JP2017129388A - Hazardous material search method by casing-type earth retaining construction, and casing-type earth retaining construction - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hazardous material search method by a casing-type earth retaining construction, capable of shortening a construction period concerning a hazardous material search and accurately searching for hazardous materials.SOLUTION: This hazardous material search method that includes a step for confirming and searching for a magnetic abnormality detected through magnetic searching includes: a step for press-fitting a casing-type earth retaining construction to which a magnetic sensor can be attached into the ground so as to surround the magnetic abnormality; a step for drilling and removing sands/rocks inside the casing-type earth retaining construction after press-fitting of the casing-type earth retaining construction in the press-fitting step; and a step for measuring magnetism in the ground by using the magnetic sensor attached to the casing-type earth retaining construction, the step being executed in parallel with the press-fitting step and the drilling and removing step.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a hazardous material search method using a casing type earth retaining method and a casing type earth retaining method.

  Currently, shells and bombs used in past wars, regardless of whether in Japan or overseas, may remain in the ground as dangerous items such as unexploded shells for some reason. There has been a frequent problem that such dangerous materials explode upon receiving some impact during underground construction, causing personal and physical damage.

  In order to proceed underground construction safely and smoothly, it is important to confirm the presence of such dangerous materials in advance, and to perform excavation work and remove them if dangerous materials are present.

  The general method for confirming and removing such dangerous goods is the process of confirming the presence of dangerous goods by rough exploration using both horizontal and vertical exploration, and finally confirming artificially and removing dangerous goods. It is the method which passes through the process to do.

  Horizontal exploration is exploration up to 1.0 m below the ground surface, and vertical exploration is exploration at a depth deeper than 1.0 m below the ground surface.

  Horizontal exploration is a magnetic exploration carried out on the ground surface. Specifically, an operator performs magnetic confirmation using a magnetic sensor such as a double-coil magnetic inclinometer, and is detected by magnetic confirmation. Hazardous materials are confirmed while repeating steps such as excavation of abnormal points (hereinafter also simply referred to as “abnormal points”) and re-confirmation of magnetism.

  In the vertical exploration, an exploration hole is drilled by a machine such as a boring machine, and a magnetic sensor is inserted therein to detect the presence of a dangerous substance remaining deep underground.

  Here, if the depth of vertical exploration is about 1.5m below the ground surface and is relatively shallow, temporary earth retaining work is not necessary for excavation, and dangerous materials are confirmed by mechanical excavation, manual excavation, and subsequent confirmation work. can do. On the other hand, when the depth of vertical exploration is deeper than about 1.50 m below the ground surface, temporary earth retaining work is required for excavation. Temporary earth retaining works include the following methods (1) to (2).

(1) Temporary earth retaining is performed by liner plate type earth retaining work, lightweight steel sheet pile earth retaining work, etc., and dangerous materials are confirmed and removed while repeating mechanical excavation, manual excavation and subsequent magnetic exploration.
(2) Conduct large-scale temporary earth retaining by means of steel sheet pile retaining works, etc., and confirm and remove dangerous materials while repeating mechanical excavation, manpower excavation and subsequent magnetic exploration.

  As a magnetic exploration technique using a magnetic sensor, for example, a technique disclosed in Patent Document 1 is known. In Patent Document 1, as shown in FIG. 11, a casing 101 made of a non-magnetic material is pressed into the ground by hitting excavation to excavate an exploration hole 102 having a diameter of about 100 mm. A technique is disclosed in which the presence of a magnetic substance is confirmed by inserting a magnetic disk 103 and measuring the change in the amount of magnetic field in the ground by the magnetic sensor 103.

Japanese Patent Laid-Open No. 11-183633

  By the way, when confirming a dangerous substance in a deep underground position by the vertical survey, or when removing the dangerous substance after confirming the presence of a magnetic substance, that is, a dangerous substance by the technique disclosed in Patent Document 1 above. Large temporary earth retaining work such as steel sheet pile earth retaining work was necessary.

  The necessity of a large temporary earth retaining construction has a problem of prolonging the construction period and greatly affecting the safety, environment and the like in the surrounding area. The prolonged construction period also caused the problem of high construction costs.

  A common earth retaining material used for vertical exploration is steel. For this reason, when checking dangerous materials by repeating mechanical drilling, manual drilling and subsequent magnetic surveys in vertical surveys, the magnetism of the earth retaining material interferes with the magnetism of the dangerous materials, and the position and size of the dangerous materials are accurately determined. There was a problem that it was difficult to confirm.

  And if the location and size of the dangerous goods cannot be confirmed accurately, the construction period has become longer to be cautious because the possibility of exploding the dangerous goods increases.

  The present invention has been made in view of the above points, and shortens the construction period for exploration of dangerous goods, and also enables a dangerous substance exploration method and casing-type earth retaining work by a casing-type earth excavation machine capable of exploring dangerous goods with high accuracy. Is intended to provide.

