JP2012031702A - Device for pressing in pneumatic caisson - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air leakage prevention device which can impose a great tensioning force on an anchor material, which can flexibly absorb a construction error of the anchor material, and which sufficiently secures airtightness even under high air pressure.SOLUTION: An anchor material 1 is made of a plurality of grease-impregnated unbonded prestressing steel strands 11. An air leakage prevention device 2 includes a casing pipe 3 in which a filler 21 is housed and through which each of the prestressing steel strands 11 is to be individually inserted, and upper and lower heads 4 and 5 which are provided in upper and lower openings of the casing pipe 3, respectively, and which comprise insertion portions 40 and 50 for individually inserting the prestressing steel strands 11, respectively, and packing compressing portions 40p and 50p for compressing gland packing 12 attached to each of the prestressing steel strands 11.

Description

  The present invention relates to a pneumatic caisson press-fitting device, and more particularly to a pneumatic caisson press-fitting device that uses a press-fitting jack and an anchor material to press-fit a caisson housing into the ground and deposit it.

  2. Description of the Related Art Conventionally, there is known a press-fitting method in which a caisson skeleton is press-fitted into a ground using a press-fitting jack and an anchor material, and is laid down. In this press-fitting method, a plurality of anchor materials are arranged near the caisson housing in the height direction of the caisson housing, the lower ends of the anchor materials are fixed to the ground, and a plurality of press-fitting jacks are installed on the caisson housing. In this method, the upper ends of the anchor members are connected to the press-fitting jacks, and the caisson housing is press-fitted into the ground by using a plurality of press-fitting jacks as reaction forces of the anchor members. In this type of construction method, as shown in FIG. 6A, the anchor material 7 is arranged outside the caisson housing c, and a press-fitting girder 71 is installed on the caisson housing c, and the press-fitting jack 8 is installed thereon. As shown in FIG. 6 (b), the anchor material 7 is arranged outside the caisson housing c, the supporting beam 72 is embedded in the caisson housing c, and the press-fitting girder 73 is erected thereon to press fit. As shown in FIG. 6 (c), the anchor material 7 is disposed inside the caisson housing c through the work room ceiling slab c1 and placed on the work room ceiling slab c1. The working room ceiling slab loading method for installing the press-in jack 8 is roughly classified into three methods. Of these, the working room ceiling slab loading method does not require beam or girder replacement work compared to the other two structures. The advantage is that the construction period can be shortened. For example, when the process is strict and there is no room to change the press-fitting girder every time the side wall is started up (that is, when the single girder method cannot be adopted) or when this work is a construction property, it will be pushed into the structure. This is suitable when the steel material such as the support column cannot be left (that is, when the cantilever method cannot be adopted).

  Patent Document 1 proposes a press-fitting device used for such a working room ceiling slab loading method. In the press-fitting device of this document 1, as shown in FIG. 7, a plurality of anchor material passage holes c10 are provided at predetermined intervals in the lower part of the caisson housing c and the work room ceiling slab c1, and these holes c10 are provided. In addition, the anchor material 7 (with the lower end fixed to the ground) is penetrated, and a hermetic anchor threading device 9 for injecting and sealing a filler into the space between each hole c10 and each anchor material 7 is installed. Then, press-fitting jacks 8 are installed on the work room ceiling slab c1 corresponding to these anchor members 7, and the upper ends of the anchor members 7 are connected to these jacks 8. In this way, the caisson housing c is press-fitted into the ground G by using the anchor members 7 as reaction forces by the plurality of press-fitting jacks 8 and is laid down.

  According to such a press-fitting device, the anchor member 7 is disposed inside the caisson housing c through the work room ceiling slab c1, and the anchor material 7 is used as a reaction force by the press-in jack 8 installed on the work room ceiling slab c1. The press-fitting and sinking of the caisson housing c can be carried out without the need to install and remove the press-in girder, thereby improving work efficiency and saving labor. Since it can be performed inside, it can be installed in close proximity to other structures, and the advantage of the method of press-fitting and sinking the caisson housing c using the anchor material 7 as a reaction force, that is, for deep ground excavation, soft ground However, it is possible to control the settling, there are various effects such as improvement of construction accuracy and ensuring process management.

Japanese Patent No. 3439859

However, the conventional press-fitting device used for such a working room ceiling slab loading method has the following problems.
(1) A simple anchor rod is used as the anchor material, and such a single-wire structure anchor material cannot load a high tension required for press-fitting and sinking the caisson housing.
(2) When a construction error occurs in the anchor rod, a horizontal force is generated in the anchor threading device due to the eccentricity or inclination of the anchor rod. For this reason, the air tightness of the hole for anchor material passage by the anchor threading device is lowered and leakage occurs. There is a risk that air will increase or an excessive load is applied to the anchor threading device to cause damage, and it is difficult to ensure airtightness in the hole for anchor material threading.
(3) Since the anchor threading device has a simple airtight structure using a simple packing, its applicability is limited, and application at high atmospheric pressure cannot be expected.

