JP2015196989A - Method for removing gas from ground and tunnel-boring method - Google Patents
Method for removing gas from ground and tunnel-boring method Download PDFInfo
- Publication number
- JP2015196989A JP2015196989A JP2014075495A JP2014075495A JP2015196989A JP 2015196989 A JP2015196989 A JP 2015196989A JP 2014075495 A JP2014075495 A JP 2014075495A JP 2014075495 A JP2014075495 A JP 2014075495A JP 2015196989 A JP2015196989 A JP 2015196989A
- Authority
- JP
- Japan
- Prior art keywords
- water
- water pipe
- ground
- gas
- head
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims abstract description 65
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 296
- 238000005086 pumping Methods 0.000 claims abstract description 16
- 230000008569 process Effects 0.000 claims abstract description 13
- 239000003673 groundwater Substances 0.000 claims description 122
- 239000004576 sand Substances 0.000 claims description 66
- 238000009412 basement excavation Methods 0.000 claims description 12
- 239000013049 sediment Substances 0.000 claims description 5
- 238000007599 discharging Methods 0.000 claims description 4
- 230000035699 permeability Effects 0.000 claims description 3
- 238000011900 installation process Methods 0.000 abstract 1
- 238000010276 construction Methods 0.000 description 24
- 238000000926 separation method Methods 0.000 description 14
- 239000004927 clay Substances 0.000 description 9
- 230000008859 change Effects 0.000 description 6
- 230000007423 decrease Effects 0.000 description 6
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 6
- 238000009434 installation Methods 0.000 description 5
- 238000002627 tracheal intubation Methods 0.000 description 5
- 230000002093 peripheral effect Effects 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 238000005553 drilling Methods 0.000 description 3
- 239000013505 freshwater Substances 0.000 description 3
- 238000011835 investigation Methods 0.000 description 3
- 238000004891 communication Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 230000005641 tunneling Effects 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 238000012790 confirmation Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000005192 partition Methods 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 239000002689 soil Substances 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
Landscapes
- Excavating Of Shafts Or Tunnels (AREA)
Abstract
Description
本発明は、地盤からガスを除去するガス除去方法及び地盤へのトンネル掘進方法に関する。 The present invention relates to a gas removal method for removing gas from the ground and a tunnel excavation method to the ground.
トンネル工事としては、例えば、シールド掘進機で地盤を掘削して横坑を形成すると共に、この横坑周壁にセグメントリングを構築しつつトンネルを掘進するシールド工法が一般的に採用されている。この工法では、シールド掘進機の後方にて次々にセグメントをトンネル周方向に連結してセグメントリングを構築すると共に、隣接するセグメントリング同士をトンネル軸方向で連結することで円筒状の覆工体を構築する。この工法において、掘削中に、シールド掘進機の胴体となる筒状のシールド本体内に可燃性ガスが流入すると、シールド本体内に配置されている動力及び制御用の電気機器等が発する火花により、シールド本体内でガス爆発を起こすおそれがあるため、各種防爆対策が行われている。 As tunnel construction, for example, a shield construction method is generally employed in which a ground is excavated by a shield excavator to form a horizontal shaft, and a tunnel is excavated while a segment ring is constructed on the peripheral wall of the horizontal shaft. In this method, segments are connected one after the other in the tunnel circumferential direction behind the shield machine to construct a segment ring, and adjacent segment rings are connected in the tunnel axis direction to form a cylindrical lining body. To construct. In this construction method, when flammable gas flows into the cylindrical shield body that becomes the body of the shield machine during excavation, the sparks generated by the power and control electrical devices arranged in the shield body, Various explosion-proof measures have been taken because there is a risk of a gas explosion in the shield body.
特許文献１には、シールド工法において、防爆対策がなされた一例が開示されている。
具体的には、特許文献１には、シールド掘進機のシールド本体の前方に隔壁を介してカッタヘッドを設けると共に、シールド本体の後方と構築したセグメントリングとの間をシールするテールシール及びエアカーテンを設けることにより、シールド本体内へのガスの流入を抑制し、シールド本体内の安全を図る技術が開示されている。
Patent Document 1 discloses an example in which an explosion-proof measure is taken in the shield method.
Specifically, Patent Document 1 discloses a tail seal and an air curtain that provide a cutter head via a partition wall in front of a shield body of a shield machine and seal between the rear of the shield body and the constructed segment ring. By providing the above, there is disclosed a technology for suppressing the inflow of gas into the shield body and ensuring safety in the shield body.
しかしながら、特許文献１に開示された技術では、シールド掘進機のシールド本体内へのガスの流入を抑制するものの、可燃性ガス等が存在しうる地盤の領域で工事を行う状況については変わりがない。
このため、ガスの発生源を処置して根本的な対策を行うことが望まれており、例えば、地下水を揚水してガスを除去することが考えられる。この場合、地下水の揚水による地盤等への影響範囲を可能な限り狭める必要があり、その工夫が求められている。
However, although the technique disclosed in Patent Document 1 suppresses the inflow of gas into the shield body of the shield machine, there is no change in the situation of construction in the ground area where flammable gas or the like may exist. .
For this reason, it is desired to take radical measures by treating the gas generation source. For example, it is conceivable to remove the gas by pumping up groundwater. In this case, it is necessary to narrow the range of influence of groundwater pumping on the ground as much as possible, and a device for this is required.
本発明は、このような課題に着目してなされたものであり、地下水の揚水による地盤等への影響範囲を可能な限り狭めることが可能な地盤からのガス除去方法及びトンネル掘進方法を提供することを目的とする。 The present invention has been made paying attention to such problems, and provides a gas removal method and a tunnel excavation method from the ground that can narrow the range of influence on the ground and the like by pumping groundwater as much as possible. For the purpose.
上記課題に対して、本発明に係る地盤からのガス除去方法は、その一態様として、ガスと地下水を含む帯水層を有する地盤からガスを除去するガス除去方法であって、ストレーナ部を少なくとも下端側に備えた通水管を、該通水管の上端側が前記地盤の地表から突設され、前記下端側が前記帯水層に位置するように配置し、前記帯水層から前記ストレーナ部を介して前記通水管内に地下水を流入させる通水管配置工程と、前記帯水層の地下水の水頭と釣り合うときの前記通水管内の水の水頭を基準水頭とし、前記通水管内の水の水頭が前記基準水頭より予め定める水頭差だけ低くなるように、前記通水管内の水を揚水して前記通水管内の水位を低下させる水位低下工程と、を備え、前記通水管内の水位を低下させることにより前記帯水層内のガスを前記通水管内に導いて除去する構成とした。 In response to the above problems, a method for removing gas from the ground according to the present invention includes, as one aspect thereof, a gas removing method for removing gas from a ground having an aquifer containing gas and groundwater, wherein at least a strainer portion is provided. A water pipe provided on the lower end side is arranged so that the upper end side of the water pipe protrudes from the ground surface of the ground, and the lower end side is located in the aquifer, and from the aquifer through the strainer portion A water pipe arrangement step for flowing ground water into the water pipe, and a water head in the water pipe when the ground water head in the aquifer is balanced with a water head as a reference head, and the water head in the water pipe is the water head A water level lowering step for lowering the water level in the water pipe by pumping the water in the water pipe so as to be lower than the reference head by a predetermined water head difference, and lowering the water level in the water pipe In the aquifer The scan was configured to remove lead on the water flow pipe.
また、本発明に係るトンネル掘進方法は、その一態様として、上記一態様のガス除去方法によって、前記地盤の前記帯水層からガスを除去した後、前記地盤を掘進する。 Moreover, the tunnel excavation method according to the present invention, as one aspect thereof, excavates the ground after removing gas from the aquifer of the ground by the gas removal method of the above aspect.
本発明に係る地盤からのガス除去方法の上記一態様によると、ストレーナ部を少なくとも下端側に備えた通水管を、その下端側が帯水層に位置するように配置し、帯水層からストレーナ部を介して通水管内に地下水を流入させ、通水管内の水の水頭が帯水層の地下水の水頭と釣り合うときの通水管内の水の水頭を基準水頭とし、通水管内の水頭が基準水頭より予め定める水頭差だけ低くなるように揚水して、帯水層からガスを除去している。これにより、地下水が通水部内に、例えば自然流入等して通水管内の水の水頭と帯水層の地下水の水頭とが釣り合う状態を基準とし、この基準状態から水頭差をつけることができるため、通水部内と帯水層との間に意図する水頭差を適切につけることができる。したがって、この水頭差を、例えば、通水管を中心とするガス除去の対象範囲円の半径に応じて定めることにより、地下水の揚水による地盤等への影響範囲をガス除去に必要な範囲内に収めることができる。
このようにして、地下水の揚水による地盤等への影響範囲を可能な限り狭めることが可能な地盤からのガス除去方法を提供することができる。
According to the above aspect of the method for removing gas from the ground according to the present invention, the water pipe having the strainer portion at least on the lower end side is disposed so that the lower end side is located in the aquifer, and the strainer portion is disposed from the aquifer layer. The water head in the water pipe is the reference head, and the water head in the water pipe is the standard when the water head in the water pipe is balanced with the ground water head of the aquifer. The water is pumped up so as to be lower than the water head by a predetermined water head difference to remove gas from the aquifer. Thus, the ground water can flow into the water flow part, for example, by natural inflow, etc., and the water head in the water pipe and the ground water head in the aquifer balance with each other as a reference, and a water head difference can be made from this reference state. Therefore, the intended water head difference can be appropriately set between the inside of the water passing portion and the aquifer. Therefore, by defining this water head difference according to the radius of the target range circle of gas removal centering on the water pipe, for example, the range of influence on the ground due to pumping of groundwater falls within the range necessary for gas removal. be able to.
In this way, it is possible to provide a method for removing gas from the ground, which can narrow the range of influence of groundwater pumping on the ground as much as possible.
