JP4319231B2 - Approach caisson and method for constructing tunnel approach section composed of caisson - Google Patents

Description

  The present invention relates to an approach caisson and a method for constructing a tunnel approach unit using the caisson.

  When constructing a road tunnel underground, there are sections that enter the underground from the ground and are connected to the underground main section, and conversely, sections that exit from the underground main section to the ground. Approach section).

  The main line section is often constructed by a shield method, and it is common to ensure that the thickness of the top cover of the tunnel is greater than the tunnel diameter in order to suppress the impact of land subsidence due to excavation.

  On the other hand, the approach section is shallower than the main section where the cover is built with a tunnel diameter or larger.

  Since this approach section is relatively shallow from the ground surface, underground tunnels were previously constructed by the open-cut method using auxiliary methods such as ground improvement.

  However, in recent years, instead of the above construction method, there is a tendency to construct an underground tunnel using a caisson method that has high quality as an underground structure and has little influence on the surroundings.

  When an underground tunnel is constructed using this caisson method, a plurality of caissons are juxtaposed and connected to each other, but in order to disassemble the side walls of adjacent caissons, the side walls have a predetermined thickness, and Since it is made of reinforced concrete, it took time to dismantle the work, prolonging the construction period and increasing the cost, and there was a problem that a large amount of concrete and waste such as reinforced scrap were generated.

  The present invention has been proposed in view of the above, and the object is to facilitate disassembly work, shorten the construction period, and as a result, reduce costs and reduce waste. The object is to provide an approach caisson and a method for constructing a tunnel approach unit using the caisson.

According to the first aspect of the present invention, the first side wall on the road longitudinal direction side of the pneumatic caisson is constituted by a temporary wall that can be assembled and disassembled and has a function of a mountain retaining wall, and is connected to or fixed to the temporary wall. The second side wall in the transverse direction is made of concrete, the lower part of the first side wall is fixed to the upper part of the pneumatic slab formed in the lower part of the caisson housing, and the upper part is supported or fixed by the supporting means or fixing means. It is characterized by that.
According to a second aspect of the present invention, in the approach caisson according to the first aspect, a belly raising material is provided inside the first side wall, and a support is fastened to the belly raising material.
According to a third aspect of the present invention, in the approach caisson according to the first aspect, a reinforcing structure is disposed inside the first side wall, the reinforcing structure is fixed to the upper portion of the pneumatic slab, and the reinforcing structure It is characterized by comprising a material and a longitudinal material or an oblique material and being fastened to a support work.
According to a fourth aspect of the present invention, in the caisson for approach according to the first aspect, a reinforcing structure is provided at a substantially intermediate position between the first side walls provided on both sides of the caisson housing in the longitudinal direction of the road. And
According to a fifth aspect of the present invention, in the approach caisson according to the first aspect, an upper slab or a beam is provided on an upper portion of the caisson housing, and the first side wall is fixed to the upper slab or the beam. And
In the invention of claim 6, the first side wall on the road longitudinal direction side of the pneumatic caisson is constituted by a temporary wall that can be assembled and disassembled and has a function of a mountain retaining wall, and the road transverse direction fixed to the temporary wall A second side wall on the side is made of concrete, an appropriate number of caisson housings having the first and second side walls are set in the longitudinal direction of the road, and the first side wall made of the temporary wall is removed. The approach part is constructed.
According to a seventh aspect of the present invention, in the method for constructing a tunnel approach portion according to the sixth aspect, the first side wall reinforcing reinforcing material provided in the first and second side walls and the caisson housing for sinking It is characterized by removing and constructing equipment.
The invention according to claim 8 is the method for constructing a tunnel approach section according to claim 6, wherein the appropriate number of caisson housings having the first and second side walls are disposed at intervals and are adjacent to each other. Providing a continuous wall connecting the second side walls outside the second side walls, excavating between the first side walls facing each other, and forming a space for connecting adjacent caisson housings to each other; Features.

According to the caisson for approach and the construction method of the caisson tunnel of the present invention, since the side wall in the longitudinal direction of the road is constituted by a temporary wall that can be assembled and disassembled, the disassembly work is easy and can be easily removed. Can be shortened, and thus the cost can be reduced.
In addition, there is no waste such as concrete lump or rebar scrap, and the constituent members are reusable and can be diverted to others, which is economical.

