JPH07197785A - Prediction method for displacement of tunnel internal space - Google Patents
Prediction method for displacement of tunnel internal spaceInfo
- Publication number
- JPH07197785A JPH07197785A JP35240993A JP35240993A JPH07197785A JP H07197785 A JPH07197785 A JP H07197785A JP 35240993 A JP35240993 A JP 35240993A JP 35240993 A JP35240993 A JP 35240993A JP H07197785 A JPH07197785 A JP H07197785A
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- JP
- Japan
- Prior art keywords
- displacement
- curve
- tunnel
- displacement amount
- excavation
- 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.)
- Granted
Links
- 238000006073 displacement reaction Methods 0.000 title claims abstract description 176
- 238000000034 method Methods 0.000 title claims description 33
- 238000009412 basement excavation Methods 0.000 claims abstract description 36
- 238000005259 measurement Methods 0.000 claims abstract description 31
- 238000004364 calculation method Methods 0.000 abstract description 4
- 238000004088 simulation Methods 0.000 abstract 1
- 238000007726 management method Methods 0.000 description 40
- 238000010276 construction Methods 0.000 description 11
- 230000002787 reinforcement Effects 0.000 description 5
- 230000005856 abnormality Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 229910000831 Steel Inorganic materials 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 2
- 239000004567 concrete Substances 0.000 description 2
- 239000011378 shotcrete Substances 0.000 description 2
- 238000007619 statistical method Methods 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 238000013459 approach Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000011065 in-situ storage Methods 0.000 description 1
- 238000010561 standard procedure Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
Landscapes
- Excavating Of Shafts Or Tunnels (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明はトンネル内空変位の予測
方法に係り、特に掘削開始に際し、変位管理レベルを設
定するとともに、初期段階での変位速度をもとに、以後
のトンネル内空変位の経時変化を簡易な仮想曲線により
予測するようにしたトンネル内空変位の予測方法に関す
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for predicting air displacement in a tunnel, and particularly when starting excavation, a displacement management level is set and the air displacement in the tunnel thereafter is determined based on the displacement speed in the initial stage. The present invention relates to a method for predicting sky displacement in a tunnel, which predicts the change over time of a tunnel with a simple virtual curve.
【０００２】[0002]
【従来の技術】近年、山岳トンネルの標準工法として普
及してきたＮＡＴＭは、掘削過程で得られた種々の計測
結果に基づいて支保工、地山の安定性を確認し、その計
測データを対策工の検討にフィードバックさせ、効率の
良い施工を行えるという特徴を有している。この計測デ
ータのうち、特に計測断面の内空変位と天端沈下量とは
掘削地山の性状と掘削の進行に伴う周辺地山の応力再配
分を加味したトンネルの挙動を総合的に判断することの
できる重要な計測項目であり、蓄積された計測データを
もとにトンネル掘削時の地山安定性が判定される。また
実施工においては、地山の最終変位量がどの程度に収束
するかを計測で得られた変位曲線の経時変化をもとに早
期に精度良く推定することが、補強工等の要否を的確に
判断し、適切な支保パターンで対応していくために重要
になってくる。そこで、この要請に応えて計測データを
もとにトンネルの最終的な変位を予測するための予測手
法が種々提案されてきている。2. Description of the Related Art In recent years, NATM, which has become widespread as a standard method for mountain tunnels, supports the support and confirms the stability of the ground based on various measurement results obtained during the excavation process, and measures the measured data. It has the feature that it can be fed back to the examination and efficient construction can be performed. Among these measurement data, especially the in-air displacement of the measurement section and the crown subsidence amount comprehensively judge the behavior of the tunnel considering the properties of the excavated ground and the stress redistribution of the surrounding ground accompanying the progress of excavation. This is an important measurement item that can be achieved, and the ground stability during tunnel excavation is judged based on the accumulated measurement data. Also, in the actual work, it is necessary to estimate the extent to which the final displacement amount of the natural ground converges based on the change over time of the displacement curve obtained by measurement, with high accuracy at an early stage. It becomes important to make accurate judgments and respond with appropriate support patterns. Therefore, in response to this request, various prediction methods for predicting the final displacement of the tunnel based on the measurement data have been proposed.
【０００３】たとえば掘削進行中の地山変位の最終収束
値と収束に至る時間を推定する簡便法として二倍時間法
が知られている（近藤達敏：「ＮＡＴＭ工法によるトン
ネル掘削における変位予測」応用地質調査事務所年報 N
o.1, p.234, 1979 参照）。この二倍時間法では、任意
の切羽距離Ｌiにおける変位の実測値をＵiとし、またＬ
k＝２Ｌiにおける実測値をＵkとしたとき、これらの関
係が一般式（式１）によって表せると仮定し、この両者
の値を利用して最終変位収束値Ａ（式２）と任意の切羽
距離Ｌにおける変位Ｕを求めるようになっている。For example, a double time method is known as a simple method for estimating the final convergence value of ground displacement during excavation and the time to reach convergence (Tatsutoshi Kondo: "Displacement prediction in tunnel excavation by NATM method"). Applied Geological Survey Office Annual Report N
o.1, p.234, 1979). In this double time method, the measured value of the displacement at an arbitrary face distance L i is U i, and L
When the measured value at k = 2L i is U k , it is assumed that these relationships can be expressed by a general expression (Equation 1), and using both values, the final displacement convergence value A (Equation 2) and an arbitrary The displacement U at the face distance L is calculated.
