JP4649201B2 - Non-land adjustment mat and construction method of non-land adjustment mat - Google Patents

Description

  The present invention relates to a non-land adjustment mat that is interposed between a pressure receiving plate and a ground surface, and performs a non-land adjustment of the ground surface, and a construction method of the non-land adjustment mat.

  A ground anchor method is known as an example of a method for stabilizing a slope or the like. The ground anchor method is designed to stabilize the slope by applying tension to the ground anchor fixed on the stable ground and transmitting this tension to the ground side via the pressure plate installed on the slope. It is composed.

  In the ground anchor method with such a configuration, when a pressure receiving plate is installed on the cut slope where the unevenness of the ground surface is remarkable and tension is applied to the ground anchor, stress concentration occurs in a part of the pressure receiving plate. Cracks may occur in the pressure receiving plate.

  For this reason, when installing a pressure receiving plate on a cut slope with severe irregularities on the ground surface, a bag-like uneven adjustment mat is interposed between the pressure receiving plate and the ground surface to temporarily tension the ground anchor. After that, grout is injected into the unevenness adjustment mat to absorb the unevenness of the ground surface, and the adhesion between the pressure receiving plate and the ground surface is enhanced.

  As an example of the unevenness adjustment mat having such a configuration, an unevenness adjustment mat has been proposed in which the outer shape is formed in substantially the same shape and size as the pressure receiving plate, and one chamber that can be filled with grout is provided. (For example, refer to Patent Document 1).

  Further, as another example of the non-land adjustment mat, a non-land adjustment mat is configured by combining a plurality of divided bodies, and according to the shape and size of the pressure receiving plate, an appropriate amount is provided between the pressure receiving plate and the ground surface. A configuration in which a number of divided bodies are interposed has been proposed.

Further, as another example of the unevenness adjustment mat, the interior is divided into two chambers, a first chamber located in the center and a second chamber located outside thereof, and grouts are provided in each of the first chamber and the second chamber. Has been proposed (see, for example, Patent Document 2).
Utility Model Registration No. 2530211 JP 2001-295271 A

  By the way, among the various unevenness adjustment mats having the above-described configuration, the unevenness adjustment mat described in Patent Document 1 is a surface of the ground surface when a ground anchor is temporarily tensioned and grout is injected therein. Due to the inclination, the pressure of the grout increases as it goes to the lower end portion of the unevenness adjustment mat, the lower end portion of the unevenness adjustment mat expands greatly, and the installation angle of the pressure receiving plate changes. For this reason, when this tension force is given to the ground anchor, a crack may occur in the pressure receiving plate. In addition, the pressure receiving plate for the ground anchor is designed so that the rigidity is higher as it is closer to the center because a large load acts on the center portion. However, the structure described in Patent Document 1 is structurally It is not sufficient to support such a large load, and problems such as tilting of the pressure receiving plate occur, making it difficult to stably support the pressure receiving plate in the long term.

  In addition, in the case of the unevenness adjustment mat configured by combining a plurality of divided bodies, it is necessary to install a plurality of divided bodies according to the shape and size of the pressure receiving plate, and for each divided body Because the grout must be injected, it takes time and effort to install and inject the grout. Further, this type of uneven adjustment mat is also not sufficient to support a large load acting on the central portion of the pressure receiving plate structurally, similar to the one described in Patent Document 1, and the pressure receiving in the long term. It becomes difficult to support the plate stably.

  Furthermore, the unevenness adjustment mat described in Patent Document 2 absorbs the concave portion of the opening of the hole for the ground anchor by injecting grout into the two chambers of the central portion and the outer portion thereof, respectively. However, this unevenness adjustment mat is not sufficient to support a large load acting on the central portion of the pressure receiving plate, and it becomes difficult to stably support the pressure receiving plate in the long term.

  The present invention has been made in view of the conventional problems as described above, and is easy to install and inject grout, and can stably support the pressure receiving plate for a long period of time. It is an object of the present invention to provide a non-land adjustment mat that can keep the angle between the axis of the pressure plate and the bottom surface of the pressure receiving plate at a predetermined angle.