  In order to achieve the above-mentioned object, the method for searching for dangerous goods by the casing type earth retaining work according to the present invention includes the step of confirming and searching for anomalous magnetic points detected by magnetic exploration including horizontal exploration and vertical exploration. A method in which a casing type earth retaining work to which a magnetic sensor can be attached is press-fitted into the ground so as to surround the magnetic anomaly point, and after the casing type earth retaining work is indented in the press-fitting process. Performed in parallel with the step of excavating and excavating sediment and rocks inside the casing type debris, the step of press-fitting and the step of excavating and excavating, using a magnetic sensor attached to the casing type debris And measuring the underground magnetism.

  In order to achieve the above object, a casing type earth retaining work according to the present invention is a casing type earth retaining work used in exploration of dangerous materials, and the casing type earth retaining work is a cylindrical housing, and The inner surface of the casing is provided with at least two hollow tubes extending vertically upward and downward and capable of being inserted through the magnetic sensor.

  ADVANTAGE OF THE INVENTION According to this invention, while shortening the construction period concerning a dangerous material search, a dangerous material can be searched accurately.

It is a flowchart which shows an example of the implementation procedure of the magnetic exploration of a dangerous material which concerns on embodiment of this invention. It is a schematic diagram for demonstrating the magnetic exploration which concerns on embodiment of this invention. It is a flowchart which shows an example of the implementation procedure of the abnormal point confirmation search which concerns on embodiment of this invention. It is a schematic diagram for demonstrating the abnormal point confirmation search which concerns on embodiment of this invention. It is a perspective view showing an example of the 1st casing type earth retaining work concerning the embodiment of the present invention. It is a perspective view showing an example of a casing type earth retaining work according to an embodiment of the present invention. It is a figure explaining the detection range of the magnetic sensor which concerns on embodiment of this invention. It is a figure for demonstrating an example of the connection mechanism of the casing type earth retaining machine which concerns on embodiment of this invention. It is a figure for demonstrating an example of the connection aspect of the steel pipes provided in the casing type earth retaining work which concerns on embodiment of this invention. It is the figure which looked at the casing-type earth retaining work shown in FIG. 6 from the downward direction. It is a schematic diagram for demonstrating an example of the search method of the magnetic body in the conventional underground.

  Hereinafter, embodiments of the present invention will be described.

[Magnetic exploration of dangerous materials]
FIG. 1 is a flowchart showing an example of a procedure for performing a magnetic exploration of a dangerous material according to an embodiment of the present invention. FIG. 2 is a schematic diagram for explaining magnetic exploration according to the embodiment of the present invention.

  Magnetic exploration of dangerous materials such as unexploded bullets is carried out according to the procedure shown in FIG. Hereinafter, each procedure shown in the flowchart of FIG. 1 will be described with reference to FIG. 2 as appropriate.

  First, in step S1, horizontal exploration is performed (reference S1 in FIG. 1). Horizontal exploration is magnetic exploration performed on the ground surface 1 (see FIG. 2). Specifically, in a predetermined exploration range of the ground surface 1, an operator uses a magnetic sensor (not shown) such as a double-coil magnetic inclinometer to detect a dangerous object within 1.0 m below the ground surface 1. This is an exploration to check if there is any. This horizontal exploration is for grasping the existence of dangerous materials such as unexploded bombs existing in the relatively shallow area of the exploration range.

  When it is confirmed by the horizontal exploration according to step S1 that there is a dangerous substance within a range of 1.0 m below the ground surface 1, the dangerous substance is removed by human work. If it is confirmed that there is no dangerous substance within the same range, the process proceeds to the subsequent vertical exploration in step S2.

  If it progresses to step S2, vertical survey will be performed (code | symbol S2 in FIG. 1). The vertical exploration is a magnetic exploration in which the exploration hole 3 is drilled by a boring machine 2 or the like, and a magnetic sensor (not shown) is inserted into the exploration hole 3 to check for the presence of dangerous substances as magnetic materials. Drilling is performed by non-core boring. In order to protect the hole wall of the exploration hole 3, a guide pipe (stainless steel pipe) 4 is inserted, and drilling work and exploration work are repeated to the planned depth while confirming the safety of the hole bottom from the exploration start position. Make a hole.

  Thereafter, the process proceeds to step S3, where an abnormal reaction is detected and recorded (reference S3 in FIG. 1). In step S3, a magnetic anomaly reaction, that is, a reaction of the magnetic substance is detected based on the measurement result obtained by measuring the change in the magnetic quantity in the ground by the magnetic sensor in step S2, and the presence of the magnetic substance is confirmed and recorded.

  Specifically, the presence or absence of a magnetic body is determined based on the output of the magnetic sensor in step S3. When there is no magnetic material, the output of the magnetic sensor is almost a linear waveform. On the other hand, when a magnetic material is present, the output of the magnetic sensor has a wavy waveform. By analyzing recording paper with two or more types of measurement ranges of the magnetic sensor, the embedding depth of the magnetic material, the distance from the magnetic sensor to the magnetic material, the amount of magnetism, and the position and size of the magnetic material are calculated. Record this.

