JP7236776B1 - Underfloor reinforcement method and underfloor reinforcement structure - Google Patents

Abstract

An object of the present invention is to provide an underfloor reinforcement method and the like in which the strength of a reinforced portion is improved. SOLUTION: An underfloor reinforcement method of the present invention is a method for reinforcing an underfloor by filling a cavity 3 between a ground 2 and a floor 1, and a through hole 4 connected to the cavity 3 is provided in the floor 1. a step of inserting a rod-shaped drill into the cavity 3 side from the through hole 4 to dig down the ground 2 to form a vertical hole extending downward from the cavity 3 directly below the through hole 4; A step of supplying the liquid ground strengthening agent 5 to the cavity 3 and the vertical hole from the through hole 4, and inserting a drill into the vertical hole from the through hole 4 to stir the ground strengthening agent 5 in the vertical hole, thereby supplying the ground strengthening agent 5 around the vertical hole A step of infiltrating into the soil and holding the shape of the vertical hole by the hardening action of the ground strengthening agent 5, then supplying foaming resin from the through hole 4 so as to fill the cavity 3 and the vertical hole, and the cavity 3 and a step of closing the through hole 4 after the vertical hole is filled with a foaming resin. [Selection drawing] Fig. 6

Description

Application of Article 30, Paragraph 2 of the Patent Law (1) Posting address (top page) https://reiwa-corp. net/ (Invention listing page) https://reiwa-corp. net/construction. html Posted on July 1, 2021

The present invention relates to an underfloor reinforcement method and an underfloor reinforcement structure.

Floors of factories, warehouses, etc. are generally made of cementitious materials such as concrete and mortar. This type of floor is usually formed in layers (plates) having a predetermined thickness so as to cover the ground. Such floors are widely used because they are excellent in strength, load capacity, and the like.

By the way, it is known that cavities are formed on the underside of this type of floor over time. Cavities are mainly caused by vibrations generated by various mechanical devices (e.g., machine tools) installed on the floor and moving objects (e.g., forklifts) that move on the floor. It is believed to be formed to subside. Since such a cavity is formed between the floor and the ground, the part of the floor where the cavity is formed is separated from the ground and is in a state of floating in the air. In other words, since the floor in the hollowed-out portion is not supported by the ground, it supports the load only by its own strength. If the floor in such a state is left as it is, damage such as cracks occurs in the floor, and in some cases, the floor collapses.

In addition, since moisture (moisture) tends to accumulate in the cavity, if cracks or the like occur in the floor, moisture may enter the interior of the floor through the cracks or the like. Reinforcing bars are generally buried inside the floor for the purpose of reinforcement. will expand. As a result, cracks or the like grow further and the floor is destroyed.

Conventionally, before the floor is destroyed due to such a cavity, an operation is performed to fill the cavity and reinforce the underfloor.

For example, in Patent Document 1, a through hole of 0.5 cm to 1.0 cm is formed in the concrete floor where the cavity is formed, and water is injected into the cavity through the through hole to inject water into the ground. It is described that after permeation, the through holes are stuffed with cotton, and a predetermined resin is injected through the cotton. The resin injected in this manner foams and expands, filling the cavity with the resin. In addition, the through-hole is finally closed with concrete. Such an underfloor reinforcement method has attracted attention in recent years because it does not require replacement of the floor, is easy to construct, and is advantageous in terms of cost.

Patent No. 6885641

There is room for improvement in conventional underfloor reinforcement methods. For example, with the passage of time, there is a risk that the resin filled in the cavity will be displaced from the floor or the ground due to the effects of vibrations and the like, resulting in the formation of new cavities at the reinforced locations. Therefore, in this type of underfloor reinforcement method, it has been desired to further improve the strength of the repaired portion.

SUMMARY OF THE INVENTION An object of the present invention is to provide an underfloor reinforcement method or the like in which the strength of a reinforced portion is improved.

