JP2006104714A - Method and device for preventing blocking of underground water pumping facility, and blocking preventive underground water pumping facility - Google Patents

Method and device for preventing blocking of underground water pumping facility, and blocking preventive underground water pumping facility Download PDF

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JP2006104714A
JP2006104714A JP2004290568A JP2004290568A JP2006104714A JP 2006104714 A JP2006104714 A JP 2006104714A JP 2004290568 A JP2004290568 A JP 2004290568A JP 2004290568 A JP2004290568 A JP 2004290568A JP 2006104714 A JP2006104714 A JP 2006104714A
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pumping
groundwater
upper space
reactive gas
air supply
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Fumio Imadate
文雄 今立
Hidetoshi Konishi
秀利 小西
Ryuta Nakayama
龍太 中山
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Kajima Corp
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Kajima Corp
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Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and a device for preventing blocking of a pumping facility while continuing to pump. <P>SOLUTION: Air supply pipes 21 leading close to the underground water level H1 are provided in a pumping well 11 of the pumping facility 10 continuously pumping underground water W, and an underground water upper space P in the pumping well 11 is filled with low reactive gas G through the air supply pipes 21. Low reactive gas G is continuously supplied at a flow rate corresponding to the leakage speed of low reactive gas G from the upper space P to suppress oxidation of underground water components. When sidewalls of the pumping well 11 are provided with water collecting passages 31 facing the side, it is preferable to lead the air supply pipes 21 into the water collecting passages 31 from the inside of the pumping well 11 to fill the upper space P and the internal spaces of the water collecting passages 31 with the low reactive gas. It is further preferable to provide an oxygen analyzer for measuring oxygen concentration in the underground water upper space P in the pumping well 11 and to fill the low reactive gas G so that the oxygen concentration in the upper space P is not more than the oxidation suppressing concentration of the underground water components. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

本発明は地下水揚水設備の閉塞防止方法及び装置並びに閉塞防止型地下水揚水設備に関し、とくに地下水を継続的に揚水する揚水設備において地下水成分の酸化による閉塞を防止する方法及び装置並びにそれを用いた閉塞防止型地下水揚水設備に関する。   BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clogging prevention method and apparatus for groundwater pumping equipment and a clogging prevention type groundwater pumping equipment, and more particularly, a method and apparatus for preventing clogging due to oxidation of groundwater components in a pumping equipment for continuously pumping groundwater, and clogging using the same. It relates to prevention-type groundwater pumping equipment.

地上又は地中に大型の構造物(原子炉建屋、石油貯蔵タンク、ガス貯蔵タンク等)を構築する場合に、地下水による構造物の浮き上がり防止、構造物の耐水対策、構造物の合理的設計等を目的として、構造物下方の地下水位を低下させる揚水設備(排水設備と呼ばれることもある)を設けることがある。非特許文献1は、図5に示すように、この場合原子力発電所の原子炉建屋である構造物3に設けた地下水揚水設備の構造を開示する。図示例の揚水設備は、構造物3の基礎直下に敷設され岩盤1中の地下水を集めるドレン管32と、構造物3の基礎周囲に敷設されドレン管32より集水する集水管31と、集水管31の地下水を地上に排出する揚水井11とからなる。図中の符号34は、原子炉建屋に隣接するタービン建屋を示す。   When building large structures on the ground or underground (reactor buildings, oil storage tanks, gas storage tanks, etc.), prevention of floating structures due to groundwater, water resistance measures for structures, rational design of structures, etc. For this purpose, a pumping facility (sometimes called a drainage facility) that lowers the groundwater level below the structure may be provided. As shown in FIG. 5, Non-Patent Document 1 discloses the structure of a groundwater pumping facility provided in a structure 3 that is a reactor building of a nuclear power plant in this case. The pumping facility in the illustrated example includes a drain pipe 32 that is laid directly under the foundation of the structure 3 and collects groundwater in the rock 1, a water collection pipe 31 that is laid around the foundation of the structure 3 and collects water from the drain pipe 32, It consists of a pumping well 11 that discharges the groundwater of the water pipe 31 to the ground. Reference numeral 34 in the figure indicates a turbine building adjacent to the reactor building.

図5のドレン管32は、例えば管径φ=100mmの有孔塩ビ管であり、構造物3の周辺岩盤1の揚圧力解析に基づき配置位置及び数を選定する。集水管31は、例えば管径φ=800mmの有孔ヒューム管であり、周辺岩盤1の湧水量解析に基づき、その湧水量より集水管31及びドレン管32の流下能力が大きくなるように、管径を選定する。揚水井11は、地下約38.7mに構築したRC造の集水ピット14と、その集水ピット14から地上に至る鋼製筒体(シャフト)とにより構成される。集水ピット14には揚水ポンプ(図示せず)が装入される。ドレン管32及び集水管31に集めた地下水を集水ピット14に流下させ、集水ピット14の地下水を揚水ポンプで継続的に地上へ排出することにより、構造物3の下方の地下水位を下げて構造物3に作用する揚圧力を低減する。   The drain pipe 32 in FIG. 5 is a perforated PVC pipe having a pipe diameter of φ = 100 mm, for example, and the arrangement position and number are selected based on the uplift analysis of the surrounding rock mass 1 of the structure 3. The water collecting pipe 31 is, for example, a perforated fume pipe having a pipe diameter of φ = 800 mm. Based on the analysis of the amount of spring water in the surrounding rock mass 1, the water collecting pipe 31 and the drain pipe 32 have a larger flow capacity than the spring water volume. Select the diameter. The pumping well 11 is composed of a RC water collecting pit 14 constructed approximately 38.7m underground and a steel cylinder (shaft) extending from the water collecting pit 14 to the ground. The water collecting pit 14 is charged with a pump (not shown). The groundwater collected in the drain pipe 32 and the water collection pipe 31 is caused to flow down to the water collection pit 14, and the groundwater level in the water collection pit 14 is continuously discharged to the ground with a pump to lower the groundwater level below the structure 3. The lifting pressure acting on the structure 3 is reduced.

また図6に示すように、液状化のおそれのある砂層地盤41の下方に粘土層地盤42が分布している地盤1上に建物その他の構造物3を構築する場合に、砂層地盤41の液状化防止対策を目的として、構造物3下方の地下水位を低下させる揚水設備を設けることがある(特許文献1参照)。図6の構造物3は、基礎底面が砂層地盤41中の深い位置まで掘り込まれ、粘土層地盤42の下方の支持層43に根入れした杭基礎45により支持されている。その構造物3の周囲に粘土層地盤42に到達する止水壁(鉄筋コンクリート地中連続壁、鋼矢板等)46を構築して構造物3を取り囲み、構造物3の基礎底面から粘土層地盤42に至る揚水井11を設け、揚水井11及び揚水装置15を介して止水壁46で囲まれた砂層地盤41の地下水を継続的に排出することにより、砂層地盤41の地下水位を下げて地震時における砂層地盤41の液状化を防止する。同様の揚水設備は、地下水位が高い砂礫層の地下掘削工事等において、地下水位低下工法(揚水工法)を適用する場合にも用いられる(特許文献2参照)。   Further, as shown in FIG. 6, when building or other structure 3 is constructed on the ground 1 where the clay layer ground 42 is distributed below the sand layer ground 41 which may be liquefied, the liquid of the sand layer ground 41 For the purpose of preventing water pollution, a pumping facility for lowering the groundwater level below the structure 3 may be provided (see Patent Document 1). The structure 3 in FIG. 6 is supported by a pile foundation 45 that is dug up to a deep position in the sand layer ground 41 and is embedded in a support layer 43 below the clay layer ground 42. Around the structure 3, a water blocking wall (reinforced concrete underground continuous wall, steel sheet pile, etc.) 46 that reaches the clay layer ground 42 is constructed to surround the structure 3, and the clay layer ground 42 from the bottom surface of the structure 3 The groundwater level of the sand layer ground 41 is lowered by continuously discharging the groundwater of the sand layer ground 41 surrounded by the water blocking wall 46 through the pumping well 11 and the pumping device 15. The liquefaction of the sand layer ground 41 at the time is prevented. The same pumping equipment is also used when a groundwater level lowering method (pumping method) is applied in underground excavation work of a gravel layer having a high groundwater level (see Patent Document 2).

