JP7393452B2 - Method for estimating ground data from construction data - Google Patents

Method for estimating ground data from construction data Download PDF

Info

Publication number
JP7393452B2
JP7393452B2 JP2022022185A JP2022022185A JP7393452B2 JP 7393452 B2 JP7393452 B2 JP 7393452B2 JP 2022022185 A JP2022022185 A JP 2022022185A JP 2022022185 A JP2022022185 A JP 2022022185A JP 7393452 B2 JP7393452 B2 JP 7393452B2
Authority
JP
Japan
Prior art keywords
data
construction
ground
value
estimating
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.)
Active
Application number
JP2022022185A
Other languages
Japanese (ja)
Other versions
JP2023119337A (en
Inventor
健二 原田
祐司 山下
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Fudo Tetra Corp
Original Assignee
Fudo Tetra Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Fudo Tetra Corp filed Critical Fudo Tetra Corp
Priority to JP2022022185A priority Critical patent/JP7393452B2/en
Publication of JP2023119337A publication Critical patent/JP2023119337A/en
Application granted granted Critical
Publication of JP7393452B2 publication Critical patent/JP7393452B2/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Landscapes

  • Investigation Of Foundation Soil And Reinforcement Of Foundation Soil By Compacting Or Drainage (AREA)

Description

本発明は、施工データからの地盤データの推定方法に関する。 The present invention relates to a method for estimating ground data from construction data.

従来、削孔機による削孔データ(削孔時のオーガマシンの駆動モータの電流値、深度等)から地盤のN値を推定することが試みられている(例えば特許文献1参照)。また、本施工に先立って行われる事前作業として、削孔機による削孔データ(削孔時の送水圧、回転トルク、削孔速度等)から地盤のN値及び細粒分含有率を推定することが試みられている(例えば特許文献2参照)。 Conventionally, attempts have been made to estimate the N value of the ground from drilling data (current value of the drive motor of the auger machine during drilling, depth, etc.) by a drilling machine (see, for example, Patent Document 1). In addition, as a preliminary work performed prior to the actual construction, the N value and fine particle content of the ground are estimated from the drilling data (water supply pressure during drilling, rotational torque, drilling speed, etc.) using the drilling machine. This has been attempted (for example, see Patent Document 2).

特開2019-157346号公報Japanese Patent Application Publication No. 2019-157346 特開2020-100949号公報Japanese Patent Application Publication No. 2020-100949

しかしながら、前記従来のN値と細粒分含有率の推定方法では、オペレータの習熟度によって結果がばらつくことがあり、また、粘性土では値が小さくなるため、硬さの見極めが困難であり、施工データから地盤データを簡単かつ確実に推定する方法の開発が望まれている。 However, with the conventional methods for estimating the N value and fines content, the results may vary depending on the skill level of the operator, and the values are small for clayey soils, making it difficult to determine the hardness. It is desired to develop a method to easily and reliably estimate ground data from construction data.

そこで、本発明は、前記した課題を解決すべくなされたものであり、液状化対策である静的締固め砂杭工法を施工する際の施工データによりジャストポイントでのN値と細粒分含有率の地盤データを推定し、推定されたN値と細粒分含有率より地盤の液状化強度を簡単かつ確実に算出することができる施工データからの地盤データの推定方法を提供することを目的とする。 Therefore, the present invention was made to solve the above-mentioned problems, and the N value and fine particle content at the just point were determined based on construction data when constructing the static compaction sand pile method, which is a countermeasure against liquefaction. The purpose is to provide a method for estimating ground data from construction data that can easily and reliably calculate the liquefaction strength of the ground from the estimated N value and fine particle content. shall be.

本発明は、施工データからの地盤データの推定方法であって、施工中に得られる、少なくともオーガー電流値と貫入装置の油圧と貫入速度の施工データより、コーン貫入試験で得られた補正コーン貫入抵抗と周面摩擦抵抗との関係を求め、この関係を用いた地点における施工データより、前記補正コーン貫入抵抗と前記周面摩擦抵抗を推定し、前記コーン貫入試験で用いられるN値と細粒分含有率の推定式により対象地盤のN値と細粒分含有率を推定することを特徴とする。 The present invention is a method for estimating ground data from construction data, in which the corrected cone penetration value obtained in a cone penetration test is calculated from construction data of at least auger current value, oil pressure of a penetration device, and penetration speed obtained during construction. The relationship between the resistance and the circumferential frictional resistance is determined, and the corrected cone penetration resistance and the circumferential frictional resistance are estimated from the construction data at the point using this relationship, and the N value and fine grain used in the cone penetration test are estimated. The method is characterized by estimating the N value and fine grain content of the target ground using a formula for estimating the fine grain content.

