JP2020165287A

JP2020165287A - Combination structure of steel material, construction method of earth retaining wall, and removal method of upper pile for earth retaining wall

Info

Publication number: JP2020165287A
Application number: JP2020040371A
Authority: JP
Inventors: 義明平形; Yoshiaki Hirakata; 貴司小野; Takashi Ono; 俊久福原; Toshihisa Fukuhara
Original assignee: Marufuji Sheetpiling Co Ltd
Current assignee: Marufuji Sheetpiling Co Ltd
Priority date: 2019-03-29
Filing date: 2020-03-09
Publication date: 2020-10-08
Anticipated expiration: 2040-03-09
Also published as: JP7413091B2

Abstract

To provide a construction method of a core material and an earth retaining wall which can quickly and simply perform a removal work of an upper pile of a core material for earth retaining wall.SOLUTION: In a combination structure 100 in which an upper pile 10 and a lower pile 20 are connected to each other by connection means 30 in a releasable manner, the connection means 30 includes a sheath member 31 mounted on the upper pile 10 and the lower pile 20, and a column member 32 inserted into a space defined by the sheath member 31. The upper pile 10 and the lower pile 20 are connected to each other by inserting the column member 32 into the space defined by the sheath member 31. When the upper pile 10 is removed, the connection state between the upper pile 10 and the lower pile 20 is released by pulling up the upper pile 10.SELECTED DRAWING: Figure 3

Description

本発明は，土留め壁用の芯材などに用いられる鋼材の組合せ構造体に関する。また，本発明は，この組合せ構造体を用いた土留め壁の構築方法や，土留め壁用の上杭の撤去方法に関する。 The present invention relates to a combination structure of steel materials used as a core material for earth retaining walls. The present invention also relates to a method for constructing an earth retaining wall using this combination structure and a method for removing an upper pile for an earth retaining wall.

従来から，トンネル構造物等の地下構造物を地中に建設するにあたり，事前にその周囲に土留め壁を構築して，施工場所周囲の土壁の崩落や地下水の流入を防ぎながら，地下の作業空間を掘削する工事が行われている。土留め壁の構築方法としては，例えばＳＭＷ（Soil Mixing Wall）工法やＴＲＤ（Trench cutting Re-mixing Deep wall）工法が一般的に知られている。これらの工法では，地表面から地中を掘削し，掘削孔にＨ形鋼などからなる複数の芯材を間隔をあけて並列に挿入した後，その掘削孔にセメントミルクを流し込んで固化させることで，地表面から不透水層に達するソイルセメント製の土留め壁を構築する。 Conventionally, when constructing an underground structure such as a tunnel structure in the ground, an earth retaining wall is constructed around it in advance to prevent the earth wall around the construction site from collapsing and the inflow of groundwater. Construction work is underway to excavate the work space. As a method for constructing an earth retaining wall, for example, a SMW (Soil Mixing Wall) method or a TRD (Trench cutting Re-mixing Deep wall) method is generally known. In these construction methods, the underground is excavated from the ground surface, multiple core materials made of H-shaped steel, etc. are inserted in parallel at intervals in the excavation hole, and then cement milk is poured into the excavation hole to solidify it. Then, a soil cement retaining wall that reaches the impermeable layer from the ground surface will be constructed.

図１には，土留め壁の構築工法を模式的に示している。土留め壁の構築では，Ｈ形鋼等の芯材を複数建て込で土留め壁の構築した後，施工場所の掘削を進める掘削された施工場所にて地下構造物の構築を行う。地下構造物の構築後は，掘削場所の埋め戻しを行う。また，地下構造物の施工場所付近において，将来的に道路トンネルの構築工事や，通信ケーブル，水道管，ガス管等の埋設工事が行われる可能性があるため，埋め戻し時に，地中に埋設した芯材のうち，地表面から将来的に工事が予想される深さまでの範囲（要撤去範囲）については，芯材の部分的な撤去が求められる場合がある。つまり，図１に示されるように，芯材のうちの要撤去範囲に位置する上杭を，それより下方に位置する下杭から切り離して撤去することで，道路トンネルや通信ケーブル等を埋設できるスペースを確保する。 FIG. 1 schematically shows the construction method of the earth retaining wall. In the construction of the earth retaining wall, after the earth retaining wall is constructed by building a plurality of core materials such as H-shaped steel, the underground structure is constructed at the excavated construction site where the excavation of the construction site is promoted. After the construction of the underground structure, the excavation site will be backfilled. In addition, there is a possibility that road tunnel construction work and burial work of communication cables, water pipes, gas pipes, etc. will be carried out in the vicinity of the construction site of the underground structure, so it will be buried in the ground at the time of backfilling. Partial removal of the core material may be required for the range from the ground surface to the depth where construction is expected in the future (removal required range). That is, as shown in FIG. 1, the road tunnel, the communication cable, etc. can be buried by removing the upper pile located in the required removal range of the core material from the lower pile located below it. Secure space.

ところで，土留め壁用の芯材として単純なＨ形鋼を用いた場合，芯材の上杭（上部）を撤去する際に，Ｈ形鋼を切断する作業が必要となるため，撤去作業に時間がかかるという問題がある。このような問題を解決するために，例えば特許文献１及び特許文献２では，別体の上杭と下杭を連結した組合せ構造体を土留め壁用の芯材として利用することが提案されている。 By the way, when a simple H-shaped steel is used as the core material for the earth retaining wall, it is necessary to cut the H-shaped steel when removing the upper pile (upper part) of the core material. There is a problem that it takes time. In order to solve such a problem, for example, Patent Document 1 and Patent Document 2 propose to use a combined structure in which separate upper piles and lower piles are connected as a core material for a retaining wall. There is.

特開２０１０−２２２９４４号公報Japanese Unexamined Patent Publication No. 2010-22944 特開２０１５−０６３８１２号公報JP-A-2015-063812

特許文献１及び特許文献２に開示された土留め壁用の芯材は，上杭と下杭の連結手段として，基本的に，上杭と下杭の継ぎ目部分に充てがう鋼材と，この鋼材と各杭とを締結するためのボルトを用いることとしている。また，このボルトは，水平方向（芯材の長手方向と直交する方向）に差し込まれることとなる。 The core material for the earth retaining wall disclosed in Patent Document 1 and Patent Document 2 is basically a steel material to be applied to the joint portion between the upper pile and the lower pile as a means for connecting the upper pile and the lower pile, and this. Bolts are used to fasten the steel material to each pile. Further, this bolt is inserted in the horizontal direction (the direction orthogonal to the longitudinal direction of the core material).

