JP4863399B2 - Ground reinforcement method and structure - Google Patents

Description

  The present invention relates to a ground reinforcing method and a reinforcing structure when an excavator is joined to an existing structure in the ground and a road surface located above the underground joint is covered with a cover plate.

Conventionally, for example, an existing structure constructed in the ground such as a common ditch or a tunnel and a new tunnel constructed by advancing an excavating machine such as a shield machine toward the existing structure. There is known a technique for joining to the substrate (for example, see Patent Document 1).
When joining these existing structures and the newly constructed mine shafts, a part of the side surface of the existing structure is cut and opened.
JP 2005-120699 A

By the way, there is a case where a main road or the like is provided directly above the underground joint portion between the existing structure as described above and the newly established mine shaft. In this way, when a road is provided directly above the underground junction, the collapse of the underground junction between the existing structure to which the side of the existing structure is open and connected and the newly constructed tunnel, the settlement of the road surface, etc. In order to prevent this, it has been practiced to reinforce the ground around the underground joint by laying a lining plate to cover the road surface or by placing an H steel pile or the like in the ground.
However, in places where there are many underground buried objects such as water pipes and gas pipes, it is necessary to drive such H steel piles after transferring these underground buried objects, which takes time. Furthermore, after the construction of the underground joint, it is troublesome because the H steel piles and the like must be extracted, and the construction period may be prolonged.

  An object of the present invention is to provide a ground reinforcing method and a reinforcing structure capable of securely and firmly reinforcing the ground around the underground joint even in a place where there are many underground buried objects.

  In order to solve the above problems, the invention described in claim 1 is a ground reinforcing method, in which the excavator is jointed to an existing structure such as a joint groove, and the ground joint When the road surface located above is covered with a lining plate, the excavation ground in which the excavator advances is infused and infiltrated with a consolidation material along the excavation ground in advance, and further, The surroundings of the excavated ground located near the underground joints are improved by mixing and curing these hardened materials and the ground while cutting the ground by high pressure injection of the hardened material around the excavated ground. It is characterized by reinforcing.

  The invention according to claim 2 is a ground reinforcing structure, and an existing structure such as a common groove below the road surface covered by the lining plate, and an excavator that advances toward the existing structure. An underground joint portion where the underground excavation machine is located, and the excavation ground in which the excavator advances is consolidated by injecting and infiltrating a consolidation material along the excavation ground, and the underground The periphery of the excavated ground located in the vicinity of the joint is improved and reinforced by mixing and curing the hardened material and the ground while cutting the ground by high pressure injection of the hardened material around the excavated ground. It is characterized by being.

  The invention according to claim 3 is the ground reinforcement structure according to claim 2, wherein the excavated ground includes a surface layer ground and a support layer that supports the surface layer ground, and the consolidated material is at least the It is characterized by being infused into the surface ground.

According to the present invention, since the excavation ground in which the excavator advances is consolidated and the periphery of the excavation ground located near the underground joint portion below the road surface is improved and reinforced by the hardener, unlike the conventional case, Even if there are buried objects, there is no need to relocate and there is no need to cast H steel piles, etc., so even in places where there are many underground objects, the ground around the underground joints is reinforced reliably and firmly. be able to.
Furthermore, unlike the conventional case, there is no need to move even if there is an underground buried object, and there is no need to drive H steel piles or the like, so the construction period can be shortened.

  Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 show a configuration of an embodiment to which the present invention is applied. An existing structure 1 such as a joint groove and an excavating machine 2 traveling toward the existing structure 1 are located below a road surface 4. The state in which the underground joint part 3 to be joined is located is shown.
The ground 5 shown in FIGS. 1 and 2 includes a surface layer ground 5A and a support layer 5B that supports the surface layer ground.

  The excavator 2 according to the present embodiment is a so-called shield machine, which proceeds while excavating the ground 5 and sequentially assembles segments covering the wall surface along the wall surface of the shield tunnel formed by excavation. By going, the tunnel 2a can be newly established.

The underground joint portion 3 is a ground joint portion between the side surface of the existing structure 1 and the excavator 2 that travels in a direction crossing the existing structure 1, that is, the existing structure 1, It is also an underground joint portion with a newly formed tunnel 2a formed by the excavator 2.
As shown in FIG. 3, a connecting passage 6 that connects the existing structure 1 and the newly formed mine shaft 2 a is formed in the underground joint portion 3.

  The road surface 4 is located immediately above the underground joint 3. A lining plate 4a is laid on the road surface 4, and the sag of the road surface 4 can be prevented by the lining plate 4a.

  In the ground 5 of the present embodiment, a plurality of remaining piles 7 that are driven from the surface ground 5A to the support layer 5B are embedded in the vicinity of the underground joint portion 3, and further, the surface ground 5A. The existing pipe 8 such as a sewage pipe is buried.

