JP2012162889A - Segment ring joint structure and underground structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a segment ring joint structure and an underground structure which can reduce a construction period in the case of constructing a structure using segments and also minimize accumulated errors.SOLUTION: A segment ring joint structure 60 includes a segment ring formed by combining adjacent segments in a transverse direction, an adjustment joint 61 that is a clearance formed between adjacent segment rings in a longitudinal direction, a long bolt 62 for joining together adjacent segment rings through the adjustment joint 61, and a filler 63 filling the adjustment joint 61.

Description

  The present invention relates to a segmented joint structure and an underground structure.

  When constructing an underground structure, a plurality of segments may be arranged side by side and adjacent segments may be joined to form an outer shell.

  For example, in the shield method, the segment ring is assembled behind the shield machine, and the segment ring is sequentially connected to the face side of the existing segment ring to construct an underground structure (see Patent Document 1).

  Further, in the propulsion method, an underground structure is constructed by assembling segment rings on the wellhead side (vertical shaft side) and sequentially connecting new segment rings from the wellhead side of the existing segment ring (Patent Document 2). reference).

  As described above, the construction of the underground structure using the conventional segment is generally performed by so-called one-push construction in which the segments are sequentially assembled from one side.

JP 2009-161988 JP 2005-264552 A

  On the other hand, the inventor of the present application has developed a technique for constructing a steel shell frame by constructing a concrete frame, digging down the lower ground, and arranging steel segments on the floored surface.

However, when the segments are arranged by one-pushing work in the construction of the steel shell frame, the assembly work of the segments can be performed only at one place, which hinders the shortening of the construction period.
In addition, if the construction extension due to the one-sided construction is long, there is a possibility that the manufacturing errors and construction errors of the segments are accumulated. When the accumulated error increases, for example, when joining with another structure, it is necessary to adjust the error at the joint, and the work is troublesome.

  From this point of view, the present invention can shorten the construction period when constructing a structure using segments, and can reduce the cumulative error to the minimum, and the segmenting joint structure and the underground It is an object to provide a structure.

  In order to solve the above problems, the segment ring joint structure of the present invention is a gap formed between a segment ring formed by combining segments adjacent in the transverse direction and the segment rings adjacent in the longitudinal direction. An adjustment joint, a long bolt that connects adjacent segment rings with the adjustment joint interposed therebetween, and a filler filled in the adjustment joint are provided.

According to such a segmenting joint structure, even if an error occurs in the longitudinal direction due to manufacturing errors or construction errors during segment manufacture, it can be absorbed by the adjustment joint, so that the structure can be produced with high quality. Can be built.
As described above, according to the present invention, since errors in the longitudinal direction can be absorbed, it is possible to simultaneously perform the segment assembling work at a plurality of locations, and the construction period can be greatly shortened.

  You may provide the shielding plate which shields the inner space side of the said adjustment joint. If it does in this way, the said shielding plate will function as a formwork, and it can prevent that the filler with which the adjustment joint was filled flows out into an inner side.

  In addition, even if an error has occurred if a long hole passes through the shielding plate and the shielding plate is fixed to the segment ring by a bolt that penetrates the long hole, the segment ring Easy to install.

  Moreover, if the water swelling material is arrange | positioned at the adjustment joint side surface of the said segment ring, a water stop performance will improve.

  Further, the underground structure of the present invention has a concrete frame and a steel shell frame formed on the lower side of the concrete frame, and the steel shell frame includes a plurality of segments arranged in parallel, It is formed by joining the adjacent segments, and the steel shell housing is adjacent to the adjustment joint, which is a gap formed between adjacent segments in the longitudinal direction, with the adjustment joint interposed therebetween. A segment ring joint structure including a long bolt that connects the segments to each other and a filler filled in the adjustment joint is formed for each predetermined section.

Such an underground structure can absorb segment errors that occur in the longitudinal direction due to the segmented joint structure, so it is possible to perform steel shell frame construction in the underground space at multiple locations simultaneously, resulting in early and high quality. Can be built.
The segmenting joint structure absorbs accumulated errors due to construction errors and factory manufacturing errors, so that the segment installation accuracy is improved and there is no deviation in the joint with the concrete formed on the upper side.

  According to the segmenting joint structure and the underground structure of the present invention, it is possible to shorten the work period when constructing a structure using segments, and to minimize the accumulated error.

It is a cross-sectional view of an underground structure according to an embodiment of the present invention. It is a bar arrangement diagram of a concrete frame. It is a steel arrangement figure of a concrete frame. It is a fracture perspective view of an underground structure concerning an embodiment of the present invention. It is a top view of the steel segment for floor slabs, and the steel segment for corner parts. It is a cross-sectional view of a steel segment for floor slabs and a steel segment for corners. (A) is a side view of the steel segment for a side wall, (b) is XX sectional drawing of (a). (A) is a YY sectional view of (a) of FIG. 7, (b) is an enlarged sectional view of (a), (c) is a Z1 partial view of (a) of FIG. 7, (d) is Z2 of FIG. FIG. (A) is a cross-sectional view which shows a primary excavation process, (b) is a cross-sectional view which shows a 1st frame construction process. (A) is a cross-sectional view showing a process following (b) of FIG. 13, and (b) is a cross-sectional view showing a secondary excavation process. (A) And (b) is a cross-sectional view which shows a 2nd housing construction process. It is a cross-sectional view which shows a support | pillar construction process. (A) is a plan view showing an assembly state of a segment, (b) is a plan view showing a process following (a), and (c) follows (a) when it does not have a segment ring joint structure. It is a top view which shows a process, and is a case where it has a segment ring joint structure.

