JP2007009640A - Shore strut for supporting retaining wall and its construction method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shore strut for supporting a retaining wall excellent in workability and capable of being manufactured at a low cost, and its construction method. <P>SOLUTION: The shore strut 1 for allowing a pair of retaining walls 21, 21 to support each other is extended between the retaining walls 21, 21 arranged at an interval. The shore strut 1 comprises side-part steel beam members 2, 2 arranged on both sides and a concrete beam member 3 sandwiched between the beam members 2, 2. The beam members 2, 2 and the concrete beam member 3 are integrated with each other. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a retaining wall supporting beam for supporting a retaining wall used when constructing a lower road of a three-dimensional crossing road and a method for laying the retaining wall.

  Conventionally, when constructing a dugdown type three-dimensional crossing road, concrete piles such as a large number of PC sheet piles or H-shaped PC piles in a continuous arrangement with the side edges abutting each other on both sides of the planned lower road construction area (excavation area) in the ground The lower road of the three-dimensional crossing road is excavated with the earth retaining wall between the two retaining walls after supporting the earth pressure of the adjacent non-excavated part with this retaining wall. The method of building is known.

  In such a construction method, for example, since the earth pressure from the unexcavated part adjacent to the deep excavation is large, the proof strength of the self-supporting earth retaining wall is not enough or the longitudinal length of the earth retaining wall is to be shortened. In this case, after excavating a predetermined depth of the ground between the retaining walls to a predetermined depth, the retaining walls are connected to each other through the beams by piercing the struts between the retaining walls. It is supported by the earth retaining wall, and the earth pressure of the adjacent unexcavated part is supported.

  However, the conventional techniques as described above have a problem in that, when the excavation area has a large width and depth, a large amount of beams (struts) are required, which increases the construction cost. In addition, when the excavation area is large, the compressive force acting on the beam (strut) due to the bending moment applied to the both retaining walls also increases, so the beam becomes larger correspondingly, increasing the weight and transporting. There was a problem that the installation work was not easy.

  SUMMARY OF THE INVENTION In view of the above-described conventional problems, an object of the present invention is to provide a retaining wall supporting beam that is excellent in workability and that can be manufactured at low cost, and a method for laying the same.

  In order to solve the above-mentioned conventional problems and achieve the intended object, the invention according to claim 1 is provided between a pair of earth retaining walls arranged at a distance from each other. A retaining wall supporting beam for supporting walls with each other, comprising steel side beam members arranged on both sides, and concrete concrete beam members sandwiched between the both side beam members The retaining wall supporting cut beam in which the both-side beam material and the concrete beam material are integrated.

  The invention according to claim 2 is characterized in that, in addition to the structure of claim 1, it has a formwork member that closes the lower surface of the part between both side beam members.

  According to a third aspect of the present invention, in addition to the configuration of the first or second aspect, the side beam member integrally has a flange portion protruding outward from the upper edge and / or the lower edge.

  According to a fourth aspect of the present invention, in addition to the configuration of the third aspect, the flange portion has an anchor insertion hole through which an anchor member protruding upward from the upper edge of the retaining wall is inserted. .

  The invention according to claim 5 includes, in addition to the configuration of claims 1 to 3 or 4, a bolt that penetrates the concrete beam material and has both ends projecting to the outer surface side of the both side beam materials, The concrete beam member and the both side beam members are integrated by tightening a nut to a bolt end protruding to the side.

  According to the sixth aspect of the present invention, in addition to the configuration of the first to fourth or fifth aspects, the side beam member is a cross-sectional core member in which a lateral flange is integrally projected on one side of both upper and lower ends of a longitudinal web. It is characterized by the fact that it is made of a U-shaped channel steel.

  According to a seventh aspect of the present invention, there is provided a retaining wall supporting cut beam that is spanned between a pair of retaining walls that are spaced apart from each other and that supports the both retaining walls. When laying between the walls, a pair of side beam members spaced apart from each other are bridged between the two retaining walls, and then concrete is placed between the both side beam members to provide the concrete beam material. The retaining wall supporting beam is constructed by integrating the both side beam members and the concrete beam material to form the retaining wall supporting beam.

  According to an eighth aspect of the invention, in addition to the configuration of the seventh aspect, the side beam member is cut according to the distance between the both retaining walls, and then spanned between the both retaining walls. .

