81, 81 are circularly arranged at a predetermined pitch in the longitudinal direction of the outer tube 9 to be inserted into the hole 4. A predetermined number of rubber sleeves 19, 19, 19 are provided between the bags 81. From the outlet After the grout is pressed into the bag body by the inner pipe to form the packer, the plastic grout is pressed from the inner pipe, or the plastic grout is injected by the interval method. In this case, the plastic grout Is a cement bentonite exhibiting a suspension type plasticity, a slag added, and water glass, bentonite, slaked lime, etc. are added to these to adjust the plasticity and strength.
[0054]
Thus, in the embodiment shown in FIG. 12, the hole 4 is formed at a predetermined portion, the bag body 81 is provided only at the portion of the uppermost outer tube 9, and the ground 3 is formed below the bag body 81. The outer peripheral surface of the outer pipe 9 for each zone of the surface layer 20, sand layer 21, viscous soil layer 22, and gravel layer 23 Discharge port Are provided with rubber sleeves 19, 19... So that a plastic grout chemical can be selectively injected into each zone of each region, and a predetermined portion of the hole 4 is separated. Water in the ground 3 is discharged through the drain material 18 'in response to continuous injection by the plastic grout interval method in which a drain material 18' such as injection or sand drain is provided in the region and injected into the injection pipe 9. Thus, there is no deviation of the plastic grout to be injected through the drain material 18 ', and compaction acts intermittently to strengthen the ground as a whole, and the ground is not raised.
[0055]
Of course in the embodiment. The concentration, strength and fluidity of the plastic grout can be selected according to the soil quality and relative density of each formation zone of the ground 3.
[0056]
In this embodiment, since the drainage by the drain material 18 'is intermittently performed, the excessive supply of the chemical solution of the plastic grout does not occur. Therefore, as long as the ground 3 is not raised, the ground surface is not generated. Deformation etc. can be avoided.
[0057]
Of course, the embodiments of the invention of this application are not limited to the above-described embodiments.
[0058]
Thus, when the plastic grout is injected into the ground 3, the uplift of the ground 3 is measured, and the amount of plastic grout injected, the specific gravity, the interval time lag, etc. are adjusted to the uplift. Of course, it is also possible to control only the ground uplift during the construction without controlling.
[0059]
【The invention's effect】
As described above, according to the invention of this application, in the plastic grout injection construction that basically improves the strength of the ground, when the plastic grout is injected, the upward protrusion of the ground is suppressed, the lateral displacement of the drilling hole, etc. By preventing the soil from being strengthened laterally, it is possible to achieve an excellent effect that the improvement work by the suspension type plastic grout and the liquefaction prevention measures for the ground can be surely performed.
[0060]
In particular, by making the grout a plastic grout, the fluidity is lower than the dehydration at the advanced part in the ground of the injected liquid while maintaining the fluidity in the step of pumping the grout at the time of the first grout injection. However, it is possible to increase the strength of the surrounding soil by increasing the density of the surrounding soil without splitting the surrounding ground while forming a thin film whose surface is solidifying. In addition, in order to obtain a large increase in strength, there is an advantage that interval injection can be performed in order to divide and inject the entire injection amount. In this case, if a part of the predetermined injection amount is pumped and then the pumping is stopped, the plastic grout Loses fluidity, solidifies and consolidates the ground around the injection, and then the next injection of plastic grout to be injected solidifies the previously injected plastic grout, and therefore does not split the surrounding ground, etc. The polymer grout is polymerized in a thin film in the lateral direction, and the injection of the plastic grout is expanded while the surrounding ground is expanded while forming a new consolidated region. In this way, by injecting a plurality of times by the interval method while passing through a predetermined time lag, the ground consolidation dewatering action is performed in the area, and the ground uplift in the area is avoided, and only the lateral reinforcement is performed. It is carried out as designed and has the excellent effect of improving soft ground and preventing liquefaction.
