JP2019127822A - Earth retaining structure and earth retaining method - Google Patents

Abstract

To further enhance rigidity of a double earth retaining wall, and economically improve the double earth retaining wall.SOLUTION: A first wall body 11 is driven into the ground so as to partition an open-cut side and a natural ground side. A second wall body 12 is driven into the ground on the natural ground side rather than the first wall body 11 with an interval from the first wall body 11. A head connection material 13 connects the head of the first wall body 11 and the head of the second wall body 12. The first and second wall bodies 11 and 12 and the head connection material 13 are rigidly joined to each other to form a rigid-framed structure, and restrict the ground between the first and second wall bodies 11 and 12.SELECTED DRAWING: Figure 1

Description

  The present invention divides the cut and cut side (cut and cut area) and the ground side (non cut and cut area) at the time of cut and ground work of the ground, and performs earth setting (and water stopping) to the construction site. About.

Usually, the earth retaining (mountain retaining) used in the excavation work is constructed by placing steel sheet piles or H-steel to construct the earth retaining wall, and with the rigidity and strength of the earth retaining wall, it can withstand earth pressure and water pressure, Ensure safety.
In the case of self-supporting earth retaining, the earth retaining specification (earth retaining wall specification) is determined according to the depth and ground conditions of excavation, and the necessary steel sheet pile and H steel specification are determined. Even in the case of support types such as cut beams and ground anchors, the entire earth retaining specification is determined by the balance between the support specification and the retaining wall specification.

  Among them, when the self-supporting height of the earth retaining is increased or when the support specifications are simplified, the specifications of the earth retaining wall that supports it are improved.

A double earth retaining wall can be considered as one of the measures in such a case.
For example, in Patent Document 1, there are double underground continuous walls, which are used as an inner cutoff wall and an outer cutoff wall, and these heads (top ends) are fastened with tie rods. It is disclosed.

Japanese Patent Application Laid-Open No. 57-155421

  However, although the connection with the tie rod can usually resist the force in the pulling direction, it cannot resist the force in the compression direction. Also, basically, they are not integrated because they are only connected by pins at one point. Therefore, it can not be said that the inner and outer closing walls are not integrated, but the inner and outer closing walls and the soil between them are integrated. Therefore, there is still room for improvement from the viewpoint of increasing rigidity and strength and improving economy.

  The present invention has been made in view of such a situation, and it is an object of the present invention to further increase the rigidity of the double structure retaining wall and to make it economically superior.

In order to solve the above problems, the earth retaining structure according to the present invention is
A first wall that is driven into the ground so as to divide the cut and cut side and the ground side;
A second wall which is driven into the ground on the ground side of the first wall at a distance from the first wall;
A head connector connecting the head of the first wall and the head of the second wall;
Comprising
The first and second walls and the head connecting member may be rigidly connected to form a rigid frame structure.

Moreover, the earth retaining method according to the present invention is
Driving the first and second walls spaced apart from each other so as to divide the ground side from the cut and cut side and the ground side;
A step of connecting the head of the first wall and the head of the second wall with a head connecting member after driving the first and second walls;
Including
In the connecting step, the first and second wall bodies and the head connecting material are rigidly joined so as to form a rigid frame structure and restrain the ground between the first and second wall bodies. It is characterized by that.

  According to the present invention, not only the head of the first wall body and the head of the second wall body are connected by the head connecting material, but also the first and second wall bodies and the head connecting material. The butt is rigidly joined and has a gate-type rigid frame structure. Therefore, the displacement and rotation of the heads of the first and second wall bodies are constrained, and the rigidity and strength of the double earth retaining wall by the first and second wall bodies can be increased. Moreover, the ground between the first and second walls can be restrained by the first and second walls being constrained to each other. As a result, the rigidity of the internal ground greatly contributes to increasing the rigidity of the double earth retaining wall. Accordingly, the rigidity of one earth retaining wall can be exerted by a rigidity of 2 or more, and it is possible to provide an earth retaining wall that is excellent in rigidity and strength as well as economically.

The figure which shows the construction example of the open cut construction using a double earth retaining wall as one embodiment of the present invention Plan view of double earth retaining wall using steel sheet pile Enlarged view of the connection structure by the head connection material The top view of the connection structure corresponded to the AA arrow cross section of FIG. 3 Illustration of solidifying material injection Explanation of the well point method Top view showing the deformation mode of double retaining wall using steel sheet pile A diagram showing a modification of the head connecting member An illustration of the case where the second wall on the support side is driven diagonally The figure which shows embodiment of the head connection by cast-in-place concrete Top view of the embodiment of FIG. The figure which shows embodiment of the ground improvement and head connection using a high-pressure jet stirring method Figure showing an embodiment of a head connection with precast concrete blocks The figure which shows the embodiment (before connection) of the head connection by the joining steel materials of steel sheet pile utilization. The figure which shows the state after head connection of embodiment of FIG. The figure shown about the head connection material using the steel sheet pile of embodiment of FIG. The figure which shows the embodiment of the head connection by the joining steel materials formed by combining a steel plate The figure which shows the embodiment of the head connection by cross type joint steel materials The figure which shows embodiment of the head connection using the guide steel material at the time of steel sheet pile driving Figure 19 shows a variant of the embodiment of Figure 19 Figure showing an embodiment of a triple earth retaining wall

Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 is a view showing a construction example of an open cut work using a double earth retaining wall as one embodiment of the present invention, and FIG. 2 is a plan view of a double earth retaining wall using a steel sheet pile.

  The earth retaining structure 10 of the present embodiment is a double structure (double earth retaining wall) of a first wall 11 and a second wall 12.

In the present embodiment, steel sheet piles (sheet piles) are used as wall members constituting the first and second wall bodies 11 and 12.
As shown in FIG. 2, the steel sheet pile is bent in a trapezoidal cross section, one surface of the front and back is convex, the other surface is concave, and has joints at both ends. Therefore, a steel retaining sheet (wall body) can be constructed with a row of steel sheet piles by arranging the steel sheet piles alternately in the reverse direction and connecting adjacent steel sheet piles with joints.

