JPH0584773B2 - - Google Patents

Description

[Detailed Description of the Invention] (Technical Field) The present invention relates to a method for constructing underground beams on land where facilities such as low-rise buildings, railways, roads, etc. This paper relates to a method for constructing underground beams suitable for the foundation of new structures.

(Prior art) As a method of constructing a new structure above an existing facility without interfering with the use of above-ground facilities such as railways and roads, the foundation for the new structure is generally A method has been adopted in which a structure is installed underground at the location where the facility is installed, a support is connected to the top of the foundation, and a structure is constructed on top of the support. When constructing such structures, it is necessary to construct not only the supports and structures but also the foundations themselves without interfering with the use of existing facilities.

One method of constructing a foundation for a new structure without interfering with the use of existing facilities is to install a plurality of piles on the side of an existing facility and use the piles as a foundation. However, with this method, the foundation only includes a plurality of piles and does not include underground beams such as foundation beams, especially beams that extend across the existing facility, so the durability of the newly constructed structure is reduced. Horizontal force is small. For this reason, although conventional methods can be applied to structures with small height and weight such as low-rise buildings and viaducts, they cannot be applied to structures with large height and weight such as high-rise buildings. It is difficult to apply it to the construction of

(Objective of the Invention) The present invention makes it possible to easily construct an underground beam that resists large loads under an existing facility on the ground without interfering with the use of the existing facility. , aims to provide a method for constructing underground beams.

(Structure of the Invention) A method for constructing an underground beam according to the present invention provides a method for constructing a plurality of pipes including at least one metal fitting buried in a main pipe part and partially protruding into a space defined by the inner surface of the pipe main part. a first step of providing a conduit defined by and extending horizontally from the shaft by a pipe propulsion method; a second step of arranging reinforcing bars extending along the conduit within the conduit; and a third step of constructing a beam by pouring concrete.

(Operations and Effects of the Invention) In the first step, a conduit extending horizontally below existing facilities such as low-rise buildings, railways, roads, etc. provided on the ground is provided. Since this pipeline is constructed using the pipe propulsion method, it can be constructed without interfering with the use of existing facilities.

Through the second and third steps, underground beams are constructed using underground conduits. Reinforced concrete, which is made up of reinforcing bars and solidified concrete in the pipe, is integrated with the pipe by metal fittings that protrude into the pipe. As a result, the load acting on the pipe is reliably transmitted to the reinforced concrete, and not only the reinforced concrete but also the pipe itself acts as part of the beam that receives the load, and as a result, large loads cannot be applied to the beam. can.

According to the present invention, since a pipe provided with a metal fitting protruding into the main body of the pipe is used, the pipe itself also acts as a part of the beam, as described above, and as a result, the pipe installed by the pipe propulsion method can be In conjunction with this, underground beams capable of resisting large loads can be easily constructed below existing facilities on the ground without interfering with their use.

A hume pipe may be used as the propulsion pipe, but when a hume pipe is used, the reinforced concrete inside the pipe is not integrated with the pipe, so the load acting on the pipe is not effectively transmitted to the reinforced concrete. Although the reinforced concrete in the conduit acts as a beam that resists loads, the conduit itself does not effectively act as a beam that resists loads, and as a result, it is possible to apply a larger load to the beam than in the present invention. Can not.

(Example) Hereinafter, an example of the present invention shown in the drawings will be described.

As shown in FIG. 1A, a shaft 22 is excavated on the side of an existing facility 20 provided on the ground.
Inside the shaft 22, there are a plurality of pipes 24 such as Huyume pipes.
An existing propulsion device 28 is installed which propels the pipe in a substantially horizontal direction to form the conduit 26. The cross-sectional shape of each tube 24 may be rectangular or circular. Moreover, the pipe 24 can also be made into a steel pipe. Each tube 24 has the same size and shape. Propulsion device 28 includes a plurality of jacks that advance tube 24.

Each tube 24 is moved forward by the propulsion device 28 by the length of one tube with the cutting edge 30 placed at the most distal end thereof, and then a new tube is placed at the rearmost end.The process is repeated. This will lead to gradual progress. As a result, the conduit 26 is gradually extended.

When the pipe 26 is formed by a distance corresponding to the distance between the shaft excavator fixed positions 32 and 34 separated from the shaft 22, the telescopic body 36 shown in FIGS. be done.

As shown in FIGS. 2 and 3, the expandable body 36 includes a rectangular steel casing 38 having approximately the same outer diameter shape and dimensions as the tube 24, and a rectangular steel casing 38.
and a plurality of jacks 40 supported inside. Each jack 40 is removably fixed to the casing 38 by a belt so that it extends and contracts around the axis of the tube 24 and in the axial direction of the conduit 26.

