JP2010116715A - Retaining wall construction method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a retaining wall construction method reducing the volume of a cut section for constructing a skeleton (reducing the excavated-removed amount of soil) and reducing soil pressure to the skeleton in an L-shaped or inverted L-shaped retaining wall structure. <P>SOLUTION: The cut section 20 for constructing the skeleton is formed by excavating-removing soil in a retaining wall construction place in a state of providing an inclined bottom face part 22 of almost the same gradient as a stable gradient θ of the site ground in a depth range section where a bottom slab part 12 of a retaining wall to be constructed is located. The bottom slab part 12 is constructed on the inclined bottom face part 22 of the cut section 20 in a state of forming the lower face of the bottom slab part 12 of the skeleton 1 into an inclined part 13 of the same gradient as the inclined bottom face part 22, and after constructing a vertical slab part 11 of the skeleton 1 in an outer end position or an outer end side position of the bottom slab part 12, soil S is filled inside the skeleton 1. The volume of the cut section 20 can thereby be reduced, and soil pressure to the skeleton 1 can be reduced. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a retaining wall construction method for constructing an L-shaped or inverted T-shaped retaining wall on a road side surface, a created land side surface, or a slope such as a mountain surface.

  In order to construct a retaining wall on the side of the road, the side of the constructed land, or the slope of the mountain, it is necessary to excavate and excavate the ground at the retaining wall construction site and form a cut section for retaining wall construction there. is there.

  6A to 6C show a retaining wall construction method for constructing a road on a slope 102 such as a mountain surface. In this example, the retaining wall (concrete frame) 101 is inverted T The type is adopted.

  An inverted T-type retaining wall (frame) 101 shown in FIG. 6C is obtained by continuously connecting a vertical plate portion 111 in a vertical posture at a position close to the outer end of a bottom plate portion 112 having the same thickness and facing in the horizontal direction. However, in order to secure the road W formed inside the vertical plate portion 111 by the required width W, the height H of the vertical plate portion 111 and the depth length L of the bottom plate portion 112 as the casing 101 are considerably large. It is necessary to be safe. For example, when the required width W of the road is 4 m, the housing 101 is constructed such that the overall height H of the housing 101 is about 4 m, and the depth length L of the bottom plate portion 112 is less than about 3 m. In general, the depth length L of the bottom plate portion 112 is set to about 70% of the total height H of the casing 101.

In order to construct the retaining wall of FIG. 6C, first, as shown in FIG. 6A, on the mountain surface (slope) 102, the range indicated by the two-dot chain line (corresponding to the size of the retaining wall to be constructed). The excavated area 120 is excavated and discharged to form a cut section 120 for retaining wall construction. The bottom surface portion 121 of the cut portion 120 is horizontal with a depth width L ₁ slightly longer than the depth length L of the bottom plate portion 112 because the bottom surface of the bottom plate portion 112 of the retaining wall (frame) 101 to be constructed is a horizontal plane. It is formed in a shape. The horizontal bottom surface portion 121 is stepped down by a predetermined depth (for example, about 50 cm) in order to embed the frame bottom plate portion 112 (outward protruding plate 114) constructed thereon. Then, the cut back portion 120 is formed by excavating the inclined back surface portion 123 at an inclination angle (about 65 ° in the illustrated example) so that the soil does not collapse from the back end portion of the cut portion bottom surface portion (horizontal bottom surface portion) 121. . In other words, the cut portion 120 in this case is obtained by excavating and discharging soil in a range connecting the points a, b, c, and d in FIG.

Next, as shown in FIG. 6 (B), a retaining wall (frame) 101 is constructed in the cut portion 121. However, when building the chassis 101 by spotting ready-mixed concrete, first, the height of the bottom plate portion 112 is set. After the height H ₁ portion is constructed, the height H ₂ portion of the vertical plate portion 111 is constructed. In this case, the bottom plate portion 112 and the vertical plate portion 111 are constructed by assembling molds and filling and solidifying the ready-mixed concrete in the molds. In another example, a precast concrete case 101 made of precast concrete may be used instead of building the case 101 on site.

