JP6543177B2 - Building method - Google Patents

Description

  The present invention relates to a method of constructing a frame in a space formed by a dam stay drilling method.

  When a space with a certain depth and area is formed on the ground by excavation, a mountain retaining wall is constructed in advance in the ground so that the surrounding ground is not collapsed during the excavation. Patent Document 1 discloses a shield start shaft 1 having a retaining wall, and an aspect of supporting the retaining wall by the uplift 3 and the retaining anchor 4.

Unexamined-Japanese-Patent No. 2000-232493

  It is described in paragraph [0006] of Patent Document 1 that "there is no need to provide a cutting beam in a vertical shaft because a configuration using a ground anchor is made, and a working space can be secured". The cutting beam is a beam installed horizontally between a pair of facing wall walls, that is, in the excavated space. An anchor (grand anchor) supports a mountain retaining wall by fastening an anchor body and a mountain retaining wall installed in the ground behind the mountain retaining wall with a steel wire.

  When comparing the cutting beam and the anchor from the viewpoint of the working cost involved in the installation, the cutting beam is superior in that the cost can be reduced compared to the anchor. On the other hand, the anchor is superior to the cut beam in terms of securing a working space for constructing the housing. Since the cutting beam is installed in the excavated space as described above, it may interfere with subsequent work. For example, after a space is formed by excavation, when a frame is gradually built from the lower side in this space, the cutting beam located below will interfere with the frame construction work if it is installed as it is. Therefore, the construction is proceeded while the work space is secured by sequentially removing the lower cutting beams.

  Even if it is recognized that the unremoved cutting beam will interfere with the operation to be performed next, it may not be possible to remove the cutting beam only after the predetermined work has been performed. For example, although it is desirable to carry out the finishing work on the upper part of the frame with all cut beams including the cut beam located at the top of the space removed, the ground material should be between the retaining wall and the side of the frame. It may not be possible to remove all the cutting beams only after the filling operation has been carried out. That is, in the conventional frame construction site using the cutting beam, the work to be performed next can not be carried out, and other work may have to be carried out first, and this causes the hindrance to the realization of the construction period shortening. It is one of the

  The present invention forms a space by digging between a pair of facing mountain walls, and then increases the degree of freedom of the work sequence in a series of constructions for constructing a frame in this space, thereby shortening the construction period sufficiently. Aims to provide a method of constructing a frame that can realize

  The frame construction method according to the present invention comprises the steps of: (A): constructing a pair of facing wall walls in the ground; (B): excavating the ground between the pair of mountain walls, and (C) sequentially installing a plurality of first cut beams supporting the retaining wall exposed in accordance with the drilling; and (C): the first cut positioned below in the space formed by the drilling in the step (B). A step of constructing a housing while removing the beam, and (D): a second cutting between the housing and the retaining wall constructed by the step (C) in a state where at least one first cutting beam is left. Step of installing the beam, (E): step of removing the first cut beam not removed after the step (D), and (F): the first cut beam not removed after the step (E). Performing the work on the top of the enclosure that was hindered and could not be performed.

  According to the above-mentioned frame construction method, all the first cut beams are removed by supporting the mountain wall by the frame constructed in the (C) step and the second cut beam installed in the (D) step. (Step (E)). For this reason, if it is after the (E) process, the operation (the (F) process) in the upper part of the case which was not able to be carried out by being interrupted by the unremoved 1st cutting beam can be implemented at arbitrary timings. As a result, the construction period of the frame construction work can be shortened. (F) As an example of the structure constructed | assembled at a process, the collar wall extended upwards from the upper surface of a housing is mentioned.

  The method for building a frame may further include the step of filling the ground material between the side surface of the frame and the retaining wall after the step (G): the step (D). By filling the area with ground material (soil, sand, concrete, fluidizing material, etc.), it is possible to eliminate the gap between the housing and the ground around it. The gap may be filled back with the ground material generated by the excavation in the step (B). In addition, the wall may be finally removed or may remain as it is.

  In the above-described method for constructing a frame, it is preferable to carry out the step (F) and the step (G) in parallel from the viewpoint of realizing further shortening of the work period.