  Embodiments of the present invention will be described below with reference to the drawings.

Figure 1 is an explanatory diagram in the case of constructing the approach section by arranging a plurality of pneumatic caisson a ₁ ~a _n tunnel direction through the gap, i.e. the road longitudinal sectional direction. Figure 1 is a shield tunnel, D is the tunnel diameter, H is overburden, 2 consists of pneumatic caisson a ₁ caisson approach portion constructed using a ~a _n and the approach portion tunnel, 3 on the ground portion is there.

  First, an outline of a caisson tunnel construction method according to the present invention will be described with reference to FIG.

Pneumatic caisson used in the present invention is sinking (hereinafter, simply caissons that) a ₁ ~a _n road longitudinal direction, that is, the predetermined depth in the direction of extension of the tunnel road for example with an interval b of about 2m~3m The The interval b is set to about 2 m to 3 m. This interval b is suitable for ground improvement and excavation work, but other intervals may be used.

These caissons a ₁ ~a _n is the number sequence required to approach segment, in the present invention the first side wall A readily having the function of a road longitudinal direction of the mountain Tomekabe of each caisson a ₁ ~a _n It is characterized by comprising a temporary wall that can be assembled and disassembled. The caisson temporary wall structure will be described later.

When building approach section and sinking the second caissons a ₂ at intervals b adjacent the first caissons a _1, which is already sinking. Thereafter, the _{third to n-th} caissons a ₃ to an are sequentially deposited in the same manner.

  After the necessary number is set, a part or almost the whole of the caisson tunnel can be constructed by constructing a joint and disassembling the first side walls A adjacent to each other. In addition, the code | symbol B in FIG. 1 is the 2nd side wall of the road cross-sectional direction fixed to the 1st side wall A. As shown in FIG. The second side wall B is made of ordinary concrete.

In this case, the first caisson a ₁ can be connected to the ground road through a simple excavation tunnel by dismantling and removing the side wall A opposite to the adjacent second caisson a _2. it can.

The caisson a _n of the n, and removed by disassembling the sidewall A of the opposite side of the fourth caissons a ₄ side of the adjacent, is to complete the caisson tunnel by binding to shield tunnel 1 which is separately constructed it can.

For the fourth caissons a _4, can also be used as a starting shaft piles or reach elevational piling shield excavator shield tunnel construction necessary.

  Next, a configuration example of the caisson of the present invention and details of a road tunnel construction method using the caisson will be described.

  2 is a cross-sectional view of the caisson used in the present invention when viewed in the longitudinal direction of the road, FIG. 3 is a vertical cross-sectional view taken along the line m-m in FIG. 2, and FIG. -N line sectional drawing is shown. FIG. 5 is a partially enlarged explanatory view showing a configuration example of the first side wall.

2 to 4, a traveling rail 5 is laid on the ceiling surface of the pressurized slab 4 of the first caisson a ₁ , and the excavator 6 can travel in the pressurized working chamber 7 through the traveling rail 5. cage, ground G is excavated using the excavator 6, caisson a ₁ with the drilling will settle. 4a is a blade opening, 8 is a manlock for an operator to enter and exit the pressurized working chamber, and 8a is the man shaft. Reference numeral 9 denotes a material lock used when the excavator is carried in and out of the pneumatic working chamber, and the excavated soil is discharged to the ground side. 9a is a material shaft thereof, and 10 is a groundwater level.

  In these figures, reference numeral 11 denotes a holding girder as a support made of an H-shaped steel material obliquely arranged for reinforcing the first side wall, and 12 denotes an upright girder as a mountain retaining material, which is also made of an H-type steel material. , 13 are reinforcing girders provided as necessary, and the first side wall A is supported and reinforced by these reinforcing materials. 14 is a fixed anchor steel bar, in FIG. 2, 15 is a presser girder, 28 is a lower fixed girder as a fixing tool, and in FIG. 3, 16 is a steel sheet pile serving as a mountain retaining wall.