本発明に係るトンネル掘進方法の上記一態様によると、上記一態様の地盤からのガス除去方法によって、地盤の帯水層からガスを除去した後、地盤を掘進する構成であるため、地下水の揚水による地盤等への影響範囲を可能な限り狭めると共に安全にトンネル掘進を行うことができる。 According to the one aspect of the tunnel excavation method according to the present invention, since the gas is removed from the ground aquifer by the gas removal method from the ground according to the one aspect, the ground is pumped, so that the groundwater is pumped. It is possible to narrow the range of influence on the ground as much as possible and to tunnel safely.
以下、添付図面参照して本発明に係る地盤からのガス除去方法及びトンネル掘進方法の実施形態について説明する。 Hereinafter, embodiments of a gas removal method and a tunnel excavation method according to the present invention will be described with reference to the accompanying drawings.
図１は、本発明の一実施形態におけるガス除去装置１の概略構成を説明するための、イメージ図であり、トンネルを掘進する領域の地盤の断面図でもある。 FIG. 1 is an image diagram for explaining a schematic configuration of a gas removal device 1 according to an embodiment of the present invention, and is also a sectional view of the ground in a region where a tunnel is dug.
本実施形態における地盤は、砂層（砂礫層も含む）Ｇ１と、この砂層Ｇ１の上方に隣接し砂層Ｇ１より透水性の低い粘土層Ｇ０とを含む地盤で構成されているものとする。このように、粘土層Ｇ０の下層に砂層Ｇ１がある場合、その砂層Ｇ１に地下水が存在する可能性がある。そして、その砂層Ｇ１では、地下水内に可燃性ガス（例えば、メタンガス）等のガスが溶存すると共に、この地下水内の溶存ガス濃度が飽和して砂層Ｇ１内に可燃性ガス等のガスが地下水と分離して存在している場合がある。この砂層Ｇ１に地下水と分離して存在するガスは、粘土層Ｇ０によって閉塞され、砂層Ｇ１の粘土層側にガス溜りとなって大量に滞留している場合がある。この場合、砂層Ｇ１はガスを含むガス溜り領域Ｇ１ｇと地下水を含む地下水領域Ｇ１ｗとに区分され、ガス溜り領域Ｇ１ｇのガスは、粘土層Ｇ０と地下水領域Ｇ１ｗとに挟まれた状態となっている。 The ground in the present embodiment is configured by a ground including a sand layer (including a gravel layer) G1 and a clay layer G0 adjacent to the upper side of the sand layer G1 and having a lower water permeability than the sand layer G1. Thus, when the sand layer G1 exists in the lower layer of the clay layer G0, ground water may exist in the sand layer G1. In the sand layer G1, a gas such as a flammable gas (for example, methane gas) is dissolved in the ground water, and the concentration of the dissolved gas in the ground water is saturated, so that a gas such as a flammable gas and the ground water is contained in the sand layer G1. May exist separately. The gas existing separately from the groundwater in the sand layer G1 may be blocked by the clay layer G0 and may remain in a large amount as a gas reservoir on the clay layer side of the sand layer G1. In this case, the sand layer G1 is divided into a gas reservoir region G1g containing gas and a groundwater region G1w containing groundwater, and the gas in the gas reservoir region G1g is sandwiched between the clay layer G0 and the groundwater region G1w. .
本実施形態において、地盤の砂層Ｇ１にはガス溜り領域Ｇ１ｇがあるものとする。そして、このガス溜り領域Ｇ１ｇに既に存在しているガスを「分離ガス」と言い、地下水が大気圧等に減圧されその減圧分だけ溶解できなくなって気化して地下水から遊離したガスを「遊離ガス」と言うものとする。以下において、「分離ガス」と「遊離ガス」とを区別する必要がない場合は、それぞれ単に「ガス」と言う。なお、地下水が存在する砂層Ｇ１が、本発明に係るガス除去方法における「帯水層」に相当する。 In the present embodiment, it is assumed that the ground sand layer G1 has a gas accumulation region G1g. The gas that already exists in the gas reservoir region G1g is called “separation gas”, and the groundwater is reduced to atmospheric pressure or the like and cannot be dissolved by the reduced pressure. ". In the following, when it is not necessary to distinguish between “separated gas” and “free gas”, each is simply referred to as “gas”. In addition, the sand layer G1 in which groundwater exists corresponds to the “aquifer” in the gas removal method according to the present invention.
上記ガス除去装置１は、地下水を含む砂層Ｇ１を有する地盤から可燃性ガス等のガスを除去するものであり、外管２と内管３とを備えた通水管４と、揚水ポンプ５と、気水分離器６とを含んで構成される。 The gas removal device 1 removes a gas such as a combustible gas from the ground having a sand layer G1 containing groundwater, a water pipe 4 provided with an outer pipe 2 and an inner pipe 3, a pumping pump 5, And a steam / water separator 6.
前記通水管４は、例えば外管２と内管３とを備えた２重管であり、その上端側が地盤の地表から突設され、下端側が砂層Ｇ１に位置するよう配置されている。また、本実施形態においては、通水管４は、地盤の地表から砂層Ｇ１まで削孔されたボーリング孔内の上下方向に挿通されている。 The water pipe 4 is, for example, a double pipe provided with an outer pipe 2 and an inner pipe 3, and an upper end side thereof is provided so as to project from the ground surface of the ground, and a lower end side thereof is disposed on the sand layer G <b> 1. Moreover, in this embodiment, the water flow pipe 4 is penetrated in the up-down direction in the boring hole drilled from the ground surface to the sand layer G1.
前記外管２は、例えば、鋼管製であり、地盤の地表から粘土層Ｇ０を砂層Ｇ１の上方の適宜深さまで掘削ロッド等で削孔されたボーリング孔内に挿管されている。外管２の下端側は粘土層Ｇ０に位置し、その挿通方向下端は開口している。また、外管２の上端側は地表から適宜高さだけ突設され、その突設方向上端は閉止されている。外管２の管内は、外管２の周壁から径外方向へ突設された連結管２ａを介して、気水分離器６の内部空間と連通している。なお、砂層Ｇ１の深さは、例えば、地盤調査時等に事前に確認することができるため、外管設置用の本堀の際に砂層Ｇ１の手前でボーリングを止めることができる。 The outer pipe 2 is made of, for example, a steel pipe, and is inserted into a boring hole in which the clay layer G0 is drilled from the ground surface to an appropriate depth above the sand layer G1 with a drilling rod or the like. The lower end side of the outer tube 2 is located in the clay layer G0, and the lower end in the insertion direction is open. Moreover, the upper end side of the outer tube 2 protrudes from the ground surface by an appropriate height, and the upper end in the protruding direction is closed. The inside of the outer pipe 2 communicates with the internal space of the steam / water separator 6 through a connecting pipe 2 a that protrudes radially outward from the peripheral wall of the outer pipe 2. In addition, since the depth of the sand layer G1 can be confirmed in advance, for example, at the time of ground investigation, the boring can be stopped before the sand layer G1 in the main moat for installing the outer pipe.
前記内管３は、外管２より外径が小さく、その周壁に貫通孔３ａが適宜形成された筒状のストレーナである。内管３の下端側は、内管３と同径の掘削ロッド等で、外管２の挿管用のボーリング孔の底部から砂層Ｇ１の地下水領域Ｇ１ｗが存在する部分まで削孔されたボーリング孔に挿管されている。このように、内管３は、外管２内に挿通され、その下端側が砂層Ｇ１（地下水領域Ｇ１ｗ）に位置し、上端側が地表から適宜高さだけ突設するように配置されている。これにより、外管２と内管３とを備えた２重管構造の通水管４が構成される。なお、内管３の下端側の外管２から露出している部分が、本発明に係る「ストレーナ部」４ａに相当する。このようにして、ストレーナ部４ａを下端側に備えた通水管４を、下端側が砂層Ｇ１に位置するように配置し、砂層Ｇ１からストレーナ部４ａを介して通水管４内に地下水を流入させるように構成されている。 The inner tube 3 is a cylindrical strainer having an outer diameter smaller than that of the outer tube 2 and having a through hole 3a appropriately formed on the peripheral wall thereof. The lower end side of the inner pipe 3 is a drilling rod or the like having the same diameter as the inner pipe 3, and is a borehole drilled from the bottom of the intubation borehole for the outer pipe 2 to the portion where the groundwater region G1w of the sand layer G1 exists. Has been intubated. Thus, the inner pipe 3 is inserted into the outer pipe 2, and the lower end side thereof is positioned in the sand layer G1 (groundwater region G1w), and the upper end side is disposed so as to protrude from the ground surface by an appropriate height. Thereby, the water flow pipe 4 of the double pipe structure provided with the outer pipe | tube 2 and the inner pipe | tube 3 is comprised. The portion exposed from the outer tube 2 on the lower end side of the inner tube 3 corresponds to the “strainer portion” 4a according to the present invention. In this way, the water pipe 4 provided with the strainer part 4a on the lower end side is arranged so that the lower end side is located in the sand layer G1, and the ground water is caused to flow into the water pipe 4 from the sand layer G1 through the strainer part 4a. It is configured.
前記揚水ポンプ５は、上記通水管４内の水を揚水して通水管４内の水位を低下させるものであり、例えば、内管２内の適宜位置（図１では、地下水面より下方）に設けられる。この揚水ポンプ５から揚水された水は、気水分離器６内へ排出される。地下水の揚水時において、内管３内には、地下水領域Ｇ１ｗから地下水が流入すると共に、ガス溜り領域Ｇ１ｇから分離ガスが流入する。内管３内に流入した分離ガスのうち、空気よりも軽いガス（例えば、メタンガス）は、内管３内及び外管２内を上昇し、外管２の上端側に設けられた連通管２ａを経由して、気水分離器６に導入される。 The pump 5 pumps the water in the water pipe 4 to lower the water level in the water pipe 4, for example, at an appropriate position in the inner pipe 2 (below the groundwater surface in FIG. 1). Provided. The water pumped from the pump 5 is discharged into the steam separator 6. When the groundwater is pumped, groundwater flows into the inner pipe 3 from the groundwater region G1w and separated gas flows from the gas reservoir region G1g. Of the separated gas that has flowed into the inner pipe 3, a gas that is lighter than air (for example, methane gas) rises in the inner pipe 3 and the outer pipe 2, and a communication pipe 2 a provided on the upper end side of the outer pipe 2. And is introduced into the steam separator 6.