【数１】 [Equation 1]
【０００４】[0004]
【発明が解決しようとする課題】ところが、前述の二倍
時間法やその他の統計的手法では掘削初期段階において
変位量の予測に必要な切羽距離の所定の変位値を得るこ
とはできない。このため初期段階では前述の予測手法を
適用することができないという問題がある。また、従来
計画段階においては所定の定量的な管理目標データを設
定しておくことができない上、また掘削当初は蓄積され
た計測データも少ないので、初期段階で生じた変位デー
タがその地点以後の掘削に活かされていなかった。さら
に前述の二倍時間法では計測時の切羽距離を正確に２倍
ごとに設定することがきわめて困難であるためラグラン
ジェの補間公式等によりデータ補間を行わなければなら
ず計算が煩雑である。そのため現場で簡易的な計算方法
により予測する方法の開発が望まれていた。However, the above-mentioned double time method and other statistical methods cannot obtain a predetermined displacement value of the face distance necessary for predicting the displacement amount in the initial stage of excavation. Therefore, there is a problem that the above-described prediction method cannot be applied in the initial stage. In addition, in the conventional planning stage, it is not possible to set predetermined quantitative management target data, and since there is little measurement data accumulated at the beginning of excavation, the displacement data generated in the initial stage is It wasn't used for excavation. Further, in the above-mentioned double time method, it is extremely difficult to accurately set the face distance at the time of measurement every two times, and therefore data interpolation must be performed by the Lagrange's interpolation formula or the like, and the calculation is complicated. Therefore, it has been desired to develop a method for making a prediction on site using a simple calculation method.
【０００５】そこで、本発明の目的は前述した従来の技
術が有する問題点を解消し、簡易な仮想曲線を設定する
ことにより計画段階で定量的な変位管理レベル値を決定
するとともに、トンネルの掘削開始直後に得られた初期
内空変位速度から最終変位量を早期に予測できるように
したトンネル内空変位の予測方法を提供することにあ
る。Therefore, an object of the present invention is to solve the above-mentioned problems of the conventional technique and to determine a quantitative displacement management level value at the planning stage by setting a simple virtual curve and to excavate a tunnel. It is an object of the present invention to provide a method for predicting the inner air displacement of a tunnel that can predict the final amount of displacement early from the initial inner air displacement velocity obtained immediately after the start.
【０００６】[0006]
【課題を解決するための手段】上記目的を達成するため
に、本発明は所定の管理最大変位量から変位管理レベル
を段階的に設定し、該変位管理レベルに対応する最終変
位量を計測開始後の経時期間とトンネル内空変位量とを
パラメータとした関数曲線により算定してトンネル掘削
時の内空変位の管理曲線を設定するとともに、掘削開始
直後時に得られた初期変位速度をもとに前記関数曲線に
より変位予想曲線を求め、最終変位量を予測するように
したことを特徴とするものである。In order to achieve the above object, the present invention sets a displacement management level stepwise from a predetermined management maximum displacement amount and starts measuring a final displacement amount corresponding to the displacement management level. The control curve of the inner air displacement during tunnel excavation is set by calculating with a function curve that uses the elapsed time afterwards and the amount of air displacement inside the tunnel as parameters, and based on the initial displacement speed obtained immediately after the start of excavation. The displacement prediction curve is obtained from the function curve, and the final displacement amount is predicted.
【０００７】前記関数曲線は少なくとも１次変位円弧曲
線と２次変位円弧曲線とからなるように設定することが
好ましい。このとき前記１次円弧曲線は変位量軸と経時
日数軸を軸とする直交座標系上で、１次変位収束日数あ
るいは間隔日数経過後の１次変位収束点に相当する経時
日数値の直線上に円弧中心点を有し、原点と１次変位収
束点とを通過し、前記２次円弧曲線は前記１次変位収束
点と前記最終変位量を得る２次変位収束点とを通過し、
該２次変位収束点に相当する経時日数値の直線上に円弧
中心点を有するように設定することが好ましい。It is preferable that the function curve is set to include at least a primary displacement arc curve and a secondary displacement arc curve. At this time, the primary circular arc curve is on a straight line of the numerical values of elapsed days corresponding to the primary displacement convergence point after the primary displacement convergence days or the interval days on an orthogonal coordinate system having the displacement amount axis and the elapsed days axis as axes. Has an arc center point, passes through the origin and the primary displacement convergence point, and the secondary arc curve passes through the primary displacement convergence point and the secondary displacement convergence point for obtaining the final displacement amount,
It is preferable to set the arc center point on the straight line of the elapsed day numerical value corresponding to the secondary displacement convergence point.