本発明によれば、静的締固め砂杭工法を施工する際の施工データにより地盤を判別することにより、ジャストポイントでの液状化層・非液状化層を区別し、液状化層に対しては必要な強度に応じた杭径を造成して過剰施工することなく最適な地盤を提供することができる。 According to the present invention, by determining the ground based on the construction data when constructing the static compaction sand pile method, the liquefaction layer and non-liquefaction layer are distinguished at the just point, and the liquefaction layer is By creating the pile diameter according to the required strength, it is possible to provide the optimum ground without over-construction.

また、静的締固め砂杭工法を施工する際の施工データにより地盤の液状化強度を算出することにより、ジャストポイントでの液状化層・非液状化層を区別し、液状化層に対しては強度に応じた杭径を造成して過剰施工することなく最適な地盤を提供することができる。これにより、過剰施工の防止に寄与することができ、コストダウンを図ることができる。 In addition, by calculating the liquefaction strength of the ground from the construction data when constructing the static compaction sand pile method, we can distinguish between liquefied and non-liquefied layers at just points, and By creating the pile diameter according to the strength, it is possible to provide the optimum ground without over-construction. This can contribute to preventing excessive construction and reduce costs.

図1(a)は本発明の実施形態における施工データを得る静的締固め砂杭のケーシング貫入機構の説明図である。図1(b)は地盤データを得るコーン貫入試験のロッド貫入機構の説明図である。FIG. 1(a) is an explanatory diagram of a casing penetration mechanism of a statically compacted sand pile for obtaining construction data in an embodiment of the present invention. FIG. 1(b) is an explanatory diagram of a rod penetration mechanism for a cone penetration test to obtain ground data. 上記施工データからの地盤データの各値の推定手順を説明する流れ図である。It is a flow chart explaining the estimation procedure of each value of ground data from the above-mentioned construction data. 図3(a)は上記施工データから地盤データのN値を推定した結果を示す図である。図3(b)は上記施工データから地盤データの細粒分含有率を推定した結果を示す図である。FIG. 3(a) is a diagram showing the result of estimating the N value of the ground data from the construction data. FIG. 3(b) is a diagram showing the result of estimating the fine particle content of the ground data from the construction data.

以下、本発明の一実施形態を図面に基づいて説明する。 Hereinafter, one embodiment of the present invention will be described based on the drawings.

図1(a)は、本発明の実施形態における施工データを得る静的締固め砂杭のケーシング貫入機構の説明図である。図1(b)は、地盤データを得るコーン貫入試験のロッド貫入機構の説明図である。図2は、施工データからの地盤データの各値の推定手順を説明する流れ図である。図3(a)は、施工データから地盤データのN値を推定した結果を示す図である。図3(b)は、施工データから地盤データの細粒分含有率を推定した結果を示す図である。 FIG. 1(a) is an explanatory diagram of a casing penetration mechanism of a statically compacted sand pile for obtaining construction data in an embodiment of the present invention. FIG. 1(b) is an explanatory diagram of a rod penetration mechanism for a cone penetration test to obtain ground data. FIG. 2 is a flowchart illustrating a procedure for estimating each value of ground data from construction data. FIG. 3(a) is a diagram showing the result of estimating the N value of ground data from construction data. FIG. 3(b) is a diagram showing the result of estimating the fine particle content of the ground data from the construction data.