  The retaining wall supporting beam according to the present invention is a retaining wall supporting beam for supporting each retaining wall, which is spanned between a pair of retaining walls arranged at a distance from each other. A steel side beam member disposed on both sides and a concrete concrete beam member sandwiched between the both side beam members, and the both side beam member and the concrete beam member are integrated. As a result, a high buckling strength can be obtained, and since the structure is simple, it can be manufactured at low cost and the construction cost can be reduced.

  By having a formwork member that closes the lower surface of the space between both side beam members, it is possible to place concrete between the side beam members by spot casting. After passing, the concrete beam material can be formed, and the steel side beam material can be handled independently until it is installed between the two retaining walls, so that it can be easily transported and installed.

  Since the side beam member integrally has a flange portion that protrudes outward from the upper edge and / or the lower edge, the cut beam can be suitably fixed to the upper edge portion of the earth retaining wall or the flank.

  The flange portion has an anchor insertion hole through which an anchor member protruding upward from the upper edge of the retaining wall is inserted, so that the end portion of the beam can be suitably fixed to the retaining wall.

  The concrete beam material and the both side beams are provided by including bolts penetrating the concrete beam material, both ends projecting to the outer surface side of the both side beam materials, and tightening nuts to the bolt end portions projecting to the outer surface side. After the use, the side beam material and the concrete beam material can be easily separated after use, and can be easily transported after use. Can be reused.

  The side beams are made of U-shaped channel steel with a horizontal flange projecting integrally on one side of the top and bottom ends of the vertical web, to match the distance between the two retaining walls. Thus, cutting or anchor insertion holes can be easily formed, and the length can be adjusted suitably.

  According to the present invention, there is provided a retaining wall support for spanning between a pair of retaining walls arranged at a distance from each other and for supporting the both retaining walls. When laying a cutting beam between the retaining walls, a pair of side beam members spaced apart from each other are bridged between the both retaining walls, and then concrete is placed between the both side beam members. A concrete beam material is formed by casting, and the both side beam materials and the concrete beam material are integrated to form the retaining wall supporting cut beam. Since it is formed after the side beam members are bridged between them, transportation and installation work can be easily performed.

  After the side beam material is cut according to the distance between the both retaining walls, the length of the beam can be easily adjusted at the site by bridging between the both retaining walls.

  Next, an embodiment of a retaining wall supporting beam according to the present invention will be described with reference to the drawings.

  As shown in FIG. 1 and FIG. 2, the retaining wall supporting cut beam 1 is sandwiched between the steel side beam members 2 arranged on both sides and the both side beam materials 2 and 2. A steel-concrete composite beam comprising two concrete beam members 2 and 2 and a concrete beam member 3 integrated between the retaining walls arranged at intervals. It is built over and supports both retaining walls.

  Further, the cut beam 1 is removably supported on the lower edge and both ends of the side beam members 2 and 2, and is formed with a mold member 4 for closing the lower surface and both end surfaces of the portion between the side beam members 2 and 2. Formwork members 5 and 5 are provided.

  The side beam member 2 is composed of a U-shaped cross-section steel sheet in which upper and lower flanges 7 and 8 are integrally projected on one side of the upper and lower ends of the vertical web 6. , 2 are arranged side by side with the flanges 7 and 8 facing each other outward (on the side opposite to the other side beam member 2).

  Bolt insertion holes 9, 9... Are formed in the web 6 at a predetermined interval, and bolts 10 are inserted between the webs 6 and 6 through the bolt insertion holes 9 and project outside the webs 6 and 6. Nuts 11 and 11 are screwed into the bolt ends.

  The lower flange 8 is formed with anchor insertion holes 12 at both ends in the longitudinal direction, and anchor bolts projecting upward from the anchor insertion holes 12 to the upper edge of the earth retaining wall or the flank are provided at the lower part. The end of the beam 1 can be fixed to the retaining wall by being penetrated by the flange 8 and tightening a nut to the anchor bolt.

  The concrete beam 3 has a reinforcing bar structure in which reinforcing bars (not shown) are arranged, and the lower surface and both end surfaces thereof are closed by the formwork members 4 and 5, and only the upper surface is opened between both side beam members 2 and 2. It is formed by casting cast-in-place concrete.

