JP5875138B2

JP5875138B2 - Foundation pile construction method considering site conditions

Info

Publication number: JP5875138B2
Application number: JP2011080722A
Authority: JP
Inventors: 木谷　好伸; 好伸木谷
Original assignee: Mitani Sekisan Co Ltd
Current assignee: Mitani Sekisan Co Ltd
Priority date: 2011-03-31
Filing date: 2011-03-31
Publication date: 2016-03-02
Anticipated expiration: 2031-03-31
Also published as: JP2012215013A

Description

この発明は、本施工を前に、試験施工をして現場状況を確認して（特に支持層地盤の土質）、その後に本施工をすることを特徴とする現場状況を考慮した基礎杭の構築方法に関する。 This invention is a construction of a foundation pile that takes into account the site situation, which is characterized by conducting a test construction before the main construction and confirming the site situation (especially the soil texture of the support layer ground) and then carrying out the main construction. Regarding the method.

通常、基礎杭を構築する場合には、現場内の１ヶ所又は複数カ所、あるいは現場近辺でボーリングデータを採取し、また要求される基礎杭の性能などを加味して、支持層地盤の深さ・厚さ・土質を推定して、
・工法
・掘削深さ、掘削径、
・注入するセメントミルクの配合など
を決めて、本施工していた。
一般的には、予め設計した施工仕様通りに施工していた。とりわけ、根固め部は、支持力に与える影響が大きいため、掘削している最中に掘削ヘッドの電流値などのデータを元に、掘削位置で異なる支持層地盤をその杭ごとに判断して最適な施工をする工法も提案されている（特許文献１）。 Usually, when constructing foundation piles, the borehole data is collected at one or more locations in the site or near the site, and the required performance of the foundation pile is taken into account, and the depth of the support layer ground.・ Estimate thickness and soil quality,
・ Construction method ・ Drilling depth, drilling diameter,
・ The construction of the cement milk to be injected was decided and this construction was done.
In general, construction was performed according to construction specifications designed in advance. In particular, since the root consolidation part has a large influence on the bearing capacity, during the excavation, the support layer ground that is different at the excavation position is determined for each pile based on data such as the current value of the excavation head. A method for optimal construction has also been proposed (Patent Document 1).

特開２００６−１６９８２８JP 2006-169828 A

前記従来の技術では、その掘削位置で、支持層地盤に達したかどうか、どの程度、支持層地盤に掘り下げたのかは判断できるが、支持層地盤の土の様子については、考慮していなかった。一般に、既製杭を使用する工法では、杭穴内にセメントミルクを注入して、杭穴充填物と置換して、杭穴内（根固め部）をセメントミルクで満たし、あるいは注入したセメントミルクを杭穴残留物と撹拌混合して、ソイルセメントを形成していた。
従って、掘削位置、すなわち基礎杭構築位置の土の性状は、固化セメントミルクやソイルセメントの性能に影響を及ぼすことも考えられる。 In the conventional technique, it can be determined whether or not the support layer ground has been reached at the excavation position, and how much it has been dug into the support layer ground, but the state of the soil of the support layer ground has not been considered. . In general, in the construction method using ready-made piles, cement milk is injected into the pile holes and replaced with the pile hole filling, and the inside of the pile holes (root consolidation part) is filled with cement milk, or the injected cement milk is filled with the pile holes. It was stirred and mixed with the residue to form a soil cement.
Therefore, the soil properties at the excavation position, that is, the foundation pile construction position, may affect the performance of the solidified cement milk or the soil cement.

そこでこの発明では、本施工前の試験施工をして、支持層地盤の土の性状を考慮して、本施工を実施することにより、前記問題点を解決した。 So, in this invention, the said problem was solved by performing the test construction before this construction and implementing this construction in consideration of the property of the soil of the support layer ground.