図1(a),(b)に示すように、施工データからの地盤データの推定方法は、静的締固め砂杭工法に用いられるケーシング貫入機構1とコーン貫入試験(CPT:Cone Penetration Test)に用いられるロッド貫入機構10とが類似していることに着目し、ケーシング貫入機構1の貫入データ(電流値A、油圧P、貫入速度S)をコーン貫入試験の計測値である補正コーン貫入抵抗(qt)と周面摩擦抵抗(fs)に対応させ、コーン貫入試験の計測値からN値と細粒分含有率(Fc)への推定式にする方法を使って、ケーシング貫入機構1の施工データからコーン貫入試験のN値と細粒分含有率(Fc)の地盤情報を推定する方法である。ここで、コーン貫入試験のN値は、地盤の硬さを現す指標である。また、細粒分とは、粘土とシルトのことであり、細粒分含有率(Fc)は、細粒分含有率試験によって求めることができ、細粒分(粘土・シルト)の少ない地盤ほど液状化を起こし易いため、液状化強度(R)の算出が必要とされる。 As shown in Figures 1(a) and (b), the method for estimating ground data from construction data is based on the casing penetration mechanism 1 used in static compaction sand pile construction method and the cone penetration test (CPT). Focusing on the similarity of the rod penetration mechanism 10 used in (qt) and circumferential frictional resistance (fs), and use a method to estimate the N value and fine particle content (Fc) from the measured values of the cone penetration test. This is a method of estimating ground information such as the N value of the cone penetration test and the fines content (Fc) from the data. Here, the N value of the cone penetration test is an index showing the hardness of the ground. In addition, fine particles refer to clay and silt, and the fine particle content (Fc) can be determined by a fine particle content test. Since liquefaction is likely to occur, it is necessary to calculate the liquefaction strength (R).

次に、図2を用いて施工データからの地盤データの各値の推定手順を説明する。尚、図1(a)中及び図2中「SAVE」は、静的締固め砂杭工法による施工の略である。 Next, a procedure for estimating each value of ground data from construction data will be described using FIG. 2. In addition, "SAVE" in FIG. 1(a) and FIG. 2 is an abbreviation for construction by static compaction sand pile construction method.

ケーシング貫入機構1の施工データからコーン貫入試験の計測値を推定し、N値や細粒分含有率(Fc)値への換算式に倣って両者を推定する際に、まず、図2で<S1>で示すように、ケーシング貫入機構1の貫入データである電流値A、油圧P、貫入速度Sからコーン貫入試験の補正コーン貫入抵抗(qt)と周面摩擦抵抗(fs)を推定する。この補正コーン貫入抵抗(qt)は、下記の式(1)から求めることができる。 When estimating the measurement value of the cone penetration test from the construction data of the casing penetration mechanism 1 and following the conversion formula to the N value and fine particle content (Fc) value, first, in Fig. 2 < As shown in S1>, the corrected cone penetration resistance (qt) and peripheral surface friction resistance (fs) of the cone penetration test are estimated from the current value A, oil pressure P, and penetration speed S, which are penetration data of the casing penetration mechanism 1. This corrected cone penetration resistance (qt) can be obtained from the following equation (1).

qt=qc+u(1-a) ・・・・・・式(1)
ここで、qtは補正コーン貫入抵抗(MPa)、qcは測定コーン貫入抵抗(MPa)、uコーンの円柱延長部での間隙水圧(MPa)、aは有効面積比(An/Ac)であり、Acはコーン底部の断面積、Anはロードセル又はシャフトの断面積である。
qt=qc+u 2 (1-a) ...Formula (1)
Here, qt is the corrected cone penetration resistance (MPa), qc is the measured cone penetration resistance (MPa), u2 is the pore water pressure at the cylindrical extension of the cone (MPa), and a is the effective area ratio (An/Ac). where Ac is the cross-sectional area of the cone bottom and An is the cross-sectional area of the load cell or shaft.

次に、図2で<S2>で示すように、補正コーン貫入抵抗(qt)と周面摩擦抵抗(fs)から基準化先端抵抗(Qt)と基準化周面摩擦比(Fr)を推定する。この基準化先端抵抗(Qt)は、下記の式(2)から求めることができ、また、基準化周面摩擦比(Fr)は、下記の式(3)から求めることができる。 Next, as shown by <S2> in Fig. 2, the normalized tip resistance (Qt) and the normalized circumferential friction ratio (Fr) are estimated from the corrected cone penetration resistance (qt) and the circumferential frictional resistance (fs). . This normalized tip resistance (Qt) can be obtained from the following equation (2), and the normalized circumferential surface friction ratio (Fr) can be obtained from the following equation (3).