しかしながら，ボルトを水平方向に差し込んで上杭と下杭を連結すると，上杭の撤去作業を行うときには，上杭と下杭の連結を解除するために，少なくともボルトが露出する位置まで地面を掘り返さなければならない。さらに，ボルトを外して上杭と下杭を切り離した後に，再度地面を埋め戻す作業も必要となる。このことは，例えば特許文献２でも説明されている。このような上下杭の連結形態では，上杭の撤去作業に時間がかかるという問題があった。 However, if the bolts are inserted horizontally to connect the upper and lower piles, the ground is dug up to at least the position where the bolts are exposed in order to disconnect the upper and lower piles when removing the upper piles. There must be. Furthermore, after removing the bolts and separating the upper and lower piles, it is necessary to backfill the ground again. This is also explained, for example, in Patent Document 2. In such a connected form of upper and lower piles, there is a problem that it takes time to remove the upper piles.

また，上下杭の継ぎ目をボルト締めする場合，ボルトやナットが地中に位置することとなる。このとき，地中に含まれる小石や砂がボルトとナットの間やボルト穴に入り込み，上杭の撤去作業時にこれらの小石や砂が障害となって，ボルトを回転させることが困難になる場合がある。また，地中に含まれる水分によってボルトやナットに錆が生じて，この錆がボルトの回転の障害となることも考えられる。 In addition, when bolting the joints of the upper and lower piles, the bolts and nuts are located in the ground. At this time, if pebbles or sand contained in the ground enter between the bolt and nut or in the bolt hole, and these pebbles or sand become an obstacle during the removal work of the upper pile, it becomes difficult to rotate the bolt. There is. It is also possible that the moisture contained in the ground causes rust on the bolts and nuts, which hinders the rotation of the bolts.

そこで，本発明は，例えば土留め壁用の芯材として用いられる鋼材の組合せ構造体において，上杭の撤去作業を迅速かつ簡単に実施できるようにすることを目的とする。 Therefore, an object of the present invention is to make it possible to quickly and easily remove the upper pile in a steel combination structure used as a core material for a retaining wall, for example.

本発明の発明者は，従来発明の問題点を解決する手段について鋭意検討した結果，例えば筒状又は断面Ｌ字形の鞘部材とこの鞘部材によって画定された空間に差し込まれる柱部材とを上下杭の連結手段として利用して，上下杭を垂直方向（芯材の長手方向）に連結することとした。これにより，ボルトを水平方向に差し込む必要がなくなるため，上杭の撤去作業を迅速かつ簡単に実施できるようになる。そして，本発明者は，上記知見に基づけば従来技術の課題を解決できることに想到し，本発明を完成させた。具体的に説明すると，本発明は以下の構成又は工程を有する。 As a result of diligent studies on means for solving the problems of the prior invention, the inventor of the present invention, for example, piles up and down a tubular or L-shaped cross-section sheath member and a pillar member inserted into the space defined by the sheath member. It was decided to connect the upper and lower piles in the vertical direction (longitudinal direction of the core material) by using it as a connecting means. This eliminates the need to insert bolts in the horizontal direction, which makes it possible to quickly and easily remove the upper pile. Then, the present inventor has come up with the idea that the problems of the prior art can be solved based on the above findings, and has completed the present invention. Specifically, the present invention has the following configurations or steps.

本発明の第１の側面は，土留め壁の芯材などに利用される鋼材の組合せ構造体１００に関する。本発明に係る組合せ構造体１００は，上杭１０，下杭２０，及び連結手段３０を備え，上杭１０と下杭２０が連結手段３０によって解除可能に連結されたものである。上杭１０及び下杭２０は，例えばＨ形鋼，Ｌ形鋼（山形鋼），Ｔ形鋼，Ｉ形鋼など，公知の形鋼材料を用いることができる。ここで，連結手段３０は，鞘部材３１と柱部材３２を備える。鞘部材３１は，柱部材３２を差し込むための空間を画定するための部材であり，上杭１０と下杭２０の一方又は両方にその長手方向に沿って取り付けられている。例えば，鞘部材３１としては，例えば，角形鋼管や円形鋼管などの筒状部材や，断面Ｌ字形や断面コの字形などのアングル部材を用いることができる。鞘部材３１として筒状部材を用いた場合，その筒状部材によって画定された内部空間に柱部材３２を差し込むことができる。また，鞘部材３１として例えば断面Ｌ形のアングル部材を用いた場合，Ｈ形鋼からなる上杭１０又は下杭２０のフランジプレートとウェブプレートに接するようにアングル部材を取り付けることで，これらのアングル部材，フランジプレート，及びウェブプレートによって，柱部材３２を差し込むための空間が画定される。柱部材３２は，鞘部材３１によって画定された空間に差し込まれる部材である。柱部材３２としては，鞘部材３１によって画定された空間より一回り径の小さい鋼管を用いることができる。また，柱部材３２は，上杭１０と下杭２０の両方に取り付けられた鞘部材３１によって画定された空間に差し込まれるか，又は鞘部材３１が取り付けられていない上杭１０と下杭２０の他方に固定されている。このように，鞘部材３１と柱部材３２を利用して上杭１０と下杭２０を垂直方向に連結する。これにより，地表面から上杭１０を上方に向かって引き上げることで，上杭１０を撤去することができる。従って，本発明によれば，上杭１０の撤去のために地面を掘り返したり地面を埋め戻す作業を省略することができる。 The first aspect of the present invention relates to a steel combination structure 100 used as a core material for a retaining wall or the like. The combined structure 100 according to the present invention includes an upper pile 10, a lower pile 20, and a connecting means 30, and the upper pile 10 and the lower pile 20 are detachably connected by the connecting means 30. For the upper pile 10 and the lower pile 20, known shaped steel materials such as H-shaped steel, L-shaped steel (angle steel), T-shaped steel, and I-shaped steel can be used. Here, the connecting means 30 includes a sheath member 31 and a pillar member 32. The sheath member 31 is a member for defining a space for inserting the pillar member 32, and is attached to one or both of the upper pile 10 and the lower pile 20 along the longitudinal direction thereof. For example, as the sheath member 31, for example, a tubular member such as a square steel pipe or a circular steel pipe, or an angle member having an L-shaped cross section or a U-shaped cross section can be used. When a tubular member is used as the sheath member 31, the pillar member 32 can be inserted into the internal space defined by the tubular member. Further, when an angle member having an L-shaped cross section is used as the sheath member 31, for example, by attaching the angle member so as to be in contact with the flange plate and the web plate of the upper pile 10 or the lower pile 20 made of H-shaped steel, these angles are formed. A space for inserting the column member 32 is defined by the member, the flange plate, and the web plate. The pillar member 32 is a member that is inserted into the space defined by the sheath member 31. As the column member 32, a steel pipe having a diameter smaller than that of the space defined by the sheath member 31 can be used. Further, the column member 32 is inserted into the space defined by the sheath member 31 attached to both the upper pile 10 and the lower pile 20, or the upper pile 10 and the lower pile 20 to which the sheath member 31 is not attached are inserted. It is fixed to the other. In this way, the upper pile 10 and the lower pile 20 are vertically connected by using the sheath member 31 and the pillar member 32. As a result, the upper pile 10 can be removed by pulling the upper pile 10 upward from the ground surface. Therefore, according to the present invention, it is possible to omit the work of digging up the ground or backfilling the ground for removing the upper pile 10.

