Rainfall type slope siphon pre-discharge quantity configuration method

Abstract

The application discloses a rainfall type slope siphon pre-discharge fixed-amount configuration method, which comprises the following steps: obtaining three types of core data; a background calculation module determines the infiltration recharge parameter, the water storage parameter, the lag response parameter, the safety reserve parameter and the single siphon pipe design effective flow according to the three types of core data, calculates the design rainfall, the effective infiltration amount, the predicted groundwater level rising amount, the allowed highest groundwater level, the pre-depression, the pre-discharge amount, the siphon pipe number and the latest starting time; and outputs the four core results of the pre-depression, the pre-discharge amount, the siphon pipe number and the latest starting time, and generates a construction instruction, which is used for controlling the siphon drainage execution unit to start the corresponding number of siphon branches before the latest starting time and to control the groundwater level to be lowered below the target water level. The method directly converts the rainfall early warning into the pre-depression, the pre-discharge amount, the siphon pipe number and the latest starting time, and forms the drainage control instruction which can be directly constructed.

Description

Technical Field

[0001] This invention belongs to the field of slope groundwater control and rainfall-induced landslide prevention technology, specifically involving a quantitative configuration method for pre-drainage siphon in rainfall-induced slopes. Background Technology

[0002] Rainfall is a significant external factor inducing instability in soil slopes, landslides of accumulated layers, residual soil slopes, strongly weathered and fractured rock and soil slopes, and reservoir bank slopes. After entering the slope, rainfall reduces the matric suction in unsaturated areas and replenishes aquifers near the slip zone or potential sliding surface, causing groundwater levels to rise, pore water pressure to increase, and effective stress to decrease, ultimately leading to a reduction in shear strength and safety factor. For slopes with low-permeability slip zones, thick overburden layers, interconnected fissures, or trailing water catchment areas, the most dangerous moment is often not the peak rainfall time, but rather the lag peak groundwater level that occurs several hours to several days after the rainfall ends.

[0003] Existing rainfall-based landslide early warning systems primarily rely on rainfall thresholds, displacement thresholds, pore pressure thresholds, groundwater level thresholds, or a combination of multiple indicators to determine the severity of the landslide. While they can output warning levels such as blue, yellow, orange, and red, they typically cannot provide further, on-site drainage solutions that can be directly implemented. The warning level answers the question of "how high the level of danger," but what's truly needed on-site is answering questions like "how many meters the groundwater level needs to be lowered in advance, how much water needs to be drained, how many siphon pipes need to be activated, and when the latest activation time should be." Therefore, a quantitative transmission gap exists between early warning and drainage execution.

[0004] Existing siphon drainage technologies can solve problems such as long-term removal of deep groundwater, pressure relief from inclined boreholes, siphon activation, non-powered drainage maintenance, and pipeline flow monitoring. For example, existing methods for self-balancing siphon drainage using inclined boreholes on slopes have been disclosed, achieving the drainage of deep groundwater on slopes through inclined boreholes and siphon pipes; existing methods for activating slope siphon drainage systems have been disclosed, activating the siphon system through structures such as water tanks and drainage pipes. The focus of these technologies is on the siphon pipeline structure, siphon activation reliability, and long-term drainage capacity, but they do not calculate the groundwater level depth that should be lowered in advance before heavy rainfall based on future rainfall forecasts, nor do they further convert the forecast rainfall into pre-drainage volume, the number of siphon pipes, and the latest activation time.

[0005] Traditionally, stability calculations and drainage configurations are often performed by different disciplines. Stability calculations provide safety factors or allowable water levels, drainage designs provide pipe diameters, orifice spacing, or flow capacity, and on-site early warning systems provide rainfall levels. The lack of a closed-loop quantitative chain between these components, from rainfall forecasting to construction actions, leads to two common problems in engineering projects: first, warnings are issued but drainage is delayed, and the groundwater level does not have enough time to drop; second, drainage systems are blindly fully activated or over-configured, resulting in resource waste and management chaos.

[0006] Therefore, there is an urgent need for an engineering method that can connect forecasted rainfall, groundwater response, maximum allowable groundwater level on slopes, pre-drawdown depth, pre-drainage volume, number of siphon pipes, and latest start time. This method must be supported by sound theoretical principles and be verifiable by design units; it must also include simplified on-site formulas, quick reference tables for parameters, unreachability assessment mechanisms, and manual emergency modes, enabling ordinary on-site engineers to quickly formulate executable instructions before heavy rainfall arrives. Summary of the Invention

[0007] This invention provides a quantitative configuration method for pre-drainage siphoning of rainfall-induced slopes to solve the aforementioned technical problems, specifically employing the following technical solution: A quantitative configuration method for pre-drainage siphoning of rainfall-prone slopes includes the following steps: S1: Acquire three types of core data, including the basic parameters of the target slope, the current controlled groundwater level H0, and the forecasted rainfall information within the future preset time window; S2: The background calculation module determines the infiltration recharge parameters, water storage parameters, hysteresis response parameters, safety reserve parameters, and the design effective flow rate of a single siphon pipe based on the three types of core data, and calculates the design rainfall, effective infiltration volume, and expected groundwater level rise ΔH. R Permissible maximum groundwater level H allow Pre-drainage depth (m), pre-drainage volume (V), number of siphon pipes (N), and latest start time (t) start ; S3: Output the pre-drainage depth m, pre-drainage volume V, number of siphon pipes N, and latest start time t. start Four core results are generated, and a construction instruction is produced to control the siphon drainage actuator at the latest start time t. start The corresponding number of siphon branches will be activated to lower the groundwater level below the target level.

[0008] Furthermore, the basic parameters of the target slope include slope type, engineering grade, geological type, and controlled area A. c Permissible maximum groundwater level H allow Target safety factor F T At least one of the following: service range of the drainage hole or safe water level level; The forecast rainfall information includes the forecast cumulative rainfall R, rainfall intensity sequence I(t), and peak rainfall intensity I for the next 6h, 12h, 24h, 48h, or 72h. peak Rainfall duration T rain and forecast lead time T lead ; The background calculation module calculates the design rainfall R according to the following formula. design : R design=K r R Among them, K r The forecast amplification factor is K. r It is determined by the uncertainty of the forecast, the level of engineering work, and the level of rainfall.

[0009] Furthermore, the estimated rise in groundwater level Calculate using the following simplified engineering formula:

[0010] Among them, C H The groundwater level rise coefficient is determined for every 100mm of design rainfall.

[0011] Furthermore, the background calculation module calculates the effective infiltration amount according to the following formula: r e (t)=η(t)I(t)

[0012] Where r e (t) represents the effective infiltration intensity, η(t) represents the infiltration recharge coefficient, I(t) represents the rainfall intensity, and R... e (t k ) is up to t k The cumulative effective infiltration rainfall at any given time.

[0013] Furthermore, when the background calculation module calculates the expected time-series rise in groundwater level, it calculates according to the response function model:

[0014] Where, ΔH R,j (t k ) represents the j-th control partition in t k The rise in groundwater level at time ρ j S is the correction factor for the supply area and control area. j G is the specific yield or equivalent storage coefficient. j This is the groundwater hysteresis response function; The groundwater hysteresis response function is determined according to the following piecewise function: G j (s)=0, s<τ j

[0015] Where s is the elapsed time after the infiltration pulse occurs, and τ j T is the lag time from rainfall infiltration to the response of the groundwater level. g,j is the groundwater response time constant.

[0016] Furthermore, the maximum permissible groundwater level H allow The value is determined by back-calculation of the target safety factor, the verified safety water level gauge, the monitoring and early warning threshold, or the value verified by the design unit; when using stability back-calculation, the background calculation module solves for F. s (H allow )=F T F s (H) is the slope safety factor function that varies with groundwater level, F T The target safety factor.

[0017] Furthermore, the pre-descent depth m is determined according to the following formula: m=max(H0+ΔH R -H allow +m s ,0) Where, m s For safety reserves, the depth is reduced; when H0 + ΔH R ≤H allow -m s At that time, pre-drainage is not initiated or only normal drainage is maintained; The pre-drainage volume Determine using the following formula: V=SA c m in, For water supply specificity, storage coefficient, or equivalent storage coefficient, A c To control the area; when the control area cannot be directly determined, it is determined by the service range of the drainage hole, the radius of influence of the pumping test, the area of ​​the zone, or the background numerical seepage model; The single siphon tube is designed to have an effective flow rate Q. design The theoretical flow rate Q of the pipeline is determined as follows: First, calculate the pipeline's theoretical flow rate Q based on the pipe diameter, pipe length, effective head difference, friction coefficient, and local resistance coefficient. pipe Then obtain the stable flow rate Q during on-site testing. test and soil recharge capacity to drainage holes Q bore And determine it according to the following formula: Q base =min(Q pipe Q test Q bore ) Q design =η q Q base Where, η qTo account for air resistance, blockage, incomplete pipe filling, joint leakage, and continuous operation fluctuations in the operating efficiency coefficient; when the flow rate value in the pipe diameter and flow rate quick reference table already includes the operating reduction factor, the flow rate value in the pipe diameter and flow rate quick reference table is used as Q. design The candidate values ​​are not multiplied by η again. q .

[0018] Furthermore, the number N of the siphon tubes is determined according to the following formula:

[0019] Among them, T avail The available pre-scheduling time is represented by ceil(·), which rounds up.