In order to solve the above problems, the present invention employs the following means.
That is, the invention according to claim 1 is a non-landing adjustment mat interposed between the pressure receiving plate and the ground surface of the ground, and includes a first mat portion having a first chamber in which grout can be filled. And a second mat portion having a second chamber capable of being filled with grout, and having an area ratio between the first mat portion and the entire mat portion. The area of the first mat portion and the second mat portion is set so as to correspond to the ratio of the safety factor for short-term ground strength and the safety factor for long-term ground strength.
According to the unevenness adjustment mat according to the present invention, a short-term load can be supported by the first mat portion, and a long-term load can be supported by the cooperation of the first mat portion and the second mat portion, The pressure receiving plate can be stably supported over a long period of time.

The invention according to claim 2 is the unevenness adjustment mat according to claim 1, wherein the first mat portion is formed in a circular shape and the second mat portion is formed in an annular shape. .
According to the unevenness adjustment mat according to the present invention, the entire outer shape can be formed in a circular shape, so that the rigidity with respect to the load can be made uniform over the entire center portion.

The invention according to claim 3 is the unevenness adjustment mat according to claim 1 or 2, wherein the first mat portion and the second mat portion are integrally formed.
According to the unevenness adjustment mat according to the present invention, the first mat portion and the second mat portion are integrally formed, so that the construction is facilitated.

The invention according to claim 4 is the unevenness adjustment mat according to claim 1 or 2, wherein the first mat portion and the second mat portion are formed separately. .
According to the unevenness adjusting mat according to the present invention, the first mat portion and the second mat portion are formed separately from each other. Can be used together or installed separately.

The invention according to claim 5 includes a first mat portion having a first chamber in which grout can be filled, and a second chamber which is provided outside the first mat portion and can be filled with grout. A second mat portion, and an area ratio between the first mat portion and all the mat portions corresponds to a ratio of a safety factor with respect to a short-term ground strength and a safety factor with respect to a long-term ground strength of the ground. And a non-land adjustment mat construction method in which the areas of the first mat portion and the second mat portion are set, wherein the non-land adjustment mat is installed on the ground surface of the ground, Temporary tension applying process for temporarily supporting the pressure-receiving plate and the unevenness adjustment mat on the ground by installing a pressure-receiving plate at the top of the ground, inserting a ground anchor through the center of the plate, and applying a temporary tension to the ground anchor And the unevenness adjustment map A first grout injection process for adjusting the ground surface by filling the first chamber of the first mat portion with ground, and applying a main tension to the ground anchor so that the pressure receiving plate and the uneven land adjustment mat are placed on the ground. And a second tension injection step of filling the second chamber of the second mat portion of the unevenness adjustment mat with a second grout filling step.
According to the construction method of the non-land adjustment mat according to the present invention, in the provisional tension applying step, the pressure receiving plate is installed on the ground surface via the non-land adjustment mat, and temporary tension is applied to the ground anchor. The unevenness adjustment mat and the pressure receiving plate are temporarily supported on the ground surface. In the first grout injection step, the pressure receiving plate is supported in parallel to the ground surface by filling the first chamber of the first mat portion with grout. Then, after the grout is hardened, in the main tension applying step, the main pressure is applied to the ground anchor, whereby the pressure receiving plate is finally supported on the ground surface via the unevenness adjustment mat. In the second grout injection step, the pressure receiving plate is supported by the first mat portion and the second mat portion by injecting grout into the second chamber of the second mat portion.