The first wall 11 is driven into the ground (ground before cutting) G so as to separate the cutting side and the ground side.
The second wall body 12 is driven in parallel with the first wall body 11 at a distance of about 1 m, for example, on the ground closer to the ground than the first wall body 11.
Note that either the first wall body 11 driving step and the second wall body 12 driving step may be performed first or may be performed in parallel.

The earth retaining structure 10 of the present embodiment further includes a head connecting member 13 that connects and fixes the head of the first wall 11 and the head of the second wall 12.
In other words, the step of connecting the head of the first wall 11 and the head of the second wall 12 with the head connecting member 13 after the driving step of the first and second walls 11, 12. Carry out.

  Here, the first and second wall bodies 11, 12 and the head connecting member 13 are rigidly joined to form a ramen structure (a portal ramen structure), and the first and second wall bodies 11, Restrain the ground between the twelve.

The length in the depth direction of the double earth retaining wall is set according to the conditions at the site from the viewpoint of design, the viewpoint of workability, the viewpoint of economy, and the like. Usually, the length of the first wall body 11 disposed on the inner side is determined by the stability of the retaining wall of the design retaining wall, and the length of the second wall body 12 disposed on the outer side is , Determined in the range necessary to ensure the shear resistance as a wall. For this reason, in general, as shown in FIG. 1, the length of the second wall 12 is slightly shorter than the length of the first wall 11.
However, it is not necessarily limited to this. The length of the first wall body 11 and the length of the second wall body 12 may be the same, or the length of the first wall body 11 is shorter than the length of the second wall body 12. Sometimes it becomes.

  The concrete structure of the head connection member 13 for the said rigid connection is demonstrated with FIG.3 and FIG.4. FIG. 3 is an enlarged view of the connection structure using the head connection material, and FIG. 4 is a plan view of the connection structure corresponding to the cross section taken along the line AA of FIG.

The head connecting member 13 includes a beam 31 extending in a direction (horizontal direction) intersecting the first and second walls 11 and 12 above the first and second walls 11 and 12. And joints 32 and 33 that bend and extend downward from both ends of the beam 31.
Each of the joint portions 32 and 33 is fastened and fixed to the head of the first and second wall bodies 11 and 12 at a plurality of points in the vertical direction, as described later.

One joint portion 32 is integrally formed with the beam portion 31.
The other joint portion 33 is a member separate from the beam portion 31 and is attached to the beam portion 31 so as to be adjustable in position in the longitudinal direction. This is to enable to cope with the variation in the distance between the first and second walls 11 and 12.

  For this reason, the other joining portion (joining member) 33 has an attachment hole and is fitted to the beam portion 31 of the head connecting member 13. Then, the joint portion 33 is positioned and fixed in the longitudinal direction of the beam portion 31 by lock nuts 34 and 35 screwed to the beam portion 31 and arranged at the front and back of the joint portion 33. Further, the joint portion 33 is positioned in the circumferential direction of the beam portion 31 by providing a key and a key groove in the fitting portion between the beam portion 31 and the joint portion 33.

  The one joint portion 32 is also bifurcated and fitted to the head of one of the first and second wall bodies 11 and 12 (for example, the wall body 12) so as to sandwich the same. That is, the joint portion 32 includes a pair of front and rear sandwiching plates 32a and 32b that are integral with the beam portion 31, and a fitting groove 32c that opens downwardly in a U-shape between the pair of sandwiching plates 32a and 32b. , It fits into the head of one wall.

Then, the head of the wall 12 and the head connecting member 13 are clamped and fixed at two upper and lower clamping portions (pressing bolts) 41 and 42 of either one of the pair of front and rear clamping plates 32a and 32b. And the joint 32 of the
That is, the heads of the wall 12 are clamped between the clamping plate 32b and the bolts 41 and 42 by pressing the tips of the bolts 41 and 42 screwed into the clamping plate 32a against the wall 12.

  The other joint portion 33 is also bifurcated and fitted to the head of one of the first and second wall bodies 11 and 12 (for example, the wall body 11) so as to sandwich it. That is, the joint portion 33 has a pair of front and rear holding plates 33a and 33b, and a fitting groove 33c which opens downward in a U-shape between them, and the fitting groove 33c allows the other wall body to be formed. Fit on the head.

Of the pair of front and rear clamping plates 33a and 33b, two clamping and fixing portions (pressing bolts) 51 and 52 on one clamping plate 33a and two clamping and fixing portions (pressing) on the other clamping plate 33b. The bolts 53 and 54 fasten and fix the head of the wall 11 and the joint 33 of the head connecting member 13.
That is, the ends of the bolts 51 and 52 screwed to the clamping plate 33a are pressed against one surface of the wall body 11, and the tips of the bolts 53 and 54 screwed to the clamping plate 33b are pressed to the other surface of the wall body 11. By pressing, the head of the wall 11 is held between the bolts 51 and 52 on the holding plate 33 a side and the bolts 53 and 54 on the holding plate 33 b side.

  It should be noted that the fastening fixing parts (pressing bolts) 51 to 54 on the joint 33 side are provided symmetrically, and the fastening fixing parts (pressing bolts) are provided at four places on the upper and lower left and right sides on the one clamping plate 33a side. Also on the holding plate 33b side, fastening fixing portions (pressing bolts) are provided at four places in the vertical and horizontal directions.

  According to this embodiment, the head of the first wall 11 and the head of the second wall 12 are not only connected by the head connecting member 13, but also the first and second walls 11. 12 and the head connecting member 13 are rigidly joined to form a portal ramen structure. Thus, the first and second walls 11, 12 can be integrated to resist tension and compression, and the displacement and rotation of the heads of the first and second walls 11, 12 are constrained. The rigidity and strength of the double earth retaining wall by the first and second wall bodies 11 and 12 can be increased.

