JP6451929B2 - Method of embedding measuring equipment - Google Patents

Description

  The present invention relates to a method for embedding a measuring instrument that is mainly applied when performing ground improvement.

  When building a structure, it is necessary to transmit the load of the structure to the support layer of the ground through the foundation of the structure such as a direct foundation, pile foundation, caisson foundation, etc., but the ground is soft Therefore, it is necessary to increase the bearing capacity by improving the ground itself.

  The ground improvement is used to increase the bearing capacity as described above, as well as to prevent land subsidence and liquefaction. There are various types of soil improvement, including sandy ground or viscous land. It is properly used according to the difference in ground properties such as the board.

  Here, when performing ground improvement, is monitoring whether the chemical reaction is proceeding as expected in the ground improvement using cement-based solidification material, and whether the load is expected as expected in the improved ground area? In such cases, it is necessary to place various measuring devices such as strain gauges, thermometers, earth pressure gauges in the ground improvement area.

JP-A-62-78310

  As a method of installing the measuring device in the ground improvement area, drain the soil block that is the target of ground improvement, install the measuring device, and then fill the improvement material, or drill a borehole after the ground improvement. There is a method of inserting a measuring instrument into the hole.

  However, the method of ground improvement after installing measuring equipment like the former tends to cause problems such as disconnection of the measurement cable during ground improvement, and the method of drilling a borehole after ground improvement like the latter. However, it takes time for drilling, resulting in an increase in cost.

  Incidentally, in Patent Document 1, after the measurement tube 3 is inserted into the outer tube 1, the outer tube is embedded in the ground, and the outer tube 1 is pulled out and removed to expose the measurement tube 3 in the ground. A configuration is disclosed in which a water level meter 13 is suspended in a porous tube 8 disposed in the measuring tube 3. According to such a configuration, the water level meter 13 measures the level of groundwater flowing in through the porous tube 8. Although it is possible to measure the strain and earth pressure around the strain gauge 10 and earth pressure gauge 11 because they are buried in the composite 7, it is difficult.

  The present invention has been made in consideration of the above-described circumstances, and is capable of measuring a measurement device for monitoring during ground improvement and a survey after the improvement in a form that is economically excellent without fear of disconnection or the like. An object of the present invention is to provide a method of embedding a measuring instrument that can accurately perform the above.

In order to achieve the above object, the method of embedding a measuring instrument according to the present invention forms a creation region in the ground, to which the first solidifying material is added and mixed, as described in claim 1,
At the same time as or before or after the forming step, the closing portion is detachably attached to the distal end opening of the hollow tube, and one end of the long holding member is attached to the vicinity of the center of the inner surface of the closing portion to hold the long shape. A predetermined measuring instrument is placed in the internal space of the hollow tube in a state attached to the member,
Before the first solidified material is solidified, the hollow tube penetrates into the forming region, and after penetrating to a predetermined depth, the elongated holding member is substantially parallel to the material axis of the hollow tube. A measuring device that supports the other end on the ground side so that only the hollow tube is pulled out from the forming region and the measuring device is left in the forming region together with the long holding member and the blocking portion. The measuring device is attached to the elongate holding member while being separated from one end of the elongate holding member so that the measuring device is left at a desired observation depth. .
Moreover, the method for embedding a measuring device according to the present invention is a method in which cables connected to the measuring device are wired along the long holding member.

  Moreover, the embedding method of the measuring device which concerns on this invention forms the said elongate holding member with a nonmagnetic material.

  Moreover, the embedment method of the measuring instrument according to the present invention is to fill the penetration hole of the hollow tube formed in the formation region with the second solidified material after the drawing step.

  Further, in the method of embedding a measuring instrument according to the present invention, the closed portion is configured in a conical shape and is attached to the tip opening so that the cone bottom is on the tip opening side. The bottom outer diameter of the closed portion is made larger than the outer diameter of the hollow tube so as to protrude sideways from the outer peripheral surface of the empty tube.

  Moreover, the method of embedding a measuring instrument according to the present invention is configured such that the hollow tube can be divided in the circumferential direction and the material axis direction.

