JP2803409B2 - Liquefaction countermeasure structure for embankment - Google Patents
Liquefaction countermeasure structure for embankmentInfo
- Publication number
- JP2803409B2 JP2803409B2 JP3266156A JP26615691A JP2803409B2 JP 2803409 B2 JP2803409 B2 JP 2803409B2 JP 3266156 A JP3266156 A JP 3266156A JP 26615691 A JP26615691 A JP 26615691A JP 2803409 B2 JP2803409 B2 JP 2803409B2
- Authority
- JP
- Japan
- Prior art keywords
- liquefaction
- embankment
- pile
- ground
- sheet pile
- 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.)
- Expired - Lifetime
Links
Landscapes
- Pit Excavations, Shoring, Fill Or Stabilisation Of Slopes (AREA)
- Investigation Of Foundation Soil And Reinforcement Of Foundation Soil By Compacting Or Drainage (AREA)
Description
【0001】[0001]
【産業上の利用分野】本発明は排水機能を有する液状化
抑止杭または液状化抑止矢板を用いた盛土の液状化対策
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 an embankment liquefaction countermeasure structure using a liquefaction inhibiting pile or a liquefaction inhibiting sheet pile having a drainage function.
【0002】[0002]
【従来の技術】液状化のおそれのある地盤(以下、単に
液状化地盤と呼ぶ)上にある盛土構造物に対し、従来検
討されている液状化対策構造としては、壁構造方式、杭
離散配置方式、締固め方式、排水方式が挙げられる。こ
れらの特徴を以下に述べる。2. Description of the Related Art For embankment structures on the ground where liquefaction is likely to occur (hereinafter, simply referred to as liquefaction ground), liquefaction countermeasures that have been studied so far include a wall structure method and a discrete pile arrangement. System, compaction system and drainage system. These features are described below.
【0003】(1) 壁構造方式 壁構造方式は図11に例示するように、盛土1の両側に
鋼矢板21または鋼管矢板(図示せず)からなる壁構造
物を形成し、タイロッド20を用いて壁構造物の頭部ど
うしを所定ピッチで連結するものである。液状化しない
軟弱地盤では、これにより地震時の盛土1の変状(沈
下、法面のすべり、盛土下の地盤の側方流動の総称)を
防止することができ、急速施工が可能である。(1) Wall Structure Method As shown in FIG. 11, a wall structure made of a steel sheet pile 21 or a steel pipe sheet pile (not shown) is formed on both sides of an embankment 1 as shown in FIG. To connect the heads of the wall structures at a predetermined pitch. In soft ground that does not liquefy, this can prevent deformation of the embankment 1 during earthquakes (general term of subsidence, slip of the slope, lateral flow of the ground under the embankment), and rapid construction is possible.
【0004】液状化地盤上の盛土への適用においては、
盛土断面の幅が狭い場合、盛土1の周辺の地盤が液状化
するような地震力においても、本方式の構造の持つ強
度、剛性による地盤拘束効果が発揮され、盛土1下部の
過剰間隙水圧の上昇および地盤の強度低下を抑制し、盛
土1の変状を抑えることができる。In application to embankment on liquefied ground,
When the width of the embankment section is narrow, even under the seismic force where the ground around the embankment 1 becomes liquefied, the ground restraining effect due to the strength and rigidity of the structure of this method is exerted, and the excess pore water pressure at the lower part of the embankment 1 is reduced. The rise and the decrease in the strength of the ground can be suppressed, and the deformation of the embankment 1 can be suppressed.
【0005】(2) 杭離散配置方式 杭離散配置方式は図12に例示するように、盛土1の両
側に杭22を中心間隔2D(D:杭径)で千鳥状に打設
するものである。(2) Discrete pile placement method In the pile discrete placement method, as shown in FIG. 12, piles 22 are staggered on both sides of the embankment 1 at a center interval 2D (D: pile diameter). .
【0006】本方式では盛土1延長方向の杭22の頭部
どうしを鉄筋コンクリート製の笠コンクリートまたはコ
ンクリート基礎6で連結し、またタイロッド20を用い
て盛土1の両側の杭22どうしを所定ピッチで連結して
いる。In this method, the heads of the piles 22 in the extending direction of the embankment 1 are connected to each other by a reinforced concrete cap or concrete foundation 6, and the piles 22 on both sides of the embankment 1 are connected at a predetermined pitch by using a tie rod 20. doing.
【0007】本方式も液状化しない軟弱地盤において矢
板壁構造方式と同様の利点を有し、さらに杭22を離散
配置しているため、地下水の流れを遮断することがな
い。This method also has the same advantages as the sheet pile wall structure method on soft ground that does not liquefy, and furthermore, since the piles 22 are arranged discretely, the flow of groundwater is not interrupted.
