JP2015001399A - Calculation method, calculation device, calculation program for predicting settlement of object surrounded with viscous material and computer readable recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a calculation method, a calculation device and a calculation program for predicting the settlement of an object surrounded with a viscous material, which enable the settlement behavior of the object surrounded with the viscous material to be more accurately and easily predicted and calculated, and to provided a computer readable recording medium.SOLUTION: The calculation method for predicting the settlement of an object surrounded with a viscous material comprises: a step 1 of regarding a viscous material as a viscous fluid and setting the settlement force of the object; a step 2 of setting the settlement velocity of the object to be a temporary settlement velocity and calculating the viscous flow velocity of the viscous fluid around the object and resistance force acting on the surface of the object; a step 3 (a step 4) of setting the temporary settlement velocity a little smaller (larger) when the resistance force is larger (smaller) than the set settlement force and calculating the resistance force; and a step 5 of repeating the step 3 and the step 4 and stopping the calculation when the integrated value of the resistance force converges in an error range and obtaining a temporary settlement velocity found when the calculation is stopped as a settlement velocity value.

Description

  The present invention relates to a method for predicting settlement of an object surrounded by a viscous material, a calculation device, a calculation program, and a computer-readable recording medium storing the program, and in particular, a wet clay-based cushioning material such as bentonite-based clay material. The present invention relates to a subsidence prediction calculation method, a calculation device, a calculation program, and a computer-readable recording medium for an object such as a radioactive waste surrounded by a solid waste.

  Conventionally, in geological disposal of high-level radioactive waste, as shown in FIG. 10, the periphery of the waste body 2 is surrounded by a bentonite-based clay material 1 having a thickness of 0.3 to 1 m called a buffer material, and the earth pressure from the surroundings is reduced. In addition to buffering, it is considered to suppress the intrusion of groundwater and suppress the leakage of radioactive substances from the waste body 2 (see, for example, Non-Patent Document 1).

The merit of surrounding the waste body with a bentonite-based material having a thickness of 0.3 m to 1 m lies in the following features of this material.
(1) The permeability coefficient of high-density bentonite material that can be achieved with realizable energy is 1E-10 to 1E-13 m / s, and the permeability coefficient of general ground materials (1E-5 to 1E-8 m / s). ) Is less water permeable than Here, the symbol E means a power of 10. For example, “E-5” means “10 to the fifth power”, and “1E-5” means “0.00001”.
(2) Since bentonite is more flexible than concrete, cracks are unlikely to occur, and existing cracks are sealed by the water-absorbing swelling behavior of bentonite when groundwater enters from the surroundings. Therefore, it does not become an outstanding water path.
(3) Since bentonite is a naturally occurring clay material, it does not easily deteriorate even after a long period of tens of thousands of years.

Next, a phenomenon that is a prediction target of the present invention will be described.
As shown in FIG. 11, the waste body 2 storing radioactive waste has a density higher than that of the clay material 1 surrounding the periphery, so that it gradually sinks and changes its position over a long period of time. However, since the thickness of the barrier material (clay material) changes over time, the ability to suppress the advection diffusion of radioactive materials is reduced. Therefore, in order to evaluate future safety, it has been required to correctly predict the settlement of the waste body 2.

  In relation to these phenomena, there is an existing method for evaluating and predicting the phenomenon of pore water in the clay being squeezed out when the clay receives a load, as a consolidation phenomenon (for example, regarding the long-term settlement behavior of clay) Non-patent document 2).

  Moreover, as a structure for suppressing such settlement behavior, for example, a frame support structure using a clay-based waterstop material disclosed in Patent Document 1 below is known.

"Technical reliability of geological disposal of high-level radioactive waste in Japan-Geological disposal research and development 2nd report-General report", Nuclear Fuel Cycle Development Organization, November 1999 "Soil Mechanics", Koichiro Ichiro, Yagi Norio, Yoshikuni Hiroshi, Gihodo Publishing, May 1990

Japanese Patent No. 4329054

  By the way, in the method of predicting the settlement rate and the amount of settlement as a soil compaction phenomenon, although the clay existing under the object increases in density and decreases in thickness, the clay particles move from the bottom to the side of the object. Therefore, there is a concern that the amount of settlement is estimated to be small.

Actually, a clay material in which bentonite having a dry density of 0.2 g / cm ³ is saturated with water is soft and easily deforms by viscosity. Fig. 12 shows the behavior when a cylindrical object (penetration cylinder 50mmφ) penetrates into such clay with a constant load (800g). It clearly behaves like a viscous fluid. You can see that That is, there has been a demand for a method for estimating the sinking speed and sinking amount of an object as more conservative values by regarding clay as a viscous fluid.

  Further, there has been no simple calculation method for accurately predicting and calculating a behavior accompanied by an extreme change in shape as shown in FIGS.

  On the other hand, when calculating clay as a pure viscous fluid, since the object is a rigid body, the boundary between the viscous fluid and the object should always change only at a constant speed without causing a change in shape. In order to calculate the motion of a purely viscous fluid under such conditions, there is a problem that it cannot be calculated simply by boundary conditions in which a certain force is applied to the viscous fluid.

  The present invention has been made in view of the above, and is a predictive calculation method for the settlement of an object surrounded by a viscous material, capable of predicting and calculating the settlement behavior of the object surrounded by the viscous material more accurately and simply, An object of the present invention is to provide a computing device, a computing program, and a computer-readable recording medium.

  In order to solve the above-described problem and achieve the object, the settlement prediction calculation method for an object surrounded by a viscous material according to the present invention is a method for predicting and calculating the settlement of an object surrounded by a viscous material, Considering the viscous material as a viscous fluid, the subsidence force of the object surrounded by the viscous fluid is set as a value obtained by subtracting the buoyancy received from the viscous fluid from the gravity acting on the object; Is set to a temporary settlement velocity that is an arbitrary speed, and the viscous flow velocity of the viscous fluid around the object when the object sinks at the set temporary settlement velocity is calculated by regarding the viscous fluid as a simple viscous fluid. At the same time, if the drag force acting on the surface of the object from the viscous fluid is calculated in step 2, and if the integrated value of the calculated drag force is larger than the set squat force, the provisional squat velocity is set slightly smaller, Viscosity Step 3 for calculating the drag acting on the surface of the object from the body, and if the integrated value of the calculated drag is smaller than the set squat force, the provisional squat velocity is set slightly larger, and again from the viscous fluid Repeat step 4 for calculating the drag acting on the surface of the object, and repeat step 3 and step 4 and stop the calculation when the integrated value of the calculated drag converges to the preset subsidence error range. And a step 5 for obtaining the provisional settlement speed at that time as a settlement speed value corresponding to the settlement force.