  In order to carry out the method for embedding a measuring instrument according to the present invention, first, a formation region in which the first solidifying material is added and mixed is formed in the ground.

  Next, a measuring instrument is placed in the internal space of the hollow tube simultaneously with or before or after the above-described forming step.

  Here, a closed portion is detachably attached to the distal end opening of the hollow tube, and one end of a long holding member is attached near the center of the inner surface of the closed portion. It is attached to a scale-shaped holding member.

  Next, before the first solidified material is solidified, the hollow tube penetrates into the forming region, and after penetrating to a predetermined depth, the long holding member becomes substantially parallel to the material axis of the hollow tube. As described above, while supporting the other end on the ground side, only the hollow tube is pulled out from the creation region, and the measuring instrument is left in the creation region together with the long holding member and the blocking portion.

  In this way, since the formation region has not yet solidified, the penetration hole of the hollow tube formed in the formation region is coupled with the fact that the back earth pressure acts from behind. The instrument gradually contracts as it is pulled out, and eventually disappears, and the measuring instrument left in the penetration hole is also embedded naturally in the creation area.

  Then, when the creation region is solidified by the action of the first solidifying material, the creation body in which the measuring device is embedded is built in the ground.

  Therefore, the measuring instrument can be embedded in the formed body in an economically excellent manner without fear of disconnection or the like, and can be embedded in the formed body in direct contact with the formed body. It is possible to accurately measure pressure and strain.

  The long holding member may be anything as long as it is a member extending along the material axis, but a wire rod such as a wire and a rod rod such as a rod are typical examples.

  In addition, it is arbitrary what kind of material the long holding member is made of, and if the measuring device is made of a device that is not affected by electromagnetic noise, for example, an electric strain gauge or an optical measuring device, The above-mentioned long holding member may be formed of a magnetic material, but if this is formed of a non-magnetic material such as a plastic material, the measurement may be performed when using a measuring instrument that is susceptible to electromagnetic noise. It is possible to eliminate the influence of the magnetic material on the device.

  The first solidifying material also includes a chemical solution with an appropriate gel time, but a cement-based solidifying material such as cement or quicklime is a typical example.

  As the first solidifying material solidifies, a formation is constructed in the formation region formed in the ground. Such a formation may be a lump, lattice, wall, pile, column, or any other shape. The construction method is arbitrary, such as deep mixing treatment method, quick lime pile method, soil cement method, etc., and the first solidified material can be used as a soil material such as sand and gravel. It is optional whether to mix and stir at the current position or to fill the mixture with separately mixed and stirred on site.

  Any measuring device is applicable as long as it is a device that measures physical or chemical properties in the constructed body, and includes strain gauges, thermometers, earth pressure gauges, and the like.

  Here, if the penetration hole of the hollow tube formed in the formation region does not sufficiently shrink even after the hollow tube is pulled out, and a void is generated around the measuring instrument, after the drawing step, What is necessary is just to fill this penetration hole with the 2nd solidification material.

  If it does in this way, the above-mentioned effect of being able to embed a measuring instrument in this formation object in the form which contacts a formation object directly can be exhibited reliably.

  Unlike the first solidifying material, the second solidifying material may be solidified in a short time.

  The blocking portion may have any configuration as long as it can smoothly penetrate the hollow tube into the forming region without causing the material constituting the forming region to flow into the hollow tube. The conical portion is attached to the tip opening so that the bottom of the cone is on the side of the tip opening described above, and the closed portion of the closing portion is protruded laterally from the outer peripheral surface of the hollow tube. If the outer diameter of the bottom part is made larger than the outer diameter of the hollow tube, it becomes possible to reliably leave the closed part together with the elongated holding member in the construction area when the hollow tube is pulled out. Can be reliably positioned at a desired location in the construction body.

  Since the long holding member serves to hold the measuring device in a predetermined position, it is not necessary after the creation area becomes a creation body. In such a configuration, the hollow tube may be integrally formed.

  Here, if the hollow tube is configured to be divided in the circumferential direction and the material axis direction, the hollow tube can be disassembled and removed every time the hollow tube is pulled up to a certain height. It is not necessary to hold the tube in an upright state, and the other end supporting height of the long holding member can be kept low.

