JP2821556B2 - Underground diaphragm wall for shield excavation - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shield excavation underground continuous wall having a starting and reaching part for starting or reaching a shield excavator for excavating underground, and more particularly to an improvement of the starting and reaching part. is there.

[0002]

2. Description of the Related Art As a conventional shield excavation underground continuous wall, for example, as shown in FIG. 8, an underground continuous wall 100 made of reinforced concrete is constructed underground, and a shield excavator 17 of the underground continuous wall 100 is used. The ground improvement is performed on the back side 101 of the starting part or the reaching part 102 to prevent groundwater spouting, and the reinforced concrete of the starting reaching part 103 is manually excavated before the shield excavator 17 is started or reached. Met.

On the other hand, as shown in FIGS. 9A and 9B,
A rope-shaped or rod-shaped fiber reinforcing material (not shown) made of carbon fiber and synthetic resin is embedded in concrete, and a large number of fiber-reinforced concrete members 104 that can be excavated by the shield excavator 17 are prepared. The member 104 is connected to a long steel material 105 such as an H-section steel,
An underground continuous wall component 106 used for the starting and reaching portion 103 of the underground continuous wall 100 is formed. Then, the underground continuous wall constituting member 106 is arranged such that the fiber reinforced concrete member 104 is aligned with the opening of the starting and reaching portion 103 (Japanese Patent Laid-Open No. 5-302490).

[0004] In a shaft for a shield method constructed for excavating a tunnel using a shield excavator, at least the structure of a wall portion of the shaft through which the shield excavator passes is made of carbon fiber, glass fiber or aramid fiber. A shaft for a shield construction method of a concrete structure using a reinforcing bar-like reinforcing material obtained by impregnating either of them with a resin is known (Japanese Patent Laid-Open No. 2-176093).

Further, a rod, plate, L-shaped, T-shaped, groove-shaped segment in which any one of carbon fiber, glass fiber, aramid fiber, or vinylon is impregnated with a resin for a segment constituting a wall portion of the tunnel. , Cylinders, molding materials such as square tubes, or
There is known a shield tunnel segment having a concrete structure reinforced by using the short fiber or the steel fiber (Japanese Patent Laid-Open No. 4-213695).

[0006]

However, when the underground continuous wall 100 constructed of the conventional reinforced concrete shown in FIG. 8 is excavated by the shield excavator 17, the reinforced concrete is manually driven regardless of the shield excavator 17. Since it is necessary to directly excavate, excavation is extremely difficult, the construction period is long, the construction cost is high, and there is a problem of disposal of the excavated reinforced concrete waste. Furthermore, in order to prevent groundwater spouting during excavation, it is necessary to improve the ground of the back side 101 of the underground continuous wall 100 or the reaching portion 102. For this reason, the ground improvement process was additionally required, and the problem of groundwater contamination by the treatment chemicals occurred.

On the other hand, the underground continuous wall 100 having the starting and reaching portion 103 formed of the fiber reinforced concrete member 104 shown in FIG.
, The construction of the underground continuous wall 100 is complicated and the construction period is long, and the carbon fiber is expensive and the underground continuous wall 100 is uneconomical.

Further, a shaft for shield method disclosed in Japanese Patent Application Laid-Open No. 2-176093 or Japanese Patent Application Laid-Open No.
In the shield tunnel segment disclosed in Japanese Patent Application Publication No. 5 (1993) -1995, the starting and reaching portion is a reinforcing member made of a concrete base material impregnated with an inorganic fiber or an organic fiber in a resin or a bar-shaped or plate-shaped reinforcing material. It is reinforced with wood,
Similar to the starting and reaching part shown in FIG. 9, there is a problem that the construction is complicated, the excavation by the shield excavator takes time, and the construction period is long.

It is an object of the present invention to provide an economical underground wall for shield excavation which is easy to construct and excavate, has a short construction period, can eliminate groundwater pollution, and is inexpensive.

[0010]

In order to achieve the above object, the present invention comprises a plurality of elongated rigid members,
Shield excavation formed of concrete or mortar provided between the adjacent rigid members and having a start reaching portion of a shield excavator that starts or reaches the ground at a predetermined depth position in the ground. In the underground continuous wall, the starting reaching part is a plurality of composite members obtained by reinforcing a plastic foam with inorganic fibers instead of the rigid member, and a connecting member that connects both ends of the composite member to the rigid member, respectively. Is replaced by

Further, in the above invention, the starting reaching portion is provided with concrete or mortar between the adjacent composite members.

