JP3703900B2 - Pile driving management device - Google Patents

Description

ここで
Ｒｕ：動的極限支持力
ｅｆ：機械効率
ｗｈ：ラム重量
Ｈ ：ラム落下高
Ｓ ：貫入量
Ｋ ：リバウンド量
【０００６】
非接触型の一例は杭表面に貼り付けたターゲットシートを一定距離離れた場所からＣＣＤカメラで撮像し、ハンマー内のラムの落下により杭を強打した時のターゲットシートの動きすなわち杭の挙動を計測するものである。図９はその測定装置を概略的に示す図である。図９において、１〜５は図７の測定対象と同一のものであり８はターゲットシート、９はハロゲン光源、１０はＣＣＤカメラ、１１はカメラコントローラ、１２は計測演算装置、１３はペンレコーダを示す。図９のように構成された装置では杭１の側面にターゲットシート８を貼り付け、ハロゲン光源９で十分なコントラストが得られるように照明してその画像をＣＣＤカメラ１０で撮像し、カメラコントローラ１１から出力される撮像信号を計測演算装置１２で処理して、概略１ｍｓ毎にターゲットシート８の撮像位置を求めこの位置に対応したアナログ電圧を出力し、これをペンレコーダ１３で記録し杭の変位量を求めることができる。
【０００７】
【発明が解決しようとする課題】
接触型ではハンマーで杭を強打するとき、作業者は適当な段階で杭に記録紙を張り付け、記録ペンを保持する必要があり、作業の途中に頭上から物が落下する危険が大きく、また船上の作業では足場が不安定となってより危険が増す問題があり、そのため作業者の危険性が極めて大きかった。また作業者による記録後スケールを用いて貫入量、リバウンド量を読みとり杭の支持力を計算して求めるため現場での作業に迅速性がなく、記録結果及び読みとり値に作業者の個人差による誤差が含まれるといった欠点がある。
【０００８】
一方非接触型では、作業の危険性は改善されるが打込み杭毎にターゲットシートとなるものを正確に取り付ける現場作業を必要とするため杭打ち作業の中断が必要であること、また杭の打込み測定範囲がターゲットシートとＣＣＤカメラ間の距離及び視野で限定されるため杭の打込み長全体にわたって連続した計測ができないといった欠点がある。
【０００９】
この発明は、前述の従来の課題を改善し、杭の打込み方向の変位量を非接触で、リアルタイムに且つ高精度でしかも容易に測定可能とし、さらに人手をわずらわすことなく、杭の打撃回数、貫入量、リバウンド量、支持力、杭の全打ち込み長さ等のデータを連続して取得し杭打施工管理を行える装置を提供することを目的とする。
【００１０】
この発明は、船上での計測のようにセンサ部が杭に対して相対的に上下動揺している場合でも、動揺成分をキャンセルして精度良く計測可能とすることを目的としている。
【００１１】
またこの発明は、船上での計測のように杭とセンサ部間の相対距離が大きく変動してセンサ部の計測領域から外れる場合でも、杭とセンサ部間の相対距離変動に対応してセンサ部の位置を追従制御することで、安定した計測を可能とすることを目的としている。
【００１２】
【課題を解決するための手段】
この発明に係わる杭打施工管理装置は、レーザ光のドップラ効果を利用して杭との相対速度及び相対変位を測定するためのセンサ部と信号処理部、さらにこの速度信号、変位信号をもとにハンマーの打撃による打撃波形データを取得し、このデータからハンマーの打撃間隔、杭の貫入量、リバウンド量を抽出して、打撃エネルギー、打撃回数を演算すると共に杭の支持力、杭の全打ち込み長さを演算し、表示及び出力するデータ処理部とを具備し、装置設置部の動揺による杭との相対上下動によって発生する変位測定誤差を、打撃前後の速度値を抽出してその間の時間で台形積分することにより装置自身の動揺による変位量を求め、元の計測変位データから減算することで測定対象物の真の変位変化を求めるものである。
【００１５】
また、この発明に係わる杭打施工管理装置は、打撃による杭の貫入速度を検出するための閾値を設け、上記速度データがこの閾値を越えた瞬間を打撃タイミングとして検出し、この前後の速度データ及び変位データを打撃波形として抽出している。
【００１６】
この発明に係わる杭打施工管理装置は、打撃タイミングより一定時間前の変位データを一定時間平均して変位零値とし、また前記打撃タイミングより一定時間後の変位データを一定時間平均して変位終了値として、変位終了値から変位零値を減算した値を貫入量としている。
【００１７】
また、この発明に係わる杭打施工管理装置は、打撃タイミングから一定時間後までの変位データから変位最大値を求め、この変位最大値から前記変位終了値を減算した値をリバウンド量としている。
【００１８】
【発明の実施の形態】
実施の形態１．