  The present invention solves such a conventional problem, and in this type of pneumatic caisson press-fitting device, in particular, the anchor material can be loaded with high tension required for press-fitting caisson housing. An object of the present invention is to flexibly absorb the construction error of the anchor material and to provide a dedicated air leakage prevention device that can sufficiently ensure airtightness even at high atmospheric pressure.

  In order to achieve the above-described object, the present invention provides a plurality of anchor members inserted into the respective holes provided in a work room ceiling slab formed on the lower side of the pneumatic caisson, with a plurality of holes for passing the anchor members. A plurality of air leakage prevention devices that are hermetically inserted into the holes and block gaps between the holes and the anchor materials, and correspond to the anchor materials on the pneumatic caisson. A plurality of press-fitting jacks for pressing down the pneumatic caisson, each anchor member having a lower end fixed to the ground below the working chamber, and an upper end side connected to each press-fitting jack In each of the pneumatic caisson press-fitting devices, the pneumatic caissons are press-fitted into the ground by using the anchor members as reaction forces by the press-fitting jacks. Material consists of a line of a plurality of PC steel is coated with a member having airtightness, and summarized in that.

Moreover, it is preferable that each part of this press-fitting device is embodied as follows.
(1) An unbonded tube is adopted as a member having airtightness. In this case, it is desirable that a filler such as grease is injected into the unbonded tube.
(2) Each of the plurality of air leakage prevention devices is formed in a substantially cylindrical shape that can be fitted into each hole for passing through the anchor material, accommodates a filler, and inserts a wire from each PC steel in an airtight manner. A pipe and a PC steel wire insertion portion, each of which is provided so as to be able to seal the opening at both the upper and lower ends of the casing pipe, and through which a plurality of PC steel wires can be passed through the casing pipe, and each PC A packing is attached to the steel strand in the vicinity of the wire insertion portion from the PC steel, each packing has a packing compression portion that can be compressed in the wire insertion portion from each PC steel, An upper head and a lower head that are hermetically inserted are provided.
(3) Each of the upper head and the lower head is provided in an airtight manner in the opening of the casing pipe, and has a plurality of PC steel wire insertion holes through which a plurality of PC steel wires passed through the casing pipe can be individually inserted. A head plate and a plurality of PC steel wire insertion holes which are provided on the head plate so as to be superposed and can communicate with the wire insertion holes from each PC steel of the head plate, and around each PC steel wire insertion hole. A pressing plate having a plurality of pressing portions formed in a protruding shape and capable of compressing the packing attached to the wire of the PC steel toward the head plate. In this way, the PC steel wire insertion portion is constituted by the plurality of PC steel wire insertion holes and the plurality of PC steel wire insertion holes of the press plate, and the head plate and the press plate protrusions A packing compression part is comprised by this.
(4) The presser plate of the lower head has a substantially tapered shape in which the wire insertion holes are gradually expanded from the inside to the outside from a plurality of PC steels.
(5) Gland packing is adopted for packing of each PC steel strand, and it is mounted in a multi-stage around the strand of each PC steel.
(6) A grease that exhibits fluidity at a high temperature and has a hard property with a consistency of about 200 at room temperature is used for the filler.

According to the press-fitting device of the present invention, the anchor material is composed of a plurality of PC steel strands covered with an airtight member such as an unbonded tube. It is possible to load the high tension required for press-fitting the caisson housing, and to absorb the error flexibly even if there is a construction error in the anchor material due to the flexibility of the PC steel strand. There is a special effect that you can.
Further, in this press-fitting device, a plurality of air leakage prevention devices are respectively inserted into the holes for passing the anchor material, and a filler such as grease is injected and sealed in the gap between the hole and the anchor material. The gap between the anchor material insertion portion and the anchor material is obtained by compressing the casing pipe and the packing such as the gland packing attached to the anchor material at the upper and lower openings of the casing pipe. The upper and lower heads are embedded and sealed, and the gap between each anchor material passing hole and each anchor material inserted through each hole is blocked by a triple blocking structure at three locations. There is a remarkable effect that airtightness can be sufficiently secured even at high atmospheric pressure.

Front sectional view showing a pneumatic caisson press-fitting device according to an embodiment of the present invention. Front cross-sectional view of the same press-fitting device, particularly an air leak prevention device Cross-sectional view showing the anchor material of the same press-fitting device in enlargement Front sectional view showing the upper part of the air leakage prevention device of the same press-fitting device in an enlarged manner Front sectional view of the same press-fitting device, particularly the lower part of the air leakage prevention device Figure showing various conventional methods of press-fitting caisson enclosures into the ground using press-fit jacks and anchor materials Front sectional view showing the press-fitting device used in the conventional ceiling slab loading method in particular

  Next, embodiments for carrying out the present invention will be described with reference to the drawings. FIG. 1 shows a pneumatic caisson press-fitting device, and FIGS.

