JPH0485499A - Construction of excavation space - Google Patents

Abstract

PURPOSE:To reduce a construction period by providing work spaces on both sides of excavation directions in excavation spaces, and boring bores for burying cylindrical shores by using an excavator to construct a pipe roof. CONSTITUTION:Work spaces such as vertical shafts 39 and 40 are provided on both sides of excavation directions in excavation spaces such as tunnels, etc., to be excavated, and a plurality of pipe roof burying bores 49 are bored along sections of the excavation spaces 35 by using an excavator. Cylindrical shores such as pipe roofs 41, etc., of concrete are constructed in the pipe roof burying bores 49. After that, the pipe roofs 41 are connected to each other in the horizontal direction to construct arc-shaped shores 33, and a bedrock downward of the shores 33 is excavated to form the excavation spaces 35. According to the constitution, execution efficiency can be promoted.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention relates to a method for constructing an excavated space suitable for use in constructing large-section tunnels, subway station areas, large underground spaces, and the like.

(b), Prior Art FIG. 19 is a sectional view showing an example of a conventional large-section tunnel.

Conventionally, a tunnel 3 with a large cross section was built in the ground 37 with low ground strength.
5, for example, as shown in FIG. 19, a plurality of steel pipes 50 are installed along the cross section of the tunnel 35 to be excavated.
After stabilizing the face 17 by burying it continuously in an annular shape to form a shoring 33, a large section of the tunnel 35 is formed by excavating the wide area of the ground 19 surrounded by the shoring 33. Was.

(C) 1 Problem to be Solved by the Invention However, in the case of stiffness, the steel pipe 50 corresponding to the length of the tunnel 35 to be excavated
It was necessary to bury a plurality of steel pipes, which caused problems in the workability of the steel pipe 50. In addition, when excavating the 9 parts above the ground inside the shoring 33, especially in water-logged ground, the adjacent steel pipe 50
There was an inconvenience that moisture 15 such as groundwater entered the ground 19 through the gap between the two, making the stabilization measures for the face 17 incomplete.

In order to solve the above-mentioned problems, the first object of the present invention is to provide a method for constructing an excavated space with good workability.
Furthermore, a second object is to provide a method for constructing an excavation space with excellent stability of the face.

(d) Means for solving the zero problem, that is, the present invention excavates the ground (19) and excavates the excavated space (3).
5), work spaces (
39, 40), and a shield excavator (1) is used to drill a cylindrical support burial hole along the cross section of the excavation space (35) to be excavated so as to communicate these work spaces (39, 40). (49) are drilled, and these cylindrical support embedding holes (49) are drilled.
), respectively construct cylindrical supports (41) made of cast-in-place concrete (21), and connect these cylindrical supports (41) tangentially to each other to form an arch-shaped support (
33) and excavate the ground (19) below the constructed shoring (33) to form an excavated space (35).

Furthermore, the present invention provides a concrete layer (21) consisting of cast-in-place concrete (21) for each of the above-mentioned cylindrical supports (41).
') and a water stop layer (5') provided on its outer periphery, and from these cylindrical supports (41) to the support (3').
3), the water stop layers (5') are stacked on top of each other.

Note that the numbers in parentheses are for convenience to indicate corresponding elements in the drawings, and therefore, this description is not limited to the descriptions on the drawings. r (e) below
The same applies to the column ``, action''.

(e) 8 Effects With the above configuration, the present invention operates so that the shoring (33) made of cast-in-place concrete (21) is constructed prior to excavation of the earth (19).

Further, in the present invention, the water stop layer (5') acts to prevent moisture (15) from entering from the ground (19) outside the excavation space (35).

(f), Example Embodiments of the present invention will be described below based on the drawings.

Fig. 1 is a front sectional view showing an example of a tunnel excavation site to which an embodiment of the method for constructing an excavated space according to the present invention is applied; Fig. 2 is a sectional view taken along II-ri@ in Fig. 1; Fig. 3; is an enlarged view of the tunnel portion of the tunnel excavation site shown in Figure 1.

