WO2010052806A1 - Retaining wall block and retaining wall - Google Patents

Retaining wall block and retaining wall Download PDF

Info

Publication number
WO2010052806A1
WO2010052806A1 PCT/JP2009/001653 JP2009001653W WO2010052806A1 WO 2010052806 A1 WO2010052806 A1 WO 2010052806A1 JP 2009001653 W JP2009001653 W JP 2009001653W WO 2010052806 A1 WO2010052806 A1 WO 2010052806A1
Authority
WO
WIPO (PCT)
Prior art keywords
retaining wall
surface portion
back surface
wall blocks
height
Prior art date
Application number
PCT/JP2009/001653
Other languages
French (fr)
Inventor
Motoyasu Itoi
Original Assignee
Hakogata Yoheki Kenkyusyo Corp.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hakogata Yoheki Kenkyusyo Corp. filed Critical Hakogata Yoheki Kenkyusyo Corp.
Priority to RU2011114475/03A priority Critical patent/RU2011114475A/en
Priority to CN2009801439047A priority patent/CN102203349B/en
Publication of WO2010052806A1 publication Critical patent/WO2010052806A1/en

Links

Images

Classifications

    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D29/00—Independent underground or underwater structures; Retaining walls
    • E02D29/02—Retaining or protecting walls
    • E02D29/025—Retaining or protecting walls made up of similar modular elements stacked without mortar
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D29/00—Independent underground or underwater structures; Retaining walls
    • E02D29/02—Retaining or protecting walls
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02B—HYDRAULIC ENGINEERING
    • E02B3/00—Engineering works in connection with control or use of streams, rivers, coasts, or other marine sites; Sealings or joints for engineering works in general
    • E02B3/04—Structures or apparatus for, or methods of, protecting banks, coasts, or harbours
    • E02B3/12—Revetment of banks, dams, watercourses, or the like, e.g. the sea-floor
    • E02B3/14—Preformed blocks or slabs for forming essentially continuous surfaces; Arrangements thereof
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D17/00—Excavations; Bordering of excavations; Making embankments
    • E02D17/20—Securing of slopes or inclines

