JP2008002071A

JP2008002071A - Impervious sheet construction method and impervious sheet construction apparatus

Info

Publication number: JP2008002071A
Application number: JP2006169898A
Authority: JP
Inventors: Masaya Kawada; 雅也河田; Juichi Ise; 寿一伊勢; Katsuhiko Yokoyama; 勝彦横山
Original assignee: Shimizu Construction Co Ltd; Shimizu Corp
Current assignee: Shimizu Construction Co Ltd; Shimizu Corp
Priority date: 2006-06-20
Filing date: 2006-06-20
Publication date: 2008-01-10
Anticipated expiration: 2026-06-20
Also published as: JP4771157B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a joint structure, surely constructed even when the joint structure of impervious sheets is a little complicated, and having high reliability of impervious performance to be economical. <P>SOLUTION: In this impervious sheet construction method for installing the impervious sheet in a groove 2 or the like, a rolled part 3c of the impervious sheet 3 put in the groove 2 or the like is moved along the groove 2 or the like, to deploy the rolled impervious sheet 3, the sheet edge 3a inside of the roll is rotated along the groove 2 or the like 2 toward the opposite direction to the moving direction of the roll, whereby the end part of the impervious sheet 3 is folded back to pull up the sheet edge 3a outside the groove 2 or the like. and outside the groove 2 or the like, the sheet edge outside the roll of a new impervious sheet is joined to the sheet edge 3a of the preceding installed impervious sheet 3. After that, the sheet edge 3a of the preceding installed impervious sheet 3 and the new impervious sheet are turned downward to thereby return the folded-back end part of the impervious sheet 3 to the initial state and also put the impervious sheet in the groove 2 or the like. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

本発明は、地中遮水壁を構成する遮水シートを設置するための遮水シートの施工方法およびその施工方法に用いられる遮水シート施工装置に関する。 The present invention relates to a construction method for a water shielding sheet for installing a water shielding sheet constituting an underground impermeable wall and a water shielding sheet construction apparatus used for the construction method.

例えば産業廃棄物の最終処分場などでは、汚染物の流出を防止するために遮水壁で最終処分場を囲み、外部と仕切る必要がある。遮水壁としては、その地盤の透水性が高い場合や地盤の地耐力が低い場合、簡単且つ高い水密性を確保できる高密度ポリエチレン製の遮水シート等を使用した遮水シート工法が採用される場合が多い。遮水シート工法は、地盤に所定深さの溝を掘削するとともにこの溝内をソイルセメント等で満たした後、溝の中に遮水シートを設置する工法である。なお、地盤を所定長さ、所定深さで攪拌して面状（壁状）の地盤攪拌体を造成し、この地盤攪拌体の中に遮水シートを設置してもよい。 For example, in a final disposal site for industrial waste, it is necessary to enclose the final disposal site with a water shielding wall and to separate it from the outside in order to prevent the outflow of contaminants. As the impermeable wall, when the ground has high water permeability or when the ground strength is low, the impermeable sheet construction method using a high density polyethylene impermeable sheet, etc. that can ensure easy and high water tightness is adopted. There are many cases. The impermeable sheet construction method is a method of excavating a groove of a predetermined depth in the ground and filling the groove with soil cement and then installing the impermeable sheet in the groove. The ground may be stirred at a predetermined length and depth to form a planar (wall-like) ground stirring body, and a water shielding sheet may be installed in the ground stirring body.

上記した遮水シート工法における従来の遮水シートの施工方法としては、まず、予め遮水シートの一端に雄形のシートジョイナーを付設するとともに他端に雌形のシートジョイナーを付設しておく。そして、遮水シートをロール状に巻き、そのロール状の遮水シートを、地盤に形成された溝の中に挿入する。その後、ロール状の遮水シートから遮水シートを引き出しつつロール状の遮水シートのロール部分を溝方向に移動させて遮水シートを展張させる。次いで、同様にロール状に巻かれた新たな遮水シートを溝の中に挿入する。このとき、先行して設置された遮水シートのシートジョイナーに新たな遮水シートのシートジョイナーを嵌合させながら挿入を行う。その後、先行の遮水シートと同様に新たな遮水シートを展張する。この工程を繰り返すことで、互いに継手された複数の遮水シートが溝の中に設置される（例えば、特許文献１参照。）。
特公平４−３３３２５号公報 As a conventional method for constructing a water shielding sheet in the above-described water shielding sheet construction method, first, a male sheet joiner is attached to one end of the water shielding sheet in advance, and a female sheet joiner is attached to the other end. Then, the water-impervious sheet is wound into a roll shape, and the roll-shaped water-impervious sheet is inserted into a groove formed in the ground. Thereafter, the roll-off sheet is extended from the roll-like sheet by moving the roll portion of the roll-like sheet in the groove direction while pulling out the sheet. Next, a new water-impervious sheet wound in the same manner is inserted into the groove. At this time, insertion is performed while fitting a new water-impervious sheet joiner into a sheet-joiner of the water-impervious sheet installed in advance. After that, a new water-impervious sheet is extended in the same manner as the preceding water-impervious sheet. By repeating this process, a plurality of water-impervious sheets joined together are installed in the groove (see, for example, Patent Document 1).
Japanese Patent Publication No. 4-33325

しかしながら、上記した従来の遮水シートの施工方法では、例えば、遮水シートの継手構造として、雄雌のシートジョイナーが密着した状態で嵌合される継手構造や、雄雌のシートジョイナーの嵌合箇所に止水材を介在させる継手構造を適用すると、ソイルセメント等で満たされた溝の中や地盤攪拌体の中は作業性が悪いため、継手作業が困難であり、施工できない場合もある。したがって、従来の遮水シートの施工方法では、作業性を考慮して簡易的な継手構造にする必要があるが、簡易的な継手構造にすると、遮水性能をソイルセメントに期待しなければならず、遮水性能の信頼性が低いとともに経済性も悪いという問題がある。 However, in the conventional water shielding sheet construction method described above, for example, as a joint structure of a water shielding sheet, a joint structure in which male and female seat joiners are fitted in close contact with each other, and male and female seat joiners are fitted. When a joint structure in which a water stop material is interposed at a location is applied, the work in the groove filled with soil cement or the like or the ground stirring body is poor in workability, so joint work is difficult and construction may not be possible. Therefore, in the conventional method of constructing a water shielding sheet, it is necessary to make a simple joint structure in consideration of workability. However, if a simple joint structure is used, water shielding performance must be expected from the soil cement. In addition, there is a problem that the reliability of the water shielding performance is low and the economic efficiency is also poor.

本発明は、上記した従来の問題が考慮されたものであり、遮水シート同士の継手構造が多少複雑である場合でも確実に施工することができ、遮水性能の信頼性が高く経済的である継手構造を適用することができる遮水シートの施工方法、およびその施工方法を実現することができる遮水シート施工装置を提供することを目的としている。 The present invention takes the above-mentioned conventional problems into consideration, and can be reliably constructed even when the joint structure between the water shielding sheets is somewhat complicated, and the water shielding performance is highly reliable and economical. It aims at providing the construction method of the impermeable sheet which can apply a certain joint structure, and the impermeable sheet construction apparatus which can implement | achieve the construction method.

請求項１記載の発明は、地盤に形成された溝、又は地盤を連続的に攪拌して造成された地盤攪拌体の中に、複数の遮水シートを互いに継手させた状態でそれぞれ設置する遮水シートの施工方法において、ロール状に巻かれた状態で前記溝又は地盤攪拌体内に入れられた前記遮水シートのロール部分を前記溝又は地盤攪拌体に沿って移動させることで、ロール状に巻かれた前記遮水シートを展張し、ロール内側にあった前記遮水シートの一方のシート端をロール移動方向の反対方向に向けて前記溝又は地盤攪拌体に沿って回動させることで、該遮水シートの端部を折り返えし、前記一方のシート端を前記溝又は地盤攪拌体の外に引き上げ、該溝又は地盤攪拌体の外で、先行して設置された前記遮水シートの前記一方のシート端に、ロール状に巻かれた新たな遮水シートのロール外側にある他方のシート端を継手し、その後、先行して設置された前記遮水シートの前記一方のシート端および前記新たな遮水シートを下方向に回動させることで、先行して設置された前記遮水シートの折り返された端部を元に戻すとともに前記新たな遮水シートを前記溝又は地盤攪拌体内に入れることを特徴としている。 According to the first aspect of the present invention, a plurality of water-impervious sheets are respectively installed in a state where a plurality of water-impervious sheets are coupled to each other in a groove formed in the ground or a ground stirring body formed by continuously stirring the ground. In the construction method of the water sheet, by moving the roll portion of the water shielding sheet placed in the groove or the ground stirring body in a state wound in a roll shape, along the groove or the ground stirring body, in a roll shape By expanding the rolled water-impervious sheet and turning the one sheet end of the water-impervious sheet that was inside the roll along the groove or ground stirring body in the direction opposite to the roll moving direction, Folding the end of the water-impervious sheet, pulling up the one sheet end to the outside of the groove or ground agitator, and the water-impervious sheet previously installed outside the groove or ground agitator On one end of the sheet The other sheet end outside the roll of the new water-impervious sheet is joined, and then the one sheet end and the new water-impervious sheet of the previously installed water-impervious sheet are rotated downward. By moving, the folded-back end portion of the water-impervious sheet installed in advance is returned to the original position, and the new water-impervious sheet is put into the groove or ground agitator.

このような特徴により、溝又は地盤攪拌体の中でロール状のものを展張することで遮水シートが溝又は地盤攪拌体の中に設置されるとともに、遮水シート同士の継手作業が溝又は地盤攪拌体の外で行われるため、継手作業の作業効率が向上する。 By such a feature, the roll-shaped thing in the groove or the ground stirring body is stretched so that the water shielding sheet is installed in the groove or the ground stirring body, and the joint work between the water shielding sheets is performed in the groove or Since it is performed outside the ground stirring body, the work efficiency of the joint work is improved.

また、請求項２記載の発明は、請求項１記載の遮水シートの施工方法において、前記遮水シートの前記一方のシート端には、雄型又は雌型の第１のジョイント冶具が付設され、前記遮水シートの前記他方のシート端には、前記第１のジョイント冶具と対を成す雌型又は雄型の第２のジョイント冶具が付設されており、前記溝又は地盤攪拌体の外で、先行して設置された前記遮水シートの前記一方のシート端と前記新たな遮水シートの前記他方のシート端とを継手する際、先行して設置された前記遮水シートの前記第１のジョイント冶具と前記新たな遮水シートの前記第２のジョイント冶具とを嵌合させるとともに、その嵌合箇所に止水材を介在させることを特徴としている。 The invention according to claim 2 is the construction method of the water shielding sheet according to claim 1, wherein the one sheet end of the water shielding sheet is provided with a first joint jig of a male type or a female type. The other sheet end of the water-impervious sheet is provided with a female or male second joint jig that forms a pair with the first joint jig, outside the groove or ground stirring body. When the one sheet end of the water-impervious sheet installed in advance is joined to the other sheet end of the new water-impervious sheet, the first of the water-impervious sheet installed in advance The joint jig and the second joint jig of the new water shielding sheet are fitted together, and a water stop material is interposed at the fitting position.

