JP5172899B2 - Vibration relaxation structure - Google Patents

Description

  The present invention relates to a vibration relaxation structure, and more particularly to a vibration relaxation structure disposed in a work chamber of a caisson housing in a pneumatic caisson method.

  Conventionally, regarding the sinking work of the caisson frame in the pneumatic caisson method used for shafts and bridge foundations used as underground structures, there is a problem that the caisson frame will be oversunk when the excavation site is soft ground, Various methods have been proposed as countermeasures for preventing the caisson housing from being excessively settled (see, for example, Patent Document 1).

  On the other hand, as a problem related to the sinking operation of the caisson skeleton when the excavation site is hard ground, a large vibration is generated due to an impact when the caisson skeleton sinks. The vibration generated by the impact when the caisson housing sinks may be transmitted to houses around the construction site, and as a result, the construction may have to be interrupted. It was.

Japanese Patent No. 2883859

  In order to suppress the occurrence of vibration by reducing the sinking amount of the caisson housing, it has been considered that the excavation depth below the blade edge portion is decreased to cause the above problem. However, because the ground support force is small due to the small resistance area of the blade edge part, it becomes difficult for the blade edge part to penetrate into the ground and suppress the amount of subsidence. It became difficult and the problem could not be solved.

  In addition, there was a method to reduce the amount of caisson housing sinking by arranging multiple wooden sandles with timbers in the work room, but when the caisson housing is heavily loaded, More space is required, and if there are many places where wooden sandals are arranged, the space for excavation work and the like decreases. For this reason, it has become necessary to spend a lot of time for assembling a large number of wooden sanddles, and there is a problem that work efficiency of excavation work deteriorates due to a lack of space for excavation work.

  In addition, since the wooden sanddle has a low compressive strength, the amount of shrinkage due to the compression becomes large, and the caisson housing subsidence suppression effect is hardly obtained. In addition, when the caisson housing sinks, the timber of the assembled wooden sandle scatters, and the caisson housing sinking amount may not be exhibited at all.

  The present invention has been made in view of such circumstances, and can reduce the shock and vibration when the caisson housing sinks in the pneumatic caisson method, and can reduce the time for installation and removal. An object is to provide a structure.

In order to solve the above-mentioned problem, the invention according to claim 1 of the present invention is arranged between the ceiling slab of the work room of the caisson housing and the ground below the caisson housing in the pneumatic caisson method. A vibration mitigating structure that sometimes receives the impact load, provided to protrude downward from the ceiling slab of the work chamber, and a transmission material made of a highly rigid material, and placed under the transmission material, Cushion material that is deformed when subjected to a predetermined impact load, and a gap adjustment that is placed under the transmission material and arranged to fill a gap generated between the cushion material and the transmission material or the ground has a timber, and when subsidence of the caisson skeleton, impact load is transmitted to the cushion member via the transfer material, thereby reducing the impact load by the cushion member is deformed Together has become earthenware pots that, connecting a side surface of the ceiling slab and the transmitted member of the working chamber, and with the vibrational relaxation structure having a hanging member for preventing the falling from the ceiling slab of the transmission member It is characterized by.

  According to the invention described in claim 1 of the present invention, since the vibration damping structure has a structure having a highly rigid transmission material, a cushion material and a gap adjusting material placed under the rigid transmission material, this vibration damping structure is provided. By using the structure to sink the caisson housing on the hard ground, the transmission material is not deformed and the cushioning material is deformed by a necessary and sufficient amount. The repulsive force and the impact load at the time can be reduced, and as a result, the vibration due to the repulsive force and the impact can be surely suppressed and reduced.

  In addition, since the transmission material is provided so as to protrude downward from the ceiling slab, installation and removal of only the cushioning material and the gap adjustment material other than the transmission material is sufficient when installing and removing the vibration mitigation structure. The work amount and work time required for installing and removing the vibration relaxation structure can be shortened.

In addition, since it has a suspension member for preventing the transmission material from falling from the ceiling slab, it is possible to prevent it even if the transmission material fixed to the ceiling slab is about to fall. As a result, work safety can be maintained, increase in work amount and work time can be minimized, and occurrence of extra vibration can be prevented.

