JP2004204583A - Bracket for mounting invert - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bracket for mounting an invert making it possible to stably and durably install a floor slab-shaped invert segment on the bottom of an arcuate segment. <P>SOLUTION: A plurality of arcuate segments 11 are laid to form a ring and brackets 12, 12 for mounting the invert are fixed to the inner peripheral face of respective arcuate segments 11, 11 located in the lower right and left parts, The floor slab-shaped invert segments 13 are put over in between the brackets 12, 12 for mounting the invert. The bracket 12 for mounting the invert is provided with an arcuate circular plate part 26 fixed to the inner peripheral face of the arcuate segment 11 and a support base 27 supporting the floor slab-shaped invert segment 13. The arcuate plate part 26 and the support base 27 are integrally precast by ultra-high strength mortar or concrete having a special composition. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an invert mounting bracket for mounting a floor plate-like invert segment.
[0002]
[Prior art]
In shield tunnels, concrete segments are often employed along the excavation holes behind the excavation of the shield excavator.
[0003]
That is, an arc-shaped concrete segment 1 as shown in FIG. 6 is lining along an excavation hole (not shown), and at the bottom of this concrete segment 1, at the time of temporary construction, an H-shape is used as a sleeper for laying a track. Temporary materials such as steel or square steel are used, and in the final form, it is common that the temporary materials are removed and in-place concrete inverts 2 are constructed.
[0004]
In recent years, from the viewpoint of cost reduction, speeding up and lengthening of tunnel construction have been progressing, and there has been a problem that a time required for removing temporary materials and a time required for jointing time relating to the quality of cast-in-place concrete are prolonged.
[0005]
On the other hand, there is one in which a precast-formed invert segment is installed at the bottom of an arc-shaped concrete segment, that is, an arch segment, to simplify installation of temporary track equipment such as rails and sleepers (for example, Patent Document 1). , Patent Document 2).
[0006]
[Patent Document 1]
JP-A-2002-13394 (page 3-4, FIG. 1-7)
[0007]
[Patent Document 2]
JP-A-2002-47898 (page 4-5, FIG. 1-8)
[0008]
[Problems to be solved by the invention]
Since the invert segment is formed into a D-shaped cross-section so as to fill the bottom of the arch segment, it is heavy and not easy to handle, and the transport means for transporting and lifting these segments is also large. is there.
[0009]
On the other hand, if the invert segment having the D-shaped cross section is formed into a floor plate shape, the weight can be reduced. However, in order to stably install the floor plate invert segment at the bottom of the arcuate arch segment, it is necessary to interpose the invert segment between them. A mounting bracket is required, and since this type of mounting bracket is usually made of steel from the viewpoint of strength, there is a durability problem that the mounting bracket is easily corroded by seawater in the case of a submarine tunnel or the like. .
[0010]
The present invention has been made in view of such a point, and an object of the present invention is to provide an invert mounting bracket capable of stably and durably installing a floor plate-shaped invert segment at the bottom of an arc-shaped segment. Things.
[0011]
[Means for Solving the Problems]
The invention described in claim 1 is an arc-shaped surface plate portion fixed to the inner peripheral surface of an arc-shaped segment lining along the excavation hole of the shield tunnel, and circles located on the lower left and right portions of the excavation hole. A support base for supporting the floor plate-shaped invert segment installed over the arc-shaped segments, wherein the arc-shaped face plate and the support base are cement, aggregate particles having a maximum particle size of 2 mm or less, and primary particles. Pozzolanic reaction particles having a particle size of 1 μm or less, needle-like or flaky particles having an average particle size of 1 mm or less, a premix material containing at least one dispersant, water and metal fibers are mixed, and cement and pozzolanic particles are mixed. The mass ratio of water to the total mass of the reaction particles is in the range of 8 to 24%, the length of the metal fiber is 2 mm or more, the ratio of the length to the diameter of the metal fiber is 20 or more, and the aggregate particles Invert installation integrally precast with a composition satisfying the condition that the ratio of the average length of the metal fibers to the maximum particle size is 10 or more and the amount of the metal fibers is less than 4% of the concrete volume after setting. It is a bracket for, the arc-shaped face plate portion fixed to the inner peripheral surface of the arc-shaped segment and the support base portion for supporting the floor plate-shaped invert segment are precast molded integrally with the composition, so that the arc-shaped segment Therefore, the floor plate-like invert segment can be installed stably, and since the invert mounting bracket is made of mortar or concrete instead of steel, in order to prevent corrosion against seawater when durability is required in a submarine tunnel or the like, It is valid. In addition, since a high-strength and dense invert mounting bracket is formed from the composition, the thickness of the member such as the arc-shaped face plate portion can be reduced, the weight can be reduced, and the lifting capacity during construction can be reduced. The efficiency of tunnel invert installation work can be improved.
