CN111680401B - A method and system for predicting service life of landfill engineering drainage system - Google Patents

Abstract

The invention discloses a method and system for predicting the service life of a landfill engineering drainage system, which includes: obtaining relevant parameters of the siltation material after the drainage system is blocked; dividing the drainage system into several drainage units, and calculating each drainage system respectively. The actual flow gradient and maximum flow distance of the leachate in the drainage unit; based on the relevant parameters of the blockage, the actual flow gradient and maximum flow distance data of the leachate in each drainage unit, the permeability coefficients at different locations at different times are calculated; based on the permeability coefficient , calculate the maximum leachate water level above the anti-seepage system in the landfill; based on the maximum leachate water level, predict the service life of the landfill project drainage system. The invention has the advantages of large prediction advance, high spatial distribution prediction accuracy, no need for monitoring wells and no reliance on monitoring well layout.

Description

A method and system for predicting service life of landfill engineering drainage system

Technical field

The invention relates to the technical field of life prediction of drainage systems, and in particular to a method and system for predicting the service life of drainage systems in landfill projects.

Background technique

The statements in this section merely provide background technical information related to the present invention and do not necessarily constitute prior art.

The drainage system is an important functional unit to ensure the long-term environmental safety of hazardous waste landfills. A fully functional drainage system can ensure that leachate is quickly drained away, thereby ensuring the stability of the landfill and controlling leachate leakage. On the contrary, the failure of the drainage system due to blockage will cause the leachate level in the landfill to be too high, which will increase the temperature of the anti-seepage membrane, shorten the life of the anti-seepage membrane, increase the risk of leakage, and even reduce the stability of the landfill. causing safety accidents. Therefore, it is of great significance to predict the service life of the landfill drainage system and determine when it will fail.

In the existing technology, regarding the service life of the drainage system, the main method is to install landfill leachate monitoring wells and observe the changes in leachate water level to judge or predict the life expiration. This method can only predict based on water level trends after running for a long time. The prediction is poor in advance, and since leachate hydrology is different at different locations in the landfill, the accuracy of the prediction depends on the location and number of monitoring wells, and the prediction results are less accurate.

Contents of the invention

In view of this, the present invention proposes a method and system for predicting the service life of the landfill engineering drainage system. It adopts a simulation experiment-model combination method to obtain the characteristics of the blocking material through experiments. According to the parameters obtained through the experiment and the actual conditions of the drainage system, Process parameters (slope of drainage pipes, spacing of drainage branch pipes, etc.), meteorological characteristics), etc. are used to predict the drainage performance at different locations of the drainage system.

According to the first aspect of the embodiment of the present invention, a method for predicting the service life of a landfill engineering drainage system is provided, including:

Obtain the relevant parameters of the siltation material after the drainage system is silted up;

Divide the drainage system into several drainage units, and calculate the actual flow slope and maximum flow distance of the leachate in each drainage unit;

Based on the relevant parameters of the siltation material, the actual flow slope and maximum flow distance of the leachate in each drainage unit, the permeability coefficients at different locations at different times are calculated;

Based on the permeability coefficient, calculate the maximum leachate level above the anti-seepage system in the landfill;

Based on the maximum leachate level, the service life of the landfill project drainage system is predicted.

According to the second aspect of the embodiment of the present invention, a landfill engineering drainage system service life prediction system is provided, including:

A device used to obtain relevant parameters of the siltation material after siltation in the drainage system;

A device used to divide the drainage system into several drainage units and calculate the actual flow slope parameters and maximum flow distance parameters of the leachate in each drainage unit;

A device used to predict the permeability coefficient at different times and locations based on the parameter data obtained above;

means for calculating the maximum leachate level above the anti-seepage system in the landfill based on said permeability coefficient;

A device used to predict the service life of the landfill project drainage system based on the maximum leachate level.

