JP2016217014A - Open shield method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve stabilization of natural ground and the like by decreasing the possibility of occurrence of collapse by reducing the formation of a tail void in the rear of a tail part.SOLUTION: In an open shield machine, an open shield machine body is divided into a plurality of parts in a longitudinal direction, and a front end of a rear machine body as a tail machine is fitted into a rear end of a front machine body as a front machine so that it can be bent via mutual fitting parts. A steel plate with a thickness smaller than the wall thickness of the tail part is extended and attached to a rear end part of a tail part side wall of the tail machine.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an open shield machine used for an open shield method.

  As is well known, the open shield method is a rational method that takes advantage of the open cut method (open method) and the shield method.

First, when explaining the open shield machine used in the open shield method, it is also shown in the following patent document, but basically the front side consisting of connecting the left and right side wall plates and the length of these side wall plates between them, It is a shield machine with an open rear and upper surface.
JP 2015-48659 A

  Then, as shown in FIGS. 7 and 8, the aircraft is divided into a plurality of parts in the front-rear direction, and the front end of the rear aircraft as the tail machine 23 is fitted into the rear end of the front aircraft as the front machine 22, It can be bent at the fitting part.

  The front machine 22 is mainly used for excavation, and has a front end and an upper surface as open surfaces, and the middle folding jacks 24 are arranged on the left and right and rearward and rearward in a plurality of stages. On the other hand, the tail machine 23 installs the concrete box 4, and the propulsion jacks (shield jacks) 3 are arranged in the upper and lower stages in the machine body with the front and rear facing backward. ing.

  In the figure, 16 is a movable split blade provided at the front end of the front machine 22, 17 is a slide jack of this movable split blade, 27 is a earth retaining plate provided at the rear end of the tail machine 23, 29 is a bulkhead type earth retaining plate, Reference numeral 30 denotes a press bar (push angle).

  The movable dividing blade 16 is a slide-type earth retaining device for preventing the collapse of the side rocks during excavation, and expands and contracts from the tip of the shield machine.

  The front machine 22 and the tail machine 23 of the open shield machine 1 are both shield machines having left, right, and side walls 1a and bottom plates 1b connected to the side walls 1a, with the front, rear and top surfaces opened.

  Since the tail machine 23 has the bottom plate 1b, the box 4 can be laid without worrying about boiling and heaving.

  The bent portion formed by the combination of the front machine 22 and the tail machine 23 is used for direction / gradient correction and curve construction. The front machine 22 and the tail machine 23 of the shield machine 1 can be bent by the middle folding jack 24 housed in the middle folding section. In the figure, reference numeral 38 denotes a towing jack, which connects a front machine 22 and a tail machine 23 by stretching a PC steel wire, but such a towing jack 38 may not be provided.

  The earth retaining plate 29 is used for partitioning the excavation part and the hydraulic equipment storage part in front of the open shield machine 1 and is compacted by pressing the excavation earth and sand, which is useful when constructing high groundwater or soft soil.

  Next, the construction procedure of the open shield method performed using such an open shield machine 1 will be described with reference to FIGS. 9 to 12, and the outline will be described with reference to FIG. 13. As shown in FIG. 1 is installed, and the propulsion jack 3 of the shield machine 1 is extended to take the reaction force against the reaction force wall 9 in the starting pit and advance the shield machine 1 to form an underground structure. The body 4 is suspended from above and set behind the propulsion jack 3 contracted in the tail portion 23 a formed by the tail machine 23 of the shield machine 1.

  The start pit 8 is constituted by a retaining wall, and in order to start the open shield machine 1, a part of this retaining wall is mirror-cut. If necessary, the ground is improved in the front part of the starting pit 8 by chemical injection or the like. Sometimes it is left. 9 to 12, reference numeral 39 denotes a lining plate, which covers the start pit 8 with this, thereby making it possible to release traffic and the like outside the working hours.

  Next, the earth and sand are excavated and discharged from the front or upper surface of the open shield machine 1 with an excavator 6 such as an excavator.

