阅读说明：本技术 一种深地工程原位应力场和渗流场超重力模拟系统 (Deep ground engineering in-situ stress field and seepage field hypergravity simulation system ) 是由 徐文杰 詹良通 陈云敏 李珂 李金龙 于 2019-06-27 设计创作，主要内容包括：本发明公开了一种深地工程原位应力场和渗流场超重力模拟系统,包括：三轴压力室,用于放置模型,并提供深地构筑物的原位轴压、围压以及所处的渗流场；模拟控制装置,用于向三轴压力室提供压力液体和孔隙水以产生前述轴压、围压和渗流场,并控制轴压、围压和渗流场的量值；信号采集装置,用于在试验过程中监测模型变形和渗流过程。本发明提高了模拟试验的相似性、可靠型和准确性,且可以通过控制单元的指令向三轴压力室输出精度达1%的压力或构成精度达1%的孔隙水压力差。(The invention discloses a deep ground engineering in-situ stress field and seepage field hypergravity simulation system, which comprises: the triaxial pressure chamber is used for placing a model and providing in-situ axial pressure, confining pressure and a located seepage field of a deep structure; the analog control device is used for providing pressure liquid and pore water to the triaxial pressure chamber to generate the axial pressure, the confining pressure and the seepage field and controlling the magnitude of the axial pressure, the confining pressure and the seepage field; and the signal acquisition device is used for monitoring the deformation and seepage process of the model in the test process. The invention improves the similarity, reliability and accuracy of the simulation test, and can output pressure with the precision of 1% or form pore water pressure difference with the precision of 1% to the triaxial pressure chamber through the instruction of the control unit.)

1. A deep ground engineering normal position stress field and seepage field hypergravity analog system includes:

the triaxial pressure chamber is used for placing a model and providing in-situ axial pressure, confining pressure and a located seepage field of a deep structure;

the analog control device is used for providing pressure liquid and pore water to the triaxial pressure chamber to generate the axial pressure, the confining pressure and the seepage field and controlling the magnitude of the axial pressure, the confining pressure and the seepage field;

the signal acquisition device is used for monitoring the deformation and seepage processes of the model in the test process;

when a simulation test is carried out, the three-axis pressure chamber is placed on a supergravity centrifugal machine, and the centrifugal acceleration generated by the supergravity centrifugal machine is n times (n is an integer larger than 1) of the gravity acceleration g so as to enable the model to be in a supergravity state, thereby generating the self-weight stress with gradient; and (3) enabling the confining pressure liquid to be in a supergravity state, so as to generate the confining pressure with gradient.

2. The deep ground engineering in-situ stress field and seepage field hypergravity simulation system of claim 1, characterized in that: the triaxial pressure chamber comprises four channels which are respectively an axial pressure channel, a confining pressure channel, a pore water inlet channel and a pore water outlet channel.

3. The deep project in-situ stress field and seepage field supergravity simulation system of claim 1 or 2, characterized in that: the simulation control device comprises a main control unit, a pressure seepage control unit, a data feedback unit and a source and sink unit.

4. The deep project in-situ stress field and seepage field supergravity simulation system of claim 2 or 3, wherein: the pressure seepage control units are four and are respectively an axial pressure control unit, a confining pressure control unit, a pore water inlet control unit and a pore water outlet control unit, so that the axial pressure, the confining pressure and the seepage field of the model can be independently controlled.

5. The deep ground engineering in-situ stress field and seepage field hypergravity simulation system of claim 4, wherein:

the axial pressure control unit is connected with the axial pressure channel and used for controlling axial pressure in the triaxial pressure chamber;

the confining pressure control unit is connected with the confining pressure channel and is used for controlling confining pressure in the triaxial pressure chamber;

the pore water inlet control unit is connected with the pore water inlet channel, the pore water outlet control unit is connected with the pore water outlet channel, and the pore water inlet control unit and the pore water outlet control unit form pressure difference of pore water at an inlet and an outlet and are used for controlling a seepage field in the triaxial pressure chamber.

6. The deep project in-situ stress field and seepage field supergravity simulation system of claim 2 or 3, wherein: the data feedback unit is used for collecting the axial pressure, the confining pressure and the pore water flow which are output to the triaxial pressure chamber from the pressure seepage control unit in the simulation process, and transmitting the collected data to the main control unit.

7. The deep ground engineering in-situ stress field and seepage field hypergravity simulation system of claim 3, wherein:

the source sink unit is used for providing pressure liquid and/or pore water for the pressure seepage control unit.