【０００８】[0008]
【作用】本発明によれば、所定の管理最大変位量から変
位管理レベルを段階的に設定し、該変位管理レベルに対
応する最終変位量を計測開始後の経時期間とトンネル内
空変位量とをパラメータとした関数曲線により算定して
トンネル掘削時の内空変位の管理曲線を設定するととも
に、掘削開始直後時に得られた初期変位速度をもとに前
記関数曲線により変位予想曲線を求め、最終変位量を予
測するようにしたので、計画段階で定量的な管理レベル
を設定することができるとともに、掘削初期段階におい
て最終変位量を予測でき、その値に応じて適切な対策工
を迅速に実施できる。前記関数曲線は少なくとも１次変
位円弧曲線と２次変位円弧曲線とからなるように設定し
たので、簡易な計算手法により変位予測を行うことがで
きる。According to the present invention, the displacement management level is set stepwise from a predetermined management maximum displacement amount, and the final displacement amount corresponding to the displacement management level is set to the elapsed time after the start of measurement and the empty displacement amount in the tunnel. A control curve for the inner-air displacement at the time of tunnel excavation is set by calculating with a function curve that uses as a parameter, and a displacement prediction curve is obtained from the above-mentioned function curve based on the initial displacement speed obtained immediately after the start of excavation, and the final Since the displacement amount is predicted, a quantitative management level can be set at the planning stage, and the final displacement amount can be predicted at the initial stage of excavation, and appropriate countermeasures can be promptly taken according to the value. it can. Since the function curve is set to include at least a primary displacement arc curve and a secondary displacement arc curve, the displacement can be predicted by a simple calculation method.
【０００９】[0009]
【実施例】以下本発明によるトンネル内空変位の予測方
法の一実施例を添付図面を参照して説明する。本発明に
よるトンネル内空変位の予測方法は、計画段階に定量的
な管理レベルを設定する「管理レベル設定段階」と、掘
削開始直後に得られた内空変位の初期変位速度を利用し
て最終変位量を推定し、この値と前記管理レベルとの対
比を行って所定の対応策を決定する「変位予測段階」と
から構成されている。以下、管理レベル設定段階と変位
予測段階とに分けて各段階での作業手順を説明する。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the method for predicting the air displacement in a tunnel according to the present invention will be described below with reference to the accompanying drawings. The tunnel inner air displacement prediction method according to the present invention uses a "management level setting stage" in which a quantitative control level is set in the planning stage, and an initial displacement velocity of the inner air displacement obtained immediately after the start of excavation. It comprises a "displacement prediction stage" in which the displacement amount is estimated, and this value is compared with the management level to determine a predetermined countermeasure. Hereinafter, the operation procedure at each stage will be described separately for the management level setting stage and the displacement prediction stage.
【００１０】１．管理レベル設定段階 管理レベル設定作業は計画段階において実施される。以
下、図１の作業フローチャートを参照してその手順につ
いて説明する。まず、所定の解析手法により最終変位量
を設定する（ステップ１００）。本実施例では桜井春輔
氏（神戸大学教授）の提案した「限界ひずみ理論」を用
いて最大変位量を算定している。この限界ひずみ理論を
用いた方法の他、有限要素法の地盤変位解析結果や地盤
調査結果に基づく統計的手法等も使用することができ
る。1. Management level setting stage Management level setting work is carried out in the planning stage. The procedure will be described below with reference to the work flow chart of FIG. First, the final displacement amount is set by a predetermined analysis method (step 100). In the present embodiment, the maximum displacement amount is calculated using the "critical strain theory" proposed by Shunsuke Sakurai (Professor, Kobe University). In addition to the method using the limit strain theory, a statistical method based on the ground displacement analysis result of the finite element method or the ground survey result can also be used.
【００１１】この限界ひずみ理論は採取した試料の一軸
圧縮強度とその試料の極限ひずみとの相関関係図（図示
せず：前記論文に掲載）を利用して対象地盤の最大変位
量を求めるもので、対象となるトンネル半径ａに対する
半径方向変位量Ｖを以下の（式３）により直接算出する
ことができる。 Ｖ＝ε0・ａ …（式３） このとき本実施例において、適用する対象地盤の一軸圧
縮強度がσC＝５０kg/cm2であるとすると、前記相関関
係図より極限ひずみε0はε0＝０．０１９となり、トン
ネル半径ａ＝５５０cmのトンネルの場合、同式より半径
方向変位量Ｖは Ｖ＝０．０１９×５５０＝１０．５（ｃｍ） となる。ここで実際のトンネル切羽における掘削直後の
応力解放により計測開始までに生じる先行変位率δ0を
考慮して以下のように管理最大変位量Ｘ0maxを設定する
ことが望ましい。 Ｘ0max＝Ｖ・（１−δ0） …（式４） 通常の地山の場合、δ0＝０．３程度が好ましい。した
がって、本実施例では一例としてＸ0max＝７．０ｃｍに
設定して以下の管理曲線および管理レベルの設定作業を
説明する。This critical strain theory is to obtain the maximum amount of displacement of the target ground using a correlation diagram (not shown: published in the above paper) between the uniaxial compressive strength of the sample and the ultimate strain of the sample. The displacement amount V in the radial direction with respect to the target tunnel radius a can be directly calculated by the following (formula 3). V = ε 0 · a (Equation 3) At this time, assuming that the uniaxial compressive strength of the target ground to be applied in this embodiment is σ C = 50 kg / cm 2 , the ultimate strain ε 0 is ε from the correlation diagram. In the case of a tunnel having a tunnel radius a = 550 cm, the displacement V in the radial direction is V = 0.19 × 550 = 10.5 (cm) according to the same equation. Here, it is desirable to set the management maximum displacement amount X0max as follows in consideration of the preceding displacement rate δ 0 generated by the stress release immediately after excavation in the actual tunnel face until the start of measurement. X0max = V (1-δ 0 ) (Equation 4) In the case of ordinary ground, δ 0 = 0.3 is preferable. Therefore, in the present embodiment, as an example, the following setting operation of the control curve and the control level will be described by setting X0max = 7.0 cm.