【0008】(3) 地盤締固め方式 地盤締固め方式は図13に例示するように、液状化地盤
4上の盛土1の両側を締固めるもの(サンドコンパクシ
ョンパイル工法他)であり、盛土1の断面の大きさによ
っては図14に例示するように、押え盛土24を併用す
る方法もある。図中、13は砂杭等の地盤締固め工を示
す。(3) Ground Compaction Method The ground compaction method is a method of compacting both sides of the embankment 1 on the liquefied ground 4 (sand compaction pile method and the like) as shown in FIG. Depending on the size of the cross section, there is also a method of using the holding embankment 24 together, as illustrated in FIG. In the figure, reference numeral 13 denotes a ground compaction work such as a sand pile.
【0009】本方式は周辺地盤が液状化するような地震
力においても、締固め効果により締固め地盤内での過剰
間隙水圧の上昇を抑制するとともに、地盤拘束効果によ
り盛土の変状を抑えることができる。また、本方式では
砂材を用い、液状化地盤4そのものを締固めるので、盛
土1下の地下水の流れを遮断することがない。This method suppresses the rise of excess pore water pressure in the compacted ground by the compacting effect and suppresses the deformation of the embankment by the ground restraining effect even under the seismic force that liquefies the surrounding ground. Can be. Further, in this method, since the liquefied ground 4 itself is compacted by using the sand material, the flow of the groundwater under the embankment 1 is not interrupted.
【0010】(4) 排水方式 排水方式は図15に例示するように、盛土1の両側に地
震の際の液状化地盤4内での過剰間隙水圧の上昇を抑制
する目的で、砕石ドレーンや樹脂ドレーン等の排水材2
5を柱状に設けるものである。(4) Drainage system As shown in FIG. 15, the drainage system is provided on both sides of the embankment 1 with the purpose of suppressing excessive rise in pore water pressure in the liquefied ground 4 during an earthquake. Drainage material such as drain 2
5 is provided in a columnar shape.
【0011】本方式は盛土幅および高さが小さい場合、
盛土1の周辺地盤が液状化しても排水材25の排水効果
によってその周辺地盤の過剰間隙水圧の上昇を抑制し、
噴砂を抑えるとともに、地盤の強度低下、盛土1の変状
を抑えることができる。また、本方式は地下水の流れを
遮断することがない。In this method, when the embankment width and height are small,
Even if the surrounding ground of the embankment 1 is liquefied, the drainage effect of the drainage material 25 suppresses the rise of the excess pore water pressure of the surrounding ground,
In addition to suppressing sand blasting, it is possible to suppress a decrease in ground strength and deformation of the embankment 1. Also, this method does not interrupt the flow of groundwater.
【0012】[0012]
【発明が解決しようとする課題】上述した液状化地盤上
にある盛土構造物の液状化対策構造には、以下のような
問題点がある。The liquefaction countermeasure structure of the embankment structure on the liquefied ground has the following problems.
【0013】(1) 壁構造方式 盛土断面幅(特に法部)が広くなるにつれ、盛土の両側
に設けられた壁構造の持つ強度、剛性による地盤拘束効
果が低減し、壁構造によって囲まれた地盤内でも過剰間
隙水圧が上昇し、壁面が流線となって壁面沿いに噴砂が
みられ、盛土の変状が大きくなる。(1) Wall structure method As the cross section width of the embankment (particularly the slope) becomes wider, the ground restraining effect due to the strength and rigidity of the wall structures provided on both sides of the embankment is reduced, and the embankment is surrounded by the wall structure. Excess pore water pressure also rises in the ground, the wall surface becomes streamline, sand erosion is seen along the wall surface, and the deformation of the embankment increases.
【0014】なお、過剰間隙水圧の上昇時において壁構
造に作用する水圧(1−K0 )Δu〔K0 :初期土圧係
数、Δu:過剰間隙水圧〕も増加するため、過剰間隙水
圧が上昇しない場合に比べ、壁構造の持つ強度、剛性を
さらに高める必要があり、不経済となる。When the excess pore water pressure rises, the water pressure (1-K 0 ) Δu (K 0 : initial earth pressure coefficient, Δu: excess pore water pressure) acting on the wall structure also increases, so that the excess pore water pressure rises. It is necessary to further increase the strength and stiffness of the wall structure as compared with the case where it is not performed, which is uneconomical.
【0015】さらに、壁構造物が地下水の流れを遮断す
るため、地下水環境が変化する。Furthermore, the groundwater environment changes because the wall structure blocks the flow of groundwater.
【0016】(2) 杭離散配置方式 地震の際、盛土法尻部下面の地盤での過剰間隙水圧の上
昇により地盤強度が低減し、杭間から砂が抜け出して盛
土の変状が生じるため、本方式は液状化地盤上の盛土に
は適さない。(2) Discrete pile arrangement method In the event of an earthquake, the ground strength is reduced due to an increase in excess pore water pressure on the ground under the bottom of the embankment method, and sand is released from between the piles to cause deformation of the embankment. This method is not suitable for embankment on liquefied ground.