8. The deep ground engineering in-situ stress field and seepage field hypergravity simulation system of claim 7, wherein: the pressure seepage control unit comprises a pressure seepage controller and a pressure seepage regulator; after receiving the pressure liquid or pore water output from the source collecting unit, the pressure seepage regulator monitors the flow of the liquid and outputs the liquid to the main control unit, and dynamically regulates the flow of the liquid output by the pressure seepage regulator according to the feedback of the main control unit.

9. The deep ground engineering in-situ stress field and seepage field hypergravity simulation system of claim 8, wherein: the pressure seepage controller comprises a driving assembly, a liquid storage assembly, a control assembly and an output assembly, wherein the driving assembly is used for converting the thrust of pressure liquid output by the source collection unit to the self into the thrust of the pressure liquid output by the source collection unit to the liquid storage assembly, the liquid storage assembly is a container for storing the pressure liquid or pore water, the liquid in the container is not communicated with the liquid output by the source collection unit, the liquid storage assembly conveys the liquid in the liquid storage assembly to the output assembly through a pipeline after receiving the thrust of the driving assembly to the self, the control assembly is connected with the pressure seepage regulator and used for controlling the flow of the liquid input into the driving assembly, and the output assembly is connected with the liquid storage assembly and used for outputting the pressure liquid or the pore water in the liquid storage assembly to the triaxial pressure chamber.

10. The deep ground engineering in-situ stress field and seepage field hypergravity simulation system of claim 1, characterized in that: the signal acquisition device comprises sensors for displacement, deformation, humidity and the like and is used for monitoring the deformation and seepage processes of the sample in the test process.

Technical Field

The invention relates to a physical simulation test system in the field of geotechnical engineering, in particular to a supergravity simulation system for an in-situ stress field and a seepage field of deep earth engineering.

Background

Deep earth engineering (deep earth engineering) refers to an engineering process that takes place during the construction of deep structures in a deep earth environment and during the operation thereof. Common deep-ground structures may be deep-ground reservoirs, geothermal engineering, cavern natural gas reservoirs, etc.

Among them, deep earth environment (deep earth environment) refers to an environment at a depth of more than one hundred meters from the earth surface.

The in-situ stress field and the seepage field of the deep structure have the following five characteristics at the same time: (1) the pressure (axial pressure) of an overlying rock stratum on a deep structure is large and can reach 20MPa under the depth of a thousand meters; (2) the confining pressure of the deep structure is large and can reach 20MPa under the depth of kilometer level; (3) the deep structure reaches the scale of hundred meters, and the self-weight stress and the confining pressure change along the height direction of the deep structure, so that a self-weight stress gradient and a confining pressure gradient are formed; (4) the stress field and the seepage field of the deep structure are mutually coupled, the occurring engineering process is very complex, the change of related parameters such as deformation, stress, saturation and the like is difficult to describe by a mathematical model and is obtained by depending on the experiment; (5) the changes of the stress field and the seepage field are long, and the parameter changes are stable for hundreds of years or even thousands of years. In-situ (in-situ) means that the original condition of the material is not changed or isolated from the original system when a certain parameter is measured. Prototype (prototype) refers to an entity in the original system, and in the present invention, refers to a deep structure in a deep ground environment; a model (model) refers to a scaled down (or enlarged or the same size as the original system) physical object that is manufactured according to the similarity theory. The in-situ stress field and the seepage field are the stress field and the seepage field of the prototype.

Other geotechnical engineering research objects do not have the five characteristics at the same time, and are essentially different from deep ground engineering.

In order to measure the change of related parameters such as deformation, stress, saturation and the like in deep ground engineering, a test is required. The test includes in-situ test and simulation test. In situ testing refers to testing performed in situ, such as by setting up an instrument to measure in an existing deep disposal library. When the in-situ test of the deep ground engineering is carried out, on one hand, a tester is required to carry equipment to enter the deep ground environment to work, and on the other hand, part of experimental objects are national engineering equipment which is still in service, so that the in-situ test lacks time flexibility and operation convenience. In addition, as the characteristics (5) of the stress field and the seepage field of the deep ground engineering, the complete measurement of the parameter change requires test time on the scale of hundreds of years or even thousands of years, which is far longer than the time scale involved in social or technical activities in a general sense.