  Thereafter, the process proceeds to step S4, and the search is terminated (reference S4 in FIG. 1). In step S4, the guide pipe 4 inserted into the ground in step S2 is pulled out and the exploration hole 3 is backfilled. In this backfilling, in order to prevent ground subsidence, a backfilling material suitable for each layer is used for each layer divided into a base layer, a base layer, and a surface layer.

  As described above, the magnetic exploration of the dangerous substance as the magnetic body is performed by the procedure shown in steps S1 to S4. In addition, when it determines with there being no dangerous substance as a magnetic body by the process which concerns on these steps S1-S4, normal underground construction etc. are performed. On the other hand, if it is determined that there is a dangerous substance as a magnetic substance, that is, if a magnetic abnormal point (abnormal point) is detected, the process proceeds to the confirmation exploration shown in FIG.

[Abnormal point confirmation exploration]
FIG. 3 is a flowchart showing an example of an execution procedure of abnormal point confirmation exploration according to the embodiment of the present invention. FIG. 4 is a schematic diagram for explaining the abnormal point confirmation exploration according to the embodiment of the present invention. Drawing 5 is a figure showing an example of the 1st casing type earth retaining work concerning the embodiment of the present invention. FIG. 6 is a diagram illustrating an example of a casing-type earth retaining device according to the embodiment of the present invention.

  When it is determined by the series of processes shown in FIG. 1 that there is a magnetic substance, that is, when a magnetic abnormal point (abnormal point) is detected, a confirmation exploration of the abnormal point is subsequently performed according to the procedure shown in FIG. Hereinafter, each procedure shown in the flowchart shown in FIG. 3 will be described with reference to FIGS. 4 to 6 as appropriate.

  In FIG. 4, four casing-type earth retaining works 30 are in the ground in the order of the first casing-type earth retaining work 11, the second casing-type earth retaining work 12, the third casing-type earth retaining work 13, and the fourth casing-type earth retaining work 14. The press-fit state is illustrated.

  FIG. 5 illustrates a state in which half of the first casing type earth retaining work 11 is press-fitted into the ground. In FIG. 6, the perspective view of the state to which these 1st casing type earth retaining works 11-the 4th casing type earth retaining work 14 were connected is shown. In addition, the connection mechanism of the 1st casing type earth retaining work 11-the 4th casing type earth retaining work 14 is later mentioned using FIG.

  First, in step S10, the position of the abnormal point is selected and leveling is performed (reference S10 in FIG. 3). In step S10, the abnormal point position is selected based on the output data of the magnetic sensor when it is determined in FIG. Thereafter, according to the selected abnormal point position, the presser 21 and the hydraulic clamshell 22 (hereinafter, collectively referred to as “casing type earth retaining construction machine 20”, refer to FIG. 4) are arranged. Plan, check the ground in advance, and install unevenness and iron plate as necessary.

  Next, it progresses to step S11 and the casing type earth retaining construction machine 20 is carried in (code | symbol S11 in FIG. 3). The casing type earth retaining construction machine 20 is the press-fitting machine 21 and the hydraulic clam shell 22 as described above.

  The press-fitting machine 21 according to the present embodiment is a machine that installs a hollow cylindrical first casing type earth retaining work 11 to a fourth casing type earth retaining work 14 so as to penetrate into the ground. It is a press-fitting machine or a swing-type press-fitting machine that press-fits while swung. On the other hand, the hydraulic clam shell 22 is an excavating machine that digs up the sediment and rocks inside the casings of the first casing type debris 11 to the fourth casing type debris 14. In step S11, other equipment used is also carried in.

  Then, it progresses to step S12 and the carried-in casing-type earth retaining construction machine 20 is installed (code | symbol S12 in FIG. 3). In step S12, the press-fitting machine 21 uses a level and an adjustment jack so that the first casing-type earth retaining work 11 to the fourth casing-type earth retaining work 14 can be press-fitted so as to surround the abnormal point with the abnormal point position substantially at the center. Set horizontally. The casing-type earth retaining construction machine 20 performs a trial operation, and installs a co-rotation preventing anchor and a counterweight (not shown) as necessary.

  Then, it progresses to step S13 and builds the 1st casing type earth retaining work 11 first (code | symbol S13 in FIG. 3). In Step S13, the chuck of the upper frame of the press-fitting machine 21 is released, and the first casing type earth retaining work 11 is installed by a crane (not shown). Thereafter, the chuck is tightened to fix the first casing type earth retaining work 11.

  Subsequently, the process proceeds to step S14, and magnetic measurement is performed in parallel with the press-fitting and excavation earthing (reference S14 in FIG. 3). In step S14, the press-fitting machine 21 is operated to first rotate the entire circumference while allowing the first casing-type earthwork 11 to penetrate into the ground A at a certain depth (for example, approximately half the height of the first casing-type earthwork 11). Press-fit or swing press-fit. Thereafter, the sand and rocks inside the first casing type earth retaining work 11 are excavated and discharged by the hydraulic clam shell 22.