  As shown in FIG. 1, the underground structure according to the embodiment of the present invention is a culvert constructed by an open-cut method, and a steel body formed on a lower side of the concrete body A and a concrete body A that also serves as a mountain retaining support. A shell frame B and a column C formed between the concrete frame A and the steel shell frame B are provided.

<Concrete body A>
The concrete frame A is a main frame designed to withstand earth water pressure and an overload, but is constructed prior to the steel shell frame B and the column C except for the joint with the steel shell frame B. When digging between the mountain walls W, W, it functions as a mountain retaining support. The concrete frame A of this embodiment includes a top plate portion A1, a side wall portion A2 along the mountain retaining wall W, and a vertical beam portion A3 extending in the longitudinal direction.

  The concrete frame A is a steel reinforced concrete structure (SRC structure), and is composed of cast-in-place concrete and reinforcing steel materials such as steel frames 11 to 13 and reinforcing bars (not shown). In the present embodiment, in addition to the transverse steel frame 11, the side wall core steel frame 12, the longitudinal steel frame 13, etc., as shown in FIG. 2, the slab main bar 14, the side wall main bar 15, the vertical beam main bar 16, the shear reinforcement bar 17, the hunch bar 18, etc. The concrete is reinforced by. Of course, the concrete case A may be precast.

  As shown in FIG. 3, a plurality of transverse steel frames 11 are arranged in parallel at intervals in the front-rear direction (longitudinal direction). In addition, illustration of a reinforcing bar is abbreviate | omitted in FIG. Each transverse steel frame 11 is arranged so that the material axis direction is the horizontal direction (left-right direction). The transverse steel frame 11 of the present embodiment is made of an H-shaped steel, but may be changed to an I-shaped steel or a grooved steel.

  Adjacent transverse steel frames 11, 11 are connected by a plurality of connecting members 11a, 11a,. In addition, the edge part of the connection material 11a is connected to the stiffener of the crossing steel frame 11. FIG. As shown in FIG. 2, the end of the transverse steel frame 11 is placed on a bracket W2 provided on the core material W1 of the mountain retaining wall W, and the end surface of the transverse steel frame 11 and the inner wall surface of the mountain retaining wall W are A support member 11b is interposed therebetween.

  The side wall core steel frame 12 is a reinforcing steel material disposed in the side wall portion A2, and is disposed such that the material axis direction is the vertical direction. The upper end part of the side wall core steel frame 12 is joined to the lower surface of the end part of the transverse steel frame 11. Triangular reinforcing ribs 12 a are arranged at the inner corners of the joint between the transverse steel frame 11 and the side wall core steel frame 12. The side wall core steel frame 12 of the present embodiment is made of H-section steel, but may be changed to I-section steel or groove-section steel.

  The longitudinal steel frame 13 is a reinforcing steel material disposed in the upper half portion of the longitudinal beam portion A3, and is disposed such that the material axis direction is the longitudinal direction (see FIG. 3). The end of the longitudinal steel frame 13 is connected to a bracket protruding from the web of the transverse steel frame 11. Although the longitudinal steel frame 13 of this embodiment consists of channel steel, you may change into H-section steel, I-section steel, angle steel, etc.

  The slab main bar 14 is a reinforcing steel material arranged along the upper surface and the lower surface of the top plate portion A1, and is arranged so that the longitudinal direction is the horizontal direction. The slab main bar 14 penetrates the vertical beam part A3, and both ends of the slab main bar 14 are fixed to the concrete of the side wall parts A2 and A2.

  The side wall main reinforcement 15 is a reinforcing steel material arranged along the outer wall surface (wall surface on the mountain retaining wall W side) and the inner wall surface (wall surface on the inner sky side) of the side wall portion A2, so that the longitudinal direction becomes the vertical direction. Is arranged. In addition, the side wall main reinforcement 15 has entered the steel shell frame B.

  The longitudinal beam main reinforcing bars 16 are reinforcing steel members arranged along the upper surface and the lower surface of the longitudinal beam portion A3, and are arranged so that the longitudinal direction is the longitudinal direction.

  The shear reinforcing bar 17 is a reinforcing steel material arranged in a direction intersecting with the slab main bar 14 or the side wall main bar 15.

  The haunch bar 18 is a reinforcing steel material arranged in the haunch part, and the upper half of the haunch bar 18 is fixed to the concrete of the top plate portion A1.

<Steel shell B>
A steel shell frame B shown in FIG. 1 is a permanent frame designed to withstand soil water pressure and an overload. The steel shell frame B has a steel slab structure floor slab B1 along the floored surface T2 and a steel shell structure side wall B2 along the mountain retaining wall W, and has a U-shaped cross-sectional view. .
Further, as shown in FIG. 4, a segmenting joint structure J1 is formed in the steel shell frame B for each predetermined section (for example, 10 m) in the longitudinal direction.