Figure 4 is a front sectional view showing an example of a shield excavator; FIG. 5 is a sectional view taken along the line v-va in FIG. 4.

FIG. 6 is a sectional view taken along line VI-VI in FIG. 4.

Figure 7 is an enlarged view of the jacking part of the shield excavator shown in Figure 4, Figure 8 is a sectional view taken along the line ■-■ in Figure 7, and Figures 9 to 16 are examples of the construction order of the pipe roof. FIG. 17 is an enlarged view showing how the pipe roofs forming the tunnel shown in FIG. 3 are connected to each other.

FIG. 18 is a diagram showing an example of the results of a compressive strength test of a waterproof material.

As shown in FIGS. 1 and 2, the tunnel excavation site 36 is excavated to a predetermined depth Dl from the surface of the ground 37 at a predetermined interval L3 in the horizontal direction of arrows A and B. It has two vertical shafts 39.40, and between these vertical shafts 39.40 there are two tunnels 35 with large cross sections, the first
A predetermined distance L2 apart in the directions of arrows C and D, which are the left and right directions in the figure, and in the direction perpendicular to the plane of the paper, that is, arrow A in FIG.
It is formed in a shape extending in the B direction. Each tunnel 35
As shown in Fig. 3, the tunnel lining 4 has a semicircular cross section.
2, and an invert 4 at the bottom of the tunnel 35.
3 has been constructed. In addition, a support 33 formed in an arch shape is provided on the ground 19 at the outer periphery of the tunnel lining 42.
is buried, and the shoring 33 is made up of a plurality of pipe roofs 41. That is, a plurality of pipe roofs 41 made of concrete or the like are formed in a cylindrical shape with an outer diameter D2 and an inner diameter D3, and are buried continuously in a circular shape laterally along the tunnel lining 42. roof 4
1 forms an arch-shaped support 33 as a whole.

Further, the shield excavator 1 used for constructing the pipe roof 41 is as shown in FIG.

It has a cylindrical outer shell 2, and a cutter 3 is rotatably supported on the front surface of the outer shell 2, that is, the left side surface in FIG. A partition wall 2a is provided inside the outer shell 2,
A mud feeding pipe 4 and a mud draining pipe 8 are provided in the partition wall 2a so as to communicate with the left and right spaces in FIG. 4 of the partition wall 2a. Also,
The cutter 3 is connected to a drive motor 3a provided on a partition wall 2a of the outer shell 2, and a plurality of digging jacks 6 are connected to the partition wall 2a. They are arranged in an annular pattern along 2. Excavation jack 6
A ram 6a is provided on the main body 6b so as to be able to protrude and retreat in the directions of arrows A and B. Furthermore, a cylindrical press ring 7 is provided inside the outer shell 2. It is provided so as to be able to freely slide in the directions of arrows A and B in FIG. 4 so as to be in contact with the circumferential surface.

As shown in FIG. 5, on the press ring 7, a plurality of press link jacks 9 are arranged in an annular shape along the outer shell 2 at predetermined intervals. As shown in FIG. 5 and FIG.
It is provided so as to face the side surface 7a of the shield excavator 1, that is, toward the rear of the shield excavator 1. The discharge pipe 10 is provided with a cylinder 10b for cleaning the inside of the discharge pipe in such a manner that a rod 10c can protrude and retract in the directions of arrows A and B, and a supply hose 3o is further connected to the discharge pipe 10.

By the way, at the tip of the ram 6a of the excavation jack 6, there is a gauge ring 1 formed in an annular shape, as shown in FIG.
1 is attached to the gauge ring 11, and as shown in FIG. 7, engagement grooves 11a are formed in an annular shape around the entire circumference of the gauge ring 11.