【００１２】ここで、管理最大変位量Ｘ0maxをもとに各
管理レベルの範囲を以下の表１に示したように設定す
る。ここで示した各管理レベルは従来のトンネル施工デ
ータを参考して設定することが好ましい。Here, the range of each management level is set as shown in Table 1 below based on the maximum management displacement amount X0max. Each management level shown here is preferably set with reference to conventional tunnel construction data.
【表１】 また、併せて各管理レベルに対応した計測体制及び対策
工を選定するための対策工選定フローチャート（図２参
照）も作成することが好ましい。この対策工選定フロー
チャートでは予想最終変位量が属する各管理レベルに応
じて検討及び対応すべき対策工が掲げられている。その
内容については後述する。[Table 1] In addition, it is also preferable to create a countermeasure work selection flowchart (see FIG. 2) for selecting a measurement system and countermeasure work corresponding to each management level. In this countermeasure work selection flowchart, the countermeasure works to be examined and dealt with are listed according to each management level to which the expected final displacement amount belongs. The contents will be described later.
【００１３】次に、図３に示した各管理レベルを区分け
する各管理曲線を設定する。まず上半掘削時に生じる一
次変位が収束するまでの収束日数を設定する（ステップ
１１０）。この一次変位の収束日数とは上半を掘削して
設けられた計測断面での計測開始から変位が収束するま
での日数を言い、過去の施工実績から設定することも可
能であるが、本実施例では初期値として１０（日）とす
る。さらに計測可能な全体変位量（Ｘmax）に対する一
次変位量（Ｘ1）の比率αを設定する（ステップ１２
０）。従って全体変位量（Ｘmax）と一次変位量（Ｘ1）
との関係を（式５）で示すことができる。 Ｘmax＝α・Ｘ1 …（式５）Next, each management curve that divides each management level shown in FIG. 3 is set. First, the number of convergence days until the primary displacement generated during the upper half excavation converges is set (step 110). The number of days for the primary displacement to converge is the number of days from the start of measurement on the measurement section provided by excavating the upper half until the displacement converges, which can be set from past construction results, but this implementation In the example, the initial value is 10 (days). Further, the ratio α of the primary displacement amount (X 1 ) to the total measurable displacement amount (Xmax) is set (step 12).
0). Therefore total displacement (Xmax) and the primary displacement (X 1)
Can be expressed by (Equation 5). Xmax = α · X 1 (Equation 5)
【００１４】ここでＸ軸を経時日数（日）とし、Ｙ軸を
変位量（ｍｍ）とした直交座標系において、原点（０，
０）と一次変位収束点（１０，Ｘ1）を通り、Ｘ＝１０
を中央縦距とする半径Ｒの単曲線を仮想変位半径とする
円弧の一部を変位曲線として設定する（ステップ１３
０）。この仮想半径Ｒの算出は以下の（式６）を変形し
て（式７）により求めるのが簡便である。 （Ｘ−１０）2＋｛Ｙ−（Ｒ−Ｘ1）｝2＝Ｒ2 …（式６） ここで（式６）は原点を通過するので、Ｘ＝０，Ｙ＝０とにより Ｒ＝（１０2＋Ｘ1 2）／（２×Ｘ1） …（式７） さらに以後の掘削に対応するために一次変位が収束した
時点（Ｘ＝１０日）から下半掘削の影響による二次変位
発生開始までの間隔日数Ａを設定する（ステップ１４
０）。この間、一次変位量はその値を保持され、この間
隔日数Ａ間、Ｙ＝Ｘ1なる直線部が形成される。この間
隔日数Ａの設定に際し、二次変位は図４に示したように
下半切羽が計測断面に対して接近距離０．５Ｄ（Ｄ：ト
ンネル直径）となる位置に到達した時に開始すると仮定
する。In the Cartesian coordinate system in which the X-axis is the number of days elapsed (days) and the Y-axis is the amount of displacement (mm), the origin (0,
0) and the first-order displacement convergence point (10, X 1 ), and X = 10
Is set as the displacement curve (step 13).
0). It is easy to calculate the virtual radius R by modifying (Equation 6) below and obtaining it by (Equation 7). (X-10) 2 + {Y− (R−X 1 )} 2 = R 2 (Equation 6) Since (Equation 6) passes through the origin, R = 0 by X = 0 and Y = 0. (10 2 + X 1 2 ) / (2 × X 1 ) (Equation 7) Secondary displacement due to the influence of the lower half excavation from the time when the primary displacement converges (X = 10 days) to cope with the subsequent excavation. Set the interval days A until the start of occurrence (step 14
0). During this period, the value of the primary displacement amount is maintained, and during this interval days A, a straight line portion Y = X 1 is formed. When setting the interval days A, it is assumed that the secondary displacement starts when the lower half face reaches a position where the approach distance is 0.5 D (D: tunnel diameter) with respect to the measurement cross section as shown in FIG. .