Qt=(qt-σV0)/σV0’ ・・・・・・・式(2)
ここで、qtは先端抵抗である補正コーン貫入抵抗、σV0は上載圧(MPa)、σV0’は有効上載圧(MPa)である。
Qt=(qt-σ V0 )/σ V0 '...Formula (2)
Here, qt is the corrected cone penetration resistance which is the tip resistance, σ V0 is the overload pressure (MPa), and σ V0 ′ is the effective overload pressure (MPa).

Fr=fs/(qt-σV0) ・・・・・・・式(3)
ここで、Frは基準化周面摩擦比、fsは周面摩擦抵抗、qtは先端抵抗である補正コーン貫入抵抗、σV0は上載圧(MPa)である。
Fr=fs/(qt-σ V0 ) ...Formula (3)
Here, Fr is the normalized peripheral surface friction ratio, fs is the peripheral surface friction resistance, qt is the corrected cone penetration resistance which is the tip resistance, and σ V0 is the overload pressure (MPa).

次に、図2で<S3>で示すように、基準化先端抵抗(Qt)と基準化周面摩擦比(Fr)から土質性状指数(Ic)を推定する。この土質性状指数(Ic)は、下記の式(4)から求めることができる。 Next, as shown by <S3> in FIG. 2, the soil property index (Ic) is estimated from the normalized tip resistance (Qt) and the normalized circumferential friction ratio (Fr). This soil property index (Ic) can be obtained from the following equation (4).

Ic={(3.47-logQt)+(1.22+logFr)0.5 ・・・・・・式(4)
ここで、Icは土質性状指数、Frは基準化周面摩擦比である。
Ic={(3.47-logQt) 2 + (1.22+logFr) 2 } 0.5 ...Formula (4)
Here, Ic is a soil property index, and Fr is a normalized peripheral surface friction ratio.

次に、図2で<S4>で示すように、土質性状指数(Ic)と補正コーン貫入抵抗(qt)及び周面摩擦抵抗(fs)からN値と細粒分含有率(Fc)を推定する。このコーン貫入試験から換算したN値(Nc)は、下記の式(5)から求めることができ、また、細粒分含有率(Fc)は、下記の式(6)から求めることができる。 Next, as shown by <S4> in Figure 2, the N value and fine grain content (Fc) are estimated from the soil property index (Ic), corrected cone penetration resistance (qt), and circumferential friction resistance (fs). do. The N value (Nc) calculated from this cone penetration test can be determined from the following equation (5), and the fine particle content (Fc) can be determined from the following equation (6).

Nc=0.341×Ic1.94(qt-0.2)(1.34-0.0927Ic) ・・・・・・式(5)
ここで、NcはN値、qtは先端抵抗である補正コーン貫入抵抗、qt>0.2MPaである。
Nc=0.341×Ic 1.94 (qt-0.2) (1.34-0.0927Ic) ...Formula (5)
Here, Nc is the N value, qt is the corrected cone penetration resistance which is the tip resistance, and qt>0.2 MPa.

Fc=1.0×Ic4.2 (%) ・・・・・・式(6)
ここで、Fcは細粒分含有率、Icは土質性状指数である。
Fc=1.0×Ic 4.2 (%) ...Formula (6)
Here, Fc is the fine particle content and Ic is the soil property index.

そして、上記推定されたN値(Nc)と細粒分含有率(Fc)より液状化強度(R)を算出することができる。これにより、液状化の可能性の無い粘性土地盤や液状化に対し十分な強度を有する砂地盤での打設杭の拡径を省略することができる。このように、施工データからの地盤データの推定方法では、静的締固め砂杭工法を施工する際の施工データにより地盤の液状化強度(R)を算出することができるため、ジャストポイントでの液状化層・非液状化層を区別し、液状化層に対しては強度に応じた杭径を造成して過剰施工することなく最適な地盤を提供することができる。これにより、過剰施工の防止に寄与することができ、施工の低コスト化を図ることができる。 Then, the liquefaction strength (R) can be calculated from the estimated N value (Nc) and the fine particle content (Fc). Thereby, it is possible to omit the diameter expansion of a driven pile in a sticky ground that has no possibility of liquefaction or in a sandy ground that has sufficient strength against liquefaction. In this way, with the method of estimating ground data from construction data, the liquefaction strength (R) of the ground can be calculated from the construction data when constructing the static compaction sand pile method, so it is possible to calculate the liquefaction strength (R) of the ground at just the point. It is possible to distinguish between liquefied and non-liquefied layers, create piles with diameters that match the strength of liquefied layers, and provide the optimal ground without over-construction. This can contribute to preventing excessive construction and reduce construction costs.