  In the above construction method of the frame, as long as it is a place where the stay plate can be supported by the frame and the second cut beam, there is no limitation on the place where the frame is installed in the second cut beam. The second cutting beam may be installed between the

  A box structure (more specifically, a road, a railway, a waterway, a buried underground and other underdrains, etc.) extending in the extension direction of the mountain retaining wall may be mentioned as an example of the frame constructed by the above-mentioned method of constructing a frame. When the housing to be constructed has a certain length (for example, 50 m or more), the effect of shortening the work period according to the present invention becomes more remarkable.

  According to the present invention, after forming a space by excavating between a pair of facing mountain walls, it is possible to increase the degree of freedom in the order of work in a series of constructions for constructing a frame in this space, It is possible to realize the sufficient construction period shortening.

FIG. 1: is sectional drawing which shows an example of the frame built in the excavation ditch | groove formed of the dam stay excavation construction method. FIG. 2 is a plan view of the case shown in FIG. 1 as viewed from above. Fig.3 (a) is sectional drawing which shows the state which built a pair of mountain retaining wall in the division which should build a frame, FIG.3 (b) is a mountain stay exposed by excavation of the ground between a pair of mountain retaining walls. It is sectional drawing which shows the state which installed two 1st cutting beams in the upper part of the wall. FIG. 4 (a) is a cross-sectional view showing a state in which excavation of the ground has progressed further from the state shown in FIG. 3 (b) and a mountain anchor is installed below the first cut beam of the second stage from above. FIG. 4 (b) is a cross-sectional view showing a state in which excavation of the ground has further progressed from the state shown in FIG. 4 (a) and two first cutting beams are further installed below the mountain anchor. It is. FIG. 5 (a) is a cross-sectional view showing a state in which the first protective layer is laid on the bottom of the digging groove, and FIG. 5 (b) is a first protective after removing the lowermost first cut beam. It is sectional drawing which shows the state which further laid the 2nd protective layer on the layer. FIG. 6 (a) is a cross-sectional view showing a state in which the outer scaffold is assembled along the inner surface of the retaining wall and the formwork for placing a bottom plate is assembled, and FIG. 6 (b) is a bottom plate It is sectional drawing which shows the state which was carried out. Fig.7 (a) is sectional drawing which shows the state which performed casting and the side backfilling of the resurfacing concrete, FIG.7 (b) is the 2nd step from the bottom which became unnecessary by casting of the resurfacing concrete It is sectional drawing which shows the state which removed the 1st cutting beam. FIG. 8 (a) is a cross-sectional view showing an assembled state of a mold for placing a side wall and a column, and FIG. 8 (b) is a cross-sectional view showing a side wall and a column. FIG. 9 (a) is a cross-sectional view showing the assembled state of a form for placing a top plate and a column after removing the first cut beam of the second stage from the top, and FIG. 9 (b) is a sectional view It is sectional drawing which shows the state which built the top plate, a support | pillar, and a beam. FIG. 10 (a) is a cross-sectional view showing a state in which the mountain anchor and the outer scaffold are removed, and FIG. 10 (b) is an outer surface of the casing and an inner surface of the mountain wall with the first cut beam at the top And a second cut beam installed between them. FIG. 11 (a) is a cross-sectional view showing a state in which the first cut beam of the uppermost step which has become unnecessary after the mountain stay wall is supported by the top plate and the second cut beam is removed, FIG. 11 (b) is It is sectional drawing which shows the state which comprised a pair of facing wall on a top plate. FIG. 12 (a) is a cross-sectional view showing the side of a plurality of rods constructed to line up continuously, and FIG. 12 (b) is a plurality of rods aligned between the outer surfaces of the rods and the inner surface of the retaining wall. It is sectional drawing which shows a mode that a side part back-loading operation is implemented, removing the 2nd cutting beam of (1). FIG. 13 is a cross-sectional view showing a state in which side backfilling and placing of replacement concrete are performed. Fig.14 (a) is sectional drawing which shows the state which installed the 1st cutting beam instead of the mountain stay anchor shown in FIG. 4 (a), and FIG.14 (b) is a total of five 1st cuttings in a excavation ditch It is sectional drawing which shows the state which supported the retaining wall 1A, 2B by the beam. Fig.15 (a) is sectional drawing which shows the state which constructed the side wall and support column on the bottom plate, and FIG.15 (b) is the inside of the housing in the middle of construction after removal of the 1st cutting beam installed instead of the mountain stay anchor. It is sectional drawing which shows the state which installed the re-changing beam to this, and put the changing concrete on the outer side. FIG. 16 (a) is a cross-sectional view showing a state where a top plate, a beam and the like are constructed after removing the first cut beam of the second stage from the top, and FIG. 16 (b) is a sectional view by the top plate and the second cut beam. It is sectional drawing which shows the state which removed the 1st cutting beam of the top step which became unnecessary after supporting a mountain retaining wall. FIG. 17 (a) is a cross-sectional view showing the side surfaces of a plurality of rods constructed to be arranged side by side, and FIG. 17 (b) is a plurality of rods arranged between the outer surface of the rods and the inner surface of the retaining wall. It is sectional drawing which shows a mode that a side part back-loading operation is implemented, removing the 2nd cutting beam of (1). FIG. 18 is a cross-sectional view showing a state where replacement concrete has been cast on the side of the top plate of the frame.