Definitions

  • the present invention relates to precast concrete retaining wall blocks which are arranged in a lateral direction along a slope such as a flattening and an embankment, and which are stacked in a height direction in a plurality of tiers, filling materials such as crushed stones and cobblestones are charged in the retaining wall blocks, thereby constructing a retaining wall for preventing the slope from falling, and the invention also relates to the retaining wall constructed of the retaining wall blocks.
  • retaining walls in which reinforcements are incorporated in the retaining wall in the construction field and concrete is poured, and the retaining wall is integrally formed along the slope
  • retaining wall blocks having standard predetermined shape are stacked and constructed along the slope.
  • the retaining wall of the latter type is made of so-called precast concrete in which the retaining wall blocks are previously produced in a factory, the retaining wall can inexpensively and easily be constructed.
  • Patent Document 1 JP 3823075
  • each retaining wall block 50 described in the patent document 1 is formed into a box-like shape as a whole whose top and bottom are opened. That is, each retaining wall block 50 is integrally provided with a surface portion 51, a stay portion 52 which is separated away from the surface portion 51 and which is in parallel to the surface portion 51, and a pair of connecting portions 54 and 55 which connect the surface portion 51 and the stay portion 52 with each other.
  • the surface portion 51 has substantially a rectangular shape.
  • the stay portion 52 also has substantially a rectangular shape lower than the surface portion 51 in height.
  • the pair of connecting portions 54 and 55 are partially notched, and have substantially rectangular shapes.
  • a space 56 whose upper and lower surfaces are opened is formed by the surface portion 51, the connecting portions 54 and 55 and the stay portion 52. Filling materials such as crushed stones and cobblestones are charged into the space 56.
  • the pair of connecting portions 54 and 55 connect the surface portion 51 and the stay portion 52 at locations deviated inward from left and right edges of the surface portion 51 and the stay portion 52 by predetermined length. Therefore, the surface portion 51 and the stay portion 52 are formed with so-called ears 57 and 58 projecting outward from the connection between the pair of connecting portions 54 and 55. As shown in Fig.
  • a box-like space 59 whose upper and lower surfaces are opened is formed between adjacent retaining wall blocks 50 by the ears 57 and 58, and filling material can be charged into the space 59.
  • the height of the stay portion 52 is about 1/2 of the height of the surface portion 51, and the pair of connecting portions 54 and 55 also have the same height as that of the stay portion 52 except the connection portion with respect to the surface portion 51.
  • a retaining wall 60 provided on a slope such as flattening and embankment is constructed as follows using the retaining wall blocks 50. As shown in Fig. 6, the ground 62 at a rising portion of a slope 61 is excavated with a predetermined width and to predetermined depth to form a groove 63.
  • Crushed stones or cobblestones are charged in the groove 63 by a predetermined thickness, thereby forming base surfaces 64.
  • Retaining wall blocks 50 are arranged on the base surfaces 64 laterally, i.e., in a direction perpendicular to a sheet plane of Fig. 6 such that the retaining wall blocks 50 come into contact with the slope 61.
  • Filling material 66 such as crushed stones and cobblestones is charged into the spaces 56 and 59 of the retaining wall blocks 50.
  • filling material 66 is charged into a space between the slope 61 and the stay portions 52.
  • the filling material 66 is charged up to the height of the upper end of the surface portion 51. With this, horizontal surface 67 is formed.
  • the first step of the retaining wall 60 is constructed in this manner.
  • Retaining wall blocks 50 for constituting a second step are arranged in the lateral direction on the first step horizontal surface 67 such that the retaining wall blocks 50 comes into contact with the slope 61. That is, the second step retaining wall blocks 50 are arranged such that they are deviated toward the slope 61 than the first step.
  • filling material 66 is charged into the second step retaining wall blocks 50, a second step horizontal surface 67 having the same height as that of an upper end of the surface portion 51 is formed, and the second step is constructed.
  • the retaining wall 60 including a plurality of steps is constructed.
  • the retaining wall 60 including the retaining wall blocks 50 described in the patent document 1 is also relatively stable, and it is possible to prevent the slope 61 such as flattening and embankment from falling to some extent.
  • the wall is susceptible to improvement.
  • Fig. 7 schematically shows, in an enlarged scale, a portion of the retaining wall 60 provided on the slope 61, a predetermined step retaining wall block 50, and upper step retaining wall block 50. Points relating to the stability will be explained with reference to Fig. 7.
  • filling material 66 at a location sandwiched between the stay portion 52 and the surface portion 51 of a lower step retaining wall block 50 is completely restrained from flowing in the horizontal direction.
  • a filling material 66 at a location sandwiched between the surface portion 51 and an extension surface 69 shown with a dashed line in Fig. 7, i.e., the extension surface 69 of the stay portion 52 in the vertical direction does not easily flow in the horizontal direction due to the friction force with lower filling material 66. Therefore, it is conceived that a friction force with respect to slip of the upper step in the horizontal direction with respect to the lower step of the retaining wall 60 is generated in a friction surface 71 shown with a thick line mainly in Fig. 7. Then, since resistance to slip is determined by the width of the friction surface 71 in the horizontal direction, it is preferable that the width of the friction surface 71 in the horizontal direction is wider.
  • the slope portion 61 shown with a dotted line in Fig. 7 collapses.
  • filling material 66 flows such as to fill the collapsed portion.
  • a portion of the filling material 66 that flows is located rearward of a surface including the stay portion 52 and the extension surface 69 perpendicular to the stay portion 52, i.e., a backfill portion 73. Therefore, if the capacity of the backfill portion 73 is great, the amount of filling material 66 which flows and becomes lost is increased, and the retaining wall block 50 inclines rearward. It is preferable that the capacity of the backfill portion 73 is small with respect to collapse of the slope.
  • the retaining wall block 50 receives the weight of an upper step retaining wall 60 and the weight of a filling material 66 charged inside.
  • the weight is applied to the entire projection plane 74 in the vertical direction of the retaining wall block 50.
  • the projection plane 74 is shown with a thick line in Fig. 7. If the area of the projection plane 74 is great, the retaining wall block 50 efficiently receives the weight and thus, it is possible to restrain the retaining wall block 50 from deviating in the horizontal direction with against the soil pressure in the horizontal direction received from the slope 61. That is, if the area of the projection plane 74 is great, the anchor effect becomes high.
  • the weight of the surface portion 51 is about twice as heavy as the stay portion 52, the weights of the pair of connecting portions 54 and 55 are great near the surface portion 51 but their weights near the stay portion 52 are small.
  • front portion of loads applied to the ground by the surface portion 51 of the retaining wall block 50, the pair of connecting portions 54 and 55 and the bottom of the stay portion 52 are greater than rear portion of the loads as shown in the graph 75 which shows load distribution. That is, it can not be said that the balance of the retaining wall block 50 is the best.
  • the retaining wall block 50 placed on the ground caves into the ground and may incline forward.
  • the filling material 66 is no so-called isotropic material having the same dynamic properties in all directions, but for convenience sake, the filling material 66 is handled as material having properties of the isotropic material. Then, since a principal stress in the vertical direction by the weight of the upper step retaining wall 60 and a principal stress in the horizontal direction by earth pressure of the slope 61 are applied to the filling material 66 charged into the retaining wall block 50, the maximum shearing stress is applied to a surface which is inclined with respect to a main axis of the principal stresses through angle of 45 degrees.
  • the maximum shearing force applied to the filling material 66 charged into the retaining wall block 50 is applied to a plane 76 shown with a dotted line in Fig. 7. That is, there is a danger that slip is generated on the plane 76 and the retaining wall 60 falls. In reality, since the plane 76 is blocked at the lowest surface portion 51 of the upper step retaining wall block 50, slip is not generated relatively easily. If the plane 76 is blocked near the central portion of the surface portion 51 of the upper step retaining wall block 50, slip on the plane 76 is reliably suppressed.
  • the pair of the connecting portions 54 and 55 of the retaining wall block 50 become long, the amount of filling material 66 charged therein is increased, the material cost is increased, and the construction cost is increased. Further, the retaining wall block 50 is increased in size, and cost required for transportation is also increased. Further, there is a problem that since the pair of connecting portions 54 and 55 become long, the thickness of the retaining wall 60 is increased correspondingly, and the retaining wall 60 largely project forward from the slope 61.
  • a retaining wall block integrally includes a surface portion which is exposed on a front side when a retaining wall is constructed, a back surface portion which is hidden on a back side and a pair of connecting portions which connect the surface portion and the back surface portion with each other.
  • the back surface portion is lower than the surface portion, and the back surface portion is inclined rearward through a predetermined angle such that a distance between the surface portion and an upper portion of the back surface portion is greater than a distance between the surface portion and a lower portion of the back surface portion.
  • the surface portion and the back surface portion are connected to each other through the pair of connecting portions at locations deviated inward from left and right edges by a predetermined length.
  • a height of the pair of connecting portions on the side of the surface portion is substantially the same as that of the surface portion, and a height of the connecting portions on the side of the back surface portion is substantially the same as that of the back surface portion.
  • an invention described in claim 1 provides retaining wall blocks made of precast concrete which are butted against each other in a lateral direction along a slop such as flattening and embankment and stacked in predetermined number of steps in a height direction, in which filling materials such as crushed stones and cobblestones are charged inside the retaining wall blocks, a retaining wall which prevents the slop from falling is constructed, wherein each of the retaining wall blocks comprises a substantially rectangular surface portion which is exposed on a front side when the retaining wall is constructed, a substantially rectangular back surface portion which is hidden on a back side when the retaining wall is constructed, and a pair of connecting portions which are disposed at a predetermined distance therebetween and which connects the surface portion and the back surface portion with each other at a predetermined distance therebetween, the surface portion, the back surface portion and the pair of connecting portions are integrally formed into a substantially box-like shape whose top and bottom are opened, a space portion into which the filling materials are
  • the surface portion and the back surface portion are connected to each other through the pair of connecting portions at locations deviated inward from left and right edges by predetermined length, a height of each of the pair of connecting portions on the side of the surface portion is substantially the same as a height of the surface portion, and a height of each of the pair of connecting portions on the side of the back surface portion is substantially the same as a height of the back surface portion.
  • a height of each of the pair of connecting portions on the side of the surface portion is substantially the same as a height of the surface portion, and the pair of connecting portions become lower in a stepwise manner, and a height of each of the pair of connecting portions on the side of the back surface portion is substantially the same as a height of the back surface portion.
  • At least one of butted portions of the surface portions of the adjacent retaining wall blocks which are butted against each other when the retaining wall is constructed is formed with a notch, and a slit through which rainwater or springwater is discharged is formed when the retaining wall block are butted against each other.
  • a lateral width of the back surface portion is narrower than that of the surface portion and with this, a projecting plane play is formed between butted portions of the back surface portions of the adjacent retaining wall blocks when the retaining wall is constructed.
  • a surface of the surface portion is formed with a design such as a graphic or a pattern.
  • An invention described in claim 7 provides a retaining wall constructed of the retaining wall blocks according to any one of claims 1 to 6, wherein the retaining wall blocks are butted against each other in a lateral direction adjacent to a slope such as flattening and embankment, filling materials such as crushed stones and cobblestones are charged inside the retaining wall blocks, and one step retaining wall is constructed.
  • the first step retaining wall comprises a plurality of retaining wall blocks which are butted against each other in the lateral direction in adjacent to the slope such as flattening and embankment, in which filling materials such as crushed stones and cobblestones are charged inside the retaining wall blocks to a height of the retaining wall blocks
  • the second step retaining wall comprises a plurality of retaining wall blocks which are butted against each other in the lateral direction such as to deviate toward the slope along the slope on the first step retaining wall, and filling materials such as crushed stones and cobblestones are charged inside the retaining wall blocks to a height of the retaining wall blocks
  • the third step retaining wall comprises a plurality of retaining wall blocks which are butted against each other in the lateral direction such as to
  • the retaining wall block includes a surface portion, a back surface portion and a pair of connecting portions.
  • the back surface portion is lower than the surface portion.