Means for solving the above problems are as follows. Namely
<1> An underfloor reinforcement method for reinforcing an underfloor by filling a cavity formed between the ground and a floor having a predetermined thickness constructed on the ground, wherein the underfloor is pierced in the thickness direction. a through-hole forming step of forming a through-hole connected to the cavity while inserting a rod-shaped drill into the cavity side from the through-hole and digging down the ground with the drill to form the cavity just below the through-hole a vertical hole forming step of forming a vertical hole extending downward from the through hole; a first supply step of supplying a liquid soil strengthening agent to the cavity and the vertical hole from the through hole; and inserting the drill into the vertical hole from the through hole By stirring the ground reinforcement in the vertical hole with the drill, the ground reinforcement is permeated into the soil around the vertical hole, and the shape of the vertical hole is maintained by the hardening action of the ground reinforcement. a vertical hole shape retaining step; after the vertical hole shape retaining step, a second supplying step of supplying a foamable resin from the through hole so as to fill the cavity and the vertical hole; and a closing step of closing the through-hole after being filled with resin.

<2> In the second supply step, a nozzle for supplying the expandable resin is inserted into the through hole, and a gap formed between the through hole and the nozzle is filled with a water retaining liquid impregnated with liquid. The underfloor reinforcement method according to <1> above, wherein the underfloor reinforcement is covered with an elastic sheet.

<3> In the closing step, the water-retaining sheet used in the second supplying step is packed into the through-hole, and the through-hole is closed with a cement-based material so as to cover the packed water-retaining sheet. The underfloor reinforcement method according to <2>.

<4> An underfloor reinforcing structure that fills a cavity formed between a ground and a floor having a predetermined thickness constructed on the ground, wherein the cavity is formed in the floor and penetrates the cavity in the thickness direction. a through hole that is formed immediately below the through hole and extends downward from the cavity and retains its shape due to the hardening action of a soil strengthening agent that has permeated the surrounding soil; and the cavity and the vertical hole. An underfloor reinforcing structure comprising: a foamed resin made of foamable resin filling the through-hole; and a plug closing the through-hole.

ADVANTAGE OF THE INVENTION According to this invention, the underfloor reinforcement method etc. which the intensity|strength of a reinforcement location improved can be provided.

Explanatory drawing showing an example of a floor constructed on the ground Explanatory drawing showing a state in which a cavity is formed between the floor and the ground Explanatory drawing showing a through-hole forming process Explanatory drawing showing vertical hole forming process Explanatory drawing showing a vertical hole formed by digging the ground in the vertical hole formation process Explanatory drawing showing the first supply process Explanatory drawing showing vertical hole shape retention process Explanatory drawing showing a vertical hole in which the surrounding mixture hardens and retains its shape Explanatory drawing showing the second supply process Explanatory diagram showing the closing process Enlarged cross-sectional view of a plug that closes a through hole

[Embodiment 1]
An underfloor reinforcing method according to Embodiment 1 of the present invention will be described below with reference to FIGS. 1 to 11. FIG. FIG. 1 is an explanatory diagram showing an example of a floor 1 constructed on the ground 2. As shown in FIG. Here, first, the floor 1 to which the underfloor reinforcement method of this embodiment is applied will be briefly described. The floor 1 is a layered (plate-like) member having a predetermined thickness and made mainly of a cement-based material (base material) such as concrete or mortar. Examples of such a floor 1 include a concrete floor, a mortar floor, and the like. Further, reinforcing members such as reinforcing bars may be arranged inside the floor 1 . A floor 1 is a floor of a building such as a factory, a warehouse, or a store.

In other embodiments, as long as the object of the present invention is not impaired, the present embodiment can be applied to floors of civil engineering buildings formed on the ground, road surfaces such as roads and runways, in addition to floors of buildings. A form of underfloor reinforcement method may be applied. FIG. 1 shows a state in which the floor 1 is constructed directly on the surface 2a of the ground 2. As shown in FIG. In other embodiments, the surface 2a of the ground 2 may be formed with another layer (for example, a crushed stone layer) for the purpose of ground reinforcement, etc., as long as the object of the present invention is not impaired.

As shown in FIG. 1, when the floor 1 is constructed on the ground 2, no cavity is seen between the ground 2 and the floor 1 at the beginning. In the following description, it is assumed that floor 1 is a "concrete floor" having a predetermined thickness (0.5 mm to 20 mm).