  Embodiments of the present invention will be described in detail with reference to the drawings. Although the case where the present invention is applied to a construction for constructing a box structure in the basement is exemplified here in order to construct a highway with a total of four lanes in the basement here, the scope of application of the present invention is not limited thereto. .

First Embodiment
FIG. 1: is sectional drawing which shows an example of the box body structure (housing) constructed | assembled in the excavation ditch (space) formed of the dam stay excavation method. FIG. 2 is a plan view of the box structure 10 shown in FIG. 1 as viewed from above. As shown in FIGS. 1 and 2, the box structure 10 mainly includes the bottom plate 11 constructed on the bottom of the digging groove Ga via the protective layers 10 a and 10 b and the upper portions from both ends of the bottom plate 11 as main structures. Provided at the central portion of the top plate 13 and the side walls 12A, 12B extending, a plurality of columns 12C extending upward from the central portion of the bottom plate 11, the top plate 13 constituting the ceiling of the box structure 10 And an opening 15. A pair of weir walls 20A and 20B is provided on the top plate 13 along the opening 15 at the top of the box structure 10.

  Bottom plate 11, side walls 12A and 12B, top plate 13, opening 15, and weir walls 20A and 20B all extend in the extending direction of the expressway. The plurality of support columns 12C are provided side by side in the extending direction of the expressway (see FIG. 2), and form a central separator that divides the expressway of four lanes in total by two lanes on one side. The opening 15 plays the role of a vent. The openings 15 are separated by a plurality of beams 14. The strength of the top plate 13 is maintained by the beams 14.

In the present embodiment, in constructing the box structure 10, a cutting beam and an anchor are used in combination as a support work. More specifically, four cut beams K1 to K4 (a plurality of first cut beams) and Yamadome anchor A are used in combination as a support. The frame construction method according to the present embodiment includes the following steps.
(A): A step of constructing a pair of facing wall walls 1A and 1B in the ground.
(B): excavating the ground G between the pair of mountain retaining walls 1A, 1B, and cutting beams K1, K2 supporting the mountain retaining walls 1A, 1B exposed along with the excavation of the ground G, mountain retaining anchor A, And a step of sequentially installing the cutting beams K3 and K4.
(C): (b) After the completion of excavation of the ground G in the step, a step of constructing the box structure 10 in the digging groove Ga while sequentially removing from the cutting beam K4 located below.
(D) In a state in which the cutting beam K1 located at the uppermost stage is left, the cutting beam K5 (c) between the outer surface of the box structure 10 constructed by the step (c) and the inner surface of each of the retaining walls 1A and 1B Step of installing the second cutting beam).
(E): A step of removing the unremoved cutting beam K1 after the step (d).
(F): A step of performing work on the upper portion of the box structure 10 which could not be carried out after being interrupted by the unremoved cutting beam K1 after the step (e).
(G): After constructing a plurality of box structures 10 in the extending direction of the expressway, remove the plurality of box structures 10 while sequentially removing the cut beams K arranged to align in the extending direction of the expressway Carrying out the filling (side back-filling) of the ground material 18 between the outer surface of the lower part and the inner surface of each of the retaining walls 1A, 1B.
(H): A step of placing replacement concrete 19 between the top plate 13 and the inner surface of the retaining wall 1A, 1B.
Each step will be described below.

