JP2020066843A - Tunnel deformation prediction method and deformation prediction system - Google Patents

Abstract

To provide a tunnel deformation prediction method and a deformation prediction system respectively for effectively predicting future deformation of a tunnel.SOLUTION: A tunnel deformation prediction method and a deformation prediction system according to this invention respectively includes: a borehole measuring step of drilling the borehole, also inserting and arranging the diameter displacement measuring device of the borehole into the drilled borehole, and further starting measurement of the diameter displacement of the borehole; a parameter setting process of setting the parameter used for creep analysis by means of comparing a time-series variation in the diameter displacement of the borehole obtained by measurement with the time-series variation in the diameter displacement of the borehole obtained by an analysis; and an analysis step of performing a creep analysis by using the set parameters for an analysis model obtained by dividing the ground around the tunnel and the lining structure into a plurality of elements.SELECTED DRAWING: Figure 10

Description

  The present disclosure relates to a tunnel deformation prediction method and a deformation prediction system.

  In the construction of mountain tunnels, it is necessary to change the support work pattern and apply auxiliary construction methods when the ground condition changes, such as when entering the soft ground belt as the tunnel is dug. In order to select an appropriate support pattern according to changes in the ground, it is desirable to properly understand the ground conditions around the tunnel including the front of the face and predict future deformation of the tunnel.

  For example, in Patent Document 1, a total station installed inside a tunnel pit capable of distance measurement and angle measurement measures displacement in the tunnel extension direction for a face face after excavation, and has a tunnel extension that is held in advance. A technique for predicting the final displacement amount of a tunnel is disclosed based on the correlation data between the displacement speed in the direction and the final displacement amount.

JP, 2008-298433, A

  By the way, in order to predict the future deformation of the tunnel with high accuracy, it is necessary to consider the time-dependent coefficient (parameter) that controls the temporal change of the ground around the tunnel. In the technique described in Patent Document 1, since the displacement of the tunnel is measured in the state where the support work is constructed, the displacement amount in which the deformation is suppressed by the support work is measured. For this reason, in order to set the parameters with high accuracy and predict the deformation of the tunnel with high accuracy, it is necessary to remove the effect of support work, which requires labor for analysis and sufficiently secures the prediction accuracy. It may not be possible.

  The techniques of this disclosure aim to effectively predict future deformations of tunnels.

  The method of the present disclosure includes drilling a boring hole from at least one of a face of a tunnel, a side wall, and a bottom plate toward a natural ground, and inserting and arranging a hole diameter displacement measuring device in the boring hole that has been drilled. Compare the drilling measurement process that starts measuring the hole diameter displacement of the boring hole, the time series change of the hole diameter displacement of the boring hole obtained by the measurement, and the time series change of the hole diameter displacement of the boring hole obtained by analysis Then, the parameter setting step of setting the parameters used for the creep analysis, and the creep analysis using the set parameters for the analysis model in which the ground around the tunnel and the lining structure are divided into a plurality of elements And an analysis step for performing.

  Further, in the drilling measurement step, it is preferable to start measuring the hole diameter displacement within one hour at the latest after drilling the boring hole. Further, in the drilling measurement step, the boring hole is drilled deeper than the diameter of the tunnel, and the hole diameter displacement measuring device is inserted from the tunnel in the boring hole to a predetermined measurement position separated by the diameter or more. It is preferable to arrange and measure the hole diameter displacement.

  In the parameter setting step, it is preferable that at least a first creep parameter that controls the strain rate and a second creep parameter that controls the creep rupture time are set as the parameters.

  A system of the present disclosure is a hole diameter displacement measuring device that is inserted and arranged in a boring hole drilled from at least one or more of a face face, a side wall, and a bottom plate of a tunnel toward a surrounding ground, and measures a hole diameter displacement of the boring hole. , Calculating the hole diameter displacement analysis value of the boring hole, and comparing the time series change of the hole diameter displacement measurement value obtained by the hole diameter displacement measuring device and the time series change of the hole diameter displacement analysis value obtained by analysis. And an analysis device that performs creep analysis on an analysis model in which the surrounding ground of the tunnel and the lining structure are divided into a plurality of elements using the parameters set as described above.