前記気水分離器６は、揚水ポンプ５から送られてきた地下水と、この地下水が例えば大気圧に減圧されることによって地下水から遊離した遊離ガスと、連通管２ａを経由して導入された分離ガスとを、水とガス（分離ガスと遊離ガス）とに分離する。 The steam separator 6 is separated from the groundwater sent from the pump 5, the free gas released from the groundwater when the groundwater is depressurized to atmospheric pressure, for example, and the separation introduced via the communication pipe 2a. The gas is separated into water and gas (separated gas and free gas).
次に、通水管４内の水位を低下させた場合に、砂層Ｇ１内の地下水の水位（水頭）が低下する範囲について説明する。 Next, the range in which the water level (water head) in the sand layer G1 decreases when the water level in the water conduit 4 is lowered will be described.
まず、通水管４内の水頭を孔内水頭ｈとし、砂層Ｇ１における地下水の水頭を地下水頭ｈ’とする。そして、後述するように、孔内水頭ｈが地下水頭ｈ’と釣り合っている基準水頭ｈａ（平衡水位）の状態において、揚水ポンプ５を作動させ、孔内水頭ｈを基準水頭ｈａから水頭差Δｈ0だけ低くしてｈｂとなるようにしたとする。この場合、この通水管４を中心として地下水頭ｈ’が低下する範囲の円の半径（以下において、「影響半径」と言う）Ｒは、例えば、下記（１）式（イ・ぺ・クサキンの式）で表される。ここで、Ｈは砂層Ｇ１の厚さ（ｍ）、ｋは砂層Ｇ１の透水係数（ｍ／ｓ）を示す。 First, the water head in the water conduit 4 is defined as a hole head h, and the ground water head in the sand layer G1 is defined as a ground water head h ′. Then, as will be described later, in the state of the reference head ha (equilibrium water level) in which the bore head h is balanced with the ground head h ′, the pump 5 is operated to change the head head h from the reference head ha to the head difference Δh. Suppose that the value is lowered by 0 to be hb. In this case, the radius of the circle (hereinafter referred to as “influence radius”) R in the range where the groundwater head h ′ is lowered around the water pipe 4 is expressed by, for example, the following equation (1) (Expression) Here, H represents the thickness (m) of the sand layer G1, and k represents the hydraulic conductivity (m / s) of the sand layer G1.
上記（１）式より、影響半径Ｒは、水頭差Δｈ０を大きくするほど大きくなる。また、通水管４内の水頭を低下させたとき、通水管４を中心とする影響半径Ｒ内の領域（以下において、「影響範囲」と言う）において、通水管４内と砂層Ｇ１との間に圧力勾配が生じる。したがって、影響範囲は、水頭差Δｈ0に起因して地下水の水位（水頭）が低下する範囲であると共に、水頭差Δｈ0に起因して生じる圧力勾配によって砂層Ｇ１からガスを除去可能な範囲でもある。つまり、Ｒは、影響半径であると共に後述するガス除去の対象範囲の円の半径でもある。例えば、砂層Ｇ１の厚さＨを５（ｍ）、透水係数ｋを１．０×１０-3（ｍ／ｓ）とした場合、水頭差Δｈ0が１．２３（ｍ）では、影響半径Ｒ（＝ガス除去の対象範囲円の半径）は５０（ｍ）となり、水頭差Δｈ0が２．４６（ｍ）では影響半径Ｒは１００（ｍ）となり、水頭差Δｈ0が４．９２（ｍ）では影響半径Ｒは２００（ｍ）となる。 From the above equation (1), the influence radius R increases as the head difference Δh 0 increases. Further, when the water head in the water pipe 4 is lowered, in the region within the influence radius R centering on the water pipe 4 (hereinafter referred to as “influence range”), the space between the water pipe 4 and the sand layer G1. A pressure gradient is generated. Therefore, the influence range is due to the water head difference Delta] h 0 and with the ground water level (water head) is in the range to be lowered, even in the range capable of removing gas from sand G1 by the pressure gradient caused by the water head difference Delta] h 0 is there. That is, R is an influence radius and a radius of a circle in a target range of gas removal described later. For example, when the thickness H of the sand layer G1 is 5 (m) and the water permeability coefficient k is 1.0 × 10 −3 (m / s), when the head difference Δh 0 is 1.23 (m), the influence radius R (= The radius of the target range circle for gas removal) is 50 (m), and when the head difference Δh 0 is 2.46 (m), the influence radius R is 100 (m) and the head difference Δh 0 is 4.92 (m). ), The influence radius R is 200 (m).
また、通水管４からの距離をｒ（つまり、通水管４を中心とする任意円の半径ｒ＜影響半径Ｒ）とし、内管２の半径をｒ0とし、孔内水頭ｈをΔｈ0だけ低下させたときの、通水管から距離ｒの任意の位置における砂層Ｇ１内の地下水頭ｈ’の低下量をΔｈ’とした場合、下記（２）式（Ｔｈｉｅｍの式）の関係が成り立つ。
２πｋＨ（Ｈ−Δｈ’）／（２．３ｌｏｇ10（Ｒ／ｒ））
＝２πｋＨ（Ｈ−Δｈ0）／（２．３ｌｏｇ10（Ｒ／ｒ0））・・・・・（２）
Further, the distance from the water pipe 4 is r (that is, the radius r of the arbitrary circle centering on the water pipe 4 <the influence radius R), the radius of the inner pipe 2 is r 0, and the head of the hole h is Δh 0. When the amount of decrease of the groundwater head h ′ in the sand layer G1 at an arbitrary position r from the water conduit when Δh ′ is Δh ′, the following relationship (2) (Thiem's equation) holds.
2πkH (H−Δh ′) / (2.3log 10 (R / r))
= 2πkH (H−Δh 0 ) / (2.3 log 10 (R / r 0 )) (2)
ここで、図２は、通水管４から任意の距離ｒにおける地下水頭の低下量Δｈ’の変化を上記（２）式に基づいて示した図である。図２においては、砂層Ｇ１の厚さＨを５（ｍ）、透水係数ｋを１．０×１０-3（ｍ／ｓ）、ｒ0を４３（ｍｍ）とした場合に、Δｈ0を１．２３（ｍ）、２．４６（ｍ）、４．９２（ｍ）としたときの距離ｒとΔｈ’との関係をそれぞれ示している。図２から分かるように、通水管４から離れ、影響半径Ｒ（５０、１００、２００）に近づくほど地下水頭の低下量Δｈ’が少なくなり、影響半径Ｒを超えると地下水頭ｈ’の低下はなくなる。つまり、影響半径Ｒを超えた領域での地下水頭ｈ’は変化しないので、この影響半径Ｒを超えた領域の地盤への影響はない。また、通水管４内の孔内水頭ｈを低下させた量（Δｈ０）が大きいほど影響半径Ｒが大きくなる。したがって、図１に示すように、この水頭差Δｈ0を、コントロールすることにより、地下水頭ｈ’（図１に一点鎖線で示す）の低下範囲（影響範囲）を定めることができ、地盤への影響範囲及びガスの除去範囲を適宜決めることができる。 Here, FIG. 2 is a diagram showing the change of the groundwater head drop amount Δh ′ at an arbitrary distance r from the water conduit 4 based on the above equation (2). In FIG. 2, when the thickness H of the sand layer G1 is 5 (m), the hydraulic conductivity k is 1.0 × 10 −3 (m / s), and r 0 is 43 (mm), Δh 0 is 1 .23 (m), 2.46 (m), and 4.92 (m), the relationship between the distance r and Δh ′ is shown. As can be seen from FIG. 2, the amount of decrease Δh ′ of the groundwater head decreases as the distance from the water pipe 4 approaches the influence radius R (50, 100, 200), and when the influence radius R is exceeded, the decrease in the groundwater head h ′ decreases. Disappear. That is, since the groundwater head h ′ in the region exceeding the influence radius R does not change, there is no influence on the ground in the region exceeding the influence radius R. Further, the larger the amount (Δh 0 ) of reducing the in-hole head h in the water pipe 4 is, the larger the influence radius R is. Therefore, as shown in FIG. 1, by controlling this hydraulic head difference Δh 0 , it is possible to determine the reduction range (influence range) of the ground water head h ′ (indicated by the alternate long and short dash line in FIG. 1). The influence range and the gas removal range can be appropriately determined.
次に、本発明に係るガス除去方法の一実施形態を、図１及び図２を参照して、上記ガス除去装置１を用いた場合で説明する。なお、事前の地盤調査により、地表から砂層Ｇ１までの深さは予め分かっているものとして説明する。 Next, an embodiment of the gas removal method according to the present invention will be described with reference to FIGS. 1 and 2 in the case where the gas removal apparatus 1 is used. It is assumed that the depth from the ground surface to the sand layer G1 is known in advance by a preliminary ground survey.