It is the schematic which shows the structure of the caisson housing in the pneumatic caisson construction method provided with the vibration mitigation structure which concerns on embodiment of this invention. It is a front view which shows the structure of the vibration relaxation structure which concerns on embodiment of this invention. It is AA sectional drawing of FIG. It is an arrangement plan of a vibration mitigation structure concerning an embodiment of the present invention in a work room of a caisson housing. It is explanatory drawing of the installation operation | work of the vibration relaxation structure which concerns on embodiment of this invention. It is explanatory drawing of the installation operation | work of the vibration relaxation structure which concerns on embodiment of this invention.

  Embodiments of the present invention will be described below.

  First, the configuration of the caisson casing 1 in the pneumatic caisson method will be briefly described with reference to FIG.

  As shown in FIG. 1, a side wall 1a is formed in the caisson housing 1 of the present embodiment along the vertical direction, and a blade edge portion 7 is formed below the side wall 1a. In addition, a work chamber 2 for performing excavation work in a high-pressure state is provided at a location surrounded by the lower ground G in the caisson housing 1, the blade edge portion 7, and the ceiling slab 3 that connects the side walls 1 a in the horizontal direction. Is formed. In addition, a load water W for promoting the settlement of the caisson housing 1 can be loaded above the ceiling slab 3. An excavator 6 for subsidence excavation of the caisson housing 1 is suspended on the lower surface of the work chamber slab 3 so as to be remotely operable.

  In addition, since FIG. 1 is a schematic diagram, the material shaft provided in the vertical direction in the caisson housing 1, the material lock connected to the upper portion of the material shaft, and also provided in the vertical direction in the caisson housing 1. A plurality of members and devices necessary for a pneumatic caisson method including a man shaft for a person to move up and down, a man lock connected to the upper portion of the man shaft, an air supply pipe, an exhaust pipe, and the like are omitted.

  In the work chamber 2 of the caisson housing 1, a vibration mitigation structure that receives and reduces the repulsive force and impact load when the caisson housing 1 sinks, and suppresses and reduces vibrations generated by the repulsive force and impact load. 10 is arranged between the ceiling slab 3 and the ground G below it. Hereinafter, the vibration relaxation structure 10 of the present embodiment will be described.

  First, the configuration of the vibration relaxation structure 10 of the present embodiment will be described with reference to FIGS. The vibration relaxation structure 10 according to the present embodiment includes a transmission material 20, a cushion material 30, a dispersion material 40, and a gap adjustment material 50. Hereinafter, each member will be described in order.

  The transmission material 20 protrudes downward from the ceiling slab 3 of the work chamber 2 and is made of a material having high rigidity. The transmission member 20 is a member for transmitting an impact load transmitted from the caisson housing 1 when the caisson housing 1 is lowered. This transmission material 20 has a structure that is fixed (or integrated) to the ceiling slab 3 of the work room 2 so that it does not move or break even when the caisson housing 1 sinks, and is installed every time the caisson housing 1 sinks. There is no need to remove it.

  The transmission material 20 according to the present embodiment is configured by connecting a plurality of steel materials (particularly H steel) 21 in a columnar shape in the vertical direction and connecting the nine steel materials 21 in three rows. They are connected in × 3 rows to form a substantially square shape in plan view. The shape of the transmission material 20 may be appropriate, and may be a substantially circular shape, an elliptical shape, a rectangular shape other than a square shape, or other free shapes in plan view.

  In addition, the transmission material 20 of the present embodiment connects a plurality of steel materials 21 with bolts 22 and, if necessary, passes a plurality of connection materials 23 made of channels, angles, and other steel materials in the horizontal direction, It is configured to reinforce the surroundings. In addition, a connection reinforcing member 24 for reinforcing the fixation with the ceiling slab 3 is disposed in a horizontal direction at a location in contact with the ceiling slab 3. In the present embodiment, a reinforcing material 4 such as an iron plate or H steel is fixed to the ceiling slab 3 where the transmitting material 20 is fixed by bolting or welding, and the transmitting material 20 is fixed to the reinforcing material 4. The transmission member 20 is fixed to the ceiling slab 3 through the reinforcing member 4 by fixing 20 by bolting or welding. By doing in this way, an impact load is distributed also from the transmission material 20 to the ceiling slab 3. The reinforcing material 4 may be attached to the ceiling slab 3 later, or may be embedded in the ceiling slab 3 in advance. Further, the ceiling slab 3 and the reinforcing material 4, and the reinforcing material 4 and the transmission material 20 may be configured to be removable as necessary.