  Then, after the construction of the casing 101 (or after installation), as shown in FIG. 6C, the soil S is filled inside the vertical plate portion 111, and the soil Sa is also filled above the outward projecting plate 114. Then, the retaining wall for the road is completed. Even in the case of an L-shaped retaining wall (frame), it is constructed by the above-described process.

  Incidentally, as shown in FIGS. 6B and 6C, in the conventional inverted T-type (or L-type) retaining wall 101, the depth length L of the bottom plate portion 112 is considerably long, and the bottom plate portion 112 is provided. Therefore, it is necessary to excavate and discharge the volume of the cut portion 120 to be formed on the mountain surface (slope) 102 to be considerably large. For example, in the retaining wall structure of FIG. 6, it is necessary to excavate and remove the soil in the range connecting the points a, b, c, and d in FIG. There was a problem that it was expensive.

  Further, in the conventional inverted T-type retaining wall structure shown in FIG. 6C (the same applies to the L-type), earth pressure is applied laterally from the mountain side to the housing 101. This soil pressure is generated at a portion exceeding a stable gradient (which varies depending on the quality of the soil in the field, but is approximately 30 ° to 60 °). However, in the retaining wall structure shown in FIG. Pressure is generated over the entire height range H of the housing 101. Therefore, the retaining wall structure of this conventional example has a problem that the sliding action to the housing 101 due to earth pressure is increased (the stability of the retaining wall is lowered).

  Therefore, in the present invention, in the L-type or inverted T-type retaining wall structure, even if the overall height and depth length of the frame are the same, the volume of the cut portion is reduced (the amount of soil excavation and soil removal is reduced). It is an object of the present invention to provide a retaining wall construction method capable of reducing the earth pressure on the frame.

  The present invention has the following configuration as means for solving the above problems.

[Invention of Claim 1 of the Present Application]
The invention of claim 1 of the present application is a retaining wall construction method for constructing an L-shaped or inverted T-shaped retaining wall on a road side, a built-up land side surface, or a slope of a mountain surface, etc. It is intended for hitting on-site.

  As will be described later, the retaining wall (or frame) constructed in the present invention is provided with an inclined portion having substantially the same gradient as the stable gradient on the bottom surface of the bottom plate portion, so that the cross section of the bottom plate portion has a substantially triangular shape. However, including those having a bottom plate portion having a substantially triangular cross section, it is referred to as an L-shaped or inverted T-shaped retaining wall (or frame).

  In the retaining wall construction method according to claim 1, first, the ground of the retaining wall construction site is inclined to the bottom of the depth range where the bottom plate portion of the retaining wall to be constructed is located, and the inclined bottom surface having substantially the same slope as the stable slope at which the site ground does not collapse. Excavation and earth excavation in the state where the section is provided, a cut section for building the frame is formed at the retaining wall construction site.

  The above-mentioned stable gradient is a gradient at which soil does not collapse in a natural state, and is generally 30 ° to 60 °, although it depends on the quality of the site ground. The stable gradient here includes not only a linear gradient but also a case where it is inclined in a stepped or meandering manner.

  And while constructing the bottom slab part in a state in which the bottom surface of the bottom slab part of the frame is inclined with the same slope as the inclined bottom part by placing ready-mixed concrete on the inclined bottom part of the cut part, The vertical plate portion of the frame is constructed at the outer end position (in the case of an L-type retaining wall) of the bottom plate portion or at a position closer to the outer end (in the case of an inverted T-type retaining wall). In the case constructed in this manner, the lower surface of the bottom slab portion becomes an inclined portion having the same gradient as the gradient (stable gradient) of the inclined bottom surface portion of the cut portion.

  After that (after building the housing), the retaining wall is constructed by filling the inside of the housing with soil.

  In the retaining wall construction method according to claim 1, the bottom surface of the cut portion is excavated with a slope that is substantially the same as a stable gradient that does not cause the ground to collapse. Therefore, compared with the conventional case where the bottom portion of the cut portion is excavated horizontally. Therefore, the amount of excavation and soil removal in the cut area is small. In addition, in the retaining wall constructed by this retaining wall construction method, an inclined portion having the same gradient as the stable gradient is provided on the lower surface of the bottom slab portion of the frame, so that it is within the height range of the inclined portion (lower surface) of the bottom slab portion. There is no earth pressure. In other words, the earth pressure acts only on the upper part of the frame serving as the retaining wall above the height part of the inclined part of the bottom plate part.