Further, in the figure, an excavation ground 5a through which the excavating machine 2 travels is shown, and a surrounding 5b of the excavation ground 5a located near the underground joint 3 below the road surface 4 is shown.
The excavation ground 5a is located along the traveling route of the excavator 2 as shown in FIGS. Further, as shown in FIGS. 1, 4, and 5, the portion located below the road surface 4 is set to have an excavation width that is at least approximately equal to the width dimension of the excavator 2.

  Further, as shown in FIGS. 1 to 5, the surrounding 5b of the excavated ground 5a is disposed over at least both sides and the tip of the excavated ground 5a, and the excavated ground located below the road surface 4 is disposed. It is formed so as to wrap the tip portion of the ground 5a.

  A caking material is injected and infiltrated into the excavated ground 5a along the excavated ground, and a hardening material is injected at a high pressure around 5b of the excavated ground 5a.

  The consolidated material is for solidifying and stabilizing the excavation ground 5a, and is injected and penetrated into at least the surface layer ground 5A. Therefore, when the excavation ground 5a is excavated by the excavator 2, the tunnel 2a It is possible to stably perform excavation work such as preventing the crown of the top of the roof from collapsing and obtaining a water stop effect.

  As this solidifying material, for example, sodium silicate called a main agent and a water glass-based inorganic solution type injection material called a curing agent are used, but not limited thereto, the ground conditions and the purpose of injection, It is preferable to change appropriately considering the surrounding environment.

  The excavation ground 5a located below the road surface 4 is located inside the circumference 5b where the hardened material is injected at a high pressure around the excavation ground 5a. The consolidated material is injected and penetrated in a relatively narrow range. On the other hand, in the excavated ground 5a that is not located below the road surface 4, the hardened material is not injected at a high pressure around it, and the solidified material is injected and penetrated in a relatively wide range in order to further stabilize the ground 5.

  The hardened material is a cement-based material that is injected at a high pressure around the ground 5b of the excavated ground 5a, and is grounded by being injected at high pressure from an injection nozzle of a double tube rod (described later) inserted into the ground 5 from the ground surface. While being cut, is mixed with the ground 5 that has been cut, and a pile-like improved body can be formed in the portion where the hardened material and the ground are mixed. That is, the circumference 5b of the excavation ground 5a is constituted by this improved body.

  This improved body has high strength by being hardened, and not only can the surrounding ground 5 be reinforced reliably and firmly, but also the lining plate 4a of the road surface 4 located above the improved body can be surely secured. Can be supported.

  In addition, as shown in FIG. 1, although the said hardening | curing material is injected by high pressure in the range a little narrower than the laying range of the lining board 4a of the said road surface 4, it is high pressure in the range which can support the said lining board 4a. If it is injected, it is not restricted to this.

And the surrounding 5b of the said excavation ground 5a in which such a hardening material was jetted by high pressure was arrange | positioned over the both sides and the front-end | tip part of the said excavation ground 5a as mentioned above. Accordingly, the surrounding 5b located on both sides of the excavated ground 5a is improved and reinforced with a hardener, so that the lining plate 4a of the road surface 4 located above the underground joint 3 can be reliably and firmly supported. Therefore, the sinking of the road surface 4 can be prevented reliably.
Further, by improving and reinforcing the periphery 5b located at the tip of the excavated ground 5a with a hardened material, the ground 5 at the connecting portion between the existing structure 1 and the newly established mine shaft 2a can be reliably and firmly supported. Therefore, it is possible to reliably prevent the connection passage 6 from collapsing.
That is, if the surrounding 5b of the excavated ground 5a to which the hardener is jetted at high pressure is disposed at least on both sides and the tip of the excavated ground 5a, the ground 5 around the underground joint 3 is provided. Can be reinforced reliably and firmly.

  Next, a method for reinforcing the ground 5 will be described with reference to the drawings.

First, the hardened material is sprayed from the ground surface to the periphery 5b of the excavated ground 5a.
At that time, the ground 5 is cut and a high-pressure injection device (not shown) having a double tube rod for high-pressure injection of the hardened material is installed on the ground.

Then, while cutting the ground 5 with the double tube rod, the double tube rod is inserted to a predetermined depth of the ground 5.
Here, as shown in FIGS. 2 to 5, the predetermined depth can be appropriately changed as long as the strength of the underground joint portion 3 can be maintained.

That is, since the connection passage 6 is open, particularly strength must be maintained. Therefore, the curing material is injected at a depth of at least a depth substantially equal to the length of the connection passage 6 in the vertical direction. It is necessary to improve and reinforce the periphery of the connection passage 6.
Further, the hardened material is injected into the periphery of the remaining pile 7 relatively deeply along the length direction of the remaining pile 7 and is reinforced for improvement. That is, the remaining pile 7 is removed in order to reinforce the surrounding area by high-pressure jetting the hardened material to a relatively deep position along the length direction of the remaining pile 7 in this way. Even if it leaves, the surrounding ground 5 can be reliably reinforced by the improved body which the said hardening material hardened | cured.

