JP2000087350A - Frost heaving relaxation structure - Google Patents
Frost heaving relaxation structureInfo
- Publication number
- JP2000087350A JP2000087350A JP10259020A JP25902098A JP2000087350A JP 2000087350 A JP2000087350 A JP 2000087350A JP 10259020 A JP10259020 A JP 10259020A JP 25902098 A JP25902098 A JP 25902098A JP 2000087350 A JP2000087350 A JP 2000087350A
- Authority
- JP
- Japan
- Prior art keywords
- head
- frost heave
- steel rod
- support plate
- ground
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 77
- 239000010959 steel Substances 0.000 claims abstract description 77
- 230000005489 elastic deformation Effects 0.000 claims abstract description 8
- 230000000116 mitigating effect Effects 0.000 claims description 27
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 claims description 7
- 230000003449 preventive effect Effects 0.000 claims description 3
- 230000000694 effects Effects 0.000 description 3
- 239000002344 surface layer Substances 0.000 description 3
- 230000006835 compression Effects 0.000 description 2
- 238000007906 compression Methods 0.000 description 2
- 239000011440 grout Substances 0.000 description 2
- 239000003112 inhibitor Substances 0.000 description 2
- 229920006311 Urethane elastomer Polymers 0.000 description 1
- 238000004873 anchoring Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000004568 cement Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000035876 healing Effects 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
Landscapes
- Piles And Underground Anchors (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、凍上により定着頭
部背面の地盤が膨張し、アンカーやロックボルト等の定
着力が増大して破断に到ることを防止する凍上緩和構造
に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frost heave mitigation structure for preventing the ground behind the fixing head from expanding due to frost heave and increasing the anchoring force of anchors and lock bolts, etc., thereby preventing the frost heave from breaking. .
【０００２】[0002]
【従来の技術】一般に、掘削した斜面等の地盤の崩壊を
防ぐために施す、いわゆる土留めには、地盤にアンカー
孔を掘削し、このアンカー孔に、アンカーテンドンを挿
入するとともに、端部を地表に引き出した状態とし、次
いで、セメントペースト等のグラウト材をアンカー孔内
に充填して硬化させ、この後、ジャッキにより土留め壁
に反力を取ってアンカーテンドンを緊張・定着させる、
いわゆる地盤アンカー工法が多く用いられている。この
アンカーテンドンとしては、ＰＣ鋼棒やＰＣストランド
が通常用いられている。2. Description of the Related Art Generally, in so-called earth retaining, which is performed to prevent collapse of ground such as excavated slopes, an anchor hole is excavated in the ground, an uncurtain don is inserted into the anchor hole, and an end is grounded. Then, grout material such as cement paste is filled into the anchor hole and hardened, and thereafter, a counter force is applied to the earth retaining wall by a jack to tension and fix the uncurtain don.
The so-called ground anchor method is often used. As this uncurtain don, a PC steel rod or a PC strand is usually used.
【０００３】図４に、アンカー構造の一例を示す。この
図に示すように、地盤１には、断面略円形のアンカー孔
２が地表から傾斜させて削孔されており、アンカー孔２
にはＰＣ鋼棒等の鋼棒３が挿入されている。鋼棒３の下
端側（一端側）は、グラウト等によって地盤１に一体的
に定着、固定されている。そして、鋼棒３の頭部側は、
地盤１の表層に沿って形成された土留め壁５および支圧
板６を貫通して地表に引き出されるとともに、鋼棒３に
螺着する頭部定着具７により支圧板６を介して土留め壁
５に反力を取った状態で緊張、定着されている。FIG. 4 shows an example of an anchor structure. As shown in this figure, an anchor hole 2 having a substantially circular cross section is drilled in the ground 1 so as to be inclined from the surface of the ground.
A steel rod 3 such as a PC steel rod is inserted into the hole. The lower end (one end) of the steel rod 3 is integrally fixed and fixed to the ground 1 by grout or the like. And the head side of the steel bar 3
The earth retaining wall 5 formed along the surface layer of the ground 1 and the retaining plate 6 are drawn out to the surface through the retaining plate 6, and the retaining wall is fixed to the steel rod 3 via the retaining plate 6 by the head fixing device 7 screwed to the steel rod 3. He is nervous and firmly established with a reaction force to 5.