このような特徴により、第１、第２のジョイント冶具同士の嵌合作業が溝又は地盤攪拌体の外で行われることで、第１、第２のジョイント冶具の間に止水材を適正に介在させることが可能であり、そして、この止水材によって継手箇所の止水性が確保される。 With such a feature, the fitting work between the first and second joint jigs is performed outside the groove or the ground stirring body, so that the water-stopping material can be appropriately disposed between the first and second joint jigs. It is possible to intervene, and the water stoppage of the joint portion is ensured by this waterstop material.

請求項３記載の発明は、請求項１又は２記載の遮水シートの施工方法に用いられる遮水シート施工装置であって、前記溝又は地盤攪拌体の外に位置する回転軸を中心に前記溝又は地盤攪拌体に沿って回転可能に設けられているとともにロール状に巻かれた前記遮水シートを引き出し展張可能に保持する保持部材と、該保持部材を前記溝又は地盤攪拌体に沿って水平方向に移動させる移動手段と、前記保持部材を前記溝又は地盤攪拌体に沿って回動させる回動手段とが備えられ、前記保持部材には、前記溝又は地盤攪拌体内で展張された前記遮水シートの一方のシート端が係止されていることを特徴としている。 Invention of Claim 3 is a water-impervious sheet construction apparatus used for the construction method of the water-impervious sheet according to claim 1 or 2, wherein the rotating shaft located outside the groove or ground stirring body is the center. A holding member that is rotatably provided along the groove or the ground stirring body and holds the water-impervious sheet wound in a roll shape so as to be stretchable, and the holding member along the groove or the ground stirring body A moving means for moving in the horizontal direction and a rotating means for rotating the holding member along the groove or the ground stirring body are provided, and the holding member is extended in the groove or the ground stirring body. It is characterized in that one sheet end of the water shielding sheet is locked.

このような特徴により、ロール状の遮水シートを展張可能に保持した保持部材が、溝又は地盤攪拌体の中に入れられ、この保持部材が移動手段によって水平方向に動かされることで、ロール状の遮水シートが溝又は地盤攪拌体の中で展張される。また、遮水シートを展張した後に、遮水シートの一方のシート端が係止されている保持部材を回動手段によって溝又は地盤攪拌体に沿って回動させることで、保持部材とともに一方のシート端が回動し、遮水シートの端部が折り返えされ、一方のシート端が溝又は地盤攪拌体の外に引き上げられる。さらに、保持部材を一方のシート端から取り外してロール状に巻かれた新たな遮水シートに取り付けるとともに、先行して設置された遮水シートの一方のシート端と新たな遮水シートの他方のシート端とを継手し、その後、保持部材を回動手段によって溝又は地盤攪拌体に沿って回動させることで、保持部材とともに、先行して設置された遮水シートの一方のシート端および新たな遮水シートが下方側にそれぞれ回動し、折り返された遮水シートの一方側の端部が元に戻されるとともに、新たな遮水シートが溝又は地盤攪拌体内に入れられる。 By such a feature, the holding member holding the roll-shaped water-impervious sheet so as to be stretchable is placed in the groove or the ground stirring body, and this holding member is moved in the horizontal direction by the moving means, so that the roll shape The water shielding sheet is spread in the groove or the ground stirring body. Moreover, after extending the water-impervious sheet, the holding member on which one sheet end of the water-impervious sheet is locked is rotated along the groove or the ground stirring body by the rotating means, so that The sheet end rotates, the end portion of the water-impervious sheet is folded back, and one sheet end is pulled up out of the groove or the ground stirring body. Further, the holding member is detached from one sheet end and attached to a new water-impervious sheet wound in a roll shape, and one end of the previously installed water-impervious sheet and the other of the new water-impervious sheet are installed. The sheet end is jointed, and then the holding member is rotated along the groove or the ground agitating body by the rotating means, so that one end of the water-impervious sheet previously installed together with the holding member and a new one Each of the water-impervious sheets rotates downward, and the end of one side of the folded water-impervious sheet is returned to its original position, and a new water-impervious sheet is put into the groove or the ground stirring body.

本発明に係る遮水シートの施工方法によれば、ロール状の遮水シートを溝又は地盤攪拌体の中で展張することで遮水シートが設置されるとともに、遮水シート同士の継手作業が溝又は地盤攪拌体の外で行われることで継手作業の作業効率が向上するため、遮水シート同士の継手構造が多少複雑である場合でも確実に施工することができ、これによって、遮水性能の信頼性が高く経済的である継手構造を採用することができる。 According to the construction method of the water-impervious sheet according to the present invention, the roll-shaped water-impervious sheet is stretched in the groove or the ground agitator to install the water-impervious sheet, and the joint work between the impermeable sheets is performed. Since the work efficiency of the joint work is improved by being performed outside the groove or the ground stirring body, even if the joint structure between the water shielding sheets is somewhat complicated, it can be reliably constructed. It is possible to employ a joint structure that is highly reliable and economical.

また、遮水シートの一方のシート端に第１のジョイント冶具を付設させ、他方のシート端に第２のジョイント冶具を付設させ、遮水シート同士を継手する際、先行して設置された遮水シートの第１のジョイント冶具と新たな遮水シートの第２のジョイント冶具とを嵌合させるとともに、その嵌合箇所に止水材を介在させることで、継手箇所の止水性が確保され、これによって、継手箇所の遮水性能についての信頼性を向上させることができる。 Further, when the first joint jig is attached to one sheet end of the water shielding sheet and the second joint jig is attached to the other sheet end, and the water shielding sheets are joined to each other, While fitting the first joint jig of the water sheet and the second joint jig of the new water-impervious sheet, and by interposing a water-stopping material at the fitting location, water-stopping of the joint location is ensured, Thereby, the reliability about the water shielding performance of a joint location can be improved.

また、本発明に係る遮水シート施工装置によれば、溝又は地盤攪拌体の中で展張された遮水シートの一方のシート端を回動させること等が可能であり、上記した遮水シートの施工方法を実施することができる。 Moreover, according to the impermeable sheet construction apparatus according to the present invention, it is possible to rotate one sheet end of the impermeable sheet stretched in the groove or the ground stirring body, and the above described impermeable sheet The construction method can be implemented.

以下、本発明に係る遮水シートの施工方法および遮水シート施工装置の実施の形態について、図面に基いて説明する。なお、図１は遮水シート３を用いて地盤Ｇ内に遮水壁１を構築するときの Hereinafter, embodiments of a water shielding sheet construction method and a water shielding sheet construction apparatus according to the present invention will be described with reference to the drawings. In addition, FIG. 1 shows when the impermeable wall 1 is constructed in the ground G using the impermeable sheet 3.

まず、遮水シート３を用いて地盤Ｇ内に構築される遮水壁１の構成について説明する。 First, the structure of the impermeable wall 1 constructed in the ground G using the impermeable sheet 3 will be described.

図１は遮水壁１を表す立断面図である。図１に示すように、遮水壁１は、地盤Ｇを所定長さ、所定深さＨで攪拌することで地盤Ｇ内に面状（壁状）に鉛直に造成された地盤攪拌体２と、地盤攪拌体２内に鉛直にそれぞれ埋設された複数の遮水シート３…とから構成されている。 FIG. 1 is an elevational sectional view showing the impermeable wall 1. As shown in FIG. 1, the impermeable wall 1 includes a ground stirring body 2 that is vertically formed in a planar shape (wall shape) in the ground G by stirring the ground G at a predetermined length and a predetermined depth H. , And a plurality of water shielding sheets 3 embedded vertically in the ground stirring body 2.

地盤攪拌体２は、地盤Ｇに水やベントナイト、フライアッシュ等の添加材を加えて攪拌したものであり、攪拌当初には流動性を有するものである。添加材としては、セメント等の固化材も含まれるが、これらの固化材を加えれば、遮水シート展張後に時間の経過とともに地盤攪拌体が流動性を失って固化するので、展張した遮水シートが早期に安定する。なお、地下水が高い地盤の場合は、これらの添加材を加えないで攪拌するだけで流動性を有することがあり、この場合は添加材を加えないこともある。また、地下水が低い地盤の場合は、固化材を加えなくても、脱水によって流動性を失い固化状態となることもあり、この場合は固化材を加えないこともある。 The ground stirrer 2 is obtained by adding an additive such as water, bentonite, fly ash or the like to the ground G and stirring, and has fluidity at the beginning of stirring. Additives include solidified materials such as cement, but if these solidified materials are added, the ground stirrer loses its fluidity and solidifies over time after the waterproof sheet is stretched. Stabilizes early. In addition, in the ground with high groundwater, it may have fluidity | liquidity only by stirring, without adding these additives, and an additive may not be added in this case. In the case of ground with low groundwater, even if no solidifying material is added, fluidity may be lost due to dehydration, resulting in a solidified state. In this case, the solidifying material may not be added.

遮水シート３は、例えばフレキシブルポリマーアロイ製のシート等であり、高い水密性を有するとともに、弾力性を有する柔らかな材質のものからなり、さらに、地盤攪拌体２内に設置する際に破損しない程度の強度及び厚さを有するものである。 The water-impervious sheet 3 is, for example, a sheet made of a flexible polymer alloy, and is made of a soft material having high water tightness and elasticity, and is not damaged when installed in the ground stirring body 2. It has a certain strength and thickness.

図２は遮水シート３，３同士の継手部分を表す拡大平面図である。図１，図２に示すように、鉛直（深さ）方向に延在する遮水シート３の側端のうち、一方のシート端（以下、第１シート端３ａと記す。）には、その第１シート端３ａに沿って延在する雄ジョイント４（第１のジョイント冶具）が付設されており、他方のシート端（以下、第２シート端３ｂと記す。）には、その第２シート端３ｂに沿って延在する雌ジョイント５（第２のジョイント冶具）が付設されている。雄ジョイント４と雌ジョイント５とは、互いに嵌合される一対のジョイント冶具であり、雄ジョイント４の先端部４ａが雌ジョイント５の溝状の凹部５ａの中に嵌め込まれることで連結される継手構造である。隣接する遮水シート３，３同士は、一方の遮水シート３の第１シート端３ａに付設された雄ジョイント４と、他方の遮水シート３の第２シート端３ｂに付設された雌ジョイント５とが嵌合されることで継手されている。 FIG. 2 is an enlarged plan view showing a joint portion between the water shielding sheets 3 and 3. As shown in FIGS. 1 and 2, among the side edges of the water shielding sheet 3 extending in the vertical (depth) direction, one of the sheet edges (hereinafter referred to as the first sheet edge 3 a) A male joint 4 (first joint jig) extending along the first sheet end 3a is attached, and the second sheet end (hereinafter referred to as the second sheet end 3b) is provided with the second sheet. A female joint 5 (second joint jig) extending along the end 3b is attached. The male joint 4 and the female joint 5 are a pair of joint jigs that are fitted to each other, and a joint that is connected by fitting the distal end portion 4 a of the male joint 4 into the groove-shaped recess 5 a of the female joint 5. Structure. Adjacent water-impervious sheets 3, 3 are a male joint 4 attached to the first sheet end 3 a of one water-impervious sheet 3 and a female joint attached to the second sheet end 3 b of the other water-impervious sheet 3. 5 and 5 are fitted together.