As shown in FIGS. 2 and 3, a plurality of erection girders 12 are provided in the height direction at a predetermined interval on the inner side of the first side wall A that is a temporary wall. The guard girder 11 is disposed obliquely inside the caisson a ₁ , one end is erected, and the bolt 12 is fastened to the girder 12 using bolts and nuts, if necessary, using a fastener such as a PC steel wire, and the other end is a pneumatic slab. 4 is fastened to support and reinforce the first side wall A. The upper part of the first side wall A is supported by a stand-up girder 11 or the like on the upper erection girder provided on the upper side. Also, as shown in FIG. 3, one end of a reinforcing beam 13 is similarly fastened to both inner ends of the erection beam 12 using bolts, nuts, or the like, if necessary. Such fastening means are known per se.

Next, a configuration example of the first side wall A will be described. The first side wall A of the caisson a _{1 in} the longitudinal direction of the road is formed by combining inexpensive and diversified general-purpose members. Specifically, as shown in FIG. 5, a corrugated steel sheet pile 16 and a fixed anchor steel rod 14 disposed on the inner side thereof, and the fixed anchor steel rod 14 provided with a support portion on a pneumatic slab, are used for steel. A presser girder 15 (see FIG. 2) provided on the upper portion of the sheet pile 16 is provided. The side wall structure can be strengthened by pressing, supporting, and fixing the head of the steel sheet pile 16 with the pressing beam 15. In FIG. 5, 16a is a steel sheet pile joint, 16b is a steel sheet pile fastening portion, and 16c is a steel sheet pile fastening portion anchor provided in the second side wall B in the road section direction. Also caisson _a 2 ~a _n of second to n formed in the same manner. A prestressed concrete plate may be used instead of the steel sheet pile 16.

  In the caisson housing, prior to the construction of the first side wall A, a caisson base is first manufactured. The caisson base is composed of a compressed air slab 4, a blade edge 4a, and a pair of second side walls B in the road cross-sectional direction, and these are integrally formed of reinforced concrete. A first side wall A, which is a temporary wall that is easy to assemble and disassemble, is constructed at the opening in the longitudinal direction of the road of the caisson base. A holding girder 15 is provided to support the first side wall A, and an uprising girder 12 is provided on the inner side. Reinforcing materials such as the diagonal girder 11 and the lower fixed girder 28 are fastened to form a caisson housing. The first side wall A and the second side wall B are fixed by connection or appropriate fixing means such as bolts and nuts.

  Next, a case where a caisson tunnel is constructed using the caisson configured as described above will be described.

6 is a plan view of, for example, first to third caissons a _{1 to} a ₃ that have been laid, FIG. 7 is a side view of the same, and the internal structure of the _second half of the caisson a ₂ is taken as a cross section. The explanatory drawing shown is shown. In FIG. 6 and FIG. 7, illustration of members such as the erection girder 12, the holding girder 11, and the reinforcing girder 13 is omitted for convenience of explanation.

The caissons a _{1 to} a ₃ are sequentially deposited in the longitudinal direction of the road.

When the caissons a _{1 to} a ₃ are set, a space b is formed between them, and the ends of the second side walls B in the road section direction are overlapped from the top to the bottom outside the space b. For example, the continuous wall 17 is formed and closed. As shown in FIG. 7, the upper end of the continuous wall 17 is substantially the same as the upper end of the caisson a _{1 to} a ₃ (between the first side walls in the adjacent road longitudinal direction), and the lower end is the blade edge of the caisson a _{1 to} a ₃ . Make it deeper than 4a. A space b exists between the inside of the continuous wall 17 and the outer surface of the side wall B in the road section direction, and this portion is ground improved and water is stopped. In FIG. 7, the symbol b ′ is the ground improvement portion. Reference numeral 29 denotes bottom-filled concrete placed below the pressurized slab 4.

Next, as shown in FIG. 9, the space | interval b part is excavated to the predetermined depth, the ground improvement part b 'is left in the lower part, and the space for couple | bonding adjacent caisson is ensured. As shown in FIG. 9, the bottom part of the space | interval b is made into the bottom plate 18 with reinforced concrete. The upper surface of the bottom plate 18 is substantially flush with the upper surface of the pressure slab 4. The inside of the pressurized working chamber 7 of each of the caissons a _{1 to} a ₃ is set to a predetermined depth, and then bottom-filled concrete 29 is formed. The same applies to the caisson _a 4 ~a _n of fourth to n.