  Moreover, in this Embodiment, it has the suspension member 60 which connects the ceiling slab 3 and the side surface of the transmission member 20 as a countermeasure against fall of the transmission material 20. The suspension member 60 of the present embodiment is installed by welding the suspension piece 62 for hanging the chain 61 on both the ceiling slab 3 and the portion of the connecting member 23 constituting the transmission member 20 that protrudes from the steel 21 to the side surface. The chain 61 is stretched and connected to each other. In addition, you may make it take a fall prevention measure by another method. Moreover, it is preferable that the plane size of the transmission material 20 is the same as or smaller than the plane size of the dispersion material 40 described later so that the excavator 6 can easily pass through the work chamber 2.

  The cushion material 30 is configured to be deformed when subjected to a predetermined impact load (in this embodiment, to be deformed so as to be crushed). By this deformation, the caisson housing 1 passes through the transmission material 20. It is designed to absorb and reduce the repulsive force and impact load when the caisson housing 1 is sunk. Then, by reducing the repulsive force and the impact load, the vibration generated when the caisson housing 1 sinks is suppressed and alleviated to reduce the vibration.

  The cushion material 30 is placed on the ground G below (directly below) the transmission material 20 that protrudes from the ceiling slab 3. In this embodiment, a wooden thing such as a so-called drum drop is assembled in a cross-beam shape. The cushion material 30 is not limited to a wooden material, and may be a rubber such as a fender. Further, the thickness of the cushion material 30 may be changeable according to the height of the work chamber 2 or in order to adjust the sinking amount of the caisson housing 1, for example as in the present embodiment. In the case of a structure in which simple wooden objects are assembled, they may be configured in a single stage, in a two-stage grid pattern, or in a three-stage or more grid pattern. The cushion material 30 is preferably made of a material having a strength lower than that of the natural ground. In addition to changing the thickness of the cushion material 30, the amount of settlement can be adjusted by changing to a material having different stretchability. The cushion member 30 can be reused if it has a predetermined elasticity even after the caisson is sunk, but is replaced with a new one when the predetermined elasticity is lost.

  The dispersion material 40 is placed below the transmission material 20. In this embodiment, the dispersion material 40 is placed immediately above the cushion material 30, and the impact load transmitted through the transmission material 20 is evenly distributed. It is a member that is dispersed and transmitted to the cushion material 30. In the present embodiment, the dispersion material 40 is formed by combining steel materials such as H steel in a substantially plate shape. As the dispersion material 40, a material having high rigidity and small stretchability is used. For example, metals and alloys other than steel and iron can be used. Further, the shape of the dispersion material 40 may be any shape that can uniformly disperse the impact load, and may be a steel plate or the like.

  The dispersing material is not limited to the one placed below the transmission material 20 as in the present embodiment, and may be configured to be fixed to the lower portion of the transmission material 20 by bolts, welding, or the like. As described above, when the dispersion material is fixed to the lower portion of the transmission material 20, not only the transmission material 20 but also the dispersion material is installed and removed when the vibration relaxation structure 10 is installed and removed. Therefore, the work efficiency can be improved, and work efficiency can be improved.

  The gap adjusting material 50 is placed below the transmission material 20. In this embodiment, the gap adjustment material 50 is placed immediately above the dispersion material 40, and the transmission material 20 and the cushion material 30 (here, the transmission material 20). And disperse material 40). In some cases, the gap adjusting material 50 may be disposed below the cushion material 30. In this case, the gap adjusting material 50 serves to fill a gap generated between the cushion material 30 and the ground G. Will have.