また、雄ジョイント４と雌ジョイント５との嵌合箇所には、止水性能を発揮する止水材６が介在されている。止水材６は、雄ジョイント４や雌ジョイント５の延在方向に延在する例えばゴム等の弾性材料からなる棒状の部材であり、雌ジョイント５の凹部５ａの中に配置され、雌ジョイント５の凹部５ａの内側面と雄ジョイント４の先端部４ａとの間に介在されている。 Further, a water-stop material 6 that exhibits water-stop performance is interposed at a fitting portion between the male joint 4 and the female joint 5. The water stop material 6 is a rod-shaped member made of an elastic material such as rubber extending in the extending direction of the male joint 4 or the female joint 5, and is disposed in the recess 5 a of the female joint 5. Is interposed between the inner surface of the recess 5a and the tip 4a of the male joint 4.

図３は地盤攪拌体２内に入れるときの遮水シート３の状態を表す断面図である。図３に示すように、地盤攪拌体２内に入れるときの遮水シート３は、第１シート端３ａを内側にして（第２シート端３ｂを外側にして）ロール状に巻かれた状態になっている。具体的には、遮水シート３は、断面形状Ｃ形の円筒形の軸芯鋼管９に巻き付けられている。軸芯鋼管９には、軸線方向に延在するスリット９ａが形成されており、スリット９ａから軸芯鋼管９内に、第１シート端３ａに付設された雄ジョイント４が差し込まれている。スリット９ａの幅寸法は、雄ジョイント４の基端部４ｂの厚さよりも大きくて先端部４ａの厚さよりも小さくなっており、軸芯鋼管９内にある雄ジョイント４が係止されてスリット９ａから引き抜きできない状態になっている。また、軸芯鋼管９は、少なくとも一方端が開放されており、軸芯鋼管９と雄ジョイント４とを軸線方向に相対移動させることで取り外し可能になっている。 FIG. 3 is a cross-sectional view showing a state of the water-impervious sheet 3 when it is put into the ground stirring body 2. As shown in FIG. 3, the water-impervious sheet 3 when placed in the ground stirring body 2 is wound in a roll shape with the first sheet end 3 a on the inner side (with the second sheet end 3 b on the outer side). It has become. Specifically, the water shielding sheet 3 is wound around a cylindrical shaft core steel tube 9 having a C-shaped cross section. A slit 9a extending in the axial direction is formed in the shaft core steel tube 9, and the male joint 4 attached to the first sheet end 3a is inserted into the shaft core steel tube 9 from the slit 9a. The width dimension of the slit 9a is larger than the thickness of the base end portion 4b of the male joint 4 and smaller than the thickness of the distal end portion 4a, and the male joint 4 in the shaft core steel pipe 9 is locked to form the slit 9a. It cannot be pulled out from. Further, the shaft core steel pipe 9 is open at least at one end, and can be removed by relatively moving the shaft core steel pipe 9 and the male joint 4 in the axial direction.

次に、地盤Ｇに上記した地盤攪拌体２を造成する際に使用する設備について説明する。 Next, the equipment used when the above-described ground stirring body 2 is created on the ground G will be described.

図４は地盤攪拌体２を造成する際の施工システムと施工機械を表す図である。図４に示すように、地盤攪拌体２を造成する際は、セメントミルク等の液状の添加材を製造する添加材製造手段１０と、製造された添加材を所定量だけ地盤攪拌体２内に送る添加材流入手段１１と、地盤Ｇと添加材とを攪拌混合する地盤攪拌機１２と、残土の搬出を行うバックホウ等の掘削機１３とが使用される。 FIG. 4 is a diagram illustrating a construction system and a construction machine when the ground stirring body 2 is created. As shown in FIG. 4, when creating the ground stirring body 2, the additive manufacturing means 10 for manufacturing a liquid additive such as cement milk and a predetermined amount of the manufactured additive in the ground stirring body 2 are produced. An additive material inflow means 11 to be sent, a ground stirrer 12 for stirring and mixing the ground G and the additive material, and an excavator 13 such as a backhoe for carrying out the remaining soil are used.

添加材製造手段１０は、サイロ１４，スラリープラント１５，水槽１６及び発電機１７から構成されており、添加材製造手段１０によって、液状の添加材が製造されるとともに製造された添加材が添加材流入手段１１に送られる。添加材流入手段１１はグラウトポンプ１８，流量計１９及び空気圧縮機２０から構成されており、添加材流入手段１１によって、添加材は地盤攪拌機１２が攪拌している地盤Ｇ内に圧送される。なお、この添加材製造手段１０は、セメント等の固化材に替えてベントナイト等の添加材をスラリー状にするのにも用いられる。 The additive material manufacturing means 10 includes a silo 14, a slurry plant 15, a water tank 16, and a generator 17. The additive material manufacturing means 10 manufactures a liquid additive material and the manufactured additive material is an additive material. It is sent to the inflow means 11. The additive material inflow means 11 includes a grout pump 18, a flow meter 19 and an air compressor 20. The additive material inflow means 11 pumps the additive material into the ground G where the ground agitator 12 is agitating. The additive manufacturing means 10 is also used to make an additive such as bentonite into a slurry instead of a solidifying material such as cement.

図５は地盤攪拌機１２を表す斜視図である。図５に示すように、地盤攪拌機１２は、ベースマシン５１に可動アーム５０が備えられ、この可動アーム５０にフレーム５２が取り付けられた概略構成からなる。このフレーム５２は、上部には油圧モータ等の原動機に連結された駆動輪５３と、下部には従動輪５４を有し、この駆動輪５３と従動輪５４との間にエンドレスチェーン５５が巻き掛けられ、エンドレスチェーン５５は駆動輪５３の駆動回転によって駆動輪５３と従動輪５４との間を周回するようになっている。また、エンドレスチェーン５５は、その全周方向外側に一定間隔で攪拌羽根５６を有している。この攪拌羽根５６の周回によって、地盤Ｇが攪拌され、添加材や固化材を添加すれば、地盤Ｇが添加材や固化材とともに攪拌混合され、セメントであれば地盤攪拌体２はソイルセメントとなる。 FIG. 5 is a perspective view showing the ground agitator 12. As shown in FIG. 5, the ground agitator 12 has a schematic configuration in which a movable arm 50 is provided in a base machine 51 and a frame 52 is attached to the movable arm 50. The frame 52 has a driving wheel 53 connected to a prime mover such as a hydraulic motor at the upper part and a driven wheel 54 at the lower part, and an endless chain 55 is wound between the driving wheel 53 and the driven wheel 54. The endless chain 55 circulates between the drive wheel 53 and the driven wheel 54 by the drive rotation of the drive wheel 53. The endless chain 55 has stirring blades 56 at regular intervals on the outer periphery in the entire circumference. If the ground G is stirred by the circulation of the stirring blade 56 and an additive or a solidifying material is added, the ground G is stirred and mixed together with the additive or the solidifying material. If it is cement, the ground stirring body 2 becomes a soil cement. .

次に、地盤Ｇ内に造成された地盤攪拌体２内に複数の遮水シート３…を設置する遮水シート施工装置３０について説明する。 Next, the water shielding sheet construction apparatus 30 that installs a plurality of water shielding sheets 3 in the ground stirring body 2 created in the ground G will be described.

図６，図７は遮水シート３を施工する遮水シート施工装置３０を表す図である。図６，図７に示すように、遮水シート施工装置３０は、ロール状に巻かれた遮水シート３を保持部材３１で保持し、このロール状の遮水シート３を地盤攪拌体２内で展張させて遮水シート３を設置する装置であり、地盤Ｇ上を走行可能な重機である。遮水シート施工装置３０には、地盤Ｇ上を走行するベースマシン３３（移動手段）と、ベースマシン３３に装備された略鉛直に立設されたマスト部３４と、マスト部３４に沿って上下動する上下動部３２と、上下動部３２に対して回転軸４９で軸支されて鉛直方向に回転可能に取り付けられているとともにロール状の遮水シート３を保持する保持部材３１と、上下動部３２を上下動させて保持部材３１を昇降させる昇降機構３６と、保持部材３１を地盤攪拌体２に沿って鉛直回転させる回動機構３７（回動手段）とが備えられている。 6 and 7 are views showing a water shielding sheet construction apparatus 30 for constructing the water shielding sheet 3. As shown in FIGS. 6 and 7, the impermeable sheet construction apparatus 30 holds the impermeable sheet 3 wound in a roll shape with a holding member 31, and the roll-shaped impermeable sheet 3 in the ground agitator 2. It is a device for installing the water-impervious sheet 3 by being extended by a heavy machine capable of traveling on the ground G. The water-impervious sheet construction apparatus 30 includes a base machine 33 (moving means) that travels on the ground G, a substantially vertical mast part 34 that is installed in the base machine 33, and a vertical movement along the mast part 34. A vertically moving portion 32 that moves, a holding member 31 that is pivotally supported by a rotating shaft 49 and is rotatably attached to the vertically moving portion 32 and that holds the roll-shaped water-impervious sheet 3; An elevating mechanism 36 that moves the moving part 32 up and down to raise and lower the holding member 31 and a rotating mechanism 37 (rotating means) that vertically rotates the holding member 31 along the ground stirring body 2 are provided.

図８は保持部材３１を表す側面図であり、図９は保持部材３１の下端部を表す拡大側面図であり、図１０は保持部材３１の上部を表す拡大側面図である。図７，図８，図９，図１０に示すように、保持部材３１は、ロール状に巻かれた遮水シート３を引き出し展張可能（軸回転可能）に保持する部材であり、保持部材３１の上端部は、地盤攪拌体２の外（地盤攪拌体２の上方）に位置する回転軸４９を介して上下動部３２に取り付けられ、保持部材３１は、回転軸４９を中心にして鉛直回転可能に設けられている。また、保持部材３１には、矩形鋼管等からなるロッド状の本体部６０が備えられており、この本体部６０の下端側面には、ロール状の遮水シート３が載せられるブラケット状の受け部６３が設けられている。受け部６３は、本体部６０の軸線に対して直交して突設されており、その上面には、開放された軸芯鋼管９の下端に回転自在に挿嵌される突起６３ａが形成されている。 FIG. 8 is a side view showing the holding member 31, FIG. 9 is an enlarged side view showing the lower end portion of the holding member 31, and FIG. 10 is an enlarged side view showing the upper part of the holding member 31. As shown in FIGS. 7, 8, 9, and 10, the holding member 31 is a member that holds the water shielding sheet 3 wound in a roll shape so that the water shielding sheet 3 can be drawn and stretched (rotatable). Is attached to the vertical movement part 32 via a rotation shaft 49 located outside the ground stirring body 2 (above the ground stirring body 2), and the holding member 31 rotates vertically around the rotation shaft 49. It is provided as possible. Further, the holding member 31 is provided with a rod-shaped main body portion 60 made of a rectangular steel pipe or the like, and a bracket-shaped receiving portion on which the roll-shaped water-impervious sheet 3 is placed on the lower end side surface of the main body portion 60. 63 is provided. The receiving part 63 protrudes perpendicularly to the axis of the main body part 60, and a protrusion 63 a that is rotatably inserted into the lower end of the open shaft steel pipe 9 is formed on the upper surface thereof. Yes.