  • a height of the pair of connecting portions on the side of the surface portion is substantially the same as a height of the surface portion, and a height of the connecting portions on the side of the back surface portion is substantially the same as a height of the back surface portion. Therefore, when the retaining wall is constructed of the retaining wall blocks, the retaining wall blocks can be stacked such that lower step retaining wall blocks and upper step retaining wall blocks are not in contact with each other. With this, deformation generated in a certain step retaining wall blocks stacked in a plurality of steps is not transmitted to the entire retaining wall.
  • the retaining wall constructed of the retaining wall blocks of the invention is stable. Further, since the back surface portion is inclined through a predetermined angle, the retaining wall constructed of the retaining wall blocks of the invention is more stable than a retaining wall constructed of conventional retaining wall blocks. Further, the amount of filling materials charged inside the retaining wall blocks is substantially the same as the amount of filling materials charged inside the conventional retaining wall blocks.
  • the retaining wall may be constructed of one step retaining wall blocks or of many step retaining wall blocks. Therefore, a retaining wall having optimal number of steps can be constructed in accordance with a height of a slope such as flattening and embankment.
  • FIG. 1 is a partially sectional perspective view showing a retaining wall according to an embodiment including retaining wall blocks of the embodiment.
  • FIG. 2 is a perspective view of adjacent two retaining wall blocks of the embodiment.
  • FIG. 3 is a side sectional view of the retaining wall of the embodiment.
  • FIG. 4 is a side sectional view of the retaining wall schematically showing effect of the retaining wall of the embodiment.
  • FIG. 5 is a perspective view showing conventional retaining wall blocks
  • FIG. 6 is a side sectional view of a retaining wall including conventional retaining wall blocks.
  • Fig. 7 is a side sectional view of the retaining wall schematically showing effect of the conventional retaining wall. Description of Embodiments
  • Each retaining wall block 1 has a substantially box-like shape whose top and bottom are opened. The shape thereof will be explained in detail later.
  • the retaining wall block 1 belongs to a so-called box-like retaining wall block, or bottle-like retaining wall block.
  • Filling materials 30 such as crushed stones and cobblestones are charged into or inside the retaining wall block 1. As shown in Fig.
  • retaining wall blocks 1 are arranged along a slope 21 such as flattening and embankment such that the retaining wall blocks 1 butt against each other in the lateral direction, the filling materials 30 are charged inside the retaining wall blocks 1, another retaining wall blocks 1 are stacked thereon, filling materials 30 are charged inside of the retaining wall blocks 1, and the retaining wall 20 is constructed in the same manner.
  • Predetermined patterns M are formed on a surface from which the retaining wall blocks 1 are exposed, i.e., a front surface. Therefore, the retaining wall 20 of the embodiment has beautiful appearance.
  • each retaining wall block 1 of the embodiment is made of precast concrete.
  • each retaining wall block 1 includes a substantially rectangular plate-like surface portion 2 having a predetermined thickness, a rectangular plate-like back surface portion 3 having a predetermined thickness, and a pair of connecting portions 5 and 6 connecting the surface portion 2 and the back surface portion 3 with each other and having a predetermined thickness.
  • These members are integrally molded into a substantially box-like shape such that the top and bottom thereof are opened. With this, the surface portion 2, the back surface portion 3 and the pair of connecting portions 5 and 6 forms, therein, a box-like space 7 whose upper and lower portions are opened.
  • the filling materials such as crushed stones and cobblestones are charged into the box- like space 7 when the retaining wall is constructed.
  • the surface portion 2 and the back surface portion 3 are integrally connected to each other by the pair of connecting portions 5 and 6 at their left and right end edges or at locations deviated inward from the butted portions by predetermined length. Therefore, portions projecting outward from connected portions of the pair of connecting portions 5 and 6, i.e., ear portions 9 and 10 are formed on the surface portion 2 and the back surface portion 3.
  • a box-like space 11 whose upper and lower portions are opened is formed between the adjacent two retaining wall blocks 1 by the ear portions 9 and 10.
  • the filling materials are charged into the box-like space 11 also.
  • Predetermined shallow notches 12 are formed in left and right butted portions of the surface portion 2.
  • Slits 13 are formed in the butted portions of the adjacent retaining wall blocks 1 by the notches 12 when the retaining wall is constructed. Rain stored in the retaining wall 20 or springwater is discharged out from the slits 13.
  • the height of the back surface portion 3 is about 1/2 of that of the surface portion 2. Therefore, when the retaining wall is constructed, the space formed by the slope 21 and the surface portion 2 of the retaining wall block 1 is not completely divided by the back surface portion 3. That is, only the height of the back surface portion 3 is divided, and an upper space of the back surface portion 3 is continuous. In other words, the filling materials charged in front of the back surface portion 3 and the filling materials charged on the side of the slope 21 located rearward are continuous above the back surface portion 3. With this, a strong retaining wall can be constructed.
  • the lateral width of the back surface portion 3 is slightly narrower than that of the surface portion 2.
  • a predetermined play 13 is formed between the back surface portions 3 of the two butted retaining wall blocks 1 when the retaining wall is constructed. With this play 13, even if the slope is curved, the retaining wall blocks 1 can be arranged in the lateral direction without generating a gap between the end edges of the surface portions 2.
  • a distance between the surface portion 2 and an upper end 15 of the back surface portion 3 is greater than a distance between the surface portion 2 and the lower end 16. That is, since the back surface portion 3 is rearwardly inclined. Since the back surface portion 3 is rearwardly inclined, the retaining wall including the retaining wall blocks 1 of the embodiment has higher stability as compared with the conventional retaining wall block as will be explained later.
  • lower ends of the pair of connecting portions 5 and 6 have substantially the same height as lower ends of the surface portion 2 and the back surface portion 3.
  • the upper ends includes a slanting surface which is inclined from the surface portion 2 by a predetermined amount, a first horizontal surface extending horizontally from a terminal end of the slanting surface, and a second horizontal surface which is lowered in a stepwise manner from the terminal end of the first horizontal surface and extends horizontally.
  • the second horizontal surface has the same height as that of the back surface portion 3.
  • the retaining wall block 1 is high only at the surface portion 2 and a front portion 17 near the surface portion 2, and a central portion and a rear portion of the retaining wall block 1 are low.
  • the retaining wall blocks 1 can be stacked on one another such that upper step retaining wall blocks 1 and lower step retaining wall blocks 1 do not come into contact with each other.
  • a construction method of the retaining wall 20 according to the embodiment constructed on the slope 21 such as the flattening and embankment will be explained.
  • the ground 22 at a rising portion of the slope 21 is excavated to a predetermined depth, and a groove 23 extending along the slope 21 is formed.
  • a mesh made of high density polyethylene resin, i.e., geotextile 24 laid on the groove 23, and crushed stones, cobblestones or the like is laid thereon to a predetermined thickness. The crushed stones or cobblestones are enclosed by the geotextile 24 to form a base surface 25.
  • the retaining wall blocks 1 are arranged on the base surface 25 in the lateral direction, i.e., in a direction perpendicular to the sheet surface of Fig. 3 and are butted against each other such that the back surface portions 3 of the retaining wall blocks 1 are in contact with the slope 21.
  • Filling materials 30 such as crushed stones and cobblestones are charged into the spaces 7 and 11 in the retaining wall blocks 1 up to the upper end height of the surface portion 2.
  • filling materials 30 are charged also into spaces between the slope 21 and the back surface portions 3. With this, a first step horizontal surface 31 is formed.
  • crushed stones or cobblestones are laid also on a portion of the groove 23 in front of the surface portion 2 which is not filled with the crushed stones or cobblestones by the geotextile 24 to the same level as the surface of the ground 22. With this, construction of the first step retaining wall 20 is completed.
  • Retaining wall blocks 1 for constructing second step are placed on the first step horizontal surface 31 and arranged in the lateral direction. At that time, the retaining wall blocks 1 are deviated rearward from the first step retaining wall blocks 1 along the inclination of the slope 21. The same filling materials 30 as those of the first step are charged into the second step retaining wall blocks 2, and a horizontal surface 31 having the same height as that of the upper end of the surface portion 2 is formed. With this, the construction of the second step of the retaining wall 20 is completed. The retaining wall 20 having the plurality of steps is constructed in the same manner.
  • the filling materials 30 charged into the retaining wall block 1 mesh with each other, a strong friction force is generated. Further, a strong friction force is generated also between the filling materials 30 and the slope 21. Therefore, the retaining wall 20 is strongly maintained by the friction force, and this prevents the slope 21 from falling.
  • the upper step retaining wall blocks 1 are deviated rearward from the lower step retaining wall blocks 1, only the front portion of the retaining wall block 1 is high and the central portion and the rear portion of the retaining wall block 1 are low. Therefore, the upper step and lower step retaining wall blocks 1 do not come into direct contact with each other. Thus, a rotation moment generated in arbitrary step retaining wall blocks 1 is not transmitted to its upper or lower step retaining wall blocks 1.
  • step retaining wall blocks 1 are rotated or inclined by deformation of the ground or the like, its upper or lower step retaining wall blocks 1 are not inclined and stability there of can be maintained.
  • Deformation generated in the retaining wall 20 is limited to a specific step, and this is not exerted on the entire blocks.
  • FIG. 4 schematically shows a specific step retaining wall blocks 1 which are portions of the retaining wall 20 constructed on the slope 21, and its upper step retaining wall blocks 1 placed on the specific step retaining wall blocks 1. The reason why the stability of the retaining wall 20 is enhanced because the back surface portion 3 is inclined rearward will be explained with reference to Fig. 4.
  • a friction force of a lower step of the retaining wall 20 with respect to slip of the upper step in the horizontal direction is applied on a friction surface 33 shown with a thick line in Fig. 4.
  • the friction surface 33 is a portion of the horizontal surface 31 located forward from an intersection between the horizontal surface 31 and an extension of an edge of the back surface portion 3 of the lower step retaining wall block 1 in a perpendicular direction.
  • An extension surface 32 of the edge of the back surface portion 3 is shown with a dashed line.
  • a friction force with respect to slip in the horizontal direction is determined by a width of the friction surface 33 in the horizontal direction. In this embodiment, since the back surface portion 3 is inclined rearward, the width of the friction surface 33 in the horizontal direction is wide correspondingly. With this, slip of the upper step in the horizontal direction with respect to the lower step of the retaining wall 20 is sufficiently suppressed.
  • the weight that the retaining wall block 1 receives from the filling materials 30 charged into upper step and inside of the retaining wall 20 is applied to the entire projecting plane of the retaining wall block 1 in the vertical direction.
  • the projecting plane is shown with a plane 38 shown with a thick line in Fig. 4.
  • the area of the plane 38 is large and the retaining wall block 1 can efficiently receive the weight.
  • the retaining wall block 1 receives horizontal earth pressure from the slope 21, the retaining wall block 1 is not deviated in the horizontal direction.
  • a graph 39 shows a load that the surface portion 2 of the retaining wall block 1, the pair of connecting portions 5 and 6 and the bottom of the back surface portion 3 apply to the ground.
  • the load that the retaining wall block 1 of the embodiment applies to the ground is distributed relatively uniformly.
  • the retaining wall block 1 has excellent balance, and even if the ground is soft, the retaining wall block 1 does not incline.
  • the maximum shearing force applied to the filling materials 30 charged into the retaining wall block 1 is applied to a plane 41 which inclines with respect to the horizontal plane through angle of 45 degrees shown with dotted line in Fig. 4.
  • the plane 41 is deviated rearward.
  • the plane 41 is blocked by an interior of the surface portion 2 of the upper step retaining wall block 1, i.e., by the central portion thereof. Even if a shearing force greater than a level that the filling material 30 can permit is generated, slip is not generated on the plane 41.
  • the retaining wall 20 of the embodiment since the plane 41 on which the maximum shearing stress is generated and slip is easily generated is reliably blocked by the retaining wall block 1, stability is high.
  • the size of the retaining wall block 1 of the embodiment is not limited, but the following size can be employed.
  • the surface portion 2 has width of 200cm x height of 100 cm x thickness of 12 cm
  • the back surface portion 3 has width of 186cm x heigh of 50cm x thickness of 12cm.
  • Each of the pair of connecting portions 5 and 6 has bottom width of 125cm x upper portion width of 150cm x thickness 12cm.
  • the retaining wall block 1 has lateral size of 200cm x depth of 150cm x height of 100cm.
  • the inclination angle of the rearwardly inclined back surface portion 3 is not limited, preferable angle is 55 to 70 degrees, and more preferably 60 to 65 degrees.
  • filling materials charged into the retaining wall block 1 are coarse-grained slugs, earth materials such as regenerative aggregates which are crushed concrete.
  • the retaining wall block of the embodiment can be utilized as a block constructing a retaining wall including only one step, and can also be utilized as a revetment block of river and coast.