  In addition, each of the transmission material 20, the gap adjusting material 50, the dispersion material 40, and the cushion material 30 according to the present embodiment is configured to be placed and not fixed. Thereby, since the work time of installation and removal of the vibration relaxation structure 10 can be shortened, it is preferable.

  Thus, the transmission material 20 is provided so as to protrude downward from the ceiling slab 3, and between the transmission material 20 and the ground G, the cushion material 30 and the dispersion material 40 are installed in order from the bottom, and the dispersion material 40. Since the gap adjusting material 50 is disposed so as to fill the gap S between the transmission material 20 and the transmission material 20, the cushion material 30 is interposed via the transmission material 20, the gap adjustment material 50, and the dispersion material 40 when the caisson housing 1 sinks. The impact load is transmitted to the cushion member 30, and the cushion material 30 is deformed so that the impact load can be reduced. And the cushion material 30 has an appropriate cushioning property and absorbs and reduces the repulsive force and impact load when the caisson housing 1 sinks, thereby suppressing the vibration generated by the repulsive force and impact load. It can be relaxed.

  In addition, since the transmission material 20 is provided so as to protrude downward from the ceiling slab 3, when the caisson sinks once and the vibration mitigation structure 10 is reassembled, the amount of work for assembling the wooden sanddle from scratch. In addition, the work amount and work time for assembling the cushion material 30, the dispersion material 40, and the gap adjusting material 50 may be sufficient without requiring work time. As a result, the work amount and work time required for the pneumatic caisson method can be shortened.

  In addition, the vibration relaxation structure 10 is arranged in an appropriate number and an appropriate place depending on the size, weight, shape, etc. of the caisson housing 1. In the present embodiment, as shown in FIG. 4, ten vibration relaxation structures 10 are arranged in the work chamber 2 having a rectangular shape in plan view surrounded by the side wall 1a. Further, as shown in FIG. 4, when the partition wall 1b is provided above the work chamber 2 in the caisson housing 1, it is better to dispose each of the plurality of vibration relaxation structures 10 below the partition wall 1b. .

  Next, the procedure of installation and removal work of the vibration relaxation structure 10 according to the present embodiment will be described with reference to FIGS.

  First, the material of the vibration relaxation structure 10 such as the steel material 21 and wood is transported to the work chamber 2 through the material shaft. Next, as shown in FIG. 5, the reinforcing material 4 is fixed to the ceiling slab 3 of the work chamber 2 of the caisson housing 1 by bolting or welding, and the connection reinforcing material 24 is fixed below the reinforcing material 4.

  Next, as shown in FIG. 5, the steel material 21 is transported and lifted by the table lifter 5 and is fixed to the reinforcing material 4 and the connecting reinforcing material 24 by bolts 22 or welding, respectively. Fix it.

  Next, as shown in FIG. 6, the fixed steel materials 21 are further fixed by a connecting material 23 so as to surround the periphery. As a measure for preventing the transmission material 20 from dropping, the suspension piece 62 of the suspension member 60 is fixed to the ceiling slab 3 and the side surface of the transmission material 20 (here, fixed by welding), and the chain 61 of the suspension member 60 is fixed to the suspension piece 62. give. Thereby, the transmission material 20 in the vibration relaxation structure 10 is completed.

  Next, as shown in FIG. 6, the drum-dropped wood as the cushion material 30 is placed on the ground G below (directly below) the transmission material 20. Here, the timber is assembled in a two-tiered pattern. The cushioning material 30 may be installed by stacking wood one by one and assembling the cushioning material 30, but the wood is previously joined one by one with nails or scissors, If the cushion material 30 is assembled by overlapping the two layers, the time required for the installation work can be shortened. Further, it is also possible to join a plurality of timbers (in this case, two tiers) necessary with nails, scissors or the like in advance and place them on the ground G.

  Next, as shown in FIG. 6, a dispersion material 40 in which steel materials are assembled in a substantially plate shape is placed.

  Finally, as shown in FIG. 2, the vibration reducing structure 10 is completed by placing the gap adjusting material 50 so as to just fit the gap S. By repeating this as many times as necessary, the caisson housing 1 is ready to sink.