【0017】(3) 地盤締固め方式 本方式を既設盛土に適用する場合は、盛土断面幅に関わ
らず盛土法尻部より外側に締固め地盤を形成せざるを得
ず、盛土両側の締固め地盤間の幅が広くなり、壁構造と
同様の傾向がみられる。このため、押え盛土との併用
(図14)等の必要が生じ、不経済となる。(3) Soil compaction method When this method is applied to an existing embankment, compaction ground must be formed outside the bottom of the embankment method regardless of the width of the embankment, and compaction on both sides of the embankment. The width between the grounds becomes wider, and the same tendency as the wall structure is observed. For this reason, it is necessary to use it together with the embankment (FIG. 14) or the like, which is uneconomical.
【0018】また、盛土が新設か既設かに関わらず、液
状化地盤内で発生する過剰間隙水圧の締固め地盤への伝
達により、その境界面近くの締固め地盤のせん断強度は
低下し、その低下の程度が不明なため、締固め幅にある
程度余裕を持たせる必要がある。その結果、経済性が損
なわれるとともに、施工期間も長くなる。[0018] Regardless of whether the embankment is new or existing, the transmission of the excess pore water pressure generated in the liquefied ground to the compacted ground reduces the shear strength of the compacted ground near the boundary surface. Since the degree of the decrease is unknown, it is necessary to allow some space in the compaction width. As a result, economic efficiency is impaired and the construction period is lengthened.
【0019】(4) 排水方式 本方式で、地震時の排水効果が期待される領域は排水位
置から約1mであるため、過剰間隙水圧抑制による地盤
強度の低下抑制域も約1mと広くない。その上、排水材
自体に砕石ドレーンや樹脂ドレーン等を使用しているた
め、鋼製の排水材を適用した場合と比べ、せん断強度は
小さい。そのため、鋼製の排水材を適用した場合と比べ
施工幅は広がり、その結果、経済性が損なわれるととも
に、施工期間も長くなる。(4) Drainage method In this method, the area where the drainage effect in the event of an earthquake is expected is about 1 m from the drainage position, so the area where the decrease in ground strength due to excessive pore water pressure suppression is not as large as about 1 m. In addition, since a crushed stone drain or a resin drain is used for the drainage material itself, the shear strength is lower than when steel drainage material is used. Therefore, compared with the case where a steel drainage material is applied, the construction width is widened, and as a result, economic efficiency is impaired and the construction period is lengthened.
【0020】本発明は上述のような従来技術における問
題点を解決することを目的としたものである。すなわ
ち、液状化地盤上に大規模な盛土を設ける際、盛土下を
流れる地下水を遮断することなく、地震の際の盛土周辺
および下面の地盤内に発生する過剰間隙水圧を逸散さ
せ、地盤拘束効果と相まって盛土の変状を防止するとと
もに、液状化対策構造の施工性と経済性を向上させるこ
とを目的とする。An object of the present invention is to solve the problems in the prior art as described above. In other words, when a large-scale embankment is installed on the liquefied ground, the excess pore water pressure generated around the embankment and the ground under the embankment during the earthquake is dissipated without interrupting the groundwater flowing under the embankment, The purpose is to prevent deformation of the embankment in combination with the effect, and to improve the workability and economic efficiency of the liquefaction countermeasure structure.
【0021】[0021]
【課題を解決するための手段】以下、本発明の概要を実
施例に対応する図面の符号を用いて説明する。An outline of the present invention will be described below with reference to the drawings corresponding to the embodiments.
【0022】本発明の盛土の液状化対策構造は盛土1の
法面または法尻近傍に、透水性と排水性を兼ね備えた列
状に並んだ液状化抑止杭2または壁状になった液状化抑
止矢板3を設置することにより、盛土1下の液状化地盤
4、非液状化地盤5中の地下水の流れを遮断せず、かつ
地震の際に生じる液状化地盤4内の過剰間隙水圧の上昇
を抑え、液状化抑止杭2、液状化抑止矢板3に沿う噴砂
を防止するとともに、その強度、剛性により盛土の変状
を防止するものである。The liquefaction countermeasure structure of the embankment of the present invention comprises a row of liquefaction-inhibiting piles 2 or a wall-shaped liquefaction having both water permeability and drainage on the slope surface or near the bottom of the embankment 1. The installation of the deterrent sheet pile 3 does not interrupt the flow of groundwater in the liquefied ground 4 and the non-liquefied ground 5 under the embankment 1, and increases the excess pore water pressure in the liquefied ground 4 generated during an earthquake. To prevent sand blasting along the liquefaction inhibiting pile 2 and the liquefaction inhibiting sheet pile 3, and to prevent deformation of the embankment by its strength and rigidity.
【0023】そのため、本発明では液状化抑止杭2を構
成する杭として、例えば杭本体の液状化地盤4内に位置
する部分に多数の小孔11を形成した有孔部を有する液
状化抑止杭2a、あるいは長手方向の中空部を有し、液
状化地盤4内に位置する部分に多数の小孔11を形成し
た排水用部材13を有する液状化抑止杭2b等を用い
る。For this reason, in the present invention, a liquefaction-preventing pile having, as a pile constituting the liquefaction-preventing pile 2, a perforated portion having a large number of small holes 11 formed in a portion of the pile body located in the liquefied ground 4, for example 2a, or a liquefaction prevention pile 2b having a drainage member 13 having a hollow portion in the longitudinal direction and having a number of small holes 11 formed in a portion located in the liquefied ground 4 is used.
