JP6426029B2 - Temporary wall and temporary wall construction method - Google Patents

Description

  The present invention relates to a temporary wall provided on at least a part of the side surface of a pneumatic caisson case and a temporary wall method used for at least a part of the side surface.

  Conventionally, as an economical approach caisson which facilitates dismantling, can reduce the construction period and costs, and can reduce waste, and as a construction method of a tunnel approach section using the caisson A caisson for approach disclosed in Patent Document 1 has been proposed.

  In the approach caisson disclosed in Patent Document 1, the first side wall in the road longitudinal direction side of the pneumatic caisson is composed of a temporary wall which can be assembled and disassembled and has a function of a mountain retaining wall, and the first side wall The lower portion is fixed to the upper portion of the pneumatic slab formed at the lower portion of the caisson rod body, and the upper portion is supported or fixed by a supporting means or fixing means.

  The approach caisson disclosed in Patent Document 1 constitutes a temporary wall, in particular, by making a dismantleable steel sheet pile or steel pipe function as a retaining wall in the first side wall on the road longitudinal direction side of the pneumatic caisson. It is In addition, the caisson for approach disclosed in Patent Document 1 may be replaced by a steel sheet pile, and a prestressed concrete plate may be used.

JP, 2009-002032, A

  However, in the approach caisson disclosed in Patent Document 1, a plurality of steel sheet piles are arranged in the width direction, and the coupling portions are engaged with each other, so that a temporary wall is formed of the plurality of steel sheet piles. There is a problem that the workability of the inside of the pneumatic caisson is significantly reduced because the water blocking performance of the joint portion of the steel sheet pile becomes insufficient and a large amount of water leakage is generated from the fitting portion of the joint portion. .

  Moreover, since the caisson for approach disclosed in Patent Document 1 has a plurality of steel sheet piles extending continuously in the vertical direction, when removing each steel sheet pile, it is located above the pneumatic caisson. It is necessary to pull out the steel sheet pile to the direction, and by ensuring that the steel sheet pile can not be installed between the upper structure and the lower structure of the pneumatic caisson, sufficient water blocking performance is secured above the steel sheet pile. There was a problem that it became difficult.

  Further, in the approach caisson disclosed in Patent Document 1, since each of the plurality of steel sheet piles extends continuously in the vertical direction, the earth pressure or water pressure acting from the side of the temporary wall depends on the depth. Although it becomes different, it becomes necessary to design the yield strength of the steel sheet pile on the basis of the maximum earth pressure or water pressure, which makes the construction cost of a temporary wall composed of a plurality of steel sheet piles excessive. Also, there was a problem that construction period increased.

  Furthermore, the caisson for approach disclosed in Patent Document 1 cuts the prestressed concrete plate with a wire saw when removing a temporary wall, even when using a prestressed concrete plate in place of a steel sheet pile. After that, it is necessary to carry out the prestressed concrete plate fragmented by cutting, so the removal cost of the temporary wall composed of the prestressed concrete plate becomes excessive, and the removal period increases. there were.

  Then, this invention is devised in view of the problem mentioned above, and the place made as the purpose is construction and removal of a temporary wall, securing sufficient waterproof performance with a plurality of precast concrete blocks. It is an object of the present invention to provide a temporary wall and temporary wall construction method that can be implemented easily and quickly.

  The temporary wall according to the first aspect of the present invention is a temporary wall provided on the side surface of at least a part of a box of a pneumatic caisson, and is provided with a plurality of precast concrete blocks provided stacked from the bottom to the top and a plurality of the precast concrete blocks. A plurality of the precast concrete blocks are provided integrally in the upper part of the lower structure of the box before the box is sunk, and the plurality of precast concrete blocks are sunk in the box. After being allowed to separate, each of the precast concrete blocks is separated from each other and removed laterally from the space formed above the lower structure of the box.