According to a third aspect of the embodiment of the present invention, a terminal device is provided, which includes a processor and a computer-readable storage medium. The processor is used to implement each instruction; the computer-readable storage medium is used to store a plurality of instructions. The instructions are suitable for the processor to load and execute the above-mentioned service life prediction method of the landfill engineering drainage system.

According to a fourth aspect of the embodiment of the present invention, a computer-readable storage medium is provided, in which a plurality of instructions are stored, and the instructions are suitable for loading and executing the above-mentioned landfill engineering guidance system by a processor of a terminal device. Service life prediction method.

Compared with the prior art, the beneficial effects of the present invention are:

(1) This invention proposes for the first time a method for predicting the service life of the landfill engineering drainage system, which can effectively predict when the landfill drainage system will expire and fail, and then engineering measures can be taken in advance to extend the life of the drainage system, or Before its failure leads to accidental consequences, the landfill should be closed to avoid excessive leachate levels due to failure of the drainage system, which may lead to landfill landslides, serious leakage of leachate and other environmental and safety accidents.

(2) The present invention adopts a simulation experiment-model combination method to obtain the characteristics of the blocking material through experiments, and based on the parameters obtained through the experiment, the actual process parameters of the drainage system (slope of the drainage pipe, spacing of drainage branch pipes, etc.), meteorological characteristics) etc. to predict the drainage performance at different locations of the drainage system. And select the fastest deteriorating part of the drainage system as the life prediction object for life prediction. It has the advantages of large prediction advance, high spatial distribution prediction accuracy, no need for monitoring wells and no reliance on monitoring well layout.

Additional advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Description of the drawings

Figure 1 is a flow chart of a method for predicting the service life of a landfill engineering drainage system according to an embodiment of the present invention;

Figure 2 is a schematic diagram of a blocking experimental device according to an embodiment of the present invention;

Figure 3 is a schematic diagram of the slopes in different areas;

Figure 4 is a schematic diagram for calculating the slope of a landfill site according to an embodiment of the present invention;

Figures 5(a)-(d) are simplified diagrams of the spatio-temporal evolution process of drainage medium blockage in a drainage system according to an embodiment of the present invention.

Detailed ways

It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the present application. Unless otherwise defined, all technical and scientific terms used herein have the same meanings commonly understood by one of ordinary skill in the art to which this application belongs.

It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, the singular forms are intended to include the plural forms as well, unless the context clearly indicates otherwise. Furthermore, it will be understood that the terms "including" and "having" and any variations thereof are intended to cover non-exclusive A process, method, system, product or apparatus that includes, for example, a series of steps or units need not be limited to those steps or units that are expressly listed, but may include steps or units that are not expressly listed or that are not expressly listed. Other steps or units inherent to the product or equipment.

The embodiments and features of the embodiments of the present invention may be combined with each other without conflict.

Embodiment 1

According to an embodiment of the present invention, an embodiment of a method for predicting the service life of a landfill engineering drainage system is provided. Figure 1 is a flow chart of a method for predicting the service life of a landfill engineering drainage system according to an embodiment of the invention, as shown in As shown in Figure 1, the method includes the following steps:

Step S101: Obtain the relevant parameters of the blockage after the drainage system is blocked;

Specifically, in the above steps, through the drainage system performance simulation experiment, the blockage is confirmed and the characteristic parameters of the blockage are obtained. In this embodiment, the performance simulation experiment of the drainage system is shown in Figure 2, which is a cylinder made of organic glass. At the bottom of the column, 30cm thick pebbles with an average particle size of about 20mm are laid to simulate the drainage medium. On top of the drainage medium, 30cm thick pebbles with an average particle size of 6mm are laid (or geotextile is laid, or not, depending on the experimental needs) as a back filter. layer. In the drainage system performance simulation experiment, in order to avoid the existence of preferential flow, the diameter of the experimental device must be at least 6 times or more than the particle size. The diameter of this device is 25cm and the height is 100cm to meet the requirements of the particle size/device size ratio.