  Moreover, the ground between the 1st and 2nd wall bodies 11 and 12 can be restrained because the 1st and 2nd wall bodies 11 and 12 are restrained mutually. As a result, the rigidity of the internal ground greatly contributes to increasing the rigidity of the double earth retaining wall. Particularly in the case of sand ground, since it has a large shear resistance, a greater rigidity can be obtained. Therefore, the rigidity of one earth retaining wall × 2 or more can be exhibited.

Further, in order to enhance the effect of increasing the rigidity due to the ground between the first and second wall bodies 11, 12, the ground between the first and second wall bodies 11, 12 may be reinforced.
Specifically, as shown in FIG. 5, after the first and second wall bodies 11 and 12 are driven, a solidifying material (chemical solution) 60 is injected into the ground between the first and second wall bodies 11 and 12. By reinforcing the ground. The injection of the solidifying material 60 is performed by boring at a plurality of locations on the ground between the first and second walls 11 and 12.

Alternatively, as shown in FIG. 6, after the first and second wall bodies 11 and 12 are driven, the groundwater level between the first and second wall bodies 11 and 12 is lowered by the well point method.
That is, by installing a water collecting pipe 61 called a well point on the ground between the first and second wall bodies 11 and 12, and applying a negative pressure to the ground by a pump 62 on the ground side, the groundwater is sucked. Lower the rank.

  The groundwater level can be lowered and the ground between the first and second wall bodies 11 and 12 can be reinforced by the installation of the water collection facility (the water collection pipe 61 and the pump 62) and the operation during the excavation. . In the case where the first and second walls 11 and 12 surround four sides of the open area, the water collection facility (water collection pipe 61) may be provided by boring in one place.

Next, a modification of the double earth retaining wall using a steel sheet pile will be described with reference to the plan view of FIG.
In FIG. 2, the first and second wall bodies 11 and 12 made of steel sheet piles are arranged in the same phase in which the convex shapes are in the same direction. On the other hand, in FIG. 7, the convex shapes are arranged in the opposite phase in the opposite direction. When there is no restriction on the site on the natural mountain side, by arranging as shown in FIG. 7, a greater shear resistance can be secured, and a greater rigidity-up effect can be obtained.
Further, in FIG. 7, the central portions of the steel sheet piles are connected at the position of the longest distance by the head connecting member 13. This can enhance the ground restraint effect.

In addition, in the said embodiment (FIG. 2, FIG. 7), although the head connection material 13 connected the center part of the steel sheet piles, the steel sheet pile adjacent at each edge part of the head connection material 13 is used. The connection portion (joint portion) may be connected in a sandwiching manner.
Moreover, the space | interval of the head connection material 13 which adjoins in the continuous direction of the 1st and 2nd wall bodies 11 and 12 is not restricted to the example of illustration, but is made smaller and it connects with more head connection materials 13 more It is good also as a structure to do.

  Also, the head of the retaining wall may be covered with a lining board. Therefore, the head connecting member 13 may use a lining plate and be integrated with it.

  Moreover, in the said embodiment, although the head connection material 13 has connected the head of the 1st wall body 11 and the head of the 2nd wall body 12 mechanically, as shown in FIG. The concrete is used as the head connecting member 70, and the concrete is placed so as to connect the head of the first wall 11 and the head of the second wall 12, and the first and second walls are connected. The bodies 11 and 12 may be integrated.

  Moreover, in the said embodiment, although the steel sheet pile was used as a wall member which comprises a wall and the wall was formed by the row | line | column of a steel sheet pile, you may use H steel as a wall member which comprises a wall. In the case of using H steel, for example, a wall made of soil mortar is constructed in the ground, and before hardening of the soil mortar, the earth is anchored by driving the H steel as a core material at predetermined intervals in the continuous direction of the wall. Form a wall. And a double earth retaining wall is formed by such a method, and the heads of the H steels are connected with a head connecting material to form a ramen structure.

Next, a deformation mode in which the support-side second wall body 12 is driven obliquely will be described with reference to FIG.
In FIG. 1, the first and second wall bodies 11 and 12 are driven perpendicularly to the ground and arranged in parallel to each other. On the other hand, in FIG. 9, the first wall body 11 is driven perpendicularly to the ground, but the second wall body 12 is driven obliquely so that the distance from the first wall body 11 increases toward the lower side. .

With the configuration as shown in FIG. 9, the following effects can be obtained.
That is, as shown in FIG. 9, passive earth pressure acts on the first wall 11 as shown, and larger active earth pressure acts on the second wall 12 as shown. . However, since the second wall body 12 is disposed obliquely, the component force of the load acts on the second wall body 12 as an axial force (force in a direction along the wall body 12). The force acting as a bending moment on the wall 12 is reduced. And it becomes advantageous also in stress by the increase in axial force. Therefore, the specification of the wall can be reduced by that amount, which is economical.

  Further, another embodiment of the present invention will be described below.

  In the embodiment of FIGS. 10 and 11, the heads of the first and second wall bodies 11 and 12 are connected by cast-in concrete.

  For example, as shown in FIG. 10A, the heads of the first and second walls 11 and 12 are projected to the ground side from the ground G in a state where the first and second walls 11 and 12 are driven in. Let Then, on the heads of the first and second wall bodies 11 and 12, a projection member 101 for integration (for preventing slippage) such as a headed stud or a deformed reinforcing bar is attached by welding or the like in a direction facing each other. (However, it may be pre-installed at the factory). In this state, concrete 102 is placed between the heads of the first and second wall bodies 11 and 12. When casting the concrete 102, a mold may be installed on the ground G, or may be cast on the ground G as it is without installing the mold.

  The cast concrete 102 connects the heads of the first and second walls 11 and 12 through the projecting members 101 projecting from the heads of the first and second walls 11 and 12. be able to. Therefore, in the present embodiment, the projection member 101 and the cast-in-place concrete 102 constitute the head connecting member 13, whereby the earth retaining structure 10 is constructed, and it becomes possible to cut and cut.