  In the cut beam 1 constructed in this manner, the bolts 10, 10... Penetrate through the concrete beam material 3, and both end portions thereof protrude to the outer surface side of both webs 6, 6, and nuts are provided at the end portions of the bolts. By tightening 11 and 11, the concrete beam material 3 and the side beam materials 2 and 2 are integrated.

  Next, a cut beam type retaining method using the retaining wall supporting cut beam will be described.

  First, as shown in FIG. 3, for example, earth retaining walls 21 and 21 are installed on both sides of the ground where the lower road of the dugdown type three-dimensional intersection road is constructed, that is, the planned excavation area 20, and adjacent non-excavated The earth pressure of the part 22 is supported.

  The retaining wall 21 is formed by, for example, placing a number of H-type PC piles in a vertically downward direction from the ground surface in an arrangement in which the side edges are in contact with each other, and if necessary, concrete in the gaps between the H-type PC piles. It is formed by filling.

  Next, the planned excavation area 20 ground between the both retaining walls 21 and 21 is excavated to a predetermined depth, that is, about half the planned excavation depth.

  When excavation is completed to a predetermined depth in this way, as shown in FIG. 4, the cap concrete 23 is placed on the upper edge of the both retaining walls 21, 21. At this time, the anchor bolt 24 is projected upward in accordance with a predetermined position of the cap concrete 23, that is, the installation position of the cut beam 1.

  Then, a plurality of retaining wall supporting beams 1, 1... Are bridged between the both retaining walls 21, 21, that is, the cap concrete 23, 23 in the wall direction. The other retaining wall 21 is supported through the retaining wall supporting beam 1.

  The method of laying the retaining wall supporting cut beam 1 is as follows. First, the side beam members 2 and 2 are brought into the field, and the side beam members 2 are cut in accordance with the distance between the both retaining walls 21 and 21. The anchor insertion hole 12 is formed in the lower flange 8 by a drill or the like in accordance with the position of the anchor bolts 24, 24.

  As described above, the side beam member 2 is composed only of grooved steel, so that its own weight is small and it can be easily transported, and cutting and drilling can be easily performed according to installation conditions, so that work efficiency is improved. Good.

  Next, after arranging a pair of side beam members 2 and 2 with the flanges 7 and 8 facing outward (opposite side of the other side beam member 2), the two side beam members 2, The bolts 10 are passed through the two bolt insertion holes 9, 9... And inserted between the beam members 2 and 2 on both sides, and the nuts 11 are tightened to the bolt ends protruding outward.

  Further, the lower surface and both ends of the portion between the side beam members 2 and 2 are closed by the mold members 4 and 5 to form the concrete beam molding mold 25 with only the upper surface opened.

  The concrete beam forming mold 25 is lifted by a crane or the like, and as shown in FIG. 5, it is bridged between the retaining walls 21, 21, that is, between the cap concrete 23, 23, and protrudes upward from the cap concrete 23. The end of the mold 25 is placed on the cap concrete 23 in a state where the bolt 24 is passed through the anchor insertion hole 12.

  Then, by tightening the nut 26 to the anchor bolt 24, the concrete beam forming mold 25 is fixed in a state of being bridged between the both retaining walls 21, 21.

  Next, reinforcing bars and other necessary items are placed in the mold 25, and concrete is filled into the mold 25 from the upper surface opening, that is, between the beam members 2 and 2 on both sides by spot casting.

  Then, the concrete is sufficiently cured to form a concrete beam 3 integrated with the beam members 2 and 2 on both sides, and a composite girder in which the beam members 2 and 2 and the concrete beam material 3 are integrated. It is formed.

  The formwork members 4 and 5 may be removed after the concrete is solidified, or may be part of the beam 1 while attached.

  Next, the remaining portion of the planned excavation ground is excavated to a predetermined depth in a state where the retaining wall 21 is supported by the counterpart retaining wall 21 through the beam 1.

  When all of the earth and sand in the planned excavation area has been excavated, as shown in FIG. 6, concrete is cast on the bottom portion thereof to form a bottom slab 27.

  Then, the cut beam 1 is detached from the upper edge portions of the both retaining walls 21 and 21, that is, the shaded concrete 23, and lifted and removed by a crane or the like.

  The both retaining walls 21 and 21 are formed with the concrete bottom slab 27 so that they can stand up to withstand the earth pressure of the unexcavated portion even if the cut beams 1, 1... Are removed.