  In parallel with the press-fitting and excavation earthing, an operator can use an elongated cylindrical magnetic sensor 15 (for example, a uniaxial differential fluxgate type magnetic detector) from the upper opening of the first casing type earth retaining work 11. Is inserted into the inner guide pipe 19 and suspended until the tip of the magnetic sensor 15 reaches the lower end of the first casing-type earth retaining work 11 (see FIG. 5). . The inner guide pipe 19 is suspended at its hanging position and hanging direction by a clamp 18 or the like, and is hung vertically downward from the upper opening of the first casing type earth retaining work 11. The clamps 18 are provided at two positions on both ends of the diameter of the upper opening of the first casing type earth retaining work 11.

  The magnetic sensor 15 and the cable 16 are inserted through the inner guide tube 19. The inner guide tube 19 is a hollow tube formed of titanium or the like that is a nonmagnetic material, and has an inner diameter that allows the magnetic sensor 15 and the cable 16 to be inserted. The inner guide pipe 19 is constituted by connecting a plurality of pipes of 1 m units, for example. Then, the magnetic sensor 15 measures the underground magnetism while rotating or swinging the first casing type earth retaining work 11 by the press-fitting machine 21. The measurement result is transmitted to the analysis device 17 via the cable 16.

  The first casing type earth retaining machine 11 shown in FIG. 5 is a cylindrical housing having a cross-sectional circle diameter of 2 m and a height of 2 m. The lower edge end portion 11a of the first casing type earth retaining work 11 is formed in a sawtooth shape. This makes it possible to easily press into the ground. Such a first casing type earth retaining work 11 is formed of a non-magnetic material such as stainless steel.

  Thus, the 1st casing type earth retaining machine 11 and the inner guide pipe 19 are comprised with the nonmagnetic material. Therefore, when the magnetic sensor 15 inserted in the inner guide pipe 19 measures magnetism, the magnetic sensor 15 does not react to the casing-type earth retaining work 11 or the inner guide pipe 19. Therefore, it is possible to perform accurate magnetic measurement, that is, to specify the exact position of a dangerous object.

  Moreover, in the process corresponding to step S14 according to the conventional method, after the press-fitting and excavation and earth excavation, the operator descends into the first casing type earth retaining work 11 and directly performs the magnetic measurement. For this reason, it took time and labor for the worker to get down to the basement, and there were also significant safety disadvantages. On the other hand, according to the present embodiment, direct magnetic measurement by an operator is not necessary, and press-fitting / excavation soil excavation and magnetic measurement can be performed in parallel. Therefore, it leads to shortening of the construction period related to dangerous goods confirmation exploration.

  Furthermore, according to the first casing type earth retaining work 11 according to the present embodiment, the detection range of the magnetic sensor 15 is the range indicated by the hatched portion in FIG. FIG. 7 is a diagram illustrating the detection range of the magnetic sensor according to the embodiment of the invention. The hatched portion shown in FIG. 7 shows a view of the detection range of the magnetic sensor 15 as viewed from above in the vertical direction when all of the first casing type earth retaining work 11 to the fourth casing type earth retaining work 14 are press-fitted into the ground. However, the same applies to the case where only the first casing type earth retaining work 11 is press-fitted into the ground. This is because the magnetic sensor 15 itself rotates or swings around the rotation center axis of the casing-type earthwork 11 as the casing-type earthwork 11 rotates or swings around the circumference, and the detection range of the magnetic sensor 15 is limited. For example, it is caused by being about 1 m in the horizontal direction. Therefore, since the magnetic sensor 15 can uniformly measure the magnetism inside and outside the casing-type earth retaining member 11, it is possible to accurately check and search for dangerous materials.

  If the analysis device 17 detects an abnormal magnetic reaction based on the output of the magnetic sensor 15 in step S14 in FIG. 3, the press-fitting and excavation and earthing operations are temporarily stopped.

  Thereafter, the process proceeds to step S15, where an abnormal point is confirmed (reference S15 in FIG. 3). In step S15, the magnetically abnormal reactant detected based on the output of the magnetic sensor 15 is confirmed. If the reactant is a non-dangerous material such as a reinforcing bar, the removal work is performed only by the operator. On the other hand, if the reactant is dangerous, contact the local police and the bomb disposal team to ensure the safety of the surrounding area before removing it.

  Further, after removing the magnetically abnormal reactant in step S15, the disappearance of the magnetically abnormal reaction by the magnetic sensor 15 and the remaining magnetically abnormal reactant are confirmed again. This is to prevent the presence of a magnetic material that has not been removed when there are a plurality of magnetic materials, and to reliably remove the magnetic material.