上述した地下水揚水設備は何れも、構造物又は工事現場を維持管理する上で重要な設備であり、長期に亘り必要十分な量の地下水の揚水を継続する必要がある。しかし、図5及び図6に示すように揚水設備は地下深くに設けられており、周辺地盤から浸透する地下水中の溶存成分の影響を受けて機能が経時的に低下するおそれがある。例えば図5の揚水設備において、周辺地盤1に鉄分が含まれていると、揚水設備内に進入した鉄イオンが空気(酸素)により酸化されて不溶性の水酸化鉄を生成し、揚水井11の集水ピット14・集水管31・ドレン管32に不溶性酸化物質が徐々に堆積してそれらを閉塞させる。揚水井11・集水管31・ドレン管32が閉塞すると、上述した揚圧力解析・湧水量解析によって定めた地下水量が排水できなくなり、新たな揚水井11を設ける等の対策が必要となる。このため従来は、定期的に作業員が揚水井11の集水ピット14に降り、高圧水の吹き付け等により揚水井11内に堆積した不溶性酸化物質を人力で除去する清掃作業を行っている。   All of the above-described groundwater pumping facilities are important facilities for maintaining and managing structures or construction sites, and it is necessary to continue pumping a necessary and sufficient amount of groundwater for a long period of time. However, as shown in FIG. 5 and FIG. 6, the pumping equipment is provided deep underground, and there is a risk that the function will deteriorate over time due to the influence of dissolved components in the groundwater penetrating from the surrounding ground. For example, in the pumping facility shown in FIG. 5, if the surrounding ground 1 contains iron, iron ions that have entered the pumping facility are oxidized by air (oxygen) to produce insoluble iron hydroxide. Insoluble oxide substances gradually accumulate in the water collecting pit 14, the water collecting pipe 31, and the drain pipe 32 to block them. When the pumping well 11, the water collecting pipe 31, and the drain pipe 32 are blocked, the amount of groundwater determined by the above-described pumping pressure analysis and spring water analysis cannot be drained, and measures such as providing a new pumping well 11 are required. For this reason, conventionally, a worker regularly goes down to the water collecting pit 14 of the pumping well 11 and performs a cleaning operation to manually remove insoluble oxide substances accumulated in the pumping well 11 by blowing high-pressure water or the like.

安田悟他「女川原子力発電所第3号機地下水排水設備の設計・施工」電力土木第294号、社団法人電力土木技術協会、2001年7月、pp.59-63Satoru Yasuda et al. “Design and Construction of Onagawa Nuclear Power Station Unit 3 Groundwater Drainage System” Electric Power Engineering No. 294, Japan Electric Power Engineering Association, July 2001, pp.59-63 特開平11−323896号公報JP-A-11-323896 特開2001−323477号公報JP 2001-323477 A

しかし、上述した揚水井11の清掃方法は、地下深い揚水井11の内部に作業員が降りる危険作業を伴うと共に、作業員の安全確保のため清掃作業時に揚水を中断しなければならない問題点がある。このため、地下水を絶えず排出することが要求される揚水設備では、清掃作業を考慮して予備井を含む複数の揚水井11を設けることが必要となる。予備井のない必要最小限の数の揚水井11によって地下水を経済的に排出するためには、揚水を中断することなく揚水井の閉塞を防止する技術の開発が必要である。   However, the above-described cleaning method for the pumping well 11 involves a dangerous work in which the worker gets down into the deep underground pumping well 11, and the pumping water must be interrupted during the cleaning work to ensure the safety of the worker. is there. For this reason, in a pumping facility that requires continuous discharge of groundwater, it is necessary to provide a plurality of pumping wells 11 including a reserve well in consideration of cleaning work. In order to discharge groundwater economically with the minimum number of pumping wells 11 without reserve wells, it is necessary to develop a technique for preventing the blocking of pumping wells without interrupting pumping.

また、従来の揚水井11の清掃方法は、揚水井11の側方に連なる集水管31やドレン管32内の堆積物を十分に除去できない問題点もある。例えば図5の揚水設備において、集水ピット14に降りた作業員が集水管31やドレン管32の内部まで入り込むことは困難であり、集水管31やドレン管32の内部の堆積物を十分に除去できないため、従来の清掃方法では集水管31やドレン管32の閉塞のおそれが残る。集水管31やドレン管32を含む揚水設備10のあらゆる部分の閉塞を防止できる技術の開発が望まれている。   In addition, the conventional method for cleaning the pumping well 11 has a problem in that the deposits in the water collecting pipe 31 and the drain pipe 32 connected to the side of the pumping well 11 cannot be sufficiently removed. For example, in the pumping facility shown in FIG. 5, it is difficult for a worker who has descended into the water collecting pit 14 to enter the water collecting pipe 31 and the drain pipe 32, and the sediment inside the water collecting pipe 31 and the drain pipe 32 is sufficiently removed. Since it cannot be removed, there is a risk that the water collecting pipe 31 and the drain pipe 32 may be blocked by the conventional cleaning method. Development of a technique capable of preventing clogging of all parts of the pumping facility 10 including the water collecting pipe 31 and the drain pipe 32 is desired.

そこで本発明の目的は、揚水を継続しつつ揚水設備の閉塞を防ぐ閉塞防止方法及び装置を提供することにある。   Accordingly, an object of the present invention is to provide a blockage prevention method and apparatus for preventing blockage of a pumping facility while continuing pumping.

図1の実施例を参照するに、本発明による地下水揚水設備の閉塞防止方法は、地下水Wを継続的に揚水する揚水設備10の揚水井11内に地下水位H1近傍に至る送気管21を設け、送気管21を介して揚水井11内の地下水上部空間Pに低反応性ガスGを充填し、上部空間Pからの低反応性ガスGの漏洩速度Vに応じた流量で低反応性ガスGを継続的に補給して地下水成分の酸化を抑制してなるものである。好ましくは、揚水井11の側壁に側方向きの集水路31が設けられている場合に、送気管21を集水路31内に導入して上部空間P及び集水路31内に低反応性ガスGを充填する。 Referring to the embodiment of FIG. 1, the method for preventing clogging of a groundwater pumping facility according to the present invention includes an air pipe 21 that reaches the vicinity of the groundwater level H 1 in a pumping well 11 of a pumping facility 10 that pumps groundwater W continuously. The low-reactive gas G is filled into the groundwater upper space P in the pumping well 11 through the air pipe 21 and the flow rate is in accordance with the leakage rate V of the low-reactive gas G from the upper space P. G is continuously replenished to suppress oxidation of groundwater components. Preferably, when the lateral water collecting channel 31 is provided on the side wall of the pumping well 11, the air supply pipe 21 is introduced into the water collecting channel 31, and the low-reactive gas G is introduced into the upper space P and the water collecting channel 31. Fill.