次に、図1(a),(b)~図3(a),(b)を用いて、静的締固め砂杭工法の施工による杭打ちの場合のN値と細粒分含有率(Fc)の推定方法について説明する。 Next, using Figures 1 (a), (b) to 3 (a), (b), we will calculate the N value and fine particle content ( A method for estimating Fc) will be explained.

液状化対策である静的締固め砂杭工法は、図1(a)に示すように、ケーシング2の上部に取付られた電動オーガーの回転力と、ラックとピニオン等で構成された油圧を用いた押し込み装置(いずれも図示省略)により構成されるケーシング貫入機構1を併用して、地盤G中にケーシング2を貫入するものである。一方、図1(b)に示すように、地盤調査に用いられるロッド貫入機構10によるコーン貫入試験(CPT)は、ロッド11の先端にコーン12を取り付け、ロッド11を油圧による押し込み力で地盤G中に静的に貫入させて、貫入時の先端抵抗としての補正コーン貫入抵抗(qt)と周面摩擦抵抗(fs)を測定し、N値と細粒分含有率(Fc)を間接的に求めるものであり、スケールの違いがあるが、地中貫入機構が類似している。 The static compaction sand pile construction method, which is a countermeasure against liquefaction, uses the rotational force of an electric auger attached to the top of the casing 2 and hydraulic pressure composed of a rack and pinion, etc., as shown in Figure 1 (a). The casing 2 is penetrated into the ground G using a casing penetration mechanism 1 constituted by a pushing device (all not shown). On the other hand, as shown in FIG. 1(b), in the cone penetration test (CPT) using the rod penetration mechanism 10 used for ground investigation, a cone 12 is attached to the tip of the rod 11, and the rod 11 is pushed into the ground by hydraulic force. The corrected cone penetration resistance (qt) as the tip resistance during penetration and the peripheral surface friction resistance (fs) were measured by statically penetrating the cone, and the N value and fine particle content (Fc) were indirectly measured. Although the scale is different, the underground penetration mechanism is similar.

コーン貫入試験(CPT)では、先端抵抗としての補正コーン貫入抵抗(qt)と、周面摩擦として周面摩擦抵抗(fs)が計測される。従って、静的締固め工法の施工中のデータより、補正コーン貫入抵抗(qt)と周面摩擦抵抗(fs)を推定できれば、コーン貫入試験のN値と細粒分含有率(Fc)の推定式を用いて、施工中の地盤のN値と細粒分含有率(Fc)を各深度において推測することができる。液状化対策工事においては、推定されたN値と細粒分含有率(Fc)より液状化強度(R)を算出することができる。これにより、液状化の可能性の無い粘性土地盤や液状化に対し十分な強度を有する砂地盤での打設杭の拡径を省略することができる。 In the cone penetration test (CPT), corrected cone penetration resistance (qt) as tip resistance and circumferential surface friction resistance (fs) as circumferential surface friction are measured. Therefore, if the corrected cone penetration resistance (qt) and peripheral surface friction resistance (fs) can be estimated from the data during construction of the static compaction method, the N value and fine particle content (Fc) of the cone penetration test can be estimated. Using the formula, the N value and fine particle content (Fc) of the ground under construction can be estimated at each depth. In liquefaction countermeasure construction, the liquefaction strength (R) can be calculated from the estimated N value and fine particle content (Fc). Thereby, it is possible to omit the diameter expansion of a driven pile in a sticky ground that has no possibility of liquefaction or in a sandy ground that has sufficient strength against liquefaction.

次に、液状化対策である静的締固め砂杭工法を施工する際の施工データより、補正コーン貫入抵抗(qt)と周面摩擦抵抗(fs)を求める方法について説明する。 Next, a method for determining corrected cone penetration resistance (qt) and circumferential surface friction resistance (fs) from construction data when constructing the static compaction sand pile method, which is a measure against liquefaction, will be explained.