図１はこの発明の実施の形態１を示したものであり、１〜６は従来の測定対象と同一のものである。１４は杭１の速度に比例したドップラ信号を検出するセンサ部、１５、１６はセンサ部１４から照射されるレーザビーム、１７は照射レーザビーム１５、１６が杭１で反射された散乱光、１８はセンサ部で検出したドップラ信号から杭１の速度及び変位を演算出力する信号処理部、１９、２０は各々信号処理部１８から出力される速度及び変位のアナログ電圧信号、２１はこの速度及び変位信号を処理してハンマー２内のラム３の落下エネルギー、打撃回数、杭１の貫入量、リバウンド量、支持力等を演算処理するデータ処理部であり、２２は計測結果を出力するためのプリンターである。なお、データ処理部２１を構成している２３、２４はアナログ電圧信号をデジタルデータに変換するＡ／Ｄ変換器、２５はＡ／Ｄ変換したデータを蓄積するためのメモリー、２６は速度及び変位データから各種演算を行う機能、入力機能及び表示機能を持つ演算処理部である。また図６は杭１に対するセンサ部１４の設置条件を示したものであり、センサ部１４の計測領域は照射レーザビーム１５、１６の交差領域で与えられ照射レーザビーム１５、１６の交点を中心として前後Δｌの範囲であるため、センサ部１４は杭１に対し測定基準距離ｌの位置に設置される。なお通常測定基準距離ｌは１ｍ、計測領域Δｌは１４０ｍｍ程度の値である。
【００１９】
上記のように構成された杭打施工管理装置においては、センサ部１４から交差角φで照射される２つのレーザビーム１５、１６の散乱光１７をセンサ部１４で受光し電気信号に変換するとドップラー効果により次式に示す杭１の移動速度Ｖに比例したドップラ周波数ｆｄの周波数信号が得られる。
【００２０】
ｆｄ＝（２Ｖ／λ）・ｓｉｎ（φ／２） （２）
ここで
Ｖ：杭１の移動速度
λ：レーザ光の波長
φ：２つのレーザビーム１４、１５の交差角
【００２１】
センサ部１４で得られたドップラ周波数信号は信号処理部１８で杭１の移動する速度データ１９及びこの時間積分として求まる変位データ２０に変換処理出力される。ここで図２は信号処理部１８から出力される速度データ１９及変位データ２０の時間軸波形を示す図である。また図３はデータ処理部２１の処理フローを示すフローチャートであり、図中のＳ１〜Ｓ１６はフローチャートの各ステップを示しており、これに基づきデータ処理手順を説明する。ステップＳ１で処理を起動し、ステップＳ２で測定年月日、工事名、施工場所等の工事情報と図２に示した演算開始時間α、演算終了時間β、変位零点平均時間ａ、貫入量平均時間ｂ、立上り判定レベルｅ、ラム重量ｗｈ、及びあらかじめハンマーにより定まるラム落下高Ｈと毎分当たりの打撃回数の関係テーブル等の測定条件を入力する。ここで、例えば油圧方式のハンマー２ではラム落下高Ｈが数段階切替えられる機構となっており、ラム３が杭を打撃した時刻から油圧力でラム３を高さＨだけ押し上げてその後ラム３が高さＨだけ落下して再度杭を打撃する時刻までに要する時間はこのラム落下高Ｈに一対一に対応した時間となるため、ラム落下高Ｈと毎分当たりの打撃回数は一対一の関係にありハンマーの性能諸元として予め示されている。
【００２２】
次に測定開始キーを押すとステップＳ３で測定処理が開始され、ステップＳ４で信号処理部１８から出力される速度データ１９及変位データ２０をＡ／Ｄ変換器２３、２４でデジタル値に変換してメモリー２４に読み込み、ステップＳ５で図２に示す速度波形からラム３の打撃タイミングを速度の立上り判定レベルｅを越えた速度タイミングで検出し、ステップＳ６ではステップＳ５を通過した毎に打撃回数カウンタを更新して打撃回数を積算カウントし、ステップＳ７で前回の打撃タイミング時刻から今回の打撃タイミング時刻を引いて打撃間隔時間Δｔｎを求め、ステップＳ８で打撃間隔時間Δｔｎの逆数を演算し毎分当たりの打撃回数を求めラム落下高Ｈと毎分当たりの打撃回数の関係テーブルよりラム落下高Ｈを決定しラム落下高Ｈとラム重量ｗｈを乗算して打撃エネルギーを演算する。続いてステップＳ９で打撃タイミングより演算開始時間α前の変位データを変位零点平均時間ａだけ平均した値を変位の零点Ｆ₀ とし、ステップＳ１０で打撃タイミングから打撃タイミングより演算終了β後までの変位データから最大値を求めこれより変位の零点Ｆ₀ を減算した値を最大変位量Ｆｍａｘとし、ステップＳ１１で打撃タイミングより演算終了時間β後の変位データを貫入量平均時間ｂだけ平均した値から変位の零点Ｆ₀ を減算した値を貫入量Ｆｓとするとともにこれを一打撃毎に累積加算して杭の累積貫入量ΣＦｓを求め、ステップＳ１２で最大変位量Ｆｍａｘから貫入量Ｆｓを減算した値をリバウンド量Ｆｋとする。上記貫入量Ｆｓ、リバウンド量Ｆｋ及び打撃エネルギーＨ×ｗｈを用いてステップＳ１３で前述で示した支持力算出式の一例である（１）式の演算を実施して支持力を求め、ステップＳ１４で以上の処理によって求まった累積打撃回数ｎ、打撃間隔Δｔｎ、貫入量Ｆｓ、累積貫入量ΣＦｓ、リバウンド量Ｆｋ、支持力を表示出力し、ステップＳ１５で測定終了キーが押されていなければ以上の処理を繰り返し一打撃毎に表示出力データがリアルタイムにて更新される。なおステップＳ１５で測定終了キーが押されていれば測定を終了し、ステップＳ１６で上記一連のデータ処理で得られたデータを集計し帳票としてまとめプリントアウト出力する。