The expandable body 36 is placed at the rear end of the preceding tube with each jack 40 contracted, and after a new tube is placed behind the expandable body 36, it is advanced together with each tube 24 by the propulsion device 28. .

When each tube 24 is advanced until the front half of the cutting edge 30 reaches below the planned shaft excavation position 34 as shown in FIG. is extended to. As a result, as shown in FIG. 1D, from the shaft 22, through the planned shaft excavation position 32,
A conduit 26 is formed that reaches the.

Each of the above operations is carried out in the starting shaft 22.
Since it can be carried out both indoors and underground, it does not interfere with the use of existing facilities 20 above ground.

Next, as shown in FIG. 4A, the propulsion device 28 is removed and the jack 4 of the telescoping body 36 is
0 is removed, and piles 42 are provided at the bottom of the shaft 22 and at the planned shaft excavation positions 32 and 34, respectively. When installing piles at the planned shaft excavation position 32,
A portion of the bottom of the casing 38 of the telescopic body 36 is cut and removed. The piles 42 are preferably cast-in-place piles.

A large-diameter boring excavator for removing the jack 40, cutting the casing, and constructing the pile can be carried in using the conduit 26. Moreover, excavated earth and sand can be discharged from the shaft 22 using the pipe line 26. Therefore, each of these pile driving operations can be performed without interfering with the use of the existing facility 20.

Next, as shown in FIG. 4B, the cutting edge 30 is removed, and the shaft 44 is placed at the planned shaft excavation positions 32, 34.
46 will be excavated. The shafts 44 and 46 are connected to the pipe line 26
If a predetermined portion is excavated from below to above using the excavation method, the excavation can be performed without interfering with the use of the existing facility 20. The excavated earth and sand at this time can also be discharged from the shaft 22 using the pipe line 26.

Next, a reinforcing bar cage 48 using a plurality of reinforcing bars is inserted into the conduit 26, and a reinforcing bar cage 50 extending in the vertical direction is placed in each of the shafts 22, 44, 46. A formwork is arranged around each reinforcing bar cage 50, and concrete is poured into the space defined by the formwork and into the pipe line 26.

As a result, as shown in FIG. 4C, the pipe line 26
A beam 52 is formed in each of the shafts 22, 44, and 46, and a support column 54 is formed in each shaft 22, 44, 46, extending from the shaft to the ground.
The beam 52 and each post 54 are connected to each other and to the pile 42
connected to. These operations can also be performed using the conduit 26. The tube 24 defining the conduit 26 functions as part of the beam 52 because it is bonded to the concrete placed within the conduit 26.

With the above method, the vertical shafts 22, 44, 46 are located below the existing facility 20, as shown in FIG.
A beam 56 extending from the shaft in a direction perpendicular to the beam 52 and a beam 62 extending parallel to the beam 52 from the other plurality of shafts 58 and 60 are formed. For this reason, beams are constructed in a grid pattern below the existing facility 20.

The lattice-shaped beams shown in FIG. 5 are constructed, for example, after forming the pipe 26 from the shaft 22 to the shaft 46 as shown in FIG. As shown in FIG. 66
Construction work for pipelines extending in the direction of each shaft 22, 4
4, 46, 58, and 60, construction work of the shafts 42 and supports (not shown), placement work of reinforcing bar cages in each conduit, and work of pouring concrete into each conduit in that order or as appropriate. It can be constructed by performing the steps in the following order.

The work of carrying in materials such as the pipe 24 and the work of transporting excavated earth and sand during the construction of each shaft, each support and each beam in FIG. 5 may be performed only from the shaft 22, or from the other shafts 44, 46, 56 may also be used.

FIG. 6 shows a beam 52 formed below a multiple-track railway track 70 by the above-described method.
4 and 46 with the piles 42 and struts 54 provided therein. The shaft 44 is excavated at the center in the width direction of the land for the railway line 70.

FIG. 7 shows a concrete building 72 constructed on top of the pillars 54 extending upward from the beams 52 and piles 42 constructed below the road by the method described above.
shows. The centrally located pillar 54 projects above the ground from a median strip 76 that separates the left and right roadways 74 from each other. On the other hand, the pillars on both sides can be made to protrude above the ground from the sides of the roadway 74, or can be made to protrude above the ground from the sidewalk 78. Note that the piles 42, beams 52, and supports 54 are constructed avoiding buried objects 80 such as gas pipes and water pipes, and buried objects 82 such as sewer pipes.