  The temporary wall according to a second aspect of the present invention is the temporary wall according to the first aspect, wherein the plurality of precast concrete blocks are each formed with a through hole penetrating in the vertical direction, and before sinking the box, the plurality of precast concrete blocks The wire rod is continuously inserted into each of the through holes formed in and the tension force is applied to the wire rod to be integrated and installed, and after the box is sunk, the wire rod The present invention is characterized in that each of the precast concrete blocks is separated from each other by eliminating the tension force.

  In the temporary wall according to the third aspect of the present invention, in the first aspect or the second aspect of the present invention, the plurality of precast concrete blocks are provided with notches cut out in the wall thickness direction of the box, and the box is sunk Later, each of the precast concrete blocks is removed to the side of the box by being lifted by a jack device installed in the notch.

  In the temporary wall according to the fourth invention, in any one of the first invention to the third invention, the plurality of precast concrete blocks are formed with through holes penetrating in the vertical direction in each, and the thickness direction of the box The cut-outs are cut out and the wire rod is inserted continuously through each of the through holes formed in the plurality of precast concrete blocks before the box is sunk, and the box is sunk After being made to separate, each said precast-concrete block is isolate | separated from each other by cut | disconnecting the said wire in the said notch part.

  The temporary wall construction method according to the fifth aspect of the present invention is a temporary wall construction method used for at least a part of the side surface of a pneumatic caisson box, wherein a plurality of precast concrete blocks are placed from above from below from below before sinking the box. And the installation step of integrating and installing the lower part of the box above the lower part of the box, and after sinking the box, the precast concrete blocks are separated from each other and the upper part of the lower part of the box is And a removing step of removing the space to the side of the box.

  According to the first to fifth aspects of the invention, the steel sheet is not constructed by fitting the plurality of steel sheet piles at the joint portion, but the water blocking material is provided in the gaps of the plurality of precast concrete blocks. Since the water blocking material can be adhered using self-weight and tension of the wire rod, it is possible to remarkably improve the water blocking performance by the water blocking material and to improve the workability inside the pneumatic caisson. It becomes.

  According to the first to fifth inventions, instead of being constructed of a plurality of steel sheet piles continuously extending in the wall height direction, each precast concrete block is directed upward in the wall height direction like a steel sheet pile. In the space between the upper structure and the lower structure of the box, a side wall for removal is built inside the side of the box, and the box is placed above the plurality of precast concrete blocks. Since the upper structure can be constructed integrally, it is possible to strongly integrate the removal side wall, the upper structure and the lower structure with each other to significantly improve the overall waterproof performance of the box.

  According to the first to fifth inventions, it is not constructed of a single prestressed concrete plate or the like extending continuously in the wall height direction, but a plurality of precast concrete blocks are made upward from below in the wall height direction. As it is built by stacking, it is possible to easily separate and carry out each precast concrete block without requiring an operation of cutting a single prestressed concrete plate or the like with a wire saw or the like. The temporary wall removal cost can be reduced, and the temporary construction period can be shortened.

  According to the first to fifth inventions, when laying subways or roads at a plurality of locations of the box, spaces having different depths are formed at the plurality of locations in the wall height direction, but the depth When the earth pressure or water pressure is large in the deep layer, the tension of the wire is increased, and the earth pressure or water pressure is small in the shallow layer. Since the tension of the wire can be reduced and rationally designed, there is no need to design a temporary wall with maximum load pressure or earth pressure, and the construction cost and construction period of the temporary wall can be rationalized. Can be reduced and shortened.