【００１５】本実施例では下半掘削に伴って生じる二次
変位も変位開始から１０日間で収束すると仮定し、Ｘ＝
（１０＋Ａ＋１０）なる直線上に円弧中心点を有して二
次変位開始日での変位点（１０＋Ａ，Ｘ1）を通り、前
記仮想変位半径Ｒとする二次変位管理曲線を設定する
（ステップ１５０）。このとき前記表１に示した管理レ
ベルに基づく各変位管理曲線を設定し、実測値が属する
管理レベル値により所定の対策工等を行えるようになっ
ている（図２参照）。In the present embodiment, it is assumed that the secondary displacement caused by the lower half excavation also converges within 10 days from the start of displacement, and X =
A secondary displacement management curve having the virtual displacement radius R is set by passing through the displacement point (10 + A, X 1 ) at the secondary displacement start date with an arc center point on the straight line (10 + A + 10) (step 150). ). At this time, each displacement management curve based on the management level shown in Table 1 is set, and a predetermined countermeasure work or the like can be performed according to the management level value to which the actually measured value belongs (see FIG. 2).
【００１６】２．変位予測段階 前記変位管理曲線を設定して求めた定量的な管理レベル
値を踏まえてトンネル掘削を開始する。掘削初期段階に
おける計測データの収集に際し、以後の変位予測のため
に初期変位速度Ｖ0を計測する。ここで掘削初期段階と
は坑口から１００ｍ程度掘進する間を指し、この間では
計測データが蓄積されていないので、設定すべき各定数
は地盤原位置試験等の結果や類似した地質のトンネル施
工実績から設定することが好ましい。2. Displacement prediction stage Tunnel excavation is started based on the quantitative management level value obtained by setting the displacement management curve. At the time of collecting measurement data in the initial stage of excavation, the initial displacement velocity V 0 is measured for subsequent displacement prediction. Here, the initial stage of excavation refers to the period of excavation of about 100 m from the wellhead, and since measurement data has not been accumulated during this period, each constant to be set is based on the results of ground in-situ tests, etc., and the tunnel construction results of similar geology. It is preferable to set.
【００１７】また、掘削が進行していくに連れて計測断
面も所定距離ごとに設置されていくので、蓄積された計
測データをもとに一次変位の収束時期や最終変位に対す
る一次変位量の割合等を当初の設定値から現場の地盤状
況により合った値とすることができる。Further, as the excavation progresses, the measurement cross sections are also installed at predetermined distances. Therefore, based on the accumulated measurement data, the convergence time of the primary displacement and the ratio of the primary displacement to the final displacement are calculated. It is possible to change the values such as the above from the initially set values according to the ground conditions at the site.
【００１８】ここで、実際の計測が開始された段階で得
られた初期変位速度Ｖ0をもとに全体変位量Ｘmaxを予測
する方法を図５を参照して説明する。なお、計測は掘削
に引き続いて施工される吹付コンクリート等の一次支保
工完了直後から開始されるが、このとき最初に計測され
る初期値と１日経過後の計測値との差を初期変位速度Ｖ
0（ｍｍ／日）として定義し、この初期変位速度Ｖ0を利
用して最終変位量としての全体変位量Ｘmaxを予測する
ことができる。A method of predicting the total displacement amount Xmax based on the initial displacement velocity V 0 obtained at the stage when the actual measurement is started will be described with reference to FIG. It should be noted that the measurement is started immediately after the completion of the primary support work such as shotcrete that is constructed following the excavation. At this time, the difference between the initially measured value and the measured value after one day has passed is the initial displacement velocity V.
It is defined as 0 (mm / day), and the initial displacement speed V 0 can be used to predict the total displacement amount Xmax as the final displacement amount.
【００１９】初期変位速度Ｖ0は及び仮想変位半径Ｒは
以上の定義より下式で求めることができる（ステップ２
００、２１０）。 Ｖ0＝√（Ｒ2−９2）−√（Ｒ2−１０2） …（式８） Ｒ＝√（Ｖ0 2＋３６２Ｖ0 2＋３６１）／（２×Ｖ0） …（式９） さらに（式９）から一次変位量Ｘ1を求めると（式１０）のようになる（ステ ップ２２０）。 Ｘ1＝Ｒ−√（Ｒ2−１０2） （ｃｍ） …（式１０） この一次変位量Ｘ1から最終変位量たる全体変位量Ｘmax
を推定する（ステップ２３０）。このとき全体変位量Ｘ
maxはを推定するために下式のように前記比率（α）を
採用することができる。この比率（α）は初期において
はα＝２に設定されているが、掘削が進行して計測デー
タが蓄積されてきたら、各計測断面で得られた変位状況
に合った比率を使用することが好ましい。 Ｘmax＝α・Ｘ1 …（式１１） このとき得られた全体変位量Ｘmaxを前記変位管理曲線
にプロットすることにより予想される最終変位に対する
適正な支保パターンの検討を加えることができる。The initial displacement velocity V 0 and the virtual displacement radius R can be obtained by the following equations based on the above definitions (step 2
00, 210). V 0 = √ (R 2 −9 2 ) −√ (R 2 −10 2 ) (Equation 8) R = √ (V 0 2 +362 V 0 2 +361) / (2 × V 0 ) (Equation 9) When the primary displacement amount X 1 is obtained from (Equation 9), it becomes as shown in (Equation 10) (Step 220). X 1 = R−√ (R 2 −10 2 ) (cm) (Equation 10) The total displacement amount Xmax which is the final displacement amount from this primary displacement amount X 1.
