JP2011017218A - Method for installing and recovering earth pressure gauge, and structure for installing the earth pressure gauge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To recover an earth pressure gauge, which is installed below a loading slab, without damaging the earth pressure gauge, after a loading test.SOLUTION: Silica sand 20 is leveled off in a hole section 18 which is formed by digging down the ground 30; and the earth pressure gauge 12 is installed. A resin sheet 22 is arranged in such a manner as to cover a top surface of the silica sand 20 and a pressure receiving surface 12A of the earth pressure gauge 12; and a peripheral edge 22A of the sheet 22 is exposed on the ground 30 around the hole section 18. In addition, mortar is infilled onto the top surface of the sheet 22 and hardened, so as to form a mortar layer 24. The loading slab 16 made of a concrete slab, in which a wire mesh bar 26 is arranged, is constructed on the ground 30 and the mortar layer 24. After the loading test is performed by applying a vertical load to the loading slab 16, the loading slab 16 is lifted by heavy equipment. Thus, the mortar layer 24 and the sheet 22 below the loading slab 16 are pulled up integrally with the loading slab 16; and the earth pressure gauge 12 is separated from the mortar layer 24. In this state, the earth pressure gauge 12 exposed in the hole section 18 is recovered.

Description

  The present invention relates to a soil pressure gauge installation / recovery method and a soil pressure gauge installation structure.

  A plurality of earth pressure gauges are installed below the loading plate used for large-scale loading tests and the like to measure the bearing capacity of the loading plate.

  In Patent Document 1 below, a soil pressure gauge is installed at a point where the earth pressure is to be measured, and then the soil pressure gauge is fixed by pouring concrete or the like, and the pressure receiving portion of the earth pressure gauge is exposed to the outside of the concrete. A pressure gauge installation structure is disclosed.

  Further, in Patent Document 2 below, a long pressure-receiving beam that abuts the measured portion of the ground and receives the earth pressure of the measured portion, and a surface opposite to the surface that abuts the measured portion of the pressure-receiving beam Discloses a soil pressure gauge including a plurality of load cells in the longitudinal direction. This earth pressure gauge is embedded in the structure.

JP 2000-97787 A JP-A-6-249724

  However, in the configurations described in Patent Documents 1 and 2, when the earth pressure gauge is installed below the loading plate and the supporting force of the installation ground is measured, the earth pressure gauge is fixed to the loading plate and cannot be recovered.

  Here, when these earth pressure gauges are to be collected, after the large-scale loading test is completed, the loaded plate must be destroyed and the individual earth pressure gauges must be taken out, which requires a large-scale work. In addition, the earth pressure gauge may be damaged due to an impact at the time of recovery and removal, causing problems in measurement accuracy and device characteristics, and it is difficult to reuse the earth pressure gauge.

  In consideration of the above-described facts, the present invention has an object to obtain a soil pressure gauge installation / recovery method and a soil pressure gauge installation structure capable of recovering a soil pressure gauge installed below a loading plate without damaging it after the end of a loading test. .

  In order to achieve the above object, the earth pressure gauge installation / recovery method according to the invention of claim 1 includes a step of installing an earth pressure gauge on the foundation ground, a release material provided on the earth pressure gauge, and a earth pressure gauge made of a hardened material. , A step of constructing a loading plate on top of the hardened material and the foundation ground, a step of performing a loading test by applying a vertical force to the loading plate, and a loading plate described above after the loading test is completed. And pulling the earth pressure gauge away from the foundation ground by the release material, and recovering the earth pressure gauge from the foundation ground.

  According to the first aspect of the present invention, the earth pressure gauge is installed on the foundation ground, the release material is provided on the upper part of the earth pressure gauge, and the earth pressure gauge is protected by the hardened material. Furthermore, a loading plate is constructed on the hardened material and the upper part of the foundation ground. Then, by carrying out a loading test by applying a vertical force to the loading plate, the supporting force of the foundation ground on which the loading plate is installed is measured by the earth pressure gauge. When collecting the earth pressure gauge after completion of the loading test, the loading plate is lifted upward. At that time, the hardened material is not fixed to the earth pressure gauge by the release material, and the hardened material is separated from the earth pressure gauge, so that the earth pressure gauge can be easily recovered from the foundation ground. Thereby, the earth pressure gauge installed under the loading plate can be recovered without being damaged after the loading test is completed.

