JP4278135B2 - Anti-vibration structure of ground and its construction method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an anti-vibration structure for a ground and a method for constructing the same, which reduce the propagation of vibrations generated from railways, roads and the like to the surroundings.
[0002]
[Prior art]
Vibration generated from vehicles traveling on railways and roads propagates inside the ground and spreads to the periphery. For this reason, since buildings built along railway lines and the like are subject to vibration for a long time, measures to reduce the vibration have been conventionally taken.
Vibration reduction measures can be broadly divided into three parts: (1) a method of vibration isolation with a vibration source, (2) a method of providing a vibration isolation wall or vibration isolation groove on the ground as a vibration propagation path, and (3) vibration There is a way to dampen the building foundation and frame that are transmitted.
Among them, the method (2) of providing the vibration-proof wall is a method of blocking the vibration propagation path in the ground. That is, the wave impedance ratio between the vibration-proof wall and the surrounding ground is made large or small, and the propagated vibration is reflected by the vibration-proof wall so that the vibration is not transmitted further. A concrete underground wall is often used as the vibration-proof wall, and the vibration reduction effect increases as the depth of the underground wall is made larger than the wavelength of propagation vibration and the wall thickness is increased. For this reason, a large underground wall is constructed.
Moreover, the flat plate block construction method (refer FIG. 7, patent document 1) which installs the concrete flat block a inside the ground c separated from the vibration source b is known. Further, Patent Document 2 discloses a method in which a pair of anti-vibration blocks are arranged obliquely at an interval and the vibration propagated from the vibration source b is released from between the anti-vibration blocks to the deep part of the ground. .
[0003]
[Patent Document 1]
Patent No. 2850187 [Patent Document 2]
JP 2000-273890 A (FIG. 3)
[0004]
[Problems to be solved by the invention]
The above-described conventional ground vibration isolating structure has the following problems.
<I> In the method of constructing the underground wall, if it is not constructed to the deep part of the ground, the number of diffracted waves that pass through the underground wall increases and the blocking effect is reduced, so that a large underground wall is constructed. For this reason, the construction cost becomes high, and it may be difficult to implement such as when there is a subway or a common groove in the deep ground.
<B> A method of excavating a groove in the ground to insulate vibration is an ideal method, but as the groove becomes deeper, it becomes difficult to maintain the shape. A method of injecting a soft filler in order to maintain the shape of the groove is also conceivable, but the vibration-proofing effect is reduced due to the vibration that propagates through the filler.
<C> The flat plate block construction method is a method of damping the entire ground by installing a flat plate block a that is hard to vibrate. However, there is also a vibration that propagates through the rigid flat plate block a, and the end of the flat block a There is a possibility that the vibration b2 propagates from the portion toward the periphery.
[0005]
OBJECT OF THE INVENTION
The present invention was made to solve the conventional problems as described above, and the ground that can reduce the spread of vibration to the surroundings by propagating the vibration propagated from the vibration source to the ground only in a limited area. An object of the present invention is to provide an anti-vibration structure and its construction method.
It is another object of the present invention to provide a method for constructing an anti-vibration structure for the ground that can be constructed under a railway or road in service.
It is another object of the present invention to provide a ground vibration isolation structure that can be economically constructed and has a highly effective vibration isolation performance, and a method for constructing the same.
The present invention achieves at least one of these objects.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the ground vibration isolation structure of the present invention is a ground vibration isolation structure that reduces the spread of vibration propagating through the ground from a vibration source on the ground, Propagating from the vibration source to the ground, comprising a ground improvement body constructed at a position spaced apart from the vibration source, and a propagation suppression wall connected to the end of the ground improvement body and having an upper surface connected to the ground surface The vibration is damped in the ground surrounded by the ground improvement body and the propagation suppression wall. Here, the ground improvement body can be formed in an italic body that is arranged upward as it is farther from the center of the vibration source, with the lower side of the vibration source as the lowest point.
Moreover, in the above-described ground vibration isolation structure, the ground improvement body is a high-rigid body that is built integrally by adding a solidifying material to the ground, or a concrete or mortar that is integrally formed in a gap excavated from the ground. It is a high-rigidity body to be constructed, and the propagation suppression wall is a hollow or constructed by a low-rigidity body.