Is estimated (step 230). Total displacement X at this time
To estimate max, the ratio (α) can be adopted as in the following equation. This ratio (α) is initially set to α = 2, but if excavation progresses and measurement data is accumulated, it is possible to use a ratio that matches the displacement status obtained at each measurement cross section. preferable. Xmax = α · X 1 (Equation 11) By plotting the total displacement amount Xmax obtained at this time on the displacement management curve, it is possible to examine an appropriate support pattern for the expected final displacement.
【００２０】ここで、図６により初期変位速度Ｖ0が求
められた時の全体変位量Ｘmaxの予測方法について、具
体的な数値を当てはめた変位曲線を用いて説明する。初
期変位速度Ｖ0としてＶ0＝９mm／日が得られたとき、変
位仮想半径Ｒは以下の式で求めることができる。 Ｒ＝√（０．９4＋３６２＋０．９2＋３６１）／（２×
０．９）＝１４．２（ｃｍ） また、一次変位量（Ｘ1）及び全体変位量（Ｘmax）は同
様に Ｘ1＝１４．２−√（１４．２2−１０2） ＝４．１（ｃｍ）＝４１（ｍｍ） Ｘmax＝α・Ｘ1 ＝２×４１＝８２（ｍｍ） となる。このとき図３に示した管理レベルにこの全体変
位量Ｘmaxをプロットすると、管理レベルＩＶに達す
る。図２に示した対策工選定フローチャートに基づき、
該当する管理レベルに達した予想変位量に対応した対策
工を早急に実施しなければならないことが早期に判明す
る。Now, a method of predicting the total displacement amount Xmax when the initial displacement velocity V 0 is obtained from FIG. 6 will be described with reference to displacement curves to which concrete numerical values are applied. When V 0 = 9 mm / day is obtained as the initial displacement velocity V 0 , the virtual displacement radius R can be obtained by the following formula. R = √ (0.9 4 + 362 + 0.9 2 +361) / (2 ×
0.9) = 14.2 (cm) Further, the primary displacement amount (X 1 ) and the total displacement amount (Xmax) are also X 1 = 14.2−√ (14.2 2 −10 2 ) = 4. 1 (cm) = 41 (mm) Xmax = α · X 1 = 2 × 41 = 82 (mm). At this time, when this total displacement amount Xmax is plotted on the management level shown in FIG. 3, the management level IV is reached. Based on the countermeasure selection flowchart shown in Fig. 2,
It becomes clear at an early stage that countermeasure work must be carried out immediately corresponding to the expected displacement amount that has reached the relevant management level.
【００２１】ここで本実施例で設定した対策工選定フロ
ーチャートの内容について図２及び図３を参照して説明
する。図３に示したように管理最大変位量Ｘ0maxにより
設定された各管理レベルＩ〜ＩＶは３本の管理曲線Ｌ１
〜Ｌ３により区画されており、この管理レベルＩ〜ＩＶ
に対応した施工、計測管理体制及び対策工が図２のフロ
ーチャートに示されている。The contents of the countermeasure selection flow chart set in this embodiment will be described with reference to FIGS. 2 and 3. As shown in FIG. 3, each control level I to IV set by the control maximum displacement amount X0max has three control curves L1.
~ L3, and this management level I ~ IV
The flow chart in Fig. 2 shows the construction, measurement management system and countermeasures corresponding to the above.
【００２２】以下、図２に示した対策工選定フローチャ
ートについて簡単に説明する。発生変位がレベルＩ内の
場合には通常の支保パターン及び施工サイクルで工事を
行っていけば良い（ステップ３００）。変位がレベルII
の場合には吹付コンクリートや支保鋼の支保部材の状態
を観察し、ひび割れ等の発生や支保鋼に変形が生じるよ
うな異常があるかを確認する（ステップ３１０）。異常
が発見された場合には観察や計測の頻度を増やしたりし
て変形の進行が過度に進行していないかを逐次把握する
（ステップ３２０）。一方、特に異常がない場合には通
常の施工体制に戻しても良い。The countermeasure work selection flowchart shown in FIG. 2 will be briefly described below. When the generated displacement is within the level I, it is sufficient to carry out the construction with the normal support pattern and construction cycle (step 300). Displacement is level II
In the case of 1, the state of the supporting members of the shotcrete and the supporting steel is observed, and it is confirmed whether there is an abnormality such as cracking or deformation of the supporting steel (step 310). If an abnormality is found, the frequency of observation and measurement is increased to sequentially grasp whether the deformation is excessively advanced (step 320). On the other hand, if there is no particular abnormality, the normal construction system may be restored.