[0012]
According to a second aspect of the present invention, the composition for the invert mounting bracket according to the first aspect further includes a quartz powder having an average particle diameter of 3 to 20 μm, and is manufactured using the composition including the quartz powder. The inverted mounting bracket can be further densified, and the durability can be improved.
[0013]
According to a third aspect of the present invention, there is provided the invert mounting bracket according to the first or second aspect, wherein the arc-shaped face plate portion has an elongated mounting hole elongated in an arc direction, and the bolt inserted into the elongated mounting hole. The mounting slot is formed in the arc-shaped face plate of the invert mounting bracket in the direction of the arc even if a mounting error in the rolling direction occurs when the arc-shaped segment is installed. Thereby, the mounting error of the arc-shaped segment in the rolling direction can be absorbed, and the mounting error can be dealt with.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail with reference to one embodiment shown in FIGS.
[0015]
As shown in FIG. 1, a plurality of arc-shaped segments 11 are covered in a ring shape along an excavation hole (not shown) of the shield tunnel, and each arc-shaped segment located on the lower left and right portions of the excavation hole among them. Inverting brackets 12, 12 are fixed to the inner peripheral surfaces of the segments 11, 11, respectively. A floor plate-like inverting segment 13 is installed between the inverting brackets 12, 12, respectively.
[0016]
The arc segment 11, the invert mounting bracket 12, and the floor plate invert segment 13 are precast products made of mortar or concrete with reinforcing bars.
[0017]
In particular, the invert mounting bracket 12 is made of cement, aggregate particles having a maximum particle size of 2 mm or less, pozzolan-based reaction particles having a primary particle size of 1 μm or less, and needle-like or flaky particles having an average particle size of 1 mm or less. A premix material containing a dispersant, water and metal fibers are mixed, and the mass ratio of water to the total mass of cement and pozzolanic reaction particles is in the range of 8 to 24%; 2 mm or more, the ratio of the length to the diameter of the metal fiber is 20 or more, the ratio of the average length of the metal fiber to the maximum particle size of the aggregate particles is 10 or more, and the amount of the metal fiber is the concrete volume after setting. Is a precast product with a composition that satisfies the condition of being less than 4% (e.g., trademark registration No. 4294262 "Dactal").
[0018]
Mortar or concrete products precast with this composition have a bending strength of 25 MPa or more and a compressive strength of 150 MPa or more.
[0019]
Furthermore, by including quartz powder having an average particle size of 3 to 20 μm in the composition, the mortar or concrete product can be further densified, and the durability can be improved.
[0020]
As shown in FIG. 2, a washer fitting recess 14 and a bolt insertion hole 15 were formed in the floor plate-like invert segment 13, and the floor plate-like invert segment 13 was inserted into the bolt insertion hole 15 through a washer 16 engaged with the washer fitting recess 14. The floor plate-shaped invert segment 13 is fixed to the invert mounting bracket 12 by screwing the tip of the bolt 17 into an insert 18 embedded in the upper surface of the invert mounting bracket 12.
[0021]
On the left and right ends of the floor plate-like invert segment 13, slanting downward inclined surfaces 19 are formed so as to be substantially parallel to the inner peripheral surface of the arc-shaped segment 11.
[0022]
A track 22 for carrying in the segment is laid on the upper surface of the floor plate-shaped invert segment 13 via a buffer plate 21 made of hard rubber or the like. The track 22 is fixed to the upper surface of the floor plate-shaped invert segment 13 by a holding member 23 screwed.
[0023]
Then, as the shield excavator (not shown) excavates, it is necessary to sequentially construct the floor plate-shaped invert segment 13 behind the excavation part via the arc-shaped segment 11 and the invert mounting bracket 12. These precast products are carried in from the entrance of the shield tunnel by a transport device (not shown) such as a trolley moving on the track 22.
[0024]
As shown in FIGS. 2 to 4, the invert mounting bracket 12 is provided with an arc-shaped face plate fixed to the inner peripheral surface of an arc-shaped segment 11 lining along an excavation hole (not shown) of the shield tunnel. Part 26 and a support base 27 for supporting a floor plate-shaped invert segment 13 which is installed to be bridged between the arc-shaped segments 11 and 11 located on the lower left and right parts of the excavation hole. The part 26 and the support base 27 are integrally precast by the ultrahigh strength mortar or concrete.