すなわちこの発明は、予め、「配合条件」及び「掘削条件」を設定して、構築現場で「試験掘削」をして、以下のような条件を満たした状態で、本施工を行うことを特徴とする現場状況を考慮した基礎杭の構築方法である。
(1-1) 現場で要求される条件から予め、「細粒分含有率Ａ％」を設定しておく。
(1-2) 支持層地盤から採取した土の「細粒分含有率Ａ１％」を算出すると共に、本施工時又は「試験掘削」時のセメント系材料の「配合条件」を決める。
(1-3) 前記「細粒分含有率Ａ１％」が、
前記「細粒分含有率Ａ１％」≦前記「細粒分含有率Ａ％」
を満たさない場合には、前記「配合条件」及び／又は前記「掘削条件」を修正する。
前記「細粒分含有率Ａ１％」が、
前記「細粒分含有率Ａ１％」≦前記「細粒分含有率Ａ％」
を満している場合には、前記「配合条件」および前記「掘削条件」でそのまま試験掘削をする。
(2) 前記「配合条件」と「掘削条件」で、「試験掘削」として、杭穴を掘削して、前記支持層地盤付近の未固結試料を採取して、地上で、予め定めた「土塊の状態Ｂ」を満たすかどうかを判定する。
(3) 前記「土塊の状態Ｂ」を満たさない場合には、前記「掘削条件」を再設定して、再度「試験掘削」をする。
(4-1) 前記「土塊の状態Ｂ」を満たす場合には、予め定めた「基準比重Ｃ」を満たすか否かを判定して、満たす場合には、速成養生条件での固化強度を測定して「早期固化強度」とする。
(4-2) 前記「基準比重Ｃ」を満たさない場合には、前記「配合条件」を再設定して、再度「試験掘削」をする。
(4-3) 前記「早期固化強度」が予め定めた「基準固化強度Ｄ」の条件を満さない場合には、再度「配合条件」を設定して、再度「試験掘削」を行う。
(4-4) 前記「早期固化強度」が予め定めた「基準固化強度Ｄ」の条件を満たす場合には、本施工を行う。
(5)前記本施工は、当初又は変更された「掘削条件」で杭穴を掘削して、該杭穴内に当初又は変更された「配合条件」のセメント材料を充填すると共に、前記杭穴内に杭構造物を埋設して基礎杭構造を構築する。 That is, the present invention is characterized in that “mixing conditions” and “excavation conditions” are set in advance, “test excavation” is performed at the construction site, and the main construction is performed in a state where the following conditions are satisfied. It is the construction method of the foundation pile in consideration of the field situation.
(1-1) “Fine grain content A%” is set in advance based on the conditions required on site.
(1-2) Calculate the “fine grain content A1%” of the soil sampled from the support layer ground and determine the “mixing conditions” of the cementitious material during the main construction or “test excavation”.
(1-3) The “fine grain content A1%”
Said “fine particle content A1%” ≦ “fine particle content A%”
If not, the “mixing condition” and / or the “excavation condition” are corrected.
Said “fine particle content A1%”
Said “fine particle content A1%” ≦ “fine particle content A%”
If the full to have a will to directly test drilling in the "blending conditions" and the "drilling conditions".
(2) In the above “blending conditions” and “excavation conditions”, as a “test excavation”, a pile hole is excavated, an unconsolidated sample near the support layer ground is collected, and a predetermined “ It is determined whether or not the “Blood state B” is satisfied.
(3) If the “clot state B” is not satisfied, the “excavation condition” is reset and “test excavation” is performed again.
(4-1) When satisfying the “Blood state B”, it is determined whether or not a predetermined “reference specific gravity C” is satisfied, and when it is satisfied, the solidification strength under the rapid curing condition is measured. Thus, it is referred to as “early solidification strength”.
(4-2) If the “reference specific gravity C” is not satisfied, the “mixing condition” is reset and “test excavation” is performed again.
(4-3) If the “early solidification strength” does not satisfy the predetermined “reference solidification strength D” condition, the “mixing condition” is set again and the “test excavation” is performed again.
(4-4) If the “early solidification strength” satisfies the predetermined “standard solidification strength D”, this construction is performed.
(5) In the construction, the pile hole is excavated under the original or changed “excavation condition”, and the cement material of the original or changed “mixing condition” is filled in the pile hole. The foundation pile structure is constructed by burying the pile structure.

また、他の発明は、予め、「配合条件」及び「掘削条件」を設定して、構築現場で「試験掘削」をして、以下のような条件を満たした状態で、本施工を行うことを特徴とする現場状況を考慮した基礎杭の構築方法である。
(1-1) 現場で要求される条件から予め、「細粒分含有率Ａ％」を設定しておく。
(1-2) 支持層地盤から採取した土の「細粒分含有率Ａ１％」を算出すると共に、本施工時又は「試験掘削」時のセメント系材料の「配合条件」を決める。
(1-3) 前記「細粒分含有率Ａ１％」が、
前記「細粒分含有率Ａ１％」≦前記「細粒分含有率Ａ％」
を満たさない場合には、前記「配合条件」及び／又は前記「掘削条件」を修正する。
前記「細粒分含有率Ａ１％」が、
前記「細粒分含有率Ａ１％」≦前記「細粒分含有率Ａ％」
を満している場合には、前記「配合条件」および前記「掘削条件」でそのまま試験掘削をする。
(2) 前記「配合条件」と設定「掘削条件」で、「試験掘削」として、杭穴を掘削して、前記支持層地盤付近の未固結試料を採取して、以下の条件の少なくとも１つを満たした場合に、本施工をする。
(a)前記未固結試料が、予め定めた「土塊の状態Ｂ」を満たす。
(b)前記未固結試料が、予め定めた「基準比重Ｃ」を満たす。
(c)前記未固結試料を速成特殊養生で固化強度を測定して「早期固化強度」とし、「早期固化強度」が予め定めた「基準固化強度Ｄ」を満たす。
(3) 上記(2)の条件を満たさない場合には、前記「掘削条件」及び前記「配合条件」の一方又は両方を修正する。
(4) 前記本施工は、当初又は変更された「掘削条件」で杭穴を掘削して、該杭穴内に当初又は変更された「配合条件」のセメント材料を充填すると共に、前記杭穴内に杭構造物を埋設して基礎杭構造を構築する。 In another invention, the “mixing condition” and the “excavation condition” are set in advance, the “test excavation” is performed at the construction site, and the main construction is performed in a state where the following conditions are satisfied. It is a construction method of the foundation pile which considered the field situation characterized by.
(1-1) “Fine grain content A%” is set in advance based on the conditions required on site.
(1-2) Calculate the “fine grain content A1%” of the soil sampled from the support layer ground and determine the “mixing conditions” of the cementitious material during the main construction or “test excavation”.
(1-3) The “fine grain content A1%”
Said “fine particle content A1%” ≦ “fine particle content A%”
If not, the “mixing condition” and / or the “excavation condition” are corrected.
Said “fine particle content A1%”
Said “fine particle content A1%” ≦ “fine particle content A%”
If the full to have a will to directly test drilling in the "blending conditions" and the "drilling conditions".
(2) As the “testing excavation” in the “mixing condition” and the setting “excavation condition”, a pile hole is excavated, an unconsolidated sample near the support layer ground is collected, and at least one of the following conditions is obtained. This construction will be carried out when one is satisfied.
(a) The unconsolidated sample satisfies a predetermined “clot state B”.
(b) The unconsolidated sample satisfies a predetermined “reference specific gravity C”.
(c) The solidified strength of the unconsolidated sample is measured by rapid aging special curing to obtain “early solidified strength”, and the “early solidified strength” satisfies a predetermined “reference solidified strength D”.
(3) If the above condition (2) is not satisfied, either or both of the “excavation condition” and the “mixing condition” are corrected.
(4) In the construction, the pile hole is excavated under the original or changed “excavation condition”, and the cement material of the original or changed “mixing condition” is filled in the pile hole, and the pile hole is filled with the cement material. The foundation pile structure is constructed by burying the pile structure.