Among them, 1. test bench, 2. water supply tank, 3. water inlet, 4. flow buffer zone, 5. pressure gauge, 6. outlet hole, used to measure segmented drainage, 7. water outlet, 8. return flow Slot, 9. Air pressure sensor, 10. Electromagnetic induction automatic ventilation valve.

The test bench provides a place for the water supply tank; the water supply tank is used to store leachate; the water inlet is the leachate flow inlet; the function of the flow buffer zone is to allow the siltation carried by the leachate to settle naturally to avoid blocking the water outlet; the pressure gauge It is used to measure the water pressure corresponding to the outflow hole; the outflow hole is used to measure the water pressure and drainage porosity; the water outlet is the leachate outlet; the return tank is used to collect the outflow leachate and measure the composition changes; the air pressure sensor is used Observe whether there is gas produced in the device; the electromagnetic induction automatic ventilation valve is used to ensure stable air pressure in the device.

Select the leachate corresponding to the landfill site or the synthetic leachate prepared according to the composition analysis as the sample required for the simulation test. Use a peristaltic pump to inject the leachate with a flow rate of 1.5L/d (converted to rainfall of approximately 400mm/year. The The hydraulic retention time of the leachate in the device is about 7 days under the flow rate conditions), and the water flow direction is from top to bottom; the water outlet is connected to the overflow pipe (the height of the overflow opening is equal to or slightly greater than the surface height of the reverse filter layer) to form a saturated The seepage conditions simulate the saturated conditions of the actual site; the overflow pipe outlet is connected to a U-shaped pipe, and the U-shaped pipe is filled with water to prevent the gas generated in the experiment from overflowing. The experiment was conducted under constant temperature conditions, and the temperature was set to 27 to 28 degrees.

As shown in Figure 2, there are three-way valves at different heights on the right side of the experimental device. One end of the three-way is connected to the pressure sensor and the other end is connected to the outflow pipe. By reading the pressure difference at different height sections with a pressure gauge, and combining it with the water outlet flow rate, the vertical saturated permeability coefficient at different height positions can be calculated; when water injection is stopped, the outlet pipe is opened in sections and the flow rate of each height section is measured. The water output, combined with its initial volume, can be used to calculate the drainage porosity at different heights.

Regularly measure and analyze the drainage volume and hydraulic head at different locations, and calculate the drainage porosity and permeability coefficient at different locations and at different times according to formula (1-1) and formula (1-2);

In the formula: DPV (t) is the drainage porosity at time t, dimensionless; V _d (t) is the drainage volume between any two outflow holes at time t, L; V _T is the drainage volume between any two outflow holes at time t The small column volume, L

In the formula: k(t) is the permeability coefficient at time t, cm/s; Q(t) is the flow rate of the water outlet at time t, L/d; h is the height difference between any two pressure measuring ports, m; ΔH (t) is the head pressure difference between any two pressure gauges, m; 86.4 is the unit conversion factor from (L/d) to (cm ³ /s).

Determining whether blockage occurs in the device through DPV(t) and k(t) is not applicable to the leachate level calculation in Section 4. After confirming the blockage, collect the blockage produced in the device for composition analysis to obtain relevant Parameters: ρ _c is the dry density of the blocked material, mg/L; f _ca is the calcium content in the total blocked material.

Step S102: Divide the drainage system into several drainage units, and calculate the actual flow slope parameters and maximum flow distance parameters of the leachate in each drainage unit.

Normally, a relatively independent drainage unit is composed of two drainage branch pipes and a drainage main pipe. When the slope of the landfill bottom is uniformly distributed in space and the properties of the bottom of the landfill are regular, each unit can be regarded as approximately similar, and its maximum leachate head is also similar. However, under the project conditions of this embodiment, the slopes of different areas are shown in Figure 3. In different areas of the landfill, there are different differences in the slope of the reservoir bottom, the slope of the drainage pipe, the length of the drainage path, etc. Therefore, according to the drainage branch pipe It is separated from the main drainage pipe and divided into several drainage units. The maximum water level calculation is performed on each unit to determine whether different drainage units can achieve effective drainage and meet the requirement that the maximum leachate water level is less than 30cm.