It is a perspective view which shows the main body structure where the temporary wall to which this invention is applied is introduce | transduced. It is a front view which shows the main body structure where the temporary wall to which this invention is applied is introduce | transduced from the outer side of a box. It is a top view showing the main part structure where a temporary wall to which the present invention is applied is introduced. It is a perspective view showing a temporary wall to which the present invention is applied. It is a front view showing a plurality of precast concrete blocks before sinking a box with a temporary wall to which the present invention is applied. (A) is a top view which shows each precast concrete block by the temporary wall to which this invention is applied, (b) is a rear view shown from the inside of the box. It is an enlarged front view which shows the water blocking material of the temporary wall to which this invention is applied. (A) is an enlarged plan view showing both sides in the wall width direction of each precast concrete block with temporary walls to which the present invention is applied, and (b) is an enlarged side view showing the upper end in the wall height direction . It is a front view showing a plurality of precast concrete blocks after sinking a box with a temporary wall to which the present invention is applied. It is an expanded side view which shows the wire cut | disconnected by the notch part of the temporary wall to which this invention is applied. It is an expanded side view which shows the roller car for transportation installed in the notch part of the temporary wall to which this invention is applied. It is an enlarged side view showing a jack installed in a notch of a temporary wall to which the present invention is applied. It is a side view which shows the installation process of the temporary wall construction method to which this invention is applied. It is a side view which shows the removal process of the temporary wall construction method to which this invention is applied. It is a front view showing a box in which spaces of different depths are formed at a plurality of locations in the wall height direction with temporary walls to which the present invention is applied. It is a front view showing a modification of a main part structure where a temporary wall to which the present invention is applied is introduced from the outside of a box.

  Hereinafter, the form for implementing temporary wall 1 to which the present invention is applied is explained in detail, referring to drawings.

  The temporary wall 1 to which the present invention is applied is, as shown in FIG. 1, a pneumatic caisson used in a latent box construction method to construct a main body structure 8 such as a sewage pump station, underground control pond, subway or road tunnel. It will be introduced into the box 7.

  With the latent box construction method, as shown in FIG. 2, a concrete box 7 built on the ground is installed above the ground, and then in a work room 77 provided below the box 7, By feeding compressed air in accordance with the groundwater pressure, the ground is excavated and removed in the working chamber 77 while the inflow of groundwater is prevented, and the case 7 is sunk.

  The box 7 is formed in, for example, a substantially rectangular parallelepiped shape, and includes an upper structure 73 formed in the upper part of the rectangular solid and a lower structure 74 formed in the lower part of the rectangular solid. The box 7 is a side wall 75 between the upper structure 73 and the lower structure 74, and as shown in FIG. 3, the structural side wall 71 is erected without being removed before and after the box 7 is sunk. And a removal side wall 72 which is removed after sinking the box 7.

  As shown in FIG. 3A, the plurality of boxes 7 are arranged in a row by sinking the plurality of boxes 7 as shown in FIG. 3A, thereby continuously connecting the plurality of boxes 7 in the laying direction L such as a subway or a road tunnel. Then, the main structure 8 is constructed to extend in the laying direction L.

  At this time, the box 7 is provided with the structural side wall 71 on the side surface 75 extending substantially parallel to the laying direction L, and the removal side wall 72 provided on the side surface 75 substantially orthogonal to the laying direction L. After sinking the box 7 so as to allow passage of a subway, a road tunnel, etc. on the side surface 75 substantially orthogonal to L, the removal side wall 72 is removed and the plurality of boxes 7 are connected It will be

  As shown in FIG. 3 (b), the box 7 is placed by placing a plurality of boxes 7 in a sunk state, depending on the installation area of a large-scale sewage pump station, underground control reservoir, etc. The main body structure 8 is constructed so that the plurality of boxes 7 are integrated in a planar shape.

  At this time, the box 7 is provided with the structural side wall 71 on the side surface 75 forming an extension of the sewage pump station, underground adjustment reservoir, etc., and on the side surface 75 disposed inside the sewage pump station, underground adjustment reservoir, etc. After the box 7 is sunk and allowed to sink so that a large-scale installation area can be realized by providing the side wall 72 for removal, the side wall 72 for removal is removed and the plurality of boxes 7 It becomes connected.

  The temporary wall 1 to which the present invention is applied is provided as the removal side wall 72 on at least a part of the side surface 75 of the pneumatic caisson case 7, for example, at four places in the substantially rectangular parallelepiped case 7. When the side surface 75 of this is formed, it will be provided in the side surface 75 of one to four places.