また、軸芯鋼管９上端には、軸芯延長部材６４が継手されている。具体的には、軸芯延長部材６４の下端には軸芯鋼管９上端に回転拘束状態で嵌合する嵌合孔６４ａが形成され、この嵌合孔６４ａ内に軸芯鋼管９の上端が差し込まれることで継手されている。また、軸芯延長部材６４の上部には、回転自在なベアリング部６４ｂが付設されている。 A shaft core extending member 64 is jointed to the upper end of the shaft steel tube 9. Specifically, the lower end of the shaft core extending member 64 is formed with a fitting hole 64a that is fitted to the upper end of the shaft core steel tube 9 in a rotationally restricted state, and the upper end of the shaft core steel tube 9 is inserted into the fitting hole 64a. It is jointed by being. Further, a rotatable bearing portion 64 b is attached to the upper portion of the shaft core extending member 64.

図１１は図１０に示すＡ−Ａ間の断面図であり、図１２は図１０に示すＢ−Ｂ間の断面図である。図１０，図１１，図１２に示すように、本体部６０の上部には、軸芯鋼管９の上端に継手された軸芯延長部材６４を着脱自在に把持する把持機構６５が設けられている。把持機構６５は、軸芯延長部材６４のベアリング部６４ｂを把持する上部把持機構６６と、軸芯延長部材６４の下部を直接把持する下部把持機構６７とからなっており、上部把持機構６６で軸芯延長部材６４のベアリング部６４ｂを把持している時には軸芯鋼管９は回転自在に保持され、下部把持機構６７で軸芯延長部材６４の下部を把持している時には軸芯鋼管９は回転拘束状態(回転しない)で保持される。 11 is a cross-sectional view taken along the line AA shown in FIG. 10, and FIG. 12 is a cross-sectional view taken along the line BB shown in FIG. As shown in FIGS. 10, 11, and 12, a gripping mechanism 65 that detachably grips the shaft core extending member 64 jointed to the upper end of the shaft steel tube 9 is provided on the upper portion of the main body 60. . The gripping mechanism 65 includes an upper gripping mechanism 66 that grips the bearing portion 64 b of the shaft core extending member 64 and a lower gripping mechanism 67 that directly grips the lower portion of the shaft core extending member 64. The shaft core steel tube 9 is rotatably held when the bearing portion 64b of the core extension member 64 is gripped, and the shaft core steel tube 9 is rotationally restrained when the lower portion of the shaft core extension member 64 is gripped by the lower gripping mechanism 67. It is held in a state (not rotating).

図１０，図１１に示すように、上部把持機構６６は、本体部６０から張り出して取り付けられて２枚平行に配置された受けアーム（把持部材）６８，６８と、これらの受けアーム６８，６８の間に配置された押えアーム（把持部材）６９と、押えアーム６９の端部にその一端が取り付けられ、他端が本体部６０に取り付けられた伸縮ジャッキ（伸縮機構）７０とからなっている。押えアーム６９は、Ｌ字型形状をしており、一方の辺に相当するところは直線状で、他方の辺に相当する押え部６９ａはベアリング部６４ｂの円弧形状に合わせて内方に曲がる円弧形状とされ、中間の屈曲部６９ｂにおいて、受けアーム６８の基端部付近で受けアーム６８に対し回転可能に軸支されている。なお、受けアーム６８は、ベアリング部６４ｂを把持する受け部６８ａが、ベアリング部６４ｂの円弧形状に合わせて円弧形状とされている。 As shown in FIGS. 10 and 11, the upper gripping mechanism 66 includes two receiving arms (gripping members) 68 and 68 that are attached to the main body 60 so as to protrude from the main body 60, and these receiving arms 68 and 68. A presser arm (grip member) 69 disposed between the arm and a telescopic jack (stretching mechanism) 70 having one end attached to the end of the presser arm 69 and the other end attached to the main body 60. . The presser arm 69 has an L-shape, and a portion corresponding to one side is linear, and a presser portion 69a corresponding to the other side is an arc that bends inward in accordance with the arc shape of the bearing portion 64b. The intermediate bent portion 69b is pivotally supported with respect to the receiving arm 68 in the vicinity of the base end portion of the receiving arm 68. In the receiving arm 68, the receiving portion 68a that holds the bearing portion 64b has an arc shape in accordance with the arc shape of the bearing portion 64b.

図１０，図１２に示すように、下部把持機構６７は、上部把持機構６６と同様の構成からなり、本体部６０からそれぞれ張り出して取り付けられて２枚平行に配置された受けアーム（把持部材）６８´，６８´と、これらの受けアーム６８´，６８´の間に配置された押えアーム（把持部材）６９´と、押えアーム６９´の端部にその一端が取り付けられ、他端が本体部６０に取り付けられた伸縮ジャッキ（伸縮機構）７０´とからなっている。押えアーム６９は、Ｌ字型形状をしており、一方の辺に相当するところは直線状で、他方の辺に相当する押え部６９ａ´は軸芯延長部材６４の下部の外周形状に合わせて内方に曲がる円弧形状とされ、中間の屈曲部６９ｂ´において、受けアーム６８´の基端部付近で受けアーム６８´，６８´に対し回転可能に軸支されている。なお、受けアーム６８´，６８´は、軸芯延長部材６４を把持する受け部６８ａ´が、軸芯延長部材６４の下部の外周形状に合わせて円弧形状とされている。 As shown in FIGS. 10 and 12, the lower gripping mechanism 67 has the same configuration as the upper gripping mechanism 66, and is provided with two receiving arms (gripping members) that are attached to project from the main body 60 and are arranged in parallel. 68 ', 68', a presser arm (gripping member) 69 'disposed between the receiving arms 68', 68 ', and one end of the presser arm 69' is attached to the end, and the other end is the main body. An extension jack (extension mechanism) 70 ′ attached to the portion 60 is included. The presser arm 69 has an L shape, and a portion corresponding to one side is linear, and a presser portion 69 a ′ corresponding to the other side matches the outer peripheral shape of the lower portion of the shaft core extending member 64. It has an arcuate shape that bends inward, and is pivotally supported with respect to the receiving arms 68 ′ and 68 ′ in the vicinity of the base end of the receiving arm 68 ′ at an intermediate bent portion 69 b ′. In the receiving arms 68 ′ and 68 ′, the receiving portion 68 a ′ that holds the shaft core extending member 64 has an arc shape in accordance with the outer peripheral shape of the lower portion of the shaft core extending member 64.

図１０，図１１，図１２に示すように、把持機構６５によって軸芯延長部材６４を把持する時（取付時）には、上部把持機構６６及び下部把持機構６７の伸縮ジャッキ７０，７０´のロッド部７０ａ，７０ａ´をシリンダー部７０ｂ，７０ｂ´内にそれぞれ縮退させ、押え部６９ａ，６９ａ´と受け部６８ａ，６８ａ´とでベアリング部６４ｂや軸芯延長部材６４を挟んでそれぞれ把持する。一方、把持機構６５に把持された軸芯延長部材６４を開放する時(取外時)には、上部把持機構６６及び下部把持機構６７の伸縮ジャッキ７０，７０´のロッド部７０ａ，７０ａ´をシリンダー部７０ｂ，７０ｂ´から伸長させることで、ベアリング部６４ｂや軸芯延長部材６４下部の把持を開放する。 As shown in FIGS. 10, 11, and 12, when the shaft core extension member 64 is gripped (attached) by the gripping mechanism 65, the extension jacks 70, 70 ′ of the upper gripping mechanism 66 and the lower gripping mechanism 67 are The rod portions 70a and 70a ′ are retracted into the cylinder portions 70b and 70b ′, respectively, and the holding portions 69a and 69a ′ and the receiving portions 68a and 68a ′ hold the bearing portion 64b and the shaft core extending member 64, respectively. On the other hand, when the shaft core extending member 64 gripped by the gripping mechanism 65 is released (during removal), the rod portions 70a, 70a ′ of the extension jacks 70, 70 ′ of the upper gripping mechanism 66 and the lower gripping mechanism 67 are moved. By extending from the cylinder portions 70b and 70b ', the holding of the bearing portion 64b and the lower portion of the shaft core extending member 64 is released.

図７に示すように、上下動部３２は、マスト部３４に付設された図示せぬガイドレールに摺動可能に取り付けられた部材であり、後述する昇降機構３６のワイヤー４１に吊り下げられている。
図６，図７に示すように、昇降機構３６は、マスト部３４の上端部及びベースマシン３３上にそれぞれ付設された上下動用滑車（シーブ）３８，３８と、ベースマシン３３に搭載された上下動用巻上機（ウインチ）３９と、ウインチ３９によって巻き取られる上下動用のワイヤー４１とから構成されている。ワイヤー４１は、ウインチ３９からベースマシン３３上の上下動用のシーブ３８を経てマスト部３４上端のシーブ３８にそれぞれ巻回され、端部が上下動部３２に接続されており、上下動部３２は、ウインチ３９によってワイヤー４１を巻き取ることで上昇され、反対に、ウインチ２９を開放してワイヤー４１を送り出すことで下降される。 As shown in FIG. 7, the vertical movement portion 32 is a member slidably attached to a guide rail (not shown) attached to the mast portion 34, and is suspended from a wire 41 of an elevating mechanism 36 described later. Yes.
As shown in FIGS. 6 and 7, the elevating mechanism 36 includes vertical movement pulleys (sheves) 38 and 38 respectively attached to the upper end portion of the mast portion 34 and the base machine 33, and the upper and lower pulleys mounted on the base machine 33. A moving hoist (winch) 39 and a wire 41 for vertical movement wound up by the winch 39 are configured. The wire 41 is wound around the sheave 38 at the upper end of the mast portion 34 from the winch 39 through the sheave 38 for vertical movement on the base machine 33, and the end portion is connected to the vertical movement portion 32. It is raised by winding the wire 41 by the winch 39, and conversely, it is lowered by opening the winch 29 and feeding the wire 41.