<(A) Process>
FIG. 3 (a) shows a state in which a pair of facing wall walls 1A and 1B facing each other is formed in the entire section or a part of the section (for example, 5 m to 20 m in length) in which the box structure 10 is to be constructed. ing. The reach depth of the mountain retaining walls 1A and 1B may be set according to the size of the housing to be constructed and the groundwater level, and can be set, for example, to about 10 m to 40 m or more. In the case structure 10 which concerns on this embodiment, the reach | attainment depth of mountain retaining wall 1A, 1B is about 30 m. The separation distance between the mountain retaining wall 1A and the mountain retaining wall 1B may be set according to the size of the casing to be constructed, and can be set, for example, to 20 m to 40 m or more. In the case structure 10 which concerns on this embodiment, the separation distance of mountain retaining wall 1A, 1B is about 32 m. The mountain retaining walls 1A and 1B are preferably those having water shielding properties, and a steel sheet pile may be adopted or a continuous underground wall may be adopted.

<(B) Process>
FIG. 3 (b) shows a state in which the cut beam K1 and the cut beam K2 are sequentially installed on top of the mountain retaining walls 1A and 1B exposed as the ground G is excavated. As a method of installing cutting beams K1 and K2, a horizontal cutting beam construction method is mentioned, for example. For example, H steel can be used as a main member that constitutes the cut beams K1, K2.

  Fig.4 (a) has shown the state which excavation of the ground G advanced further from the state shown in FIG.3 (b). In the present embodiment, a plurality of mountain anchors A are installed below the cutting beam K2 in the extending direction of the expressway. Yamadome anchor A includes an anchor body a1 embedded in the ground, an anchor head a2 installed on the surface of the mountain stay wall through an uplift, and a steel wire connecting the anchor body a1 and the anchor head a2 a3 and the steel wire a3 is tensioned by, for example, a jack (not shown). Although the type of Yamadome anchor A is not particularly limited, it is preferable to be able to remove the steel wire a3 at the stage when the support of the mountain walls 1A and 1B by the Yamadome anchor A is not required.

  FIG. 4B shows a state in which excavation of the ground G is further advanced from the state shown in FIG. 4A and the excavation work is completed, that is, a state in which the digging groove Ga is completed. In the process, the cutting beam K3 and the cutting beam K4 are sequentially installed under the Yamadome anchor A. Thereby, in the cross section orthogonal to the extension direction of mountain wall 1A, 1B, it will be in the state where cutting beams and mountain anchors were used together in the height direction. More specifically, each anchor head a2 of a pair of mountain stay anchor A will be located between the cutting beam K2 located above, and the cutting beam K3 located below. In addition, H steel can be used as main members which comprise cut beams K3 and K4, similarly to cut beams K1 and K2.

<(C) Process>
FIG. 5A shows a state in which the first protective layer 10 a is formed on the bottom surface of the digging groove Ga. The first protective layer 10a can be formed, for example, by laying foundation crushed stone and leveling concrete. FIG. 5B shows a state in which a second protective layer 10b is further formed on the first protective layer 10a after removing the cutting beam K4. The second protective layer 10b can be formed, for example, by laying a bottom waterproof layer and a protective mortar layer.

  FIG. 6 (a) shows a state in which the outer scaffolds 2A and 2B are assembled along the inner surfaces of the pair of mountain retaining walls 1A and 1B. The figure also shows that the bottom plate 11 of the box structure 10 is ready to be built. That is, the figure shows a state in which the formwork 11a for placing the bottom plate 11 (and part of the side walls 12A, 12B, etc.) is assembled. A large number of reinforcing bars (not shown) are disposed in the mold 11a. By placing concrete in the formwork 11a, the bottom plate 11 is constructed as shown in FIG. 6 (b).