[0025]
As shown in FIGS. 3 and 4, the arcuate face plate portion 26 of the invert mounting bracket 12 has a mounting elongated hole formed in the arc direction at locations located on both sides of the support base portion 27 as shown in FIGS. Each of the bolts 29 inserted into these elongated mounting holes 28 is screwed into an insert 31 embedded in the inner peripheral surface of the arc segment 11 as shown in FIG. Fixed to segment 11.
[0026]
The upper and lower portions of the arc-shaped face plate portion 26 project obliquely upward and obliquely downward from the support base 27, and the upper projecting portion 32 has an inclined portion of the floor plate-like invert segment 13 as shown in FIG. By engaging with the surface portion 19, the floor plate-shaped invert segment 13 is positioned, and functions as a spacer for preventing contact interference between the floor plate-shaped invert segment 13 and the arc-shaped segment 11.
[0027]
The support base 27 of the invert mounting bracket 12 has a substantially triangular cross-section as shown in FIG. 2, and its upper surface is formed in a horizontal plane, and as shown in FIG. The insert 18 for mounting the floor plate-shaped invert segment 13 with the bolt 17 is embedded in the portion.
[0028]
Next, the operation and effect of this embodiment will be described.
[0029]
As a shield excavator (not shown) excavates, the arc-shaped segment 11, the invert mounting bracket 12, and the floor plate-shaped invert segment 13 which are precast products are carried in behind the excavation part, and as shown in FIG. A ring-shaped shield tunnel structure is formed by a plurality of arc-shaped segments 11, and an invert mounting bracket 12 is installed on each of the lower left and right portions of the shield tunnel structure, and via these invert mounting brackets 12, Then, floor plate-like invert segments 13 are sequentially laid at the bottom of the shield tunnel structure.
[0030]
That is, as shown in the lower part of FIG. 5, the bolts 29 inserted into the mounting elongated holes 28 form the left and right sides of the inner peripheral surfaces of the arc-shaped segments 11, 11 located on the lower left and right portions of the excavation hole. Each of the invert mounting brackets 12 and 12 is fixed, and further, as shown in the center of FIG. 5, a floor plate-like invert segment 13 is bridged between the left and right invert mounting brackets 12 and 12 and The floor plate-like invert segments 13 are laid down and set by the bolts 17 inserted from the washer fitting recesses 14 and the bolt insertion holes 15, and furthermore, as shown in the upper part of FIG. The two sets of tracks 22 fixed by the presser fittings 23 are respectively set and mounted.
[0031]
The invert mounting bracket 12 has an arc-shaped surface plate portion 26 fixed to the inner peripheral surface of the arc-shaped segment 11 and a support base portion 27 for supporting the floor plate-shaped invert segment 13. The floor plate-shaped invert segment 13 can be stably installed on the arc-shaped segment 11 using the invert mounting bracket 12.
[0032]
Further, like the arc-shaped segment 11 and the floor plate-shaped invert segment 13, the invert mounting bracket 12 is made of mortar or concrete instead of steel, so that the seawater when durability is required in an undersea tunnel or the like. It is effective in preventing corrosion.
[0033]
In particular, since the invert mounting bracket 12 is made of ultra-high strength mortar or concrete and is densely formed with high strength, it is possible to reduce the thickness of the arc-shaped face plate 26 and other members, thereby achieving weight reduction and crane work during construction. The lifting capacity of the machine can be reduced, so that the invert installation work of the long tunnel can be made more efficient and the crane working machine can be downsized.
[0034]
Further, even if a mounting error occurs in the rolling direction, that is, the arc direction when the arc segment 11 is installed, the mounting elongated hole 28 provided in the arc-shaped face plate portion 26 of the invert mounting bracket 12 is formed to be elongated in the arc direction. Since the mounting error of the arc-shaped segment 11 is within the range of the mounting elongated hole 28, the mounting error of the arc-shaped segment 11 can be absorbed by the mounting elongated hole 28 of the invert mounting bracket 12, The mounting error can be dealt with.
[0035]
Specifically, even when the left and right inserts 31 provided on the left and right arc-shaped segments 11 are located at different heights due to the mounting error in the rolling direction, the left and right invert mounting brackets are Since the 12 can be installed at the same height, the floor plate-shaped invert segment 13 can be installed horizontally.