  The temporary wall 1 to which the present invention is applied is, for example, as shown in FIG. 3A, of four side surfaces 75 formed in the box 7, two side surfaces 75 facing each other in the laying direction L, As shown in FIG. 3B, the side wall 75 at one place is provided as a removal side wall 72 on the side face 75 adjacent to each other at the blind end 7 in the laying direction L.

  The temporary wall 1 to which the present invention is applied includes, as shown in FIG. 4, a plurality of precast concrete blocks 2 and a water blocking material 3 provided in the gaps S of the plurality of precast concrete blocks 2.

  The precast concrete block 2 is previously formed in a substantially rectangular shape etc. in a factory etc. For example, a non-barbed concrete block in which no reinforcement is made in concrete, a reinforced concrete block in which reinforcement is made in concrete, Alternatively, a prestressed concrete block or the like in which a PC steel wire or the like is disposed inside the concrete is used.

  The precast concrete block 2 extends in the wall width direction X and is formed with a predetermined width dimension W, extends in the wall height direction Y and is formed with a predetermined height dimension H, and has a predetermined depth in the wall thickness direction Z It is formed with a dimension D. The precast concrete block 2 has, for example, a width dimension W of about 5 m to 10 m, a height dimension H of about 0.4 m to 0.8 m, and a depth dimension D of about 0.3 m to 0.7 m.

  The precast concrete block 2 is continuously penetrated from the upper surface 2a to the lower surface 2b in the wall height direction Y to form one or more through holes 20 penetrating in the vertical direction. Although the through-hole 20 is formed in the approximate center of the wall thickness direction Z, the precast concrete block 2 is not limited to this, and the through-hole 20 may be formed close to the outer side A or the inner side B in the wall thickness direction Z .

  The precast concrete block 2 is a cutout partially cut out in the wall thickness direction Z, reaching the through hole 20 in the wall thickness direction Z at a position in the wall width direction X where each through hole 20 is formed 21 are formed. In the precast concrete block 2, the cutaway portion 21 is formed on the inner side B in the wall thickness direction Z, but not limited to this, the cutaway portion 21 may be formed on the outer side A in the wall thickness direction Z.

  In the plurality of precast concrete blocks 2, a pair of mutually facing notches 21 are formed in each of the upper surface 2 a and the lower surface 2 b of mutually facing precast concrete blocks 2, and the dimensions of each notches 21 are, for example, walls It is about 150 mm to 300 mm in the width direction X, about 20 mm to 80 mm in the wall height direction Y, and about 300 mm to 700 mm in the wall thickness direction Z.

  As shown in FIG. 5, a plurality of precast concrete blocks 2 are stacked from the lower side in the wall height direction Y to the upper side. The plurality of precast concrete blocks 2 are stacked from the lower side in the wall height direction Y to the upper side, so that the plurality of precast concrete blocks 2 are stacked and provided over a plurality of stages of, for example, 10 stages to 30 stages.

  The plurality of precast concrete blocks 2 are sequentially stacked in the wall height direction Y while sinking the box 7 from the ground or the like, and repeatedly sinking the box 7 and installing the precast concrete block 2. Before the completion of the sinking, the wall 7 is piled up and integrated in the wall height direction Y above the lower structure 74 of the box 7.

  The plurality of precast concrete blocks 2 repeat the settlement of the box 7 and the installation of the precast concrete block 2 as shown in FIGS. 1 and 2, and the inner side B in the wall thickness direction Z from the side surface 75 of the box 7 And from the bottom to the top in the wall height direction Y, they are sequentially stacked and integrated.

  In the plurality of precast concrete blocks 2, as shown in FIG. 5, the through holes 20 formed in each of the precast concrete blocks 2 are superimposed on each other in a planar direction before sinking the box 7, and the wall height direction Y Stacked on In the plurality of precast concrete blocks 2, the plurality of through holes 20 are arranged continuously in a row in the wall height direction Y by the respective through holes 20 being superimposed on one another in the planar direction.