In addition, the main body 6 of each excavation jack 6 of the shield excavator 1
A substantially disk-shaped substrate 45 is provided at the right end of FIG. A guide rail 46a constituting the formwork conveying device 46 is provided in the center of the right side surface of FIG. 4 in a manner extending in the left-right direction in the figure, that is, in the directions of arrows A and B. A formwork support stand 46b is supported on the guide rail 46a so as to be movable in the directions of arrows A and B.

Since the tunnel excavation site 36 etc. has the above configuration, when constructing the tunnel 35 with a large cross section between the vertical shafts 39 and 40 shown in FIG. In order to form a stabilizing support 33, a plurality of pipe roofs 41 made of cast-in-place concrete etc. are installed in the tunnel space 35 to be excavated, as shown in FIG.
Continuously construct in an annular shape along the upper half cross section of a.

To do this, the shield excavator 1 shown in FIG. 4 is carried into the shaft 40 on the right side of FIG. 2, and the cutter 3 is moved to the left side of FIG. At the same time, a reaction frame (not shown) is installed at the rear of the shield excavator 1. In this state, mud water 14 is supplied to the face 16 side through the mud feed pipe 4 of the shield excavator 1, and the drive motor 3a
is driven to rotate the cutter 3, and further, the ram 6a of each excavation jack 6 is projected in the direction of arrow B in FIG. Press in the in direction. Then, the cutter 3 rotates once due to the pressing force, and the face 16 comes into contact with a predetermined contact pressure, and the upper face 6 is excavated by the cutter 3, and the excavated earth and sand 1
8 is mixed with muddy water 14 and carried out to the right side in FIG. 4 through the mud drain pipe 8. At the same time, the outer shell 2 is propelled in the direction of arrow A, and a pipe roof embedding hole 49 is formed at the rear of the shield excavator 1, that is, to the right in FIG.

As the via roof embedding hole 49 is formed in this manner, a concrete pipe roof 41 is constructed in the formed via roof embedding hole 49 by the following procedure. That is, when the shield excavator 1 excavates in the direction of arrow A across the length L of one ring of the formwork 13, the ram 6a of the excavation jack 6 moves in the direction of arrow B, as shown in FIG. It is in a protruding state, and the press ring 7 is also in a state of moving in the direction of arrow B.

In this state, as shown in FIG.
ram 6a is moved back by a distance L1 in the direction of arrow A. Then, the cage ring 11 separates from the stopper 22A and the formwork 13A of the part where the concrete 21 was placed just before and moves in the direction of arrow A.

A space having a distance L1 is formed between the end stop 22A and the formwork 13A and the gauge ring 11. Therefore, as shown by the imaginary line in FIG. 10, a reinforcing member 12 made of a punch plate, reinforcing bar, etc. is inserted into the space through the engagement groove 11a with an end stop 22! The formwork 13.1 is installed together with the formwork 13. Assemble and install the formwork 13. l, gauge ring 11 (wife stopper 22!l)
), a cylindrical concrete placement space 31 is formed between the press ring 7 and the end stop 22A.

In this state, as shown in FIG. 11, the concrete supply pipe 25 is connected to the formwork 13, and the concrete supply pipe 25 is
Concrete 21 is placed into concrete placement space 31 through concrete 21. In addition, at this time, concrete placement space 3
The air in 1 is removed from the air vent pipe 1 appropriately provided in the formwork 13.
3a, the concrete 21 is poured into the concrete placement space 31 smoothly.

After the concrete 21 has been placed in the concrete placement space 31 in this manner, the press ring jack 9 is driven to gradually retreat the press ring 7 in the direction of arrow A, as shown in FIG. Then, after the press ring 7 passes, the outer shell 2 and the poured concrete 21
An annular water stop material placement space 32 is formed between the two. Therefore, as the press ring 7 moves in the direction of the arrow A, a liquid water stop material 5 whose main component is ground blast furnace slab powder is supplied from the supply hose 30 through the discharge pipe 10, as shown in FIG. The water stop material is injected into the water stop material placement space 32, and the water stop material placement space 32 is filled with the water stop material 5.