  Such a head connection structure with cast-in-place concrete can resist the compressive force between the first and second walls 11 and 12, and the first and second walls 11 and 12 The tension between 12 can be countered by the projecting member 101. Further, even when a vertical shearing force is generated between the first and second wall bodies 11 and 12, the first and second wall bodies 11 and 12 are integrated with each other by the protruding member 101 and the concrete 102 to resist each other. can do. Moreover, the head connection by cast-in-place concrete can absorb installation errors between the first and second wall bodies 11 and 12.

  FIG. 10 (B) shows a modification of the embodiment of FIG. 10 (A), in which both projecting members 101 are inserted between the heads of the first and second wall bodies 11 and 12 prior to placing concrete. Reinforcing bars 103 are inserted in a connected form, and the head connecting member 13 has an RC (reinforced concrete) structure. Such a structure is suitable when the tensile force between the first and second walls 11 and 12 is large.

  FIG. 10 (C) also shows a modification of the embodiment of FIG. 10 (A), in which the first and second wall bodies 11 and 12 are ground to the head so that the head connecting member 13 does not protrude from the ground G. After driving in G, the head between the first and second walls 11 and 12 is dug down, and concrete is placed in the dug. Thereby, it can construct without making it protrude from a natural ground.

  FIG. 11 shows a plan view of the embodiment of FIG. 10, and shows two patterns of FIGS. 11 (A) and 11 (B).

  In the pattern of FIG. 11A, head connection by cast-in-place concrete 102 is performed at predetermined intervals in the extending direction of the first and second wall bodies (steel sheet piles) 11 and 12. In particular, in this example, the steel sheet piles constituting the first and second wall bodies 11 and 12 are arranged in opposite phases, and the concrete 102 for head connection is placed in the portion having the shortest distance. Thereby, the material cost of the concrete 102 for head connection can be saved. However, in the case of this example, a formwork that partitions the placement portion and the non-placement portion of the concrete 102 is required.

  In the pattern of FIG. 11B, the head connection by the cast-in-place concrete 102 is performed continuously in the extending direction of the first and second wall bodies (steel sheet piles) 11 and 12. When concrete is continuously cast, the cross-section that can resist the compressive force, tensile force, and shear force generated in the rigid head portion becomes large, so the arrangement of the projecting member 101 (FIG. 10) for integration The amount can be reduced.

  The embodiment of FIG. 12 improves the ground between the first and second walls 11 and 12 using a high pressure jet agitation method, and at the same time uses the mud (soil cement) generated along with the implementation of the method. And perform head connection.

  This will be described with reference to FIG. 12A. After the first and second wall bodies 11 and 12 are driven, the predetermined depth position of the ground is improved by a high-pressure jet stirring method. The high-pressure jet agitation method is generally a method for forming a ground improvement pile on the ground, but it is used here to improve a part of the ground in the depth direction.

  First, a boring hole 201 is formed in the ground between the first and second wall bodies 11 and 12 so as to reach a desired improved position. Next, a high-pressure injection rod 202 having an injection port on the outer periphery of the tip is inserted into the boring hole 201.

  The high pressure injection rod 202 is rotated about its axis. In addition, an injection liquid (cement-based solidification material, for example, cement milk) and compressed air are separately supplied into the high-pressure injection rod 202 from the base end side (the ground side), and the tip of the high-pressure injection rod 202 is supplied. The jet liquid is jetted together with compressed air from the outer periphery of the unit. Thereby, the ground around the injection portion can be stirred and mixed, and the ground can be improved.

  Further, when the ground is improved, the slime kneaded soil (soil cement) is discharged to the ground side through the gap between the boring hole 201 and the high pressure injection rod 202.

  Prior to high-pressure injection, the first and second wall bodies 11, 12 are used to connect the heads of the first and second wall bodies 11, 12 using the soil cement discharged at this time. A pool (concave portion) 203 for storing soil cement is formed on the ground side. The pool 203 may be formed by digging a ground surface between the first and second wall bodies 11 and 12 by a predetermined depth, and the heads of the first and second wall bodies 11 and 12 may be formed. It may be formed by protruding from the ground surface.

  Prior to the high-pressure injection, the heads of the first and second wall bodies 11 and 12 are integrated with head studs and deformed reinforcing bars so as to protrude into the pool 203 therebetween. The protruding member 204 is attached by welding or the like.

  Therefore, finally, as shown in FIG. 10B, the ground improvement block 205 is formed at a predetermined depth position between the first and second wall bodies 11 and 12. Also, in the borehole 201, the soil cement 206 solidifies in a bar shape. And the drained soil cement 207 solidifies also in the pool 203 between the heads of the first and second wall bodies 11 and 12.

  The soil cement 207 connects the heads of the first and second walls 11 and 12 through the projecting members 204 attached to the heads of the first and second walls 11 and 12. Can. Therefore, in the present embodiment, the projecting member 204 and the soil cement 207 solidified in the pool 203 constitute the head connecting member 13, whereby the earth retaining structure 10 is constructed, and it becomes possible to perform the open cutting.

  As described above, after the first and second walls 11 and 12 are driven in, the cement-based solidifying material is mixed with the ground between them by the high-pressure jet agitation method, whereby the first and second walls 11 and 12 are mixed. , The ground between 12 can be reinforced. Then, the soil cement 207 discharged at the time of the high-pressure jet stirring method is stored in the pool 203 between the heads of the first and second wall bodies 11 and 12 and solidified, so that the soil cement 207 is stored in the head. The head of the first wall body 11 and the head of the second wall body 12 can be connected by using the part connecting member 13.