  The earth pressure gauge installation / recovery method according to the invention of claim 2 is the invention of claim 1, wherein the release material is a resin sheet or a semi-solid agent.

  According to the invention described in claim 2, the release material is a resin sheet or a semi-solid agent, and the cured material does not adhere to the earth pressure gauge when the loaded plate is pulled upward, and is cured. The material can be easily separated from the earth pressure gauge.

  The earth pressure gauge installation / recovery method according to the invention of claim 3 is the invention according to claim 1 or claim 2, wherein the above-mentioned packing plate is a concrete plate with wire mesh bars.

  According to the third aspect of the present invention, the loading plate is a concrete plate with wire mesh bars, and when the loading plate is pulled upward, the loading plate is prevented from being cracked or peeled off. .

  The earth pressure gauge installation / recovery method according to the invention of claim 4 is the invention according to any one of claims 1 to 3, wherein the curable material is mortar, and the mortar is pulled up when the loading plate is pulled up. It is assumed that the release material bonded to the substrate is pulled up together with the packing plate described above together with the mortar.

  According to the fourth aspect of the present invention, since the release material bonded to the mortar is pulled up together with the loading plate together with the mortar when the loading plate is pulled up, it is not necessary to separate the release material from the earth pressure gauge by manual work or the like. The earth pressure gauge can be collected efficiently.

  The earth pressure gauge installation / recovery method according to the invention of claim 5 is the invention according to any one of claims 1 to 4, wherein a wire is embedded in the packing plate described above, and the wire is It shall be lifted by heavy equipment to lift the above mentioned packing plate.

  According to the fifth aspect of the present invention, since the wire embedded in the loading plate is lifted by a heavy machine to lift the loading plate, the loading plate can be easily lifted.

  The earth pressure gauge installation and recovery method according to the invention of claim 6 is the invention according to any one of claims 1 to 5, wherein a cable connected to the earth pressure gauge is formed on the foundation ground. It is embedded in the groove and the earth pressure gauge is recovered by pulling the cable.

  According to the invention described in claim 6, since the earth pressure gauge is recovered by pulling the cable of the earth pressure gauge embedded in the groove portion of the foundation ground, the amount of lifting of the loaded plate can be reduced, and the earth pressure gauge recovery work Can be performed efficiently.

  The earth pressure gauge installation structure according to the invention of claim 7 includes an earth pressure gauge installed on a foundation ground, a release material provided on the earth pressure gauge, and provided on the release material to protect the earth pressure gauge. And a loading plate installed on top of the hardened material and the foundation ground.

  According to invention of Claim 7, a peeling material is provided in the upper part of the earth pressure gauge installed in the foundation ground, and the earth pressure gauge is protected by the hardening material on a peeling material. A loading plate is installed on the upper portion of the hardened material and the foundation ground, and the release material can prevent the hardened material from being fixed to the earth pressure gauge. For this reason, by pulling up the loaded plate after the loading test is completed, the earth pressure gauge installed below the loaded plate can be recovered without being damaged.

  The earth pressure gauge installation structure according to the invention of claim 8 is the invention according to claim 7, wherein the release material is a resin sheet or a semi-solid agent.

  According to the invention described in claim 8, the release material is a resin sheet or a semi-solid agent, and the cured material does not adhere to the earth pressure gauge, and the cured material and the earth pressure gauge are easily separated. be able to.

  The earth pressure gauge installation structure according to the invention of claim 9 is the invention according to claim 7 or claim 8, wherein the loading plate is a concrete plate in which wire mesh bars are arranged.

  According to the ninth aspect of the present invention, the loading plate is a concrete plate with wire mesh bars, and when the loading plate is pulled up, it is possible to prevent the loading plate from cracking or peeling off. it can.

  According to the present invention, the earth pressure gauge installed below the loading plate can be recovered without being damaged after the loading test is completed.

It is a figure showing the basic composition of the earth pressure gauge installation structure to which the earth pressure gauge installation and recovery method concerning a 1st embodiment of the present invention is applied. It is a perspective view which shows the earth pressure gauge and cable which are used for the earth pressure gauge installation structure shown in FIG. It is a perspective view which shows the mortar layer used for the earth pressure gauge installation structure shown in FIG. It is a perspective view which shows the wire embed | buried under the loading plate used for a earth pressure gauge installation structure. It is a figure which shows the structure which pulled up the loading version in the earth pressure gauge installation and collection method. It is a perspective view which shows the wire embed | buried under the loading plate | board used for the earth pressure gauge installation structure to which the earth pressure gauge installation / recovery method concerning 2nd Embodiment of this invention is applied.