回動機構３７は、マスト部３４の上端部及びベースマシン３３上にそれぞれ付設された回動用滑車（シーブ）４３，４３，４３と、ベースマシン３３に搭載された回動用巻上機（ウインチ）４４と、ウインチ４４によって巻き取られる回動用のワイヤー４５と、地盤Ｇ上に設置された滑車架台４２とから構成されている。ワイヤー４５は、ウインチ４４からベースマシン３３上の回動用シーブ４３及びマスト部３４上端の２つのシーブ４３，４３をそれぞれ経て滑車架台４２に巻回され、端部が保持部材３１下端の受け部６３に接合された被掛止部６１に接続されており、保持部材３１は、ウインチ４４によってワイヤー４５を巻き取ることで鉛直方向に回動される。具体的には、ベースマシン３３（保持部材３１）よりも後方（後述する遮水シート３の移動展張方向の基端側）の位置に滑車架台４２を配置した状態で、ウインチ４４によってワイヤー４５を巻き取ることで、鉛直状態の保持部材３１が回転軸４９を回転中心にして後方に向かって鉛直回動して、第１シート端３ａは地盤攪拌体２内から引き上げられる。一方、ベースマシン３３（保持部材３１）よりも先方（後述する移動展張方向の先端側）の位置に滑車架台４２を配置した状態で、ウインチ４４によってワイヤー４５を巻き取ることで、水平状態の保持部材３１が回転軸４９を回転中心にして下方に回転して、第１シート端３ａは地盤攪拌体２内に入れられる。 The rotation mechanism 37 includes rotation pulleys (sieves) 43, 43, 43 respectively attached to the upper end of the mast 34 and the base machine 33, and a rotation hoist (winch) mounted on the base machine 33. 44, a turning wire 45 wound up by the winch 44, and a pulley mount 42 installed on the ground G. The wire 45 is wound from the winch 44 through the sheave 43 for rotation on the base machine 33 and the two sheaves 43 at the upper end of the mast 34 to the pulley base 42, and the end is a receiving portion 63 at the lower end of the holding member 31. The holding member 31 is rotated in the vertical direction by winding the wire 45 by the winch 44. Specifically, the wire 45 is connected to the wire 45 by the winch 44 in a state where the pulley mount 42 is disposed behind the base machine 33 (holding member 31) (a base end side in the moving and extending direction of the water shielding sheet 3 described later). By winding up, the holding member 31 in the vertical state vertically rotates backward about the rotation shaft 49, and the first sheet end 3a is pulled up from the ground stirring body 2. On the other hand, in a state where the pulley mount 42 is arranged at a position ahead of the base machine 33 (holding member 31) (the distal end side in the moving and extending direction described later), the wire 45 is wound up by the winch 44, thereby maintaining the horizontal state. The member 31 rotates downward with the rotation shaft 49 as the center of rotation, and the first sheet end 3 a is placed in the ground agitator 2.

次に、上記した地盤攪拌体２を造成する施工システムと施工機械を用いて地盤Ｇに地盤攪拌体２を造成した後、遮水シート施工装置３０を用いて地盤攪拌体２内に遮水シート３を設置し、上記した遮水壁１を構築する施工手順を説明する。 Next, after creating the ground stirring body 2 on the ground G using the construction system and construction machine for creating the ground stirring body 2 described above, the water shielding sheet is formed in the ground stirring body 2 using the water shielding sheet construction device 30. The construction procedure for installing 3 and constructing the above-described impermeable wall 1 will be described.

まず、所要の機械を現場に搬入して組み立てる機械搬入・組立工程を行う。具体的には、図４に示す添加材製造手段１０を構成する機材や、添加材流入手段１１を構成する機材、分解された状態の地盤攪拌機１２、掘削機１３をそれぞれ現場に搬入し、これらの機材等を組み立てて、地盤攪拌体２を造成する際の施工システムをつくる。また、図６，図７に示す遮水シート施工装置３０を分解した状態で搬入し、現場で組み立てる。さらに、図１，図３に示す複数の遮水シート３…や軸芯鋼管９、軸芯延長部材６４の材料をそれぞれ搬入し、遮水シート３を軸芯鋼管９にロール状に巻き付け、複数のロール状の遮水シート３…を製作しておく。このとき、遮水シート３の両端部に、雄ジョイント４や雌ジョイント５を付設しておく。なお、予め工場等でロール状に巻かれたロール状の遮水シート３を現場に搬入してもよく、その他の機械や設備についても、既に組み立てられたものを現場に搬入してもよい。 First, a machine carrying-in / assembling process is carried out in which a required machine is carried to the site and assembled. Specifically, the equipment constituting the additive manufacturing means 10 shown in FIG. 4, the equipment constituting the additive inflow means 11, the ground stirrer 12 and the excavator 13 in a disassembled state are brought into the field, respectively. Assembling the equipment, make a construction system when creating the ground stirring body 2. Moreover, it carries in in the state which decomposed | disassembled the impermeable sheet construction apparatus 30 shown in FIG. 6, FIG. 7, and assembles on the spot. Further, the materials of the plurality of water shielding sheets 3..., The shaft steel pipe 9 and the shaft core extending member 64 shown in FIGS. 1 and 3 are respectively carried in, and the water shielding sheets 3 are wound around the shaft steel pipe 9 in a roll shape. A roll-shaped water-impervious sheet 3 is prepared in advance. At this time, the male joint 4 and the female joint 5 are attached to both ends of the water-impervious sheet 3. In addition, the roll-shaped water-impervious sheet 3 previously wound in a roll shape at a factory or the like may be carried into the site, and other machines and equipment that have already been assembled may be carried into the site.

次に、施工ヤードの造成を行う施工ヤード造成工程を行う。具体的には、図３に示すように、掘削機１３で地盤攪拌機１２や遮水シート施工装置３０が据置・走行する範囲の整地を行うとともに鉄板等を敷設する。 Next, a construction yard creation process for creating a construction yard is performed. Specifically, as shown in FIG. 3, the excavator 13 performs leveling in a range where the ground agitator 12 and the water shielding sheet construction device 30 are installed and traveled, and lays an iron plate or the like.

次に、地盤Ｇを所定深さ(遮水壁を設けようとする深さである)で所定長さ(遮水壁を設けようとする長さである)連続的に攪拌し、地盤中に面的な広がりを有する面状の地盤攪拌体２を造成する地盤攪拌体造成工程を行う。ここで地盤攪拌体２の幅は、小さいのに越したことはないが、ロール状の遮水シートを挿入する関係からここでは６０ｃｍ程度に設定している。また、攪拌にあたっては、攪拌のみの場合、水やベントナイト、フライアッシュ、固化材としてのセメント等の添加材を混入して攪拌混合する場合がある。 Next, the ground G is continuously stirred at a predetermined depth (which is a depth where a water-impervious wall is to be provided) for a predetermined length (which is a length where a water-impervious wall is provided). A ground stirrer forming step for forming a planar ground stirrer 2 having a planar spread is performed. Here, the width of the ground stirring member 2 has never been small, but is set to about 60 cm here because of the insertion of a roll-shaped water-impervious sheet. In the case of stirring only, there may be cases where additives such as water, bentonite, fly ash, cement as a solidifying material are mixed and stirred.

ここで、添加材を添加する場合の攪拌混合について説明する。具体的には、図４に示すように添加材製造手段１０によって所定配合の添加材(必要に応じ固化材を混入してもよい)を製造する。そして、製造された添加材を添加材流入手段１１によって地盤Ｇに混入させつつ、地盤攪拌機１２のエンドレスチェーン５５を周回させることで攪拌羽根５６を周回させて、地盤Ｇとともに攪拌混合する。このとき、エンドレスチェーン５５が巻き掛けられたフレーム５２を上下および横方向、即ち深さと長さ方向に移動させることで、所定の深さ、所定の長さで連続する面状で流動状の地盤攪拌体２を造成する。また、このとき、遮水シート３の挿入・展張の作業性を考慮しつつ、地盤攪拌体２の遮水性能を適正に確保するべく、攪拌体のフロー値が所定値になるように流量計１９で混入させる添加材の注入量を調整する。具体的には、遮水シート３の挿入・展張の作業性を考慮するとともに、最低限の遮水性能（透水係数１０^−５ｃｍ／ｓｅｃ）を確保するために、攪拌体のテーブルフロー値（ＪＩＳＲ５２０１−１９８１「セメントの物理試験方法」による計測値）が１３０ｍｍ以上２５０ｍｍ以下になるように、添加材の注入量を調整し、好ましくはテーブルフロー値が１５０ｍｍ程度になるように調整する。 Here, the stirring and mixing in the case of adding the additive will be described. Specifically, as shown in FIG. 4, an additive having a predetermined composition (a solidifying material may be mixed as needed) is produced by the additive production means 10. And while mixing the manufactured additive material in the ground G by the additive material inflow means 11, the endless chain 55 of the ground agitator 12 is rotated to rotate the stirring blade 56, and the ground G is stirred and mixed. At this time, by moving the frame 52 around which the endless chain 55 is wound in the vertical and horizontal directions, that is, in the depth and length directions, a planar and fluid ground that is continuous at a predetermined depth and a predetermined length. A stirring body 2 is formed. At this time, the flow meter is used so that the flow value of the agitator becomes a predetermined value in order to appropriately ensure the water shielding performance of the ground agitator 2 while taking into consideration the workability of insertion and extension of the impermeable sheet 3. In 19, the injection amount of the additive to be mixed is adjusted. Specifically, in consideration of the workability of insertion and extension of the water shielding sheet 3, in order to ensure the minimum water shielding performance (water permeability coefficient of 10 ⁻⁵ cm / sec), the table flow value of the stirring member ( The injection amount of the additive is adjusted so that the measured value according to JIS R5201-1981 “Cement physical test method” is 130 mm or more and 250 mm or less, and preferably the table flow value is adjusted to about 150 mm.

一方、図１３（ａ）に示すように、ロール状の一枚目の遮水シート３を遮水シート施工装置３０の保持部材３１に保持させるシート保持工程を行う。具体的には、まず、図８，図１０に示すように、遮水シート３が巻き付けられている軸芯鋼管９の上端に軸芯延長部材６４を継手させ、さらに、図示しないピン等で軸芯鋼管９と軸芯延長部材６４とが外れないようにしておく。次に、図１０，図１１，図１２，図１３（ａ）に示すように、遮水シート施工装置３０の保持部材３１を水平状態に配置しておき、この状態で、遮水シート３の軸芯鋼管９の下端を本体部６０下端の受け部６３の突起６３ａに嵌合させるとともに、軸芯延長部材６４のベアリング部６４ｂを本体部６０上部に設けた上部把持機構６６で把持し、さらに下部把持機構６７でも軸芯延長部材６４を把持する。 On the other hand, as shown to Fig.13 (a), the sheet | seat holding process which hold | maintains the roll-shaped 1st water shielding sheet 3 on the holding member 31 of the water shielding sheet construction apparatus 30 is performed. Specifically, first, as shown in FIGS. 8 and 10, a shaft core extending member 64 is jointed to the upper end of the shaft steel tube 9 around which the water shielding sheet 3 is wound, and the shaft is further connected with a pin or the like (not shown). The core steel pipe 9 and the shaft core extending member 64 are kept from coming off. Next, as shown in FIGS. 10, 11, 12, and 13 (a), the holding member 31 of the water shielding sheet construction device 30 is arranged in a horizontal state, and in this state, The lower end of the shaft steel pipe 9 is fitted into the protrusion 63a of the receiving portion 63 at the lower end of the main body 60, and the bearing portion 64b of the shaft core extending member 64 is held by the upper holding mechanism 66 provided on the upper portion of the main body 60. The lower core holding mechanism 67 also holds the shaft core extending member 64.