[0007]
The ground vibration isolation structure of the present invention is a ground vibration isolation structure that reduces the spread of vibration propagating from the vibration source on the ground to the periphery, with the lower point of the vibration source as the lowest point. The lower ends of a plurality of italics arranged above the plane of the vibration source in plan view are connected to each other, and the upper ends of the italics are connected to the ground surface so that the vibration source is continuously surrounded by the plane. building a soil improvement material obtained by the integral, vibrations propagating in the ground before Symbol vibration source is characterized in that the attenuation in the ground, surrounded by soil improvement material.
[0008]
Further, the construction method of the ground vibration isolation structure of the present invention is a construction method for constructing the ground vibration isolation structure described in any of the above, wherein the ground is stirred while adding a solidifying material, or the ground A method of constructing the ground improvement body by placing concrete or mortar in a gap excavated from the ground, and constructing the propagation suppression wall from the ground surface at a position away from the vibration source toward the end of the ground improvement body It is.
Further, it is a construction method for constructing a ground vibration isolation structure described in any one of the above, wherein a ground or a shaft is constructed by excavating the ground downward from the ground surface at a position away from the vibration source, In this method, the ground improvement body is constructed from the inside of the shaft toward the direction directly below the vibration source, and the propagation suppression wall is constructed in the groove or shaft.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0010]
<I> Ground vibration isolation structure The ground vibration isolation structure referred to in the present invention refers to a structure that reduces the spread of vibration propagating from the vibration source 3 on the ground 4 to the ground 4 to the periphery.
Various types of vibration sources 3 can be mentioned. For example, vibrations generated by passage of traffic vehicles such as railroads and roads, mechanical vibrations generated from machines installed in factories, and the like are typical vibration sources 3. .
The vibration source 3 does not necessarily need to be on the ground surface 41, and corresponds to the ground surface 4 even if it is on the ground surface 41 or on the excavation surface where the ground surface 41 is excavated.
The ground vibration isolating structure of the present invention does not propagate the vibration to the ground 4 but spreads the vibration propagated from the vibration source 3 to the ground 4 only in a limited area. Is reduced. That is, in the present invention, the ground 4 in contact with the vibration source 3 is surrounded by the ground improvement body 1 or the ground improvement body 1 and the propagation suppression wall 2 so as not to leak from the area surrounded by the vibration. This reduces the spread of vibration.
[0011]
<B> Ground Improvement Body The ground improvement body 1 is a portion having a rigidity different from that of the local ground 4. If a continuous body having different rigidity exists in the ground 4, vibration propagated through the ground 4 is reflected at the boundary with the continuous body. Therefore, in the present invention, the continuous ground improvement body 1 is constructed inside the ground 4. For this reason, if the local board 4 is a soft ground, the ground improvement body 1 with a large rigidity and a heavy weight may be constructed. For example, the ground improvement body 1 can be constructed by stirring the ground 4 in place while adding a solidifying material such as cement. Or the ground improvement body 1 can be constructed | assembled by placing concrete or mortar in the clearance gap which excavated the ground. Since the ground improvement body 1 increases in strength due to the solidified material and increases in volume and weight by being constructed as a continuous body, the ground improvement body 1 itself that is subjected to vibration is less likely to vibrate and reduces propagation of vibration. be able to.
The ground improvement body 1 is constructed at a position separated from the vibration source 3. In the present invention, since the vibration 31 generated from the vibration source 3 is once propagated to the ground 4 and reflected by the ground improvement body 1, the ground improvement body 1 and the vibration source 3 should not be directly connected. For example, an italic ground improvement body 1 is constructed with the position directly below the vibration source 3 as the lowest point and arranged upward as the plane is far from the center of the vibration source 3 (see FIG. 1). In this manner, if the slant is formed so that the vicinity directly below the vibration source 3 is the lowest, the vibration 31 propagated from the vibration source 3 rebounds in the direction of the vibration source 3, so that the vibration is less likely to diverge around. .
[0012]
FIG. 4 shows an embodiment in which the ground improvement body 1 is constructed obliquely so that the vicinity of the center is the lowest. In this embodiment, since the construction is made so that the end 12 of the ground improvement body 1 is exposed to the ground surface 41, the vibration propagated from the vibration source 3 to the ground 4 is within the ground 4 surrounded by the ground improvement body 1. It becomes trapped in and becomes difficult to be transmitted to the outskirts. Moreover, since the vibration of the ground improvement body 1 is radiated | emitted to the ground through the edge part 12, the propagation of the vibration in the ground 4 will be interrupted.
