JP7005713B1 - Strut for open shield method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a press bar or strut for an open shield method, which can prevent a fall and can easily secure safety at the time of installation and removal work. A single piece of a press bar 11 and a strut 12 is a vertical member (square pillar 13) in the shape of a steel square pillar such as H-shaped steel or a steel pipe, and a pair of left and right arrangements. A plurality of pieces are used side by side, and the quadrangular prism 13 is provided with an overhang 14 at the lower part as a fall prevention member inward of the construction cross section. [Selection diagram] FIG. 5

Description

The present invention relates to struts used in an open shield method for constructing underground structures such as water and sewage systems and underground passages in urban areas.

The open shield method is a highly rational method that makes the best use of the advantages of the open-cut method and the shield method. It is propelled using an upper open shield machine (open shield machine) to prevent sediment collapse. It is a construction method that lays a box inside.

17 and 18 show the outline. In FIG. 1, reference numeral 1 denotes an open shield machine, which is a shield machine having an open front surface, a rear surface, and an upper surface composed of left and right side wall plates and bottom plates connected to these side wall plates. ..

In the open shield machine 1, the machine body is divided into a plurality of parts in the front-rear direction, and the front end of the rear machine body as the tail part 1b is fitted into the rear end of the front machine body as the front part 1a, and the mutual fitting part is formed. The center bent portion 2 is formed so that it can be bent.

The front part 1a is mainly used for excavation, and the front end and the upper surface are open surfaces. did.

On the other hand, the tail portion 1b is for installing a concrete box 4, has a bottom plate 5, and has a propulsion jack (shield jack) 3 facing rearward in the front part of the aircraft, and is moved up and down again. It is arranged in multiple stages.

In the figure, 6 is a slide retaining plate provided at the front end of the front portion 1a, and 11 is a press bar (push angle) of the present invention.

Although not shown, the open shield machine 1 is installed in the starting shaft, the propulsion jack 3 of the open shield machine 1 is extended, and the reaction force is applied to the reaction force wall in the starting shaft to advance the open shield machine 1. The first concrete box 4 forming the underground structure is suspended from above by a lifting machine 10 such as a crane, and set behind the contracted propulsion jack 3 in the tail 1b of the open shield machine 1.

An excavator 7 such as an excavator excavates and discharges earth and sand from the front surface or the upper surface of the open shield machine 1. At the same time as or after this soil removal step, the propulsion jack 3 is extended to advance the open shield machine 1.

Then, the second concrete box 4 is suspended in the tail portion 1b of the open shield machine 1 in front of the first concrete box 4. Hereinafter, the same soil removal process, advancing process, and setting process of the concrete box 4 are repeated as appropriate, and the concrete box 4 is sequentially left in the ground in a column as the open shield machine 1 advances, and further, the concrete box 4 is left in the ground. Backfilling is performed on the upper surface of 4.

When the concrete box 4 is suspended in the tail portion 1b of the open shield machine 1, a height adjusting material such as a concrete block is arranged under the concrete box 4 and concrete is provided in the tail portion 1b. The gaps on the left, right, and bottom of the box 4 are filled with the backfilling material 9 using the instantaneous grout material to perform the primary injection, and after the open shield machine 1 advances, the concrete box is used as the secondary injection. The backfill injection material 9 is injected from the inside of 4 to the outside through a grout hole.

In this way, when the open shield machine 1 reaches the reaching pit, it is removed and the construction is completed.

By the way, in the open shield method, as shown in FIGS. 19 and 20, a press bar (push angle) 11 and a strut 12 are used.

The press bar 11 is a member for distributing and transmitting the jack thrust of the propulsion jack (shield jack) 3 to the concrete box, and also has a role of preventing leakage of the backfill injection material.

The following patent document shows an example for preventing leakage of the backfill injection material, and the width of the press bar (push angle) is widened by interposing a diameter-expanding jack in the middle of the upper and lower cross members constituting the rectangular frame. The diameter can be expanded.
Japanese Unexamined Patent Publication No. 4-302618

The strut 12 is used to make up for the shortage of the jack stroke of the propulsion jack (shield jack) 3. In the open shield method, if the jack stroke is insufficient for the propulsion of one box, a strut material is installed to assist the extension and extension of the jack.

The struts 12 are additionally installed on the wall portions on both sides of the box according to the jack arrangement of the jack cross section according to the required number of jacks to be propelled, and one box is propelled.