The invention according to claim 6 is the construction method of the unevenness adjustment mat according to claim 5, wherein after the provisional tension force is applied to the ground anchor in the provisional tension application step, the first in the first grout injection step. The grout is filled in the first chamber of the mat portion, and the angle of the pressure receiving plate is adjusted so that the bottom surface of the pressure receiving plate and the long axis of the ground anchor are perpendicular to each other before the grout is cured. After the grout has hardened, the pressure receiving plate is preliminarily planned on the slope by applying the main tension to the ground anchor in the main tension applying step and filling the second chamber of the second mat portion with the main grout in the second grout injection step. It is configured to be installed at an angle.
According to the construction method of the non-land adjustment mat according to the present invention, after provisional tension is applied to the ground anchor, the grout is filled in the first chamber of the first mat portion, and before the grout is hardened, The angle of the pressure receiving plate is corrected. And after hardening the grout in the 1st room of the 1st mat part in the state where the amended angle was maintained, this tension is given to the ground anchor and the grout is filled into the 2nd room of the 2nd mat part. Thus, it is possible to ensure unevenness adjustment and a necessary pressure receiving area while maintaining the angle of the pressure receiving plate.

As described above, according to the non-land adjustment mat and the non-land adjustment mat construction method of the present invention, the grout is filled in the first chamber of the first mat portion and the second chamber of the second mat portion, respectively. The area ratio between the first mat portion and all mat portions (the sum of the first mat portion and the second mat portion) is configured so that the safety factor against short-term ground strength and the safety factor against long-term ground strength. Since the areas of the first mat portion and the second mat portion are set so as to correspond to the ratio, the short-term load can be reliably supported by the first mat portion, and the long-term The load can be reliably supported by the cooperation of the first mat portion and the second mat portion. Therefore, the pressure receiving plate does not tilt for a long time and can be supported stably. In addition, since the entire outer shape is formed in a circular shape, the rigidity with respect to the load can be made uniform over the entire center and the pressure receiving plate can be stably supported. it can. Furthermore, since the first mat portion and the second mat portion are formed integrally or separately, the first mat portion and the second mat portion can be installed together or separately according to the state of the ground surface. It can be installed and used in combination with both, increasing versatility.
Furthermore, after applying a temporary tension force to the ground anchor, the grout is filled in the first chamber of the first mat portion, and the angle of the pressure receiving plate on the non-land adjustment mat is corrected before the grout is hardened. Since the grout in the first chamber of the first mat portion is cured in a state where the first mat portion is held, the tension is applied to the ground anchor, and the grout is filled in the second chamber of the second mat portion. With the angle maintained, the unevenness adjustment and the necessary pressure receiving area can be secured.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 and 2 show an embodiment of the unevenness adjustment mat according to the present invention. FIG. 1 is a schematic plan view showing the entire unevenness adjustment mat, and FIG. 2 is an AA view of FIG. It is line sectional drawing.

  That is, the unevenness adjusting mat 1 is formed in a circular bag shape using a nonwoven fabric or a woven fabric made of synthetic fibers such as polyester as a base material, and the inside is composed of the first chamber 3 and the second chamber 11. It is divided into two chambers, and each of the first chamber 3 and the second chamber 11 can be filled with a grout 20.

  The first chamber 3 has a circular shape located at the center of the unevenness adjustment mat 1, and the portion of the unevenness adjustment mat 1 corresponding to the first chamber 3 functions as the first mat portion 2. It is configured as follows. The second chamber 11 has an annular shape positioned so as to surround the first chamber 3 on the outside of the first chamber 3 of the non-land adjustment mat 1, and the non-land corresponding to the second chamber 11. The portion of the adjustment mat 1 is configured to function as the second mat portion 10.

  The first mat portion 2 includes a circular upper wall 4, a circular lower wall 5 positioned in parallel below the upper wall 4 at a predetermined interval, and outer peripheral ends of the upper wall 4 and the lower wall 5. The first chamber 3 that is a circular space is formed in a portion surrounded by the upper wall 4, the lower wall 5, and the peripheral wall 6. Is formed.

  Between the upper wall 4 and the lower wall 5 of the first mat portion 2, an insertion hole 7 penetrating between the central portions is provided in a state of being isolated from the first chamber 3. The ground anchor 25 is configured to be inserted.

