Method for determining height of high-level drainage branch tunnel and method for analyzing water pressure of monitoring point

Abstract

The application provides a high-position water discharge branch hole setting height determination method and a monitoring point water pressure analysis method, and the high-position water discharge branch hole setting height determination method comprises the following steps: S1, determining that the most important factor affecting the tunnel operation safety in a karst area is the seepage water pressure finally acting on the lining; S2, determining the influencing factors of the seepage water pressure finally acting on the lining; the influencing factors comprise an initial seepage water pressure of a solution cavity, a reduction of the seepage water pressure by surrounding rock and a drainage condition of a water discharge hole; and S3, designing the high-position water discharge branch hole height according to the influencing factors in a water-rich filled solution cavity. The application can effectively solve the drainage problem of a solution cavity not yet found in a karst area or a drainage channel formed again in the later period, ensures the operation safety, speeds up the tunnel construction progress, can safely and quickly pass through a high-pressure water-rich solution cavity in the karst tunnel construction, and avoids the risk of water and mud inrush.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tunnel and underground engineering, and particularly relates to a method for determining the setting height of a high-level drainage branch tunnel and a method for analyzing water pressure of a monitoring point. BACKGROUND

[0002] Tunnel construction is sometimes carried out under karst geological conditions, so it is necessary to overcome the influence of karst geology on tunnel construction during the construction process. Karst is the general term for various phenomena and forms caused by the chemical dissolution and mechanical destruction of water on soluble rocks, and a large water-rich filling cavity in the construction and operation area is generally accompanied by karst. As the name implies, the cavity has the characteristics of large scale, wide connection, high water pressure and various fillings. Due to these characteristics, karst tunnels often face the risk of water and mud inrush. Water and mud inrush is the biggest geological disaster during tunnel construction, and the high-pressure water-rich filling cavity encountered by deep-buried karst tunnels poses the greatest threat to tunnel construction and is prone to disasters. How to safely and quickly pass through the high-pressure water-rich cavity has always been a key problem in karst tunnel construction.

[0003] In the rainy season in karst areas, the rainfall increases sharply, and the water pressure of the cavity or the inflow is often too large. At this time, if the drainage tunnel is not reasonably designed or the existing drainage tunnel is blocked by fillings, it is easy to cause the water pressure acting on the lining to be too large, the water pressure distribution to be uneven, and eventually lead to problems such as lining cracking or water and mud inrush.

[0004] At present, the design methods of related drainage tunnels at home and abroad are relatively single, and are often directly set below the longitudinal water channel in the drainage hole of the tunnel, or are horizontal hole type drainage tunnels for large water-rich cavities or underground rivers. Both of these two methods have certain limitations, such as the risk of drainage for undiscovered cavities or drainage channels formed later in karst areas. SUMMARY

[0005] The present application provides a method for determining the setting height of a high-level drainage branch tunnel and a method for analyzing water pressure of a monitoring point to solve the problems in the background art.

[0006] The technical scheme of the present application is as follows:

[0007] The method for determining the setting height of a high-level drainage branch tunnel is carried out for a water-rich filling cavity, and includes the following steps:

[0008] S1, determining that the most important factor affecting the safety of the lining karst area tunnel operation is the final seepage water pressure acting on the lining;

[0009] S2, determine the influencing factors of the final seepage water pressure acting on the lining; the influencing factors include the initial seepage water pressure of the cavity, the reduction of the surrounding rock to the seepage water pressure, and the drainage condition of the drainage tunnel; wherein the reduction of the surrounding rock to the seepage water pressure is based on the karst tunnel lining water pressure reduction model for water-rich filling cavity.

[0010] S3, design the height of the high-level drainage branch tunnel according to the influencing factors.

[0011] Further optimization technical scheme, for the initial seepage water pressure of the cavity, mainly through controlling the maximum value P of the possible seepage water pressure to achieve the purpose of limiting the water pressure;

[0012] The reduction of the surrounding rock to the seepage water pressure is mainly achieved by controlling the reduction coefficient M of the surrounding rock to the water pressure;

[0013] For the drainage condition of the drainage tunnel, mainly through monitoring the proportion of filling material in unit cubic cavity to control the enhancement effect on the maximum seepage water pressure.

[0014] Further optimization technical scheme, the height determination formula of the high-level drainage branch tunnel is:

[0015]

[0016] Wherein: H-the maximum water head that can be set;

[0017] M-the reduction effect coefficient of the surrounding rock to the water pressure;

[0018] N-the enhancement effect coefficient of the filling material to the water head;

[0019] P-the maximum limit water head that the lining can bear;

[0020] K-safety factor.

[0021] Further optimization technical scheme, the reduction coefficient M of the surrounding rock to the water pressure is calculated by the karst tunnel lining water pressure reduction model for water-rich filling cavity.

[0022] Further optimization technical scheme, the construction process of the karst tunnel lining water pressure reduction model for water-rich filling cavity includes the following steps:

[0023] Determine the stage related to the reduction coefficient M of the surrounding rock to the water pressure, including: seepage of cavity water in the surrounding rock crack section, seepage of cavity water in the surrounding rock non-crack section, and water pressure loading before the seepage of cavity water into the surrounding rock and cracks;

[0024] Assume that the expression of the reduction coefficient M of the surrounding rock to the water pressure is:

[0025] M=F[f(x), A(m), B(n)]

[0026] Wherein: F(f, A, B) - the function relationship between the permeability coefficient and three parts of the influencing factors;

[0027] f(x) - the function form of the fracture section of the fracture for the reduction effect of the cavity water pressure;

[0028] A(m) - the reduction effect of the non-fracture section of the surrounding rock on the water pressure of the cavity during the water pressure infiltration process;

[0029] B(n) - the increase and decrease effect of the loading kinetic energy of the cavity water pressure during the loading stage on the cavity water pressure;

[0030] The reduction coefficient M of the water pressure of the surrounding rock is analyzed, and the expression of the reduction coefficient M of the water pressure of the surrounding rock is determined.

[0031] Further optimize the technical scheme, the reduction coefficient M of the water pressure of the surrounding rock is:

[0032]

[0033] Wherein: L - the length of the surrounding rock between the water inlet point of the cavity and the lining;

[0034] l - the transverse length of the fracture channel;

[0035] k - the permeability coefficient of the non-fracture section of the surrounding rock;

[0036] v - the loading speed of the cavity water pressure;

[0037] P - the initial infiltration water pressure;

[0038] ω(l) - the correlation function of the infiltration part and the transverse length l of the fracture.

[0039] Further optimize the technical scheme, the enhancement coefficient N of the water head of the filling is:

[0040]

[0041] Wherein: Ae - the filling;

[0042] C - constant.

[0043] Further optimize the technical scheme, the maximum limit water head P that the lining can bear is obtained according to the design calculation and the long-term monitoring during the operation stage.

[0044] The water pressure analysis method of the monitoring point is carried out by the karst tunnel lining water pressure reduction model for the water-rich filling cavity to realize the quantitative analysis of the single-point water infiltration on the pore water pressure of the monitoring point under different surrounding rock characteristics.

[0045] Further optimize technical solutions, comprising the following steps:

[0046] If the surrounding rock itself has multiple penetration cracks or various forms of cracks during the penetration process, or the permeability coefficient of the surrounding rock itself changes, the surrounding rock is processed in layers or the permeability coefficient is processed by continuous integration, and the end point parameter of each layer or each integral segment is taken as the starting point parameter for calculation of the next layer or the next segment, so as to perform iterative processing;

[0047] If the monitoring point and the penetration point are not on the same horizontal line, the pore water pressure of the point on the same horizontal line and consistent with the horizontal coordinate of the monitoring point is measured, and then the penetration is carried out towards the required monitoring point according to the characteristics of the penetrating water, so as to indirectly obtain the pore water pressure of the corresponding monitoring point;

[0048] If the penetration load is not a point load, the load is split into a finite number of or continuous infinite point loads according to the micro-element method, and then the penetration calculation is carried out, and finally the corresponding parameters of the monitoring point are superimposed and summarized.

[0049] By adopting the above technical solutions, the present application has the following beneficial effects:

[0050] According to the three influencing factors of the initial penetration water pressure of the solution cavity, the reduction of the surrounding rock to the penetration water pressure and the drainage condition of the drainage tunnel, the height of the high-level drainage branch tunnel is accurately designed in the water-rich filling solution cavity, which can effectively solve the drainage problem of the undiscovered solution cavity or the drainage channel formed again in the karst area, ensure the operation safety, speed up the tunnel construction progress, safely and quickly pass through the high-pressure water-rich solution cavity in the karst tunnel construction, and avoid the risk of water and mud inrush. BRIEF DESCRIPTION OF DRAWINGS

[0051] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0052] Figure 1 The water pressure penetration process in the surrounding rock of the present application;

[0053] Figure 2 The solution cavity penetration process when the surrounding rock has multiple penetration cracks in the present application;

[0054] Figure 3 The solution cavity penetration process when the monitoring point and the penetration point are not on the same axis in the present application;

[0055] Figure 4The figure is used for the infiltration process of the solution cavity of the present application when the load is not a point load;

[0056] Figure 5 The figure is a flow chart of the height determination method for the high-level drainage branch hole of the present application. DETAILED DESCRIPTION

[0057] The technical solutions of the present application will be described in detail below in conjunction with specific embodiments, but those skilled in the art should understand that the embodiments described below are only used to illustrate the present application and should not be regarded as limiting the scope of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0058] The height determination method for the high-level drainage branch hole is carried out for the water-rich filling solution cavity, which comprises the following steps:

[0059] S1, determining that the most important factor affecting the tunnel operation safety of the lining karst area is the final seepage water pressure acting on the lining.

[0060] S2, the factors affecting the final size and distribution of the seepage water pressure acting on the lining mainly include three aspects:

[0061] 1) initial seepage water pressure of the solution cavity;

[0062] 2) reduction of the surrounding rock to the seepage water pressure;

[0063] 3) drainage condition of the drainage hole.

[0064] Among them, the reduction of the surrounding rock to the seepage water pressure is carried out based on the karst tunnel lining water pressure reduction model for the water-rich filling solution cavity.

[0065] S3, according to the three influencing factors, the height of the high-level drainage branch hole is designed in the water-rich filling solution cavity.

[0066] For the initial seepage water pressure of the solution cavity, the maximum value P of the possible seepage water pressure is mainly controlled, and the reduction coefficient M of the water pressure of the surrounding rock is mainly controlled, so as to ensure that the maximum value of the water pressure distribution acting on the outside of the lining after the seepage reduction effect of the surrounding rock, so as to achieve the purpose of limiting the water pressure.

[0067] For the drainage condition of the drainage hole, the proportion of filling materials such as stones, sludge, karst water and the like in the unit cubic solution cavity is monitored, so as to control the enhancement effect of the maximum seepage water pressure, which is equivalent to multiplying the maximum water pressure H by a magnification coefficient N.

[0068] Therefore, the height determination formula of the high-level drainage branch hole is obtained:

[0069]

[0070] H—maximum water head height that can be set;

[0071] M—surrounding rock reduction effect coefficient of water pressure;

[0072] N—filling enhancement effect coefficient of water head;

[0073] P—maximum limit water head that lining can bear;

[0074] K—safety factor, reliability index of guaranteeing structure safety, less than 1.

[0075] The present application is aimed at the selection and calculation of each parameter in the above formula and the specific process is as follows:

[0076] I. Surrounding rock reduction coefficient M of water pressure

[0077] The surrounding rock reduction coefficient M of water pressure is calculated through the karst tunnel lining water pressure reduction model for water-filled solution cavity.

[0078] Through research, it is found that when there is surrounding rock between the karst tunnel lining and the solution cavity, the solution cavity water is supplied by the solution cavity, and the initial water pressure is applied to the surrounding rock, and finally acts on the tunnel lining structure through the penetration effect, but the solution cavity seepage water pressure of the lining structure in the actual monitoring is less than the initial water pressure, and the surrounding rock has a certain proportion of reduction effect on the solution cavity seepage water pressure. Therefore, the present application proposes a karst tunnel lining water pressure reduction model for water-filled solution cavity.

[0079] The construction process of the karst tunnel lining water pressure reduction model for water-filled solution cavity includes the following steps:

[0080] Determine the stage related to the surrounding rock reduction coefficient M of water pressure. The whole process of solution cavity water penetrating the surrounding rock is mainly divided into three parts:

[0081] 1) Solution cavity water penetration in the surrounding rock crack section;

[0082] 2) Solution cavity water penetration in the surrounding rock non-crack section;

[0083] 3) Water pressure loading before solution cavity water penetrates into the surrounding rock and cracks.

[0084] As shown in Figure 1 , it can be clearly seen that there are three parts of solution cavity water penetration, first, the solution cavity water pressure acts on the surrounding rock, that is, Figure 1The water pressure shown in ③ is the uniformly distributed isotropic pressure within the cavity, represented by P in the diagram. Immediately following, the dissolved water at the crack, under the influence of water pressure P, enters the crack tangentially at the crack entrance. Driven by pressure, it undergoes a certain degree of energy loss before reaching A from B. At this point, the water pressure uniformly fills the entire crack, and the pressure begins to radiate spherically in all directions, starting from each point on the crack as a micro-unit. The stress that directly affects the monitoring point is the continuous stress distributed along the functional crack, pointing from each micro-unit to point O. Figure 1 As shown in ①; the final pore water pressure acting at the monitoring point is the sum of the continuous stress distributed along the functional fracture acting on point O, and the seepage stress after water permeates through the surrounding rock itself to the point of breakage. The process is as follows: Figure 1 The shaded area in section ② is shown.

[0085] Since the magnitude of the permeability coefficient M is closely related to these three stages, we can first assume that the expression for the permeability coefficient M is:

[0086] M = F[f(x), A(m), B(n)]

[0087] Where: F(f, A, B) — the functional relationship between the permeability coefficient and the three influencing factors;

[0088] The functional form of f(x) – the reduction effect of fracture pressure on the cavity water pressure – corresponds to… Figure 1 Part ①;

[0089] A(m) - The reduction effect of water pressure in the solution cavity on the water pressure during the water pressure seepage process in the non-fractured section of the surrounding rock, corresponding to Figure 1 Part ②;

[0090] The effect of the loading kinetic energy during the B(n)-cavity water pressure loading stage on the increase or decrease of cavity water pressure, corresponding to Figure 1 Part ③.

[0091] The reduction factor M of the assumed surrounding rock to water pressure is analyzed, and the expression for the reduction factor M of the surrounding rock to water pressure is determined.

[0092] for Figure 1 Part ① Figure 1 With y(x) = x 2For example, assuming the crack crack transverse length is l, the length of the surrounding rock between the water inlet point of the cavity and the lining is L, then y(x) is a function of L and l, and the longitudinal BC height is y(l). Among them, the function form of the crack section of the crack has two parts of the reduction effect of the water pressure of the cavity, one part is the friction effect of the friction resistance of the crack on the hydraulic energy, and the other part is the energy loss caused by forcing the seepage water to turn in the crack. The former is positively correlated with the damping coefficient of the crack and can be ignored, and the energy loss caused by the latter cannot be ignored, and the direction of the seepage water must be along the crack direction, so the energy loss effect caused by the turning must be a function of the crack form f(x) and related to l, that is, y(f(x), l) is its expression.

[0093] For Figure 1 In the second part of the second part, the seepage path (AO is taken as an example) and the incidence angle of the seepage water ∠AOD=α are functions of L and l and x and f(x), and the most important influencing factor of this part is the permeability coefficient k of the surrounding rock. The quantitative calculation of the seepage process conforms to the seepage force formula, so the expression of A(m) can be rewritten as A[k, f(x), L, l], but compared with the permeability coefficient k, f(L, l) has a lower influence on this part, and the first part already contains the influence of f(L, l), so it can be simplified to a certain extent in the following derivation.

[0094] For Figure 1 In the third part of the third part, the influence is relatively simple. The seepage water pressure P directly affects the initial pressure of the seepage water and the size of the pore water pressure acting on the monitoring point, and the direct factor affecting the size of the seepage water pressure P is the water inflow speed v of the cavity water, without additional influencing factors, so B(z) can be directly rewritten as B(v) as its expression. And because of the special influence of water pressure loading speed, when the dynamic water speed is 0, it shows a static water steady state, so the amplification coefficient is 1, and when the dynamic water speed is not 0, it shows an increasing effect, so the amplification coefficient is greater than 1, then B(v) is a fourth order polynomial of v with the first term being 1.

[0095] Therefore, the expression of the above-mentioned reduction coefficient M of the surrounding rock to the water pressure is rewritten as:

[0096]

[0097] Wherein: L- the length of the surrounding rock between the water inlet point of the cavity and the lining, m;

[0098] l- the transverse length of the crack channel, m;

[0099] k- the permeability coefficient of the non-crack section of the surrounding rock, cm / s;

[0100] v- the water pressure loading speed of the cavity, MPa / step or MPa / s;

[0101] P-initial water pressure of infiltration, MP;

[0102] ω(l)-function of correlation between the infiltration part and the transverse length l of the crack.

[0103] II. The enhancement effect coefficient N of the filling on the water head

[0104] The current research shows that, in a unit volume of cavity, the presence of a certain proportion of stable filling has a certain functional relationship with the increase of the original water head, which is mainly related to the space proportion of the filling in the unit volume and the density porosity of the filling itself.

[0105] Under the condition that other factors remain unchanged, only the space proportion of the filling is changed, it is found that the square of the space proportion of the filling and the water pressure show an exponential function relationship, that is:

[0106]

[0107] Wherein: Ae-filling;

[0108] C-constant.

[0109] For the filling itself, the physical and mechanical parameters of the main filling are obtained by sampling detection, and then the pre-and-post pressure difference of the infiltration water pressure is obtained through laboratory infiltration experiment, so as to serve as the basis for evaluating the enhancement effect coefficient N.

[0110] III. The maximum limit water head P that the lining can bear

[0111] The maximum limit water head P that the lining can bear can be obtained according to the design calculation and long-term monitoring in the operation stage.

[0112] IV. Safety factor K

[0113] The safety factor K, which is a reliability index of the structure safety, is selected according to the reliability requirement and the service life of the structure design, and in accordance with the design standard.

[0114] The monitoring point water pressure analysis method is carried out by means of the karst tunnel lining water pressure reduction model of the water-rich filling solution cavity, so as to realize the quantitative analysis of the single-point water infiltration on the monitoring point pore water pressure under different surrounding rock characteristics. If the pore water pressure of a monitoring point is too large, it is determined that the monitoring point is prone to water and mud inrush, so as to avoid the risk of water and mud inrush.

[0115] If the surrounding rock has multiple permeation cracks or multiple forms of cracks during the permeation process, or the permeation coefficient of the surrounding rock changes, the surrounding rock can be processed in layers or the permeation coefficient can be processed by continuous integration. The end point parameter of each layer or each integral segment is taken as the starting point parameter for the next layer or the next segment calculation, thereby performing iterative processing, as shown in Figure 2 .

[0116] If the monitoring point and the penetration point are not on the same horizontal line, the pore water pressure of the point with the same horizontal coordinate as the monitoring point on the same horizontal line can be measured, and then the point is taken as the starting point to perform permeation towards the required monitoring point according to the characteristics of the permeated water, thereby indirectly obtaining the pore water pressure of the corresponding monitoring point. However, since the permeation pressure obtained by the monitoring point on the non-horizontal line is smaller than the value of the monitoring point on the horizontal end, it is also safe to take a conservative simplified calculation, as shown in Figure 3 .

[0117] If the penetration load is not a point load, the load can be split into a finite number of point loads or a continuous infinite number of point loads according to the micro-element method, and then the permeation calculation is performed, and finally the corresponding parameters of the monitoring point are superimposed and summarized, as shown in Figure 4 .

[0118] Although the present application has been described in detail above with general description and specific embodiments, some modifications or improvements can be made on the basis of the present application, which is obvious to those skilled in the art. Therefore, these modifications or improvements made on the basis of not deviating from the spirit of the present application, all belong to the scope of protection required by the present application.

Claims

1. A method for determining the setting height of a high-level water discharge branch tunnel, characterized in that, The method is carried out for the water-rich filling solution cavity, and comprises the following steps: S1, determining that the most important factor affecting the tunnel operation safety of the karst area of the lining is the final seepage water pressure acting on the lining; S2, determining the influencing factors of the final seepage water pressure acting on the lining; the influencing factors comprise an initial seepage water pressure of the solution cavity, a reduction of the seepage water pressure by the surrounding rock, and a drainage condition of the drainage tunnel; wherein the reduction of the seepage water pressure by the surrounding rock is carried out based on a water pressure reduction model of the karst tunnel lining for the water-rich filling solution cavity; S3, designing a height of the high-level drainage branch tunnel according to the influencing factors in the water-rich filling solution cavity; The obtained high-level drainage branch tunnel height determination formula is: Wherein: H is a maximum water head height that can be set; M is a reduction effect coefficient of the water pressure by the surrounding rock; N is an enhancement effect coefficient of the water head by the filling material; P is a maximum limit water head that can be borne by the lining; K is a safety coefficient; The construction process of the water pressure reduction model of the karst tunnel lining for the water-rich filling solution cavity comprises the following steps: A stage related to the reduction coefficient M of the water pressure by the surrounding rock is determined, comprising: seepage of the solution cavity water in the surrounding rock crack section, seepage of the solution cavity water in the surrounding rock non-crack section, and water pressure loading of the solution cavity water before seeping into the surrounding rock and cracks; An expression of the reduction coefficient M of the water pressure by the surrounding rock is assumed as: Wherein: F(f, A, B) is a functional relationship between the seepage coefficient and three parts of influencing factors; the three parts are: 1) seepage of the solution cavity water in the surrounding rock crack section; 2) seepage of the solution cavity water in the surrounding rock non-crack section; 3) water pressure loading of the solution cavity water before seeping into the surrounding rock and cracks; - the functional form of the fracture segment of the fracture for the depletion effect of the fracture on the cavern water pressure; - the reduction effect of water pressure infiltration process of non-fracture section of surrounding rock on the water pressure of the dissolved cavity; - the effect of the loading kinetic energy of the water pressure loading stage on the increase and decrease of the water pressure of the solution cavity; The reduction coefficient M of the water pressure by the surrounding rock is analyzed to determine the expression of the reduction coefficient M of the water pressure by the surrounding rock.

2. The method of claim 1, wherein, The initial seepage water pressure of the solution cavity is mainly limited by controlling the maximum value P of the possible seepage water pressure; The reduction of the seepage water pressure by the surrounding rock is mainly limited by controlling the reduction coefficient M of the water pressure by the surrounding rock; The drainage condition of the drainage tunnel is mainly controlled by monitoring the proportion of the filling material in the unit cubic solution cavity to control the enhancement effect of the maximum seepage water pressure.

3. The method for determining the height of the high-level drainage branch tunnel according to claim 1, characterized in that, The reduction coefficient M of the water pressure by the surrounding rock is calculated by the water pressure reduction model of the karst tunnel lining for the water-rich filling solution cavity.

4. The method of claim 1, wherein, The expression of the reduction coefficient M of the water pressure by the surrounding rock is: wherein: l— ; k is a seepage coefficient of the surrounding rock non-crack section; v is a solution cavity water pressure loading speed; P is an initial seepage water pressure; - a function of the permeable section in relation to the lateral length of the fracture, l.

5. The method of claim 1, wherein, The expression of the enhancement effect coefficient N of the water head by the filling material is: Wherein: Ae is the filling material; C is a constant.

6. The method of claim 1, wherein, The maximum limit water head P that can be borne by the lining is obtained according to design calculation and long-term monitoring in the operation stage.

7. A monitoring point water pressure analysis method characterized by, The method is carried out by the water pressure reduction model of the karst tunnel lining for the water-rich filling solution cavity applied in the high-level drainage branch tunnel height determination method of any one of claims 1 to 6, to realize quantitative analysis of single-point water seepage on the pore water pressure of the monitoring point under different surrounding rock characteristics, comprising the following steps: If the surrounding rock has multiple seepage cracks or various forms of cracks or the seepage coefficient of the surrounding rock changes during the seepage process, the surrounding rock is treated in layers or the seepage coefficient is treated by continuous integration, and the end point parameter of each layer or each segment of integration is taken as the starting point parameter for the next layer or the next segment of calculation, so as to perform iterative processing; If the monitoring point and the penetration point are not on the same horizontal line, the pore water pressure of a point on the same horizontal line and having the same horizontal coordinate as the monitoring point is measured, and then the point is taken as the starting point to perform seepage according to the characteristics of the seepage water, so as to indirectly obtain the pore water pressure of the corresponding monitoring point; If the penetration load is not a point load, the load is split into a finite number of or a continuous infinite number of point loads according to the micro-element method, and then seepage calculation is performed, and finally the corresponding parameters of the monitoring point are superimposed and summarized.

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