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
  • Mining & Mineral Resources (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Paleontology (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Environmental & Geological Engineering (AREA)
  • Retaining Walls (AREA)
  • Revetment (AREA)
  • Ocean & Marine Engineering (AREA)
  • Mechanical Engineering (AREA)

Abstract

Each of retaining wall blocks (1) includes a surface portion (2) which is exposed on a front side when a retaining wall is constructed, a back surface portion (3) which is hidden on a back side, and a pair of connecting portions (5,6) which connect the surface portion (2) and the back surface portion (3) with each other at a predetermined distance therebetween, the surface portion (2), the back surface portion (3) and the connecting portions (5,6) are integrally formed into a substantially box-like shape whose top and bottom are opened. The back surface portion (3) is inclined with respect to the surface portion (2) through a predetermined angle such that the back surface portion (3) is lower than the surface portion (2) and a distance between the surface portion (2) and an upper end (15) of the back surface portion (3) is greater than a distance between the surface portion (2) and a lower end (16) of the back surface portion (3).

Description

RETAINING WALL BLOCK AND RETAINING WALL
The present invention relates to precast concrete retaining wall blocks which are arranged in a lateral direction along a slope such as a flattening and an embankment, and which are stacked in a height direction in a plurality of tiers, filling materials such as crushed stones and cobblestones are charged in the retaining wall blocks, thereby constructing a retaining wall for preventing the slope from falling, and the invention also relates to the retaining wall constructed of the retaining wall blocks.
In civil engineering work such as construction of building, road, railroad, construction such as so-called flattening for excavating the ground higher than its periphery, and so-called embankment for increasing the height of the ground by heaping up earth and sand is carried out. In the case of a high-pitched slanting surface formed by the flattening and embankment, earth and sand are destroyed by rainfall or earthquake and the high-pitched slanting surface falls easily. Thus, the slanting surface, i.e., the slope is provided with a retaining wall which is wall-like civil engineering construction to prevent it from falling. A surface of the retaining wall is provided with a predetermined pattern to maintain excellent outward appearance. There is a type of retaining walls in which reinforcements are incorporated in the retaining wall in the construction field and concrete is poured, and the retaining wall is integrally formed along the slope, and there is another type of retaining walls in which retaining wall blocks having standard predetermined shape are stacked and constructed along the slope. The retaining wall of the latter type is made of so-called precast concrete in which the retaining wall blocks are previously produced in a factory, the retaining wall can inexpensively and easily be constructed.
PLT 1
Patent Document 1: JP 3823075
The patent document 1 describes retaining wall blocks made of precast concrete. As shown in Fig. 5, each retaining wall block 50 described in the patent document 1 is formed into a box-like shape as a whole whose top and bottom are opened. That is, each retaining wall block 50 is integrally provided with a surface portion 51, a stay portion 52 which is separated away from the surface portion 51 and which is in parallel to the surface portion 51, and a pair of connecting portions 54 and 55 which connect the surface portion 51 and the stay portion 52 with each other. The surface portion 51 has substantially a rectangular shape. The stay portion 52 also has substantially a rectangular shape lower than the surface portion 51 in height. The pair of connecting portions 54 and 55 are partially notched, and have substantially rectangular shapes. Since the retaining wall block 50 has the above-described structure, a space 56 whose upper and lower surfaces are opened is formed by the surface portion 51, the connecting portions 54 and 55 and the stay portion 52. Filling materials such as crushed stones and cobblestones are charged into the space 56. The pair of connecting portions 54 and 55 connect the surface portion 51 and the stay portion 52 at locations deviated inward from left and right edges of the surface portion 51 and the stay portion 52 by predetermined length. Therefore, the surface portion 51 and the stay portion 52 are formed with so-called ears 57 and 58 projecting outward from the connection between the pair of connecting portions 54 and 55. As shown in Fig. 5, a box-like space 59 whose upper and lower surfaces are opened is formed between adjacent retaining wall blocks 50 by the ears 57 and 58, and filling material can be charged into the space 59. In the retaining wall block 50 described in patent document 1, the height of the stay portion 52 is about 1/2 of the height of the surface portion 51, and the pair of connecting portions 54 and 55 also have the same height as that of the stay portion 52 except the connection portion with respect to the surface portion 51.
A retaining wall 60 provided on a slope such as flattening and embankment is constructed as follows using the retaining wall blocks 50. As shown in Fig. 6, the ground 62 at a rising portion of a slope 61 is excavated with a predetermined width and to predetermined depth to form a groove 63. Crushed stones or cobblestones are charged in the groove 63 by a predetermined thickness, thereby forming base surfaces 64. Retaining wall blocks 50 are arranged on the base surfaces 64 laterally, i.e., in a direction perpendicular to a sheet plane of Fig. 6 such that the retaining wall blocks 50 come into contact with the slope 61. Filling material 66 such as crushed stones and cobblestones is charged into the spaces 56 and 59 of the retaining wall blocks 50. Similarly, filling material 66 is charged into a space between the slope 61 and the stay portions 52. The filling material 66 is charged up to the height of the upper end of the surface portion 51. With this, horizontal surface 67 is formed. The first step of the retaining wall 60 is constructed in this manner. Retaining wall blocks 50 for constituting a second step are arranged in the lateral direction on the first step horizontal surface 67 such that the retaining wall blocks 50 comes into contact with the slope 61. That is, the second step retaining wall blocks 50 are arranged such that they are deviated toward the slope 61 than the first step. Like the first step, filling material 66 is charged into the second step retaining wall blocks 50, a second step horizontal surface 67 having the same height as that of an upper end of the surface portion 51 is formed, and the second step is constructed. Similarly, the retaining wall 60 including a plurality of steps is constructed.
As described above, since the filling materials 66 held in the retaining wall block 50 mesh each other, a strong friction force is generated. A strong friction force is generated also between the filling material 66 and the slope 61. Therefore, the shape of the retaining wall 60 is maintained by the friction force, and this prevents the slope 61 from falling. Upper step retaining wall blocks 50 are deviated rearward with respect to lower step retaining wall blocks 50 along the slope 61, only the surface portion 51 of the retaining wall block 50 is high, and the connecting portions 54 and 55 and the stay portion 52 are low. Therefore, lower step and upper step retaining wall blocks 50 do not come into contact directly. Thus, rotation moment generated in retaining wall blocks 50 of arbitrary step is not transmitted to upper and lower step retaining wall blocks 50. Therefore, even if retaining wall blocks 50 of arbitrary step are rotated and inclined by deformation of the ground or the like, adjacent upper and lower step retaining wall blocks 50 are not inclined and stability can be maintained. According to the retaining wall 60 including the retaining wall blocks 50 described in the patent document 1, even if the ground is deformed by ground subsidence, outflow of earth and sand or earthquake, the deformation of the retaining wall 60 is limited in a certain step, and the deformation is not transmitted to the entire wall. Therefore, the retaining wall 60 has a feature that the wall is relatively stable and does not fall easily.
The retaining wall 60 including the retaining wall blocks 50 described in the patent document 1 is also relatively stable, and it is possible to prevent the slope 61 such as flattening and embankment from falling to some extent. However, in order to enhance the stability, the wall is susceptible to improvement. Fig. 7 schematically shows, in an enlarged scale, a portion of the retaining wall 60 provided on the slope 61, a predetermined step retaining wall block 50, and upper step retaining wall block 50. Points relating to the stability will be explained with reference to Fig. 7.
(Point 1) Friction force for suppressing slip in horizontal direction
In Fig. 7, filling material 66 at a location sandwiched between the stay portion 52 and the surface portion 51 of a lower step retaining wall block 50 is completely restrained from flowing in the horizontal direction. A filling material 66 at a location sandwiched between the surface portion 51 and an extension surface 69 shown with a dashed line in Fig. 7, i.e., the extension surface 69 of the stay portion 52 in the vertical direction does not easily flow in the horizontal direction due to the friction force with lower filling material 66. Therefore, it is conceived that a friction force with respect to slip of the upper step in the horizontal direction with respect to the lower step of the retaining wall 60 is generated in a friction surface 71 shown with a thick line mainly in Fig. 7. Then, since resistance to slip is determined by the width of the friction surface 71 in the horizontal direction, it is preferable that the width of the friction surface 71 in the horizontal direction is wider.
(Point 2) Influence exerted on collapse of slope
If earth and sand flow out from the ground forming the slope 61, the slope portion 61 shown with a dotted line in Fig. 7 collapses. With this, filling material 66 flows such as to fill the collapsed portion. A portion of the filling material 66 that flows is located rearward of a surface including the stay portion 52 and the extension surface 69 perpendicular to the stay portion 52, i.e., a backfill portion 73. Therefore, if the capacity of the backfill portion 73 is great, the amount of filling material 66 which flows and becomes lost is increased, and the retaining wall block 50 inclines rearward. It is preferable that the capacity of the backfill portion 73 is small with respect to collapse of the slope.
(Point 3) Anchor effect
The retaining wall block 50 receives the weight of an upper step retaining wall 60 and the weight of a filling material 66 charged inside. The weight is applied to the entire projection plane 74 in the vertical direction of the retaining wall block 50. The projection plane 74 is shown with a thick line in Fig. 7. If the area of the projection plane 74 is great, the retaining wall block 50 efficiently receives the weight and thus, it is possible to restrain the retaining wall block 50 from deviating in the horizontal direction with against the soil pressure in the horizontal direction received from the slope 61. That is, if the area of the projection plane 74 is great, the anchor effect becomes high.
(Point 4) Balance of retaining wall block
In the retaining wall block 50, the weight of the surface portion 51 is about twice as heavy as the stay portion 52, the weights of the pair of connecting portions 54 and 55 are great near the surface portion 51 but their weights near the stay portion 52 are small. Thus, front portion of loads applied to the ground by the surface portion 51 of the retaining wall block 50, the pair of connecting portions 54 and 55 and the bottom of the stay portion 52 are greater than rear portion of the loads as shown in the graph 75 which shows load distribution. That is, it can not be said that the balance of the retaining wall block 50 is the best. When the ground is soft, the retaining wall block 50 placed on the ground caves into the ground and may incline forward.
(Point 5) Surface to which maximum shearing stress is applied
The filling material 66 is no so-called isotropic material having the same dynamic properties in all directions, but for convenience sake, the filling material 66 is handled as material having properties of the isotropic material. Then, since a principal stress in the vertical direction by the weight of the upper step retaining wall 60 and a principal stress in the horizontal direction by earth pressure of the slope 61 are applied to the filling material 66 charged into the retaining wall block 50, the maximum shearing stress is applied to a surface which is inclined with respect to a main axis of the principal stresses through angle of 45 degrees. Therefore, the maximum shearing force applied to the filling material 66 charged into the retaining wall block 50 is applied to a plane 76 shown with a dotted line in Fig. 7. That is, there is a danger that slip is generated on the plane 76 and the retaining wall 60 falls. In reality, since the plane 76 is blocked at the lowest surface portion 51 of the upper step retaining wall block 50, slip is not generated relatively easily. If the plane 76 is blocked near the central portion of the surface portion 51 of the upper step retaining wall block 50, slip on the plane 76 is reliably suppressed.