本発明に係る組合せ構造体１００は，棒状部材３３をさらに備えることが好ましい。棒状部材３３は，鞘部材３１によって画定された空間に差し込まれた状態の柱部材３２をその長手方向に貫通し，上杭１０と下杭２０を連結する方向に軸力が付与される部材である。すなわち，棒状部材３３によって，上杭１０と下杭２０との当接面に圧縮荷重が付与されることとなる。棒状部材３３の例は，ネジ節鉄筋であるが，鞘部材３１と柱部材３２を互いに近づける方向に引張力を加えることのできる部材であれば，例えばスチールワイヤーやその他の鉄筋を用いることもできる。このように，鞘部材３１と柱部材３２を長手方向に貫通する棒状部材３３を利用することで，鞘部材３１と柱部材３２の連結を強固に維持することができ，さらに上杭１０及び下杭２０に軸力を与えることで組合せ構造体１００全体の強度を高めることができる。また，上杭１０の撤去時には棒状部材３３を垂直方向に引き抜けば済むため，上杭１０の撤去作業を迅速かつ簡単に実施することができる。 The combined structure 100 according to the present invention preferably further includes a rod-shaped member 33. The rod-shaped member 33 is a member that penetrates the pillar member 32 in a state of being inserted into the space defined by the sheath member 31 in the longitudinal direction thereof, and applies an axial force in the direction of connecting the upper pile 10 and the lower pile 20. is there. That is, the rod-shaped member 33 applies a compressive load to the contact surface between the upper pile 10 and the lower pile 20. An example of the rod-shaped member 33 is a threaded reinforcing bar, but for example, a steel wire or other reinforcing bar may be used as long as it is a member capable of applying a tensile force in a direction in which the sheath member 31 and the column member 32 are brought closer to each other. .. In this way, by using the rod-shaped member 33 that penetrates the sheath member 31 and the pillar member 32 in the longitudinal direction, the connection between the sheath member 31 and the pillar member 32 can be firmly maintained, and the upper pile 10 and the lower pile 10 and the lower By applying an axial force to the pile 20, the strength of the combined structure 100 as a whole can be increased. Further, since the rod-shaped member 33 only needs to be pulled out in the vertical direction when the upper pile 10 is removed, the removal work of the upper pile 10 can be carried out quickly and easily.

本発明に係る組合せ構造体１００において，棒状部材３３はネジ節鉄筋であることが特に好ましい。この場合，棒状部材３３は，鞘部材３１と柱部材３２に対して螺合される。これにより，例えば地表面から棒状部材３３をねじ込むことで鞘部材３１と柱部材３２を連結することができる。また，棒状部材３３を反対方向に回すことで，鞘部材３１と柱部材３２の連結状態を簡単に解除できる。 In the combined structure 100 according to the present invention, it is particularly preferable that the rod-shaped member 33 is a threaded reinforcing bar. In this case, the rod-shaped member 33 is screwed into the sheath member 31 and the pillar member 32. Thereby, for example, the sheath member 31 and the pillar member 32 can be connected by screwing the rod-shaped member 33 from the ground surface. Further, by turning the rod-shaped member 33 in the opposite direction, the connected state of the sheath member 31 and the pillar member 32 can be easily released.

本発明に係る組合せ構造体１００において，上杭１０及び下杭２０は，対向する一対のフランジプレート１１，２１の面に直交するようにウェブプレート１２，２２が形成されたＨ形鋼であってもよい。この場合，鞘部材３１は，上杭１０と下杭２０の一方又は両方のウェブプレート１２，２２の両面側にそれぞれ少なくとも１箇所ずつ取り付けられていることが好ましい。このように，Ｈ形鋼の両面にそれぞれ鞘部材３１を固定しておくことで，上杭１０及び下杭２０の連結状態を強固に維持できる。 In the combined structure 100 according to the present invention, the upper pile 10 and the lower pile 20 are H-shaped steels in which the web plates 12 and 22 are formed so as to be orthogonal to the surfaces of the pair of flange plates 11 and 21 facing each other. May be good. In this case, it is preferable that the sheath member 31 is attached to at least one location on each of the web plates 12 and 22 of one or both of the upper pile 10 and the lower pile 20. By fixing the sheath members 31 to both sides of the H-shaped steel in this way, the connected state of the upper pile 10 and the lower pile 20 can be firmly maintained.