【０００４】鋼棒３の上端および頭部定着具７は、支圧
板６の上面に取付ネジ１０，１０で固定されたヘッドキ
ャップ１１内に形成された貯留空間１２に収納されてい
る。そして、貯留空間１２には、鋼棒３に錆が発生する
ことを防止するために防錆油１３が充填されている。[0004] The upper end of the steel bar 3 and the head fixing device 7 are accommodated in a storage space 12 formed in a head cap 11 fixed to the upper surface of the support plate 6 with mounting screws 10, 10. The storage space 12 is filled with a rust-preventive oil 13 in order to prevent rust from being generated on the steel bar 3.
【０００５】[0005]
【発明が解決しようとする課題】しかしながら、上述し
たようなアンカー構造には、以下のような問題が存在す
る。寒冷地においては、地盤１の表層が凍結して氷の結
晶が膨張することにより地盤面が盛り上がる、いわゆる
凍上が発生する。この凍上が地盤１と土留め壁５との間
に発生すると、土留め壁５が持ち上げられることによ
り、下端側が地盤１に固定された鋼棒３には、支圧板６
および頭部定着具７を介して頭部側に引張する力が働
く。However, the above-described anchor structure has the following problems. In a cold region, the surface layer of the ground 1 freezes and ice crystals expand, so that the ground surface rises, that is, so-called frost heave occurs. When the frost heave occurs between the ground 1 and the retaining wall 5, the retaining wall 5 is lifted, so that the steel rod 3 having the lower end fixed to the ground 1 supports the supporting plate 6.
In addition, a pulling force acts on the head via the head fixing device 7.
【０００６】ところが、この鋼棒３には、頭部定着部７
によって予め緊張力が加えられているので、上記凍上に
よってさらに引張力が加わると、鋼棒３の弾性限度を越
えてしまい所定の有効緊張力が維持できなかったり、凍
上による盛り上がりが大きい場合には、頭部定着部７と
支圧板６との間で鋼棒３が破断してしまうという可能性
もあった。However, the steel rod 3 has a head fixing portion 7.
When a tensile force is further applied by the above-mentioned frost heaving, the elastic limit of the steel bar 3 is exceeded and a predetermined effective tension cannot be maintained. Further, there is a possibility that the steel bar 3 is broken between the head fixing portion 7 and the supporting plate 6.
【０００７】本発明は、以上のような点を考慮してなさ
れたもので、凍上により地盤が盛り上がった際にも、鋼
棒が破断することなく、有効緊張力を維持することので
きる凍上緩和構造を提供することを目的とする。[0007] The present invention has been made in view of the above points, and even when the ground rises due to frost heave, the steel rod is not broken, and the frost heave mitigation can maintain the effective tension. The purpose is to provide a structure.
【０００８】[0008]
【課題を解決するための手段】上記の目的を達成するた
めに本発明は、以下の構成を採用している。請求項１記
載の凍上緩和構造は、鋼棒の一端側が地盤に固定され、
頭部側が支圧板を介して頭部定着具によって前記地盤に
反力を取って緊張、定着され、凍上により前記支圧板お
よび頭部定着具を介して前記鋼棒に加わる緊張力の増加
を緩和する凍上緩和構造であって、前記頭部定着具と支
圧板との間に、弾性復元力により前記鋼棒に前記緊張力
を生じさせる弾性部材が、少なくとも前記地盤の凍上に
より前記支圧板が移動したときの移動長に対応する弾性
変形長を有した状態で介装され、凍上時に前記鋼棒に加
わる緊張力を、前記弾性部材が弾性変形して該緊張力の
増加を緩和することを特徴とするものである。In order to achieve the above object, the present invention employs the following constitution. In the frost heave mitigation structure according to claim 1, one end of the steel rod is fixed to the ground,
The head side is tensioned and fixed by taking a reaction force to the ground by the head fixing device via the support plate, and the increase in the tension applied to the steel rod by the frost heave via the support plate and the head fixing device is reduced. An elastic member that generates the tension on the steel rod by elastic restoring force between the head fixing device and the support plate, the support plate moves at least due to frost heave of the ground. The elastic member is interposed in a state having an elastic deformation length corresponding to the moving length when the steel rod is frozen, and the elastic member elastically deforms the tension applied to the steel rod at the time of frosting, thereby reducing the increase in the tension. It is assumed that.