To enhance safety of the retaining wall 60, in the retaining wall block 50 described in patent document 1 for example, improvement to increase the length of the pair of connecting portions 54 and 55 to further widen a distance between the surface portion 51 and the stay portion 52 is conceived. With this, the width of the friction surface 71 in the horizontal direction is widened, and slip in the horizontal direction can be suppressed, the plane 74 is widened, the anchor effect is enhanced, balance of the retaining wall block 50 is enhanced, and the plane 76 on which the maximum shearing stress is generated is reliably blocked at the central portion of the surface portion 51 of the upper step retaining wall block 50. Therefore, safety of the retaining wall 60 is enhanced. If the pair of the connecting portions 54 and 55 of the retaining wall block 50 become long, the amount of filling material 66 charged therein is increased, the material cost is increased, and the construction cost is increased. Further, the retaining wall block 50 is increased in size, and cost required for transportation is also increased. Further, there is a problem that since the pair of connecting portions 54 and 55 become long, the thickness of the retaining wall 60 is increased correspondingly, and the retaining wall 60 largely project forward from the slope 61.
It is an object of the present invention to provide a retaining wall block capable of constructing a safe retaining wall, and a retaining wall constructed of such retaining wall blocks. More specifically, it is an object of the invention to provide a retaining wall block capable of constructing a retaining wall whose thickness is not increased more than necessary, the amount of filling material to be charged therein and a size of the block are almost the same as those of the conventional block, material cost and transportation cost are not especially increased, but high safety is secured, and it is an object of the invention to provide a retaining wall constructed of such retaining wall blocks.
According to the present invention, to achieve the above object, a retaining wall block integrally includes a surface portion which is exposed on a front side when a retaining wall is constructed, a back surface portion which is hidden on a back side and a pair of connecting portions which connect the surface portion and the back surface portion with each other. The back surface portion is lower than the surface portion, and the back surface portion is inclined rearward through a predetermined angle such that a distance between the surface portion and an upper portion of the back surface portion is greater than a distance between the surface portion and a lower portion of the back surface portion. The surface portion and the back surface portion are connected to each other through the pair of connecting portions at locations deviated inward from left and right edges by a predetermined length. A height of the pair of connecting portions on the side of the surface portion is substantially the same as that of the surface portion, and a height of the connecting portions on the side of the back surface portion is substantially the same as that of the back surface portion.
That is, to achieve the above object, an invention described in claim 1 provides retaining wall blocks made of precast concrete which are butted against each other in a lateral direction along a slop such as flattening and embankment and stacked in predetermined number of steps in a height direction, in which filling materials such as crushed stones and cobblestones are charged inside the retaining wall blocks, a retaining wall which prevents the slop from falling is constructed, wherein each of the retaining wall blocks comprises a substantially rectangular surface portion which is exposed on a front side when the retaining wall is constructed, a substantially rectangular back surface portion which is hidden on a back side when the retaining wall is constructed, and a pair of connecting portions which are disposed at a predetermined distance therebetween and which connects the surface portion and the back surface portion with each other at a predetermined distance therebetween, the surface portion, the back surface portion and the pair of connecting portions are integrally formed into a substantially box-like shape whose top and bottom are opened, a space portion into which the filling materials are charged is formed inside the surface portion, the back surface portion and the pair of connecting portions, and the back surface portion is lower than the surface portion, and the back surface portion is inclined with respect to the surface portion through a predetermined angle such that a distance between upper portions of the back surface portion and the surface portion is greater than a distance between lower portions of the back surface portion and the surface portion.
According to an invention described in claim 2, in the retaining wall blocks described in claim 1, the surface portion and the back surface portion are connected to each other through the pair of connecting portions at locations deviated inward from left and right edges by predetermined length, a height of each of the pair of connecting portions on the side of the surface portion is substantially the same as a height of the surface portion, and a height of each of the pair of connecting portions on the side of the back surface portion is substantially the same as a height of the back surface portion.
According to an invention described in claim 3, in the retaining wall blocks described in claim 2, a height of each of the pair of connecting portions on the side of the surface portion is substantially the same as a height of the surface portion, and the pair of connecting portions become lower in a stepwise manner, and a height of each of the pair of connecting portions on the side of the back surface portion is substantially the same as a height of the back surface portion.
According to an invention described in claim 4, in the retaining wall blocks described in any one of claims 1 to 3, at least one of butted portions of the surface portions of the adjacent retaining wall blocks which are butted against each other when the retaining wall is constructed is formed with a notch, and a slit through which rainwater or springwater is discharged is formed when the retaining wall block are butted against each other.
According to an invention described in claim 5, in the retaining wall blocks described in any one of claims 1 to 4, a lateral width of the back surface portion is narrower than that of the surface portion and with this, a projecting plane play is formed between butted portions of the back surface portions of the adjacent retaining wall blocks when the retaining wall is constructed.
According to an invention described in claim 6, in the retaining wall blocks described in any one of claims 1 to 5, a surface of the surface portion is formed with a design such as a graphic or a pattern.
An invention described in claim 7 provides a retaining wall constructed of the retaining wall blocks according to any one of claims 1 to 6, wherein the retaining wall blocks are butted against each other in a lateral direction adjacent to a slope such as flattening and embankment, filling materials such as crushed stones and cobblestones are charged inside the retaining wall blocks, and one step retaining wall is constructed.
The retaining wall of an invention described in claim 8 constructed of the retaining wall blocks according to any one of claims 1 to 6, further comprises a first step retaining wall, a second step retaining wall, and a third step retaining wall, and at least one or more step retaining walls, wherein the first step retaining wall comprises a plurality of retaining wall blocks which are butted against each other in the lateral direction in adjacent to the slope such as flattening and embankment, in which filling materials such as crushed stones and cobblestones are charged inside the retaining wall blocks to a height of the retaining wall blocks, the second step retaining wall comprises a plurality of retaining wall blocks which are butted against each other in the lateral direction such as to deviate toward the slope along the slope on the first step retaining wall, and filling materials such as crushed stones and cobblestones are charged inside the retaining wall blocks to a height of the retaining wall blocks, the third step retaining wall comprises a plurality of retaining wall blocks which are butted against each other in the lateral direction such as to deviate toward the slope along the slope on the second step retaining wall, and filling materials such as crushed stones and cobblestones are charged inside the retaining wall blocks to a height of the retaining wall blocks, and the one or more step retaining walls are constructed in the same manner.
According to the present invention, the retaining wall block includes a surface portion, a back surface portion and a pair of connecting portions. The back surface portion is lower than the surface portion. A height of the pair of connecting portions on the side of the surface portion is substantially the same as a height of the surface portion, and a height of the connecting portions on the side of the back surface portion is substantially the same as a height of the back surface portion. Therefore, when the retaining wall is constructed of the retaining wall blocks, the retaining wall blocks can be stacked such that lower step retaining wall blocks and upper step retaining wall blocks are not in contact with each other. With this, deformation generated in a certain step retaining wall blocks stacked in a plurality of steps is not transmitted to the entire retaining wall. Thus, there is an effect that the retaining wall constructed of the retaining wall blocks of the invention is stable. Further, since the back surface portion is inclined through a predetermined angle, the retaining wall constructed of the retaining wall blocks of the invention is more stable than a retaining wall constructed of conventional retaining wall blocks. Further, the amount of filling materials charged inside the retaining wall blocks is substantially the same as the amount of filling materials charged inside the conventional retaining wall blocks. According to another invention, the retaining wall may be constructed of one step retaining wall blocks or of many step retaining wall blocks. Therefore, a retaining wall having optimal number of steps can be constructed in accordance with a height of a slope such as flattening and embankment.
Fig. 1 is a partially sectional perspective view showing a retaining wall according to an embodiment including retaining wall blocks of the embodiment. Fig. 2 is a perspective view of adjacent two retaining wall blocks of the embodiment. Fig. 3 is a side sectional view of the retaining wall of the embodiment. Fig. 4 is a side sectional view of the retaining wall schematically showing effect of the retaining wall of the embodiment. Fig. 5 is a perspective view showing conventional retaining wall blocks. Fig. 6 is a side sectional view of a retaining wall including conventional retaining wall blocks. Fig. 7 is a side sectional view of the retaining wall schematically showing effect of the conventional retaining wall.
An embodiment of the present invention will be explained below.
Each retaining wall block 1 according to the embodiment has a substantially box-like shape whose top and bottom are opened. The shape thereof will be explained in detail later. The retaining wall block 1 belongs to a so-called box-like retaining wall block, or bottle-like retaining wall block. Filling materials 30 such as crushed stones and cobblestones are charged into or inside the retaining wall block 1. As shown in Fig. 1, according to a retaining wall 20 of the embodiment, retaining wall blocks 1 are arranged along a slope 21 such as flattening and embankment such that the retaining wall blocks 1 butt against each other in the lateral direction, the filling materials 30 are charged inside the retaining wall blocks 1, another retaining wall blocks 1 are stacked thereon, filling materials 30 are charged inside of the retaining wall blocks 1, and the retaining wall 20 is constructed in the same manner. Predetermined patterns M are formed on a surface from which the retaining wall blocks 1 are exposed, i.e., a front surface. Therefore, the retaining wall 20 of the embodiment has beautiful appearance.