The press ring 7 moves in the direction of arrow A, and as shown in FIG.
When the excavation position is substantially aligned with the installation position B, as shown in FIG. 15, the ram 6a of the excavation jack 6 is driven to protrude in the direction of arrow B, and the cutter 3 is rotated to start the excavation operation.

Then, as already mentioned, the outer shell 2 starts to move in the direction of the arrow in FIG. Tail void 2 between
7 is formed. Therefore, as the outer shell 2 moves in the direction of the arrow, the press ring jack 9 is driven to gradually move the press ring 7 in the direction of the arrow B in synchronization with the movement of the outer shell 2. Then, the previously cast uncured water stop material 5 in the water stop material placement space 32 is pressed by the press ring 7 and flows to fill the tail void 27.

In this way, as shown in FIG. 16, when the press ring 7 is moved in the direction of the arrow B as the outer shell 2 moves in the direction of the arrow B, the tail void 27 that occurs as a result of the movement of the outer shell 2 can be effectively removed. It is then filled with water stop material 5. At this time, the water stop material 5 moves due to the press pressure of the press ring 7 in the form of being clogged between the particles of concrete 21 in the concrete placement space 31 and between the particles of earth and sand constituting the ground 19, as shown in FIG. As shown in FIG.
A water stop layer 5'' is formed in a cylindrical shape surrounding the press ring 1'. Also, since the press ring 7 is formed in a cylindrical shape, the water stop material 5 is uniformly pressurized over the entire circumference of the ring. Therefore, the filling operation of the tail void 27 is performed uniformly and in good condition all around the outer shell 2. In this way, the outer shell 2 is filled with the formwork 1.
When the press ring 7 is propelled by a length Ll corresponding to one ring of 3, the side surface 7a of the press ring 7 matches the rear end 2b of the outer shell 2, as shown in FIG. Construction of the pipe roof 41 is completed.

In addition, when the pipe roof 41 for one ring is constructed,
In order to construct the next one-ring pipe roof 41 in front of the constructed pipe roof 41, that is, on the left side in FIG.
As already mentioned, in this state, the ram 6a of the digging jack 6 is moved in the direction of the arrow A by a distance L1, as shown in FIG. 1o.
22. Since the concrete 21 constituting the concrete layer 21' in the part that is in contact with the concrete layer 21' has already hardened sufficiently into an annular shape, the pouring surface 29 stands on its own together with the end stop 22B without collapsing, and the subsequent reinforcing member 12 installation work is also carried out smoothly.

In this way, the construction of the pipe roof 41 is repeated one ring at a time in the direction of arrow A in FIG.
The construction of the pipe roof 41 is completed, which consists of a concrete layer 21' formed in a cylindrical shape and a water stop layer 5' formed in a concentric cylindrical shape surrounding the outer peripheral surface of the concrete layer 21'.

In this way, the first pipe roof construction point P1 shown in FIG.
When construction of one pipe route 241 is completed, the shield excavator 1 is turned left and right inside the shaft 39, and the cutter 3 is directed to the right in FIG. 2, that is, to the shaft 40 side. Next, the shield excavator 1 is moved to the second pipe roof construction point P2.
At the same time, a reaction frame (not shown) is installed behind the seal 1 (excavator 1). Construction of a pipe roof 41 having a length L3 is started at the pipe roof construction point P2.Then, the shield excavator 1 constructs the pipe roof 41 while excavating from the shaft 39 toward the right in FIG. The shield excavator 1 reaches the shaft 40 on the middle right side, that is, the shaft 40 where construction of the pipe roof 41 has started at the first pipe roof construction point P1.
The construction of the two pipe roofs 41, 41 (the first pipe roof construction point P1 and the second pipe roof construction point P2) is completed while the vehicle reaches this point and returns to the shaft 40.

