JP3108735B2 - Reconstruction method of large diameter sewer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for reconstructing a large-diameter sewer for rebuilding an existing old sewer such as a sewer into a new large-diameter sewer using a shield machine.

[0002]

2. Description of the Related Art In recent years, sewers and other sewers have become obsolete and have become unusable and have reached the limit of water flow. Various methods of filling have been developed, and as a measure to improve water flow, a method of expanding a new sewer at another location has been adopted. The construction method of this new sewer employs a so-called shield method using a shield excavator, or a propulsion method of excavating a precast concrete pipe while extruding it from behind.

[0003]

In recent years, a sewer constructed from Taisho to the early Showa era has become obsolete and must be rebuilt as a structure. In addition, there are places where there is a limit in space for the construction of new sewers, and it is difficult to secure new space for constructing sewers as a measure to improve water flow. It is necessary to construct a pipe with a caliber, and in this case, there is a problem that construction must be performed without stopping water flow.

[0004] In view of such a problem, the present invention can easily construct a large-diameter sewer at the same position while crushing an existing old sewer, and further maintain a water-permeable state when reconstructing the sewer. The purpose is to provide a method for reconstructing large-diameter sewers that can be constructed.

[0005]

SUMMARY OF THE INVENTION In order to solve the conventional problems as described above and to achieve the intended purpose, a main feature of the present invention is to assemble a segment inside a rear end to form a lining, On the front side of the partition wall in the casing of the shield machine that advances by taking a reaction force against the lining, an existing culvert can penetrate into the center part, and a turning cutter for digging outside the existing culvert, The shield excavator is moved forward while excavating the existing sewer in the center of the cutter and excavating the outside of the sewer, and at the same time entering the casing tip while mixing and solidifying a solidifying agent in the excavated earth and sand. The water blocking wall made of excavated earth and sand that solidifies sequentially in the front end of the casing has a sealing effect against external soil water pressure, and the ends of the water blocking wall and the existing sewer are crushed sequentially and carried out. The existing sewer In the reconstruction method of large-diameter sewer to build a Shinkanmizo while removed by.

[0006]

In the method for reconstructing a large-diameter sewer according to the present invention, a shield machine is installed at an end of an existing sewer to be reconstructed from a shaft previously excavated and formed, and an existing sewer is installed at a central portion of a cutter. Is made to enter and excavate.

During excavation, the outer peripheral portion of the existing sewer is excavated by a cutter and introduced into the front side of the partition wall in the casing. At the same time, a cement-based solidifying agent is mainly injected into the excavated soil and stirred. As a result, the water is solidified in the casing and a water blocking wall is formed. The water blocking wall provides a sealing effect against external soil water pressure.

The water stop wall thus formed is crushed sequentially from the rear end while leaving a constant thickness every time the shield excavator excavates, and the rear end of the existing sewer is crushed, and It is carried out by the excavated earth and sand removal device. In the rear end of the shield machine, lining is formed by assembling the segments every fixed stroke, and the shield machine is propelled by taking a reaction force to the lining.

Further, by using the water stopping plug and the water pipe penetrating therethrough, a new pipe can be constructed while maintaining the water flow of the existing pipe.

[0010]

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

In the method of the present invention, as shown in FIG. 1, a shield excavator B provided with a revolving cutter 2 at the center of a casing 1 and having an opening into which an existing sewer A can enter is provided at the front end. The shield machine B is provided with a sediment discharging device 4 including a screw-type or belt-type conveyor inside a rear wall of a partition wall 3 that separates a front excavation portion from a rear side. And a segment assembling apparatus (not shown) for sequentially assembling the segments to construct the lining C and a propulsion apparatus (not shown) for propelling the assembled lining C with a reaction force. You.

The cutter 2 is supported at the tip of a swivel cylinder 5 rotatably supported in the front end of the casing 1. For example, a large number of cutters 2 are provided on spokes 6 arranged radially from the swivel cylinder 5 toward the center thereof. Can be used. In addition, a type in which a slit and a bit are provided on a ring-shaped face plate may be used. Further, when the existing sewer A is not circular, a type provided with a copy cutter that moves in and out at the tip of the spoke 6 is used.

The turning cylinder 5 is turned by a driving source 5a such as a hydraulic motor supported on the partition 3.

The slurry-type cement-based solidifying agent is passed through the revolving cylinder 5 and the solidifying agent supply passage (not shown) provided in the spokes 6 of the cutter 2, and solidified in the spokes 6 of the cutter 2. The material is injected into the excavated earth and sand from the agent injection nozzle 7. In addition, the solidifying agent may be caused to flow out from the tip of the copy cutter.

Further, on the inner surface of the swivel cylinder 5, an earthen blow-through prevention tool 8 is fixed. As an example, a disk-shaped one having a large number of radial slits 9 and a large number of excavating bits 10, 10,... It may be spoke-shaped.