  As shown in FIG. 1, a pneumatic caisson C (hereinafter referred to as caisson housing C) has a work room ceiling slab 101 formed on the lower side of the interior, and a work room 102 provided below the work room ceiling slab 101. In the case of the caisson casing C, a plurality of anchor material passing holes 100 are formed in the work room ceiling slab 101 in a circular shape at equal intervals in the circumferential direction. The press-fitting device A includes a plurality of anchor members 1 inserted into the holes 100 and a plurality of air leaks that are airtightly inserted into the holes 100 and block the gaps between the holes 100 and the anchor members 1. The prevention device 2 and a plurality of press-fitting jacks 6 that are installed on the caisson housing C corresponding to each anchor member 1 and press down the caisson housing C are configured.

  In this press-fitting device A, each of the plurality of anchor members 1 is composed of a plurality of PC steel strands 11 covered with an airtight member 10, as shown in FIG. 2, and in this case, as shown in FIG. In addition, an unbonded tube is employed for the member 10 having airtightness, and the unbonded tube 10 is filled with a filler (grease) 211 and is composed of a plurality of unbonded PC steel wires containing grease. Further, as shown in FIGS. 4 and 5, packings 12 are attached to the PC steel strands 11 at predetermined positions corresponding to the upper and lower portions of the air leakage prevention device 2 described later. In this case, a gland packing is adopted as the packing 12, and each PC steel is mounted in a predetermined range around the wire 11 in a multi-stage shape in the axial direction. Each of these PC steel stranded wires 11 is respectively passed through a plurality of anchor material passage holes 100 provided in the work room ceiling slab 101, and the lower end portion is provided below the work room 102 via an anchor body (not shown). It is fixed to the ground, and the upper end side is connected to the press-fit jack 6 on the work room ceiling slab 101.

  As shown in FIG. 2, each of the plurality of air leakage prevention devices 2 is formed in a substantially cylindrical shape that can be fitted into each hole 100 for passing through the anchor material, and has a semi-solid or semi-fluid filling material 21 therein. The casing pipe 3 is hermetically sealed and inserted in the casing pipe 3 in an airtight manner, and the openings 301 and 302 are provided in the upper and lower ends 301 and 302 of the casing pipe 3 so as to be able to be sealed, respectively. PC steel strand insertion portions 40 and 50 through which a plurality of PC steel strands 11 can be inserted, and packings 12 attached to these PC steel strands 11 are inserted into the respective PC steel strand insertion portions 40 and 50. It has compressible packing compression parts 40p, 50p, and is provided with an upper head 4 and a lower head 5 that are inserted through each PC steel wire 11 in an airtight manner.

  In the case of this air leakage prevention device 2, the casing pipe 3 is a cylindrical pipe having substantially the same diameter and the same length as the hole 100 so that the casing pipe 3 can be fitted into the hole 100 for anchor material passage as shown in FIG. 4 and 5, the upper and lower ends are respectively opened, and the supporting plates 31 and 32 projecting outward are integrally formed around the upper opening 301 and the lower opening 302, respectively. The In this case, the upper bearing plate 31 has an appropriate thickness and is formed to have a smaller diameter than the lower bearing plate 32, and the lower bearing plate 32 has an appropriate thickness, and the upper bearing plate. The diameter is larger than 31. The upper and lower pressure bearing plates 31 and 32 are provided with screw holes 310 and 320 at predetermined positions, respectively. 4 and 5, the casing pipe 3 is provided with a filler inlet 311 on the lower side of the peripheral surface and a filler outlet 312 on the upper side of the peripheral surface. The inlet 311 and the outlet 312 are formed of a small-diameter pipe material, and protrude slightly outward from the peripheral surface of the casing pipe 3 to extend to the upper head 4 above the casing pipe 3. When this casing pipe 3 is inserted into the hole 100 for passing through the anchor material of the work room ceiling slab 101, the filler 21 is injected through the filler inlet 311. In the case of the air leakage prevention device 2, a grease that exhibits fluidity at a high temperature (about 60 ° C.) and has a hard property with a consistency of about 200 at room temperature is used for the filler 21.

  In the case of this air leakage prevention device 2, the upper head 4 and the lower head 5 are provided in an airtight manner in the upper opening 301 and the lower opening 302 of the casing pipe 3, respectively, as shown in FIGS. Head plates 42 and 52 having a plurality of PC steel strand insertion holes 41 and 51 through which a plurality of PC steel strands 11 are individually inserted, and on the head plates 42 and 52 (head plates 42 and 52 A plurality of PC steel wire insertion holes 43 and 53 and the PC steel wire insertion holes 42, which can communicate with the PC steel wire insertion holes 41 and 51 of the head plates 42 and 52. , 53 is formed in a projecting shape around 53, and has a pressing portion 44, 54 having a pressing portion 44, 54 that can compress the packing 12 attached to the strand 11 of PC steel toward the head plates 42, 52. And a 45 and 55.