The flowchart which showed the implementation procedure of the embedding method of the measuring device which concerns on this embodiment. Explanatory drawing which showed the implementation procedure of the embedding method of the measuring device which concerns on this embodiment. Explanatory drawing which showed the implementation procedure of the embedding method of the measuring device which concerns on this embodiment continuously. Explanatory drawing which showed the implementation procedure of the embedding method of the measuring device which concerns on this embodiment continuously. Explanatory drawing which showed the implementation procedure of the embedding method of the measuring device which concerns on this embodiment continuously. Explanatory drawing which showed the embedding method of the measuring device which concerns on a modification. Explanatory drawing which showed the embedding method of the measuring device which concerns on another modification.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a method for embedding a measuring device according to the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a flowchart showing an execution procedure of a measuring instrument embedding method according to the present embodiment. In order to carry out the method of embedding the measuring instrument according to the present embodiment, first, as shown in FIG. 2 (a), the formation region 2 in which the cement-based solidifying material as the first solidifying material is added and mixed is formed in the ground 1. (Step 101).

  The formation region 2 can be formed using, for example, a deep mixing method, and specifically, while injecting a cement-based solidifying material, such as cement slurry, into the ground 1 through an injection pipe (not shown). The ground 1 may be mixed and stirred with a stirring blade (same as above).

  For example, if it is desired to construct a columnar structure, the formation region 2 may be performed by repeating the above-described mixing and stirring operation with a stirring blade at a predetermined pitch along the horizontal direction, and a wall-shaped structure is desired. If there is, the above mixing and stirring operation may be repeated continuously, for example, while gradually overlapping along the horizontal direction orthogonal to the figure.

  On the other hand, separately from step 101, a hollow tube 3 made of hard vinyl chloride or the like is prepared, and a measurement sensor 5 as a measuring instrument is provided in the internal space 4 of the hollow tube as shown in FIG. (Step 102).

  Here, a conical blocking portion 7 is detachably attached to the distal end opening 6 of the hollow tube 3, and a holding wire 8 as a long holding member is provided near the center of the inner surface of the blocking portion. One end is attached, and the measurement sensor 5 is attached along the holding wire 8.

  The measurement sensor 5 can be composed of, for example, a soil pressure gauge, a strain gauge, a thermometer, and the like, and appropriately determines the type, position, or number to be attached to the holding wire 8 according to the index to be observed and the observation depth.

  When attaching the measurement sensor 5, the holding wire 8 is pulled straight so as to be parallel to the material axis of the hollow tube 3, and the measurement sensor is positioned at each position corresponding to the depth when it penetrates into the creation region 2 in that state. 5 may be attached.

  Cables 9 such as a data communication cable and a power cable connected to the measurement sensor 5 are wired along the holding wire 8 and bound to the holding wire.

  The holding wire 8 is made of a non-magnetic material, for example, a plastic material such as vinylon or polyester so that the magnetic sensor does not affect the measurement sensor 5.

  The closed portion 7 has a bottom outer diameter larger than the outer diameter of the hollow tube 3 so that the conical bottom portion protrudes laterally from the outer peripheral surface of the hollow tube 3. The conical bottom is mounted on the tip opening so that it is on the tip opening 6 side.

  Next, before the cement slurry in the formation region 2 is solidified, the measurement sensor is connected to the hollow tube 3 as shown in FIG. 3 and the holding wire 8 attached to the closed portion so that the closed portion 7 becomes the lower end. With 5 attached (see FIG. 2B), it penetrates into the formation area 2 (step 103).

  The penetration of the hollow tube 3 into the creation region 2 can be performed by, for example, a boring machine.

  If the hollow tube 3 is penetrated to a predetermined depth, the other end is next to the ground side so that the holding wire 8 is substantially parallel to the material axis of the hollow tube 3 as shown in FIG. While supporting, only the hollow tube 3 is pulled out from the forming region 2 (step 104).

  The holding wire 8 can be stretched substantially parallel to the material axis of the hollow tube 3 by applying tension, for example, by a winch (not shown) to the other end.

