A method and system for determining the amount of water seepage in an underground tunnel and waterproofing material

Abstract

The present disclosure relates to underground tunnel structure, and specifically provides a method and system for determining the water seepage amount of underground tunnel and waterproof material, wherein the method comprises: establishing a simplified model for calculating the water seepage amount of deep underground tunnel; solving the analytical solution and calculating the water seepage amount of underground tunnel; and selecting the waterproof material meeting the requirements according to the water seepage amount. The present disclosure can quantitatively calculate the water seepage amount of deep underground tunnel according to different strata, water-resisting curtain, waterproof material and the setting parameters of drain blind pipe spacing, thereby guiding the waterproof and anti-seepage design of tunnel structure and selecting material in detail. The present disclosure has good social and economic benefits in terms of the safety of tunnel structure, detailed waterproof design and saving of engineering investment.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of underground tunnel structure, and particularly to a method and system for determining the water seepage amount of an underground tunnel and waterproof material. BACKGROUND

[0002] Groundwater control is an important issue that cannot be avoided in the development of underground space. In the shallow underground space of a city, there are relatively mature groundwater control technologies, while the groundwater control of deep urban tunnels is still a new issue that needs to be explored technically to provide technical accumulation for the upcoming development of deep urban underground space.

[0003] Currently, the waterproofing of urban shallow underground tunnels and other structures mainly involves setting a waterproof curtain and a full waterproof layer, combined with structural self-waterproofing design. The composite waterproof layer uses waterproof boards (PVC) or on-site sprayed waterproof materials with geotextiles as a buffer layer between the waterproof curtain and the secondary lining. The drainage of underground tunnel structures mainly uses open drainage, and common drainage ditches include: (1) Ring drainage blind ditch: a ring drainage blind ditch is uniformly arranged along the longitudinal direction of the transverse structure, which directly collects groundwater seeped from the surrounding structure and the waterproof curtain. (2) Longitudinal drainage blind ditch: unlike the vertical shaft structure, the longitudinal drainage blind ditch only needs to be set at the bottom of the external drainage system, which collects groundwater collected by the ring drainage ditch and drains the drainage system inside the transverse structure space. At the same time of setting the drainage ditch, the internal structure more commonly uses horizontal ditches or longitudinal drainage ditches, which are then further concentrated and drained, and some structures use locally set water blind pipes or drainage holes to ensure that there is no open water operation during construction and no seepage water during operation.

[0004] Many existing waterproofing and drainage technologies are suitable for spaces 50m or shallower, and are less mature for use below 50m. Moreover, there are still the following problems: 1) The existing waterproofing and seepage prevention design does not consider the size of external seepage, determines the waterproofing level according to the structure depth, and selects the corresponding waterproofing material; 2) Different professions have different waterproofing and seepage prevention design methods, such as railway, water conservancy and power, and civil air defense engineering, but they do not have the characteristics of quantitative calculation and appropriate material selection, which may cause problems such as insufficient waterproofing material in the rich water section and excessive waterproofing material in the poor water section. 3) There is no relatively clear description of the waterproofing and seepage prevention design of deep urban underground structures, which can be used as a reference for the experience of shallow structure waterproofing and seepage prevention to some extent, but the differences with existing shallow projects are still very obvious.

[0005] In summary, the current city deep underground tunnel waterproof and anti-seepage design is mostly conventional coiled material and paint with multiple layers and multiple thicknesses, which cannot be designed according to the high water head characteristics of deep underground space. Moreover, there is no unified method for calculating the tunnel seepage amount in various industries, which makes the waterproofing of deep underground tunnels unable to be linked to the seepage amount. This may lead to the problem of insufficient waterproof material in the water-rich section of the deep underground tunnel and redundant waterproof material in the water-poor section. SUMMARY

[0006] To solve the above-mentioned prior art problems, the present disclosure provides a method for determining the seepage amount of an underground tunnel and waterproof material, comprising:

[0007] establishing a simplified model for calculating the seepage amount of a deep underground tunnel;

[0008] solving the analytical solution and calculating the seepage amount of the underground tunnel;

[0009] selecting waterproof material that meets the requirements according to the size of the seepage amount.

[0010] Preferably, the establishment of the simplified model for calculating the seepage amount of a deep underground tunnel is parameterized characteristics, including:

[0011] the outer diameter r1 of the secondary lining, the outer diameter r0 of the waterproof curtain, the thickness T of the waterproof curtain, and the permeability coefficient k of the waterproof curtain c , the thickness t of the gap surface layer, and the permeability coefficient k of the gap surface layer m , the center distance of the outer periphery of the waterproof curtain is h0, the center water head of the outer periphery of the tunnel secondary lining is h1, and D is the spacing of the drainage blind pipe.

[0012] Preferably, the characteristics of the simplified model include:

[0013] the water pressure outside the tunnel is an equivalent radial pressure;

[0014] the water pressure acting on the curtain ring follows a linear distribution along the longitudinal axis of the tunnel;

[0015] drainage blind pipes with a spacing of D are arranged along the longitudinal direction of the tunnel, the water head at the drainage pipe is 0, and the maximum value h 1max is reached in the middle of the line connecting the two drainage pipes.

[0016] Preferably, the solving of the analytical solution and the calculation of the seepage amount of the underground tunnel specifically include:

[0017] the tunnel seepage amount Q1 in each range with a spacing of D is:

[0018] .

[0019] Preferably, the seepage amount of the waterproof curtain per meter of the tunnel is:

[0020] .

[0021] Preferably, the seepage flow of the tunnel in the range of the gap face layer with a distance D is:

[0022]

[0023] Wherein, Ai is the unit hydraulic slope.

[0024] Preferably, in the range of x=(0, D / 2), the water head distribution satisfies:

[0025] .

[0026] Preferably, the distribution of the water head in any longitudinal axial x and any radial r plane is:

[0027]

[0028] Wherein, h(r) is the radial water head height of the secondary lining, and h(x) is the longitudinal axial water head height of the secondary lining.

[0029] Preferably, the waterproof material selected according to the size of the seepage water quantity to meet the requirements comprises:

[0030] According to the calculated size of the seepage water quantity, combined with the deep underground tunnel waterproof and anti-seepage design specification, the physical index requirements of the waterproof material, and the targeted selection of the waterproof material capable of resisting the seepage water quantity.

[0031] The present disclosure also provides a system for determining the seepage water quantity and waterproof material of an underground tunnel, which is used in the method for determining the seepage water quantity and waterproof material of an underground tunnel, and comprises:

[0032] The model establishing module is configured to establish a simplified model for calculating the seepage water quantity of a deep underground tunnel.

[0033] The solving module is configured to solve the analytical solution and calculate the seepage water quantity of the underground tunnel.

[0034] The material selection module is configured to select a waterproof material that meets the requirements according to the size of the seepage water quantity. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 The tunnel seepage water quantity calculation parameter distribution diagram provided by the present disclosure;

[0036] Figure 2 The tunnel drainage blind pipe inter-water pressure distribution diagram provided by the present disclosure;

[0037] Figure 3 The curtain ring seepage flow calculation microelement model diagram provided by the present disclosure. DETAILED DESCRIPTION

[0038] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this disclosure.

[0039] Currently, waterproofing and seepage prevention designs for deep urban underground tunnels mostly rely on multi-layered and multi-thick layers of conventional rolled materials and coatings, failing to address the specific characteristics of high water head in deep underground spaces. Furthermore, there is no unified method across industries for calculating tunnel seepage, making it impossible to correlate waterproofing with seepage volume. This can lead to insufficient waterproofing material in water-rich sections and redundant material in water-scarce sections of deep underground tunnels. Therefore, it is crucial to develop a method for quantitatively calculating seepage volume in deep underground tunnels by considering parameters such as different geological strata, impermeable curtains, waterproofing materials, and drainage pipe spacing. This will guide the waterproofing and seepage prevention design of tunnel structures and enable refined material selection, which is of great significance for the design and construction of urban underground tunnel projects.