また図1のブロック図を参照するに、本発明による地下水揚水設備の閉塞防止装置は、地下水Wを継続的に揚水する揚水設備10の揚水井11内の地下水位H1近傍に開口する送気管21、送気管21を介して揚水井11内の地下水上部空間Pに低反応性ガスGを充填する送気装置22、及び上部空間Pからの低反応性ガスGの漏洩速度Vに応じて送気装置22の流量を制御する制御装置25を備えてなるものである。好ましくは、図2に示すように、揚水井11内の地下水上部空間Pの酸素濃度を計測する酸素濃度計28を設け、上部空間Pの酸素濃度が地下水成分の酸化抑制濃度以下となるように送気装置22の流量を制御する。 Also in reference to the block diagram of FIG. 1, obstruction prevention apparatus of groundwater pumping installation according to the invention, feed opening into groundwater level H 1 near the inside pumping well 11 of pumping equipment 10 for continuously pumping the groundwater W trachea 21, the air supply device 22 for filling the groundwater upper space P in the pumping well 11 with the low reactive gas G through the air supply pipe 21, and the low reactive gas G leakage rate V from the upper space P A control device 25 for controlling the flow rate of the gas device 22 is provided. Preferably, as shown in FIG. 2, an oxygen concentration meter 28 for measuring the oxygen concentration in the groundwater upper space P in the pumping well 11 is provided so that the oxygen concentration in the upper space P is equal to or lower than the oxidation suppression concentration of the groundwater component. The flow rate of the air supply device 22 is controlled.

更に図1の実施例を参照するに、本発明による閉塞防止型地下水揚水設備は、地上又は地中構造物3の下方の地下水位Hを低下させる揚水設備10において、構造物3の直下又は周縁に掘削した地下水層に至る揚水井11、揚水井11内の地下水Wを継続的に揚水する揚水装置15、揚水井11内の地下水位H1近傍に開口する送気管21、送気管21を介して揚水井11内の地下水上部空間Pに低反応性ガスGを充填する送気装置22、及び上部空間Pからの低反応性ガスGの漏洩速度Vに応じて送気装置22の流量を制御する制御装置25を備えてなるものである。 Further, referring to the embodiment of FIG. 1, the blockage prevention type groundwater pumping facility according to the present invention is a pumping facility 10 that lowers the groundwater level H below the ground or underground structure 3, just below or around the structure 3. pumping well 11 reaching the ground water layers were drilled through the pumping continuously pumping to pumping equipment 15 the ground water W in well 11, feed pipe 21 open to the groundwater level H 1 near the inside pumping well 11, feed pipe 21 The air supply device 22 that fills the groundwater upper space P in the pumping well 11 with the low reactive gas G, and the flow rate of the air supply device 22 according to the leakage velocity V of the low reactive gas G from the upper space P is controlled. The control device 25 is provided.

本発明による地下水揚水設備の閉塞防止方法及び装置は、地下水位近傍に至る送気管を介して揚水井内の地下水上部空間に低反応性ガスを充填し、上部空間からの低反応性ガスの漏洩速度に応じた流量で低反応性ガスを継続的に補給して地下水成分の酸化を抑制するので、次の顕著な効果を奏する。   The method and apparatus for preventing clogging of a groundwater pumping facility according to the present invention fills the groundwater upper space in the pumping well with a low reactive gas via an air pipe reaching the vicinity of the groundwater level, and leaks the low reactive gas from the upper space. Since the low-reactive gas is continuously replenished at a flow rate according to the above and the oxidation of the groundwater component is suppressed, the following remarkable effects are exhibited.

(イ)揚水作業を停止することなく揚水設備の閉塞を防止できるので、予備井を設ける必要がなく、必要最小限の数の揚水井による経済的な揚水が実現できる。
(ロ)揚水井の内部だけでなく、揚水井の側方に連なる集水路やドレン管の内部を含む揚水設備のあらゆる部分の閉塞を有効に防止できる。
(ハ)危険作業を伴う定期的な清掃作業の必要性を減らし、揚水井の閉塞を安全に且つ低コストで防止することができる。
(ニ)既存の揚水井にも容易に適用可能であり、送気管を配置するだけで閉塞を効果的に防止できる。
(ホ)低反応性ガスの送入流量は自動制御が可能であり、自動揚水システム等と組み合わせることにより揚水設備の省力化・自動化に寄与できる。
(A) Since the pumping equipment can be prevented from being blocked without stopping the pumping work, it is not necessary to provide a reserve well, and economical pumping with the minimum number of pumping wells can be realized.
(B) Not only the inside of the pumping well, but also blockage of all parts of the pumping equipment including the inside of the water collecting channel and the drain pipe connected to the side of the pumping well can be effectively prevented.
(C) It is possible to reduce the necessity of periodic cleaning work involving dangerous work, and to prevent the pumping well from being blocked safely and at low cost.
(D) It can be easily applied to existing pumping wells, and can be effectively prevented from being clogged simply by arranging an air pipe.
(E) The flow rate of low-reactive gas can be automatically controlled, and it can contribute to labor saving and automation of pumping equipment when combined with an automatic pumping system.

図1は、地盤1中の地下水層に達する深さに構築した地下LNG(液化天然ガス)貯蔵タンク等の構造物3に設けた揚水設備10に本発明を適用した実施例を示す。図示例の揚水設備10は、構造物3の基礎直下の地下水を集めるドレン管32と、そのドレン管32を取り囲む環状の集水管31と、集水管31に連なる集水ピット14から地上に揚水する揚水井11とを有する。例えば地盤1を地下水層まで掘り下げてドレン管32・集水管31・集水ピット14を敷設し、砕石又は砂等によりドレン管32及び集水管31を埋め戻してドレン層6を形成すると共に集水ピット14から地上に至る揚水井11を据え付け、ドレン層6上に構造物3及び揚水井11を囲むようにコンクリートを打設することにより構造物3と揚水設備10とを一体的に構築する。ドレン管32及び集水管31の配置位置・数・管径等は、図5の場合と同様に設計することができる。本発明は、図1及び図5のように集水管31・ドレン管32を有する揚水設備10に有効に適用できるが、例えば図6のように集水管31・ドレン管32のない揚水設備10にも適用可能である。   FIG. 1 shows an embodiment in which the present invention is applied to a pumping facility 10 provided in a structure 3 such as an underground LNG (liquefied natural gas) storage tank constructed to a depth reaching a groundwater layer in the ground 1. The pumping facility 10 in the illustrated example pumps ground water from a drain pipe 32 that collects groundwater directly under the foundation of the structure 3, an annular water collecting pipe 31 that surrounds the drain pipe 32, and a water collecting pit 14 that is connected to the water collecting pipe 31. And a pumping well 11. For example, the ground 1 is dug down to the groundwater layer, the drain pipe 32, the water collecting pipe 31, and the water collecting pit 14 are laid, and the drain pipe 32 and the water collecting pipe 31 are backfilled with crushed stone or sand to form the drain layer 6 and collect the water. The pumping well 11 extending from the pit 14 to the ground is installed, and the structure 3 and the pumping equipment 10 are integrally constructed by placing concrete on the drain layer 6 so as to surround the structure 3 and the pumping well 11. The arrangement position, number, diameter, etc. of the drain pipe 32 and the water collecting pipe 31 can be designed in the same manner as in FIG. The present invention can be effectively applied to the pumping equipment 10 having the water collecting pipe 31 and the drain pipe 32 as shown in FIGS. 1 and 5. For example, the pumping equipment 10 without the water collecting pipe 31 and the drain pipe 32 is used as shown in FIG. Is also applicable.