  In the case of the upper head 4, as shown in FIG. 4, the head plate 42 is formed in a substantially inverted hat shape that can be fitted into the upper opening 301 of the casing pipe 3, and can be fitted into the upper opening 301 of the casing pipe 3. A cylindrical portion 421 having an appropriate thickness, and an appropriate thickness having a plurality of PC steel wire insertion holes 41 through which a plurality of PC steel strands 11 can be inserted at the center of the lower end surface of the cylindrical portion 421. A bottom 422, an opening 423 through which a plurality of PC steel wires 11 can be inserted at the upper end surface of the cylindrical portion 421, protrudes outward around the opening 423, and contacts the upper bearing plate 31 of the casing pipe 3. And a flange 424 having an appropriate thickness that can be contacted. It should be noted that screw holes 425 and 426 are provided at predetermined positions on the edge around the upper opening 423 of the head plate 42 and the flange 424, respectively. The presser plate 45 is formed in a substantially disk shape that can be engaged with the upper opening 423 of the head plate 42 and the edge of the opening 423, covers the upper opening 423 of the head plate 42, and contacts the peripheral edge thereof. A main body portion 451 having a plurality of PC steel wire insertion holes 43 corresponding to each PC steel wire insertion hole 41 in the center of the circular plane, and a head plate of the main body portion 451. A plurality of pressing portions 44 that surround the periphery of the wire insertion hole 43 from each PC steel and project into a cylindrical shape of a predetermined length are provided on one side facing 42. In addition, a screw hole 450 is provided at a predetermined position on the outer peripheral portion of the main body portion 451 (around the outside of the pressing portion 44). In this way, when the casing pipe 3 is inserted into the hole 100 for passing through the anchor material of the working room ceiling slab 101, and a plurality of PC steel strands 11 are inserted into the casing pipe 3, the casing pipe 3 A head plate 42 and a presser plate 45 are sequentially attached to the upper part in a concentric manner. The head plate 42 is inserted into the upper opening 423 from the PC steel wire insertion hole 41 of the bottom 422 to the upper opening 423 of each PC steel, and the cylindrical portion 421 is fitted into the upper opening 301 of the casing pipe 3. A peripheral flange 424 is brought into contact with the upper bearing plate 31 of the casing pipe 3 via a seat packing 221, and is provided in the screw hole 310 provided in the bearing plate 31 of the casing pipe 3 and the flange 424 of the head plate 42. A bolt 231 is tightened and attached to the screw hole 426. And the packing 12 is passed through the wire insertion hole 41 from each PC steel of the head plate 42, and a predetermined portion of each PC steel wire 11 arranged in the opening 423. In this case, the gland packing 12 is multi-staged. Installed. The holding plate 45 is superposed on the head plate 42 by inserting the PC steel wires 11 from the pressing portions 44 into the PC steel wire insertion holes 43. In this case, the pressing plate 45 is fitted into the opening 423 of the head plate 42 such that each pressing portion 44 on one side of the main body 451 faces the opening 423 of the head plate 42, and the outer periphery of the main body 451 is the head. A screw hole 425 provided on the edge of the opening 423 of the head plate 42 and a screw hole provided on the outer periphery of the presser plate 45 are brought into contact with the edge of the opening 423 of the plate 42 via the sheet packing 222. A bolt 232 is tightened and attached to 450. In this way, the head plate 42 and the presser plate 45 are assembled, and a plurality of PC steel wire insertion holes 41 of the head plate 42 and a plurality of PC steel wire insertion holes 43 of the presser plate 45 are connected to the upper head 4 with a PC. The wire insertion part 40 is comprised from steel, and the packing compression part 40p is comprised by each pressing part 44 of the head plate 42 (around each wire penetration hole 41 from each PC steel) and the pressing plate 45. As shown in FIG.