【００２３】レベルIIIの場合にはステップ３２０レベ
ルの観察と計測とを実施し、その変形等の収束判定を行
う（ステップ３３０）。変形が収束の傾向にある場合に
はレベルIIの観察、計測体制に戻して良く、変形が収束
しないような場合にはレベルIVに相当する措置として現
在掘削が進められている切羽での掘削を中止し、上半閉
合や切羽吹付コンクリート施工等の第１段階補強工を施
工する（ステップ３４０）。その結果変形が収束するよ
うならレベルIIの観察、計測体制に戻して良い。一方、
第１段階補強工を施工しても変形が収束しない場合には
第２段階補強工を施工する（ステップ３５０）。さらに
第２段階補強工によっても変形が収束しない場合には早
急に全面補強工を行う必要がある（ステップ３６０）。
このように掘削初期の段階で変形予測とそれに対する適
切な対策工を設定することができる。In the case of level III, the observation and measurement at the level of step 320 are carried out, and the convergence of deformation and the like is judged (step 330). If the deformation tends to converge, it may be possible to return to the level II observation and measurement system.If the deformation does not converge, excavation at the face where the excavation is currently underway is carried out as a measure equivalent to level IV. The operation is stopped, and the first-stage reinforcement work such as the first half closing and the face shot concrete construction is performed (step 340). As a result, if the deformation converges, you may return to the level II observation and measurement system. on the other hand,
If the deformation does not converge even if the first stage reinforcement is applied, the second stage reinforcement is applied (step 350). Further, if the deformation does not converge even by the second stage reinforcement work, it is necessary to perform the entire surface reinforcement work immediately (step 360).
In this way, deformation prediction and appropriate countermeasures can be set at the early stage of excavation.
【００２４】以上の管理曲線の設定及び初期変位速度Ｖ
0を得た後の最終変位量（Ｘmax）の推定はパーソナルコ
ンピュータ等を用いて簡単に処理できるので、地山状況
の急激な変化等に対しても迅速にその変化を予測するこ
とができる。また、初期変位速度Ｖ0を得た後に２日経
過後、３日経過後の変位量も実績値としてとらえ、Ｎ日
後の変位量を推定ことも可能である。Setting of the above control curve and initial displacement velocity V
Since the estimation of the final displacement amount (Xmax) after obtaining 0 can be easily processed by using a personal computer or the like, the change can be predicted quickly even for a sudden change in the ground condition. It is also possible to estimate the displacement amount after N days by capturing the displacement amount after 2 days and 3 days after obtaining the initial displacement velocity V 0 as the actual value.
【００２５】[0025]
【発明の効果】以上の説明から明らかなように、本発明
によれば計画段階において簡易な算定式を使用して定量
的な管理レベル値を容易に設定でき、その管理レベル値
をもとに初期段階における施工状態を定量的に把握で
き、これにより掘削当初に得られた計測データから精度
良く最終変形量を予測でき、その予測結果を早い段階で
以後の施工にフィードバックすることができるという効
果を奏する。As is apparent from the above description, according to the present invention, it is possible to easily set a quantitative management level value by using a simple formula at the planning stage, and based on the management level value. The effect that the construction state in the initial stage can be quantitatively grasped, and thus the final deformation amount can be accurately predicted from the measurement data obtained at the beginning of excavation, and the prediction result can be fed back to subsequent construction at an early stage. Play.
【図１】本発明によるトンネル内空変位の予測方法の一
実施例での管理曲線の設定手順を示した作業フローチャ
ート。FIG. 1 is a work flow chart showing a procedure for setting a control curve in an embodiment of a method for predicting an air displacement in a tunnel according to the present invention.
【図２】本発明のトンネル内空変位の予測方法で使用さ
れた管理レベルごとの対策工選定手順の一例を示したフ
ローチャート。FIG. 2 is a flow chart showing an example of a procedure for selecting countermeasures for each management level used in the method for predicting aerial displacement in a tunnel according to the present invention.
【図３】変位管理曲線及び設定管理レベルの一例を示し
た変位曲線図。FIG. 3 is a displacement curve diagram showing an example of a displacement management curve and a setting management level.
【図４】トンネル掘削における下半掘削時の２次変位開
始時期を模式的に示したトンネル断面図。FIG. 4 is a tunnel cross-sectional view schematically showing a secondary displacement start time at the time of excavating the lower half of the tunnel.
【図５】初期変位速度Ｖ0が求められた時の最終変位量
Ｘmaxを推定する作業手順を示したフローチャート。FIG. 5 is a flowchart showing a work procedure for estimating a final displacement amount Xmax when an initial displacement velocity V 0 is obtained.
【図６】図５に示した作業手順により最終変位量Ｘmax
を求めた際の予想変位曲線の一例を示した変位曲線図。6 is a final displacement amount Xmax according to the work procedure shown in FIG.
The displacement curve figure which showed an example of the expected displacement curve when it calculated | required.