図示例の揚水設備10は、揚水井11を介して揚水する揚水装置15を有し、ドレン管32及び集水管31から集水ピット14に流下する地下水Wを継続的に地上の排水溝5に排出し、ドレン層6の地下水位H1を周囲の地下水位H0よりも低下させる。ドレン層6の地下水位H1を下げることにより、構造物3に作用する揚圧力を低減させ、構造物3の基礎部が地下水中に水没するのを防止する。揚水装置15に揚水ポンプ17及び揚水管16と、ポンプ17の制御装置と、地下水位H1又はH0の計測装置とを含め、ドレン層6が適当な地下水位H1となるように揚水ポンプ17を自動制御することができる。 The pumping facility 10 in the illustrated example has a pumping device 15 that pumps water through a pumping well 11, and continuously drains groundwater W flowing from the drain pipe 32 and the water collecting pipe 31 to the water collecting pit 14 into the drainage groove 5 on the ground. It discharged, lowering than groundwater level H 0 surrounding groundwater level H 1 of the drain layer 6. By lowering the water table H 1 of the drain layer 6, to reduce the uplift acting on the structure 3, foundation structure 3 is prevented from submerged groundwater. And pump 17 and riser pipe 16 to the pumping device 15, a control device of the pump 17, including a measuring device for underground water level H 1 or H 0, water pumps as drainage layer 6 is suitable groundwater level H 1 17 can be controlled automatically.

また図示例の揚水設備10は、揚水井11の地下水上部空間Pに低反応性ガスGを充填する閉塞防止装置を有し、揚水装置15による揚水作業を継続しながら、地下水W中の溶存成分(例えば鉄イオン)の酸化を抑えて不溶性酸化物質(例えば水酸化鉄)の堆積を防止する。図示例の閉塞防止装置は、揚水井11内の地下水位H1近傍に開口する送気管21と、送気管21を介して揚水設備10の地下水上部空間Pに低反応性ガスGを充填する送気装置22と、送気装置22の流量を制御する制御装置25とを有する。なお、図示例の揚水設備10は集水管31に連なる4本の井戸を設け、その内の1本を揚水井11とし、他の3本を予備井12としている。例えば揚水井11の点検時に何れかの予備井12を用いて地下水Wを揚水することができる。但し本発明は、揚水井11のみであっても揚水作業と閉塞防止作業との同時作業が可能であり、予備井12を必須とするものではない。予備井12を設けた場合は、揚水設備10への空気進入路となる予備井12にも送気管21及び送気装置22を設け、揚水井11及び予備井12を介して揚水設備10の内部に低反応性ガスGを充填する。 Further, the pumping facility 10 in the illustrated example has a blockage prevention device that fills the groundwater upper space P of the pumping well 11 with the low-reactive gas G, and dissolved components in the groundwater W while continuing the pumping work by the pumping device 15. Oxidation of (for example, iron ions) is suppressed and deposition of insoluble oxidizing substances (for example, iron hydroxide) is prevented. The blockage prevention apparatus in the illustrated example has an air supply pipe 21 that opens near the groundwater level H 1 in the pumping well 11, and a low-reactive gas G that fills the groundwater upper space P of the pumping equipment 10 through the air supply pipe 21. The air device 22 includes a control device 25 that controls the flow rate of the air supply device 22. The illustrated pumping facility 10 has four wells connected to the water collecting pipe 31, one of which is a pumping well 11 and the other three are reserve wells 12. For example, when the pumping well 11 is inspected, the groundwater W can be pumped using any of the reserve wells 12. However, in the present invention, even if only the pumping well 11 is used, the pumping work and the blocking prevention work can be performed simultaneously, and the reserve well 12 is not essential. When the reserve well 12 is provided, the reserve well 12 serving as an air entry path to the pumping equipment 10 is also provided with the air supply pipe 21 and the air supply device 22, and the inside of the pumping equipment 10 through the pumping well 11 and the reserve well 12 Is filled with a low-reactive gas G.

閉塞防止装置の送気管21は、例えば金属製ホース又は適当な耐圧材料製ホースである。送気管21の先端開口をドレン層6の地下水位H1の僅か上方に臨ませるか、又は低反応性ガスGが不水溶性である場合は送気管21の先端を地下水中に開口させてもよい。図示例では送気管21を揚水井11の内側に吊り下げているが、送気管21を地盤1又は構造物3内に設置し、その先端開口のみを揚水井11内の地下水位H1近傍に臨ませてもよい。好ましくは、送気管21の先端開口を揚水井11内から集水管31又はドレン管32に導入し、集水管31及びドレン管32内の空間にも低反応性ガスGを充填する。揚水設備10の全体に低反応性ガスGを効率的に充填するためには、集水管31又はドレン管32から充填することが有効である。図示例のように送気管21の先端を分岐させ、一方を揚水井11内に開口させ、他方を集水管31内に開口させてもよい。 The air supply pipe 21 of the blocking prevention device is, for example, a metal hose or a suitable pressure resistant material hose. Even if the leading end of the air pipe 21 faces slightly above the groundwater level H 1 of the drain layer 6 or the low reactive gas G is water-insoluble, the tip of the air pipe 21 may be opened in the groundwater. Good. In the example shown in the figure, the air pipe 21 is suspended inside the pumping well 11, but the air pipe 21 is installed in the ground 1 or the structure 3, and only the tip opening thereof is near the groundwater level H 1 in the pumping well 11. You may make it come. Preferably, the front end opening of the air supply pipe 21 is introduced from the pumping well 11 into the water collection pipe 31 or the drain pipe 32, and the space in the water collection pipe 31 and the drain pipe 32 is also filled with the low-reactive gas G. In order to efficiently fill the entire pumping equipment 10 with the low-reactive gas G, it is effective to fill from the water collecting pipe 31 or the drain pipe 32. As shown in the example of the drawing, the tip of the air supply pipe 21 may be branched, one may be opened in the pumping well 11 and the other may be opened in the water collection pipe 31.

低反応性ガスGは、常温で気体の物質のうち可燃性のもの(メタン・エタン・プロパン・ブタン等)、爆発性のもの(酸素・水素等)、有害性のもの(アンモニア・塩素・シアン・硫化水素等)を除いたアルゴン・キセノン・クリプトン・ネオン・ヘリウム・窒素等の不活性ガス又は二酸化炭素とすることができる。好ましくは低反応性ガスGを、大量供給が可能で且つ比重が空気と同等又はこれより大きい窒素(対空気比重0.967)、アルゴン(同1.380)又は二酸化炭素(同1.529)とする。揚水設備10がコンクリート製である場合はコンクリート中性化の原因となる二酸化炭素の使用は避けることが望ましく、コスト面からは窒素ガスが実用的である。低反応性ガスGをこれらの混合ガスとしてもよい。   Low reactive gases G are flammable substances (methane, ethane, propane, butane, etc.), explosive substances (oxygen, hydrogen, etc.), and hazardous substances (ammonia, chlorine, cyanide) at room temperature. -Inert gas or carbon dioxide such as argon, xenon, krypton, neon, helium, nitrogen, etc., excluding hydrogen sulfide. Preferably, the low-reactive gas G is nitrogen (a specific gravity of 0.967), argon (1.380), or carbon dioxide (1.529), which can be supplied in a large amount and has a specific gravity equal to or greater than that of air. When the pumping equipment 10 is made of concrete, it is desirable to avoid the use of carbon dioxide, which causes neutralization of concrete, and nitrogen gas is practical from the viewpoint of cost. The low reactive gas G may be a mixed gas thereof.