【０００９】従って、本発明の凍上緩和構造では、常態
において、鋼棒の頭部側が弾性部材の弾性復元力により
地盤に反力を取った状態で緊張、定着される。そして、
凍上時に支圧板が頭部側に移動すると弾性部材が弾性変
形する。これにより、頭部定着具を介して鋼棒が支圧板
の移動長分、引張されることを防止する。Therefore, in the frost heave mitigation structure of the present invention, under normal conditions, the head side of the steel rod is tensioned and fixed in a state where it takes a reaction force on the ground due to the elastic restoring force of the elastic member. And
When the support plate moves toward the head during frost heaving, the elastic member is elastically deformed. This prevents the steel bar from being pulled by the moving length of the support plate via the head fixing device.
【００１０】請求項２記載の凍上緩和構造は、請求項１
記載の凍上緩和構造において、前記支圧板の背面側に
は、前記頭部側に開口して前記弾性部材を収容する有底
円筒状の円筒部が設けられ、該円筒部は、前記鋼棒の一
端側が挿入されるアンカー孔内に配置されていることを
特徴とするものである。The frost heave mitigation structure according to the second aspect is the first aspect.
In the frost heave mitigation structure described in the above, on the back side of the support plate, there is provided a bottomed cylindrical portion that opens to the head side and accommodates the elastic member, and the cylindrical portion is formed of the steel rod. The one end side is arranged in an anchor hole to be inserted.
【００１１】従って、本発明の凍上緩和構造では、円筒
部に収容された弾性部材の一端側がアンカー孔内に位置
することになるので、弾性部材の頭部側が地盤から突出
する量を小さくすることができる。Therefore, in the frost heave mitigation structure of the present invention, since one end of the elastic member housed in the cylindrical portion is located in the anchor hole, the amount by which the head side of the elastic member protrudes from the ground is reduced. Can be.
【００１２】請求項３記載の凍上緩和構造は、請求項１
または２記載の凍上緩和構造において、前記支圧板の頭
部側には、防錆剤貯留用のヘッドキャップを装着するた
めの突部が前記支圧板から立設され、前記鋼棒の前記頭
部側端縁と、前記突部の前記頭部側端縁との間の距離変
化により、前記凍上による移動長が測定されることを特
徴とするものである。According to a third aspect of the present invention, a frost heave mitigation structure is provided.
In the frost heave mitigation structure described in Item 2 or 2, a protrusion for mounting a head cap for storing a rust preventive agent is provided upright on the head side of the support plate from the support plate, and the head of the steel rod is provided. The movement length due to frost heave is measured based on a change in distance between a side edge and the edge of the protrusion on the head side.
【００１３】従って、本発明の凍上緩和構造では、凍上
が発生しても、一端が地盤に固定された鋼棒の頭部側端
縁は移動しないが、支圧板は上記頭部側へ凍上厚さ分移
動する。そのため、鋼棒の頭部側端縁と、支圧板の突部
の頭部側端縁との間の距離変化により、凍上による移動
長を測定することができる。Therefore, in the frost heave mitigation structure of the present invention, even when frost heave occurs, the head side edge of the steel rod having one end fixed to the ground does not move, but the supporting plate moves to the above head side to the frost heave thickness. Move a distance. Therefore, the movement length due to frost heave can be measured by a change in the distance between the head-side edge of the steel bar and the head-side edge of the protrusion of the support plate.
【００１４】[0014]
【発明の実施の形態】以下、本発明の凍上緩和構造の実
施の形態を、図１および図２を参照して説明する。これ
らの図において、従来例として示した図４と同一の構成
要素には同一符号を付し、その説明を簡略化する。図１
に示すように、土留め壁５の表面には、鋼棒３の緊張力
を支圧する支圧板１８が配置されている。支圧板１８の
背面側には、頭部側に開口する有底円筒状の円筒部２５
がアンカー孔２内に位置するように突設されている。円
筒部２５の底部２８には、鋼棒３が貫通する貫通孔２９
が形成されている。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a frost heave relaxation structure according to the present invention will be described below with reference to FIGS. In these drawings, the same components as those in FIG. 4 shown as a conventional example are denoted by the same reference numerals, and description thereof will be simplified. FIG.
As shown in the figure, a support plate 18 for supporting the tension of the steel bar 3 is arranged on the surface of the retaining wall 5. On the back side of the support plate 18, a cylindrical portion 25 having a bottomed cylindrical shape and opening to the head side.
Are provided so as to be located in the anchor hole 2. A through hole 29 through which the steel bar 3 passes is formed in the bottom portion 28 of the cylindrical portion 25.
Are formed.
【００１５】また、支圧板１８の頭部側には、外周に雄
ネジが形成された突部３０が立設されている。この突部
３０には、ヘッドキャップ２１が支圧板１８との間にＯ
リング３２を介して螺着している。ヘッドキャップ２１
の内部には、鋼棒３を防錆する防錆剤が貯留される貯留
空間３１が鋼棒３の頭部側を収納するように形成されて
いる。On the head side of the support plate 18, a protrusion 30 having an external thread formed on the outer periphery is provided upright. The head cap 21 has an O.sub.
It is screwed via a ring 32. Head cap 21
Is formed with a storage space 31 in which a rust inhibitor for preventing rust of the steel rod 3 is stored to accommodate the head side of the steel rod 3.
【００１６】鋼棒３の頭部側には、頭部定着具７が螺着
しており、頭部定着具７の下端にはカラー１９が配置さ
れている。カラー１９には、鋼棒３が挿通する挿通孔２
２と、背面側に向けて開口する段部２３とが形成されて
いる。そして、頭部定着具７と支圧板１８との間には、
カラー１９を介してコイルスプリング（弾性部材）２０
が介装されている。A head fixing device 7 is screwed to the head side of the steel bar 3, and a collar 19 is disposed at a lower end of the head fixing device 7. The collar 19 has an insertion hole 2 through which the steel rod 3 is inserted.
2 and a step 23 that opens toward the back side. And, between the head fixing device 7 and the supporting plate 18,
Coil spring (elastic member) 20 through collar 19
Is interposed.
【００１７】コイルスプリング２０は、頭部側がカラー
１９の段部２３に、背面側が支圧板１８の円筒部２５の
底部２８に圧縮状態で係合した状態で支圧板１８の円筒
部２５内に収容されているコイルスプリング２０のバネ
定数は、鋼棒３の有効緊張力を出力可能、且つ鋼棒３の
引張り強度に対して十分小さくなるように設定されてい
る。The coil spring 20 is housed in the cylindrical portion 25 of the support plate 18 in a state where the head side is engaged with the step portion 23 of the collar 19 and the back side is engaged with the bottom portion 28 of the cylindrical portion 25 of the support plate 18 in a compressed state. The spring constant of the coil spring 20 is set so that the effective tension of the steel bar 3 can be output and the tensile strength of the steel bar 3 is sufficiently small.
【００１８】すなわち、鋼棒３の断面積をＡ、自由長を
Ｌ、ヤング係数をＥとすると、引張り荷重Ｐと伸びλの
関係は次式で表される。 Ｐ＝λ×（Ａ×Ｅ／Ｌ） …（１） この式における（Ａ×Ｅ／Ｌ）は、バネ定数に相当して
おり、コイルスプリング２０のバネ定数は鋼棒３の（Ａ
×Ｅ／Ｌ）で算出される値よりも十分小さく設定されて
いる。また、コイルスプリング２０は、凍上が発生して
いない常時には所定の常時設計力が、凍上が発生してコ
イルスプリング２０が所定量撓んだ時には所定の凍上時
設計力が鋼棒３に伝達されるように、バネ定数および圧
縮量が設定されている。That is, if the sectional area of the steel rod 3 is A, the free length is L, and the Young's modulus is E, the relationship between the tensile load P and the elongation λ is expressed by the following equation. P = λ × (A × E / L) (1) In this equation, (A × E / L) corresponds to the spring constant, and the spring constant of the coil spring 20 is (A) of the steel rod 3.