[0061]
Thus, the injection of the plastic grout is made step-up or step-down in the axial direction of the drilling hole, and injection is carried out by the interval method through a predetermined time lag. Thus, an excellent effect is achieved in that only the lateral consolidation dehydration is performed.
[0062]
In addition, by injecting plastic grout in an interval manner through a predetermined time lag in a lateral direction with respect to a predetermined plurality of holes formed at predetermined intervals on the ground in a predetermined area, There is an excellent effect that strengthening through the side consolidation dehydration of a vast area of ground is performed at once.
[0063]
In addition to the step-up method and the step-down method in the axial direction of the drilling hole, by performing the three-dimensional injection of plastic grout through the interval method in the lateral direction, the ground can be integrated. An excellent effect is achieved in that it is strengthened.
[0064]
Further, by inserting a bag body or bag packer at a predetermined pitch into the injection tube inserted into the drilling hole and injecting plastic grout into the bag body by the interval method, the plastic grout that has oozed out of the bag body is drilled. Gelling action with the side wall, forming a packer of a size larger than the actual packer size, so the plastic grout injected into the adjacent bag body, etc. crosses the bag body and escapes vertically, An excellent effect is achieved in that no displacement such as a ground uplift occurs.
[0065]
For this reason, there arises an effect that the tensile strength of the injection pipe or the tensile material tangled to the injection pipe is given to the ground.
[0066]
Thus, when the plastic grout is injected into the drilling hole by the interval method, a drain material such as a paper drain is provided, so that the dehydrated portion removed in accordance with the injection of the plastic grout Since the drainage can be actively drained through the drain material, an excellent effect is achieved in that the ground can be improved more smoothly due to the strength of the ground accompanying consolidation.
[0067]
Therefore, when the plastic grout is injected into the ground by the interval method, the displacement of the ground is measured with a laser beam or the like, and the displacement is measured in real time via a computer or the like. There is an excellent effect that the timing can be adjusted so that the strength of the ground can be improved as designed.
[0068]
In this way, by injecting the plastic grout repeatedly through the interval method and at a constant time lag, there is an effect that the consolidation can be repeated and the ground strengthening can be performed more precisely as designed.
[0069]
And, as in the conventional mode, by injecting the solution type drug into the ground continuously and continuously, the injected drug splits the ground and escapes, and coagulates with a predetermined gel time over time. , The compaction action can not be achieved, and the strength of the formed solids can be avoided only by the fact that the strength of the sand gel formed by mixing the filler and sand on the ground is not much different. When a simple suspension-type injection is infiltrated, there is no phenomenon that the strength of the solidified product due to clogging increases between the particles, and no improvement in strength can be expected. Is done.
[0070]
Further, according to the invention of this application, since there is no ground uplift, there is no possibility that the building constructed on the ground will be inclined by the ground uplift. .
[0071]
Also, by mixing the prescribed chemicals with plastic grout. There is also a flexible effect that the fluidity and strength can be adjusted appropriately.
[0072]
In addition, when the plastic grout is injected into the ground, there is also a construction flexibility that can increase or decrease the pouring input and the number of injections according to the ground conditions.
[0073]
Thus, when the plastic grout of the invention of this application is injected, an appropriate double packer method and other rod injection methods can be selected. Also There is an effect.
[0074]
In addition, the plastic grout used in the invention of this application is a substantially non-penetrating injection material, and may be a suspension type instantaneous setting property or an injection material having plasticity such as viscosity, Preferably, the homogel has a compounding property having a final strength of a predetermined value or more.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a model diagram of ground reinforcement by plastic grout press-fitting, (A) is a side view of solidified pillars joined by plastic grout with respect to a region to be improved, and (B) is a partial sectional view of the same.
FIG. 2 is a ground reinforcement model in which a plastic grout is press-fitted into the ground with respect to an injection tube having a tensile strengthening degree, and (C) is a ground strengthening model diagram of the bag packer in the ground due to the plastic grout. (D) is a partial sectional plan view of the same, and (e) and (f) are structural sectional views of applying a tensile force to the bag body.