  FIG. 7A shows a state in which replacement concrete 17 is placed between the two ends of the bottom plate 11 and the inner surfaces of the mountain retaining walls 1A and 1B. Also, the filling of the ground material 18 (side back-filling) into the gap between the both ends of the bottom plate 11 and the inner surface of the mountain retaining wall 1A, 1B is performed. Specific examples of the ground material 18 include soil, sand, concrete, fluidizing material and the like. The side backfilling may be performed on the ground material generated by the excavation of the ground G. After the mountain walls 1A and 1B are supported by the bottom plate 11 and the replacement concrete 17, the cut beam K3 is removed as shown in FIG. 7 (b).

  FIG. 8 (a) shows a state in which the side walls 12A, 12B and the molds 12a, 12b, 12c for placing the support 12C are assembled. A number of reinforcing bars (not shown) are arranged in the formwork 12a, 12b, 12c. By pouring concrete on the formwork 12a, 12b, 12c, as shown in FIG. 8 (b), the side walls 12A, 12B and the support 12C are constructed respectively.

  FIG. 9 (a) shows a state where the top plate 13 and the formwork 13a, 14a for placing the beam 14 are assembled after removing the cutting beam K2. A large number of reinforcing bars (not shown) are respectively disposed in the molds 13a and 14a. By placing concrete in the formwork 13a, 14a, the top plate 13 and the beam 14 are respectively constructed as shown in FIG. 9 (b).

<(D) Process>
FIG. 10 (a) shows a state in which the mountain stay anchor A and the outer scaffolds 2A and 2B have been removed. FIG. 10 (b) is cut between the outer surface of the box structure 10 constructed by the step (c) and the inner surface of each of the retaining walls 1A and 1B, with the cutting beam K1 located at the uppermost stage being left. The state where the beam K5 is installed is shown. The top plate 13 and the cutting beam K5 support the upper portions of the mountain retaining walls 1A and 1B. For example, H steel can be used as a main member constituting the cutting beam K5 as in the case of the cutting beams K1 and K2.

<(E) Process>
FIG. 11 (a) shows a state in which the uppermost cutting beam K1 is removed after supporting the retaining walls 1A and 1B by the top plate 13 and the cutting beam K5. By removing the cutting beam K1, it is possible to carry out the operation (the (f) step) at the upper part of the box structure 10 which can not be carried out due to the cutting beam K1 at an arbitrary timing. Here, "the upper portion of the box structure 10 which can not be carried out due to the cut beam K1" is an area above the box structure 10, and the height position of the cut beam K1 and above it. It means the area (the upper area of the box structure 10 that interferes with the cutting beam K1).

<(F) Process>
FIG. 11B shows a state in which a pair of weir walls 20A and 20B extending upward from the top plate 13 is constructed after removal of the cutting beam K1.

<(G) process>
Fig.12 (a) has shown the state by which several box structure 10 was constructed along the extension direction of the expressway. A plurality of cut beams K5 are arranged at predetermined intervals in the extension direction of the expressway between the plurality of box body structures 10 and the mountain retaining walls 1A and 1B. FIG. 12 (b) shows the ground material between the outer surface of the plurality of box structure 10 and the inner surface of each of the retaining walls 1A and 1B while sequentially removing the plurality of cut beams K5 aligned in the extension direction of the expressway. It shows a state of carrying out an operation of filling 18 (side backfilling). Implementing side-side back-loading on a plurality of box structures 10 collectively to improve work efficiency as compared to performing side-side back-loading on each box structure 10 it can. From the viewpoint of shortening the construction period, the steps (f) and (g) may be performed in parallel.

<(H) Process>
FIG. 13 shows a state in which replacement concrete is placed between the top plate 13 of the box structure 10 and the inner surfaces of the mountain retaining walls 1A and 1B. The top plate 13 and the replacement concrete 19 support the upper portions of the mountain walls 1A and 1B. Thereafter, through an operation of filling the ground material 18 in the grooves on the top plate 13 and the like, the case structure 10 shown in FIG. 1 is constructed. In addition, mountain wall 1A, 1B may be removed finally, and may remain as it is.