× E / L). The coil spring 20 transmits a predetermined design force to the steel rod 3 when frost heave occurs and a predetermined constant design force when the frost heave occurs and the coil spring 20 is bent by a predetermined amount. Thus, the spring constant and the amount of compression are set.
【００１９】上記の構成の凍上緩和構造の作用について
以下に説明する。図２に示すように、凍上により地盤１
の表層に、例えば厚さＬ１の凍上部１ａが発生すると、
土留め壁５、支圧板１８、ヘッドキャップ２１もこれに
追従して頭部側へ移動する。これにより、支圧板１８の
底部２８も頭部側へ移動するが、下端側が凍上の発生し
ていない地盤１に固定されている鋼棒３は移動しない。
従って、カラー１９と底部２８とが長さＬ１接近するこ
とになり、コイルスプリング２０が長さＬ１だけ弾性変
形して圧縮される。The operation of the frost heave mitigation structure having the above configuration will be described below. As shown in FIG.
For example, when a frozen portion 1a having a thickness L1 occurs on the surface layer of
The retaining wall 5, the support plate 18, and the head cap 21 also follow this and move toward the head. Accordingly, the bottom portion 28 of the support plate 18 also moves to the head side, but the steel bar 3 fixed to the ground 1 at which the lower end side does not have frost formation does not move.
Therefore, the collar 19 and the bottom portion 28 approach the length L1, and the coil spring 20 is elastically deformed by the length L1 and compressed.
【００２０】この圧縮によりコイルスプリング２０の弾
性復元力がバネ定数に長さＬ１を乗じた量増加して、鋼
棒３にはカラー１９、頭部定着具７を介して緊張力が増
す方向への荷重が加わる。すなわち、凍上前に常時設計
力が作用していた鋼棒３には、凍上によって所定の凍上
時設計力が伝達されることになる。しかしながら、コイ
ルスプリング２０のバネ定数が鋼棒３と比較して十分小
さいため、この荷重を鋼棒３の引張り強度に対して十分
小さい弾性範囲内に抑えることができる。Due to this compression, the elastic restoring force of the coil spring 20 increases by an amount obtained by multiplying the spring constant by the length L 1, and the tension is increased in the steel rod 3 via the collar 19 and the head fixing device 7. Load is applied. That is, a predetermined design force at the time of frost heaving is transmitted to the steel rod 3 to which the design force has always acted before the frost heaving. However, since the spring constant of the coil spring 20 is sufficiently smaller than that of the steel rod 3, this load can be suppressed within an elastic range sufficiently smaller than the tensile strength of the steel rod 3.
【００２１】一方、図２に示すように、凍上前の鋼棒３
の頭部側端縁と突部３０の頭部側端縁との距離は長さＬ
３であるが、凍上後の鋼棒３の頭部側端縁と突部３０の
頭部側端縁との距離は長さＬ２に変化する。したがっ
て、上記の長さＬ２、Ｌ３を測定して、これらの差を算
出することにより、支圧板１８の移動長、すなわち、凍
上部１ａの厚さＬ１を求めることができ、さらに、既知
のコイルスプリング２０のバネ定数に厚さＬ１を乗じる
ことにより、凍上により鋼棒３に加わった荷重も求める
ことができる。On the other hand, as shown in FIG.
The distance between the head-side edge of the projection 30 and the head-side edge of the protrusion 30 is a length L.
However, the distance between the head-side edge of the steel bar 3 after frost heave and the head-side edge of the protrusion 30 changes to the length L2. Therefore, by measuring the lengths L2 and L3 and calculating the difference between them, the moving length of the support plate 18, that is, the thickness L1 of the frozen part 1a can be obtained. By multiplying the spring constant of the spring 20 by the thickness L1, the load applied to the steel bar 3 by frost heave can also be obtained.