【００２３】
本構成の杭打施工管理装置によれば、ラム３の落下衝撃による打撃波形を１打撃毎に検出し、この打撃波形の回数を数えることにより打撃回数ｎを求め、この打撃波形の発生する時間間隔Δｔｎをもとにラム３の落下エネルギーを演算し、打撃波形の変位データ２０から貫入量Ｆｓとリバウンド量Ｆｋを求め、さらにこの貫入量Ｆｓの積算値を求めることにより杭１の累積貫入量ΣＦｓを求め、貫入量Ｆｓ、リバウンド量Ｆｋ、ラム３の落下エネルギーから杭の支持力を演算し表示出力をおこなうので、杭打作業の開始から終了まで連続して一打撃毎の累積打撃回数、打撃間隔、貫入量、累積貫入量、リバウンド量、支持力等のデータをリアルタイムで計測可能であり、これらのデータの集計作業も自動化することが可能である。
【００２４】
実施の形態２．
図４はこの発明の実施の形態２を示す動揺補正処理説明図であり、図４（ｂ）はセンサ部１４の上下等の動揺によって発生する変位変化量が実際の打撃による変位変化に重畳した場合の変位波形を示すもので図４（ａ）はこのときの速度波形を示している。ここで動揺成分による変位変化量（シフト量）は、演算開始時刻ｔｓｔにおける速度値Ｖｓｔと演算終了時刻ｔｅｎｄにおける速度値Ｖｅｎｄを直線で結び次式に示すように台形積分することで近似的に求めることがでる。
【００２５】
Ｆｅｃ＝（１／２）・（Ｖｓｔ＋Ｖｅｎｄ）・（ｔｅｎｄ−ｔｓｔ） （３）
ここで
Ｆｅｃ：動揺変位補正値
【００２６】
したがって変位量に動揺成分が重畳した場合であっても、動揺変位補正値Ｆｅｃを演算して減算することにより精度良い計測が実現できる。なおこの動揺補正方式では動揺周期３Ｈｚ、動揺振幅±２５ｍｍの条件下において、演算開始時刻ｔｓｔ〜演算終了時刻ｔｅｎｄまでの時間間隔が０．４秒以下であれば±１ｍｍの精度で補正可能である。
【００２７】
実施の形態３．
図５はこの発明の実施の形態３を示したものであり、図中１〜２１は実施の形態１と同一のものである。２７は超音波の往復時間により距離を求める超音波距離計で代表される非接触な距離計、２８は上記距離計２７の出力と測定基準距離ｌとの差から制御信号を出力するコントローラ、２９は上記コントローラ２８の出力を受けてセンサ部１４及び距離計２７を杭１に対し前後に移動させるリニアアクチュエータ、３０は杭打船、３１は海水である。
【００２８】
以上の構成の杭打施工管理装置において、杭１とセンサ部１４の相対距離が測定基準距離ｌから変化すると、距離計２７の測定距離出力を受けてコントローラ２８は測定基準距離ｌに対する変位量が零となるよう制御信号をリニアアクチュエータ２９に与え、常に杭１とセンサ部１４の相対距離が測定基準距離ｌに一致するよう動作して、波浪により杭打船３０から杭１を海水３１中に打ち込む際に杭１とセンサ部１４の相対距離が大きく変動しても安定した計測が可能となる。
【００２９】
【発明の効果】
この発明は、以上説明したように構成されているので、以下に記載されるような効果を有する。
【００３０】
この発明によれば、レーザ光のドップラー効果を利用しているので非接触で杭の移動する速度及び変位を人手をわずらわすことなく自動計測ができ、速度及び変位を連続して取得できるため杭打施工管理に必要な打撃回数、杭支持力、累積貫入量等を連続してリアルタイムで表示出力することが可能となり、またデータ処理部に杭打施工管理データが全て集まり打ち込み記録等の集計作業も自動化できるので、現在人力等によってほとんど行われている杭打施工管理の作業の安全化、省力化に大きな効果が得られる。
【００３１】
またこの発明によれば、船上での計測のようにセンサ部が杭に対して相対的に動揺している場合でも動揺成分をキャンセルすることができ、計測精度を向上させ、適用範囲を拡大させる効果がある。
【図面の簡単な説明】
【図１】 この発明の実施の形態１を示す杭打施工管理機の構成図である。
【図２】 この発明の実施の形態１の動作波形図である。
【図３】 この発明の実施の形態１のフローチャートである。
【図４】 この発明の実施の形態２の動作波形図である。
【図５】 この発明の実施の形態３を示す杭打施工管理機の構成図である。
【図６】 この発明で適用するセンサ部の測定範囲を示す概要図である。
【図７】 従来の記録ペン式リバウンド量計測方法を示す構成図である。
【図８】 従来の動作波形を示す図である。
【図９】 従来の非接触式リバウンド量計測装置を示す構成図である。
【符号の説明】