  A part of the peripheral wall 6 of the first mat portion 2 is provided with a through hole 8 that penetrates the inside and outside of the first chamber 3, and a pipe-shaped first inlet 9 is integrally connected to the peripheral portion of the through hole 8. The grout 20 is filled into the first chamber 3 through the first inlet 9.

  The second mat portion 10 has an annular upper wall 12 whose inner peripheral end is integrally connected to the outer peripheral end of the upper wall 4 of the first mat portion 2, and a predetermined interval below the upper wall 12. The lower end of the first mat portion 2 is integrally connected to the outer peripheral end portion of the lower wall 5 and the outer peripheral end portion is integrally connected to the outer peripheral end portion of the upper wall 12. A second chamber 11, which is an annular space, is formed in a portion that includes the wall 13 and is surrounded by the upper wall 12, the lower wall 13, and the peripheral wall 6 of the first mat portion 2.

  A part of the upper wall 12 of the second mat portion 10 is provided with a through hole 14 penetrating the inside and outside of the second chamber 11, and a pipe-like second inlet 15 is integrally connected to the peripheral portion of the through hole 14. The grout 20 is filled into the second chamber 11 through the second inlet 15.

  A portion of the upper wall 12 of the second mat portion 10 adjacent to the second inlet 15 is provided with a through hole 16 that penetrates the inside and outside of the second chamber 11, and the inside of the through hole 16 is the second of the first mat portion 2. One injection port 9 is inserted and drawn out to the outer portion of the second mat portion 10. Note that the first injection port 9 may be drawn out to the outer portion of the second mat portion 10 through the inner portion of the second injection port 15.

  The upper wall 4, the lower wall 5, the peripheral wall 6, and the upper wall 12, the lower wall 13 of the second mat portion 10 may be formed integrally, or they may be formed separately. Alternatively, they may be integrally connected by an appropriate means.

The area of the first mat portion 2 is set to 50 to 70% of the entire area of the unevenness adjustment mat 1.
That is, the first mat portion 2 and the entire mat portion (the sum of the first mat portion 2 and the second mat portion 10) of the unevenness adjustment mat 1 have a safety factor against the short-term ground strength of the ground at the construction target location. The area ratio is set so as to correspond to the ratio of the safety factor to the long-term ground strength.

For example, if the ground strength of the construction site is 300 kN / m ² , the safety factor s1 = 2 for short-term ground strength, and the safety factor s2 = 3 for long-term ground strength, the short-term load is 150 kN / m ² , the long-term load is 100 kN / m ² .
Therefore, if the area of the first mat portion 2 is a1, and the area of the second mat portion 10 is a2,
(A1 + a2): a1 = 150: 100 = 3: 2
a1: a2 = 100: 50 = 2: 1 (1)
Thus, the area ratio between the first mat portion 2 and the second mat portion 10 may be set with this ratio.

Next, the construction method of the unevenness adjustment mat 1 configured as described above will be described with reference to FIGS.
(1) Temporary tension applying step As shown in FIG. 3, the non-land adjustment mat 1 is installed on the ground surface 27 of the ground 26, and the pressure receiving plate 30 is installed on the top of the non-land adjustment mat 1. The ground anchor 25 that has been fixed in advance is inserted through the insertion hole 7 at the center of the unevenness adjustment mat 1 and the insertion hole 31 at the center of the pressure receiving plate 30, and protrudes from the upper surface of the pressure receiving plate 30. The fixing tool 35 is fixed to the head of the head, a temporary tension is applied to the ground anchor 25 using a jack, and the pressure receiving plate 30 and the unevenness adjustment mat 1 are temporarily supported on the ground surface 27 of the ground 26.

(2) First Grout Injection Step As shown in FIG. 4, the grout 20 is injected into the first chamber 3 of the first mat portion 2 of the unevenness adjustment mat 1 through the first injection port 9. 3 is filled with a predetermined amount of grout 20 to adjust the unevenness of the ground surface 27, absorb the unevenness of the ground surface 27, and support the pressure receiving plate 30 parallel to the ground surface 27.

