JP3334950B2 - Caisson frame structure and formwork unit for the frame - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

A. The present invention relates to a caisson construction method in a caisson method as a means of constructing an underground structure such as an underground foundation buried underground, a basement, and the like. The present invention relates to a formwork for constructing a frame structure.

(2) Conventional technology The applicant of the present invention has previously filed a PCT application (JP93 / 00043).
(Hereinafter referred to as “prior application technology”): A bottom plate is formed at a lower end of a caisson body having a substantially box-shaped cross section, and a first cutting edge portion having a diameter larger than that of the caisson body is formed below the bottom plate, and the bottom plate and the first cutting edge are formed. And a caisson chamber partitioned from the caisson body by a portion, and a leading blade tip portion extending below the center of the bottom plate and projecting from the first blade tip portion with a diameter as small as possible is provided. The caisson body is a caisson laying method in which a number of water holes are formed in the body of the caisson, and the water flow is discharged toward the caisson chamber from a discharge port at the tip of the leading edge. Discharging the excavated agitated soil based on the water flow from a discharge port communicating with the caisson chamber; A bottom plate is formed at a lower end of a caisson body having a substantially box-shaped cross section, and a first cutting edge portion having a diameter larger than that of the caisson body is formed below the bottom plate, and the bottom plate and the first cutting edge are formed. And a caisson chamber partitioned from the caisson body by a portion, wherein the caisson body is a caisson squatting method in which a number of water passage holes are formed to conduct inside and outside. Filling water is injected, and the caisson is settled by excavating earth and sand in the caisson room, and after the caisson is laid, a fixing agent is injected from the inside of the caisson body through a water hole. Caisson's sinking method was proposed.

In the prior art, as a means for constructing a caisson skeleton, a caisson skeleton is constructed by connecting a concrete structure in which a concrete frame is successively upwardly connected to a cast-in-place structure and a pre-cast plate manufactured in advance. And a precast frame structure. However, although there is an advantage that the shape of the frame 1 can be freely changed in the cast-in-place frame structure, it is difficult to assemble the formwork in the filling water, and the arrangement of the water holes is accurately determined. There is a problem that it is difficult to carry out the operation and it takes time and effort. In addition, although there is an advantage that the construction efficiency can be significantly improved in the precast type frame structure, one unit (unit) is heavy, and an unbalanced load occurs during assembly and installation, and the balance of sedimentation is reduced. There is a problem that the precast plate may be destroyed, and manufacturing facilities for producing the precast plate and labor are required.

(3) Problems to be Solved by the Invention The present invention has been made in view of the above-mentioned circumstances, and has an advantage of construction in place, which is an advantage of a cast-in-place type, and an accuracy of construction, which is an advantage of a precast type. It is an object of the present invention to provide a skeleton structure which is less affected by an eccentric load in order to overcome these drawbacks while utilizing it.

B. Structure of the Invention (1) Means for Solving the Problems The caisson frame structure of the present invention employs the following technical means to achieve the above object. That is, at the lower end of the caisson skeleton having a substantially box-shaped cross-section, a blade edge portion having a diameter larger than that of the caisson skeleton is formed, and the caisson skeleton is formed with a large number of water passage holes that conduct inside and outside. In the caisson, a cylindrical joint comprising an inner form plate and an outer form plate which is opposed to the outer side of the inner form plate in parallel with a spacer at a predetermined interval and also serves as a water passage hole. A notch concave portion is formed at a corner portion of the form body having a unit length, and the cylindrical joint is disposed at an intersection of the form bodies. Are formed by sealingly connecting the upper and lower sides of the form plate vertically to each other, and filling the interior space of the form body with concrete. Construction. The caisson skeleton form unit of the present invention is applied to the construction of the skeleton structure, and has two rectangular form plates each having a notch concave portion having a predetermined radius of curvature at each corner. A mold body that is placed in parallel with a predetermined interval with spacer streaks, and a cylindrical body that has at least the width of the mold body and has a hollow portion inside as a water passage hole. The notch of the form body is fixed by inner and outer flanges fixed to the outer both ends of the cylindrical body and holding the form plate.
Cylindrical joint disposed over the recess , and a horizontal joint sandwiched between the upper side and the lower side of the form plate of the form body,
A vertical joint clamped to a side of the form plate of the form body.