まず、外管挿管用の孔を地盤の地表から粘土層Ｇ０を砂層Ｇ１の上方の適宜深さまで例えば掘削ロッド等でボーリングし、このボーリング孔内に外管２を挿管する。次に、例えば内管３と同径の掘削ロッド等で、外管挿管用のボーリング孔の底部から砂層Ｇ１の地下水領域Ｇ１ｗまで、内管挿管用の孔を削孔する。そして、このボーリング孔内に内管３を挿管する。そして、内管挿管用のボーリング孔が削孔されて内管３が地下水領域Ｇ１ｗに配置されると、地下水の圧力によって、通水管４内に、地下水が自然流入し始める。このようにして、ストレーナ部４ａを下端側に備えた通水管４を、その下端側が砂層Ｇ１の地下水領域Ｇ１ｗに位置するように配置し、地下水領域Ｇ１ｗからストレーナ部４ａを介して通水管４内に地下水を流入させる。この工程が、本発明に係るガス除去方法における「通水管配置」に相当する。
本実施形態において、「通水管配置工程」は、具体的には、上述したように、地盤の地表から砂層Ｇ１（地下水領域Ｇ１ｗ）まで削孔されたボーリング孔内に通水管４を挿通することで、通水管４の下端側を地下水領域Ｇ１ｗに位置させ、地下水の圧力によって、地下水領域Ｇ１ｗからストレーナ部４ａを介して通水管４内に地下水を流入させる構成である。
First, the outer tube intubation hole is bored from the ground surface to the appropriate depth above the sand layer G1, for example, with an excavating rod, and the outer tube 2 is intubated into the borehole. Next, for example, an inner tube intubation hole is drilled from the bottom of the outer tube intubation borehole to the groundwater region G1w of the sand layer G1 with an excavating rod having the same diameter as the inner tube 3. Then, the inner tube 3 is inserted into the borehole. When the bore hole for intubating the inner pipe is drilled and the inner pipe 3 is disposed in the groundwater region G1w, the groundwater naturally starts to flow into the water pipe 4 due to the pressure of the groundwater. In this way, the water pipe 4 provided with the strainer part 4a on the lower end side is arranged so that the lower end side is located in the groundwater area G1w of the sand layer G1, and the water pipe 4 is inserted into the water pipe 4 from the groundwater area G1w via the strainer part 4a. Inflow of groundwater into This step corresponds to “water pipe arrangement” in the gas removal method according to the present invention.
In the present embodiment, specifically, as described above, the “water pipe arrangement step” is to insert the water pipe 4 into the borehole drilled from the ground surface to the sand layer G1 (groundwater region G1w). Thus, the lower end side of the water pipe 4 is positioned in the groundwater area G1w, and the groundwater flows into the water pipe 4 from the groundwater area G1w through the strainer portion 4a by the pressure of the groundwater.
そして、本実施形態においては、通水管４内の水位は、地下水の圧力によって、地下水面（図１参照）から徐々に上昇し、通水管４内の孔内水頭ｈが地下水頭ｈ’と釣り合う水位（平衡水位）に至る。この工程が、本発明に係るガス除去方法の「通水管配置工程」に含まれる「通水管内の水の水頭を帯水層の地下水の水頭と釣り合わせる水頭釣り合わせ工程」に相当する。
なお、通水管４内の水位が平衡水位の状態では、孔内水頭ｈと地下水頭ｈ’が釣り合っているため、通水管４内と地下水領域Ｇ１ｗとの間に圧力勾配がない。したがって、この平衡水位の状態では、通水管４のごく近傍の分離ガスが通水管４内に流入する程度である。つまり、砂層Ｇ１に分離ガスが大量に滞留していたとしても、通水管４の周辺の大半の分離ガスは、通水管４の方向に移動して通水管４内に流入して地表に自然に噴出することはない。
In the present embodiment, the water level in the water pipe 4 gradually rises from the ground water surface (see FIG. 1) due to the pressure of the ground water, and the in-hole water head h in the water pipe 4 is balanced with the ground water head h ′. It reaches the water level (equilibrium water level). This step corresponds to a “water head balancing step of balancing the water head in the water pipe with the water head of the groundwater in the aquifer” included in the “water pipe arrangement step” of the gas removal method according to the present invention.
In addition, in the state where the water level in the water pipe 4 is an equilibrium water level, there is no pressure gradient between the water pipe 4 and the groundwater region G1w because the water head h in the hole and the ground water head h ′ are balanced. Therefore, in the state of this equilibrium water level, the separation gas in the vicinity of the water pipe 4 is such that it flows into the water pipe 4. That is, even if a large amount of separation gas stays in the sand layer G1, most of the separation gas around the water pipe 4 moves in the direction of the water pipe 4 and flows into the water pipe 4 to naturally reach the ground surface. It does not erupt.
次に、上記のように砂層Ｇ１の地下水頭ｈ’と釣り合うときの通水管４内の孔内水頭ｈを基準水頭ｈａ（平衡水位）とする。そして、この平衡水位の状態で、揚水ポンプ５を作動させ、孔内水頭ｈが基準水頭ｈａより予め定めた水頭差Δｈ０だけ低くなるように揚水して、孔内水位を平衡水位から低下させその低下させた水位で孔内水位を維持する。揚水ポンプ５から揚水された水は、気水分離器６内へ排出される。水頭差Δｈ０（＝ｈａ−ｈｂ）は、通水管４を中心とするガス除去の対象範囲円の半径Ｒ（この半径Ｒは前述したように影響半径Ｒと一致する。）に応じて定める。具体的には、トンネル工事の範囲に応じて、ガス除去に必要な対象範囲円の半径Ｒを決め、例えば、その半径Ｒと上記（１）式に基づいて、必要な水頭差Δｈ０を定める。 Next, the in-hole water head h in the water conduit 4 when balancing with the ground water head h ′ of the sand layer G1 as described above is set as the reference water head ha (equilibrium water level). In this state of equilibrium water level, the pump 5 is operated to pump the water so that the water head h in the hole is lower than the reference water head ha by a predetermined head difference Δh 0 , thereby lowering the water level in the hole from the equilibrium water level. The water level in the pores is maintained at the lowered water level. The water pumped from the pump 5 is discharged into the steam separator 6. The water head difference Δh 0 (= ha−hb) is determined according to the radius R of the gas removal target circle centered on the water pipe 4 (this radius R coincides with the influence radius R as described above). Specifically, the radius R of the target range circle necessary for gas removal is determined according to the tunnel construction range, and for example, the required water head difference Δh 0 is determined based on the radius R and the above equation (1). .
このように、孔内水頭ｈと地下水頭ｈ’との間に水頭差をつけると、通水管４内と地下水領域Ｇ１ｗとの間に圧力勾配が生じる。この圧力勾配により、通水管４内に、地下水が流入すると共に、ガス溜り領域Ｇ１ｇから分離ガスが流入する。地下水は、揚水ポンプ５により気水分離器６まで送水される。また、通水管４（内管３）内に流入した分離ガスのうち、空気よりも軽いガス（例えば、メタンガス）は、内管３を上昇し、連結管２ａを経由して気水分離器６に導入される。そして、気水分離器６により、ガス（分離ガスと遊離ガス）と地下水とを分離する。
このようにして、孔内水頭ｈが地下水頭ｈ’と釣り合うときの基準水頭ｈａより、通水管４を中心とするガス除去の対象範囲円の半径ｒに応じて予め定める水頭差Δｈ０だけ低くなるように、通水管４内の水を揚水して通水管４内の水位を低下させる。この工程が、本発明に係るガス除去方法における「水位低下工程」に相当する。
このように、通水管４内の水位を低下させることにより、地下水と共に、帯水層内の分離ガスと地下水に溶存されているガスとを通水管４内に導いて、地盤（帯水層Ｇ１）からガスを除去する。
Thus, if a head difference is made between the bore head h and the ground head h ′, a pressure gradient is generated between the water pipe 4 and the ground water region G1w. Due to this pressure gradient, groundwater flows into the water conduit 4 and separation gas flows from the gas reservoir region G1g. The groundwater is sent to the steam separator 6 by the pumping pump 5. Of the separated gas flowing into the water pipe 4 (inner pipe 3), a gas lighter than air (for example, methane gas) rises in the inner pipe 3 and is connected to the steam separator 6 via the connecting pipe 2a. To be introduced. Then, the gas (separated gas and free gas) and the groundwater are separated by the steam separator 6.
In this way, the reference head ha when the in-hole head h is balanced with the ground head h ′ is lower by a predetermined head difference Δh 0 according to the radius r of the gas removal target circle around the water pipe 4. Thus, the water in the water pipe 4 is pumped and the water level in the water pipe 4 is lowered. This step corresponds to a “water level lowering step” in the gas removal method according to the present invention.
Thus, by lowering the water level in the water conduit 4, the separation gas in the aquifer and the gas dissolved in the ground water are introduced into the water conduit 4 together with the ground water, and the ground (the aquifer G1) ) Gas is removed.
ここで、事前の地下水調査により、地下水の溶存ガス量を把握することができるため、この溶存ガス量、気水分離器６における圧力（減圧値）及び地下水の揚水速度等により、気水分離器６で分離されて排気等されるガス（分離ガス＋遊離ガス）のうち遊離ガス分の流量については、予め想定することができる。したがって、例えば、気水分離器６から排気されるガスの流量が、遊離ガス分の想定流量まで低下したとき、ガス溜り領域Ｇ１ｇから分離ガスが除去できたものと判断することができる。このようにして、ガス除去の終了判断をするとよい。 Here, since the amount of dissolved gas in the groundwater can be grasped by the preliminary groundwater survey, the air / water separator is determined by the amount of dissolved gas, the pressure in the steam / water separator 6 (pressure reduction value), the pumping speed of the groundwater, and the like. The flow rate of free gas in the gas (separated gas + free gas) separated and exhausted at 6 can be assumed in advance. Therefore, for example, when the flow rate of the gas exhausted from the steam separator 6 is reduced to the assumed flow rate for the free gas, it can be determined that the separation gas has been removed from the gas reservoir region G1g. In this way, it is preferable to determine the end of gas removal.
