JP7396331B2 - Improvement structure of existing quay wall and construction method of the improvement structure - Google Patents

Improvement structure of existing quay wall and construction method of the improvement structure Download PDF

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JP7396331B2
JP7396331B2 JP2021104555A JP2021104555A JP7396331B2 JP 7396331 B2 JP7396331 B2 JP 7396331B2 JP 2021104555 A JP2021104555 A JP 2021104555A JP 2021104555 A JP2021104555 A JP 2021104555A JP 7396331 B2 JP7396331 B2 JP 7396331B2
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進吾 粟津
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Description

本発明は、既存岸壁における既存壁体の水域側に設けられて既存岸壁を改良する既存岸壁の改良構造及びその施工方法に関する。
なお、本明細書における岸壁には、直立壁を有する矢板式岸壁、重力式岸壁、セル式岸壁等の船舶の接岸機能を有するものの他、同様の直立壁を有して船舶の接岸機能を有していない護岸や、同様の直立壁を有した防波堤も含む。 The present invention relates to an improved structure for an existing quay that is installed on the water side of an existing wall to improve the existing quay, and a method for constructing the same.
Note that in this specification, quays include those that have a berthing function for ships, such as sheet pile type berths, gravity type berths, and cell type berths that have upright walls, as well as those that have similar upright walls and have a berthing function for ships. It also includes breakwaters with unconstructed seawalls and similar upright walls.

既存岸壁として矢板式岸壁を例に挙げて以下説明する。
既存の矢板式岸壁４１としては、図２２に示すように、複数の矢板を水底地盤４３に打設して形成した既存壁体４５の上端の上部工４７を陸上部４８に設け、この上部工４７と控え工４９をタイ材５１で連結して支持するようにしたものがある。 An explanation will be given below using a sheet pile type quay as an example of an existing quay.
As shown in FIG. 22, the existing sheet pile type quay 41 has a superstructure 47 at the upper end of an existing wall 45 formed by driving a plurality of sheet piles into the underwater ground 43, and is installed on the land portion 48. 47 and a support work 49 are connected and supported by a tie material 51.

このような矢板式岸壁４１においては、例えば、改訂された港湾基準への対応、耐震性向上、エプロン上の上載荷重の増加、船舶の大型化に伴う岸壁水深の増深、既存構造の劣化対応、供用期間の延長等の要因により補強等の改良が必要となる場合がある。この場合、港湾計画への影響を最小限とするため、岸壁法線の水域側への前出しは、なるべく小さく（できれば無し）することが望ましい。 For such a sheet pile type quay 41, for example, it is necessary to comply with revised port standards, improve seismic resistance, increase the overload on the apron, increase the depth of the quay due to the increase in the size of ships, and cope with deterioration of the existing structure. Improvements such as reinforcement may be required due to factors such as extension of service life. In this case, in order to minimize the impact on port planning, it is desirable to minimize (preferably eliminate) the extension of the normal line of the quay toward the water area.

既存の矢板式岸壁の改良構造の例としては、例えば特許文献１に開示された、「既設岸壁の改修補強構造」がある。
同文献に開示の「既設岸壁の改修補強構造」は、「矢板壁をタイ材を介して控え工で支持してなる既設岸壁の改修補強構造であって、既設控え工の反岸壁側に、該既設控え工から離間されて独立して設けられ、下端部が所定深度まで立て込まれた新設控え工と、該新設控え工の頭部から既設矢板壁の所定位置に向けて斜め下方に延設されて、両端が該新設控え工と既設矢板壁とに止着された新設のタイ材と、を有し、
前記新設控え工は、鋼管内にコンクリートを充填されて形成される鋼管杭であるとともに、前記既設控え工に沿って適宜間隔を空けて複数配設され、前記新設タイ材は、前記鋼管杭から放射状に複数設けられている、ことを特徴とする」（請求項４参照）ものである。 An example of an improved structure for an existing sheet pile type quay is the "Renovation and Reinforcement Structure for an Existing Quay" disclosed in Patent Document 1, for example.
The ``renovation and reinforcement structure for an existing quay'' disclosed in the same document is a ``renovation and reinforcement structure for an existing quay in which a sheet pile wall is supported by a support work through tie materials, and on the side opposite to the quay wall of the existing support work, A new buttress is installed separately and separated from the existing support, and its lower end is built up to a predetermined depth, and the new support works extends diagonally downward from the head of the new support to a predetermined position on the existing sheet pile wall. and a newly installed tie material having both ends fixed to the newly installed buttress and the existing sheet pile wall,
The new construction tie material is a steel pipe pile formed by filling a steel pipe with concrete, and a plurality of the new construction tie materials are arranged at appropriate intervals along the existing construction construction, and the new tie material is separated from the steel pipe pile. (see claim 4).

この方法によると、既設の矢板壁との係止位置を任意に設置可能であり、かつ矢板壁に発生する曲げモーメントを低減できるため、改良方法として有効な方法である。 According to this method, the locking position with the existing sheet pile wall can be set arbitrarily, and the bending moment generated in the sheet pile wall can be reduced, so it is an effective method as an improvement method.

また、特許文献２に開示された「既設矢板岸壁の補強構造」では、既設矢板壁の水域側に頭部にＬ形構造物を有する杭式構造物を設置し、Ｌ形構造物と既存矢板壁と一体化することで補強する構造が提案されている。この方法によると、既存矢板壁の水域側のみを改良する補強構造なので、陸上部での施工が制限される場合でも適用ができる。 In addition, in the "reinforcement structure for existing sheet pile quay wall" disclosed in Patent Document 2, a pile type structure having an L-shaped structure at the head is installed on the water side of the existing sheet pile wall, and the L-shaped structure and the existing sheet pile A structure has been proposed that is reinforced by integrating with the wall. According to this method, the reinforcement structure improves only the water side of the existing sheet pile wall, so it can be applied even when construction on land is restricted.

特許第４８７６９９１号公報Patent No. 4876991 特許第５３４７８９８号公報Patent No. 5347898

特許文献１に開示の構造は、工事における岸壁占有期間の短縮化を図ることを目的の一つとしており、それ故に陸側に新設の控え工を設置することが必須となっている。
しかしながら、既存の矢板式岸壁の改良工事においては、陸域側での施工が制限される場合もあり、このような場合には適用できないという問題がある。
また、新設タイ材が、鋼管杭から放射状に複数設けられていることから、タイ材の張力管理が難しいという問題もある。 One of the purposes of the structure disclosed in Patent Document 1 is to shorten the quay occupancy period during construction, and therefore it is essential to install a new support work on the land side.
However, in the improvement work of an existing sheet pile type quay, there are cases where construction on the land side is restricted, and there is a problem that it cannot be applied in such cases.
Furthermore, since a plurality of new ties are installed radially from the steel pipe pile, there is also the problem that it is difficult to manage the tension of the ties.

上記の説明は既存岸壁が矢板式岸壁を例に挙げたが、既存岸壁にはケーソンを用いた重力式岸壁やセル式岸壁等の直立壁を有するものがあり、この場合においても、陸上部での施工が制限される場合があり、同様の問題がある。 The above explanation uses an example where the existing quay is a sheet pile type quay, but there are also existing quays that have upright walls such as gravity type quays using caissons and cell type quays, and even in this case, it is possible to There are similar problems in that construction may be restricted.

特許文献２に開示の構造は、陸域側の施工は必要ないが、補強効果を発揮するためには既存矢板壁とＬ形構造物とを一体化させる必要がある。これは、水底地盤近くの浅い地盤内では、地震時に土が杭の間をすり抜けて流動するため、Ｌ形構造物と既存矢板壁を一体化しなければ既存矢板壁の変形を抑えることができないためである。一体化のためには、既存矢板壁に水中スタッド溶接を多量に行う必要があり、施工コストが高額になるとともに、溶接による矢板壁の脆化が懸念されるという問題がある。
また、既存壁体への溶接が必要という点から、ケーソンを用いた重力式岸壁等のコンクリートによる直立壁には適用できない。 The structure disclosed in Patent Document 2 does not require construction on the land side, but in order to exhibit a reinforcing effect, it is necessary to integrate the existing sheet pile wall and the L-shaped structure. This is because in the shallow ground near the underwater ground, soil slips between the piles and flows during an earthquake, so deformation of the existing sheet pile wall cannot be suppressed unless the L-shaped structure and the existing sheet pile wall are integrated. It is. In order to integrate, it is necessary to perform a large amount of underwater stud welding to the existing sheet pile wall, which raises the problem of high construction costs and concerns that the sheet pile wall may become brittle due to welding.
Furthermore, since it requires welding to the existing wall, it cannot be applied to vertical concrete walls such as gravity type quays using caissons.

本発明はかかる課題を解決するためになされたものであり、陸上部での施工が制限される場合にも適用可能な既存岸壁の改良構造及び該改良構造の施工方法を提供することを目的としている。 The present invention has been made to solve such problems, and aims to provide an improved structure for existing quay walls and a construction method for the improved structure, which can be applied even when construction on land is restricted. There is.

（１）本発明に係る既存岸壁の改良構造は、周壁面部と通水口が設けられた天面部と複数の杭挿通孔とを有し、既存岸壁における既存壁体の水域側の水底地盤に配設された箱状構造体と、
該箱状構造体の前記杭挿通孔に挿通されて、前記水底地盤に打設された複数の杭と、
前記杭挿通孔と前記杭との隙間に配設された間詰材と、
前記既存壁体と前記箱状構造体との間に配設されて前記既存壁体からの水平力を前記箱状構造体に伝達する水平力伝達部材と、を備えたことを特徴とするものである。 (1) The improved structure of an existing quay wall according to the present invention has a peripheral wall surface portion, a top surface portion provided with a water inlet, and a plurality of pile insertion holes, and is attached to the water bottom ground on the water body side of the existing wall body of the existing quay wall. A box-like structure arranged,
a plurality of piles inserted into the pile insertion holes of the box-like structure and driven into the underwater ground;
a filler material disposed in a gap between the pile insertion hole and the pile;
A horizontal force transmitting member disposed between the existing wall and the box-like structure to transmit horizontal force from the existing wall to the box-like structure. It is.