静的締固め砂杭工法の一般的な施工では、管理計器により、施工に要した時間、貫入深度が記録される。これに合わせて、電動オーガーの電圧(電流値A)、押し込み装置の油圧Pを計測できるように計器を設置する。貫入時間と深度の関係より、各深度における貫入速度Sを求め、電流値Aと油圧Pの測定結果を合わせて、補正コーン貫入抵抗(qt)と周面摩擦抵抗(fs)との関係性を求める。この関係性を求める方法としては、単回帰分析、多変量解析、機械学習、多数のデータを集めた経験則に基づく統計的手法など多くの手法を用いることができるが、本実施例においては、単回帰による施工データより補正コーン貫入抵抗(qt)と周面摩擦抵抗(fs)を求めた。具体的には、現地で測定したコーン貫入試験の補正コーン貫入抵抗(qt)と施工中に得られた油圧Pを貫入速度Sで除した値(P/S)と、周面摩擦抵抗(fs)と施工中に得られた電流値Aを貫入速度Sで除した値(A/S)との関係性を求めた。このように、油圧P、電流値A、貫入速度Sを直接使うのではなく、油圧Pと電流値Aを貫入速度Sで除した各値(P/SとA/S)を用いたのは、試行錯誤の結果、最も再現性が良いことが分かったためである。それを図2に示す手順により計算を進め、最終結果であるN値と細粒分含有率(Fc)を求めたのが図3(a),(b)である。コーン貫入試験より求めたN値と細粒分含有率(Fc)は細かく変動しているので、深度1m毎に平均値を求めると、上記方法により推定した値とほぼ一致していることが分かる。近傍でのN値と細粒分含有率(Fc)を求める場合は、ここに使用した施工データと補正コーン貫入抵抗(qt)と周面摩擦抵抗(fs)との関係を用いることができる。 During general construction using the statically compacted sand pile method, control instruments record the time required for construction and the depth of penetration. In line with this, instruments will be installed to measure the voltage (current value A) of the electric auger and the oil pressure P of the pushing device. From the relationship between penetration time and depth, find the penetration speed S at each depth, and combine the measurement results of current value A and oil pressure P to find the relationship between corrected cone penetration resistance (qt) and peripheral surface friction resistance (fs). demand. Many methods can be used to determine this relationship, such as simple regression analysis, multivariate analysis, machine learning, and statistical methods based on empirical rules based on a large amount of data. Corrected cone penetration resistance (qt) and circumferential surface friction resistance (fs) were determined from construction data obtained by simple regression. Specifically, the corrected cone penetration resistance (qt) of the cone penetration test measured on site, the value obtained by dividing the oil pressure P obtained during construction by the penetration speed S (P/S), and the peripheral surface friction resistance (fs ) and the value obtained by dividing the current value A obtained during construction by the penetration speed S (A/S) was determined. In this way, instead of directly using oil pressure P, current value A, and penetration speed S, we used the values (P/S and A/S) obtained by dividing oil pressure P and current value A by penetration speed S. As a result of trial and error, this method was found to have the best reproducibility. The calculation was carried out according to the procedure shown in FIG. 2, and the final results of the N value and fine particle content (Fc) are shown in FIGS. 3(a) and 3(b). Since the N value and fine particle content (Fc) determined from the cone penetration test fluctuate finely, when the average value is determined for every 1 m depth, it is found that it almost matches the value estimated by the above method. . When determining the N value and fine particle content (Fc) in the vicinity, the construction data used here, the relationship between the corrected cone penetration resistance (qt) and the peripheral surface friction resistance (fs) can be used.

このように、液状化対策である静的締固め砂杭工法を施工する際の施工データにより、施工中の地盤のジャストポイントでのN値と細粒分含有率(Fc)の地盤データを各深度毎に推定し、推定されたN値と細粒分含有率(Fc)より液状化強度(R)を算出することができる。これにより、液状化の可能性の無い粘性土地盤や液状化に対し十分な強度を有する砂地盤での打設杭の拡径を省略することができる。 In this way, the ground data of the N value and fine particle content (Fc) at the just point of the ground during construction can be calculated based on the construction data when implementing the static compaction sand pile method, which is a liquefaction countermeasure. The liquefaction strength (R) can be estimated for each depth and calculated from the estimated N value and fine particle content (Fc). Thereby, it is possible to omit the diameter expansion of a driven pile in a sticky ground that has no possibility of liquefaction or in a sandy ground that has sufficient strength against liquefaction.