本発明の第２の側面は，土留め壁の構築方法に関する。本発明に係る土留め壁の構築方法は，上記した第１の側面に係る組合せ構造体１００を地中に埋設する工程を含む。その他の工程は，公知の工程に従えばよい。すなわち，公知のＳＭＷ工法やＴＲＤ工法では，地面を掘削する工程，掘削孔に組合せ構造体を挿入する工程，掘削孔にセメントミルクを流し込んで固化させる工程などが含まれる。 The second aspect of the present invention relates to a method for constructing a retaining wall. The method for constructing a retaining wall according to the present invention includes a step of burying the combined structure 100 according to the first side surface described above in the ground. Other steps may follow known steps. That is, the known SMW method and TRD method include a step of excavating the ground, a step of inserting a combined structure into the excavation hole, a step of pouring cement milk into the excavation hole and solidifying the structure.

本発明の第３の側面は，土留め壁用上杭の撤去方法に関する。本発明に係る上杭の撤去方法は，上記した第１の側面に係る組合せ構造体１００のうち，下杭２０を地中に残して，上杭１０及び柱部材３２を引き抜く工程を含む。なお，組合せ構造体１００に棒状部材３３が含まれる場合には，上杭１０及び柱部材３２とともに棒状部材３３が引き抜かれる。 A third aspect of the present invention relates to a method for removing an upper pile for a retaining wall. The method for removing the upper pile according to the present invention includes a step of pulling out the upper pile 10 and the column member 32 while leaving the lower pile 20 in the ground among the combined structure 100 related to the first side surface described above. When the combination structure 100 includes the rod-shaped member 33, the rod-shaped member 33 is pulled out together with the upper pile 10 and the pillar member 32.

本発明によれば，例えば土留め壁用の芯材を構成する上杭を迅速かつ簡単に撤去することができる。 According to the present invention, for example, the upper pile constituting the core material for the earth retaining wall can be quickly and easily removed.

図１は，土留め壁用の芯材の埋設工程と上杭の撤去工程の概要を示した模式図である。FIG. 1 is a schematic view showing an outline of a process of burying a core material for a retaining wall and a process of removing an upper pile. 図２は，第１の実施形態に係る組合せ構造体の構成物品を示した分解斜視図である。FIG. 2 is an exploded perspective view showing the constituent articles of the combination structure according to the first embodiment. 図３は，図２に示した組合せ構造体の組み立て方法を示している。FIG. 3 shows a method of assembling the combination structure shown in FIG. 図４は，第１の実施形態に係る組合せ構造体を示した断面図である。FIG. 4 is a cross-sectional view showing the combined structure according to the first embodiment. 図５は，第２の実施形態に係る組合せ構造体を示した断面図である。FIG. 5 is a cross-sectional view showing the combined structure according to the second embodiment. 図６は，第３の実施形態に係る組合せ構造体を示した断面図である。FIG. 6 is a cross-sectional view showing the combined structure according to the third embodiment. 図７は，第４の実施形態に係る組合せ構造体を示した断面図である。FIG. 7 is a cross-sectional view showing the combined structure according to the fourth embodiment. 図８は，第５の実施形態に係る組合せ構造体を示した断面図である。FIG. 8 is a cross-sectional view showing the combined structure according to the fifth embodiment.

以下，図面を用いて本発明を実施するための形態について説明する。本発明は，以下に説明する形態に限定されるものではなく，以下の形態から当業者が自明な範囲で適宜変更したものも含む。 Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. The present invention is not limited to the forms described below, and includes those appropriately modified by those skilled in the art from the following forms to the extent obvious to those skilled in the art.

図２から図４を参照して，本発明に係る組合せ構造体１００の第１の実施形態について説明する。図２は組合せ構造体１００の構成物品を示し，図３は組合せ構造体１００の組み立て方法を示し，図４は，組合せ構造体１００の長手方向断面図と幅方向断面図（Ａ−Ａ，Ｂ−Ｂ）を示している。組合せ構造体１００の用途例は，ＳＭＷ工法等で利用する土留め壁の芯材であるが，これに限定されず，例えば一般的な建築資材として使用することも可能である。 A first embodiment of the combinational structure 100 according to the present invention will be described with reference to FIGS. 2 to 4. FIG. 2 shows the constituent articles of the combination structure 100, FIG. 3 shows a method of assembling the combination structure 100, and FIG. 4 is a longitudinal sectional view and a width sectional view (AA, B) of the combination structure 100. -B) is shown. An example of use of the combined structure 100 is a core material for a retaining wall used in the SMW method or the like, but the present invention is not limited to this, and for example, it can be used as a general building material.

組合せ構造体１００は，基本的に，上杭１０と，下杭２０と，これらの連結手段３０を備える。図示した例において，上杭１０及び下杭２０としては公知のＨ形鋼を用いている。Ｈ形鋼は，対向する一対のフランジプレート１１，２１と，これらのフランジプレート１１，２１の面に直交するウェブプレート１２，２２とからなり，断面形状がＨ形となる。連結手段３０は，上杭１０と下杭２０を長手方向に連結する。すなわち，連結手段３０は，上杭１０のＨ形の下端面と下杭２０のＨ形の上端面とを当接させた状態で両者を連結する。本発明はこの連結手段３０に特徴を有するものである。 The combination structure 100 basically includes an upper pile 10, a lower pile 20, and a connecting means 30 thereof. In the illustrated example, known H-shaped steel is used as the upper pile 10 and the lower pile 20. The H-shaped steel is composed of a pair of flange plates 11 and 21 facing each other and web plates 12 and 22 orthogonal to the surfaces of these flange plates 11 and 21, and has an H-shaped cross section. The connecting means 30 connects the upper pile 10 and the lower pile 20 in the longitudinal direction. That is, the connecting means 30 connects the upper pile 10 with the H-shaped lower end surface and the lower pile 20 with the H-shaped upper end surface in contact with each other. The present invention is characterized by the connecting means 30.

第１の実施形態において，連結手段３０は，鞘部材３１，柱部材３２，棒状部材３３，及びナットプレート３４を含む。本実施形態において，鞘部材３１は，上杭１０と下杭２０の両方に，それぞれ４箇所ずつ（合計８箇所）に固定されている。また，柱部材３２は，上杭１０と下杭２０には固定されずに，これらの杭１０，２０の内部に挿入される。 In the first embodiment, the connecting means 30 includes a sheath member 31, a pillar member 32, a rod-shaped member 33, and a nut plate 34. In the present embodiment, the sheath member 31 is fixed to both the upper pile 10 and the lower pile 20 at four locations (a total of eight locations). Further, the pillar member 32 is not fixed to the upper pile 10 and the lower pile 20, but is inserted inside the piles 10 and 20.