（２）また、上記（１）に記載のものにおいて、前記杭は、前記杭挿通孔の下端から鋼管直径３倍以上の長さの範囲において、降伏強度400N/mm2以上及び／又は鋼管杭の外径R(mm)と鋼管杭の肉厚t(mm)との比R/tがR/t≦80であることを特徴とするものである。 (2) In addition, in the item described in (1) above, the pile has a yield strength of 400 N/mm 2 or more and/or a steel pipe pile in a length range of 3 times or more the steel pipe diameter from the lower end of the pile insertion hole. The ratio R/t of the outer diameter R (mm) of the steel pipe pile to the wall thickness t (mm) of the steel pipe pile is R/t≦80.

（３）また、上記（１）又は（２）に記載のものにおいて、前記既存岸壁が、下端側を地盤に根入れすると共に上端側をタイ材によって控え工で支持する矢板式岸壁の場合において、前記水平力伝達部材が（１）式を満たす位置に配置されていることを特徴とするものである。

Figure 0007396331000001
ここで、
D：既存岸壁の矢板の根入長(m)
HT：既存岸壁の水底地盤からタイ材取り付け位置までの高さ(m)
E：既存岸壁の矢板のヤング率(kN/m2)
I：既存岸壁の単位幅あたりの矢板の断面２次モーメント(m4/m)
lh：既存岸壁の矢板が根入れされている地盤の地盤反力係数(kN/m3)
H：水底地盤から水平力伝達部材上端までの高さ(m) (3) Furthermore, in the case described in (1) or (2) above, if the existing quay is a sheet pile type quay whose lower end is rooted in the ground and whose upper end is supported by tie materials with a buttress; , the horizontal force transmitting member is arranged at a position that satisfies equation (1).
Figure 0007396331000001
 here,
D: Penetration length of existing quay sheet pile (m)
H T : Height (m) from the underwater ground of the existing quay to the tie material installation position
E: Young's modulus of existing quay sheet pile (kN/m 2 )
I: Second moment of inertia of sheet pile per unit width of existing quay (m 4 /m)
l h : Ground reaction force coefficient of the ground into which the existing quay sheet pile is embedded (kN/m 3 )
H: Height from the bottom of the water to the top of the horizontal force transmission member (m)

（４）また、上記（１）乃至（３）のいずれかに記載の既存岸壁の改良構造の施工方法であって、
前記既存壁体の水域側に、該既存壁体と所定の隙間を設けて前記箱状構造体を水底地盤に埋設する工程と、
前記箱状構造体の杭挿通孔を通して前記杭を打設する工程と、
前記杭挿通孔と前記杭との隙間に間詰材を配設する工程と、
前記既存壁体と前記箱状構造体との間に水平伝達部材を配設する工程と、を備えたことを特徴とするものである。 (4) Also, the method for constructing an improved structure for an existing quay according to any one of (1) to (3) above,
burying the box-shaped structure in underwater ground with a predetermined gap between the existing wall and the existing wall on the water body side;
Driving the pile through the pile insertion hole of the box-like structure;
arranging a filler material in the gap between the pile insertion hole and the pile;
The present invention is characterized by comprising a step of arranging a horizontal transmission member between the existing wall and the box-like structure.

（５）また、上記（４）に記載のものにおいて、前記箱状構造体を埋設する工程は、前記箱状構造体を水底地盤面に載置した後に、前記箱状構造体の通水口から内部の水を強制的に排水し、前記箱状構造体を水底地盤内に沈設させることを特徴とするものである。 (5) Further, in the item described in (4) above, the step of burying the box-like structure includes placing the box-like structure on the underwater ground surface and then opening the water inlet of the box-like structure. It is characterized in that the water inside is forcibly drained and the box-shaped structure is sunk into the underwater ground.

本発明に係る既存岸壁の改良構造は、陸上部での施工が制限される場合にも適用可能であり、施工性に優れている。
また、高コストな地盤改良をせずとも、岸壁天端の水平変形量を抑えることが可能となる。
更に、水平力伝達部材は、既存壁体からの水平力を箱状構造体に伝達できればよく、それ故に水平力伝達部材は既存壁体と箱状構造体と一体化される必要がないため、水中におけるスタッド溶接等を不要とすることができる。
箱状構造体は工場で事前製作することが可能なことから、現地での施工期間を短縮することができる。 The improved structure of an existing quay wall according to the present invention can be applied even when construction on land is restricted, and has excellent workability.
Furthermore, it is possible to suppress the amount of horizontal deformation at the top of the quay without the need for expensive ground improvement.
Furthermore, the horizontal force transmission member only needs to be able to transmit the horizontal force from the existing wall to the box-like structure, and therefore the horizontal force transmission member does not need to be integrated with the existing wall and the box-like structure. Underwater stud welding etc. can be made unnecessary.
Since the box-like structure can be prefabricated at a factory, the construction period on site can be shortened.

本発明の実施の形態１に係る既存岸壁の改良構造の説明図である。FIG. 2 is an explanatory diagram of an improved structure for an existing quay according to Embodiment 1 of the present invention. 図１に示す既存岸壁の改良構造に用いた箱状構造体の説明図である。FIG. 2 is an explanatory diagram of a box-like structure used in the improved structure of the existing quay shown in FIG. 1; 図１に示す既存岸壁の改良構造の作用を説明する説明図である。FIG. 2 is an explanatory diagram illustrating the effect of the improved structure of the existing quay shown in FIG. 1; 既存壁体に作用する荷重を説明する説明図である。It is an explanatory view explaining the load which acts on an existing wall. 実施の形態２に係る式の導出過程で行った試設計の概要を説明する説明図である。FIG. 7 is an explanatory diagram illustrating an overview of a trial design performed in the process of deriving an equation according to the second embodiment. 実施の形態２に係る式の導出過程で行った試設計の結果を整理した散布図である。7 is a scatter diagram arranging the results of a trial design performed in the process of deriving an equation according to the second embodiment. FIG. 本発明の実施の形態２に係る既存岸壁の改良構造の説明図である。It is an explanatory view of an improved structure of an existing quay according to Embodiment 2 of the present invention. 本発明の実施の形態３に係る既存岸壁の改良構造の施工方法の説明図である。It is an explanatory view of the construction method of the improvement structure of the existing quay concerning Embodiment 3 of the present invention. 本発明の実施の形態３に係る既存岸壁の改良構造の施工方法の他の態様の説明図である。It is an explanatory view of other aspects of the construction method of the improvement structure of the existing quay concerning Embodiment 3 of the present invention. 実施例１に係る改良構造の説明図である。FIG. 3 is an explanatory diagram of an improved structure according to Example 1. 実施例２に係る改良構造の説明図である。FIG. 7 is an explanatory diagram of an improved structure according to Example 2. 実施例３に係る改良構造の説明図である。FIG. 7 is an explanatory diagram of an improved structure according to Example 3. 実施例４に係る改良構造の説明図である。FIG. 7 is an explanatory diagram of an improved structure according to Example 4. 本発明の効果を確認するシミュレーション解析の対象とした既存の矢板式岸壁の説明図である。FIG. 2 is an explanatory diagram of an existing sheet pile quay that was subjected to simulation analysis to confirm the effects of the present invention. シミュレーション解析の対象とした本発明改良構造の説明図である。FIG. 3 is an explanatory diagram of the improved structure of the present invention that was subjected to simulation analysis. 図１５に示す本発明改良構造に用いた箱状構造体の説明図である。FIG. 16 is an explanatory diagram of a box-like structure used in the improved structure of the present invention shown in FIG. 15; シミュレーション解析の対象とした従来例の改良構造の説明図である。FIG. 2 is an explanatory diagram of an improved structure of a conventional example that was subjected to simulation analysis. シミュレーション解析に用いた地震動を示す図である。FIG. 3 is a diagram showing seismic motion used in simulation analysis. 改良前のシミュレーション解析結果を示す図である。FIG. 7 is a diagram showing simulation analysis results before improvement. 本発明改良構造のシミュレーション解析結果を示す図である。It is a figure which shows the simulation analysis result of the improved structure of this invention. 従来例に係る改良構造のシミュレーション解析結果を示す図である。It is a figure which shows the simulation analysis result of the improved structure based on a conventional example. 改良対象となる既存の矢板式岸壁の説明図である。It is an explanatory view of an existing sheet pile type quay that is a target of improvement. 本発明に至った経緯を説明する説明図である（その１）。FIG. 1 is an explanatory diagram illustrating the circumstances leading to the present invention (part 1). 本発明に至った経緯を説明する説明図である（その２）。FIG. 2 is an explanatory diagram illustrating the circumstances leading to the present invention (Part 2).

実施の形態を説明する前に本発明に至った経緯を説明する。
＜本発明に至った経緯＞
耐震強化岸壁に指定されている既存岸壁４１の改良設計においては、レベル２地震動（発生する可能性がある最大級の地震動）の発生後の、岸壁の使用性（緊急物資輸送等のために直ちに船舶を停泊できるか）が重要となる。このような使用性確保の観点から、地震時の岸壁天端の水域側への水平変形量を抑えることが要求される。 Before explaining the embodiments, the circumstances leading to the present invention will be explained.
<How the present invention was achieved>
In the improvement design of the existing quay 41, which is designated as an earthquake-resistant quay, the usability of the quay (immediately for the transportation of emergency supplies, etc.) will be improved after a level 2 earthquake (the largest seismic motion that can occur) occurs. (Can ships be berthed?) is important. From the viewpoint of ensuring usability, it is required to suppress the amount of horizontal deformation of the top of the quay toward the water area during an earthquake.

陸上部４８での施工が制限される場合には、地震時に既存壁体４５に作用する土圧を抑えることが難しいため、既存壁体４５の水域側地盤の変形量が小さくなるように補強することで、岸壁天端の水平変形量を抑える方法が有効となる。 If construction on the land portion 48 is restricted, it is difficult to suppress the earth pressure that acts on the existing wall 45 during an earthquake, so it is reinforced to reduce the amount of deformation of the ground on the water side of the existing wall 45. This makes it effective to suppress the amount of horizontal deformation at the top of the quay.