Specifically, as shown in Figure 4, leachate always flows along the maximum slope point. Obviously, the slope of the drainage branch pipe and the slope of the drainage main pipe are not the maximum slope. That is to say, the flow distance of leachate is not equal to the distance between the drainage branch pipes. In fact, the maximum flow distance of the leachate at this time is greater than the distance between the drainage branch pipes. At this time, the actual flow slope and maximum flow distance L of the leachate can be derived as follows:

It is assumed that the slope of the main drainage pipe perpendicular to the leachate drainage branch pipe is S1, and the slope of the drainage branch pipe is S2.

S1＝a/b, S2＝c/x, m＝a+c＝S ₁ ×b+S ₂ ×x, n＝(b ² +x ² ) ^0.5 (1-3)

The slope of S(x) changes as x changes, and can be expressed as:

Taking the derivative of the above formula, we can get:

Obviously, the slope is reaches the maximum value when

Since b ² +x ² ≠0, we have:

S ₂ ×b ² -S ₁ ×b×x＝0 (1-7)

Right now:

Therefore, when the slope S is maximum,

therefore,

In the formula: S is the maximum slope of the bottom of the drainage unit (that is, the actual leachate flow slope); S ₁ is the slope of the main drainage pipe; S ₂ is the slope of the secondary drainage pipe.

The maximum leachate flow distance from the upstream boundary (the drainage branch pipe in the upslope direction) to the downstream boundary (the drainage branch pipe in the downslope direction) is:

In the formula: L is the maximum flow distance; b is the distance between the branch pipes, m; the angle between L and b is θ, then: θ = cos ^-1 (b/L).

Step S103: Calculate the permeability coefficients at different locations at different times based on the relevant parameters of the siltation, the actual flow slope and maximum flow distance of the leachate in each drainage unit;

Specifically, referring to Figure 5(a)-(d), in order to clarify the degree of blockage and permeability coefficient at different times, the following assumptions are first made:

(1) Siltation and blockage develop the fastest the closer to the leachate drainage pipe, and will no longer change after the blockage reaches a certain level. The drainage pipe first reaches the "complete blockage" state, and then the "complete blockage" range spreads to the side away from the drainage pipe;

(2) Before reaching “complete siltation”, the porosity and thickness of siltation change linearly with distance;

(3) Assume that the clogging rate n _c and the thickness of the clogging in the drainage layer at the nearest point of the drainage pipe increase from 0, and both reach "complete clogging" at time T ₁ , that is, when t = T ₁ , B′ _L =B;

(4) Assume that the drainage medium within the distance a from the drainage pipe is completely blocked at time T _2. At this time, both v _f and B′ in this range reach their maximum values. and B.

When 0<t≤T ₁ ,

When T ₁ <t ≤ T ₂ ,

in:

In the formula: x is the horizontal distance from the drainage pipe, m; t is time, a; L is the maximum flow distance, m; c is the calcium ion concentration in the leachate, mg/L; q ₀ is the infiltration rate of the pile , m/a; v _f ^* is the maximum porosity of the siltation, dimensionless; B is the thickness of the drainage layer, m; ρ _c is the dry density of the siltation material, mg/L; f _ca is the calcium in the total siltation material The content of elements, dimensionless; b _k is the fitting coefficient of the relationship model between the permeability coefficient and porosity of the drainage medium, which is often taken as 38.2; a(t) is the length at which the siltation reaches the most severe degree, with the drainage pipe is 0, m; T ₁ is the time when the blockage at the drainage pipe reaches the most serious degree, a; T ₂ is the time when the blockage in the entire drainage layer reaches the most serious degree, that is, the time required for complete blockage, a.