１ 杭、２ ハンマー、３ ラム、４ 地盤、５ 地盤支持層、６ 記録紙、７ 記録ペン、８ ターゲットシート、９ ハロゲン光源、１０ ＣＣＤカメラ、１１ カメラコントローラ、１２ 計測演算装置、１３ ペンレコーダ、１４センサ部、１５ 照射レーザビーム、１６ 照射レーザビーム、１７ 散乱光、１８ 信号処理部、１９ 速度信号、２０ 変位信号、２１ データ処理部、２２ プリンター、２３ Ａ／Ｄ変換器１、２４ Ａ／Ｄ変換器２、２５ メモリー、２６ 演算処理部、２７ 距離計、２８ コントローラ、２９ リニアアクチュエータ、３０ 杭打船、３１ 海水。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pile driving management apparatus for managing the pile driving performed in the foundation work for constructing a structure.
[0002]
[Prior art]
When a hammer is loaded on a steel pipe pile or concrete pile, the ram in the hammer is pushed up to the height that is the hydraulic pressure or the explosive force of the diesel engine, the ram is dropped from this height and pile driving is performed by the falling energy of the ram. When the pile penetrates a certain amount and reaches the hard ground layer, a rebound phenomenon occurs that recoils along with the penetration of the pile, and the penetration amount and rebound amount for the impact energy per impact determined by the product of the mass of the ram and the drop height Is a measure of pile bearing capacity management. The drop height of the ram is selected according to the type of pile to be piled, the pile diameter, the mass of the ram, the ground condition, etc. The drop height of the ram depends on the penetration of the pile even during one pile driving operation. In some cases, construction may be carried out while changing. Conventionally, in such pile driving work, the amount of penetration and rebound is measured by recording paper on the surface of the pile just below the hammer with a constant ram drop height when the pile reaches the hard ground layer and the bearing capacity is obtained. A human power measurement method is employed in which a person directly presses a writing instrument such as a pencil to record directly.
[0003]
In addition, instead of this human power measurement, an attempt has been made to measure a small target sheet pasted on the surface of a pile with a CCD camera installed on the ship, etc. It was necessary to interrupt, and it was not possible to continuously measure the amount of penetration and rebound during pile driving.