図２３は図２２に示した既存岸壁４１の水域側に自立式矢板５３を打設して補強した構造の、地震時の変形を模擬的に示したものである。
上述したように、既存岸壁４１の地震時水平変形量を抑制するためには、岸壁の水域側地盤の変形量を抑える必要がある。しかし、水域側地盤の浅層領域は上載圧が小さく水平抵抗力も小さいため、地震時土圧が作用すると自立式矢板５３が既存岸壁４１の変形を抑えられずに撓んでしまう。結果として、既存岸壁４１の水域側に矢板を打設しても、補強効果は小さい。 FIG. 23 schematically shows the deformation of the existing quay wall 41 shown in FIG. 22, which is reinforced by driving self-supporting sheet piles 53 on the water side, during an earthquake.
As described above, in order to suppress the amount of horizontal deformation of the existing quay 41 during an earthquake, it is necessary to suppress the amount of deformation of the ground on the water side of the quay. However, since the overburden pressure and the horizontal resistance force are small in the shallow region of the water-side ground, when earth pressure is applied during an earthquake, the self-supporting sheet piles 53 cannot suppress the deformation of the existing quay wall 41 and bend. As a result, even if sheet piles are driven on the water side of the existing quay 41, the reinforcing effect is small.

図２４は既存岸壁４１の水域側に補強杭５５を打設して補強した構造の、地震時の変形を模擬的に示したものである。杭は自立式矢板５３よりも水平抵抗力が大きいが、矢板と異なり岸壁法線方向（図２４の紙面直交方向）に離散的に配置されるため、地震時に杭の間を土がすり抜ける。そのため、地震時土圧が作用すると補強杭５５は既存岸壁４１の変形を抑えられないため、既存岸壁４１の水域側に補強杭５５を打設しても、矢板と同様に補強効果は小さい。
一方、水域側地盤の深層領域は上載圧が大きいため、地震時の地盤変形量は比較的小さい。そのため、離散的に杭を配置してもすり抜ける土の移動量が小さく、逆に杭に対する地盤の水平抵抗力は大きい。 FIG. 24 schematically shows the deformation of a structure reinforced by driving reinforcing piles 55 on the water side of the existing quay 41 during an earthquake. The piles have a higher horizontal resistance force than the self-supporting sheet piles 53, but unlike the sheet piles, they are arranged discretely in the normal direction of the quay (direction perpendicular to the plane of the paper in FIG. 24), so soil can slip between the piles during an earthquake. Therefore, the reinforcing piles 55 cannot suppress the deformation of the existing quay wall 41 when earth pressure is applied during an earthquake, so even if the reinforcing piles 55 are driven on the water area side of the existing quay wall 41, the reinforcing effect is small like sheet piles.
On the other hand, the amount of ground deformation during an earthquake is relatively small because the overburden pressure is large in the deep area of the ground on the water side. Therefore, even if the piles are arranged discretely, the amount of soil movement that passes through them is small, and conversely, the horizontal resistance force of the ground against the piles is large.

以上のように、既存壁体４５の水域側地盤の変形量が小さくなるように補強するには、浅層領域は離散的に配置される杭では十分でなく矢板のように面での補強が必要であるが、深層領域は杭での補強でも有効である。
本発明はかかる知見に基づくものであり、その具体例を以下の実施の形態で詳細に説明する。 As mentioned above, in order to reinforce the existing wall 45 so that the amount of deformation of the ground on the water side side is small, it is not enough to use piles placed discretely in the shallow area, and surface reinforcement such as sheet piles is necessary. Although necessary, reinforcing the deep areas with piles is also effective.
The present invention is based on this knowledge, and specific examples thereof will be explained in detail in the following embodiments.

［実施の形態１］
本実施の形態の既存岸壁の改良構造１（以下、単に「改良構造１」という場合あり）は、図１、図２に示すように、周壁面部３と通水口５が設けられた天面部７と複数の杭挿通孔９とを有し、既存岸壁４１における既存壁体４５の水域側の水底地盤４３に配設された箱状構造体１１と、箱状構造体１１の杭挿通孔９に挿通されて、水底地盤４３に打設された複数の杭１３と、杭挿通孔９と杭１３との隙間に配設された間詰材（図示なし）と、既存壁体４５と箱状構造体１１との間に配設されて既存壁体４５からの水平力を箱状構造体１１に伝達する水平力伝達部材１２と、を備えたものである。
以下、各構成を詳細に説明する。なお、図１、２において既存岸壁４１を示した図２２と同一部分には同一の符号を付して説明を省略する。 [Embodiment 1]
As shown in FIGS. 1 and 2, an improved structure 1 for an existing quay (hereinafter simply referred to as "improved structure 1") according to the present embodiment has a top surface portion provided with a peripheral wall surface portion 3 and a water inlet 5. 7 and a plurality of pile insertion holes 9, the box-shaped structure 11 is arranged in the underwater ground 43 on the water body side of the existing wall 45 of the existing quay wall 41, and the pile insertion holes 9 of the box-shaped structure 11. A plurality of piles 13 are inserted into the water bottom ground 43, a filling material (not shown) is placed in the gap between the pile insertion hole 9 and the piles 13, and the existing wall 45 and the box-shaped The horizontal force transmitting member 12 is disposed between the box-shaped structure 11 and transmits the horizontal force from the existing wall 45 to the box-like structure 11.
Each configuration will be explained in detail below. In addition, in FIGS. 1 and 2, the same parts as those in FIG. 22 showing the existing quay wall 41 are given the same reference numerals, and the description thereof will be omitted.

＜箱状構造体＞
箱状構造体１１は、図１に示すように、既存岸壁４１における既存壁体４５の水域側の水底地盤４３に配設されている。すなわち、天面部７の位置が水底地盤４３とほぼ同一位置となり、周壁面部３が水底地盤４３に打設された状態になっている。
また、図２に示すように、４面の周壁面部３と天面部７を有する矩形状の箱形状であり、天面部７に通水口５が設けられている。もっとも、箱状構造体１１の形状は矩形状に限定されるものではない。 <Box-shaped structure>
As shown in FIG. 1, the box-like structure 11 is disposed on the water bottom ground 43 on the water body side of the existing wall 45 of the existing quay 41. That is, the position of the top surface portion 7 is substantially the same as the underwater ground 43, and the peripheral wall surface portion 3 is placed in the underwater ground 43.
Further, as shown in FIG. 2, it has a rectangular box shape having four peripheral wall surface portions 3 and a top surface portion 7, and a water passage port 5 is provided in the top surface portion 7. However, the shape of the box-like structure 11 is not limited to a rectangular shape.

また、箱状構造体１１は、四隅及び長辺の中間部に杭挿通孔９が設けられている。さらに、天面部７における杭挿通孔９を連結するように長辺及び短辺に沿って補強材としてＨ形鋼１５が設けられて剛性が高められている。また、斜めにもＨ形鋼１５が設けられている。短辺に沿ったＨ形鋼１５は水平力を軸方向で受けてこれに抵抗する側であるため設けることが好ましいが、長辺に沿ったＨ形鋼１５はなくてもよい。 Moreover, the box-like structure 11 is provided with pile insertion holes 9 at the four corners and at the intermediate portions of the long sides. Further, H-beams 15 are provided as reinforcing materials along the long and short sides so as to connect the pile insertion holes 9 in the top surface part 7 to increase rigidity. Further, H-shaped steel 15 is also provided diagonally. Although it is preferable to provide the H-shaped steel 15 along the short side because it is the side that receives horizontal force in the axial direction and resists it, the H-shaped steel 15 along the long side may be omitted.

本実施の形態の箱状構造体１１は、長辺側を既存壁体４５に対向させて配置されるが、図２（ｂ）に示すように、短辺側の壁体は２枚の鋼板１７にリブ材１９を入れた構造であり、長辺側の壁体よりも剛性が高められている。これは、既存壁体４５から水平力伝達部材１２を介して伝達される水平力を受けたときに局部座屈することなく抵抗できるようにするためである。この抵抗力を大きくするため、図２（ｂ）に示すように、長辺の中間部には短辺側の壁体と平行な仕切り壁体２１が設けられている。 The box-like structure 11 of this embodiment is arranged with the long side facing the existing wall 45, but as shown in FIG. 2(b), the short side wall is made of two steel plates. It has a structure in which a rib material 19 is inserted into the wall 17, and the rigidity is higher than that of the wall on the long side. This is to enable the horizontal force transmitted from the existing wall body 45 via the horizontal force transmission member 12 to be resisted without causing local buckling. In order to increase this resistance force, as shown in FIG. 2(b), a partition wall 21 parallel to the wall on the short side is provided in the middle of the long side.

箱状構造体１１の高さは、既存岸壁４１の水域側地盤の軟弱な深さ領域を拘束する深さまで埋設できることが好ましく、具体的には３ｍ以上が望ましい。これより高さが低いと埋設深さが浅くなり、前述した水平抵抗が発揮されない可能性がある。もっとも、埋設深さが深すぎると、施工手間が大きくなって不経済となるため、高さの上限は１０ｍくらいが好ましい。 The height of the box-like structure 11 is preferably such that it can be buried to a depth that restrains the soft depth region of the ground on the water side of the existing quay wall 41, and specifically, it is desirable to have a height of 3 m or more. If the height is lower than this, the burial depth will be shallow and the horizontal resistance described above may not be achieved. However, if the burial depth is too deep, the construction work will become large and uneconomical, so the upper limit of the height is preferably about 10 m.

杭挿通孔９は、岸壁法線直角方向（既存岸壁４１の変形する方向）に２列設けられているが、３列以上でもよい。
杭挿通孔９に杭１３が挿通されて既存壁体４５からの水平力に抵抗することになるが、箱状構造体１１の水平抵抗を確保するため、杭挿通孔９の間隔は５ｍ以上が望ましい。
また、杭挿通孔９の配置は、図２に示すように、格子状に配置されていてもよいし、あるいは千鳥状に配置されていてもよく、配置は特に限定されない。 The pile insertion holes 9 are provided in two rows in the direction perpendicular to the quay wall normal (the direction in which the existing quay wall 41 deforms), but three or more rows may be provided.
The piles 13 are inserted into the pile insertion holes 9 to resist the horizontal force from the existing wall 45, but in order to ensure the horizontal resistance of the box-like structure 11, the intervals between the pile insertion holes 9 should be 5 m or more. desirable.
Moreover, the arrangement of the pile insertion holes 9 may be arranged in a grid pattern, as shown in FIG. 2, or may be arranged in a staggered pattern, and the arrangement is not particularly limited.