  The concrete box 4 is installed by laying the box 4 in the tail part 23a of the open shield machine 1, and generally uses a lifting machine 31 such as a rough terrain crane or a crawler crane. The planned height is measured at the inner bottom, and height adjusting members 32 such as concrete blocks are installed (four locations), and the box 4 is installed thereon.

  Next, backfill injection will be described. 7 and 8 is used to disperse the propulsive force of the propulsion jack 3 and transmit it to the box 4.

  FIG. 14 shows the installation of the press bar 30, which is installed vertically so as to contact the end face of the box 4 installed in the tail portion 23a.

  After installing the press bar 30, a hydraulic jack 33 or the like is installed between the left and right press bars 30, and the press bar 30 is brought into close contact with the side plate 1a of the tail portion 23a to prevent injection leakage.

  As shown in FIG. 14, after installing the box 4 in the tail part 23 a, the gap between the inner surface of the tail part 23 a and the outer surface of the box 4 from the inside of the box 4 through the grout hole 34 of the box 4. A plastic backfill primary injection material 35 is injected and filled with an injection nozzle 36.

  5 and 6, reference numeral 25 denotes a backfill injection plant, 26 denotes a grout pipe, and an injection nozzle 36 is a tip portion thereof.

  The injection of the backfill primary injecting material 35 is performed by opening the valves for the liquid A and the liquid B and by using an injection plant remote device.

  In order to propel the open shield machine 1 by using the box 4 laid as a reaction force, the propulsion jack 3 installed inside the shield machine is used.

  As shown in FIG. 16, simultaneously with propulsion, secondary injection is performed by injecting and filling a plastic back-filling secondary injection material 37 into the tail void (the thickness of the tail bottom plate and the side plate) from the inside of the box 4. Similar to the primary injection, the secondary injection is performed by firmly fixing the injection nozzle 36 to the grout hole 34 in the bottom plate portion and the side wall portion of the box 4. In the secondary injection, the primary injection portion is drilled from the grout hole and filled from the drilled hole.

  In this way, in the open shield method, the shield machine 1 is propelled by using the laying box as a reaction force, and the concrete box 4 suspended in the tail portion of the shield machine 1 is connected to the top of the laying box, The propulsion jack 3 contracted in the tail portion of the shield machine 1 moves forward while leaving the concrete box 4 behind by using the suspended concrete box 4 as a reaction force.

  Therefore, in the construction of the open shield method, a tail void (cavity) is generated between the box and the ground as the thickness of the tail bottom plate and the side plate. If this tail void is left unattended, the stress release in the ground will proceed, causing collapse and settlement.

  FIG. 17 shows a state after the box is installed (when primary injection is completed). 23a is a tail portion of the tail machine 23, and the back side primary injection material 35 is filled between the side plates of the box 4. However, immediately after the start of excavation, a tail void 40 is generated behind the tail portion 23a with the excavation as shown in FIG.

  The tail void 40 is filled with the back-injection secondary injection material 37 by secondary injection, but immediately after the start of excavation, the side ground in the gap portion collapses before the secondary injection.

  An object of the present invention is to provide an open shield machine that eliminates the disadvantages of the conventional example, reduces the occurrence of tail voids behind the tail part, reduces the possibility of collapse, and stabilizes natural ground. It is to provide.

  In order to achieve the above object, the present invention as set forth in claim 1 divides the open shield machine body into a plurality of parts in the front-rear direction, and the front end of the rear machine body as the tail machine is inserted into the rear end of the front machine body as the front machine. In the open shield machine that can be bent at the mutual fitting part, the gist is that a steel plate thinner than the wall thickness of the tail part is attached to the rear end part of the tail part side wall of the tail machine. It is.

  According to the first aspect of the present invention, a tail void that tends to occur behind the tail portion by attaching a steel plate that is thinner than the wall thickness of the tail portion to the rear end portion of the tail portion side wall as the tail void protective steel plate. Is divided into two parts, and the tail void on the back side of the thin steel plate is protected by the steel plate to prevent collapse.

