JP3990589B2 - Reinforcing structure for shaft opening - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention assembles a plurality of segments connected on the ground, presses the assembled segments into the basement, sinks a shaft, starts an excavator from the shaft, and forms a tunnel to form a start port of the excavator The present invention relates to a reinforcing structure of an opening provided with an openable / closable gate (also referred to as a shutter) that constitutes an arrival port.
[0002]
[Prior art]
When constructing a tunnel or underground space with an excavator such as a shield excavator, first, a shaft (starting shaft and reaching shaft) for starting and reaching the excavator at both ends or an intermediate portion of the route to be excavated through the tunnel. ), The excavator is lowered into the start shaft, the lowered excavator is started from the start shaft, and a predetermined route is excavated to reach the destination shaft.
[0003]
There are various methods for constructing a shaft, for example, an urban ring method (trade name) and the like are known. Along with the deepening of the shaft to be built, very large earth pressure and water pressure act on the outside of the retaining wall that constitutes the shaft, and when the retaining wall is opened to start the excavator, There is a problem that part of the earth and sand collapses and flows into the shaft, and the excavator cannot be started.
[0004]
Therefore, conventionally, a method of forming a ground improvement part or a frozen part in front of the starting port has been performed in order to prevent the surrounding natural ground from collapsing at the time of opening or to prevent inflow of groundwater into the shaft. (Hereinafter referred to as “prior art 1”).
[0005]
However, the prior art 1 has a problem that a lot of cost and work period are required for forming the ground improvement part and the frozen part.
[0006]
For this reason, there is a need for a construction method that can start an excavator without performing ground improvement work around the start opening. JP-A-10-205280 discloses a tunnel construction method using a gate (shutter) described below. Has been. In the construction method, a start port provided in a retaining wall (also referred to as a construction wall) constituting a start shaft is sealed with a sealing material that can be excavated by an excavator. Furthermore, a gate that can be opened and closed is provided at the start opening. The gate has a strength capable of supporting earth pressure and water pressure around the start shaft. In addition, the gate is provided with a leakage prevention member for preventing the pressure chamber filling material formed in the start shaft when the excavator starts from leaking between the gate and the building wall when the gate is opened. ing. A pressure chamber that opposes the pressure outside the building wall is formed between the gate and the excavator, and then the gate is moved to open the start opening, and the excavator seals the start opening. The excavator is then started out of the starting shaft (hereinafter referred to as “prior art 2”).
[0007]
[Problems to be solved by the invention]
However, Prior Art 2 has the following problems.
[0008]
Cylindrical shafts are subjected to vertical and circumferential forces. First, regarding the vertical force, vertical jacking pressure is applied to the segment assembled on the ground (earth retaining wall) because it is pressed into the ground by the jack while being excavated underwater. Therefore, the jack pressure in the vertical direction is also applied to the opening incorporated in the segment. However, the jack pressure is a load applied only when the shaft is set, and such load is not applied after the setting is completed.
[0009]
Next, with respect to the circumferential direction, the segment after installation (the retaining wall) that has been deeply pressed into the ground is subjected to earth pressure and water pressure on the outer periphery of the retaining wall, and in the cylindrical shaft, it is the compression of the retaining member. Force is applied to the member and the opening.
[0010]
Further, the opening of the shaft is provided with an open / close gate, and when starting the excavator, the gate is pulled up to open the opening. At this time, the segment just above the gate must be prevented from coming into contact with the raised gate. Therefore, the position and size must be adjusted and arranged, for example, the digit height (thickness) must be lower (thinner) than that of a normal segment.
[0011]
However, there is a problem that if the girder height of the segment is lowered, the rigidity is insufficient, and the rigidity of the opening and surroundings is insufficient with respect to the jack pressure applied to the shaft when the shaft is set.
[0012]
Accordingly, the object of the present invention is to solve the above-mentioned problems, to counteract the pressure at the time of shaft construction and the earth pressure and water pressure around the earth retaining wall, to sufficiently secure the rigidity of the opening and its surroundings, and Another object of the present invention is to provide a reinforcing structure for a shaft opening that can ensure good workability without interfering with the raising of the gate.
[0013]
[Means for Solving the Problems]
According to the first aspect of the present invention, in the reinforcing structure of the opening in the shaft in which the opening provided with the gate is arranged to assemble a plurality of segments, and the assembled segment is press-fitted into the ground and set down, immediately above the opening The segment of the part has a double structure consisting of a first segment arranged so as not to contact the gate at the time of pulling up, and a second segment for reinforcement arranged overlapping the first segment, The second segment is characterized in that it is removably attached to the first segment.
[0014]
The invention according to claim 2 is characterized in that reinforcing members are arranged on both the left and right sides and the lower part of the opening.