次に、本実施形態におけるトンネル掘進方法を、シールド工法に適用した場合について、図３を参照して簡単に説明する。図３は、トンネル工事エリアの上面図であり、各セグメントリングの構築予定場所が点線で示されている。なお、トンネル工事エリアの地盤調査が事前に行われており、地盤が図１に示した粘土層Ｇ０及び砂層Ｇ１を含み、砂層Ｇ１（ガス溜り領域Ｇ１ｇ）の平面的な範囲が分かっているものとして以下説明する。 Next, a case where the tunnel excavation method in the present embodiment is applied to the shield method will be briefly described with reference to FIG. FIG. 3 is a top view of the tunnel construction area, where the planned construction locations of each segment ring are indicated by dotted lines. In addition, the ground investigation of the tunnel construction area has been performed in advance, and the ground includes the clay layer G0 and the sand layer G1 shown in FIG. 1, and the planar range of the sand layer G1 (gas reservoir region G1g) is known. Will be described below.
トンネル工事エリアと砂層Ｇ１（地下水及び分離ガスが存在し得る領域）とが重複するエリアについては、この重複エリアを含むようにガス除去の対象範囲円の位置を決める。通水管４は、例えば、セグメントリングの構築予定場所と干渉しない位置に配置する。これにより、トンネル掘進後も通水管４を残しておくことができる。そして、ガス除去の対象範囲円の中心位置で前述したガス除去方法によって、地盤の砂層Ｇ１からガスを除去する。その後、シールド掘進機で地盤を掘削して横坑を形成すると共に、この横坑周壁にセグメントリングを構築しつつトンネルを掘進する。トンネル掘進前に、トンネル掘進の領域からガスが除去されているため、このシールド掘進機の胴体となる筒状のシールド本体内に可燃性ガスが流入することはない。なお、通水管４は、セグメントリングの構築予定場所とずらした位置に設けるものとしたが、これに限らず、セグメントリングの構築予定場所と重複させた位置に設けてもよい。この場合、例えば、ガス除去後、トンネル掘進前に通水管４を抜き取る。 For the area where the tunnel construction area and the sand layer G1 (area where groundwater and separation gas can exist) overlap, the position of the gas removal target circle is determined so as to include this overlapping area. For example, the water pipe 4 is disposed at a position that does not interfere with the planned construction location of the segment ring. Thereby, the water conduit 4 can be left even after tunnel excavation. Then, the gas is removed from the sand layer G1 of the ground by the gas removal method described above at the center position of the gas removal target range circle. Thereafter, the ground is excavated with a shield machine to form a horizontal pit, and a tunnel is excavated while a segment ring is constructed on the peripheral wall of the horizontal mine. Since the gas is removed from the tunnel excavation area before tunnel excavation, the combustible gas does not flow into the cylindrical shield main body which is the trunk of the shield excavator. In addition, although the water pipe 4 shall be provided in the position shifted from the construction planned location of a segment ring, it is not restricted to this, You may provide in the position overlapped with the construction planned location of a segment ring. In this case, for example, after removing the gas, the water conduit 4 is extracted before tunneling.
本実施形態による地盤からのガス除去方法によれば、ストレーナ部４ａを下端側に備えた通水管４を、その下端側が砂層Ｇ１（地下水領域Ｇ１ｗ）に位置するように配置し、砂層Ｇ１からストレーナ部４ａを介して通水管４内に地下水を流入させ、通水管４内の孔内水頭ｈが砂層Ｇ１の地下水頭ｈ’と釣り合うときの通水管内の水の水頭を基準水頭とし、孔内水頭ｈが基準水頭ｈａより予め定める水頭差Δｈ0だけ低くなるように、通水管４内の水を揚水ポンプ５で揚水して、砂層Ｇ１からガスを除去する。これにより、地下水が通水部４内に、自然流入して孔内水頭ｈと地下水頭ｈ’とが釣り合う状態（平衡水位の状態）を基準とし、この基準状態から水頭差をつけることができるため、通水管４内と砂層Ｇ１との間に意図する水頭差Δｈ0を適切につけることができる。そして、この水頭差Δｈ0を、通水管４を中心とするガス除去の対象範囲円の半径Ｒに応じて定めることにより、揚水により地下水頭ｈ’が低下する範囲（影響範囲）をガス除去に必要な範囲内に収めることができる。
このようにして、地下水の揚水による地盤等への影響範囲を可能な限り狭めることが可能なガス除去方法を提供することができる。
According to the gas removal method from the ground according to the present embodiment, the water pipe 4 provided with the strainer portion 4a on the lower end side is disposed so that the lower end side is located in the sand layer G1 (groundwater region G1w), and the strainer is removed from the sand layer G1. The ground water is caused to flow into the water pipe 4 through the section 4a, and the water head in the water pipe when the water head h in the water pipe 4 is balanced with the ground water head h 'of the sand layer G1 is used as a reference water head. The water in the water conduit 4 is pumped up by the pump 5 so that the water head h is lower than the reference head ha by a predetermined head difference Δh 0 , and the gas is removed from the sand layer G1. As a result, the ground water naturally flows into the water passing portion 4 and the state where the water head h in the hole and the ground head h ′ are balanced (equilibrium water level state) can be used as a reference, and a head difference can be obtained from this reference state. Therefore, the intended water head difference Δh 0 can be appropriately set between the water pipe 4 and the sand layer G1. Then, by determining the head difference Δh 0 according to the radius R of the target range circle of gas removal centering on the water pipe 4, the range (influence range) in which the groundwater head h ′ is lowered by pumping can be removed. It can be kept within the required range.
In this way, it is possible to provide a gas removal method capable of narrowing as much as possible the range of influence of groundwater pumping on the ground.
また、実施形態において、「通水管配置工程」は、地下水の圧力によって、砂層Ｇ１（地下水領域Ｇ１ｗ）からストレーナ部４ａを介して通水管４内に地下水を自然流入させて、孔内水頭ｈと地下水頭ｈ’と釣り合わせる構成であるため、容易かつ確実に、孔内水頭ｈと地下水頭ｈ’と釣り合わせることができる。 Further, in the embodiment, the “water pipe arrangement step” is performed by causing groundwater to naturally flow into the water pipe 4 from the sand layer G1 (groundwater area G1w) through the strainer portion 4a due to the pressure of the groundwater, Since it is configured to balance with the groundwater head h ′, it can be easily and reliably balanced with the in-hole head h and the groundwater head h ′.
また、本実施形態によるトンネル掘進方法によれば、上記ガス除去方法によって、地盤の砂層Ｇ１からガスを除去した後、地盤を掘進する構成であるため、地下水の揚水による地盤等への影響範囲を可能な限り狭めると共に安全にトンネル掘進を行うことができる。 In addition, according to the tunnel excavation method according to the present embodiment, the gas is removed from the ground sand layer G1 by the gas removal method, and then the ground is excavated. Tunneling can be done safely as narrow as possible.
ここで、本実施形態において、ガス除去の対象範囲の地盤は、粘土層Ｇ０と砂層Ｇ１とを含み、その砂層Ｇ１は地下水領域Ｇ１ｗとガス溜り領域Ｇ１ｇとを含むものとした。地下水の調査等により地下水領域Ｇ１ｗから遊離する遊離ガスの量を把握することができるが、ガス溜り領域Ｇ１ｇの分離ガスの量を事前に把握することは困難である。したがって、大量に分離ガスが滞留している可能性があるガス溜り領域Ｇ１ｇからのガス除去の確実性を高めることが求められる。 Here, in this embodiment, the ground in the target range of gas removal includes the clay layer G0 and the sand layer G1, and the sand layer G1 includes the groundwater region G1w and the gas reservoir region G1g. Although the amount of free gas liberated from the groundwater region G1w can be grasped by investigation of groundwater or the like, it is difficult to grasp the amount of separated gas in the gas reservoir region G1g in advance. Therefore, it is required to increase the certainty of gas removal from the gas reservoir region G1g in which a large amount of separation gas may be retained.
本実施形態におけるガス除去方法は、通水管内の孔内水頭ｈと地下水頭ｈ’との間に水頭差Δｈ0をつけて、通水管４内と砂層Ｇ１との間に圧力勾配をつけるため、単に、砂層Ｇ１までガス抜き孔を設けて、平衡水位の状態で放置しただけでは、除去できないガス溜り領域Ｇ１ｇの分離ガスを除去することができる。したがって、ガス溜り領域Ｇ１ｇに分離ガスが大量に存在していたとしても、ガス除去の対象範囲円の半径Ｒにおいては、確実に除去することができる。 The gas removal method in the present embodiment creates a pressure gradient between the water pipe 4 and the sand layer G1 by providing a water head difference Δh 0 between the in-hole water head h and the ground water head h ′ in the water pipe. The separation gas in the gas reservoir region G1g that cannot be removed can be removed simply by providing a vent hole up to the sand layer G1 and leaving it in an equilibrium water level state. Therefore, even if a large amount of separation gas exists in the gas reservoir region G1g, it can be reliably removed at the radius R of the target gas removal circle.