  In addition, in the above-described invention, the settlement prediction calculation method for an object surrounded by another viscous material according to the present invention divides the time for which the amount of settlement is predicted in advance into a plurality of fixed time intervals, and the above-described viscous material is used. In step 6 for determining the settlement velocity value by the method for predicting the settlement of the enclosed object, and in the fixed time interval of the first time section when divided into a plurality of fixed time intervals, the object is set at a settlement velocity equal to the calculated settlement velocity value. Is calculated by subtracting the amount of settlement displacement over time to calculate the amount of settlement at this fixed time interval, and in accordance with the amount of settlement calculated in step 7, it is commensurate with the movement of the viscous fluid. It is assumed that the node of the calculation element in the finite element analysis that was initially set at this position has moved, the coordinates of the node are corrected, and the difference in the flow field of the viscous fluid is reflected in the calculation conditions. Step 8 for calculating the amount of subsidence in a fixed time interval of the time interval of step 5 is repeated in the same manner as in Step 7, and Step 8 is repeated up to the time set in advance as the time for which the amount of subsidence is to be predicted. Step 9 is further included.

  An object settlement prediction calculation apparatus for an object surrounded by a viscous material according to the present invention is an apparatus for predicting and calculating the settlement of an object surrounded by a viscous material, and regards the viscous material as a viscous fluid. First calculation means for setting the subsidence force of the object enclosed by the object as a value obtained by subtracting the buoyancy received from the viscous fluid from the gravity acting on the object, and the provisional subsidence speed which is an arbitrary speed. The viscous flow velocity of the viscous fluid around the object when the object sinks at the set temporary settling velocity is calculated considering the viscous fluid as a simple viscous fluid, and from the viscous fluid to the surface of the object. If the integrated value of the calculated drag force is larger than the set squat force, the provisional squat velocity is set slightly lower and the viscous fluid is re-applied to the surface of the object. The acting drag In the case where the third calculation means to calculate and the integrated value of the calculated drag force is smaller than the set squat force, the provisional squat velocity is set slightly larger so that the drag force acting on the surface of the object from the viscous fluid is set again. Repeat the calculation by the fourth calculation means to calculate, the third calculation means and the fourth calculation means, and stop the calculation when the calculated drag integral value converges to the preset subsidence error range, 5th calculating means which calculates | requires the temporary subsidence speed at that time as a subsidence speed value equivalent to subsidence force, It is characterized by the above-mentioned.

  In addition, in the invention described above, the apparatus for predicting the settlement of an object surrounded by another viscous material according to the present invention divides the time for which the amount of settlement is to be predicted in advance into a plurality of predetermined time intervals, and uses the above-described viscous material. Sixth computing means for obtaining a settlement velocity value by the enclosed object settlement prediction calculation device, and a settlement velocity equal to the determined settlement velocity value in a certain time interval of the first time interval when divided into a plurality of certain time intervals. It is assumed that the object moves at the seventh time calculating means for calculating the subsidence amount at a certain time interval by time integration of the subsidence displacement amount, and the viscosity according to the subsidence amount calculated by the seventh arithmetic unit. Assuming that the node of the calculation element in the finite element analysis initially set to a position commensurate with the movement of the fluid has been moved, the coordinates of the node are corrected, and the difference in the flow field of the viscous fluid is reflected in the calculation conditions. The eighth calculation means for calculating the amount of settlement in a fixed time interval of the next time section in the same manner as the seventh calculation means, and the eighth calculation means are repeated until the time set in advance as the time for which the amount of settlement is to be predicted. It further has ninth operation means for calculating the amount of settlement.

  The program for predicting the settlement of an object surrounded by a viscous material according to the present invention is a calculation program for causing a computer to execute a method for predicting and calculating the settlement of an object surrounded by a viscous material. In this case, the subsidence force of the object surrounded by the viscous fluid is set as a value obtained by subtracting the buoyancy received from the viscous fluid from the gravity acting on the object, and the subsidence speed of the object at an arbitrary speed. The viscous flow velocity of the viscous fluid around the object when the object sinks at the set temporary settlement velocity is calculated by regarding the viscous fluid as a simple viscous fluid. Step 2 for calculating the drag acting on the surface of the object from the above, and if the calculated integrated value of the drag is larger than the set squat force, the provisional squat velocity is set slightly smaller and Step 3 for calculating the drag acting on the surface of the object from the viscous fluid, and if the calculated integrated value of the drag is smaller than the set squat force, the provisional squat velocity is set slightly larger and the viscosity is set again. Step 4 for calculating the drag force acting on the surface of the object from the fluid, Step 3 and Step 4 are repeated, and calculation is performed when the integrated value of the calculated drag force converges to a preset subsidence error range. , And the computer is caused to execute step 5 for obtaining the provisional settlement speed as a settlement speed value corresponding to the settlement force.

  In addition, in the above-described invention, the settlement prediction calculation program for an object surrounded by another viscous material according to the present invention divides the time for which the settlement amount is predicted in advance into a plurality of predetermined time intervals, and the above-described viscous material is used. In step 6 for determining the settlement velocity value by the method for predicting the settlement of the enclosed object, and in the fixed time interval of the first time section when divided into a plurality of fixed time intervals, the object is set at a settlement velocity equal to the calculated settlement velocity value. Is calculated by subtracting the amount of settlement displacement over time to calculate the amount of settlement at this fixed time interval, and in accordance with the amount of settlement calculated in step 7, it is commensurate with the movement of the viscous fluid. It is assumed that the node of the calculation element in the finite element analysis initially set at the specified position has moved, the coordinates of the node are corrected, and the difference in the flow field of the viscous fluid is counteracted by the calculation conditions. Then, step 8 for calculating the amount of subsidence in a certain time interval of the next time interval in the same manner as in step 7, and step 8 is repeated until the time set in advance as the time for which the amount of subsidence is to be predicted. It is characterized by having a computer execute step 9 of calculating.

  A computer-readable recording medium according to the present invention is a computer-readable recording medium that records the above-described calculation program.

