JP2016164330A - Ground improvement method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ground improvement method capable of accurately measuring deviation of a drilled borehole from a planned construction position and minimizing deviation of the center of the borehole from the center of a measurement device or deviation of the center of the drilled borehole from the center of an injector or an agitation device as much as possible.SOLUTION: A measurement device (3) is inserted into a pipe (2A) located on the most inner side in radial direction of a multiple-pipe part of a multiple-pipe injection device or a multiple-pipe agitation device that is inserted in a borehole (H). A position (including presence or absence of inclination, curve and others) of the pipe (2A) located on the most inner side in radial direction is measured by the measurement device (3) while the measurement device (3) is being pulled out of the pipe (2A) located on the most inner side in radial direction.SELECTED DRAWING: Figure 2

Description

The present invention relates to a technique for injecting and injecting a chemical solution and a solidified material into a ground to be improved, or stirring the mixture with a stirring blade while discharging the chemical solution or a solidified material to the ground to form an underground solidified body.

With reference to FIGS. 8-12, the construction procedure of the ground improvement construction method which concerns is demonstrated.
First, as shown in FIG. 8, the boring hole H is cut by the drilling device 11 having the casing 11A. In FIG. 8, the illustration of the inner rod and the like is omitted.
Next, the guide pipe 12 is inserted into the boring hole H (FIG. 9), the measuring device 13 is inserted into the guide pipe 12 (FIG. 10), and the position, inclination and bending of the cut boring hole H are checked. measure.

And as shown in FIG. 11, the measuring apparatus 13 and the guide pipe 12 are pulled out from the boring hole H, and the injection apparatus 14 is inserted in the casing 11A. Although not shown, the casing 11A may be first pulled out, the measuring device 13 and the guide pipe 12 may be pulled out, and then the injection device 14 may be inserted.
In a state where the casing 11A, the measuring device 13, and the guide pipe 12 are pulled out and the injection device 14 is inserted into the boring hole H (FIG. 12), the cutting fluid (for example, high-pressure water) J is injected from the injection device 14 and rotated. While doing (arrow R), pulling up (arrow U), an underground solid body is formed.

Here, since the cutting diameter of the bored hole H to be cut and the outer diameter of the guide pipe 12 are large, when the guide pipe 12 is inserted into the bored hole H (FIG. 9), as shown in FIG. There are cases where the twelve central axes CLG are inserted with an eccentricity (deviation amount δ1) with respect to the central axis CLH of the boring hole (that is, the central axis of the casing 11A).
Further, since the inner diameter of the guide pipe 12 is large, there is a possibility that the measuring device 13 is unevenly arranged in the guide pipe 12 as shown in FIG. In FIG. 14, the central axis CLM of the measuring device 13 is eccentric with respect to the central axis CLG of the guide pipe 12, and the amount of deviation is indicated by a symbol “δ2”.

Further, as shown in FIG. 15, there is a possibility that the central axis CLJ of the injection device 14 is deviated from the central axis CLH of the boring hole H (deviation amount δ3).
As shown in FIG. 16, the center axis CLJ of the injection device 14 is eccentric by the maximum deviation amount “δ1 + δ2 + δ3” with respect to the center axis CLH of the boring hole H. There is a possibility that.

The center axis CLJ of the injection device 14 is deviated by an eccentric amount “δ1 + δ2 + δ3” with respect to the central axis CLH of the boring hole H. ”, And the underground solid body does not continue when the underground wall is formed, and there is a possibility that the predetermined action (water stopping action, earth retaining action) may not be achieved.
Although FIGS. 8-16 demonstrated the ground improvement construction method using the injection apparatus 14, the same problem exists also in the ground improvement construction method using the stirring apparatus which has a stirring blade.
However, an effective solution for the problem that the central axis of the injection device or the stirring device is deviated with respect to the central axis CLH of the boring hole H described above has not yet been proposed.

As another conventional technique, for example, a technique is disclosed in which a position information transmitting device is incorporated at the tip of a boring rod and the tip position of a boring hole cut by the boring rod is measured.
However, since a cutting bit is provided at the tip of the boring rod and a cutting tip is embedded in the cutting bit, if a position information transmission device is further incorporated, the structure becomes complicated and the manufacturing cost of the cutting bit increases. Resulting in.
Further, when the soil is cut, various vibrations, impacts and noises are generated, so that the position information transmission device which is a precision machine is used in a harsh environment. And as a result of being used in a harsh environment, there arises a problem that the possibility of failure of the position information transmitting device increases.
Furthermore, even if the position of the cut boring hole can be accurately grasped, the center of the boring hole and the center of the injection device or the stirring device inserted into the boring hole are prevented from being deviated. I can't do that.

