JP2009068213A - Construction method for underground structure using caisson, and caisson with cut-off device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cut-off method for construction of an underground structure, which enables a bedrock section to be more accurately constructed than by excavation without timbering and a New Austrian Tunnelling Method, by constructing natural ground having an upper section with a high coefficient of permeability by a pneumatic caisson method. <P>SOLUTION: The natural ground 21 with the high coefficient of permeability until a leading end of a cutting edge 2 of the caisson reaches bedrock 22 is excavated by the pneumatic caisson method, so that the caisson can be settled. When the leading end of the cutting edge 2 of the caisson reaches the bedrock 22, a grout material is infilled into a void between an outer surface of a caisson skeleton 1 and the natural ground 21. Subsequently, the bedrock section is excavated by the excavation without timbering and the New Austrian Tunnelling Method. In the case of the production of sump water from the bedrock 22 during the excavation of the bedrock section, after the sump water is temporarily stopped by applying working air pressure consistent with sump water pressure, cut-off grouting is performed, and the bedrock section is excavated to a predetermined depth, so that the prescribed underground structure can be constructed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a construction method for water stoppage when a caisson is set, and a caisson with a water stop device for carrying out this water stoppage method.

  In recent years, there are an increasing number of cases in which caisson is deeply penetrated from the ground to provide underground space.

  The excavation of the rock part on the ground or in the tunnel is generally possible by the underground digging or natom method, but if there is a highly permeable ground in the upper part of the underground rock mass, the excavation is difficult by the digging or natom method . In such a case, a method of penetrating the caisson deeply into the rock is often adopted by the pneumatic caisson method.

  When the caisson is constructed to penetrate deeply into the rock mass by the pneumatic caisson method, it is easy to excavate the ground with high permeability coefficient, but excavation of the rock mass requires blasting work under high pressure. Will be forced to work hard. Japanese Patent Laid-Open No. 9-158197 is a prior example of excavation by blasting work. In addition, there is a problem that the work efficiency is poor due to the restriction of the working time under high atmospheric pressure, the number of processes is increased, and the construction period is lengthened, resulting in an increase in cost.

  In order to solve this problem, it is conceivable that the process and cost can be reduced by constructing a natural ground with a high hydraulic conductivity in the upper part by the pneumatic caisson method and constructing the rock mass by the atmospheric pressure natom method.

However, if it is constructed at atmospheric pressure during the construction by the Natom method, there is a problem that groundwater flows into the working chamber from the gap between the caisson housing and the natural ground, making construction difficult. Even if groundwater does not flow from the gap between the caisson body and the natural ground, spring water may be generated from the excavation site in the rock and the construction may be difficult.
JP-A-9-158197

  The present invention has been made in view of the above circumstances. The purpose of the present invention is to construct a natural ground with a high permeability coefficient by a pneumatic caisson method, and to accurately construct a rock portion by digging or natom method. An object of the present invention is to provide a method for constructing an underground structure using caisson.

  Moreover, the other object of this invention is to provide the caisson with a water stop apparatus which can implement the said water stop method of this invention exactly.

  In order to achieve the above object, in claim 1, the caisson is sunk by excavating a highly water-permeable ground 21 until the tip of the caisson blade 2 reaches the rock 22 by a pneumatic caisson method. When the tip of the caisson blade 2 reaches or penetrates the bedrock 22, the gap g between the outer surface of the caisson housing 1 and the natural ground 21 is filled with a grout material 23 to block the water supply, and the bedrock portion is dug. Or, it is excavated by the Natom method, and the rock portion is excavated to a predetermined depth to construct a predetermined underground structure.

  Further, in order to better achieve the above object, in claim 2, in the underground structure construction method according to claim 1, the inner surface of the blade edge 2 and the inner surface of the blade edge 2 toward the upper surface of the bedrock 22. A space 19 is formed by the partition plate 17 and the bedrock 22 attached in this manner, and the space 19 is filled with a grout material 23a, so that the grout material 23 in the gap g is prevented from leaking into the work chamber 3. ing.

  Furthermore, in order to achieve the object, according to claim 3, in the method for constructing an underground structure according to claim 1, 2, or 3, the pressure in the work room 3 of the caisson is lowered, and spring water is placed in the work room 3. In the case of the occurrence of water, the gap g between the outer surface of the blade edge 2 and the rock mass 22 is stopped, and then the rock mass is excavated by a natural digging or natom method, and the rock mass 22 is springed during the excavation of the rock mass. If this occurs, the work pressure corresponding to the spring pressure is applied to the caisson's pressure equipment to temporarily stop the spring, and then a water stop grout or lining is carried out to lower the work pressure and remove the bedrock part. A predetermined underground structure is constructed by excavating to a predetermined depth.

  Furthermore, in order to achieve the above-described object more reliably, in claim 4, there is a significant layer of spring water in the rock 22 during excavation of the rock portion, and when it reaches, the spring pressure is increased by the caisson pressure equipment. The work pressure is commensurate with the water pressure, the spring water is stopped, the support work 28 is installed, the lining 29 is applied, the water is stopped, the work pressure is lowered, and the work is excavated by the natural digging or the natom method, and underground in the bedrock I try to build a structure.

  In the fifth aspect, the caisson attaches a partition plate 17 extending from the inner surface of the blade edge 2 toward the upper surface of the rock mass 22 in the work chamber 3, and the inner surface of the blade mouth 2, the upper surface of the rock mass 22, and the partition plate 17. To form a space 19, a second inlet 18 is provided on the partition plate 17 on the side of the working chamber 3, and the grout material 23 can be supplied to the second inlet 18 from the side of the working chamber 3. Connected to pumping equipment.

  In the method according to the first aspect of the present invention, the natural ground 21 is excavated by the pneumatic caisson method until the tip of the caisson blade edge 2 reaches or penetrates the rock 22 to sink the caisson. When the tip of the caisson blade 2 reaches or penetrates the bedrock 22, the gap between the outer surface of the caisson housing 1 and the ground 21 is filled with the grout material 23, the water supply is closed, and the tip of the blade 2. Prevents water leakage from the room to the work room 3. Thereby, after the front-end | tip part of the blade edge | tip 2 reaches the rock mass 22, it can prevent reliably the water leak in the working chamber 3, and the inundation of spring water. Therefore, the bedrock portion can be excavated efficiently by the bare digging or the natom method, the number of processes can be reduced, and the construction period can be shortened, so that the cost can be reduced.

  Further, according to the method of the present invention, since the tip end of the blade edge 2 reaches or penetrates the bedrock 22, the water is stopped so that water leakage or spring water does not enter the work chamber 3 as described above. It is not necessary to keep the inside of the work chamber 3 at a high atmospheric pressure in order to suppress the generation of water and spring water. Therefore, there is an effect that the operator can be released from the troublesome work under the high atmospheric pressure and the excavation work can be performed safely.

  Further, in the method of the present invention described in claim 2, a space 19 is formed by the partition plate 17 between the inner surface of the blade edge 2 and the upper surface of the rock 22 and the space 19 is filled with the grout material 23, Since the grout material 23 is prevented from leaking into the work chamber 3 from the 21 side, there is an effect that construction can be performed more efficiently.

  Furthermore, in the method of the present invention according to claims 3 and 4, even if there is a spring layer such as a pressurized sand layer or a crush zone in the bedrock, the spring water is stopped by the caisson pressure equipment, and the support work 28 is After installation and lining 29, an underground structure can be constructed in the rock mass by performing an underground digging or a natom method.

  Furthermore, in the caisson of the present invention according to claim 5, a partition plate 17 extending from the inner surface of the blade edge 2 toward the upper surface of the bedrock 22 is attached, and the inner surface of the blade mouth 2, the upper surface of the bedrock 22, the partition plate 17, The space 19 is formed by the above, and the second injection port 18 is provided on the work chamber 3 side of the partition plate 17, and the grout material 23 is filled into the space 19 through the second injection port 18. Since the grout material 23 is prevented from leaking into the work chamber 3, the method of the present invention can be implemented more accurately.

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

  FIGS. 1 to 5 show Example 1 of the present invention, and FIG. 1 is a longitudinal side view of a caisson with a water stop device, in a state in which the tip of the blade edge is submerged until it reaches the upper surface of the rock mass. Fig. 2 is a longitudinal side view of a state in which the rock mass is excavated and the caisson is submerged. Fig. 3 is a longitudinal side view of the state in which an underground structure is constructed by excavating the rock mass to a predetermined depth. 4 is a cross-sectional view taken along line AA in FIG. 1, and FIG. 5 is an enlarged view of a portion B in FIG.

  In the embodiment of the present invention shown in FIGS. 1 to 5, the pneumatic caisson is surrounded by a caisson housing 1, a blade edge 2 formed at the lower part thereof, an inner surface of the blade edge 2, and a work chamber slab 4. The working chamber 3, the upper chamber 5 surrounded by the upper surface of the working chamber slab 4, the lower surface of the upper slab 6, and the lower inner surface of the caisson housing 1, and the ceiling surface of the working chamber 3 through the working chamber slab 4 and the ground. A material shaft 7 extending toward the top, a material lock 8 installed at the top, a man shaft 9 extending from the ceiling surface of the work chamber 3 to the ground via the work chamber slab 4, and a manlock 10 installed at the top And equipped with pneumatic equipment and excavator. The pneumatic equipment and excavator are not shown.

  The pneumatic caisson is provided with a water stop device.

  The water stop device includes a first injection passage 11 for grout material, a first injection port 12 provided in the first injection passage 11, a second injection passage 13, and a grout material pumping facility ( (Not shown).

  The first injection passage 11 is provided in the direction of the working chamber slab 4 from the upper surface of the caisson housing 1 through the inside using a pipe. Further, a plurality of the first injection passages 11 are provided at a predetermined interval. Further, the upper end portion of each first injection passage 11 is connected to a grout material pumping facility.

  The first injection ports 12 are provided in the first injection passages 11 so that the grout material 23 can be injected into the gap between the outer surface of the caisson housing 1 and the natural ground 21. A plurality of first injection ports 12 are provided at a predetermined interval in the height direction of the caisson housing 1.

  The second injection passage 13 is obliquely inserted from the upper surface of the working chamber slab 4 toward the outer surface of the lower portion of the blade edge 2 by a pipe, and is formed in the space between the outer surface of the lower portion of the blade edge 2 and the bedrock 22. The grout material 23 is provided so as to be injected. A plurality of second injection passages 13 are also provided at a predetermined interval. Moreover, the upper end part of each 2nd injection | pouring channel | path 13 is connected to the grout material pumping equipment.

  As shown in an enlarged view in FIG. 5, a check valve 14 is provided on the outlet side of each second injection passage 13. This check valve 14 prevents the grout material 23 filled in the gap between the caisson housing 1 and the natural ground 21 and the water staying in the gap from flowing back into the second injection passage 13. Yes.

  Next, an example of the construction method of the present invention will be described in relation to the operation of the first embodiment configured as described above.

  First, a caisson is constructed on the ground, the caisson is installed at a position where it should be submerged, and equipment and facilities necessary for the pneumatic caisson method are attached to the caisson.

  And the natural water 21 with high water permeability is excavated by the pneumatic caisson method. That is, the work chamber 3 is kept in a pressurized state, the bottom ground of the work chamber 3 is excavated by an excavator, the excavated soil is lifted to the ground, and the excavation work is repeated, as shown in FIG. The caisson is lowered until the tip of the blade edge 2 reaches or penetrates the upper surface 22 ′ of the rock 22.

  Next, the grout material 23 is pumped to the first injection passages 11 from the grout material pumping equipment installed on the ground, and the grout material 23 is passed through the first injection passages 11 by the first injection ports 12. The gap g between the outer surface of the caisson housing 1 and the natural ground 21 is filled to close the water supply.

  Next, the air pressure in the work chamber 3 is gradually reduced, and the presence or absence of the occurrence of spring water from the tip of the blade edge 2 into the work chamber 3 is inspected.

  If spring water is generated in the work chamber 3 from the tip of the blade 2, the second injection passage 13 and the check valve 14 pass through the work chamber 3 from the grout material pumping equipment installed in the upper chamber 5. The water stop effect is increased by filling the gap g between the blade edge 2 and the rock mass 22 with the grout material 23 through (see FIG. 5).

  After the grout material 23 is filled in the gap g between the blade edge 2 and the rock mass 22, the check valve 14 automatically closes the outlet of the second injection passage 13, so that the outer surface of the caisson housing 1 and the ground 21 It is possible to prevent the backflow of the grout material 23 and water filled in between to the second injection passage 13.

  After stopping the water leakage from the tip of the blade edge 2 to the working chamber 3 by the water stop operation described above, the pressure is lowered and the rock 22 is blasted, and the rock portion is excavated to a predetermined depth by bare digging or natom method. Then, the excavated sediment is lifted to the ground and discharged. At this time, leave the caisson pressure equipment.

  When spring water is generated from the rock mass 22 during excavation of the rock mass, the working pressure corresponding to the spring pressure is applied by the existing pressure equipment, the spring water is temporarily stopped, and the rock mass 22 is excavated Stop the spring water by grouting the spring water of the natural ground.

  Thereafter, the pressure in the space where the rock 22 is excavated is reduced to the atmospheric pressure, and then the excavation is performed again by the bare digging or the natom method and excavating to a predetermined depth. The Natom method is generally used for the construction of mountain tunnels, but here it will be used in the vertical direction to construct the rock mass.

  At the time of construction by the above-mentioned Natom method, support works and lock bolts are installed as necessary.

  The above excavation work is repeated to excavate the rock portion to a predetermined depth, and as shown in FIG. 3, a lining 25 is applied to the excavated space 24 to construct a desired underground structure 26.

  According to the first embodiment described above, until the tip portion of the blade edge 2 reaches the rock mass 22, the ground 21 having high water permeability is excavated by the pneumatic caisson method, and the tip portion of the blade edge 2 is rock bed. When reaching 22, water leakage entering the working chamber 3 from the gap between the outer surface of the caisson housing 1 and the natural ground 21 through the tip of the blade 2 and the atmospheric pressure in the working chamber 3 were gradually reduced. The spring 22 generated in the working chamber 3 from the tip of the cutting edge 2 and the spring generated during the excavation of the rock part are stopped, and then the rock 22 is excavated by the bare or natom method. Therefore, the rock portion can be excavated accurately and efficiently by bare digging or natom method, the number of steps of rock excavation can be reduced, and the construction period can be shortened, so that the cost can be reduced.

  Further, according to the first embodiment, when the rock 22 is excavated, water can be effectively stopped by the water stop device described above, so that the work chamber 3 is kept at a high atmospheric pressure in order to suppress water leakage and spring water. Therefore, it is possible to relieve the worker from troublesome work under high pressure.

  In the first embodiment, a check valve 14 may be provided at the outlet of each first inlet 12.

  Moreover, the grout material pumping equipment which pumps the grout material 23 to the 1st injection path 11 or the 2nd injection path 13 may be installed on the ground, and all may be piped from the ground.

  Next, FIG. 6 and FIG. 7 show Example 2 of this invention, FIG. 6 is a vertical side view of a caisson with a water stop device, and FIG. 7 is an enlarged view of a portion C in FIG.

  In Example 2 shown in these drawings, a partition plate attachment 15 (see FIG. 7 for details) is fixed to the inner surface of the blade 2 of the caisson.

  A partition plate 17 is attached to the partition plate attaching tool 15 via a fixing tool 16 such as a bolt.

  The partition plate 17 is formed of a metal plate, a plastic plate, or the like so that the cross section extending from the inner surface of the blade edge 2 toward the upper surface 22 ′ of the bedrock 22 has a substantially square shape. And this partition plate 17 is attached so that the front-end | tip part can be earth | grounded to the upper surface 22 'of the rock mass 22. As shown in FIG.

  A space 19 is formed by the inner surface of the blade edge 2, the upper surface 22 ′ of the rock mass 22, and the partition plate 17 in a state where the tip of the blade edge 2 reaches the upper surface 22 ′ of the rock mass 22.

  A plurality of second inlets 18 are provided on the partition plate 17 on the side of the working chamber 3 at a predetermined interval. Each second inlet 18 is connected to the upper chamber 5 or a grout material pumping facility (not shown) installed on the ground so that the space 19 can be filled with the grout material 23a from the working chamber 3 side. It has become. The grout material 23a may be the same as or different from the grout material 23 filled in the gap g.

  In the second embodiment configured as described above, the caisson was sunk until the tip of the blade edge 2 reached the upper surface 22 ′ of the rock 22, and the pressure in the working chamber 3 was gradually reduced to almost atmospheric pressure. When the grout material 23 filled in the gap g between the outer surface of the caisson housing 1 and the natural ground 21 leaks into the work chamber 3 from the tip of the blade edge 2, the inner surface of the blade edge 2 and the upper surface 22 'of the rock 22 The space 19 formed by the partition plate 17 is filled with the grout material 23a through the second inlet 18 to prevent it. As a procedure, the grout material 23 a may be filled first through the second inlet 18.

  By filling the space 19 with the grout material 23, the trouble that the grout material 23 filled between the outer surface of the caisson housing 1 and the natural ground 21 leaks into the work chamber 3 from the tip end of the blade edge 2 is eliminated. The water effect can be further enhanced.

  Other configurations and operations in the second embodiment are the same as those in the first embodiment.

  FIG. 8: shows the vertical side view of the caisson with a water stop apparatus concerning Example 3 of this invention.

  This embodiment is related to a construction method in the case where there is a spring layer 27 in which the spring water is remarkably present in the bedrock 22. That is, in the process of the construction state shown in FIG. 3 of Example 1, in the process of excavating the rock portion to a predetermined depth and applying the lining 25, a remarkable layer 27 of spring water such as a pressurized sand layer or a crush zone is formed on the rock 22. Yes, when you reach it, with the existing pneumatic equipment, apply the working pressure corresponding to the spring pressure, temporarily stop the spring, install the support 28, install the formwork not shown, The lining concrete is placed, the lining 29 is performed, and a lock bolt 30 or the like is installed in the lining 29 as necessary. Thereafter, the space excavated from the rock mass 22 is returned to the atmospheric pressure, and the underground structure 26 is constructed by excavating to a predetermined depth by performing an unearthed or natom construction method. Reference numeral 24 in the figure is a space excavated to a predetermined depth in this way.

  Of course, this construction method can also be applied to the second embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS It is Example 1 of this invention, Comprising: It is a vertical side view in the state where the caisson was sunk until the front-end | tip part of the blade edge reached | attained the rock surface. In the Example 1, it is a vertical side view of the state which excavated the rock part and subsidized the caisson. In the Example 1, it is a vertical side view of the state which excavated the rock part to the predetermined depth and constructed the underground structure. It is an AA line crossing top view of FIG. It is an enlarged view of B part of FIG. Example 2 of the present invention is shown, and is a longitudinal side view of a state where an underground structure is constructed by excavating a rock portion to a predetermined depth. FIG. 7 is an enlarged view of a portion C in FIG. 6. It is Example 3 which shows Example 3 of this invention, and is an explanatory view in the case of constructing an underground structure on the rock mass with a remarkable spring layer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Caisson housing 2 Cutting edge 3 Work chamber 4 Work chamber slab 5 Upper chamber 6 Upper slab 7 Material shaft 8 Material lock 9 Man shaft 10 Man lock 11 1st injection path 12 1st injection path 13 2nd injection path 14 Check valve 15 Partition plate fixture 16 Partition plate fixture 17 Partition plate 18 Second injection port 19 Space formed by the inner surface of the blade edge, the upper surface of the rock mass, and the partition plate 21 Natural ground 22 Rock mass 22 'Upper surface of the rock mass 23 , 23a Grout material 24 Space excavated to a predetermined depth 25 Lining 26 Underground structure 27 Spring layer 28 Supporting work 29 Covering 30 Rock bolt

Claims (5)

The caisson blade (2) until the tip of the caisson blade (2) reaches the bedrock (22) is excavated by the pneumatic caisson method to sink the caisson.
When the tip of the caisson blade (2) reaches or penetrates the bedrock (22), the gap (g) between the outer surface of the caisson housing (1) and the ground (21) is filled with grout material (23). Block the water channel, excavate the rock part by unearthing or natom method,
Excavate the rock part to a predetermined depth and construct a predetermined underground structure,
The construction method of the underground structure using the caisson characterized by this. A space (19) is formed by the inner surface of the blade edge (2), the partition plate (17) attached from the inner surface of the blade edge (2) toward the upper surface of the rock mass (22), and the rock mass (22). The space (19) is filled with a grout material (23a) to prevent the grout material (23) in the gap (g) from leaking into the working chamber (3).
The construction method of an underground structure using the caisson according to claim 1. When the pressure in the work room (3) of caisson is lowered and spring water is generated in the work room (3), the gap (g) between the outer surface of the blade (2) and the bedrock (22) is stopped. After the water is drained, the rock mass is excavated by bare digging or natom method, and when spring water is generated from the rock mass (22) during excavation of the rock mass, the work pressure corresponding to the spring pressure is adjusted by the caisson pressure equipment. Hang it to temporarily stop the spring water, then perform a water stop grout or lining,
The method for constructing an underground structure using caisson according to claim 1 or 2, wherein the working pressure is lowered to excavate a rock portion to a predetermined depth to construct a predetermined underground structure. During excavation of the rock mass, there is a remarkable layer of spring water in the rock mass (22), and when it reaches it, the caisson pressure equipment stops the spring by applying a working pressure corresponding to the spring pressure, and supports (28) is installed, lining (29) is performed and water is stopped,
After that, reduce the working air pressure, excavate by bare digging or natom construction method, build underground structure in the rock,
The construction method according to claim 1, 2 or 3 for an underground structure. A partition plate (17) extending from the inner surface of the blade edge (2) toward the upper surface of the bedrock (22) is attached in the caisson work chamber (3), and the inner surface of the blade edge (2) and the bedrock (22) A space (19) is formed by the upper surface and the partition plate (17),
The partition plate (17) is provided with a second inlet (18) on the side of the working chamber (3), and the grout material (23) is supplied to the second inlet (18) from the side of the working chamber (3). Connected to grout material pumping equipment,
A caisson with a water stop device characterized by that.

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