  Moreover, although the thin steel plate portion may move and collapse, this portion has a smaller volume than the conventional one.

  As described above, the open shield machine of the present invention can reduce the occurrence of tail voids behind the tail part, reduce the possibility of collapse, and stabilize the natural ground.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a side view showing an embodiment of an open shield machine according to the present invention, and FIG. 2 is an explanatory view of the same. The same components as those in FIGS.

  The open shield machine 1 is divided into a plurality of parts in the front-rear direction, and the front end of the rear body as the tail machine 23 is fitted into the rear end of the front body as the front machine 22 and can be bent at the mutual fitting portion. It was. In this figure, the illustration of the bent jack 24 in FIGS. 7 and 8 is omitted.

  The front machine 22 is mainly used for excavation, and has a front end and an upper surface as open surfaces. Inside the machine, a middle folding jack (not shown) is arranged on the left and right sides, and arranged in multiple stages on the top and bottom. doing. On the other hand, the tail machine 23 installs the concrete box 4, and the propulsion jacks (shield jacks) 3 are arranged in the upper and lower stages in the machine body with the propulsion jacks (shield jacks) 3 facing left and right. .

  In the figure, 16 is a movable split blade provided at the front end of the front machine 22, 27 is a earth retaining plate provided at the rear end of the tail machine 23, 29 is a partition type earth retaining plate, and 30 is a press bar (push angle).

  In the figure, 4 is a concrete box, and excavator 6 such as an excavator excavates and removes earth and sand from the front or top surface of open shield machine 1, and open shield machine 1 extends propulsion jack 3 to expand concrete box 4. Since the space is created in the tail portion 23a formed by the tail machine 23 of the shield machine 1, the new concrete box 4 is suspended from above and contracted. Set behind jack 3.

  The backfill injection is as described in FIGS. 14 to 16. In FIGS. 1 and 2, 35 is a backfill primary injection material, 37 is a backfill secondary injection material, and the backfill primary injection material 35. After the box 4 is installed in the tail portion 23a, the gap between the inner surface of the tail portion 23a and the outer surface of the box 4 is injected and filled from the inside of the box 4 through the grout hole of the box 4 The secondary injection material 37 is injected into the tail void (the thickness of the tail bottom plate and the side plate) from the inside of the box 4 simultaneously with the propulsion of the open shield machine 1.

  In the present invention, the steel plate 10 thinner than the wall thickness of the tail portion 23a is attached to the rear end portion of the side wall of the tail portion 23a of the tail machine 23 as a tail void protective steel plate.

  The steel plate 10 has the outer surface position matched to the outer surface position of the side wall of the tail portion 23a, and the height is also matched to the height of the side wall of the tail portion 23a.

  The thickness of the thin steel plate 10 is not particularly limited as long as the thickness thereof is thinner than the side wall of the tail portion 23a, and the protruding width from the side wall of the tail portion 23a is appropriately determined on the condition that the tail void protection can be performed.

  Next, the usage and operation will be described. In the present invention, the steel plate 10 thinner than the wall thickness of the tail portion 23a is attached to the rear end portion of the side wall of the tail portion 23a of the tail machine 23 as described above, as shown in FIG. As described above, the tail void is divided into the tail void 41 and the tail void 42 in the state immediately after the completion of the primary injection after the box installation and immediately after the start of the excavation as shown in FIG.

  Of these, the tail void 41 is protected by the steel plate 10.

  Further, although there is a possibility that the tail void 42 is collapsed, the tail void 42 is a portion generated in the thin steel plate 10 and its volume is very small compared to the conventional one shown in FIGS. 17 and 18. .

  As a result, the risk of collapse is also reduced.