[0020] The latest start time Determine using the following formula:

[0021] Among them, t c T represents the moment when the groundwater level first reaches a dangerous level or the safety factor falls below the target value without drainage. op Allowance for water filling, air venting, inspection, and personnel on-site operations.

[0022] Furthermore, when the background calculation module performs time-series verification, it calculates the control groundwater level before, during, and after the rain according to the groundwater level-volume balance recursive formula, and verifies that the control groundwater level does not exceed the maximum allowable groundwater level or that the verification safety factor is not lower than the target safety factor.

[0023] Furthermore, when the maximum number N of available siphon tubes in the existing siphon system... max The corresponding maximum displacement V max =N max Q design T avail If the pre-drainage volume is less than the required pre-drainage volume V, the system outputs an unreachable warning and calculates the difference in drainage volume ΔV = VV. max Calculate the supplementary drainage capacity Q add ≥ΔV / T avail Choose at least one alternative from the following options: adding a siphon pipe, activating an emergency large-diameter branch pipe, adding drainage boreholes, extending the pre-drainage time, or using a temporary pump.

[0024] When the measured rainfall deviates from the predicted rainfall by more than 20%, the measured rate of groundwater level rise exceeds the predicted value, or the measured flow rate of a single siphon is lower than Q... design When 80% of the time has elapsed, the background calculation module recalculates m, V, N, and t. start And update the construction instructions.

[0025] When the system experiences a power outage, communication interruption, or automatic control failure, on-site engineers manually calculate m, V, N, and t using a parameter quick reference table. start And the corresponding number of siphon pipes are activated by manually opening and closing valves.

[0026] Furthermore, when the target slope is a large-scale rainfall-prone slope, the background calculation module divides it into multiple control zones based on catchment boundaries, slip zone depth, stratum lithology, groundwater level response lag, historical deformation zones, and drainage well service areas, and calculates m, V, N, and t for each zone respectively. start The drainage priority is output according to the pre-drainage depth, the rate of rise of groundwater level, the rate of increase of pore pressure, and the safety factor gap.

[0027] The advantages of this invention also lie in the quantitative configuration method for pre-drainage of siphons on rain-prone slopes, which transforms the rain warning from a risk level indication into a pre-drainage depth, pre-drainage volume, number of siphon pipes, and latest start time, forming a drainage control command that can be directly constructed, and realizing a complete quantitative conversion chain from weather forecast to siphon drainage execution unit control action.

[0028] The advantage of this invention also lies in the quantitative configuration method of pre-drainage for rainfall-type slope siphons, which transforms the groundwater level safety control from experience-based judgment to calculable and verifiable pre-drainage depth calculation, avoiding insufficient pre-drainage caused by starting drainage solely based on rainfall thresholds. Furthermore, the pre-drainage depth is further converted into pre-drainage volume and the number of siphon pipes, so that safety requirements are matched with drainage execution capabilities.

[0029] The advantages of this invention also lie in the quantitative configuration method for pre-drainage of rainfall-type slope siphons provided. Through parameter quick lookup tables, applicable conditions, error descriptions, and rolling calibration methods, a conservative initial plan can be formed even for slopes without historical monitoring data. This plan can be gradually corrected based on actual rainfall, water level, and flow rate. At the same time, by identifying whether the existing siphon system is sufficient to complete the pre-drainage task within the forecast lead time, the invention proactively provides solutions for adding pipes, emergency branch lines, or pump drainage.

[0030] The advantages of this invention also lie in the quantitative configuration method for pre-drainage of rainfall-type slope siphons. Through a hardware execution unit, the calculation results are implemented into the slope groundwater level control technology. In the event of system power failure, communication interruption, or automatic control failure, on-site engineers can still manually make emergency decisions through a parameter quick reference table. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the quantitative configuration method for pre-drainage of rainfall-type slope siphons in this application. Detailed Implementation

[0033] Embodiments of the present invention are described in detail below. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0034] In the description of this application, it should be noted that, unless otherwise specified and limited, the terms "installation", "connection" and "linkage" should be interpreted broadly, and can refer to mechanical or electrical connections, or internal connections between two components, or direct connections. "Up", "down", "left", "right", etc., are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may change.

[0035] The operating logic of this invention is as follows: First, determine how much future rainfall will raise the groundwater level; then, determine the maximum allowable rise of the groundwater level on the slope; next, calculate how much the groundwater level must be lowered in advance; finally, convert the pre-lowering depth into drainage volume, number of pipes, and start-up time. On-site engineers do not need to manually calculate integrals, exponential responses, stability iterations, or pipe flow losses; the system backend saves all intermediate calculation logs, while the frontend only displays the pre-lowering depth m, pre-drainage volume V, number of siphon pipes N, and latest start-up time t. start Construction instructions.

[0036] To ensure the verifiability of theoretical calculations, this invention divides the slope into one or more control zones. Each zone is assumed to have approximately consistent recharge conditions, specific yield, response lag time, drainage service area, and safe water level control requirements within the forecast time window. For small to medium-sized slopes, a representative control borehole or representative profile can be used; for large slopes, zones should be divided according to catchment boundaries, lithology, slip zone depth, historical deformation, pore pressure response, and drainage borehole service area.

[0037] Ω = {Ω1, Ω2, ..., Ω} n} In the above formula, Ω represents the set of target slope control zones. j This represents the j-th control zone. When n=1, it is a single profile or single control hole mode; when n>1, it is a large slope zoning mode.

[0038] Weather forecasts suffer from spatial resolution, peak rainfall periods, and short-term intensity errors. To avoid underestimating the effects of heavy rainfall, this invention amplifies the forecast cumulative rainfall to the designed rainfall amount.

[0039] R design =K r R In the formula, R represents the forecast cumulative rainfall, in mm; K r R is the forecast amplification factor. design To design rainfall. K r It is not an arbitrary safety factor, but a conservative correction factor determined by forecast uncertainty, engineering level, and rainfall level.

[0040] Let the actual cumulative rainfall be R. real The relative amount of forecast error is ε R Then there is R real =R(1+ε R ) If we take ε R The upper confidence quantile or engineering conservative value is ε. R,P Then it can be made K r =1+ε R For ordinary engineering projects, K can be taken as K. r =1.0 to 1.2, K can be taken as 1.0 for important projects or heavy rainstorm scenarios. r =1.0 to 1.5, and should be updated on a rolling basis with actual rainfall.

[0041] Forecasted rainfall cannot be directly equated with groundwater recharge. After rainfall reaches the slope, it undergoes processes such as vegetation interception, surface runoff, slope runoff, temporary storage in the unsaturated zone, and deep recharge. Only a portion of these processes constitutes an effective infiltration recharge for controlling the groundwater level.

[0042] Starting from the decomposition of rainfall intensity: I(t) = I int (t)+I run (t)+I stor (t)+r e (t) In the above formula, I(t) represents the rainfall intensity, I int (t) represents the retained loss term, I run (t) represents the surface runoff term, I stor (t) represents a shallow temporary storage item, r e (t) represents the effective infiltration intensity into the controlled groundwater system.

[0043] Combining the effects of the first three factors that are difficult to measure in real time into the infiltration recharge coefficient η(t), we get: r e (t)=η(t)I(t) The cumulative effective infiltration rainfall is:

[0044] η(t) can be determined by historical rainfall-groundwater level event inversion, double-ring infiltration test, artificial rainfall test, soil-water characteristic curve, infiltration test, or engineering experience table. For slopes with well-developed fissures, gravelly soils, or significant back-edge catchment, the upper limit should be taken or it should be calibrated in conjunction with the recharge area correction factor.

[0045] When a more detailed consideration of the relationship between rainfall intensity and infiltration capacity is required, an infiltration capacity function can be used in the background. This part is for background verification and is not necessarily calculated on the field front end.

[0046]

[0047] Among them, f c (t) represents the soil infiltration capacity, K s Let ψ be the saturated permeability coefficient. f Let Δθ be the wetting front suction head, Δθ be the difference between the saturated volumetric water content and the initial volumetric water content, F(t) be the cumulative infiltration depth, and χ be the saturated front suction head. d This represents the effective recharge ratio to the deep control aquifer. When data is insufficient, χ² can be used. d Incorporate into η processing.

[0048] Effective infiltration into the slope does not immediately raise the controlling groundwater level. The seepage path, fracture connectivity, the thickness of the aquifer above the slip zone, and its storage capacity all contribute to the time lag. This invention uses a response function to describe the process by which effective infiltration transforms into groundwater level rise.

[0049] For the j-th partition, a water balance is performed, and the infiltration recharge volume is approximately ρ. j A c,j R e,j Groundwater level rise ΔH R,j The corresponding water storage volume is approximately S j A c,j ΔH R,j From the water balance, the hysteresis-free limit form can be obtained: S j A c,j ΔH R,j =ρ j A c,j R e,j Approximately A on both sides c,j have to:

[0050] Considering time delays and recursion, the effective infiltration contribution of each historical time step is summed, and its value at time t is expressed by a response function. k The time has been converted into the proportion of water level rise:

[0051] The above formula is one of the core formulas for predicting groundwater level rise in the background of this invention.

[0052] The response function can be derived from a first-order reservoir model. It is assumed that a certain infiltration pulse will eventually cause a water level increment ΔH. ∞ The actual water level increment over time follows a first-order process:

[0053] Integrating the above equation with the initial condition ΔH(0)=0 and considering the lag time τ, we get:

[0054] In the above formula, τ is the lag time for effective infiltration to reach the controlling aquifer and cause an observable response in the groundwater level, and T is the time lag time. g This represents the groundwater response time constant. The lag time can be obtained through cross-correlation analysis of the rainfall sequence and the groundwater level rise rate sequence.

[0055] The above formula indicates that if the effective infiltration intensity sequence and the groundwater level rise rate sequence have the greatest correlation at a lag of 1 hour, then this lag of 1 hour is taken as τ.

[0056] A rise in groundwater level increases pore water pressure near the slip zone, reducing the effective normal stress and thus decreasing shear strength. The effective stress shear strength can be expressed as:

[0057] Where, τ f Where c is the shear strength, c′ is the effective cohesion, σ is the total normal stress, and u is the pore water pressure. This is the effective internal friction angle.

[0058] When expressing the safety factor using the slice method, it can be written as:

[0059] Pore ​​water pressure can be calculated based on the difference between the groundwater level and the slip surface elevation:

[0060] Where, γ w For water specific weight, H(x) i Let z be the groundwater level elevation at the location of the i-th block. s,i Let be the elevation of the i-th block's sliding surface. This means that when the value is less than zero, it is taken as zero.

[0061] To transform stability requirements into water level control requirements, this invention reverse-engineers the groundwater level at which the safety factor equals the target safety factor: F s (H allow )=F T In the above formula, H allow This refers to the highest permissible groundwater level. This level can be determined by the slice method, the strength reduction method, existing safety water level tables for the project, monitoring thresholds, or the water level verified by the design unit. Typically, a rise in the groundwater level will monotonically decrease the safety factor; therefore, a bisection method can be used for searching. The upper bound of the search can be taken as the historical highest water level or surface elevation, and the lower bound can be taken as the water level below the slip surface or the historical lowest water level, iterating until… Less than the preset precision.

[0062] If drainage is not carried out before rainfall, the groundwater level at any future time can be represented as: H pred (t)=H0+ΔH R (t) To ensure that the groundwater level does not exceed the maximum allowable groundwater level during rainfall and the subsequent lag period, and to maintain a safety reserve of [m]. s Lowering should be done in advance before rainfall. ,make: H0-m+ΔH R (t)≤H allow -m s Taking the most unfavorable value over all time periods and rearranging the terms, we can obtain the lower limit of the required pre-descent depth:

[0063] When the predicted water level is not close to the allowable water level, mechanical forced drainage should not be carried out; therefore, a non-negative value should be used.

[0064] The above formula is the core inverse formula for calculating the pre-descent depth in this invention, which converts future rainfall risks into groundwater level space that should be freed up before rainfall.

[0065] In the simplified front-end engineering mode, the maximum expected lift ΔH is available. R By replacing the timing function, we get: m=max(H0+ΔH R -H allow +m s ,0) Compared to the approach of placing the safety reserve outside the maximum value function, the above formula is better able to avoid the situation of forced pre-discharge even in light rain or when the safety margin is sufficient, and is consistent with the rainfall level table and on-site operation logic.

[0066] The safety reserve drawdown depth can be determined using the following formula:

[0067] In the formula, z α σ H This represents the confidence control value for groundwater level prediction error. To convert the safety factor margin to the water level margin, m inst Water level is calculated based on instrument error, in meters. op This provides operational margins for construction and operation. Values ​​can be taken from the engineering grade table if data is insufficient.

[0068] In this invention, the current controlled groundwater level H0 can be the measured groundwater level of the control borehole, the equivalent groundwater level of the control profile, or the average groundwater level of the control zone. For the single control borehole mode, the system defaults to the control borehole being located at a representative position within the drainage influence zone, and its water level changes reflecting groundwater level changes within the control zone. For the multiple monitoring borehole mode, the controlled groundwater level is the equivalent water level obtained by weighting multiple monitoring boreholes according to their drainage service area.

[0069] Among them, H i For the groundwater level of the i-th monitoring well, w i This represents the service area or influence weight of the monitoring well. Control area A c The area within which the groundwater level can generate an effective response after pre-drainage can be determined by the service area of ​​the drainage well, the radius of influence of the drainage test, the zoning boundary, or a numerical seepage model. If the water level in the well drops rapidly during the test drainage process while the water level response in the control well is not obvious, the control area of ​​a single well should be reduced or the number of drainage wells should be increased.

[0070] Pre-draw depth indicates the extent to which the groundwater level should be lowered, but construction requires determining how much water needs to be drained. The drainable storage capacity corresponding to the groundwater level reduction is determined by the specific yield or equivalent storage coefficient and the controlled area.

[0071] For spatially non-uniform control zones, the micro-element water volume can be expressed as: dV=S(x,y)m(x,y)dA The integral yields:

[0072] When S and m within a partition can be approximated by their mean, a simplified engineering formula is obtained: V=SA c m The physical meaning of the above formula is: the larger the controlled area, the larger the water storage parameters, and the greater the pre-drainage depth, the greater the required pre-drainage volume.

[0073] The capacity of a single siphon pipe cannot be estimated solely based on the pipe diameter; factors such as pipe length, effective head difference, friction loss, local loss, air resistance, blockage, and soil recharge capacity into the borehole should also be considered.

[0074] Taking the inlet and outlet as energy sections, according to Bernoulli's equation, neglecting the velocity head difference and combining friction loss and local loss, we can obtain:

[0075] The average flow velocity is obtained by solving for:

[0076] The theoretical flow rate of the pipeline is:

[0077] In the above formula, A p Let g be the cross-sectional area of ​​the siphon, g be the acceleration due to gravity, and ΔH be the acceleration due to gravity. eff The effective head difference is given by λ, the friction coefficient is given by L, the pipe length is given by d, and ∑ζ is the sum of local resistance coefficients.

[0078] The actual drainage capacity is also limited by the soil's ability to replenish the drainage hole. For a section of the hole that can be approximated as radially replenished, the perimeter replenishment capacity can be estimated using the following formula:

[0079] In the formula, k h Let be the horizontal permeability coefficient, b be the effective aquifer thickness, Δh be the hydraulic head difference between the inside and outside of the borehole, and r be the horizontal permeability coefficient. e To influence the radius, r w Where is the orifice radius. This formula is used to prevent the theoretical flow capacity of the pipe from exceeding the actual water supply capacity of the soil.

[0080] Therefore, the effective flow rate of a single design is determined by the following formula: Q base =min(Q pipe Q test Q bore ) Q design =η q Q base In the above formula, Q test To ensure stable flow during on-site testing, η q This is the operating efficiency coefficient. If the flow rate value in the pipe diameter flow rate quick lookup table already includes the operating reduction factor, then the flow rate value (table value) in that pipe diameter flow rate quick lookup table can be directly used as Q. design The candidate values ​​must not be multiplied by η again. q .

[0081] To complete the pre-drainage task, within the available pre-drainage time, the total drainage volume of N siphon pipes should not be less than the required pre-drainage volume: NQ design T avail ≥V The number of siphon tubes that need to be activated can be obtained from the above formula:

[0082] The time required to complete the pre-layout after configuring N pipes is:

[0083] Without drainage, the moment when the groundwater level first reaches the danger level or the safety factor falls below the target value is denoted as t. c Considering the margin T for on-site water filling, air venting, and inspection operations. op The latest startup time is: t start =t c -T req -T op The maximum drainage capacity of the existing system is: V max =N max Q design T avail like V max <V This indicates that the existing siphon system alone cannot complete the required pre-drainage task within the available time, and the system should output an unreachable warning. The differential drainage volume is: ΔV=VV max The required supplemental drainage capacity is:

[0084] Based on the above suggestions, the system adds a siphon pipe, activates an emergency large-diameter branch, adds boreholes, extends the pre-drainage time, or uses a temporary pump. The technical significance of the unattainability judgment is that the system does not output solutions that are superficially satisfactory but cannot be implemented in practice.

[0085] After calculating the pre-drainage depth, pre-drainage volume, and number of pipes, the system should also verify whether the groundwater level consistently meets the safe water level requirements during the rainfall period and the post-rain lag period. Water balance is then recursively calculated using a time step Δt.

[0086] In the formula, A R,j For the replenishment area, Q side,j,k For flank resupply, Q nat,j,k As a natural excretion, Q drain,j,k For artificial siphon drainage, the denominator Sj A c,j This represents the amount of water stored per unit change in water level.

[0087] The conditions for full-process safety verification are: H j,k ≤H allow,j Or F s,j,k ≥F T If the above formula is not satisfied at any partition or at any time, m should be increased, N should be increased, and t should be advanced. start Or provide an unreachable emergency plan.

[0088] The simplified parameters for the project are not fixed empirical values, but can be gradually corrected by measured rainfall, water level, and flow rate. This invention preferably employs exponential smoothing or weighted updates, allowing the parameters to be gradually transformed from a general table to a table specific to this slope.

[0089]

[0090] C H,new =(1-α)C H,old +αC H,obs Among them, C H,obs The design rainfall water level rise coefficient per 100mm is calculated from the actual rainfall event. α is the update weight, which should be between 0.2 and 0.5. A larger value should be taken when the monitoring data quality is high.

[0091] The effective flow rate of a single design can also be updated on a rolling basis: Q design,new =(1-β)Q design,old +βQ test,new In the formula, β is the flow update weight. Q should be updated after each trial run or operation. design This is to prevent the actual flow rate from deviating from the meter value due to blockage, air resistance, or aging of the pipeline.

[0092] This invention requires all parameters to have a clearly defined source. Parameter sources are divided into four categories: direct field measurement, indoor or field testing, historical event inversion, and empirical quick reference tables. When parameters are insufficient, conservative initial values ​​can be given using empirical tables, but formal projects should be calibrated through rolling calibration using monitoring data.

[0093] The following lists the main parameters involved in the formulas and engineering applications of this invention in the format of "parameter symbol - physical meaning and unit - source of information - uncertainty and calibration".

[0094] (a) Zoning and water level parameters.

[0095] Ω j, the j-th control zone. The unit is dimensionless. It is a calculation unit used to represent the target slope divided according to catchment boundaries, slip zone depth, strata lithology, deformation zones, and drainage hole service areas. Sources include topographic mapping, engineering geological profiles, monitoring zones, and drainage system layouts. Overly coarse zoning can mask localized high risks, while overly fine zoning increases the complexity of construction scheduling.

[0096] H0 represents the current controlled groundwater level, in meters (m). It indicates the equivalent groundwater level elevation at the start of the forecast calculation for the control borehole, control profile, or control zone. The source is groundwater level gauges, manual measurements from monitoring wells, or conversion from pore pressure gauge readings. This parameter is directly incorporated into the pre-drawdown calculation; a unified elevation benchmark should be used, and the reading time should be recorded.

[0097] H i With w i Monitoring well water levels and their representative weights. H i The units are m and w i It is dimensionless or area-weighted. Used to determine the equivalent H0 under multiple monitoring well conditions. The source is the measured water level and drainage service area, radius of influence, or zone area of ​​each monitoring well.

[0098] H pred The predicted groundwater level after rainfall. The unit is meters (m). This represents the highest control groundwater level that may be reached after future rainfall without pre-drainage, calculated as H0 + ΔH. R Alternatively, it can be obtained from a time-series model. It is influenced by rainfall forecasts, infiltration coefficients, water storage parameters, and hysteresis functions.

[0099] H allow The maximum permissible groundwater level. The unit is meters (m). This represents the highest permissible groundwater level when the target safety factor or safe water level requirement is met. Sources include stability back-calculation, safe water level tables, design unit-approved thresholds, or historical hazard water level inversions. Taking too high a value will underestimate the pre-drawdown depth; important slopes should be rechecked.

[0100] H pre The groundwater level after pre-drainage. The unit is meters (m). This represents the target groundwater level after pre-drainage and before the start of rainfall, obtained according to H0-m, and should be confirmed by actual measurement from the control borehole.

[0101] (ii) Rainfall and infiltration parameters.

[0102] R represents the predicted cumulative rainfall, in mm. The data source is weather forecasts, weather interfaces, or rolling corrections from on-site rain gauges. For short-duration heavy rainfall, the error is larger; K should be used instead. r Zoom in and update in real time.

[0103] I(t), rainfall intensity sequence. Units are mm / h or m / h. Sources include hourly forecasts, radar nowcasts, or field rain gauges. Peak rainfall intensity affects infiltration capacity and temporal peak value.

[0104] I peak Peak rainfall intensity. Unit: mm / h. Source: Forecast rainfall processline or field rain gauge data; used to identify short-duration heavy rainfall and rapid response slope risks.

[0105] T rain Rainfall duration. Unit: hours. Source: Forecast rainfall processline. Affects effective infiltration accumulation and post-rain lag peak.

[0106] T lead Forecast lead time. Unit: hours. Source: the difference between the forecast release time and the expected start time of rainfall. This parameter determines the upper limit of available advance scheduling time.

[0107] K r Forecast amplification factor. Dimensionless. Sources include rainfall level, forecast reliability, engineering level, and historical forecast error statistics. A value that is too low will underestimate the predicted drawdown depth, while a value that is too high may lead to excessive drainage.

[0108] R design Design rainfall. Unit: mm. According to R... design =K r The value obtained from R is the input for calculating groundwater level rise, not the actual measurement.

[0109] Infiltration recharge coefficient. Dimensionless. Represents the proportion of rainfall entering the groundwater system that controls its flow. Sources include historical rainfall-water level inversion, double-ring infiltration tests, artificial rainfall tests, soil-water characteristic curves, or geological experience tables. (The last part, "ΔH," appears to be incomplete and requires further context.) R Highly sensitive.

[0110] r e (t) and R e Effective infiltration intensity and cumulative effective infiltration volume. e (t) is in mm / h or m / h, R e The unit is mm or m. (From r) e =ηI is obtained by summing the time period, or it can be calculated by the background infiltration capacity model.

[0111] K s ψ f Δθ, F(t) and χ d Infiltration capacity verification parameters. s ψ is the saturated permeability coefficient, in m / s. f Δθ is the wetting front suction head, in meters; Δθ is the difference between saturated and initial moisture content, dimensionless; F(t) is the cumulative infiltration depth, in meters; χ dThis represents the deep recharge ratio, dimensionless. Sources include indoor infiltration tests, soil-water characteristic curves, moisture content tests, tracer tests, or historical data inversion. This set of parameters is primarily used for backend verification; it can be merged into C on the frontend. H .

[0112] (III) Groundwater response and water storage parameters.

[0113] ρ, a correction factor for the recharge area and control area. Dimensionless. Used to reflect the effects of trailing edge catchment, lateral fissures, and catchment areas exceeding control areas. Sources include the catchment area / control area ratio, topographic runoff analysis, historical event inversion, or tracer experiments.

[0114] S or S y Water yield or equivalent storage coefficient. Dimensionless. Represents the proportion of water that can be drained per unit area when the groundwater level drops by a unit height. Sources include pumping recovery tests, water level fluctuation methods, laboratory tests, geological experience tables, or inverse calculations from formulas. For pre-drainage volume V and water level rise ΔH... R Both are sensitive.

[0115] G(s), the groundwater hysteresis response function. Dimensionless. Represents the proportion of effective infiltration that translates into water level rise after time s. Sourced from historical rainfall-water level response fitting; values ​​are taken from the response level table when no data is available.

[0116] τ, response lag time. The unit is hours (h). It represents the delay from rainfall infiltration to the start of the response at the control groundwater level. Sources include cross-correlation analysis, historical event observations, or response level tables. This parameter has a significant impact on the latest activation time.

[0117] T g , the response time constant. The unit is hours (h). It represents how quickly the groundwater level responds from the start to near its peak. It is derived from historical response curve fitting and can be approximated by the time it takes to reach approximately 63% of its peak value.

[0118] A c Controlled area. Unit is m. 2 This represents the groundwater area affected and controlled by a single pre-drainage operation. The source is the service area of ​​the drainage well, zone boundaries, the radius of influence of the pumping test, or a numerical seepage model. It is proportional to V.

[0119] A R Supply area. Unit: m. 2 This represents the catchment area effectively supplied by rainfall into the control zone. The sources are topographic runoff, trailing catchment boundaries, and fissure connectivity analysis, and can be simplified by incorporating ρ.

[0120] Q side With Q nat Lateral replenishment and natural excretion. Unit: m. 3 / h. Sources include lateral boundary water level, permeability coefficient, hydraulic gradient, historical water level decay curves, or numerical models. Natural discharge can be conservatively ignored when data is insufficient.

[0121] (iv) Pre-drainage calculation parameters.

[0122] m, pre-drawing depth. The unit is meters. Calculated by the aforementioned formula and confirmed by the water level gauge, it is one of the four core outputs of this invention.

[0123] m s Safety reserve drawdown depth. Unit: meters. Source: error statistics, sensitivity analysis, engineering grade tables, or calculations using the aforementioned corresponding formulas. Larger values ​​are used for important slopes, while smaller values ​​are used for temporary emergency slopes, but increased patrols are still necessary.

[0124] V, pre-drainage volume. Unit: m³ 3 . From V=SA c m-or partitioned integral calculation is one of the four core outputs of this invention.

[0125] C H The water level rise coefficient corresponding to 100mm of design rainfall. The unit is m / 100mm. It is derived from theoretical parameter conversion, historical rainfall inversion, geological quick reference tables, or rolling calibration, and is a key parameter for simplifying the front-end engineering.

[0126] (v) Siphon flow rate and pipeline parameters.

[0127] Q pipe Theoretical flow rate of the pipeline. Unit: m³ / s 3 / h. Calculated using Bernoulli's equation and head loss. This value cannot be directly used as the design flow rate; it must be the smaller of the stable flow rate during field testing and the orifice recharge capacity.

[0128] Q test A stable flow rate was achieved during on-site testing. The unit is m³ / s. 3 / h. The data source is the continuous test discharge record after filling and venting a single siphon pipe. It is recommended to record at least the flow rate, venting status, and control orifice water level response.

[0129] Q bore Peripheral supply capacity. Unit: m. 3 / h. This value is derived from drainage tests, borehole water level recovery curves, or radial seepage estimates. If this value is less than the pipeline capacity, drainage is limited by the soil's water supply.

[0130] Q base With Q design The reference flow rate and the effective flow rate of a single tube. The unit is m³. 3 / h. Q base =min(Q pipe Q test Q boreQ design )=η q Q base If the quick lookup table already includes operational reductions, the table value must not be reduced again.

[0131] η q Operating efficiency coefficient. Dimensionless. Sourced from field trial operation, historical maintenance records, or experience tables, typically ranging from 0.6 to 0.9, used to reflect fluctuations in operation such as non-full pipe, air resistance, and continuous operation.