  As shown in FIG. 1, the floor slab B1 constitutes the floor of the underground part. Moreover, side wall part B2 comprises a part of side wall of an underground part, and is joined to side wall part A2 of the upper concrete frame A (side wall junction part J2).

  As shown in FIG. 4, the steel shell frame B of the present embodiment includes a floor segment steel segment 20, a corner steel segment 30, and two types of side wall steel segments 40 and 50. Has been. That is, the steel shell frame B is formed by a plurality of steel segments (a steel segment 20 for floor slabs, a steel segment 30 for corner portions, and steel segments 40 and 50 for side walls).

In the following description, a U-shaped unit composed of four steel segments 20, 30, 40, 50 is referred to as a “ring” following the shield tunnel. A joint portion (joint portion) between steel segments belonging to the same ring is referred to as a “segment joint”, and a joint portion (joint portion) between rings adjacent in the longitudinal direction is referred to as a “ring joint”.
Further, “front / rear / left / right” is based on the state of FIG.

  The floor slab steel segment 20, the corner steel segment 30, and the side wall steel segments 40, 50 are juxtaposed so as to be in a potato assembly state, and the segment joints are continuous in the longitudinal direction. . That is, the position of the segment joint of one ring coincides with the position of the segment joint of another adjacent ring.

  The steel segment 20 for floor slabs is a normal type steel segment in which other steel segments are arranged on the front, rear, left and right sides thereof, and has a bottomed box shape with an upper surface opened. As shown in FIGS. 5 and 6, the floor slab steel segment 20 includes a skin plate 21, a pair of front and rear main girder plates 22 and 22, a pair of left and right joint plates 23 and 23, and a main girder plate 22, A plurality of vertical ribs 24, 24,. The floor slab steel segment 20 is joined to two steel segments (another floor slab steel segment 20 and a corner steel segment 30) belonging to the same ring via each joint plate 23. The steel plates 20 are joined to the floor slab segments 20 belonging to other adjacent rings via the main girder plates 22. In addition, although illustration is abbreviate | omitted, the sealing material is affixed on the outer surface of the main girder plate 22 and the joint plate 23. FIG.

  The skin plate 21 is an outer shell (bottom) of the steel segment 20 for floor slab, and is made of a steel plate having a rectangular shape in plan view.

  The main girder plate 22 is erected on the front edge and the rear edge of the skin plate 21, and is abutted against the main girder plate 22 of another floor slab steel segment 20 adjacent in the longitudinal direction. A fixing bolt b1 for a ring joint is inserted through the main girder plate 22. In this embodiment, the main girder plates 22 are joined together using the fixing bolt b1.

  The joint plate 23 includes a water-stop end plate 23a erected on the skin plate 21, and structural reinforcing plates 23b and 23b disposed on the front and rear edges of the end plate 23a. The end face plate 23a is abutted against a joint plate of another segment adjacent in the same ring. The end face plate 23 a is fixed to the skin plate 21 and the main girder plates 22 and 22. The reinforcing plate 23b is disposed on the left and right edges of the main girder plate 21, and is fixed to the inner surfaces of the main girder plate 21 and the end face plate 23a. A fixing bolt b2 for a segment joint is inserted through the end face plate 23a and the reinforcing plate 23b. In the present embodiment, the main girder plates 22 (32) are made continuous with each other by a tensile joining method using the fixing bolt b2. That is, the fixing bolt b2 joins the end face plates 23a (32a) and connects the main girder plates 22 (32) to each other in the segment joint. An axial force equivalent to 75% of the yield axial force of the fixed bolt b2 is introduced to the fixed bolt b2 as an initial introduction axial force. The fixing method using the fixing bolt b2 is not limited to this.

  Note that, when a force that causes a mesh opening is applied to the segment joint, load transmission between the main girder plate 22 and the fixing bolt b2 is mainly performed through the reinforcing plate 23b. Since the portion exceeding the fulcrum of the “leverage reaction force” (portion only of the end face plate 23a) does not contribute to the load transmission, the end face plate 23a can be thinned, and thus the joint structure can be rationalized. Can do.

  The tensile joining method is a joining method in which a strong tightening force is applied to the bolts to generate a large compressive force between the steel segments, and the tensile external force acting in the bolt axis direction cancels this. . When performing tensile joining, high-strength bolts are often used, but ordinary bolts may be used. If the tensile joining method is employed, it is possible to suppress a decrease in rigidity at the joint portion, and furthermore, it is possible to suppress the opening of the joint portion.

  The vertical ribs 24 are arranged in parallel with the joint plate 23. The vertical ribs 24 are erected on the skin plate 21 and fixed to the skin plate 21 and the main girder plates 22 and 22.

  As shown in FIG. 4, the corner steel segment 30 is disposed at the corner where the floor slab B <b> 1 and the side wall B <b> 2 intersect. It is interposed between the steel segments 40. In the present embodiment, since the corner steel segments 30 are arranged side by side so as to be in the potato assembly state, the upper end surfaces of the plurality of corner steel segments 30, 30,. Become one.