Therefore, a physical simulation test conducted in a laboratory is more preferable. The physical simulation test refers to a simulation test in which a model is a real object, such as a test in which a library prototype is processed with a height of 1m in a laboratory instead of a depth of 100m, and pressure is applied to the top, bottom and side surfaces thereof with a pressure device. Hereinafter, the physical simulation test is simply referred to as a simulation test. The simulation test method is that the model is placed in the test device, and the surface of the model is applied with force and/or pore water by the test device, so that the model generates a stress field and/or a seepage field. When the applied force and/or the flow rate of the water flowing into the pore space meet specific requirements, an in-situ stress field and/or a seepage field can be generated. In view of the laboratory site size limitations, deep ground engineering simulations typically employ models with dimensions below 10 m. Other geotechnical engineering does not have five characteristics of deep ground engineering at the same time, so that the model used in the simulation of other geotechnical engineering does not need to meet the five conditions at the same time.

As described above, in the simulation test, the axial pressures of the upper and lower bottom surfaces of the model are determined values and can be easily applied. The confining pressure of the model is usually applied by extruding the model around pressure liquid through the side surface of the model, the confining pressure at the top of the model is the set pressure of the device, and the confining pressure at the bottom of the model is the sum of the top confining pressure and the dead weight of the pressure liquid at the bottom of the model. Since the density of the pressure liquid is generally smaller than that of the rock and the height of the model is smaller, the dead weight of the pressure liquid at the bottom of the model is negligibly small, and thus, a confining pressure gradient similar to that of the prototype cannot be formed. The dead weight stress of the model is related to the dimension of the model, but the dimension of the model of a simulation test is below 10 meters, so the difference between the dead weight stress at the top and the bottom is only 1/10 of the prototype. The simulation of the seepage field is typically formed by injecting pore water inside the model. Since the stress field of the model is different from that of the prototype, the resulting seepage field is also different from that of the prototype. In conclusion, the in-situ seepage field and the in-situ stress field cannot be restored in the simulation test of the deep land engineering.

Wherein the stress field is a general description of the instantaneous stress state of all points in the object. Stress state (stresstate) refers to the stress in all possible directions at a certain point in an object. Stress (stress) is an internal force that causes interaction between parts in an object when the object is deformed by external factors (stress, humidity, temperature field change, etc.). The effect of the stress is to resist the action of such external causes and attempt to restore the object from the deformed position to the pre-deformed position.

The seepage field is a general description of the fluid pressure conditions at all points inside the rock-soil body. Seepage (seepage) refers to the flow of pore water in a medium. In continuous rock-soil masses, seepage occurs when two points have different pore water pressures. In deep ground engineering, a common form of seepage is the flow of groundwater in rock or deep ground engineering structures or between the two. Pore water pressure (pore water pressure) refers to the pressure generated by pore water. Pore water (porewater) refers to a liquid, usually water, that exists in the pores of the rock-soil mass, and may be other liquids.

Wherein overburden pressure (overburden pressure) refers to the pressure caused by the weight of the rock mass overlying the study object, and is directed vertically downward with a value that increases linearly with depth. Axial pressure (axialpressure) refers to pressure directed perpendicular to the cross-section and directed inward of the cross-section. In the simulation test system, the axial pressure of the deep ground project refers to overburden pressure at the top and bottom surfaces of the model.

Wherein, confining pressure (confining pressure) refers to the pressure applied by the surrounding rock mass to the research object in the rock-soil body, and the direction is horizontal and vertical to the contact surface and points to the object. The confining pressure in a deep-ground environment, which is primarily due to overburden pressure, is generally considered to be equal in value to overburden pressure and increases linearly with depth.

Wherein, the dead weight stress (geostatic stress/self-weight stress) refers to the stress caused by the self weight in the rock-soil body. The dead weight stress of any point in the rock-soil body in the vertical direction is equal to the mass of the rock-soil column in unit area above the point.

To illustrate the differences more specifically, a set of prototype and model stress field simulation scenarios are taken as an example. The prototype is a 100m high rock at a depth of 1000m, with a heavy weight of 25kN/m3 for the surrounding rock and rock. The stress on the material is shown in figure 1: the top axial pressure is 25MPa, the bottom axial pressure is 27.5MPa, the top confining pressure is 25MPa, the bottom confining pressure is 27.5MPa, the difference between the top and the bottom of the self-weight stress is 2.5MPa, and the fluid pressure is related to the flow and distribution condition of underground water. The model was 1m high rock, and the weight was 25kN/m 3. The top axial pressure is 25MPa, the top confining pressure is 25MPa, the confining pressure liquid is oil, and the gravity is 8kN/m 3. As shown in the figure 2 of the pressure of each direction, the axial pressure at the bottom of the model is the sum of the top axial pressure and the gravity of the model and is 25.025MPa, and the confining pressure at the bottom is the sum of the top confining pressure and the gravity of oil and is 25.008 MPa. The difference between the top and the bottom of the model's dead weight stress is 0.025 MPa. Obviously, the stress field of the model is much different from the prototype.