(2) Function In the construction of the caisson frame, the laterally arranged form bodies are joined to each other at the sides of the form plate by a vertical joint, and then the upper section of the arranged form bodies is joined together. A cylindrical joint is installed in the part, and a horizontal joint is interposed on the upper side of the lower mold body. Thereafter, the upper formwork body is installed to engage these cylindrical and horizontal joints.

(3) Embodiment An embodiment of the caisson frame structure of the present invention will be described with reference to the drawings. 1 to 12 show one embodiment. 1 and 2 show the entire caisson C submerged in the ground E. FIG.
In these figures, H denotes a hole formed due to the sinking of the caisson C, S denotes a gap between the caisson C and the hole H, W denotes filling water, G denotes a guide wall, F denotes a footing, and K denotes a caisson chamber. .

As shown in the figure, this caisson C is
It is composed of a box-shaped caisson frame 1, a bottom plate 2 at the bottom of the caisson frame 1, and a cutting edge portion 3 that is suspended from an outer edge of the bottom plate 2. The caisson frame 1 is provided with a large number of water holes 4 that communicate between inside and outside. Bottom board 2 is frame 1
And a communication hole 2a is opened at the center thereof, and the bottom plate 2 and the cutting edge portion 3 are integrally formed to form a footing F, and the internal space forms a caisson chamber K. I do. The filling water W is filled into the caisson frame 1, the caisson chamber K, and the gap S.

Thus, the caisson frame 1 is constituted by a combination of the frame unit U for the frame of the caisson. The frame unit U for the skeleton is applied to the standard form unit U ₁ applied to the flat wall portion of the skeleton ₁ , the form unit U ₂ for the corner applied to the corner, and applied to the lowermost part, that is, the base of the skeleton 1. Takes various aspects of the base form unit U ₃ ,
The basic technical ideas are common.

[0010] FIGS. 3-8 in the caisson of the present embodiment skeleton-body form unit (hereinafter simply referred to as "mold unit") shows a standard form unit U ₁ of the key aspects of the U. That is, FIGS. 3 and 4 disassemble and show the entire configuration, and FIGS. 5 to 8 show the configuration of each part thereof. This formwork unit U ₁
A form body 5 substantially holding a space for filled concrete and substantially forming a cube, a cylindrical joint 6 disposed at each corner of the form body 5, and disposed above and below the form body 5. It includes a horizontal joint 7 and vertical joints 8 arranged on both sides of the form body 5. Further, it includes a connecting reinforcing bar 9.

[0011] Hereinafter will be described the detailed structure of each part of the standard form unit U _1. Form body 5 As shown in FIGS. 3 to 5, the form body 5 has two rectangular form plates 10 arranged in parallel with a plurality of spacer streaks 11 at predetermined intervals. Adopt a rigid structure. The formwork plate 10 is made of a thin steel plate, and the formwork plate 10a disposed outside the frame 1 and the inside formwork plate 10b both have the same shape. The spacer streaks 11 are welded to the form plate 10 at right angles to each other, are arranged at equal intervals in the horizontal direction, and are arranged in two upper and lower stages (upper stage 11a and lower stage 11b), but are not limited to this embodiment. . Numeral 12 denotes a vertical streak, which is fixed by welding vertically to an intermediate position between the upper and lower spacer streaks 11a, 11b and straddling the respective spacer streaks 11a, 11b. Reference numeral 13 denotes a horizontal streak, which is fixed to the spacer streak 11a and the vertical streak 12 by welding. In the present embodiment, the upper horizontal line 13a and the lower horizontal line 13b are arranged to face each other with the vertical line 12 interposed therebetween.
Or a mode fixed to the vertical streaks 12. Further, any one of the horizontal streaks 13 may be omitted, or all the horizontal streaks 13 may be omitted. Can also. What is important in the formwork body 5 is that notch recesses 15 having a predetermined radius of curvature of a quadrant are formed in the four corners of the formwork plate 10. The mold body 5 are those that are most weight in the members constituting the mold unit U _1, as a guide the possibility of handling manual specifications (length, height, width, and weight) are determined Can be