JP 2006-152594 A

The present invention has been proposed in view of the above-described problems of the prior art, and can accurately measure that the cut bored hole is deviated from the planned construction position, and the center of the borehole can be measured. It is an object of the present invention to provide a ground improvement method capable of minimizing the deviation between the center of the measuring device and the center of the cut borehole and the center of the injection device or the stirring device.

The ground improvement method of the present invention is a ground improvement method using a multi-tube spraying device or a multi-tube stirring device,
Inserting the measuring device (3) into the tube (2A) located radially inward of the multiple tube portion of the device inserted into the borehole (H);
While extracting the measuring device (3) from the radially innermost tube (2A), the measuring device (3) measures the position of the radially innermost tube (2A) (inclination, bending). (Including measurement of the presence or absence, etc.).

In the present invention, it is preferable to cut the boring hole (H) with a multiple tube.
Or the process of cutting a boring hole (H) with a casing,
It is preferable to include a step of inserting a multi-tube injection device or a multi-tube stirring device into the cut borehole (H).

In the present invention, boring holes (H, H1-H3) are cut,
Measure the drilled boring holes (H, H1 to H3) (position, inclination, bending, etc.)
Whether the thickness dimension (t) of the overlapping region (CR) with the adjacent underground consolidated body is equal to or greater than a predetermined dimension (predetermined effective thickness) when creating the underground consolidated body (S1 to S3) Determine whether or not
When forming the underground solid body (S1 to S3), the thickness dimension (t) of the overlapping area (CR) with the adjacent underground solid body does not exceed the predetermined dimension (predetermined effective thickness) It is preferable to increase the improved diameter of the underground consolidated body.

Or in this invention, a boring hole (H, H1-H3) is cut,
Measure the drilled boring holes (H, H1 to H3) (position, inclination, bending, etc.)
The thickness dimension (t) of the overlapping area (CR) with the underground part (GC) of the adjacent building when the underground consolidated body (S2) is formed is equal to or greater than a predetermined dimension (predetermined effective thickness). Whether or not
The thickness dimension (t) of the overlapping area (CR) with the underground part (GC) of the adjacent building is not more than a predetermined dimension (predetermined effective thickness) when building the underground consolidated body (S2). In some cases, it is preferable to increase the improved diameter of the underground solid body (S2).

According to the present invention having the above-described configuration, a pipe (2A: a double pipe jet apparatus or a double pipe stirrer located at the radially innermost side of a multi pipe section of a multi pipe jet apparatus or a multi pipe stirrer. By using a measuring device (3) that can be inserted into the inner pipe (if any), the position, inclination, presence / absence of bending, etc. of the pipe (2A) located radially inwardly is measured, so that a borehole The position in (H), inclination, presence / absence of bending, etc. can be determined.
Since the measuring device (3) that can be inserted into the tube (2A) located at the innermost radial direction is used, the multi-tube injection device or the multi-tube stirring device can be reduced in size. Therefore, the cost in the ground improvement construction method such as the cost of boring hole (H) cutting can be kept low.

Further, according to the present invention, the measuring device (3) is inserted into the radially innermost tube (2A) of the multiple tube portion of the multiple tube injection device or the multiple tube stirring device, Since the inner diameter dimension of the tube (2A) located at the outer diameter and the outer diameter dimension of the measuring device (3) can be reduced, the deviation amount of the measuring device (3) in the pipe (2A) located radially inwardly Becomes smaller.
Similarly, since the inner diameter of the bored hole (H) cut by the multiple pipe (2: for example, double pipe drilling device) or the casing can be reduced, the multiple bores are cut into the cut borehole (H). When the tube injection device or the multi-tube agitator is inserted, the deviation amount between the central axis (CLH) of the boring hole (H) and the central axis of the multi-tube injector or the multi-tube agitator is also reduced.
In addition, it is not necessary to insert a guide pipe into the bored hole (H) cut as in the prior art and insert a measuring device into the guide pipe, so the labor required for construction is reduced accordingly. In addition, there is no problem of deviation between the central axis of the boring hole and the central axis of the guide pipe.
Therefore, according to the present invention, the deviation amount between the central axis of the boring hole and the central axis of the multi-tube injection device or the multi-tube agitator can be kept small, and the accuracy and quality of the position of the underground consolidated body to be formed Becomes higher.