  As shown in FIGS. 5 and 6, the steel segment 30 for the corner portion according to the present embodiment includes a skin plate 31 serving as an outer shell, and a main girder plate 32 provided at the front and rear edges of the skin plate 31. , 32, joint plates 33, 33 provided on the side and upper edges of the skin plate 31, and vertical ribs 34, 34 provided between the main girder plates 32, 32. Further, although not shown in the drawings, a sealing material is attached to the outer surfaces of the main girder plate 32 and the joint plate 33.

  The skin plate 31 is obtained by connecting a steel plate arranged along the floored surface T2 (see FIG. 1) and a steel plate arranged along the mountain retaining wall W (see FIG. 1). It is L-shaped.

  The main girder plate 32 has an L shape corresponding to the skin plate 31. As shown in FIG. 5, the main girder plate 32 is abutted against the main girder plate 32 of another corner steel segment 30 adjacent in the longitudinal direction.

  Each of the joint plates 33 and 33 includes a water stop end plate 33a and structural reinforcing plates 33b and 33b disposed on the front and rear edges of the end plate 33a. The end face plate 33a is abutted against the floor slab segment 20 or the side wall segment 40 in the same ring.

  As shown in FIG. 4, the lower side steel segment 40 for the side wall is a normal type steel segment in which other steel segments are arranged at the front, rear, top and bottom thereof, and the inner side surface (side surface on the inner side) is open. It has a box shape.

  The lower side wall steel segment 40 has the same configuration as that of the normal type floor slab segment 20 and becomes an outer shell as shown in FIGS. 7A and 7B. A skin plate 41, a pair of front and rear main girder plates 42, 42, a pair of upper and lower joint plates 43, 43, and a plurality of vertical ribs 44, 44,. ing. In addition, although illustration is abbreviate | omitted, the sealing material is affixed on the outer surface of the main girder plate 42 and the joint plate 43. FIG.

  The lower side wall steel segment 40 is joined to two steel segments (corner steel segment 30 and upper side wall steel segment 50) belonging to the same ring via each joint plate 43. These are joined to the side wall steel segments 40 belonging to other adjacent rings via the main girder plates 42.

  As shown in FIG. 4, the upper side steel segment 50 for side walls is a boundary installation type steel segment installed at the boundary between the side wall portion A2 of the upper concrete frame and the side wall portion B2 of the steel shell frame B. In addition, a box-shaped main body portion 5A having an open inner surface and a bottomed rectangular tube-shaped tubular portion 5B having an upper surface opened are provided. The main body 5A is joined to the first side wall steel segment 40 belonging to the same ring, and is joined to the main body 5A of the side wall steel segment 40 belonging to another adjacent ring. Further, the tubular portion 5B is joined to the tubular portion 5B of the side wall steel segment 50 belonging to another adjacent ring. In addition, although illustration is abbreviate | omitted, the sealing material is affixed on the outer surface of the main girder plate 52 and the joint plate 53. FIG.

  As shown in FIG. 7A, the upper side steel segment 50 for the side wall includes a partition plate 55 and a stress transmission plate 56 in addition to the skin plate 51, the main girder plate 52, the joint plate 53 and the vertical rib 54. And perforated steel plate gibels 57, 57,..., And penetrating rebars 58, 58,.

The skin plate 51, the main girder plates 52, 52, the joint plate 53, and the vertical ribs 54 have the same configuration as that of the normal-type side wall steel segment 40.
That is, the skin plate 51 is an outer shell of the main body portion 5A and the cylindrical portion 5B, and the main girder plate 52 is erected on the front edge and the rear edge of the skin plate 51. The joint plate 53 includes a water stop end plate 53a erected on the skin plate 51, and structural reinforcing plates 53b and 53b disposed on the front and rear edges of the end plate 53a. The vertical ribs 54 are arranged in parallel with the joint plate 53.

  The partition plate 55 is disposed at the boundary between the main body portion 5A and the cylindrical portion 5B. The partition plate 55 according to the present embodiment is disposed above the vertical rib 54 and is parallel to the joint plate 53. The partition plate 55 is made of a single steel plate having a thickness equivalent to that of the reinforcing plate 53b, and is fixed to the skin plate 51 and the main girder plates 52, 52.

  The stress transmission plate 56 constitutes the inner surface of the cylindrical portion 5B, and is disposed to face the upper half of the skin plate 51 (the outer surface of the cylindrical portion 5B). The stress transmission plate 56 is made of a steel plate. A front edge portion and a rear edge portion of the stress transmission plate 56 are joined to the first connection plates 52a and 52a using a plurality of bolts b3, and a lower edge portion of the stress transmission plate 56 uses a plurality of bolts b3. Then, it is joined to the second connection plate 55a. The first connection plate 52 a is fixed to the side end of the main girder plate 52, and the second connection plate 55 a is fixed to the side end of the partition plate 55.