As shown in FIGS. 3, 4, and 6, the cylindrical joint 6 is mainly composed of a cylindrical body 17 having a penetrating hollow portion and having a predetermined length. A flange 18 is fixed on the outside. The hollow portion of the cylindrical body 17 forms the water passage hole 4 and communicates with the inside and outside of the frame 1. The flange 18 includes an outer flange 18a and an inner flange 18b that are opposed to each other at a predetermined interval at both ends of the cylindrical body 17, and a mold 18 of the form body 5 is inserted into a gap 18c formed by the outer and inner flanges 18a and 18b. The notch recess 15 of the frame plate 10 is received, and the frame plate 10 is clamped. In the present embodiment, the bottom of the gap 18c is the outer peripheral surface of the cylindrical body 17, and the radius of curvature of the cylindrical body 17 matches the radius of curvature of the notch recess 15. Therefore, when the bottom of the gap 18c is formed by another member, the notch recess 1
5 is adjusted to this radius of curvature, and the radius of curvature can be adjusted and changed as appropriate.

Horizontal joint 7 As shown in FIGS. 3, 4 and 7, the horizontal joint 7 is mounted on the upper side and the lower side of the form plate 10 of the form body 5, and the upper and lower form bodies 5 are provided. Connect each other. The horizontal joint 7 includes an outer flange 20b and an inner flange 20c with an intermediate member 20a interposed therebetween.
The form plate 10 of the form body 5 is received in the gap 20d formed by the form 20c, and the upper side and the lower side of the form plate 10 are clamped.

Vertical joint 8 As shown in FIGS. 3, 4 and 8, the vertical joint 8 is mounted on the side of the form plate 10 of the form body 5, and is connected to the form body 5 in the lateral direction. Connect. Like the horizontal joint 7, the vertical joint 8 is composed of an outer flange 22b and an inner flange 22c with an intermediate member 22a interposed therebetween, and the mold of the mold body 5 is inserted into a gap 22d formed by the outer and inner flanges 22b, 22c. The frame plate 10 is received and the side of the frame plate 10 is clamped. Both ends 23 of the vertical joint 8 are formed in a concave curved surface, and the outer peripheral edge of the flange 8 of the cylindrical joint 6 abuts.

[0015] For even corners for formwork unit U _2, similar to the standard form unit U _1, the mold body 5, a cylindrical joint 6,
Although it is constituted by a horizontal joint 7 and a vertical joint 8, the structures of the form body 5 and the horizontal joint 7 bent at right angles are different because they are used at the corners. Figure 9 shows a mold body 5 of the corner mold frame unit U _2. The horizontal joint 7 includes an outer form plate 10a and an inner form plate 10 of the form body 5A.
There are two types, one for the outside and one for the inside, corresponding to the shape of b. The base form unit U ₃ is provided with a form body 5.
Except that the cutout recess 15 of the lower side portion of is not formed conforms to the configuration of the standard form unit U _1.

FIG. 10 shows a state in which the form unit U is vertically and horizontally connected to form a frame 1. FIG. 11 shows the procedure of the connection operation. The cylindrical joint 6 is disposed at a place where the four form bodies 5 intersect, and secures the water passage hole 4.
The horizontal joint 7 is interposed between the upper and lower form bodies 5 and connects the upper and lower form bodies 5 to each other. The vertical joint 8 is interposed between the form bodies 5 in the lateral direction, and connects the form bodies 5 in the lateral direction. That is, the form bodies 5 are connected in the vertical and horizontal directions by the joints 6, 7, and 8, and the internal space of the form body 5 is maintained in a sealed state. Further, as shown in the figure, in the inside of the form body 5, the connecting reinforcing bar 9 extends between the upper form body 5 and the lower form body 5 by the spacer bars 11.
It is fixed to. In the present embodiment, the same arrangement is adopted in one arrangement in the horizontal direction, but the present invention is not limited to this mode.