次に、図１３（ａ），図１３（ｂ）に示すように、流動状の地盤攪拌体２内に、保持部材３１に保持された１枚目のロール状の遮水シート３を挿入するシート挿入工程を行う。具体的には、まず、図１３（ａ）に示すように、昇降機構３６によって上下動部３２を上昇させる。このとき、保持部材３１は鉛直回転自在になっており、上下動部３２が上昇するとともに、保持部材３１が鉛直方向に回動して地盤Ｇの上方で鉛直状態になり、保持部材３１に保持されたロール状の遮水シート３も鉛直状態になる。次いで、図１３（ｂ）に示すように、遮水シート施工装置３０を動かして、保持部材３１に保持されたロール状の遮水シート３を地盤攪拌体２の端部上方に配置する。次いで、昇降機構３６によって上下動部３２を下降させ、保持部材３１とともにロール状の遮水シート３を地盤攪拌体２内に挿入する。このとき、地盤攪拌体２の端部に予め鉛直に打設されたロッド状の固定部材２７に、ロール状の遮水シート３の外側にある図３に示す雌ジョイント５を固定させる。 Next, as shown in FIGS. 13 (a) and 13 (b), the first roll-shaped water-impervious sheet 3 held by the holding member 31 is inserted into the fluid ground stirrer 2. A sheet insertion process is performed. Specifically, first, as shown in FIG. 13A, the vertical movement unit 32 is raised by the lifting mechanism 36. At this time, the holding member 31 is freely rotatable in the vertical direction, and the vertical movement unit 32 is raised, and the holding member 31 is rotated in the vertical direction to be in a vertical state above the ground G and is held by the holding member 31. The rolled water-impervious sheet 3 is also in a vertical state. Next, as shown in FIG. 13 (b), the impermeable sheet construction apparatus 30 is moved, and the roll-shaped impermeable sheet 3 held by the holding member 31 is arranged above the end of the ground stirring body 2. Next, the vertically moving portion 32 is lowered by the elevating mechanism 36, and the roll-shaped water-impervious sheet 3 is inserted into the ground stirring body 2 together with the holding member 31. At this time, the female joint 5 shown in FIG. 3 on the outer side of the roll-shaped water-impervious sheet 3 is fixed to a rod-shaped fixing member 27 that is vertically driven in advance at the end of the ground stirring body 2.

次に、図１４（ａ）に示すように、ロール状の遮水シート３を地盤攪拌体２内で展張させるシート展張工程を行う。具体的には、図１２に示す下部把持機構６７を解除した後、ベースマシン３３によって遮水シート施工装置３０を地盤攪拌体２に沿って固定部材２７から離れる方向に水平移動させることで、保持部材３１を同様に地盤攪拌体２に沿って固定部材２７から離れる方向に水平移動させる。このとき、保持部材３１に保持された遮水シート３のロール部分３ｃは、保持部材３１とともに、固定された第２シート端３ｂから離れる方向に水平移動しながら軸回転し、地盤攪拌体２内で引き出されて（巻きほぐされて）横引き展開される。ロール状の遮水シート３が完全に展張されたところで、ベースマシン３３の走行を停止させる。 Next, as shown to Fig.14 (a), the sheet | seat extension process which expands the roll-shaped water-impervious sheet 3 within the ground stirring body 2 is performed. Specifically, after the lower gripping mechanism 67 shown in FIG. 12 is released, the base machine 33 horizontally moves the impermeable sheet construction apparatus 30 along the ground agitator 2 in the direction away from the fixing member 27, thereby holding it. Similarly, the member 31 is horizontally moved in the direction away from the fixing member 27 along the ground stirring body 2. At this time, the roll portion 3c of the water-impervious sheet 3 held by the holding member 31 rotates together with the holding member 31 while horizontally moving in a direction away from the fixed second sheet end 3b, so that the inside of the ground stirring body 2 Is pulled out (unrolled) and expanded horizontally. When the roll-shaped water-impervious sheet 3 is completely expanded, the traveling of the base machine 33 is stopped.

次に、図１４（ｂ）に示すように、展張された遮水シート３の第１シート端３ａ（雄ジョイント４）を、回動機構３７によって、保持部材３１とともに地盤攪拌体２内から引き上げるシート端引上げ工程を行う。具体的には、図６，図７，図１４（ｂ）に示すように、滑車架台４２をベースマシン３３の後方に配置した状態で、ウインチ４４によってワイヤー４５を巻き取って保持部材３１の下端にワイヤー４５を介して牽引力を与え、地盤攪拌体２の外にある回転軸４９を回転中心にして、鉛直状態の保持部材３１を後方に向けて鉛直回動させる。このとき、保持部材３１に掛止されている雄ジョイント４（第１シート端３ａ）が保持部材３１とともに後方に向けて鉛直回動し、これにより、遮水シート３の端部が折り返され、第１シート端３ａが地盤攪拌体２内から気中（地盤攪拌体２の外）に引き上げられる。そして、保持部材３１（第１シート端３ａ）が完全に引き上げられて水平に配置されたところでウインチ４４を停止して、保持部材３１（第１シート端３ａ）の回動を停止させる。 Next, as shown in FIG. 14 (b), the first sheet end 3 a (male joint 4) of the stretched water-impervious sheet 3 is pulled up from the ground agitator 2 together with the holding member 31 by the rotation mechanism 37. A sheet edge pulling process is performed. Specifically, as shown in FIGS. 6, 7, and 14 (b), the lower end of the holding member 31 is wound by winding the wire 45 with the winch 44 in a state where the pulley mount 42 is disposed behind the base machine 33. A traction force is applied to the first and second holding members 31 in the vertical state with the rotating shaft 49 outside the ground stirring body 2 as the rotation center, and the vertical holding member 31 is rotated backward. At this time, the male joint 4 (first sheet end 3a) hooked to the holding member 31 rotates vertically together with the holding member 31, and thereby the end portion of the water shielding sheet 3 is folded back. The first sheet end 3a is pulled up from the ground stirring body 2 into the air (outside the ground stirring body 2). The winch 44 is stopped when the holding member 31 (first sheet end 3a) is completely pulled up and disposed horizontally, and the rotation of the holding member 31 (first sheet end 3a) is stopped.

次に、図１４（ｂ），図１５，図１６に示すように、地盤攪拌体２の外で、１枚目の遮水シート３の第１シート端３ａと、２枚目の（新たな）遮水シート３´の第２シート端３ｂ´とを継手するとともに、ロール状に巻かれた２枚目の遮水シート３´を保持部材３１に保持させるシート継手・保持工程を行う。具体的には、図１０，図１１，図１２，図１５に示すように、地盤攪拌体２内から引き上げられた保持部材３１の上部把持機構６６および下部把持機構６７をそれぞれ解除するとともに軸芯鋼管９の上端から軸芯延長部材６４を引き抜き、保持部材３１から軸芯鋼管９を取り外す。なお、軸芯鋼管９を保持部材３１から取り外すとき或いは雄ジョイント４を軸芯鋼管９から取り外すときに遮水シート３の第１シート端３ａがずれて地盤攪拌体２内に落下しないように落下防止用として、または、１枚目と２枚目の遮水シート３を継手するときの作業用として、シート押え部材７２が取り付けられた継手作業台７１を、ヒンジ７３を介して本体部６０に回動可能に取り付けておくことが好ましい。上記した継手作業台７１が備えられることで、前記した取り外し作業や継手作業をする際には、継手作業台７１を水平に回動させて、この上に１枚目の遮水シート３の第１シート端３ａ付近を載せ、遮水シート３の上方からシート押え部材７２で固定することことができ、上記作業が行い易くなる。次いで、図１５に示すように、軸芯鋼管９を軸線方向にスライドさせ、１枚目の遮水シート３の第１シート端３ａに付設された雄ジョイント４から軸芯鋼管９を取り外す。次いで、図１６に示すように、１枚目の遮水シート３の雄ジョイント４に、軸芯鋼管９´に巻回された２枚目の遮水シート３´のロール外側にある雌ジョイント５´を嵌合させながら、ロール状の２枚目の遮水シート３´を軸線方向にスライドさせ、１枚目の遮水シート３の第１シート端３ａと２枚目の遮水シート３´の第２シート端３ｂ´とを継手させる。このとき、その継手箇所に止水材６を介在させる。なお、この止水材６は、雄ジョイント４の先端部や雌ジョイント５´の内側面に予め接着しておいてもよく、或いは、雄ジョイント４と雌ジョイント５´とを嵌合させる際に、それらの間に配置してもよい。次いで、図１０，図１１，図１２，図１６に示すように、１枚目の遮水シート３と同様に、２枚目の遮水シート３´の軸芯鋼管９´上端に軸芯延長部材６４を継手させ、軸芯鋼管９´下端を保持部材３１の受け部６３の突起６３ａに嵌合させ、軸芯延長部材６４のベアリング部６４ｂを上部把持機構６６で把持し、さらに下部把持機構６７で軸芯延長部材６４を把持することで、２枚目の遮水シート３´を保持部材３１に保持させる。 Next, as shown in FIGS. 14B, 15, and 16, the first sheet end 3 a of the first impermeable sheet 3 and the second (new ) A sheet coupling / holding step is performed in which the holding member 31 holds the second water-impervious sheet 3 ′ wound in a roll shape together with the second sheet end 3 b ′ of the water-impervious sheet 3 ′. Specifically, as shown in FIGS. 10, 11, 12, and 15, the upper gripping mechanism 66 and the lower gripping mechanism 67 of the holding member 31 lifted from the ground stirring body 2 are respectively released and the shaft core is released. The shaft core extending member 64 is pulled out from the upper end of the steel pipe 9, and the shaft core steel tube 9 is removed from the holding member 31. In addition, when removing the shaft steel tube 9 from the holding member 31 or when removing the male joint 4 from the shaft steel tube 9, the first sheet end 3 a of the water shielding sheet 3 is displaced so as not to fall into the ground stirring body 2. A joint work table 71 to which a sheet pressing member 72 is attached is attached to the main body 60 via a hinge 73 for prevention or for work when joining the first and second water shielding sheets 3 together. It is preferable to attach so that rotation is possible. By providing the above-described joint work table 71, when performing the above-described removal work and joint work, the joint work table 71 is rotated horizontally, and the first water-impervious sheet 3 of the first water shielding sheet 3 is placed thereon. 1 sheet edge 3a vicinity can be mounted, and it can fix with the sheet | seat pressing member 72 from the upper direction of the water-impervious sheet 3, and it becomes easy to perform the said operation | work. Next, as shown in FIG. 15, the axial steel tube 9 is slid in the axial direction, and the axial steel tube 9 is removed from the male joint 4 attached to the first sheet end 3 a of the first water-impervious sheet 3. Next, as shown in FIG. 16, the female joint 5 on the outer side of the roll of the second water-impervious sheet 3 ′ wound around the axial steel pipe 9 ′ around the male joint 4 of the first water-impervious sheet 3. ′, The roll-shaped second impermeable sheet 3 ′ is slid in the axial direction, and the first sheet end 3 a of the first impermeable sheet 3 and the second impermeable sheet 3 ′. And the second sheet end 3b '. At this time, the water stop material 6 is interposed in the joint location. The water blocking material 6 may be bonded in advance to the tip of the male joint 4 and the inner surface of the female joint 5 ', or when the male joint 4 and the female joint 5' are fitted together. , May be placed between them. Next, as shown in FIG. 10, FIG. 11, FIG. 12, and FIG. 16, the shaft core is extended to the upper end of the shaft steel tube 9 ′ of the second water shielding sheet 3 ′ in the same manner as the first water shielding sheet 3. The member 64 is joined, the lower end of the shaft steel pipe 9 'is fitted to the protrusion 63a of the receiving portion 63 of the holding member 31, the bearing portion 64b of the shaft core extending member 64 is gripped by the upper gripping mechanism 66, and the lower gripping mechanism The second water-impervious sheet 3 ′ is held by the holding member 31 by gripping the shaft core extending member 64 at 67.