  When the disappearance of the magnetic abnormal reaction is confirmed, the inner guide tube 19 through which the magnetic sensor 15 and the cable 16 are inserted is temporarily pulled out. Thereafter, the press-fitting machine 21 causes the first casing-type earthwork 11 to penetrate further into the ground A by a certain depth (for example, approximately the remaining half of the height of the first casing-type earthwork 11), and the entire circumference is rotary press-fitting or rocking press-fitting. Let

  In parallel with the press-fitting and excavation earthing, the operator again inserts the cable 16 having the magnetic sensor 15 attached to the tip from the upper opening of the first casing type earth retaining work 11 and is inserted into the inner guide pipe 19. Is inserted and suspended until the tip of the magnetic sensor 15 reaches the lower end of the first casing type earth retaining work 11. The inner guide pipe 19 is suspended at its hanging position and hanging direction by the clamp 18 and the like as described above, and is hung vertically downward from the upper opening of the first casing type earth retaining work 11.

  Then, the magnetic sensor 15 measures the underground magnetism while rotating or swinging the first casing type earth retaining work 11 by the press-fitting machine 21. The measurement result is transmitted to the analysis device 17 via the cable 16. Thereafter, the analysis by the analysis device 17 and, if necessary, removal work and subsequent disappearance confirmation work of the magnetic abnormal reaction are performed. Thereafter, the magnetic sensor 15 and the cable 16 are pulled out, and the process proceeds to the next step.

  Thereafter, the process returns to step S13 in FIG. 3 and the second casing type earth retaining work 12 is built (reference S13 in FIG. 3). In this step S13, the chuck of the upper frame of the press-fitting machine 21 is released, and the second casing type earth retaining work 12 is built by a crane (not shown). Thereafter, the chuck is tightened, and the second casing type earth retaining machine 12 is fixed.

  Subsequently, the process proceeds to step S14, and magnetic measurement is performed in parallel with the press-fitting and excavation earthing (reference S14 in FIG. 3). In step S14, the second casing type earth retaining work 12 is connected to the upper part of the first casing type earth retaining work 11, and the press-fitting machine 21 is operated to connect the first casing type earth retaining work 11 and the second casing type earth retaining work 12 to the ground. While being penetrated into A at a certain depth (for example, approximately half the height of the second casing type earth retaining machine 12), the entire circumference is rotationally pressed or rocked. Thereafter, the sand and rocks inside the first casing type earth retaining work 11 which is pressed deeper into the ground are excavated and discharged by the hydraulic clamshell 22.

  In parallel with the press-fitting and excavation earthing, the operator is inserted into the inner guide pipe 19 from the upper opening of the second casing type earth retaining work 12 with the cable 16 having the magnetic sensor 15 attached to the tip. A sword is inserted and hung until the tip of the magnetic sensor 15 reaches the lower end of the first casing type earth retaining work 11. The inner guide pipe 19 is suspended in the vertical position from the upper opening of the second casing type earth retaining work 12 by fixing the hanging position and the hanging direction by a clamp (corresponding to the clamp 18) or the like in the same manner as described above. . The clamps here are provided at two positions on both ends of the diameter of the upper opening circle of the second casing type earth retaining machine 12.

  Then, the magnetism in the ground is measured by the magnetic sensor 15 while the press casing 21 rotates or swings the first casing type earth retaining work 11 and the second casing type earth retaining work 12. The measurement result is transmitted to the analysis device 17 via the cable 16. Thereafter, the analysis by the analysis device 17 and, if necessary, removal work and subsequent disappearance confirmation work of the magnetic abnormal reaction are performed. Thereafter, the inner guide pipe 19 through which the magnetic sensor 15 and the cable 16 are inserted is pulled out, and the processes such as press-fitting, excavation and excavation, magnetic measurement and analysis of the second casing type earth retaining device 12 are repeated.

  Note that the specific configuration of the second casing type earth retaining work 12 is the same as that of the first casing type earth retaining work 11 except that it does not have the lower edge end portion 11a formed in a sawtooth shape. Is omitted.

  Thereafter, the process returns to step S13 in FIG. 3 and the third casing type earth retaining work 13 is built (reference S13 in FIG. 3). In this step S13, the chuck of the upper frame of the press-fitting machine 21 is released, and the third casing type earth retaining work 13 is installed by a crane (not shown). Thereafter, the chuck is tightened, and the third casing type earth retaining work 13 is fixed.

  Subsequently, the process proceeds to step S14, and magnetic measurement is performed in parallel with the press-fitting and excavation earthing (reference S14 in FIG. 3). In step S14, the third casing type earth retaining work 13 is connected to the upper part of the second casing type earth retaining work 12, and the press-fitting machine 21 is operated, so that the third casing type earth retaining work 13, the second casing type earth retaining work 12 and the second The one casing type earth retaining work 11 is inserted into the ground A at a certain depth (for example, approximately half the height of the third casing type earth retaining work 13) while being fully or rotationally pressed around the circumference. Thereafter, the sand and rocks inside the first casing type earth retaining work 11 which is pressed deeper into the ground are excavated and discharged by the hydraulic clamshell 22.

