JP3794869B2 - Inserting elements for building underground structures into natural ground - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for inserting an underground structure building element into a natural ground, and more particularly to a method for inserting an element when building an underground structure below a railway track or road using a lining element. .
[0002]
[Prior art]
One of the methods for constructing underground structures that cross three-dimensionally below railroad tracks and roads is the URT (Under Railway / Road Tunnel) method, in which a large number of long steel elements are inserted into the ground and covered. Are known.
[0003]
As shown in FIG. 1, this construction method includes a large number of long lining elements 2, 3 arranged in parallel by traction or propulsion so as to divide the cross section of the structure into the natural ground below the track 1. After laying concrete into the element and constructing the lining wall 4, excavating the ground inside the lining wall 4, the lining wall 4 is structured like a box-shaped ramen or circular This is a construction method.
[0004]
As a lining element used in such a construction method, a reference lining element having a rectangular cross section and a U-shaped connecting lining element that is sequentially connected to the side portion thereof, and all joints between the elements are connected. The applicant has already proposed a construction method that can be connected in a strong state (Japanese Patent Application No. 10-289120, Japanese Patent Application No. 10-360333).
[0005]
These reference lining elements and connection lining elements are both made of steel, and their structures are shown in FIGS. That is, as shown in FIG. 2, the reference lining element 2 is formed into a quadrangular section by four plates 5, and a substantially C-shaped joint 6 is provided along the longitudinal direction at each corner. .
[0006]
Further, as shown in FIG. 3, the connecting lining element 3 is formed in a U-shaped cross section by three plates 7 and 8, and joints 9 and 10 are provided at each corner and the open end of the plate 7. Each is provided along the longitudinal direction. The reference lining element 2 is first inserted into the ground, and then the connecting lining element 3 is inserted into the ground on both sides of the reference lining element 2.
[0007]
At that time, as shown in FIG. 4 only on one side, the connecting lining element 3 is inserted into the natural ground while fitting the joint 10 on the open side to the joint 6 of the reference lining element 2. A connecting lining element 3 is inserted into the natural ground in parallel with the connecting lining element 3 previously inserted in the natural ground. The joint 10 is inserted into the ground while being fitted to the joint 9 on the corner portion side of the preceding connecting lining element. In this way, the connecting lining elements 3 are sequentially inserted into the ground, and the lining wall 4 as shown in FIG. 1 is constructed.
[0008]
The joints 6, 9 and 10 are all made of steel, and as shown in an enlarged view in FIG. 5, are provided with a base portion 11, an inclined plate-like portion 12 and a curved portion 13 respectively extending from the base portion 11, A bulging portion 14 is formed at the tip of the shape portion 12. The fitting groove 15 into which the joints are fitted is defined in a substantially C shape by the inner surfaces of the plate-like part 12 and the curved part 13, and the bulging part 14 of one joint is fitted in the fitting groove 15 of the other joint. By joining, both joints are connected.
[0009]
When the lining wall 4 composed of the lining element having such a joint is used as the main body structure, the tensile force generated in the member is transmitted by the joint between the elements, so the joint portion needs to have sufficient strength. To do. For this reason, there is sufficient play at the time of mating, but after the mating is completed, it is fixed by injecting grout into the gap to bear the tensile force.
[0010]
By the way, when foreign elements such as earth and sand are caught in the fitting groove 15 when the element is inserted into the ground or when this leaks out during the grouting, the grouting is incomplete and the joint exhibits sufficient strength. I can't. For this reason, conventionally, a countermeasure as shown in FIG. 9 is taken. That is, as shown in FIG. 9 (a), the steel plate 51 (welded to the base 11) is welded to the base 11 outer surface (surface exposed to the ground) of the joints 6 and 9 of the elements that are inserted into the ground previously. ) To fix the end of the leaf spring 52. The leaf spring 52 is bent and covers the inlet portion of the fitting groove 15.
[0011]
And as shown in FIG.9 (b), the part exposed to the starting shaft of the leaf | plate spring 52 at the time of insertion to the natural ground of the element to follow is expanded, and the joint 10 of the element to follow is in that state. It is fitted into joints 6 and 9 of the preceding element and inserted into the ground.
[0012]
However, the conventional countermeasure has a problem that the leaf spring 52 is deformed or damaged when the subsequent element is inserted into the ground. As a result, the earth and sand etc. entered the gap 53 between the fitted joints 6, 9 and the joint 10, or the injected grout leaked. The cause is that when the joint is fitted, the portion inserted in the ground of the leaf spring 52 is lifted and fitted, so if the formation is hard or there is gravel, the leaf spring 52 However, it is conceivable that the plate spring 52 is not opened sufficiently but is broken in the lateral direction at that portion, and as a result, the leaf spring 52 is fitted without being opened and twisted into the joint.