[0004]
The method by manpower measurement is with a recording pen in direct contact with the pile whose displacement is to be measured. FIG. 7 schematically shows the measurement method. In FIG. 7, 1 is a pile, 2 is a hammer, 3 is a ram, 4 is the ground, 5 is a ground support layer, 6 is a recording paper, and 7 is a recording pen. The recording paper 6 is affixed to the side surface of the stake 1, and a recording pen 7 such as a pencil is brought into contact with the recording paper 6 and is directly held by a human. Next, when the ram 3 built in the hammer 2 is dropped from the height H and struck strongly, the displacement amount of the pile is recorded on the recording paper 6, and the amount is measured with a scale. . FIG. 8 is a diagram showing an example of recording on recording paper, with the horizontal axis representing time and the vertical axis representing displacement. As shown in FIG. 8, the struck pile 1 penetrates into the ground 4 and rebounds and rebounds in the vicinity of reaching the ground support layer 5. Assuming that l1 due to one stroke of the ram 3 is the maximum displacement amount, K is the rebound amount, S is the penetration amount, and there is a relationship of l1 = K + S. In pile driving work, this rebound amount K and penetration amount S are It is used to determine the bearing capacity of the pile and is used as a construction management standard. An example of a formula for calculating the bearing capacity of a pile is shown below. Although this contact type is simple and clear, there are many problems to be solved as described later, so the non-contact type has been studied.
[0005]

Where Ru: Dynamic limit bearing force ef: Mechanical efficiency wh: Ram weight H: Ram drop height S: Penetration amount K: Rebound amount
An example of a non-contact type is to capture the target sheet attached to the surface of the pile with a CCD camera from a certain distance, and measure the movement of the target sheet, that is, the behavior of the pile when the pile is struck by the fall of the ram in the hammer. To do. FIG. 9 schematically shows the measuring apparatus. In FIG. 9, 1 to 5 are the same as the measurement object of FIG. 7, 8 is a target sheet, 9 is a halogen light source, 10 is a CCD camera, 11 is a camera controller, 12 is a measurement calculation device, and 13 is a pen recorder. Show. In the apparatus configured as shown in FIG. 9, a target sheet 8 is attached to the side surface of the pile 1, illumination is performed with a halogen light source 9 so that sufficient contrast is obtained, and the image is captured by the CCD camera 10. Is processed by the measurement arithmetic unit 12 to determine the imaging position of the target sheet 8 approximately every 1 ms, and an analog voltage corresponding to this position is output, and this is recorded by the pen recorder 13 and the displacement of the pile The amount can be determined.
[0007]
[Problems to be solved by the invention]
In the contact type, when hammering a pile with a hammer, the operator must attach a recording paper to the pile at an appropriate stage and hold the recording pen, and there is a great risk that objects will fall from overhead during the work. In this work, there was a problem that the scaffolding became unstable and the danger increased, so the danger of the worker was extremely great. In addition, since the intrusion amount and rebound amount are read using the scale after recording by the operator and the bearing capacity of the pile is calculated, the work at the site is not quick, and the recorded results and reading values are subject to errors due to individual differences among the operators. Is included.
[0008]
On the other hand, in the non-contact type, although the risk of work is improved, it is necessary to interrupt the pile driving work because it requires field work to accurately attach the target sheet for each driven pile, and the driving of the pile Since the measurement range is limited by the distance between the target sheet and the CCD camera and the visual field, there is a drawback that continuous measurement cannot be performed over the entire pile driving length.
[0009]
The present invention improves the above-mentioned conventional problems, makes it possible to measure the displacement in the driving direction of the pile in a non-contact manner, in real time, with high accuracy and easily, and further, without hitting the manpower, An object is to provide a device capable of continuously acquiring data such as the number of times, penetration amount, rebound amount, supporting force, total pile driving length, and the like to perform pile driving management.
[0010]
The object of the present invention is to cancel the sway component and enable accurate measurement even when the sensor unit sways up and down relative to the pile as in the measurement on a ship.
[0011]
In addition, even when the relative distance between the pile and the sensor unit greatly fluctuates and deviates from the measurement area of the sensor unit as in the measurement on the ship, the sensor unit responds to the relative distance fluctuation between the pile and the sensor unit. The purpose is to enable stable measurement by tracking control of the position.
[0012]
[Means for Solving the Problems]
The pile driving management apparatus according to the present invention uses a sensor unit and a signal processing unit for measuring relative speed and relative displacement with a pile using the Doppler effect of laser light, and further based on the speed signal and displacement signal. The hammer waveform is obtained from the hammer, and the hammer hit interval, pile penetration, and rebound amount are extracted from this data to calculate the strike energy and the number of strikes. It has a data processing unit that calculates the length, displays and outputs it , extracts the displacement measurement error caused by the relative vertical movement with the pile due to the shaking of the device installation unit, extracts the speed value before and after hitting, and the time between Thus, the amount of displacement due to the shaking of the apparatus itself is obtained by trapezoidal integration, and the true displacement change of the measurement object is obtained by subtracting from the original measured displacement data .
