JP2001152476A - Aseismic ground - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aseismic ground capable of obtaining a sufficient earth quake resistance for an existing underground structure in a narrow construction work irrespective of the use condition of the structure. SOLUTION: The aseismic ground is provided with a vertical ditch 12 excavated in the ground 25 so as to surround an existing underground structure 30 with a specified distance from the structure and a bag body 11 inserted in the vertical ditch and filled with a fluid. When the peripheral ground is displaced by an earthquake, the bag body is deformed to attenuate the displacement of the ground. Hence, an external force to be transmitted to the existing underground structure is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an earthquake-resistant ground provided around an existing underground structure.

[0002]

2. Description of the Related Art Underground structures are not easily affected by vibration characteristics due to the inertial force of the structures themselves, unlike underground structures, because the underground structures are surrounded by the ground when considering seismic performance. The characteristic is that it is easily affected by the ground displacement caused by the ground. For example, as shown in FIG.
When the existing underground structure 30 is buried in the soft ground 25, the ground displacement due to the earthquake is transmitted as shown by an arrow, transmitted to the existing underground structure 30, and the existing underground structure is Force deformation.

Therefore, in order to improve the seismic resistance of an existing underground structure, a method of attaching a reinforcing member inside the structure or improving the ground around a wide area of the structure and solidifying the structure is conventionally performed. Have been.

[0004]

However, when a reinforcing member is mounted inside a structure, the use of the structure is temporarily restricted, and it is difficult to perform reinforcement work using the structure. There is a disadvantage that the construction cost is increased. In particular, when the structure is a water channel, reinforcement work is very difficult, and long-term work is required. On the other hand, when the surrounding ground of the structure is solidified, wide-ranging improvements are required in order to obtain sufficient seismic performance, and there is a drawback that the presence or absence of surrounding buildings becomes a problem.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an earthquake-resistant ground capable of obtaining sufficient earthquake resistance of an existing underground structure in a narrow range of construction without being affected by the usage of the structure. is there.

[0006]

According to the present invention, there is provided a vertical groove or a vertical hole formed in the ground at a predetermined distance so as to surround an existing underground structure, and the vertical groove or the vertical hole. A bag filled with fluid, which is inserted into the inside of the ground, and when the surrounding ground is displaced during an earthquake, the bag deforms to attenuate the ground displacement, and An earthquake-resistant ground characterized by reducing an external force transmitted to a structure is provided.

In the present invention, the fluid is preferably a liquid having a specific gravity greater than that of groundwater, and most preferably, the specific gravity of the liquid is approximately 1.1 to 2.0. By filling the bag with a liquid having a specific gravity greater than that of groundwater in this way, the bag inserted into the vertical groove or the vertical hole can be prevented from floating by groundwater, and the vertical groove or the The collapse of the vertical hole can be prevented. Therefore, the bag body is stably disposed inside the vertical groove or the vertical hole, and reliably separates the ground surrounding the existing underground structure from the ground outer than the vertical groove or the vertical hole, and the ground displacement is the same as the existing ground. Prevents transmission to underground structures.

It is preferable that a gap having a predetermined depth is provided above the bag in the vertical groove or the vertical hole. By providing the gap in this manner, the bag body that has been compressed and deformed by the ground displacement moves to the gap, promptly attenuates the ground displacement, and prevents the bag body from bursting.

Further, the vertical holes may be provided in a staggered arrangement at predetermined intervals, or the vertical holes may be arranged so that a plurality of the vertical holes communicate with each other. The plurality of vertical holes provided in a staggered arrangement at predetermined intervals do not actually define the ground surrounding the existing underground structure and the ground on the outer periphery than the vertical holes, but when the ground displacement is transmitted In addition, the vertical holes in different rows are deformed so as to be alternately overlapped, thereby preventing the ground displacement from being transmitted to the existing underground structure.

[0010]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1A is a simplified longitudinal sectional view of an earthquake-resistant ground according to the present invention, and FIG. 1B is a plan layout view of FIG. 1A. 1 (a) and 1 (b), a soft ground 25 where large displacement is likely to occur during an earthquake is deposited above a hard ground 26, and in many cases, an existing underground structure 30 such as a common ditch or a subway is used. Is buried in the soft ground 25. In such a soft ground 25, the underground structure 30 may be extended to a depth reaching the hard ground 26.
The ground is excavated to a deeper depth, and a vertical groove 12 is provided so as to surround the existing underground structure 30 from both sides, and the bag body 11 is sunk in the vertical groove 12 to form the earthquake-resistant ground 10. .