  Moreover, both the earth retaining walls 21 and 21 are used as side walls of a structure such as a lower road while being left in that position.

  On the other hand, the cut beam 1 is removed by loosening and removing the nuts 11, 11 at both ends of the bolt spanned between the side beam members 2, 2. Can be separated into the side beam members 2 and 2 and the concrete beam member 3.

  Therefore, when the cut beam 1 is transported from the construction site, the side beam material 2 having a light weight can be transported separately from the concrete beam material 3, which is efficient. On the other hand, the concrete beam material 3 can be crushed on the spot and conveyed as waste material.

  Further, by separating the side beam material 2 and the concrete beam material 3, the side beam material 2 can be reused.

  In the above-described embodiment, an example in which a U-shaped grooved steel is used for the side beam member 2 has been described, but an H-shaped steel, an I-shaped steel, a rectangular steel pipe, or the like may be used instead of the grooved steel. good.

  Furthermore, in the above-described embodiment, the example in which the concrete beam material is formed by placing the side beam material between the both retaining walls and then placing concrete between the side beam materials has been described. Then, after the side beam material and the concrete beam material are integrated, they may be installed between the two retaining walls.

  Further, the cut beam may be formed by combining a concrete beam material and a side beam material separately molded in advance.

  Furthermore, in the above-mentioned embodiment, the earth retaining wall made of the H-type PC pile is shown as an example. However, the earth retaining wall may be one using a PC sheet pile or other concrete piles, etc. It may be a wall.

It is a side view which shows an example of the retaining wall supporting cut beam which concerns on this invention. It is an expanded sectional view of a retaining wall supporting cut beam same as the above. It is sectional drawing which shows the state of the earth retaining installation process of the shear beam type earth retaining method using the beam according to the present invention. It is sectional drawing which shows the state of a beam installation process same as the above. It is a perspective view which shows the installation state of the side beam material in FIG. It is sectional drawing which shows the state of the bottom slab installation process of the cut beam type earth retaining method using the cut beam which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Retaining wall support cut beam 2 Side beam material 3 Concrete beam material 4,5 Formwork member 6 Web 7 Upper flange 8 Lower flange 18 Bolt insertion hole 10 Bolt 11 Nut 12 Anchor insertion hole 20 Planned excavation area 21 Earth retaining Wall 22 Non-excavated portion 23 Shade concrete 24 Anchor bolt 25 Form for molding concrete beam material 26 Nut 27 Concrete bottom plate

Claims (8)

In the retaining wall supporting beam that is spanned between a pair of retaining walls arranged at a distance from each other and supports both retaining walls.
Steel side beam members arranged on both sides and concrete concrete beam members sandwiched between the both side beam members, and the both side beam materials and the concrete beam material are integrated. A retaining wall supporting cut-off beam.   The retaining wall supporting cut beam according to claim 1, further comprising a formwork member that closes a lower surface of a portion between both side beam members.   3. The retaining wall supporting cut beam according to claim 1, wherein the side beam member integrally has a flange portion protruding outward from the upper edge and / or the lower edge.   The retaining wall supporting beam according to claim 3, wherein the flange portion has an anchor insertion hole into which an anchor member protruding upward from an upper edge of the retaining wall is inserted.   The concrete beam material and the both side beams are provided by including bolts penetrating the concrete beam material, both ends projecting to the outer surface side of the both side beam materials, and tightening nuts to the bolt end portions projecting to the outer surface side. The retaining wall supporting cut beam according to claim 1, wherein the material is integrated.   6. The earth retaining member according to claim 1, wherein the side beams are made of U-shaped channel steel having a lateral flange integrally projecting on one side of both upper and lower ends of a longitudinal web. Wall support beam. When spanning between a pair of retaining walls arranged between a pair of retaining walls spaced apart from each other, the retaining wall supporting beam for supporting the both retaining walls is constructed between the retaining walls,
A pair of side beam members spaced apart from each other are bridged between the two retaining walls, and then concrete is placed between the both side beam members to form a concrete beam member. A construction method for a retaining wall supporting cut beam, characterized in that a beam material and a concrete beam material are integrated into the retaining wall supporting cut beam.   The method for laying a retaining wall supporting cut beam according to claim 7, wherein a side beam member is cut in accordance with a distance between the both retaining walls, and then spanned between the both retaining walls.