Step S104: Based on the permeability coefficient, calculate the maximum leachate level above the anti-seepage system in the landfill;

Specifically, the method for estimating the maximum leachate level above the anti-seepage system in a landfill can be achieved using the following formula:

Among them: y _max is the maximum leachate water level above the anti-seepage system in the landfill, m; L is the maximum flow distance, m; r is the net recharge amount of water in the landfill per unit time (net recharge intensity), cm/ d; S is the slope of the landfill bottom, dimensionless; k is the saturated permeability coefficient of the medium, cm/s.

As an optional implementation, the method of estimating the maximum leachate level above the anti-seepage system in the landfill can also be implemented using the following formula:

The main calculation parameters involved in this formula are the same as formula (1-17), which are L, r, k and α, but this formula is simpler, α is the slope of the guide layer.

As another optional implementation, the method of estimating the maximum leachate level above the anti-seepage system in the landfill can also be implemented using the following formula:

In the formula: λ=r/(k×tan ² α), called the characteristic parameter, which characterizes the leachate supply and drainage characteristics.

As another optional implementation, the extended DuPult assumption considers that streamlines are parallel to the pad and equipotential lines are perpendicular to the pad. Therefore, the governing equation for the distribution of leachate head above the anti-seepage system was established based on the extended form of DuPuit's assumption, and the formula for estimating the maximum leachate water level above the anti-seepage system in the landfill was derived as follows:

If R<0.25, y _max is calculated according to the following formula:

If R=0.25, y _max is calculated according to the following formula:

If R>0.25, y _max is calculated according to the following formula:

Among them: R=r/(k×sinα); A=(1-4R) ^1/2 ; B=(4R-1) ^1/2 ; k is the saturated permeability coefficient of the medium; L is the distance from the upstream boundary to the downstream boundary The maximum leachate flow distance; S is the maximum slope of the bottom of the drainage unit (that is, the actual leachate flow slope).

Step S105: Based on the maximum leachate level, predict the service life of the landfill project drainage system.

Specifically, a linear correlation between the maximum leachate level and the life of the landfill drainage system is established;

Based on the linear correlation, the service life of the landfill drainage system corresponding to the maximum leachate level is obtained.

In order to accurately design the leachate drainage system in the landfill liner during landfill design, the maximum leachate head that may occur on the landfill liner must be estimated. The United States and many foreign countries require the maximum leachate head to be within 30cm. my country's "Pollution Control Standards for Hazardous Waste Landfills" and "Pollution Control Standards for Domestic Waste Landfills" also stipulate that the operation and closure of landfills must ensure that the depth of leachate on the anti-seepage liner is not greater than 30cm.

When the leachate level (y _max ) in the landfill exceeds 30cm, it is determined that the life of the drainage system has expired, and the service life of the drainage system is the time between the start of operation of the landfill.

Embodiment 2

According to an embodiment of the present invention, an embodiment of a service life prediction system for a landfill engineering drainage system is also provided. The system includes:

A device used to obtain relevant parameters of the siltation material after siltation in the drainage system;

A device used to divide the drainage system into several drainage units and calculate the actual flow slope parameters and maximum flow distance parameters of the leachate in each drainage unit;

A device used to predict the permeability coefficient at different times and locations based on the parameter data obtained above;

means for calculating the maximum leachate level above the anti-seepage system in the landfill based on said permeability coefficient;

A device used to predict the service life of the landfill project drainage system based on the maximum leachate level.

It should be noted here that each of the above devices corresponds to steps S101 to S105 in Embodiment 1. The examples and application scenarios implemented by the above modules and corresponding steps are the same, but are not limited to the contents disclosed in Embodiment 1 above. It should be noted that the above-mentioned modules, as part of the system, can be executed in a computer system such as a set of computer-executable instructions.