FIG. 2 is an explanatory diagram showing a state in which a cavity 3 is formed between the floor 1 and the ground 2. As shown in FIG. With the passage of time, the ground 2 under the floor 1 may loosen and sink under the influence of vibrations and the like from vibration sources (machine tools, forklifts, etc.) installed on the floor 1 . FIG. 2 shows a state in which the ground 2 is loosened and a cavity 3 having a predetermined depth is formed between the bottom surface 1b of the floor 1 and the surface 2a of the ground 2. As shown in FIG. The underfloor reinforcement method of the present embodiment reinforces the underfloor 1 by filling the cavity 3 formed under the floor 1 with a predetermined resin (hardened foam resin).

The underfloor reinforcement method of this embodiment mainly includes a through hole forming step, a vertical hole forming step, a first supply step, a vertical hole shape maintaining step, a second supply step, and a closing step.

The through-hole forming step is a step of forming through-holes 4 that extend through the floor 1 in the thickness direction and are connected to the cavities 3 . FIG. 3 is an explanatory view showing the through-hole forming process. In this through-hole forming step, a drill D is used in a portion of the floor 1 that overlaps the cavity 3 in the vertical direction, and a predetermined hole diameter (for example, A through hole 4 having a diameter of about 10 mm to 15 mm is formed. The through hole 4 is connected to the cavity 3 while passing through the floor 1 in the thickness direction (vertical direction). The through hole 4 is provided in the floor 1 so as to overlap with the cavity 3 when the floor 1 is viewed from the upper surface 1a side. The size of the through hole 4 is usually very small compared to the cavity 3 . Only one or two or more such through-holes 4 may be formed in one cavity 3 on the lower side of the floor 1 . It is preferable that a plurality of through-holes 4 are formed in one cavity 3 from the viewpoint of further improving the strength of the reinforced portion. When a plurality of through-holes 4 are formed in the floor 1, it is preferable to set the interval between adjacent through-holes 4 to a predetermined size (for example, in the range of 50 cm to 100 cm). Further, examples of the drill D used in the through-hole forming step include commercially available concrete drills. After the through holes 4 are formed in the floor 1 by the through hole forming process, the vertical hole forming process is performed.

In the vertical hole forming process, a vertical hole 31 extending downward from the cavity 3 is formed directly below the through hole 4 by inserting a rod-shaped drill D from the through hole 4 to the cavity 3 side and digging the ground 2 with the drill D. It is a process. FIG. 4 is an explanatory diagram showing the vertical hole forming process.

In the vertical hole forming step, a vertical hole 31 connected to the cavity 3 is formed directly below the through hole 4 . As the drill D used in the vertical hole forming process, it is inserted into the through hole 4 and is longer than the depth of the cavity 3 and digs down the ground 2 to a predetermined depth (length) below the cavity 3. There is no particular limitation as long as the vertical hole 31 can be formed. Therefore, normally, the drill D used in the above-described through hole forming process is used as it is in the vertical hole forming process. In another embodiment, a drill prepared separately from the drill used in the through hole forming process may be used in the vertical hole forming process. FIG. 4 shows the drill D used in the through-hole forming step.

In the vertical hole forming step, a bar-shaped drill D having a predetermined length is inserted into the through hole 4 provided in the floor 1 from the upper surface 1a side of the floor 1 toward the lower surface 1b side. The tip of the drill D inserted into the through-hole 4 is pressed against the bottom of the cavity 3 directly below the through-hole 4 (that is, the surface 2a of the ground 2), and the drill D in this state is rotated to remove the ground. 2 is dug down by a drill D to form a vertical hole 31 connected to the cavity 3. As a whole, the vertical hole 31 has a bottomed cylindrical shape that is open upward. The depth (length in the vertical direction) of the vertical hole 31 is not particularly limited as long as the object of the present invention is not impaired. It is preferable to set the depth to about 5 times. The depth of the vertical hole 31 is preferably 10 cm to 30 cm, for example. The inner diameter of the vertical hole 31 is substantially the same as the diameter of the through hole 4 provided in the floor 1 .

FIG. 5 is an explanatory diagram showing a vertical hole 31 formed by digging the ground 2 by the vertical hole forming process. The vertical hole 31 is directly below the through hole 4 and connected with the cavity 3 . After the vertical holes 31 are formed in this manner, the first supply step is performed.