Furthermore, in the same construction procedure, the shield excavator 1 is made to reciprocate between both shafts 39 and 40 to excavate the remaining pipe roof construction point, that is, the third pipe roof construction point P3.
At the seventeenth pipe roof construction point P17, the construction of the pipe roof 41 is sequentially performed. Then, these pipe roofs 41, as shown in FIG.
An arch-shaped support 33 is formed on the upper half section of the tunnel space 35a to be excavated. At this time, as shown in FIG. 17, the pipe roofs 41 and 41 adjacent to each other are constructed so that the water stop layer 5' portion of the thickness T2 overlaps, and these water stop layers 5' are formed as a whole.

As shown in FIG. 3, it is formed integrally and continuously in an annular shape along the upper half section of the tunnel space 35a to be excavated. When constructing the pipe roof 41 at a pipe roof construction site adjacent to the existing pipe roof 241, the cutter 3 of the shield excavator 1 excavates the water stop layer 5' of the existing pipe roof 41. Although the operation is performed, the water stop material 5 constituting the water stop layer 5' is
As shown in the figure, since only a compressive strength of about 50 kgf/d is developed at the 4-week strength, the cutting resistance by the cutter 3 is negligibly small compared to the face 16, and the shield excavator 1
There are no words that may interfere with directional control.

In this way, as shown in FIG. 3, when the arch-shaped support 33 is formed along the upper half section of the tunnel space 35a to be excavated, the portion of the ground 19 below the support 33 is removed using a power shovel or the like. A tunnel space 35a having a large cross section is formed by excavating with an excavating means (not shown) and slitting the tunnel on the side of the tunnel entrance. At this time, since the arch-shaped support 33 supports the ground 9, the ground 19
The occurrence of collapse, deformation, etc. of Since the water is completely shut off, it is possible to prevent moisture 15 such as groundwater from entering from the external ground 19. Therefore.

The portion of the ground 19 to be excavated is water-tightened and stabilized by the water-stopping layer 5', making it possible to perform the excavation operation of the large-section tunnel space 35a safely and quickly.

In this way, a portion of the ground 19 below the arch-shaped support 33 is excavated, and a tunnel space 35a with a large cross section is formed between the vertical shafts 39 and 40 with a length L3 in the direction of arrows A and B in FIG. Now, as shown in FIG. 3, an invert 43 is constructed by connecting both legs of the arch-shaped shoring 33 in the directions of arrows C and D, and a tunnel lining 42 is installed inside the shoring 33. It is constructed in an arcuate curved shape along the shoring 33. At this time, the arch-shaped support 33 is placed on the ground 1.
9 is supported, the occurrence of collapse, deformation, etc. of the ground 19 is prevented, and construction work of the invert 43 and tunnel lining 42 can be performed safely. In addition, shoring 3
As already mentioned, the tail void 27 that occurred when constructing the vibe roof 41 that constitutes the tunnel 35 is filled with the waterproof material 5, and the tunnel 35 that is made up of the shoring 33, the invert 43, and the tunnel lining 42 is filled with the waterproof material 5. As shown in Fig. 3, the whole is formed into a substantially cylindrical shape, so
Since it can strongly resist earth pressure, water pressure, etc. from the ground 19 on the outer periphery, it becomes possible to significantly suppress ground subsidence after construction of the tunnel 35.

By the way, as shown in FIG. 1 and FIG.
9. Arrow A parallel to tunnel 35, communicating between 40
, are provided over a length L3 in the B direction, so that the inner holes 41a of the pipe roof 41 can be used for various incidental facilities of the tunnel 35, such as ventilation holes, drainage holes, or the communication of the power cable conduit 1. It can be effectively used as a cable conduit.

In addition, in the above-mentioned embodiment, the case where one shield excavator 1 is made to reciprocate between two vertical shafts 39 and 40 and constructs a plurality of pipe roofs 41 has been explained, but multiple shield excavators 1 of the same type By simultaneously constructing the pipe roof 41 using the shield excavator 1, the construction period can be shortened. Furthermore, it is also possible to construct a curved pipe roof 41 using a bendable shield excavator 1 to construct a tunnel 35 having a large curved cross section.