  In the plurality of precast concrete blocks 2, one wire 22 such as a PC steel wire is inserted from the upper end to the lower end of the plurality of through holes 20 arranged in a row. The sheath tube is inserted into the through hole 20 of the plurality of precast concrete blocks 2 as needed, and each of the upper end 22a and the lower end 22b of the wire rod 22 is, for example, the uppermost precast concrete block 2 and the lower The PC steel rod 41 embedded in the structure 74 is connected and fixed by the coupler 42.

  A plurality of precast concrete blocks 2 are made continuous with the plurality of through holes 20 arranged in a row, and the wire 22 is inserted, and if necessary, a tensile force is introduced from the upper end 22 a of the wire 22 to make the wire 22 By being fixed, tension is applied to the wire 22, and the wire 22 to which this tension is applied is integrated in the wall height direction Y firmly.

  Each of the precast concrete blocks 2 is extended to the outside in the wall thickness direction Z on each of the upper surface 2a and the lower surface 2b, and extends in the wall width direction X, as shown in FIG. The water blocking material 3 extending in the thickness direction Z is disposed continuously in the wall width direction X and the wall thickness direction Z. In each precast concrete block 2, the water blocking material 3 can be installed not only on the upper surface 2 a and the lower surface 2 b but also on the inner surface 2 c of the inner side B in the wall thickness direction Z.

  As shown in FIG. 7, the plurality of precast concrete blocks 2 are provided in the gap S with a water blocking material 3 such as water expandable rubber or synthetic resin. In each precast concrete block 2, the water blocking material 3 is installed in the grooved 3a formed in each of the upper surface 2a and the lower surface 2b, and the water blocking material 3 of the upper surface 2a and the water blocking material 3 of the lower surface 2b are It makes it mutually oppose in the wall height direction Y, and makes it stick.

  In the plurality of precast concrete blocks 2, the water blocking material 3 is sufficiently adhered by the self-weight of each precast concrete block 2, and in particular, tension is applied to the wire rod 22, thereby firmly adhering the water blocking material 3 It will be possible to The precast concrete block 2 is provided with a water blocking material 3 in order to prevent the infiltration of ground water from the gap S, and the water blocking material 3 may be provided by any arrangement location or arrangement method.

  The plurality of precast concrete blocks 2 are provided by cast-in-place concrete or the like on the inner side B in the wall thickness direction Z as shown in FIG. 8 in a state of being stacked and integrated before sinking the box 7. While both sides in the wall width direction X are fixed to the projecting portion 76, the upper end in the wall height direction Y is fixed.

  A plurality of precast concrete blocks 2 are, as shown in FIG. 8A, on both sides in the wall width direction X, PC steel rods 41 embedded in each precast concrete block 2 and protrusions extending in the wall thickness direction Z The PC steel rod 41 attached to 76 is fixed by the coupler 42 to the protrusion 76 from the inside B in the wall thickness direction Z.

  In addition, as the PC steel rod 41 and the coupler 42 of the precast concrete block 2, those which are embedded in advance are used. The PC steel rod 41 of the protruding portion 76 is inserted into a hole provided later in the protruding portion 76 by a sheath tube or the like, fixed by a nut or the like, and attached.

  A plurality of precast concrete blocks 2 are fixed to the projecting portion 76 from the inner side B in the wall thickness direction Z so that holes are not formed in the outer surface 2 d of the outer side A in the wall thickness direction Z with each precast concrete block 2 However, the present invention is not limited to this, and it may be fixed to the projecting portion 76 by the PC steel rod 41 or the like from the outside A in the wall thickness direction Z.

  As shown in FIG. 8 (b), a plurality of precast concrete blocks 2 are sandwiched between the upper surface 2 a of the uppermost precast concrete block 2 and the upper structure 73 at the upper end in the wall height direction Y, as shown in FIG. The top precast concrete block 2 is pushed downward by the jack 51.

  The plurality of precast concrete blocks 2 are pushed downward by the jacks 51, and the water blocking material 3 is installed between the inner surface 2 c of the uppermost precast concrete block 2 and the upper structure 73. The plurality of precast concrete blocks 2 are connected by a coupler 42 with a PC steel rod 41 embedded in the uppermost precast concrete block 2 and a PC steel rod 41 extending in the wall thickness direction Z and attached to the protrusion 76 As a result, the protrusion 76 is fixed from the inside B in the wall thickness direction Z.