  When performing these operations, if necessary, the interval portion may be hermetically sealed with a pressure air lid, fixed, and a pressure lock (none of which is shown) may be provided to apply pressure according to the groundwater pressure. As a result, it is possible to securely excavate while suppressing the occurrence of heaving and boiling.

The adjacent first side walls A in the longitudinal direction of the road are dismantled and removed to form a continuous caisson tunnel space by a plurality of _{first to nth} caissons a ₁ to an.

  By using this space portion, as shown in FIG. 1, the caisson approach portion and the tunnel 2 made of the caisson approach portion are constructed from the ground side, and the caisson tunnel can be easily constructed.

In the case of disassembling the first side wall A, first removing the copy digit 11 is a reinforcing member in the caisson a ₁ ~a _n, then removing the wale digit 12. If there is a reinforcing beam 13, it is also removed. The lower fixed girder 28 is also removed. Since these are fastened with bolts, nuts, PC steel wires, etc., they can be easily disassembled.

  Next, both are separated via bolts and nuts between the presser girder 15 and the fixed anchor steel bar 14, the presser girder 15 is removed, and the parts such as the steel sheet pile joint 16a and the steel sheet pile fastening portion 16b are separated to form a steel sheet pile. 16 may be removed, and then the fixed anchor steel rod 14 may be removed.

  Each of these disassembled members can be diverted to another caisson tunnel, for example. In constructing the tunnel approach section, it is a matter of course that the caisson housing installation facilities such as the excavator 6, the man shaft 8a, the man lock 8, the material shaft 9a, and the material lock 9 are also removed.

  10 to 12 show a second embodiment of the caisson of the present invention. 10 is a cross-sectional view of the caisson as viewed from the longitudinal direction of the road, FIG. 11 is a cross-sectional view taken along the line oo in FIG. 10, and FIG. 12 is a cross-sectional view taken along the line pp in FIG. The figure is shown.

In this embodiment, since the caisson a ₁ ′ is made large, reinforcing structures 19 and 19 ′ as reinforcing members for resisting the bending moment generated mainly in the crossing direction of the road and increasing the rigidity of the caisson when set up are provided. It is provided and fixed integrally with the side wall and the pressure slab. The reinforcing structure 19 is provided in the caisson a ′ and substantially in the middle portion of the second side wall B in the cross-sectional direction of the road, and the reinforcing structure 19 ′ is inscribed and fixed inside the first side wall A.
In the present embodiment, the reinforcing structures 19 and 19 ′ constitute a truss structure with the cross member 25, the vertical member 26, and / or the diagonal member 27. In this case, the cross member 25 is essential, but at least one of the diagonal member 27 and the vertical member 26 is sufficient. Each of these may be made of steel, but is not necessarily steel, and may be prestressed concrete, for example.

  The truss structure may be a truss structure composed of diagonal members 27 and cross members 25. Moreover, it is good also as a plate-girder structure which attached the steel plate to the space divided by the vertical beam 26 and the horizontal beam 25. The reinforcing structures 19 and 19 'have a function of maintaining a predetermined rigidity in the road cross-sectional direction of the pneumatic caisson. Further, in this reinforcing structure 19 ′, the appropriate retaining beam member 11 of the reinforcing structure 19 ′ is attached as a mountain retaining material, and the other end is fixed to the upper surface of the pneumatic slab 4 to act on the first side wall A. It also has the function of supporting earth pressure and water pressure.

Reinforcing material 20 for reinforcement is provided on both sides of the reinforcing structure 19 provided in the central portion in the caisson a ₁ ′. The fire striking material 20 provided on both sides of the reinforcing structure 19 is provided at an appropriate interval in the height direction, and one end of the fire striking material 20 is fastened to the reinforcing structure 19 using a fastener, and the other end is the second side wall B. It is fastened to the inner wall. Depending on the scale, there may be no fire hitting material 20.

The interior of the caisson a ₁ ′ is divided into left and right first and second chambers 21 and 22 in the reinforcing structure 19. For this reason, the first and second chambers 21 and 22 are each provided with a man shaft 8a having a man lock 8 at the top and a material shaft 9a having a material lock 9 at the top. In the state shown in FIG. 11, the upper side is the man shaft 8a and the lower side is the material shaft 9a, but the arrangement relationship may be reversed.

  The first side wall A in the longitudinal direction of the road provided in a direction orthogonal to the second side wall B on the crossing direction side is basically a steel sheet pile or H that can be assembled and disassembled and receives water pressure and earth pressure. The point which has the mountain retaining wall comprised combining steel materials etc. is the same as that of 1st Example. For this reason, also in this embodiment, since the assembly and disassembly of the first side wall A are easy, the process can be shortened. Moreover, since these members can be reused after being disassembled, resources can be saved and costs can be reduced.

  In this embodiment, as shown in FIG. 12, side wall attachment members 23 are provided along the height direction at both ends inside the second side wall B. Further, a slab attachment material 24 is provided below the side wall attachment material 23. 10 and 12, reference numeral 31 denotes an upper fixed girder.

Further, in this embodiment, since caisson a ₁ is large, as described above, 'the corresponding configuration at the reinforcing structure 19' reinforcing structure 19, 19 inside of one end of the refrain digits 11 as shoring The other end of the guard girder 11 is fastened to the pneumatic slab 4, and the guard girder 11 is disposed obliquely and reinforced. Although the reinforcing structure 19 ′ has been described with respect to an example of at least one or more double structures in the substantially horizontal direction, if the scale is large, a double structure or more may be used if necessary. Further, the reinforcing structure 19 ′ has four layers in the height direction, but the layer structure can be appropriately increased or decreased according to the scale.

  As described above, the reinforcing structure 19 'inside the first side wall A is constituted by the truss structure shown in FIG. That is, a slab attachment member 24, a sidewall attachment member 23, and an upper fixed girder 31 are incorporated in a frame shape on the pneumatic slab 4 and in rectangular space portions in the left and right second side walls B, B, and this rectangular frame In the shaped member, cross members 25 are provided at appropriate intervals in the horizontal direction (road cross-sectional direction), and vertical members 26 are provided at appropriate intervals in the vertical direction (height direction) to form a lattice shape. Further, diagonal members 27 are provided and reinforced in window-like space portions defined by the cross members 25 and the vertical members 26, respectively.

  Other caissons are similarly configured.

  Next, the road tunnel construction method of this 2nd Example is demonstrated.

First, caisson a ₁ ′ is laid down in the longitudinal direction of the road in the same manner as in the first embodiment, and other required numbers of caissons are laid down sequentially at intervals. The sinking operation is performed by a known method using the excavator 6. The processing of the interval portion is the same as that of the first embodiment shown in FIGS.

  After the laying, the excavator 6 is disassembled as appropriate or recovered through the material shaft 9a by turning it upside down, and then the man shaft 8a having the man lock 8, the material shaft 9a having the material lock 9, etc. Collect and remove the installation equipment.

  Further, if there is a fire striking material 20, it is removed, and then the reinforcing structure 19 is removed.

  In addition, the reinforcing material such as the girder 11 is also removed.

  Next, inside the first side wall A, reinforcing members such as the upper fixed girder 31, the vertical member 26, the diagonal member 27, the cross member 25, the side wall attachment member 23, the slab attachment member 24, etc. are disassembled and removed in an appropriate procedure. To do.

  Next, the first side wall A is removed.

  Since the 1st side wall A combines the steel sheet pile, H steel materials, etc. which were fastened and integrated with the volt | bolt, the nut, the PC steel wire, etc., it can be disassembled easily. Moreover, the point which can be reused after a disassembly is the same as that of 1st Example.

  Note that the approach section in this embodiment is not limited to the example that leads from the ground to the basement as shown in FIG. 1, but for example, as shown in FIG. The present invention can also be applied to the case of going out and other cases.

In the second embodiment, the case where the reinforcing structure 19 is provided at the substantially central portion of the caisson a ₁ ′ has been described. However, when the main girder structure is disposed on the slab itself, the reinforcing structure 19 is disposed. You don't have to.

  14 and 15 show a third embodiment of the present invention. 14 is a cross-sectional view of the caisson as viewed from the longitudinal direction of the road, and FIG. 15 is a cross-sectional view taken along the line qq in FIG.