また、本実施形態において、内管挿管用の孔が削孔されて内管３が地下水領域Ｇ１ｗに配置され、地下水の圧力によって、通水管４内に、地下水が自然流入し始め、通水管４内の水位は、通水管４内の孔内水頭ｈが地下水頭ｈ’と釣り合う水位（平衡水位）に至る（水頭釣り合わせ工程）。ここで、水頭釣り合わせ工程の後、工事日程等の都合上、実際に揚水ポンプ５を作動させて、水位低下工程を実施するまでには所定の期間を要する場合がある。この場合、揚水ポンプ５を作動させる前に、この平衡水位の状態が、雨水の影響等による地下水頭ｈ’の上昇等により、意図せず崩れてしまう可能性がある。
このような場合に、通水管４内に向かって地下水の流入及び分離ガスの流入が始まり、ひとたび通水管４内に分離ガスと共に地下水が流入すると、気液二相の状態となり、通水管４内の比重が低下する。その結果、通水管４内の水は、地下水の圧力によってさらに押し上げられ、通水管４の孔口から水が地表側に流れ出すと共に、ガスが大気に勢いよく放出される噴発状態となる可能性がある。このような状態で放置するとガス溜り領域Ｇ１ｇから大量に可燃性ガス等が、気水分離器６の排出口を介して地表に放出されるおそれがある。
Further, in the present embodiment, the inner pipe intubation hole is drilled and the inner pipe 3 is disposed in the groundwater region G1w, and groundwater begins to naturally flow into the water pipe 4 due to the pressure of the groundwater. The water level in the water reaches a water level (equilibrium water level) in which the water head h in the hole in the water pipe 4 is balanced with the ground water head h ′ (water head balancing step). Here, a predetermined period may be required after actually performing the water level lowering process after actually operating the pumping pump 5 due to the construction schedule and the like after the head balance process. In this case, before the pumping pump 5 is operated, the state of the equilibrium water level may be unintentionally collapsed due to an increase in the groundwater head h ′ due to the influence of rainwater or the like.
In such a case, the inflow of groundwater and separation gas into the water pipe 4 starts, and once the groundwater flows into the water pipe 4 together with the separation gas, a gas-liquid two-phase state is formed. The specific gravity is reduced. As a result, the water in the water conduit 4 is further pushed up by the pressure of the groundwater, and there is a possibility that the water will flow out from the hole of the water conduit 4 to the surface side and the gas will be ejected vigorously to the atmosphere. There is. If left in such a state, a large amount of combustible gas or the like may be released from the gas reservoir region G1g to the ground surface via the outlet of the steam separator 6.
このような噴発状態の発生を防止するために、例えば、通水管配置工程において、通水管４の下端側を地下水領域Ｇ１ｗに位置させた後、通水管４内を加圧し、この加圧を水頭釣り合わせ工程の開始前に解除する工程（加圧工程）を更に設ける構成とする。これにより、通水管４の下端側を地下水領域Ｇ１ｗに位置させた後、揚水ポンプ５を実際に作動させるまでに所定の期間を要することが予め分かっている場合は、通水管４内を加圧することで噴発状態にならないようにして安全な状態で放置し、その後実際に揚水ポンプ５を作動させる日程になったとき、加圧を解除して、水頭釣り合わせ工程を経て続けて水位低下工程を行うことができる。このため、通水管４の下端側を地下水領域Ｇ１ｗに位置させた後、直ぐに水位低下工程を実施できない場合であっても、噴発状態の発生を防止して、工事エリアにおける安全を確保することができる。
なお、噴発状態の発生の防止は、上記加圧工程を設ける構成に限らず、例えば、揚水ポンプ５の作動前に平衡水位の状態が意図せず崩れてしまっても、通水管４の孔口から地下水が流れ出さないように、通水管４の地表から孔口までの高さを、所定高さ余裕をもたせて突設する構成としてもよい。
In order to prevent the occurrence of such an ejection state, for example, in the water pipe arrangement step, after the lower end side of the water pipe 4 is positioned in the groundwater region G1w, the inside of the water pipe 4 is pressurized and this pressurization is performed. It is set as the structure which further provides the process (pressurization process) canceled before the start of a head balance process. Thereby, after the lower end side of the water pipe 4 is positioned in the groundwater region G1w, when it is known in advance that a predetermined period is required until the pumping pump 5 is actually operated, the inside of the water pipe 4 is pressurized. If it is time to leave it in a safe state so that it does not erupt and then actually operate the pump 5, release the pressurization and continue the water head balancing step to continue the water level lowering step It can be performed. For this reason, even if the water level lowering process cannot be performed immediately after the lower end side of the water pipe 4 is positioned in the groundwater region G1w, the occurrence of an eruption state is prevented to ensure safety in the construction area. Can do.
In addition, prevention of generation | occurrence | production of an ejection state is not restricted to the structure which provides the said pressurization process, For example, even if the state of an equilibrium water level collapses unintentionally before the operation of the pump 5, the hole of the water pipe 4 It is good also as a structure which protrudes with the height from the ground surface of the water flow pipe 4 to a hole mouth with a predetermined height margin so that groundwater may not flow out from the mouth.
また、本実施形態において、通水管４は外管２と内管３とを備えた２重管構造の場合で説明したが、これに限らず、例えば単管構造でもよく、ストレーナ部４ａを少なくとも下端側に備えていればどのような構造でもよい。 In the present embodiment, the water pipe 4 is described as a double pipe structure including the outer pipe 2 and the inner pipe 3. However, the present invention is not limited to this. For example, a single pipe structure may be used. Any structure may be used as long as it is provided on the lower end side.
そして、本実施形態において、通水管配置工程は、地盤の地表から砂層Ｇ１（地下水領域Ｇ１ｗ）まで削孔されたボーリング孔内に通水管４（外管２及び内管３）を挿通することで、通水管４の下端側を地下水領域Ｇ１ｗに位置させ、地下水の圧力によって、地下水領域Ｇ１ｗからストレーナ部４ａを介して通水管４内に地下水を流入させる構成としたが、これに限らない。例えば、外管２を地盤に圧入し、外管２内の土砂等を掘削しつつその外管２内に泥水を供給し、外管２内の掘削土砂を泥水と共に外管２外（地表側）に排出し、その後、同様の手順で内管３の圧入、泥水供給及び掘削土砂の排出を行った後、外管２及び内管３内の泥水を排出することで、地下水領域Ｇ１ｗからストレーナ部４ａを介して通水管４内に地下水を流入させる構成としてもよい。つまり、通水管配置工程は、通水管４を地盤に圧入することで、通水管４の下端側を地下水領域Ｇ１ｗに位置させ、通水管４内の土砂を掘削しつつこの通水管４内に泥水を供給し、通水管４内の掘削土砂を泥水と共に該通水管を介して地表側へ排出することで、地下水領域Ｇ１ｗからストレーナ部４ａを介して通水管４内に地下水を流入させる構成としてもよい。このように、通水管配置工程が、通水管４内の掘削土砂及び泥水を地下水に置換する清水置換工程を含む場合、例えば、事前の地下水調査等により地下水頭ｈ’を調査しておき、この清水置換工程において、孔内水頭ｈが想定される地下水頭ｈ’と釣り合う状態に至るように、掘削土砂及び泥水の排出量等をコントロールして清水置換を行う。また、この場合、外管２の上端の閉止は開放可能に構成する。 And in this embodiment, a water pipe arrangement | positioning process inserts the water pipe 4 (the outer pipe 2 and the inner pipe 3) in the boring hole drilled from the ground surface to the sand layer G1 (groundwater area G1w). Although the lower end side of the water pipe 4 is positioned in the groundwater area G1w and the groundwater flows into the water pipe 4 from the groundwater area G1w through the strainer portion 4a by the pressure of the groundwater, the present invention is not limited thereto. For example, the outer pipe 2 is press-fitted into the ground, mud is supplied into the outer pipe 2 while excavating the earth and sand in the outer pipe 2, and the excavated earth and sand in the outer pipe 2 together with the mud is outside the outer pipe 2 (surface side) ), And then press-fitting the inner pipe 3, supplying muddy water and discharging the excavated sediment in the same procedure, and then discharging the muddy water in the outer pipe 2 and the inner pipe 3 to thereby remove the strainer from the groundwater region G1w. It is good also as a structure which flows in groundwater in the water flow pipe 4 via the part 4a. That is, in the water pipe arrangement step, the water pipe 4 is press-fitted into the ground so that the lower end side of the water pipe 4 is positioned in the groundwater region G1w, and mud is contained in the water pipe 4 while excavating the soil in the water pipe 4. The groundwater is allowed to flow from the groundwater region G1w through the strainer section 4a into the water pipe 4 by discharging the excavated sediment in the water pipe 4 to the surface side through the water pipe together with the muddy water. Good. Thus, when the water pipe arrangement process includes a fresh water replacement process in which the excavated sediment and mud water in the water pipe 4 is replaced with ground water, for example, the ground water head h ′ is investigated by a preliminary ground water survey or the like. In the fresh water replacement step, the fresh water replacement is performed by controlling the amount of excavated sediment and mud discharge so that the bore head h is balanced with the assumed ground head h ′. In this case, the upper end of the outer tube 2 is configured to be openable.
本実施形態においては、図３に示すようにガス除去は１箇所で行う場合で説明したが、トンネル工事エリアとガス溜り領域Ｇ１ｇとの重複エリアが、例えば図４に示すように比較的広い場合等においては、ガス除去は、地盤の複数の位置でそれぞれ行うようにするとよい。工事エリアが広い場合に、一箇所からガス除去を行うと工事エリアと直接関係のない部分からもガスを除去することになり、地盤への影響範囲が広がるためである。このように、工事エリアを分割し各分割エリアをそれぞれカバーできるようにガス除去の対象範囲円の半径Ｒを決めれば、影響範囲をさらに狭めることができる。この場合、図４に示すように各ガス除去の対象範囲円を、それぞれ一部重複するようにしてもよいし、図示省略するが、接するようにしてもよい。例えば、接するようにする場合であって、図４に示すように、通水管４の設置間隔Ｌを等間隔とし、各位置でのガス除去の対象範囲円の半径Ｒを一致させた場合は、Ｒ＝Ｌ／２となる。
また、各位置での水頭差Δｈ0は、同じ水頭差を用いてもよいし、それぞれの場所で設定するようにしてもよい。つまり、図４に示すように、各場所でのガス除去の対象範囲円の半径を一致させてもよいし、後述するように、それぞれの場所で設定してもよい。各場所で設定する場合、具体的には、各場所で、通水管を配置する前に地盤の状況を試堀したボーリング孔等により調査し、その調査結果に応じて、ガス除去の対象範囲円の半径を適宜決める。
In the present embodiment, the case where gas removal is performed at one place as shown in FIG. 3 has been described, but the overlapping area between the tunnel construction area and the gas reservoir area G1g is relatively wide as shown in FIG. 4, for example. For example, gas removal may be performed at a plurality of positions on the ground. If the construction area is large, removing gas from one location will also remove the gas from a portion that is not directly related to the construction area, thus expanding the range of influence on the ground. As described above, if the radius R of the target circle for gas removal is determined so that the construction area is divided and each divided area can be covered, the influence range can be further narrowed. In this case, as shown in FIG. 4, the target range circles of each gas removal may be partially overlapped or may be in contact with each other although not shown. For example, in the case of making contact, as shown in FIG. 4, when the installation interval L of the water pipe 4 is made equal, and the radius R of the target range circle of gas removal at each position is matched, R = L / 2.