天面部７に設けた通水口５は、例えば蓋部材（図示なし）等によって開閉可能になっており、箱状構造体１１を水上移送する際には閉じた状態にする。また、箱状構造体１１を沈設する際には開放して排気口及び排水口として使用する。排水口として使用する際には排水ポンプと接続することから、直径100mm程度の円形形状が望ましい。
なお、箱状構造体１１の材質は特に限定されず、鋼製、コンクリート製のいずれでもよい。 The water inlet 5 provided in the top surface part 7 can be opened and closed, for example, by a lid member (not shown), and is kept in a closed state when the box-like structure 11 is transported on water. Moreover, when the box-like structure 11 is sunk, it is opened and used as an exhaust port and a drain port. When used as a drain, it is desirable to have a circular shape with a diameter of about 100 mm, as it will be connected to a drainage pump.
The material of the box-like structure 11 is not particularly limited, and may be made of steel or concrete.

＜杭＞
杭１３は箱状構造体１１の杭挿通孔９に挿通されて、海底地盤に打設されている。杭１３は例えば鋼管杭が好ましいが、これに限定されるものではない。
打設された杭１３は複数本であり、これらの配置は、箱状構造体１１の杭挿通孔９に合わせて、格子状に配置されてもよいし、千鳥状に配置されてもよく、配置は特に限定されない。また、図１に示す例では、直杭としているが、複数の杭１３の全部又は一部を斜杭としてもよい。 <Pile>
The pile 13 is inserted into the pile insertion hole 9 of the box-like structure 11 and is driven into the seabed ground. The pile 13 is preferably a steel pipe pile, for example, but is not limited to this.
A plurality of piles 13 are driven, and these may be arranged in a grid pattern or staggered in accordance with the pile insertion holes 9 of the box-like structure 11. The arrangement is not particularly limited. Further, in the example shown in FIG. 1, straight piles are used, but all or a part of the plurality of piles 13 may be slanted piles.

本発明では、箱状構造体１１から杭１３に荷重が伝達することで、杭１３における杭挿通孔９の下端付近に大きな変形が生じる。そのため、杭挿通孔９の下端から鋼管杭の直径の３倍以上の長さ範囲は、杭１３の変形性能を高くすることで合理的な設計が可能となる。具体的には、一般的に使用される降伏強度235N/mm2級や315N/mm2級の鋼管杭よりも降伏強度400N/mm2以上の鋼管杭を使用することが望ましい。 In the present invention, when the load is transmitted from the box-like structure 11 to the pile 13, large deformation occurs in the vicinity of the lower end of the pile insertion hole 9 in the pile 13. Therefore, the length range from the lower end of the pile insertion hole 9 to three times or more the diameter of the steel pipe pile can be rationally designed by increasing the deformation performance of the pile 13. Specifically, it is preferable to use steel pipe piles with a yield strength of 400 N/mm 2 or more , rather than the commonly used steel pipe piles with a yield strength of 235 N/mm 2 class or 315 N/mm 2 class.

また、鋼管杭の径厚比がR/t=100程度になると、局部座屈が発生する可能性が高くなり、許容できる変形量が小さくなるため、R/t≦80とすることが望ましい。ここで、R：鋼管杭の外径(mm)、t：鋼管杭の肉厚(mm)である。なお、これらの条件は、杭挿通孔９の下端付近のみでなく、全ての部位について満たされていても問題ない。 In addition, when the diameter-thickness ratio of the steel pipe pile is around R/t=100, there is a high possibility that local buckling will occur and the allowable amount of deformation becomes small, so it is desirable that R/t≦80. Here, R: outer diameter of the steel pipe pile (mm), t: wall thickness of the steel pipe pile (mm). Note that there is no problem even if these conditions are satisfied not only near the lower end of the pile insertion hole 9 but also in all parts.

＜間詰材＞
間詰材は、杭１３が挿通された杭挿通孔９と杭１３との隙間に配設されて箱状構造体１１と杭１３とを一体化するためのもので、水中コンクリート又は水中モルタルが望ましい。この一体化の手法は従来のジャケット式岸壁、ストラット式岸壁で用いられる手法、具体的にはグラウト材の注入によればよい。 <Filling material>
The filling material is disposed in the gap between the pile insertion hole 9 through which the pile 13 is inserted and the pile 13 to integrate the box-shaped structure 11 and the pile 13, and is made of underwater concrete or underwater mortar. desirable. This integration method may be the method used in conventional jacket-type quay walls or strut-type quay walls, specifically, injection of grout material.

＜水平力伝達部材＞
水平力伝達部材１２は、既存壁体４５と箱状構造体１１との隙間に配設されて既存壁体４５が水域側に変形しようとする水平力を箱状構造体１１に伝達するものである。地震の揺れにより、既存壁体４５は一時的には陸域側に変形するが、徐々に水域側への変形が大きくなる。すなわち、水平力伝達部材１２は既存壁体４５の陸域側への変形を抑える必要がないため、引張力を伝達する必要はなく、圧縮力の伝達機能のみあればよい。水平力伝達部材１２はかかる機能を発揮できれば、その材料等は限定されず、例えば石材、水中コンクリート、水中モルタルなど、箱状構造体１１と既存壁体４５の水平方向の圧縮力の伝達が可能なものであればよい。 <Horizontal force transmission member>
The horizontal force transmission member 12 is disposed in the gap between the existing wall 45 and the box-like structure 11 and transmits the horizontal force that causes the existing wall 45 to deform toward the water area to the box-like structure 11. be. Due to the shaking of the earthquake, the existing wall 45 is temporarily deformed toward the land area, but the deformation toward the water area gradually increases. That is, since the horizontal force transmitting member 12 does not need to suppress the deformation of the existing wall 45 toward the land side, it is not necessary to transmit tensile force, and only needs to have a compressive force transmitting function. The material of the horizontal force transmitting member 12 is not limited as long as it can perform such a function. For example, it can be made of stone, underwater concrete, underwater mortar, etc., which can transmit the compressive force in the horizontal direction between the box-like structure 11 and the existing wall 45. It is fine as long as it is something.

もっとも、水平力伝達部材１２の上部は確実に水平力を伝達できるように、水中コンクリートまたは水中モルタルで構成するのが望ましい。
既存壁体４５に作用する荷重（例えば地震時荷重やエプロン上に物を置いたときの荷重、増深によって生じた土圧増分等）は、水平力伝達部材１２とその下方の地盤を介して箱状構造体１１に伝達されるため、箱状構造体１１には水平力のみが伝達される構造である。このため、既存壁体４５と箱状構造体１１とを一体化する必要がなく、水中におけるスタッド溶接等を不要とすることができる。 However, it is desirable that the upper part of the horizontal force transmission member 12 be made of underwater concrete or underwater mortar so that the horizontal force can be reliably transmitted.
Loads that act on the existing wall 45 (for example, earthquake loads, loads when objects are placed on the apron, increased earth pressure due to deepening, etc.) are transmitted through the horizontal force transmission member 12 and the ground below it. Since the force is transmitted to the box-like structure 11, the structure is such that only horizontal force is transmitted to the box-like structure 11. Therefore, there is no need to integrate the existing wall body 45 and the box-like structure 11, and it is possible to eliminate the need for underwater stud welding or the like.

上記のように構成された本実施の形態に係る改良構造１の作用を図３に基づいて説明する。図３は本実施の形態の改良構造１における地震時の変形を模擬的に示したものである。
本実施の形態では、既存岸壁４１の水域側地盤の浅層領域は箱状構造体１１内に拘束されることで一体となって変形する。箱状構造体１１は、間詰材を通して鋼管杭と一体化されているため、鋼管杭の水平抵抗によって変形量を小さくすることができる。 The operation of the improved structure 1 according to the present embodiment configured as described above will be explained based on FIG. 3. FIG. 3 schematically shows deformation during an earthquake in the improved structure 1 of this embodiment.
In this embodiment, the shallow region of the ground on the water side of the existing quay 41 is restrained within the box-like structure 11 and thereby deforms as a unit. Since the box-like structure 11 is integrated with the steel pipe pile through the filler material, the amount of deformation can be reduced by the horizontal resistance of the steel pipe pile.

箱状構造体１１より深部の地盤は上載圧が大きいので、前述のように、離散的に配置された鋼管杭でも大きな水平抵抗を期待できる。これらのことから、本実施の形態の改良構造１では、水平力伝達部材１２を通して箱状構造体１１の水平抵抗を既存壁体４５に伝えることで、岸壁天端の水平変形量を抑えることが可能となる。 Since the ground deeper than the box-like structure 11 has a high overburden pressure, as described above, even with discretely arranged steel pipe piles, a large horizontal resistance can be expected. For these reasons, in the improved structure 1 of the present embodiment, by transmitting the horizontal resistance of the box-like structure 11 to the existing wall 45 through the horizontal force transmission member 12, it is possible to suppress the amount of horizontal deformation at the top of the quay. It becomes possible.

［実施の形態２］
本実施の形態は、水平力伝達部材１２の位置の最適化を図ったものである。すなわち、本実施の形態に係る既存岸壁４１の改良構造１は、既存岸壁４１が、下端側を地盤に根入れすると共に上端側をタイ材５１によって控え工４９で支持する矢板式岸壁の場合において、水平力伝達部材が（１）式を満たす位置に配置されていることを特徴とするものである。 [Embodiment 2]
This embodiment aims at optimizing the position of the horizontal force transmitting member 12. That is, the improved structure 1 of the existing quay 41 according to the present embodiment is a sheet pile type quay where the existing quay 41 is a sheet pile type quay whose lower end is rooted in the ground and whose upper end is supported by the tie material 51 and the support work 49. , the horizontal force transmitting member is arranged at a position that satisfies equation (1).