  In the first embodiment shown in FIGS. 2 to 5, the upper part of the caisson is of the open type, but in this embodiment, the upper slab 4A is provided and reinforced, and the first side wall A is made of a steel pipe. It has a feature that the structure of the temporary wall is simpler than that of the first embodiment.

  The lower end of the mountain retaining wall 30 is made of a highly rigid steel pipe, embedded in the upper surfaces of both ends of the pneumatic slab 4 on the road longitudinal direction side (see FIG. 22 for details), and from one end side to the other end side in the road cross-sectional direction. It stands upright in the shape of a wall. A lower fixing girder 31 ′ for reinforcement is provided along the road cross-sectional direction inside the lower part of the retaining wall 30, and the lower part of the retaining wall 30 is reinforced and fixed. If the lower fixed girder 31 ′ is provided at the lower portion of the retaining wall 30 in this way, the lower end portion of the retaining wall 30 may not be embedded in the pressure air flav depending on the scale (see FIG. 21 for details).

  Further, an upper slab 4A is provided inside the upper part of the mountain retaining wall 30, and upper fixed girders 31A extending along the cross-sectional direction of the road are provided at both upper ends on the road longitudinal direction side of the upper slab 4A. The upper part of the mountain retaining wall 30 is supported and fixed.

  The mountain retaining wall 30 is coated with a release material on the outer and / or inner surface 30a so that it can be easily pulled and removed. Since the other parts are basically the same as those in the first embodiment, the same reference numerals are used for the same parts and the detailed description is omitted.

  However, in this embodiment, since a steel pipe having high rigidity is used for the mountain retaining wall 30, there is no need to particularly upset or support.

  In the construction of the caisson tunnel, the first side wall A formed by the mountain retaining wall 30 between the upper slab 4A and the pressurized slab 4 may be removed. Other processes such as the lower side of the pressure slab 4 may be basically performed in the same manner as in the first embodiment.

  16 and 17 show a fourth embodiment of the present invention. FIG. 16 is a cross-sectional view of the road in the longitudinal direction, and FIG. 17 is a cross-sectional view taken along line rr in FIG. In the third embodiment, the upper slab 4A is provided. In this embodiment, instead of the upper slab 4A, the beams 4B extending in the transverse direction of the road and connecting the second side walls B are appropriately spaced in the longitudinal direction of the road. The point provided in is different.

  In this embodiment, a beam 4B is provided on the inside upper part of each first side wall A, and each first side wall A is supported and fixed to the beam 4B. An upper fixed girder 31A is provided above the beam 4B.

  Moreover, the beam 4B is provided also in the substantially central part, and each 2nd side wall B is connected and reinforced through the beam 4B. Others are the same as in the third embodiment.

  18 to 22 show a fifth embodiment of the present invention. 18 is a cross-sectional view of the caisson as viewed from the longitudinal direction of the road, FIG. 19 is a cross-sectional view taken along the line ss in FIG. 18, and FIG. 20 is a cross-sectional view taken along the line tt in FIG. FIGS. 21 and 21 show an example of mounting of a retaining wall on a pneumatic slab, and FIG. 22 shows another example.

  Also in this embodiment, an upper slab 4A is provided on the pressure slab 4 as in the third embodiment shown in FIG. In the fifth embodiment, the first side wall A that constitutes the temporary wall is formed of a mountain retaining wall 30, and an upright spar 12 that is a reinforcing material is fastened to the inside of the mountain retaining wall 30. Inside the erection girder 12, a retaining girder 11 as a reinforcing material is provided and reinforced.

  As shown in FIG. 18, the guard girder 11 as a supporting work is composed of a guard girder arranged obliquely on the lower side and a girder arranged obliquely on the upper side. One end of the lower holding girder 11 is erected and provided on the side of the girder 12 via a support member, and the other end is provided on the side of the pneumatic slab 4 via the support member.

  One end of the upper girder 11 is provided on the side of the spar 12 through the support member, and the other end is provided on the upper slab 4A side through the support member.

  FIG. 21 shows details of an installation example of the lower portion of the mountain retaining wall 30 with respect to the pressure slab 4. In the example of FIG. 21, the lower end of the retaining wall 30 is provided on the pressurized slab 4, the lower fixed girder 31 ′ is provided on the inner side of the retaining wall 30 and on the pressurized slab 4, and the fixing anchor 32 is used. Are fixed. In this example, a fixing tool 33 is constituted by the fixing anchor 32 and the lower fixing beam 31 '.