  According to the method for predicting the settlement of an object surrounded by a viscous material according to the present invention, it is a method for predicting and calculating the settlement of an object surrounded by a viscous material, and the viscous material is regarded as a viscous fluid. The subsidence force of the object surrounded by is set as a value obtained by subtracting the buoyancy received from the viscous fluid from the gravity acting on the object, and the subsidence speed of the object is set to a temporary subsidence speed which is an arbitrary speed. Then, the viscous flow velocity of the viscous fluid around the object when the object sinks at the set temporary settling velocity is calculated by regarding the viscous fluid as a simple viscous fluid and acting on the surface of the object from the viscous fluid Step 2 for calculating the drag force, and if the calculated integrated value of the drag force is larger than the set squat force, set the provisional squat velocity slightly lower so that the drag force acting on the surface of the object from the viscous fluid is set again. Calculation Step 3 and a step of calculating the drag acting on the surface of the object from the viscous fluid again by setting the provisional settlement speed slightly higher when the integrated value of the calculated drag is smaller than the set squat force. 4 and the above steps 3 and 4 are repeated, and the calculation is stopped when the calculated integrated value of the drag converges to the preset subsidence error range, and the temporary subsidence speed at that time is subsidized. Step 5 obtained as a settlement velocity value corresponding to force has an effect that the settlement behavior of the object surrounded by the viscous material can be predicted and calculated more accurately and simply.

  In addition, according to the subsidence prediction calculation method for an object surrounded by another viscous material according to the present invention, the time for which the amount of subsidence is predicted in advance is divided into a plurality of predetermined time intervals and surrounded by the above-described viscous material. The object moves at a subsidence speed equal to the subsidence speed value obtained in step 6 for obtaining the subsidence speed value by the object subsidence prediction calculation method and in a constant time interval of the first time section when divided into a plurality of constant time intervals. Assuming that the amount of subsidence displacement is integrated over time, step 7 calculates the amount of subsidence at this fixed time interval, and at a position commensurate with the movement of the viscous fluid according to the amount of subsidence calculated in step 7. Assuming that the node of the calculation element in the initially set finite element analysis has moved, the coordinates of the node are corrected, and the difference in the flow field of the viscous fluid is reflected in the calculation conditions. Step 8 for calculating the amount of subsidence in the time interval in the same manner as in Step 7 and Step 9 for calculating the final amount of subsidence by repeating Step 8 until a time set in advance as the time for which the amount of subsidence is to be predicted. Therefore, in addition to the above effects, the cumulative value of the amount of sinking of an object after an arbitrary time (for example, 100 years, 1000 years, 10,000 years, and 100,000 years later) can be predicted and calculated more accurately and simply. There is an effect.

  Also, according to the settlement calculation apparatus for an object surrounded by a viscous material according to the present invention, an apparatus for predicting and calculating the settlement of an object surrounded by a viscous material, the viscous material is regarded as a viscous fluid. A first computing means for setting the subsidence force of the object surrounded by the viscous fluid as a value obtained by subtracting the buoyancy received from the viscous fluid from the gravity acting on the object; Set the subsidence velocity, calculate the viscous flow velocity of the viscous fluid around the object when the object subsides at the set temporary subsidence velocity, considering the viscous fluid as a simple viscous fluid, When the integrated value of the calculated drag force is larger than the set squat force, the provisional squat velocity is set slightly smaller, and the object of the object is again changed from the viscous fluid. Acting on the surface In the case where the third calculation means for calculating the force and the calculated integrated value of the drag force is smaller than the settling force, the temporary settling velocity is set slightly larger, and the viscous fluid acts on the surface of the object again. Repeat the calculation by the fourth calculation means for calculating the drag, the third calculation means and the fourth calculation means, and stop the calculation when the integrated value of the calculated drag converges to the preset subsidence error range And a fifth calculation means for obtaining the provisional settlement velocity at that time as a settlement velocity value corresponding to the settlement force, so that the settlement behavior of the object surrounded by the viscous material can be predicted and calculated more accurately and simply. There is an effect that can be done.

  In addition, according to the settlement prediction calculation apparatus for an object surrounded by another viscous material according to the present invention, the time for which the amount of settlement is predicted in advance is divided into a plurality of predetermined time intervals, and is surrounded by the above-described viscous material. The sixth computing means for obtaining a settlement velocity value by the object settlement prediction calculation device, and the object with a settlement velocity equal to the determined settlement velocity value in a fixed time interval of the first time section when divided into a plurality of fixed time intervals. 7th calculating means for calculating the subsidence amount at this fixed time interval by integrating the subsidence displacement amount with time, and the movement of the viscous fluid according to the subsidence amount calculated by the seventh calculation unit. It is assumed that the node of the calculation element in the finite element analysis that was initially set to the position corresponding to the position is corrected, the coordinates of the node are corrected, the difference in the flow field of the viscous fluid is reflected in the calculation condition, and the next time interval The eighth calculation means for calculating the amount of settlement at regular intervals in the same manner as the seventh calculation means, and the eighth calculation means are repeated up to the time set in advance as the time for which the amount of settlement is to be predicted to calculate the final amount of settlement. In addition to the above-described effect, the ninth calculation means further includes the accumulated value of the amount of object subsidence after an arbitrary period of time (for example, 100 years, 1000 years, 10,000 years, and 100,000 years later). There is an effect that the prediction calculation can be performed.

  The program for predicting the settlement of an object surrounded by a viscous material according to the present invention is a calculation program for causing a computer to execute a method for predicting and calculating the settlement of an object surrounded by a viscous material. In this case, the subsidence force of the object surrounded by the viscous fluid is set as a value obtained by subtracting the buoyancy received from the viscous fluid from the gravity acting on the object, and the subsidence speed of the object at an arbitrary speed. The viscous flow velocity of the viscous fluid around the object when the object sinks at the set temporary settlement velocity is calculated by regarding the viscous fluid as a simple viscous fluid. Step 2 for calculating the drag acting on the surface of the object from the above, and if the calculated integrated value of the drag is larger than the set squat force, the provisional squat velocity is set slightly smaller and Step 3 for calculating the drag acting on the surface of the object from the viscous fluid, and if the calculated integrated value of the drag is smaller than the set squat force, the provisional squat velocity is set slightly larger and the viscosity is set again. Step 4 for calculating the drag force acting on the surface of the object from the fluid, Step 3 and Step 4 are repeated, and calculation is performed when the integrated value of the calculated drag force converges to a preset subsidence error range. , And the computer executes step 5 for determining the provisional settlement velocity at that time as a settlement velocity value corresponding to the settlement force, so that the settlement behavior of the object surrounded by the viscous material can be predicted more accurately and simply. There is an effect that can be done.

  In addition, in the above-described invention, the settlement prediction calculation program for an object surrounded by another viscous material according to the present invention divides the time for which the settlement amount is predicted in advance into a plurality of predetermined time intervals, and the above-described viscous material is used. In step 6 for determining the settlement velocity value by the method for predicting the settlement of the enclosed object, and in the fixed time interval of the first time section when divided into a plurality of fixed time intervals, the object is set at a settlement velocity equal to the calculated settlement velocity value. Is calculated by subtracting the amount of settlement displacement over time to calculate the amount of settlement at this fixed time interval, and in accordance with the amount of settlement calculated in step 7, it is commensurate with the movement of the viscous fluid. It is assumed that the node of the calculation element in the finite element analysis initially set at the specified position has moved, the coordinates of the node are corrected, and the difference in the flow field of the viscous fluid is counteracted by the calculation conditions. Then, step 8 for calculating the amount of subsidence in a certain time interval of the next time interval in the same manner as in step 7, and step 8 is repeated until the time set in advance as the time for which the amount of subsidence is to be predicted. In addition to the above-described effect, the computer executes step 9 for calculating the total amount of object subsidence after an arbitrary time (for example, 100 years, 1000 years, 10,000 years, and 100,000 years later). There is an effect that the prediction calculation can be accurately and simply performed.

FIG. 1 is an explanatory diagram of a load and a drag force acting on an object embedded in a viscous body. FIG. 2 is an example of the method for predicting the settlement of an object surrounded by a viscous material according to the present invention, and is a flowchart of iterative calculation for evaluating the settlement speed. FIG. 3 is a diagram illustrating an analysis model for verification based on Stokes' law. FIG. 4 is a diagram showing an example of the sag of the sphere obtained by the finite element analysis method to which the present invention is applied. FIGS. 5-1 is a figure which shows the model (the 1) which estimates and calculates a settlement phenomenon with the calculation method by this invention, and is a figure which shows the geometric shape of the flow field at the time of calculation start. FIG. 5-2 is a diagram showing a model (part 1) for predicting and calculating the settlement phenomenon by the calculation method according to the present invention, and is a diagram showing the geometric shape of the flow field in the middle of the calculation. FIG. 6 is a graph showing the calculation results for the model (part 1) of FIG. 5-1, in relation to the passage of time and the amount of settlement. FIG. 7 is a diagram showing a model (part 2) for predicting and calculating a settlement phenomenon by the calculation method according to the present invention. FIG. 8 is a graph showing the calculation results for the model (part 2) of FIG. 7 in relation to the passage of time and the amount of settlement. FIG. 9 is a diagram showing an example of plotting the settlement velocity and the flow velocity of the viscous body on a vertical section, (1) is a diagram related to the model (part 1) of FIG. 5-1, and (2) is a diagram of FIG. It is a figure regarding a model (the 2). FIG. 10 is a diagram showing an example of the use of bentonite clay material in geological disposal of conventional high-level radioactive waste, (1) is a schematic diagram when the waste is placed vertically, and (2) is the waste It is a schematic diagram at the time of placing horizontally. FIG. 11 is an image diagram of long-term settlement behavior when a conventional high-level radioactive waste is placed vertically. FIG. 12 is a behavior photograph when a cylindrical object (penetration cylinder 50 mmφ) is penetrated with a constant load (800 g) into clay saturated with water.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of an object settlement prediction calculation method, a calculation apparatus, a calculation program, and a computer-readable recording medium according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

  The method for predicting the settlement of an object surrounded by a viscous material according to the present invention is a method for predicting and calculating the settlement of an object surrounded by a viscous material, and includes steps 1 to 5.

  In step 1, the viscous material is regarded as a viscous fluid, and the settlement force of the object surrounded by the viscous fluid is set as a value obtained by subtracting the buoyancy received from the viscous fluid from the gravity acting on the object.

  Step 2 sets the subsidence speed of the object to a temporary subsidence speed, which is an arbitrary speed, and sets the viscous flow velocity of the viscous fluid around the object when the object subsides at the set temporary subsidence speed. It is calculated as a simple viscous fluid, and the drag acting on the surface of the object from the viscous fluid is calculated.

  Step 3 is to calculate the drag acting on the surface of the object again from the viscous fluid by setting the provisional settlement speed slightly lower when the integrated value of the calculated drag is larger than the set squat force. is there.

  Step 4 is to calculate the drag acting on the surface of the object from the viscous fluid anew by setting the provisional settlement speed slightly higher when the calculated integrated value of the drag is smaller than the set settlement force. is there.

  Step 5 repeats Step 3 and Step 4 and stops the calculation when the integrated value of the calculated drag converges to the preset subsidence error range, and the provisional subsidence velocity at that time is subtracted from the subsidence force. It is obtained as a settlement speed value corresponding to.

  According to the above configuration, the subsidence behavior of the object surrounded by the viscous material can be predicted and calculated more accurately and simply.

  Moreover, the subsidence prediction calculation method for an object surrounded by a viscous material according to the present invention may further include the following steps 6 to 9 in addition to the above configuration.

  Step 6 divides the time for which the amount of settlement is to be predicted in advance into a plurality of predetermined time intervals, and obtains the settlement speed value by the above-described method for predicting the settlement of the object surrounded by the viscous material.

  Step 7 considers that the object moves at a settling velocity equal to the calculated settling velocity value at a fixed time interval of the first time interval when divided into a plurality of fixed time intervals, and integrates the subsidence displacement amount over time. Thus, the amount of settlement in this fixed time interval is calculated.

  Step 8 assumes that the node of the calculation element in the initially set finite element analysis has moved to a position commensurate with the movement of the viscous fluid according to the amount of settlement calculated in Step 7, and corrected the coordinates of the node. The amount of settlement in a certain time interval of the time interval is calculated in the same manner as in Step 7.

  In step 9, the final settlement amount is calculated by repeating step 8 until a time set in advance as a time for which the settlement amount is desired to be predicted.

  According to the above configuration, the accumulated amount of subsidence of an object is reflected by reflecting the difference in the flow field of the viscous fluid in a calculation condition after an arbitrary time has elapsed (for example, 100 years, 1000 years, 10,000 years, and 100,000 years later). There is an effect that the value can be predicted and calculated more accurately and simply.

  Moreover, as a settlement prediction calculation apparatus of the object enclosed by the viscous material which concerns on this invention, it comprises so that the processing content of said step 1-5 may be provided with the 1st-5th calculating means which each calculates by a computer. be able to. Further, in addition to this configuration, it may be configured to further include sixth to ninth calculation means for calculating the processing contents of the above steps 6 to 9 by a computer.

  Moreover, as a settlement prediction calculation program of the object surrounded by the viscous material which concerns on this invention, it can comprise so that said computer may perform said steps 1-5, respectively. Further, in addition to this configuration, the above steps 6 to 9 may be further executed by the computer.

  The computer-readable recording medium according to the present invention can be configured by a computer-readable recording medium that records the above-described calculation program.

Next, the basic principle of the calculation method of the present invention described above will be described in more detail.
(1) Modeling the clay material as a pure viscous fluid In the present invention, the bentonite clay material is regarded as a pure viscous fluid and modeled as follows. Here, a viscous fluid that does not have elastic or plastic properties is called a pure viscous fluid. The constitutive equation of the pure viscous fluid is expressed by the following equation.

  Here, S is a stress tensor, -p is an isotropic component of stress, and I is a unit tensor.

  D is a strain rate tensor, Θ is a volume expansion rate, μ is called a viscosity, and λ is called a second viscosity.

  Here, v is a velocity vector.

  For an incompressible fluid, since Θ≡0, the above constitutive equation is as follows.

Low molecular weight fluids such as water, air, alcohol and glycerin are classified as Newtonian fluids. For Newtonian fluids, the viscosity μ is independent of the shear strain rate D _ij . That is,

On the other hand, the flow of molten polymer, rubber, particle suspension, petroleum, etc. differs from the Newtonian fluid, and the viscosity μ depends on the shear strain rate, so the viscosity is shear viscosity, shear dependent viscosity, or simply Also called viscosity, apparent viscosity. Hereafter, this is simply referred to as viscosity η. If the magnitude of the shear strain rate D _ij is expressed by γ dots (•),

  The SI unit of viscosity η is [Pa · s], and the cgs unit is [Poise].

  Table 1 shows typical fluid viscosity orders.

(2) Calculation Method (2-1) Governing Equation As the governing equation used for the calculation, an incompressible fluid is assumed, and the following Navier-Stokes equations of motion and continuous equations are handled.

Here, ρ is the density of the fluid, and f is the load vector.
Rewriting the constitutive equation of the above pure viscous fluid,

  The assumption of incompressibility is an acceptable approximation for many flow problems dealing with water, clay paste and molten resin. In general, in high-viscosity flow problems, the viscous force and pressure gradient predominately determine the flow situation, so the approximation (Stokes equation) ignoring the nonlinear term in the second term on the left side of the Navier-Stokes equation of motion is often used. Yes.

(2-2) Finite element method In order to analyze the above-mentioned problem by the finite element method, the flow velocity and pressure of the viscous fluid are set as unknown quantities. It is assumed that so-called mixed interpolation is adopted which is constant.

(2-3) Calculation Method of Object Settlement Speed The settling speed of an object embedded in a viscous fluid (hereinafter sometimes referred to as a viscous body) is a load acting on the object as shown in FIG. From the balance condition between buoyancy and fluid drag, the following equation is used for evaluation.

Here, the left side is the load acting on the object, g is the gravitational acceleration, ρ _w is the density of the object, ρ _b is the wet density of the viscous material, and V _w is the volume of the object. The right side represents the drag generated with the flow of bentonite, and S · n is the surface force acting on the surface of the object (surface area S _w ) from the viscous material.

The object is regarded as a rigid body that does not deform, and the analysis target is a viscous body that becomes a flow region. The surface force distribution acting on the object from the viscous body is unknown, and satisfies the condition that the integral value is balanced with the load. Accordingly, as the flow boundary condition, the object surface is regarded as a speed regulation boundary with a constant settling velocity u _w , and u _w satisfying the balance condition is obtained through the iterative calculation shown in the flowchart of FIG.

That is, as shown in FIG. 2, (1) First, the initial value u ₀ of the provisional settlement speed of the object is set (step S11), and this initial value u ₀ is set as the provisional settlement speed u _w , A subsidence force _fw (a value obtained by subtracting the buoyant force received from the viscous body from the gravity acting on the object) is set (step S12). (2) A viscous body and its boundary are set, the viscous body is divided into a finite number of elements, and calculation information such as coordinate information and physical property information of nodes constituting the elements is arranged. (3) the flow deformation behavior of the viscous body with the proviso that the object at a sink rate u _w provisional set to subsidence calculated by the finite element method as a viscous fluid (step S13), and drag f the surface of the object receives from viscous An integral value of _r is obtained (step S14). (4) when the drag f _r acting on the calculated object does not match the sinking force f _w provisionally set (No in step S15), and change the sink rate u ^* _w, such as the difference shrinks (Step S16), the process returns to step S13, and the calculation of (3) is performed. Repeat the calculation of (3) and (4), the calculated value of force f _r acting on the object, the calculation in the case were predetermined error range is set in advance with respect to subsidence force f _w The process ends (Yes in step S15).

Incidentally, in step S16 described above, the correction method of changing the sink rate of the temporary, for ^example, it can be used a formula such as _{^{u * w = ωu 'w +}} (1-ω) u w. Here, u ′ _w = u _w (f _w / f _r ) and 0 ≦ ω ≦ 1.

(2-4) Subsidence amount calculation method Since the object subsidence speed can be accurately estimated and calculated as described above, the following method is used to calculate the cumulative amount of subsidence after a predetermined time. To do.

(1) A period (for example, 10,000 years) in which a settlement phenomenon is to be predicted is divided into a plurality of sections (for example, 100 years × 100 sections).
(2) The position of the object in the viscous body in the first time interval is reflected in the boundary condition, and the settlement speed of the object is calculated by the method described above (the flowchart in FIG. 2).
(3) The sinking speed of the object in the first time section is regarded as sinking at the constant sinking speed calculated in (2) above, and the sinking amount is calculated by time integration.
(4) The node information is corrected to the geometric shape of each element when the coordinate position of the boundary between the object and the viscous body is shifted to reflect the amount of settlement of the object in the first time interval. "). As a result of this correction, for example, as shown in the difference between FIGS. 5A and 5B, a region where the region width of the viscous material changes to a narrow condition and a region where the viscous material changes to a wide condition are reflected in the calculation model.
(5) Based on the corrected position information of the object and the viscous body, the calculation of (2) and (3) is performed in the next second time interval, and the calculation condition of (4) is corrected again. In addition, a settlement prediction calculation for the next third time interval is performed.
(6) When the calculation of (5) is repeated and the settlement amount is calculated until a predetermined period, the calculation is terminated.

(2-5) Verification of Settlement Speed Calculation Method Here, the result of verifying the validity of the drag evaluation method of the present invention shown in the previous section (2-4) based on Stokes' law is shown.

According to Stokes's law, force f _r acting on the sphere of radius R that moves in the fluid viscosity η at a constant velocity u is given by the following equation.

  Stokes's law is derived analytically by ignoring the inertial term in the momentum equation and adopting the assumption that the fluid velocity is zero at infinity. it can. For example, when the sinking object is a sphere with a radius of 2 m and the viscosity η of the viscous body is 1E + 14 Pa · s, the drag force that the sphere receives when the settlement speed v = 1E−3 m / s is 1.85E + 12N according to Stokes' law. Is calculated.

  In the calculation method of the present invention, an axisymmetric cylindrical coordinate system is adopted as a coordinate system to be calculated, and an analysis model as shown in FIG. 3 is adopted. The left side, top side, and right side were set as a wall boundary with zero flow velocity, the bottom side was set as an axisymmetric boundary, and the sphere surface was set as a speed regulation boundary at a constant speed.

  The target drag for convergence calculation was 1.885E + 12N, and the viscosity η was 1E + 14 Pa · s. The result of the iterative calculation shown in FIG. 2 with the provisional settlement speed set to 0.02 m / s converges to the settlement speed v = 1E-3 m / s set in the theoretical calculation as shown in FIG. I was able to confirm that.

  Table 2 compares the exact solution obtained from Stokes' law with the drag calculated by the finite element (FEM) analysis according to the present invention. Both were confirmed to show good agreement.

  Next, a description will be given of prediction calculation examples (No. 1, No. 2) of the settlement amount according to the present invention.

(3) Prediction calculation example 1
FIG. 5A shows the geometric shape of the flow field at the start of calculation of the analysis model (part 1) for predicting and calculating the settlement phenomenon by the calculation method according to the present invention. As shown in FIG. 5A, the object of analysis is the settlement of the waste overpack 2 when the high-level radioactive waste is placed vertically in the viscous material 1. Table 3 shows the calculation conditions. FIG. 5-2 shows a geometrical shape when the waste overpack sinks 0.3 m as an example of the difference in the flow field during the calculation step.

  FIG. 6 is a graph showing the calculation results in relation to the passage of time and the amount of settlement. As shown in FIG. 6, the subsidence amount was calculated to be about 0.65 m in 500,000 years.

(4) Prediction calculation example 2
FIG. 7 shows another analysis model (part 2) for predicting and calculating the settlement phenomenon by the calculation method according to the present invention. As shown in FIG. 7, this model simulates the case where the settlement suppression measure shown in Patent Document 1 is applied to a case where high-level radioactive waste is placed vertically. The settlement restraining material 3 arranged at the lower left and right is a rock arranged in a ring shape at the bottom of the vertically disposed disposal hole.

  The analysis object is the settlement of the waste overpack 2 when the high-level radioactive waste is vertically placed in the viscous material 1 as in FIGS. 5A and 5B, and the calculation conditions are the same as the first ( (See Table 3). However, the calculation was performed by setting boundary conditions so that the boundary surface between the settlement settling material 3 arranged in a ring shape at the bottom of the vertically disposed disposal hole and the viscous material (a bentonite clay material called a buffer material) becomes a fixed point.

  FIG. 8 is a graph showing the calculation results in relation to the passage of time and the amount of settlement. As shown in FIG. 8, the amount of settlement was calculated to be about 0.2 m in 500,000 years. Since the amount of settlement was reduced as compared with the result of the above “prediction calculation example 1”, it was possible to predict and evaluate that the settlement suppression measures by the settlement suppression material 3 were effective.

  FIG. 9 shows an example in which the settlement speed and the flow velocity of the viscous body, which are the calculation results predicted under the above two calculation conditions (part 1 and part 2), are plotted on a vertical section. The arrow indicates the flow direction of the viscous body. The difference that the flow of the viscous body is suppressed by the settlement suppression measure by the settlement suppression material 3 is clearly shown.

  As described above, according to the method for predicting the settlement of an object surrounded by a viscous material according to the present invention, a method for predicting and calculating the settlement of an object surrounded by a viscous material, the viscous material being a viscous fluid Considering this, step 1 for setting the sinking force of the object surrounded by the viscous fluid as a value obtained by subtracting the buoyancy received from the viscous fluid from the gravity acting on the object, and the sinking speed of the object is an arbitrary speed. Set the provisional settlement velocity, calculate the viscous flow velocity of the viscous fluid around the object when the object sinks at the set provisional settlement velocity, considering the viscous fluid as a simple viscous fluid, and from the viscous fluid Step 2 for calculating the drag acting on the surface of the object, and if the integrated value of the calculated drag is larger than the set squat force, the provisional squat velocity is set slightly lower and the object is surface Step 3 for calculating the acting drag and if the calculated integrated value of the drag is smaller than the set squat force, the provisional squat velocity is set to be slightly larger, and the viscous fluid acts on the surface of the object again. The step 4 for calculating the drag, the step 3 and the step 4 are repeated, and the calculation is stopped when the calculated integrated value of the drag converges to the preset subsidence error range. Therefore, the settlement behavior of the object surrounded by the viscous material can be predicted and calculated more accurately and simply.

  In addition, according to the subsidence prediction calculation method for an object surrounded by another viscous material according to the present invention, the time for which the amount of subsidence is predicted in advance is divided into a plurality of predetermined time intervals and surrounded by the above-described viscous material. The object moves at a subsidence speed equal to the subsidence speed value obtained in step 6 for obtaining the subsidence speed value by the object subsidence prediction calculation method and in a constant time interval of the first time section when divided into a plurality of constant time intervals. Assuming that the amount of subsidence displacement is integrated over time, step 7 calculates the amount of subsidence at this fixed time interval, and at a position commensurate with the movement of the viscous fluid according to the amount of subsidence calculated in step 7. Assuming that the node of the calculation element in the initially set finite element analysis has moved, the coordinates of the node are corrected, and the difference in the flow field of the viscous fluid is reflected in the calculation conditions. Step 8 for calculating the amount of subsidence in the time interval in the same manner as in Step 7 and Step 9 for calculating the final amount of subsidence by repeating Step 8 until a time set in advance as the time for which the amount of subsidence is to be predicted. Therefore, in addition to the above effects, the cumulative value of the amount of sinking of an object after an arbitrary time (for example, 100 years, 1000 years, 10,000 years, and 100,000 years later) can be predicted and calculated more accurately and simply. .

  Also, according to the settlement calculation apparatus for an object surrounded by a viscous material according to the present invention, an apparatus for predicting and calculating the settlement of an object surrounded by a viscous material, the viscous material is regarded as a viscous fluid. A first computing means for setting the subsidence force of the object surrounded by the viscous fluid as a value obtained by subtracting the buoyancy received from the viscous fluid from the gravity acting on the object; Set the subsidence velocity, calculate the viscous flow velocity of the viscous fluid around the object when the object subsides at the set temporary subsidence velocity, considering the viscous fluid as a simple viscous fluid, When the integrated value of the calculated drag force is larger than the set squat force, the provisional squat velocity is set slightly smaller, and the object of the object is again changed from the viscous fluid. Acting on the surface In the case where the third calculation means for calculating the force and the calculated integrated value of the drag force is smaller than the settling force, the temporary settling velocity is set slightly larger, and the viscous fluid acts on the surface of the object again. Repeat the calculation by the fourth calculation means for calculating the drag, the third calculation means and the fourth calculation means, and stop the calculation when the integrated value of the calculated drag converges to the preset subsidence error range And a fifth calculation means for obtaining the provisional settlement velocity at that time as a settlement velocity value corresponding to the settlement force, so that the settlement behavior of the object surrounded by the viscous material can be predicted and calculated more accurately and simply. it can.

  In addition, according to the settlement prediction calculation apparatus for an object surrounded by another viscous material according to the present invention, the time for which the amount of settlement is predicted in advance is divided into a plurality of predetermined time intervals, and is surrounded by the above-described viscous material. The sixth computing means for obtaining a settlement velocity value by the object settlement prediction calculation device, and the object with a settlement velocity equal to the determined settlement velocity value in a fixed time interval of the first time section when divided into a plurality of fixed time intervals. 7th calculating means for calculating the subsidence amount at this fixed time interval by integrating the subsidence displacement amount with time, and the movement of the viscous fluid according to the subsidence amount calculated by the seventh calculation unit. It is assumed that the node of the calculation element in the finite element analysis that was initially set to the position corresponding to the position is corrected, the coordinates of the node are corrected, the difference in the flow field of the viscous fluid is reflected in the calculation condition, and the next time interval The eighth calculation means for calculating the amount of settlement at regular intervals in the same manner as the seventh calculation means, and the eighth calculation means are repeated up to the time set in advance as the time for which the amount of settlement is to be predicted to calculate the final amount of settlement. In addition to the above-described effect, the ninth calculation means further includes the accumulated value of the amount of object subsidence after an arbitrary period of time (for example, 100 years, 1000 years, 10,000 years, and 100,000 years later). Can be predicted.

  The program for predicting the settlement of an object surrounded by a viscous material according to the present invention is a calculation program for causing a computer to execute a method for predicting and calculating the settlement of an object surrounded by a viscous material. In this case, the subsidence force of the object surrounded by the viscous fluid is set as a value obtained by subtracting the buoyancy received from the viscous fluid from the gravity acting on the object, and the subsidence speed of the object at an arbitrary speed. The viscous flow velocity of the viscous fluid around the object when the object sinks at the set temporary settlement velocity is calculated by regarding the viscous fluid as a simple viscous fluid. Step 2 for calculating the drag acting on the surface of the object from the above, and if the calculated integrated value of the drag is larger than the set squat force, the provisional squat velocity is set slightly smaller and Step 3 for calculating the drag acting on the surface of the object from the viscous fluid, and if the calculated integrated value of the drag is smaller than the set squat force, the provisional squat velocity is set slightly larger and the viscosity is set again. Step 4 for calculating the drag force acting on the surface of the object from the fluid, Step 3 and Step 4 are repeated, and calculation is performed when the integrated value of the calculated drag force converges to a preset subsidence error range. , And the computer executes step 5 for determining the provisional settlement velocity at that time as a settlement velocity value corresponding to the settlement force, so that the settlement behavior of the object surrounded by the viscous material can be predicted more accurately and simply. can do.

  In addition, in the above-described invention, the settlement prediction calculation program for an object surrounded by another viscous material according to the present invention divides the time for which the settlement amount is predicted in advance into a plurality of predetermined time intervals, and the above-described viscous material is used. In step 6 for determining the settlement velocity value by the method for predicting the settlement of the enclosed object, and in the fixed time interval of the first time section when divided into a plurality of fixed time intervals, the object is set at a settlement velocity equal to the calculated settlement velocity value. Is calculated by subtracting the amount of settlement displacement over time to calculate the amount of settlement at this fixed time interval, and in accordance with the amount of settlement calculated in step 7, it is commensurate with the movement of the viscous fluid. It is assumed that the node of the calculation element in the finite element analysis initially set at the specified position has moved, the coordinates of the node are corrected, and the difference in the flow field of the viscous fluid is counteracted by the calculation conditions. Then, step 8 for calculating the amount of subsidence in a certain time interval of the next time interval in the same manner as in step 7, and step 8 is repeated until the time set in advance as the time for which the amount of subsidence is to be predicted. In addition to the above-described effect, the computer executes step 9 for calculating the total amount of object subsidence after an arbitrary time (for example, 100 years, 1000 years, 10,000 years, and 100,000 years later). Predictive calculation can be performed accurately and simply.

  As described above, the subsidence prediction calculation method, calculation apparatus, calculation program, and computer-readable recording medium of an object surrounded by a viscous material according to the present invention are surrounded by a wet clay-based cushioning material such as bentonite-based clay material. It is useful for predicting the settlement of an object such as a radioactive waste, and is particularly suitable for predicting and calculating the settlement behavior of an object more accurately and simply.

1 Bentonite clay material (buffer material)
2 Waste 3 Subsidence suppression material

Claims (7)

A method for predicting and calculating the settlement of an object surrounded by a viscous material,
Setting the subsidence force of the object surrounded by the viscous fluid as a viscous fluid as a viscous fluid, and setting the subtraction force as a value obtained by subtracting the buoyancy received from the viscous fluid from the gravity acting on the object;
Set the subsidence velocity of the object to a temporary subsidence velocity that is an arbitrary speed, and set the viscous flow velocity of the viscous fluid around the object when the object subsides at the set subsidence velocity to the viscous fluid as a simple viscous fluid. Step 2 for calculating the drag acting on the surface of the object from the viscous fluid,
When the calculated integrated value of the drag force is larger than the set squat force, the provisional squat velocity is set slightly smaller, and the drag force acting on the surface of the object from the viscous fluid is calculated again.
If the integrated value of the calculated drag force is smaller than the set squat force, step 4 for setting the provisional squat velocity slightly higher and calculating the drag force acting on the surface of the object from the viscous fluid again;
Step 3 and Step 4 are repeated, and the calculation is stopped when the calculated integrated value of the drag force converges to the preset subsidence error range, and the temporary subsidence speed at that time corresponds to the subsidence force. And a step 5 for determining a settlement velocity value to be calculated, a settlement prediction calculation method for an object surrounded by a viscous material. Dividing the time for which the amount of subsidence is to be predicted in advance into a plurality of predetermined time intervals, and obtaining a subsidence velocity value by the subsidence prediction calculation method for the object surrounded by the viscous material according to claim 1;
It is assumed that the object moves at a settling velocity equal to the calculated settling velocity value in the fixed time interval of the first time interval when divided into a plurality of fixed time intervals, and this is performed by integrating the amount of subsidence displacement over time. Step 7 for calculating the amount of settlement at regular time intervals;
According to the subsidence amount calculated in step 7, it is assumed that the node of the calculation element in the finite element analysis initially set to a position corresponding to the movement of the viscous fluid, the coordinates of the node are corrected, and the flow of the viscous fluid Step 8 for calculating the subsidence amount in a fixed time interval of the next time section in the same manner as in Step 7 by reflecting the difference in the field in the calculation conditions;
The object surrounded by the viscous material according to claim 1, further comprising a step 9 of repeating the step 8 to a time set in advance as a time for which the amount of subsidence is to be predicted to calculate a final amount of subsidence. Subsidence prediction calculation method. An apparatus for predicting and calculating the settlement of an object surrounded by a viscous material,
A first computing means that regards the viscous material as a viscous fluid, and sets the subsidence force of the object surrounded by the viscous fluid as a value obtained by subtracting the buoyancy received from the viscous fluid from the gravity acting on the object;
Set the subsidence velocity of the object to a temporary subsidence velocity that is an arbitrary speed, and set the viscous flow velocity of the viscous fluid around the object when the object subsides at the set subsidence velocity to the viscous fluid as a simple viscous fluid. Second calculating means for calculating the drag acting on the surface of the object from the viscous fluid,
If the calculated integrated value of the drag force is larger than the set squat force, a third computing means for setting the provisional squat velocity slightly lower and calculating the drag force acting on the surface of the object from the viscous fluid again;
If the calculated integrated value of the drag force is smaller than the set squat force, fourth calculation means for setting the provisional squat velocity slightly higher and calculating the drag force acting on the surface of the object from the viscous fluid again;
The calculation by the third calculating means and the fourth calculating means is repeated, and the calculation is stopped when the calculated integrated value of the drag force converges to the preset subsidence error range, and the temporary subsidence speed at that time is calculated. And a fifth computing means for obtaining a settlement velocity value corresponding to the settlement force. A settlement prediction calculation apparatus for an object surrounded by a viscous material. Dividing the time for which the amount of subsidence is to be predicted in advance into a plurality of fixed time intervals, and calculating the subsidence velocity value by the subsidence prediction calculation device for the object surrounded by the viscous material according to claim 3,
It is assumed that the object moves at a settling velocity equal to the calculated settling velocity value in the fixed time interval of the first time interval when divided into a plurality of fixed time intervals, and this is performed by integrating the amount of subsidence displacement over time. A seventh calculating means for calculating a sinking amount at a fixed time interval;
According to the amount of settlement calculated by the seventh computing means, the node of the calculation element in the finite element analysis initially set to a position commensurate with the movement of the viscous fluid is corrected, the coordinates of the node are corrected, An eighth calculating means for calculating the subsidence amount in a fixed time interval of the next time section in the same manner as the seventh calculating means by reflecting the difference in the flow field in the calculation conditions;
4. The ninth calculation means further includes ninth calculation means for calculating a final subsidence amount by repeating the eighth calculation unit until a time set in advance as a time for which the subsidence amount is desired to be predicted. For predicting the settlement of objects. A calculation program for causing a computer to execute a method for predicting and calculating the settlement of an object surrounded by a viscous material,
Setting the subsidence force of the object surrounded by the viscous fluid as a viscous fluid as a viscous fluid, and setting the subtraction force as a value obtained by subtracting the buoyancy received from the viscous fluid from the gravity acting on the object;
Set the subsidence velocity of the object to a temporary subsidence velocity that is an arbitrary speed, and set the viscous flow velocity of the viscous fluid around the object when the object subsides at the set subsidence velocity to the viscous fluid as a simple viscous fluid. Step 2 for calculating the drag acting on the surface of the object from the viscous fluid,
When the calculated integrated value of the drag force is larger than the set squat force, the provisional squat velocity is set slightly smaller, and the drag force acting on the surface of the object from the viscous fluid is calculated again.
If the integrated value of the calculated drag force is smaller than the set squat force, step 4 for setting the provisional squat velocity slightly higher and calculating the drag force acting on the surface of the object from the viscous fluid again;
Step 3 and Step 4 are repeated, and the calculation is stopped when the calculated integrated value of the drag force converges to the preset subsidence error range, and the temporary subsidence speed at that time corresponds to the subsidence force. A program for predicting the settlement of an object surrounded by a viscous material, which causes a computer to execute step 5 as a settlement velocity value. Dividing the time for which the amount of subsidence is to be predicted in advance into a plurality of predetermined time intervals, and obtaining a subsidence velocity value by the subsidence prediction calculation method for the object surrounded by the viscous material according to claim 5;
It is assumed that the object moves at a settling velocity equal to the calculated settling velocity value in the fixed time interval of the first time interval when divided into a plurality of fixed time intervals, and this is performed by integrating the amount of subsidence displacement over time. Step 7 for calculating the amount of settlement at regular time intervals;
According to the subsidence amount calculated in step 7, it is assumed that the node of the calculation element in the finite element analysis initially set to a position corresponding to the movement of the viscous fluid, the coordinates of the node are corrected, and the flow of the viscous fluid Step 8 for calculating the subsidence amount in a fixed time interval of the next time section in the same manner as in Step 7 by reflecting the difference in the field in the calculation conditions;
6. The step 8 is repeated until a time set in advance as a time for which the amount of subsidence is to be predicted, and the step 9 for calculating the final amount of subsidence is executed by the computer. Program for predicting the settlement of objects.   A computer-readable recording medium in which the calculation program according to claim 5 or 6 is recorded.