次に、図１７（ａ）に示すように、１枚目の遮水シート３の第１シート端３ａおよび２枚目の遮水シート３´を保持部材３１とともに下方に回動させることで、１枚目の遮水シート３の折り返された端部を元に戻すとともに、ロール状の２枚目の遮水シート３´を地盤攪拌体２内に入れるシート入れ工程を行う。具体的には、図６，図７，図１７（ａ）に示すように、滑車架台４２をベースマシン３３の先方に配置した状態で、ウインチ４４によってワイヤー４５を巻き取って保持部材３１の下端にワイヤー４５を介して牽引力を与え、地盤攪拌体２の外にある回転軸４９を回転中心にして、水平状態の保持部材３１を下方（シート端引上げ工程のときと反対の方向）に向けて鉛直回動させる。このとき、保持部材３１に保持されたロール状の２枚目の遮水シート３´、およびその遮水シート３´の第２シート端３ｂ´に継手された１枚目の遮水シート３の第１シート端３ａは、保持部材３１とともに下方に向けて鉛直回動し、これにより、折り返された遮水シート３の端部は広げられ、１枚目の遮水シート３の第１シート端３ａおよび２枚目の遮水シート３´は地盤攪拌体２の中に入れられる。そして、保持部材３１（１枚目の遮水シート３の第１シート端３ａおよび２枚目の遮水シート３´）が地盤攪拌体２内で鉛直に配置されたところでウインチ４４を停止して、保持部材３１の回動を停止させる。なお、水平状態の保持部材３１を下方に向けて鉛直回動させる方法として、滑車架台４２をベースマシン３３の後方に配置したままで、ウインチ４４によってワイヤー４５を巻き戻すことで、保持部材３１を下方に鉛直回動させる方法もある。 Next, as shown in FIG. 17 (a), by rotating the first sheet end 3a of the first impermeable sheet 3 and the second impermeable sheet 3 ′ together with the holding member 31, While the folded end of the first water-impervious sheet 3 is returned to the original position, a sheet inserting step of putting the roll-shaped second water-impervious sheet 3 ′ into the ground stirring body 2 is performed. Specifically, as shown in FIGS. 6, 7, and 17 (a), the wire 45 is wound up by the winch 44 and the lower end of the holding member 31 in a state where the pulley mount 42 is disposed at the front of the base machine 33. A traction force is applied to the wire 45 via the rotating shaft 49 outside the ground stirring body 2 and the horizontal holding member 31 is directed downward (in the opposite direction to the sheet end pulling process). Turn vertically. At this time, the roll-shaped second water-impervious sheet 3 ′ held by the holding member 31 and the first water-impervious sheet 3 joined to the second sheet end 3 b ′ of the water-impervious sheet 3 ′ The first sheet end 3 a rotates vertically downward together with the holding member 31, whereby the end portion of the folded water-impervious sheet 3 is expanded and the first sheet end of the first water-impervious sheet 3 is expanded. 3 a and the second water-impervious sheet 3 ′ are placed in the ground stirring body 2. Then, the winch 44 is stopped when the holding member 31 (the first sheet end 3a of the first impermeable sheet 3 and the second impermeable sheet 3 ') is vertically arranged in the ground stirring body 2. Then, the rotation of the holding member 31 is stopped. As a method of vertically rotating the holding member 31 in the horizontal state downward, the wire 45 is rewound by the winch 44 while the pulley mount 42 is disposed behind the base machine 33, so that the holding member 31 is There is also a method of vertically rotating downward.

次に、図１７（ｂ）に示すように、１枚目の遮水シート３と同様に、２枚目の遮水シート３´について上記したシート展張工程を行うことで、２枚目の遮水シート３´を展張する。その後、上記したシート端引上げ工程、シート継手・保持工程、シート入れ工程、シート展張工程を順次繰り返し行う。 Next, as shown in FIG. 17B, the second sheet of water shielding sheet 3 ′ is subjected to the above-described sheet extending process as in the case of the first sheet of water shielding sheet 3, thereby performing the second sheet of water shielding. Spread the water sheet 3 '. Thereafter, the sheet end pulling process, the sheet joint / holding process, the sheet inserting process, and the sheet stretching process are sequentially repeated.

上記した構成からなる遮水シート３の施工方法によれば、ロール状の遮水シート３を展張した後、遮水シート３の第１シート端３ａを後方に向けて回動させることで、遮水シート３の端部を折り返えして第１シート端３ａを地盤攪拌体２の外に引き上げ、その後、地盤攪拌体２の外で、先行の遮水シート３の第１シート端３ａに新たな遮水シート３´の第２シート端３ｂを継手することにより、遮水シート３，３´同士の継手作業の作業効率が向上するため、遮水シート３，３´同士の継手構造（雄ジョイント４，雌ジョイント５）が多少複雑な構造である場合でも確実に施工することができる。これによって、遮水シート３，３´同士の継手構造に、遮水性能の信頼性が高く経済的である継手構造を採用することができる。 According to the construction method of the water-impervious sheet 3 having the above-described configuration, after the roll-shaped water-impervious sheet 3 is stretched, the first sheet end 3a of the water-impervious sheet 3 is rotated rearward to The end of the water sheet 3 is folded back and the first sheet end 3a is pulled out of the ground agitator 2 and then outside the ground agitator 2 to the first sheet end 3a of the preceding water shielding sheet 3. By jointing the second sheet end 3b of the new water-impervious sheet 3 ′, the work efficiency of the joint work between the water-impervious sheets 3 and 3 ′ is improved. Even if the male joint 4 and the female joint 5) have a somewhat complicated structure, it can be reliably constructed. As a result, a joint structure that is highly reliable in water shielding performance and economical can be adopted as the joint structure between the water shielding sheets 3 and 3 '.

また、地盤攪拌体２の外で、先行の遮水シート３の第１シート端３ａに新たな遮水シート３´の第２シート端３ｂを継手する際、先行の遮水シート３の第１シート端３ａに付設された雄ジョイント４と、新たな遮水シート３´の第２シート端３ｂに付設された雌ジョイント５とを嵌合させるとともに、その嵌合箇所に止水材６を介在させることにより、止水材６によって継手箇所の止水性が確保される。これによって、遮水シート３，３´同士の継手箇所の遮水性能についての信頼性を向上させることができる。なお、雄ジョイント４と雌ジョイント５との嵌合作業が地盤攪拌体２の外の気中で行われるため、雄ジョイント４と雌ジョイント５との間に止水材６を適正に介在させることが可能である。 In addition, when the second sheet end 3b of the new water-impervious sheet 3 'is joined to the first sheet end 3a of the preceding water-impervious sheet 3 outside the ground stirring body 2, the first of the preceding water-impervious sheet 3 is joined. The male joint 4 attached to the sheet end 3a and the female joint 5 attached to the second sheet end 3b of the new water-impervious sheet 3 ′ are fitted, and a water-stopping material 6 is interposed at the fitting position. By doing so, the water stoppage of the joint location is ensured by the waterstop material 6. Thereby, the reliability about the water shielding performance of the joint location of the water shielding sheets 3 and 3 'can be improved. In addition, since the fitting operation | work with the male joint 4 and the female joint 5 is performed in the air outside the ground stirring body 2, the water stop material 6 should be appropriately interposed between the male joint 4 and the female joint 5. Is possible.

また、上記した構成からなる遮水シート施工装置３０によれば、地盤攪拌体２の外に位置する回転軸４９を中心に鉛直方向に回転可能に設けられてロール状の遮水シート３，３´を引き出し展張可能に保持する保持部材３１と、この保持部材３１を水平方向に移動させるベースマシン３３と、保持部材３１を鉛直方向に回動させる回動機構３７とが備えられていることにより、地盤攪拌体２内のロール状の遮水シート３を展張させること、展張された遮水シート３の第１シート端３ａを鉛直方向に回動させること、新たな遮水シート３´に継手させた後、先行の遮水シート３の第１シート端３ａおよび新たなロール状の遮水シート３´を鉛直方向に回動させて地盤攪拌体２内に入れること等が可能であり、上記した遮水シート３の施工方法を実施することができる。 Moreover, according to the impermeable sheet construction apparatus 30 having the above-described configuration, the roll-shaped impermeable sheets 3, 3 are provided so as to be rotatable in the vertical direction around the rotation shaft 49 located outside the ground stirring body 2. And a base machine 33 that moves the holding member 31 in the horizontal direction, and a rotation mechanism 37 that rotates the holding member 31 in the vertical direction. , Extending the roll-shaped water-impervious sheet 3 in the ground agitator 2, rotating the first sheet end 3 a of the expanded water-impervious sheet 3 in the vertical direction, and fitting a new water-impervious sheet 3 ′ Then, the first sheet end 3a of the preceding water-impervious sheet 3 and the new roll-shaped water-impervious sheet 3 'can be rotated in the vertical direction and put into the ground stirring body 2, etc. The construction method of the waterproof sheet 3 It can be.

以上、本発明に係る遮水シートの施工方法および遮水シート施工装置の実施の形態について説明したが、本発明は上記した実施の形態に限定されるものではなく、その趣旨を逸脱しない範囲で適宜変更可能である。例えば、上記した実施の形態では、ロール内側の第１シート端３ａに雄ジョイント４が付設され、ロール外側の第２シート端３ｂに雌ジョイント５が付設されているが、本発明は、第１シート端３ａに雌型のジョイント冶具が付設され、第２シート端３ｂに雄型のジョイント冶具が付設されていてもよい。 As mentioned above, although the construction method of the impermeable sheet and embodiment of the impermeable sheet construction apparatus concerning the present invention were explained, the present invention is not limited to the above-mentioned embodiment, and is in the range which does not deviate from the meaning. It can be changed as appropriate. For example, in the above-described embodiment, the male joint 4 is attached to the first sheet end 3a inside the roll, and the female joint 5 is attached to the second sheet end 3b outside the roll. A female joint jig may be attached to the sheet end 3a, and a male joint jig may be attached to the second sheet end 3b.