  After that, when the caisson housing 1 is sunk, a predetermined amount of wood as the cushion material 30 is crushed, so that the cushion material 30, the dispersion material 40, and the gap adjusting material 50 are excavated to allow the cushion material 30 and the like to be taken out. Remove. Then, a new cushion material 30, a dispersion material 40, and a gap adjustment material 50 are placed again below the fixed transmission material 20. By repeating this, the sinking work of the caisson housing 1 is performed.

  When the surface of the ceiling slab 3 is concrete and it is necessary to fix the transmission material 20 made of steel or the like, as in the present embodiment, as the reinforcing material 4, a material that becomes a dispersion material such as an iron plate is interposed between them. It only has to be installed and fixed with a ceiling slab 3 and an anchor.

  Further, as a method for installing the transmission material 20 using the table lifter 5, all or one of the steel materials 21 on the ground G can be used by lifting the steel materials 21 one by one and fixing them to the ceiling slab 3. Alternatively, only the portions may be connected and then lifted and fixed to the ceiling slab 3.

  As described above, in the vibration relaxation structure 10 of the present embodiment, the vibration relaxation structure 10 includes the highly rigid transmission material 20, the cushion 30 material and the gap adjustment material 50 placed therebelow. Therefore, by performing the sinking operation of the caisson housing 1 in the hard ground G using the vibration relaxation structure 10, the transmission material 20 is not deformed and the cushion material 30 is deformed by a necessary and sufficient amount. The caisson housing 1 can maintain an appropriate amount of sinking and reduce the repulsive force and impact load at the time of subsidence. As a result, it is possible to reliably suppress and mitigate vibration due to the repulsive force and impact.

  In addition, since the transmission material 20 is provided so as to protrude downward from the ceiling slab 3, only the cushion material 30 and the gap adjustment material 50 other than the transmission material 20 are provided when the vibration mitigation structure 10 is installed and removed. Therefore, the amount of work and the time required for installing and removing the vibration mitigation structure 10 can be shortened. Moreover, it becomes possible to adjust the sinking amount of the caisson housing 1 by changing the material of the cushion material 30 and how to assemble the cushion material 30 and adjusting the height thereof.

  Further, in the vibration relaxation structure 10 of the present embodiment, in addition to the above-described effects, the dispersion material 40 is placed below the transmission material 20, so that the dispersion material 40 has an impact when the caisson housing 1 is subsidized. The load can be evenly distributed. As a result, the impact load at the time of sinking can be further reduced, and the vibration caused by the impact can be more reliably suppressed and mitigated.

  Further, in the vibration relaxation structure 10 of the present embodiment, in addition to the above-described effects, the transmission material 20 is fixed to the reinforcing material 4 fixed to the ceiling slab 3, so that the transmission material 20 is attached to the ceiling slab 3. The transmission material 20 can be more firmly fixed to the ceiling slab 3 and the impact load transmitted from the transmission material 20 to the ceiling slab 3 can be dispersed.

  In addition, in the vibration relaxation structure 10 according to the present embodiment, the thickness of the cushion material 30 can be changed in addition to the above-described effects. Therefore, the sinking amount of the caisson housing 1 depends on various conditions such as the state of the ground G. When it is necessary to adjust the caisson housing 1, the amount of settlement of the caisson housing 1 can be easily adjusted according to the situation.

  In addition to the effects described above, the vibration relaxation structure 10 according to the present embodiment includes the suspension member 60 for preventing the transmission material 20 from dropping from the ceiling slab 3. Even if the transmission material 20 is about to fall, it can be prevented. As a result, the safety of the work can be maintained, the increase in the work amount and the work time can be minimized, and the extra vibration. Can be prevented.

  Further, if the dispersion material is fixed to the lower portion of the transmission material 20 without being placed under the transmission material 20, the dispersion material can evenly distribute the impact load when the caisson housing 1 sinks. As a result, the impact load during subsidence can be further reduced, vibration due to the impact can be more reliably suppressed and mitigated, and the dispersion material is fixed to the lower portion of the transmission material 20 to reduce vibration. At the time of installation and removal of the relaxation structure 10, it is not necessary to install and remove the dispersion material together with the transmission material 20. As a result, the amount of work and time required for installation and removal of the vibration relaxation structure 10 are reduced. It can be shortened.