  Here, since the bottom outer diameter of the closed portion is larger than the outer diameter of the hollow tube 3 so that the conical bottom portion of the closed portion 7 protrudes laterally from the outer peripheral surface of the hollow tube 3, The tension applied to the wire 8 balances with the ground reaction force received from the peripheral edge of the conical bottom portion in the closed portion 7, and the holding wire 8 does not sag.

  The tension applied to the holding wire 8 is maintained after the hollow tube 3 is pulled out until the cement-based solidified material is solidified.

  Thus, when only the hollow tube 3 is pulled out from the formation area 2 while supporting the other end of the holding wire 8 on the ground side, the measurement sensor 5 is left in the formation area 2 together with the holding wire 8 and the blocking portion 7. However, since the formation region 2 is not yet solidified, the penetration hole 41 of the hollow tube 3 formed in the formation region 2 is coupled with the fact that the back earth pressure acts from behind. As the pipe is pulled out, it gradually contracts and eventually disappears as shown in FIG. 5B, and the measurement sensor 5 left in the penetration hole 41 is also naturally embedded in the formation region 2.

  And when the formation area | region 2 solidified by the effect | action of the cement-type solidification material, as shown in FIG. 5, the formation body 51 with which the measurement sensor 5 was embed | buried is built in the ground 1. FIG.

  As described above, according to the method for embedding a measuring instrument according to the present embodiment, before the cement-based solidified material solidifies, the hollow tube 3 penetrates into the formation region 2, and after penetrating to a predetermined depth, Since only the hollow tube 3 is pulled out from the creation region 2, the measurement sensor 5 is coupled with the fact that the creation region 2 is not yet solidified, and the back earth pressure acts from behind. 2 and embedded in the formed body 51 after the cement-based solidifying material is solidified.

  Therefore, the measurement sensor 5 can be embedded in the formed body 51 in a form that is economically excellent without fear of disconnection or the like, and can be embedded in the formed body in direct contact with the formed body 51. Therefore, it is possible to accurately measure earth pressure and strain.

  Moreover, according to the method of embedding a measuring instrument according to the present embodiment, when the hollow tube 3 is pulled out, the other end is supported on the ground side so that the holding wire 8 is substantially parallel to the material axis of the hollow tube 3. As a result, the measurement sensor 5 can be prevented from coming into contact with the inner surface of the hollow tube 3 and, after the hollow tube 3 is pulled out, until the cement-based solidified material is solidified, the holding wire 8 Since the tension applied to is maintained, the measurement sensor 5 can be embedded at a desired depth position.

  Moreover, according to the embedding method of the measuring device according to the present embodiment, the outer diameter of the bottom of the closed portion is set so that the conical bottom portion of the closed portion 7 protrudes laterally from the outer peripheral surface of the hollow tube 3. Since the outer diameter of 3 is larger, when the hollow tube 3 is pulled out, the closing portion 7 can be reliably left in the forming region 2 and the tension applied to the holding wire 8 is increased in the closing portion 7. Since the support wire 8 is reliably supported at the peripheral edge of the conical bottom portion, the slack of the holding wire 8 is prevented, and thus the measurement sensor 5 can be reliably positioned at a desired position in the formed body 51.

  In addition, according to the method for embedding a measuring instrument according to the present embodiment, the holding wire 8 is made of a nonmagnetic material, for example, a plastic material such as vinylon or polyester, so that the influence of magnetism reaches the measuring sensor 5. There is no fear.

  In the present embodiment, the long holding member of the present invention is configured by the holding wire 8, but it may be configured by a rod instead of this. In such a configuration, one end of the rod is attached to the vicinity of the center of the inner surface of the closing portion 7, and the other end may be prevented from shaking in the direction perpendicular to the material axis.

  Moreover, in this embodiment, after pulling out the hollow tube 3 from the creation region 2, the penetration hole 41 of the hollow tube 3 formed in the creation region gradually contracts and eventually disappears, and as a result Although the measurement sensor 5 left in the penetration hole 41 is also naturally embedded in the formation region 2, as shown in FIG. 6, the penetration hole 41 in the formation region 2 after the hollow tube 3 is pulled out. Is not sufficiently contracted, and a gap 61 is assumed to be generated around the measurement sensor 5.