  In the case of the lower head 5, as shown in FIG. 5, the head plate 52 is formed in a substantially cylindrical shape that can be connected to the lower opening 302 of the casing pipe 3, and is appropriately connected to the lower opening 302 of the casing pipe 3. A cylindrical portion 521 having a thickness, and a top portion 522 having an appropriate thickness having a plurality of PC steel wire insertion holes 51 through which a plurality of PC steel wires 11 can be inserted at the center of the upper end surface of the cylindrical portion 521. In addition, the lower end surface of the cylindrical portion 521 is provided with an opening 523 through which a plurality of PC steel wires 11 can be inserted. It should be noted that screw holes 524 and 525 are provided at predetermined positions on the edge and the outer periphery of the head plate 52 around the lower opening 523, respectively. The presser plate 55 is formed in a substantially disk shape that can be engaged with the lower opening 523 of the head plate 52 and the edge of the opening 523, and can cover the lower opening 523 of the head plate 52 and contact the peripheral edge thereof. A main body portion 551 having a plurality of PC steel wire insertion holes 53 corresponding to the PC steel wire insertion holes 51 in the center of the circular plane, and the head plate 52 of the main body portion 551. And a plurality of pressing portions 54 that surround the periphery of the wire insertion hole 53 from each PC steel and project into a cylindrical shape having a predetermined length. Further, in this presser plate 55, the wire insertion hole 53 is formed from the inner side of each PC steel of the main body portion 551 (in this case, the middle portion between the upper end and the lower end of the main body portion 551) to the outer side (in this case, the main body portion). It is formed in a tapered shape that is gradually expanded (expanded diameter) toward the lower end of 551. In addition, a screw hole 550 is provided in a predetermined position on the outer peripheral portion of the main body portion 551 (around the outside of the pressing portion 54). The lower head 5 is connected to the lower opening 302 of the casing pipe 3 via a fixing ring 56 and a presser ring 57. In this case, the fixing ring 56 is formed in a ring shape having an appropriate thickness that can surround the outer periphery of the head plate 52. Note that screw holes 561, 562, and 563 are provided at predetermined positions on the edge and the outer periphery of the lower opening 560 of the fixing ring 56, respectively. The presser ring 57 is formed in a substantially hat shape that can be engaged between the fixing ring 56 and the lower head 5, and a cylindrical portion 571 fitted between the fixing ring 56 and the lower head 5, and the cylindrical portion 571. And a flange 572 that abuts the edge of the lower opening 560 of the fixing ring 56 at the lower end. Screw holes 573 and 574 are provided at predetermined positions on the flange 572 and the outer peripheral portion of the presser ring 56, respectively. In this way, when the casing pipe 3 is inserted into the hole 100 for passing through the anchor material of the working room ceiling slab 101, and a plurality of PC steel strands 11 are inserted into the casing pipe 3, the casing pipe 3 A fixing ring 56, a head plate 52, a presser ring 57, and a presser plate 55 are sequentially attached to the lower part. In this case, the fixing ring 56 is brought into contact with the lower part of the casing 3 (between the bearing pressure plate 32 and the fixing ring 56 of the casing pipe 3) via the seat packing 223, and the screw provided on the bearing pressure plate 32 of the casing pipe 3. A bolt 233 is fastened and fixed between the hole 320 and a screw hole 563 provided in the outer peripheral portion of the fixing ring 56. In the head plate 52, each PC steel strand 11 is inserted into a plurality of PC steel strands through the lower opening 523 and the top portion 522 into the wire insertion hole 51, and the cylindrical portion 521 is disposed in the fixing ring 56. A holding ring 57 is fitted between the ring 521 and the fixing ring 56 via the packing 24, the pressing ring 57 compresses the packing 24, and the flange 572 of the holding ring 57 is brought into contact with the edge of the fixing ring 56. The head plate 52 is pressed into the fixing ring 56 by the pressing action of the presser ring 57. The bolts 234 are tightened between the screw holes 562 provided on the outer peripheral portion of the fixing ring 56, the screw holes 574 provided on the outer peripheral portion of the holding ring 57, and the screw holes 525 provided on the outer peripheral portion of the head plate 52. In addition, the bolts 235 are fastened and fixed between the screw holes 561 provided at the opening edge of the fixing ring 56 and the screw holes 573 provided in the flange 572 of the presser ring 57. Then, the packing 12 is passed through the wire insertion hole 51 from each PC steel of the head plate 52, and a predetermined portion of each PC steel wire 11 disposed in the opening 523. In this case, the gland packing 12 is multi-staged. Installed. The presser plate 55 is superposed on the head plate 52 by inserting each PC steel wire 11 from each PC steel through the wire insertion hole 53 to each pressing portion 54. In this case, the pressing plate 55 is fitted into the opening 523 of the head plate 52 such that each pressing portion 54 on one side of the main body 551 faces the opening 523 of the head plate 52, and the outer peripheral portion of the main body 551 is the head. Screw holes 524 provided on the edge of the opening 523 of the head plate 52 and screw holes provided on the outer periphery of the presser plate 55 are brought into contact with the edge of the opening 523 of the plate 52 via the sheet packing 224. The bolt 236 is tightened and attached to the 550. In this way, the head plate 52 and the holding plate 55 are assembled, and a plurality of PC steel wire insertion holes 51 of the head plate 52 and a plurality of PC steel wire insertion holes 53 of the holding plate 55 are used to connect the PC to the lower head 5. The wire insertion part 50 is comprised from steel, and the packing compression part 50p is comprised by each press part 54 of the head plate 52 (around each wire penetration hole 51 from each PC steel) and the pressing plate 55. As shown in FIG.

  A hydraulic center hole jack is employed for the plurality of press-fit jacks 6. Each of these jacks 6 is installed on the work room ceiling slab 101 at a position corresponding to each anchor material passing hole 100. Then, each anchor material 1 passed through each anchor material passing hole 100 is penetrated by each press-fit jack 6 and connected to each press-fit jack 6 via an anchor fixing hardware 61 attached to each anchor material 1. Is done.