Here, it has been conventionally practiced to create underground walls by constructing a plurality of cylindrical underground consolidated bodies and constructing them so that some of the adjacent underground consolidated bodies overlap. Yes.
In order to maintain the desired strength of the underground wall to be created, the thickness dimension (t) of the region (CR) where a part of the adjacent underground consolidated body overlaps is greater than or equal to a predetermined effective thickness. Must.
However, when the center line of any of the underground consolidated bodies (S1, S3) is inclined with respect to the vertical direction, the thickness of the overlapping region (CR) in a certain horizontal section (HR1-HR1). Even if (t) has a predetermined effective thickness, another horizontal cross section (HR2-HR2) does not overlap with an adjacent underground solid body and may not have a desired strength as an underground wall. There is.

In the present invention, boring holes (H1 to H3: boring hole center lines CLH1 to CLH3) are cut,
Measure the bored holes (H1-H3) (tilt, bend)
Whether or not the overlapping region (CR) thickness dimension (t) with the adjacent underground solid body after the formation of the underground solid body (S1 to S3) is greater than or equal to a predetermined dimension (predetermined effective thickness). Judging
In the case where the overlapping region (CR) thickness dimension (t) with the adjacent underground solid body does not exceed the predetermined dimension (predetermined effective thickness) after forming the underground solid body (S1 to S3) If it is configured to increase the improved diameter of the underground solid body (cutting diameter by cutting fluid injection),
If the cut boreholes (H1 to H3) are inclined with respect to the vertical direction and the overlapping area (CR) thickness dimension (t) with the adjacent underground solid body is not less than a predetermined dimension (predetermined effective thickness) even without a radius of ground consolidation body: to increase the (R cutting diameter by cutting fluid _{ejection) (δ R 1, δ R} 2) by overlapping region (CR) thick with an adjacent ground consolidated body The dimension (t) is increased.
As a result, the overlapping region (CR) thickness dimension (t) with the adjacent underground consolidated body can also be increased to a predetermined dimension (predetermined effective thickness) or more.

Here, after forming the underground solid body (S1 to S3), the overlapping region (CR) thickness dimension (t) with the adjacent underground solid body is equal to or greater than a predetermined dimension (predetermined effective thickness). This can be easily determined from the inclination of the cut boring holes (H1 to H3), the cutting diameter R (improved diameter) and the depth (thickness) dimension T of the underground solid body.
Further, according to the present invention, not only when the overlapping region (CR) thickness dimension (t) with the adjacent underground consolidated body does not exceed the predetermined dimension (predetermined effective thickness), but also the adjacent building Even when the thickness dimension (t) of the overlapping area (CR) with the underground part (GC) does not reach the predetermined dimension (predetermined effective thickness), the radius (R) of the underground solid body is increased, Can be dealt with.

It is explanatory drawing which shows 1 process of the ground improvement construction method which concerns on 1st Embodiment of this invention. It is explanatory drawing which shows the process following FIG. FIG. 3 is an explanatory diagram illustrating a process following the process in FIG. 2. It is front sectional drawing which shows the ground improvement construction method which concerns on 2nd Embodiment of this invention. It is explanatory drawing which shows the HR1 arrow cross section of FIG. It is explanatory drawing which shows the HR2 arrow cross section of FIG. 4, Comprising: It is explanatory drawing which shows the state before performing the diameter expansion process by 2nd Embodiment. It is explanatory drawing which shows the HR2 arrow cross section of FIG. 4, Comprising: It is explanatory drawing which shows the state after performing the diameter expansion process by 2nd Embodiment. It is explanatory drawing which shows the boring hole cutting process in the conventional ground improvement construction method. It is explanatory drawing which shows the process of inserting a guide pipe in the boring hole cut in FIG. It is explanatory drawing which shows the process of inserting the measuring device in a guide pipe and measuring the position of a boring hole, the inclination, and the presence or absence of bending. It is explanatory drawing which shows the state which pulled out the measuring device and the guide pipe, and inserted the injection device in the casing. It is explanatory drawing which shows the state which pulled out the casing. In the process shown in FIG. 9, it is explanatory drawing which shows the state which the guide pipe deviated within the boring hole. In FIG. 13, it is explanatory drawing which shows the state in which the measuring device is deviated within the guide pipe. It is explanatory drawing which shows the state in which the injection apparatus has deviated within the boring hole. FIG. 15 is an explanatory diagram showing a state in which the deviation of the guide pipe in the borehole shown in FIG. 13, the deviation of the measuring device in the guide pipe shown in FIG. 14, and the deviation of the injection device in the borehole shown in FIG. is there. It is a perspective view which shows the ground improvement construction method which concerns on 3rd Embodiment of this invention. It is a bottom view of FIG. It is a perspective view which shows the modification of 3rd Embodiment. FIG. 20 is a bottom view of FIG. 19.