[0040] Based on this, such as Figure 1 As shown in the embodiments of this disclosure, a method for determining the seepage volume and waterproofing materials of deep underground tunnels in cities is provided.

[0041] First, a simplified model of deep underground tunnels and drainage blind pipes in the city can be established to obtain the characteristic parameter values ​​of the simplified tunnel model, including: outer diameter r1 of the secondary lining (secondary lining) or segments, outer diameter r0 of the outer ring of the waterproof curtain, thickness T of the waterproof curtain ring, and permeability coefficient k of the waterproof curtain. c Thickness t of the gap surface layer (waterproof layer), permeability k of the gap surface layer (waterproof layer) m The center distance from the outer perimeter of the waterproof curtain ring to the groundwater head is h0, the center distance from the outer perimeter of the tunnel secondary lining or segment is h1, and the center distance from the drainage blind pipe is D.

[0042] The parameters obtained above are then substituted into the theoretical analytical calculation to obtain the seepage volume Q of the deep underground tunnel in the city.

[0043] Finally, based on the calculated seepage volume and the specifications for waterproofing and seepage prevention design of deep underground tunnels, waterproofing materials capable of withstanding that volume of seepage can be selected. Specifically, indoor tests can be conducted to verify the minimum elongation, impermeability, and other characteristic parameters of the waterproofing material required for that seepage volume, allowing for the rational and economical selection of appropriate waterproofing materials to achieve precise waterproofing and seepage prevention.

[0044] In a specific implementation scenario, in the process of tunnel waterproof and anti-seepage design, according to the calculated seepage amount, combined with the specification requirements of deep underground tunnel waterproof and anti-seepage design, the waterproof material that can resist the seepage amount can be selected. Specifically, the minimum elongation, impermeability and other characteristic parameters of the required waterproof material under the seepage amount can be verified through indoor test, and the corresponding waterproof material can be selected reasonably and economically, so as to achieve the requirement of precise waterproof and anti-seepage.

[0045] By simplifying the model parameters between the external water pressure of the urban deep underground tunnel and its size, the waterproof curtain and the drainage blind pipe, the seepage amount of the underground tunnel is quantitatively obtained, and then according to the size of the seepage amount, combined with the specification requirements of deep underground tunnel waterproof and anti-seepage design, the waterproof material that can resist the seepage amount can be selected, which has important engineering practical significance and application prospect for fine waterproof and drainage design.

[0046] The present disclosure can quantitatively calculate the seepage amount of the deep underground tunnel according to the setting parameters of different strata, waterproof curtains, waterproof materials and drainage blind pipe spacing, so as to guide the waterproof and anti-seepage design of the tunnel structure and select materials finely. It has good social and economic benefits in terms of safety of tunnel structure, fine waterproof design and economy of engineering investment.

[0047] In a specific implementation scenario, the method of the present disclosure includes three stages: (1) establishing a simplified model for calculating the seepage amount of deep underground tunnel; (2) solving the analytical solution and calculating the seepage amount of underground tunnel; (3) selecting waterproof materials that meet the requirements according to the size of the seepage amount.

[0048] (1) Establish a simplified model for calculating the seepage amount of deep underground tunnel. As shown in Figure 1 .

[0049] Taking the following urban deep tunnel as the research object, the tunnel cross-sectional shape is circular, and the parameterized characteristics are: the outer diameter r1 of the secondary lining or segment, the outer diameter r0 of the waterproof curtain ring, the thickness T of the waterproof curtain ring, the permeability coefficient k c of the waterproof curtain ring, the thickness t of the gap surface layer (waterproof layer), the permeability coefficient k m of the gap surface layer (waterproof layer), the center distance of the outer periphery of the waterproof curtain ring from the groundwater head height h0, and the center water head height h1 of the outer periphery of the tunnel secondary lining or segment. It is assumed that the tunnel lining and the surrounding rock-soil body are homogeneous, the self-weight of the medium is ignored, the permeability coefficient of the material is the same in all directions, the seepage direction is mainly radial, and the influence of buoyancy is not considered.

[0050] The urban deep tunnel has the following characteristics:

[0051] 1) The water pressure water head height of groundwater acting on the outer periphery of the tunnel is much larger than the diameter of the tunnel, so the external water pressure is assumed to be an equivalent radial pressure.