  And after inserting a double tube rod to the predetermined depth, the said hardening material with air is injected at high pressure from the injection nozzle of this double tube rod. At this time, the spray nozzle of the double tube rod is rotated in the ground 5. And a hardening material and the ground 5 are mixed and hardened, and the said pile-shaped improvement body is created.

  The ejection amount of the curing material is, for example, 60 liters / min, and the pile-like improved body is set to have a diameter of, for example, 1000 mm to 2000 mm.

  In addition, the method for injecting such a hardened material at a high pressure employs the JSG method in the present embodiment, but is not limited thereto, and can be appropriately changed without departing from the gist of the present invention.

The above operations are repeated as appropriate to improve and reinforce the surrounding 5b of the excavated ground 5a as shown in FIGS. 1 and 2, and then the consolidated material is injected and penetrated from the ground surface into the excavated ground 5a.
At that time, the ground 5 is cut, and an injection device (not shown) having a double tube rod for injecting the consolidated material is installed on the ground.

Then, while cutting the ground 5 with the double tube rod, the double tube rod is inserted to a predetermined depth of the ground 5.
Here, as shown in FIG. 2, the predetermined depth is between the surface layer ground 5A and the upper end of the support layer 5b, but at least the surface layer ground 5A is injected and infiltrated with a consolidated material. It can be changed as appropriate depending on the ground conditions.
In addition, since the part close | similar to the ground surface becomes a shallow position from the road surface 4, a caking additive is not inject | poured.

  And after inserting a double pipe rod to the predetermined depth, the said solidification material is inject | poured and penetrate | infiltrated into the excavation ground 5a of the ground 5 from this double pipe rod. In addition, the excavation ground 5 into which this consolidated material has been injected and penetrated is gelled by this consolidated material.

  In this embodiment, a bi-mode method is employed as the method for injecting and penetrating the consolidated material, but the method is not limited to this, and can be changed as appropriate without departing from the spirit of the present invention. It is.

  Thereafter, the strength of the improved body is inspected, for example, by collecting a sample of a pile-shaped improved body formed at the place where the hardened material is jetted at high pressure.

  If there is no problem in the strength inspection, a plurality of lining plates 4a are laid on the road surface 4 above the excavated ground 5a to reinforce the road surface 4.

  And after the reinforcement work of the whole ground 5 including the reinforcement of the said road surface 4 is completed in this way, the digging ground 5 is excavated by the said excavating machine 2, and the mine 2a is formed, this mine 2a and the said existing structure 1 To the ground.

According to the present embodiment, the excavating ground 5a through which the excavating machine 2 proceeds is consolidated, and the surrounding 5b of the excavating ground 5a located near the underground joint 3 below the road surface 4 is improved and reinforced by the hardener. Therefore, unlike the conventional case, even if there are underground buried objects such as the remaining piles 7 and the existing pipes 8, there is no need to relocate them, and there is no need to cast H steel piles. Even in places where there are many objects, the ground around the underground joint 3 can be reinforced reliably and firmly.
Further, unlike the conventional case, even if there is an underground buried object, it is not necessary to move it, and it is not necessary to drive H steel piles or the like, so that the construction period can be shortened.

It is a top view which shows an example of the ground reinforcement structure of this invention. It is a sectional side view of the ground reinforcement structure shown in FIG. It is DD sectional drawing of the ground reinforcement structure shown to FIG. 1 and FIG. It is EE sectional drawing of the ground reinforcement structure shown to FIG. 1 and FIG. It is FF sectional drawing of the ground reinforcement structure shown to FIG. 1 and FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Existing structure 2 Excavator 2a Tunnel 3 Underground joint part 4 Road surface 4a Covering board 5 Ground 5a Excavation ground 5b Around

Claims (3)

An existing structure such as a joint ditch and a new tunnel constructed by advancing a digging machine toward the existing structure are jointed in the direction crossing each other and located above the underground joint. When lining the road surface to be covered with a lining plate,
In advance, the excavation ground in which the excavation machine proceeds, inject and infiltrate the consolidation material along the excavation ground, solidify,
Further, the hardened material and the ground are mixed while cutting the ground by high-pressure spraying the hardened material around the excavated ground around the excavated ground located near the underground joint portion below the road surface. A method for reinforcing a ground characterized by improving and reinforcing by hardening. Under the road surface covered by the lining plate, the existing structure such as a common groove and the new tunnel constructed by advancing the excavator toward the existing structure are underground The underground joint to be joined is located,
The excavation ground where the excavation machine proceeds is consolidated by injecting and infiltrating a consolidation material along the excavation ground,
The circumference of the excavated ground located in the vicinity of the underground joint is improved by mixing and curing the hardened material and the ground while cutting the ground by high-pressure injection of the hardened material around the excavated ground. Ground reinforcement structure characterized by being reinforced.   The ground according to claim 2, wherein the excavation ground includes a surface layer ground and a support layer that supports the surface layer ground, and the consolidated material is injected and infiltrated into at least the surface layer ground. Reinforced structure.

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