According to a third aspect of the present invention, reinforcing members are disposed on both the left and right sides and the lower portion of the opening, and the upper portion of the opening after the second segment is removed is reinforced at the upper portion of the opening. reinforcing beams for concatenates between an upper portion of the reinforcing member of the right and left sides of the opening and has a particular feature which is mounted so as not to contact with the gate.
[0015]
According to a fourth aspect of the present invention, there is provided transmission means for transmitting a load applied to the segment when the shaft is set to the gate closing the opening, and the transmission means includes the double-structured segment and the opening. It is characterized in that it is arranged so as to be interposed between the gate blocking the part.
[0016]
In the present invention, the segment immediately above the shaft opening has a double structure including a first segment and a second segment. If the normal segment is arranged immediately above the opening, it will come into contact with the gate when the gate of the opening is lifted, so the first segment has a thinner digit height (thickness) than the normal segment, and , Arrange so as not to contact the gate when the gate is lifted. The second segment is disposed so as to overlap the inside of the first segment and reinforces the first segment. The thickness of the double-structured segment that overlaps the first and second segments has the same or higher girder height (thickness) as the other segments. It can resist the vertical jack pressure applied and ensure rigidity, and can also counter the circumferential force caused by earth pressure and water pressure applied to the shaft. Since the second segment is removed from the first segment after the sinking is completed and before the gate is lifted, it does not come into contact with the gate to be lifted.
[0017]
Further, a member as a load transmitting means is disposed between the double-structured segment and the gate when the opening is closed, and the jack pressure is received by the gate when the opening is closed through the member.
[0018]
Further, reinforcing members are arranged on both the left and right sides and the top and bottom of the opening. In the upper part of the opening, the double-structured segment plays the role of a reinforcing member until the gate is lifted, but after the gate is lifted, it is at a position inside the shaft that does not contact the gate as a reinforcing member that changes to the removed second segment. The reinforcement beams are connected and connected between the upper portions of the left and right reinforcement members. In this way, by arranging the reinforcing members on the left and right and top and bottom of the opening, it is possible to counter the circumferential force caused by the water pressure and earth pressure applied to the shaft after the shaft is removed after the shaft is set.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
[0020]
1 to 14 are drawings according to an embodiment of the present invention, FIG. 1 is a front view showing a shaft and an opening, FIG. 2 is a cross-sectional view taken along line AA in FIG. 1, and FIG. 4 is a cross-sectional view taken along the line C-C of FIG. 1, FIG. 5 is a cross-sectional view showing the shaft and the opening when the opening is closed by a gate, and FIG. 6 is a reinforcing beam. 7 is a cross-sectional view of the shaft opening when the gate is closed and when the gate is closed, FIG. 7 is a cross-sectional view of the shaft opening after the reinforcement beam is installed and when the gate is lifted (when the opening is opened), and FIG. 1 is a cross-sectional view taken along the line DD of FIG. 1 when the gate is pulled up, FIG. 9 is a partially enlarged view of FIG. 6, FIG. 10 is a partially enlarged view of FIG. FIG. 12 is a front view, FIG. 13 is a sectional view showing a second segment constituting a double-structured segment, and FIG. 14 is a front view. That.
[0021]
Construction of the cylindrical shaft 1 is performed by an urban ring method or the like in which a plurality of steel segments 2 are assembled into a cylindrical shape on the ground, and the assembled segment (ring) 2 is pressed into the basement and set. When the segment 2 is assembled, the opening 3 including the open / close gate 6 is also assembled at the same time. The gate 6 is assembled with the opening 3 closed. Hereinafter, for the sake of explanation, each segment (segment piece) is referred to as segment 2, and the assembled segment ring (earth retaining wall) is referred to as ring 20. Segment 2 is made of steel or concrete. The segment 2 is slightly bent because the shaft 1 is cylindrical.
[0022]
As shown in FIGS. 1, 5, and 7 to 10, the opening 3 arranged in the ring 20 assembled by the plurality of segments 2 includes a quadrangular frame member 4 and a quadrangle provided in the frame member 4. The opening 5 is provided. The opening 5 is made large enough for the shield excavator 30 to pass through. A slit 11 into which the open / close gate 6 can be inserted is provided on the upper portion of the frame member 4, and the gate 6 passes through the slit 11 and is lifted upward.