  Thus, as shown in FIG. 1, each anchor member 1 has a gap between each PC steel strand 11 and each hole 100 for anchor material passage of the work room ceiling slab 101, and each air leakage prevention device. 2, the lower end is fixed to the ground below the working chamber 102, the upper end side is connected to each press-fitting jack 6 on the working-chamber ceiling slab 101, and each anchoring material 6 is reacted by each press-fitting jack 6. The caisson housing C is press-fitted into the ground and then set.

The press-fitting method of the caisson housing C using the press-fitting device A is as follows.
(1) First, the caisson housing C is installed in a place where the caisson housing C should be set.
(2) Next, drilling holes and anchor material 1 are inserted into the ground through a plurality of holes 100 for anchor material passage provided beforehand in the work room ceiling slab 101 of the caisson housing C and the casing pipe 3, and each anchor material is inserted. Fix the lower end of 1 to the ground. Next, installation of the upper head 4, installation of the lower head 5 after excavation directly under the caisson housing C, and injection and filling of the grease 21 from the filler inlet 311 are completed, and the assembly of the air leakage prevention device 2 is completed. As a result, the gap between each anchor material passing hole 100 and each anchor material 1 is formed in the triple structure of the air leakage prevention device 2, that is, the grease 21 in the casing pipe 3, the upper head 4 and the lower head 5 Each of these packings (gland packing) 12 is used.
(3) Next, press-fit jacks 6 are installed at positions corresponding to the holes 100 for passing through the anchor material on the work room ceiling slab 101, and each anchor material is fixed to these press-fit jacks 6 via anchor material fixing hardware 61. 1 is connected.
(4) After setting each member on the caisson housing C in this way, the ground at the bottom of the work chamber 102 of the caisson housing C is excavated by hand or mechanical excavation, and the excavated soil is caisson shaft (not shown) and It is transported to the ground through caisson lock (not shown) and dumped.
(5) After excavating the ground in the work chamber 102 in this way, the caisson housing C is press-fitted with the anchor members 1 as reaction forces by the press-fitting jacks 6 and set. Then, after the caisson housing C is set, the upper part of the caisson housing C is constructed. When the amount of grease 21 in the air leakage prevention device 2 decreases during the press-fitting and setting of the caisson housing C, the grease 21 is replenished through the filler inlet 311.
(6) And after excavating the ground at the bottom of the working chamber 102, the press-fitting jack 6 with the anchor material 1 as a reaction force, the caisson housing C is press-fitted, the caisson housing C is press-fitted, and the caisson housing C is inserted. The work to build the upper part of the building is repeated, and the caisson structure is submerged deep underground.

In the method using the press-fitting apparatus A, a plurality of PC steel strands 11 are used for each of the plurality of anchor members 1, so that even if a construction error occurs during the construction of each anchor member 1, 11, the construction error of the anchor material 1 can be absorbed flexibly. These PC steel strands 11 are covered with the unbonded tube 10, and the unbonded tube 10 is filled with the grease 211, so that there is no gap between the PC steel wires 11 causing air leakage and completely. In addition, the PC steel stranded wire 11 itself is excellent in durability and can apply high tension required for the press-fitting and sinking of the caisson housing C. It becomes possible to press-fit with high loading pressure.
And these anchor materials 1 are the triple air leak prevention structure by the air leak prevention apparatus 2 in the space | gap part between each anchor material penetration hole 100 and each anchor material 1, ie, the inside of the casing pipe 3 Since it is blocked by the filler (grease) 21 and each packing (gland packing) 12 of the upper head 4 and the lower head 5, the space between each anchor material passing hole 100 and each anchor material 1 is surely secured. Sealed. In this case, a gland packing having high durability and sealability is adopted for the packing 12, which is mounted in a multi-stage shape at a predetermined position of the anchor material 1, and the packing compression portions 40 p, 50 p of the upper head 4 and the lower head 5. And the gap between each anchor material passing hole 100 and each anchor material 1 is filled in each part of the upper head 4 and the lower head 5, so that each part of the upper head 4 and the lower head 5 is sufficient. A sealing action is obtained, whereby the grease 21 in the casing pipe 3 is reliably sealed, and the airtightness of the space between each anchor material passage hole 100 and each anchor material 1 is sufficiently secured. And the high sealing property which such a filler 21 and the packing 12 have is suitable for the construction which press-fits the caisson housing C with high loading pressure using the anchor material 1 which consists of the wire 11 from said unbonded PC steel. Become. In this way, this air leakage prevention device 2 can be used even under a high pressure condition of 1 MPa class, and has the capability of blocking air leakage only with the filler 21 or with only the packing 12 of the lower head 5, and during the construction. Even if the filler 21 or the packing 12 of the upper head 4 is damaged at any location, these parts can be safely replaced. In addition, airtightness is ensured even under high pressure in this way, so that a pneumatic caisson foundation for deep underground in places where anchors can not be installed due to site restrictions and where single-girder structures and cantilever structures cannot be used. Can be adopted.