[First Embodiment]
Hereinafter, a first embodiment of the earth pressure gauge installation / recovery method of the present invention will be described with reference to FIGS.

  FIG. 1 shows an overall configuration of a soil pressure gauge installation structure 10 to which the soil pressure gauge installation / recovery method is applied. As shown in this figure, the earth pressure gauge installation structure 10 includes a loading plate 16 for loading test as a structure constructed on the ground 30 (foundation ground), and a soil installed on the lower side of the loading plate 16. And a pressure gauge 12.

  The loading plate 16 is made of a concrete plate (foundation concrete) constructed so as to be in contact with the ground 30, and a plurality of girders (lower pedestals) (not shown) are arranged on the loading plate 16, and are illustrated on the girders. A plurality of jacks that are not arranged are arranged. On the jack, a plurality of reaction force girders (upper pedestal) (not shown) are arranged as pressure receivers, and both ends of the reaction force girder (upper pedestal) are connected to reaction force piles embedded in the ground 30. ing. In the loading test, a test load in the vertical direction is applied from above the loading plate 16 with a plurality of jacks, and the loading strength of the ground 30 is investigated by sinking the loading plate 16. A non-moving beam (not shown) is supported at a place away from the ground 30 on which the loading plate 16 is placed and not affected by the settlement of the ground 30. The amount of settlement of the loading plate 16 is measured using this fixed beam as a reference.

  A hole 18 formed by digging the ground 30 is formed at a position of the ground 30 facing the loading plate 16. The installation surface 18A at the bottom of the hole 18 is almost uniformly rolled and shaped so as to be the same as the rolled state of the surrounding ground 30. The installation surface 18 </ b> A is covered with the uniform sand 20 having a substantially uniform particle diameter, and the earth pressure gauge 12 is installed on the top surface of the sand 20. The earth pressure gauge 12 is installed almost horizontally with the pressure receiving surface 12A facing upward.

As shown in FIGS. 1 and 2-1, a measurement cable 14 is connected to the side portion of the earth pressure gauge 12, and the cable 14 is inserted into a groove portion 32 excavated to the side of the hole portion 18. Has been. The earth pressure gauge 12 has a disk shape, and the hole 18 is dug into a cylindrical shape. In the present embodiment, the earth pressure gauge 12 has a diameter of about 100 mm and a thickness of about 20 mm, and the depth of the hole 18 is set to about 100 mm.

  After the earth pressure gauge 12 is installed, by tightening the sand 20 in the gap between the hole 18 and the earth pressure gauge 12, the earth pressure gauge 12 is tightened so as not to move. Since the crushed sand 20 may damage the stress concentration or the earth pressure gauge 12 when crushed stones are mixed, it is preferable that the crushed sand 20 is sieved in advance to obtain a substantially uniform particle size.

  The upper surface of the cinnabar 20 is spread at substantially the same height as the pressure receiving surface 12A of the earth pressure gauge 12. A resin sheet 22 as a release material is disposed so as to cover the upper part of the sand 20 in the hole 18 and the pressure receiving surface 12A of the earth pressure gauge 12. The sheet 22 is formed in a circular shape, and the peripheral edge 22 </ b> A is exposed on the ground 30 around the hole 18.

  Further, as shown in FIGS. 1 and 2-2, the mortar layer 24 is formed by curing the mortar as a curing material so as to cover the upper surface of the sheet 22 in the hole 18. The mortar layer 24 is provided up to almost the same height as the surface of the ground 30. As shown in FIG. 2B, the cable 14 inserted through the groove portion 32 on the side of the hole portion 18 is embedded in the groove portion 32 by rolling over the earth and sand from above.

  On the ground 30 and the mortar layer 24, the loading plate 16 is constructed by placing a wire mesh bar 26 and placing concrete. The wire mesh bar 26 is a welded wire mesh composed of a plurality of horizontal bars 26A and a plurality of vertical bars 26B, and reinforces the loading plate 16 and prevents cracks. Instead of the wire mesh bars 26, a plurality of reinforcing bars may be arranged.