図示例では低反応性ガスGを窒素ガスとし、送気装置22に窒素ガスの製造装置23又は貯蔵タンクを接続している。例えば、製造装置23において液化窒素を気化させる方法又は圧縮空気を酸素吸着剤に通して高純度窒素ガスとする方法により窒素ガスG(純度99%)を製造し、制御装置25で流量を制御しながら、送気装置22によって送気管21に窒素ガスGを送入する。   In the illustrated example, the low-reactive gas G is nitrogen gas, and a nitrogen gas production device 23 or a storage tank is connected to the air supply device 22. For example, the production apparatus 23 produces nitrogen gas G (purity 99%) by vaporizing liquefied nitrogen or by passing compressed air through an oxygen adsorbent to produce high purity nitrogen gas, and the controller 25 controls the flow rate. However, the nitrogen gas G is sent into the air supply pipe 21 by the air supply device 22.

図示例の制御装置25は、揚水井11の大きさに応じて、その地下水上部空間Pの酸素濃度を地下水中の溶存成分を酸化しない濃度(以下、酸化抑制濃度という。例えば1%)以下とするのに要する所定流量の窒素ガスGの充填時間Tを記憶した充填検知手段27を有する。送気装置22による窒素ガスGの送入を所定流量で充填時間T以上継続する制御により、揚水井11内に窒素ガスGを充填する。窒素ガスGの充填に要する充填時間Tは、揚水井11の大きさと窒素ガスGの対空気比重及び所定送入流量とに応じて、予め実験的又は経験的に定めることができる。ドレン管32及び集水管31内に空気が多少残る可能性はあるが、時間経過と共に地下水W中の溶存成分の酸化に消費されるので、揚水設備10の全空間に窒素ガスGを充満できる。また、充填検知手段27に各予備井12の充填時間Tを記憶し、予備井12毎に窒素ガスGを充填することができる。   According to the size of the pumping well 11, the control device 25 in the illustrated example sets the oxygen concentration in the groundwater upper space P to a concentration that does not oxidize dissolved components in the groundwater (hereinafter referred to as oxidation suppression concentration; for example, 1%) or less. It has a filling detection means 27 that stores the filling time T of the nitrogen gas G at a predetermined flow rate required for this. The pumping well 11 is filled with the nitrogen gas G by controlling the inflow of the nitrogen gas G by the air supply device 22 at a predetermined flow rate for at least the filling time T. The filling time T required for filling the nitrogen gas G can be determined in advance experimentally or empirically according to the size of the pumping well 11, the specific gravity of the nitrogen gas G with respect to the air, and the predetermined flow rate. Although there is a possibility that some air remains in the drain pipe 32 and the water collecting pipe 31, it is consumed for the oxidation of dissolved components in the groundwater W over time, so that the entire space of the pumping equipment 10 can be filled with the nitrogen gas G. Further, it is possible to store the filling time T of each spare well 12 in the filling detection means 27 and to fill the reserve well 12 with nitrogen gas G.

揚水井11に充填された窒素ガスGは空気より比重が小さいため、揚水井11の気密性の程度に応じて徐々に漏洩する。このため、窒素ガスGによる充填を検知したのち、制御装置25により窒素ガスGの漏洩速度Vを若干超える送入流量で窒素ガスGの送入を継続することにより、揚水井11の上部空間Pの酸素濃度を地下水成分の酸化抑制濃度以下に維持する。窒素ガスGの漏洩速度Vは揚水井11の大きさ・気密性と窒素ガスGの対空気比重とに応じて変わるため、揚水井11からの漏洩速度Vを直接的に計測することは困難であるが、本発明者は後述するように、揚水井11を窒素ガスGで充填した後の上部空間Pの酸素濃度の変化から窒素ガスGの漏洩速度Vを実験的又は経験的に把握できることを見出した。揚水井11の上部開口には適当な蓋13を設け、窒素ガスGの漏洩をできる限り抑えることが望ましい。図示例の制御装置25は、揚水井11又は予備井12毎に窒素ガスGの漏洩速度Vを記憶した記憶手段26を有し、その漏洩速度Vに応じて送入装置22の送入流量を制御する。   Since the nitrogen gas G filled in the pumping well 11 has a specific gravity smaller than that of air, it gradually leaks according to the degree of airtightness of the pumping well 11. For this reason, after detecting the filling with the nitrogen gas G, the control device 25 continues to feed the nitrogen gas G at a feed flow rate that slightly exceeds the leakage velocity V of the nitrogen gas G, whereby the upper space P of the pumping well 11 The oxygen concentration of the water is kept below the oxidation inhibition concentration of the groundwater component. Since the leakage rate V of the nitrogen gas G varies depending on the size / tightness of the pumping well 11 and the specific gravity of the nitrogen gas G to the air, it is difficult to directly measure the leakage rate V from the pumping well 11. However, as described later, the present inventor can experimentally or empirically grasp the leakage rate V of the nitrogen gas G from the change in the oxygen concentration in the upper space P after the pumping well 11 is filled with the nitrogen gas G. I found it. It is desirable to provide an appropriate lid 13 at the upper opening of the pumping well 11 to suppress leakage of the nitrogen gas G as much as possible. The control device 25 in the illustrated example has storage means 26 that stores the leakage rate V of the nitrogen gas G for each pumping well 11 or reserve well 12, and the inflow rate of the infeed device 22 is set according to the leakage rate V. Control.

図2に示すように、揚水井11内の地下水上部空間Pに酸素濃度を計測する酸素濃度計28を設け、制御装置25と酸素濃度計28とを接続し、制御装置25の充填検知手段27により上部空間Pの酸素濃度が地下水成分の酸化抑制濃度以下となるように送気装置22の流量を制御することも可能である。この場合は、揚水井11内の異なる深さ位置にそれぞれ酸素濃度計28を設け、複数の酸素濃度計28によって揚水井11の内部全体への窒素ガスGの充填を検知することができる。但し、地下深い揚水井11の内部の酸素濃度を計測するには多数の酸素濃度計28が必要であり、また図示例のように予備井12を設けた場合はその各々に酸素濃度計28を設ける必要があるので、酸素濃度計28の実用的・経済的な設置が難しい場合がある。本発明は酸素濃度計28を必須とするものではなく、上述したように充填時間T及び漏洩速度Vに応じて送気装置22の流量を制御すれば足りる。   As shown in FIG. 2, an oxygen concentration meter 28 for measuring the oxygen concentration is provided in the groundwater upper space P in the pumping well 11, and the control device 25 and the oxygen concentration meter 28 are connected to each other. Thus, it is possible to control the flow rate of the air supply device 22 so that the oxygen concentration in the upper space P is equal to or lower than the oxidation suppression concentration of the groundwater component. In this case, oxygen concentration meters 28 are provided at different depth positions in the pumping well 11, and the filling of the nitrogen gas G into the entire interior of the pumping well 11 can be detected by the plurality of oxygen concentration meters 28. However, in order to measure the oxygen concentration inside the deep pumping well 11, a large number of oxygen concentration meters 28 are necessary, and when the reserve well 12 is provided as shown in the figure, an oxygen concentration meter 28 is provided for each of them. Since it is necessary to provide an oxygen concentration meter 28, it may be difficult to install it practically and economically. The present invention does not require the oxygen concentration meter 28, and it is sufficient to control the flow rate of the air supply device 22 in accordance with the filling time T and the leakage speed V as described above.