Hereinafter, embodiments of the present invention will be described with reference to FIGS.
First, a first embodiment of the present invention will be described with reference to FIGS.
FIG. 1 shows a process of cutting a boring hole H using a double pipe drilling device 2 in a ground G on which an underground solid body is to be created. The double-pipe drilling device 2 is a known one having an inner tube 2A, an outer tube 2B, and an injection section 2C at the tip.
When cutting the boring hole H, the ground is removed by injecting a cutting fluid (for example, high-pressure water) downward from the injection unit 2C from an external supply source (not shown) through the flow path in the inner pipe 2A. The boring hole H can be cut by cutting. Here, the slurry generated when cutting the ground is discharged to the ground side from an annular passage formed between the inner tube 2A and the outer tube 2B. Cutting of the boring hole H by jetting the cutting fluid downward from the jet part 2C is performed up to a predetermined depth position corresponding to the vertical lower limit position of the underground solid body to be formed. Cutting of the boring hole H is completed at a vertical position corresponding to the vertical lower limit position of the consolidated body.

Here, when cutting the boring hole H, not only the double tube drilling apparatus 2 but also other types of cutting apparatuses (not shown) can be used.
In that case (for example, when the boring hole H is cut using a casing), after the boring hole H is cut, a multi-pipe (for example, a multi-pipe injection device or a multi-pipe stirring device) is inserted into the boring hole H.

Here, the double-pipe drilling device 2 according to the first embodiment is configured such that, after the cutting of the boring hole H is completed, the fluid injection flow path in the injection unit 2C is switched to switch the double-pipe injection device (multi-tube injection device). After cutting the boring hole H, a cutting fluid (for example, high-pressure water) is sprayed from the jetting part 2C in the horizontal direction, and is solidified downward from the jetting part 2C to the ground below. The binder can be discharged. Therefore, an underground solidified body can be formed by pulling up the injection device including the injection unit 2C while rotating.
In the formation of the underground consolidated body, the cutting fluid is supplied from an external supply source (not shown) to the injection unit 2C through the flow path between the inner tube 2A and the outer tube 2B. It is supplied to the injection unit 2C through a flow path in the pipe 2A.
However, as the double pipe drilling device, only the type capable of switching the injection flow path of the compressed fluid in the injection section 2C as described above is not used. Boring hole H can be cut with a casing, and after cutting the boring hole, the casing is lifted to the ground, and a multi-tube spraying device or a multi-tube stirring device is newly inserted into the boring hole H to form an underground solid body. It is.

After cutting the borehole H, before the formation of the underground solid body, as shown in FIG. 2, the pipe located at the innermost radial direction of the double pipe drilling device 2 (multiple pipe) The measuring device 3 is inserted into an inner pipe 2A.
The diameter of the measuring device 3 is so small that the measuring device 3 can be inserted into the inner tube 2 </ b> A located radially inward of the double tube drilling device 2.
When the measuring device 3 is inserted into the inner tube 2A, the gap between the inner tube 2A and the inner wall of the inner tube 2A is small. Therefore, the deviation amount between the central axis of the inner tube 2A and the central axis of the measuring device 3 is also extremely small. .