  According to the above embodiment, by using the cutting beams K1 to K4 and the Yamato anchor A as support for use in the step (b), cutting in the construction work of the box structure 10 in the subsequent step (c) It is possible to realize an aspect in which the beam replacement work is not performed. This makes it possible to sufficiently shorten the construction period for construction of the frame. In addition to this, according to the above-mentioned embodiment, by supporting the mountain retaining walls 1A and 1B by the box structure 10 constructed in the step (c) and the cutting beam K5 installed in the step (d), cutting is performed. All the beams K1 to K4 can be removed (step (e)). For this reason, if it is after the (e) process, the operation (the (f) process) in the upper part of the box structure 10 which was not able to be implemented by being interrupted by the cross beam K1 can be implemented at arbitrary timings. Increasing the degree of freedom in the work order contributes to shortening the construction period of the entire work.

Second Embodiment
In the above-mentioned embodiment, although the case where mountain stay anchor A was installed between cut beam K2 and cut beam K3 was illustrated, a cut beam K similar to cut beam K2 etc. instead of mountain stay anchor A is described below. An embodiment in which the (first cut beam) is installed between the cut beam K2 and the cut beam K3 will be described.

  Fig.14 (a) is sectional drawing which shows typically the state which installed the cutting beam K instead of the mountain stay anchor A shown to Fig.4 (a). FIG. 14B is a cross-sectional view showing a state in which the mountain walls 1A and 2B are supported by a total of five cutting beams in the digging groove Ga. Fig. 14 (b) shows a state in which excavation of the ground G is further advanced from the state shown in Fig. 14 (a) and the excavation work is completed, that is, a state in which the digging groove Ga is completed. In the process, a cutting beam K3 and a cutting beam K4 are sequentially installed below the cutting beam K. In the present embodiment, as shown in FIG. 14 (b), only a cutting beam (first cutting beam) is used in the height direction in the cross section orthogonal to the extending direction of the mountain retaining walls 1A and 1B, This is different from the first embodiment in which the cutting beam and the Yamadome anchor are used in combination (see FIG. 4B).

  From the state shown in FIG. 14 (b), the lower part of the box structure 10 is constructed in the same manner as the first embodiment (see FIGS. 5 to 7). Hereinafter, differences between the present embodiment and the first embodiment will be mainly described with reference to FIGS.

  FIG. 15A shows the side walls 12A and 12B and the support 12C built on the bottom plate 11. As shown in FIG. In the present embodiment, since the cut beam K is present in the box structure in the process of construction, the entire side walls 12A, 12B and the columns 12C are not constructed at this stage, and their upper portions are separately provided in later steps. Be built. That is, in the present embodiment, depending on the installation height of the cutting beam K, the side walls 12A, 12B and the support 12C are constructed in a plurality of steps, which is different from the first embodiment (see FIG. 8B). ).

  FIG. 15 (b) shows a state in which the replacement beam M is installed in the box structure in the process of construction and the replacement concrete 17a is cast on the outside thereof after removal of the cutting beam K. In the present embodiment, after removal of the cutting beam K, a point to install the reworking beam M and the reworking concrete 17a for supporting the mountain retaining walls 1A, 1B, and the ground material 18 prior to the reworking concrete 17a. It differs from the first embodiment in that side backfilling is performed according to (see FIG. 8 (b)). In addition, according to the first embodiment, since the mountain retaining walls 1A and 1B are supported by the mountain retaining anchor A at the time of excavating the ground between the pair of mountain retaining walls 1A and 1B, at the time of construction of the box structure 10 The work of installing the reworking beam M can be eliminated (see FIG. 9). In other words, in the first embodiment, at the height at which the reworking beam M is to be installed, the mountain retaining walls 1A and 1B are used as the retaining anchors A so that the installation work of the reworking beam M becomes unnecessary in the step (C). Support.

  FIG. 16 (a) shows a state in which a cutting beam K5 is installed between the outer surface of the box structure 10 and the inner surfaces of the retaining walls 1A and 1B while leaving the cutting beam K1 positioned at the uppermost step. ing. After supporting the retaining walls 1A and 1B by the top plate 13 and the cutting beam K5, removing the uppermost cutting beam K1 causes the work in the upper portion of the box structure 10 to be interrupted due to the cutting beam K1 Can be implemented at any time. FIG. 16B shows a state where a pair of weir walls 20A and 20B extending upward from the top plate 13 is constructed after removal of the cutting beam K1.