[0013]
<C> Propagation suppression wall The propagation suppression wall 2 is a wall body that is disposed at the end 12 of the ground improvement body 1 and suppresses vibration generated from the end 12 of the ground improvement body 1 from diffusing to the periphery. is there. The propagation suppression wall 2 is preferably a soft low-rigid body filled with water so that vibrations are absorbed and difficult to propagate. Moreover, if it is the depth which can maintain a shape, it can also be set as a hollow groove | channel.
When the ground improvement body 1 is constructed of a material having high rigidity, the vibration 31 that has propagated through the ground 4 from the vibration source 3 and reached the ground improvement body 1 is also propagated in the continuous ground improvement body 1 from the end 12. There is a possibility that the vibration 31 may diverge toward the surrounding ground. For this reason, the propagation suppression wall 2 is constructed in order to eliminate leakage of the vibration 31 from the end 12 of the ground improvement body 1. Although the propagation suppression wall 2 may be constructed only to the depth connected to the end portion 12 of the ground improvement body 1, it can also be constructed to a deeper portion to enhance the effect.
The vibration 31 is propagated on the ground 4 on the vibration source 3 side of the propagation suppressing wall 2 and hardly propagates to the ground 4 on the opposite side of the vibration source 3.
[0014]
As the low-rigidity body, a plastic water storage block 22 as shown in FIG. 5 is stacked in the excavated groove and remains hollow, or is configured by pouring water or storing rainwater. Can do. Also, a box-shaped plastic can be inserted into the groove to maintain the shape of the groove. The outer periphery of the box can be covered with a water shielding sheet to keep the inside of the box hollow, or the box can be covered with a water permeable sheet so that the inside of the box is filled with water.
[0015]
Alternatively, the cylindrical hollow pipe 23 can be inserted into the ground 4 in a staggered arrangement to form the propagation suppression wall 2. The cross-sectional shape of the hollow pipe 23 is not limited to a circle, and a quadrangle and a polygon can be adopted. The hollow pipe 23 can be made of a synthetic resin material or a mesh-like metal material.
The hollow pipe 23 can be left empty without being filled with anything, but a soft low-rigidity material such as a tire chip, polystyrene foam, gel, water-sealed rubber tube, or muddy water having a large specific gravity can be used. It may be filled. Moreover, it can also make it easy to deform | transform by making a cut | interruption in the longitudinal direction of the hollow pipe 23. FIG.
[0016]
Hereinafter, the construction method of the ground vibration isolation structure of the present invention will be described with reference to the drawings.
[0017]
<I> Method of building a ground improvement body from the ground surface (Figs. 2 and 4)
A known ground improvement construction method can be applied to the method of constructing the ground improvement body 1. For example, a high-pressure jet stirring method or a mechanical stirring method that stirs the ground while injecting a solidifying material can be applied. Known solidifying materials such as cement and lime can be used as the solidifying material.
FIG. 2 shows a method of constructing the ground improvement body 1 by continuously constructing the columnar improvement portion 11 from the ground surface 41 into the ground 4. For example, an auger excavator that performs high-pressure stirring injection is installed on the ground surface 41, and the columnar improvement portion 11 is partially constructed only at a predetermined depth. The continuous ground improvement body 1 can be constructed | assembled by wrapping and building the columnar improvement part 11 little by little in the horizontal direction. Also, a method of cutting and stirring the ground with a chain cutter can be applied.
[0018]
A known method of constructing an anchor body by excavating and stirring the ground obliquely while adding cement can also be applied. In this case, since the columnar anchor body is constructed, a single ground improvement body 1 is constructed by driving a plurality of anchor bodies so that the anchor bodies are continuous. When a plurality of anchor bodies are driven obliquely from the ground surface 41, the ground improvement body 1 having a shape as shown in FIG. 4 is constructed.
In addition, after constructing the ground improvement body 1 from the surface 41 to the direction directly below the vibration source 3, excavate the place farthest from the vibration source 3 of the ground improvement body 1 and pile up the water storage block 22 and propagate it. The suppression wall 2 can be completed, or the propagation suppression wall 2 can be completed by pouring water or excess rainwater into the groove 21 thereafter.