【００２２】本実施の形態の凍上緩和構造では、コイル
スプリング２０がその弾性復元力により鋼棒３を緊張、
定着させることができるとともに、凍上により支圧板１
８が長さＬ１移動しても、コイルスプリング２０が弾性
変形してこの移動量を吸収するため、鋼棒３にはこの移
動が伝達されない。そのため、鋼棒３に加わる緊張力
を、鋼棒３の引張りによる多大なものではなく、これよ
りも数十分の一程度の大きさであるコイルスプリング２
０の弾性変形によるものに大幅に緩和することができる
ので、緊張力が弾性限度を限度を越えて所定の有効緊張
力を維持できなくなったり、鋼棒３自体が破断してしま
うことを防止できる。また、上記のように、凍上時、コ
イルスプリング２０の弾性変形よる荷重が鋼棒３に加わ
っても、この荷重は所定の凍上時設計力なので、鋼棒３
は適正な有効緊張力を維持することができる。In the frost heave mitigation structure of the present embodiment, the coil spring 20 tensions the steel bar 3 by its elastic restoring force.
Fixing plate 1
Even if the length 8 moves by the length L1, the coil spring 20 elastically deforms and absorbs the moving amount, so that the movement is not transmitted to the steel rod 3. For this reason, the tension applied to the steel bar 3 is not so great as to be caused by the tension of the steel bar 3, but is about several tenths larger than this.
Since the elastic deformation can be greatly reduced to zero, it is possible to prevent the tension from exceeding the elastic limit and maintaining the predetermined effective tension, or preventing the steel rod 3 itself from breaking. . Further, as described above, even when a load due to the elastic deformation of the coil spring 20 is applied to the steel bar 3 during frost heaving, the load is a predetermined design force during frost heaving.
Can maintain proper effective tension.
【００２３】また、本実施の形態の凍上緩和構造では、
鋼棒３の頭部側端縁と突部３０の頭部側端縁との距離を
測定するだけで、土留め壁５の背面側で発生するため通
常目視できない凍上の有無や、凍上厚さ、さらには、凍
上により鋼棒３に加わった荷重も容易に確認することが
できる。さらに、本実施の形態の凍上緩和構造では、コ
イルスプリング２０を収容する支圧板１８の円筒部２５
がアンカー孔内に配置されているので、地表に突出する
鋼棒３の長さも短くすることができ、外観性も向上す
る。加えて、本構造では、鋼棒３、頭部定着具７および
コイルスプリング２０がヘッドキャップ２１に内蔵され
て防錆剤に浸漬されるので、これらを長期間防錆するこ
ともでき、従って凍上による事故も長期間防止すること
ができる。Also, in the frost heave mitigation structure of the present embodiment,
Just by measuring the distance between the head-side edge of the steel rod 3 and the head-side edge of the protrusion 30, it is generated on the back side of the retaining wall 5 and cannot be visually observed. Further, the load applied to the steel bar 3 by frost heave can be easily confirmed. Further, in the frost heave mitigation structure of the present embodiment, the cylindrical portion 25 of the support plate 18 that accommodates the coil spring 20 is provided.
Are arranged in the anchor hole, so that the length of the steel rod 3 projecting to the ground surface can be shortened, and the appearance is improved. In addition, in this structure, since the steel rod 3, the head fixing device 7 and the coil spring 20 are built in the head cap 21 and immersed in the rust preventive, they can be rust-proofed for a long period of time. Can be prevented for a long time.
【００２４】なお、上記実施の形態において、弾性部材
をコイルスプリングとする構成としたが、これに限られ
ることなく、皿バネやウレタンゴム等の弾性部材であっ
てもよい。また鋼棒としては、ＰＣ鋼棒や異形ＰＣ鋼棒
や図３に示すように、異形丸鋼にネジを形成したもの、
さらにロックボルトを用いる構成であってもよい。In the above embodiment, the elastic member is a coil spring. However, the present invention is not limited to this, and may be an elastic member such as a disc spring or urethane rubber. As the steel rod, a PC steel rod, a deformed PC steel rod, or a screw formed on a deformed round steel as shown in FIG.
Further, a configuration using a lock bolt may be employed.