  Further, the hole diameter displacement measuring device is provided on at least one of an elongated main body part to be inserted into the boring hole and one end side and the other end side in the longitudinal direction of the main body part so that the main body part is bored. A support portion supported in the hole; and a measurement portion provided in the main body portion for measuring the hole diameter displacement, the measurement portion protruding from the main body portion and elastically contacting the inner wall of the boring hole. It is preferable to have an elastically deformable member and a detection unit for detecting the hole diameter displacement amount based on the deformation of the elastically deformable member that follows the change in the hole diameter.

  According to the technique of the present disclosure, future deformation of a tunnel can be effectively predicted.

It is a typical whole block diagram which shows the deformation | transformation prediction system which concerns on this embodiment. It is a typical sectional view showing a main part of a hole diameter displacement measuring device concerning this embodiment. It is a typical perspective view showing the 1st hole support part of the hole diameter displacement measuring device concerning this embodiment. It is a typical sectional view showing a measuring part of a hole diameter displacement measuring device concerning this embodiment. It is a mimetic diagram explaining a measuring procedure of hole diameter displacement of a boring hole using a hole diameter displacement measuring device concerning this embodiment. It is a mimetic diagram explaining a measuring procedure of hole diameter displacement of a boring hole using a hole diameter displacement measuring device concerning this embodiment. It is a functional block diagram which shows the information processing apparatus which concerns on this embodiment, and a related peripheral structure. It is a schematic diagram which shows an example of the time series graph image which concerns on this embodiment. It is a figure which shows typically an example of the analysis result image which concerns on this embodiment. It is a flowchart explaining the procedure of the deformation | transformation prediction method of the tunnel which concerns on this embodiment.

  Hereinafter, a tunnel deformation prediction method and a deformation prediction system according to the present embodiment will be described with reference to the accompanying drawings. The same parts are designated by the same reference numerals and have the same names and functions. Therefore, detailed description thereof will not be repeated.

[overall structure]
FIG. 1 is a schematic overall configuration diagram showing a tunnel deformation prediction system 1 according to the present embodiment.

  As shown in FIG. 1, the deformation prediction system 1 includes a hole diameter displacement measuring device 2 for measuring a hole diameter displacement of a boring hole drilled from a face or side wall of a tunnel to a ground, and a tunnel based on the measured hole diameter displacement. The information processing apparatus 100 is configured to perform various kinds of processing such as creep analysis for predicting future deformation of the.

  The hole diameter displacement measuring device 2 includes an elongated body portion 10, a first in-hole support portion 20A provided on the distal end side of the body portion 10, and a second hole inside the base end portion of the body portion 10. The support section 20B and the measurement section 30 provided between the in-hole support sections 20A and 20B of the main body section 10 are provided. Further, a connection adapter 71 for connecting and fixing the insertion rod 70 (see FIG. 5) is provided at the base end of the main body 10.

[Main body]
The main body part 10 arranges a total of four angle members 11A to 11D formed of aluminum or the like in a substantially L-shaped cross section in a rectangular shape, and the angle members 11A to 11D in the longitudinal direction (Z direction in the drawing). ) Are provided in parallel with each other.

  Specifically, as shown in FIG. 2, the respective angle members 11A to 11D are arranged so as to face each other at predetermined intervals so that the L-shapes face the opposite sides. That is, the substantially cross-shaped (+ -shaped) space 12 opened in four directions is defined by the facing side surfaces of the respective angle members 11A to 11D. The angle members 11A to 11D are connected and fixed to each other by fastening bolts and nuts (not shown) to a plurality of brackets 15A to 15D spanning the opposite side surfaces thereof. The cross-sectional dimension D of the main body portion 10 is set to about 4 cm, which can ensure a sufficient clearance with the boring hole, so that the main body portion 10 can be easily inserted into the boring hole. The length of each angle member 11A to 11D in the longitudinal direction is about 91 cm, and the total length in the longitudinal direction including the connection adapter 71 (see FIG. 1) of the main body 10 is about 1 m. It is said that. The size of the main body 10 is not limited to these numerical values, and can be set appropriately according to the hole diameter, depth, etc. of the boring hole to be measured.

  In the following description, the facing space X1 of the pair of angle members 11A and 11B is the first slit, the facing space X2 of the pair of angle members 11C and 11D is the second slit, and the facing space Y1 of the pair of angle members 11B and 11C. Is referred to as a third slit, and the facing space Y2 between the pair of angle members 11A and 11D is referred to as a fourth slit. The direction in which the first slit X1 and the second slit X2 are opened is called the X direction, and the direction in which the third slit Y1 and the fourth slit Y2 are opened is called the Y direction.

[Hole support part]
Next, detailed structures of the first hole supporting portion 20A and the second hole supporting portion 20B will be described. Since the first and second in-hole supporting portions 20A and 20B have substantially the same structure, the first in-hole supporting portion 20A on the distal end side will be described below and the second in-hole supporting portion on the proximal end side will be described below. Description of the unit 20B is omitted.

  FIG. 3 is a schematic perspective view showing the first in-hole support portion 20A. The first hole supporting portion 20A includes a first supporting ring member 21, a second supporting ring member 22, a first bracket 23, a second bracket 24, a third bracket 25, and a fourth bracket 26. It is configured with.

  The brackets 23 to 26 are arranged to face each other in the longitudinal direction Z of the main body 10 with a predetermined space therebetween. The brackets 23 to 26 are fixed to the angle members 11A to 11D of the main body 10 by fastening bolts and nuts (not shown).

  The first and second supporting ring members 21, 22 are thin plate ring members made of steel that are elastically deformable, and are arranged so that their radial directions are orthogonal to each other. The ring width of the first and second supporting ring members 21, 22 is preferably about 1 cm.

  The first supporting ring member 21 is inserted and arranged in the first slit X1 and the second slit X2. More specifically, the first supporting ring member 21 is fastened and fixed to the second bracket 24 and the fourth bracket 26 at two diagonal points in the longitudinal direction Z of the main body 10 with bolts and nuts (not shown). Portions protruding from the slits X1 and X2 are provided so as to extend outward from the main body 10 in the X direction in a semicircular arc shape.

  The second supporting ring member 22 is inserted and arranged in the third slit Y1 and the fourth slit Y2. More specifically, the second supporting ring member 22 is fastened and fixed to the first bracket 23 and the third bracket 25 at two diagonal points in the longitudinal direction Z of the main body 10 with bolts and nuts (not shown). A portion protruding from each of the slits Y1 and Y2 is provided so as to protrude from the main body portion 10 in the semi-circular shape outward in the Y direction.

  According to the first in-hole supporting portion 20A configured as described above, when the main body portion 10 is inserted and arranged at a predetermined position in the boring hole, the first and second supporting ring members 21 and 22 cause the inner wall of the boring hole. By elastically contacting with and deforming inward in the radial direction, the main body portion 10 can be reliably held at the substantially central position of the boring hole. When inserting the main body 10 into the boring hole or collecting the main body 10 from the boring hole, the first and second supporting ring members 21 and 22 elastically deform while sliding on the inner walls of the boring hole. The part 10 can be smoothly moved in the boring hole.

[Measuring section]
Next, details of the measuring unit 30 will be described with reference to FIG. FIG. 4A is a schematic vertical cross-sectional view showing the measuring unit 30 in the Y direction, and FIG. 4B is a schematic horizontal cross-sectional view showing the measuring unit 30 in the X direction. It is a figure. The measuring unit 30 includes a first measuring unit 40 that mainly measures the hole diameter displacement of the boring hole in the X direction, and a second measuring unit 50 that measures the hole diameter displacement of the boring hole mainly in the Y direction.

[First measuring section]
As shown in FIG. 4 (A), the first measuring unit 40 includes a first measuring ring member 41, a first slider member 42, and a first detecting unit 43.

  The first measuring ring member 41 is formed by bending an elastically deformable thin steel plate into a substantially C-shape that opens toward the base end side of the main body 10. The ring width of the first measuring ring member 41 is preferably about 1 cm.

  The first measurement ring member 41 is inserted and arranged in the first slit X1 and the second slit X2. More specifically, the first measurement ring member 41 has its open end portion 41A fastened and fixed to a first fixing bracket 48 fixed to the main body portion 10 with a bolt nut or the like (not shown), and each slit X1. , X2 are provided so as to project from the main body 10 outward in the X direction in a substantially semi-circular shape.

  Further, the first measurement ring member 41 has a curved end portion 41B opposite to the open side end portion 41A elastically contacted with the first slider member 42 or fastened and fixed by a bolt nut or the like not shown. The first slider member 42 is slidably held along the longitudinal direction Z in the facing space of each angle member 11A to 11D that functions as a guide rail.

  That is, when the portion of the first measuring ring member 41 protruding from the main body portion 10 is deformed following the inner diameter in the radial direction as the hole diameter of the boring hole is reduced, the entire first measuring ring member 41 moves to the first fixing bracket 48. The first slider member 42 is configured to slide in the Z1 direction in the drawing by extending in the longitudinal direction Z of the main body 10 at the fulcrum.

  The first detection unit 43 includes an elastically deformable first flexure element 44, and a first strain gauge 45 attached to the first flexure element 44. The first flexure element 44 is, for example, a band plate member formed of a metal such as copper, and has one end side fixed to the first slider member 42 and the other end side fixed to the second fixing bracket 58. Thus, it is provided in a curved state between the first slider member 42 and the second fixing bracket 58.

  When the first slider member 42 slides in the Z1 direction in the drawing due to the deformation of the first measuring ring member 41, the first detecting unit 43 causes the first flexure element 44 to be curved and deformed. The strain generated in the strain element 44 is detected as a change in the resistance value or the voltage value of the first strain gauge 45. The amount of change in the resistance value or voltage value of the first strain gauge 45 is transmitted to the information processing device 100 (see FIG. 1) connected via a lead wire (not shown).

[Second measuring section]
As shown in FIG. 4B, the second measuring unit 50 is configured to include a second measuring ring member 51, a second slider member 52, and a second detecting unit 53.

  The second measuring ring member 51 is formed by bending an elastically deformable steel thin plate into a substantially C-shape that opens to the tip side of the main body 10. The ring width of the second measuring ring member 51 is preferably about 1 cm.

  The second measuring ring member 51 is inserted and arranged in the third slit Y1 and the fourth slit Y2. More specifically, the second measurement ring member 51 has its open side end portion 51A fastened and fixed to a second fixing bracket 58 fixed to the main body portion 10 with a bolt nut or the like (not shown), and each slit Y1. , Y2 are provided so as to project from the main body 10 outward in the Y direction in a substantially semi-circular shape.

  Further, the second measurement ring member 51 has a curved end portion 51B opposite to the open end portion 51A elastically supported by the second slider member 52 or fastened and fixed by a bolt nut or the like not shown. The second slider member 52 is slidably held along the longitudinal direction Z in the facing space of each angle member 11A to 11D that functions as a guide rail.

  That is, when the portion of the second measuring ring member 51 protruding from the main body portion 10 is deformed following the inner diameter in the radial direction as the hole diameter of the boring hole is reduced, the entire second measuring ring member 51 moves to the second fixing bracket 58. The second slider member 52 is configured to slide in the Z2 direction in the drawing by extending in the longitudinal direction Z of the main body 10 at the fulcrum.

  The second detection unit 53 includes an elastically deformable second strain body 54 and a second strain gauge 55 attached to the second strain body 54. The second flexure body 54 is, for example, a strip plate member formed of a metal such as copper, and has one end side fixed to the second slider member 52 and the other end side fixed to the first fixing bracket 48. Thus, the second slider member 52 and the first fixing bracket 48 are provided in a curved state.

  When the second slider member 52 slides in the Z2 direction in the figure due to the deformation of the second measuring ring member 51, the second detector 53 bends and deforms the second flexure element 54 accordingly, and thus The strain generated in the strain element 54 is configured to be detected as a change in the resistance value or the voltage value of the second strain gauge 55. The change amount of the resistance value or the voltage value of the second strain gauge 55 is transmitted to the information processing device 100 (see FIG. 1) connected via a lead wire (not shown).

[Information processing equipment]
Returning to FIG. 1, the information processing device 100 is, for example, a processing device that performs calculations such as a personal computer, and includes a CPU (Central Processing Unit) 101 and a main storage device 102 configured by a RAM (Random Access Memory) and the like. , And an auxiliary storage device 103 configured by a hard disk or the like. The auxiliary storage device 103 stores an analysis program and the like for realizing a creep analysis described later. Various processes such as creep analysis are realized by the CPU 101 reading a program stored in the auxiliary storage device 103 into the main storage device 102 and executing the program.

  The input device 180 includes, for example, a keyboard, a mouse, and the like connected to the information processing device 100, and inputs various information and instructions to the information processing device 100. The display device 190 is, for example, a display connected to the information processing device 100, and displays various images based on the image data supplied from the information processing device 100. Further, the display device 190 displays a screen for inputting various conditions for performing analysis, an analysis model, an analysis result, and the like.

[Measurement method]
Next, a procedure for measuring the hole diameter displacement of the boring hole 300 using the hole diameter displacement measuring device 2 according to the present embodiment will be described with reference to FIGS. In the drawings, reference numeral T is a tunnel, reference numeral G is a ground, reference numeral 200 is a face, reference numeral 210 is a steel support, and reference numeral 220 is a shotcrete.

  As shown in FIG. 5A, the boring hole 300 is drilled from the face 200 to the front using a drill device 400 such as a drill jumbo (first step). In the illustrated example, the boring hole 300 is drilled in a substantially horizontal direction, but it may be drilled in the vertical direction or diagonally forward. Further, the boring hole 300 may be drilled from the side wall or the bottom plate of the tunnel T in the radial direction.

  In the present embodiment, the boring hole 300 is provided in the natural ground G where the main body 10 is not greatly affected by stress relief of the tunnel T and mechanical influences of the lining structure (steel support 210, sprayed concrete 220, etc.). Preferably, the holes are drilled at a depth (for example, about 20 m) longer than the diameter of the tunnel T.

  After boring the boring hole 300, as shown in FIG. 5B, the operator quickly inserts the main body 10 into the boring hole 300 by gripping and pushing in the insertion rod 70 ( Second step). At this time, the main body 10 smoothly moves in the boring hole 300 while being stably supported by the supporting ring members 21 and 22 which are in sliding contact with the inner wall of the boring hole 300. That is, the main body portion 10 can be easily inserted into a desired measurement position in a short time without being hindered by the inner wall irregularities of the boring hole 300 or the small stones remaining in the boring hole 300.

  As shown in FIG. 6 (A), if the main body portion 10 is inserted to a predetermined measurement position in the boring hole 300 (in the illustrated example, the tip portion separated from the face 200 by the diameter of the tunnel T or more), the hole diameter displacement Immediately start measurement (third step). In the present embodiment, since the second step of inserting the main body portion 10 can be performed in a short time, the time required from the completion of drilling of the boring hole 300 to the start of measurement can be surely shortened, and changes immediately after drilling. Therefore, it becomes possible to effectively measure the hole diameter displacement of the boring hole 300 from the initial stage. In addition, by inserting the main body portion 10 from the face 200 to the tip of the boring hole 300 that is more than the diameter of the tunnel T and performing the measurement, it is possible to effectively perform the hole diameter displacement that does not include the mechanical influence of the lining structure or the like. It becomes possible to measure.

  When the measurement of the hole diameter displacement of the boring hole 300 is completed after a predetermined time has elapsed from the start of the measurement of the hole diameter displacement, the operator grasps the insertion rod 70 and pulls it out, as shown in FIG. 6 (B). As a result, the main body 10 is recovered from the boring hole 300 (fourth step). At this time, the main body 10 smoothly moves in the boring hole 300 while being stably supported by the supporting ring members 21 and 22. That is, the main body 10 can be reliably recovered without being hindered by the inner wall irregularities of the boring hole 300 or the small stones remaining in the boring hole 300.

  According to the hole diameter displacement measuring device 2 of the present embodiment described in detail above, a plurality of ring members 21, 22, 41, 51, slider members 42, 52, strain elements 44, 54 and the strain gauges 45 and 55 have a simple structure, the cost of the device can be effectively suppressed, and the size of the entire device can be reduced.

  Further, the main body 10 is made of the angle members 11A to 11D made of aluminum, and the ring members 21, 22, 41, 51 are made of thin steel plates, so that the weight of the entire apparatus can be reduced. Therefore, workability at the time of insertion and collection can be surely improved.

  Further, since the supporting ring members 21 and 22 elastically contacting the inner wall of the boring hole are provided so as to project in a semi-circular arc shape in the four directions orthogonal to the main body part 10, the main body part 10 is substantially at the center of the boring hole during measurement. It can be effectively held at the position, and the measurement accuracy of the hole diameter displacement can be improved.

[Prediction of tunnel deformation]
FIG. 7 is a functional block diagram showing the information processing apparatus 100 according to the present embodiment and related peripheral configurations. The information processing apparatus 100 includes a control unit 110, a hole diameter displacement measurement value calculation unit 120, a hole diameter displacement analysis unit 130, a parameter setting unit 140, a creep analysis unit 150, and an output unit 160 as some functional elements. Have.

  The control unit 110 controls the overall operation of the information processing device 100. Further, the control unit 110 accepts various requests input by the operator via the input device 180. In addition, the control unit 110 controls the hole diameter displacement measurement value calculation unit 120, the hole diameter displacement analysis unit 130, the parameter setting unit 140, the creep analysis unit 150, and the output unit 160 according to the received request to meet the request from the operator. Performs various processing according to the above.

  The hole diameter displacement measurement value calculation unit 120 calculates the hole diameter displacement measurement value Δdm of the boring hole in real time based on the amount of change in the resistance value or the voltage value of the strain gauges 45 and 55 input from the hole diameter displacement measuring device 2. For the hole diameter displacement measurement value Δdm, refer to, for example, a well-known arithmetic expression including the change amount of the resistance value or the voltage value of the strain gauges 45 and 55 as an input value, or a map in which the relationship between them is defined in advance by experiments or the like. You can obtain it by doing. The hole diameter displacement measurement value Δdm calculated by the hole diameter displacement measurement value calculation unit 120 is transmitted to the output unit 160.

  The hole diameter displacement analysis unit 130 calculates the hole diameter displacement analysis value Δda of the boring hole using a finite difference method or a finite element method that models the boring hole. Specifically, the hole diameter displacement analysis unit 130 calculates the hole diameter displacement analysis value Δda according to the following mathematical expression (1) including various parameters necessary for performing the creep analysis described later and time.

但し、Ｅ：ヤング率
ｖ：ポアソン比
Ａ：主に歪み速度を支配する第１クリープパラメータ
Ｂ：主にクリープ破壊時間を支配する第２クリープパラメータ
ｑ：主に応力に対するクリープ挙動の感度を支配する第３クリープパラメータ
φ：破壊前の第１内部摩擦角
φτ：破壊後の第２内部摩擦角
ｃｒ：破壊後の粘着力
Ｔ：時間

However, E: Young's modulus v: Poisson's ratio A: First creep parameter that mainly controls the strain rate B: Second creep parameter that mainly controls the creep rupture time q: Mainly controls the sensitivity of creep behavior to stress Third creep parameter φ: First internal friction angle before fracture φτ: Second internal friction angle after fracture cr: Adhesive force after fracture T: Time

  These various parameters are set by the control unit 110 receiving values input from the input device 180 according to the operation of the operator. The Young's modulus E, the Poisson's ratio v, the first internal friction angle φ, the second internal friction angle φτ, and the adhesive force cr are set based on known values or the like according to the type of the ground around the tunnel. The third creep parameter q is set to an empirical value (for example, 0.006) obtained from a uniaxial compression test or the like. Further, the first creep parameter A and the second creep parameter B are set by a parameter study in which the operator appropriately adjusts arbitrary values. The hole diameter displacement analysis value Δda calculated by the hole diameter displacement analysis unit 130 is transmitted to the output unit 160.

  The output unit 160 generates the hole diameter displacement measurement value Δdm acquired from the hole diameter displacement measurement value calculation unit 120 and the hole diameter displacement analysis value Δda acquired from the hole diameter displacement analysis unit 130 in a time series graph image and transmits the time series graph image to the display device 190. .

  FIG. 8 is a schematic diagram showing an example of a time-series graph image displayed on the display device 190. In the time-series graph image, the elapsed time T is set on the horizontal axis, the hole diameter displacement measurement value Δdm is set on the vertical axis, and the hole diameter displacement Δd indicating a time series change of the hole diameter displacement analysis value Δda is set. The operator operates the input device 180 while referring to the time-series graph image to adjust the creep parameters A and B to arbitrary values, and sets the time-series change curve of the hole-diameter displacement analysis value Δda to the time-series of the hole-diameter displacement measurement value Δdm. A parameter study is performed to find the optimum values of various parameters by curve fitting the change curve. The optimum values of various parameters obtained by the parameter study are stored in the memory (main storage device 102 or auxiliary storage device 103 shown in FIG. 1) by the parameter setting unit 140.

  The creep analysis unit 150 performs creep analysis by the finite difference method or the finite element method using the optimum values of various parameters stored in the memory. Specifically, the creep analysis unit 150 performs creep analysis on an analysis model in which the ground around the tunnel and the lining structure are divided into a plurality of elements, thereby performing shear strain (and / or stress) of each element. ) Is calculated. The analysis result by the creep analysis unit 150 is transmitted to the output unit 160, and the output unit 160 generates an analysis result image and transmits it to the display device 190.