【0024】また、液状化抑止矢板3の場合は、壁状構
造物を構成する矢板のうち少なくとも一部の矢板につい
て、例えば矢板本体全面を穿孔した鋼管矢板形式の液状
化抑止矢板3a、あるいは前記液状化抑止杭2b同様の
排水用部材13を有する板状の液状化抑止矢板3b等を
用いる。In the case of the liquefaction inhibiting sheet pile 3, at least a part of the sheet piles constituting the wall-like structure, for example, a steel pipe sheet pile type liquefaction inhibiting sheet pile 3a in which the entire sheet pile body is perforated, or the aforementioned liquefaction inhibiting sheet pile 3a. A plate-like liquefaction-inhibiting sheet pile 3b having a drainage member 13 similar to the liquefaction-inhibiting pile 2b is used.
【0025】また、地震時に液状化抑止杭2aまたは2
b、液状化抑止矢板3aまたは3bに流入する地中水の
排水対策としては、該液状化抑止杭または液状化抑止矢
板の頭部の周囲から地下水位よりも高い位置まで盛土延
長方向に砕石マット8、または砕石マット8および盲暗
渠9を設けるとよい。In addition, the liquefaction prevention pile 2a or 2
b. As a countermeasure against drainage of underground water flowing into the liquefaction-preventing sheet pile 3a or 3b, a crushed rock mat in the embankment extension direction from the periphery of the liquefaction-suppressing pile or the head of the liquefaction-suppressing sheet pile to a position higher than the groundwater level. 8, or a crushed stone mat 8 and a blind culvert 9 may be provided.
【0026】[0026]
【作用】本構造は盛土において最も液状化しやすい部位
へ、強度、剛性の大きな液状化抑止杭または液状化抑止
矢板を液状化地盤下の非液状化地盤内まで適切に設ける
ことにより、地震時にこれら液状化抑止杭または液状化
抑止矢板周辺の過剰間隙水圧の上昇を抑制し、地盤強度
低下を防ぐとともに、杭または矢板としての地盤拘束効
果により盛土の変状を抑えることかできる。[Function] This structure is designed to provide a liquefaction-preventing pile or liquefaction-preventing sheet pile with high strength and rigidity to the most liquefiable part of the embankment up to the non-liquefied ground under the liquefied ground. It is possible to suppress the rise of the excess pore water pressure around the liquefaction inhibiting pile or liquefaction inhibiting sheet pile, prevent the ground strength from decreasing, and suppress the deformation of the embankment by the soil restraining effect as the pile or the sheet pile.
【0027】さらに、液状化抑止杭または液状化抑止矢
板の排水機能により同表面での流線の形成を妨げ、噴砂
を防止する。Further, the drainage function of the liquefaction suppression pile or the liquefaction suppression sheet pile prevents the formation of streamlines on the same surface, thereby preventing sand blasting.
【0028】また、本構造では離散配置される液状化抑
止杭または壁状に配置される液状化抑止矢板に透水性を
持たせることにより、地中水の流れを遮断することな
く、地下水環境を維持する。In this structure, the liquefaction-prevention piles or the liquefaction-prevention sheet piles arranged in the form of walls are made permeable so that the groundwater environment can be reduced without interrupting the flow of groundwater. maintain.
【0029】[0029]
【実施例】次に図示した実施例について説明する。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the illustrated embodiment will be described.
【0030】図1は盛土の液状化対策に排水機能および
透水性を有する液状化抑止杭3aを用いた場合の一実施
例を示したものである。FIG. 1 shows an embodiment in which a liquefaction inhibiting pile 3a having a drainage function and water permeability is used for liquefaction countermeasures for embankment.
【0031】すなわち、壁構造方式における通常の土留
用矢板の代わりに、鋼管矢板の所定区間に多数の開口部
およびフィルターを設けた液状化抑止矢板3a(図4参
照)を用い、液状化抑止矢板3a頭部の笠コンクリート
またはコンクリート基礎6により盛土延長方向の液状化
抑止矢板3aどうしを連結し、タイロッド7により盛土
延長直角方向の液状化抑止矢板3a連結している。ま
た、液状化抑止矢板3aの上部の排水位置には砕石マッ
ト8を埋戻しにより設けてある。That is, a liquefaction-preventing sheet pile 3a (see FIG. 4) in which a number of openings and filters are provided in a predetermined section of a steel pipe sheet-pile is used instead of a normal pile sheet pile in a wall structure system. The liquefaction-preventing sheet piles 3a in the embankment extension direction are connected to each other by a shading concrete or concrete foundation 6 at the head of the 3a, and the liquefaction suppression sheet piles 3a in the direction perpendicular to the embankment extension direction are connected by tie rods 7. In addition, a crushed stone mat 8 is provided by backfilling at a drain position above the liquefaction inhibiting sheet pile 3a.