  The perforated steel plate gibels 57, 57,... Function as a shear transmission member, and are disposed above the partition plate 55. The inner peripheral surface (skin plate 51, main girder plate 52) of the cylindrical portion 5B. Or, it is fixed to the stress transmission plate 56). The skin plate 51 and the stress transmission plate 56 are provided with a plurality (four in this embodiment) of perforated steel plate gibbles 57, 67,. A plurality of (three in the present embodiment) perforated steel plate gibels 57, 57,. Note that the plurality of perforated steel plate gibels 57, 57,... Arranged on the same plane are arranged so that the through holes provided in each are aligned in a straight line.

  The penetration reinforcing bar 58 is inserted through the through hole of the perforated steel plate gibber 57. The plurality of penetrating rebars 58, 58,... Arranged along the skin plate 51 are all arranged in the front-rear direction (horizontal direction), and a plurality of perforated steel plate gibels 57 protruding from the skin plate 51. , 57,... Although not shown, the same applies to a plurality of penetrating rebars arranged along the stress transmission plate 56. The plurality of penetrating reinforcing bars 58, 58,... Arranged along the main girder plate 52 are all arranged in the vertical direction (vertical direction), and have a plurality of perforations protruding from the main girder plate 52. It intersects with the steel plate gibels 57, 57,.

<Segmenting joint structure 60>
The segment ring joint structure 60 is formed for each predetermined section, and as shown in FIG. 8A, between the rings (steel segments 20, 30, 40, 50) adjacent in the longitudinal direction. The formed adjustment joint 61, a long bolt 62 that connects adjacent rings across the adjustment joint 61, a filler 63 filled in the adjustment joint 61, and the inner side of the adjustment joint 61 are shielded. And a shielding plate 64.

The adjustment joint 61 is a gap formed between rings (segment 50 in FIG. 8A) adjacent to each other in the longitudinal direction.
The width of the adjustment joint 61 is not limited, but is designed as 50 mm in the present embodiment.

As shown in FIG. 8B, the long bolt 62 penetrates through the main girder plates 52, 52 of the adjacent steel segments 50, 50 and joins the rings together in a state where the adjustment joint 61 is secured. . Although not shown, the same applies to the steel segments 20, 30, and 40.
An adjustment ring 65 is provided around the long bolt 62 in the adjustment joint 61.

  The adjustment ring 65 is a cylindrical member having an inner diameter larger than the outer diameter of the long bolt 62, prevents adhesion of the long bolt 62 and the filler 63, and ensures the width of the adjustment joint 61.

The filler 63 is filled in the adjustment joint 61 and hardened to join the rings together with the long bolt 62.
That is, in the adjustment joint 61, the filler 63 resists the compressive force, and the long bolt 62 resists the tensile force, thereby joining the rings together.

In the present embodiment, high fluidity mortar is adopted as the filler 63, but the material constituting the filler 63 is not limited to this.
Further, the filler 63 is injected simultaneously with the backfill material 71 (see FIG. 11B) filled in the back surface of the ring (corner steel segment 30 and side wall steel segments 40, 50). .

  The shielding plate 64 is fixed to the inner space of the corner steel segment 30 and the side wall steel segments 40 and 50 in order to prevent the filler 63 filled in the adjustment joint 61 from flowing out. Yes.

  The shielding plate 64 is formed of a steel plate and has a plurality of elongated holes 64a, 64a,... The shielding plate 64 secures a width that secures a fixing allowance on both sides of the adjustment joint 61, and a steel plate having a width of 350 mm is used in this embodiment. The shape of the shielding plate 64 is not limited.

As shown in FIGS. 8B and 8C, the shielding plate 64 is a fixing bolt that penetrates the elongated hole 64a in a state of being disposed across the adjacent steel segments 50 with the adjustment joint 61 interposed therebetween. It is fixed to the adjacent steel segment 50 by b4. The shielding plate 64 is similarly fixed to the steel segments 30 and 40.
A mounting plate 66 is fixed to the main girder plate 52 of the steel segment 50 facing the segment ring joint structure 60 corresponding to the position of the long hole 64a of the shielding plate 64. Similarly, mounting plates 66 are also fixed to the steel segments 30 and 40, respectively.

  The mounting plate 66 is a rectangular steel plate in which a bolt hole for inserting the fixing bolt b4 is formed. As shown in FIG. 7B, the mounting plate 66 is integrally formed with the inner space side end of the main girder plate 52. It is fixed.

In the cylindrical portion 5B of the upper-side side wall steel segment 50, as shown in FIGS. 7A and 8D, a mounting plate 66 is disposed on the inner surface of the stress transmission plate 56. FIG.
That is, the fixing bolt b4 penetrates the elongated hole 64a of the mounting plate 66 and the stress transmission plate 56 and is joined to the first connection plates 52a and 52a.

  A water swelling material is installed on the side surface of the segments 20, 30, 40, 50 facing the adjustment joint 61, and groundwater from the boundary between the segments 20, 30, 40, 50 and the filler 63 is provided. Infiltration is prevented.

<Joint part of upper concrete frame A and steel shell frame B>
The side wall joint portion J2 (section in which the upper concrete housing A transitions to the steel shell housing B) has the side wall main reinforcement 15 and the shear reinforcement 17 in the internal space (skin plate 51 and a pair of main girders 52, 52). And a space surrounded by the stress transmission plate 56), the inner space of the cylindrical portion 5B is filled with concrete (not shown).

That is, as shown in FIG. 2, the side wall joint portion J2 includes a cylindrical portion 5B (skin plate 51, a pair of main girders 52, 52 and a stress transmission plate 56) of the side wall steel segment 50, and a cylindrical portion 5B. Are filled in the internal space of the tubular portion 5B. The plurality of side wall reinforcing bars 15, 15,... Reaching the inner space of the cylindrical portion 5B are filled with the plurality of shear reinforcing bars 17, 17,. And made up of concrete.
Note that the configuration of the side wall joint portion J2 is not limited to this.

<Post C>
The support column C shown in FIG. 1 is a permanent structure designed to withstand soil water pressure and an overload. The column C of the present embodiment is erected on the steel shell frame B and supports the vertical beam portion A3 of the upper concrete frame A. In addition, the support | pillar C is a concrete filling steel pipe structure (CFT structure).
<How to build underground structures>

  As shown in FIG. 10, the construction method of the underground structure according to the present embodiment forms an upper concrete frame A that is a part of the main frame, and digs the ground while using the upper concrete frame A as a mountain retaining support. After that, as shown in FIG. 11, a plurality of steel segments 20 to 50 are juxtaposed on the lower side of the upper concrete frame A, and the adjacent steel segments 20 to 50 are joined, so that That is, a steel shell frame B that is a part of is formed.

Hereinafter, with reference to FIG. 9 thru | or FIG. 12, the construction method of the underground structure which concerns on this embodiment is demonstrated in detail.
The underground structure construction method according to the present embodiment includes a primary excavation process, a first chassis construction process, a secondary excavation process, a second chassis construction process, and a strut construction process.

  The primary excavation step is a step of digging the ground between the mountain retaining walls W, W to the lower side of the planned construction position of the concrete frame A, as shown in FIG. The mountain retaining wall W is a so-called columnar continuous underground wall. To construct the Yamato wall W, excavate the ground with an earth auger, mix and agitate the excavated soil and cement slurry at the original position to form a soil cement, lift the earth auger from the excavation hole, The core material W1 may be built in the ground (excavation hole) before the soil cement is hardened.

  When excavating the ground, the soil cement inside the core material W1 is scraped to expose the core material W1. When the core material W1 is exposed, the bracket W2 is installed on the core material W1.

  When the ground is dug down to the floored surface T1, an intermediate pile M is constructed between the retaining walls W, W, and as shown in FIG. Install the jack M1. In addition, the intermediate pile M temporarily receives the intermediate part of the upper concrete frame A, and consists of the soil cement pile which uses H-shaped steel as a core material.

  The first housing construction step is a step of forming the concrete housing A. In the first building construction process, first, a slab formwork or beam formwork is installed on the floored surface T1, and a lower slab main bar 14 or vertical beam main bar 15 (see FIG. 2) is arranged thereon. Make a streak. Next, the transverse steel frame 11 is installed between the brackets W2 and W2, and a support member 11b (see FIG. 2) is installed between the end surface of the transverse steel frame 11 and the inner wall surface of the mountain retaining wall. Restrain movement. Note that the side wall core steel 12 is joined to the transverse steel 11 in advance.

  When the plurality of transverse steel frames 11, 11,... Are installed, the longitudinal steel frame 13 and the connecting material 11a (see FIG. 3) are installed, and further, the upper slab main bar 14, the side wall main bar 15, and the upper vertical beam main bar shown in FIG. 16, shear reinforcement bar 17, haunch bar 18 etc. are arranged. Then, concrete is cast and cured until it reaches a predetermined strength.

  Thus, when the mold is removed while jacking up the jack M1 of the intermediate pile M, as shown in FIG. 10 (a), an upper concrete frame A that also serves as a mountain retaining support appears. In addition, when constructing an underground structure below the existing structure, the existing structure is replaced with the upper concrete frame A.

  As shown in FIG. 10B, the secondary excavation process is a process of digging the lower ground of the upper concrete frame A to the floor surface T2. In the secondary excavation process, the upper concrete frame A is used as a mountain retaining support. In the present embodiment, the cut beam K is installed below the upper concrete frame A. However, the presence or absence of the cut beam K, the number of steps, and the like may be appropriately set according to the excavation depth and the excavation width.

  After excavation to the floor surface T2, although not shown, a waterproof sheet is laid along the floor surface T2 and the inner wall surface of the mountain retaining wall W, and protective mortar and foundation concrete are placed on the waterproof sheet.

  As shown in FIG. 11, in the second case construction step, a plurality of steel segments 20, 30, 40, 50 are arranged in parallel on the lower side of the upper concrete case A, and these are joined together to form a steel shell case. This is a step of forming B. The second frame construction process includes a steel floor slab construction process, a steel wall construction process, and the like.