  As described above, according to the press-fitting device A, the air leakage prevention device 2 is installed in each of the plurality of holes 100 for anchor material passage provided in advance in the work room ceiling slab 101 of the caisson housing C. A plurality of anchor members 1 are passed through the work room ceiling slab 101 through the air leakage prevention device 2, the lower ends of the anchor members 1 are fixed to the ground below the work chamber 102, and the upper ends are on the work room ceiling slab 101. Each caulking jack 6 is connected to each press-fit jack 6 and each anchor material 1 is used as a reaction force to press-fit the caisson housing C into the ground and set it down. Therefore, it is necessary to construct and remove the press-fit reaction force girder. Therefore, work efficiency can be improved and labor saving can be achieved, and the caisson housing C can be immediately constructed after the caisson housing C is set. Since all installation work can be carried out inside the caisson housing C, it is possible to perform close construction on other structures, and because it is possible to control sedimentation even in deep excavation and soft ground, construction accuracy is improved. The conventional work room ceiling slab loading, which can ensure the process control, and can press the pneumatic caisson into the hard sand layer and the gravel layer with the minimum pre-drilling. The advantage of the method can be utilized as it is.

  And in this press-fit apparatus A, since the anchor material 1 employs a plurality of PC steel wires 11 covered with a member having airtightness, such as unbonded PC steel wire containing grease, the anchor material 1 Even if a construction error occurs, the flexibility of the PC steel wire 11 allows the construction error of the anchor material 1 to be absorbed flexibly, and a higher tension is applied compared to a conventional anchor rod or the like. The caisson housing C can be press-fitted and submerged at a high load pressure.

In the press-fitting device A, in particular, each of the plurality of air leakage prevention devices 2 is formed in a substantially cylindrical shape, and the casing pipe 3 in which the filler 21 is accommodated, and the openings 301 at both upper and lower ends of the casing pipe 3. , 302 are provided so that the openings 301 and 302 can be hermetically sealed, and a plurality of PC steel strands 11 through which a plurality of PC steel strands 11 are inserted through the casing pipe 3 can be inserted. An upper head 4 and a lower head 5 which have packing compression portions 40p, 50p that can compress the packing 12 attached to the PC steel at the wire insertion portions 40, 50, respectively, Since the gap between each anchor material passing hole 100 and each anchor material 1 inserted through each hole 100 is blocked by three triple air leakage blocking structures, even at high atmospheric pressure It is possible to sufficiently ensure the tightness, it is possible to reliably prevent the leakage of compressed air from the hole 100 of the anchor member through which is provided in the working chamber ceiling slab 101.
In this case, a gland packing is used for the packing 12, which is attached to the anchor material 1 in a multistage shape and compressed by the packing compression portions 40 p and 50 p of the upper head 4 and the lower head 5. Compared with a new packing, its sealing performance can be greatly improved.
Further, in this case, each of the plurality of air leak prevention devices 2 is formed in a substantially cylindrical shape that can be fitted into each anchor material passing hole 100, and the filler 21 is accommodated, and each PC steel strand 11 is connected. The casing pipe 3 that is inserted in an airtight manner and the openings 301 and 302 at the upper and lower ends of the casing pipe 3 are provided so that the openings 301 and 302 can be sealed, and a plurality of PC steel strands 11 that are passed through the casing pipe 3 are inserted. A packing 12 is attached to each of the PC steel strands 11 in close proximity to the PC steel strands 40 and 50, and each of the packings 12 is inserted into each PC steel. The upper and lower heads 4 and 5 have packing compression parts 40p and 50p that can be compressed in the parts 40 and 50, and each PC steel wire 11 is hermetically inserted. Are respectively inserted into the holes 100 for passing through the anchor material of the working room ceiling slab 101, and the upper head 4 and the lower head 5 are installed on the upper and lower sides of the casing pipes 3 to prevent air leakage. The apparatus 2 can be easily installed with a small number of parts in the holes 100 for passing through the anchor members of the work room ceiling slab 101. Furthermore, in the lower head 5, since the wire insertion holes 53 are gradually tapered from the inside to the outside from the plurality of PC steels, when there is a construction error of the anchor material 1, The substantially tapered shape of the insertion hole 53 can absorb construction errors of the anchor material 1.
Further, in this case, the filler 21 of the casing pipe 3 and the filler 211 of the unbonded tube 10 exhibit fluidity at a high temperature (about 60 ° C.) and have a hard property with a consistency of about 200 at room temperature. Therefore, the fillers 21 and 211 can be reliably poured also between the steel wires in the casing pipe 3 and the unbonded tube 10, and effective blocking performance against air leakage can be obtained.