In summary, the simulation test of deep ground engineering has the advantages of convenient operation and flexible time arrangement, but still has the disadvantages of limited simulation time scale and incapability of completely restoring the confining pressure gradient and the self-weight stress gradient. Under normal gravity, there is no way to simulate the stress field and the seepage field of deep ground engineering well.

Disclosure of Invention

In order to overcome the defects that the simulation time scale is limited and the in-situ stress field and the seepage field cannot be completely reduced in the prior art, the invention aims to provide the deep ground engineering in-situ stress field and seepage field hypergravity simulation system, which can simultaneously provide high confining pressure and high stress in a simulation test and can simulate in-situ confining pressure and a self-weight stress gradient so as to truly reduce the in-situ stress field and the seepage field of a deep ground structure, and the test result can more reliably and accurately reflect the prototype condition.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a deep ground engineering normal position stress field and seepage field hypergravity analog system includes:

the triaxial pressure chamber is used for placing a model and providing in-situ axial pressure, confining pressure and a located seepage field of a deep structure;

the analog control device is used for providing pressure liquid and pore water for the triaxial pressure chamber to generate the axial pressure, the confining pressure and the seepage field, and can independently and precisely control the magnitude of the axial pressure, the confining pressure and the seepage field; the signal acquisition device is used for monitoring the deformation and seepage processes of the model in the test process;

when a simulation test is carried out, the three-axis pressure chamber is placed on a supergravity centrifugal machine, and the centrifugal acceleration generated by the supergravity centrifugal machine is n times (n is an integer larger than 1) of the gravity acceleration g, so that the model is in a supergravity state.

Preferably, n is an integer of 100 or more.

The supergravity centrifuge rotates at a constant angular velocity ω, and provides a centrifugal acceleration equal to "r + 2" (r is the distance from any point in the model to the center of rotation). If the model is made of the same material as the prototype, then when the centrifugal acceleration is n times the gravitational acceleration (ng 2 of r), the subject at the model depth hm will have the same vertical stress as the subject at the prototype hp nhm: σ m ═ σ p. The principle of the most basic similarity ratio of the supergravity centrifugal simulation is that when a model with the size reduced by n times bears the gravity acceleration by n times, the stress field of the model is the in-situ stress field. For example, when n is 10, i.e., acceleration is 10g, the stress level at a depth of 1 meter in the model is the same as the stress field at 10 meters in the prototype; when n is 100, i.e. the acceleration is 100g, the stress level in the model at a depth of 1 meter is the same as the stress field in the prototype at 100 meters.

The technical scheme can be further improved by the following technical measures:

preferably, the triaxial pressure chamber comprises four channels, which are respectively an axial pressure channel, a confining pressure channel, a pore water inlet channel and a pore water outlet channel.

Preferably, the simulation control device comprises a main control unit, a pressure seepage control unit, a data feedback unit and a source and sink unit. The number of the pressure seepage control units is four, and the four pressure seepage control units are respectively an axial pressure control unit, a confining pressure control unit, a pore water inlet control unit and a pore water outlet control unit.

Preferably, the axial pressure control unit is connected with the axial pressure channel and used for controlling the axial pressure in the triaxial pressure chamber; the confining pressure control unit is connected with the confining pressure channel and is used for controlling confining pressure in the triaxial pressure chamber; the pore water inlet control unit is connected with the pore water inlet channel, the pore water outlet control unit is connected with the pore water outlet channel, and the pore water inlet control unit and the pore water outlet control unit form pressure difference of pore water at an inlet and an outlet and are used for controlling a seepage field in the triaxial pressure chamber.

Preferably, the data feedback unit is used for collecting the axial pressure, the confining pressure and the pore pressure in the triaxial pressure chamber in the simulation process, and transmitting the collected data to the main control unit.

Preferably, the source sink unit is adapted to provide pressure fluid and/or pore water to the pressure seepage control unit.

Preferably, the pressure seepage control unit comprises a pressure seepage controller and a pressure seepage regulator; after receiving the pressure liquid or pore water output from the source collecting unit, the pressure seepage regulator monitors the flow of the pressure liquid and outputs the pressure liquid to the main control unit, and the pressure seepage regulator dynamically regulates the flow of the pressure liquid output by the pressure seepage controller according to the feedback of the main control unit.