  The boring holes 201 between the first and second walls 11 and 12 are formed at predetermined intervals in the extending direction of the first and second walls 11 and 12, and the ground improvement mass 205 is formed in the same direction. Should be wrapped. Thereby, the soil cement 207 in the pool 203 also continues in the extending direction of the first and second wall bodies 11 and 12.

  The embodiment of FIG. 13 connects the heads of the first and second wall bodies (steel sheet piles) 11 and 12 using a precast concrete block. FIG. 13A is a longitudinal sectional view, and FIG. 13B is a plan view.

  In the state where the first and second wall bodies (steel sheet piles) 11 and 12 are driven, the heads of the first and second wall bodies 11 and 12 are projected from the ground to the ground side. Then, a rectangular parallelepiped (or plate-like) precast concrete block 301 is placed between the heads of the first and second walls 11 and 12 (in this example, at the shortest distance between steel sheet piles to save material costs). Deploy.

  The precast concrete block 301 may be placed on the ground, but the hook 302 is formed by reinforcing bars embedded in advance, and is suspended at the upper end portions of the first and second wall bodies 11 and 12, If it is made to float from the ground, it will not be affected by the unevenness of the ground.

The first and second wall bodies (steel sheet piles) 11 and 12 and the precast concrete block 301 are fastened and fixed by a fastening member 303.
As the fastening member 303, a PC steel rod (or reinforcing bar) of a total screw and a nut are used.

  For this reason, the hole for PC steel bars is provided in the steel sheet pile which comprises the 1st and 2nd wall bodies 11 and 12. FIG. Although this hole can be provided in the steel sheet pile in advance, the construction error can be absorbed by drilling after the driving.

  The precast concrete block 301 may or may not be provided with holes for PC steel bars.

  When a hole for a PC steel bar is provided in the precast concrete block 301, it is fastened and fixed to the precast concrete block 301 through the PC steel bar 303 as shown on the upper side of FIG. It can be fixed more reliably by passing it through.

  When a hole for a PC steel bar is not provided in the precast concrete block 301, a PC steel bar 303 is arranged around the precast concrete block 301 as shown in the lower side of FIG. By not passing through, it is possible to eliminate the need for drilling of the precast concrete block.

  If the installation error between the steel sheet piles is large, a rubber plate may be sandwiched between the steel sheet piles and the precast concrete block, or non-shrinkage mortar may be filled.

  By clamping and fixing the PC steel rod, the necessary tensile force is introduced to the PC steel rod, and the pair of steel sheet piles can be integrated. By tensioning the PC steel bar, a compressive force is introduced into the precast concrete block, and the steel sheet pile and the precast concrete block are not separated from each other, so that a large rigidity is obtained.

Therefore, in this embodiment, the head connection material 13 is comprised by the precast concrete block 301 and the fastening member (PC steel bar) 303, and the earth retaining structure 10 is constructed | assembled by this, and excavation is attained.
Here, the precast concrete block and the PC steel rod can resist the bending moment generated in the rigid joint, and the shear force can be resisted by the frictional force between the steel sheet pile and the precast concrete block.

  In addition, since the earth retaining becomes unnecessary and the precast concrete block and the PC steel rod are removable when removing it, removal becomes easy, and diversion becomes possible.

  The embodiment of FIGS. 14-16 connects the head of the 1st and 2nd wall bodies 11 and 12 which consist of a row of steel sheet piles by the joint steel materials of steel sheet pile utilization.

  FIG. 14A is a plan view before the head connection, and FIG. 14B is a view taken along the line BB in FIG. 14A, and the state before the head connection will be described.

  The 1st and 2nd wall bodies 11 and 12 are each comprised by the row | line | column of steel sheet piles 401, 402, 403, 404, 405, ..., and the steel sheet piles 401-405 of each row | line | column are driven into the ground G. Connected to the adjacent steel sheet piles by joints.

Here, a pair of recesses 412 are formed in the row of steel sheet piles by making the height of the pair of steel sheet piles 402 facing each other lower than the height of the adjacent steel sheet piles 401 and 403 that are connected by joints.
Similarly, a pair of recessed parts 414 are formed in the row of steel sheet piles by making the height of a pair of steel sheet piles 404 facing each other lower than the height of both adjacent steel sheet piles 403 and 405 connected by joints.

By doing in this way, recessed part 412,414, ... is formed in the row | line | column direction of a steel sheet pile at a predetermined space | interval.
In addition, as a method of lowering the height of the steel sheet piles 402, 404,... Can be considered.

  FIG. 15 (A) is a plan view after head connection, and FIG. 15 (B) is a B-B arrow view of FIG. 15 (A).

  The head connecting member 13 of the present embodiment uses the recesses 412, 414,..., The steel sheet piles constituting the first wall body 11, and the steel constituting the second wall body 12. Connect with a row of sheet piles.

  That is, one head connecting member 13 can be fitted into the pair of recesses 412 and can be connected to both adjacent steel sheet piles 401 and 403 by joints (a length corresponding to the depth of the recess 412). The steel sheet pile 422 and a steel material (for example, two steel plates) 432 connecting the pair of short steel sheet piles 422 are configured. The pair of short steel sheet piles 422 and the steel material 432 are fixed by welding or the like.

  In addition, another head connecting member 13 can be fitted into the pair of recesses 414 and can be connected to both adjacent steel sheet piles 403 and 405 by joints (the length corresponding to the depth of the recess 414). The steel sheet pile 424 and a steel material (for example, two steel plates) 434 connecting the pair of short steel sheet piles 424 are configured. The pair of short steel sheet piles 424 and the steel material 434 are fixed by welding or the like.

Therefore, a pair of short steel sheet piles 422 of one head connecting member 13 is inserted into the recess 412, and the joints at both ends of the short steel sheet pile 422 are connected to the joints of the adjacent steel sheet piles 401 and 403.
Further, a pair of short steel sheet piles 424 of another head coupling member 13 is inserted into the recess 414, and joints at both ends of the short steel sheet pile 424 are connected to joints of the adjacent steel sheet piles 403 and 405.