[0132] A p , d, L, λ, ∑ζ, ΔH eff And g, the hydraulic parameters of the pipeline. A p Let d be the pipe cross-sectional area, d be the inner diameter, L be the pipe length, λ be the friction coefficient, ∑ζ be the sum of local resistance coefficients, and ΔH be the total friction coefficient. eff The effective head difference is given, and g is the acceleration due to gravity. The data is derived from material specifications, construction layout, hydraulic manuals, and on-site trial runs for calibration.

[0133] (vi) Timing, stability and scheduling parameters.

[0134] N and N max The number of tubes required to start and the maximum number of available tubes are specified. The unit is tubes. N is calculated using the corresponding formula mentioned above. max The number of emergency access routes is determined by the on-site equipment log, the number of emergency access routes, and the on-site inventory.

[0135] T avail T req T op t c and t start Timing parameters. T avail T is the available pre-scheduling time. req The time required to complete the pre-scheduling, T op For operating margin, t c t represents the time when the dangerous water level is reached. start This is the latest start time. The data is derived from the forecast lead time, timing verification, and construction organization records.

[0136] F s With F T Slope safety factor and target safety factor. Dimensionless. F s Derived from slice method, strength reduction method or project stability model; F T It originates from the engineering grade, design requirements, and owner's safety control requirements.

[0137] u i γ w W i α i l i and zs,i Stability calculation parameters. c′ is the effective cohesion. For the effective internal friction angle, u i γ is the pore water pressure. w For water specific gravity, W i For the weight of the strip, α i Let l be the angle of inclination of the strip surface. i z is the length of the sliding surface. s,i This represents the elevation of the slip surface. The data is derived from indoor tests, pore pressure monitoring, exploration profiles, and geometric calculations.

[0138] α, β and P j Rolling calibration and priority parameters. α and β are update weights, ranging from 0.2 to 0.5 depending on the quality of the monitoring data; Pj is the zonal drainage priority index, used for zonal scheduling, and does not replace the safety factor verification.

[0139] The detailed steps for obtaining core parameters are as follows: The current control groundwater level H0 is obtained. Priority should be given to using long-term stable operating water level gauges or manually verified values ​​from monitoring wells. Before heavy rainfall, a reading should be taken at least once at the forecast start time, and the sensor number, well location, wellhead elevation, elevation reference, and reading time should be recorded. If a pore pressure gauge is used for conversion, the following formula should be used:

[0140] In the formula, z p γ is the elevation of the pore water gauge measuring point, u is the pore water pressure, and γ is the pore water pressure. w It is water-weighted.

[0141] Permissible maximum groundwater level H allow The water level should be obtained primarily through inverse calculation using a stability model; if a stability model is unavailable, the design unit's verified safe water level, historically adjusted dangerous water levels, or a safe water level table can be used. Formal projects should maintain calculation logs or records of safe water level verification.

[0142] Obtaining the specific water supply or equivalent storage coefficient S. Pumping recovery tests or water level fluctuation methods are preferred. During the trial run, the drainage volume and the drop in water level at the control well can be recorded, and the equivalent storage parameters can be calculated using the following formula:

[0143] In the formula, V test ΔH represents the cumulative outflow during the trial discharge phase. test To control the steady drop in well water level, when data is insufficient, consult tables according to geological type and take conservative values.

[0144] Control area A cThe area of ​​a small to medium-sized slope can be determined based on the service area of ​​drainage holes, the representative area of ​​control holes, or the area of ​​the treatment zone; large slopes should be classified in conjunction with the catchment boundary, slip zone depth, radius of influence of drainage holes, and numerical seepage model. If the water level in the hole drops rapidly while the control hole does not respond, the control area of ​​a single hole should be reduced or the number of holes should be increased.

[0145] Water level rise coefficient C H The data can be obtained through theoretical calculations or by inversion from historical events. When historical data is unavailable, default values ​​are used from the geological parameter table, and the data is calibrated using measured water levels after the first rainfall. Historical event inversion is performed according to the corresponding formulas mentioned above.

[0146] Single-unit design effective flow rate Q design The flow rate must be obtained. The theoretical flow rate must not be used alone. It should be initially estimated based on the pipe diameter flow rate table, then confirmed through on-site trial runs, and compared with the soil's ability to replenish the borehole. The smaller value should be multiplied by the operational reduction factor. If the measured flow rate is lower than Q during continuous operation... design 80% of the time should trigger water replenishment, air venting, sludge removal, pipe addition, or pump discharge.

[0147] Response lag time τ and response time constant T g The data is obtained by cross-correlation of rainfall sequences with groundwater level rise rates when historical data is available, and by estimating T based on the time it takes for the water level to reach approximately 63% of its peak value. g When no data is available, values ​​are taken from the response level table and updated after the first rainfall.

[0148] To avoid exposing on-site personnel to too many intermediate variables, this invention compresses the back-end theoretical formulas into front-end engineering formulas, but each engineering formula can be traced back to the back-end physical process.

[0149] The rainfall mechanism is designed. The backend follows R... design =K r R is used to determine K in conjunction with forecast error statistics. r The front desk only needs to select K from the rainfall level table. r The simplification is based on converting forecast uncertainty into a conservative rainfall input.

[0150] Effective infiltration stage. The backend calculates based on r-=ηI or the infiltration capacity model; the frontend does not output r- separately, but instead combines η, ρ, S, and G into C. H The simplification is based on compressing infiltration, recharge area, water storage capacity, and hysteresis response into a single water level rise coefficient corresponding to 100mm of design rainfall.

[0151] Water level rise phase. The backend follows... Calculate the time-series water level; the front end is calculated according to ΔH. R =C H R design / 100 is used to calculate the maximum rise. This simplification is based on pre-summarizing the background timing peaks into C. H .

[0152] Allowable water level parameters. Backend solution F. s (H allow )=F T The front-end can read the safe water level table or the design approval value. The simplification is based on solidifying the stability iteration results into a verifiable water level.

[0153] Pre-descent depth stage. The backend uses the most unfavorable value m=max{max t [H0+ΔH R (t)-H allow +m s ],0};The front end uses m=max(H0+ΔH R -H allow +m s The simplification is based on replacing the entire process function with the maximum predicted lift.

[0154] Pre-drainage stage. The backend uses... The front end uses V=SA. c m. The simplification is based on equating the water storage parameters and pre-drainage depth within the zone to their mean values.

[0155] Single-pipe flow control. The backend uses Q. design =η q min(Q pipe Q test Q bore The front end uses a pipe diameter-head difference-pipe length table and is calibrated by trial runs. The simplification is based on pre-tabulating Bernoulli's equation and head loss calculations, and using trial run results to ensure the reliability of the project.

[0156] The number of pipes and startup time are considered. Both the backend and frontend use N=ceil(V / (Q)). design T avail )) and t start =t c -V / (NQ design )-T op The simplification is based on converting the complex timing verification results into the latest start time and the number of siphon tubes that need to be opened and closed.

[0157] The key to engineering formulas lies in C. H From the theoretical water balance equation, we can obtain:

[0158] And because: R e =ηR design Substituting, we get:

[0159] When R design When 100mm = 0.1m, the groundwater level rise corresponding to 100mm of design rainfall is:

[0160] Therefore, the simplified formula for the engineering process is:

[0161] It is not an arbitrary empirical number, but a combination of parameters including infiltration recharge coefficient, recharge area correction, peak response ratio, and specific yield. When historical data is available, it can be directly derived from measured water levels; when no data is available, the geological parameter table provides a default range. Important projects should be calibrated using theoretical formulas or measured events. The simplified engineering table is used for general slopes and emergency preliminary calculations, with an error target of approximately ±25%.

[0162] The following quick reference information serves as default values ​​for projects lacking historical data or with insufficient information. These values ​​represent initial estimates and should be revised based on field tests, monitoring data, and stability calculations in the formal design.

[0163] (a) Quick reference table of geological parameters.

[0164] Clay or colluvial clay. Recommended values ​​for η: 0.10 to 0.25, S: 0.03 to 0.08, τ: 12h to 48h, T: g Recommended for 24 to 72 hours, C H Recommended range: 0.20 to 0.60 m / 100 mm. Applicable to slopes with low infiltration and significant post-rain lag; lower values ​​are acceptable for short-duration light rain, while upper values ​​should be used for continuous heavy rain; important projects should be reviewed.

[0165] Silt or silty clay. Recommended concentrations: η 0.20 to 0.40, S 0.06 to 0.12, τ 6h to 24h, T g Recommended 12h to 36h, C H Recommended value: 0.30 to 0.80 m / 100 mm. Suitable for slopes sensitive to continuous rainfall; use the upper-middle value when there are sand layers.

[0166] Sandy soil or sandy interlayers. Recommended η: 0.40 to 0.70, S: 0.10 to 0.25, τ: 1 h to 12 h, T: ... g Recommended for 6 hours to 24 hours, C H Recommended range: 0.25 to 0.70 m / 100 mm. Rapid response is expected; however, attention should be paid to short-duration heavy rainfall, and the shorter conservative value should be used for the lag time.

[0167] Gravelly soil or strongly weathered fissured body. η is recommended to be 0.50 to 0.85, S to 0.15 to 0.30, τ to 0 h to 12 h, T g Recommended for 3 hours to 24 hours, C H Recommended range: 0.20 to 0.60 m / 100 mm. When the dominant channel is obvious, take the upper limit of η or ρ; side supply should be checked separately.