Figure 0007396331000002
ここで、
D：既存岸壁の矢板の根入長(m)
HT：既存岸壁の水底地盤からタイ材取り付け位置までの高さ(m)
E：既存岸壁の矢板のヤング率(kN/m2)
I：既存岸壁の単位幅あたりの矢板の断面２次モーメント(m4/m)
lh：既存岸壁の矢板が根入れされている地盤の地盤反力係数(kN/m3)
H：水底地盤から水平力伝達部材上端までの高さ(m)
Figure 0007396331000002
 here,
D: Penetration length of existing quay sheet pile (m)
H T : Height (m) from the underwater ground of the existing quay to the tie material installation position
E: Young's modulus of existing quay sheet pile (kN/m 2 )
I: Second moment of inertia of sheet pile per unit width of existing quay (m 4 /m)
l h : Ground reaction force coefficient of the ground into which the existing quay sheet pile is embedded (kN/m 3 )
H: Height from the bottom of the water to the top of the horizontal force transmission member (m)

以下、（１）式の導出した過程を説明する。
水平力伝達部材１２を通じて、既存壁体４５にかかる荷重が箱状構造体１１に伝達するとき、既存壁体４５に作用するせん断力も箱状構造体１１に伝達する。箱状構造体１１に伝達するせん断力が大きいと、箱状構造体１１の水域側への変形量が増大するため、既設壁体の水域側への変形量や作用する曲げモーメントも増大する。そのため、既存壁体４５に作用するせん断力が小さい位置に、水平力伝達部材１２が存在することが望ましい。 The process of deriving equation (1) will be described below.
When the load applied to the existing wall 45 is transmitted to the box-like structure 11 through the horizontal force transmission member 12, the shear force acting on the existing wall 45 is also transmitted to the box-like structure 11. When the shear force transmitted to the box-like structure 11 is large, the amount of deformation of the box-like structure 11 toward the water area increases, and therefore the amount of deformation of the existing wall toward the water area and the acting bending moment also increase. Therefore, it is desirable that the horizontal force transmission member 12 be located at a position where the shearing force acting on the existing wall 45 is small.

既存岸壁４１が、下端側を地盤に根入れすると共に上端側をタイ材５１によって控え工４９で支持する矢板式岸壁の場合における、既存壁体４５に作用する荷重を図４に示す。図４(a)は既存壁体４５に作用する土圧分布を模式的に示したものであり、上部の支点はタイ材５１取付点を、下部の支点は水底地盤４３を表している。このとき、図４(b)に示すようなせん断力と、図４(c)に示すような曲げモーメントが発生する。ここで、水域に凸となる場合を正の曲げモーメントとする（＋Ｍと表記）。
既設壁体に作用するせん断力が０になる位置は、作用する曲げモーメントの変曲点（増加から減少に変わる位置）と等しくなる。これは水底地盤４３より上の範囲において、既存壁体４５に作用する最大曲げモーメントの発生位置とも一致する。 FIG. 4 shows the load acting on the existing wall body 45 in the case where the existing quay wall 41 is a sheet pile type quay wall whose lower end side is rooted in the ground and whose upper end side is supported by a tie material 51 and a support work 49. FIG. 4(a) schematically shows the earth pressure distribution acting on the existing wall 45, and the upper fulcrum represents the attachment point of the tie material 51, and the lower fulcrum represents the underwater ground 43. At this time, a shearing force as shown in FIG. 4(b) and a bending moment as shown in FIG. 4(c) are generated. Here, the case where the bending moment is convex in the water area is defined as a positive bending moment (denoted as +M).
The position where the shear force acting on the existing wall becomes zero is equal to the inflection point (the position where the bending moment changes from increasing to decreasing). This also coincides with the position where the maximum bending moment acting on the existing wall 45 occurs in the range above the water bottom ground 43.

矢板式岸壁における矢板への最大曲げモーメントの発生位置は、既存壁体４５の壁高さ、タイ材５１の取り付け位置、鋼材の降伏強度、矢板の形状、地盤条件、設計震度等により変化する。そこで、さまざまな条件における矢板式岸壁の試設計を実施し、最大曲げモーメントの発生位置を調べた。 The position at which the maximum bending moment is applied to the sheet pile in a sheet pile type quay varies depending on the wall height of the existing wall 45, the attachment position of the tie material 51, the yield strength of the steel material, the shape of the sheet pile, ground conditions, design seismic intensity, etc. Therefore, we carried out a trial design of a sheet pile type quay under various conditions and investigated the location where the maximum bending moment occurs.

試設計の概要を図５に示す。なお、図５において図１と同一部分及び対応する部分には同一の符号を付してある。
矢板式岸壁は、図５に示すように、矢板の下端側を水底地盤４３に根入れすると共に、上端側をタイ材５１によって控え工４９で支持してなるものを対象としている。
試計算の条件は次に示すとおりである。
水深は-4.5m、-7.5m、-10.5m、-14m、-17m、-20mの６種類で岸壁天端は+3m、タイ材５１取り付け点は+2mで固定した。また、残留水位は+1mで固定とした。
水底地盤４３は、緩い、中位、堅い、の３種類とした。せん断抵抗角と地盤反力係数lhは、「緩い」では、30°と24MN/m3、「中位」では、35°と38MN/m3、「堅い」では40°と58MN/m3とした。
矢板式岸壁の背後には裏込石を配置することにし、せん断抵抗角は40°とした。地盤の単位体積重量は、水底地盤４３、裏込石とも共通で水中単位体積重量は10kN/m3、気中では18kN/m3とした。
設計震度は、レベル１地震を対象として、地域ごとの設計地震動を用いて検討地点の地盤の1次元地震応答解析結果から設計震度を求めることになっているが、本検討では0.05、0.15、0.25を対象とした。
矢板は鋼製とし、鋼材の降伏強度の特性値は、SKY400として235N/mm2、SKY490として315N/mm2の他に、最大600N/mm2までを想定した。
国内外のさまざまな形状の矢板を対象に試設計を行い、矢板に発生する最大応力が、235～600N/mm2の間に収まる形状を対象に、最大曲げモーメントの発生位置を調べた。 Figure 5 shows an overview of the trial design. In FIG. 5, the same parts and corresponding parts as in FIG. 1 are given the same reference numerals.
As shown in FIG. 5, the sheet pile type quay is intended for one in which the lower end side of the sheet pile is rooted in the water bottom ground 43, and the upper end side is supported by a tie material 51 with a support work 49.
The conditions for the trial calculation are as follows.
There are six types of water depth: -4.5m, -7.5m, -10.5m, -14m, -17m, and -20m.The top of the quay was fixed at +3m, and the tie material 51 attachment point was fixed at +2m. In addition, the residual water level was fixed at +1m.
Three types of underwater ground 43 were used: loose, medium, and hard. The shear resistance angle and ground reaction force coefficient l h are 30° and 24MN/m 3 for "loose", 35° and 38MN/m 3 for "medium", and 40° and 58MN/m 3 for "hard". And so.
Backfill stones were placed behind the sheet pile type quay, and the shear resistance angle was set at 40°. The unit volume weight of the ground was the same for both the underwater ground 43 and the backfill stone, and the unit volume weight in water was 10 kN/m 3 and in air it was 18 kN/m 3 .
The design seismic intensity is aimed at level 1 earthquakes and is determined from the results of one-dimensional seismic response analysis of the ground at the study point using the design seismic motion for each region, but in this study, it is 0.05, 0.15, 0.25. The target was
The sheet piles are made of steel, and the characteristic value of the yield strength of the steel material is assumed to be 235N/mm 2 for SKY400, 315N/mm 2 for SKY490, and a maximum of 600N/mm 2 .
We conducted trial designs for sheet piles of various shapes from Japan and overseas, and investigated the location where the maximum bending moment occurs for shapes where the maximum stress generated in the sheet piles falls between 235 and 600 N/mm 2 .

試設計の実施数は１０００以上あるため、結果の一部を表１に示す。設計条件として「水深」、「水底地盤からタイ材取り付け位置までの高さHT」、「水底地盤条件」、「設計震度」を、設計に用いた矢板条件として「ヤング率E」、「断面二次モーメントI」、「断面係数」を、試設計の結果として「矢板に発生する応力」、「矢板の根入長D」、「最大曲げモーメントの発生位置H」を、結果の考察として「(HT)4/(EI)×lh」、「H/D」を示している。 Since more than 1000 trial designs were conducted, some of the results are shown in Table 1. The design conditions are ``water depth'', ``height H T from the water bottom ground to the tie installation position'', ``water bottom ground conditions'', and ``design seismic intensity'', and the sheet pile conditions used in the design are ``Young's modulus E'' and ``cross section. ``secondary moment I'' and ``section modulus'', ``stress generated in the sheet pile'', ``sheet pile penetration length D'', and ``maximum bending moment occurrence position H'' as a result of the trial design; (H T ) 4 /(EI)×l h ", "H/D" is shown.

Figure 0007396331000003
Figure 0007396331000003

表１に示されたものの中から考察すると、ばらつきはあるが「(HT)4/(EI)×lh」が大きくなるほど「H/D」の値が大きくなる傾向にある。すべての試設計の結果について、横軸に「(HT)4/(EI)×lh」を、縦軸に「H/D」をとった散布図を図６に示す。両者には相関があり、「H/D」は下式で示す範囲に分布していることが分かる。 Considering the results shown in Table 1, although there are variations, there is a tendency for the value of "H/D" to increase as "(H T ) 4 /(EI)×l h " increases. Figure 6 shows a scatter diagram with "(H T ) 4 /(EI)×l h " plotted on the horizontal axis and "H/D" plotted on the vertical axis for the results of all trial designs. It can be seen that there is a correlation between the two, and that "H/D" is distributed within the range shown by the formula below.

Figure 0007396331000004
Figure 0007396331000004

岸壁改良の設計をする場合、既存壁体４５の「水底地盤からタイ材取り付け位置までの高さHT」、「ヤング率E」、「断面二次モーメントI」、「地盤反力係数lh」、「矢板の根入長D」は既知であることが多いので、下記に示す式（１）に従って水平力伝達部材１２の位置を決めることで、効果的に既存壁体４５を改良することができる。
なお、岸壁改良に伴って、水域側の水底地盤の掘削による増深が行われる場合、D、HT、Hは増深後の値を使用するものとする。 When designing quay wall improvement, the existing wall 45's "height H T from the water bottom ground to the tie attachment position,""Young's modulus E,""secondary moment of area I," and "ground reaction force coefficient l h ” and “the penetration length D of the sheet pile” are often known, so the existing wall 45 can be effectively improved by determining the position of the horizontal force transmitting member 12 according to the formula (1) shown below. I can do it.
In addition, if the depth is increased by excavating the water bottom ground on the water area side due to quay wall improvement, the values after deepening shall be used for D, H T , and H.