  In such a case, after pulling out the hollow tube 3, the penetration hole 41 may be filled with fresh mortar as the second solidifying material as shown in FIG.

  In this way, the fresh mortar filled in the gap 61 is solidified in a form integrated with the formation region 2 to form the formation 51, so that the measurement sensor 5 is in direct contact with the formation 51. The effect mentioned above that it can embed | buy in a formed body can be exhibited reliably.

  In this embodiment, the tension to the holding wire 8 is maintained after the hollow tube 3 is pulled out until the cement-based solidified material is solidified. If 41 is contracted to some extent and the measuring sensor 5 is constrained in the formation area 2 and the fall or displacement of the measurement sensor 5 is prevented, before the formation area 2 is sufficiently solidified to become the formation body 51, the holding wire The tension of 8 may be loosened.

  Although not particularly mentioned in the present embodiment, in the above-described embodiment, while the tension is applied to the holding wire 8, the holding wire is inserted into the hollow tube 3. When the hollow tube cannot be removed and the tension on the holding wire 8 can be relaxed, the other end of the holding wire is removed from the ground side, for example, the winch, or cut near the ground. By doing so, it becomes possible to remove the holding wire 8 from the hollow tube 3 and remove the hollow tube 3 from the site.

  Therefore, while applying tension to the holding wire 8, the hollow tube 3 must be held in an upright state, and the other end supporting height of the holding wire 8 is set to the hollow tube accordingly. Must be at least 3 lengths.

  However, as shown in FIG. 7, instead of the hollow tube 3, if a hollow tube 3a that can be divided in the circumferential direction and the material axis direction is used, each time the hollow tube 3a is pulled up to a certain height, Since the vicinity of the upper end can be dismantled and removed, it is not necessary to hold the hollow tube 3a in an upright state, and the other end supporting height of the holding wire 8 can be kept low.

  In addition, since the hollow tube 3a can be disassembled and removed without interfering with the cables 9 bound to the holding wire 8, it is necessary to connect the cables 9 via a connector. There is no need to worry about loss during data transmission.

DESCRIPTION OF SYMBOLS 1 Ground 2 Creation area 3, 3a Hollow tube 5 Measuring sensor (measuring instrument)
6 Tip opening 7 Blocking part 8 Holding wire (long holding member)
41 Penetration hole 51 formation body

Claims (6)

Forming a formation region in which the first solidifying material is added and mixed in the ground;
At the same time as or before or after the forming step, the closing portion is detachably attached to the distal end opening of the hollow tube, and one end of the long holding member is attached to the vicinity of the center of the inner surface of the closing portion to hold the long shape. A predetermined measuring instrument is placed in the internal space of the hollow tube in a state attached to the member,
Before the first solidified material is solidified, the hollow tube penetrates into the forming region, and after penetrating to a predetermined depth, the elongated holding member is substantially parallel to the material axis of the hollow tube. A measuring device that supports the other end on the ground side so that only the hollow tube is pulled out from the forming region and the measuring device is left in the forming region together with the long holding member and the blocking portion. The measuring device is attached to the elongate holding member while being separated from one end of the elongate holding member so that the measuring device is left at a desired observation depth. Method of burying measuring equipment. The method of embedding a measuring device according to claim 1, wherein cables connected to the measuring device are wired along the elongated holding member. The method for embedding a measuring instrument according to claim 1 or 2, wherein the elongated holding member is formed of a nonmagnetic material. The method of embedding a measuring instrument according to any one of claims 1 to 3 , wherein after the drawing step, a second solidifying material is filled in the penetration hole of the hollow tube formed in the forming region. The closed portion is configured in a conical shape, and is attached to the tip opening so that the cone bottom is on the tip opening side, and the cone bottom protrudes laterally from the outer peripheral surface of the hollow tube. The method for embedding a measuring instrument according to any one of claims 1 to 4 , wherein an outer diameter of the bottom of the closed portion is larger than an outer diameter of the hollow tube. The method of embedding a measuring instrument according to any one of claims 1 to 4 , wherein the hollow tube is configured to be divided in a circumferential direction and a material axis direction.

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