  In this case, since the area of the first mat portion 2 is set to 50 to 70% of the entire area of the unevenness adjustment mat 1, it is sufficient to ensure a safety factor against the short-term ground strength of the ground surface 27. A support force is obtained, and the main tension force applied to the ground anchor 25 can be sufficiently supported in the next main tension step.

(3) Main tension applying step As shown in FIG. 4, after the grout 20 filled in the first chamber 3 is cured, the main anchor is applied to the ground anchor 25 using a jack, and the pressure receiving plate 30 and the non-landing The adjustment mat 1 is fully supported on the ground surface 27 of the ground 26. In this case, as described above, even if the main tension applied to the ground anchor 25 acts on the unevenness adjustment mat 1 via the pressure receiving plate 30, the area of the first mat portion 2 of the unevenness adjustment mat 1 is reduced for a short time. Since it is set to a value sufficient to ensure a safety factor against the ground strength, the tension force from the ground anchor 25 can be sufficiently supported. Therefore, the pressure receiving plate 30 is not inclined with respect to the ground surface 27, and the pressure receiving plate 30 can be kept parallel to the ground surface 27.

(4) Second Grout Injection Step As shown in FIG. 5, the grout 20 is injected into the second chamber 11 of the second mat portion 10 of the uneven adjustment mat 1 through the second injection port 15, A predetermined amount of grout 20 is filled in the chamber 11. In this process, since the area of all mat parts (the sum of the first mat part 2 and the second mat part 10) is set to a value sufficient to ensure a long-term safety factor against earth resistance, The tension from the ground anchor 25 can be dispersed throughout the unevenness adjustment mat 1, and the pressure receiving plate 30 can be stably supported over a long period of time.

  In the above description, after the non-land adjustment mat 1 and the pressure receiving plate 30 are installed, both are temporarily supported on the ground surface 27 by temporary tension, and thereafter, in the first chamber 3 of the first mat portion 2. The grout 20 is filled into the second chamber 11 of the second mat portion 10 and then the grout 20 is filled. After the temporary tension, the first chamber 3 of the first mat 2 and You may comprise so that the grout 20 may be filled into both the 2nd chambers 11 of the 2nd mat | matte part 10, and this tension may be performed after that. Further, after installing the unevenness adjusting mat 1 and the pressure receiving plate 30, the tension is applied to fill the first chamber 3 of the first mat portion 2 with the grout 20, and then the second chamber of the second mat portion 10. 11 may be filled with grout.

  In the construction method of the unevenness adjustment mat 1 and the unevenness adjustment mat 1 according to the present embodiment configured as described above, the unevenness adjustment mat 1 is composed of the first mat portion 2 and the second mat portion 10. In addition, the area ratio of the first mat portion 2 and all mat portions (the sum of the first mat portion 2 and the second mat portion 10) is set to a safety factor for short-term ground strength and safety for long-term ground strength. Since the first mat portion 2 is initially filled with the grout 20 and fully tensioned and then the second mat portion 10 is filled with the grout 20, the tension is set to a value corresponding to the ratio with the rate. Thus, even if the main tension force from the ground anchor 25 acts on the pressure receiving plate 30, the tension force can be sufficiently supported by the first mat portion 2. Therefore, the pressure receiving plate 30 does not tilt in the short term, and the pressure receiving plate 30 can be stably supported.

  Moreover, after filling the grout 20 in the 1st mat part 2, the tension force from the ground anchor 25 is disperse | distributed to the whole unevenness adjustment mat 1 by filling the grout 20 in the 2nd mat part 10. Therefore, the pressure receiving plate 30 does not tilt for a long time, and the pressure receiving plate 30 can be stably supported.

  Furthermore, since the entire outer shape is formed in a circular shape, when subjected to a tension force from the ground anchor 25, the rigidity against bending can be made uniform around the central portion where the load is concentrated. Therefore, the pressure receiving plate 30 can be stably supported.