By doing in this way, the row | line | column of the steel sheet pile which makes the 1st wall body 11 and the row | line | column of the steel sheet pile which makes the 2nd wall body 12 can be connected.
In addition, the upper end part of the steel sheet pile 402 and the lower end part of the steel sheet pile 422, and the upper end part of the steel sheet pile 404 and the lower end part of the steel sheet pile 424 may be integrated by welding if necessary.

  In addition, when a large compressive force acts on a steel material (for example, two steel plates 432) that connects steel sheet piles (for example, 422) constituting the head connection material, in the case of a steel plate, it is considered that buckling occurs. The buckling can be prevented by increasing the number or by reinforcing with another steel material, and buckling can also be prevented by filling concrete.

  16 (A) to 16 (C) show a head connecting material using a steel sheet pile that can be used in the embodiment of FIG.

  FIG. 16A shows a head connecting material using a steel sheet pile that connects a pair of steel sheet piles arranged in opposite phases at the shortest distance, and FIG. 16B shows a pair of steel sheet pile arranged in opposite phases the longest distance. FIG. 16 (C) shows a steel sheet pile head connection material that connects a pair of steel sheet piles arranged in the same phase.

The embodiment of FIG. 17 connects the heads of the first and second wall bodies 11 and 12 using a joint steel material formed by combining steel plates.
17A is a front view of the head connecting portion, FIG. 17B is a plan view, and FIG. 17C is a view taken along the line CC in FIG. 17A.

  The head connecting member 13 of the present embodiment includes a first joint steel member 501 fixed to the head of the first wall 11 and a second joint steel member fixed to the head of the second wall 12. 502 and a spliced steel plate 503 that connects the first joining steel material 501 and the second joining steel material 502.

  The first bonding steel material 501 is welded to two first steel plates 511 sandwiching the head of the first wall body 11 from above and the upper end portion of the first steel plate 511, and is horizontal to the second wall body 12 side. It consists of a second steel plate 512 protruding like a bowl in the direction, and a third steel plate 513 welded to the first and second steel plates 511 and 512 and disposed in a vertical plane perpendicular to these.

  The second joining steel material 502 is welded to the two first steel plates 521 sandwiching the head of the second wall body 12 from above and the upper end of the first steel plate 521, and is horizontal to the first wall body 11 side. It consists of a second steel plate 522 protruding like a bowl in the direction, and a third steel plate 523 welded to the first and second steel plates 521 and 522 and disposed in a vertical plane perpendicular to these.

  The welded steel plates 503 are applied to the third steel plates 513 and 523 of the first and second joint steel materials 501 and 502 so as to straddle them, and connect them. Two splicing steel plates 503 are also provided and are attached to the front and back surfaces of both third steel plates 513 and 523 and are fixed together.

Here, each of the two first steel plates 511 and 521 is installed so as to cover the first and second wall bodies 11 and 12 from above, and is fixed by pressing bolts.
The third steel plates 513 and 523 and the welding steel plate 503 are fixed by bolts. By setting the insertion hole of the bolt to be a long hole, it is possible to absorb installation errors of the first and second wall bodies 11 and 12. In addition, the bolt insertion hole on the splicing steel plate 503 side is, for example, a long slot in the horizontal direction, and the bolt insertion hole on the third steel plates 513, 523 side is, for example, a long slot in the vertical direction. Can also be absorbed.
Moreover, by adopting a method of assembling with a bolt at the site in this way, it is possible to easily remove and reuse.

The embodiment of FIG. 18 connects the heads of the first and second wall bodies 11 and 12 using a cross-type joint steel material.
FIG. 18 (A) is a front view of the head connection portion, and FIG. 18 (B) is a plan view.

  The head connecting member 13 of the present embodiment includes a first longitudinal steel member 601, a second longitudinal steel member 602, a first cross steel member 603, and a second cross steel member 604. Each of these steel materials is an angle material, and both ends of the angle material of the first and second cross steel materials 603 and 604 are used by being cut obliquely.

The first longitudinal steel member 601 is welded and fixed to the head of the first wall 11 and disposed in the longitudinal direction.
The second vertical steel member 602 is welded and fixed to the head of the second wall 12 and is arranged in the vertical direction.
Both the first and second vertical steel members 601 and 602 are formed with bolt insertion holes on one side of the angle member in advance, and the other sides on the surfaces of the first and second wall bodies 11 and 12 facing each other. Weld the circumference in the state of contact.

Both ends of the first cross steel material 603 are bolted to the upper part of the first vertical steel material 601 and the lower part of the second vertical steel material 602, respectively, and are arranged in an oblique direction.
Both ends of the second cross steel material 604 are bolted to the lower part of the first vertical steel material 601 and the upper part of the second vertical steel material 602, respectively, and are arranged in an oblique direction.
Therefore, the first cross steel material 603 and the second cross steel material 604 cross in an X shape.

  Here, the bolt insertion holes of the first and second cross steel members 603, 604 may be formed in advance, but after welding and fixing of the first and second longitudinal steel members 601, 602 at the site, the first and second The hole positions of the second longitudinal steel members 601 and 602 may be confirmed to make holes. This makes it possible to absorb construction errors.

  Thus, the first and second cross steel materials 603 and 604 are used by using the first and second vertical steel materials 601 and 602 and the first and second cross steel materials 603 and 604. And the rigidity of the head connection part of the 2nd wall bodies 11 and 12 can be enlarged.

Furthermore, by bolting the intersections 605 of the first and second cross steels 603 and 604, a more rigid truss structure can be obtained, and further improvement in rigidity can be expected.
The bolt fixing portions of the first and second longitudinal steel members 601 and 602 and the first and second cross steel members 603 and 604 are preferably bolt-fixed at a plurality of locations, but are bolt-fixed at one location. When it becomes the structure to perform, rigid coupling | bonding can be ensured by bolting the intersection part 605 of the 1st and 2nd cross steel materials 603 and 604. FIG.