  In addition, as the PC steel rod 41 and the coupler 42 of the precast concrete block 2, those which are embedded in advance are used. The PC steel rod 41 of the protruding portion 76 is inserted into a hole provided later in the protruding portion 76 by a sheath tube or the like, fixed by a nut or the like, and attached.

  The plurality of precast concrete blocks 2 are separated from each other as shown in FIG. 9, after the sedimentation of the box 7 is completed, the respective precast concrete blocks 2 stacked in the wall height direction Y are separated from each other. The space 70 between the upper structure 73 and the lower structure 74 is removed.

  The plurality of precast concrete blocks 2 release the connection by the coupler 42 at each of the upper end 22 a and the lower end 22 b of the wire rod 22 so as to eliminate the tension of the wire rod 22 and a plurality of penetrations arranged in a row By pulling out the wire 22 from the upper end of the hole 20, each precast concrete block 2 is separated from each other from the integrated state in the wall height direction Y.

  The plurality of precast concrete blocks 2 are not limited to those in which the wire 22 is pulled out from the upper ends of the plurality of through holes 20 arranged in a row, and as shown in FIG. The wires 22 may be cut to eliminate the tension of the wires 22 so that the precast concrete blocks 2 may be separated from each other in the wall height direction Y.

  The plurality of precast concrete blocks 2 are, as shown in FIG. 11, the wall height direction Y of the pair of notches 21 facing each other from the size of the gap S formed to be separated by about 3 mm to 7 mm in the wall height direction Y. The opening dimension h is larger, and the jack device 5 such as the transport roller wheel 52 having a jack-up function is installed in the opening inside 21 a of the notch 21.

  When the plurality of precast concrete blocks 2 are separated from each other in the wall height direction Y as shown in FIG. 11A, the height of the walls is increased by the transport roller wheel 52 installed in the opening inside 21a of the notch 21. The upper stage precast concrete block 2 is lifted toward the upper side in the direction Y, and as shown in FIG. 11 (b), while the upper stage precast concrete block 2 is lifted upward, the transport roller wheel 52 has a wall thickness Forward move toward the outside A in the direction Z.

  The plurality of precast concrete blocks 2 are moved to the outer side A in the wall thickness direction Z by advancing the transport roller wheel 52 toward the outer side A in the wall thickness direction Z while lifting the upper precast concrete block 2 upward. The upper precast concrete block 2 is moved toward the top, and the upper precast concrete block 2 is carried out to the side of the box 7.

  From the state where the plurality of precast concrete blocks 2 are sequentially stacked and integrated from the bottom to the top in the wall height direction Y, each precast concrete block 2 is directed from the top to the bottom in the wall height direction Y By being taken out sequentially while being separated from each other, the space 70 formed above the lower structure 74 of the box 7 is removed to the side of the box 7.

  As shown in FIG. 12 (a), the jacks 51 are installed in the opening inside 21a of the notch 21 and the upper cast cast concrete block 2 is lifted by the jacks 51, and then the jacks 51 are jacked. The upper precast concrete block 2 is carried out to the side of the box 7 toward the outer side A in the wall thickness direction Z as shown in FIG. May be

  The temporary wall 1 to which the present invention is applied, as shown in FIG. 3, is provided as a side wall 72 for removal before sinking the box 7 on the side surfaces 75 of the plurality of boxes 7 constructed as the main structure 8. After the box 7 is sunk while preventing the infiltration of the ground water by the removal side wall 72, the side walls 72 for removal are formed when the plurality of boxes 7 are connected in order to construct the main body structure 8. Will be removed.

  The temporary wall construction method to which the present invention is applied is used to provide the side wall 75 for removal on the side surface 75 of the pneumatic caisson case 7 and, as shown in FIG. In the installation step of integrating the plurality of precast concrete blocks 2 in the wall height direction Y and installing the box 7 as shown in FIG. A separation process of separating the integrated state in the direction Y from each other and removing the space 70 formed above the lower structure 74 of the box 7 to the side of the box 7 is provided.