  As shown in FIG. 3, inside the loading plate 16, two wires are arranged on the lower side of the wire mesh reinforcement 26 along the arrangement direction of the wire mesh reinforcement 26 (the direction of the lateral reinforcement 26 </ b> A in this embodiment). 28 is buried. Both sides of the two wires 28 are exposed to the outside from both sides of the loading plate 16. At both ends of the wire 28, ring-shaped hook portions 28A are provided. The loading plate 16 can be lifted by hanging and hanging the latching portion 28A of the wire 28 with a heavy machine or the like.

  Next, the operation of the earth pressure gauge installation structure 10 and the earth pressure gauge installation / recovery method of this embodiment will be described.

  As shown in FIG. 1 and FIG. 2A, the installation part of the earth pressure gauge 12 is formed by excavating the hole 18 in the ground 30 and spreading the sand 20 on the installation surface 18A of the hole 18. To do. Then, the earth pressure gauge 12 is installed almost horizontally on the upper surface of the cinnabar 20.

  After that, the sand 20 is spread over the gap between the hole 18 and the earth pressure gauge 12, and the upper surface of the sand sand 20 is spread to the same height as the pressure receiving surface 12 A of the earth pressure gauge 12. And the sheet | seat 22 is arrange | positioned so that the upper surface of the sand 20 and the pressure-receiving surface 12A of the earth pressure gauge 12 may be covered, and the peripheral part 22A of the sheet | seat 22 is exposed on the ground 30 around the hole part 18. FIG.

  Next, as shown in FIGS. 1 and 2-2, the mortar layer 24 is formed by filling and curing the mortar so as to cover the upper surface of the sheet 22 in the hole 18. The mortar layer 24 is formed at substantially the same height as the surface of the ground 30.

  Next, the loading plate 16 is constructed by placing wire mesh bars 26 and placing concrete on the ground 30 and the mortar layer 24. At that time, the wire 28 is embedded along the lower side of the wire mesh line 26.

  After constructing the loading plate 16, a loading test is performed by applying a test load in the vertical direction to the loading plate 16, and the supporting force of the ground 30 is measured by the earth pressure gauge 12. In the loading test of the present embodiment, the loading plate 16 on the ground 30 is sunk, for example, from the surface of the ground 30 to a position of 40 cm to 60 cm.

  After that, as shown in FIG. 3, the loading plate 16 is lifted by lifting the latching portion 28 </ b> A of the wire 28 exposed from the loading plate 16 with a heavy machine (the loading plate 16 is pulled up). As a result, as shown in FIG. 4, the mortar layer 24 fixed to the lower surface of the loading plate 16 and the sheet 22 attached to the lower surface of the loading plate 16 and the mortar layer 24 are pulled up from the ground 30 together with the loading plate 16. . At that time, the mortar layer 24 is not fixed to the upper surface of the earth pressure gauge 12 by the sheet 22, and the mortar layer 24 can be easily separated from the earth pressure gauge 12.

  By pulling up the loading plate 16, the earth pressure gauge 12 in the hole 18 is exposed, and the cable 14 (see FIG. 2-1) of the earth pressure gauge 12 inserted through the groove 32 on the side of the hole 18 is pulled. Thus, the earth pressure gauge 12 is collected. The earth pressure gauge 12 may be collected by connecting a collecting wire (not shown) other than the measurement cable 14 to the earth pressure gauge 12 and pulling the collecting wire.

  In this earth pressure gauge installation / recovery method, the earth pressure gauge 12 installed below the loading plate 16 can be recovered without being damaged after the loading test is completed, and the earth pressure gauge 12 can be reused.

  In addition, since the loading plate 16 is a concrete plate with wire mesh bars 26, when the loading plate 16 is pulled up from the ground 30, it is possible to prevent the loading plate 16 from cracking or peeling off.

  Further, when the loading plate 16 is pulled up, the sheet 22 attached to the lower surface of the loading plate 16 and the mortar layer 24 is pulled up together with the loading plate 16, so that the sheet 22 and the earth pressure gauge 12 are separated manually. There is no need, and the collection work of the earth pressure gauge 12 becomes easy.

  Further, since the wire 28 embedded in the loading plate 16 is lifted by a heavy machine to lift the loading plate 16, the lifting operation of the loading plate 16 is facilitated.

  Furthermore, since the earth pressure gauge 12 is recovered by pulling the cable 14 of the earth pressure gauge 12 embedded in the groove portion 32 of the ground 30, it is possible to reduce the amount of lifting of the loading plate 16, and the collection work of the earth pressure gauge 12 is efficient. Can be done well.