Preferably, the pressure seepage controller comprises a driving assembly, a liquid storage assembly, a control assembly and an output assembly, wherein the driving assembly is used for converting the thrust of the pressure liquid output by the source and sink unit to the self to the thrust of the pressure liquid output by the source and sink unit to the liquid storage assembly, the liquid storage assembly is a container for storing the pressure liquid or pore water, the liquid in the container is not communicated with the liquid output by the source and sink unit, the liquid storage assembly conveys the liquid in the liquid storage assembly to the output assembly through a pipeline after receiving the thrust of the driving assembly to the self, the control assembly is connected with the pressure regulator and is used for controlling the flow rate of the liquid input into the driving assembly, and the output assembly is connected with the liquid storage assembly and is used for outputting the pressure liquid or the pore water in the liquid storage assembly to the three-axis.

Preferably, the signal acquisition device comprises sensors for displacement, deformation, humidity and the like, and is used for monitoring the deformation and seepage process of the sample in the test process.

Preferably, the triaxial pressure chamber further comprises an axial pressure simulation assembly, a confining pressure simulation assembly and a seepage simulation assembly. The axial pressure simulation assembly is connected with the axial pressure channel and comprises a pair of axial pressure heads positioned at the top and the bottom of the model in the triaxial pressure chamber, one of the axial pressure heads is fixed, the other axial pressure head can move up and down, and axial pressure is applied to the model under the driving of pressure liquid.

Preferably, the confining pressure simulation assembly is connected with a confining pressure channel, pressure liquid output from the confining pressure channel is guided into the triaxial pressure chamber, and surrounding pressure is generated on the triaxial pressure chamber through the liquid surrounding the model.

Preferably, the seepage simulation assembly is connected with the pore water inlet channel and the pore water outlet channel, and guides the pore water output from the pore water inlet channel to enter the porous plate contacted with one end of the model and then enter the model, and then flows out of the porous plate contacted with the other end of the model and flows into the pore water outlet channel, so that the model generates an in-situ pore water pressure difference, thereby forming an in-situ seepage field.

Preferably, the porous plate is a waterproof plate with the same shape as the bottom of the model, circular holes are arranged on the porous plate, the distribution density of the holes is more than or equal to 30, the outer sides of the model and the porous plate are wrapped with a waterproof rubber membrane so that the model and the porous plate are positioned in the same closed cavity, and the waterproof rubber membrane is only provided with a pore water inlet and a pore water outlet so that pore water forms a seepage field in the model.

Due to the adoption of the technical measures, the invention has the beneficial effects that:

the test device can simulate the self-weight stress field gradient and the confining pressure gradient through the hypergravity centrifuge, and simultaneously simulate confining pressure, axial pressure and pore water flow through the pressure seepage control unit, so that the stress field and the seepage field of the model can be ensured to be in-situ stress field and seepage field, and the similarity, reliability and accuracy of the simulation test are improved.

The number of the pressure seepage control units in the test device is four, and the four pressure seepage control units are respectively an axial pressure control unit, a confining pressure control unit, a pore water inlet control unit and a pore water outlet control unit; each unit comprises a pressure seepage controller and a pressure seepage regulator, and can receive the pressure fed back by the main control unit so as to regulate the output pressure of the pressure seepage controller, and can output the pressure with the precision of 1% or form the pore water pressure difference with the precision of 1% to the three-shaft pressure chamber through the instruction of the control unit.

Drawings

FIG. 1 is a force analysis diagram of a rock prototype in deep ground engineering.

FIG. 2 is a graph of the force analysis of the model in a simulation under normal gravity;

FIG. 3 is an overall schematic view of a first embodiment of the present invention;

FIG. 4 is a control schematic diagram of a first embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a triaxial cell according to a first embodiment of the present invention;

in the figure: 1-a hypergravity centrifuge; 2-a three-axis pressure chamber; 2011-upper ram; 2012-lower ram; 2013-pressing the channel axially; 2021-confining pressure channel; 2031-pore water inlet channel; 2032-pore water outlet channel; 204-top perforated plate; 205-bottom perforated plate; 206-a signal acquisition device; 2061-signal acquisition channel; 5-a main control unit; 601-axial pressure control unit; 6011-axial pressure controller; 6012-an axial pressure regulator; 602-confining pressure control unit; 6021-confining pressure controller; 6022-surrounding pressure regulator; 603-a pore water inlet control unit; 6031-pore water inlet controller; 6032-pore water inlet regulator; 604-pore water outlet control unit; 6041-pore water outlet controller; 6042-pore water outlet regulator; 7-a data feedback unit; 8-a source sink unit; 9-pipeline; 10-model.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. The following examples are intended to illustrate the invention only and are not intended to limit the scope of the invention. Further, it should be understood that various changes or modifications of the present invention may be made by those skilled in the art after reading the teaching of the present invention, and such equivalents may fall within the scope of the present invention as defined in the appended claims.