In the open shield method, the press bar 11 and strut 12 are basically square pillars in order to secure a path for people to enter the box body from the box body starting shaft and shield machine, and a space is provided in the middle part. Secure it and place it according to the position in the extension direction of the walls on both sides of the box.

The members in the shape of a basic square pillar are arranged on the left and right, and in some cases, they are configured as a U-shaped frame body in which the lower part is connected by a cross member, or a rectangular frame body in which the upper part and the lower part are connected by a cross member. ..

Depending on the cross section of the box to be propelled, the strut 12 may have a high height, and there is a risk of tipping over in the cross section direction.

Further, when the strut 12 is widened in the cross-sectional direction as a fall prevention, the approach path to the inside of the box is obstructed, the weight of the member becomes heavy, and the workability deteriorates.

When propelling with the propulsion jack (shield jack) 3, the press bar 11 and the strut 12 are sandwiched between the concrete box 4 and the jack, so the possibility of tipping over in the extension direction is low, but the strut When the jack is retracted in order to add 12, there is a risk that the press bar 11 and the strut 12 will tip over on the jack side.

An object of the present invention is to provide a strut for an open shield method, which can eliminate the inconvenience of the above-mentioned conventional example, prevent the fall, and can easily secure safety during installation and removal work.

In order to achieve the above object, the present invention according to claim 1 laterally serves a member in the shape of a quadrangular prism composed of left and right paired members as a fall prevention member inward in the construction cross section while having a distance between the left and right members. The gist is that the legs are overhanging with wood .

According to the first aspect of the present invention, it is possible to prevent the fall by projecting inward of the construction cross section provided at the lower part.

The gist of the present invention according to claim 2 is to arrange a reinforcing member as needed depending on the height.

According to the second aspect of the present invention, when the overhang is a cross member, the strength of the truss can be increased by combining the overhang with the diagonal member as a reinforcing member.

The gist of the present invention according to claim 3 is that the invention can be connected to each other in the construction extension direction by a connecting metal fitting to form an integrated structure in the construction extension direction .

According to the third aspect of the present invention, in order to prevent the jack from tipping over in the extension direction when the jack is retracted, each strut and the press bar are connected by a connecting metal fitting in the extension direction, so that the press bar and the strut are connected. By doing so, the strut member has an integral structure that is long in the propulsion extension direction, and can play a role of preventing the fall.

As described above, the strut for the open shield method of the present invention can prevent the strut from tipping over, and can easily ensure safety during installation and removal work.

It is a vertical sectional side view which shows the 1st example of the open shield method using the strut of this invention. It is a cross-sectional plan view which shows the 1st example of the open shield method using the strut of this invention. It is a vertical sectional front view of the strut part of the open shield method using the strut of this invention. It is a side view which shows the 1st Embodiment of the strut for the open shield method of this invention. It is a top view which shows 1st Embodiment of the strut for the open shield method of this invention. It is a front view which shows the 1st Embodiment of the strut for the open shield method of this invention. It is a vertical sectional side view which shows the 2nd example of the open shield method using the strut of this invention. It is a cross-sectional plan view which shows the 2nd example of the open shield method using the strut of this invention. It is a vertical sectional front view of the box body pressure part of the open shield method using the strut of this invention. It is a vertical sectional front view of the original push jack part of the open shield method using the strut of this invention. It is a side view which shows the 2nd Embodiment of the strut for the open shield method of this invention. It is a side view which shows the 3rd Embodiment of the strut for the open shield method of this invention. It is a top view which shows the 3rd Embodiment of the strut for the open shield method of this invention. It is a side view which shows the 4th Embodiment of the strut for the open shield method of this invention. It is a front view which shows the 4th Embodiment of the strut for the open shield method of this invention. It is a top view which shows the 4th Embodiment of the strut for the open shield method of this invention. It is a side view of the open shield machine advance process which shows the outline of the open shield method. It is a side view at the time of hanging a concrete box which shows the outline of an open shield method. It is a top view of the press bar strut which shows the conventional example. It is a front view of the strut which shows the conventional example.

Hereinafter, embodiments of the present invention will be described in detail with respect to the drawings. First, the first embodiment of the strut of the present invention will be described. There are cases where the strut has the same shape as the press bar and cases where the shape is different.