[Fig. 3] Fig. 3 is a structural foundation reinforcement model based on the principle of ground reinforcement, (G) is a schematic structural cross-sectional view of applying tension of injected plastic grout to the bag body, (H) is the same flat model. It is sectional drawing.
FIG. 4 is a model diagram of ground reinforcement by dehydration or water absorption.
FIG. 5 is a process diagram of a basic embodiment, wherein (i) is a cross-sectional view of an injection mode through a time lag by a step-up method, and (nu) is a cross-sectional view of an interval mode injection mode for the same zone. It is.
FIG. 6 is a cross-sectional view of an embodiment according to an interval method of injecting a plastic gel grout through a hole formed adjacent to the ground in a predetermined area.
FIGS. 7A and 7B are cross-sectional views of a consolidation process through a bag body, where FIG. 7L is a cross-sectional view at an intermediate period, FIG. 7O is a cross-sectional view at an initial stage, and FIG.
FIG. 8 is a cross-sectional view of the injection construction by the packer method, and (F) to (Y) are lateral side views of the packer bag over time.
FIG. 9 is a cross-sectional view of a construction mode in which a drain material is provided in the drilling hole to promote a dehydration effect.
FIG. 10 is a schematic diagram of a displacement measurement mode in the middle of construction of the ground. (T) is a schematic side view of a laser beam generator used for a level detection method by a level sensor, and (L) is a schematic side view of a measurement aspect of ground uplift.
FIG. 11 is a cross-sectional view of an embodiment of ground injection according to the invention of the present application, in which (So) is a cross-sectional view of a plastic gel grout injection mode of a plastic gel having a short gelation time, and (tu) is a gel. It is a schematic sectional drawing of the injection | pouring aspect of the chemical | medical solution of the plastic grout with long formation time.
FIG. 12 is a schematic cross-sectional view of a joint structure between an injection drilling hole and a drain material for accelerating the consolidation phenomenon due to the gelation time of the plastic grout injected into the ground.
FIG. 13 is a sectional view of an aspect of ground splitting when an excessive amount of plastic grout is injected at once.
[Explanation of symbols]
3 ground
9 Drilling
8 Bag (bag packer)
18 'drain material
17 Computer

Claims (7)

A plurality of drilling provided at a predetermined interval in the target ground to be improved, in the improved method of the soft ground to improve the strength of該地board by injecting grout from the drilling, provided one or a plurality of the bag body In addition, an injection pipe having a discharge port provided at least below the bag body is installed in the hole, and a grout is press-fitted into the bag body to form a packer, and then a plastic grout is pressed into the ground from the discharge port. A method for improving soft ground, wherein the soil is strengthened by increasing the density of the surrounding soil by pushing the soil particles to the periphery instead of infiltrating the soil particles while suppressing the rise of the ground. According to claim 1, an improved method of soft ground according to claim 1 for repeated injections due interval method of plasticity grout. 2. The method for improving soft ground according to claim 1, wherein the plastic grout is press-fitted into the ground through a discharge port of an injection pipe provided with a sleeve, thereby strengthening the ground. The method for improving a soft ground according to claim 1, wherein dehydration with a drain material or water absorption with a water absorption pipe is used in combination. The method for improving soft ground according to claim 1, wherein, when the plastic grout is press-fitted, press-fitting is performed while measuring displacement of the ground. The method for improving soft ground according to claim 1, wherein, when the plastic grout is press-fitted, the amount of the plastic grout is set and pressed into each soil layer of the target ground to be improved. In claim 1, after calculating the gap and strength of the ground, the amount of plastic grout injection is set for each soil layer of the target ground to be improved , and the strength of the consolidated column and the soil in the compressed region The improvement method of the soft ground of Claim 1 which sets the intensity | strength as a composite ground from an increase density and each area ratio.

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