尚、前記実施例によれば、施工データからコーン貫入試験(CPT)の補正コーン貫入抵抗(qt)と周面摩擦抵抗(fs)を求めたが、施工データから三成分コーン貫入試験(CPTU)の測定コーン貫入抵抗(qc)と周面摩擦抵抗(fs)を求めても良い。 According to the above example, the corrected cone penetration resistance (qt) and peripheral surface friction resistance (fs) of the cone penetration test (CPT) were determined from the construction data, but the corrected cone penetration resistance (qt) and peripheral surface friction resistance (fs) of the cone penetration test (CPTU) were determined from the construction data. The measurement cone penetration resistance (qc) and peripheral surface friction resistance (fs) may also be determined.

1 ケーシング貫入機構
2 ケーシング
10 ロッド貫入機構
11 ロッド
12 コーン
G 地盤
A オーガー電流値
P 貫入装置の油圧
S 貫入速度
qt 補正コーン貫入抵抗
fs 周面摩擦抵抗
Fc 細粒分含有率
1 Casing penetration mechanism 2 Casing 10 Rod penetration mechanism 11 Rod 12 Cone G Ground A Auger current value P Oil pressure of penetration device S Penetration speed qt Corrected cone penetration resistance fs Circumferential friction resistance Fc Fine particle content

Claims (4)

施工中に得られる、少なくともオーガー電流値と貫入装置の油圧と貫入速度の施工データより、コーン貫入試験で得られた補正コーン貫入抵抗と周面摩擦抵抗との関係を求め、この関係を用いた地点における施工データより、前記補正コーン貫入抵抗と前記周面摩擦抵抗を推定し、前記コーン貫入試験で用いられるN値と細粒分含有率の推定式により対象地盤のN値と細粒分含有率を推定することを特徴とする施工データからの地盤データの推定方法。 From the construction data of at least the auger current value, the oil pressure of the penetration device, and the penetration speed obtained during construction, the relationship between the corrected cone penetration resistance obtained in the cone penetration test and the circumferential friction resistance was determined, and this relationship was used. The corrected cone penetration resistance and the circumferential surface friction resistance are estimated from the construction data at the point, and the N value and fine grain content of the target ground are estimated using the formula for estimating the N value and fine grain content used in the cone penetration test. A method for estimating ground data from construction data, characterized by estimating a ratio. 請求項1記載の施工データからの地盤データの推定方法であって、
前記施工データと前記コーン貫入試験で得られた補正コーン貫入抵抗及び周面摩擦抵抗の関係は、単回帰分析と、多変量解析と、機械学習のうちのいずれかにより求めることを特徴とする施工データからの地盤データの推定方法。
A method for estimating ground data from construction data according to claim 1, comprising:
The construction method is characterized in that the relationship between the construction data and the corrected cone penetration resistance and peripheral surface friction resistance obtained in the cone penetration test is determined by one of simple regression analysis, multivariate analysis, and machine learning. Method for estimating ground data from data.
請求項1記載の施工データからの地盤データの推定方法であって、
前記コーン貫入試験で得られた補正コーン貫入抵抗と周面摩擦抵抗との関係は、それぞれ施工中に得られた前記貫入装置の油圧を貫入速度で除した値と、電流値を貫入速度で除した値を用いて求めることを特徴とする施工データからの地盤データの推定方法。
A method for estimating ground data from construction data according to claim 1, comprising:
The relationship between the corrected cone penetration resistance and peripheral surface friction resistance obtained in the cone penetration test is calculated by dividing the hydraulic pressure of the penetration device obtained during construction by the penetration speed, and the current value divided by the penetration speed. A method for estimating ground data from construction data, which is characterized in that it is calculated using the calculated value.
請求項3記載の施工データからの地盤データの推定方法であって、
静的締固め砂杭工法を施工する際の施工データにより、施工中の地盤のN値と細粒分含有率の地盤データを各深度毎に推定し、推定されたN値と細粒分含有率より液状化強度を算出することを特徴とする施工データからの地盤データの推定方法。
A method for estimating ground data from construction data according to claim 3, comprising:
Based on the construction data when constructing the static compacted sand pile method, the ground data of the N value and fine grain content of the ground during construction is estimated for each depth, and the estimated N value and fine grain content are estimated at each depth. A method for estimating ground data from construction data, which is characterized by calculating liquefaction strength from the ratio.
JP2022022185A 2022-02-16 2022-02-16 Method for estimating ground data from construction data Active JP7393452B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2022022185A JP7393452B2 (en) 2022-02-16 2022-02-16 Method for estimating ground data from construction data