[0013]
Furthermore, when the cause is seen about the leaf | plate spring 52 itself, it is thought that it originates in insufficient intensity | strength and a width | variety being too large. However, in the conventional countermeasures, as described above, the leaf spring is expected to have two effects of preventing the inflow of earth and sand into the joint portion when the element is inserted and preventing the leakage of grout after the joint is fitted. The width cannot be reduced, and the plate thickness cannot be increased too much in order to increase the strength.
[0014]
[Problems to be solved by the invention]
The present invention has been made based on the technical background as described above, and achieves the following object.
An object of the present invention is to provide a method for inserting an element for constructing an underground structure into a natural ground, which can prevent sediment and the like from flowing into the joint when the element is inserted, and can develop sufficient strength at the joint. There is.
[0015]
Another object of the present invention is to provide a method for inserting an underground structure building element into a natural ground that can prevent leakage of grout injected together.
[0016]
[Means for Solving the Problems]
The present invention employs the following means in order to achieve the above object.
That is, according to the present invention, in constructing an underground structure, a large number of long lining elements having substantially C-shaped joints along the longitudinal direction are arranged in parallel while fitting the joints between adjacent ones. It is a method of inserting into the natural ground,
The joint includes a base portion, an inclined plate-like portion and a curved portion, each extending from the base portion and having a bulging portion formed at a tip thereof, and a fitting groove into which the joints are fitted includes the inclined plate-like portion and the It is defined in a substantially C shape by the inner surface with the curved portion, and the two joints are fitted to each other by fitting the bulging portion of one joint into the fitting groove of the other joint,
Among the joints of the lining element inserted in advance of the ground, the fitting groove is closed to the joint to be fitted to the joint of the lining element to be inserted into the ground after the following. As a closing member , a dummy joint having a shape similar to the joint is fitted in advance , each having a portion corresponding to the inclined plate-like portion and the curved portion of the joint ,
The joint of the preceding lining element is provided with a shielding plate having one end fixed to the base of the joint and the other end abutting against the outer surface of the curved joint corresponding part of the dummy joint.
With the insertion into the natural ground of the trailing lining elements, extruding said dummy fitting by its joint, and replace the fitting of the rear row lining element with said dummy joint, rear the shielding plate by the substitution In the method of inserting an underground structure building element into a natural ground, the outer lining element joint is brought into contact with the outer surface of the curved portion .
[0017]
According to this invention, since the closing member is fitted in the joint of the preceding lining element in advance, earth and sand do not flow into the joint when the preceding lining element is inserted into the ground, and the rear When the row lining element is inserted into the ground, the blocking member is pushed out and replaced with the joint of the succeeding lining element, so that earth and sand do not flow into the joint even when the joint is fitted.
[0018]
On the outer surface of the joint of the preceding lining element, a shielding plate for shielding a gap between the joints fitted to each other is provided. The blockage member prevents the earth and sand from flowing into the joint. Therefore, the shielding plate only needs to have a function of preventing leakage of grout injected after fitting, so that the width of the shielding plate can be reduced so that it can be easily spread and the thickness of the shielding plate can be reduced. Can be increased to have sufficient strength.
[0019]
The closing member can be a shape that simply closes the fitting groove of the joint, or a dummy joint with a fitting portion similar in shape to the joint. In the former case, the shielding plate is a leaf spring similar to the conventional one. Can be configured. In the latter case, since the shape of the shielding plate is held by the dummy joint, positive springiness is not necessary, and therefore a steel plate or the like can be used.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. In constructing the underground structure, the reference lining element 2 and the connecting lining element 3 as shown in FIGS. 2 and 3 can be used as the lining elements. Then, as described with reference to FIG. 4, while fitting the joints 6 and 10 and the joints 9 and 10 of adjacent elements, these elements are juxtaposed and sequentially inserted into the ground, as shown in FIG. Build a subterranean structure. The above points are the same as in the prior art.
[0021]
As shown in FIG. 6A as a reference example , a closing member 20 is fitted in advance to the joints 6 and 9 of the elements 2 and 3 that are inserted into the natural ground in advance. The closing member 20 includes a protrusion 21 that fits in the fitting groove 15 of the joints 6 and 9, and a lid portion 22, and is made of a resin material such as acetal. Further, a steel plate 23 is fixed to the outer surface of the base 11 of the joints 6 and 9 by welding, and an end of a leaf spring 24 that is a shielding plate is sandwiched and fixed between the steel plate 23 and the base 11. The other end of the leaf spring 24 is in pressure contact with the outer end of the bulging portion 14.
[0022]
When the trailing lining element 3 is inserted into the natural ground, the portion of the leaf spring 24 in the starting shaft is expanded and, as shown in FIG. 6B, the joint 10 of the trailing lining element 3 is used. The closing member 20 is pushed out to the reach shaft side, and the closing member 20 and the joint 10 are replaced. The extruded blocking member 20 can be reused.