  In the above description, the first mat portion 2 and the second mat portion 10 of the unevenness adjustment mat 1 are integrally formed. However, the first mat portion 2 and the second mat portion 10 are formed separately. The two may be combined and installed between the pressure receiving plate 30 and the ground surface 27. In this case, the same operation and effect are naturally obtained.

It is the schematic plan view which showed one Embodiment of the unevenness adjustment mat by this invention. It is the sectional view on the AA line of FIG. It is explanatory drawing which showed the construction method of the unevenness adjustment mat by this invention, Comprising: It is explanatory drawing which showed the temporary tension | tensile_strength provision process. It is explanatory drawing which showed the 1st grout injection | pouring process and this tension | tensile_strength provision process. It is explanatory drawing which showed the 2nd grout injection | pouring process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Non-land adjustment mat 2 1st mat part 3 1st chamber 4, 12 Upper wall 5, 13 Lower wall 6 Perimeter wall 7 Insertion hole 8, 14, 16 Through-hole 9 1st inlet 10 2nd mat part 11 2nd chamber 15 Second inlet 20 Grout 25 Ground anchor 26 Ground 27 Ground surface 30 Pressure receiving plate 31 Insertion hole 35 Fixing tool

Claims (6)

A non-land adjustment mat interposed between the pressure plate and the ground surface,
A first mat portion having a first chamber capable of filling grout therein, and a second mat portion provided outside the first mat portion and having a second chamber capable of filling grout therein,
The first mat portion and the mat portion so that the area ratio of the first mat portion and all the mat portions corresponds to the ratio of the safety factor for the short-term ground strength and the safety factor for the long-term ground strength of the ground. An unevenness adjustment mat, wherein an area of the second mat portion is set.   The unevenness adjusting mat according to claim 1, wherein the first mat portion is formed in a circular shape, and the second mat portion is formed in an annular shape.   The unevenness adjustment mat according to claim 1 or 2, wherein the first mat portion and the second mat portion are formed integrally.   The unevenness adjustment mat according to claim 1 or 2, wherein the first mat portion and the second mat portion are formed separately. A first mat portion having a first chamber capable of filling grout therein, and a second mat portion provided outside the first mat portion and having a second chamber capable of filling grout therein, The first mat portion and the mat portion so that the area ratio of the first mat portion and all the mat portions corresponds to the ratio of the safety factor for the short-term ground strength and the safety factor for the long-term ground strength of the ground. It is a construction method of the unevenness adjustment mat which set the area of the 2nd mat part,
The non-land adjustment mat is installed on the ground surface, and a pressure receiving plate is installed on the top of the non-land adjustment mat, and a ground anchor is inserted through the center of the mat to provide temporary tension to the ground anchor. Thus, a provisional tension applying step for temporarily supporting the pressure receiving plate and the non-land adjustment mat on the ground, and a non-land adjustment of the ground surface by filling the first chamber of the first mat portion of the non-land adjustment mat with the grout. A first grout injecting step, a main tension applying step of applying a main tension to the ground anchor to fully support the pressure receiving plate and the non-landing adjustment mat on the ground, and a second of the second mat portion of the non-landing adjusting mat. The construction method of the non-land adjustment mat | matte characterized by including the 2nd grout injection | pouring process filled with grout indoors. After provisional tension is applied to the ground anchor in the provisional tension applying step, the first chamber of the first mat portion is filled with grout in the first grout injection step, and the bottom surface of the pressure receiving plate and the ground anchor are set before the grout is cured. After adjusting the angle of the pressure receiving plate so that the major axis of the first plate is at right angles and the grout in the first chamber of the first mat portion is hardened, the main tension is applied to the ground anchor in the main tension applying step, and the second grout is injected. 6. The unevenness adjustment mat according to claim 5, wherein the pressure receiving plate is installed on the slope at a predetermined angle by filling grout in the second chamber of the second mat portion in the process. Construction method.

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