A hollow support shaft 11 for supporting a plug is protruded from the partition wall 3 toward the front side, and a plug 12 for closing the inside of the existing culvert A is supported at the tip thereof. The stopper 12 has a rubber tube-shaped water-stopping material 13 fixed on the outer periphery thereof, which is expanded by injection of water or air.

A water passage 14 is formed in the plug 12 and the support shaft 11 for flowing water in the existing pipe A, and a water pipe 16 is connected to a rear end thereof.

Further, on the front side of the partition wall 3, a crushing device 15 composed of a gripping bucket or nibble is installed.

In carrying out the method of the present invention, for example, a shaft is dug at a desired construction start position, and an existing pipe A is installed in the shaft.
Expose the end of Next, the shield excavator B is lowered into the shaft, the existing sewer A is inserted into the center of the cutter 2 as shown in FIG. 1, the turning cylinder 5 is rotated, and the solidified material is excavated from the nozzle 7 of the cutter 2. Dig while pouring in.

At this time, the plug 12 is inserted into the existing sewer A, the sealing material 13 is expanded to plug the existing sewer A, and the rear end of the support shaft 11 is connected to the water passage 14. The communicating water pipes 16 are connected, and the excavation work is performed while the water, sludge, and the like in the existing sewer A are passed by the pump 17.

During the excavation, the earth and sand a first excavated by the cutter 2 has fluidity by being injected and stirred with a slurry-type cement-based solidifying agent. It is packed as a dense mud with no gap between the surface and solidifies gradually. Then, the water blocking wall b is solidified to the extent that it can stand on the front surface of the earthen blow-through prevention tool 8.

Next, the solidified improved earth and sand is shaved at the rear end surface by turning of the earthen blow-through prevention tool 8, and is sequentially dropped on the front side of the partition wall 3, and is carried out by the earth and sand unloading device 4.

After the excavation of a predetermined stroke, that is, the ring width of the lining C is performed by the segments, the projecting portion of the existing pipe A exposed on the front side of the partition wall 3 is crushed by the crushing device. The crushing is carried out by 15 and carried out by the earth and sand carrying-out device 4, and at the same time, the segments are assembled at the rear end of the casing. After completion of these carrying-out and assembling work, the excavation work is repeated in the same manner as described above.
To build.

[0024]

According to the method for reconstructing a large-diameter sewer according to the present invention, the earth and sand around the existing sewer is excavated and introduced into a casing, and a solidifying agent is injected into the casing and agitated. The existing sewer and excavated sand were removed while being filled with stable and improved sediment solidified between the sewer and the sewer.Therefore, the ground was damaged due to poor backfill around the existing sewer and groundwater channels. Even in a stable state, it is possible to safely and easily eliminate an existing sewer and reconstruct a large-diameter sewer by a shield method.

Further, the construction can be carried out without stopping the water passages through the plugs supported by the support shafts and the plugs.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view schematically showing one state of an execution step of the present invention.

FIG. 2 is a front view of one side of the excavating cutter.

FIG. 3 is a front view of an example of the above-mentioned earthen luggage blow-through prevention device.

[Explanation of symbols]

 Reference Signs List A Existing sewer B Shield excavator C Lining D New sewer a Sediment b Water blocking wall 1 Casing 2 Cutter 3 Partition wall 4 Sediment discharge device 5 Rotating cylinder 6 Spoke 7 Solidifying agent injection nozzle 8 Clod blow-through prevention tool 9 Slit 10 bit DESCRIPTION OF SYMBOLS 11 Support shaft 12 Plug 13 Seal material 14 Water passage 15 Crusher

Claims (3)

(57) [Claims] 1. A lining is formed by assembling segments inside a rear end, and an existing culvert is provided at a central portion on a front side of a partition wall in a casing of a shield machine which advances by taking a reaction force against the lining. A revolving cutter that is capable of penetrating and excavating the outside of the existing sewer, wherein the shield machine is advanced while excavating the outside of the sewer by penetrating the existing sewer into the center portion of the cutter. At the same time, a solidifying agent is mixed into the excavated earth and sand, and is stirred and penetrated into the front end of the casing, and the sealing effect against external soil water pressure is provided by the water stop wall constituted by the excavated earth and sand that solidifies sequentially in the front end of the casing. A method of reconstructing a large-diameter sewer in which a new sewer is constructed while removing the existing sewer by sequentially crushing and discharging the ends of the water stop wall and the existing sewer. 2. The method for reconstructing a large-diameter sewer according to claim 1, wherein the revolving cutter is supported inside the distal end of the casing and is integrally provided at the distal end of the revolving cylinder. 3. A water-stopping pipe is provided at a tip end of a support shaft protruding from a tip end of a casing so as to support a slidable water-stopping plug while closing an existing pipe, and penetrating through the plug. 3. The method for reconstructing a large-diameter sewer according to claim 1, wherein the excavation is performed while flowing water in the existing sewer through the water pipe.