また、前記において、(2)(a)(b)(c)の総ての条件を満たさない場合に、「配合条件」と「掘削条件」を変更して、再度、「試験掘削」をすることを特徴とする現場状況を考慮した基礎杭の構築方法である。 In addition, in the above, when not satisfying all the conditions of (2) (a) (b) (c), the "mixing conditions" and "excavation conditions" are changed, and "test excavation" is performed again. It is the construction method of the foundation pile which considered the field situation characterized by this.

また、他の発明は、予め、「配合条件」及び「掘削条件」を設定して、構築現場で「試験掘削」をして、以下のような条件を満たした状態で、本施工を行うことを特徴とする現場状況を考慮した基礎杭の構築方法である。
(1) 予め設定した「配合条件」「掘削条件」で、「試験掘削」として、杭穴を掘削して、支持層地盤付近の未固結試料を採取して、以下の条件の少なくとも１つを満たした場合に、本施工をする。
(a) 前記「試験掘削」またはその他の方法により、支持層地盤から採取した土が、予め設定した「細粒分含有率Ａ％」以下の条件を満たす。
(b) 前記未固結試料が、予め定めた「土塊の状態Ｂ」を満たす。
(c) 前記未固結試料が、予め定めた「基準比重Ｃ」を満たす。
(d) 前記未固結試料を速成特殊養生で固化強度を測定して「早期固化強度」とし、「早期固化強度」が予め定めた「基準固化強度Ｄ」を満たす。
(2) 上記(1)の条件を満たさない場合には、前記「掘削条件」及び／又は前記「配合条件」を修正する。
(3) 前記本施工は、当初又は変更された「掘削条件」で杭穴を掘削して、該杭穴内に当初又は変更された「配合条件」のセメント材料を充填すると共に、前記杭穴内に杭構造物を埋設して基礎杭構造を構築する。 In another invention, the “mixing condition” and the “excavation condition” are set in advance, the “test excavation” is performed at the construction site, and the main construction is performed in a state where the following conditions are satisfied. It is a construction method of the foundation pile which considered the field situation characterized by.
(1) at preset "blending conditions""diggingcondition", as "test drilling", and drilling Kuiana, the unconsolidated sample supporting region layer near the ground were taken, at least one of the following conditions This construction will be carried out when one is satisfied.
(a) The soil collected from the support layer ground by the “test excavation” or other method satisfies the condition of “fine particle content A%” or less set in advance.
(b) The unconsolidated sample satisfies a predetermined “clot state B”.
(c) The unconsolidated sample satisfies a predetermined “reference specific gravity C”.
(d) The solidified strength of the unconsolidated sample is measured by rapid-curing special curing to obtain “early solidified strength”, and “early solidified strength” satisfies a predetermined “reference solidified strength D”.
(2) If the above condition (1) is not satisfied, the “digging condition” and / or the “mixing condition” are corrected.
(3) In the construction, the pile hole is excavated under the original or changed “excavation condition”, and the cement material of the original or changed “mixing condition” is filled into the pile hole, and the pile hole is filled with the cement material. The foundation pile structure is constructed by burying the pile structure.

また、前記各発明において、
「細粒分含有率Ａ％」を、「１５％」とする。
「土塊の状態Ｂ」を、「予め設定した大きさの土塊が存在しないこと」とする。
「基準比重Ｃ」を、「比重値１．６以上」とする。
「基準固化強度Ｄ」を、「７Ｎ／ｍｍ^２」とする。
ことを特徴とする現場状況を考慮した基礎杭の構築方法である。 In each of the above inventions,
The “fine particle content A%” is set to “15%”.
The “clot state B” is assumed to be “there is no clot having a preset size”.
“Reference specific gravity C” is set to “specific gravity value 1.6 or more”.
“Standard solidification strength D” is set to “7 N / mm ² ”.
It is the construction method of the foundation pile which considered the field situation characterized by this.