[実験例1]
図3に示すような直径1.2m、深さ12mの集水管31付き揚水井11を用いて、本発明の閉塞防止装置の効果を確認する実験を行った。揚水井11には送気管21を挿入し、その先端開口を揚水ポンプ17の運転停止時の地下水位H1より10〜20cm程度高い位置に臨ませた。揚水井11の上部空間Pの深さ6m、4m、2mの位置及び蓋13の直下にそれぞれ酸素濃度計28a、28b、28c、28dを固定し、各酸素濃度計28a〜28dをコンピュータ29の濃度記録手段27aに接続した。先ず、送気装置22により十分な大きな所定流量で送気管21に窒素ガスGを供給し、各酸素濃度計28a〜28dの酸素濃度が何れも実質上0%となるまでの充填時間Tを計測した。窒素ガスGによる揚水井11の充填を確認したのち窒素ガスGの供給を停止し、1時間毎に各酸素濃度計28a〜28dの酸素濃度を濃度記録手段27aに記録した。
[Experimental Example 1]
Using a pumping well 11 with a water collecting pipe 31 having a diameter of 1.2 m and a depth of 12 m as shown in FIG. 3, an experiment for confirming the effect of the blocking prevention device of the present invention was conducted. Pumping insert the flue 21 to the well 11 and to face the front end opening to 10~20cm about a position higher than the groundwater level H 1 upon stopping of water pumps 17. The oximeters 28a, 28b, 28c and 28d are fixed at positions 6m, 4m and 2m deep in the upper space P of the pumping well 11 and directly under the lid 13, respectively. The recording means 27a was connected. First, nitrogen gas G is supplied to the air supply pipe 21 at a sufficiently large predetermined flow rate by the air supply device 22, and the filling time T until the oxygen concentration of each of the oxygen concentration meters 28a to 28d becomes substantially 0% is measured. did. After confirming the filling of the pumping well 11 with the nitrogen gas G, the supply of the nitrogen gas G was stopped, and the oxygen concentrations of the oxygen concentration meters 28a to 28d were recorded in the concentration recording means 27a every hour.

図4は、窒素ガスGの供給停止後における揚水井11の上部空間Pの深さ6m、4m、2mの位置における酸素濃度変化を示す。地下水中の溶存成分を酸化しない上部空間Pの酸素濃度(酸化抑制濃度)を1%と仮定すると、実質上0%の酸素濃度が酸化抑制濃度以上となる経過時間は、図4の実験結果から深さ2mで約3.5時間、深さ4mで約7.85時間、深さ6mで約12.1時間であることが分かる。すなわち、揚水井11の地下水上部空間Pでは、窒素ガスGの漏洩に応じて酸化抑制濃度の境界位置は上部開口から徐々に下降しており、その境界位置の下降速度は深さ2mで0.57(=2/3.5)m/時、深さ4mで0.51(=4/7.85)m/時、深さ6mで0.50(=6/12.1)m/時であり、それらの平均値は0.53m/時であった。地下水成分の酸化抑制という観点からは、この酸化抑制濃度の境界位置の下降速度を窒素ガスGの漏洩速度Vと考えることができる。   FIG. 4 shows changes in oxygen concentration at positions 6 m, 4 m, and 2 m deep in the upper space P of the pumping well 11 after the supply of nitrogen gas G is stopped. Assuming that the oxygen concentration (oxidation inhibitory concentration) in the upper space P that does not oxidize dissolved components in groundwater is 1%, the elapsed time when the oxygen concentration of 0% is substantially equal to or greater than the oxidation inhibitory concentration is obtained from the experimental results of FIG. It can be seen that it is about 3.5 hours at a depth of 2 m, about 7.85 hours at a depth of 4 m, and about 12.1 hours at a depth of 6 m. That is, in the groundwater upper space P of the pumping well 11, the boundary position of the oxidation inhibition concentration gradually descends from the upper opening according to the leakage of the nitrogen gas G, and the descending speed of the boundary position is 0.57 (2 m depth). = 2 / 3.5) m / hour, 0.51 (= 4 / 7.85) m / hour at a depth of 4 m, 0.50 (= 6 / 12.1) m / hour at a depth of 6 m, and the average value is 0.53 m / hour Met. From the viewpoint of suppressing oxidation of the groundwater component, the rate of decrease of the boundary position of the oxidation suppression concentration can be considered as the leakage rate V of the nitrogen gas G.

図4の実験結果から本発明者は、直径1.2mの揚水井11では、上述した窒素ガスGの漏洩速度Vに対応する毎時約0.60m3(≒0.6m×0.6m×3.14×0.53m≒600リットル)の流量で、地下水位H1近傍に窒素ガスGを継続的に供給すれば、揚水井11内の地下水上部空間Pの酸素濃度をほぼ酸化抑制濃度以下に維持できることを見出した。また本発明者は、揚水井11の直径・深さが異なる場合や窒素ガス以外の低反応性ガスGを用いた場合も、本実験と同様にして上部空間Pからの低反応性ガスGの漏洩速度Vを、上述した酸化抑制濃度の境界位置の下降速度から実験的に求めることができることを見出した。 From the experimental results shown in FIG. 4, the present inventor found that the pumping well 11 having a diameter of 1.2 m is approximately 0.60 m 3 (≈0.6 m × 0.6 m × 3.14 × 0.53 m≈) corresponding to the leakage velocity V of the nitrogen gas G described above. It was found that if the nitrogen gas G is continuously supplied in the vicinity of the groundwater level H 1 at a flow rate of 600 liters), the oxygen concentration in the groundwater upper space P in the pumping well 11 can be maintained below the oxidation inhibition concentration. In addition, the present inventor also uses the low-reactive gas G from the upper space P in the same manner as in this experiment even when the diameter and depth of the pumping well 11 are different or when the low-reactive gas G other than nitrogen gas is used. It has been found that the leakage speed V can be experimentally determined from the descending speed of the boundary position of the oxidation inhibition concentration described above.

次に、図1の閉塞防止装置を図3の揚水井11に適用し、上述した実験で求めた窒素ガスGの充填時間T及び漏洩速度Vを制御装置25に記憶し、揚水井11の上部空間Pの酸素濃度を地下水成分の酸化抑制濃度以下に維持する実験を行った。制御装置25により送入装置22を所定送入流量に調節し、窒素ガスGを充填時間T以上継続して送入したところ、各酸素濃度計28a〜28dの酸素濃度は何れも1%以下となり、揚水井11の上部空間Pに窒素ガスGを充填することができた。また、充填確認後に送入装置22の送入流量を、上述した窒素ガスGの漏洩速度Vに対応する600リットル/時(=10リットル/分)に調整して窒素ガスGの供給を継続したところ、各酸素濃度計28a〜28dの酸素濃度を何れも1%以下に維持することができた。すなわち、本発明の閉塞防止装置により、揚水井11の上部空間Pの酸素濃度を地下水成分の酸化抑制濃度以下に維持できることが確認できた。   Next, the blockage prevention device of FIG. 1 is applied to the pumping well 11 of FIG. 3, the filling time T and the leak rate V of the nitrogen gas G obtained in the above-described experiment are stored in the control device 25, An experiment was conducted to maintain the oxygen concentration in the space P below the oxidation suppression concentration of the groundwater component. When the control device 25 adjusts the infeed device 22 to a predetermined inflow rate and nitrogen gas G is continuously fed for more than the filling time T, the oxygen concentration in each of the oxygen concentration meters 28a to 28d becomes 1% or less. The upper space P of the pumping well 11 could be filled with nitrogen gas G. Further, after the filling was confirmed, the feed flow rate of the feed device 22 was adjusted to 600 liters / hour (= 10 liters / minute) corresponding to the leakage rate V of the nitrogen gas G described above, and the supply of the nitrogen gas G was continued. However, the oxygen concentrations of the oxygen concentration meters 28a to 28d were all maintained at 1% or less. That is, it was confirmed that the oxygen concentration in the upper space P of the pumping well 11 can be maintained below the oxidation inhibiting concentration of the groundwater component by the blockage preventing device of the present invention.