【0032】本実施例は液状化抑止矢板3aの排水効果
により、地震の際に液状化地盤4内で生じる過剰間隙水
圧の上昇を液状化抑止矢板3aの近傍で抑制し、液状化
地盤4の強度低下を防ぐことができる。また、矢板とし
ての強度、剛性を有する液状化抑止矢板3aを液状化地
盤4下の非液状化地盤5まで根入れすることにより、地
盤拘束効果を発揮し、地盤の変状を抑えることができ
る。In this embodiment, due to the drainage effect of the liquefaction-preventing sheet pile 3a, an increase in excess pore water pressure generated in the liquefaction ground 4 during an earthquake is suppressed in the vicinity of the liquefaction prevention sheet pile 3a. A decrease in strength can be prevented. In addition, the liquefaction-preventing sheet pile 3a having strength and rigidity as a sheet pile is laid into the non-liquefied ground 5 under the liquefied ground 4, thereby exhibiting a ground restraining effect and suppressing deformation of the ground. .
【0033】なお、自立式矢板の設計において、液状化
抑止矢板3aのみで盛土1の安定が可能となる場合、タ
イロッド7等を省くことができる。In the design of the self-supporting sheet pile, when the embankment 1 can be stabilized only by the liquefaction-preventing sheet pile 3a, the tie rod 7 and the like can be omitted.
【0034】なお、液状化抑止矢板3aに代え、図5、
図6に示すような板状の液状化抑止矢板3bあるいは図
2、図3に示すような液状化抑止杭2a、2bを用いて
もよい。液状化抑止杭2a、2bの場合には、これらを
適切な杭ピッチで打設することにより、液状化抑止杭間
の砂が一種の壁構造を形成し、液状化抑止矢板3aと同
様な効果を示す。In place of the liquefaction-preventing sheet pile 3a, FIG.
A plate-like liquefaction-inhibiting sheet pile 3b as shown in FIG. 6 or a liquefaction-inhibiting pile 2a, 2b as shown in FIGS. 2 and 3 may be used. In the case of the liquefaction prevention piles 2a and 2b, by sanding them at an appropriate pile pitch, the sand between the liquefaction prevention piles forms a kind of wall structure and has the same effect as the liquefaction prevention sheet pile 3a. Is shown.
【0035】図2および図3は本発明において使用され
る液状化抑止杭の例を、図4および図5、図6は本発明
において使用される液状化抑止矢板の例を示す。FIGS. 2 and 3 show examples of the liquefaction inhibiting pile used in the present invention, and FIGS. 4, 5 and 6 show examples of the liquefaction inhibiting sheet pile used in the present invention.
【0036】図2の液状化抑止杭2aは鋼管の所定区
間、すなわち、液状化地盤の厚さにわたり、多数の開口
部11を形成し、その開口部11に土砂の流入を防ぐた
めのフィルター12を設け、鋼管内部を排水空間とした
ものである(特開昭61−146910号公報参照)。The liquefaction-preventing pile 2a shown in FIG. 2 has a number of openings 11 formed over a predetermined section of the steel pipe, that is, the thickness of the liquefied ground, and a filter 12 for preventing the inflow of earth and sand into the openings 11. And the inside of the steel pipe is used as a drainage space (see JP-A-61-146910).
【0037】図3の液状化抑止杭2bは鋼管外面長手方
向所定区間に排水用部材13を設けたもので、排水用部
材13に多数の開口部11と開口部11からの地盤の土
砂の侵入を防ぐためのフィルター12を設けたものであ
る。The liquefaction prevention pile 2b in FIG. 3 is provided with a drainage member 13 at a predetermined section in the longitudinal direction of the outer surface of the steel pipe. The drainage member 13 has a large number of openings 11 and intrusion of soil from the ground through the openings 11. This is provided with a filter 12 for preventing the above.
【0038】図4の液状化抑止矢板3aは雄雌の継手1
4、15を有する鋼管矢板の所定区間に多数の開口部1
1を形成し、この開口部11に土砂の侵入を防ぐための
フィルター12を設け、鋼管内部を排水空間としている
(特開平1−226920号公報等参照)。The liquefaction-preventing sheet pile 3a shown in FIG.
A number of openings 1 are provided in a predetermined section of a steel sheet pile having
A filter 12 for preventing intrusion of earth and sand is provided in the opening 11, and the inside of the steel pipe is used as a drainage space (see Japanese Patent Application Laid-Open No. 1-226920).