As shown in FIGS. 4 to 6, the strut 12 is a vertical member (square pillar 13) in the shape of a steel square pillar such as H-shaped steel or a steel pipe, and the strut 12 is divided into left and right pairs. As a member, which is arranged with a distance to the left and right, it is a member in the shape of a quadrangular prism and is configured as a pair to be arranged on the left and right, and a plurality of pieces are used side by side.

When H-shaped steel is used, as shown in FIG. 5, the open surface between the flanges is closed with a steel plate to form a tubular shape.

The square pillar 13 is provided with an overhang 14 at the lower part as a fall prevention member inward in the construction cross section. In the open shield method, the inside of this construction cross section indicates the inside direction of the cross section in the excavation direction by the open shield machine or the cross section in the construction extension direction of the underground structure by the concrete box.

In the case of the present embodiment, the overhang 14 is a leg body made of a cross member, whereby the square pillar 13 can stand on its own.

Reinforcing members 15 made of diagonal members were arranged according to the height of the quadrangular prism 13 or, if necessary, and combined with the overhang 14 to form a truss. The width of the cross member forming the overhang 14 is substantially the same as the width of the quadrangular prism 13, and the plate thickness of the reinforcing member 15 made of the diagonal member may be smaller than that of the overhang 14.

The overhang length of the overhang 14 is such that when the quadrangular prisms 13 are arranged on the left and right, a sufficient distance can be secured between the tips of the overhangs 14 to pass each other.

On the other hand, as shown in FIGS. 1 to 3, the press bar 11 is a vertical member in the shape of a square pillar made of steel such as H-shaped steel or a steel pipe, and is configured as a pair arranged on the left and right. The two were connected at the lower part by the cross member 11a, and the whole was framed in a horizontal U shape.

The press bar 11 has a height such that the upper part protrudes above the concrete box 4, and when the cross member 11a is framed in a horizontal U shape, the cross member 11a becomes an overhang 14 inward of the construction cross section. ..

Next, the usage will be described. Since the general outline of the open shield method is the same as that described with reference to FIGS. 14 and 15, the description thereof will be omitted.

As shown in FIGS. 1 to 3, before advancing the open shield machine 1, the press bar 11 is suspended between the propulsion jack 3 and the front end of the concrete box 4, and the inner circumference of the open shield machine 1 is watertight. Arrange so as to be in contact with. In the figure, 27 is a slide jack that drives the slide retaining plate 6 of the open shield machine 1.

If the propulsion jack 3 is applied to the square pillar 13 of the press bar 11 and a slight pressing force is applied to the square pillar 13, the press bar 11 is fixed in that state.

After arranging the press bar 11, the gap around the concrete box 4 is filled with a grout material (not shown), but the press bar 11 prevents the grout material from flowing out to the front part of the open shield machine 1.

The propulsion jack 3 is extended to advance the open shield machine 1 by using the concrete box 4 as a reaction force. After that, pull up the press bar 11 upward.

By the way, the installation work of the press bar 11 is the work of installing vertically so as to be in contact with the end face of the concrete box 4 arranged in the tail part 1b, and the removal work is the work of installing the tail part after the propulsion is completed. The press bar 11 is removed from 1b and temporarily placed on the ground.

Further, to explain in detail, the installation work follows the following procedure.
i) Inspect tools such as hanging brackets and wires to check the fixing status.
ii) Lift the press bars 11 one by one and install them in the specified positions.
iii) After installation, the press bar 11 is pressed by the propulsion jack 3 to prevent it from tipping over, but the press bar 11 is designed to prevent the square columns 13 arranged on the left and right by the cross member 11a from tipping inside the construction cross section.

In addition, the removal work follows the procedure below.
i) Confirm that propulsion and clearance backfilling have been completed.
ii) Inspect tools such as hanging metal fittings and wires, check the fixing status, release the pressure of the propulsion jack 3, and remove the press bar 11.

Further, when the strut 12 is used, if the strut 12 is installed in front of the press bar 11 and the propulsion jack 3 is applied to the strut 12 and a slight pressing force is applied to the strut 12, the press bar 11 and The strut 12 is fixed in that state.

Even in the hanging arrangement of the struts 12, the struts 12 can stand on their own by the overhanging 14, and the quadrangular prism 13 can be prevented from falling inward in the construction cross section.

By using the strut 12, the stroke of the propulsion jack 3 can be shortened by the thickness of the strut 12.

Also, the number of struts 12 used will be increased as needed.

8 to 10 show other embodiments of the present invention, and both have the same shape as the press bar 11 or the strut 12.