更に本発明者は、揚水井11の上部空間Pの酸素濃度を地下水成分の酸化抑制濃度以下に維持した状態で、揚水井11の地下水Wを採取して水質(酸化還元電位、溶存酸素濃度、溶存性鉄イオン濃度等)を調査した。その結果、地下水Wの溶存酸素濃度は低く、溶存性鉄イオン濃度は高いことが確認できた。このことから、本発明により地下水W中の鉄イオンの酸化を防止でき、本発明が地下水W中の水酸化鉄の堆積防止に有効であることが確認できた。   Further, the present inventor collected the groundwater W of the pumping well 11 while maintaining the oxygen concentration in the upper space P of the pumping well 11 below the oxidation inhibiting concentration of the groundwater component, and the water quality (redox potential, dissolved oxygen concentration, The concentration of dissolved iron ions was investigated. As a result, it was confirmed that the dissolved oxygen concentration in the groundwater W was low and the dissolved iron ion concentration was high. From this, it was confirmed that the present invention can prevent the oxidation of iron ions in the groundwater W, and that the present invention is effective in preventing the deposition of iron hydroxide in the groundwater W.

こうして本発明の目的である「揚水を継続しつつ揚水設備の閉塞を防ぐ閉塞防止方法及び装置」を達成することができる。   Thus, the “closure prevention method and apparatus for preventing blockage of the pumping equipment while continuing pumping”, which is the object of the present invention, can be achieved.

図2は、本発明の閉塞防止型地下水揚水設備10の他の実施例を示す。図示例の揚水設備10には、揚水装置15で揚水した地下水Wから酸化抑制対象成分(例えば、鉄イオン)を除去する水処理装置18が設けられている。閉鎖防止装置を設けた本発明の揚水設備10では、揚水井11・集水管31・ドレン管32において地下水W中の溶存成分が酸化されないため、環境負荷低減の観点から、揚水装置15で揚水したのち排水溝5へ放流する前に、地下水W中のその溶存成分(酸化抑制対象成分)を除去することが望ましい。   FIG. 2 shows another embodiment of the blockage prevention type groundwater pumping facility 10 of the present invention. The pumping equipment 10 in the illustrated example is provided with a water treatment device 18 that removes an oxidation suppression target component (for example, iron ions) from the groundwater W pumped by the pumping device 15. In the pumping facility 10 of the present invention provided with the closure prevention device, since the dissolved components in the groundwater W are not oxidized in the pumping well 11, the water collecting pipe 31, and the drain pipe 32, the water is pumped by the pumping device 15 from the viewpoint of reducing the environmental load. It is desirable to remove the dissolved component (oxidation suppression target component) in the groundwater W before discharging into the drainage groove 5 later.

図示例の水処理装置18では、例えば揚水した地下水Wに次亜塩素酸ナトリウム等の酸化剤を添加して地下水W中の酸化抑制対象成分(例えば鉄イオン)を酸化して不溶性酸化物質(例えば水酸化鉄)を生成させたのち、高分子凝集剤を添加して濃縮沈殿槽において不溶性酸化物を凝集・沈澱させる。沈殿物をフィルタープレスで脱水処理し、脱水ケーキは廃棄物として処分する。濃縮沈殿槽においてオーバーフローした上澄み液のみをpH調整して排水溝5に放流する。   In the water treatment apparatus 18 in the illustrated example, for example, an oxidizing agent such as sodium hypochlorite is added to the pumped ground water W to oxidize the oxidation suppression target component (for example, iron ions) in the ground water W, and thereby insoluble oxidizing substances (for example, After the formation of iron hydroxide), a polymer flocculant is added to agglomerate and precipitate insoluble oxides in a concentration precipitation tank. The precipitate is dehydrated with a filter press, and the dehydrated cake is disposed of as waste. Only the supernatant liquid overflowed in the concentration sedimentation tank is adjusted in pH and discharged into the drainage groove 5.

本発明の一実施例の説明図であるIt is explanatory drawing of one Example of this invention. 本発明の他の実施例の説明図であるIt is explanatory drawing of the other Example of this invention. 揚水井に充填した低反応性ガスの漏洩速度を求める実験の説明図である。It is explanatory drawing of experiment which calculates | requires the leak rate of the low reactive gas with which the pumping well was filled. 図3の実験による低反応性ガスの漏洩速度の実験結果の一例を示すグラフである。It is a graph which shows an example of the experimental result of the leak rate of the low reactive gas by the experiment of FIG. 従来の原子力建屋の地下水揚水設備の説明図である。It is explanatory drawing of the underground water pumping equipment of the conventional nuclear power building. 従来の液状化対策用の地下水揚水設備の説明図である。It is explanatory drawing of the groundwater pumping equipment for the conventional liquefaction countermeasures.

符号の説明Explanation of symbols

1…地盤(岩盤) 3…構造物 5…排水溝
6…ドレン層 10…揚水設備 11…揚水井
12…予備井 13…蓋 14…集水ピット
15…揚水装置 16…揚水管 17…揚水ポンプ
18…水処理装置 21…送気管 22…送気装置
23…ガス製造装置(ガスタンク) 25…制御装置
26…記憶手段 27…充填検知手段 27a…濃度記録手段
28…酸素濃度計 29…コンピュータ 31…集水管(集水路)
32…ドレン管 34…タービン建屋
41…砂層地盤 42…粘土層地盤 43…支持層地盤
45…基礎杭 46…止水壁
G…低反応性ガス(窒素ガス) H…地下水位
P…上部空間 T…充填時間 V…漏洩速度
W…地下水
DESCRIPTION OF SYMBOLS 1 ... Ground (bedrock) 3 ... Structure 5 ... Drainage channel 6 ... Drain layer 10 ... Pumping equipment 11 ... Pumping well
12 ... Reserve well 13 ... Lid 14 ... Catchment pit
15 ... Pumping device 16 ... Pumping pipe 17 ... Pumping pump
18 ... Water treatment device 21 ... Air supply tube 22 ... Air supply device
23… Gas production equipment (gas tank) 25… Control equipment
26 ... Storage means 27 ... Filling detection means 27a ... Concentration recording means
28 ... Oxygen meter 29 ... Computer 31 ... Catchment pipe (collection channel)
32 ... Drain pipe 34 ... Turbine building
41 ... Sand layer ground 42 ... Clay layer ground 43 ... Support layer ground
45 ... Foundation pile 46 ... Water blocking wall G ... Low reactive gas (nitrogen gas) H ... Groundwater level P ... Upper space T ... Filling time V ... Leakage speed W ... Groundwater

Claims (12)