The first supply step is a step of supplying the liquid ground strengthening agent 5 from the through hole 4 to the cavity 3 and the vertical hole 31 . FIG. 6 is an explanatory diagram showing the first supply step. The soil strengthening agent 5 is liquid, and penetrates into the soil 2b that forms the ground 2 from the surface 2a of the ground 2, etc., and hardens the ground 2 in the permeated portion. As shown in FIG. 6, since the ground 2 is formed with a vertical hole 31, the ground strengthening agent 5 is also supplied into the vertical hole 31. As shown in FIG. In this embodiment, a soil strengthening agent 5 that hardens by reacting with moisture contained in the soil 2b or the like is used. Examples of such ground reinforcement agents 5 include isocyanate-based ground reinforcement agents (eg, polymethylene polyphenyl polyisocyanate). In addition, the soil strengthening agent 5 may contain a solvent or the like as appropriate.

In the first supply step, the soil strengthening agent 5 is supplied, for example, using a supply device (for example, an electric mini-pump, maximum discharge pressure: 1.4 MPa) provided with a predetermined discharge nozzle 6. In this case, the tip of the elongated discharge nozzle 6 is inserted into the cavity 3 through the through hole 4, and the liquid ground strengthening agent 5 is discharged from the discharge nozzle 6 in that state. In addition, the method of supplying the soil strengthening agent 5 into the cavity 3 is not limited to this, and is appropriately selected according to the purpose. The supply amount of the ground strengthening agent 5 is appropriately set according to the conditions of the ground 2 (for example, the type and moisture content of the soil 2b).

After the soil strengthening agent 5 is supplied into the cavity 3 and the vertical hole 31 by the first supply step, the discharge nozzle 6 is appropriately extracted from the through hole 4, and the next vertical hole shape retention step is performed.

In the vertical hole shape retention process, the drill D is inserted from the through hole 4 into the vertical hole 31 and the ground strengthening agent 5 in the vertical hole 31 is stirred by the drill D, so that the ground strengthening agent 5 is spread around the vertical hole 31 (peripheral surface and bottom surface ) to maintain the shape of the vertical hole 31 by the hardening action of the soil strengthening agent 5 . FIG. 7 is an explanatory diagram showing the vertical hole shape retaining process.

After the first supply step, the vertical hole 31 is in a state of containing the liquid soil strengthening agent 5 . When the drill D is inserted into such a vertical hole 31 and the soil strengthening agent 5 in the vertical hole 31 is stirred by rotation of the drill D, the soil strengthening agent 5 mixes with the soil 2b that constitutes the ground 2, and the vertical hole The soil around 31 (perimeter and bottom) will be forcibly penetrated. At that time, the soil strengthening agent 5 permeates efficiently so as to spread outward from the peripheral surface of the vertical hole 31 or the like.

A mixture M of the soil strengthening agent 5 and the soil 2b is present around the drill D inserted into the vertical hole 31 and rotated. Such a mixture M forms the perimeter and bottom surface of the well 31 . In such a state, when the mixture M hardens due to the hardening action of the soil strengthening agent 5, a vertical hole 31 whose shape is retained is obtained in the soil 2. FIG. 8 is an explanatory diagram showing the vertical hole 31 in a state where the surrounding mixture M is cured and the shape is maintained.

The drill D used in the vertical hole shape retaining process may be the same as that used in the above-described vertical hole forming process and through hole forming process, or another separately prepared drill may be used. From the viewpoint of improving work efficiency, etc., it is preferable to use the same drill D as that used in the vertical hole forming process and the through hole forming process in the vertical hole shape maintaining process.

After the first supply step, the liquid ground strengthening agent 5 stored in the vertical hole 31 permeates into the soil existing around the vertical hole 31 without being stirred by the drill D. However, if agitation by the drill D is not performed, the soil existing on the bottom side of the cavity 3 will flow into the vertical hole 31, or the vertical hole 31 will lose its shape, and the vertical hole 31 of sufficient size cannot be secured. There is Moreover, if the drill D is not used for stirring, the penetration of the ground strengthening agent 5 tends to become uneven, and the shape of the vertical hole 31 may be difficult to maintain. Therefore, it is necessary to perform the vertical hole shape retention step after the first supply step and before the soil strengthening agent 5 in the vertical hole 31 permeates into the soil.

The second supply step is a step of supplying the foamable resin 8 from the through hole 4 so as to fill the cavity 3 and the vertical hole 31 after the vertical hole shape retaining step. FIG. 9 is an explanatory diagram showing the second supply step. The foamable resin 8 is liquid in an uncured state. Such uncured foamable resin 8 expands in volume due to foaming and hardens to become a solid resin (foamed resin 80 to be described later).

As the foaming resin 8, a general one used in the method of filling the cavity 3 of this type can be used. As the foaming resin 8, for example, a urethane-based foaming resin composed of a main agent and a catalyst can be used. The main agent of the urethane-based foaming resin includes, for example, methylenebis(4,1-phenylene)=diisocyanate. Moreover, the catalyst for the urethane-based foaming resin includes, for example, dimethylmyristylamine. The urethane-based foaming resin is composed of a liquid composition in which such a main agent and a catalyst are blended in predetermined proportions. In addition, the foaming resin 8 such as a urethane-based foaming resin may appropriately contain a solvent or the like.

In the second supply step, the supply of the expandable resin 8 is performed using, for example, a supply device provided with a predetermined discharge nozzle 6A. As this supply device, for example, the same device (equipped with the same discharge pressure) as used in the first supply step can be used. As shown in FIG. 9, the tip of a longitudinal discharge nozzle 6A is inserted into the cavity 3 through the through hole 4, and a predetermined amount of liquid foaming resin 8 is discharged from the discharge nozzle 6A in that state. is discharged. The method of supplying the expandable resin 8 into the cavity 3 is not limited to this, and can be appropriately selected according to the purpose.

When the foaming resin 8 is supplied using the discharge nozzle 6</b>A in this manner, the vertical hole 31 and the cavity 3 are filled with the foaming resin 8 . After a predetermined amount of foamable resin 8 is supplied to cavity 3 and vertical hole 3, discharge nozzle 6A is removed from through hole 4 as appropriate. The foaming resin 8 supplied to the cavity 3 and the vertical hole 3 undergoes a chemical reaction accompanied by foaming with the lapse of time, expands in volume and hardens.

In the second supply step, when the foamable resin 8 is supplied from the through hole 4 into the cavity 3 and the vertical hole 31, the foamable resin 8 is prevented from overflowing from the through hole 4 to the outside (upper surface 1a side of the floor 1). may be treated accordingly. For example, when the discharge nozzle 6A is inserted into the through-hole 4 to supply the foamable resin 8, the gap formed between the through-hole 4 and the discharge nozzle 6A is filled with a water-retentive sheet (waste paper) of a predetermined size. etc.) containing a liquid such as water may be used to prevent the expandable resin 8 from overflowing from the through hole 4 to the outside. The outflow prevention material 7 is preferably a water-retentive sheet that contains liquid and is formed in a ring so as to surround the through-hole 4 .

The closing step is a step of closing the through hole 4 after the cavity 3 and the vertical hole 31 are filled with the foamable resin 8 . FIG. 10 is an explanatory view showing the closing step, and FIG. 11 is an enlarged cross-sectional view of the plug 9 that closes the through hole 4. As shown in FIG. In this closing step, the through hole 4 is closed with a plug 9 made of at least a cement-based material such as mortar. As shown in FIG. 11, in the closing step, first, the lower portion of the through hole 4 is filled with the rolled outflow prevention material 7 (water retaining sheet) used in the above-described second supply step. is preferred. Next, it is preferable to fill the through holes 4 with a porous member 10 made of a plastic sponge or the like placed on the rolled outflow prevention material 7 . Then, the plug 9 made of the above-described cementitious material is formed on the porous member 10 in an overlapping manner. By closing the through hole 4 with the plug 9 in this manner, the airtightness and watertightness of the floor 1 in the portion where the through hole 4 is formed are maintained.

Through the through-hole forming process, vertical hole forming process, first supply process, vertical hole shape maintaining process, second supply process, and closing process as described above, the cavity 3 and the vertical hole 31 formed under the floor 1 are By filling with a foamed resin 80 that is a cured product of the foamable resin 8, the bottom of the floor 1 is reinforced. Therefore, the ground 2 below the floor 1 is reinforced by the foamed resin 80, and the reinforced ground 2 supports the floor 1 from below, thereby reinforcing the floor 1. - 特許庁