As shown in FIGS. 4 to 6, the single piece of the press bar 11 and the strut 12 is a vertical member (square pillar 13) in the shape of a steel square pillar such as H-shaped steel or a steel pipe. It is configured as a pair arranged on the left and right, and a plurality of pieces are used side by side. The square pillar 13 is provided with an overhang 14 at the lower part as a fall prevention member inward of the construction cross section.

In this embodiment, the propulsion method is also used in the open shield method, and when crossing directly under a structure such as a bridge girder or a large pipe, the excavator 9 or the lifting machine can be placed where it is located. Since the construction of the open shield method becomes impossible, the open shield machine is set at the rear of the concrete box 4, and the open shield machine 1 is pushed out together with the concrete box 4.

The construction example shown in the figure is a propulsion method in which a starting pit 17 is formed on the side of a structure such as a bridge with a retaining steel sheet pile 16, a bearing wall 18 is provided here, and a concrete box 4 is propelled by a push jack 19. Is to do.

In the figure, 20 shows a pedestal made of H-shaped steel laid on the foundation concrete, and 21 shows a guide steel provided on the side of the starting pit 17 to guide the progress of the concrete box 4.

11 to 16 show further improvements of the present invention, in which the press bar 11 and the strut 12 are provided with a connecting metal fitting 23 at the center of the square column 13 so as to be mutually connectable in the construction extension direction.

In the example of FIG. 11, the connecting metal fitting 23 is composed of a hook-shaped ring hanging metal fitting 24a and a protrusion 24b, and the hanging metal fitting 24a is hung on the protrusion 24b in a state where the square pillars 13 are arranged side by side to connect the two. ..

In the example of FIGS. 12 and 13, the connecting metal fitting 23 is a connecting piece 25a and a connecting piece 25b having a pin insertion hole projecting from the central side of the quadrangular prism 13, and a pin for connecting the connecting piece 25a and the connecting piece 25b. It was composed of 26, and the connecting piece 25a and the connecting piece 25b were overlapped with each other in a state where the square pillars 13 were arranged side by side, and the pin 26 was inserted and fixed.

In the examples of FIGS. 14 to 16, the connecting metal fitting 23 is composed of a protrusion and a recess in which the protrusion fits, and the protrusion 28 is projected on the front front side of the quadrangular prism 13 in, for example, three stages of upper, middle, and lower. A recess 29 into which the protrusion 28 is fitted is formed on the back side of the square pillar 13.

By fitting the protrusion 28 into the recess 29 of the adjacent quadrangular prism 13, the quadrangular prisms 13 are connected to each other, and the press bar 11 and the strut 12 can be connected to the central portion of the quadrangular prism 13 in the construction extension direction. Become.

In the illustrated example, the protrusion 28 is cylindrical, but is not particularly limited, and may be a square or a polygon, and the recess 29 has a shape corresponding to this.

To prevent the jack from tipping over in the extension direction when the jack is retracted in this way, by connecting each strut 12 and the press bar 11 with the connecting metal fitting 23, the strut member has an integrated structure that is long in the propulsion extension direction, and plays a role of preventing the fall. Can be fulfilled.

1 ... Open shield machine 1a ... Front part 1b ... Tail part 2 ... Middle folding part 3 ... Propulsion jack 4 ... Concrete box 5 ... Bottom plate 6 ... Slide retaining plate 7 ... Excavator 8 ... Middle folding jack 9 ... Backfill injection material 10 ... Lifting machine 11 ... Press bar 11a ... Cross member 12 ... Strut 13 ... Square pillar 14 ... Overhang 15 ... Reinforcing member 16 ... Retaining steel sheet pile 17 ... Starting pit 18 ... Supporting wall 19 ... Main push jack 20 ... Cradle Work 21 ... Guide steel 23 ... Connecting bracket 24a ... Hanging bracket 24b ... Protrusion 25a ... Connecting piece 25b ... Connecting piece 26 ... Pin 27 ... Slide jack 28 ... Projection 29 ... Recess

Claims (3)

It is a divided left and right pair member, and it is a member in the shape of a square pillar that is arranged with a distance to the left and right. A strut for the open shield method that features. The strut for the open shield tunneling method according to claim 1, wherein a reinforcing member is arranged as needed depending on the height. The strut for an open shield tunneling method according to claim 1 or 2, wherein connecting metal fittings are provided in the construction extension direction and the struts can be connected to each other to form an integrated structure in the construction extension direction .

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