[0023]
As shown in FIGS. 1, 2, 6, 9, and 11 to 14, the segment immediately above the opening 3 has a double structure including a first segment 21 and a second segment 22. Yes. As shown in FIGS. 11 and 12, the first segment 21 constitutes upper and lower main girders 13 and 13, left and right side plates 14 and 14, a plurality of vertical ribs 15 between the side plates 14 and 14, and an outer peripheral surface of the shaft. It consists of a skin plate 16, and the vertical rib 15 has an angled portion 15 a that is bent into an L shape on the inner side of the shaft. As shown in FIGS. 13 and 14, the second segment 22 includes upper and lower main girders 23 and 23, left and right side plates 24 and 24, and a plurality of vertical ribs 25 between the side plates 24 and 24. The outer side of the shaft is bent in an L shape to form an angle portion 25a. 17 and 27 are bolt holes. The side plates 14 and 24 and the vertical ribs 15 and 25 of the first and second segments have a girder height corresponding to the lifted position of the gate. That is, the first segment 21 is constrained to have a height that does not hinder the pulling of the gate, and the second segment 22 is sized and shaped so that it can be attached to the inside of the first segment 21. The total digit height of the first segment 21 and the second segment 22 is restricted to be equal to or less than the thickness of the frame member 4.
[0024]
The second segment 22 is arranged inside the first segment 21, and the second segment 22 is attached to the first segment 21 by bolt connection through bolt holes provided in the angle portions 15 a and 25 a of the vertical ribs 15 and 25. The double-structured segment composed of the first and second segments 21 and 22 has a height equal to or higher than that of the normal segment 2, that is, a thickness, and thus has such a double structure. When the shaft 1 is set, the reinforcement structure can withstand the jacking pressure at the time of setting as with the normal segment 2.
[0025]
In FIG. 1, the range in which the gate 6 is pulled up is indicated by the symbol H. When the first segment 21 is assembled to the ring 20, the first segment 21 is assembled by adjusting the arrangement position and the girder height so as not to contact the gate 6 when the gate 6 is pulled up. If the second segment 22 is removed from the first segment 21, the raised gate 6 does not contact the first segment 21. The first and second segments 21 and 22 having such a double structure are in a range wider than the range H in which the gate 6 is pulled up, that is, in a range exceeding the height and width of the gate 6 at a portion immediately above the opening 3. If it is not arranged, it becomes an obstacle when the gate 6 is pulled up. Therefore, in the embodiment of FIG. 1, a plurality of pieces, specifically four pieces in the height direction and two pieces in the width direction are arranged in total. . By removing the second segment 22 from the first segment 21, the gate 6 can be pulled up without contacting the first segment after the second segment is removed.
[0026]
Next, reinforcement around the opening will be described.
[0027]
As shown in FIG. 1, reinforcing members 7 and 8 are vertically arranged outside the frame member 4 on both left and right sides of the frame member 4 constituting the opening 3. Further, as shown in FIGS. 1 and 4 to 5, a reinforcing member 9 is horizontally provided on the outer side of the frame member 4 below the frame member 4. The lower reinforcing member 9 is bent with substantially the same curvature as the ring 20. On the other hand, the first and second segments 21 and 22 having the above-described double structure are disposed immediately above the opening 3, but the upper portions of the left and right reinforcing members 9 are disposed above the opening 3. 6-8, the linear reinforcement beam 10 is connected and attached to the position on the inner side of the shaft 1 (ring 20) that does not contact the gate 6. The reinforcing beam 10 reinforces the opening 3 against the circumferential force applied to the ring 20 when the second segment 22 is removed and after removal.
[0028]
Next, means for transmitting the jack pressure to the gate will be described.
[0029]
The opening 3 is assembled with the gate 6 closed when the segment 2 is assembled to the ring 20. As shown in FIGS. 5, 6, and 9, a transmission member 12 is attached to the closed gate 6 as a means for transmitting the jack pressure transmitted to the segment 2 (ring 20). The upper part of the transmission member 12 is attached to the segments 21 and 22 having a double structure, and the lower end thereof is attached in contact with the upper end of the closed gate 6 to fix the gate 6. The transmission member 12 that fixes the gate 6 in this way acts as a member that transmits thrust and vertical axial force to the gate 6 by jack pressure during construction of the shaft 1 (urban ring construction method), thereby opening the opening 3. Has the effect of reinforcing. The transmission member 12 can be removed, and when the gate 6 is pulled up, it is removed as shown in FIGS.
[0030]
[Action]
Next, the starting process of the shield excavator by the starting shaft having the opening reinforcing structure of the present invention will be described.
[0031]
(1) On the ground, a ring 20 having a double-structured segment composed of a first segment 21 and a second segment 22 is assembled immediately above the opening 3. The gate 6 provided in the opening 3 is closed during assembly.
[0032]
{Circle around (2)} The transmission member 12 is attached to the lower part of the double-structured segment composed of the first segment 21 and the second segment 22. The lower end of the transmission member 12 is brought into contact with the upper end of the gate 6 closing the opening 3 to fix the gate 6.
[0033]
(3) The ring 20 is set by the urban ring method. Due to the reinforcement of the double-structured segment comprising the first segment 21 and the second segment 22 and the transmission member 12, the opening 3 strongly opposes the load, water pressure, and earth pressure caused by the jacking pressure when set. After installation, an entrance metal frame 29 having an entrance packing 28 is attached inside the opening 3. Next, the reinforcing beam 10 is connected and attached to the upper portion of the opening 3 between the reinforcing members 7 and 8.