Furthermore, in any of the above invention, the composite member, the plastic foam made of rigid urethane resin is obtained by reinforced with the inorganic fibers made of long glass fibers.

Further, in any of the above inventions, the connection member is formed in a shape to be fitted to an end of the composite member.

Further, in any of the above inventions, the connection member can be welded to the rigid member.

[0015] In any of the above inventions, the rigid member is an H-section steel or steel sheet pile.

[0016]

According to the shield excavation underground continuous wall of the present invention,
The starting reaching portion including a plurality of composite members reinforced with plastic foam and inorganic fibers, and a connecting member for connecting both ends of the composite member to the rigid members, respectively, uses a foam resin for the plurality of composite members. The excavation resistance is low and the excavation is easy. When manufacturing a composite member, it is possible to fill a large space by the foaming action of the resin, making it easy to manufacture. In addition, the starting part formed by this composite member is lightweight, and the rigid member connected to it is also a whole. And it is easy to transport and build.

Further, the underground continuous wall for shield excavation includes:
While being able to withstand the earth pressure and water pressure on the back side of the underground continuous wall sufficiently, when starting or reaching the shield excavator,
It is possible to directly and easily excavate the composite member,
There is no need to break reinforced concrete as in the past. Therefore, it is an economical underground wall for shield excavation that is easy to construct and excavate, has a short construction period, can eliminate groundwater pollution, and does not require cost.

Further, in the above invention, the starting and reaching part in which concrete or mortar is provided between the adjacent composite members can reduce the number of composite members in the starting and reaching part in addition to the function of the above-mentioned invention, and reduce the number of composite members. The cost of fabricating connected rigid members and the construction of underground diaphragm walls is reduced, and the area ratio of concrete or mortar between adjacent composite members is relatively small, and the excavation resistance at the starting point is small.

In addition, the start reaching portion can withstand the water pressure on the back side of the underground continuous wall during the excavation work by the shield excavator by attaching an entrance using a sealing material, and Excavation work can be performed stably. Further, since it is not necessary to improve the ground using a chemical solution injection or the like on the back side of the underground continuous wall, there is no risk of groundwater contamination.

Further, in any one of the above inventions, the composite member in which a plastic foam made of a hard urethane resin is reinforced with inorganic fibers of long glass fibers may have an inexpensive glass length in addition to the effects of any of the above inventions. A starting portion using fibers can be obtained, and the cost can be reduced. or,
Since the plastic foam is made of hard urethane resin, it has bending and compressive strength, and can be easily obtained at relatively low cost.

Further, in any one of the above-mentioned inventions, the one in which the connecting member is formed into a shape fitting into the end of the composite member has the effect of the above-mentioned one of the inventions. Therefore, it can be easily and reliably connected to the rigid member. The joint between the composite member and the connection member can be more firmly connected by using an adhesive or a fastening means together at the portion where the composite member and the connection member are fitted.

Further, in any one of the above inventions, the one in which the connection member can be welded to the rigid member is characterized in that the connection between the connection member and the rigid member is made firm, easy and reliable, in addition to the operation of any of the above inventions. Can be done.

[0023] In any of the above inventions, the rigid member may be an H-section steel or steel sheet pile, in addition to the operation of any of the above inventions, the connecting member may be formed of a steel material, and the rigidity of the connecting member may be reduced. It is easier to connect the members by welding, and the reliability is increased in terms of strength.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a shield excavation underground continuous wall according to the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows an embodiment of a shield excavation underground continuous wall according to the present invention, and FIG.
(B) is a cross-sectional view taken along the line II of (A), and FIG. 2 is a cross-sectional view of a shaft 18 formed by the underground continuous wall for shield excavation of FIG. 1. In FIG. 1, the shield excavation underground continuous wall 1 of the present embodiment is a plurality of long rigid members H
It is formed of a shaped steel 4 and concrete or mortar 5 provided between adjacent H-shaped steels 4, and further, as shown in FIG. 2, starts underground at a predetermined depth position in the ground or It has a start reaching portion 7 of a shield excavator 17 that reaches from underground. The H-section steel 4 in this embodiment may use a steel sheet pile instead.