[Second Embodiment]
Next, the earth pressure gauge installation structure to which the earth pressure gauge installation / recovery method of the second embodiment of the present invention is applied will be described. In addition, the same code | symbol is attached | subjected to the member same as 1st Embodiment, and the overlapping description is abbreviate | omitted.

  As shown in FIG. 5, in the earth pressure gauge installation structure 50, two wires 52 are embedded diagonally on the loading plate 16 on the lower side of the wire mesh bars 26 inside the loading plate 16. Each of the two wires 52 is formed in an endless shape, and both ring-shaped end portions exposed from the corners of the loading plate 16 serve as latching portions 52A. The latching portions 52 </ b> A are provided at four corners of the loading plate 16.

  In such a earth pressure gauge installation structure 50, the loading plate 16 is lifted (lifted) by lifting the latching portion 52A of the wire 52 exposed from the loading plate 16 with a heavy machine. At that time, since the latching portions 52A of the four wires 52 at the corners of the loading plate 16 are lifted, the loading plate 16 can be lifted stably. And the earth pressure gauge 12 (refer FIG. 1) can be collect | recovered in the state which pulled up the loading version 16. FIG.

[Supplementary explanation]
In the said 1st and 2nd embodiment, although the loading plate 16 was lifted with the heavy machine using the wires 28 and 52, it is not limited to this. For example, when the weight of the loading plate 16 exceeds the lifting capacity of the heavy machinery, a plate-like member or the like is inserted between the edge of the loading plate 16 and the ground 30 and loaded by the lever principle using a jack. The plate 16 may be pulled up.

  In the said 1st Embodiment, although the resin-made sheet | seat 22 as a peeling material was arrange | positioned on the earth pressure gauge 12, and the mortar layer 24 was provided on the sheet | seat 22, it is not limited to this, The earth pressure gauge 12 and Any other release material may be used as long as it is a material that can be separated from the mortar layer 24 (a material that can prevent the mortar from adhering to the earth pressure gauge 12). As the release material, for example, a semi-solid agent such as grease can be used.

  In the first embodiment, mortar is used as the curing material, but concrete, resin, or the like may be used instead of mortar.

DESCRIPTION OF SYMBOLS 10 Earth pressure gauge installation structure 12 Earth pressure gauge 14 Cable 16 Loading plate 18 Hole part 20 Sand 22 Sheet 22A Peripheral part 24 Mortar layer 26 Wire mesh reinforcement 28 Wire 28A Hanging part 30 Ground 32 Groove part 50 Earth pressure gauge installation structure 52 Wire 52A Hanging Part

Claims (9)

Installing a soil pressure gauge on the foundation ground;
Providing a release material on the top of the earth pressure gauge, and protecting the earth pressure gauge with a curing material;
A step of constructing a loading plate on top of the hardened material and the foundation ground;
A process of performing a loading test by applying a vertical force to the packing plate described above;
A step of pulling up the packing plate described above after completion of the loading test, and separating the earth pressure gauge and the cured material by the release material;
Recovering the earth pressure gauge from the foundation ground;
Earth pressure gauge installation and recovery method.   The earth pressure gauge installation / recovery method according to claim 1, wherein the release material is a resin sheet or a semi-solid agent.   3. The earth pressure gauge installation / recovery method according to claim 1, wherein the packing plate is a concrete plate with wire mesh bars.   The said hardening material is a mortar, The said peeling material adhere | attached on the said mortar at the time of raising of the said loading plate is pulled up with the said loading plate together with the said mortar as described in any one of Claim 1-3. Earth pressure gauge installation and collection method.   The earth pressure gauge installation / recovery method according to any one of claims 1 to 4, wherein a wire is embedded in the packing plate, and the loading plate is lifted by lifting the wire with a heavy machine. A cable connected to the earth pressure gauge is embedded in a groove formed in the foundation ground,
The earth pressure gauge installation / recovery method according to any one of claims 1 to 5, wherein the earth pressure gauge is recovered by pulling the cable. Earth pressure gauge installed on the foundation ground,
A release material provided on the earth pressure gauge;
A curing material provided on the release material and protecting the earth pressure gauge;
A loading plate constructed on top of the hardened material and the foundation ground;
Earth pressure gauge installation structure.   The earth pressure gauge installation structure according to claim 7, wherein the release material is a resin sheet or a semi-solid agent.   The earth pressure gauge installation structure according to claim 7 or 8, wherein the loading plate is a concrete plate in which wire mesh bars are arranged.

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