As shown in FIG. 2, the measuring device 3 has a measuring part (radio wave transmission part: not shown with reference numerals) near the tip in the insertion direction (lower end in FIG. 2) in the vicinity of the boring hole H (lower end in FIG. 2). Inserted until position is reached.
At the time of measurement by the measurement device 3, for example, a signal is transmitted from the measurement unit (radio wave transmission unit) not specified, and the signal is received by a ground reception unit (not shown) by either a wired or wireless method. . The signal is sent every predetermined unit time, and the position and movement locus of the measuring apparatus 3 (measurement unit) are determined based on the difference between the displacement amount and the position in the previous measurement cycle. Then, from the position and movement trajectory of the measuring device 3, the position, inclination, presence / absence of bending of the inner tube 2A of the double tube drilling device 2 are measured.

In the measuring device 3, when the measuring device 3 is inserted into the inner tube 2A (FIG. 2), measurement is performed from the inner tube 2A by measuring (in the measuring device 3) and determining the position and movement locus. There is a type that performs measurement when the device 3 is pulled out and determines the position (of the measurement device 3) and the movement locus. Any type can be used. For example, in the first embodiment shown in the figure, a type is used in which measurement is performed when the measuring device 3 is pulled out from the inner tube 2A and the position and the movement locus are determined (of the measuring device 3).
The measurement by the measuring device 3 will be described in more detail. For example, when the measuring device 3 is pulled out from the inner tube 2A in the state shown in FIG. 2, the moving direction and moving distance (withdrawing direction and (Drawing distance) is calculated, and the calculation result is superimposed (integrated) over the entire drawing of the measuring device 3 to determine the drawing locus of the measuring device 3, and the position, inclination, and bending of the inner tube 2A are determined from the locus. The presence or absence is determined.

FIG. 3 shows a state in which the underground solid body forming step is performed by using the injection device (the injection device having the injection part 2C) after the measurement device 3 is pulled out from the inner tube 2A. As described above, the double-pipe drilling device 2 according to the first embodiment, after cutting the boring hole H, switches the injection flow path of the cutting fluid of the injection unit 2C to create an underground consolidated body. It also has a function as.
Here, in the illustrated first embodiment, since the boring hole H is cut using the double tube drilling device 2 in which the measuring device 3 can be inserted into the inner tube 2A, the inner diameter of the cut boring hole H is also set. small. Therefore, the deviation amount between the central axis of the boring hole H and the central axis of the injection part 2C is small.

When the switching of the injection flow path of the injection unit 2 of the double pipe drilling device 2 is completed, the cutting fluid (for example, high pressure water) jet (jet) J from the injection unit 2C of the double pipe drilling device 2 in the horizontal direction. Is sprayed horizontally on the ground G, and simultaneously, a caking material (not shown in FIG. 3) is discharged downward from the spraying section 2C.
And the injection | pouring part 2C of the double pipe | tube drilling apparatus 2 is rotated (arrow R), pulling up (arrow U), and an underground solid body (not shown) are created.
The steps described in FIGS. 1 to 3 are repeatedly performed until the formation of the underground consolidated body is completed.

According to 1st Embodiment of FIGS. 1-3, by using the double pipe drilling apparatus 2 and the measuring apparatus 3 which can be inserted in the inner pipe 2A of the double pipe drilling apparatus 2, the inner pipe 2A The position, inclination, presence / absence of bending, etc. are measured, so that the position, inclination, presence / absence of bending, etc. in the borehole H can be determined.
Since the measuring device 3 that can be inserted into the inner tube 2A is used, the equipment used can be reduced in size, so that the cost of cutting the boring hole H can be kept low.

In the illustrated first embodiment, the measuring device 3 is inserted into the inner tube 2A of the double tube drilling device 2, so that the inner diameter of the inner tube 2A and the outer diameter of the measuring device 3 can be reduced. The deviation amount of the measuring device 3 in the inner pipe 2A is also reduced.
Similarly, since the inner diameter of the bored hole H cut by the double-pipe drilling device 2 in which the measuring device 3 can be inserted into the inner tube 2A can be reduced, an injection device (injection) is injected into the cut bored hole H. When the portion 2C) is inserted, the amount of deviation between the central axis of the boring hole H and the central axis of the injection device is also reduced.
In addition, in the illustrated first embodiment, since it is not necessary to insert a guide pipe into the bore hole H and insert a measuring device into the guide pipe, construction labor is reduced and the center of the bore hole H is reduced. There is no deviation between the shaft and the central axis of the guide pipe.
As a result, according to the illustrated first embodiment, the amount of deviation between the central axis of the boring hole H and the central axis of the injection device can be kept small. Therefore, the construction accuracy of the underground solid body to be formed is improved and the quality is improved.