前記における本施工は、杭構造物を既製杭とし、掘削した杭穴内に既製杭を納める先堀工法に最も適しているが、既製杭の中堀工法にも適用できる。また、本施工は、杭構造物を鉄筋かごとして、杭穴内にコンクリートを充填するいわゆる現場造成杭にも適用できる。 This construction in the above is most suitable for the pre-drilling method in which the pile structure is a ready-made pile and the ready-made pile is placed in the excavated pile hole, but can also be applied to the intermediate-drilling method of the ready-made pile. This construction can also be applied to so-called field-built piles in which pile structures are used as reinforcing steel cages and concrete is filled into the pile holes.

この発明では、予め設定した「配合条件」「掘削条件」を、本施工前に、現場から採取した支持層地盤の土や未固結試料から「細粒分含有率Ａ」「土塊の状態Ｂ」「基準比重Ｃ」「基準固化強度Ｄ」の１つ又は複数、望ましくは全部を満たすことを確認して、満たさない場合には「配合条件」「掘削条件」を修正する。よって、より現場の特性に応じた条件で基礎杭を構築でき、より品質の高い基礎杭とすることができる。 In the present invention, the “ mixing conditions” and “ excavation conditions” set in advance are determined from the soil and unconsolidated sample of the support layer ground collected from the site before the main construction, and the “fine particle content A” and “clot state B”. It is confirmed that one or more, preferably all of “standard specific gravity C” and “standard solidification strength D” are satisfied. If not, “ mixing condition” and “ excavation condition” are corrected. Therefore, a foundation pile can be constructed on the condition according to the characteristic of the field more, and it can be set as a higher quality foundation pile.

図１は、この発明の実施形態を説明するフローチャートである。FIG. 1 is a flowchart for explaining an embodiment of the present invention.

（１）施工現場では、地盤や建造物などの設計条件に基づき、基礎杭構造の構築に際して、「配合条件」「掘削条件」などが設定される。
（２）この発明は、本施工に先立ち、支持層地盤から採取した土に対して、粒土試験を行い、細粒分含有率条件Ａを満たすように「配合条件」「掘削条件」を再度決める。
（３）（２）で定めた「配合条件」「掘削条件」で、構築現場にて「試験掘削」をして支持層地盤の未固結試料を採取する。
（４）採取した未固結試料が「土塊の状態Ｂ」「基準比重Ｃ」「基準固化強度Ｄ」を満たした場合に、前記条件で本施工を行う。
Ｂ〜Ｃの条件を満たさない場合には、当初設定した条件を、Ｂ〜Ｃの条件を満たすように「配合条件」「掘削条件」を修正して、修正した条件で本施工をする。 (1) At the construction site, “mixing conditions”, “ excavation conditions”, etc. are set when building the foundation pile structure based on the design conditions of the ground and buildings.
(2) Prior to the main construction, this invention performs a grain soil test on the soil sampled from the support layer ground, and again sets the “blending conditions” and “ excavation conditions” so as to satisfy the fine grain content condition A. Decide.
(3) Under the “mixing conditions” and “excavation conditions” defined in (2), perform “test excavation” at the construction site and collect an unconsolidated sample of the support layer ground.
(4) When the collected unconsolidated sample satisfies the “clot state B”, “reference specific gravity C”, and “reference solidification strength D”, the main construction is performed under the above conditions.
When the conditions of B to C are not satisfied, the “mixing condition” and “excavation condition” are corrected so as to satisfy the conditions of B to C with the originally set conditions, and the main construction is performed under the corrected conditions.

図面に基づき、この発明の実施例を説明する。 Embodiments of the present invention will be described with reference to the drawings.

１．試験掘削 1. Test drilling

（１）試験掘削は、予め設定したセメントミルク（セメント系材料）の「配合」と、
「掘削条件」で行う。 (1) The test excavation consists of “mixing” of cement milk (cement-based material) set in advance,
Performed under “Drilling conditions”.

（２）「配合」として、例えば、セメントミルクの固化強度が材令２８日で、１４Ｎ／ｍｍ^２以上、となるような濃度とする。
また、「掘削条件」として、掘削ロッドを回転して、杭穴内を掘削しながら杭穴残存物と撹拌する場合、回転数、下降速度などを設定する。また。上記配合のセメントミルクの注入量、注入位置、注入方法（撹拌か置換かも含めて）なども設定する。従って、試験掘削では、本施工と同じ穴径、深さで施工することになるが、本施工を再現できれば縮小寸法で施工することもできる。 (2) As “mixing”, for example, the concentration is such that the solidification strength of cement milk is 14 N / mm ² or more at 28 days of material age.
Further, as the “excavation condition”, when the excavation rod is rotated and the pile hole residue is agitated while excavating the inside of the pile hole, the rotation speed, the descent speed, and the like are set. Also. The injection amount, injection position, injection method (including agitation or replacement) of the above-described cement milk are also set. Therefore, in the test excavation, the construction is performed with the same hole diameter and depth as the main construction, but if the main construction can be reproduced, the construction can be performed with a reduced size.

（３）掘削場所は、構築現場敷地内で、本施工用の杭の１本又は数本の掘削を行う。また本施工の掘削位置とは別に、本施工に影響の無い位置で掘削することもできるが、この場合は、本施工の掘削位置と地盤性状が大きく異ならない位置で行う。 (3) Excavation place excavates one or several piles for this construction within the construction site site. In addition to the excavation position of the main construction, excavation can also be performed at a position that does not affect the main construction, but in this case, the excavation position of the main construction and the ground properties are not significantly different.