  Fig.17 (a) has shown the state by which several box structure 10 was constructed along the extension direction of the expressway. A plurality of cut beams K5 are arranged at predetermined intervals in the extension direction of the expressway between the plurality of box body structures 10 and the mountain retaining walls 1A and 1B. FIG. 17 (b) shows the outer surfaces of the plurality of box structures 10 and the retaining walls 1A and 1B above the replacement concrete 17a while sequentially removing the plurality of cut beams K5 aligned in the extension direction of the expressway. The filling of the ground material 18 (side backfilling) is performed between each of the inner surfaces. Implementing side-side back-loading on a plurality of box structures 10 collectively to improve work efficiency as compared to performing side-side back-loading on each box structure 10 it can.

  FIG. 18 shows a state in which replacement concrete is placed between the top plate 13 of the box structure 10 and the inner surfaces of the mountain retaining walls 1A and 1B. The top plate 13 and the replacement concrete 19 support the upper portions of the mountain walls 1A and 1B. Thereafter, through an operation of filling the ground material 18 in the grooves on the top plate 13 and the like, the case structure 10 shown in FIG. 1 is constructed. The replacement beam M may be removed at an appropriate timing.

  According to the second embodiment, the supporting beams 1A and 1B are supported by the box structure 10 constructed in the step (c) and the cutting beam K5 installed in the step (d), whereby the cutting beams K1 to K1 are formed. All K4 can be removed (step (e)). For this reason, if it is after the (e) process, the operation (the (f) process) in the upper part of the box structure 10 which was not able to be implemented by being interrupted by the cross beam K1 can be implemented at arbitrary timings. Increasing the degree of freedom in the work order contributes to shortening the construction period of the entire work.

  As mentioned above, although embodiment of this invention was described in detail, this invention is not limited to the said embodiment. For example, in the above embodiment, the case where the expressway is constructed underground by constructing the case structure 10 in the digging groove Ga has been illustrated, but roads other than the expressway, railways, waterways, underground tunnels and others The present invention may be applied to construction such as culvert.

1A, 1B: mountain retaining wall, 2A, 2B: outer scaffold, 10: box structure (body), 11: bottom plate, 11a, 12a, 12b, 12c, 13a, 14a: formwork, 12A, 12B: side wall, 12C ... Strut 13 13 top version 14 beam 17 17, 17a, 19 replacement concrete 18 ground material 20A, 20B wall, G ground, Ga digging groove (space) A: mountain Anchor, K1 to K4, K: cut beam (first cut beam), K5: cut beam (second cut beam), M: repacked beam.

Claims (6)

(A): building a pair of facing wall walls in the ground;
(B): excavating the ground between the pair of mountain retaining walls, and sequentially installing a plurality of first cutting beams supporting the mountain retaining wall exposed as the ground excavates;
(C): constructing a casing while removing the first cutting beam located below in the space formed by the excavation of the (B) step;
(D): installing a second cutting beam between the casing constructed in the step (C) and the retaining wall in a state in which at least one of the first cutting beams is left;
(E): removing the unremoved first cutting beam after the step (D);
(F): after the step (E), performing the work on the upper portion of the casing which has been hindered by the unremoved first cutting beam;
(G): after the step (D), filling the ground material between the casing and the retaining wall;
Only including,
The mountain retaining wall is a steel sheet pile or a continuous underground wall,
The case is a box structure having a bottom plate and a top plate,
The gap between the box structure and the retaining wall is continuous from the height of the bottom plate to the height of the top plate,
The frame construction method which implements said (F) process and said (G) process in parallel . The frame construction method according to claim 1, wherein in the step (D), the second cutting beam is installed between a side portion of the housing and the mountain retaining wall. The method for constructing a casing according to claim 1 or 2, wherein the casing is a casing structure extending in the extension direction of the mountain retaining wall. The frame construction method according to claim 3, wherein the box structure is an underground expressway. The rod construction method according to any one of claims 1 to 4 , wherein in the step (F), a collar wall extending upward from the upper surface of the housing is constructed. In the (B) step, the plurality of first cutting beams and the mountain stay anchor are used in combination in the height direction, and at least one first cutting beam is installed below the mountain stay anchor. The box construction method as described in any one of 5.

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