The water head difference Δh 0 at each position may be the same water head difference or may be set at each location. That is, as shown in FIG. 4, the radius of the target range circle for gas removal at each location may be matched, or may be set at each location as described later. When setting at each location, specifically, at each location, investigate the ground conditions before placing the water pipes using a drilling hole, etc. The radius is determined appropriately.
このように、地盤調査の結果に応じて、ガス除去の対象範囲円の半径を適宜決める（つまり、水頭差Δｈ0をそれぞれ設定する）変形例について、以下の図５及び図６に基づいて、詳細に説明する。図５は、通水管４の設置間隔Ｌと各位置での半径Ｒとの関係を示した図であり、図６は、この変形例におけるガス除去の施工手順を示すフロー図である。 As described above, according to the results of the ground survey, the radius of the gas removal target range circle is appropriately determined (that is, the water head difference Δh 0 is set), based on the following FIG. 5 and FIG. This will be described in detail. FIG. 5 is a diagram showing the relationship between the installation interval L of the water pipe 4 and the radius R at each position, and FIG. 6 is a flowchart showing the gas removal construction procedure in this modification.
本変形例のガス除去方法においては、地盤の複数の位置でガス除去を行う構成とし、地盤の第１の位置No.ｎにおいて、所定間隔Ｌの半分に一致させたガス除去の対象範囲円の半径Ｒ（＝Ｌ／２）に応じて定めた水頭差Δｈ’で水位低下工程を行った後、この第１の位置No.ｎから所定間隔Ｌだけ離間させた第２の位置No.ｎ（＝ｎ＋１）で、通水管配置工程を行う。
そして、第２の位置No.ｎ（＝ｎ＋１）でガスが発生し又は砂層Ｇ１が存在する場合には、該第２の位置No.ｎ（＝ｎ＋１）において、所定間隔Ｌの半分に一致させた半径Ｒ（＝Ｌ／２）に応じて定めた水頭差Δｈ’で、水位低下工程を行う。
一方、第２の位置No.ｎ（＝ｎ＋１）でガスが発生せずかつ砂層Ｇ１が存在しない場合には、No.ｎ−１として第１の位置において、所定間隔Ｌに一致させた半径Ｒ（＝Ｌ）に応じて定めた水頭差Δｈ’で水位低下工程を行う。
In the gas removal method of the present modification, gas removal is performed at a plurality of positions on the ground, and the gas removal target range circle that matches the half of the predetermined interval L at the first position No. n of the ground. After performing the water level lowering step with the water head difference Δh ′ determined according to the radius R (= L / 2), the second position No. n (separated by a predetermined distance L from the first position No. n) = N + 1), the water pipe arrangement step is performed.
When gas is generated at the second position No. n (= n + 1) or the sand layer G1 exists, the second position No. n (= n + 1) is made to coincide with half of the predetermined interval L. The water level lowering step is performed with a water head difference Δh ′ determined according to the radius R (= L / 2).
On the other hand, when no gas is generated at the second position No. n (= n + 1) and the sand layer G1 is not present, the radius R matched with the predetermined interval L at the first position as No. n−1. The water level lowering step is performed with a water head difference Δh ′ determined according to (= L).
具体的には、図５及び図６に示すように、最初の位置No.ｎ（＝１）で地盤調査を行いガスの発生又は砂層Ｇ１が確認されたものとし（ＳＴＥＰ１）、この位置で影響半径Ｌ／２を対象としたガス除去を実施する（ＳＴＥＰ２）。そして、通水管４の設置間隔Ｌだけ離間させた次の位置No.ｎ（＝２）で地盤調査を行う（ＳＴＥＰ３）。その結果、この次の位置No.ｎ（＝２）で、ガスの発生又は砂層Ｇ１の確認がされた場合（ＳＴＥＰ４：Ｙｅｓ）、この次の位置No.ｎ（＝２）で影響半径Ｌ／２を対象としたガス除去を実施する（ＳＴＥＰ５）。一方、ガスの発生又は砂層Ｇ１のいずれも確認されない場合（ＳＴＥＰ４：Ｎｏ）、１つ前の位置No.ｎ−１（＝１）で影響半径をＬ／２からＬに拡大させて、この影響半径Ｌを対象としたガス除去を実施する（ＳＴＥＰ６）。そして、ＳＴＥＰ５又はＳＴＥＰ６の後、上記次の位置No.ｎ（＝２）がガス除去の最終位置であった場合（ＳＴＥＰ７：Ｙｅｓ）、ガス除去は終了し、最終位置でない場合（ＳＴＥＰ７：Ｎｏ）、ＳＴＥＰ３に戻り、更に次のNo.３の位置で、ＳＴＥＰ３〜ＳＴＥＰ７を実施し、これを最終位置まで繰り返す。 Specifically, as shown in FIG. 5 and FIG. 6, it is assumed that a ground survey was performed at the first position No. n (= 1) and gas generation or sand layer G1 was confirmed (STEP 1). Gas removal for the radius L / 2 is performed (STEP 2). Then, a ground survey is performed at the next position No. n (= 2) separated by the installation interval L of the water pipe 4 (STEP 3). As a result, when the generation of gas or the confirmation of the sand layer G1 is confirmed at this next position No. n (= 2) (STEP 4: Yes), the influence radius L / at the next position No. n (= 2). Gas removal for 2 is performed (STEP 5). On the other hand, when neither gas generation nor sand layer G1 is confirmed (STEP 4: No), the influence radius is increased from L / 2 to L at the previous position No. n-1 (= 1). Gas removal for the radius L is performed (STEP 6). Then, after STEP5 or STEP6, when the next position No. n (= 2) is the final position for gas removal (STEP7: Yes), the gas removal is completed, but not the final position (STEP7: No). Returning to STEP 3, STEP 3 to STEP 7 are further performed at the next position No. 3, and this is repeated until the final position.
このような変形例によれば、各位置で順次地盤調査を実施して、各位置でガスの発生又は砂層Ｇ１の確認がされた場合には、通水管４の設置間隔Ｌの半分に一致させた影響半径Ｌ／２でそれぞれガス除去を行い、影響範囲を最小限に収めることができる。そして、第２の位置No.ｎ（＝ｎ＋１）において、ガスの発生又は砂層Ｇ１の確認がいずれもできなかった場合、その第２の位置No.ｎ（＝ｎ＋１）から第１の位置No.ｎのガス除去の対象範囲円に至るまでの領域に、ガスが存在する可能性がある。この場合であっても、第１の位置No.ｎで、再度ガス除去を、影響半径を２倍に拡大して実施する構成であるため、No.ｎ＋１の通水管４とNo.ｎのガス除去の対象範囲円との間に広がっている可能性のあるガス溜り範囲をカバーすることができ、ガス除去の確実性をさらに高めることができる。 According to such a modified example, when the ground survey is sequentially performed at each position, and gas generation or sand layer G1 is confirmed at each position, it is made to coincide with half of the installation interval L of the water pipe 4. Gas removal can be carried out at the affected radius L / 2 to minimize the affected range. If neither gas generation nor sand layer G1 can be confirmed at the second position No. n (= n + 1), the first position No. n from the second position No. n (= n + 1). There is a possibility that gas exists in a region up to a target circle for n gas removal. Even in this case, the gas removal is performed again at the first position No. n with the influence radius doubled, so that the No. n + 1 water pipe 4 and the No. n gas are used. It is possible to cover the gas pool range that may be spread between the removal target range circle and further improve the reliability of gas removal.
以上、本発明の好ましい実施形態について説明したが、本発明は上記実施形態に制限されるものではなく、本発明の技術的思想に基づいて種々の変形及び変更が可能である。 As mentioned above, although preferable embodiment of this invention was described, this invention is not restrict | limited to the said embodiment, A various deformation | transformation and change are possible based on the technical idea of this invention.
４・・・・通水管
４ａ・・・ストレーナ部
Ｇ１・・・砂層（帯水層）
ｈａ・・・基準水頭
ｈ・・・・孔内水頭（通水管内の水の水頭）
ｈ’・・・地下水頭（帯水層の地下水の水頭）
Δｈ0・・・水頭差
Ｒ・・・・ガス除去の対象範囲円の半径
4 .... Water pipe 4a ... Strainer part G1 ... Sand layer (Aquifer)
ha: Reference head h ... Head water in the hole (water head in the water pipe)
h '・ ・ ・ Groundwater head (Aquifer groundwater head)
Δh 0・ ・ ・ Water head difference R ・ ・ ・ Radius of gas removal target range circle
Claims (8)
ストレーナ部を少なくとも下端側に備えた通水管を、該下端側が前記帯水層に位置するように配置し、前記帯水層から前記ストレーナ部を介して前記通水管内に地下水を流入させる通水管配置工程と、
前記帯水層の地下水の水頭と釣り合うときの前記通水管内の水の水頭を基準水頭とし、前記通水管内の水の水頭が前記基準水頭より予め定める水頭差だけ低くなるように、前記通水管内の水を揚水して前記通水管内の水位を低下させる水位低下工程と、
を備え、前記通水管内の水位を低下させることにより前記帯水層内のガスを前記通水管内に導いて除去することを特徴とする地盤からのガス除去方法。 A gas removal method for removing gas from a ground having an aquifer containing gas and groundwater,
A water pipe provided with a strainer part at least on the lower end side is arranged so that the lower end side is located in the aquifer, and a water pipe into which ground water flows from the aquifer through the strainer part into the water pipe The placement process;
The head of the water in the water pipe when it is balanced with the head of the groundwater in the aquifer is used as a reference head, and the water head in the water pipe is lower than the reference head by a predetermined head difference. A water level lowering step of pumping up water in the water pipe to lower the water level in the water pipe;
A gas removal method from the ground, wherein the gas in the aquifer is guided and removed into the water pipe by lowering the water level in the water pipe.