The retaining wall block 1 of the embodiment is made of precast concrete. As shown in Fig. 2, each retaining wall block 1 includes a substantially rectangular plate-like surface portion 2 having a predetermined thickness, a rectangular plate-like back surface portion 3 having a predetermined thickness, and a pair of connecting portions 5 and 6 connecting the surface portion 2 and the back surface portion 3 with each other and having a predetermined thickness. These members are integrally molded into a substantially box-like shape such that the top and bottom thereof are opened. With this, the surface portion 2, the back surface portion 3 and the pair of connecting portions 5 and 6 forms, therein, a box-like space 7 whose upper and lower portions are opened. The filling materials such as crushed stones and cobblestones are charged into the box-like space 7 when the retaining wall is constructed. The surface portion 2 and the back surface portion 3 are integrally connected to each other by the pair of connecting portions 5 and 6 at their left and right end edges or at locations deviated inward from the butted portions by predetermined length. Therefore, portions projecting outward from connected portions of the pair of connecting portions 5 and 6, i.e., ear portions 9 and 10 are formed on the surface portion 2 and the back surface portion 3. As shown in Fig. 2, a box-like space 11 whose upper and lower portions are opened is formed between the adjacent two retaining wall blocks 1 by the ear portions 9 and 10. The filling materials are charged into the box-like space 11 also. Predetermined shallow notches 12 are formed in left and right butted portions of the surface portion 2. Slits 13 are formed in the butted portions of the adjacent retaining wall blocks 1 by the notches 12 when the retaining wall is constructed. Rain stored in the retaining wall 20 or springwater is discharged out from the slits 13.
The height of the back surface portion 3 is about 1/2 of that of the surface portion 2. Therefore, when the retaining wall is constructed, the space formed by the slope 21 and the surface portion 2 of the retaining wall block 1 is not completely divided by the back surface portion 3. That is, only the height of the back surface portion 3 is divided, and an upper space of the back surface portion 3 is continuous. In other words, the filling materials charged in front of the back surface portion 3 and the filling materials charged on the side of the slope 21 located rearward are continuous above the back surface portion 3. With this, a strong retaining wall can be constructed. The lateral width of the back surface portion 3 is slightly narrower than that of the surface portion 2. Therefore, a predetermined play 13 is formed between the back surface portions 3 of the two butted retaining wall blocks 1 when the retaining wall is constructed. With this play 13, even if the slope is curved, the retaining wall blocks 1 can be arranged in the lateral direction without generating a gap between the end edges of the surface portions 2.
In the retaining wall block 1 of the embodiment, a distance between the surface portion 2 and an upper end 15 of the back surface portion 3 is greater than a distance between the surface portion 2 and the lower end 16. That is, since the back surface portion 3 is rearwardly inclined. Since the back surface portion 3 is rearwardly inclined, the retaining wall including the retaining wall blocks 1 of the embodiment has higher stability as compared with the conventional retaining wall block as will be explained later.
As shown in the perspective view in Fig. 2, lower ends of the pair of connecting portions 5 and 6 have substantially the same height as lower ends of the surface portion 2 and the back surface portion 3. However, the upper ends includes a slanting surface which is inclined from the surface portion 2 by a predetermined amount, a first horizontal surface extending horizontally from a terminal end of the slanting surface, and a second horizontal surface which is lowered in a stepwise manner from the terminal end of the first horizontal surface and extends horizontally. The second horizontal surface has the same height as that of the back surface portion 3. In other words, the retaining wall block 1 is high only at the surface portion 2 and a front portion 17 near the surface portion 2, and a central portion and a rear portion of the retaining wall block 1 are low. Thus, when the retaining wall is constructed of the retaining wall blocks 1, the retaining wall blocks 1 can be stacked on one another such that upper step retaining wall blocks 1 and lower step retaining wall blocks 1 do not come into contact with each other.
A construction method of the retaining wall 20 according to the embodiment constructed on the slope 21 such as the flattening and embankment will be explained. As shown in Fig. 3, the ground 22 at a rising portion of the slope 21 is excavated to a predetermined depth, and a groove 23 extending along the slope 21 is formed. A mesh made of high density polyethylene resin, i.e., geotextile 24 laid on the groove 23, and crushed stones, cobblestones or the like is laid thereon to a predetermined thickness. The crushed stones or cobblestones are enclosed by the geotextile 24 to form a base surface 25. The retaining wall blocks 1 are arranged on the base surface 25 in the lateral direction, i.e., in a direction perpendicular to the sheet surface of Fig. 3 and are butted against each other such that the back surface portions 3 of the retaining wall blocks 1 are in contact with the slope 21. Filling materials 30 such as crushed stones and cobblestones are charged into the spaces 7 and 11 in the retaining wall blocks 1 up to the upper end height of the surface portion 2. Likewise, filling materials 30 are charged also into spaces between the slope 21 and the back surface portions 3. With this, a first step horizontal surface 31 is formed. The crushed stones or cobblestones are laid also on a portion of the groove 23 in front of the surface portion 2 which is not filled with the crushed stones or cobblestones by the geotextile 24 to the same level as the surface of the ground 22. With this, construction of the first step retaining wall 20 is completed.
Retaining wall blocks 1 for constructing second step are placed on the first step horizontal surface 31 and arranged in the lateral direction. At that time, the retaining wall blocks 1 are deviated rearward from the first step retaining wall blocks 1 along the inclination of the slope 21. The same filling materials 30 as those of the first step are charged into the second step retaining wall blocks 2, and a horizontal surface 31 having the same height as that of the upper end of the surface portion 2 is formed. With this, the construction of the second step of the retaining wall 20 is completed. The retaining wall 20 having the plurality of steps is constructed in the same manner.
Since the filling materials 30 charged into the retaining wall block 1 mesh with each other, a strong friction force is generated. Further, a strong friction force is generated also between the filling materials 30 and the slope 21. Therefore, the retaining wall 20 is strongly maintained by the friction force, and this prevents the slope 21 from falling. In the retaining wall 20, the upper step retaining wall blocks 1 are deviated rearward from the lower step retaining wall blocks 1, only the front portion of the retaining wall block 1 is high and the central portion and the rear portion of the retaining wall block 1 are low. Therefore, the upper step and lower step retaining wall blocks 1 do not come into direct contact with each other. Thus, a rotation moment generated in arbitrary step retaining wall blocks 1 is not transmitted to its upper or lower step retaining wall blocks 1. Thus, even if arbitrary step retaining wall blocks 1 are rotated or inclined by deformation of the ground or the like, its upper or lower step retaining wall blocks 1 are not inclined and stability there of can be maintained. Deformation generated in the retaining wall 20 is limited to a specific step, and this is not exerted on the entire blocks.
Effect of the back surface portion 3 of the retaining wall block 1 according to the embodiment which is inclined rearward will be explained. Fig. 4 schematically shows a specific step retaining wall blocks 1 which are portions of the retaining wall 20 constructed on the slope 21, and its upper step retaining wall blocks 1 placed on the specific step retaining wall blocks 1. The reason why the stability of the retaining wall 20 is enhanced because the back surface portion 3 is inclined rearward will be explained with reference to Fig. 4.
(Point 1) Friction force which suppresses slip in horizontal direction
A friction force of a lower step of the retaining wall 20 with respect to slip of the upper step in the horizontal direction is applied on a friction surface 33 shown with a thick line in Fig. 4. The friction surface 33 is a portion of the horizontal surface 31 located forward from an intersection between the horizontal surface 31 and an extension of an edge of the back surface portion 3 of the lower step retaining wall block 1 in a perpendicular direction. An extension surface 32 of the edge of the back surface portion 3 is shown with a dashed line. A friction force with respect to slip in the horizontal direction is determined by a width of the friction surface 33 in the horizontal direction. In this embodiment, since the back surface portion 3 is inclined rearward, the width of the friction surface 33 in the horizontal direction is wide correspondingly. With this, slip of the upper step in the horizontal direction with respect to the lower step of the retaining wall 20 is sufficiently suppressed.
(Point 2) Influence on collapse of slope
Earth and sand flow out from the ground forming the slope 21 and the slope 21 collapses as shown with dotted line 35 in Fig. 4. With this, filling materials 30 located rearward from a surface including the back surface portion 3 and the extension surface 32, i.e., a portion of the backfill portion 36 flow such as to fill the collapsed portion. In this embodiment, since the back surface portion 3 is inclined rearward, the extension surface 32 approaches the slope 21. Thus, the capacity of the backfill portion 36 is small. The amount of flowing filling materials 30 is small, and the retaining wall block 1 does not incline rearward.
(Point 3) Anchor effect
The weight that the retaining wall block 1 receives from the filling materials 30 charged into upper step and inside of the retaining wall 20 is applied to the entire projecting plane of the retaining wall block 1 in the vertical direction. The projecting plane is shown with a plane 38 shown with a thick line in Fig. 4. In this embodiment, since the back surface portion 3 inclines rearward, the area of the plane 38 is large and the retaining wall block 1 can efficiently receive the weight. Thus, even if the retaining wall block 1 receives horizontal earth pressure from the slope 21, the retaining wall block 1 is not deviated in the horizontal direction.
(Point 4) Balance of retaining wall block
In this embodiment, since the back surface portion 3 inclines rearward, the back surface portion 3 can receives the weight of the filling materials 30 and the weight of the upper step through the filling materials 30. Therefore, a load that the bottom of the back surface portion 3 applies to the ground is relatively large. In Fig. 4, a graph 39 shows a load that the surface portion 2 of the retaining wall block 1, the pair of connecting portions 5 and 6 and the bottom of the back surface portion 3 apply to the ground. As can be understood from the graph 39, the load that the retaining wall block 1 of the embodiment applies to the ground is distributed relatively uniformly. Thus, the retaining wall block 1 has excellent balance, and even if the ground is soft, the retaining wall block 1 does not incline.
(Point 5) Application surface of maximum shearing stress
The maximum shearing force applied to the filling materials 30 charged into the retaining wall block 1 is applied to a plane 41 which inclines with respect to the horizontal plane through angle of 45 degrees shown with dotted line in Fig. 4. In this embodiment, since the back surface portion 3 inclines rearward, the plane 41 is deviated rearward. Thus, the plane 41 is blocked by an interior of the surface portion 2 of the upper step retaining wall block 1, i.e., by the central portion thereof. Even if a shearing force greater than a level that the filling material 30 can permit is generated, slip is not generated on the plane 41. According to the retaining wall 20 of the embodiment, since the plane 41 on which the maximum shearing stress is generated and slip is easily generated is reliably blocked by the retaining wall block 1, stability is high.
The size of the retaining wall block 1 of the embodiment is not limited, but the following size can be employed. The surface portion 2 has width of 200cm x height of 100 cm x thickness of 12 cm, the back surface portion 3 has width of 186cm x heigh of 50cm x thickness of 12cm. Each of the pair of connecting portions 5 and 6 has bottom width of 125cm x upper portion width of 150cm x thickness 12cm. With this, the retaining wall block 1 has lateral size of 200cm x depth of 150cm x height of 100cm. Although the inclination angle of the rearwardly inclined back surface portion 3 is not limited, preferable angle is 55 to 70 degrees, and more preferably 60 to 65 degrees.
In addition to the crushed stone and cobblestones, preferable examples of the filling materials charged into the retaining wall block 1 are coarse-grained slugs, earth materials such as regenerative aggregates which are crushed concrete.
The retaining wall block of the embodiment can be utilized as a block constructing a retaining wall including only one step, and can also be utilized as a revetment block of river and coast.
1 retaining wall block
2 surface portion
3 back surface portion
5, 6 pair of connecting portions
7 space
20 retaining wall
21 slope
22 ground
30 filling material
31 horizontal surface