本実施形態において，鞘部材３１は，柱部材３２を挿入可能な筒状の部材であり，その内部空間が各杭１０，２０の長手方向（すなわち垂直方向）に沿って延在するように各杭１０，２０に固定されている。鞘部材３１の断面形状は，四角筒状であることが好ましいが，円筒状（楕円筒状含む）であってもよいし，五角筒状，六角筒状，その他多角筒状であってもよい。鞘部材３１としては，一般的な角形鋼管を用いると良い。鞘部材３１は，各杭１０，２０に解離不能に固着される。例えば，鞘部材３１を各杭１０，２０に溶接すればよい。Ｈ形鋼からなる各杭１０，２０には，フランジプレート１１，２１とウェブプレート１２，２２が直交することで４つの角部が形成されているが，図示した例において，各鞘部材３１は，４つの角部のそれぞれに固定されている。このため，各鞘部材３１は，それぞれフランジプレート１１，２１とウェブプレート１２，２２に当接した状態で固定（溶接）されている。これにより，鞘部材３１の接合強度を高めることができる。また，各鞘部材３１の長さは，それが固定される杭１０，２０の長さに対して，５０〜１００％とすればよく，７０〜１００％であることが特に好ましい。 In the present embodiment, the sheath member 31 is a tubular member into which the pillar member 32 can be inserted, and each of the sheath members 31 extends along the longitudinal direction (that is, the vertical direction) of the piles 10 and 20. It is fixed to the piles 10 and 20. The cross-sectional shape of the sheath member 31 is preferably a square cylinder, but it may be cylindrical (including an elliptical cylinder), a pentagonal cylinder, a hexagonal cylinder, or another polygonal cylinder. .. As the sheath member 31, a general square steel pipe may be used. The sheath member 31 is nondissociatively fixed to the piles 10 and 20. For example, the sheath member 31 may be welded to the piles 10 and 20 respectively. Four corners are formed on the piles 10 and 20 made of H-shaped steel by making the flange plates 11 and 21 and the web plates 12 and 22 orthogonal to each other. In the illustrated example, each sheath member 31 is , It is fixed to each of the four corners. Therefore, each sheath member 31 is fixed (welded) in a state of being in contact with the flange plates 11 and 21 and the web plates 12 and 22, respectively. As a result, the joint strength of the sheath member 31 can be increased. Further, the length of each sheath member 31 may be 50 to 100% with respect to the length of the piles 10 and 20 to which the sheath member 31 is fixed, and is particularly preferably 70 to 100%.

柱部材３２は，鞘部材３１の内部空間に挿入される部材であり，上杭１０と下杭２０の継ぎ目を中心にして上下に延びるように配置される。上杭１０と下杭２０を上下に連結して地中に埋設すると，それらの継ぎ目には土圧や水圧に応じた剪断力が加わることとなる。柱部材３２はこの剪断力に耐え得るものを採用すればよい。柱部材３２の断面形状は，鞘部材３１と同様に四角筒状であることが好ましいが，円筒状，五角筒状，六角筒状，その他多角筒状であってもよい。また，柱部材３２は，鞘部材３１と相似形の断面形状を持つものを採用することが好ましいが，鞘部材３１の内部に挿入可能なものであれば，鞘部材３１と異なる断面形状を持つものを利用することもできる。なお，ここでは，柱部材３２としては，鞘部材３１と同様に，一般的な角形鋼管を用いると良い。ただし，柱部材３２の外径サイズは，鞘部材３１の内形サイズ以下とする。また，柱部材３２を鞘部材３１に挿入して，両者の中心軸を揃えたときに，柱部材３２の外面と鞘部材３１の内面の間に多少のクリアランス（隙間）が設けられていると良い。例えばクリアランス幅は，１ｍｍ〜５０ｍｍであることが好ましく，５ｍｍ〜２０ｍｍであることが特に好ましい。柱部材３２は，上杭１０と下杭２０に設けられた鞘部材３１と同じ本数用意すればよい。本実施形態では，４本の柱部材３２が必要となる。 The pillar member 32 is a member inserted into the internal space of the sheath member 31, and is arranged so as to extend vertically about the joint between the upper pile 10 and the lower pile 20. When the upper pile 10 and the lower pile 20 are connected vertically and buried in the ground, a shearing force corresponding to earth pressure or water pressure is applied to the joints thereof. As the column member 32, one that can withstand this shearing force may be adopted. The cross-sectional shape of the pillar member 32 is preferably a square cylinder like the sheath member 31, but may be a cylinder, a pentagon, a hexagon, or any other polygonal cylinder. Further, the pillar member 32 preferably has a cross-sectional shape similar to that of the sheath member 31, but has a cross-sectional shape different from that of the sheath member 31 as long as it can be inserted inside the sheath member 31. You can also use things. Here, as the column member 32, it is preferable to use a general square steel pipe as in the sheath member 31. However, the outer diameter size of the pillar member 32 shall be less than or equal to the inner diameter size of the sheath member 31. Further, when the pillar member 32 is inserted into the sheath member 31 and the central axes of the two are aligned, some clearance (gap) is provided between the outer surface of the pillar member 32 and the inner surface of the sheath member 31. good. For example, the clearance width is preferably 1 mm to 50 mm, and particularly preferably 5 mm to 20 mm. The same number of column members 32 as the sheath members 31 provided on the upper pile 10 and the lower pile 20 may be prepared. In this embodiment, four pillar members 32 are required.