Ｌ１，Ｌ２，Ｌ３ 管理曲線 Ａ 間隔日数 Ｒ 仮想変位半径 Ｘ0max 管理最大変位量 Ｘ1 １次変位量 Ｘmax 全体変位量（全体変位量） L1, L2, L3 control curve A interval days R virtual displacement radius X0max control maximum displacement amount X1 primary displacement amount Xmax overall displacement amount (overall displacement amount)
Claims (4)
を段階的に設定し、該変位管理レベルに対応する最終変
位量を計測開始後の経時期間とトンネル内空変位量とを
パラメータとした関数曲線により算定してトンネル掘削
時の内空変位の管理曲線を設定するとともに、掘削開始
直後時に得られた初期変位速度をもとに前記関数曲線に
より変位予想曲線を求め、最終変位量を予測するように
したことを特徴とするトンネル内空変位の予測方法。1. A displacement management level is set stepwise from a predetermined maximum management displacement amount, and a final displacement amount corresponding to the displacement management level is set with parameters of the elapsed time after the start of measurement and the amount of empty space in the tunnel. The control curve for the inner-air displacement during tunnel excavation is set by calculating from the function curve, and the displacement prediction curve is obtained from the function curve based on the initial displacement speed obtained immediately after the start of excavation, and the final displacement amount is predicted. A method for predicting air displacement in a tunnel, characterized in that
線と２次変位円弧曲線とからなることを特徴とする請求
項１記載のトンネル内空変位の予測方法。2. The method for predicting air displacement in a tunnel according to claim 1, wherein the function curve comprises at least a primary displacement arc curve and a secondary displacement arc curve.
を軸とする直交座標系上で、１次変位収束日数に相当す
る経時日数値の直線上に円弧中心点を有し、原点と１次
変位収束点とを通過することを特徴とする請求項１記載
のトンネル内空変位の予測方法。3. The primary arc curve has an arc center point on a straight line of numerical values of elapsed days corresponding to the number of days of primary displacement convergence on an orthogonal coordinate system having a displacement amount axis and an elapsed days axis as axes. The method for predicting the air displacement in a tunnel according to claim 1, wherein the method passes through an origin and a first-order displacement convergence point.
るいは間隔日数経過後の１次変位収束点と前記最終変位
量を得る２次変位収束点とを通過し、該２次変位収束点
に相当する経時日数値の直線上に円弧中心点を有するこ
とを特徴とする請求項１記載のトンネル内空変位の予測
方法。4. The secondary arc curve passes through the primary displacement convergence point or the primary displacement convergence point after a lapse of the interval days and the secondary displacement convergence point for obtaining the final displacement amount, and the secondary displacement convergence point is obtained. The method for predicting air displacement in a tunnel according to claim 1, wherein an arc center point is provided on a straight line of a day-time numerical value corresponding to a point.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP35240993A JP3308371B2 (en) | 1993-12-29 | 1993-12-29 | Prediction method of empty displacement in tunnel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP35240993A JP3308371B2 (en) | 1993-12-29 | 1993-12-29 | Prediction method of empty displacement in tunnel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH07197785A true JPH07197785A (en) | 1995-08-01 |
| JP3308371B2 JP3308371B2 (en) | 2002-07-29 |
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ID=18423880
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|---|---|---|---|
| JP35240993A Expired - Fee Related JP3308371B2 (en) | 1993-12-29 | 1993-12-29 | Prediction method of empty displacement in tunnel |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008298433A (en) * | 2007-05-29 | 2008-12-11 | Enzan Kobo:Kk | Prediction method for tunnel final displacement |
| JP2012112111A (en) * | 2010-11-22 | 2012-06-14 | Shimizu Corp | Stability evaluation method and stability evaluation device |
| JP2020200648A (en) * | 2019-06-10 | 2020-12-17 | 公益財団法人鉄道総合技術研究所 | Deformed tunnel countermeasure effect prediction program and effect prediction method thereof and deformed tunnel countermeasure effect prediction device |
| CN113377017A (en) * | 2021-07-19 | 2021-09-10 | 中国铁建重工集团股份有限公司 | Earth pressure balance shield machine and propelling speed prediction method, device and medium thereof |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2011163017A (en) * | 2010-02-10 | 2011-08-25 | Kajima Corp | Device, gear and method for determining soundness of tunnel |
-
1993
- 1993-12-29 JP JP35240993A patent/JP3308371B2/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008298433A (en) * | 2007-05-29 | 2008-12-11 | Enzan Kobo:Kk | Prediction method for tunnel final displacement |
| JP2012112111A (en) * | 2010-11-22 | 2012-06-14 | Shimizu Corp | Stability evaluation method and stability evaluation device |
| JP2020200648A (en) * | 2019-06-10 | 2020-12-17 | 公益財団法人鉄道総合技術研究所 | Deformed tunnel countermeasure effect prediction program and effect prediction method thereof and deformed tunnel countermeasure effect prediction device |
| CN113377017A (en) * | 2021-07-19 | 2021-09-10 | 中国铁建重工集团股份有限公司 | Earth pressure balance shield machine and propelling speed prediction method, device and medium thereof |
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| Publication number | Publication date |
|---|---|
| JP3308371B2 (en) | 2002-07-29 |
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