[0168] (II) Quick Reference Table for Rainfall Levels. Light rain is defined as a 24-hour cumulative rainfall of less than 10 mm, K. r A value of 1.0 is generally used; pre-drainage is not typically initiated. Moderate rainfall is 10mm to 25mm. (K) r Use a value of 1.0 to 1.1; for secondary and tertiary slopes, low-frequency verification is recommended; heavy rainfall is 25mm to 50mm; K r Take a value of 1.1 to 1.2, calculate m, and decide whether to pre-drain based on the current water level; for heavy rainfall of 50mm to 100mm, K r If the value is between 1.2 and 1.3, the pre-sorting calculation should be initiated and N and t should be output. start Heavy rain or above is defined as rainfall exceeding 100 mm, K r If the value is between 1.3 and 1.5, mandatory verification should be performed to ensure it is not achievable and emergency branch lines or pumps should be prepared.

[0169] (III) Quick Reference Table for Response Levels. Rapid response is applicable to sandy soil, gravelly soil, and fractured soil. The peak value usually appears 3 to 24 hours after the start of rainfall. The value should be taken based on the shorter time period and the response should be initiated earlier. Medium response is applicable to silt, silty clay, and colluvial soil. The peak value usually appears 12 to 48 hours after rainfall. The rainfall period and 1 to 2 days after rainfall should be checked simultaneously. Slow response is applicable to clay, thick overburden, and low-permeability slip zones. The peak value usually appears 24 to 96 hours after rainfall. The focus should be on checking the delayed peak value after rainfall, and it is not advisable to only look at the end of rainfall.

[0170] (iv) Quick Reference Table for Pipe Diameter and Flow Rate. Under the initial conditions of a total PE pipe length of approximately 60m, a friction factor of 0.035, a local resistance factor of 3.5, and an operating reduction factor of 0.80, the flow rates of a 4mm pipe at head differences of 5m, 10m, and 15m are approximately 0.016, 0.022, and 0.027 m³ / h, respectively. 3 / h·root; 6mm pipe is approximately 0.043, 0.061 and 0.074m. 3 / h·root; 8mm pipe is approximately 0.088, 0.124 and 0.152m. 3 / h·root; 12mm pipe is approximately 0.241, 0.341, and 0.417m. 3 / h·root; 16mm pipe is approximately 0.492, 0.696 and 0.853m 3 / h·root. In actual engineering, the design value should be controlled by both the stable flow rate of the on-site test discharge and the single-hole recharge capacity. The smaller of the three values ​​should be taken as the design value. If the table value already includes the reduction, it should not be reduced again.

[0171] (v) Quick Reference Table for Engineering Grades. Safety Reserve (m) for Grade I or Important Slopes. s The recommended depth is 0.50m to 1.00m, and should be verified using precise theoretical formulas and under unfavorable rainfall scenarios; for secondary or conventionally treated slopes, the depth should be [m]. s A range of 0.30m to 0.50m is recommended; a simplified formula can be used and verified in the background. For level 3 or temporary emergency slopes, the recommended m... s A depth of 0.20m to 0.30m is recommended for short-term emergency use, and patrols must be intensified.

[0172] The formula for quick engineering estimation is: forecast rainfall changes water level, safe water level determines drawdown depth; multiply the expected drawdown depth by the water storage volume to get the drainage volume; divide the drainage volume by the single-pipe flow rate and time to get the number of pipes.

[0173] R design =K r R

[0174] m=max(H0+ΔH R -H allow +m s ,0) V=SA c m

[0175]

[0176] The above formulas are for on-site engineering applications. If there is no electricity or network on site, engineers can use rainfall forecasts, artificial water level readings, geological parameter tables, pipe diameter and flow meters, and operation cards to complete manual emergency calculations.

[0177] The system of this invention includes the following modules: 1. Data Input Module. Used to input slope type, engineering grade, H0, R, I. peak T rain These three types of core data belong to the front-end visible modules.

[0178] 2. Parameter Quick Lookup Module. Used for automatically selecting K. r S, η, τ, T g C H m s Q design These parameters mainly run in the background.

[0179] 3. Backend calculation module. Used to calculate ΔH. R H allow m, V, N and t start And save the intermediate calculation logs.

[0180] 4. Time-series verification module. Used to verify the control groundwater level and slope safety factor before, during, and after rainfall.

[0181] 5. Unreachable Detection Module. Used to determine whether the existing siphon system is sufficient and output suggestions for adding pipes, emergency branches, extending pre-drainage time, or pumping.

[0182] 6. Valve control interface. Used for valves controlled according to N, t... start Automatically or manually enable / disable siphon branches based on partition priority.

[0183] 7. Siphon drainage actuator. This includes the on-site physical structure such as the inclined borehole, the permeable section inside the borehole, the siphon pipe assembly, the flow meter, and the drainage outlet.

[0184] 8. Construction Instruction Output Module. This module generates four core results and one construction instruction, forming a standardized on-site construction operation card.

[0185] Based on the foregoing, this application discloses a quantitative configuration method for pre-drainage siphons on rainfall-prone slopes, comprising the following steps: S1: Acquire three types of core data, including the basic parameters of the target slope, the current controlled groundwater level H0, and the forecasted rainfall information within a preset time window. The current controlled groundwater level H0 is obtained through groundwater level sensors, manual measurement from monitoring wells, or calculation using pore water pressure gauges.

[0186] S2: The background calculation module determines the infiltration recharge parameters, water storage parameters, hysteresis response parameters, safety reserve parameters, and the design effective flow rate of a single siphon pipe based on the three types of core data, and calculates the design rainfall, effective infiltration volume, and expected groundwater level rise ΔH. R Permissible maximum groundwater level H allow Pre-drainage depth (m), pre-drainage volume (V), number of siphon pipes (N), and latest start time (t) start ; S3: Output the pre-drainage depth m, pre-drainage volume V, number of siphon pipes N, and latest start time t. start Four core results are generated, and a construction instruction is produced to control the siphon drainage actuator at the latest start time. The corresponding number of siphon branches are activated to lower the controlled groundwater level below the target level. The siphon drainage actuator includes a tilting pressure relief borehole, a permeable section inside the borehole, a siphon pipe assembly, a flow meter, and a drainage outlet.

[0187] In the embodiments of this application, the basic parameters of the target slope include slope type, engineering grade, geological type, and control area A. c Permissible maximum groundwater level H allow Target safety factor FT At least one of the following: service area of ​​drainage hole or safe water level level; when the controlled area or the maximum allowable groundwater level is missing, the default value shall be determined by the background calculation module based on the service area of ​​drainage hole, representative profile, engineering level, on-site monitoring threshold or stability calculation results.

[0188] The forecast rainfall information includes the forecast cumulative rainfall R for the next 6 hours, 12 hours, 24 hours, 48 ​​hours, or 72 hours. Rainfall intensity sequence I(t) Peak rainfall intensity I peak Rainfall duration T rain and forecast lead time T lead ; The background calculation module calculates the design rainfall R according to the following formula. design : R design =K r R Among them, K r The forecast amplification factor is K. r It is determined by the uncertainty of the forecast, the level of engineering work, and the level of rainfall.

[0189] In the embodiments of this application, the predicted groundwater level rise... Calculate using the following simplified engineering formula:

[0190] Among them, C H The control groundwater level rise coefficient is determined for every 100mm of design rainfall. The C... H The parameters are obtained from geological type, infiltration recharge coefficient, water supply specificity, recharge area correction coefficient, and groundwater hysteresis response level through parameter quick lookup tables, historical rainfall-groundwater level monitoring data, or rolling calibration.

[0191] In an embodiment of this application, the background calculation module calculates the effective infiltration amount according to the following formula: r e (t)=η(t)I(t)

[0192] Where r e (t) represents the effective infiltration intensity, η(t) represents the infiltration recharge coefficient, I(t) represents the rainfall intensity, and R... e (t k ) is up to t k The cumulative effective infiltration rainfall at any given time.

[0193] In the embodiments of this application, when the background calculation module calculates the expected time-series rise in groundwater level, it calculates according to the response function model:

[0194] Where, ΔH R,j (t k ) represents the j-th control partition in t k The rise in groundwater level at time ρ j S is the correction factor for the supply area and control area. j G is the specific yield or equivalent storage coefficient. j This is the groundwater hysteresis response function; The groundwater hysteresis response function is determined according to the following piecewise function: G j (s)=0, s<τ j

[0195] Where s is the elapsed time after the infiltration pulse occurs, and τ j T is the lag time from rainfall infiltration to the response of the groundwater level. g,j is the groundwater response time constant.

[0196] In the embodiments of this application, the maximum allowable groundwater level H allow The value is determined by back-calculation of the target safety factor, the verified safety water level gauge, the monitoring and early warning threshold, or the value verified by the design unit; when using stability back-calculation, the background calculation module solves for F. s (H allow )=F T F s (H) is the slope safety factor function that varies with groundwater level, F T The target safety factor.