棒状部材３３は，鞘部材３１に差し込まれた状態の柱部材３２をその長手方向に貫通するように配置される部材であり，上杭１０と下杭２０とを連結する方向（すなわち垂直方向）に軸力が付与される。本実施形態において，棒状部材３３として，外表面全体にネジ節を有するネジ節鉄筋が用いられる。また，上杭１０に固定された鞘部材３１の上端部と下杭２０に固定された鞘部材３１の下端部に，それぞれ棒状部材３３（ネジ節鉄筋）が螺合するナットプレート３４が固定されている。このため，上方から下方に向かって棒状部材３３を挿入すると，棒状部材３３は，まず上側のナットプレート３４にねじ込まれ，その後柱部材３２と鞘部材３１の内部空間を通過して，下側のナットプレート３４に到達して再びねじ込まれるようになっている。これにより，棒状部材３３に垂直方向に軸力が付与されて，上杭１０と下杭２０とがより強く締結される。また，棒状部材３３は，上杭１０と下杭２０の継ぎ目を超えて上下に延在するものであるため，柱部材３２と共に上杭１０と下杭２０の継ぎ目に加わる剪断力を負担する。棒状部材３３はこのように使用されるものであるため，棒状部材３３の長さは柱部材３２よりも長くなる。より具体的には，上杭１０に取り付けられた鞘部材３１と下杭２０に取り付けられた鞘部材３１の長さを合わせた長さよりも，棒状部材３３は長いものとなる。 The rod-shaped member 33 is a member arranged so as to penetrate the pillar member 32 inserted into the sheath member 31 in the longitudinal direction thereof, and is a direction (that is, a vertical direction) for connecting the upper pile 10 and the lower pile 20. Axial force is applied to. In the present embodiment, as the rod-shaped member 33, a threaded reinforcing bar having a threaded node on the entire outer surface is used. Further, a nut plate 34 into which a rod-shaped member 33 (screw joint reinforcing bar) is screwed is fixed to the upper end portion of the sheath member 31 fixed to the upper pile 10 and the lower end portion of the sheath member 31 fixed to the lower pile 20. ing. Therefore, when the rod-shaped member 33 is inserted from the upper side to the lower side, the rod-shaped member 33 is first screwed into the upper nut plate 34, then passes through the internal spaces of the pillar member 32 and the sheath member 31, and is on the lower side. It reaches the nut plate 34 and is screwed in again. As a result, an axial force is applied to the rod-shaped member 33 in the vertical direction, and the upper pile 10 and the lower pile 20 are more strongly fastened. Further, since the rod-shaped member 33 extends vertically beyond the joint between the upper pile 10 and the lower pile 20, it bears the shearing force applied to the joint between the upper pile 10 and the lower pile 20 together with the pillar member 32. Since the rod-shaped member 33 is used in this way, the length of the rod-shaped member 33 is longer than that of the pillar member 32. More specifically, the rod-shaped member 33 is longer than the total length of the sheath member 31 attached to the upper pile 10 and the sheath member 31 attached to the lower pile 20.

上記のようにして組み立てられた組合せ構造体１００は，一般的な方法で地中に埋設されて，ＳＭＷ工法等の土留め壁用の芯材として利用できる。また，組合せ構造体１００の上杭１０を撤去する際には，まず，各棒状部材３３（ネジ節鉄筋）を軸回転させながら上方に引き抜き，これにより上杭１０と下杭２０の連結状態を緩める。このとき，地表面をある程度掘削して，棒状部材３３の引き抜きの障害となる土砂を排除してもよい。次に，上杭１０とこれに固定された鞘部材３１を地上へ引き上げ，その後柱部材３２も同様に地上へ引き上げる。最後に，掘削孔を埋め戻して地表面を元に戻す。これにより，地中には下杭２０とこれに固定された鞘部材３１のみが残留することとなる。このようにすれば，上杭１０を撤去する際に，上杭１０と下杭２０の継ぎ目付近まで地表を掘削する必要がなくなるため，上杭１０の撤去作業を迅速かつ効率的に行うことができる。また，本発明では，上杭１０と下杭２０を連結するために垂直方向に延びる棒状部材３３を利用しており，この棒状部材３３の大部分は鞘部材３１及び柱部材３２の内部空間に保管される。このため，棒状部材３３に土砂が直接付着することを抑制でき，棒状部材３３を軸回転させて引き抜き易い状態を維持できる。このように，本発明では上杭１０と下杭２０の連結状態を比較的簡単に解除することができる。 The combined structure 100 assembled as described above can be buried in the ground by a general method and used as a core material for a retaining wall such as the SMW method. Further, when removing the upper pile 10 of the combination structure 100, first, each rod-shaped member 33 (screw joint reinforcing bar) is pulled out upward while rotating about the axis, whereby the connected state of the upper pile 10 and the lower pile 20 is changed. loosen. At this time, the ground surface may be excavated to some extent to remove the earth and sand that hinder the pulling out of the rod-shaped member 33. Next, the upper pile 10 and the sheath member 31 fixed to the upper pile 10 are pulled up to the ground, and then the pillar member 32 is also pulled up to the ground in the same manner. Finally, the excavation hole is backfilled to restore the ground surface. As a result, only the lower pile 20 and the sheath member 31 fixed to the lower pile 20 remain in the ground. In this way, when removing the upper pile 10, it is not necessary to excavate the ground surface near the joint between the upper pile 10 and the lower pile 20, so that the removal work of the upper pile 10 can be performed quickly and efficiently. it can. Further, in the present invention, a rod-shaped member 33 extending in the vertical direction is used to connect the upper pile 10 and the lower pile 20, and most of the rod-shaped member 33 is in the internal space of the sheath member 31 and the pillar member 32. It is stored. Therefore, it is possible to suppress the direct adhesion of earth and sand to the rod-shaped member 33, and it is possible to maintain a state in which the rod-shaped member 33 can be axially rotated to be easily pulled out. As described above, in the present invention, the connected state of the upper pile 10 and the lower pile 20 can be released relatively easily.

図５は，本発明に係る組合せ構造体１００の第２の実施形態を示している。以下の実施形態については，第１の実施形態と同じ構造について説明を割愛し，第１の実施形態と異なる点を中心に説明を行う。図５に示されるように，第２の実施形態は，上杭１０と下杭２０の継ぎ目に補強手段４０を配置するとともに，上杭１０と下杭２０に固定する鞘部材３１の一部をＨ形鋼の中心部分に据えている点で，第１の実施形態と異なる。 FIG. 5 shows a second embodiment of the combination structure 100 according to the present invention. Regarding the following embodiments, the same structure as that of the first embodiment will be omitted from the description, and the description will be focused on the differences from the first embodiment. As shown in FIG. 5, in the second embodiment, the reinforcing means 40 is arranged at the joint between the upper pile 10 and the lower pile 20, and a part of the sheath member 31 fixed to the upper pile 10 and the lower pile 20 is provided. It differs from the first embodiment in that it is installed in the central portion of the H-section steel.