  The embodiment of FIG. 19 is to connect the heads of the first and second wall bodies 11 and 12 formed of a row of steel sheet piles, using a guide steel material at the time of driving the steel sheet piles.

  FIGS. 19A to 19C are shown in order of construction of the retaining wall, and the left side of each figure is a longitudinal sectional view, and the right side is a plan view.

  First, as shown in FIG. 19 (A), a pair of guide steel materials 701 and 702 made of, for example, H-shaped steel are disposed on the ground G, sandwiching an area to be driven of steel sheet piles constituting the first wall 11. . Then, the steel sheet piles constituting the first wall body 11 are driven one by one while being guided by the pair of guide steel materials 701 and 702.

Next, as shown in FIG. 19 (B), after the construction of the first wall body 11 in at least one section, the steel sheet pile constituting the second wall body 12 is sandwiched and the H-shape is similarly sandwiched. A pair of guide steels 703 and 704 made of steel are disposed on the ground G.
At this time, among the guide steel materials 701 and 702 for the first wall body 11, the guide steel material 702 on the second wall body 12 side is not removed, but is left as it is, and only the guide steel material 701 on the opposite side is removed. The removed guide steel 701 can be diverted as the guide steel 703 or 704.
Then, the steel sheet piles constituting the second wall body 12 are driven one by one while being guided by a pair of guide steel materials 703 and 704.

Next, as shown in FIG. 19C, after the construction of the first and second wall bodies 11 and 12 in at least one section, the first of the guide steel materials 703 and 704 for the second wall body 12 The guide steel 703 on the wall 11 side is not removed but is left as it is, and only the guide steel 704 on the opposite side is removed.
Thereby, the guide steel materials 702 and 703 are left between the heads of the first and second wall bodies 11 and 12.

  Therefore, as in the present example, when the distance between the first and second walls 11 and 12 corresponds to two guide steels, the first and second walls 11 and 12 and the guide steels 702 and 703 can be By welding or bolt fixing, the guide steel materials 702 and 703 can be used as the head connecting material.

  In this example, the distance between the first and second walls 11 and 12 corresponds to two guide steels, but the distance between the first and second walls 11 and 12 is one guide steel The same applies to the case of minutes.

  In addition, as shown in a modified embodiment of FIG. 20, when the distance between the first and second wall bodies 11 and 12 is wide, etc., a suitable auxiliary steel material 705 separately manufactured is installed between the guide steel materials 702 and 703, What is necessary is just to integrate by welding or bolt fixation.

The embodiment of FIG. 21 is a triple earth retaining wall.
Therefore, the earth retaining structure 10 of this embodiment is a triple structure (triple earth retaining wall) of the first wall 11, the second wall 12, and the third wall 14.

  Also in this embodiment, a steel sheet pile (sheet pile) is used as a wall member that constitutes the first, second, and third wall bodies 11, 12, and 14.

The first wall 11 is driven into the ground (ground before cutting) G so as to separate the cutting side and the ground side.
The second wall body 12 is driven in parallel to the ground wall closer to the ground than the first wall body 11 with an interval of, for example, about 0.5 to 1 m from the first wall body 11.
The third wall body 14 is parallel to the ground on the ground mountain side of the second wall body 12 with an interval of, for example, about 0.5 to 1 m from the second wall body 12 (or the embodiment of FIG. 9). In the same way as the second wall 12).

  The earth retaining structure 10 of the present embodiment further includes a head connecting member 13 that connects and fixes the head of the first wall 11 and the head of the second wall 12, and the second wall 12. And a head connecting member 13 ′ for connecting and fixing the head of the third wall body 14 to the head of the third wall body 14.

  In other words, after the first, second and third wall bodies 11, 12, and 14 are driven in, the head portion of the first wall body 11 and the head portion of the second wall body 12 are connected to the head connecting material. 13, a step of connecting the head of the second wall 12 and the head of the third wall 14 with the head connecting member 13 ′ is performed.

  Here, the first, second and third wall bodies 11, 12, 14 and the head connecting members 13, 13 ′ are rigidly joined to form a ramen structure (a portal ramen structure), and the first The ground between the second and third wall bodies 11, 12, and 14 is restrained. Thus, the triple earth retaining wall can exert effects beyond the double earth retaining wall.

  With respect to the specific structure of the head connecting members 13 and 13 ′ for the rigid joint, the structure shown in the embodiment of FIGS. 1 to 9 and further the embodiment shown in FIGS. 10 to 20 can be applied. .

  As is apparent from the above description, the illustrated embodiments merely illustrate the present invention, and the present invention, in addition to those directly shown by the described embodiments, is a person skilled in the art within the scope of the claims. Needless to say, the present invention includes various improvements and changes made by the above.

DESCRIPTION OF SYMBOLS 10 Earth retaining structure 11 1st wall body 12 2nd wall body 13, 13 'Head connection material 14 3rd wall body 31 Beam part 32 Junction part 32a, 32b Holding plate 32c Fitting groove 33 Junction part 33a , 33b Clamping plate 33c Fitting groove 34, 35 Lock nut 41, 42, 51 to 54 Tightening fixing portion (pressing bolt)
60 Solidification material 61 Water collection pipe 62 Pump 70 Head connection material (concrete)
101 Protruding member 102 Cast-in-place concrete 103 Reinforcing bar 201 Boring hole 202 High-pressure injection rod 203 Pool (recess)
204 Protruding member 205 Ground improvement block 206, 207 Soil cement 301 Precast concrete block 302 Hook 303 Fastening member (PC steel bar)
401 to 405 Steel sheet piles 412, 414 Recesses 422, 424 Short steel sheet piles 432, 434 constituting the head coupling material (two steel plates)
501 first joint steel material 502 second joint steel material 503 welded steel plate 511, 521 first steel plate 512, 522 second steel plate 513, 523 third steel plate 601 first longitudinal steel material 602 second longitudinal steel material 603 first cross steel material 604 Second cross steel 605 intersections 701 to 704 Guide steel 705 Supplement steel