Figure 0007396331000005
ここで、
D：既存岸壁の矢板の根入長(m)
HT：既存岸壁の水底地盤からタイ材取り付け位置までの高さ(m)
E：既存岸壁の矢板のヤング率(kN/m2)
I：既存岸壁の単位幅あたりの矢板の断面２次モーメント(m4/m)
lh：既存岸壁の矢板が根入れされている地盤の地盤反力係数(kN/m3)
H：水底地盤から水平力伝達部材上端までの高さ(m)
Figure 0007396331000005
 here,
D: Penetration length of existing quay sheet pile (m)
H T : Height (m) from the underwater ground of the existing quay to the tie material installation position
E: Young's modulus of existing quay sheet pile (kN/m 2 )
I: Second moment of inertia of sheet pile per unit width of existing quay (m 4 /m)
l h : Ground reaction force coefficient of the ground into which the existing quay sheet pile is embedded (kN/m 3 )
H: Height from the bottom of the water to the top of the horizontal force transmission member (m)

水平力伝達部材１２が式（１）の位置にある場合の、岸壁改良構造の一例を図７に示す。箱状構造体１１の既存壁体４５側の杭挿通孔９の上端が、水平力伝達部材１２の位置と同じ高さに位置しており、水平力伝達部材１２より下部の箱状構造体１１と既存壁体４５との隙間は、砂や固化処理土などで中詰めされる。 FIG. 7 shows an example of the quay wall improvement structure when the horizontal force transmission member 12 is in the position shown by equation (1). The upper end of the pile insertion hole 9 on the existing wall 45 side of the box-shaped structure 11 is located at the same height as the horizontal force transmission member 12, and the box-shaped structure 11 below the horizontal force transmission member 12 is located at the same height as the horizontal force transmission member 12. The gap between the wall 45 and the existing wall 45 is filled with sand, solidified soil, or the like.

［実施の形態３］
次に実施の形態１、２に示した既存岸壁の改良構造１の施工方法について説明する。
箱状構造体１１を予め工場等において製作し、改良する既存岸壁４１のある施工現場に搬入する。
施工現場では、既存壁体４５の水域側に既存壁体４５と所定の隙間を設けて箱状構造体１１を水底地盤４３に埋設する（箱状構造体１１埋設工程）。この際、後述する間詰工程において確実に間詰材を配設できるように、杭挿通孔９の内部に地盤の土が入らないよう、杭挿通孔９の下端に蓋を設けておいてもよい。 [Embodiment 3]
Next, a construction method of the existing quay wall improvement structure 1 shown in Embodiments 1 and 2 will be explained.
The box-like structure 11 is manufactured in advance in a factory or the like and transported to a construction site where the existing quay 41 to be improved is located.
At the construction site, the box-like structure 11 is buried in the underwater ground 43 with a predetermined gap between the existing wall 45 and the existing wall 45 on the water side (box-like structure 11 burying step). At this time, a cover may be provided at the lower end of the pile insertion hole 9 to prevent soil from entering the pile insertion hole 9 so that the filler material can be placed reliably in the filling process described later. good.

その後、箱状構造体１１の杭挿通孔９を通して鋼管杭等の杭１３を打設する（杭打設工程）。
次に、杭挿通孔９と杭１３との隙間に、間詰材を配設する（間詰工程）。間詰材は、箱状構造体１１と杭１３とを一体化するためのもので、水中コンクリート又は水中モルタルが望ましい。
最後に、箱状構造体１１と既存壁体４５との隙間に、水中コンクリート又は水中モルタルを打設して水平力伝達部材１２を構築する（水平力伝達部材構築工程）。 Thereafter, a pile 13 such as a steel pipe pile is driven through the pile insertion hole 9 of the box-like structure 11 (pile driving step).
Next, a filling material is provided in the gap between the pile insertion hole 9 and the pile 13 (filling step). The filling material is for integrating the box-like structure 11 and the piles 13, and is preferably underwater concrete or underwater mortar.
Finally, underwater concrete or underwater mortar is placed in the gap between the box-like structure 11 and the existing wall 45 to construct the horizontal force transmitting member 12 (horizontal force transmitting member construction step).

なお、施工順序は特に限定されず、どの工程を先に行ってもよい。特に、杭１３の打設位置精度を確保する必要があるが、箱状構造体１１埋設工程の前に杭打設工程を行うことで、箱状構造体１１の埋設時に杭挿通孔９の内部に土が入りにくくなることが想定されるので、杭挿通孔９の下端に蓋を設けずに間詰材を配設することが可能になるという効果が考えられる。 Note that the construction order is not particularly limited, and any step may be performed first. In particular, it is necessary to ensure the accuracy of the driving position of the piles 13, but by performing the pile driving process before the box-like structure 11 burying process, it is possible to Since it is assumed that it becomes difficult for soil to enter the pile insertion hole 9, it is possible to have the effect that it becomes possible to arrange the filler material at the lower end of the pile insertion hole 9 without providing a cover.

以上のように、本実施の形態によれば、陸上部４８での施工がなく水域側のみでの施工が可能であり、陸側の施工が制限される場合にも適用可能である。
また、既存壁体４５と箱状構造体１１との間では、水平力を伝達できればよく、それ故に既存壁体４５と箱状構造体１１は一体化される必要がなく、水中におけるスタッド溶接等を不要とすることができる。スタッド溶接の場合、鋼材が溶接に対応した成分のものでないと溶接による脆化が懸念されるが、本実施の形態ではこのようなことが懸念されることがない。 As described above, according to the present embodiment, construction can be performed only on the water side without construction on the land portion 48, and can be applied even when construction on the land side is restricted.
In addition, it is sufficient that horizontal force can be transmitted between the existing wall 45 and the box-like structure 11, and therefore the existing wall 45 and the box-like structure 11 do not need to be integrated, such as underwater stud welding, etc. can be made unnecessary. In the case of stud welding, there is a concern that the steel material may become embrittled due to welding if it does not have a composition compatible with welding, but this embodiment does not have such concerns.

なお、本実施の形態では、既存壁体４５の水域側に、箱状構造体１１が埋設されるため、岸壁法線が水域側に出っ張ることがある。この場合には、船舶の接岸の支障とならないように、図１に示すように、既存の上部工４７を水域側に拡幅する増幅上部工２２を設置するようにすればよい。もっとも、増幅上部工２２は岸壁全長の必要はなく、また、増幅上部工２２を設けることなく接岸用の防舷材を変えることで対応可能なこともある。 In addition, in this embodiment, since the box-like structure 11 is buried on the water body side of the existing wall body 45, the quay wall normal line may protrude toward the water body side. In this case, an amplifying superstructure 22 that widens the existing superstructure 47 toward the water area may be installed, as shown in FIG. 1, so as not to interfere with the berthing of ships. However, the amplifying superstructure 22 does not need to span the entire length of the quay wall, and it may be possible to cope with this by changing the fender material for berthing without providing the amplifying superstructure 22.

なお、前述の箱状構造体１１埋設工程において、水底地盤４３の掘削を行わずに箱状構造体１１を埋設できる合理的な施工方法について図８に基づいて説明する。なお、図８において図１と同一部分及び対応する部分には同一の符号が付してある。後述の図９においても同じである。
施工現場に搬入された箱状構造体１１は、天面部７の通水口５を通じて内部の空気量や水量を調整することができる。
そこで、通水口５を閉じた状態で箱状構造体１１の内部の空気量を調整して水面に浮かぶように浮力を調整し、水面を曳航させることで、埋設場所の位置調整を容易に行うことができる（図８（ａ）参照）。 In addition, in the above-mentioned box-like structure 11 burying process, a rational construction method that can bury the box-like structure 11 without excavating the underwater ground 43 will be explained based on FIG. In FIG. 8, the same parts and corresponding parts as in FIG. 1 are given the same reference numerals. The same applies to FIG. 9, which will be described later.
The box-like structure 11 carried to the construction site can adjust the amount of air and water inside through the water inlet 5 of the top surface 7.
Therefore, with the water inlet 5 closed, the amount of air inside the box-like structure 11 is adjusted to adjust the buoyancy so that it floats on the water surface, and by towing the water surface, the position of the burial site can be easily adjusted. (See FIG. 8(a)).

次に、箱状構造体１１の内部の空気を排気することで箱状構造体１１を水中に沈め、水底地盤４３上に自沈させる（図８（ｂ）参照）。その後、ポンプ等で通水口５から内部の水を強制的に排水する。排水することで、箱状構造体１１の内外に生じる水圧差によって発生するサクション力により、箱状構造体１１が地盤内に押し込まれる。その結果、箱状構造体１１を地盤内に沈設させることができる（図８（ｃ）参照）。箱状構造体１１の沈設後に、杭１３を打設する（図８（ｄ）参照）。 Next, by exhausting the air inside the box-like structure 11, the box-like structure 11 is submerged in water and scuttled onto the underwater ground 43 (see FIG. 8(b)). Thereafter, the water inside is forcibly drained from the water inlet 5 using a pump or the like. By draining water, the box-like structure 11 is pushed into the ground by the suction force generated by the water pressure difference between the inside and outside of the box-like structure 11. As a result, the box-like structure 11 can be sunk into the ground (see FIG. 8(c)). After sinking the box-like structure 11, the piles 13 are driven (see FIG. 8(d)).