  In the installation step, as shown in FIG. 13, a plurality of precast concrete blocks 2 are sequentially stacked upward from below in the wall height direction Y, and the upper structure of the box 7 above the plurality of precast concrete blocks 2 By constructing 73, a plurality of precast concrete blocks 2 are integrally installed in the wall height direction Y in the space 70 formed above the lower structure 74 of the box 7. In the installation step, as shown in FIG. 5, the wire 22 is inserted continuously through the plurality of through holes 20 arranged in a row, and a tensile force is introduced from the upper end 22a of the wire 22 as necessary. Since the wire 22 is fixed, the plurality of precast concrete blocks 2 are firmly integrated in the wall height direction Y.

  In the installation step, as shown in FIG. 7, the water blocking material 3 such as water expansible rubber is provided in the gaps S of the plurality of precast concrete blocks 2 so that ground water from the gaps S of the plurality of precast concrete blocks 2 is provided. Prevent water penetration and improve the water blocking performance. In the installation step, as shown in FIG. 8, with the plurality of precast concrete blocks 2, each of both sides in the wall width direction X and the upper end in the wall height direction Y are fixed to the projecting portion 76 provided by cast-in-place concrete Thus, it is possible to prevent the infiltration of groundwater from both sides in the wall width direction X and the upper end in the wall height direction Y to improve the water blocking performance.

  In the removal step, as shown in FIG. 9, the wire 22 is pulled out from the upper ends of the plurality of through holes 20 arranged in a row, or as shown in FIG. The respective precast concrete blocks 2 are separated from one another in the wall height direction Y by cutting by means of a wire or the like to eliminate the tension of the wire 22. In the removal step, as shown in FIG. 11 and FIG. 12, each precast concrete block 2 is sequentially arranged by the transport roller wheel 52 installed in the opening inside 21 a of the notch 21 or the jack device 5 such as the jack 51. It is lifted and taken out, and removed from the space 70 formed above the lower structure 74 of the box 7 to the side of the box 7.

  In the removal process, as shown in FIG. 14, each precast concrete block 2 is removed, and as shown in FIG. 15, each removed precast concrete block 2 is buried under the subway or the road. The disposal cost required for disposal of each precast concrete block 2 can be reduced.

  The temporary wall 1 to which the present invention is applied is not constructed by fitting a plurality of steel sheet piles at a joint portion, and as shown in FIG. 7, gaps S in the wall height direction Y of a plurality of precast concrete blocks 2 Since the water blocking material 3 is provided and the water blocking material 3 can be adhered by utilizing the self-weight of the precast concrete block 2 and the tension of the wire rod 22, the water blocking performance by the water blocking material 3 is significantly improved. It is possible to improve the working efficiency inside the pneumatic caisson.

  The temporary wall 1 to which the present invention is applied is not constructed of a plurality of steel sheet piles continuously extending in the wall height direction Y, and as shown in FIG. 14, each precast concrete block 2 is made like a steel sheet pile. There is no need to pull it upward in the wall height direction Y. At this time, in the space 70 between the upper structure 73 and the lower structure 74 of the box 7, the temporary wall 1 to which the present invention is applied is constructed with the side wall 72 for removal on the inside B of the side surface 75 of the box 7 Since the upper structure 73 of the box 7 can be integrally constructed above the plurality of precast concrete blocks 2, the side wall 72 for removal, the upper structure 73 and the lower structure 74 are firmly integrated with each other, It is possible to significantly improve the overall waterproof performance of the body 7.

  The temporary wall 1 to which the present invention is applied is not constructed of a single prestressed concrete plate or the like continuously extending in the wall height direction Y, but a plurality of precast concrete blocks 2 are made from below in the wall height direction Y Since it is built up in the upper part, each precast concrete block 2 is easily separated and taken out without requiring a work of cutting a single prestressed concrete plate or the like with a wire saw or the like. While being able to reduce the removal cost of the temporary wall 1, it becomes possible to shorten the removal construction period of the temporary wall 1.