Here, as shown in FIG. 1 (b), a plurality of bags 11 having a predetermined width are used, and these are continuously provided without gaps to fill the vertical grooves 12 so that the inside of the bag 11 is formed. Is filled with a liquid having a specific gravity of about 1.1 to 2.0, for example, bentonite, and a space 14 is provided above the bag body 11 in the vertical groove 12. At the upper end of the vertical groove 12, a reinforcing member 13 for preventing collapse of the groove wall is provided.
A cover (not shown) is provided on 4.

When the ground is displaced by the earthquake in the soft ground 25 which has been earthquake-resistant as described above, the displacement is transmitted from the soft ground on the outer periphery of the bag body 11 to the vertical groove 12, and the bag body 11 is compressed and deformed. To absorb ground displacement. Therefore,
The displacement transmitted into the soft ground 25 surrounding the existing underground structure 30 from both sides is attenuated, and the external force transmitted to the existing underground structure 30 is significantly reduced.

Next, FIG. 2A is a simplified vertical sectional view of the earthquake-resistant ground different from FIGS. 1A and 1B, and FIG.
FIG. 2 is a plan layout view of FIG. In FIG. 2A, the ground is excavated to a depth reaching the hard ground 26 or deeper than the existing underground structure 30 to form the vertical hole 16.
A plurality of the vertical holes 16 are provided on both sides of the existing underground structure 30 in a staggered arrangement alternately in two rows.
The bag body 15 is sunk in 6 to form the earthquake-resistant ground 20. The bag body 15 is filled with a liquid having a specific gravity of about 1.1 to 2.0 as in the case of the earthquake-resistant ground shown in FIG. 1, and a reinforcing member 18 is provided above the bag body 11 in the vertical hole 16. A gap 17 is provided by being reinforced with a cover, and is closed by a lid (not shown).

Here, in the earthquake-resistant ground 20, FIG.
As shown in the figure, since the plurality of vertical holes 16 are arranged alternately in two rows in a staggered manner, the ground is displaced by the earthquake, and the displacement is transmitted from the soft ground on the outer periphery of the bag body 11 to the vertical holes 16. Then, the bag body 15 in each vertical hole 16 is compressed and deformed to absorb the ground displacement, and the external force transmitted to the soft ground 25 on both sides of the existing underground structure 30 is attenuated.

[0015]

According to the present invention, a vertical groove or a vertical hole is formed in the ground so as to surround an existing underground structure, and a bag filled with fluid is inserted into the vertical groove or the vertical hole. Therefore, even if the ground on the outer periphery of the vertical groove or vertical hole is displaced, the deformation of the bag body attenuates the displacement of the ground surrounding the existing underground structure, The transmitted external force can be reduced. Therefore, in the present invention, as a construction space for constructing an earthquake-resistant ground, only the space required for drilling a vertical groove or a vertical hole surrounding an existing underground structure is sufficient, and as in the related art, the existing ground is required. The progress of the construction is not affected by the usage of the medium-sized structure, and the seismic resistance of the existing underground structure can be reinforced with a small area of construction.

[Brief description of the drawings]

FIG. 1A is a simplified vertical sectional view of an earthquake-resistant ground according to the present invention, and FIG. 1B is a plan layout view of FIG.

FIG. 2 (a) is a simplified vertical sectional view of an earthquake-resistant ground different from FIG. 1, and FIG. 2 (b) is a plan layout view of FIG.

FIG. 3 is a simplified vertical sectional view showing an existing underground structure.

[Explanation of symbols]

 10, 20 Earthquake-resistant ground 11 Bag body 12 Vertical groove 14 Void 15 Bag body 16 Vertical hole 17 Void 25 Soft ground 26 Hard ground 30 Existing underground structure

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masuo Funabiki 2-5-8 Kitaaoyama, Minato-ku, Tokyo F-term (reference) 2D043 CA20 EA08

Claims (4)

[Claims] 1. A vertical groove or a vertical hole drilled in the ground at a predetermined distance so as to surround an existing underground structure, and a fluid inserted into the vertical groove or the vertical hole. A filled bag body, wherein when the surrounding ground is displaced during an earthquake, the bag body is deformed to attenuate the ground displacement and reduce external force transmitted to the existing underground structure. Earthquake resistant ground. 2. The earthquake-resistant ground according to claim 1, wherein the fluid is a liquid having a specific gravity larger than that of groundwater. 3. The earthquake-resistant ground according to claim 1, wherein a void having a predetermined depth is provided above the bag body in the vertical groove or the vertical hole. 4. The earthquake-resistant ground according to claim 1, wherein said vertical holes are provided in a staggered arrangement at predetermined intervals.