２．各種条件 2. Various conditions

（１）細粒分含有率条件Ａ
構築現場でのボーリングの際又はその他の方法により採取した支持層地盤の土を粒度試験をする。試験方法は、ふるい試験など通常行われる方法による。粒度試験の結果の細粒分含有率Ａ１％を算出する。現場で要求される条件から、予め細粒分含有率Ａ０％を設定しておく。 (1) Fine grain content condition A
The soil of the support layer ground sampled during drilling at the construction site or by other methods is subjected to a particle size test. The test method is a commonly performed method such as a sieve test. The fine particle content A1% as a result of the particle size test is calculated. From the conditions required at the site, a fine particle content A0% is set in advance.

Ａ１≦Ａ０
がこの条件を満たす条件である。ここで、たとえば、
Ａ０≧１５％
とする。なお、Ａ０は上記数値が好ましいが、土質にもよるが、０〜１００％の範囲で適宜設定できる。例えば、土丹層であれば、細粒分１００％の場合もあるが、施工によりセメントミルクと混合・置換を行えば充分な強度を確保できるので、細粒分が多い場合には施工方法の検討も行う。 A1 ≦ A0
Is a condition that satisfies this condition. Where, for example,
A0 ≧ 15%
And In addition, although the above-mentioned numerical value is preferable, A0 can be suitably set in the range of 0 to 100% although it depends on the soil. For example, in the case of the Dotan layer, the fine grain content may be 100%, but sufficient strength can be ensured by mixing and replacing with cement milk by construction. Also consider.

（２）未固結試料の土塊条件Ｂ
試験掘削の結果、支持層地盤から採取した未固結試料を目視で土塊の有無を確認する。未固結試料は、杭穴内にセメントミルクを注入して杭穴残存物と撹拌して、ソイルセメントとしたものである。
「予め設定した土塊の大きさ（例えば、５ｍｍ）以上の土塊が存在しない」するか否かで、この条件を満たすかどうかを判断する。なお、土塊の大きさは上記数値が好ましいが、１０ｃｍ以下の範囲で適宜設定できる。また、未固結試料内の土塊混入率が２０％（体積比）以下となることが好ましい。 (2) Clot condition B of unconsolidated sample
As a result of the test excavation, an unconsolidated sample collected from the support layer ground is visually checked for the presence of a mass. The unconsolidated sample is a soil cement obtained by injecting cement milk into a pile hole and stirring the pile hole residue.
Whether or not this condition is satisfied is determined based on whether or not “a lump larger than a predetermined lump size (for example, 5 mm) does not exist”. In addition, although the said numerical value is preferable, the magnitude | size of a clot can be set suitably in the range of 10 cm or less. Moreover, it is preferable that the soil mass mixing rate in an unconsolidated sample will be 20% (volume ratio) or less.

（３）未固結試料の比重条件Ｃ
試験掘削の結果、支持層地盤から採取した未固結試料の温度及び比重を測定する。測定した比重は、試料中のセメントミルクの量（セメント成分の含有量）が多ければ比重は増加し、土の粒子が多ければ比重は減少するので、比重と固化強度は統計的に比例関係にあり、固化強度を算出できるので、これを利用して、比重から、所定の固化強度を得られるかどうかを推定するものである。
この場合、温度を併せて測定することが望ましい。セメントミルクの温度・セメントミルク注入前の杭穴残地物の温度と、未固結試料の温度を比較することにより、セメント成分の固化反応熱による上昇温度分がわかる。上昇温度により、セメント成分の固化反応がどの程度進行しているか推定できる。固化反応の進行により、比重が変化（増加）するからである。従って、温度により、比重を修正することもできる。
たとえば、測定した比重値をＣ１とした場合、予め設定した基準比重値をＣ０とした場合、
Ｃ１≧Ｃ０
となっていればこの条件を満たす。Ｃ０は例えば「１．７５」とする。Ｃ０は上記数値が好ましいが、１．６以上の範囲で適宜設定できる。 (3) Specific gravity condition C of unconsolidated sample
As a result of the test excavation, the temperature and specific gravity of the unconsolidated sample collected from the support layer ground are measured. The measured specific gravity increases as the amount of cement milk in the sample (content of cement component) increases, and the specific gravity decreases as there are more soil particles. Yes, since the solidification strength can be calculated, this is used to estimate whether a predetermined solidification strength can be obtained from the specific gravity.
In this case, it is desirable to measure temperature together. By comparing the temperature of the cement milk, the temperature of the pile hole residue before the cement milk injection, and the temperature of the unconsolidated sample, the temperature rise due to the heat of solidification reaction of the cement component can be found. It can be estimated how much the solidification reaction of the cement component is proceeding from the rising temperature. This is because the specific gravity changes (increases) as the solidification reaction proceeds. Therefore, the specific gravity can be corrected by the temperature.
For example, when the measured specific gravity value is C1, when the preset reference specific gravity value is C0,
C1 ≧ C0
If so, this condition is satisfied. For example, C0 is “1.75”. C0 is preferably the above numerical value, but can be appropriately set within a range of 1.6 or more.