FIGS. 8 and 9 show an embodiment of the pipe 24 used in the pipe propulsion method in the construction method described above. The tube 24 includes a plurality of sheath tubes 84 which are embedded in the tube main body at intervals around the axis of the tube and which penetrate the tube main body in the axial direction, and an annular sheath tube arranged to surround the sheath tubes. multiple reinforcing bars 8
6, and a plurality of short reinforcing bars or hardware 8 that extend from the sheath pipe 84 toward the center of the pipe 24 and partially protrude into the space defined by the inner surface of the main body of the pipe.
8.

The pipe 24 shown in FIGS. 8 and 9 is inserted into the ground by a pipe propulsion method so that the sheath pipe 84 of the pipe is aligned with the sheath pipe 84 of the adjacent pipe 24, as shown in FIG. 10. will be placed in sheath tube 84
A long reinforcing bar 90 is passed through each pipe 24 and extends in the axial direction of the pipe line. The elongated reinforcing bar 90 is then secured to the tube 24 by a graft material that is injected into the sheath tube 84.

As a result, the adjacent pipes 24 are connected to each other by the reinforcing bars 90 and the grout material, so that a stronger pipe is formed than in the case where adjacent pipes are not connected to each other, and the pipe can bear a large load. .

A reinforcing bar cage 48 is also placed inside the conduit 26 shown in FIG. 10, and concrete is placed therein. As a result, the portion of the hardware 88 that protrudes into the pipe line 26 is embedded in the concrete. It is also cast in the space defined by the formwork 92 around the reinforcing bar cage 50 placed in the shaft 44.

The reinforced concrete made up of the reinforcing bar cage 48 and solidified concrete in the pipe line 26 is integrated with the pipe line 26 by a metal fitting 88 protruding into the pipe line 26 . As a result, the load acting on the pipe 26 is effectively transmitted to the reinforced concrete, and not only the reinforced concrete but also the pipe 26 itself acts as a beam receiving the load, and as a result, a large load is applied to the underground beam. be able to.

However, when a Huyum pipe is used as a propulsion pipe, the reinforced concrete inside the pipe is not integrated with the pipe, so the load acting on the pipe is not effectively transmitted to the reinforced concrete, and the reinforced concrete inside the pipe is However, as already mentioned, the conduit itself does not effectively act as a beam that resists the load, and as a result, it is not possible to apply a large load to the beam.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view for explaining the process of forming a conduit by the pipe propulsion method, Fig. 2 is a longitudinal cross-sectional view showing an example of an expandable body used in the pipe propulsion method, and Fig. 3
The figure is a right side view of the expandable body shown in Fig. 2, Fig. 4 is a vertical cross-sectional view for explaining the process of constructing piles, beams, and supports, and Fig. 5 shows an example of the constructed beam. A plan view, Fig. 6 is a vertical cross-sectional view showing a beam constructed below a railway track, Fig. 7 is a diagram showing an example of a building using a beam constructed below a road as a foundation, and Fig. FIG. 8 is a longitudinal cross-sectional view showing one embodiment of the tube used in the present invention, FIG. 9 is a cross-sectional view taken along line 9-9 in FIG. 8, and FIG. FIG. 3 is a sectional view showing an example of constructing a beam using 20: Existing facilities, 22, 44, 46, 58,
60: Pit, 24: Pipe, 26: Conduit, 28: Propulsion device, 30: Blade, 42: Pile, 48, 50: Rebar cage, 52, 56, 62: Beam, 54: Support, 84:
Sheath pipe, 86: Annular reinforcing bar, 88: Hardware, 9
0: Long reinforcing bar.

Claims (1)

[Scope of Claims] 1. Defined by a plurality of pipes including at least one metal fitting buried in a pipe main body and partially protruding into a space defined by the inner surface of the pipe main body, and extending horizontally from a shaft. A first step of installing an extending conduit using the pipe propulsion method, a second step of arranging reinforcing bars extending along the conduit within the conduit, and placing concrete within the conduit to form a beam. and a third step of constructing an underground beam. 2. Each of the pipes includes at least one sheath pipe that is embedded in the pipe main body and passes through the pipe main body in the axial direction of the pipe, and in the first step, the sheath pipe is connected to the pipe line. With the sheath tubes of adjacent tubes aligned so as to extend in the axial direction, each tube is advanced, and a long reinforcing bar extending in the axial direction is passed through each tube into the sheath tube, and the The method for constructing an underground beam according to claim 1, which includes fixing long reinforcing bars to the sheath pipe with grout.