[0197] In the embodiments of this application, the pre-descent depth Determine using the following formula: m=max(H0+ΔH R -H allow +m s ,0) Where, m s For safety reserves, the depth is reduced; when H0 + ΔH R ≤H allow -m s At that time, pre-drainage is not initiated or only normal drainage is maintained; The pre-drainage volume Determine using the following formula: V=SA c m in, For water supply specificity, storage coefficient, or equivalent storage coefficient, A c To control the area; when the control area cannot be directly determined, it is determined by the service area of ​​the drainage holes, the radius of influence of the pumping test, the area of ​​the zone, or the numerical seepage model in the background; The single siphon tube is designed to have an effective flow rate Q. design The theoretical flow rate Q of the pipeline is determined as follows: First, calculate the pipeline's theoretical flow rate Q based on the pipe diameter, pipe length, effective head difference, friction coefficient, and local resistance coefficient. pipe Then obtain the stable flow rate Q during on-site testing. test and soil recharge capacity to drainage holes Q bore And determine it according to the following formula: Q base =min(Q pipe Q test Q bore ) Q design =η q Q base Where, η q To account for air resistance, blockage, incomplete pipe flow, joint leakage, and continuous operational fluctuations, the operating efficiency coefficient is used as Q when the flow rate value in the pipe diameter and flow rate quick lookup table already includes the operating reduction factor. design The candidate values ​​are not multiplied by η again. q .

[0198] In the embodiments of this application, the number N of siphon tubes is determined according to the following formula:

[0199] Among them, T avail The available pre-scheduling time is represented by ceil(·), which rounds up.

[0200] The latest start time Determine using the following formula:

[0201] Among them, t c T represents the moment when the groundwater level first reaches a dangerous level or the safety factor falls below the target value without drainage. op Allowance for water filling, air venting, inspection, and personnel on-site operations.

[0202] In the embodiments of this application, when the background calculation module performs time-series verification, it calculates the control groundwater level before, during and after the rain according to the groundwater level-volume balance recursive formula, and verifies that the control groundwater level does not exceed the maximum allowable groundwater level or that the verification safety factor is not lower than the target safety factor.

[0203] In the embodiments of this application, when the maximum number of available siphon tubes N in the existing siphon system max The corresponding maximum displacement V max =N max Q design T avail If the pre-drainage volume is less than the required pre-drainage volume V, the system outputs an unreachable warning and calculates the difference in drainage volume ΔV = VV. max Calculate the supplementary drainage capacity Q add ≥ΔV / T avail Choose at least one alternative from the following options: adding a siphon pipe, activating an emergency large-diameter branch pipe, adding drainage boreholes, extending the pre-drainage time, or using a temporary pump.

[0204] When the measured rainfall deviates from the predicted rainfall by more than 20%, the measured rate of groundwater level rise exceeds the predicted value, or the measured flow rate of a single siphon is lower than Q... design When 80% of the time has elapsed, the background calculation module recalculates m, V, N, and t. start And update the construction instructions.

[0205] When the system experiences a power outage, communication interruption, or automatic control failure, on-site engineers manually calculate m, V, N, and t using a parameter quick reference table. start And the corresponding number of siphon pipes are activated by manually opening and closing valves.

[0206] In the embodiments of this application, when the target slope is a large-scale rainfall-type slope, the background calculation module divides the slope into multiple control zones according to the catchment boundary, slip zone depth, stratum lithology, groundwater level response lag, historical deformation zoning, and drainage hole service area, and calculates m, V, N, and t for each zone respectively. start The drainage priority is output according to the pre-drainage depth, the rate of rise of groundwater level, the rate of increase of pore pressure, and the safety factor gap.

[0207] Example 1: Comparison of theoretical formulas and simplified engineering formulas for calculating residual soil accumulation slopes in southern regions. A residual soil slope in southern China, with controlled zone area A c =2500m 2 The current controlled groundwater level elevation H0 = 188.10m. Based on the stability model or safe water level table, the maximum permissible groundwater level H0 is determined to be... allow =188.20m. Rainfall forecast for the next 24 hours: 10mm / h from 0-6h, 6mm / h from 6-18h, and 2mm / h from 18-24h. Forecast lead time is 72 hours.

[0208] The parameters for this embodiment are as follows: Control area A c =2500m 2The source is the service area of ​​the drainage hole and the zoning boundary; the equivalent water storage parameter S=0.08, source is the pumping recovery test and geological parameter table; the current control water level H0=188.10m, source is the control hole water level gauge; the maximum allowable water level H allow =188.20m, sourced from stability back-calculation or safety water level gauge; safety reserve m s =0.20m, corresponding to Level III emergency conditions; forecast cumulative rainfall R=144mm, sourced from meteorological forecast; water level rise coefficient C H =0.55m / 100mm, which is the upper-middle value taken from the table for a silty clay-gravel mixed slope; the predicted amplification factor K r =1.05, a conservative value for typical engineering projects; the design effective flow rate Q of a single 12mm siphon pipe. design =0.36m 3 / h, sourced from pipe diameter tables, field test runs, and values ​​reduced during operation; operating margin T op =6h, used for water filling, air venting, and inspection.

[0209] The first step is to calculate the cumulative rainfall: R = 10 × 6 + 6 × 12 + 2 × 6 = 144 mm The second step is to calculate the design rainfall: R design =K r R = 1.05 × 144 = 151.2 mm The third step is to calculate the expected rise in groundwater level using a simplified engineering formula:

[0210] If a background response function model is adopted, with η=0.45, ρ=1.10, S=0.08, τ=6h, and T... g =12h, and by recursively extrapolating at 1-hour time steps, the maximum uplift during the post-rain lag period is approximately 0.828m. The simplified engineering value of 0.832m differs very little from the precise value in the background, indicating that the table value under these parameters has a verifiable basis.

[0211] The key moment results calculated by the background response function are as follows: at 6 hours, the uplift is 0.000m, indicating that the rainfall has not yet been transmitted to the control aquifer; at 12 hours, the uplift is 0.091m, indicating that the control water level has begun to respond; at 24 hours, the uplift is 0.444m, indicating that the peak value has not yet been reached when the rainfall ends; at 36 hours, the uplift is 0.720m, indicating a significant post-rain lag response; and at 48 hours, the uplift is approximately 0.828m, which is the maximum uplift within the calculation time window.

[0212] The fourth step is to calculate the predicted highest groundwater level after rainfall: H pred =H0+ΔHR =188.10 + 0.832 = 188.932m Step 5: Calculate the required pre-descent depth: m=max(188.10+0.832-188.20+0.20,0)=0.932m This value indicates that the groundwater level needs to be lowered by at least 0.932m before rainfall.

[0213] Step 6: Calculate the pre-drainage volume: V=SA c m = 0.08 × 2500 × 0.932 = 186.4m 3 Step 7: Calculate available pre-scheduling time: T avail =72-6=66h Single siphon tube design effective flow rate Q design =0.36m 3 The / h figure already takes into account the theoretical flow rate of the pipeline, the stable flow rate of the on-site test discharge, the soil replenishment capacity, and the operational reduction. Therefore, the operating efficiency coefficient will not be multiplied separately in the calculation of the number of pipes.

[0214]

[0215] Considering air resistance, blockage, inspection delays, and operational redundancy during heavy rainfall, the output is set to 10 units with approximately 20% redundancy.

[0216] Step 8: Generate construction instructions: Activate all 10 12mm emergency siphon pipes 66 hours before the forecast of heavy rainfall begins, and run them continuously until the groundwater level in the control well is below 187.17m; during the rainfall, check the outflow rate and control well water level every 3 hours. If the average flow rate of a single pipe is below 0.29m... 3 If the water level continues to rise, immediately start the backup pipe or temporary pump.

[0217] Full-process verification: H pre =H0-m=188.10-0.932=187.168m H max =H pre +ΔH R =187.168 + 0.832 = 188.000m H max The water level is 188.20m below the maximum allowable groundwater level, leaving a safety margin of approximately 0.20m.

[0218] Example 2: Application of Empirical Models for Slopes Without Historical Data A small to medium-sized silty clay slope lacks historical rainfall-groundwater level data, with only one site survey, water level borehole data, and weather forecast available. The slope engineering grade is Class II, and the controlled area is defined as A, based on the service area of ​​the drainage boreholes. c =1800m 2 The current groundwater level H0 = 126.40m. The design unit provides the maximum permissible groundwater level H. allow =126.70m. Heavy rain of 80mm is forecast for the next 24 hours, with the forecast given 48 hours in advance.

[0219] Look up K from table r =1.20, silty clay C H =0.50m / 100mm, S=0.07, m s =0.30m, 12mm siphon pipe under a 10m head difference condition Q design =0.34m 3 / h·root, operating margin T op =4h.

[0220] R design =1.20×80=96mm ΔH R =0.50×96100=0.48m m=max(126.40+0.48-126.70+0.30,0)=0.48m V = 0.07 × 1800 × 0.48 = 60.48m 3 T avail =48-4=44h

[0221] For secondary slopes, it is recommended to have 2 spare sections, with 7 sections to be started on-site. This embodiment reflects a model without historical data: all key parameters have table lookup sources and include safety reserves; after the first rainfall, C should be updated based on measured rainfall and water level rise. H Q is updated based on the measured siphon flow rate. design .

[0222] Example 3: Zoning Calculation and Drainage Priority for Large Slopes Large-scale rainfall-prone slopes are divided into three control zones based on water catchment and lithological conditions, and the calculations are as follows.

[0223] The calculation results for the large slope zoning are as follows. In the rear recharge zone, H0 = 188.10 m, H... allow =188.20m, ΔH R =0.832m, m s =0.20m. The calculated value is m=0.932m; This area Ac =2500m2, S=0.08, V=186.4m3, Q design =0.36m 3 / h, based on a 66h available time, 8 shafts are needed, so 10 shafts will be executed. The main sliding zone has H0=190.25m and H... allow =190.40m, ΔH R =0.450m, m s =0.20m, thus m=0.500m; Area A c =3000m 2 S=0.06, V=90.0m 3 Q design =0.30m 3 / h, 5 pipes are needed, 6 pipes will be executed. The drainage control zone has H0 = 185.50m and H... allow =185.90m, ΔH R =1.100m, m s =0.25m, thus m=0.950m; Area A c =1800m², S=0.10, V=171.0m 3 Q design =0.36m 3 / h requires 8 roots, and 10 roots will be executed.