【００２５】[0025]
【発明の効果】以上説明したように、請求項１に係る凍
上緩和構造は、頭部定着具と支圧板との間に、弾性復元
力により鋼棒に緊張力を生じさせる弾性部材が介装さ
れ、凍上時に鋼棒に加わる緊張力を弾性部材が弾性変形
して緊張力の増加を緩和する構成となっている。これに
より、この凍上緩和構造では、地山の凍結等が発生する
寒冷地で、凍結上昇が発生しても、鋼棒の有効緊張力を
保ち、また凍上による鋼棒の破断事故を防止できるとい
う効果が得られる。As described above, in the frost heave mitigation structure according to the first aspect, the elastic member for generating the tension on the steel rod by the elastic restoring force is interposed between the head fixing device and the supporting plate. The elastic member elastically deforms the tension applied to the steel rod during frost heaving, thereby reducing the increase in the tension. As a result, the frost heave mitigation structure can maintain the effective tension of the steel rod and prevent the steel rod from being broken due to frost heave even in a cold area where the ground freezes, etc. The effect is obtained.
【００２６】請求項２に係る凍上緩和構造は、支圧板の
背面側に弾性部材を収容する円筒部が設けられ、この円
筒部がアンカー孔内に配置される構成となっている。こ
れにより、この凍上緩和構造では、地表に突出する鋼棒
の長さも短くすることができ、外観性が向上するという
効果が得られる。According to a second aspect of the present invention, the frost heave mitigation structure has a configuration in which a cylindrical portion for accommodating an elastic member is provided on the back side of the support plate, and the cylindrical portion is disposed in the anchor hole. Thus, in the frost heave mitigation structure, the length of the steel rod projecting to the surface of the ground can be shortened, and the effect of improving the appearance can be obtained.
【００２７】請求項３に係る凍上緩和構造は、防錆剤貯
留用のヘッドキャップが装着される突部が立設され、鋼
棒の頭部側端縁と突部の頭部側端縁との間の距離変化に
より、凍上による移動長が測定される構成となってい
る。これにより、この凍上緩和構造では、鋼棒、弾性部
材等を長期間防錆することができるので、凍上による事
故も長期間防止することができるとともに、通常目視で
きない凍上の有無や、凍上厚さ、さらには凍上により鋼
棒に加わる荷重も容易に確認できるという効果が得られ
る。According to a third aspect of the present invention, there is provided a frost healing mitigation structure in which a projection for mounting a head cap for storing a rust inhibitor is erected, and a head-side edge of a steel rod and a head-side edge of the projection are provided. The movement length due to frost heave is measured by the change in distance between. Thus, in this frost heave mitigation structure, steel rods, elastic members, etc. can be rust-proofed for a long period of time, so that accidents due to frost heave can be prevented for a long period of time. Further, an effect is obtained that the load applied to the steel bar due to frost heave can be easily confirmed.
【図１】 本発明の実施の形態を示す図であって、支圧
板と頭部定着具との間にコイルスプリングが介装された
断面図である。FIG. 1 is a view showing an embodiment of the present invention, and is a cross-sectional view in which a coil spring is interposed between a supporting plate and a head fixing device.
【図２】 本発明の実施の形態を示す図であって、凍上
によりコイルスプリングが弾性変形した断面図である。FIG. 2 is a view showing the embodiment of the present invention, and is a cross-sectional view in which a coil spring is elastically deformed by frost heave.
【図３】 本発明の実施の形態を示す図であって、鋼棒
として異形丸鋼が用いられた断面図である。FIG. 3 is a view showing an embodiment of the present invention, and is a cross-sectional view in which a deformed round bar is used as a steel rod.
【図４】 従来技術による凍上緩和構造の一例を示す断
面図である。FIG. 4 is a cross-sectional view showing an example of a frost heave mitigation structure according to the related art.