The starting arrival portion 7 is composed of a plurality of composite members 8 in which a rigid urethane resin foam, which is a plastic foam, is reinforced with long glass fibers, which are inorganic fibers, and both end portions 9 of the composite member 8 are H-shaped steel. Or, it is provided with a joint fitting 11 which is a connecting member connected to the steel sheet pile 4, and concrete or mortar 5 is provided between adjacent composite members 8.

The composite member 8 is formed by reinforcing a plastic foam made of a hard urethane resin with inorganic fibers of glass long fibers. The plastic foam made of a hard urethane resin, which is a thermosetting resin, has a long glass fiber in the plastic foam. Monofilament state in the direction, that is, the long glass fiber is pressure-bonded with an adhesive alternately with a thickness of several centimeters formed from those having a dispersed form uniformly dispersed in the longitudinal direction one by one,
By forming a plate having a thickness of several tens of centimeters, a high-strength composite member 8 can be obtained.

In the above embodiment, the long glass fiber is uniformly dispersed in the longitudinal direction in a plastic foam made of a hard urethane resin which is a thermosetting resin. However, the present invention is not limited to this. There is no limitation, and the glass fiber may be uniformly dispersed not only in the longitudinal direction but also in a direction intersecting the longitudinal direction, or may be uniformly dispersed in any direction. Further, instead of glass long fibers, other inorganic fibers may be uniformly dispersed in a plastic foam made of a hard urethane resin.

The composite member 8 formed as described above is light, has excellent machinability, and is hardly corroded. Furthermore, since it is a foam having closed cells, it does not absorb water even when immersed in water for a long time, and its size and strength hardly change.

In this embodiment, as the composite member 8,
Among the commercially available lightweight corrosion-resistant structural materials, Eslon Neo-Lumbar FFU, the product code FFU-74 (manufactured by Sekisui Chemical Co., Ltd.) was used, but is not limited to this and satisfies the required characteristics. Other materials can be used as long as they cause the above. The physical properties of FFU-74 are as follows: specific gravity 0.74 water absorption 3.3 mg / cm ² bending strength 146.11 Mpa (1490 kg / cm ² ) bending Young's modulus 10.60 × 10 ³ (10.8 × 10 ⁴ kg / in cm ²⁾ compressive strength 57.85Mpa (590kg / cm ²⁾ shear strength 9.80Mpa (100kg / cm ²⁾ impact strength (Charpy) 420kg-cm / cm ² linear expansion coefficient of 1.0 × 10 ~ ⁵ is there. As shown in the above characteristic values, Eslon Neo-Lumbar is, like concrete, several hundred kg / cm ^2.
Has compressive strength.

FIGS. 3A and 3B show a starting and reaching portion of the embodiment of FIG. 1, wherein FIG. 3A is a sectional view taken along the line II-II of FIG.
3 is a cross-sectional view taken along the line III-III of FIG. 3A, and FIG. 4 is a perspective view of a connection structure between the fitting hardware 11 and the H-section steel 4 of the embodiment of FIG. As shown in FIG. 4, both end portions 9 of the composite member 8 are surrounded by the fitting hardware 11 and are fitted to the fitting hardware 11.
The joint fitting 11 is made of a steel material and formed in a square shape, and the end 9 of the composite member 8 indicated by a two-dot chain line is fitted into a concave portion 15 thereof. The outer bottom part 16 of the joint fitting 11 is welded to the H-section steel 4.

FIG. 5 shows a connection structure between the composite member 8 of the embodiment of FIG. 1 and the joint fitting 11 and the H-section steel 4, (A) is a side view when an adhesive is used, and (B) is a bolt. FIG. 3 is a side sectional view when a nut 13 and a nut 14 are used. (A), the end 9 of the composite member 8 and the joint hardware 11 are bonded via an adhesive 12. (B) fastens the composite member 8 and the joint hardware 11 using a bolt 13 and a nut 14 that penetrate the end 9 of the composite member 8 and the joint hardware 11. As a connection structure outside the composite member 8 and the joint fitting 11, the shape of the fitting structure may be changed, or the end 9 of the composite member may be connected to the joint fitting 11.
It is conceivable to connect by caulking, to provide an auxiliary projection inside the recess of the joint fitting 11 and to lock it, or to combine them.

The shape of the end 9 of the composite member and the shape of the joint fitting 11 are not limited to a circle, a rectangle, etc., but the width (thickness) is made substantially equal to the wall thickness of the underground continuous wall 1. Has an opening area large enough to completely store the outer cross section of the shield excavator.

The underground shield excavation wall 1 of the present embodiment having the above-mentioned structure operates as follows. That is, a plurality of composite members 8 in which a rigid urethane resin foam is reinforced with long glass fibers, and both end portions 9 of the composite members 8 are H
The starting reaching portion 7 including the joint fitting 11 connected to the shape steel 4 and the concrete or mortar 5 provided between the adjacent composite members 8 is excavated because the plurality of composite members 8 are formed of foam resin. Excavation is easy with low resistance. When the composite member 8 is manufactured, a large space can be filled by the foaming action of the resin, so that the manufacturing is easy. In addition, the portion of the composite member 8 is lightweight, and the H-section steel 4 to which the composite member 8 is connected is also lightweight. Easy to transport and build.

Further, the shield excavation underground continuous wall 1
Can sufficiently withstand the earth pressure and water pressure on the back side of the underground continuous wall, and can excavate the composite member 8 directly and easily when the shield excavator starts or arrives.

Furthermore, the starting and reaching portion 7 in which concrete or mortar is provided between the adjacent composite members 8 can reduce the number of the composite members 8 of the starting and reaching portion 7 and can form an H-shape in which the composite members 8 are connected. The cost of manufacturing the steel 4 and the construction of the underground diaphragm wall is reduced, and the area ratio of concrete or mortar between the adjacent composite members 8 is relatively small, and the excavation resistance at the starting point is small.

As shown in FIG. 2, an entrance (entrance) 10 provided with a seal 10a as a sealing material is attached to the starting and reaching portion 7 in a water-tight manner, so that the ground can be excavated by the shield excavator 17. Withstands the water pressure on the back side of the continuous wall 1, prevents groundwater from leaking into the underground continuous wall, enables stable excavation work, and injects chemicals on the back side of the continuous wall 1. There is no need for soil improvement, so there is no risk of groundwater contamination. When the water pressure on the back side of the underground continuous wall is high, the entrance (entrance) 10 is increased and the number of packings 10a is increased. The diameter of the front end 10b of the entrance 10 is formed slightly larger than the diameter of the base end 10c.

Further, when the composite member 8 is formed by reinforcing a plastic foam made of a hard urethane resin with inorganic fibers of long glass fibers, the starting portion 7 using inexpensive long glass fibers can be obtained. Reduce. Further, since the plastic foam is made of a hard urethane resin, it has bending and compressive strength, and can be easily obtained at relatively low cost.
Further, the start reaching portion 7 can be easily formed corresponding to the shield excavator 17 having an arbitrary cross section.

Further, the joint fitting 11 is connected to the end 9 of the composite member 8.
The composite member 8 can be easily and reliably connected to the H-shaped steel 4 via the joint hardware 11. By using an adhesive or a fastening means such as a bolt or a nut together with the fitting portion between the composite member 8 and the joint hardware 11, the composite member 8 and the joint hardware 11 can be connected more firmly.

Further, when the fitting metal 11 can be welded to the H-shaped steel 4, the connection between the fitting metal 11 and the H-shaped steel 4 can be made firm and easy.

In the case where the rigid member is an H-section steel or steel sheet pile, the joint fitting 11 is formed of a steel material.
The connection between the joint fitting 11 and the H-section steel or steel sheet pile is made easier by welding, and the reliability is increased in terms of strength.

FIG. 6 shows a cross section of the shield excavation underground continuous wall shown in FIG. 1, and FIG.
(B) is a sectional view of the underground continuous wall 1b by circular excavation. As described above, FIG.
The H-section steel 4 in (B) may use a steel sheet pile instead.

In order to construct the underground continuous wall 1a or 1b of the present embodiment, the composite member 8 and the joint fitting 11, and the joint fitting 11 and the H-section steel 4 are connected to each other and used at the starting point in a factory. A plurality of H-shaped steels 4 to be used in places other than a plurality of elongate members required for the above and a start reaching portion are prepared.

Excavate the ground.