[0034]
(5) Next, the second segment 22 bolted to the transmission member 12 and the first segment 21 is removed from the first segment 21 by removing the bolt. Even after the second segment 22 is removed, the upper part of the opening 3 reinforces the opening 3 against the circumferential force caused by the water pressure and earth pressure applied to the ring 20 after removal due to the action of the reinforcing beam 10. .
[0035]
(6) Mount the shield excavator 30 on the entrance metal frame 29. Next, the gate 6 is lifted by a chain block (not shown) or the like, and the shield excavator 30 is started.
[0036]
【The invention's effect】
As described above, according to the present invention, the following useful effects are brought about.
[0037]
(1) A double-structured segment is placed immediately above the opening, and the opening is reinforced by the double-structured segment for temporary loads caused by jacking pressure during installation by the urban ring method. Since the second segment can be removed and the gate can be lifted when the shield excavator starts later, the opening can be effectively reinforced without impairing the work efficiency.
[0038]
(2) Since the left and right and upper and lower sides of the opening are reinforced by reinforcing members and beams, the load on the gate only needs to be taken into consideration, so the load on the gate is reduced and the gate thickness is reduced. Can be made thinner.
[0039]
(3) Since the transmission means for transmitting the load applied to the segment of the double structure to the gate is provided, jack thrust and vertical axial force at the time of setting can be received by the gate.
[Brief description of the drawings]
FIG. 1 is a front view showing a shaft and an opening in a state where the opening is closed by a gate according to an embodiment of the present invention.
2 is a cross-sectional view taken along line AA of FIG. 1 before an opening is closed by a gate according to an embodiment of the present invention and a reinforcing beam is installed.
3 is a cross-sectional view taken along line BB in FIG. 1 according to the embodiment of the present invention.
4 is a cross-sectional view taken along line CC of FIG. 1 according to the embodiment of the present invention.
FIG. 5 is a sectional view showing a shaft and an opening in a state where the opening is closed by a gate according to an embodiment of the present invention.
FIG. 6 is a cross-sectional view showing the shaft and the opening after the opening is closed and the reinforcing beam is installed by the gate according to the embodiment of the present invention.
FIG. 7 is a cross-sectional view showing the shaft and the opening when the reinforcing beam according to the embodiment of the present invention is installed and when the gate is lifted.
8 is a cross-sectional view taken along the line DD of FIG. 1 after the reinforcing beam according to the embodiment of the present invention is installed and when the gate is lifted.
9 is a partially enlarged view of FIG. 6 according to the embodiment of the present invention.
10 is a partially enlarged view of FIG. 7 according to the embodiment of the present invention.
FIG. 11 is a cross-sectional view showing a first segment constituting a double-structured segment according to an embodiment of the present invention.
12 is a front view of FIG. 11 according to the embodiment of the present invention.
FIG. 13 is a cross-sectional view showing a second segment constituting a double-structured segment according to the embodiment of the present invention.
14 is a front view of FIG. 13 according to the embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Vertical shaft 2 Segment 3 Opening part 4 Frame material 5 Opening 6 Gate 7, 8, 9 Opening part reinforcement member 10 Reinforcement beam 11 Slit 12 Transmission member 13 Main beam 14 Side plate 15 Vertical rib 16 Skin plate 17 Bolt hole 20 Ring 21 1st Segment 22 Second segment 23 Main girder 24 Side plate 25 Vertical rib 27 Bolt hole 28 Entrance packing 29 Entrance metal frame 30 Shield excavator

Claims (4)

  In the reinforcement structure of the opening in the shaft where the plurality of segments are assembled by arranging the opening provided with the gate, and the assembled segment is press-fitted into the ground, the segment immediately above the opening is The first segment arranged so as not to contact the gate and the reinforcing second segment arranged so as to overlap the first segment has a double structure, and the second segment includes the first segment A structure for reinforcing a shaft opening, wherein the structure is removably attached to one segment. The reinforcement structure of the shaft opening part of Claim 1 by which the reinforcement member was arrange | positioned at the left-right both sides and the lower part of the said opening part. Reinforcing members are disposed on both the left and right sides and the lower part of the opening, and further, a reinforcing beam for reinforcing the upper part of the opening after the second segment is removed is provided on the opening. coupled between the top of the left and right sides of the reinforcing member parts, the reinforcing structure of the vertical shaft opening according to claim 1 which is mounted so as not to contact with the gate. And a transmission means for transmitting a load applied to the segment when the shaft is set up to the gate closing the opening, wherein the transmission means closes the double segment and the gate. The reinforcement structure of the shaft opening part in any one of Claims 1 thru | or 3 arrange | positioned interposing between.

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