１ 地盤 ２ アンカー孔 ３ 鋼棒 ７ 頭部定着具 １８ 支圧板 ２０ コイルスプリング（弾性部材） ２１ ヘッドキャップ ２５ 円筒部 ３０ 突部 DESCRIPTION OF SYMBOLS 1 Ground 2 Anchor hole 3 Steel rod 7 Head fixing device 18 Support plate 20 Coil spring (elastic member) 21 Head cap 25 Cylindrical part 30 Projection
Claims (3)
が支圧板を介して頭部定着具によって前記地盤に反力を
取って緊張、定着され、 凍上により前記支圧板および頭部定着具を介して前記鋼
棒に加わる緊張力の増加を緩和する凍上緩和構造であっ
て、 前記頭部定着具と支圧板との間に、弾性復元力により前
記鋼棒に前記緊張力を生じさせる弾性部材が、少なくと
も前記地盤の凍上により前記支圧板が移動したときの移
動長に対応する弾性変形長を有した状態で介装され、 凍上時に前記鋼棒に加わる緊張力を、前記弾性部材が弾
性変形して該緊張力の増加を緩和することを特徴とする
凍上緩和構造。1. One end of a steel rod is fixed to the ground, and the head side is tensioned and fixed by receiving a reaction force on the ground by a head fixing tool via a support plate, and the support plate and the head fixing by frost heave. A frost heave mitigation structure for alleviating an increase in tension applied to the steel rod via a tool, wherein the tension is generated in the steel rod by an elastic restoring force between the head fixing tool and the support plate. An elastic member is interposed at least in a state having an elastic deformation length corresponding to a moving length when the supporting plate moves due to frost heaving of the ground, and the elastic member exerts a tension applied to the steel rod during frost heaving. A frost heave mitigation structure characterized by elastic deformation to mitigate the increase in the tension.
性部材を収容する有底円筒状の円筒部が設けられ、 該円筒部は、前記鋼棒の一端側が挿入されるアンカー孔
内に配置されていることを特徴とする凍上緩和構造。2. The frost heave mitigation structure according to claim 1, wherein a bottomed cylindrical portion which is open to the head side and accommodates the elastic member is provided on the back side of the support plate. The frost heave mitigation structure, wherein the cylindrical portion is disposed in an anchor hole into which one end of the steel rod is inserted.
おいて、 前記支圧板の頭部側には、防錆剤貯留用のヘッドキャッ
プを装着するための突部が前記支圧板から立設され、 前記鋼棒の前記頭部側端縁と、前記突部の前記頭部側端
縁との間の距離変化により、前記凍上による移動長が測
定されることを特徴とする凍上緩和構造。3. The frost heave mitigation structure according to claim 1, wherein a protrusion for mounting a head cap for storing a rust preventive agent is provided upright on the head side of the support plate from the support plate. The frost heave mitigation structure, wherein a movement length due to the frost heave is measured by a change in a distance between the head side edge of the steel bar and the head side edge of the protrusion.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP25902098A JP3920471B2 (en) | 1998-09-11 | 1998-09-11 | Frost heave mitigation structure |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP25902098A JP3920471B2 (en) | 1998-09-11 | 1998-09-11 | Frost heave mitigation structure |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2000087350A true JP2000087350A (en) | 2000-03-28 |
| JP3920471B2 JP3920471B2 (en) | 2007-05-30 |
Family
ID=17328245
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP25902098A Expired - Fee Related JP3920471B2 (en) | 1998-09-11 | 1998-09-11 | Frost heave mitigation structure |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3920471B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002146793A (en) * | 2000-11-10 | 2002-05-22 | Arai Gumi Ltd | Load-introducing reinforced earth method and load- introducing reinforced earth structure |
| KR101370954B1 (en) * | 2013-04-04 | 2014-03-10 | (주) 효창이엔지 | Site surface pressure reinforced structure and method associated soil nailing |
| KR102643714B1 (en) * | 2023-07-12 | 2024-03-05 | 주식회사 에스와이텍 | Thread bar coupling device, seismic pile having the same and construction method for seismic pile |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109884112B (en) * | 2019-03-28 | 2021-07-23 | 哈尔滨工业大学 | Detection method realized by soil frost heaving detection device without external power supply |
-
1998
- 1998-09-11 JP JP25902098A patent/JP3920471B2/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002146793A (en) * | 2000-11-10 | 2002-05-22 | Arai Gumi Ltd | Load-introducing reinforced earth method and load- introducing reinforced earth structure |
| KR101370954B1 (en) * | 2013-04-04 | 2014-03-10 | (주) 효창이엔지 | Site surface pressure reinforced structure and method associated soil nailing |
| KR102643714B1 (en) * | 2023-07-12 | 2024-03-05 | 주식회사 에스와이텍 | Thread bar coupling device, seismic pile having the same and construction method for seismic pile |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3920471B2 (en) | 2007-05-30 |
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