  In parallel with the press-fitting and excavation earthing, the magnetic sensor 15 is provided from the upper opening of a cylindrical steel pipe 13a (see FIG. 6) disposed on the inner surface of the third casing type earth retaining work 13. And the inner guide pipe | tube 19 with which the cable 16 was penetrated is inserted, and it suspends until the front-end | tip of the magnetic sensor 15 arrives at the lower end of the 1st casing type earth retaining work 11. FIG. When the inner guide pipe 19 is inserted through the steel pipe 13a, the hanging position and the hanging direction of the inner guide pipe 19 are fixed.

  Then, the magnetic sensor 15 measures the underground magnetism while rotating or swinging the first casing type earth retaining work 11 to the third casing type earth retaining work 13 by the press-fitting machine 21. The measurement result is transmitted to the analysis device 17 via the cable 16. Thereafter, the analysis by the analysis device 17 and, if necessary, removal work and subsequent disappearance confirmation work of the magnetic abnormal reaction are performed. Thereafter, the inner guide pipe 19 through which the magnetic sensor 15 and the cable 16 are inserted is pulled out, and the processes such as press-fitting, excavation and excavation, magnetism measurement and analysis of the third casing type earth retaining device 13 are repeated.

  The third casing type earth retaining work 13 shown in FIG. 6 is a cylindrical casing having a cross-sectional diameter of 2 m and a height of 2 m, similarly to the first casing type earth retaining work 11 and the second casing type earth retaining work 12. However, unlike the first casing type earth retaining work 11 and the second casing type earth retaining work 12, a pair of steel pipes 13a are arranged on the inner surface of the third casing type earth retaining work 13. The pair of steel pipes 13a are hollow pipes respectively disposed along the vertical vertical direction from both ends of the diameter of the upper opening circle of the third casing type earth retaining work 13. The inner diameter of the steel pipe 13a is large enough to allow the inner guide pipe 19 to be inserted. The third casing type earth retaining machine 13 is formed of a magnetic material such as steel, for example.

  Thus, unlike the 1st casing type earth retaining work 11 and the 2nd casing type earth retaining work 12, the 3rd casing type earth retaining work 13 and the steel pipe 13a are comprised with the magnetic body. This is because the third casing type earth retaining work 13 is separated from the magnetic measurement range of the magnetic sensor 15 inserted up to the depth position of the first casing type earth retaining work 11. This is because it is not easily affected by being a magnetic material. Therefore, the 3rd casing type earth retaining machine 13 may be a magnetic body or a non-magnetic body, and is comprised with magnetic materials, such as cheap steel. Thereby, a construction cost can be suppressed at low cost.

  Thereafter, the process returns to step S13 in FIG. 3, and the fourth casing type earth retaining work 14 is built (reference S13 in FIG. 3). In this step S13, the chuck of the upper frame of the press-fitting machine 21 is released, and the fourth casing type earth retaining work 14 is built by a crane (not shown). Thereafter, the chuck is tightened, and the fourth casing type earth retaining work 14 is fixed.

  Subsequently, the process proceeds to step S14, and magnetic measurement is performed in parallel with the press-fitting and excavation earthing (reference S14 in FIG. 3). In step S14, the 4th casing type earth retaining work 14 is connected to the upper part of the 3rd casing type earth retaining work 13, the press-fitting machine 21 is operated, and the 1st casing type earth retaining work 11-the 4th casing type earth retaining work 14 are grounded. While being penetrated into A at a certain depth (for example, approximately half of the height of the fourth casing type earth retaining machine 13), the entire circumference is rotationally pressed or rocked. Thereafter, the sand and rocks inside the first casing type earth retaining work 11 which is pressed deeper into the ground are excavated and discharged by the hydraulic clamshell 22.

  In parallel with the press-fitting and excavation earthing, the operator can detect the magnetic sensor 15 from the upper opening of the cylindrical steel pipe 14a (see FIG. 6) disposed on the inner surface of the third casing type earth retaining member 14. And the inner guide pipe | tube 19 with which the cable 16 was penetrated is inserted, and it suspends until the front-end | tip of the magnetic sensor 15 arrives at the lower end of the 1st casing type earth retaining work 11. FIG. When the inner guide pipe 19 is inserted through the steel pipe 14a, the hanging position and the hanging direction of the inner guide pipe 19 are fixed.

  Then, the magnetism in the ground is measured by the magnetic sensor 15 while rotating or swinging the first casing type earth retaining work 11 to the fourth casing type earth retaining work 14 by the press-fitting machine 21. The measurement result is transmitted to the analysis device 17 via the cable 16. Thereafter, the analysis by the analysis device 17 and, if necessary, removal work and subsequent disappearance confirmation work of the magnetic abnormal reaction are performed. Thereafter, the inner guide pipe 19 into which the magnetic sensor 15 and the cable 16 are inserted is pulled out, and the processes such as press-fitting, excavation and soiling, magnetic measurement and analysis of the fourth casing type earth retaining device 14 are repeated.