（４）未固結試料の早期固化強度条件Ｄ
試験掘削の結果、支持層地盤から採取した未固結試料を養生する。一般的に、固化強度は２８日の標準養生したテストピースで圧縮試験を行って判断するが、養生期間が長すぎ、現場では使用することができない。そこで、予め条件を定めた養生条件での圧縮強度と、標準養生での圧縮強度とが、統計的に比例することがわかっている。前記養生は、例えば、材令３日又は１週間の常温の自然養生とする。
これを利用して、圧縮試験をして固化強度を測定して「早期固化強度Ｄ１」として、予め設定した同じ養生での「基準固化強度Ｄ０」を比較する。
Ｄ１≧Ｄ０
であれば、この条件を満たす。Ｄ０は例えば、７Ｎ／ｍｍ^２とする。Ｄ０は、上記数値が好ましいが、５Ｎ／ｍｍ^２以上の範囲で適宜設定できる。上記データは普通セメントを使用した「配合条件」での値であるが、異なる種類のセメントを使用することもできる。例えば、高炉セメントを使用した場合には、普通セメントとは異なる温度上昇曲線を生じるため、材令３日で、圧縮強度２Ｎ／ｍｍ^２程度でも充分な固化強度を達成できる。 (4) Early solidification strength condition D of unconsolidated sample
As a result of the test excavation, an unconsolidated sample collected from the support layer ground is cured. Generally, the solidification strength is determined by performing a compression test using a test piece that has been standardly cured for 28 days. However, the curing period is too long and cannot be used in the field. Therefore, it is known that the compressive strength under the curing conditions for which conditions are set in advance and the compressive strength under the standard curing are statistically proportional. The curing is, for example, a natural curing at room temperature for 3 days or 1 week.
Using this, a compression test is performed to measure the solidification strength, and the “preliminary solidification strength D0” in the same curing set in advance is compared as “early solidification strength D1”.
D1 ≧ D0
If so, this condition is satisfied. For example, D0 is 7 N / mm ² . D0 is preferably the above numerical value, but can be appropriately set within a range of 5 N / mm ² or more. The above data is the value of “mixing conditions” using ordinary cement, but different types of cement can also be used. For example, when blast furnace cement is used, a temperature rise curve different from that of ordinary cement is generated, so that sufficient solidification strength can be achieved even with a compressive strength of about ² N / mm ^{2 in} 3 days.

３．第１の構築方法 3. First construction method

この構築方法はより高い品質の基礎杭を構築する場合に適する。 This construction method is suitable for constructing higher quality foundation piles.

（１）予め「配合条件」「掘削条件」を設定する。これは、試験掘削用のものであるが、条件を具備した場合には、本施工のものとなる。 (1) Set “mixing conditions” and “ excavation conditions” in advance. This is for test excavation, but if the conditions are met, it will be for this construction.

（２）試験掘削をする前に、粒度試験をして、
Ａ１＜１５％
を満たしていない場合には、上記「配合条件」を見直して、「修正配合条件」を設定する。また、結果によっては、「掘削条件」を修正することもでき、この場合には「修正掘削条件」を設定する。
細粒分含有率条件を満たしている場合には、当初の「配合条件」で試験掘削をする。 (2) Before conducting a test excavation, conduct a particle size test,
A1 <15%
If the above condition is not satisfied, the above “blending conditions” are reviewed and “corrected blending conditions” are set. Further, depending on the result, the “ excavation condition” can be corrected. In this case, the “correction excavation condition” is set.
If the fine grain content rate condition is satisfied, test drilling is performed under the original “mixing condition”.

（３）試験掘削をして杭穴を形成して、杭穴内にセメントミルクを注入して、「掘削条件」に従って、掘削水や掘削泥土などをセメントミルクで置換して、あるいは、セメントミルクと撹拌混合してソイルセメントとして、「杭穴残留物」を形成する。支持層地盤で杭穴残留物を地上に採取して、「未固結試料」とする。「未固結試料」は一般にセメント成分の固化反応が未だ始まっていないか、あるいは固化反応の初期の段階にある。 (3) Perform a test excavation to form a pile hole, inject cement milk into the pile hole, and replace the drilling water or drilling mud with cement milk according to “ drilling conditions”, or Stir and mix to form “pile hole residue” as soil cement. The pile hole residue is collected on the ground with the support layer ground and set as “unconsolidated sample”. The “unconsolidated sample” generally has not yet started the cement component solidification reaction or is in the early stage of the solidification reaction.

（４）まず、未固結試料を目視して、土塊の有無を調べて、土塊条件Ｂを確認する。 (4) First, an unconsolidated sample is visually observed to check for the presence of a clot, and the clot condition B is confirmed.

土塊条件Ｂを満たしていない場合（すなわち、図１で「土塊の有無」→Ｙｅｓ）は、撹拌混合などが不足しているので「掘削条件」を再設定して、再度、試験掘削を行う。 When the clot condition B is not satisfied (that is, “presence / absence of clot” → Yes in FIG. 1), since the mixing of stirring is insufficient, the “excavation condition” is reset and the test excavation is performed again.

（５）土塊条件Ｂを満たしている場合には、未固結試料の比重を測定する。比重値が比重条件Ｃをみたしていない場合には、セメント成分を増やすように「配合条件」を変更して再度、試験掘削をする。 (5) When the soil mass condition B is satisfied, the specific gravity of the unconsolidated sample is measured. When the specific gravity value does not satisfy the specific gravity condition C, the test combination is performed again by changing the “mixing condition” so as to increase the cement component.