[0015]
In addition, the pile driving construction management device according to the present invention provides a threshold for detecting the penetration speed of the pile due to hammering, detects the moment when the speed data exceeds this threshold as the hammering timing, and velocity data before and after this The displacement data is extracted as a hitting waveform.
[0016]
The pile driving construction management device according to the present invention averages displacement data for a fixed time before the hitting timing to obtain a zero displacement, and averages displacement data after a fixed time after the hitting timing for a fixed time to complete the displacement. The value obtained by subtracting the displacement zero value from the displacement end value is the penetration amount.
[0017]
Further, the pile driving management apparatus according to the present invention obtains a displacement maximum value from displacement data from a hitting timing to a certain time later, and uses a value obtained by subtracting the displacement end value from the displacement maximum value as a rebound amount.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
FIG. 1 shows Embodiment 1 of the present invention, and 1 to 6 are the same as those of a conventional measurement object. 14 is a sensor unit that detects a Doppler signal proportional to the velocity of the pile 1, 15 and 16 are laser beams emitted from the sensor unit 14, 17 are scattered light beams of the irradiated laser beams 15 and 16 reflected by the pile 1, 18 Is a signal processing unit that calculates and outputs the speed and displacement of the pile 1 from the Doppler signal detected by the sensor unit, 19 and 20 are analog voltage signals of speed and displacement output from the signal processing unit 18, respectively, and 21 is the speed and displacement. A data processing unit that processes signals to calculate the falling energy of the ram 3 in the hammer 2, the number of hits, the amount of penetration of the pile 1, the amount of rebound, the supporting force, etc. 22 is a printer for outputting measurement results It is. Reference numerals 23 and 24 constituting the data processing unit 21 are A / D converters for converting analog voltage signals into digital data, 25 is a memory for storing A / D converted data, and 26 is speed and displacement. An arithmetic processing unit having a function of performing various calculations from data, an input function, and a display function. FIG. 6 shows the installation conditions of the sensor unit 14 with respect to the pile 1. The measurement region of the sensor unit 14 is given by the intersection region of the irradiation laser beams 15 and 16, and the intersection of the irradiation laser beams 15 and 16 is the center. Since it is in the range of front and rear Δl, the sensor unit 14 is installed at the position of the measurement reference distance l relative to the pile 1. The normal measurement reference distance l is 1 m, and the measurement region Δl is a value of about 140 mm.
[0019]
In the pile driving management apparatus configured as described above, when the scattered light 17 of the two laser beams 15 and 16 irradiated from the sensor unit 14 at the crossing angle φ is received by the sensor unit 14 and converted into electrical signals, Doppler is used. As a result, a frequency signal having a Doppler frequency fd proportional to the moving speed V of the pile 1 shown in the following equation is obtained.
[0020]
fd = (2V / λ) · sin (φ / 2) (2)
Where V: moving speed of pile 1 λ: wavelength of laser light φ: intersection angle of two laser beams 14 and 15
The Doppler frequency signal obtained by the sensor unit 14 is converted and output by the signal processing unit 18 to velocity data 19 for moving the pile 1 and displacement data 20 obtained as this time integration. Here, FIG. 2 is a diagram showing time axis waveforms of the velocity data 19 and the displacement data 20 output from the signal processing unit 18. FIG. 3 is a flowchart showing the processing flow of the data processing unit 21, and S1 to S16 in the figure show the steps of the flowchart, and the data processing procedure will be described based on this. The process is started in step S1, and in step S2, the construction date and time, construction name, construction location, and other construction information and the computation start time α, computation end time β, displacement zero average time a, penetration amount average shown in FIG. Measurement conditions such as a relation table of time b, rising judgment level e, ram weight wh, and ram fall height H determined by a hammer in advance and the number of hits per minute are input. Here, for example, the hydraulic hammer 2 has a mechanism in which the ram fall height H can be switched in several stages. The ram 3 is pushed up by the height H by hydraulic pressure from the time when the ram 3 hits the pile, and then the ram 3 The time required to drop the height H and hit the pile again is a time corresponding to the ram fall height H on a one-to-one basis, so there is a one-to-one relationship between the ram drop height H and the number of hits per minute. It is shown in advance as performance specifications of the hammer.