前記地盤の第１の位置において、前記所定間隔の半分に一致させた前記半径に応じて定めた前記水頭差で、前記水位低下工程を行った後、前記第１の位置から前記所定間隔だけ離間させた第２の位置で、前記通水管配置工程を行い、
前記第２の位置でガスが発生し又は帯水層が存在する場合には、該第２の位置において、前記所定間隔の半分に一致させた前記半径に応じて定めた前記水頭差で、前記水位低下工程を行う一方、
前記第２の位置でガスが発生せずかつ帯水層が存在しない場合には、前記第１の位置において、前記所定間隔に一致させた前記半径に応じて定めた前記水頭差で前記水位低下工程を行う、請求項５に記載の地盤からのガス除去方法。 It is configured to perform gas removal at a plurality of positions separated by a predetermined interval in the ground,
At the first position of the ground, after performing the water level lowering step with the water head difference determined according to the radius matched to half of the predetermined interval, it is separated from the first position by the predetermined interval. In the second position, the water pipe arrangement step is performed,
When gas is generated or an aquifer is present at the second position, the water head difference determined according to the radius matched to half of the predetermined interval at the second position, While performing the water level lowering process,
When no gas is generated at the second position and no aquifer exists, the water level lowers at the first position by the water head difference determined according to the radius matched with the predetermined interval. The method for removing gas from the ground according to claim 5, wherein the step is performed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2014075495A JP6276093B2 (en) | 2014-04-01 | 2014-04-01 | Tunneling method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2014075495A JP6276093B2 (en) | 2014-04-01 | 2014-04-01 | Tunneling method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2015196989A true JP2015196989A (en) | 2015-11-09 |
| JP6276093B2 JP6276093B2 (en) | 2018-02-07 |
Family
ID=54546848
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2014075495A Active JP6276093B2 (en) | 2014-04-01 | 2014-04-01 | Tunneling method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP6276093B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2017141636A (en) * | 2016-02-12 | 2017-08-17 | 博 堀江 | Combustible gas jetting predictor in earthquake time |
| CN116066154A (en) * | 2023-03-24 | 2023-05-05 | 北京城建集团有限责任公司 | Active regulation and control method for deformation of shield tunnel |
Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0258632A (en) * | 1988-08-25 | 1990-02-27 | Asia Kaiyo Sagiyou Kk | Pneumatic caisson construction and device therefor |
| US5485882A (en) * | 1994-10-27 | 1996-01-23 | Exxon Production Research Company | Low-density ball sealer for use as a diverting agent in hostile environment wells |
| JPH08326462A (en) * | 1995-05-26 | 1996-12-10 | Sekiyu Kodan | Processing method of casing set depth and device thereof |
| JP2001214428A (en) * | 2000-02-04 | 2001-08-07 | Ohbayashi Corp | Method for designing deep well |
| JP2004068398A (en) * | 2002-08-06 | 2004-03-04 | Geotop Corp | Construction method and construction device for pile |
| JP2006045839A (en) * | 2004-08-03 | 2006-02-16 | Mitsubishi Materials Natural Resources Development Corp | Well device having fluid injecting and recovering functions, and method of setting the well device |
| JP2006231222A (en) * | 2005-02-25 | 2006-09-07 | Matsushita Electric Ind Co Ltd | Purification system of soil, and apparatus for monitoring purification of soil |
| JP2006233585A (en) * | 2005-02-24 | 2006-09-07 | Nippon Steel Corp | Intra-pipe sediment excavating/discharging device and intra-pipe sediment excavating/discharging method |
| JP2006326397A (en) * | 2005-05-23 | 2006-12-07 | Nishimatsu Constr Co Ltd | System and method for purification of contaminated ground |
| JP2011012451A (en) * | 2009-07-02 | 2011-01-20 | National Institute Of Advanced Industrial Science & Technology | Methane hydrate decomposition method and device |
| JP2012082618A (en) * | 2010-10-12 | 2012-04-26 | Kajima Corp | Tunnel construction method |
| JP2012120987A (en) * | 2010-12-09 | 2012-06-28 | Maeda Corp | Method for purifying excavated soil when shield construction is performed in contaminated soil and shield excavator |
-
2014
- 2014-04-01 JP JP2014075495A patent/JP6276093B2/en active Active
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0258632A (en) * | 1988-08-25 | 1990-02-27 | Asia Kaiyo Sagiyou Kk | Pneumatic caisson construction and device therefor |
| US5485882A (en) * | 1994-10-27 | 1996-01-23 | Exxon Production Research Company | Low-density ball sealer for use as a diverting agent in hostile environment wells |
| JPH08326462A (en) * | 1995-05-26 | 1996-12-10 | Sekiyu Kodan | Processing method of casing set depth and device thereof |
| JP2001214428A (en) * | 2000-02-04 | 2001-08-07 | Ohbayashi Corp | Method for designing deep well |
| JP2004068398A (en) * | 2002-08-06 | 2004-03-04 | Geotop Corp | Construction method and construction device for pile |
| JP2006045839A (en) * | 2004-08-03 | 2006-02-16 | Mitsubishi Materials Natural Resources Development Corp | Well device having fluid injecting and recovering functions, and method of setting the well device |
| JP2006233585A (en) * | 2005-02-24 | 2006-09-07 | Nippon Steel Corp | Intra-pipe sediment excavating/discharging device and intra-pipe sediment excavating/discharging method |
| JP2006231222A (en) * | 2005-02-25 | 2006-09-07 | Matsushita Electric Ind Co Ltd | Purification system of soil, and apparatus for monitoring purification of soil |
| JP2006326397A (en) * | 2005-05-23 | 2006-12-07 | Nishimatsu Constr Co Ltd | System and method for purification of contaminated ground |
| JP2011012451A (en) * | 2009-07-02 | 2011-01-20 | National Institute Of Advanced Industrial Science & Technology | Methane hydrate decomposition method and device |
| JP2012082618A (en) * | 2010-10-12 | 2012-04-26 | Kajima Corp | Tunnel construction method |
| JP2012120987A (en) * | 2010-12-09 | 2012-06-28 | Maeda Corp | Method for purifying excavated soil when shield construction is performed in contaminated soil and shield excavator |
Non-Patent Citations (2)
| Title |
|---|
| トンネル標準示方書山岳工法編・同解説, JPN6017039725, 20 July 2006 (2006-07-20), JP, pages 139, ISSN: 0003664008 * |
| 水理公式集, JPN6017039722, 30 April 1988 (1988-04-30), JP, pages 377 - 382, ISSN: 0003664007 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2017141636A (en) * | 2016-02-12 | 2017-08-17 | 博 堀江 | Combustible gas jetting predictor in earthquake time |
| CN116066154A (en) * | 2023-03-24 | 2023-05-05 | 北京城建集团有限责任公司 | Active regulation and control method for deformation of shield tunnel |
Also Published As
| Publication number | Publication date |
|---|---|
| JP6276093B2 (en) | 2018-02-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102758633B (en) | The construction method of the good large cross-section tunnel of a kind of country rock situation | |
| CN102330545B (en) | Sand prevention method for heavy oil reservoir oil well | |
| CN106088125B (en) | Soil body underwater demolition drawing out soil equipment and its method immediately below the cutting shoe of open caisson | |
| US20150361759A1 (en) | A method of plugging a well | |
| CN109026010A (en) | A kind of mine seepage well slip casting type sinking shaft construction method | |
| CN106437522A (en) | Deep-level and high-ground-stress coal uncovering and drilling construction device and method | |
| CN104265357B (en) | Anti-burst method is taken out in a kind of strong prominent coal seam in advance | |
| CN102400713A (en) | Method for auxiliary construction of water falling in tunnel by communicated channel | |
| JP6276093B2 (en) | Tunneling method | |
| CN103742188A (en) | Coal mine pump drainage gas well and drilling method thereof | |
| CN101487376A (en) | One-time excavation construction method for large-diameter large-depth pressure regulating well pilot shaft | |
| KR20160091291A (en) | Blasting a method of underwater base rock | |
| JP2015168981A (en) | Water intake device | |
| CN102767349A (en) | Completion method for suspending sieve tube in coal bed gas horizontal well | |
| CN214576923U (en) | Coal bed gas horizontal well system | |
| JP4834569B2 (en) | Ground improvement method and ground improvement device | |
| CN114961673A (en) | Expansion method for salt cavern gas storage | |
| CN106593382A (en) | Method for collecting natural gas from producing well | |
| JP2008196261A (en) | Grouting method | |
| US20060290197A1 (en) | Oil extraction system and method | |
| KR101834567B1 (en) | Apparatus for digging underground hole and constructing casing, and method for constructing casing using this same | |
| JP5015844B2 (en) | Method for constructing shaft and upward shield used in this method | |
| WO2022177464A1 (en) | Method of forming an underground reservoir in a stratum of rock salt | |
| CN110374664B (en) | Reverse drilling construction method for high gas and outburst coal seam fresh air well | |
| JP2018009298A (en) | Ground water level lowering system and method of constructing the same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20161117 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20171010 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20171024 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20171215 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20171226 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20180111 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 6276093 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |