JP2008223437A - Underground wall structure, construction method of underground wall structure, method for constructing well in underground wall structure and method of utilizing the well constructed according to the method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an underground wall structure enabling extension of a well and a construction method for it. <P>SOLUTION: A soil cement column wall 2 is constructed by filling a column drilled hole formed by a single-shaft or multi-shaft earth auger with soil cement, and erecting a plurality of core materials 3 to be arranged in the lateral direction. Thickness and installation depth of the soil cement column wall 2 and the diameter and installation depth of the core material 1 are predetermined by designing based on the result of hydraulic investigation after the hydraulic investigation made for investigating the geology and hydraulic state such as permeability of the ground by boring the periphery of a drilling scheduled portion 5. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an underground wall structure in which a core material is embedded and a method for constructing the underground wall structure.

  Conventionally, when excavating the ground by the open-cut method, a well for draining water is constructed and groundwater is pumped to lower the groundwater level. Particularly in recent years, a method of providing a well for draining water in an underground structure such as soil cement or RC has been used.

  For example, in Patent Document 1, a steel pipe with a lid attached to the tip is inserted into an underground wall structure composed of a plurality of soil cement columns, and the ground from the lower end of the steel pipe to a predetermined depth is formed using the steel pipe as a guide. A method of drilling a hole to construct a well for draining water is disclosed. In this method, the position of the drain well to be built in the underground wall structure is determined by design in advance, and a steel pipe used as a guide for drilling the ground is installed in the soil cement column at this position. H-shaped steel is installed in soil cement pillars that do not build water drain wells.

Patent Document 2 discloses a method of constructing a plurality of drain wells and constructing an underground wall structure composed of a plurality of soil cement columns between these wells. In this method, first, a plurality of strainer-equipped steel pipes are inserted into the planned construction site of the underground wall structure, and a soil drain is constructed by filling soil cement around each strainer-equipped steel pipe. The ground between these wells is drilled and filled with soil cement, and H-shaped steel is inserted into each soil cement column to construct the underground wall structure. Finally, both ends of this underground wall structure An underground wall structure with a well for draining is constructed by connecting the parts to the well.
JP 2001-115458 A JP-A-11-81301

  However, in the method described in Patent Document 1, since a water drainage well is constructed by installing a steel pipe at a position determined in advance by design or the like, the groundwater level of the planned excavation site surrounded by the underground wall structure is determined. If the groundwater level does not decrease as expected even when pumping water from a drainage well constructed by design, etc., it is difficult to install a new steel pipe. I can't.

  In the method described in Patent Document 2, when constructing the underground wall structure, since the well has already been constructed, work must be performed while paying attention to the handling of heavy machinery so as not to damage the well. The work efficiency becomes worse.

  Then, this invention is made | formed in view of the above conventional problems, Comprising: It aims at providing the underground wall structure in which extension of a well is possible, and its construction method.

In order to achieve the above object, the underground wall structure of the present invention is an underground wall structure in which a core material is embedded, and is a cylinder having both ends opened in the vertical direction of the underground wall structure. A plurality of cores made of a steel pipe are embedded so as to be arranged in the horizontal direction (first invention).
According to the underground wall structure according to the present invention, since the core material made of the steel pipe is embedded, the strength of the underground wall structure can be improved. In addition, since a plurality of cores made of cylindrical steel pipes are embedded, if it is necessary to reduce the groundwater level around the underground wall structure, by drilling the inside of this core, It becomes possible to build a well.

The construction method of the underground wall structure of the second invention is the construction method of the underground wall structure in which the core material is embedded, wherein the hardening material constituting the underground wall structure is provided in the ground in a fluid state. A plurality of core members made of a cylindrical steel pipe having both ends opened are inserted into the hardened material in a fluid state so as to be aligned in the lateral direction.
According to the construction method of the underground wall structure according to the present invention, since a plurality of cores made of cylindrical steel pipes are embedded, if it is necessary to lower the groundwater level around the underground wall structure, It is possible to construct a well by drilling the inside of the core material.

The method for constructing a well in the underground wall structure of the third invention is a method for constructing a well in the underground wall structure, wherein the underground wall structure is provided in the underground wall structure. A core material made of a cylindrical steel pipe having both ends opened in the vertical direction is buried so as to be arranged in the horizontal direction in the plane of the underground wall structure, and selected from the plurality of core materials Alternatively, a drilling step of drilling a well in the steel pipe of a plurality of core members as a guide is performed.
According to the method for constructing a well in the underground wall structure according to the present invention, among the plurality of core materials embedded in the underground wall structure, for example, a position that does not interfere with the work or a water treatment facility is close. A core material such as a position can be selected, and a well can be drilled in the core material.
In addition, since a plurality of core materials are embedded in the underground wall structure, when lowering the groundwater level of the planned excavation site surrounded by the underground wall structure, pumping water from the well constructed by design etc. If the groundwater level does not decrease as expected even if it is performed, it becomes possible to extend the well by newly drilling the inside of the steel pipe of another core material.

4th invention WHEREIN: In 3rd invention, based on the hydraulic investigation process which investigates hydraulic conditions, such as the geology of a ground, water permeability, and the result of the said hydraulic investigation process, the number and position of a well are included. A design step of designing specifications, wherein the one or more core materials are selected based on the designed specifications in the drilling step.
According to the method for constructing a well in the underground wall structure according to the present invention, the core material at the optimum position for the well can be selected from the plurality of core materials embedded in the underground wall structure. It becomes possible.

The method of using the well of the fifth invention is characterized in that a well is constructed by the method of constructing a well in the underground wall structure of the third or fourth invention, and the well is used as a pumping well. To do.
According to the method for using a well according to the present invention, since the well is used as a pumping well, groundwater can be pumped.

The method of using the well of the sixth invention is to construct a plurality of wells by the method of constructing a well in the underground wall structure of the third or fourth invention, and to use the plurality of wells as a pumping well or a condensate well. It is characterized by using as.
According to the method of using a well according to the present invention, since a plurality of wells are respectively used as a pumping well or a condensate well, groundwater is pumped from the pumping well, and the pumped groundwater can be condensed underground in the condensate well. It becomes possible.

The method of using the well of the seventh invention is to construct a plurality of wells by the method of constructing a well in the underground wall structure of the third or fourth invention, and to use the plurality of wells as a pumping well and a condensate well. Or as an observation well.
According to the well utilization method according to the present invention, since a plurality of wells are used as a pumping well, a condensate well, or an observation well, groundwater is pumped from the pumping well, and the pumped groundwater is returned to the underground by the condensate well. It becomes possible to confirm the state of groundwater level drop at the observation well while watering.
In addition, by providing a pumping well, condensate well, and observation well in the underground wall structure, it is not necessary to secure a space for installing a well in the work site. It becomes possible.

An eighth invention is characterized in that, in the seventh invention, the observation well is also used as a pumping well or a condensate well.
According to the method of using a well according to the present invention, when the groundwater level of the planned excavation site surrounded by the underground wall structure is lowered, as expected even if the water is pumped from the well constructed as a pumping well by the design process. When the groundwater level does not decrease, the groundwater level can be efficiently reduced by using the observation well constructed for observation as a pumping well.

  According to the underground wall structure and its construction method of the present invention, it is possible to construct an underground wall structure capable of extending a well. In addition, after the construction of the underground wall structure, it is possible to provide a pumping well, a condensate well, and an observation well at a desired position.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, although the following embodiment demonstrates the case where a core material is installed in the soil cement pillar row wall which is an underground structure, this invention is applicable also when installing in underground structures, such as RC. it can.

  1 to 3 are a perspective sectional view, a longitudinal sectional view, and a plan view, respectively, showing a soil cement column wall 2 that is a first embodiment of the present invention.

  As shown in FIGS. 1-3, the soil cement column wall 2 is installed so that the circumference | surroundings of the excavation planned location 5 excavated by the open-cut construction method in order to construct | assemble an underground structure etc. may be surrounded.

  The soil cement column wall 2 is filled with soil cement in column-shaped excavation holes formed by a single-axis or multi-axis earth auger, and the core material 1 made of a round steel pipe is lined up in the horizontal direction. It is built by building multiple books.

  Further, the lower end of the soil cement column wall 2 is installed so as to penetrate the clay layer 3 of the impermeable layer that constructs the underground structure and reach the upper part of the sand layer 4 of the pressurized aquifer. The core material 1 is installed so as to penetrate the soil cement column wall 2 in the depth direction, and the lower end of the core material 1 protrudes below the soil cement column wall 2.

  In addition, in this embodiment, although the ground demonstrates the case where it consists of the clay layer 3 and the sand layer 4, it is not limited to this, For example, the ground which consists of all the sand layers 4 may be sufficient.

  Thickness and installation depth of soil cement column wall 2 and diameter and installation depth of core material 1 are drilled around the planned excavation site 5 and after the hydraulic investigation to investigate the geological condition and permeability of the ground This is determined in advance by the design performed based on the result of the hydraulic survey.

  Below, the method of drilling a well in the soil cement column wall 2 using the core material 1 mentioned above is demonstrated.

  The number of pumping wells for lowering the groundwater level, condensing wells for condensing pumped groundwater, and observation wells for observing changes in groundwater levels during design based on the results of the above hydraulic survey Determine position, depth, etc.

  Next, an earth auger is inserted into the core material 1 selected to be used as each well by this design, the soil cement is crushed and discharged, and excavated to a predetermined depth corresponding to each well. In the present embodiment, the predetermined depths of the pumping well and the observation well are, for example, the depth of the sand layer 4. Although not shown, the predetermined depth of the condensate well is the depth of another aquifer that is not in communication with the sand layer 4.

  Finally, a steel pipe with a strainer is inserted into the excavated core material 1, and a soil cement is filled between the outer periphery of the steel pipe with the strainer and the inner periphery of the core material 1, thereby drilling each well.

  Then, the groundwater is pumped up from the pumping well and the groundwater level is lowered, thereby preventing the swell due to the pressure of the groundwater under pressure when the planned excavation site 5 surrounded by the soil cement column wall 2 is excavated.

  If the groundwater level does not decrease as expected even when pumping from the pumping well when lowering the groundwater level at the planned drilling point 5, install a pumping pump in the observation well and pump the groundwater. Decrease position.

Furthermore, when the groundwater level at the planned drilling site 5 is lowered, if the groundwater level does not decrease as expected even when pumping from the pumping well, newly drilling the inside of the core material 1 and expanding the pumping well Also good.
Then, the groundwater pumped from the pumping well is condensed again into the ground through the condensate well.

  According to the core material 1 in the present embodiment described above, since the core material 1 made of a steel pipe is installed in the soil cement column wall 2, the inside of the core material 1 is excavated and the inside of the core material 1 is formed. By forming a cavity that penetrates, it is possible to easily add a well.

  In addition, since the wells are used as pumping wells, condensate wells, and observation wells, groundwater is pumped from the pumping wells, and the pumped groundwater is reconstituted underground by the condensate wells, and the state of the groundwater level is lowered. It becomes possible to confirm with.

  Then, when the groundwater level of the planned excavation site 5 surrounded by the soil cement column wall 2 is lowered, if the groundwater level is not lowered as expected even if pumping is performed from the pumping constructed by the design, It becomes possible to extend the use for pumping up by drilling the inside of the other core material 1.

  In addition, by providing a pumping well, a condensate well and an observation well in the soil cement column wall 2, it is not necessary to secure a space for installing a well in the work site. Is possible.

  In addition, in this embodiment, although the case where the core material 1 was arrange | positioned so that it might adjoin in the soil cement pillar row | line | column 2 was demonstrated, it is not limited to this, As shown in FIG. May be arranged at predetermined intervals.

  Moreover, in this embodiment, although the case where the core material 1 was installed so as to penetrate the soil cement column wall 2 was not limited to this, for example, the depth of the lower surface of the core material 1 is It may be installed so as to be the same depth as the lower surface of the soil cement column wall 2 or may be installed so as to be slightly shallower than the lower surface of the soil cement column wall 2. After the soil cement is discharged by the earth auger 22, the bottom surface of the soil cement column wall 2 may be penetrated by the rod 13 provided with a drill bit to make a well hole.

  Next, a second embodiment of the present invention will be described. In the following description, portions corresponding to the above-described embodiment are denoted by the same reference numerals, description thereof is omitted, and differences are mainly described.

FIG. 5 is a perspective view of the core material 21 according to the second embodiment of the present invention, and FIG. 6 is an enlarged plan view showing the soil cement column wall 2 which is the second embodiment of the present invention.
As shown in FIG. 5, the core member 21 includes a cylindrical steel pipe 21a and two protrusions 21b and 21c extending in the longitudinal direction along the outer peripheral surface of the steel pipe 21a.
As shown in FIG. 6, the protruding portions 21 b and 21 c of the core member 21 are positioned in parallel to each other at opposite positions on the outer periphery of the steel pipe 21 a and shifted in the opposite direction with respect to a straight line passing through the center of the steel pipe 21 a. Is provided.
The core material 21 is embedded in the soil cement column wall 2 such that the protruding portions 21b and 21c face the in-plane direction of the wall surface of the soil cement column wall 2. Further, the protrusion 21c of the core 21B adjacent to the protrusion 21b of the core 21A and the protrusion 21b of the core 21C adjacent to the protrusion 21c of the core 21A are arranged so that their tip portions overlap. The

  FIG. 7 is a partially enlarged view of FIG. As shown in FIG. 7, the width L of the protrusion 21b passes through the arcuate virtual line VLB of the outer periphery of the soil cement column 2B from the outer peripheral surface of the steel pipe 21a, and is adjacent to the outer periphery of the soil cement column 2A. It has a length until it slightly exceeds the connecting portion TH to which the outer periphery of the soil cement pillar 2B is connected.

Similarly to the protrusion 21b, the width L of the protrusion 21c also passes from the outer peripheral surface of the steel pipe 21a through the arcuate virtual line VLC of the outer periphery of the soil cement column 2C, and further, with the outer periphery of the soil cement column 2A. It has a length until it slightly exceeds the connecting portion TH to which the outer periphery of the adjacent soil cement pillar 2C is connected. In this embodiment, the width L of the protrusion 21b and the length L of the protrusion 21b are the same, but the present invention is not limited to this, and the width L of the protrusion 21b and the width of the protrusion 21c are not limited thereto. The length with L may be different.
Therefore, as described above, the protruding portion 21b of the core material 21A and the protruding portion 21c of the adjacent core material 21B partially overlap each other.

  According to the core material 21 in the present embodiment described above, by providing the protrusions 21b and 21c on the outer peripheral surface of the steel pipe 21a, the section modulus becomes larger than when only the steel pipe 21a is used, and the bending strength is improved. . Therefore, the soil cement column wall 2 in which the core material 21 is embedded has higher bending rigidity than the case where only the steel pipe 21a is embedded.

  In addition, since the protrusion 21b and the protrusion 21c are arranged substantially in parallel with the wall surface of the soil cement column wall 2, the soil cement column wall 2 is a shear load that acts perpendicularly to the wall surface during an earthquake or the like. It is possible to improve the shear strength against the.

  Further, the imaginary lines VLA, VLB, and VLC that may become sliding surfaces between the soil cement pillars 2A, 2B, and 2C are also arranged so that the protrusions 21b and 21c are perpendicular to the sliding surfaces, respectively. Therefore, the soil cement column wall 2 can improve the shear strength against a shear load acting perpendicularly to the wall surface during an earthquake or the like.

  Furthermore, by embedding the protruding portion 21b of the core material 21A and the protruding portion 21c of the adjacent core material 21B so as to overlap, the same effect as that of increasing the protruding portions 21b and 21c can be obtained. In addition, it is possible to improve the shear strength against the shear load acting perpendicularly to the wall surface of the soil cement column wall 2.

  Moreover, since the core material 21 has the protrusions 21b and 21c, the contact area with the soil cement column wall 2 is increased as compared with the case of the steel pipe 21a alone, so that the bond with the soil cement column wall 2 is strengthened. .

  In addition, in this embodiment, although the case where the core material 21 was arrange | positioned so that it might adjoin in the soil cement pillar row | line | column 2 was demonstrated, it is not limited to this, As shown in FIG. May be arranged at predetermined intervals.

  Furthermore, in this embodiment, although the case where the core material 1 which has the projection parts 1b and 1c on both sides of the steel pipe 1a was used was described, the present invention is not limited to this, and only the projection part 1b on one side is provided. A core material may be used (not shown).

  Moreover, in each embodiment mentioned above, although the case where only the core material 1 which consists of a steel pipe and only the core material 21 which has the projection parts 21b and 21c were each arrange | positioned in the soil cement column wall 2 was demonstrated, it is limited to this. For example, as shown in FIG. 9, the core material 1 and the core material 21 are alternately arranged, or as shown in FIG. 10, the core material 31 having only one protrusion 21 b and You may arrange | position with the core material 1 alternately.

  In all the above-described embodiments, the case where the core materials 1, 21, and 31 are installed in the soil cement column wall 2 is described. However, the present invention is not limited to the wall. You may install in.

  Further, in all the embodiments described above, the case where the soil cement column walls 2 are all present in the ground has been described. However, the present invention is not limited to this. May protrude.

  In all the embodiments described above, round steel pipes are used as the core materials 1, 21, and 31. However, the present invention is not limited to round shapes, and square shapes such as squares may be used.

It is a perspective sectional view showing the soil cement column wall which is the first embodiment of the present invention. It is a longitudinal cross-sectional view which shows the soil cement pillar row | line | column wall which is 1st embodiment of this invention. It is a top view which shows the soil cement column wall which is 1st embodiment of this invention. It is a figure which shows the other Example of the arrangement | positioning method of a core material. It is a perspective view of the core material which concerns on 2nd embodiment of this invention. It is an enlarged plan view which shows the soil cement column wall which is 2nd embodiment of this invention. FIG. 7 is a partially enlarged view of FIG. 6. It is a figure which shows the other Example of the arrangement | positioning method of a core material. It is a figure which shows the other Example of the arrangement | positioning method of a core material. It is a figure which shows the other Example of the arrangement | positioning method of a core material.

Explanation of symbols

1 Core material 2 Soil cement column wall 2A, 2B, 2C Soil cement column 3 Clay layer (impermeable layer)
4 Sand layer (pressured aquifer)
5 Drilling planned area 11 Core material 21 (= 21A, 21B, 21C) Core material 21a Steel pipe 21b, 21c Protrusion 31 Core material VLA, VLB, VLC Virtual line TH Connection part L Width of protrusion

Claims (8)

An underground wall structure with an embedded core material,
An underground wall structure characterized in that a plurality of core members made of cylindrical steel pipes having both ends opened in the vertical direction of the underground wall structure are embedded in a horizontal direction. In the construction method of the underground wall structure in which the core material is embedded,
Providing the hardening material constituting the underground wall structure in the ground in a fluidized state;
A method for constructing an underground wall structure, wherein a plurality of core members made of cylindrical steel pipes having both ends open are inserted into the hardened material in a fluid state so as to be arranged in a lateral direction. A method of constructing a well in an underground wall structure,
In the underground wall structure, a core member made of a tubular steel pipe having both ends opened in the vertical direction of the underground wall structure is arranged in the lateral direction within the plane of the underground wall structure. Buried in the
A method of constructing a well in an underground wall structure, comprising performing a drilling step of drilling a well in the steel pipe of one or more core materials selected from the plurality of core materials as a guide . Hydraulic investigation process to investigate the geological condition of the ground, hydraulic condition such as permeability,
A design process for designing specifications including the number and position of wells based on the results of the hydraulic survey process;
4. The method for constructing a well in an underground wall structure according to claim 3, wherein in the drilling step, the one or more core materials are selected based on the designed specifications.   5. A well utilization method, wherein a well is constructed by the method according to claim 3 or 4 and the well is used as a pumping well.   A method for using a well, wherein a plurality of wells are constructed by the method according to claim 3 or 4, and the plurality of wells are used as pumping wells or condensate wells.   A method for using a well, comprising: constructing a plurality of wells by the method according to claim 3 or 4, and utilizing the plurality of wells as a pumping well, a condensate well, or an observation well.   The well utilization method according to claim 7, wherein the observation well is also used as a pumping well or a condensate well.

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