補強手段４０は，上杭１０と下杭２０の継ぎ目に覆設された鋼板４１と，この鋼板４１を上杭１０と下杭２０のフランジプレート１１，２１に取り付けるためのボルト４２及びナット４３で構成されている。このような補強手段４０は，地下構造物を構築する際に掘削する作業空間側に設けると良い。すなわち，Ｈ形鋼からなる各杭１０，２０は，一対のフランジプレート１１，２１を有しており，一方のプレートが作業空間に面し，他方のプレートと土壁と面するように配置される。このとき，作業空間に面するフランジプレート１１，２１に対して補強手段４０を設置すればよい。これにより，補強手段４０を脱着しやすくなる。また，補強手段４０を設けることで，上杭１０と下杭２０の継ぎ目に生じる剪断力に対する組合せ構造体１００全体の強度を高めることができる。 The reinforcing means 40 includes a steel plate 41 overlaid at the joint between the upper pile 10 and the lower pile 20, and bolts 42 and nuts 43 for attaching the steel plate 41 to the flange plates 11 and 21 of the upper pile 10 and the lower pile 20. It is configured. Such a reinforcing means 40 may be provided on the work space side to be excavated when constructing an underground structure. That is, each pile 10 and 20 made of H-shaped steel has a pair of flange plates 11 and 21, and one plate is arranged so as to face the work space and the other plate and the earth wall. To. At this time, the reinforcing means 40 may be installed on the flange plates 11 and 21 facing the work space. This makes it easier to attach and detach the reinforcing means 40. Further, by providing the reinforcing means 40, the strength of the entire combined structure 100 against the shearing force generated at the joint between the upper pile 10 and the lower pile 20 can be increased.

図６は，本発明に係る組合せ構造体１００の第３の実施形態を示している。第３の実施形態では，上杭１０に鞘部材３１が取り付けられておらず，その代わりに，柱部材３２がスペーサ３５を介して上杭１０に固定されている点で，前述した第１の実施形態とは異なる。なお，図６に示した例では，柱部材３２を上杭１０に固定することとしているが，柱部材３２を下杭２０にスペーサ３５を介して固定することも可能である。 FIG. 6 shows a third embodiment of the combination structure 100 according to the present invention. In the third embodiment, the sheath member 31 is not attached to the upper pile 10, and instead, the pillar member 32 is fixed to the upper pile 10 via the spacer 35. Different from the embodiment. In the example shown in FIG. 6, the pillar member 32 is fixed to the upper pile 10, but the pillar member 32 can also be fixed to the lower pile 20 via the spacer 35.

第３の実施形態では，柱部材３２を上杭１０（又は下杭２０）に固定することで，上杭１０に取り付ける鞘部材３１を省略できるため，その分，資材コストを抑えることができる。なお，上杭１０に固定された柱部材３２を下杭２０に固定された鞘部材３１に円滑に挿入できるようにしておく必要があるが，下杭２０の鞘部材３１には厚みがあるため，柱部材３２を上杭１０の内面に直接固定してしまうと，その厚みの分だけ挿入位置がずれて，下杭２０の鞘部材３１に柱部材３２を挿入できなくなる。このため，鞘部材３１には厚みと略同じ厚みのスペーサ３５を上杭１０にまず固定し，そのスペーサ３５に柱部材３２を固定することで，柱部材３２と鞘部材３１の位置ずれを解消することとしている。 In the third embodiment, by fixing the pillar member 32 to the upper pile 10 (or the lower pile 20), the sheath member 31 attached to the upper pile 10 can be omitted, so that the material cost can be suppressed accordingly. It is necessary to make it possible to smoothly insert the pillar member 32 fixed to the upper pile 10 into the sheath member 31 fixed to the lower pile 20, but since the sheath member 31 of the lower pile 20 is thick. If the pillar member 32 is directly fixed to the inner surface of the upper pile 10, the insertion position shifts by the thickness of the pillar member 32, and the pillar member 32 cannot be inserted into the sheath member 31 of the lower pile 20. Therefore, a spacer 35 having a thickness substantially the same as the thickness of the sheath member 31 is first fixed to the upper pile 10, and the pillar member 32 is fixed to the spacer 35 to eliminate the misalignment between the pillar member 32 and the sheath member 31. I'm supposed to do it.

図７は，本発明に係る組合せ構造体１００の第４の実施形態を示している。第４の実施形態は，第３の実施形態の変形例である。第４の実施形態では，第３の実施形態と同様に，上杭１０に鞘部材３１が取り付けずに，その代わりとして，柱部材３２をスペーサ３５を介して上杭１０に固定している。さらに，第４の実施形態では，Ｈ形鋼からなる上杭１０と下杭２０のウェブプレート１２，２２から鞘部材３１や柱部材３２を離間させている。このため，鞘部材３１や柱部材３２とウェブプレート１２，２２との間には一定の空間が生じている。つまり，上杭１０において，柱部材３２はスペーサ３５を介してＨ形鋼のフランジプレート１１に固定され，下杭２０において，鞘部材３１はＨ形鋼のフランジプレート２１に固定されている。 FIG. 7 shows a fourth embodiment of the combination structure 100 according to the present invention. The fourth embodiment is a modification of the third embodiment. In the fourth embodiment, as in the third embodiment, the sheath member 31 is not attached to the upper pile 10, and instead, the pillar member 32 is fixed to the upper pile 10 via the spacer 35. Further, in the fourth embodiment, the sheath member 31 and the column member 32 are separated from the web plates 12 and 22 of the upper pile 10 and the lower pile 20 made of H-shaped steel. Therefore, a certain space is generated between the sheath member 31 or the pillar member 32 and the web plates 12 and 22. That is, in the upper pile 10, the column member 32 is fixed to the flange plate 11 of the H-shaped steel via the spacer 35, and in the lower pile 20, the sheath member 31 is fixed to the flange plate 21 of the H-shaped steel.