[0036]
In this way, using the precast mortar or concrete product that can be commonly used at the time of temporary and permanent construction, the invert mounting bracket 12 is installed on the arc-shaped segment 11 in accordance with the excavation of the shield tunnel, and the invert mounting is performed. The floor plate-shaped invert segment 13 and the track 22 can be sequentially set and set via the bracket 12 for use.
[0037]
【The invention's effect】
According to the first aspect of the present invention, since the arc-shaped face plate portion fixed to the inner peripheral surface of the arc-shaped segment and the support base portion for supporting the floor plate-shaped invert segment are integrally formed by precasting, the arc-shaped segment is formed. On the other hand, the floor plate-like invert segment can be installed stably and the bracket for mounting the invert is made of mortar or concrete instead of steel. ,It is valid. Moreover, the arc-shaped face plate portion and the support base portion are made of cement, aggregate particles having a maximum particle size of 2 mm or less, pozzolan-based reaction particles having a primary particle size of 1 μm or less, needle-like or flaky particles having an average particle size of 1 mm or less, A premix material containing at least one dispersant, water and metal fibers are mixed, and the mass ratio of water to the total mass of cement and pozzolanic reaction particles is in the range of 8 to 24%; The length is 2 mm or more, the ratio of the length to the diameter of the metal fiber is 20 or more, the ratio of the average length of the metal fiber to the maximum particle size of the aggregate particles is 10 or more, and the amount of the metal fiber is A high strength and dense bracket for invert mounting was molded with a composition that satisfies the condition that the volume is less than 4% of the concrete volume of the concrete. With attained the capacity, it can reduce the lifting capacity during construction, thereby the efficiency of the inverter installation work of long tunnels.
[0038]
According to the second aspect of the present invention, since the composition further includes quartz powder having an average particle size of 3 to 20 μm, the invert mounting bracket made of the composition containing the quartz powder has a higher density. And durability can be improved.
[0039]
According to the third aspect of the present invention, even if a mounting error occurs in the rolling direction when the arc-shaped segment is installed, the mounting long hole formed in the arc-shaped face plate portion of the invert mounting bracket is elongated in the arc direction. The mounting error in the rolling direction of the arc-shaped segment can be absorbed, and the mounting error can be dealt with.
[Brief description of the drawings]
FIG. 1 is a front view showing an embodiment of a shield tunnel structure in which a floor plate-shaped invert segment is installed on an arc-shaped segment via an invert mounting bracket according to the present invention.
FIG. 2 is an enlarged cross-sectional view of an installation location of an invert mounting bracket according to the first embodiment.
FIG. 3 is a front view of the invert mounting bracket according to the first embodiment;
FIG. 4 is a side view of a partially cutout of the invert mounting bracket.
FIG. 5 is a plan sectional view of a shield tunnel structure in which a floor plate-shaped invert segment is installed on an arc-shaped segment via the invert mounting bracket.
FIG. 6 is a sectional view showing an example of laying a track in a conventional shield tunnel.
[Explanation of symbols]
11 Arc segment
12 Invert mounting bracket
13 Floor plate invert segment
26 Arc-shaped face plate
27 Support base
28 Mounting slot
29 volt

Claims (3)

An arc-shaped face plate fixed to the inner peripheral surface of the arc-shaped segment lining along the excavation hole of the shield tunnel,
A support base for supporting a floor-plate-shaped invert segment that is installed so as to span between arc-shaped segments located on the lower left and right portions of the excavation hole,
The arc-shaped face plate and support base are
Premix material containing cement, aggregate particles having a maximum particle size of 2 mm or less, pozzolanic reaction particles having a primary particle size of 1 μm or less, needle-like or flaky particles having an average particle size of 1 mm or less, and at least one dispersant. , Water and metal fibers are mixed, and the mass ratio of water to the total mass of cement and pozzolanic reaction particles is in the range of 8 to 24%, the length of the metal fibers is 2 mm or more, and the The condition that the length ratio is 20 or more, the ratio of the average length of the metal fiber to the maximum particle size of the aggregate particles is 10 or more, and the amount of the metal fiber is less than 4% of the concrete volume after setting. A bracket for mounting an invert, wherein the bracket is integrally precast with a composition satisfying the following. The invert mounting bracket according to claim 1, wherein the composition contains quartz powder having an average particle diameter of 3 to 20 µm. The arc-shaped face plate portion has an elongated mounting hole formed elongated in the arc direction,
3. The bracket for mounting an invert according to claim 1, wherein the bracket is fixed to the arc-shaped segment by a bolt inserted into the mounting slot.

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