[0019]
<B> Method of constructing a ground improvement body from within the ground (Fig. 3)
First, a groove 21 or a shaft is excavated at a position where the propagation suppression wall 2 is constructed. Then, the ground improvement body 1 is constructed from the inside of the excavated groove 21 or the shaft toward the direction directly below the vibration source 3. If it is a method of constructing the anchor body described above, it is possible to work even in a narrow space formed by excavation.
After constructing the ground improvement body 1, the propagation control wall 2 is completed by stacking the water storage blocks 22 and the like in the groove 21, or after that, water injection or excess rainwater is introduced into the groove 21 to complete the propagation suppression wall 2. Let
[0020]
【The invention's effect】
Since the ground vibration isolation structure and its construction method of the present invention are as described above, the following effects can be obtained.
<I> The vibration is confined in the ground surrounded by the ground improvement body and the propagation suppression wall or the ground improvement body. For this reason, the vibration propagated from the vibration source to the ground is propagated only to a limited area, and the spread of the vibration to the periphery can be reduced.
<B> If the ground improvement body is constructed from the side of the vibration source directly below the vibration source, the vibration isolation structure of the ground can be constructed under a railway or road in service.
<C> Since it is only necessary to limit the area where vibrations propagate, it is possible to reduce the scale of the structure. For this reason, it can also be constructed economically.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of an embodiment of a ground vibration isolation structure according to the present invention.
FIG. 2 is a cross-sectional view of an embodiment of a ground vibration isolation structure in which a ground improvement body is constructed by a columnar improvement portion.
FIG. 3 is an explanatory diagram of an embodiment of a construction method of a ground vibration isolation structure.
FIG. 4 is a cross-sectional view of an embodiment of a ground vibration isolation structure constructed with only a ground improvement body.
FIG. 5 is a perspective view of an embodiment of a water storage block installed on a propagation suppression wall.
FIG. 6 is a perspective view of an embodiment of a hollow pipe installed on a propagation suppressing wall.
FIG. 7 is an explanatory diagram of an embodiment of a conventional ground vibration isolation structure.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Ground improvement body 2 ... Propagation suppression wall 21 ... Groove 3 ... Vibration source 31 ... Vibration 4 ... Ground

Claims (6)

A vibration isolation structure for the ground that reduces the spread of vibration propagating from the vibration source on the ground to the surroundings,
A ground improvement body constructed at a position spaced downward from the vibration source;
It is connected to the end of the ground improvement body, and consists of a propagation suppression wall whose upper surface is connected to the ground surface,
The vibration propagating from the vibration source to the ground is attenuated in the ground surrounded by the ground improvement body and the propagation suppression wall,
Anti-vibration structure of the ground. In the vibration isolation structure of the ground according to claim 1,
The ground improvement body is an italic body that is arranged upward as it is far from the center of the vibration source, with the lower point of the vibration source as the lowest point.
Anti-vibration structure of the ground. In the vibration isolation structure of the ground according to claim 1 or 2,
The ground improvement body is a high-rigidity body that is integrally constructed by adding a solidifying material to the ground and stirring, or a high-rigidity body that is integrally constructed by placing concrete or mortar in a gap excavated from the ground,
The propagation suppression wall is hollow or constructed by a low-rigidity body,
Anti-vibration structure of the ground. A vibration isolation structure for the ground that reduces the spread of vibration propagating from the vibration source on the ground to the surroundings,
A lower end of the vibration source is connected to the lower end of a plurality of italics arranged in a plan view away from the center of the vibration source with the lowermost point as the lowest point, and the upper ends of the italics are connected to the ground surface. Construct a ground improvement body that is continuous and integrated so as to surround
Vibrations propagating from the front Symbol vibration source to ground is characterized in that the attenuation in the ground, surrounded by soil improvement material,
Anti-vibration structure of the ground. A construction method for constructing a ground vibration isolation structure according to any one of claims 1 to 3,
The ground improvement body is constructed by stirring the ground while adding a solidifying material, or by placing concrete or mortar in a gap excavating the ground,
Constructing the propagation suppression wall from the surface of the ground away from the vibration source toward the end of the ground improvement body,
Construction method of ground vibration isolation structure. A construction method for constructing a ground vibration isolation structure according to any one of claims 1 to 3,
Excavating the ground downward from the ground surface at a position away from the vibration source to construct a ditch or shaft,
Build the ground improvement body from the inside of the groove or shaft toward the direction directly below the vibration source,
Constructing the propagation control wall in the groove or shaft,
Construction method of ground vibration isolation structure.

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