【0039】図5、図6の液状化抑止矢板3bは両端に
継手16を有する板状の矢板の長手方向に沿った所定区
間に排水用部材13を設けたもので、排水用部材13お
よび液状化抑止矢板3bに多数の開口部11と開口部1
1からの地盤の土砂の侵入をほせぐためのフィルター1
2を設けてある(特開平1−125413号公報等参
照)。The liquefaction-preventing sheet pile 3b shown in FIGS. 5 and 6 is provided with a drainage member 13 at a predetermined section along the longitudinal direction of a sheet-like sheet pile having joints 16 at both ends. Numerous openings 11 and openings 1 in the deterrent sheet pile 3b
Filter 1 to reduce intrusion of soil from the ground from 1
2 (see Japanese Patent Application Laid-Open No. 1-125413, etc.).
【0040】以上はそれぞれ液状化抑止杭および液状化
抑止矢板の一例を挙げたものであり、本発明で利用する
液状化抑止杭および液状化抑止矢板としては、杭または
矢板の機能と地震時の地盤内に発生する過剰間隙水圧を
逸散させるための排水機能を備えたものであれば、その
形式は問わない。The above is an example of the liquefaction-suppressing pile and the liquefaction-suppressing sheet pile, respectively. The liquefaction-suppressing pile and the liquefaction-suppressing sheet pile used in the present invention are based on the function of the pile or the sheet pile and the function at the time of earthquake. Any type can be used as long as it has a drainage function for dissipating excessive pore water pressure generated in the ground.
【0041】図7〜図10は本発明において使用される
排水用砕石マット8の設置例を示したものである。FIGS. 7 to 10 show examples of the installation of the crushed stone mat 8 for drainage used in the present invention.
【0042】排水用砕石マット8は液状化抑止杭2また
は液状化抑止矢板の頭部の周囲から地下水位よりも高い
位置まで盛土延長方向に沿って連続して施工する。The crushed stone mat 8 for drainage is continuously constructed along the embankment extending direction from the periphery of the head of the liquefaction inhibiting pile 2 or the liquefaction inhibiting sheet pile to a position higher than the groundwater level.
【0043】砕石マット8内には、さらに排水を円滑に
するための盲暗渠9等を施すこともあり、図10は盲暗
渠9を液状化抑止杭2の両側に設けた場合、図8および
図9は片側に設けた場合を示したものである。盲暗渠9
は塩化ビニール管、鉄筋コンクリート管、陶管等、地中
水排水時の透水性が確保されるものであればよい。The crushed stone mat 8 may be provided with a blind conduit 9 for smooth drainage. FIG. 10 shows a case where the blind conduit 9 is provided on both sides of the liquefaction prevention pile 2. FIG. 9 shows a case in which it is provided on one side. Culvert 9
Any material such as a vinyl chloride pipe, a reinforced concrete pipe, and a porcelain pipe may be used as long as it can ensure water permeability when draining groundwater.
【0044】なお、砕石マット8は、通常、一般の排水
路に接続されるが、排水路を設けず、砕石マット8に地
中水を貯留し、貯留した地中水を地震後に地盤への浸透
によって排水する方法もある。The crushed stone mat 8 is usually connected to a general drainage channel. However, no drainage channel is provided, the groundwater is stored in the crushed stone mat 8, and the stored groundwater is transferred to the ground after an earthquake. There is also a method of draining by infiltration.
【0045】[0045]
【発明の効果】本発明の盛土の液状化対策構造は地震時
に最も液状化しやすい盛土法面または法尻近傍に排水
性、透水性を備え、かつ杭または矢板としての強度、剛
性を有する液状化抑止杭または液状化抑止矢板を、液状
化地盤下の非液状化地盤内まで適切に設けている。これ
により、以下の効果が得られる。The liquefaction countermeasure structure of the embankment of the present invention has a drainage property and a water permeability near the embankment slope or the bottom of the embankment where liquefaction is most likely to occur during an earthquake, and has the strength and rigidity of a pile or sheet pile. Deterrent piles or liquefaction deterrent sheet piles are properly installed in the non-liquefied ground below the liquefied ground. As a result, the following effects can be obtained.
【0046】 地震時に生じる地中水の排水ルート確
保により、過剰間隙水圧上昇を抑制し、地盤強度の低減
を防止できる。By securing a drainage route for underground water generated during an earthquake, an excessive rise in pore water pressure can be suppressed, and a decrease in ground strength can be prevented.
【0047】 強度、剛性のある液状化抑止杭または
液状化抑止矢板を液状化地盤に十分に根入れすることに
より、地盤拘束効果が発揮される。The ground restraining effect is exerted by sufficiently staking the liquefaction prevention pile or the liquefaction prevention sheet pile having strength and rigidity into the liquefaction ground.
【0048】 液状化抑止杭または液状化抑止矢板の
排水機能により、同表面での流線の形成を妨げ、噴砂を
防止できる。[0048] The drainage function of the liquefaction inhibiting pile or liquefaction inhibiting sheet pile can prevent the formation of streamlines on the same surface and prevent sand blasting.
【0049】 〜により盛土の変状を抑えること
ができる。By means of the above, deformation of the embankment can be suppressed.