地下水を継続的に揚水する揚水設備の揚水井内に地下水位近傍に至る送気管を設け、前記送気管を介して揚水井内の地下水上部空間に低反応性ガスを充填し、前記上部空間からの低反応性ガスの漏洩速度に応じた流量で低反応性ガスを継続的に補給して地下水成分の酸化を抑制してなる地下水揚水設備の閉塞防止方法。 An air pipe that reaches the vicinity of the groundwater level is installed in the pumping well of the pumping facility that continuously pumps up the groundwater, and the low-reactive gas is filled in the upper space of the groundwater in the pumping well through the air pipe. A method for preventing clogging of a groundwater pumping facility, in which low-reactive gas is continuously replenished at a flow rate according to the leakage rate of the reactive gas to suppress oxidation of groundwater components. 請求項1の閉塞防止方法において、前記揚水井内の地下水上部空間に酸素濃度計を設け、前記上部空間の酸素濃度が地下水成分の酸化抑制濃度以下となるように低反応性ガスを充填してなる地下水揚水設備の閉塞防止方法。 2. The blocking prevention method according to claim 1, wherein an oxygen concentration meter is provided in an upper space of the groundwater in the pumping well, and is filled with a low-reactive gas so that the oxygen concentration in the upper space is equal to or lower than the oxidation suppression concentration of the groundwater component. How to prevent clogging of groundwater pumping equipment. 請求項1又は2の閉塞防止方法において、前記揚水井の側壁に側方向きの集水路を設け、前記送気管を集水路内に導入して前記上部空間及び集水路内に低反応性ガスを充填してなる地下水揚水設備の閉塞防止方法。 3. The blocking prevention method according to claim 1 or 2, wherein a side water collecting channel is provided on a side wall of the pumping well, and the air supply pipe is introduced into the water collecting channel so that a low reactive gas is introduced into the upper space and the water collecting channel. How to prevent clogging of filled underground water pumping equipment. 請求項1から3の何れかの閉塞防止方法において、前記低反応性ガスを窒素ガスとしてなる地下水揚水設備の閉塞防止方法。 4. The blocking prevention method according to claim 1, wherein the low-reactive gas is nitrogen gas. 地下水を継続的に揚水する揚水設備の揚水井内の地下水位近傍に開口する送気管、前記送気管を介して揚水井内の地下水上部空間に低反応性ガスを充填する送気装置、及び前記上部空間からの低反応性ガスの漏洩速度に応じて前記送気装置の流量を制御する制御装置を備えてなる地下水揚水設備の閉塞防止装置。 An air supply pipe that opens near the groundwater level in a pumping well of a pumping facility that continuously pumps groundwater, an air supply device that fills the groundwater upper space in the pumping well through the air supply pipe, and the upper space An apparatus for preventing clogging of groundwater pumping equipment, comprising a control device for controlling the flow rate of the air supply device in accordance with the leakage rate of low reactive gas from the ground. 請求項5の閉塞防止装置において、前記揚水井内の地下水上部空間の酸素濃度を計測する酸素濃度計を設け、前記上部空間の酸素濃度が地下水成分の酸化抑制濃度以下となるように前記送気装置の流量を制御してなる地下水揚水設備の閉塞防止装置。 The blockage prevention apparatus according to claim 5, wherein an oxygen concentration meter for measuring an oxygen concentration in an upper space of the groundwater in the pumping well is provided, and the air supply device is configured such that the oxygen concentration in the upper space is equal to or lower than an oxidation suppression concentration of a groundwater component. Blocking prevention device for groundwater pumping equipment by controlling the flow rate of water. 請求項5又は6の閉塞防止装置において、前記低反応性ガスを窒素ガスとしてなる地下水揚水設備の閉塞防止装置。 The blockage prevention apparatus according to claim 5 or 6, wherein the low-reactive gas is nitrogen gas. 地上又は地中構造物の下方の地下水位を低下させる揚水設備において、前記構造物の直下又は周縁に設けた地下水層に至る揚水井、前記揚水井内の地下水を継続的に揚水する揚水装置、前記揚水井内の地下水位近傍に開口する送気管、前記送気管を介して揚水井内の地下水上部空間に低反応性ガスを充填する送気装置、及び前記上部空間からの低反応性ガスの漏洩速度に応じて前記送気装置の流量を制御する制御装置を備えてなる閉塞防止型地下水揚水設備。 In the pumping equipment for lowering the groundwater level below the ground or underground structure, the pumping well that reaches the groundwater layer directly below or at the periphery of the structure, the pumping device that continuously pumps the groundwater in the pumping well, An air supply pipe that opens near the groundwater level in the pumping well, an air supply device that fills the groundwater upper space in the pumping well through the air supply pipe, and a leak rate of the low reactive gas from the upper space A blockage prevention type groundwater pumping facility comprising a control device for controlling the flow rate of the air supply device accordingly. 請求項8の揚水設備において、前記制御装置に揚水井内の地下水上部空間に設けた酸素濃度計を含め、前記上部空間の酸素濃度が地下水成分の酸化抑制濃度以下となるように前記送気装置の流量を制御してなる閉塞防止型地下水揚水設備。 9. The pumping facility according to claim 8, wherein the control device includes an oxygen concentration meter provided in an upper space of groundwater in a pumping well, so that the oxygen concentration in the upper space is equal to or lower than the oxidation suppression concentration of groundwater components. Blocking prevention type groundwater pumping equipment with controlled flow rate. 請求項8又は9の揚水設備において、前記構造物直下にドレン層を設け、前記揚水井を構造物の周縁に設け、前記揚水井の側壁にドレン層と連通する集水路を設け、前記送気管を集水路内に導入してなる閉塞防止型地下水揚水設備。 The pumping equipment according to claim 8 or 9, wherein a drain layer is provided immediately below the structure, the pumping well is provided at a peripheral edge of the structure, a water collecting channel communicating with the drain layer is provided on a side wall of the pumping well, and the air pipe Blocking prevention type groundwater pumping equipment which is introduced into the catchment channel. 請求項8から10の何れかの揚水設備において、前記低反応性ガスを窒素ガスとしてなる閉塞防止型地下水揚水設備。 The pumping equipment according to claim 8, wherein the low-reactive gas is nitrogen gas. 請求項8から11の何れかの揚水設備において、前記揚水した地下水から酸化抑制対象成分を除去する水処理装置を設けてなる閉塞防止型地下水揚水設備。 The pumping equipment according to any one of claims 8 to 11, wherein a blockage-preventing type groundwater pumping equipment is provided with a water treatment device that removes an oxidation suppression target component from the pumped groundwater.
JP2004290568A 2004-10-01 2004-10-01 Method and device for preventing blocking of underground water pumping facility, and blocking preventive underground water pumping facility Pending JP2006104714A (en)

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JP2010116688A (en) * 2008-11-11 2010-05-27 Takenaka Komuten Co Ltd Groundwater management system
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JP2010116688A (en) * 2008-11-11 2010-05-27 Takenaka Komuten Co Ltd Groundwater management system
JP2013189801A (en) * 2012-03-14 2013-09-26 Kanasashi Heavy Industries Co Ltd Underground embedded type water storage tank
JP2016102336A (en) * 2014-11-28 2016-06-02 株式会社ウェルシィ Method for preventing increase in dissolved oxygen content of groundwater
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CN107447794A (en) * 2017-07-25 2017-12-08 广州大学 The anti-floating of excavation pit plays construction method in a kind of subway protection region
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JP2019203351A (en) * 2018-05-25 2019-11-28 株式会社東京エネシス Ground water treatment system
JP2019039301A (en) * 2018-12-18 2019-03-14 株式会社ウェルシィ Method for preventing increase in dissolved oxygen amount of groundwater
CN110295625A (en) * 2019-06-28 2019-10-01 中国二十冶集团有限公司 A kind of pipe gallery waterproof method based on sponge theory
CN113186898A (en) * 2021-04-12 2021-07-30 广州市市政工程设计研究总院有限公司 Soft soil foundation reinforcement treatment method
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CN116290047A (en) * 2023-02-28 2023-06-23 中建八局第三建设有限公司 Automatic-monitoring deep foundation pit transverse connection type net-shaped precipitation construction method
CN116290047B (en) * 2023-02-28 2023-10-13 中建八局第三建设有限公司 Automatic-monitoring deep foundation pit transverse connection type net-shaped precipitation construction method

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