[Invention of claim 2 of the present application]
The invention of claim 2 of the present application is a retaining wall construction method for constructing an L-shaped or inverted T-shaped retaining wall on a road side, a built-up land side surface, or a slope of a mountain surface, etc., and precast concrete as a frame to be a retaining wall It is intended for the use of products made of steel.

  In the retaining wall construction method according to claim 2, as a precast concrete frame, a bottom plate portion and a vertical plate portion integrally formed into an L shape or an inverted T shape can be used, and a bottom plate portion and a vertical plate portion can be used. What divided each into the block body made from a precast concrete may be assembled to the L-type or reverse T-type housing in the field. In addition, when the divided block body is used, in particular, the vertical plate portion may be further divided into a plurality of parts to build up the frame.

  The frame used in the retaining wall construction method of claim 2 is provided with an inclined portion having a slope substantially the same as the stable gradient at which the site ground does not collapse on the lower surface of the bottom plate portion.

  Then, excavating and discharging the ground of the retaining wall construction site in a state where an inclined bottom surface portion having substantially the same slope as the inclined portion of the bottom surface of the bottom slab portion is provided in a portion of the depth range where the bottom slab portion of the frame is located, A cut section for building the frame is formed at the retaining wall construction site.

  Next, in a state where the inclined portion of the casing (the lower surface of the bottom slab portion) is superposed on the inclined bottom surface portion of the cut portion, the casing is installed on the cut portion.

  After that (after installation of the enclosure), the retaining wall is constructed by filling the inside of the enclosure with soil.

  In the retaining wall construction method according to the second aspect, a precast concrete is used as the frame, and in this case, the function described in the retaining wall construction method according to the first aspect is exhibited. That is, since the bottom of the cut portion is excavated with a slope that is substantially the same as the stable gradient that does not cause the ground to collapse, compared to the conventional case of excavating the bottom portion of the cut portion horizontally, Less excavation and soil removal. In addition, since the lower surface of the bottom plate portion of the casing is an inclined portion having a slope substantially the same as the stable gradient, no earth pressure is applied to the height range of the inclined portion (lower surface) of the bottom plate portion.

  In the retaining wall construction method of each invention of claim 1 and claim 2 of the present invention, the bottom part of the cut part for constructing the frame is excavated and discharged with a slope substantially the same as the stable slope where the ground does not collapse. Compared to the case where the bottom surface of the cut portion is excavated horizontally as in the conventional example shown in FIG. 6, the amount of excavating and discharging soil in the cut portion is small. Therefore, in the retaining wall construction method of each invention of the present application, the construction period for forming the cut portion can be shortened, and the cost for forming the cut portion can be reduced.

  In the inventions of claims 1 and 2, since the bottom surface of the bottom plate portion of the casing is an inclined portion having a slope substantially the same as the stable gradient, the height range of the inclined portion (bottom surface) of the bottom plate portion is not included. There is no earth pressure. Therefore, in the retaining wall constructed by the retaining wall construction method of each invention of the present application, since the earth pressure applied to the housing (becomes the body sliding force and the body overturning force) can be reduced, there is also an effect that the stability of the housing is enhanced. .

  Hereinafter, the retaining wall construction method of the present embodiment will be described with reference to FIGS. 1 (A) to 1 (C) show a retaining wall construction method according to the first embodiment of the present application, and FIGS. 2 to 5 show other forms of the casing 1 serving as retaining walls, respectively (second to fifth embodiments). ).

  In the retaining wall construction method of the present application, a retaining wall is constructed by constructing a retaining wall by hitting the housing 1 on-site as in claim 1 and using a precast concrete housing 1 as in claim 2. However, in FIGS. 1A to 1C, there is shown a retaining wall construction method in the case where the housing 1 is hit in the field.