[0052] 2) The water pressure acting on the curtain ring is the initial water head height h0 of the surrounding rock, and the water head height acting on the secondary lining is h1, which is linearly distributed along the longitudinal axis of the tunnel.

[0053] 3) The drainage blind pipe is arranged along the longitudinal direction of the tunnel with a spacing D, the water head at the drainage pipe is 0, and the maximum value h is reached in the middle of the line connecting the two drainage pipes. 1max The longitudinal axis is x-axis, the water head of the external water distributed along the longitudinal direction is h(x), and the spacing of the drainage blind pipe is D, see Figure 2 .

[0054] (2) Solve the analytical solution and calculate the water seepage quantity of the underground tunnel.

[0055] 1) Seepage in the water-resisting curtain

[0056] In the water-resisting curtain range, the model radius is r = (r1, r0), according to Darcy's law, while considering the same seepage flow on each ring surface along the r direction, the following equation can be obtained:

[0057] ............................(1)

[0058] In the formula:

[0059]

[0060] (1) Expand the formula to obtain:

[0061] ............................(2)

[0062] In the formula:

[0063]

[0064] Integrate equation (2) to obtain the expression of water head h in r direction:

[0065] ............................(3)

[0066] In the formula:

[0067]

[0068] Now consider the boundary conditions:

[0069] 1) When r = r0, the water head h = h0 = 0;

[0070] 2) When r = r1, the water head h = h(x).

[0071] Substitute equation (3) into the simultaneous equations, and the values of constants A and B can be obtained:

[0072] ............................ (4)

[0073] ............................ (5)

[0074] Thus, the distribution of water head in any longitudinal-radial plane within the waterproof curtain can be obtained:

[0075] ............................ (6)

[0076] 2) Seepage of the waterproof curtain to the gap surface layer (waterproof layer).

[0077] The permeability coefficient of the curtain ring is k c , and a microelement with a longitudinal length of dx and an arc angle of dθ is taken, as shown in Figure 3 .

[0078] According to Darcy's law, the seepage flow dq through the microelement and into the gap surface layer is:

[0079] ............................ (7)

[0080] According to 3) Within the range of x = (0, D / 2), the water head distribution satisfies:

[0081] ............................ (8)

[0082] Integrating the microelement in x = (0, D / 2) and the tunnel circumference, the half drainage q into one drainage blind pipe can be obtained:

[0083] ............................ (9)

[0084] Substituting equations (7) and (8) into equation (9), we get:

[0085]

[0086]

[0087]

[0088] ...........................(10)

[0089] By 2 and Figure 3 It can be seen that the tunnel seepage flow Q1 in each distance D range is:

[0090] .........................(11)

[0091] According to Darcy's law, the seepage flow of the gap surface layer (waterproof layer) into the tunnel in the distance D range is:

[0092] ..........................(12)

[0093] Q1=Q2, together with equation 11 and equation 12:

[0094] The peak water pressure of the secondary lining can be obtained as:

[0095] ........................(13)

[0096] Therefore, the seepage amount of each meter of tunnel waterproof curtain can be obtained as:

[0097] (14)

[0098] Wherein, the interpretation of each parameter is shown in the following table:

[0099]

[0100] (3) According to the size of seepage, select the waterproof material that meets the requirements.

[0101] According to the size of the calculated seepage, combined with the design specification of deep underground tunnel waterproof and anti-seepage, the physical index requirements of waterproof material, the waterproof material that can resist the seepage can be selected.

[0102] The minimum elongation, impermeability and other characteristic parameters of the waterproof material required under the seepage can also be verified through indoor test, and the waterproof material that meets the design requirements can be selected reasonably and economically to achieve the requirement of precise waterproof and anti-seepage.

[0103] In the description of the embodiments of the present disclosure, it needs to be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "center", "top", "bottom", "top", "bottom", "inner", "outer", "inner side", "outer side" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present disclosure and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present disclosure. Among them, "inside" refers to the inside or enclosed area or space. "Periphery" refers to the area around a particular component or a particular area.