  The embodiment described above is described in order to facilitate understanding of the present invention, and is not described in order to limit the present invention.

  For example, the transmission material 20 of the present embodiment is formed by combining H steel, but is not limited thereto, and may be a steel column made of a steel frame other than H steel, and has high rigidity. The material may be a composite material such as H steel and concrete, or a columnar body using a metal or alloy other than iron.

  Moreover, in this Embodiment, although the transmission material 20 combines H steel and it fixes to the ceiling slab 3 later, this invention is not limited to this, The ceiling slab 3 of the caisson housing 1 And may be integrated in advance. That is, when the ceiling slab 3 of the caisson housing 1 is formed, the transmission material 20 that protrudes downward in advance is also formed in an integrated state. The transmission material 20 formed in this way is formed in a columnar shape with reinforced concrete or steel reinforced concrete.

  Further, in the present embodiment, the table lifter 5 is used for transporting and lifting steel materials and the like. However, the present invention is not limited to this, and transport and the like are performed using other lifting means and lifting means. May be.

  Further, the vibration relaxation structure 10 of the present embodiment has a configuration in which the transmission material 20, the gap adjustment material 50, the dispersion material 40, and the cushion material 30 are arranged in order from the top, but the present invention is not limited thereto. Instead, the order in which the cushion material 30 other than the transmission material 20, the dispersion material 40, and the gap adjusting material 50 are arranged may be different. That is, the transmission material 20, the gap adjustment material 50, the cushion material 30, and the dispersion material 40 from the top, the transmission material 20, the dispersion material 40, the gap adjustment material 50, and the cushion material 30 from the top, the transmission material 20, from the top. Dispersing material 40, cushion material 30, and clearance adjusting material 50 in this order, transmission material 20 from above, cushioning material 30, clearance adjusting material 50, dispersion material 40 in this order, transmitting material 20, cushioning material 30, dispersing material 40 from above The order of the gap adjusting material 50 may be used.

  Moreover, although the vibration relaxation structure 10 of the present embodiment has the configuration including the transmission material 20, the cushion material 30, the dispersion material 40, and the gap adjustment material 50, the present invention is not limited to this. . For example, when the shape and area of the transmission material 20 and the cushion material 30 below the same are the same in plan view, the pattern without the dispersion material 40 is also possible, depending on the material. possible. Even in a pattern without the dispersion material 40, the order in which the cushion material 30 other than the transmission material 20 and the gap adjustment material 50 are arranged may be different. That is, the transmission material 20, the gap adjustment material 50, and the cushion material 30 may be arranged in this order from the top, or the transmission material 20, the cushion material 30, and the gap adjustment material 50 may be arranged in this order from the top.

DESCRIPTION OF SYMBOLS 1 Caisson housing | casing 1a Side wall 1b Partition 2 Work room 3 Ceiling slab 4 Reinforcement material 5 Table lifter 6 Excavator 7 Cutting edge part 10 Vibration relaxation structure 20 Transmission material 21 Steel material 22 Bolt 23 Connection material 24 Connection reinforcement material 30 Cushion material 40 Dispersion Material 50 Gap adjustment material 60 Suspension member 61 Chain 62 Suspension piece G Ground S Gap W Load water

Claims (1)

A vibration mitigation structure that is disposed between the ceiling slab of the work room of the caisson housing in the pneumatic caisson method and the ground below it, and receives the impact load when the caisson housing sinks,
Protruding downward from the ceiling slab of the working room, a transmission material made of a highly rigid material,
A cushion material placed under the transmission material and deformed when subjected to a predetermined impact load;
A gap adjusting material placed below the transmission material and arranged to fill a gap generated between the cushion material and the transmission material or the ground;
Have
When the caisson housing sinks, an impact load is transmitted to the cushion material through the transmission material, and the cushion material is deformed to reduce the impact load .
A vibration mitigating structure having a suspension member that connects the ceiling slab of the working chamber and a side surface of the transmission material and prevents the transmission material from falling from the ceiling slab .

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