  The retaining wall construction method shown in FIG. 1 (first embodiment) shows a case in which a road is constructed on a mountain surface (slope) 2 as shown in FIG. 1 (C), but is constructed in this first embodiment. As a retaining wall (concrete frame) 1, an inverted T type is adopted. Note that the inverted T-type retaining wall (casing) 1 is a continuous bottom plate portion 12 and a vertical plate portion 11 raised upward at a position near the outer end of the bottom plate portion 12. An outward projecting plate 14 that projects outward from the outer surface of the vertical plate portion 11 is integrally formed at the outer end of the bottom plate portion 12.

Further, in the retaining wall structure of FIG. 1C, when the required width W of the road constructed on the retaining wall is 4 m, for example, the overall height H of the casing 1 is about 4 m, and the depth length of the bottom plate portion 12 is. L is constructed with a size of about 3 m or less. The depth length L of the bottom plate portion 12 is approximately 70% of the height range of earth pressure applied to the housing 1 (H−H ₆ = H ₇ height range) in relation to the supporting force of the housing 1. In the first embodiment of FIG. 1, the depth length L of the bottom plate portion 12 is set to about 70% of the overall height H of the housing 1 in the same manner as the conventional example of FIG.

  And the retaining wall structure of FIG.1 (C) is constructed | assembled through each process shown to FIG. 1 (A) and FIG. 1 (B) so that it may demonstrate below.

  In the retaining wall construction method of the first embodiment, as shown in FIG. 1 (A), first, excavation and excavation of the ground of slope 2 (mountain surface in this example) where the retaining wall is to be constructed is cut. In this case, the cut portion 20 is formed by excavating and discharging soil in a range connecting the points a, b, e, f, and d.

  In FIG. 1A, the range from the point b to the point e is the horizontal bottom surface portion 21, the range from the point e to the point f is the inclined bottom surface portion 22 having the same gradient as the stable gradient θ of the site ground, and the point f. The range from point to d is the inclined back surface portion 23 inclined to such an extent that the soil does not easily collapse.

  In FIG. 1 (A), the depth of the horizontal bottom surface portion 21 from the point b to the point e is about 50 cm from the position a, and the lower part (outside) of the housing 1 constructed as shown in FIG. 1 (C). It is for embedding the direction protruding plate 14) in the ground. The horizontal bottom surface portion 21 from the point b to the point e is for providing the horizontal portion 15 on the outward portion of the bottom surface of the housing 1 constructed as shown in FIG. 1 (B) or (C). The depth width of the horizontal bottom surface portion 21 (the length from point b to point e) is about 1 m in the illustrated example. The inclined bottom surface portion 22 from the point e to the point f is for forming the inclined portion 13 on the bottom surface of the housing 1 constructed as shown in FIG. 1 (B) or (C). It is substantially the same gradient (about 35 ° in the illustrated example) as the gradient θ (generally about 30 ° to 60 °). Further, the horizontal distance (horizontal distance from point e to point f) of the inclined bottom surface portion 22 is about 2 m in the illustrated example. The slope of the inclined back surface portion 23 from the point f to the point d is, for example, at an angle of 60 ° to 70 °, so that the soil does not easily collapse. In FIG. 1A, point c is the rear end of the horizontal bottom surface 121 of the conventional example of FIG. 6A, and the sizes of the cut portions 20 and 120 of the present application and the conventional example are compared. Is for.

  In the retaining wall construction method according to the first embodiment, the ground in the range connecting the points a, b, e, f, and d shown in FIG. Therefore, it is not necessary to excavate / remove the ground in the range connecting points e, c, and f in FIG. 1 (A) as compared with the cut portion 120 of the conventional example in FIG. 6 (A).