[0022]
Next, when the measurement start key is pressed, the measurement process is started in step S3, and the speed data 19 and the displacement data 20 output from the signal processing unit 18 are converted into digital values by the A / D converters 23 and 24 in step S4. In step S5, the striking timing of the ram 3 is detected from the speed waveform shown in FIG. 2 at a speed timing exceeding the speed rising judgment level e. In step S6, the striking number counter is counted every time step S5 is passed. Is updated, and the number of hits is cumulatively counted. In step S7, the current hit timing time is subtracted from the previous hit timing time to obtain the hit interval time Δtn. In step S8, the reciprocal of the hit interval time Δtn is calculated per minute. The ram drop height H is determined from the table of the relationship between the ram drop height H and the hit count per minute. The striking energy is calculated by multiplying the ram weight wh. Subsequently, in step S9, a value obtained by averaging the displacement data before the calculation start time α from the impact timing by the displacement zero average time a is defined as a displacement zero point F _{0. In} step S10, the displacement from the impact timing to the end of the calculation β after the impact timing. the value obtained by subtracting the zero point F ₀ of the displacement than this the maximum value from the data set to the maximum displacement amount Fmax, the displacement from the value of the displacement data were averaged by penetration amount average time b after calculation end time β from striking timing in step S11 of which cumulatively added for each one striking a value obtained by subtracting the zero point F ₀ with a penetration amount Fs yield a cumulative penetration amount ΣFs of pile, the value obtained by subtracting the penetration amount Fs from the maximum displacement amount Fmax in step S12 The rebound amount is Fk. Using the penetration amount Fs, the rebound amount Fk, and the impact energy H × wh, the calculation of formula (1), which is an example of the support force calculation formula described above in step S13, is performed to obtain the support force, and in step S14 The accumulated number of hits n, the hit interval Δtn, the penetration amount Fs, the cumulative penetration amount ΣFs, the rebound amount Fk, and the support force obtained by the above processing are displayed and output. If the measurement end key is not pressed in step S15, the above processing is performed. The display output data is updated in real time for each impact. If the measurement end key has been pressed in step S15, the measurement is terminated, and in step S16, the data obtained by the series of data processing is totaled and printed out as a form.
[0023]
According to the pile driving construction management device of this configuration, the hit waveform due to the drop impact of the ram 3 is detected for each hit, the number of hits n is obtained by counting the number of hit waveforms, and the time at which this hit waveform is generated. The fall energy of the ram 3 is calculated based on the interval Δtn, the penetration amount Fs and the rebound amount Fk are obtained from the displacement data 20 of the hitting waveform, and the cumulative value of the penetration amount Fs is obtained to obtain the cumulative penetration amount of the pile 1 Since ΣFs is obtained and the pile supporting force is calculated from the penetration amount Fs, the rebound amount Fk, and the fall energy of the ram 3 and the display output is performed, the cumulative number of hits per hit from the start to the end of the pile driving work, Data such as the hitting interval, penetration amount, cumulative penetration amount, rebound amount, support force and the like can be measured in real time, and the tabulation work of these data can be automated.
[0024]
Embodiment 2. FIG.
FIG. 4 is a diagram for explaining the fluctuation correction process according to the second embodiment of the present invention. FIG. 4B is a diagram in which the displacement change amount generated by the up-and-down movement of the sensor unit 14 is superimposed on the displacement change caused by the actual hitting. FIG. 4A shows the velocity waveform at this time. Here, the displacement change amount (shift amount) due to the fluctuation component is approximately obtained by connecting the speed value Vst at the calculation start time tst and the speed value Vend at the calculation end time tend with a straight line and performing trapezoidal integration as shown in the following equation. It comes out.
[0025]
Fec = (1/2). (Vst + Vend). (Tend-tst) (3)
Where Fec: fluctuation displacement correction value
Therefore, even when a fluctuation component is superimposed on the displacement amount, accurate measurement can be realized by calculating and subtracting the fluctuation displacement correction value Fec. In this shake correction method, correction can be made with an accuracy of ± 1 mm if the time interval from the calculation start time tst to the calculation end time tend is 0.4 seconds or less under the conditions of a swing period of 3 Hz and a swing amplitude of ± 25 mm. .
[0027]
Embodiment 3 FIG.
FIG. 5 shows a third embodiment of the present invention, in which 1 to 21 are the same as those in the first embodiment. 27 is a non-contact distance meter represented by an ultrasonic distance meter that obtains a distance based on the round-trip time of the ultrasonic wave, 28 is a controller that outputs a control signal from the difference between the output of the distance meter 27 and the measurement reference distance l, 29 Is a linear actuator that receives the output of the controller 28 and moves the sensor unit 14 and the distance meter 27 back and forth with respect to the pile 1, 30 is a pile driving ship, and 31 is seawater.