In particular, in the case of this embodiment, the foamed resin 80 fills not only the cavity 3 formed under the floor 1 but also the vertical holes 31 extending downward from the cavity 3 . Therefore, of the foamed resin 80 , the body portion 81 formed by filling the cavity 3 is supported from below by the column portion 82 formed by filling the vertical hole 31 . As described above, the vertical hole 31 has its shape retained by the hardening action of the soil strengthening agent 5 that permeates the surrounding soil 2b (that is, the mixture M of the soil 2b and the soil strengthening agent 5 that constitute the ground 2 is The vertical hole 31 accommodates the column portion 82 . The columnar portion 82 has a substantially columnar shape extending in the vertical direction. Since the body part 81 is supported from below by the pillars 82 in such a state, the body part 81 has a structure in which it is difficult to dislocate and sink together with the ground 2, and it can be said that the effect of supporting the floor 1 is high. According to such an underfloor reinforcing method, the strength of the reinforced portion is improved as compared with the conventional method.

If a gap (crack or the like) that opens to the lower surface 1b side of the floor 1 is formed, the foamable resin 8 filled in the cavity 3 or the like can enter such gap. Therefore, according to the underfloor reinforcement method of this embodiment, such gaps can be repaired at the same time.

The structure under the floor 1 reinforced by the underfloor reinforcement method of this embodiment is referred to as an underfloor reinforcement structure 100 . The underfloor reinforcing structure 100 is a structure that fills the cavity 2 formed between the ground 2 and the floor 1 constructed on the ground 2 and having a predetermined thickness. Such an underfloor reinforcing structure 100 includes a through hole 4 formed in the floor 1 and penetrating in the thickness direction and connected to the cavity 3, and a through hole 4 formed directly below the through hole 4, extending downward from the cavity 3 and extending through the ground 2. A vertical hole 31 whose shape is maintained by the mixture M of the constituent soil 2b and the soil strengthening agent 5, a foamed resin 80 made of a foaming resin that fills the cavity 3 and the vertical hole 31, and a plug 9 that closes the through hole 4. Prepare.

DESCRIPTION OF SYMBOLS 1... Floor, 2... Ground, 3... Cavity, 4... Through-hole, 5... Ground strengthening agent, 6, 6A... Discharge nozzle, 7... Outflow prevention material, 8... Expandable resin, 80... Foamed resin, 81... Body part 82... Column part 9... Stopper 100... Underfloor reinforcement structure D... Drill

Claims (4)

An underfloor reinforcement method for reinforcing an underfloor by filling a cavity formed between the ground and a floor having a predetermined thickness constructed on the ground,
a through-hole forming step of forming a through-hole in the floor that penetrates in the thickness direction and is connected to the cavity;
a vertical hole forming step of forming a vertical hole extending downward from the hollow directly below the through hole by inserting a rod-shaped drill into the hollow through the through hole and digging the ground with the drill;
a first supply step of supplying a liquid soil strengthening agent from the through hole to the cavity and the vertical hole;
By inserting the drill into the vertical hole through the through hole and stirring the soil strengthening agent in the vertical hole with the drill, the soil strengthening agent is permeated into the soil around the vertical hole, and the soil strengthening agent a vertical hole shape holding step for holding the shape of the vertical hole by the hardening action of
a second supply step of supplying a foamable resin from the through hole so as to fill the cavity and the vertical hole after the vertical hole shape maintaining step;
and a closing step of closing the through-hole after the cavity and the vertical hole are filled with the foamable resin. In the second supply step, a nozzle for supplying the foamable resin is inserted into the through hole, and a gap formed between the through hole and the nozzle is filled with a water-retentive sheet containing liquid. The underfloor reinforcement method according to claim 1, wherein the underfloor reinforcement is closed. 3. The method according to claim 2, wherein in the closing step, the water-retaining sheet used in the second supplying step is packed into the through-hole, and the through-hole is closed with a cement-based material so as to cover the packed water-retaining sheet. Underfloor reinforcement method described. An underfloor reinforcing structure that fills a cavity formed between the ground and a floor having a predetermined thickness constructed on the ground,
a through hole formed in the floor and connected to the cavity while penetrating in the thickness direction;
a vertical hole formed immediately below the through-hole, extending downward from the cavity and having its shape retained by a hardening action of a soil strengthening agent permeated into the surrounding soil;
a foamed resin made of a foaming resin that fills the cavity and the vertical hole;
An underfloor reinforcing structure comprising: a plug that closes the through hole.

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