Embodiment 3

In one or more embodiments, a terminal device is disclosed, including a server. The server includes a memory, a processor, and a computer program stored in the memory and executable on the processor. The processor executes the The program implements the service life prediction method of the landfill engineering drainage system in Embodiment 1. For the sake of brevity, no further details will be given here.

It should be understood that in this embodiment, the processor may be a central processing unit (CPU). The processor may also be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASICs), off-the-shelf programmable gate arrays (FPGAs), or other programmable logic devices. , discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or the processor may be any conventional processor, etc.

The memory may include read-only memory and random access memory and provide instructions and data to the processor. A portion of the memory may also include non-volatile random access memory. For example, the memory may also store device type information.

During the implementation process, each step of the above method can be completed by instructions in the form of hardware integrated logic circuits or software in the processor.

The method for predicting the service life of the landfill engineering drainage system in Embodiment 1 can be directly implemented by a hardware processor, or implemented by a combination of hardware and software modules in the processor. The software module may be located in a storage medium that is mature in the field, such as random access memory, flash memory, read-only memory, programmable read-only memory, or electrically erasable programmable memory, registers, or the like. The storage medium is located in the memory, and the processor reads the information in the memory and completes the steps of the above method in combination with its hardware. To avoid repetition, it will not be described in detail here.

Those of ordinary skill in the art can appreciate that the units, that is, the algorithm steps of each example described in conjunction with this embodiment, can be implemented with electronic hardware or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Skilled artisans may implement the described functionality using different methods for each specific application, but such implementations should not be considered beyond the scope of this application.

Although the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, they do not limit the scope of the present invention. Those skilled in the art should understand that based on the technical solutions of the present invention, those skilled in the art do not need to perform creative work. Various modifications or variations that can be made are still within the protection scope of the present invention.

Claims (8)

1. A method for predicting the service life of the landfill engineering drainage system, which is characterized by including: Obtain the relevant parameters of the siltation material after the drainage system is silted up; Divide the drainage system into several drainage units, and calculate the actual flow slope and maximum flow distance of the leachate in each drainage unit; Based on the relevant parameters of the siltation material, the actual flow slope and maximum flow distance of the leachate in each drainage unit, the permeability coefficients at different locations at different times are calculated; Based on the permeability coefficient, calculate the maximum leachate level above the anti-seepage system in the landfill; Based on the maximum leachate level, calculate the service life of the landfill project drainage system; Through the performance simulation experiment of the drainage system, the relevant parameters of the siltation material after the drainage system is blocked are obtained. The specific process includes: Build a drainage system performance simulation experimental system to simulate the saturated conditions of the actual site; After confirming that blockage has occurred in the drainage system, conduct a component analysis of the blockage to obtain the dry density parameters of the blockage material and the calcium content parameters in the total blockage; Based on the relevant parameters of the siltation material, the actual flow slope and maximum flow distance of the leachate in each drainage unit, the permeability coefficients at different locations at different times are predicted; specifically including: When 0<t<T ₁ , When T ₁ <t ≤ T ₂ , Among them, T ₁ is the time when the blockage at the drainage pipe reaches the most serious degree; T ₂ is the time when the blockage of the entire drainage layer reaches the most serious degree, that is, the time required for complete blockage; x is the level from the drainage pipe Distance, t is time, L is horizontal drainage distance, that is, the maximum flow distance; a(t) is the length at which siltation reaches the most severe degree, with the drainage pipe being 0; c is the calcium ion concentration in the leachate; q ₀ is the infiltration rate of the pile; v _f * is the maximum porosity of the siltation; B is the thickness of the drainage layer; ρ _c is the dry density of the siltation material; f _ca is the total siltation The content of calcium in the blockage; b _k is the fitting coefficient of the relationship model between the drainage medium permeability coefficient and porosity; s is the actual leachate flow slope, k ₀ is the initial permeability coefficient of the drainage layer, that is, in the standard Required design penetration coefficient. 2. A method for predicting the service life of a landfill engineering drainage system as claimed in claim 1, characterized in that the process of confirming that blockage occurs in the drainage system includes: According to the built drainage system performance simulation experimental system, the drainage volume and hydraulic head at different locations are regularly measured and analyzed, and the drainage porosity and permeability coefficient at different locations and at different times are calculated; Determine whether the drainage system is blocked by drainage porosity and permeability coefficient. 3. A method for predicting the service life of a landfill engineering drainage system as claimed in claim 1, characterized in that the actual flow slope of the leachate in each drainage unit is the maximum slope of the bottom of the drainage unit. According to the slope of the drainage main pipe and The slope of the drainage branch pipe is determined. 4. A method for predicting the service life of a landfill engineering drainage system as claimed in claim 1, characterized in that the maximum flow distance of leachate in each drainage unit is based on the distance between the drainage branch pipes, the slope of the drainage main pipe and the drainage distance. The slope of the branch pipe is determined. 5. A method for predicting the service life of the landfill engineering drainage system as claimed in claim 1, characterized in that, based on the maximum leachate water level, predicting the service life of the landfill engineering drainage system specifically includes: Establish a linear correlation between the maximum leachate level and the life of the landfill drainage system; Based on the linear correlation, the service life of the landfill drainage system corresponding to the maximum leachate level is obtained. 6. A service life prediction system for landfill engineering drainage system, which is characterized by including: A device used to obtain relevant parameters of the siltation material after siltation in the drainage system; A device used to divide the drainage system into several drainage units and calculate the actual flow slope and maximum flow distance of the leachate in each drainage unit; A device used to predict the permeability coefficient at different locations at different times based on the actual flow gradient and maximum flow distance of the leachate in each drainage unit obtained above; means for calculating the maximum leachate level above the anti-seepage system in the landfill based on said permeability coefficient; A device for predicting the service life of the landfill project drainage system based on the maximum leachate level; Through the performance simulation experiment of the drainage system, the relevant parameters of the siltation material after the drainage system is blocked are obtained. The specific process includes: Build a drainage system performance simulation experimental system to simulate the saturated conditions of the actual site; After confirming that blockage has occurred in the drainage system, conduct a component analysis of the blockage to obtain the dry density parameters of the blockage material and the calcium content parameters in the total blockage; Based on the relevant parameters of the siltation material, the actual flow slope and maximum flow distance of the leachate in each drainage unit, the permeability coefficients at different locations at different times are predicted; specifically including: When 0<t<T ₁ , When T ₁ <t ≤ T ₂ , Among them, T ₁ is the time when the blockage at the drainage pipe reaches the most serious degree; T ₂ is the time when the blockage of the entire drainage layer reaches the most serious degree, that is, the time required for complete blockage; x is the level from the drainage pipe Distance, t is time, L is horizontal drainage distance, that is, the maximum flow distance; a(t) is the length at which siltation reaches the most severe degree, with the drainage pipe being 0; c is the calcium ion concentration in the leachate; q ₀ is the infiltration rate of the pile; v _f * is the maximum porosity of the siltation; B is the thickness of the drainage layer; ρ _c is the dry density of the siltation material; f _ca is the total siltation The content of calcium in the blockage; b _k is the fitting coefficient of the relationship model between the drainage medium permeability coefficient and porosity; s is the actual leachate flow slope, k ₀ is the initial permeability coefficient of the drainage layer, that is, in the standard Required design penetration coefficient. 7. A terminal device, which includes a processor and a computer-readable storage medium. The processor is used to implement each instruction; the computer-readable storage medium is used to store a plurality of instructions, characterized in that the instructions are suitable for loading by the processor. And implement the service life prediction method of the landfill engineering drainage system described in any one of claims 1-5. 8. A computer-readable storage medium in which a plurality of instructions are stored, characterized in that the instructions are adapted to be loaded and executed by a processor of a terminal device according to any one of claims 1-5. Service life prediction method of engineering drainage system.