  Note that the specific configuration of the fourth casing type earth retaining work 14 is the same as that of the third casing type earth retaining work 13, and the description thereof is omitted here. The steel pipe 14 a in the fourth casing type earth retaining work 14 corresponds to the steel pipe 13 a in the third casing type earth retaining work 13.

  By repeating steps S13 to S15 described above, a plurality of casing type earth retaining works are press-fitted to a depth where an abnormal point exists while adding the first casing type earth retaining works 11 to the fourth casing type earth retaining work 14. In parallel with the press-fitting and excavation, the magnetic sensor 15 performs magnetic measurement to confirm a dangerous object.

  Then, it progresses to step S16 and backfilling and drawing are performed (code | symbol S16 in FIG. 3). In step S <b> 16, the first casing type earth retaining work 11 to the fourth casing type earth retaining work 14 by the press-fitting machine 21 and the backfilling using the earth and sand generated by excavation or the like as a backfilling material are alternately performed. In the refilling, each layer thickness of 20 cm is sufficiently compacted with a tamper or the like so as not to cause ground subsidence.

  Then, it progresses to step S17 and apparatus removal and carrying out are performed (code | symbol S17 in FIG. 3). In step S17, after removing the first casing type earth retaining work 11 to the fourth casing type earth retaining work 14 extracted in step S16, the casing type earth retaining construction machine 20 is removed and carried out.

  Then, it progresses to step S18 and construction is completed (code | symbol S18 in FIG. 3). In step S18, the ground surface 1 after the equipment is removed and carried out in step S17 is leveled and the construction is completed.

  The abnormal point confirmation exploration is performed by the procedure shown in steps S10 to S18. In particular, when it is determined that there is no magnetic body (abnormal object) by the procedure according to steps S13 to S15, normal underground construction or the like is performed.

  In addition, in the said description, although the case where four casing-type earth retaining works of the 1st casing-type earth retaining work 11-the 4th casing-type earth retaining work 14 were added and press-fitted in the ground was demonstrated, it was added. The number of casing type earth retaining works is not limited to four. Further, when three or more casing-type earth retaining works are provided, the first casing-type earth retaining work 11 that is first press-fitted and the second casing-type earth retaining work 12 that is second-pressed are formed of a non-magnetic material. And it is desirable to form the 3rd casing type earth retaining work 13 etc. press-fitted after the 3rd with a magnetic body. As described above, this is for improving the measurement accuracy of the magnetic sensor 15 and realizing inexpensive construction costs.

  Further, the first casing type earth retaining work 11 and the second casing type earth retaining work 12 may be made of concrete other than stainless steel, made of titanium, or the like. Thus, by forming the first casing type earth retaining work 11 and the second casing type earth retaining work 12 disposed vertically below the casing type earth retaining work 30 with a non-magnetic material, it is possible to safely and not cause misidentification. Dangerous goods can be detected.

  In the above description, the case where the magnetic sensor 15 is a uniaxial differential fluxgate type magnetic detector has been described as an example. However, the present invention is not limited to this case. For example, a double coil type magnetic inclinometer may be used. However, a uniaxial differential fluxgate type magnetic detector is desirable. This is because when a single-axis differential fluxgate type magnetic detector is used, the amount of excavation in the vertical direction is smaller than that in the case of a double-coil type magnetic inclinometer, and the magnetic measurement in the same range as the double-coil type magnetic inclinometer. This is because it is possible.

  Moreover, in the said description, although the case where the steel pipes 13a and 14a were provided in two places in the 3rd casing type earth retaining work 13 and the 4th casing type earth retaining work 14 was mentioned as an example, it did not restrict to this case. For example, it may be provided at three or four locations at regular intervals along the upper surface opening circle of each casing type earth retaining. Further, for example, in the first casing type earth retaining work 11 and the second casing type earth retaining work 12, a non-magnetic guide pipe corresponding to the steel pipe may be provided.

[Supplement of casing type earth retaining work]
Drawing 8 is a figure for explaining an example of a connection mechanism of casing type earth retaining work concerning an embodiment of the present invention. In FIG. 8, the connection mechanism of the 1st casing type earth retaining work 11 and the 2nd casing type earth retaining work 12 is shown.

  As shown in FIG. 8, a plurality of notches 11 b are formed at the periphery of the upper surface opening of the first casing type earth retaining work 11. Each notch 11b is a pentagonal groove having an acute tip 11c. Further, three through holes (screw holes) 11d are formed side by side at approximately the middle position of each notch 11b.