Next, a procedure for constructing the frame 1 of the caisson C using the form unit U of this embodiment will be described. This construction is done with the sinking of caisson C. Hereinafter, description will be given based on the construction procedure.

(1) On the ground, the bottom plate 2 and the cutting edge 3
Is installed while maintaining the verticality. Prior to the installation, a guide wall G is formed by steel sheet pile or on-site formation, and a caisson C is guided and installed in the guide wall G.

(2) Sediment in the caisson room K of the footing portion F is excavated and removed, and the caisson C is settled.

(3) In conjunction with the sedimentation, the base of the frame 1 is constructed above the bottom 2 of the footing F. Therefore, the base mold frame unit U ₃ is used. That is,
As shown in FIG. 12 , an anchor reinforcing bar 25 is implanted in the base 2 so as to protrude upward along the vicinity of the outer periphery thereof, and the spacer bar 11 of the form body 5 of the form unit U ₃ and the anchor reinforcing bar 25 are formed. And the form bodies 5 are connected to each other by vertical joints 8 in the horizontal direction. The mold body of the base mold frame unit U ₃ 5 has no cutout recess 15 in the lower portion. Once the installation of the base formwork is complete,
Standard form unit U ₁ over 2-3 stage thereon, assembled mold using a corner mold frame unit U ₂ of a corner section. In this state, concrete is poured into the formwork.

(4) When the sedimentation of the caisson C proceeds to some extent, the filling water W is filled into the caisson C. The filling water W
Fills the gap S through the water hole 4 of the caisson frame 1,
The water pressure prevents the hole H from collapsing, and causes the caisson C to settle vertically by the water pressure balance between the inside and outside of the frame 1. When the opening 2a of the bottom plate 2 of the caisson C is closed, the filling water W is used as a load on the footing F. In the excavation in the caisson chamber K, a drilling rig (for example, a clamshell, not shown) is inserted and removed through the opening 2a in the presence of the filling water W, and the excavated earth and sand is discharged out of the caisson C. When the opening 2a of the bottom 2 of the caisson C is closed, in other words, when the caisson chamber K becomes a closed space, pressurized water is introduced into the caisson chamber K, and the ground is excavated by jet scouring of the pressurized water. The earth and sand is discharged to the outside of Caisson C by water flow conveyance.

[0022] (5) Construction of the upper building frame 1 using standard form unit U ₁ and corner mold frame unit U _2, made for each stage based on a certain assembly procedures, 3-4 After assembling the steps, concrete is poured. In this case, at each stage, the form unit U is installed without breaking the balance, in other words, without causing an unbalanced load. Since the form body 5 of the form unit U is light in weight, it is easy to handle and does not generate an uneven load. In this work, a floating work table (not shown) is installed on the filling water W in the skeleton, and the assembling work of the mold is performed via the floating work table, thereby facilitating the work.

(6) When the sedimentation of the caisson C is completed, the filling surface of the caisson C is lowered by pumping the filling water W, and the consolidating agent is injected into the gap S via the water passage hole 4 exposed thereby.

As described above, the form unit U of this embodiment
According to the construction and construction of the caisson skeleton 1 carried out by using the method, since the constituent members of the standardized formwork unit U are combined in a predetermined procedure, the construction is easy and the formwork is accurate. Is assembled. In addition, the installation of the form body 5 is quickly and easily performed by being guided by the cylindrical joint 6 of the lower form unit U already installed.
In addition, since the weight of one unit of the form unit U is small, an unbalanced load which adversely affects the installation of the unit U is not generated, and the verticality of the sedimentation of the caisson C is compensated. Book form unit U
Also, the manufacturing cost can be reduced by standardizing and manufacturing the components. In addition, with respect to the change in the wall thickness of the skeleton 1 due to the design change,
It is possible to easily cope with this change in the location only by changing the length of one.

In the above-described embodiment, the form plates 10 are connected to each other by using the horizontal joint 7 and the vertical joint 8, but these can be omitted by directly welding and joining the form plates 10. .

The present invention is not limited to the above embodiment, and various design changes can be made within the scope of the basic technical concept of the present invention.