In order to construct the underground continuous wall 1a by the groove excavation shown in FIG. 6A, as shown in FIG. Excavation is performed to form the surrounding groove 3.

In order to construct the underground continuous wall 1b by the circular excavation shown in FIG. 6 (B), the underground continuous wall 1b is wrapped in a circular shape so as to surround a predetermined place 2 on the ground and continuously in the vertical direction in the underground. Excavation to form the surrounding groove 3.

Insert the long member used for the starting and reaching part 7 prepared in the section into the surrounding groove 3 where the starting and reaching part 7 is located. The H-section steel 4 itself is inserted into a portion other than the start reaching portion 7. In the case of the underground continuous wall 1a, a long member and the H-shaped steel 4 are inserted at predetermined intervals. In the case of the underground continuous wall 1b, a long member or the H-section steel 4 is inserted into the circular excavation at a ratio of one.

At this time, concrete or mortar 5 is cast between adjacent long members inserted into the surrounding groove 3 or mortar is injected during excavation, and the long members are inserted into the mortar. There is a way to install. The mortar injected during excavation is a so-called soil mortar in which soil is mixed.

The underground continuous wall 1 thus formed
A space 19 (FIG. 2) is provided by discharging the earth and sand inside a or 1b, and a shield excavation that starts from the space 19 into the ground or reaches the space 19 from the ground at a predetermined depth position of the space 19 The start reaching section 7 of the machine 17 is provided.

FIG. 7 shows another embodiment of the shield excavation underground continuous wall according to the present invention, wherein (A) is an overall front view,
(B) is a sectional view taken along the line IV-IV of (A). The starting reaching portion 7 of the shield excavation underground continuous wall 1 in the embodiment of FIG. 7 is formed by forming the concrete or mortar 5 portion of the starting reaching portion 7 of the embodiment shown in FIG. The entire reaching portion 7 is formed of the composite member 8. Composite member 8
The fitting hardware 11 as the connecting member is the same as that described in the embodiment of FIG. 1, and the H-shaped steel or the steel sheet pile as the rigid member is also the same.

The whole of the starting and reaching portion 7 formed by the composite member 8 acts as follows in addition to the above-described underground continuous wall for shield excavation in FIG. That is, the starting reaching portion 7 including a plurality of composite members 8 reinforced with a plastic foam and inorganic fibers and a joint fitting 11 for connecting both ends of the composite member 8 to the H-section steel 4 is a plurality of composite members. Member 8
Is formed using a foam resin, so that the excavation resistance is small and the excavation can be easily performed. When the composite member 8 is manufactured, a large space can be filled by the foaming action of the resin, so that the manufacturing is easy and the starting and reaching portion 7 formed by the composite member 8 is lightweight, The shape steel 4 also becomes light as a whole, and is easy to transport and build.

Further, the shield excavation underground continuous wall 1
Can sufficiently withstand the earth pressure and water pressure on the back side of the underground continuous wall, and can directly and easily excavate the composite member 8 when the shield excavator 17 starts or arrives. There is no need to break reinforced concrete as in the conventional case. Therefore, it is an economical underground wall for shield excavation that is easy to construct and excavate, has a short construction period, can eliminate groundwater pollution, and does not require cost.

Since the structure and operation of the other parts in the embodiment of FIG. 7 are the same as those of the shield excavation underground continuous wall of FIG. 1, the same structures and operation parts are denoted by the same reference numerals.
The description is omitted.

The method of starting or reaching the shield excavator 17 is to inject muddy water into the shield cutter 17a in a state where the shield excavator 17 penetrates into the entrance 10 of the start reaching portion 7, and balance the earth pressure and the water pressure on the front of the shaft. Next, the composite member 8 and the concrete or mortar 5 are directly excavated by the shield cutter 17a and advanced into or out of the ground.
The shield excavator 17 is used depending on the soil properties of the ground, and is used under different conditions according to the soft soil properties, the hard soil layers such as weathered rocks, the Dotan layer, and the cobblestone and gravel layers. The traveling speed of the shield excavator 17 is approximately 2 mm / min for reinforced concrete excavation and approximately 30 m for ground.
m / min.

Although the present invention has been described in detail with reference to the illustrated embodiments, the present invention is not limited to those embodiments only, and various modifications can be made without departing from the spirit of the present invention. In addition, it goes without saying that a wide variety of modifications can be made.