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2022022185A JP7393452B2 (en) 2022-02-16 2022-02-16 Method for estimating ground data from construction data

Publications (2)

Publication Number Publication Date
JP2023119337A JP2023119337A (en) 2023-08-28
JP7393452B2 true JP7393452B2 (en) 2023-12-06

Family

ID=87763300

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2022022185A Active JP7393452B2 (en) 2022-02-16 2022-02-16 Method for estimating ground data from construction data

Country Status (1)

Country Link
JP (1) JP7393452B2 (en)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP6029528B2 (en) 2013-05-08 2016-11-24 大成建設株式会社 Ground evaluation method
JP2019157346A (en) 2018-03-07 2019-09-19 株式会社大林組 Ground evaluation system and ground evaluation method
JP2020100949A (en) 2018-12-20 2020-07-02 五洋建設株式会社 Estimation method of n value and fine-grain fraction content, as well as ground improvement body and information processing device

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP6029528B2 (en) 2013-05-08 2016-11-24 大成建設株式会社 Ground evaluation method
JP2019157346A (en) 2018-03-07 2019-09-19 株式会社大林組 Ground evaluation system and ground evaluation method
JP2020100949A (en) 2018-12-20 2020-07-02 五洋建設株式会社 Estimation method of n value and fine-grain fraction content, as well as ground improvement body and information processing device

Also Published As

Publication number Publication date
JP2023119337A (en) 2023-08-28

Similar Documents

Publication Publication Date Title
Jia et al. Soil dynamics and foundation modeling
Eslami et al. Efficiency of methods for determining pile axial capacity-applied to 70 cases histories in Persian Gulf northern shore
Sawant et al. Insight into pile set-up and load carrying capacity of driven piles
Everett Load transfer functions and pile performance modelling
Tanaka et al. Classification of strata using screwdriver sounding test
JP7393452B2 (en) Method for estimating ground data from construction data
Mets The bearing capacity of a single pile—Experience in Estonia
Fellenius Analysis of results of an instrumented bidirectional-cell test
Krasiński Estimation of screw displacement pile-bearing capacity based on drilling resistances
Bradshaw et al. Load transfer curves from a large-diameter pipe pile in silty soil
Jazebi et al. An investigation on the plastic zone around the tip of drilled shafts in sand
Aux et al. RSPile Analysis of Two Osterberg Cell Load Tests on Post-Grouted and Conventionally Installed Caissons in Vaughan, Ontario
Ruberti Investigation of installation torque and torque-to-capacity relationship of screw-piles and helical anchors
Fellenius et al. Testing and design of a piled foundation project. A case history
Ali Contribution of the standard penetration test SPT to the design of pile foundations in sand–Practical recommendations
Bo et al. Observational Methods and Geotechnical Issues
JP6856171B2 (en) Tip bearing capacity estimation method, tip bearing capacity management system, construction management method, and program for rotary press-fit piles
Kulkarni et al. WEAP Analysis and HSDPT for Steel Piles for Transmission Line Project Across River Hooghly
Rahardjo et al. The use of geotechnical instrumentation and cptu for investigation of geotechnical failures during construction in civil engineering projects
Niazi et al. Deep foundation analysis from cone penetrometers–a reappraisal
Shah et al. Comparing Axial Behaviour of Non-Displacement and Displacement Piles using Field Load Tests
Seymour et al. Pile design in soft clay for a Malaysian solar farm
Bouafia Contribution of the standard penetration test SPT to the design of pile foundations in sand
Shamshirgaran et al. Assessment of Time Effects on Compressive Bearing Capacity of Steel Pipe Piles Driven in Clay Deposits of Persian Gulf
Nasr et al. Geotechnical response of Strip footing resting on oil-contaminated sand improved with stone columns-Numerical Study

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20230224

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20230822

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20230911

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20231107

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20231124

R150 Certificate of patent or registration of utility model

Ref document number: 7393452

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R150