(g) 0 Detailed Description of the Invention According to the present invention, when excavating the earth 19 to construct an excavated space such as the tunnel 35, the direction of excavation of the excavated space such as the tunnel 35 to be excavated (For example, the second
Work spaces such as shafts 39 and 40 are provided on both sides of the arrows A and B in the figure, and the shield excavator 1
A plurality of cylindrical support burying holes such as the pipe roof burying hole 49 are drilled using the cylindrical support burying hole 49, and a cylindrical support such as the pipe roof 41 made of cast-in-place concrete 21 is constructed in each of these cylindrical support burying holes. At the same time, the cylindrical supports are laterally connected to each other to construct an arch-shaped support 33, and the ground 19 below the constructed support 33 is excavated to form an excavation space. Therefore, prior to excavating the ground 19, by effectively utilizing the excavation technology accumulated to date regarding the shield excavator 1, the shoring 33 made of cast-in-place concrete 21- is placed in the ground to be excavated. 19
It becomes possible to build around.

As a result, when excavating a tunnel 35 with a large cross section, the first
Unlike the conventional construction method as shown in Figure 9, a long steel pipe 50
Since there is no need to bring in materials, construction efficiency is improved, and
This can contribute to shortening the construction period.

In addition, each of the above-mentioned cylindrical supports is made of cast-in-place concrete 21
It is formed from a concrete layer 21' consisting of a concrete layer 21' and a water stop layer 5' provided on the outer periphery of the concrete layer 21'. With this configuration, the infiltration of moisture 15 such as groundwater from the ground 19 outside the excavation space is completely prevented by the water stop layer 5' formed integrally and continuously on the surface of the arch-shaped support 33. It can be prevented. This results in
Especially in stagnant ground, the stability of the face 17 is greatly increased, making it possible to carry out excavation work safely and efficiently.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view showing an example of a tunnel excavation site to which an embodiment of the excavation space construction method according to the present invention is applied. Figure 2 is a cross-sectional view taken along the line ■-■ in Figure 1, and the third
Figure 4 is a front cross-sectional view showing an example of a shield excavator, Figure 5 is a cross-sectional view taken along the line v-■ in Figure 4, and Figure 6 is a
7 is an enlarged view of the jacking part of the shield excavator shown in FIG. 4, FIG. 8 is a sectional view taken along line ■-■ in FIG. Figure 16 is a process diagram showing an example of the construction order of the pipe roof, Figure 17 is an enlarged view showing the connection between the pipe roofs that make up the tunnel shown in Figure 3, and Figure 18 is a compressive strength test of water stop material. FIG. 19 is a sectional view showing an example of a conventional large-section tunnel. 1...Shield excavator 5...Water stop material 5°...Water stop layer 19...Ground 21...Concrete 21'...Concrete Layer 33... Shoring 35... Excavation space (tunnel) 39.40... Working space (shaft) 41...
・Tubular shoring (pipe roof) 49... Tubular shoring burying hole (pipe roof burying hole) Ro Ganto Mitsui Construction Co., Ltd. agent Patent attorney Phase 1) Shinji Diagram Diagram Diagram Diagram Diagram

Claims (2)

[Claims] (1) When constructing an excavation space by excavating the ground, work spaces are provided on both sides of the excavation space to be excavated in the excavation direction, and these work spaces are communicated with each other in the excavation space to be excavated. A shield excavator is used to drill multiple cylindrical shoring holes along the cross section of the cylindrical shoring hole, and cylindrical shoring made of cast-in-place concrete is constructed in each of these cylindrical shoring holes. A method for constructing an excavation space, comprising: connecting cylindrical supports laterally to each other to construct an arch-shaped support; and excavating the ground below the constructed support to form an excavation space. . (2) Each cylindrical support is formed from a concrete layer made of cast-in-place concrete and a water stop layer provided on its outer periphery, and when constructing a support from these cylindrical supports, each of the above-mentioned The method for constructing an excavation space according to claim 1, wherein the water stop layers are stacked on top of each other.