[0224] As can be seen from the above results, although the controlled area of ​​the drainage control zone is relatively small, its pre-drawdown depth reaches 0.950m due to the expected large rise in water level and high safety reserve, and should be listed as the first priority drainage zone. The rear recharge zone has the largest pre-drainage volume and should be designated as the second priority zone. The main sliding zone is designated as the third priority zone. If only a single representative profile is used, it may be impossible to identify local high risks within the drainage control zone.

[0225] The zone drainage priority index can be calculated using the following formula:

[0226] In the above formula, w1 to w4 are weights, which can be calibrated by engineering level and historical hazards. This index is used for scheduling and does not replace the safety factor verification.

[0227] Example 4: Parameter Rolling Calibration The measured data for the three historical rainfall events are as follows: Historical event data is as follows: Event 1: Cumulative rainfall 86mm, measured water level rise 0.42m, C calculated in reverse. H,obs =0.488m / 100mm, lag time 7h; Event 2 cumulative rainfall 122mm, measured water level rise 0.67m, back-calculated C H,obs=0.549m / 100mm, lag time 6h; Event 3 cumulative rainfall 58mm, measured water level rise 0.28m, C calculated backwards. H,obs =0.483m / 100mm, lag time 8h.

[0228] The average value of the three events is 0.507m / 100mm. If the original table value C... H,old =0.55m / 100mm, taking the update weight α=0.30, then: C H,new =(1-0.30)×0.55+0.30×0.507=0.537m / 100mm This update maintains the parameters' conservatism while gradually approximating the measured response of the slope. The lag time can be taken as the average of the three events, 7 hours. If a rapid crack response occurs during subsequent heavy rainfall, the lower limit of the lag time should be adopted under the heavy rainfall scenario, and K should be taken as the threshold. r Upper limit.

[0229] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the above embodiments do not limit the present invention in any way, and all technical solutions obtained by equivalent substitution or equivalent transformation fall within the protection scope of the present invention.

Claims

1. A quantitative configuration method for pre-drainage siphoning of rainfall-induced slopes, characterized in that, Includes the following steps: S1: Acquire three types of core data, including the basic parameters of the target slope, the current controlled groundwater level H0, and the forecasted rainfall information within the future preset time window; S2: The background calculation module determines the infiltration recharge parameters, water storage parameters, hysteresis response parameters, safety reserve parameters, and the design effective flow rate of a single siphon pipe based on the three types of core data, and calculates the design rainfall, effective infiltration volume, and expected groundwater level rise ΔH. R Permissible maximum groundwater level H allow Pre-drainage depth (m), pre-drainage volume (V), number of siphon pipes (N), and latest start time (t) start ; S3: Output the pre-drainage depth m, pre-drainage volume V, number of siphon pipes N, and latest start time t. start Four core results are generated, and a construction instruction is produced to control the siphon drainage actuator at the latest start time. The corresponding number of siphon branches will be activated to lower the groundwater level below the target level.

2. The quantitative configuration method for pre-drainage of rainfall-induced slope siphons according to claim 1, characterized in that, The basic parameters of the target slope include slope type, engineering grade, geological type, and controlled area A. c Permissible maximum groundwater level H allow Target safety factor F T At least one of the following: service range of the drainage hole or safe water level level; The forecast rainfall information includes the forecast cumulative rainfall R, rainfall intensity sequence I(t), and peak rainfall intensity I for the next 6h, 12h, 24h, 48h, or 72h. peak Rainfall duration T rain and forecast lead time T lead ; The background calculation module calculates the design rainfall R according to the following formula. design : R design =K r R Among them, K r The forecast amplification factor is K. r It is determined by the uncertainty of the forecast, the level of engineering work, and the level of rainfall.

3. The quantitative configuration method for pre-drainage of rainfall-induced slope siphons according to claim 2, characterized in that, The predicted rise in groundwater level Calculate using the following simplified engineering formula: Among them, C H The groundwater level rise coefficient is determined for every 100mm of design rainfall.

4. The quantitative configuration method for pre-drainage of rainfall-induced slope siphons according to claim 1, characterized in that, The background calculation module calculates the effective infiltration amount according to the following formula: r e (t)=η(t)I(t) Where r e (t) represents the effective infiltration intensity, η(t) represents the infiltration recharge coefficient, I(t) represents the rainfall intensity, and R... e (t k ) is up to t k The cumulative effective infiltration rainfall at any given time.

5. The quantitative configuration method for pre-drainage of rainfall-induced slope siphons according to claim 4, characterized in that, When the background calculation module calculates the expected time-series rise in groundwater level, it calculates according to the response function model: Where, ΔH R,j (t k ) represents the j-th control partition in t k The rise in groundwater level at time ρ j S is the correction factor for the supply area and control area. j G is the specific yield or equivalent storage coefficient. j This is the groundwater hysteresis response function; The groundwater hysteresis response function is determined according to the following piecewise function: G j (s)=0, s<τ j Where s is the elapsed time after the infiltration pulse occurs, and τ j T is the lag time from rainfall infiltration to the response of the groundwater level. g,j is the groundwater response time constant.

6. The quantitative configuration method for pre-drainage of rainfall-induced slope siphons according to claim 1, characterized in that, The maximum allowable groundwater level H allow The value is determined by back-calculation of the target safety factor, the verified safety water level gauge, the monitoring and early warning threshold, or the value verified by the design unit; when using stability back-calculation, the background calculation module solves for F. s (H allow )=F T F s (H) is the slope safety factor function that varies with groundwater level, F T The target safety factor.

7. The quantitative configuration method for pre-drainage of rainfall-induced slope siphons according to claim 1, characterized in that, The pre-descent depth m Determine using the following formula: m=max(H0+ΔH R -H allow +m s ,0) Where, m s For safety reserves, the depth is reduced; when H0 + ΔH R ≤H allow -m s At that time, pre-drainage is not initiated or only normal drainage is maintained; The pre-drainage volume Determine using the following formula: V=SA c m in, For water supply specificity, storage coefficient, or equivalent storage coefficient, A c To control the area; when the control area cannot be directly determined, it is determined by the service range of the drainage hole, the radius of influence of the pumping test, the area of ​​the zone, or the background numerical seepage model; The single siphon tube is designed to have an effective flow rate Q. design The theoretical flow rate Q of the pipeline is determined as follows: First, calculate the pipeline's theoretical flow rate Q based on the pipe diameter, pipe length, effective head difference, friction coefficient, and local resistance coefficient. pipe Then obtain the stable flow rate Q during on-site testing. test and soil recharge capacity to drainage holes Q bore And determine it according to the following formula: Q base =min(Q pipe ,Q test ,Q bore ) Q design =η q Q base Where, η q To account for air resistance, blockage, incomplete pipe filling, joint leakage, and continuous operation fluctuations in the operating efficiency coefficient; when the flow rate value in the pipe diameter and flow rate quick reference table already includes the operating reduction factor, the flow rate value in the pipe diameter and flow rate quick reference table is used as Q. design The candidate values ​​are not multiplied by η again. q .

8. The quantitative configuration method for pre-drainage of rainfall-induced slope siphons according to claim 1, characterized in that, The number N of siphon tubes is determined according to the following formula: Among them, T avail The available pre-scheduled time is represented by ceil(·), which rounds up. The latest start time Determine using the following formula: Among them, t c T represents the moment when the groundwater level first reaches a dangerous level or the safety factor falls below the target value without drainage. op Allowance for water filling, air venting, inspection, and personnel on-site operations.

9. The quantitative configuration method for pre-drainage of rainfall-induced slope siphons according to claim 1, characterized in that, When the maximum number of available siphon tubes N in the existing siphon system max The corresponding maximum displacement V max =N max Q design T avail If the pre-drainage volume is less than the required pre-drainage volume V, the system outputs an unreachable warning and calculates the difference in drainage volume ΔV = VV. max Calculate the supplementary drainage capacity Q add ≥ΔV / T avail Choose at least one alternative from adding a siphon pipe, activating an emergency large-diameter branch pipe, adding drainage boreholes, extending the pre-drainage time, or temporary pumping. When the measured rainfall deviates from the predicted rainfall by more than 20%, the measured rate of groundwater level rise exceeds the predicted value, or the measured flow rate of a single siphon is lower than Q... design When the value reaches 80%, the background calculation module recalculates m, V, N, and t. start and update the construction instructions; When the system experiences a power outage, communication interruption, or automatic control failure, on-site engineers manually calculate m, V, N, and t using a parameter quick reference table. start And the corresponding number of siphon tubes are activated by manually opening and closing valves.

10. The quantitative configuration method for pre-drainage of rainfall-induced slope siphons according to claim 1, characterized in that, When the target slope is a large-scale rainfall-prone slope, the background calculation module divides it into multiple control zones based on catchment boundaries, slip zone depth, stratum lithology, groundwater level response lag, historical deformation zones, and drainage well service areas, and calculates m, V, N, and t for each zone. start The drainage priority is output according to the pre-drainage depth, the rate of rise of groundwater level, the rate of increase of pore pressure, and the safety factor gap.

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