  FIG. 22 shows another installation example of the lower part of the mountain retaining wall 30. In this example, the lower end portion of the retaining wall 30 is embedded in the compressed air slab 4, and the lower fixed girder 31 ′ is positioned on the inner side of the retaining wall 30 and on the pressurized slab 4, and is fixed via the fixing anchor 32. ing. In this case, since the lower end portion of the mountain retaining wall 30 is embedded, it can be fixed more firmly than in the case of fixing according to FIG.

  In addition, if a peeling material is provided in the lower part of the mountain retaining wall 30, it can be easily removed at the time of removal, and the removal workability is good. In the example of FIG. 22, the fixing tool 33 is configured by the fixing anchor 32, the lower fixing beam 31 ′, and the release agent a.

  Which fixing method is used can be arbitrarily selected according to the scale.

  The method of removing the mountain retaining wall 30 includes a method of extending the mountain retaining wall 30 to the ground and easily pulling it out, and the length of the mountain retaining wall 30 to the bottom of the upper slab 4A, and removing the fixing part from the inside. Two methods are conceivable: removing inside or from the interval b described in the first embodiment. Either one can be selected according to the scale.

  In addition, when the height of the mountain retaining wall 30 is set to be below the upper slab 4A, a separate mountain stop is required on the upper slab 4A when constructing the interval b.

  When the mountain retaining wall 30 is on the upper slab 4A, the supporting structure of the mountain retaining wall 30 on the upper slab 4A is fixed by providing a fixed girder (not shown) at a position slightly lower than the top of the mountain retaining wall 30. The fixed girder is fixed to the second side wall B, slab, or beam.

  In the case where the second side wall B protrudes on the upper slab 4A, the wall surface may be the entire surface or partial at both ends.

  When the earth covering is deep and there is a wall on the entire upper surface of the upper slab 4A, the wall is mountain-capped, but when there is no wall, backfilling is performed on the upper slab 4A. However, in order to facilitate removal of the retaining wall 30 and the fixed girder, a wall is provided in the vicinity so that the wall can be backfilled to a place where there is no wall, or the fixed girder can be easily removed. In this way, a slope is provided to perform backfilling. Note that a reserved girder is provided as necessary (not shown).

  The mountain retaining wall 30 is removed before the installation of the upper slab having the interval b.

  After the upper slab construction of the interval b, backfilling (remainder) on the upper slab 4A of the caisson is performed together with backfilling on the upper slab of the interval b.

  23 and 24 show a sixth embodiment of the present invention. FIG. 23 is a cross-sectional view of the road longitudinal direction, and FIG. 24 is a cross-sectional view taken along the line tt in FIG. This embodiment is basically different only in that a beam 4B is used instead of the upper slab 4A of the fifth embodiment. The attachment of the beam 4B is the same as in the fourth embodiment.

  In each of the above embodiments, a reserved girder is used as a supporting work, but a cut beam may be used.

An explanatory view of an example in the case of constructing a caisson tunnel using the caisson of the present invention is shown. It is a caisson concerning 1st Example of this invention, Comprising: Sectional drawing of a road longitudinal direction is shown. FIG. 3 is a cross-sectional view taken along line m-m in FIG. 2. The nn sectional view taken on the line in FIG. 3 is shown. FIG. 3 shows an enlarged explanatory view of the first side wall portion. Explanatory drawing at the time of seeing the caisson tunnel constructed | assembled using the caisson of this invention from a plane is shown. FIG. 7 is a partial cross-sectional explanatory view of the construction example of FIG. It is a top view which shows the state which removed the 1st side wall of the road longitudinal direction of a caisson in the construction method of the caisson of this invention. FIG. 9 shows a side view of FIG. 8. It is a caisson concerning 2nd Example of this invention, and sectional drawing of a road longitudinal direction is shown. A cross-sectional view taken along line oo in FIG. 10 is shown. A cross-sectional view taken along the line pp in FIG. 11 is shown. The explanatory view of other examples at the time of constructing a caisson tunnel using the caisson of the present invention is shown. Sectional drawing of 3rd Example of this invention is shown. FIG. 14 is a cross-sectional view taken along the line qq in FIG. 14 according to the third embodiment of the present invention. Sectional drawing of 4th Example of this invention is shown. FIG. 16 is a fourth embodiment of the present invention, and shows a cross-sectional view taken along line rr in FIG. Sectional drawing of 5th Example of this invention is shown. FIG. 18 is a fifth embodiment of the present invention, and shows a sectional view taken along the line ss in FIG. A cross-sectional view taken along line tt in FIG. 19 is shown. The explanatory view of one example of attachment of a mountain wall is shown. Explanatory drawing of the other example of attachment of a mountain wall is shown. Sectional drawing of 6th Example of this invention is shown. FIG. 25 is a sixth embodiment of the present invention, and shows a sectional view taken along the line tt in FIG. 23.

Explanation of symbols

A first sidewall _{a 1 ~a} n, _a 1 'caisson b spacing b' ground improvement section G Ground


DESCRIPTION OF SYMBOLS 1 Shield tunnel 2 Caisson tunnel 3 Ground part 4 Pressurized slab 4A Upper slab 4a Cutting edge 5 Running rail 6 Excavator 7 Pressurized working room 8 Manlock 8a Manshaft 9 Material lock 9a Material shaft 10 Groundwater level 11 Precise girder 12 Girder 13 Reinforcement girder 14 Fixed anchor steel bar 15 Holding girder 16 Steel sheet pile 16a Steel sheet pile joint 16b Steel sheet pile fastening part 17 Continuous wall 18 Bottom plate 19, 19 'Reinforcement structure 20 Fire-split material 21 Chamber 22 Chamber 23 Side wall attachment material 24 Slab attachment material 25 Cross member 26 Vertical member 27 Diagonal member 28 Lower fixed girder 29 Bottom-filled concrete 30 Yamato wall 30a Yamato wall surface 31 'Lower fixed girder 31 and 31A Upper fixed girder 32 Fixing anchor 33 Fixing tool

Claims (8)

The first side wall of the pneumatic caisson in the longitudinal direction of the road is composed of a temporary wall that can be assembled and disassembled and has a function of a mountain retaining wall, and is connected to or fixed to the temporary wall. The side walls are made of concrete,
The caisson for approach characterized in that the lower part of the first side wall is fixed to the upper part of the pressure slab formed in the lower part of the caisson housing, and the upper part is supported or fixed by supporting means or fixing means. The approach caisson of claim 1,
A caisson for an approach, characterized in that a belly raising material is provided inside the first side wall, and a support is fastened to the belly raising material. The approach caisson of claim 1,
A reinforcing structure is disposed inside the first side wall, the reinforcing structure is fixed to the upper portion of the compressed air slab, and the reinforcing structure includes a cross member and a vertical member or an oblique member, and a support work, Approach caisson characterized by being fastened. The approach caisson of claim 1,
A caisson for approach characterized in that a reinforcing structure is provided at a substantially middle position of the first side wall provided on both sides of the caisson housing in the longitudinal direction of the road. The approach caisson of claim 1,
An approach caisson, wherein an upper slab or a beam is provided on an upper portion of the caisson housing, and the first side wall is fixed to the upper slab or the beam. The first side wall on the road longitudinal direction side of the pneumatic caisson is constructed of a temporary wall that can be assembled and disassembled and has a function of a mountain retaining wall, and the second side wall on the road transverse direction side that is fixed to the temporary wall is Composed of concrete,
A tunnel characterized in that an appropriate number of caisson enclosures having the first and second side walls are laid down in the longitudinal direction of the road and the first side wall made of the temporary wall is removed to construct an approach portion. How to build an approach section In the construction method of the approach part for tunnels according to claim 6,
A construction method of a tunnel approach section, wherein the first side wall reinforcing reinforcing material and the caisson housing installation equipment provided in the first and second side walls are removed and constructed. The method for constructing a tunnel approach according to claim 6,
An appropriate number of caisson housings having the first and second side walls are disposed at intervals, and a continuous wall is provided on the outside between the second side walls adjacent to each other to connect the second side walls. A method for constructing a tunnel approach section, characterized in that a space for excavating between the first side walls facing each other and connecting adjacent caisson housings is formed.

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