[0056]

According to the underground continuous wall for shield excavation of the present invention, since a plurality of composite members are formed by using a foamed resin, the excavation is performed in comparison with a starting portion using concrete or non-foamed resin. Excavation is easy with low resistance. When manufacturing a composite member, the resin material of the foam resin is foamed and easily fills a large space, so that it is easy to manufacture, and at the same time, it is lightweight, and the rigid member to which it is connected is also lightweight,
Easy to transport and build.

Further, the underground continuous wall for shield excavation is
While being able to withstand the earth pressure and water pressure on the back side of the underground continuous wall sufficiently, when starting or reaching the shield excavator,
It is possible to excavate the composite member directly and easily.
Therefore, it is an economical underground wall for shield excavation that is easy to construct and excavate, has a short construction period, can eliminate groundwater pollution, and does not require cost.

[Brief description of the drawings]

1A and 1B show an embodiment of a shield excavation underground continuous wall according to the present invention, wherein FIG. 1A is an overall front view, and FIG.
FIG. 2 is a sectional view taken along line II.

2 is a sectional view of a shaft formed by the shield excavation underground continuous wall of the embodiment of FIG. 1;

FIG. 3 shows a starting and reaching part of the embodiment of FIG. 1;
FIG. 1A is a sectional view taken along the line II-II, and FIG.
FIG. 3 is a sectional view taken along line III-III.

FIG. 4 is a perspective view of a connection structure between the fitting and the H-shaped steel according to the embodiment of FIG. 1;

5A and 5B show a connection structure between the composite member of the embodiment of FIG. 1 and a fitting hardware and an H-shaped steel, wherein FIG. 5A is a side view when an adhesive is used, and FIG. It is a side sectional view in the case.

FIGS. 6A and 6B show the shield excavation underground continuous wall of the embodiment of FIG. 1, wherein FIG. 6A is a cross-sectional view obtained by trench excavation, and FIG. 6B is a cross-sectional view obtained by circular excavation.

7A and 7B show another embodiment of the shield excavation underground continuous wall according to the present invention, wherein FIG. 7A is an overall front view, and FIG.
FIG. 4 is a sectional view taken along line IV-IV of FIG.

FIG. 8 is an explanatory view showing a shield excavation underground continuous wall and a method of constructing the same according to the related art.

9A and 9B show another underground continuous wall for shield excavation and a method of constructing the same according to the related art, and FIG.
(B) is a front view of the start reaching portion as viewed from the shield excavator side.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 1a, 1b Underground continuous wall for shield excavation 4 H-section steel (rigid member) 5 Concrete or mortar 7 Start reach section 8 Composite member 9 End 11 Joint hardware (connection member) 17 Shield excavator

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Seiji Isaka 1124-16 Osawa, Koshigaya-shi, Saitama (72) Inventor Ryoichi Taniguchi 1070-28, Jorakuji, Azuchi-cho, Gamo-gun, Shiga (56) References JP-A-4-76188 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) E21D 9/06 301 E02D 5/20 102

Claims (6)

(57) [Claims] 1. A plurality of long rigid members having rigidity,
Shield excavation formed of concrete or mortar provided between the adjacent rigid members and having a start reaching portion of a shield excavator that starts or reaches the ground at a predetermined depth position in the ground. In the underground continuous wall, the starting reaching part is a plurality of composite members obtained by reinforcing a plastic foam with inorganic fibers instead of the rigid member, and a connecting member that connects both ends of the composite member to the rigid member, respectively. Underground continuous wall for shield excavation, characterized by being replaced with: 2. The vehicle according to claim 1, wherein:
An underground continuous wall for shield excavation, wherein concrete or mortar is provided between adjacent composite members. 3. The method of claim 1 or 2, wherein the composite member, the ground shield excavating to the plastic foam made of rigid urethane resin, characterized in that reinforced with the inorganic fibers made of long glass fibers Continuous wall. 4. The underground continuous wall for shield excavation according to claim 1, wherein the connection member is formed in a shape to be fitted to an end of the composite member. 5. The underground continuous wall for shield excavation according to claim 1, wherein the connection member is weldable to the rigid member. 6. The underground continuous wall for shield excavation according to claim 1, wherein the rigid member is H-shaped steel or steel sheet pile.