  On the other hand, the second casing type earth retaining work 12 connected to the first casing type earth retaining work 11 is formed such that the lower part (range of the predetermined height L from the lower surface) has a slightly shorter cross-sectional circle diameter than the other parts. On the outer surface, a projection (tenon) 12a is formed corresponding to each of the notches 11b described above. Each projecting portion 12a is a pentagonal projecting portion having an acute tip portion 12b. Further, a flat wedge (cotter) 12d in which a through-hole (screw hole) 12c corresponding to the above-described through-hole 11d is formed is provided at a substantially intermediate position of each protrusion 12a.

  With such a configuration, when the second casing type earth retaining work 12 is connected to the first casing type earth retaining work 11, each notch portion 11b and each projection portion 12a are fitted to each other, and further, a flat wedge is provided. The 12d through hole 12c and the through hole 11d are aligned. Thereafter, the through hole 12c and the through hole 11d are bolted from the inner surface side of the second casing type earth retaining member 12. Thereby, the 1st casing type earth retaining work 11 and the 2nd casing type earth retaining work 12 are connected (joined) so that the shift | offset | difference and distortion during rotation may not arise.

  The connecting mechanism between the second casing type earth retaining machine 12 and the third casing type earth retaining machine 13 and the connecting mechanism between the third casing type earth retaining machine 13 and the fourth casing type earth retaining machine 14 are the same.

  Drawing 9 is a figure for explaining an example of the connection mode of the steel pipes provided in the casing type earth retaining work concerning the embodiment of the present invention. FIG. 10 is a view of the casing type earth retaining work shown in FIG. 6 as viewed from below.

  As shown in FIG. 9, in the 3rd casing type earth retaining machine 13, the steel pipe 13a and the steel pipe 14a are connected via the connection pipe 31 so that an axial center may become the same.

  In FIG. 9, the connection aspect between the steel pipe 13a and the steel pipe 14a in FIG. 6 is shown. A connecting pipe 31 that is a C-shaped cylindrical steel pipe is fixed to the steel pipe 13 a by a bolt 32. The steel pipe 14a is inserted into the upper cylinder of the connection pipe 31 and connected. Thereby, the axial center of the steel pipe 13a and the steel pipe 14a becomes the same.

  In this way, when the first casing type debris 11 to the fourth casing type debris 14 are added and press-fitted into the ground, they are arranged in a newly added casing type depot (for example, the fourth casing type debris 14). The axial center of the hollow pipe (steel pipe 14a) provided, and the axial center of the hollow pipe (steel pipe 13a) disposed in the casing type earth retaining work (for example, the third casing type earth retaining work 13) added in front of the axial center Are connected to each other. As a result, the inner guide tube 19 through which the magnetic sensor 15 and the cable 16 are passed can be inserted.

  Although one embodiment of the present invention has been described above, the above embodiment shows one example of application of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiment. is not.

11 First casing type earth retaining 11a Guide pipe 12 Second casing type earth retaining 12a Steel pipe 13 Third casing type earth retaining 13a Steel pipe 14 Fourth casing type earth retaining 14a Steel pipe 15 Magnetic sensor 16 Cable

Claims (5)

A dangerous substance exploration method including a step of confirming and exploring magnetic anomaly points detected by magnetic exploration including horizontal exploration and vertical exploration,
A step of press-fitting a casing-type earth retaining work to which a magnetic sensor can be attached so as to surround the magnetic anomaly point;
In the step of press-fitting, the step of excavating and excavating the sediment and rocks inside the casing-type debris after the casing-type debris is press-fitted, and
A step of measuring the magnetism in the ground by using a magnetic sensor attached to the casing-type earth retaining work, which is performed in parallel with the entire-round rotation press-fitting or swinging press-fitting of the casing-type earth retaining work;
A method for exploring dangerous materials by a casing-type earth retaining device, comprising: The casing-type earth retaining work is a cylindrical housing, and at least two hollow pipes through which the magnetic sensor can be inserted are arranged vertically upward and downward on the inner surface of the housing. ,
2. The dangerous substance exploration according to claim 1, wherein, in the measuring step, the magnetic sensor connected to a cable is inserted to a lower end of the hollow tube, and magnetism in the ground is measured by the magnetic sensor. Method.   In the press-fitting step, when a plurality of the casing-type earth retaining works are added and pressed into the ground, the hollow pipe shaft disposed in the newly-added casing-type earth retaining work is finally added. 3. The dangerous substance search method according to claim 2, wherein the two are connected to each other so as to be the same as an axis of the hollow pipe disposed in the casing type earth retaining.   In the press-fitting step, when a plurality of the casing-type earth retaining works are added and press-fitted into the ground, the first casing-type earth retaining works that are first press-fitted and the second casing-type earth retaining works that are second-fitted are not The dangerous material search method according to claim 2, wherein the casing-type earth retaining member formed of a magnetic material and press-fitted after the third is formed of a magnetic material. It is a casing type earth retaining work used in hazardous material exploration,
The casing-type earth retaining work is a cylindrical housing, and at least two hollow pipes through which the magnetic sensor can be inserted are arranged vertically upward and downward on the inner surface of the housing. A casing-type earth retaining device characterized by that.

Images