  As shown in FIG. 11 (a), the steel slab construction process is a process of forming a steel slab floor slab portion B1 on the left and right floored surfaces T2. In the steel floor slab construction process, a plurality of floor slab steel segments 20 and a plurality of corner steel segments 30 are juxtaposed so as to be in a potato assembly state, and these are joined together to obtain a floor slab B1. Form. For example, the steel segment is installed using a handling machine capable of self-propelling on the floored surface T2 while holding the segment, or using a small lifting machine capable of suspending the segment. You can do it.

  The assembling of the steel segments is performed simultaneously at a plurality of locations by providing the segment ring joint structure 60 for each predetermined section. By assembling segments at multiple locations, construction time can be significantly reduced. Further, the error in the longitudinal direction caused by the assembly of the segments is absorbed by the adjustment joint 61 of the segment ring joint structure 60, thereby ensuring the quality.

  When the segments are “assembled”, the assembly order is less likely to be constrained, so various assembly orders can be adopted. For example, two types of steel segments 20 and 30 are arranged side by side, The steel segments 20 and 30 adjacent to each other in the lateral direction are joined to each other to form a horizontally long structure, and then the other steel segments 20 and 30 are juxtaposed in a horizontal row on the front side or the rear side. What is necessary is just to join the same kind of segments adjacent to each other in the longitudinal direction while joining adjacent steel segments 20 and 30. In addition, after arranging one kind of segment in parallel in the longitudinal direction, another kind of segment may be arranged in parallel in the longitudinal direction on the side.

  Adjacent segments are joined using fixing bolts b1 and b2 (see FIG. 5). In the present embodiment, the segments that are adjacent in the transverse direction (segment joints) are joined by a tensile joining method using the fixing bolt b2, thereby making it difficult for the segment joints to be reduced in rigidity, and having a uniform rigidity structure. Design as.

Next, a backing material 71 such as mortar (see FIG. 11B) is injected into the gap between the corner steel segment 30 and the retaining wall W. At this time, the filling material 63 is also filled in the adjustment joint 61 of the segment joint structure 60.
When the backing material 71 is hardened, the structure formed by connecting the steel segments 20 and 30 can function as a mountain support, so that the cut beam K can be removed.

  Further, as shown in FIG. 11 (b), a padding material 72 is placed inside the floor slab steel segment 20 and the corner steel segment 30 so that the subsequent work can be performed smoothly. And the upper surface of the floor slab B1 is smoothed. In addition, although there is no restriction | limiting in the kind and material of the padding material 72, in this embodiment, non-structural material (for example, poor mix | blend concrete, fluidized soil, etc.) is used in order to achieve cost reduction. .

The steel wall construction step is a step of forming the side wall portion B2 of the steel shell structure along the mountain retaining wall W. In the steel wall construction step, the plurality of side wall steel segments 40 and 50 are juxtaposed so as to be in a potato assembly state, and these are joined together to form the side wall portions B2 and B2. Adjacent segments are joined by fixing bolts b1 and b2 (see FIG. 7).
At this time, assembling of the side wall steel segments 40 and 50 is performed simultaneously at a plurality of locations by providing the segment ring joint structure 60 for each predetermined section.

  The installation work of the steel segment is performed, for example, using a handling machine capable of self-propelling on the filling material 72 while holding the segment, or using a small lifting machine capable of suspending the segment. You can do it. Since the upper surface of the floor slab B1 is flattened and the beam K (see FIG. 11 (a)) that hinders the movement of the construction machine has already been removed, the installation work of the steel segment is smooth. Can be done.

  Note that the lower side wall steel segment 40 is placed on the upper end surface of the corner steel segment 30 (upper joint plate 33 shown in FIG. 6). In the present embodiment, since the height positions of the upper end surfaces of the plurality of corner segment steel segments 30, 30,... Are aligned (see FIG. 4), the side wall steel segments 40 can be easily installed. it can.

  Although illustration is omitted, when the segments are staggered, a difference in height occurs in the height positions of the upper end surfaces of the plurality of corner steel segments 30, 30,... When installing the side wall steel segments 40 on the steel segments 30, it is necessary to insert them between the corner steel segments 30 and 30 on both sides thereof, so that the sealing material provided on both segments Care must be taken not to peel off.

  The upper side wall steel segment 50 is placed on the upper end surface (upper joint plate 43 shown in FIG. 7) of the lower side wall steel segment 40 without the stress transmission plate 56 attached. In this embodiment, since the height positions of the upper end surfaces of the lower side wall steel segments 40, 40,... Are aligned (see FIG. 4), the upper side wall steel segments 50 can be easily installed. it can.

  When the side wall steel segments 40 and 50 are installed, a backing material 73 such as mortar is injected into the gap between the side wall steel segments 40 and 50 and the retaining wall W as shown in FIG. The side part of the part B2 is restrained. At this time, the filling material 63 is also filled into the adjustment joint 61 of the segment joint structure 60. In the side wall part B2, since the shielding plate is installed on the inner space side of the segment joint structure 60, the filler 63 does not flow out to the inner space side.

  Then, while forming the cylindrical part 5B of the steel segment 50 for side walls (cylindrical part formation process), the side wall main reinforcement 15 and the shear reinforcement are arranged inside the cylindrical part 5B, and the cylindrical part 5B is arranged. Fill the interior space with concrete (concrete filling process). When placing concrete, a concrete injection hole (not shown) penetrating the upper concrete frame A vertically is used. In addition, concrete is cast to the upper edge of the cylindrical part 5B.