Claims (8)

  1. Retaining wall blocks made of precast concrete which are butted against each other in a lateral direction along a slope such as flattening and embankment and stacked in predetermined number of steps in a height direction, in which filling materials such as crushed stones and cobblestones are charged inside the retaining wall blocks, a retaining wall which prevents the slop from falling is constructed, wherein
    each of the retaining wall blocks comprises a substantially rectangular surface portion which is exposed on a front side when the retaining wall is constructed, a substantially rectangular back surface portion which is hidden on a back side when the retaining wall is constructed, and a pair of connecting portions which are disposed at a predetermined distance therebetween and which connects the surface portion and the back surface portion with each other at a predetermined distance therebetween, the surface portion, the back surface portion and the pair of connecting portions are integrally formed into a substantially box-like shape whose top and bottom are opened, a space portion into which the filling materials are charged is formed inside the surface portion, the back surface portion and the pair of connecting portions, and
    the back surface portion is lower than the surface portion, and the back surface portion is inclined with respect to the surface portion through a predetermined angle such that a distance between upper portions of the back surface portion and the surface portion is greater than a distance between lower portions of the back surface portion and the surface portion.
  2. The retaining wall blocks according to claim 1, wherein the surface portion and the back surface portion are connected to each other through the pair of connecting portions at locations deviated inward from left and right edges by predetermined length, a height of each of the pair of connecting portions on the side of the surface portion is substantially the same as a height of the surface portion, and a height of each of the pair of connecting portions on the side of the back surface portion is substantially the same as a height of the back surface portion.
  3. The retaining wall blocks according to claim 2, wherein a height of each of the pair of connecting portions on the side of the surface portion is substantially the same as a height of the surface portion, and the pair of connecting portions become lower in a stepwise manner, and a height of each of the pair of connecting portions on the side of the back surface portion is substantially the same as a height of the back surface portion.
  4. The retaining wall blocks according to any one of claims 1 to 3, wherein at least one of butted portions of the surface portions of the adjacent retaining wall blocks which are butted against each other when the retaining wall is constructed is formed with a notch, and a slit through which rainwater or springwater is discharged is formed when the retaining wall block are butted against each other.
  5. The retaining wall blocks according to any one of claims 1 to 4, wherein a lateral width of the back surface portion is narrower than that of the surface portion and with this, a projecting plane play is formed between butted portions of the back surface portions of the adjacent retaining wall blocks when the retaining wall is constructed.
  6. The retaining wall blocks according to any one of claims 1 to 5, wherein a surface of the surface portion is formed with a design such as a graphic or a pattern.
  7. A retaining wall constructed of the retaining wall blocks according to any one of claims 1 to 6, wherein the retaining wall blocks are butted against each other in a lateral direction adjacent to a slope such as flattening and embankment, filling materials such as crushed stones and cobblestones are charged inside the retaining wall blocks, and one step retaining wall is constructed.
  8. The retaining wall constructed of the retaining wall blocks according to any one of claims 1 to 6, further comprising a first step retaining wall, a second step retaining wall, and a third step retaining wall, and at least one or more step retaining walls, wherein
    the first step retaining wall comprises a plurality of retaining wall blocks which are butted against each other in the lateral direction in adjacent to the slope such as flattening and embankment, in which filling materials such as crushed stones and cobblestones are charged inside the retaining wall blocks to a height of the retaining wall blocks,
    the second step retaining wall comprises a plurality of retaining wall blocks which are butted against each other in the lateral direction such as to deviate toward the slope along the slope on the first step retaining wall, and filling materials such as crushed stones and cobblestones are charged inside the retaining wall blocks to a height of the retaining wall blocks,
    the third step retaining wall comprises a plurality of retaining wall blocks which are butted against each other in the lateral direction such as to deviate toward the slope along the slope on the second step retaining wall, and filling materials such as crushed stones and cobblestones are charged inside the retaining wall blocks to a height of the retaining wall blocks, and
    the one or more step retaining walls are constructed in the same manner.
PCT/JP2009/001653 2008-11-04 2009-04-09 Retaining wall block and retaining wall WO2010052806A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
RU2011114475/03A RU2011114475A (en) 2008-11-04 2009-04-09 SAVING WALL BLOCK AND SAVING WALL
CN2009801439047A CN102203349B (en) 2008-11-04 2009-04-09 Retaining wall block and retaining wall