It is a vertical side view which shows one Embodiment of the open shield machine of this invention. It is a cross-sectional top view which shows one Embodiment of the open shield machine of this invention. It is explanatory drawing after the box installation in the open shield machine of this invention (at the time of primary injection completion). It is explanatory drawing immediately after the start of excavation in the open shield machine of this invention. It is a top view which shows the outline | summary of an open shield construction method. It is a vertical side view which shows the outline | summary of an open shield construction method. It is a cross-sectional top view of an open shield machine. It is a vertical side view of an open shield machine. It is a side view of the 1st process which shows the outline of an open shield construction method. It is a side view of the 2nd process which shows the outline of an open shield construction method. It is a side view of the 3rd process which shows the outline of the open shield method. It is a side view of the 4th process which shows the outline of the open shield method. It is a perspective view which shows the outline | summary of an open shield construction method. It is explanatory drawing which shows installation of a press bar. It is explanatory drawing which shows the 1st step of backfill injection. It is explanatory drawing which shows the 2nd step of backfill injection. It is explanatory drawing after the box installation in a prior art example (at the time of primary injection completion). It is explanatory drawing immediately after the start of excavation in a prior art example.

DESCRIPTION OF SYMBOLS 1 ... Open shield machine 1a ... Side wall plate 1b ... Bottom plate 3 ... Propulsion jack (shield jack)
4 ... Concrete box 8 ... Starting pit 9 ... Reaction wall 10 ... Steel plate 16 ... Movable split edge 17 ... Slide jack 22 ... Front machine 23 ... Tail machine 23a ... Tail part 24 ... Folding jack 25 ... Backfill injection plant 26 ... Grouting pipe 27 ... Earth retaining plate 29 ... Earth retaining plate 30 ... Press bar (push angle) 31 ... Lifting machine 32 ... Height adjusting material 33 ... Hydraulic jack 34 ... Grout hole 35 ... Back-filled primary injecting material 36 ... Injection nozzle 37 ... Backfilling secondary injection material 38 ... Towing jack 39 ... Covering plates 40, 41, 42 ... Tail void

The present invention relates to open shield construction method.

  As is well known, the open shield method is a rational method that takes advantage of the open cut method (open method) and the shield method.

First, when explaining the open shield machine used in the open shield method, it is also shown in the following patent document, but basically the front side consisting of connecting the left and right side wall plates and the length of these side wall plates between them, It is a shield machine with an open rear and upper surface.
JP 2015-48659 A

  Then, as shown in FIGS. 7 and 8, the aircraft is divided into a plurality of parts in the front-rear direction, and the front end of the rear aircraft as the tail machine 23 is fitted into the rear end of the front aircraft as the front machine 22, It can be bent at the fitting part.

  The front machine 22 is mainly used for excavation, and has a front end and an upper surface as open surfaces, and the middle folding jacks 24 are arranged on the left and right and rearward and rearward in a plurality of stages. On the other hand, the tail machine 23 installs the concrete box 4, and the propulsion jacks (shield jacks) 3 are arranged in the upper and lower stages in the machine body with the front and rear facing backward. ing.

  In the figure, 16 is a movable split blade provided at the front end of the front machine 22, 17 is a slide jack of this movable split blade, 27 is a earth retaining plate provided at the rear end of the tail machine 23, 29 is a bulkhead type earth retaining plate, Reference numeral 30 denotes a press bar (push angle).

  The movable dividing blade 16 is a slide-type earth retaining device for preventing the collapse of the side rocks during excavation, and expands and contracts from the tip of the shield machine.

  The front machine 22 and the tail machine 23 of the open shield machine 1 are both shield machines having left, right, and side walls 1a and bottom plates 1b connected to the side walls 1a, with the front, rear and top surfaces opened.

  Since the tail machine 23 has the bottom plate 1b, the box 4 can be laid without worrying about boiling and heaving.

  The bent portion formed by the combination of the front machine 22 and the tail machine 23 is used for direction / gradient correction and curve construction. The front machine 22 and the tail machine 23 of the shield machine 1 can be bent by the middle folding jack 24 housed in the middle folding section. In the figure, reference numeral 38 denotes a towing jack, which connects a front machine 22 and a tail machine 23 by stretching a PC steel wire, but such a towing jack 38 may not be provided.

  The earth retaining plate 29 is used for partitioning the excavation part and the hydraulic equipment storage part in front of the open shield machine 1 and is compacted by pressing the excavation earth and sand, which is useful when constructing high groundwater or soft soil.

  Next, the construction procedure of the open shield method performed using such an open shield machine 1 will be described with reference to FIGS. 9 to 12, and the outline will be described with reference to FIG. 13. As shown in FIG. 1 is installed, and the propulsion jack 3 of the shield machine 1 is extended to take the reaction force against the reaction force wall 9 in the starting pit and advance the shield machine 1 to form an underground structure. The body 4 is suspended from above and set behind the propulsion jack 3 contracted in the tail portion 23 a formed by the tail machine 23 of the shield machine 1.

  The start pit 8 is constituted by a retaining wall, and in order to start the open shield machine 1, a part of this retaining wall is mirror-cut. If necessary, the ground is improved in the front part of the starting pit 8 by chemical injection or the like. Sometimes it is left. 9 to 12, reference numeral 39 denotes a lining plate, which covers the start pit 8 with this, thereby making it possible to release traffic and the like outside the working hours.

  Next, the earth and sand are excavated and discharged from the front or upper surface of the open shield machine 1 with an excavator 6 such as an excavator.

  The concrete box 4 is installed by laying the box 4 in the tail part 23a of the open shield machine 1, and generally uses a lifting machine 31 such as a rough terrain crane or a crawler crane. The planned height is measured at the inner bottom, and height adjusting members 32 such as concrete blocks are installed (four locations), and the box 4 is installed thereon.

  Next, backfill injection will be described. 7 and 8 is used to disperse the propulsive force of the propulsion jack 3 and transmit it to the box 4.

  FIG. 14 shows the installation of the press bar 30, which is installed vertically so as to contact the end face of the box 4 installed in the tail portion 23a.

  After installing the press bar 30, a hydraulic jack 33 or the like is installed between the left and right press bars 30, and the press bar 30 is brought into close contact with the side plate 1a of the tail portion 23a to prevent injection leakage.

  As shown in FIG. 14, after installing the box 4 in the tail part 23 a, the gap between the inner surface of the tail part 23 a and the outer surface of the box 4 from the inside of the box 4 through the grout hole 34 of the box 4. A plastic backfill primary injection material 35 is injected and filled with an injection nozzle 36.

  5 and 6, reference numeral 25 denotes a backfill injection plant, 26 denotes a grout pipe, and an injection nozzle 36 is a tip portion thereof.

  The injection of the backfill primary injecting material 35 is performed by opening the valves for the liquid A and the liquid B and by using an injection plant remote device.

  In order to propel the open shield machine 1 by using the box 4 laid as a reaction force, the propulsion jack 3 installed inside the shield machine is used.

  As shown in FIG. 16, simultaneously with propulsion, secondary injection is performed by injecting and filling a plastic back-filling secondary injection material 37 into the tail void (the thickness of the tail bottom plate and the side plate) from the inside of the box 4. Similar to the primary injection, the secondary injection is performed by firmly fixing the injection nozzle 36 to the grout hole 34 in the bottom plate portion and the side wall portion of the box 4. In the secondary injection, the primary injection portion is drilled from the grout hole and filled from the drilled hole.

  In this way, in the open shield method, the shield machine 1 is propelled by using the laying box as a reaction force, and the concrete box 4 suspended in the tail portion of the shield machine 1 is connected to the top of the laying box, The propulsion jack 3 contracted in the tail portion of the shield machine 1 moves forward while leaving the concrete box 4 behind by using the suspended concrete box 4 as a reaction force.

  Therefore, in the construction of the open shield method, a tail void (cavity) is generated between the box and the ground as the thickness of the tail bottom plate and the side plate. If this tail void is left unattended, the stress release in the ground will proceed, causing collapse and settlement.

  FIG. 17 shows a state after the box is installed (when primary injection is completed). 23a is a tail portion of the tail machine 23, and the back side primary injection material 35 is filled between the side plates of the box 4. However, immediately after the start of excavation, a tail void 40 is generated behind the tail portion 23a with the excavation as shown in FIG.

  The tail void 40 is filled with the back-injection secondary injection material 37 by secondary injection, but immediately after the start of excavation, the side ground in the gap portion collapses before the secondary injection.

An object of the present invention is to provide an open shield construction method that eliminates the disadvantages of the conventional example, reduces the occurrence of tail voids behind the tail part, reduces the possibility of collapse, and stabilizes the natural ground. It is to provide.

In order to achieve the above object, the present invention as set forth in claim 1 divides the open shield machine body into a plurality of parts in the front-rear direction, and the front end of the rear machine body as the tail machine is inserted into the rear end of the front machine body as the front machine. Then, using an open shield machine that can be bent at the mutual fitting part, an open shield machine with a steel plate that is thinner than the wall thickness of the tail part is attached to the rear end of the tail part side wall of the tail machine. The concrete box that forms the underground structure is suspended from above, set behind the propulsion jack that is shrunk in the tail formed by the tail machine of the shield machine, and open shielded by an excavator such as an excavator. Excavation and sand removal from the front or top of the machine, and the open shield machine is an open shield construction method in which a propulsion jack is extended and a reaction force is applied to the concrete box to move forward. After the concrete box is installed in the tail, the material is injected and filled into the gap between the inner surface of the tail and the outer surface of the concrete box from the inside of the box through the grout hole of the concrete box. The material is injected into the tail void from the inside of the concrete box simultaneously with the propulsion of the open shield machine, and the tail void is the tail void protected by the steel plate in the state immediately after the completion of the primary injection after the box installation and immediately after the start of the excavation. The main point is to divide into non-tail voids .

  According to the first aspect of the present invention, a tail void that tends to occur behind the tail portion by attaching a steel plate that is thinner than the wall thickness of the tail portion to the rear end portion of the tail portion side wall as the tail void protective steel plate. Is divided into two parts, and the tail void on the back side of the thin steel plate is protected by the steel plate to prevent collapse.

  Moreover, although the thin steel plate portion may move and collapse, this portion has a smaller volume than the conventional one.

As described above, the open shield method of the present invention can reduce the occurrence of tail voids behind the tail part, reduce the possibility of collapse, and stabilize the natural ground.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a longitudinal side view showing an embodiment of the open shield method of the present invention , FIG. 2 is a cross-sectional plan view of the same, and the same components as those in FIGS. 7 and 8 are given the same reference numerals.

The open shield machine 1 used in the present invention divides the fuselage into a plurality of parts in the front-rear direction, and the front end of the rear machine as the tail machine 23 is fitted into the rear end of the front machine as the front machine 22 so It was possible to bend at the joint. In this figure, the illustration of the bent jack 24 in FIGS. 7 and 8 is omitted.

  The front machine 22 is mainly used for excavation, and has a front end and an upper surface as open surfaces. Inside the machine, a middle folding jack (not shown) is arranged on the left and right sides, and arranged in multiple stages on the top and bottom. doing. On the other hand, the tail machine 23 installs the concrete box 4, and the propulsion jacks (shield jacks) 3 are arranged in the upper and lower stages in the machine body with the propulsion jacks (shield jacks) 3 facing left and right. .

  In the figure, 16 is a movable split blade provided at the front end of the front machine 22, 27 is a earth retaining plate provided at the rear end of the tail machine 23, 29 is a partition type earth retaining plate, and 30 is a press bar (push angle).

  In the figure, 4 is a concrete box, and excavator 6 such as an excavator excavates and removes earth and sand from the front or top surface of open shield machine 1, and open shield machine 1 extends propulsion jack 3 to expand concrete box 4. Since the space is created in the tail portion 23a formed by the tail machine 23 of the shield machine 1, the new concrete box 4 is suspended from above and contracted. Set behind jack 3.

  The backfill injection is as described in FIGS. 14 to 16. In FIGS. 1 and 2, 35 is a backfill primary injection material, 37 is a backfill secondary injection material, and the backfill primary injection material 35. After the box 4 is installed in the tail portion 23a, the gap between the inner surface of the tail portion 23a and the outer surface of the box 4 is injected and filled from the inside of the box 4 through the grout hole of the box 4 The secondary injection material 37 is injected into the tail void (the thickness of the tail bottom plate and the side plate) from the inside of the box 4 simultaneously with the propulsion of the open shield machine 1.

  In the present invention, the steel plate 10 thinner than the wall thickness of the tail portion 23a is attached to the rear end portion of the side wall of the tail portion 23a of the tail machine 23 as a tail void protective steel plate.

  The steel plate 10 has the outer surface position matched to the outer surface position of the side wall of the tail portion 23a, and the height is also matched to the height of the side wall of the tail portion 23a.

  The thickness of the thin steel plate 10 is not particularly limited as long as the thickness thereof is thinner than the side wall of the tail portion 23a, and the protruding width from the side wall of the tail portion 23a is appropriately determined on the condition that the tail void protection can be performed.

  Next, the usage and operation will be described. In the present invention, the steel plate 10 thinner than the wall thickness of the tail portion 23a is attached to the rear end portion of the side wall of the tail portion 23a of the tail machine 23 as described above, as shown in FIG. As described above, the tail void is divided into the tail void 41 and the tail void 42 in the state immediately after the completion of the primary injection after the box installation and immediately after the start of the excavation as shown in FIG.

  Of these, the tail void 41 is protected by the steel plate 10.

  Further, although there is a possibility that the tail void 42 is collapsed, the tail void 42 is a portion generated in the thin steel plate 10 and its volume is very small compared to the conventional one shown in FIGS. 17 and 18. .

  As a result, the risk of collapse is also reduced.

It is a vertical side view which shows one Embodiment of the open shield construction method of this invention. It is a cross-sectional top view which shows one Embodiment of the open shield construction method of this invention. It is an explanatory view of an open shield method to definitive after a box body installation (during the primary injection completion) of the present invention. Is an illustration of just tunneling Engineering started definitive open shield method of the present invention. It is a top view which shows the outline | summary of an open shield construction method. It is a vertical side view which shows the outline | summary of an open shield construction method. It is a cross-sectional top view of an open shield machine. It is a vertical side view of an open shield machine. It is a side view of the 1st process which shows the outline of an open shield construction method. It is a side view of the 2nd process which shows the outline of an open shield construction method. It is a side view of the 3rd process which shows the outline of the open shield method. It is a side view of the 4th process which shows the outline of the open shield method. It is a perspective view which shows the outline | summary of an open shield construction method. It is explanatory drawing which shows installation of a press bar. It is explanatory drawing which shows the 1st step of backfill injection. It is explanatory drawing which shows the 2nd step of backfill injection. It is explanatory drawing after the box installation in a prior art example (at the time of primary injection completion). It is explanatory drawing immediately after the start of excavation in a prior art example.

DESCRIPTION OF SYMBOLS 1 ... Open shield machine 1a ... Side wall plate 1b ... Bottom plate 3 ... Propulsion jack (shield jack)
4 ... Concrete box 8 ... Starting pit 9 ... Reaction wall 10 ... Steel plate 16 ... Movable split edge 17 ... Slide jack 22 ... Front machine 23 ... Tail machine 23a ... Tail part 24 ... Folding jack 25 ... Backfill injection plant 26 ... Grouting pipe 27 ... Earth retaining plate 29 ... Earth retaining plate 30 ... Press bar (push angle) 31 ... Lifting machine 32 ... Height adjusting material 33 ... Hydraulic jack 34 ... Grout hole 35 ... Back-filled primary injecting material 36 ... Injection nozzle 37 ... Backfilling secondary injection material 38 ... Towing jack 39 ... Covering plates 40, 41, 42 ... Tail void

Claims (1)

  The open shield machine body is divided into multiple parts in the front-rear direction, and the front end of the front machine as the front machine fits into the front end of the rear machine as the tail machine, making it possible to bend at the mutual fitting part An open shield machine characterized in that a steel plate thinner than the wall thickness of the tail part is extended and attached to the rear end of the tail part side wall of the tail machine.

Images