  In this embodiment, the packing compression portions 40p, 50p of the upper head 4 and the lower head 5 are configured by forming a plurality of pressing portions 44, 54 on the pressing plates 45, 55, but the pressing plate 45, 55 may be formed in a substantially flat plate shape, and a plurality of protruding pressing portions may be formed on one surface of the head plates 41 and 51 facing the holding plates 45 and 55. Further, instead of the plurality of pressing portions, the packing compression portions 41 and 51 are formed into flat plate-like pressing portions integrated with the pressing plates 45 and 55 or the head plates 42 and 52, and the insertion holes for the plurality of anchor members 1 are formed therein. It may be provided. Further, the pressing portion may be separated from the pressing plates 45 and 55 or the head plates 41 and 51, and a separate compression plate may be interposed between the head plates 41 and 51 and the pressing plates 45 and 55. . Even if it does in this way, the effect similar to the said embodiment can be acquired.

C Pneumatic caisson (Caisson enclosure)
DESCRIPTION OF SYMBOLS 101 Work room ceiling slab 102 Work room 100 Hole for anchor material passage A Press-fit device 1 Anchor material 10 Airtight member (unbond tube)
11 PC steel strand 12 Packing (Gland packing)
2 Air leakage prevention device 21 Filler (grease)
211 Filler (Grease)
221, 222, 223, 224 Sheet packing 231, 232, 233, 234, 235, 236 Bolt 24 Packing 3 Casing pipe 301, 302 Opening 31, 32 Bearing pressure plate 310, 320 Screw hole 311 Filler inlet 311 Filling material Discharge port 4 Upper head 40 PC steel strand insertion portion 40p Packing compression portion 41 PC steel strand insertion hole 42 Head plate 421 Cylindrical portion 422 Bottom 423 Opening 424 Flange 425, 426 Screw hole 43 PC steel strand insertion hole 44 Pressing portion 45 Presser plate 450 Screw hole 451 Main body part 5 Lower head 50 PC steel wire insertion part 50p Packing compression part 51 PC steel wire insertion hole 52 Head plate 521 Cylindrical part 522 Top 523 Opening 524, 525 Screw hole 53 PC steel wire Insertion hole 4 the pressing portion 55 pressing plate 550 threaded hole 551 main body portion 56 fixed ring 560 opening 561, 562, 563 threaded hole 57 pressing ring 571 cylindrical portion 572 flange 573 and 574 screw hole 6 pressed jacks 60 anchored bracket

Claims (6)

A plurality of anchor material passage holes are provided in the work room ceiling slab formed on the lower side of the pneumatic caisson, a plurality of anchor materials inserted through the holes, and airtightly inserted into the holes, A plurality of air leakage prevention devices that block gaps between the holes and the anchor materials, and installed on the pneumatic caisson corresponding to the anchor materials, for pressing the pneumatic caisson A plurality of press-fitting jacks, each anchor member having a lower end fixed to the ground below the working chamber, and an upper end connected to each press-fitting jack, and In a pneumatic caisson press-fitting device that presses and sinks the pneumatic caisson into the ground as a reaction force,
Each of the anchor materials is composed of a plurality of PC steel wires covered with an airtight member,
Pneumatic caisson press-fitting device characterized by that.   2. The pneumatic caisson press-fitting device according to claim 1, wherein an unbonded tube is used as the member having airtightness.   Each of the plurality of air leakage prevention devices is formed in a substantially cylindrical shape that can be fitted into each hole for passing through the anchor material, contains a filler, and a casing pipe that hermetically inserts the wire from each PC steel, The opening is provided in the upper and lower ends of the casing pipe so that the opening can be sealed, and a plurality of PC steel strands can be inserted through the casing pipe. A packing is installed near the wire insertion portion from the PC steel, and each packing has a packing compression portion that can be compressed at the wire insertion portion from the PC steel, and the wires are inserted airtightly from the PC steel. The pneumatic caisson press-fitting device according to claim 1, further comprising an upper head and a lower head.   Each of the upper head and the lower head is provided in an airtight manner in the opening of the casing pipe, and has a head plate having a plurality of PC steel strand insertion holes through which the plurality of PC steel strands passed through the casing pipe can be individually inserted. A plurality of PC steel wire insertion holes that can be connected to the wire insertion holes from each PC steel of the head plate, and projecting around the wire insertion holes from each PC steel. The pneumatic caisson press-fitting device according to claim 3, further comprising: a pressing plate that is formed and has a plurality of pressing portions that can compress the packing attached to the PC steel wire toward the head plate.   5. The pneumatic caisson press-fitting device according to claim 4, wherein the presser plate of the lower head has a substantially tapered shape in which wire insertion holes are gradually expanded from a plurality of PC steels toward the outside from the inside.   The pneumatic caisson press-fitting device according to any one of claims 1 to 5, wherein a gland packing is adopted for packing of each of the PC steel strands, and the PC steel strands are mounted in a multistage shape around the strands of each of the PC steel strands.

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