Claims (21)

A first wall that is driven into the ground so as to divide the cut and cut side and the ground side;
A second wall which is driven into the ground on the ground side of the first wall at a distance from the first wall;
A head connector connecting the head of the first wall and the head of the second wall;
Comprising
The earth retaining structure characterized in that the first and second walls and the head connecting member are rigidly joined to form a rigid frame structure.   The earth retaining structure according to claim 1, wherein each of the first and second wall bodies is formed by a row of steel sheet piles. The head connecting member has a beam portion extending in a direction intersecting with the first and second walls, and a joint portion bending and extending downward from both ends of the beam portion.
The earth retaining structure according to claim 1 or 2, wherein each of the joints is fastened and fixed to the head of the first and second walls at a plurality of points in the vertical direction.   The earth retaining structure according to claim 3, wherein each of the joints is bifurcated and fitted so as to sandwich the walls.   The earth retaining structure according to claim 1, wherein the head connecting material is concrete.   The earth retaining structure according to any one of claims 1 to 5, wherein the first and second walls are vertically driven into the ground and are parallel to each other.   The first wall may be vertically driven into the ground, and the second wall may be diagonally driven into the ground so that the distance from the first wall to the lower side may be increased. The earth retaining structure according to any one of claims 1 to 5.   The earth retaining structure according to any one of claims 1 to 7, further comprising a solidifying material injected into the ground between the first and second walls.   The water collection system according to any one of claims 1 to 7, further comprising a water collection facility for collecting water from the ground between the first and second walls to lower the groundwater level. Earth retaining structure described in. The head connecting material is
Projection members fixed to the head of the first and second walls and respectively projecting in opposite directions;
Concrete or soil cement which encases the projecting member and is solidified between the heads of the first and second walls;
The earth retaining structure according to claim 1 or 2, wherein the earth retaining structure comprises: The head connecting material is
A precast concrete block disposed between the heads of the first and second walls;
A fastening member for fastening and fixing the heads of the first and second wall bodies and the precast concrete block;
The earth retaining structure according to claim 1 or 2, wherein the earth retaining structure comprises: The head connecting material is
In the row of steel sheet piles forming the first and second wall bodies, the height of the pair of steel sheet piles facing each other is made lower than the height of the adjacent steel sheet piles that are connected by joints. A pair of recesses formed in the row,
A pair of short steel sheet piles that can be fitted in the pair of recesses and can be connected between the adjacent steel sheet piles and joints;
A steel material connecting the pair of short steel sheet piles,
The earth retaining structure according to claim 2, comprising: The head joint member includes a first joint steel member fixed to a head of the first wall, a second joint steel member fixed to a head of the second wall, and the first joint member. And a welded steel plate connecting the second joint steel members,
Each of the first and second joining steel materials is fixed to the upper ends of two first steel plates sandwiching the head of one wall body from above and horizontally on the other wall body side. A second steel plate projecting in a bowl shape in the direction, and a third steel plate fixed in the first and second steel plates and disposed in a plane orthogonal thereto,
The earth retaining structure according to claim 1 or 2, wherein the spliced steel plate is applied to and connected to both third steel plates of the first and second joining steel materials. The head connecting material is
A first longitudinal steel member fixed to the head of the first wall and disposed in the longitudinal direction;
A second longitudinal steel member fixed to the head of the second wall and disposed longitudinally;
A first cross steel material, both ends of which are fixed to the upper portion of the first vertical steel material and the lower portion of the second vertical steel material and disposed in an oblique direction,
A second cross steel material which has both end portions fixed to the lower portion of the first vertical steel material and the upper portion of the second vertical steel material and is disposed in an oblique direction and which crosses the first cross steel material;
The earth retaining structure according to claim 1 or 2, wherein the earth retaining structure comprises: A first wall that is driven into the ground so as to divide the cut and cut side and the ground side;
A second wall which is driven into the ground on the ground side of the first wall at a distance from the first wall;
A third wall which is driven into the ground closer to the ground from the second wall and spaced apart from the second wall;
A head connector for connecting the head of the first wall and the head of the second wall, and the head of the second wall and the head of the third wall; ,
Comprising
The earth retaining structure, wherein the first, second, and third wall bodies and the head connecting member are rigidly joined to form a ramen structure. Driving the first and second walls spaced apart from each other so as to divide the ground side from the cut and cut side and the ground side;
A step of connecting the head of the first wall and the head of the second wall with a head connecting member after driving the first and second walls;
Including
In the connecting step, the first and second wall bodies and the head connecting material are rigidly joined so as to form a rigid frame structure and restrain the ground between the first and second wall bodies. A soil retaining method characterized by that.   The earth retaining method according to claim 16, further comprising a step of injecting a solidifying material into a ground between the first and second wall bodies.   The earth retaining method according to claim 16, further comprising the step of collecting water from the ground between the first and second wall bodies to lower the groundwater level.   The earth retaining method according to claim 16, further comprising a step of mixing a cement-based solidified material into the ground between the first and second wall bodies by a high-pressure jet stirring method.   The soil cement is used as the head connecting member by storing and cementing the soil cement, which is drained at the time of implementation of the high-pressure jet agitation method, in the pool between the heads of the first and second walls. 20. A method according to claim 19, characterized in that it is used to connect the head of the first wall and the head of the second wall. Driving the first, second and third walls spaced apart from each other so as to separate the cut and cut sides and the ground side in the ground;
After driving the first, second and third walls, the head of the first wall and the head of the second wall, and the head of the second wall and the first Connecting the heads of the three walls with a head connector;
Including
In the connecting step, the first, second, and third wall bodies and the head connecting member form a ramen structure to restrain the ground between the first, second, and third wall bodies. As mentioned, it is characterized by having a rigid joint, a method of retaining earth.