また、上記した実施の形態では、遮水シート３，３´の第１シート端３ａに雄ジョイント４が付設され、遮水シート３，３´の第２シート端３ｂに雌ジョイント５が付設され、地盤攪拌体２の外で先行の遮水シート３の雄ジョイント４と新たな遮水シート３´の雌ジョイント５とを嵌合させることで、双方の遮水シート３，３´同士を継手しているが、本発明は、図１８に示すように、遮水シート３，３´が、第１シート端３ａ，３ａ´にＬ形のアングル材１０４，１０４´が付設（溶着）され、第２シート端３ｂ，３ｂ´に冶具等が付設されてない構成であってもよい。この場合、地盤攪拌体２の外で双方の遮水シート３，３´同士を継手する際、先行の遮水シート３のアングル材１０４に新たな遮水シート３´の第２シート端３ｂ´を現場溶着する。また、アングル材１０４，１０４´は、スリット９ａの幅よりも大きく、軸芯鋼管９に掛止されて引き抜きできない構成にする。なお、遮水シート３，３´同士を直接溶着するようにしてもよい。
その他、本発明は、遮水シート同士の継手構造が如何なる構成のものでもよく、他の構成からなる継手構造であっても適宜変更可能である。 In the above-described embodiment, the male joint 4 is attached to the first sheet end 3a of the water shielding sheets 3 and 3 ', and the female joint 5 is attached to the second sheet end 3b of the water shielding sheets 3 and 3'. By fitting the male joint 4 of the preceding water-impervious sheet 3 and the female joint 5 of the new water-impervious sheet 3 ′ outside the ground stirring body 2, both the water-impervious sheets 3, 3 ′ are joined together. However, in the present invention, as shown in FIG. 18, the water-impervious sheet 3, 3 ′ is provided (welded) with L-shaped angle members 104, 104 ′ on the first sheet ends 3 a, 3 a ′. A configuration in which a jig or the like is not attached to the second sheet ends 3b and 3b ′ may be employed. In this case, when jointing both the water shielding sheets 3 and 3 ′ outside the ground stirring body 2, the second sheet end 3 b ′ of the new water shielding sheet 3 ′ is added to the angle material 104 of the preceding water shielding sheet 3. On-site. In addition, the angle members 104 and 104 ′ are larger than the width of the slit 9 a, and are configured to be hooked on the shaft steel tube 9 and cannot be pulled out. In addition, you may make it weld the water shielding sheets 3 and 3 'directly.
In addition, in the present invention, the joint structure between the water shielding sheets may have any structure, and even a joint structure having another structure can be appropriately changed.

また、上記した実施の形態では、保持部材３１は、上部把持機構６６と受け部６３の突起６３ａとで軸芯鋼管９を軸回転自在に軸支することでロール状の遮水シート３を保持しているが、本発明は、図１９に示すように、遮水シート３を引き出すためのスリット１２２ａが形成された筒状の収納ケース１２２の中に、ロール状に巻かれた遮水シート３のロール部分３ｃを収納した構成であってもよい。 In the above-described embodiment, the holding member 31 holds the roll-shaped water-impervious sheet 3 by pivotally supporting the shaft steel tube 9 with the upper gripping mechanism 66 and the protrusion 63a of the receiving portion 63 so as to be axially rotatable. However, in the present invention, as shown in FIG. 19, the water shielding sheet 3 wound in a roll shape in a cylindrical storage case 122 in which a slit 122a for drawing out the water shielding sheet 3 is formed. The structure which accommodated this roll part 3c may be sufficient.

また、上記した実施の形態では、保持部材３１の下端にワイヤー４５を取り付け、このワイヤー４５の延在方向を滑車架台４２で調整するとともにウインチ４４で巻き上げることで、保持部材３１を鉛直回動させているが、本発明は、モータ等の回転駆動源を利用して保持部材を鉛直回動させてもよく、或いは、その他の機構によって保持部材を鉛直回動させてもよい。 In the above-described embodiment, the wire 45 is attached to the lower end of the holding member 31, and the extending direction of the wire 45 is adjusted by the pulley mount 42 and wound up by the winch 44, thereby rotating the holding member 31 vertically. However, in the present invention, the holding member may be vertically rotated using a rotational drive source such as a motor, or the holding member may be vertically rotated by another mechanism.

また、上記した実施の形態では、ほぐされた土の中に液状の添加材を混入して攪拌することで、流動体状の地盤攪拌体２を造成しているが、本発明は、ほぐされた土の中に、セメント等の固化材と水とをそれぞれ混入させて攪拌することで流動体状の地盤攪拌体２を造成してもよい。
また、上記した実施の形態では、地盤攪拌体２の中に遮水シート３を設置する場合を例にして説明しているが、本発明は、地盤に所定深さ・所定長さの溝を形成するとともに、この溝の中に遮水シートを設置してもよい。なお、溝が深い場合には、構内に安定液を満たすことが好ましい。
また、上記した実施の形態では、地盤Ｇに鉛直の地盤攪拌体２を形成し、この地盤攪拌体２内に遮水シート３を鉛直に設置する場合について説明しているが、本発明は、傾斜した地盤攪拌体や溝を形成し、この地盤攪拌体等の中に遮水シートを斜めに設置してもよい。なお、この場合、地盤攪拌体等の中に配置された遮水シートの一方のシート端は、地盤攪拌体等に沿って斜めに回動される。 Further, in the above-described embodiment, the fluid-like ground stirring body 2 is formed by mixing and stirring the liquid additive in the loosened soil, but the present invention is loosened. Alternatively, a fluid-like ground stirrer 2 may be formed by mixing and stirring a solidifying material such as cement and water in the soil.
In the above-described embodiment, the case where the water shielding sheet 3 is installed in the ground stirring body 2 is described as an example. However, the present invention provides a groove having a predetermined depth and a predetermined length in the ground. While forming, a water shielding sheet may be installed in the groove. In addition, when a groove | channel is deep, it is preferable to fill a stabilizer with a campus.
In the above-described embodiment, the case where the vertical ground stirring body 2 is formed on the ground G and the water shielding sheet 3 is vertically installed in the ground stirring body 2 has been described. An inclined ground stirring body or groove may be formed, and a water shielding sheet may be installed obliquely in the ground stirring body or the like. In this case, one sheet end of the water-impervious sheet disposed in the ground stirring body or the like is rotated obliquely along the ground stirring body or the like.

本発明の実施の形態を説明するための遮水シートを用いた遮水壁の立断面図である。It is an upright sectional view of a impermeable wall using a impermeable sheet for explaining an embodiment of the invention. 本発明の実施の形態を説明するための遮水シートを用いた遮水壁の平面図である。It is a top view of the impermeable wall using the impermeable sheet for demonstrating embodiment of this invention. 本発明の実施の形態を説明するための遮水シートの断面図である。It is sectional drawing of the water shielding sheet for demonstrating embodiment of this invention. 本発明の実施の形態を説明するための地盤攪拌体を造成する設備を表した図である。It is a figure showing the installation which creates the ground stirring body for describing embodiment of this invention. 本発明の実施の形態を説明するための地盤攪拌体を造成するときに使用する掘削機を表した図である。It is a figure showing the excavator used when creating the ground stirring body for demonstrating embodiment of this invention. 本発明の実施の形態を説明するための遮水シート施工装置を表した図である。It is a figure showing the impermeable sheet construction apparatus for describing embodiment of this invention. 本発明の実施の形態を説明するための遮水シート施工装置を表した図である。It is a figure showing the impermeable sheet construction apparatus for describing embodiment of this invention. 本発明の実施の形態を説明するための保持部材を表した図である。It is a figure showing the holding member for describing an embodiment of the invention. 本発明の実施の形態を説明するための保持部材を表した部分拡大図である。It is the elements on larger scale showing the holding member for demonstrating embodiment of this invention. 本発明の実施の形態を説明するための保持部材を表した部分拡大図である。It is the elements on larger scale showing the holding member for demonstrating embodiment of this invention. 図１０に示すＡ−Ａ間の断面図である。It is sectional drawing between AA shown in FIG. 図１０に示すＢ−Ｂ間の断面図である。It is sectional drawing between BB shown in FIG. 本発明の実施の形態を説明するための遮水シートの施工工程を表した図である。It is a figure showing the construction process of the impermeable sheet for demonstrating embodiment of this invention. 本発明の実施の形態を説明するための遮水シートの施工工程を表した図である。It is a figure showing the construction process of the impermeable sheet for demonstrating embodiment of this invention. 本発明の実施の形態を説明するための引き上げられた遮水シートのシート端を表す図である。It is a figure showing the sheet | seat end of the water-impervious sheet pulled up for demonstrating embodiment of this invention. 本発明の実施の形態を説明するための遮水シートの継手状況を表した図である。It is a figure showing the joint situation of the impermeable sheet for describing an embodiment of the invention. 本発明の実施の形態を説明するための遮水シートを施工する工程を表した図である。It is a figure showing the process of constructing the water shielding sheet for demonstrating embodiment of this invention. 本発明の他の実施の形態を説明するための遮水シートの継手状況を表した図である。It is a figure showing the joint situation of a water-proof sheet for explaining other embodiments of the present invention. 本発明の他の実施の形態を説明するための保持部材を表した図である。It is a figure showing the holding member for demonstrating other embodiment of this invention.

Explanation of symbols

２地盤攪拌体
３遮水シート
３´ 新たな遮水シート
３ａ，３ａ´ 一方のシート端
３ｂ，３ｂ´ 他方のシート端
４，４雄ジョイント（第１のジョイント冶具）
５，５´ 雌ジョイント（第２のジョイント冶具）
６止水材
３０遮水シート施工装置
３１保持部材
３３ベースマシン（移動手段）
３７回動機構（回動手段）
４９回転軸
Ｇ地盤 2 Ground stirring body 3 Water-impervious sheet 3 ′ New water-impervious sheet 3a, 3a ′ One sheet end 3b, 3b ′ The other sheet end 4, 4 Male joint (first joint jig)
5,5 'female joint (second joint jig)
6 Water blocking material 30 Water shielding sheet construction device 31 Holding member 33 Base machine (moving means)
37 Rotating mechanism (rotating means)
49 Rotation axis G Ground

Claims

In the construction method of the water shielding sheet that is installed in a state where a plurality of water shielding sheets are jointed to each other in the groove formed in the ground or the ground stirring body formed by continuously stirring the ground,
The water-impervious sheet wound in a roll shape by moving the roll portion of the water-impervious sheet placed in the groove or the ground stirrer in a state wound in a roll shape along the groove or the ground stirrer Spread
By turning the one sheet end of the water-impervious sheet located inside the roll in the direction opposite to the roll moving direction along the groove or the ground stirring body, the end of the water-impervious sheet is folded back. And pulling up the one sheet end to the outside of the groove or ground stirring body,
The other sheet end outside the roll of a new water-impervious sheet wound in a roll shape is jointed to the one sheet end of the water-impervious sheet previously installed outside the groove or ground stirring body. And
Then, the one end of the water-impervious sheet installed in advance and the end of the water-impervious sheet installed in advance by turning the new water-impervious sheet downward. The construction method of the water-impervious sheet characterized by returning the part and putting the new water-impervious sheet into the groove or the ground stirring body.

In the construction method of the impermeable sheet according to claim 1,
A male or female first joint jig is attached to the one sheet end of the water shielding sheet, and the other sheet end of the water shielding sheet is paired with the first joint jig. A female or male second joint jig is attached,
Outside the groove or ground agitator, it is installed in advance when the one sheet end of the water-impervious sheet previously installed and the other sheet end of the new water-impervious sheet are joined. In addition, the first joint jig of the water shielding sheet and the second joint jig of the new water shielding sheet are fitted together, and a water stop material is interposed at the fitting portion. Water sheet construction method.

A water shielding sheet construction apparatus used in the construction method of the water shielding sheet according to claim 1 or 2,
The water-impervious sheet that is provided so as to be rotatable along the groove or the ground stirrer around the rotation shaft located outside the groove or the ground stirrer and holds the water-impervious sheet wound in a roll shape so as to be stretchable. A holding member, a moving means for moving the holding member in the horizontal direction along the groove or the ground stirring body, and a rotating means for rotating the holding member along the groove or the ground stirring body,
The water shielding sheet construction apparatus, wherein one end of the water shielding sheet stretched in the groove or ground stirring body is locked to the holding member.