【0050】 液状化抑止杭または液状化抑止矢板の
透水性により地中水の流れを遮断せず、またこれらの頭
部排水位置から地下水位よりも高い位置まで連続する砕
石マットにより、地震時に液状化抑止杭または液状化抑
止矢板に流入する地中水の排水を行い、地下水環境を維
持することができる。[0050] without interrupting the flow of underground water by water permeability of liquefaction suppression piles or liquefaction suppression sheet pile, also of head
Continuous crushing from the head drainage position to the position higher than the groundwater level
Liquefaction control piles or liquefaction control during an earthquake
Drainage of groundwater flowing into the cut-off sheet can be performed to maintain the groundwater environment.
【図1】本発明の盛土の液状化対策構造の一実施例を示
す鉛直断面図である。FIG. 1 is a vertical sectional view showing one embodiment of a liquefaction countermeasure structure for embankment of the present invention.
【図2】本発明で使用する液状化抑止杭の一例を示す斜
視図である。FIG. 2 is a perspective view showing an example of a liquefaction inhibiting pile used in the present invention.
【図3】本発明で使用する液状化抑止杭の他の例を示す
斜視図である。FIG. 3 is a perspective view showing another example of the liquefaction suppressing pile used in the present invention.
【図4】本発明で使用する液状化抑止矢板の一例を示す
斜視図である。FIG. 4 is a perspective view showing an example of a liquefaction-preventing sheet pile used in the present invention.
【図5】本発明で使用する液状化抑止矢板の他の例を示
す斜視図である。FIG. 5 is a perspective view showing another example of the liquefaction-preventing sheet pile used in the present invention.
【図6】図5の液状化抑止矢板の背面側を示す斜視図で
ある。FIG. 6 is a perspective view showing the back side of the liquefaction-preventing sheet pile of FIG. 5;
【図7】液状化抑止杭の上部に設けた砕石マット部分の
一例を示す鉛直断面図である。FIG. 7 is a vertical sectional view showing an example of a crushed stone mat portion provided on the upper part of the liquefaction suppression pile.
【図8】液状化抑止杭の上部に設けた砕石マット部分の
他の例を示す鉛直断面図である。FIG. 8 is a vertical sectional view showing another example of the crushed stone mat portion provided on the upper part of the liquefaction prevention pile.
【図9】液状化抑止杭の上部に設けた砕石マット部分の
他の例を示す鉛直断面図である。FIG. 9 is a vertical sectional view showing another example of the crushed stone mat portion provided on the upper part of the liquefaction prevention pile.
【図10】液状化抑止杭の上部に設けた砕石マット部分
の他の例を示す鉛直断面図である。FIG. 10 is a vertical sectional view showing another example of the crushed stone mat portion provided on the upper part of the liquefaction prevention pile.
【図11】従来の壁構造方式の一例を示したもので、
(a) は水平断面図、(b) は鉛直断面図である。FIG. 11 shows an example of a conventional wall structure method.
(a) is a horizontal sectional view, (b) is a vertical sectional view.
【図12】従来の杭離散配置方式の一例を示したもの
で、(a) は水平断面図、(b) は鉛直断面図である。FIG. 12 shows an example of a conventional pile discrete arrangement method, in which (a) is a horizontal sectional view and (b) is a vertical sectional view.
【図13】従来の地盤締固め方式の一例を示す鉛直断面
図である。FIG. 13 is a vertical sectional view showing an example of a conventional ground compaction method.
【図14】従来の地盤締固め方式の他の例を示す鉛直断
面図である。FIG. 14 is a vertical sectional view showing another example of the conventional ground compaction method.
【図15】従来の排水方式の一例を示す鉛直断面図であ
る。FIG. 15 is a vertical sectional view showing an example of a conventional drainage method.
1…盛土、2…液状化抑止杭、3…液状化抑止矢板、4
…液状化地盤、5…非液状化地盤、6…笠コンクリート
またはコンクリート基礎、7…タイロッド、8…砕石マ
ット、9…盲暗渠、11…開口部、12…フィルター、
13…排水用部材、14…雄継手、15…雌継手、16
…継手1: embankment, 2: liquefaction deterrent pile, 3: liquefaction deterrent sheet pile, 4
... liquefied ground, 5: non-liquefied ground, 6: concrete or concrete foundation, 7: tie rod, 8: crushed mat, 9: blind culvert, 11: opening, 12: filter,
13 ... Drainage member, 14 ... Male joint, 15 ... Female joint, 16
… Fittings
───────────────────────────────────────────────────── フロントページの続き (72)発明者 才村 幸生 東京都千代田区大手町1丁目1番3号 住友金属工業株式会社内 (56)参考文献 特開 平2−225712(JP,A) (58)調査した分野(Int.Cl.6,DB名) E02D 3/08 E02D 17/18──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yukio Saishimura 1-3-1 Otemachi, Chiyoda-ku, Tokyo Sumitomo Metal Industries, Ltd. (56) References JP-A-2-225712 (JP, A) ( 58) Field surveyed (Int.Cl. 6 , DB name) E02D 3/08 E02D 17/18
Claims (4)
発生する過剰間隙水圧の上昇を抑制するための排水機能
を付与した液状化抑止矢板を、前記盛土法面または法尻
近傍に、液状化地盤の層厚に所要長さを加えた長さで設
け、さらに前記液状化抑止矢板の上部排水位置から地下
水位より高い位置まで連続する砕石マットを設けたこと
を特徴とする盛土の液状化対策構造。1. A liquefaction-inhibiting sheet pile provided with a drainage function for suppressing a rise in excess pore water pressure generated around an embankment and in the ground under an embankment during an earthquake is liquefied near the embankment slope or at the bottom of the embankment. It is provided with a length obtained by adding the required length to the layer thickness of the ground, and further, from the upper drainage position of the liquefaction suppression sheet pile,
A liquefaction countermeasure structure for embankment characterized by providing a continuous crushed stone mat up to a position higher than the water level .