C. Effects of the Invention According to the present invention, the following specific effects are obtained. In the caisson skeleton structure of the present invention, since the constituent members of the standardized skeleton frame unit are combined according to a predetermined procedure, construction is easy and an accurate mold is assembled. Also, since the weight of one unit of the formwork unit is small, there is no unbalanced load that adversely affects the installation, and the verticality of caisson sedimentation is compensated. The manufacturing cost can be reduced by standardizing and manufacturing the constituent members of the formwork unit for the skeleton of the present invention. Further, with respect to the change in the wall thickness of the skeleton due to the design change, it is possible to easily cope with the design change only by changing the length of the spacer streaks.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view including a partial side view of a caisson during a submerging process according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is an exploded side view of the standard formwork unit.

FIG. 4 is an exploded plan view of the standard formwork unit (a view in the direction of arrow IV in FIG. 3).

FIG. 5 is a sectional view taken along line VV of FIG. 4;

FIG. 6 is a partial cross-sectional side view of a cylindrical joint of one element of the form unit.

FIG. 7 (a) is a partially omitted side view of the horizontal joint. (b) is a sectional view taken along the line VII-VII of (a).

FIG. 8 (a) is a side view of a vertical joint. (b) is a sectional view taken along the line IIX-IIX in FIG.

FIG. 9 (a) is a side view of a mold body of the corner mold unit. (b) The figure is the plan view.

FIG. 10 is a partially broken side view showing an assembled state of the formwork unit.

FIG. 11 is an assembly work procedure diagram of the formwork unit.

FIG. 12 is a partial cross-sectional side view showing the structure of the base of the caisson body.

[Explanation of symbols]

C ... caisson, U ... formwork unit, U ₁ ... standard form unit, U ₂ ... corners for formwork unit, U ₃ ... base mold frame unit, 1 ... caisson building frame, 2 ... bottom plate, 3 ... cutting edge , 4
... water passage hole, 5 ... form body, 6 ... cylindrical joint (17 ... cylindrical body, 18 ... flange), 7 ... horizontal joint, 8 ... vertical joint, 9 ... connecting rebar, 10 ... form plate, 11 ... spacer muscle,
15 Notch recess

Claims (5)

(57) [Claims] 1. A caisson skeleton having a substantially box-shaped cross section is formed at a lower end thereof with a cutting edge portion having a diameter larger than that of the caisson skeleton. The caisson thus formed comprises: an inner form plate; and an outer form plate which is opposed to the outer side of the inner form plate in parallel with a predetermined spacing with a spacer, and has a water passage hole. A notch concave portion for receiving a cylindrical joint, which is also used as the cylindrical joint, is formed at a corner thereof, and the cylindrical joint is disposed at an intersection of the form bodies. The sides are connected in a sealed manner, the upper and lower sides of the form plate are connected in a sealed manner in the up-down direction, and the inner space of the form body is filled with concrete and formed. The caisson structure. 2. The caisson skeleton structure according to claim 1, wherein a connecting bar engaged with the spacer bar is disposed between the upper and lower form bodies. 3. A vertical joint which fits into a side of the form plate is used for connecting the form plate in the horizontal direction, and a vertical joint which fits on the upper and lower sides of the form plate is used for connecting the form plate in the vertical direction. The caisson skeleton structure according to claim 1, wherein a horizontal joint is used. 4. A mold body having a rectangular shape and two mold plates each having a notched concave portion having a predetermined radius of curvature at a corner portion thereof, which are disposed parallel to each other at a predetermined interval with spacer streaks. And having at least the length of the width of the form main body, and a hollow body inside the main body being a cylindrical body serving as a water passage hole, and being fixed to both ends on the outside of the cylindrical body to clamp the form plate. A cylindrical joint disposed over a notch recess of the form body, a horizontal joint sandwiched between upper and lower sides of a form plate of the form body, and the form body And a vertical joint sandwiched between side portions of the formwork plate of (1). 5. A caisson formwork unit according to claim 4, wherein a horizontal streak and a vertical streak spanning a spacer streak are arranged in the formwork body.