なお、施工順序は特に限定されず、どの工程を先に行ってもよい。杭打設工程を箱状構造体埋設工程より先に行った例を図９に示す。
箱状構造体１１を埋設場所の水面に曳航させ（図９（ａ）参照）、水底地盤４３上に自沈させる（図９（ｂ）参照）。
その後、杭挿通孔９に杭１３を挿通して杭１３を支持層まで打設し、杭打設に使用した仮継ぎ杭２３を残した状態にしておき（図９（ｃ）参照）、仮継ぎ杭２３をガイド軸として箱状構造体１１の沈設を行う（図９（ｄ）参照）。
このようにすることで、沈設時の強制排水時に箱状構造体１１の鉛直精度を調整する必要がなく、施工が安定すると考えられる。 Note that the construction order is not particularly limited, and any step may be performed first. FIG. 9 shows an example in which the pile driving process was performed before the box-shaped structure burying process.
The box-like structure 11 is towed to the water surface of the burial site (see FIG. 9(a)) and scuttled onto the underwater ground 43 (see FIG. 9(b)).
Thereafter, the pile 13 is inserted into the pile insertion hole 9 and driven up to the support layer, leaving the temporary joint pile 23 used for pile driving (see Figure 9(c)). The box-like structure 11 is sunk using the joint pile 23 as a guide shaft (see FIG. 9(d)).
By doing so, there is no need to adjust the vertical accuracy of the box-like structure 11 during forced drainage during submersion, and the construction is considered to be stable.

船舶の大型化に伴う岸壁水深の増深が必要な場合は、箱状構造体１１埋設工程の前に、水域側水底地盤４３を掘削して水深を深くする水底地盤掘削工程を行うようにすればよい（図１０参照）。既存岸壁４１が増深に対して構造上の余裕がない場合においても、本実施の形態では箱状構造体１１、杭１３等の諸元を適正に変更することで、構造上の余裕を持たせることができるので、増深を問題なく行うことができる。 If it is necessary to increase the quay water depth due to an increase in the size of the ship, a water bottom ground excavation process to deepen the water depth by excavating the water area side water bottom ground 43 should be performed before the box-shaped structure 11 burying process. Good (see Figure 10). Even if the existing quay wall 41 does not have a structural margin for deepening, this embodiment provides a structural margin by appropriately changing the specifications of the box-like structure 11, the piles 13, etc. Therefore, the depth can be increased without any problem.

［実施例１］
ケーソン２４を用いた重力式岸壁２５を対象に、本発明の改良構造１で増深改良を行った例を図１０に示す。図１０において、図１と同一部分及び対応する部分には同一の符号を付してある。この点、後述の図１１～図１７においても同様である。
予めケーソン２４より水域側の基礎捨石２７の一部を除去した上で、箱状構造体１１を埋設して杭１３を打設することで、基礎捨石２７の厚み分の増深が可能となる。
また、水平力伝達部材１２は、ケーソン２４のフーチング部２９に被せるように配置させることで、地震時のケーソン２４の水域側への滑動を抑えることができる。 [Example 1]
FIG. 10 shows an example of deepening and improving a gravity type quay 25 using a caisson 24 using the improved structure 1 of the present invention. In FIG. 10, the same parts and corresponding parts as in FIG. 1 are given the same reference numerals. This point also applies to FIGS. 11 to 17, which will be described later.
By removing a portion of the foundation rubble 27 on the water body side from the caisson 24 in advance, burying the box-like structure 11 and driving the piles 13, it becomes possible to increase the depth by the thickness of the foundation rubble 27. .
Furthermore, by placing the horizontal force transmitting member 12 so as to cover the footing portion 29 of the caisson 24, it is possible to suppress the caisson 24 from sliding toward the water area during an earthquake.

［実施例２］
桟橋構造物３１を対象に、本発明の改良構造１で増深改良を行った例を図１１に示す。図１１に示す例では、陸上部４８と水域との境界部には土留め擁壁３２が設けられている。
本実施例の場合は、増深による桟橋の鋼管杭の地盤反力低下に対する補強が主目的となるので、水平力伝達部材１２は配置しなくてもよい。
本実施例によれば、箱状構造体１１が地盤流動を抑制することで、鋼管杭３３に作用する荷重も抑制することができる。この点、例えば、箱状構造体１１の代わりに自立式矢板５３を打設して増深した場合は、地震時の地盤流動量が増大して桟橋の鋼管杭３３に作用する荷重が大きくなる。 [Example 2]
FIG. 11 shows an example of deepening and improving the pier structure 31 using the improved structure 1 of the present invention. In the example shown in FIG. 11, an earth retaining wall 32 is provided at the boundary between the land area 48 and the water area.
In the case of this embodiment, the horizontal force transmitting member 12 does not need to be arranged because the main purpose is to strengthen the steel pipe pile of the pier against a decrease in ground reaction force due to deepening.
According to this embodiment, since the box-like structure 11 suppresses ground flow, the load acting on the steel pipe pile 33 can also be suppressed. In this regard, for example, if the depth is increased by driving a self-supporting sheet pile 53 instead of the box-like structure 11, the amount of ground flow during an earthquake will increase and the load acting on the steel pipe piles 33 of the pier will increase. .

［実施例３］
陸域側に控え工４９を有する矢板式岸壁の隅角部の補強として、本発明の改良構造１を適用した例の平面図を図１２に示す。
控え工４９の鋼管杭３３は、地盤抵抗が十分に発揮されるという前提のもとで二次元断面として設計される。しかし、隅角部は控え工４９が入り組んだ構造となり、十分な地盤抵抗が発揮されない可能性があるため、二次元断面とみなすことができない。
そこで、図１２に示すように、本発明の改良構造１によって水域側地盤の補強を併用することで、地盤抵抗が十分に発揮されない矢板式岸壁の隅角部の補強を効果的に行うことができる。 [Example 3]
FIG. 12 shows a plan view of an example in which the improved structure 1 of the present invention is applied to reinforce the corner portion of a sheet pile type quay wall having a support structure 49 on the land area side.
The steel pipe pile 33 of the support work 49 is designed as a two-dimensional cross section on the premise that ground resistance will be sufficiently exerted. However, the corner part has a complicated structure with support works 49, and there is a possibility that sufficient ground resistance will not be exerted, so it cannot be regarded as a two-dimensional cross section.
Therefore, as shown in FIG. 12, by using the improved structure 1 of the present invention in conjunction with reinforcement of the ground on the water side, it is possible to effectively reinforce the corners of the sheet pile type quay where the ground resistance is not sufficiently exerted. can.

［実施例４］
本発明の改良構造１の岸壁以外への適用例として、重力式の津波防波堤３５の補強の例を図１３に示す。
防波堤の背面側の航路を阻害しない補強方法として、ケーソン２４の背面に自立式の鋼矢板あるいは鋼管矢板を打設する方法が考えられるが、津波波力が作用した時に鋼矢板が背面側に大きくたわみ、十分な補強効果が得られない可能性がある。
この点、本発明の改良構造１によれば、補強部分のたわみが少ないため、粘り強い構造が期待できる。
なお、津波防波堤３５の背面補強の場合には、ケーソン２４に作用する揚圧力（底から上向きにかかる津波波力）を小さくするため、水平力伝達部材１２は透水性の高いものにすることが望ましい。 [Example 4]
As an example of application of the improved structure 1 of the present invention to areas other than quay walls, an example of reinforcing a gravity-type tsunami breakwater 35 is shown in FIG.
As a reinforcing method that does not obstruct the navigation route on the back side of the breakwater, it is possible to install self-supporting steel sheet piles or steel pipe sheet piles on the back side of the caisson 24. Deflection may occur, and sufficient reinforcing effect may not be obtained.
In this regard, according to the improved structure 1 of the present invention, since the reinforcing portion has less deflection, a durable structure can be expected.
In addition, in the case of reinforcing the back of the tsunami breakwater 35, the horizontal force transmission member 12 should be made of a material with high water permeability in order to reduce the uplift force (tsunami wave force applied upward from the bottom) acting on the caisson 24. desirable.

［実施例５］
本発明の効果を確認するため、シミュレーション解析を行ったので、以下これについて説明する。
実験は、図１４に示す-12.6m水深の既存の矢板式岸壁（既存壁体４５は鋼管矢板）を対象とし、水深は変えずに補強改良を行う場合について検討した。
検討条件として、鋼材部分は50年分の標準的な腐食量による減肉を考慮した。
本発明の改良構造１を図１５に、また、用いた箱状構造体１１の形状を図１６にそれぞれ示す。
また、本発明の改良構造１の構造諸元を表２に示す。なお、表２中の改良構造における鋼管杭３３と箱状構造体１１の規格名称は、鋼板の規格を記載している。 [Example 5]
In order to confirm the effects of the present invention, a simulation analysis was performed, which will be described below.
The experiment targeted an existing sheet pile type quay wall (the existing wall 45 is a steel pipe sheet pile) at a water depth of -12.6 m as shown in Figure 14, and examined the case of reinforcement improvement without changing the water depth.
As a condition for consideration, we took into account the thickness loss of the steel parts due to the standard amount of corrosion over 50 years.
The improved structure 1 of the present invention is shown in FIG. 15, and the shape of the box-like structure 11 used is shown in FIG. 16.
Further, the structural specifications of the improved structure 1 of the present invention are shown in Table 2. In addition, the standard name of the steel pipe pile 33 and the box-shaped structure 11 in the improved structure in Table 2 describes the standard of the steel plate.

Figure 0007396331000006
Figure 0007396331000006

比較のため、従来技術として矢板式岸壁の水域側地盤の地盤改良３７を行った補強構造を図１７に示す。
地盤改良３７はセメント固化を想定しており、既存矢板の近傍は高圧噴射撹拌工法、それ以外は深層混合処理工法による原位置改良を前提としている。改良幅は、箱状構造体１１の幅と同じ6mとした。
本発明に係る改良構造１（以下、「本発明改良構造１」という）と従来技術の概算コストを比較試算すると、本発明改良構造１の方が5%程度安価となった。また、施工現場での概略工程を比較すると、本発明改良構造１は3割程度工事期間が短くなる結果となった。 For comparison, FIG. 17 shows a reinforced structure in which ground improvement 37 has been performed on the ground on the water side of a sheet pile type quay as a conventional technique.
Ground Improvement 37 assumes cement solidification, and the area near the existing sheet piles is premised on high-pressure injection stirring method, and the rest is premised on in-situ improvement using deep mixing method. The improved width was set to 6 m, which is the same as the width of the box-like structure 11.
When the estimated costs of improved structure 1 according to the present invention (hereinafter referred to as "improved structure 1 of the present invention") and the prior art were compared, the improved structure 1 of the present invention was about 5% cheaper. Furthermore, when comparing the general steps at the construction site, the improved structure 1 of the present invention resulted in a construction period approximately 30% shorter.