[0028]
When the relative distance between the pile 1 and the sensor unit 14 is changed from the measurement reference distance l in the pile driving management apparatus having the above configuration, the controller 28 receives the measurement distance output of the distance meter 27 and the amount of displacement with respect to the measurement reference distance l is increased. A control signal is given to the linear actuator 29 so that it becomes zero, and the relative distance between the pile 1 and the sensor unit 14 always operates so as to coincide with the measurement reference distance l. Stable measurement is possible even when the relative distance between the pile 1 and the sensor unit 14 varies greatly during driving.
[0029]
【The invention's effect】
Since the present invention is configured as described above, it has the effects described below.
[0030]
According to the present invention, since the Doppler effect of the laser beam is used, the speed and displacement of the pile moving in a non-contact manner can be automatically measured without bothering the manpower, and the speed and displacement can be obtained continuously. It is possible to continuously display and output the number of hits required for pile driving management, pile supporting force, cumulative penetration amount, etc. in real time, and collect all pile driving management data in the data processing section Since the work can be automated, a great effect can be obtained in the safety and labor saving of the pile driving management work that is currently performed almost manually.
[0031]
Moreover, according to this invention, even when a sensor part is rocking relatively with respect to a pile like measurement on a ship, a rocking | fluctuation component can be canceled, a measurement precision is improved and an application range is expanded. effective.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a pile driving management machine showing Embodiment 1 of the present invention.
FIG. 2 is an operation waveform diagram according to the first embodiment of the present invention.
FIG. 3 is a flowchart according to the first embodiment of the present invention.
FIG. 4 is an operation waveform diagram according to the second embodiment of the present invention.
FIG. 5 is a block diagram of a pile driving management machine showing Embodiment 3 of the present invention.
FIG. 6 is a schematic diagram showing a measurement range of a sensor unit applied in the present invention.
FIG. 7 is a configuration diagram showing a conventional recording pen type rebound amount measuring method.
FIG. 8 is a diagram showing a conventional operation waveform.
FIG. 9 is a block diagram showing a conventional non-contact type rebound amount measuring apparatus.
[Explanation of symbols]
1 Pile, 2 Hammer, 3 Ram, 4 Ground, 5 Ground support layer, 6 Recording paper, 7 Recording pen, 8 Target sheet, 9 Halogen light source, 10 CCD camera, 11 Camera controller, 12 Measurement calculation device, 13 Pen recorder, 14 sensor units, 15 irradiation laser beam, 16 irradiation laser beam, 17 scattered light, 18 signal processing unit, 19 speed signal, 20 displacement signal, 21 data processing unit, 22 printer, 23 A / D converter 1, 24 A / D converter 2, 25 Memory, 26 Arithmetic processing unit, 27 Distance meter, 28 Controller, 29 Linear actuator, 30 Pile driver, 31 Seawater.

Claims (4)

The pile that penetrates into the ground by hammering into a predetermined place is irradiated with laser light and the scattered light is received to detect the Doppler signal proportional to the penetration speed of the pile and the penetration speed of the pile from the Doppler signal And a laser Doppler velocimeter composed of a signal processing unit for calculating and outputting displacement, means for detecting the number of hits by detecting the hit waveform on the hammer pile from the output data of the laser Doppler velocimeter, and the hit waveform Means for detecting the time interval of occurrence and determining the impact energy from the time interval, means for detecting the pile penetration amount and the pile rebound amount for each hammer strike from the displacement data output from the signal processing unit, the penetration amount rebound amount; and a data processing unit and a striking energy and a means for determining the bearing capacity of the pile, the phase of the pile by shaking of the device installation unit The displacement measurement error caused by the vertical movement is extracted by extracting the velocity value before and after the impact and integrating the trapezoid with the time between them to obtain the displacement amount due to the fluctuation of the device itself, and subtracting it from the original measured displacement data A pile driving management device characterized by obtaining a true displacement change of an object.   The means for detecting the hitting waveform provides a threshold for detecting the moving speed of the pile due to hitting, detects the moment when the speed data exceeds the threshold as the hitting timing, and hits the speed data and displacement data before and after the hitting timing. The pile driving management device according to claim 1, wherein the pile driving management device is extracted as a waveform.   The means for detecting the penetration amount averages displacement data for a predetermined time before the impact timing to a displacement zero value, and averages displacement data after a certain time from the impact timing as a displacement end value, 2. The pile driving management apparatus according to claim 1, wherein a value obtained by subtracting a displacement zero value from a displacement end value is used as the penetration amount.   The means for detecting the rebound amount obtains a displacement maximum value from displacement data from a hitting timing to a predetermined time later, and uses a value obtained by subtracting the displacement end value from the displacement maximum value as a rebound amount. The pile driving construction management apparatus according to 1.

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