As a next step, as shown in FIG. 1 (B), the concrete wall is placed on the cut portion 20 formed on the mountain surface (slope) 2 to construct the retaining wall (frame) 1. In this case, The height range H ₃ of the outward projecting plate 14, the height range H ₄ from the upper surface of the outward projecting plate 14 to the upper surface of the bottom plate portion 12, and the vertical plate from the upper surface of the bottom plate portion 12 in relation to the formwork assembly. The ready-mixed concrete is placed in three steps with the height range H ₅ up to the upper surface of the part 11. The vertical plate 11 may be made of precast concrete instead of on-site. Moreover, in the example of FIG. 1 (B), although the ready-mixed concrete is laid in the state which laid the basic crushed stone on the horizontal bottom face part 21 and the inclined bottom face part 22 of the cut part 20, it does not lay the basic crushed stone. The ready-mixed concrete may be directly placed on the horizontal bottom surface portion 21 and the inclined bottom surface portion 22.

  In the case of the building construction process shown in FIG. 1B, when a precast concrete thing is used as the case 1 as in claim 2 of the present application, the case block may be lifted with a crane and installed at a predetermined position. As the precast concrete casing 1 at this time, as shown in FIG. 1 (B), a bottom plate portion 12 having a slope portion 13 having a slope substantially the same as the stable slope θ is used. In addition, as the precast-concrete-made housing 1, one that is integrally molded may be used, or a block 1 that is divided into a plurality of upper and lower parts may be stacked on site to form the housing 1.

  And after constructing the frame 1 in the cut part 20, as shown in FIG.1 (C), while filling the soil S inside the vertical plate part 11, and also filling the soil Sa also on the upper part of the outward protruding plate 14 Then, the retaining wall for the road is completed.

  In the retaining wall construction method of the first embodiment, the cut portion 20 for constructing (or installing) the frame 1 is formed on the site ground as shown by the line connecting the points e and f in FIG. Since excavation and earth removal are performed so as to form an inclined bottom surface portion 22 having a gradient substantially equal to the stable gradient θ (35 ° in the illustrated example), the cut portion bottom surface portion (b) as in the conventional example shown in FIG. Compared to the case of excavating horizontally from point (c) to point (c), it is not necessary to excavate / remove the soil in the range connecting points e, c, and f in FIG. Therefore, in the retaining wall construction method of the first embodiment, the construction period for forming the cut portion can be shortened, and the cost for forming the cut portion can be reduced.

Further, in the retaining wall constructed by the retaining wall construction method of the first embodiment, an inclined portion 13 having substantially the same gradient as the stable gradient θ is formed on the lower surface of the bottom slab portion 12 of the housing 1. Since no earth pressure is applied to the height range H ₆ of the portion 13, the earth pressure applied to the entire housing is the height H ₇ shown in FIG. 1 (C), and the earth pressure shown in the conventional example of FIG. It becomes smaller than this height range (range of the total height H of the housing). Therefore, the retaining wall constructed by the retaining wall construction method of the first embodiment can reduce the earth pressure applied to the entire body (becomes the body sliding force and the body overturning force), thereby improving the stability of the body.

  If the horizontal portion 15 is formed near the outer end of the lower surface of the frame bottom plate portion 12, the inclined portion 13 on the lower surface of the frame tries to slide obliquely outward along the inclined bottom surface portion 22 of the cut portion 20. In addition, since the horizontal portion 15 on the lower surface of the bottom plate portion abuts on the horizontal bottom surface portion 21 of the cut portion 20, sliding to the diagonally outward direction can be prevented.

  2-5, the modification (2nd-5th Example) of the housing 1 constructed in the cut part 20 is shown, respectively. In FIG. 2, a portion indicated by reference numeral 12 'indicated by a two-dot chain line indicates a bottom plate portion of the casing 1 of FIG. 1C (first embodiment).

In skeleton 1 in FIG. 2 (second embodiment), the inclined portion 13 of substantially the same slope as the stable gradient θ to the lower surface of the bottom plate portion 12 is formed, skeleton 1 in the height range H ₈ of the inclined portion 13 not applied soil pressure relative, the substantially dirt pressure is applied is the height range of H _9. The depth length of the bottom plate portion 12 may be about 70% of the height range of H ₉ where the earth pressure is substantially applied. In this second embodiment, the depth length L ₁ of the bottom plate portion 12 is set as follows. The bottom length 12 'of the first embodiment shown in FIG. 1 is shorter than the depth length L.