[0104] In the description of the embodiments of the present disclosure, the terms "first", "second", "third", "fourth" are only used for description purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second", "third", "fourth" can be explicitly or implicitly included one or more of the features. In the description of the present disclosure, unless otherwise stated, the meaning of "a plurality of" is two or more.

[0105] In the description of the embodiments of the present disclosure, it needs to be explained that, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "assembling" should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present disclosure can be understood according to the specific circumstances.

[0106] In the description of the embodiments of the present disclosure, specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0107] In the description of the embodiments of the present disclosure, it needs to be understood that "-" and "~" represent the range of the same of two numerical values, and the range includes the end points. For example: "A-B" represents a range greater than or equal to A and less than or equal to B. "A~B" represents a range greater than or equal to A and less than or equal to B.

[0108] In the description of the embodiments of the present disclosure, the term "and / or" herein is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " herein generally represents that the front and rear associated objects have an "or" relationship.

[0109] While embodiments of the present disclosure have been shown and described, it is to be understood that the embodiments can be varied, modified, substituted and otherwise changed by those skilled in the art without departing from the principles and spirit of the present disclosure, the scope of which is to be determined by the following claims and their equivalents.

Claims

1. A method of determining the amount of water seepage in an underground tunnel and a waterproofing material, characterized by, The application relates to a method for determining the water seepage amount of a deep underground tunnel and selecting waterproof materials, and a system thereof. The simplified model for calculating the water seepage amount of the deep underground tunnel comprises the following parameterized features: The features of the simplified model comprise the following: The secondary lining outer diameter r1, the waterproof curtain outer circle outer diameter r0, the waterproof curtain circle thickness T, and the waterproof curtain permeability coefficient k c The gap surface layer thickness t and the gap surface layer permeability coefficient k m The waterproof curtain circle outer periphery center distance is h0, and the tunnel secondary lining outer periphery center water head height is h1; D is the drain blind pipe interval; The water pressure outside the tunnel is equivalent radial pressure; The water pressure acting on the curtain ring is subjected to linear distribution along the longitudinal axis direction of the tunnel; The analytic solution is solved and the water seepage amount of the underground tunnel is calculated; Drainage blind pipes are arranged along the longitudinal direction of the tunnel with a spacing of D, the water head at the drainage pipes is 0, and the maximum value h is reached in the middle of the line connecting the two drainage pipes 1max ; The water seepage amount Q1 of the tunnel in each range with a distance of D is: The water seepage amount of the tunnel in each range with a distance of D is: Wherein, Ai is the unit water slope; The water seepage amount of the waterproof curtain of the tunnel per meter is: According to the water seepage amount, the waterproof material meeting the requirements is selected. In the range of x=(0, D / 2), the water head distribution meets the following formula:

2. The method of determining the amount of water seepage in an underground tunnel and waterproofing material according to claim 1, wherein, The distribution rule of the water head in any longitudinal x and any radial r plane is: 。 3. The method of determining the amount of water seepage in an underground tunnel and waterproofing material according to claim 2, wherein, Wherein, h(r) is the radial water head height of the secondary lining, and h(x) is the longitudinal water head height of the secondary lining. The method for selecting the waterproof material meeting the requirements according to the water seepage amount comprises the following steps:

4. The method of determining the amount of water seepage in an underground tunnel and waterproofing material according to claim 1, wherein, According to the calculated water seepage amount, the waterproof material capable of resisting the water seepage amount is selected in combination with the deep underground tunnel waterproof and anti-seepage design specification and the physical index requirements of the waterproof material. The system is used in the method for determining the water seepage amount of the underground tunnel and selecting the waterproof material, and comprises the following:

5. A system for determining the amount of water seepage in an underground tunnel and a waterproofing material, characterized by, The model establishing module is configured to establish the simplified model for calculating the water seepage amount of the deep underground tunnel; The solution module is configured to solve the analytic solution and calculate the water seepage amount of the underground tunnel; The material selecting module is configured to select the waterproof material meeting the requirements according to the water seepage amount. ​

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