[0023]
Thus, since the preceding elements 2 and 3 are inserted into the natural ground in the state in which the joints 6 and 9 are closed by the closing member 20, earth and sand do not flow into the joint. Further, grout is injected into the gap 25 between the joints 6 and 9 and the joint 10 fitted to each other. However, the gap 25 is shielded by the leaf spring 24, so that the grout does not leak. And since this leaf | plate spring 24 should have only a function for the leakage prevention of grout, it can reduce the width | variety and can enlarge plate | board thickness, Therefore, intensity | strength increases and it can prevent a fracture | rupture.
[0024]
In addition, the anti-corrosion liner 26 is affixed on the outer surface of the bending part 13 of the joint 10 of the element 3 to follow. Since the outer surface of the curved portion 13 is in contact with the earth and sand, rust is generated, and therefore it is necessary to consider rust allowance. However, since the joint 10 (the same applies to the other joints 6 and 9) is made by roll processing, the wall thickness cannot be increased.
[0025]
Therefore, corrosion can be prevented by sticking the rust preventive liner 26 to the outer surface of the curved portion 13. This rust-proof liner can be made of, for example, FRP, and its thickness is about several mm. The rust preventive liner 26 may be pasted at least in a thickness range where the rust allowance of the curved portion 13 cannot be expected. Although the antirust liner 26 is also shown in FIG. 5, the joints 6 and 9 are not necessary.
[0026]
FIG. 7 shows an embodiment of the present invention . In this embodiment, as shown in FIG. 7A, a dummy joint 27 is used as a closing member. This dummy joint 27 is also made of a resin material such as acetal. The dummy joint 27 has a portion 28 corresponding to the plate-like portion 12 of the joints 6, 9, 10 and a portion 29 corresponding to the curved portion 13, and the fitting portion including these portions 28, 29 is the joint 6. , 9 and 10.
[0027]
As in the case of the closing member 20 described above, the dummy joint 27 is also moved to the reach shaft side by the joint 10 as shown in FIG. 7B when the following lining element 3 is inserted into the ground. The dummy joint 27 and the joint 10 are replaced by being pushed out. The extruded dummy joint 27 can be reused.
[0028]
In this embodiment, the shielding plate is not a leaf spring but a steel plate 30. One end of the steel plate 30 is fixed to the base 11 of the joints 6 and 9 by welding, and the other end is in contact with the portion 29 of the dummy joint 27. Therefore, the shape of the steel plate 30 is maintained by the dummy joint 27, and when the subsequent element 3 is inserted into the ground, an operation of spreading the steel plate 30 is unnecessary.
[0029]
FIG. 8 shows still another embodiment. In this embodiment, the width of the steel plate 30 is somewhat increased and the bent portion 31 is provided. By doing so, leakage of grout injected into the gap 25 can be completely prevented.
[0030]
Each of the above embodiments is merely an example, and the elements and joints used can take various forms.
[0031]
【The invention's effect】
According to this invention, it is possible to prevent earth and sand from flowing into the joint portion when the element is inserted, and it is possible to prevent leakage of the injected grout, so that sufficient strength can be expressed in the joint portion. Can do.
[Brief description of the drawings]
FIG. 1 is a front view showing an entire underground structure.
FIG. 2 is a front view showing an example of an element to be used.
FIG. 3 is a front view showing an example of an element to be used.
FIG. 4 is a diagram showing elements joined by fitting of a joint.
FIG. 5 is an enlarged view showing a joint.
FIG. 6 is a diagram showing a reference example of the present invention.
FIG. 7 is a diagram showing an embodiment of the present invention .
FIG. 8 is a diagram showing still another embodiment.
FIG. 9 is a diagram illustrating a conventional example.

Claims (2)

When constructing an underground structure, a large number of elongate lining elements having substantially C-shaped joints along the longitudinal direction are inserted in parallel while the adjacent joints are fitted together. A method,
The joint includes a base portion, an inclined plate-like portion and a curved portion, each extending from the base portion and having a bulging portion formed at a tip thereof, and a fitting groove into which the joints are fitted includes the inclined plate-like portion and the It is defined in a substantially C shape by the inner surface with the curved portion, and the two joints are fitted to each other by fitting the bulging portion of one joint into the fitting groove of the other joint,
Among the joints of the lining element inserted in advance of the ground, the fitting groove is closed to the joint to be fitted to the joint of the lining element to be inserted into the ground after the following. As a closing member , a dummy joint having a shape similar to the joint is fitted in advance , each having a portion corresponding to the inclined plate-like portion and the curved portion of the joint ,
The joint of the preceding lining element is provided with a shielding plate having one end fixed to the base of the joint and the other end abutting against the outer surface of the curved joint corresponding part of the dummy joint.
With the insertion into the natural ground of the trailing lining elements, extruding said dummy fitting by its joint, and replace the fitting of the rear row lining element with said dummy joint, rear the shielding plate by the substitution A method for inserting an element for constructing an underground structure into a natural ground, wherein the joint of a row lining element is brought into contact with the outer surface of the curved portion . The said shielding board consists of steel plates, The insertion method to the natural ground of the element for underground structure construction of Claim 1 characterized by the above-mentioned.

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