  FIG. 9 is a diagram schematically showing an example of the analysis result image, (A) shows the distribution of the maximum shear strain after 20 years, and (B) shows the elements that break after 30 years. In the example shown in FIG. 9A, an analysis result was obtained in which, after 20 years, the creep of the ground near the corner of the bottom of the tunnel progressed, and the shear strain near the corner of the bottom increased. Refer to the dark areas). In addition, in the example shown in FIG. 9B, an analysis result was obtained in which the end of the bottom concrete near the corner of the bottom 30 was damaged after 30 years (see the solid line element in the figure). In this way, by predicting the future deformation of the tunnel by creep analysis using the finite difference method or the finite element method, it is useful for design modification of the support work pattern and selection of auxiliary construction method according to the state of the ground. It will be possible.

  Next, the procedure of the tunnel deformation prediction method according to the present embodiment will be described based on the flow of FIG. 10.

  In the first step S1, as described with reference to FIG. 5A, the boring hole 300 is drilled in the ground G from at least one of the face, side wall and bottom of the tunnel T using the drill device 400. . At this time, the depth of the boring hole 300 is set so that the main body portion 10 of the hole diameter displacement measuring device 2 can be inserted and installed in the natural ground G that is not greatly affected by the stress release of the tunnel T and the mechanical influence of the lining structures 210 and 220. Drills longer than the diameter of the tunnel T. This first step S1 corresponds to the first half of the drilling measurement step of the present invention.

  In the second step S2, as described with reference to FIGS. 5B and 6A, the main body 10 of the hole diameter displacement measuring device 2 is quickly inserted into the boring hole 300, and the hole diameter displacement is measured. To start immediately. Since the main body portion 10 of the hole diameter displacement measuring device 2 is configured to be easily and quickly inserted into the boring hole 300, it is possible to measure the hole diameter displacement of the boring hole 300 that changes immediately after drilling from the initial stage. it can. The second step S2 corresponds to the latter half of the hole making measurement step of the present invention. In the present embodiment, it is preferable that the interval between the end of the first step S1 and the start of the second step S2 is shorter, and for example, about 15 to 20 minutes is a guideline, and the maximum is within 1 hour. That is, the measurement of the hole diameter displacement is started within 1 hour at the latest after drilling the boring hole 100.

  In the third step S3, the hole diameter displacement measured value Δdm obtained by the measurement is compared with the hole diameter displacement analysis value Δda obtained by the analysis, and the hole diameter displacement is adjusted while appropriately adjusting the creep parameters A and B to arbitrary values. By performing curve fitting of the time-series change curve of the analysis value Δda to the time-series change curve of the hole diameter displacement measurement value Δdm, a parameter study for setting optimum values of various parameters is performed. The third step S3 corresponds to the parameter setting step of the present invention.

  In the fourth step S4, the finite difference method is applied to the analytical model obtained by dividing the ground G around the tunnel T and the lining structures 210 and 220 into a plurality of elements by using the various parameters set in the third step S3. Alternatively, the shear strain (or stress) of each element is calculated by performing creep analysis by the finite element method, and the prediction of tunnel deformation is completed. The fourth step S4 corresponds to the analysis step of the present invention.

  According to the present embodiment described in detail above, by drilling the boring hole 300 deeper than the diameter of the tunnel T and inserting and installing the main body portion 10 of the hole diameter displacement measuring device 2, stress release and lining of the tunnel T is performed. It is configured so that the hole diameter displacement that does not include the mechanical influence of the structures 210 and 220 can be effectively measured. This eliminates the need for labor such as removing the mechanical influence of the lining structures 210 and 220, and the deformation of the tunnel T can be efficiently predicted while saving labor in the analysis work.

  Further, the body portion 10 of the hole diameter displacement measuring device 2 is configured to be easily and quickly inserted into the boring hole 300. This makes it possible to measure the hole diameter displacement of the boring hole 300 that changes immediately after drilling from the initial stage, effectively improving the accuracy of creep analysis, and predicting the future deformation of the tunnel T with high accuracy. be able to.

[Other]
It should be noted that the present disclosure is not limited to the above-described embodiments, and may be appropriately modified and implemented without departing from the spirit of the present disclosure.