ただし，第４の実施形態のように構成した場合，各杭１０，２０と鞘部材３１又は柱部材３２との接合強度が低下する懸念がある。そこで，本実施形態では，各杭１０，２０のウェブプレート１２，２２と鞘部材３１又は柱部材３２とを繋ぐために，断面Ｌ形の抑えプレート３６を設けている。抑えプレート３６は，一面がウェブプレート１２，２２に固定され，これに直交する他面が鞘部材３１又は柱部材３２に固定される。このように，抑えプレート３６を設置して固定強度を向上させることとしてもよい。 However, when configured as in the fourth embodiment, there is a concern that the joint strength between the piles 10 and 20 and the sheath member 31 or the column member 32 may decrease. Therefore, in the present embodiment, a holding plate 36 having an L-shaped cross section is provided in order to connect the web plates 12 and 22 of the piles 10 and 20 to the sheath member 31 or the pillar member 32. One side of the holding plate 36 is fixed to the web plates 12 and 22, and the other side orthogonal to the web plates 12 and 22 is fixed to the sheath member 31 or the pillar member 32. In this way, the holding plate 36 may be installed to improve the fixing strength.

図８は，本発明に係る組合せ構造体１００の第５の実施形態を示している。本実施形態では，鞘部材３１として，角形鋼管の代わりに，断面Ｌ字形のアングル部材を用いている。図８に示されるように，Ｈ形鋼からなる下杭２０には，フランジプレート２１とウェブプレート２２が直交することで４つの角部が形成されているが，アングル部材３１は，４つの角部のそれぞれに固定されている。断面Ｌ字形のアングル部材３１は、フランジプレート２１とウェブプレート２２の両方に接するように配置されてている。このため、アングル部材３１，フランジプレート２１，及びウェブプレート２２によって，上杭１０に固定された柱部材２２を差し込むための空間が画定されている。このようにアングル部材３１を用いることで，例えば図６に示した実施形態のように，上杭１０に柱部材２２を固定する際にスペーサ３５を用いる必要がなくなる。つまり，図８に示した実施形態では，柱部材２２は，スペーサなしで，上杭１０に対して直接固定されている。このように，鞘部材３１は，角形鋼管などの筒状部材に限られず，断面Ｌ字形（あるいは断面コの字形）のアングル部材を用いることも可能である。 FIG. 8 shows a fifth embodiment of the combination structure 100 according to the present invention. In the present embodiment, as the sheath member 31, an angle member having an L-shaped cross section is used instead of the square steel pipe. As shown in FIG. 8, the lower pile 20 made of H-shaped steel has four corners formed by the flange plate 21 and the web plate 22 orthogonal to each other, and the angle member 31 has four corners. It is fixed to each part. The angle member 31 having an L-shaped cross section is arranged so as to be in contact with both the flange plate 21 and the web plate 22. Therefore, the angle member 31, the flange plate 21, and the web plate 22 define a space for inserting the column member 22 fixed to the upper pile 10. By using the angle member 31 in this way, it is not necessary to use the spacer 35 when fixing the column member 22 to the upper pile 10, for example, as in the embodiment shown in FIG. That is, in the embodiment shown in FIG. 8, the column member 22 is directly fixed to the upper pile 10 without a spacer. As described above, the sheath member 31 is not limited to a tubular member such as a square steel pipe, and an angle member having an L-shaped cross section (or a U-shaped cross section) can also be used.

以上，本願明細書では，本発明の内容を表現するために，図面を参照しながら本発明の実施形態の説明を行った。ただし，本発明は，上記実施形態に限定されるものではなく，本願明細書に記載された事項に基づいて当業者が自明な変更形態や改良形態を包含するものである。 As described above, in the specification of the present application, in order to express the content of the present invention, the embodiments of the present invention have been described with reference to the drawings. However, the present invention is not limited to the above embodiment, and includes modifications and improvements which are obvious to those skilled in the art based on the matters described in the present specification.

１０…上杭１１…フランジプレート
１２…ウェブプレート２０…下杭
２１…フランジプレート２２…ウェブプレート
３０…連結手段３１…鞘部材
３２…柱部材３３…棒状部材
３４…ナットプレート３５…スペーサ
３６…抑えプレート４０…補強手段
４１…鋼板４２…ボルト
４３…ナット１００…組合せ構造体 10 ... Upper pile 11 ... Flange plate 12 ... Web plate 20 ... Lower pile 21 ... Flange plate 22 ... Web plate 30 ... Connecting means 31 ... Sheath member 32 ... Pillar member 33 ... Rod-shaped member 34 ... Nut plate 35 ... Spacer 36 ... Suppressor Plate 40 ... Reinforcing means 41 ... Steel plate 42 ... Bolt 43 ... Nut 100 ... Combination structure

Claims

The upper pile (10) and the lower pile (20) are the core material (100) for the earth retaining wall, which is detachably connected by the connecting means (30).
The connecting means (30)
A sheath member (31) attached to one or both of the upper pile and the lower pile, and
A pillar member (32) inserted into the space defined by the sheath member is provided.
The pillar member is inserted into a space defined by the sheath member attached to both the upper pile and the lower pile, or is inserted into the other of the upper pile and the lower pile to which the sheath member is not attached. A fixed core material.

A rod-shaped member (33) that penetrates the pillar member in a state of being inserted into the space defined by the sheath member in the longitudinal direction thereof and applies an axial force in the direction of connecting the pillar member and the sheath member. The core material according to claim 1, further provided.

The core material according to claim 2, wherein the rod-shaped member is a threaded reinforcing bar.

The upper pile and the lower pile are H-shaped steels in which web plates (22, 23) are formed so as to be orthogonal to the surfaces of a pair of flange plates (11, 21) facing each other.
The core according to any one of claims 1 to 3, wherein the sheath member (31) is attached to both sides of one or both of the upper pile and the lower pile, respectively. Material.

A method for constructing an earth retaining wall, which comprises a step of burying the core material (100) according to any one of claims 1 to 4 in the ground.

A step of pulling out the upper pile (10) and the pillar member (32) while leaving the lower pile (20) in the ground among the core materials (100) according to any one of claims 1 to 4. How to remove the upper pile for the earth retaining wall including.