Next, a second embodiment of the present invention will be described with reference to FIGS.
Create a plurality of cylindrical underground solids by the ground improvement method shown in Fig. 1 to Fig. 3, and construct underground walls by constructing them so that some of the adjacent underground solids overlap. It has been done conventionally.
In order for the underground wall to be formed to maintain a desired strength, as shown in FIG. 5, in the cross section of the generated underground consolidated bodies S <b> 1 to S <b> 3, a part of the adjacent underground consolidated bodies The region CR where the two overlap each other (the region indicated by hatching in FIG. 5) must have a thickness dimension t equal to or greater than a predetermined thickness (so-called “effective thickness”).

In FIG. 4 showing a longitudinal section of three underground solid bodies S1 to S3 adjacent to each other, the central axis CLH2 of the underground solid body S2 (that is, the central axis of the corresponding borehole H2) is on the ground G. It extends straight in the vertical direction (boring hole H2 is properly cut). However, the central axes CLH1 and CLH3 of the underground solid bodies S1 and S3 on both sides thereof are inclined by θ1 and θ3, respectively, with respect to the vertical direction.
Even if the underground solid bodies S1 and S3 are inclined with respect to the vertical direction, as shown in FIG. 4, in the horizontal section HR1-HR1 on the upper edge side of the underground solid bodies S1 to S3, FIG. In this state, the thickness t of the overlapping region CR is maintained at a predetermined effective thickness.
On the other hand, in the horizontal section HR2-HR2 (horizontal section at a deep position) on the lower edge side of the underground solid bodies S1 to S3, the underground solid bodies S1 to S3 are adjacent as shown in FIG. It does not overlap with the underground consolidated body, and does not have the desired strength as an underground wall.

As described with reference to FIGS. 4 and 6, the underground solid bodies S <b> 1 to S <b> 3 do not overlap with the adjacent underground solid bodies, and the thickness t of the overlapping region CR becomes a predetermined effective thickness. If the ground wall does not have the desired strength (see the dotted line in FIG. 7), as shown in FIGS. 4 and 7, the injection device (not shown in FIGS. 4 to 7) is used. Increase cutting diameter (by cutting fluid injection). By increasing the cutting diameter at the time of formation of the underground solid body, the thickness dimension t in the overlapping region CR with the adjacent underground solid body is increased to an effective thickness or more, and a desired strength as an underground wall is obtained. Can have.
In FIG. 4, the cutting diameter R (the radius of the underground solid body) is increased by δ _R 1 for the inclined underground solid body S1 (cutting diameter = R + δ _R 1: FIG. 7). Also for ground solid body S3, are also inclined, the cutting diameter R (the radius of the ground consolidation body) increases by [delta] _{R 3} (cutting diameter = _R + δ R _3: 7). As a result, "the process of increasing the improved diameter of the underground consolidated body when the thickness dimension of the overlapping area with the adjacent underground consolidated body after the formation of the underground consolidated body does not exceed the predetermined dimension" Is executed.

In the horizontal section HR2-HR2 after increasing the cutting diameter and expanding the underground solid bodies S1 and S3, as indicated by the solid line in FIG. 7, the radii of the underground solid bodies S1 and S3 are respectively δ _R 1 and δ _R 3 are increased, and the thickness dimension t in the overlapping region CR is equal to or greater than the effective thickness. Therefore, desired strength can be secured as the underground wall.
When the cutting diameter R is increased to R + δ _R 1 or R + δ _R 3, a known technique such as an increase in injection pressure or a decrease in the rotation speed of the injection device may be applied.

Here, in determining whether or not the thickness dimension t in the overlapping region CR of the underground solid bodies S1 to S3 is greater than or equal to the effective thickness in the horizontal section HR2-HR2, the underground solid bodies S1 to S1. It is determined whether or not the boring holes in each of S3 (in FIGS. 4 to 7, not shown except for the central axes CLH1 to CLH3) are inclined.
When determining whether or not the thickness dimension t of the overlapping region with the adjacent underground solid body is equal to or greater than a predetermined dimension when the underground solid body is formed, first, the underground solid bodies S1 to S1. With respect to the bore holes (center axes CLH1 to CLH3) of S3, the inclination angles θ1 to θ3 (see FIG. 4) are measured based on the measurement results described in the first embodiment of FIGS. And the thickness dimension in the overlapping region CR of the underground solid bodies S1 to S3 based on the planned dimension T in the depth direction (vertical direction) of the underground solid bodies S1 to S3, the cutting diameter R of the cutting fluid jet J, and the like. t is calculated, and the calculated thickness dimension t of the overlap region CR is compared with the effective thickness (necessary for securing a desired strength as an underground wall).

When it is necessary to increase the cutting diameter R as a result of determining whether the thickness dimension t in the overlap region CR has secured the necessary effective thickness, the dimension (increase) to increase the cutting diameter R Min) δ _R 1 and δ _R 3 are the thickness dimension t (specified from the strength of the underground wall to be secured) in the overlapping region CR of the underground consolidated bodies S1 to S3, and the inclination angles θ1 to 1 of the above-described boreholes. It can be calculated from θ3, the planned dimension T in the thickness direction of the consolidated bodies S1 to S3 in various places, and the cutting diameter R (before improvement) by the cutting fluid jet J.
In FIG. 4, if the thickness dimension t in the overlap region CR is smaller than the effective thickness only in the vertical region extending from the horizontal cross section HR2-HR2 to the horizontal cross section HR3-HR3, the horizontal cross section HR2-HR2- The cutting diameter R is increased only for the area extending over the horizontal section HR3-HR3, and the cutting diameter is not increased for the vertical area extending over the horizontal sections HR1-HR1 to HR3-HR3.

According to 2nd Embodiment shown in FIGS. 4-7, even if the thickness dimension t in the duplication area | region CR of underground solid body S1-S3 has not ensured effective thickness, it is underground fixing required dimensions cutting diameter R (corresponding to the radius of the ground solid bodies S1 to S3) of the sintered body (e.g., FIG. _{4, δ R 1, δ R} 3 in FIG. 7) by increasing, ground caking The thickness dimension t in the overlapping region CR with the adjacent underground consolidated bodies of the bodies S1 to S3 can be set to be equal to or greater than a desired effective thickness.
As a result, when forming the plurality of cylindrical underground solid bodies S for underground wall formation, even if the underground solid bodies S are inclined with respect to the vertical direction, By setting the thickness dimension t in the overlapping region CR to a desired effective thickness or more, the strength required for the underground wall can be maintained.

Next, a third embodiment of the present invention will be described with reference to FIGS.
The second embodiment shown in FIGS. 4 to 7 deals with a case where the thickness dimension t in the overlapping region CR of the plurality of underground consolidated bodies S1 to S3 cannot secure an effective thickness.
On the other hand, in the third embodiment of FIGS. 17 to 20, the overlapping region CR between the underground portion GC of the building and the underground consolidated body S2, or the region sandwiched between the underground portions GC1 and GC2 of the building. The case where the thickness dimension t in the overlapping region CR of the underground solid bodies S1 and S2 to be formed is not able to secure an effective thickness is targeted.
Here, the overlapping region CR is a virtual region, although it is indicated by a dotted line in FIGS. The underground portions GC1 and GC2 of the building are not cut when the underground solid bodies S1 and S2A are formed. The overlapping region CR (virtual region) in FIGS. 12 to 15 is based on the assumption that the underground solid bodies S1 and S2A have entered the underground parts GC1 and GC2 of the building when the underground solid bodies S1 and S2A are created. It is an (assumed) overlapping region. And ensuring that the thickness dimension t in the overlap region CR has an effective thickness means that the underground consolidated bodies S1 and S2A are in close contact with the underground portions GC1 and GC2 of the building.

Initially, with reference to FIG. 17, FIG. 18, the case where it applies to the underground part GC of a building and the underground solid body S2 is demonstrated. 17 and 18, when the underground solid body S2 is formed adjacent to the underground portion GC of the building, the underground solid body S2 is inclined with respect to the vertical direction as shown in FIG. The overlapping region CR on the ground side (upper side in FIG. 17) seems to have a sufficient thickness dimension (effective thickness). However, as shown in FIG. 18, the underground part GC of the building (the lower side in FIG. 17) is not overlapped with the underground part GC of the building and the underground consolidated body S2. However, there is a case where the thickness dimension t is not sufficient (the effective thickness has not been reached).
On the other hand, in 3rd Embodiment, the improvement diameter of underground solid body S2 is increased and underground solid body S2A is formed. When the improved diameter of the underground consolidated body S2A is larger than that of the underground consolidated body S2, as shown in FIG. 18 in particular, the structure of the building on the underground side (lower side in FIG. 17) of the underground consolidated body S2A. In the overlapping region CR with the underground portion GC, a sufficient thickness dimension t2 is secured, and an effective thickness is secured.
Other configurations and functions and effects of the third embodiment shown in FIGS. 17 and 18 are the same as those of the second embodiment shown in FIGS.

19 and 20 show a modification of the third embodiment.
The third embodiment of FIGS. 17 and 18 contemplates that the width dimension t of the overlapping region CR between the underground portion GC of the building and the underground consolidated body S2A is equal to or greater than the effective thickness. 19 and 20, the thickness dimension t in the overlapping region CR of the underground solid bodies S1 and S2 formed in the region sandwiched between the underground portions GC1 and GC2 of the building is set to the effective thickness. It is a technique to make more than that.
19 and 20, the underground consolidated bodies S1 and S2A are formed in a region sandwiched between the underground portions GC1 and GC2 of the building.

Here, the underground solid body S2A is inclined with respect to the vertical direction, and the improved diameter is larger than that of the underground solid body S1. When the improved diameter of the underground solid body S2A that is inclined with respect to the vertical direction is the same as that of the underground solid body S1, the underground solid body S2A and the underground solid body S1 overlap. In the region CR, in particular, in the region on the ground side (lower side in FIG. 19) shown in FIG. 20, the width dimension t becomes small, and there is a case where the effective thickness cannot be secured.
However, as shown in FIGS. 19 and 20, since the improved diameter of the underground consolidated body S2A is larger than the improved diameter of the underground consolidated body S1, the underground side of the overlapping region CR (lower side in FIG. 19). In this region, a sufficient width dimension t (effective thickness) is secured.
Other configurations and operational effects in the modified examples of FIGS. 19 and 20 are the same as those of the second embodiment of FIGS. 4 to 7 and the third embodiment of FIGS. 17 and 18.

It should be noted that the illustrated embodiment is merely an example, and is not a description to limit the technical scope of the present invention.
For example, in the illustrated embodiment, a ground improvement method using an injection device is shown, but the present invention can be similarly applied to a ground improvement method using a stirring device having stirring blades.

DESCRIPTION OF SYMBOLS 1 ... Injection device 2 ... Double pipe drilling device (Multiple pipe drilling device)
2A ... Inner tube (tube located in the innermost radial direction of multiple tubes)
2B ... Outer tube 2C ... Injection unit 3 ... Measuring device 11 ... Drilling device 11A ... Casing 12 ... Guide pipe 13 ... Measuring device 14 ... Injection device 14A- ..Glowing part G ... Ground H ... Boring holes S1, S2, S3 ... Underground consolidated bodies GC, GC1, GC2 ... Underground part of the building

Claims (5)

In the ground improvement method using a multi-tube injection device or a multi-tube stirring device,
Inserting the measuring device into the radially innermost tube of the multiple tube portion of the device inserted into the borehole;
And a step of measuring the position of the pipe located radially inward by the measurement apparatus while pulling out the measurement apparatus from the pipe located radially innermost. The ground improvement method according to claim 1, wherein the boring hole is cut by a multiple pipe. Cutting the boring hole with the casing;
The ground improvement method according to claim 1, further comprising a step of inserting a multi-tube injection device or a multi-tube agitator into the cut borehole. Cutting the borehole,
Measure the drilled hole,
Judging whether the thickness dimension of the overlapping area with the adjacent underground solid body is equal to or greater than the predetermined dimension when creating the underground solid body,
When the thickness dimension of an overlapping region with an adjacent underground solid body does not exceed a predetermined dimension when forming the underground solid body, the improved diameter of the underground solid body is increased. The ground improvement method according to any one of 3 above. Cutting the borehole,
Measure the drilled hole,
Determine whether the thickness dimension of the overlapping area with the underground part of the adjacent building when building the underground consolidated body is equal to or greater than the predetermined dimension,
In the case of forming an underground solid body, when the thickness dimension of an overlapping region with an underground portion of an adjacent building does not exceed a predetermined dimension, the improved diameter of the underground solid body is increased. The ground improvement method according to any one of 3 above.

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