状化抑止矢板連続方向と直角方向に透過させるための開
口部、および該開口部からの砂の透過を防止するための
フィルターを設けてある請求項1記載の盛土の液状化対
策構造。2. The liquefaction inhibiting sheet pile has an opening for allowing groundwater to pass in a direction perpendicular to the liquefaction inhibiting sheet pile continuous direction, and a filter for preventing permeation of sand from the opening. The liquefaction countermeasure structure for embankment according to claim 1, further comprising:
発生する過剰間隙水圧の上昇を抑制するための排水機能
を付与した液状化抑止杭を、前記盛土法面または法尻近
傍に、液状化地盤の層厚に所要長さを加えた長さで離散
配置し、さらに前記液状化抑止杭の上部排水位置から地
下水位より高い位置まで連続する砕石マットを設けたこ
とを特徴とする盛土の液状化対策構造。3. In the ground around the embankment and under the ground during an earthquake
Drainage function to suppress the rise in excess pore water pressure
The liquefaction-preventing pile provided with
Nearby, discrete with the length of the liquefied ground plus the required length
From the upper drainage position of the liquefaction suppression pile,
A liquefaction countermeasure structure for embankment characterized by providing a continuous crushed stone mat up to a position higher than the sewage level .
せるための開口部、および該開口部からの砂の透過を防
止するためのフィルターを設けてある請求項3記載の盛
土の液状化対策構造。 4. The liquefaction prevention pile is permeable to groundwater.
Openings to prevent sand from permeating through the openings.
4. A prosthesis according to claim 3, wherein a filter for stopping the operation is provided.
Soil liquefaction prevention structure.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP3266156A JP2803409B2 (en) | 1991-10-15 | 1991-10-15 | Liquefaction countermeasure structure for embankment |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP3266156A JP2803409B2 (en) | 1991-10-15 | 1991-10-15 | Liquefaction countermeasure structure for embankment |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH05106216A JPH05106216A (en) | 1993-04-27 |
JP2803409B2 true JP2803409B2 (en) | 1998-09-24 |
Family
ID=17427070
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP3266156A Expired - Lifetime JP2803409B2 (en) | 1991-10-15 | 1991-10-15 | Liquefaction countermeasure structure for embankment |
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JP (1) | JP2803409B2 (en) |
Families Citing this family (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4965922B2 (en) * | 2006-07-21 | 2012-07-04 | 大成建設株式会社 | Embankment reinforcement structure and embankment body |
JP2008303581A (en) * | 2007-06-06 | 2008-12-18 | Public Works Research Institute | Reinforcing structure of banking support ground |
JP2008303580A (en) * | 2007-06-06 | 2008-12-18 | Public Works Research Institute | Reinforcing structure of banking support ground |
JP2008303582A (en) * | 2007-06-06 | 2008-12-18 | Public Works Research Institute | Reinforcing structure of banking support ground |
JP5782734B2 (en) * | 2011-02-15 | 2015-09-24 | 新日鐵住金株式会社 | Wall sheet with liquefaction measures and steel sheet pile with liquefaction suppression function |
JP5546053B2 (en) * | 2012-07-05 | 2014-07-09 | 株式会社トラバース | Structure liquefaction countermeasure structure and construction method |
JP6151092B2 (en) * | 2013-05-31 | 2017-06-21 | 大成建設株式会社 | Sand sand countermeasure structure |
JP6832101B2 (en) * | 2016-09-13 | 2021-02-24 | 日鉄建材株式会社 | Reinforcement structure of embankment and reinforcement method of embankment |
JP6359148B2 (en) * | 2017-05-16 | 2018-07-18 | 大成建設株式会社 | Sand sand countermeasure structure |
JP6482715B1 (en) * | 2018-10-18 | 2019-03-13 | ケミカルグラウト株式会社 | Support structure and support method for anti-side pressure structure |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
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JP2833036B2 (en) * | 1988-11-11 | 1998-12-09 | 住友金属工業株式会社 | Sheet pile with drainage function and method of mounting filter for sheet pile |
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1991
- 1991-10-15 JP JP3266156A patent/JP2803409B2/en not_active Expired - Lifetime
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