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2008283186A JP5219743B2 (en) 2008-11-04 2008-11-04 Retaining wall
JP2008-283186 2008-11-04

Publications (1)

Publication Number Publication Date
WO2010052806A1 true WO2010052806A1 (en) 2010-05-14

Family

ID=42152619

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2009/001653 WO2010052806A1 (en) 2008-11-04 2009-04-09 Retaining wall block and retaining wall

Country Status (5)

Country Link
JP (1) JP5219743B2 (en)
KR (1) KR20110086689A (en)
CN (1) CN102203349B (en)
RU (1) RU2011114475A (en)
WO (1) WO2010052806A1 (en)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10273648B2 (en) * 2016-03-02 2019-04-30 Evergreen Walls, Inc. Building elements for making retaining walls, and systems and methods of using same
US10280583B2 (en) 2017-09-28 2019-05-07 Inside Bet Llc Multi-web counterfort wall system
US10337164B2 (en) 2017-09-28 2019-07-02 Inside Bet LCC Threadbar connections for wall systems
FR3078351A1 (en) * 2018-02-27 2019-08-30 Dominique ROSSI BUILDING ELEMENT
US10400418B2 (en) * 2017-09-28 2019-09-03 Inside Bet Llc Combined counterfort retaining wall and mechanically stabilized earth wall
CN110499719A (en) * 2019-08-28 2019-11-26 四川建筑职业技术学院 A kind of mud-rock flow erosion control rib sill structure and system
CN113027519A (en) * 2021-04-20 2021-06-25 安徽马钢罗河矿业有限责任公司 Filling material self-built retaining wall and construction method
US11149402B2 (en) 2016-03-02 2021-10-19 Evergreen Walls, Inc. Building elements for making retaining walls, and systems and methods of using same

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101446666B1 (en) * 2013-01-04 2014-10-06 주식회사 에코밸리 A planting block, wall structure and planting method using the lanting block
CN104074167A (en) * 2014-07-11 2014-10-01 张家港市永诚新型建筑构件有限公司 Soil retaining brick
CN104234077B (en) * 2014-09-04 2017-01-25 昆明市东川区泥石流防治研究所 Lath bricks for retaining wall and retaining wall
JP6429760B2 (en) * 2015-11-19 2018-11-28 株式会社箱型擁壁研究所 Retaining wall and its construction method
CN105544600A (en) * 2015-12-30 2016-05-04 中铁第四勘察设计院集团有限公司 Segmented precast open-web retaining wall building block and retaining wall structure

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005105739A (en) * 2003-10-01 2005-04-21 Bonan Kogyo Kenzai Kk Construction block
JP2008163698A (en) * 2006-12-29 2008-07-17 Hakogata Yoheki Kenkyusho:Kk Retaining wall and its construction method

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4295405B2 (en) * 1999-10-22 2009-07-15 日本興業株式会社 Retaining wall block for symbiotic greening and block body used for the block
CN1194149C (en) * 2000-06-29 2005-03-23 李承勋 Block retaining wall structure and setback locator therefor
JP2002285566A (en) * 2001-03-26 2002-10-03 Landex Kogyo Kk Retaining wall construction
JP3823075B2 (en) * 2002-08-13 2006-09-20 株式会社パリティジパング Retaining wall and retaining wall block

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005105739A (en) * 2003-10-01 2005-04-21 Bonan Kogyo Kenzai Kk Construction block
JP2008163698A (en) * 2006-12-29 2008-07-17 Hakogata Yoheki Kenkyusho:Kk Retaining wall and its construction method

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10273648B2 (en) * 2016-03-02 2019-04-30 Evergreen Walls, Inc. Building elements for making retaining walls, and systems and methods of using same
US20190368151A1 (en) * 2016-03-02 2019-12-05 Evergreen Walls, Inc. Building elements for making retaining walls, and systems and methods of using same
US11149402B2 (en) 2016-03-02 2021-10-19 Evergreen Walls, Inc. Building elements for making retaining walls, and systems and methods of using same
US10280583B2 (en) 2017-09-28 2019-05-07 Inside Bet Llc Multi-web counterfort wall system
US10337164B2 (en) 2017-09-28 2019-07-02 Inside Bet LCC Threadbar connections for wall systems
US10400418B2 (en) * 2017-09-28 2019-09-03 Inside Bet Llc Combined counterfort retaining wall and mechanically stabilized earth wall
FR3078351A1 (en) * 2018-02-27 2019-08-30 Dominique ROSSI BUILDING ELEMENT
WO2019166384A1 (en) * 2018-02-27 2019-09-06 Dominique Rossi Construction element
CN110499719A (en) * 2019-08-28 2019-11-26 四川建筑职业技术学院 A kind of mud-rock flow erosion control rib sill structure and system
CN113027519A (en) * 2021-04-20 2021-06-25 安徽马钢罗河矿业有限责任公司 Filling material self-built retaining wall and construction method

Also Published As

Publication number Publication date
CN102203349A (en) 2011-09-28
RU2011114475A (en) 2012-12-20
JP2010112010A (en) 2010-05-20
KR20110086689A (en) 2011-07-29
CN102203349B (en) 2013-11-13
JP5219743B2 (en) 2013-06-26

Similar Documents

Publication Publication Date Title
WO2010052806A1 (en) Retaining wall block and retaining wall
JP6240625B2 (en) Retaining wall, creation site and creation method of creation site
KR102116085B1 (en) A Eco-friendly retain wall structure
JP4614928B2 (en) Lightweight embankment method
JP5430912B2 (en) Concrete block stacking wall
KR100574778B1 (en) Block for reinforcement or vegetation
CN109338909B (en) Integral pier reinforcing structure and construction method thereof
KR100397536B1 (en) Lateral Movement Prevention Construction Method of Bridge Abutment for using Sheet piles
JP3930544B2 (en) Light weight embankment
KR200220890Y1 (en) Lateral Movement Prevention Structure of Bridge Abutment for using Sheet piles
JP4423115B2 (en) An improved method for reducing land subsidence directly under existing embankments
JP4868589B2 (en) Support structure for construction foundation and construction method
KR102285192B1 (en) A Eco-friendly retain wall structure
JP2012046908A (en) Bank protection retaining wall structure
JP2012184551A (en) Retaining wall block
JP3771436B2 (en) Lightweight embankment structure
JP7469608B2 (en) Support structure, gravity breakwater and construction method of gravity breakwater
KR20060134651A (en) Landscape facilities and constuction method thereof
JP5130563B2 (en) Lightweight retaining wall block and lightweight retaining wall structure using the same
JP6452163B2 (en) Retaining wall structure
JP2024046940A (en) Revetment structure
KR200369484Y1 (en) block for reinforced soil retaining wall
KR101208897B1 (en) Construction method of river bank
KR20150015195A (en) Plantable block
JP2005042333A (en) Lightweight fill for road

Legal Events

Date Code Title Description
WWE Wipo information: entry into national phase

Ref document number: 200980143904.7

Country of ref document: CN

121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 09824508

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 20117008855

Country of ref document: KR

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

WWE Wipo information: entry into national phase

Ref document number: 2011114475

Country of ref document: RU

122 Ep: pct application non-entry in european phase

Ref document number: 09824508

Country of ref document: EP

Kind code of ref document: A1