The necessity and the advantage of the system will be described below by taking the deep processing library as an example.

In the present invention, a deep disposal depot (deep pharmaceutical disposol) means a device for storing high level waste in the ground at a distance of 500 to 1000m from the ground surface. The high radioactive waste is high level radioactive waste (HLW), which means radioactive waste with high content or concentration of radioactive nuclide, large heat release amount, and special shielding in operation and transportation.

The basic principle of deep disposal of high-level waste is that a nuclear waste disposal warehouse is built at hundreds of meters underground, and a multi-barrier system formed by engineering barriers and geological barriers ensures that the nuclear waste cannot cause harm to surface biospheres within tens of thousands or even millions of years. The high-emission waste is sealed in a metal disposal tank, the metal disposal tank is arranged in a disposal warehouse, and the space between the disposal tank and the surrounding rock is filled with a buffer material. The buffer material is generally made of high-compaction bentonite, and the buffer material can expand when meeting water, so that the buffer material can support surrounding rocks, and meanwhile, the bentonite has a good blocking effect on nuclides.

High level waste is buried in deep processing depots to be permanently isolated from the human living environment. The specific method for disposing the high level waste in the deep processing warehouse is as follows: the high level waste is processed into a glass-solidified body and sealed in a metal packaging container, referred to as a disposal can. A plurality of treatment tanks are contained in one treatment library. Before the disposal warehouse is built, a cave is dug in a deep rock body, a buffer barrier is filled in the cave, and the disposal warehouse is built in the buffer barrier. The reservoir surrounding rocks include hillocks, claystone, tuff, rock salt and the like, and the disposed wastes are high-level waste glass solidified bodies, spent fuel, alpha wastes and the like. Deep geological disposal of radioactive waste is a complex system engineering. The technology comprises site selection and site evaluation, underground laboratory construction and design, construction, operation and closed disposal libraries. Deep geological disposal is considered to be the most realistic and feasible method for safely disposing high level waste.

The glass solidified body, the metal packaging container, the buffer barrier, the surrounding rock and the like together form a near field of the deep processing warehouse. Water-force multi-field interactions that deeply address near-fields of the reservoir may last for centuries or even thousands of years. Water-force multi-field interaction refers to the coupling of the percolation process and the deformation process, since deformation changes the porosity ratio of the material, causing a change in the permeability coefficient; and seepage will change the saturation of the material, causing a change in the strength parameter. Disposal reservoirs are typically located in groundwater saturation zones. At the initial stage after the reservoir is closed, the interior of the reservoir is in an unsaturated state, groundwater gradually infiltrates to cause the reservoir to be saturated again, and the process is called re-saturation. The highly radioactive waste in the treatment tank continues to release heat due to decay reactions while the re-saturation process is in progress, and the build up of heat raises the temperature of the surface of the treatment tank. The interaction of multiple physical processes of heat conduction, groundwater seepage, vapor migration, buffer material expansion and surrounding rock deformation simultaneously occurs in the disposal reservoir. In the process, the engineering characteristics of the buffer material and the surrounding rock are changed due to the changes of stress, pore pressure, saturation and temperature, so that the re-saturation process is further influenced.

In the deep treatment project of the high-radioactivity waste, after the treatment warehouse is saturated again, the underground water gradually corrodes the metal treatment tank and finally enters the treatment tank to be contacted with the nuclear waste. At this time, the nuclides in the nuclear waste are dissolved in the groundwater and migrate outward and enter the surface biosphere through engineering and geological barriers. The time required for the process of re-saturation after closure of the treatment library is one of the questions that must be answered in the safety assessment of the treatment library, which takes about a hundred years. On one hand, the state after re-saturation directly affects the source strength and boundary conditions of nuclides when migrating in the near field and far field; on the other hand, the seepage, mechanics and solute migration characteristics of the near field of the treatment reservoir after the combined action of heat, water and force have an important influence on the safety evaluation of the treatment reservoir. Therefore, the research on the process of treating reservoir near-field one hundred year scale re-saturation is very important.