（６）比重条件Ｃを満たしている場合には、未固結試料を所定の型枠に入れて、所定の材令で、圧縮試験を行い、早期固化強度条件Ｄを満たしていない場合には、セメントミルクの濃度を増やすなど「配合条件」を変更して、再度、試験掘削をする。 (6) When the specific gravity condition C is satisfied, an unconsolidated sample is put into a predetermined mold, a compression test is performed with a predetermined material age, and when the early solidification strength condition D is not satisfied Change the “mixing conditions” by increasing the concentration of cement milk, etc., and test drilling again.

（７）早期固化強度条件Ｄを満たしていることを確認して、本施工に移る。この時点で条件Ａ〜Ｄの総てを見たしているので、最も高度品質の基礎杭の構築ができる。 (7) After confirming that the early solidification strength condition D is satisfied, proceed to the main construction. Since all the conditions A to D have been seen at this point, the highest quality foundation pile can be constructed.

（８）本施工では、当初の又は修正された「配合条件」「掘削条件」で、杭穴を掘削して、あるいは杭穴を掘削しながら既製杭を埋設して、基礎杭構造を構築する。 (8) In this construction, the foundation pile structure is constructed by excavating the pile holes or burying the ready-made piles while excavating the pile holes under the original or modified “mixing conditions” and “ excavation conditions”. .

（９）前記において、条件Ｂ、Ｃ、Ｄの順で確認したが、順序は任意である。また、同時に確認することもできる。
また、前記において、各条件Ｂ、Ｃ、Ｄを満たしていない場合に、それぞれ新たに「試験掘削」をしたが、「配合条件」「掘削条件」の一方又は両方を修正することにより、各条件Ｂ、Ｃ、Ｄを満たすことが統計的などによりわかっている場合もある。この場合には、「配合条件」「掘削条件」の一方又は両方を修正して、修正条件で本施工を行う。したがって、この場合には、「試験掘削」は最低１回行えば良いことになる。 (9) In the above description, the conditions B, C, and D were confirmed in this order, but the order is arbitrary. It can also be confirmed at the same time.
In addition, in the above, when each of the conditions B, C, and D is not satisfied, the “test excavation” is newly performed. However, by correcting one or both of the “mixing condition” and “ excavation condition” It may be statistically known that B, C, and D are satisfied. In this case, one or both of “mixing condition” and “ excavation condition” is corrected, and the main construction is performed under the corrected condition. Therefore, in this case, the “test excavation” may be performed at least once.

４．第２の構築方法 4). Second construction method

この構築方法は簡易な方法である。
（１）第１の構築方法と同様に、予め「配合条件」「掘削条件」を設定して、粒度試験をして、細粒分含有条件Ａを満たしていない場合には「修正配合条件」を設定する。
（２）第１の構築方法と同様に、試験掘削をして、「未固結試料」を採取する。
（３）地上で、
（ａ）土塊条件Ｂ
（ｂ）比重条件Ｃ
（ｃ）早期固化強度条件Ｄ
の内で、現場で最も重視する条件の１つ又は複数を、試験して、条件を満たすか否かを確認する。
（４）設定した１又は複数の条件を満たさない場合には、「配合条件」「施工条件」の一方又は両方を修正することにより、条件を満たすことを推定して、修正条件で本施工を行う。
設定した１又は複数の条件を満たしている場合には、当然ながら、そのままの「配合条件」「掘削条件」で本施工を行う。
（５）本施工は、前記第１の構築方法と同様である。 This construction method is a simple method.
(1) as in the first construction method, previously set to "blending conditions", "drilling Kezujo matter", and a particle size study, does not meet the fine fraction containing condition A "modified formulation Set the condition.
(2) As in the first construction method, a test excavation is performed and an “unconsolidated sample” is collected.
(3) On the ground,
(A) Clot condition B
(B) Specific gravity condition C
(C) Early solidification strength condition D
Of these, one or more of the most important conditions in the field are tested to see if the conditions are met.
(4) When one or more of the set conditions are not satisfied, it is estimated that the condition is satisfied by correcting one or both of “mixing condition” and “construction condition”, and this construction is performed under the correction condition. Do.
If the set condition or conditions are satisfied, the construction is naturally performed with the “mixing condition” and “ excavation condition” as they are.
(5) This construction is the same as the first construction method.

５．他の実施例 5. Other examples

（１）前記実施形態で、細粒分含有条件Ａを「試験掘削」前に予め確認したが、試験掘削により、支持層地盤から土を採取して、前記条件Ｂ〜Ｃに加えて条件Ａを並列に扱い、条件Ａ〜Ｄを「試験掘削」後の条件とすることもできる。 (1) In the above embodiment, the fine grain content condition A was confirmed in advance before the “test excavation”, but the soil was collected from the support layer ground by the test excavation, and in addition to the conditions B to C, the condition A Can be handled in parallel, and the conditions A to D can be the conditions after “test excavation”.