  In the temporary wall 1 to which the present invention is applied, as shown in FIG. 15, when laying subways or roads at a plurality of locations of the box 7, spaces 70 with different depths are formed at a plurality of locations in the wall height direction Y Is formed. At this time, the temporary wall 1 to which the present invention is applied is increased or decreased in the thickness of the wire 22 or the number of wires 22 in a plurality of precast concrete blocks 2 installed in the spaces 70 of different depths. If the earth pressure or water pressure is deep in the deep layer, the tension of the wire 22 should be high, and if the earth pressure or water pressure is small in the shallow layer, the tension of the wire 22 should be low, and design rationally Therefore, it becomes possible to rationally reduce and shorten the construction cost and construction period of the temporary wall 1 by eliminating the need for the load-bearing design of the temporary wall 1 based on the maximum soil pressure and water pressure.

  In addition, the temporary wall 1 to which this invention is applied does not need to be provided with the upper structure 73 above the lower structure 74 of the box 7 as shown in FIG.

  As mentioned above, although the example of the embodiment of the present invention was explained in detail, any of the above-mentioned embodiments only shows the example of the embodiment in the case of carrying out the present invention. The scope should not be interpreted in a limited manner.

1: temporary wall 2: precast concrete block 2a: upper surface 2b: lower surface 2c: inner surface 2d: outer surface 20: through hole 21: notch 21a: opening inside 22: wire 22a: upper end 22b: lower end 3: water blocking material 3a 41: PC steel rod 42: Coupler 5: Jack device 51: Jack 52: Transport roller wheel 7: Box 70: Space 71: Structural side wall 72: Removal side wall 73: Upper structure 74: Lower structure 75 Side surface 76: Projection 77: Working chamber 8: Body structure A: Outer side B: Inside S: Gap X: Wall width direction Y: Wall height direction Z: Wall thickness direction

Claims (5)

A temporary wall provided on at least a part of the side of a pneumatic caisson box,
A plurality of precast concrete blocks provided stacked from the bottom to the top, and a water blocking material provided in a gap between the plurality of precast concrete blocks;
The plurality of precast concrete blocks are integrally installed above the lower structure of the box before the box is sunk, and after the box is sunk, each of the precast concrete blocks is mutually attached. A temporary wall characterized by being separated and removed to the side of the box from the space formed above the lower structure of the box. In the plurality of precast concrete blocks, through holes penetrating in the vertical direction are respectively formed, and before sinking the box, the plurality of precast concrete blocks are continuously connected to the respective through holes formed in the plurality of precast concrete blocks to form a wire Is inserted and tension is applied to the wire to be integrated and installed, and after sinking the box, the tension of the wire is eliminated to thereby remove each of the precast concretes. The temporary wall according to claim 1, wherein the blocks are separated from one another. A plurality of the precast concrete blocks are cut out in the wall thickness direction of the box, and after the box is sunk, each of the precast concrete blocks is installed in the notch. The temporary wall according to claim 1 or 2, wherein the temporary wall is removed to the side of the box by being lifted by the device. A plurality of the precast concrete blocks are each formed with a through hole penetrating in the vertical direction, and a plurality of notched portions cut in the wall thickness direction of the box so that the box may be sunk. The wire rod is continuously inserted into each of the through holes formed in the precast concrete block, and after sinking the box, the wire rod is cut at the notch portion, thereby each precast The temporary wall according to any one of claims 1 to 3, wherein the concrete blocks are separated from each other. A temporary wall method used on at least a part of the side of a pneumatic caisson box,
Before sinking the box, a plurality of precast concrete blocks are piled up from the bottom to the top and integrated in the upper part of the lower structure of the box and installed, and after sinking the box, each A temporary wall method comprising: a removing step of separating the precast concrete blocks from each other and removing the precast concrete block from a space formed above the lower structure of the box to the side of the box.

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