  When the concrete is hardened, the non-shrink mortar 19 is filled between the upper surface of the concrete and the lower surface of the upper concrete frame A. When the non-shrink mortar 19 is filled, a mortar injection hole (not shown) penetrating the upper concrete frame A up and down is used. When the existing structure is replaced with the upper concrete frame A, the weight of the existing structure acts on the mountain retaining wall W via the upper concrete frame A, but the upper concrete frame A and the steel shell When the frame B is joined, a rectangular frame structure is formed by the upper concrete frame A and the steel shell frame B, and a part of the weight of the existing structure is attached to the floor via the structure. Since it acts on the surface T2 and the like, it is possible to reduce the burden on the mountain retaining wall W.

  The strut construction process is a process of forming the strut C. In the strut construction process, first, a steel pipe serving as an outer shell of the strut C is installed between the longitudinal beam portion A3 and the steel shell frame B, and then the concrete is filled into the steel pipe.

  After the concrete strength reaches a predetermined strength, when the intermediate pile M is removed and the ground material is backfilled in the space above the upper concrete frame A, the state shown in FIG. 1 is obtained.

  According to the underground structure according to the present embodiment, as shown in FIG. 4, since a part of the main housing has a steel shell structure, compared to the case where the entire main housing has a concrete structure, It is possible to reduce the amount of use, and in turn, it is possible to reduce the number of reinforcing bars and formwork.

Moreover, since the segment ring joint structure is provided, as shown in FIG. 13 (a), even if the segments are assembled at a plurality of locations at the same time, errors generated in the longitudinal direction can be absorbed. A structure can be constructed with high quality.
That is, when the segment ring is assembled from two locations at the same time and the segment ring joint structure is not provided, as shown in FIG. In some cases, the ring 205 cannot be disposed between the segment rings 204 and 211. On the other hand, if the segment ring joint structure J is provided, the last segment ring 205 can be disposed between the segment rings 204 and 211 as shown in FIG. Can be assembled.
By constructing the steel shell frame with high quality, it can be easily joined to the concrete frame.

Since the obstruction hole is formed in the shielding plate that prevents the filler from flowing out, it is possible to fix the shielding plate to the segment even if an error occurs in the longitudinal direction. Are better.
Moreover, since the penetration of groundwater is prevented by the water-swelling material, the water-stopping material is excellent.

  In addition, according to the construction method of an underground structure according to the present embodiment, the number of concrete, formwork, rebar, etc. can be reduced, so that the concrete placement time zone is limited. However, even if the work head is too large to use a large lifting machine, it is difficult to prolong the construction period. Moreover, the construction period can be shortened by simultaneously performing the assembly work of the segments at a plurality of locations.

  In this embodiment, since the steel segments 20, 30, 40, 50 are arranged side by side so as to be in the potato assembly state, the degree of freedom in the assembly order is increased, and as a result, construction efficiency can be improved. Become. In addition, in this embodiment, it becomes possible to suppress the rigidity fall in a segment joint and a ring joint by joining adjacent steel segments with a tension joining system, and also suppresses the opening of a joint part. It becomes possible to do.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and the above-described constituent elements can be appropriately changed without departing from the spirit of the present invention.

For example, the construction order of the underground structure is not limited to the above order.
Further, the arrangement pitch of the segment ring joint structure may be set as appropriate according to the field situation.
The shielding plate may be installed as necessary and may be omitted.

A Concrete frame B Steel shell frame 20 Steel segment 30 for floor slabs Steel segment 40, 50 for corners Steel segment 60 for side walls Segment ring joint structure 61 Adjustment joint 62 Long bolt 63 Filler 64 Shielding plate 64a Long Hole W Yamadome wall T1, T2 Floor surface

Claims (5)

A segment ring formed by combining adjacent segments in the transverse direction;
An adjustment joint that is a gap formed between the segment rings adjacent in the longitudinal direction;
Long bolts connecting adjacent segment rings across the adjustment joint; and
A segment ring joint structure comprising: a filler filled in the adjustment joint.   The segmenting joint structure according to claim 1, further comprising a shielding plate that shields an inner sky side of the adjustment joint. The shield plate has a long hole therethrough,
The segment ring joint structure according to claim 2, wherein the shielding plate is fixed to the segment ring by a bolt penetrating the elongated hole.   The segment ring joint structure according to any one of claims 1 to 3, further comprising a water swelling material disposed on a side surface of the adjustment joint of the segment ring. Concrete frame,
An underground structure having a steel shell frame formed on the lower side of the concrete frame,
The steel shell housing is formed by juxtaposing a plurality of segments and joining the adjacent segments together,
In the steel shell frame, an adjustment joint which is a gap formed between segments adjacent in the longitudinal direction, a long bolt which connects the segments adjacent to each other with the adjustment joint interposed therebetween, and the adjustment joint An underground structure, characterized in that a segment ring joint structure comprising a filled material is formed for each predetermined section.

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