Claims

Set the “mixing conditions” and “excavation conditions” in advance, perform “test excavation” at the construction site, and perform the actual construction with the following conditions satisfied. Considering the foundation pile construction method.
(1-1) “Fine grain content A%” is set in advance based on the conditions required on site.
(1-2) Calculate the “fine grain content A1%” of the soil sampled from the support layer ground and determine the “mixing conditions” of the cementitious material during the main construction or “test excavation”.
(1-3) The “fine grain content A1%”
Said “fine particle content A1%” ≦ “fine particle content A%”
If not, the “mixing condition” and / or the “excavation condition” are corrected.
Said “fine particle content A1%”
Said “fine particle content A1%” ≦ “fine particle content A%”
If the full to have a will to directly test drilling in the "blending conditions" and the "drilling conditions".
(2) In the above “blending conditions” and “excavation conditions”, as a “test excavation”, a pile hole is excavated, an unconsolidated sample near the support layer ground is collected, and a predetermined “ It is determined whether or not the “Blood state B” is satisfied.
(3) If the “clot state B” is not satisfied, the “excavation condition” is reset and “test excavation” is performed again.
(4-1) When satisfying the “Blood state B”, it is determined whether or not a predetermined “reference specific gravity C” is satisfied, and when it is satisfied, the solidification strength under the rapid curing condition is measured. Thus, it is referred to as “early solidification strength”.
(4-2) If the “reference specific gravity C” is not satisfied, the “mixing condition” is reset and “test excavation” is performed again.
(4-3) If the “early solidification strength” does not satisfy the predetermined “reference solidification strength D” condition, the “mixing condition” is set again and the “test excavation” is performed again.
(4-4) If the “early solidification strength” satisfies the predetermined “standard solidification strength D”, this construction is performed.
(5) In the construction, the pile hole is excavated under the original or changed “excavation condition”, and the cement material of the original or changed “mixing condition” is filled in the pile hole. The foundation pile structure is constructed by burying the pile structure.

Set the “mixing conditions” and “excavation conditions” in advance, perform “test excavation” at the construction site, and perform the actual construction with the following conditions satisfied. Considering the foundation pile construction method.
(1-1) “Fine grain content A%” is set in advance based on the conditions required on site.
(1-2) Calculate the “fine grain content A1%” of the soil sampled from the support layer ground and determine the “mixing conditions” of the cementitious material during the main construction or “test excavation”.
(1-3) The “fine grain content A1%”
Said “fine particle content A1%” ≦ “fine particle content A%”
If not, the “mixing condition” and / or the “excavation condition” are corrected.
Said “fine particle content A1%”
Said “fine particle content A1%” ≦ “fine particle content A%”
If the full to have a will to directly test drilling in the "blending conditions" and the "drilling conditions".
(2) As the “testing excavation” in the “mixing condition” and the setting “excavation condition”, a pile hole is excavated, an unconsolidated sample near the support layer ground is collected, and at least one of the following conditions is obtained. This construction will be carried out when one is satisfied.
(a) The unconsolidated sample satisfies a predetermined “clot state B”.
(b) The unconsolidated sample satisfies a predetermined “reference specific gravity C”.
(c) The solidified strength of the unconsolidated sample is measured by rapid aging special curing to obtain “early solidified strength”, and the “early solidified strength” satisfies a predetermined “reference solidified strength D”.
(3) If the above condition (2) is not satisfied, either or both of the “excavation condition” and the “mixing condition” are corrected.
(4) In the construction, the pile hole is excavated under the original or changed “excavation condition”, and the cement material of the original or changed “mixing condition” is filled in the pile hole, and the pile hole is filled with the cement material. The foundation pile structure is constructed by burying the pile structure.

(2) If all conditions of (a), (b), and (c) are not satisfied, the `` mixing conditions '' and `` excavation conditions '' are changed and `` test excavation '' is performed again. The construction method of the foundation pile which considered the field situation of Claim 2.

Set the “mixing conditions” and “excavation conditions” in advance, perform “test excavation” at the construction site, and perform the actual construction with the following conditions satisfied. Considering the foundation pile construction method.
(1) at preset "blending conditions""diggingcondition", as "test drilling", and drilling Kuiana, the unconsolidated sample supporting region layer near the ground were taken, at least one of the following conditions This construction will be carried out when one is satisfied.
(a) The soil collected from the support layer ground by the “test excavation” or other method satisfies the condition of “fine particle content A%” or less set in advance.
(b) The unconsolidated sample satisfies a predetermined “clot state B”.
(c) The unconsolidated sample satisfies a predetermined “reference specific gravity C”.
(d) The solidified strength of the unconsolidated sample is measured by rapid-curing special curing to obtain “early solidified strength”, and “early solidified strength” satisfies a predetermined “reference solidified strength D”.
(2) If the above condition (1) is not satisfied, the “digging condition” and / or the “mixing condition” are corrected.
(3) In the construction, the pile hole is excavated under the original or changed “excavation condition”, and the cement material of the original or changed “mixing condition” is filled into the pile hole, and the pile hole is filled with the cement material. The foundation pile structure is constructed by burying the pile structure.

The “fine particle content A%” is set to “15%”.
The “clot state B” is assumed to be “there is no clot having a preset size”.
“Reference specific gravity C” is set to “specific gravity value 1.6 or more”.
The “standard solidification strength D” is set to “7 N / mm 2”.
The construction method of the foundation pile which considered the field condition of any one of Claim 1, 2, 4 characterized by the above-mentioned.