本発明改良構造１と従来技術の耐震性能を比較するため、構造物と地盤の相互作用を考慮した地震応答解析を行った。解析プログラムは、下記の文献に示されたFLIPを用いた。
文献：Iai,S.,Matsunaga,Y.and Kameoka,T.:Strain space plasticity model for cyclic mobility, Soils and Foundations, Vol.32,No.2,pp.1-15,1992.
また、主な解析定数を表３に示す。設計対象の地震動は図１８に示すものである。 In order to compare the seismic performance of the improved structure 1 of the present invention and the conventional technology, an earthquake response analysis was conducted that took into account the interaction between the structure and the ground. The analysis program used was FLIP, which is shown in the following literature.
Literature: Iai, S., Matsunaga, Y. and Kameoka, T.: Strain space plasticity model for cyclic mobility, Soils and Foundations, Vol. 32, No. 2, pp. 1-15, 1992.
In addition, the main analysis constants are shown in Table 3. The seismic motion to be designed is shown in Figure 18.

Figure 0007396331000007
Figure 0007396331000007

岸壁天端（図１４、図１５、図１７のA点）の水平変位の時刻歴を、図１９～図２１に示す。図１９が、図１４に示した改良前のもの、図２０が図１５に示した本発明による改良後のもの、図２１が図１７に示した従来技術による改良後のものである。
ここで、水平変位は水域側への変位が負の値をとる。
図１９においては、１５秒後から２０秒後におけるA点の変位が－５０ｃｍとなるのに対し、図２０と図２１では、１５秒後から２０秒後におけるA点の変位が－４５ｃｍ程度に収まっている。この図１９～図２１に示す結果から、本発明改良構造１によって改良前よりも岸壁天端の変位を抑制することが可能となり、その耐震性能は従来技術と遜色ないことが分かる。 The time history of the horizontal displacement of the top of the quay (point A in Figures 14, 15, and 17) is shown in Figures 19 to 21. 19 shows the one before the improvement shown in FIG. 14, FIG. 20 shows the one after the improvement according to the present invention shown in FIG. 15, and FIG. 21 shows the one after the improvement according to the prior art shown in FIG. 17.
Here, the horizontal displacement toward the water area takes a negative value.
In Figure 19, the displacement of point A from 15 seconds to 20 seconds is -50cm, whereas in Figures 20 and 21, the displacement of point A from 15 seconds to 20 seconds is approximately -45cm. It's settled. From the results shown in FIGS. 19 to 21, it can be seen that the improved structure 1 of the present invention makes it possible to suppress the displacement of the top of the quay more than before the improvement, and that its seismic performance is comparable to the conventional technology.

１ 既存岸壁の改良構造
３ 周壁面部
５ 通水口
７ 天面部
９ 杭挿通孔
１１ 箱状構造体
１３ 杭
１２ 水平力伝達部材
１５ Ｈ形鋼
１７ 鋼板
１９ リブ材
２１ 仕切り壁体
２２ 増幅上部工
２３ 仮継ぎ杭
２４ ケーソン
２５ 重力式岸壁
２７ 基礎捨石
２９ フーチング部
３１ 桟橋式構造物
３２ 土留め擁壁
３３ 鋼管杭
３５ 津波防波堤
３７ 地盤改良
４１ 既存岸壁（既存の矢板式岸壁）
４３ 水底地盤
４５ 既存壁体
４７ 上部工
４８ 陸上部
４９ 控え工
５１ タイ材
５３ 自立式矢板
５５ 補強杭 1 Improved structure of existing quay 3 Peripheral wall section 5 Water inlet 7 Top section 9 Pile insertion hole 11 Box-shaped structure 13 Pile 12 Horizontal force transmission member 15 H-shaped steel 17 Steel plate 19 Rib material 21 Partition wall body 22 Amplifying superstructure 23 Temporary joint pile 24 Caisson 25 Gravity quay 27 Foundation rubble 29 Footing 31 Pier type structure 32 Earth retaining wall 33 Steel pipe pile 35 Tsunami breakwater 37 Ground improvement 41 Existing quay (existing sheet pile quay)
43 Submerged ground 45 Existing wall 47 Superstructure 48 Land section 49 Support work 51 Tie material 53 Self-supporting sheet pile 55 Reinforcement pile

Claims (4)

周壁面部と通水口が設けられた天面部と複数の杭挿通孔とを有し、既存岸壁における既存壁体の水域側の水底地盤に配設された箱状構造体と、
該箱状構造体の前記杭挿通孔に挿通されて、前記水底地盤に打設された複数の杭と、
前記杭挿通孔と前記杭との隙間に配設された間詰材と、
前記既存壁体と前記箱状構造体との間に配設されて前記既存壁体からの水平力を前記箱状構造体に伝達する水平力伝達部材と、を備え、
前記箱状構造体は、４面の周壁部と天板部を有する矩形状の箱形状であり、長辺側を前記既存岸壁に対向させて配置され、短辺側の壁体は長辺側の壁体よりも剛性が高められていることを特徴とする既存岸壁の改良構造。 A box-shaped structure having a peripheral wall surface portion, a top surface portion provided with a water inlet, and a plurality of pile insertion holes, and is disposed on the water bottom ground on the water body side of the existing wall body in the existing quay wall;
a plurality of piles inserted into the pile insertion holes of the box-like structure and driven into the underwater ground;
a filler material disposed in a gap between the pile insertion hole and the pile;
a horizontal force transmission member disposed between the existing wall and the box-like structure to transmit horizontal force from the existing wall to the box-like structure ;
The box-like structure has a rectangular box shape having four peripheral walls and a top plate, and is arranged with the long side facing the existing quay wall, and the wall on the short side faces the long side. This is an improved structure for an existing quay wall that is characterized by higher rigidity than the existing quay wall . 前記杭は、前記杭挿通孔の下端から鋼管直径３倍以上の長さの範囲において、降伏強度400N/mm2以上及び／又は鋼管杭の外径R(mm)と鋼管杭の肉厚t(mm)との比R/tがR/t≦80であることを特徴とする請求項１記載の既存岸壁の改良構造。 The pile has a yield strength of 400 N/mm 2 or more and/or an outer diameter R (mm) of the steel pipe pile and a wall thickness t ( 2. The improved structure for an existing quay wall according to claim 1, wherein the ratio R/t to the quay (mm) satisfies R/t≦80. 前記既存岸壁が、下端側を地盤に根入れすると共に上端側をタイ材によって控え工で支持する矢板式岸壁の場合において、前記水平力伝達部材が（１）式を満たす位置に配置されていることを特徴とする請求項１又は２に記載の既存岸壁の改良構造。
Figure 0007396331000008
 ここで、
D：既存岸壁の矢板の根入長(m)
HT：既存岸壁の水底地盤からタイ材取り付け位置までの高さ(m)
E：既存岸壁の矢板のヤング率(kN/m2)
I：既存岸壁の単位幅あたりの矢板の断面２次モーメント(m4/m)
lh：既存岸壁の矢板が根入れされている地盤の地盤反力係数(kN/m3)
H：水底地盤から水平力伝達部材上端までの高さ(m) In the case where the existing quay is a sheet pile type quay in which the lower end side is rooted in the ground and the upper end side is supported by tie materials with a buttress, the horizontal force transmission member is arranged at a position that satisfies formula (1). The improved structure for an existing quay according to claim 1 or 2, characterized in that:
Figure 0007396331000008
 here,
D: Penetration length of existing quay sheet pile (m)
H T : Height (m) from the underwater ground of the existing quay to the tie material installation position
E: Young's modulus of existing quay sheet pile (kN/m 2 )
I: Second moment of inertia of sheet pile per unit width of existing quay (m 4 /m)
l h : Ground reaction force coefficient of the ground into which the existing quay sheet pile is embedded (kN/m 3 )
H: Height from the bottom of the water to the top of the horizontal force transmission member (m) 請求項１乃至３のいずれかに記載の既存岸壁の改良構造の施工方法であって、
前記既存壁体の水域側に、該既存壁体と所定の隙間を設けて前記箱状構造体を水底地盤上に自沈させる工程と、
前記箱状構造体の杭挿通孔を通して前記杭を打設し、杭打設に使用した仮継ぎ杭を残した状態にする工程と、
前記箱状構造体の通水口から内部の水を強制的に排水し、前記仮継ぎ杭をガイド軸として前記箱状構造体を水底地盤内に沈設させる工程と、
前記杭挿通孔と前記杭との隙間に間詰材を配設する工程と、
前記既存壁体と前記箱状構造体との間に水平伝達部材を配設する工程と、を備えたことを特徴とする既存岸壁の改良構造の施工方法。 A method for constructing an improved structure for an existing quay according to any one of claims 1 to 3, comprising:
A step of scuttling the box-shaped structure onto the underwater ground by providing a predetermined gap with the existing wall on the water body side of the existing wall;
Driving the pile through the pile insertion hole of the box-like structure, leaving the temporary joint pile used for pile driving ;
forcibly draining water inside the box-like structure from a water inlet, and sinking the box-like structure into underwater ground using the temporary joint pile as a guide shaft;
arranging a filler material in the gap between the pile insertion hole and the pile;
A method for constructing an improved structure for an existing quay, comprising the step of arranging a horizontal transmission member between the existing wall and the box-like structure.
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JP2012097415A (en) 2010-10-29 2012-05-24 Jfe Steel Corp Steel pipe sheet pile quaywall
JP2020204151A (en) 2019-06-14 2020-12-24 Ｊｆｅスチール株式会社 Improvement structure and improvement method of existing sheet pile type quay

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012097415A (en) 2010-10-29 2012-05-24 Jfe Steel Corp Steel pipe sheet pile quaywall
JP2020204151A (en) 2019-06-14 2020-12-24 Ｊｆｅスチール株式会社 Improvement structure and improvement method of existing sheet pile type quay

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