  For example, the above embodiment has been described as being applied to the construction of a mountain tunnel, but when a deformation abnormality or the like occurs in an existing tunnel, it can also be applied to analysis of the abnormal portion.

  Further, the hole diameter displacement measuring device 2 may be configured such that the hole diameter displacements can be simultaneously measured at multiple points by connecting the plurality of main body portions 10 in the longitudinal direction and inserting them into the boring hole. Further, the number of measuring ring members 41, 51 is not limited to two in the illustrated example, and may be three or more so as to further add the measuring direction of the hole diameter displacement.

  Further, the configuration for detecting the displacement of the hole diameter is not limited to the flexure elements 44 and 54 and the strain gauges 45 and 55, but the amount of deformation of the measuring ring members 41 and 51 in the radial direction or the slider member 42. , 52 may be configured using sensors that can directly detect the slide movement amount.

DESCRIPTION OF SYMBOLS 1 Deformation prediction system 2 Hole diameter displacement measuring device 10 Main body part 11A-11D Angle material 20A 1st hole support part 20B 2nd hole support part 21 1st support ring member 22 2nd support ring member 30 Measuring part 40th DESCRIPTION OF SYMBOLS 1 Measuring part 41 1st measuring ring member 42 1st slider member 43 1st detecting part 44 1st flexure element 45 1st strain gauge 50 2nd measuring part 51 2nd measuring ring member 52 2nd slider member 53 5th 2 detection unit 54 second strain element 55 second strain gauge 100 information processing device 110 control unit 120 hole diameter displacement measurement value calculation unit 130 hole diameter displacement analysis unit 140 parameter setting unit 150 creep analysis unit 160 output unit 180 input device 190 display device

Claims (6)

While drilling a boring hole from at least one of the face of the tunnel, the side wall, and the bottom plate toward the natural ground, and inserting and arranging the hole diameter displacement measuring device into the drilled hole, the hole diameter displacement of the boring hole is measured. Drilling measurement process to start measurement,
A time-series change in hole diameter displacement of the boring hole obtained by measurement, and a time-series change in hole diameter displacement of the boring hole obtained by analysis are compared, and a parameter setting step of setting parameters used for creep analysis,
A deformation step of the tunnel, comprising: an analysis step of performing creep analysis using the set parameters for an analysis model in which the ground around the tunnel and the lining structure are divided into a plurality of elements. Prediction method. The tunnel deformation predicting method according to claim 1, wherein in the drilling measurement step, measurement of the hole diameter displacement is started within one hour at the latest after drilling the boring hole. In the drilling measurement step, the drilling hole is drilled deeper than the diameter of the tunnel, and the hole diameter displacement measuring device is inserted and arranged to a predetermined measurement position separated from the tunnel in the drilling hole by the diameter or more. The method for predicting deformation of a tunnel according to claim 1 or 2, wherein the hole diameter displacement is measured. The tunnel according to claim 1, wherein in the parameter setting step, at least a first creep parameter that governs a strain rate and a second creep parameter that governs a creep rupture time are set as the parameters. Deformation prediction method. A hole diameter displacement measuring device that is inserted and arranged in a boring hole drilled from at least one of the face of the tunnel, the side wall, and the bottom plate toward the surrounding ground, and measures the hole diameter displacement of the boring hole,
The hole diameter displacement analysis value of the boring hole is calculated, and the time series change of the hole diameter displacement measurement value obtained by the hole diameter displacement measuring device and the time series change of the hole diameter displacement analysis value obtained by analysis are compared. An analysis device for executing creep analysis on an analysis model in which the ground around the tunnel and the lining structure are divided into a plurality of elements by using the set parameters, and the deformation of the tunnel. Prediction system. The hole diameter displacement measuring device,
An elongated body portion to be inserted into the boring hole,
A support portion which is provided on at least one of one end side and the other end side in the longitudinal direction of the main body portion and supports the main body portion in the boring hole;
A measuring unit provided in the main body unit for measuring the hole diameter displacement,
The measuring unit is
A plate-shaped elastically deformable member that projects from the main body portion and elastically contacts the inner wall of the boring hole, and a detection unit that detects a hole diameter displacement amount based on deformation of the elastically deformable member that follows a change in hole diameter. 5. The tunnel deformation prediction system according to item 5.

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