  2 (second embodiment), the size of the cut portion 20 in the case of the first embodiment of FIG. 1 can be made smaller by a range connecting the points g, f, d, h. Therefore, the amount of excavation and soil removal for forming the cut portion can be further reduced as compared with the first embodiment.

  In the casing 1 of FIG. 3 (third embodiment), a stepped uneven portion is formed on the inclined portion 13 of the bottom plate portion 12. In this case, the inclined bottom surface portion 22 of the cut portion 20 is also formed in a step shape, and the inclined portion 13 (step shape) of the bottom plate portion 12 is joined to the stepped inclined bottom surface portion 22. If it does in this way, the part (13 and 22) joined in each step shape has a function which prevents the sliding of the housing 1.

  In the case 1 of FIG. 4 (fourth embodiment), the inclined portion 13 of the bottom plate portion 12 is started from a position raised from the horizontal portion 15 by a predetermined height. In this case, since the inclined portion 13 of the bottom slab portion 12 is positioned higher than the raised portion, the amount of excavation and soil removal of the cut portion 20 can be further reduced.

  The housing 1 in FIG. 5 (fifth embodiment) is formed in an L shape without the outward projecting plate 14.

  2 to 5, the inclined bottom surface portion 22 of the cut portion 20 has substantially the same gradient (about 35 °) as the stable gradient θ of the field ground, and is the same as that of the first embodiment. Has the same function.

It is process drawing which shows the retaining wall construction method of 1st Example of this application. It is explanatory drawing of the retaining wall structure constructed | assembled in 2nd Example of this application. It is explanatory drawing of the retaining wall structure constructed | assembled in 3rd Example of this application. It is explanatory drawing of the retaining wall structure constructed | assembled in 4th Example of this application. It is explanatory drawing of the retaining wall structure constructed | assembled in 5th Example of this application. It is process drawing which shows the conventional retaining wall construction method.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 is a frame, 2 is a slope (mountain surface), 11 is a vertical printing part, 12 is a bottom printing part, 13 is an inclined part, 14 is an outward projection plate, 15 is a horizontal part, 20 is a cut part, 21 is a horizontal bottom part , 22 is an inclined bottom surface portion, 23 is an inclined back surface portion, and θ is a stable gradient.

Claims (2)

Retaining wall construction method for constructing L-type or inverted T-type retaining walls with vertical plate part (11) and bottom plate part (12) on slopes (2) such as road side, created land side and mountain surface There,
The ground of the retaining wall construction site is provided with an inclined bottom surface portion (22) having the same slope as the stable slope (θ) at which the site ground does not collapse at the depth range where the bottom plate portion (12) of the retaining wall to be constructed is located. Excavation and soil removal in the state of cutting, forming a cutting part (20) for building the frame at the retaining wall construction site,
By placing ready-mixed concrete on the inclined bottom surface portion (22) of the cut portion (20), the lower surface of the bottom slab portion (12) of the frame (1) has the same slope as the inclined bottom surface portion (22). (13) While constructing the bottom plate portion (12) in the state of becoming, and constructing the vertical plate portion (11) of the housing (1) at the outer end position of the bottom plate portion (12) or a position closer to the outer end, Filling the inside of the housing (1) with soil (S),
Retaining wall construction method characterized by that. Retaining wall construction method for constructing L-type or inverted T-type retaining walls with vertical plate part (11) and bottom plate part (12) on slopes (2) such as road side, created land side and mountain surface There,
Using a precast concrete frame (1) provided with an inclined portion (13) having substantially the same gradient as the stable gradient (θ) where the ground is not collapsed on the lower surface of the bottom slab portion (12),
An inclined bottom surface portion (22) having a slope substantially the same as the inclined portion (13) of the bottom surface of the bottom slab portion (12) at the depth range where the bottom slab portion (12) of the housing (1) is located ) Is excavated and excavated to form a cut-out portion (20) for installing the frame at the retaining wall construction site,
The casing (1) was constructed in the cut section (20) in a state where the inclined section (13) of the casing (1) was polymerized on the inclined bottom section (22) of the cut section (20). Then, the soil (S) is filled inside the housing (1).
Retaining wall construction method characterized by that.

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