A tunnel leakage water treatment method

Abstract

The application provides a tunnel leakage water treatment method, and belongs to the field of tunnel leakage treatment. The technical scheme is as follows: first, the actual leakage amount of the leakage point is determined, then the relevant parameters are determined through the stratum resistivity test of the geological survey report or the electric sounding method or the electric profile method of the leakage area, the leakage amount of the condition provided with the water stop curtain and the underground channel is calculated by using the relevant laws of hydraulics, then whether the leakage amount value reaches the requirement is compared, and finally the water stop curtain and the underground channel are constructed. The beneficial effect of the application is that the application proposes a method for treating the leakage of the subway tunnel, the railway tunnel and the highway tunnel by the leakage mechanism of underground water, and the waterproof effect is better.

Description

Technical Field

[0001] This invention relates to the field of tunnel leakage control, and more particularly to a method for controlling tunnel water leakage. Background Technology

[0002] Waterproofing is one of the basic functions of a building. However, waterproofing problems persist, and leaks occur frequently. While leaks in basements of ordinary buildings generally cause minor damage, leaks in subway, railway, and highway tunnels endanger traffic safety and threaten people's lives and property. For many years, research institutions, universities, construction companies, and other relevant organizations across the country have adopted numerous new materials, processes, and technologies to improve the waterproofing effectiveness of subway, railway, and highway tunnels.

[0003] However, current waterproofing methods focus on waterproofing materials and structures, neglecting the leakage mechanism of groundwater. As a result, waterproofing design and construction largely rely on waterproofing materials, structures, and construction experience, lacking theoretical basis and leading to poor waterproofing effects.

[0004] In 1856, French engineer Charles Darcy presented Darcy's Law, laying the theoretical foundation for the development of seepage theory. Based on Darcy's Law, Jubois derived formulas for unidirectional and planar radial steady flow of groundwater, playing a crucial role in the development of groundwater hydraulics.

[0005] This invention is a method for treating leakage in subway tunnels, railway tunnels, and highway tunnels by using the theory of groundwater hydraulics. Summary of the Invention

[0006] The purpose of this invention is to provide a method for treating tunnel leakage by means of a permeation mechanism.

[0007] This invention is achieved through the following measures:

[0008] A method for treating tunnel water leakage, the specific steps of which include:

[0009] S1. Measure the actual leakage q0 at the leak point before treatment;

[0010] S2. Draw longitudinal and transverse geological profiles of the leakage area based on the engineering geological survey report. The longitudinal geological profile should cover all leakage points in subway tunnels, railway tunnels, and highway tunnels; the transverse profile should cover the area with the largest leakage.

[0011] If there is no engineering geological survey report, the resistivity of the formation shall be tested by electrical sounding or electrical profiling, with the test depth 5 meters below the seepage point; based on the test results, the soil moisture content and groundwater level elevation on the electrical profile shall be calculated and marked on the electrical profile map.

[0012] S3. Draw the corresponding leakage flow network based on the relevant data in S2. Figure 1 Based on relevant theories of groundwater hydraulics, the theoretical seepage flow rate q at the leakage point before treatment was calculated. L And compare q0 and q L The value, through q0 and q L The accuracy of the calculations in this treatment method was determined by comparison;

[0013] The groundwater hydraulics theory used in this step is Darcy's law, specifically:

[0014]

[0015] The seepage flow rate is calculated as follows:

[0016]

[0017] In the formula:

[0018] Q – Infiltration rate;

[0019] k—Comprehensive permeability coefficient of the subway tunnel wall (considering the permeability coefficients of each lining layer and structure); b—Wide width of the crack at the widest point of leakage;

[0020] l — Total length of the crack at the leakage point.

[0021] Considering that the cracks at the leakage point are generally wider in the middle and narrower at the two ends, the leakage area is...

[0022] ΔH—Vertical distance from the groundwater level to the leakage point, which can be determined by the cross-sectional view in step S2; ΔL—Construction thickness of the leakage point, including the total thickness of the lining and structure;

[0023] V – Flow velocity;

[0024] s — penetration path;

[0025] h — Head height (m).

[0026] Alternatively, the seepage flow calculation formula can be used:

[0027]

[0028] In the formula:

[0029] Q – Infiltration rate (cubic meters);

[0030] k——Comprehensive permeability coefficient of the subway tunnel wall (considering the permeability coefficients of each lining layer and structure) b——Crack width at the widest point of leakage (m);

[0031] l—Total length of the crack at the leakage point (m);

[0032] Considering that the cracks at the leakage point are generally wider in the middle and narrower at the two ends, the leakage area is...

[0033] g — gravitational acceleration 9.8 m / s² 2 ;

[0034] h — Height (m) from the leakage point to the groundwater level.

[0035] The final seepage flow rate is based on the calculation results of Formulas 2 and 3 being close to the actual measured seepage flow rate.

[0036] Drawing a seepage flow network Figure 1 Applying formulas 2 and 3 above, perform the following calculations:

[0037] When no water-stop curtain or culvert is installed, the hydraulic gradient is...

[0038]

[0039] Theoretical seepage flow rate q at the leakage point L :

[0040]

[0041] In the formula,

[0042] k - Soil permeability coefficient;

[0043] A - The area of ​​the leakage point;

[0044] H - The vertical distance between the free water surface and the watertight boundary;

[0045] h0 - The vertical distance between the water surface at the leakage point and the water-proof boundary when no water-stop curtain or culvert is installed;

[0046] Δl - Wall thickness at the location of the leak.

[0047] S4. Design the water-stopping and drainage boundaries for tunnel leakage control, i.e., the leakage control equipment, specifically a water-stopping curtain, a culvert, or a combination of a water-stopping curtain and a culvert, and draw a leakage flow network assuming the leakage control equipment is installed. Figure 2 That is, to draw the flow net behind the water-stop curtain and the culvert;

[0048] S5. According to the leakage flow net Figure 2The seepage flow rate q at the seepage point equipped with seepage control equipment is calculated based on relevant theories of groundwater hydraulics. x That is, to calculate the reduction in hydraulic gradient and the leakage q at the leakage point after the installation of the water-stop curtain and culvert. x The relevant theories of groundwater hydraulics applied include Darcy's law and the infiltration curve equation;

[0049] After the water-stop curtain and culvert are installed, the water depth h1 in the culvert will remain constant after a period of drainage, and an approximate constant gradual seepage without pressure will be formed. The shape and position of the infiltration curves on both sides will remain basically unchanged, and the situation will be consistent on each cross-section perpendicular to the axis of the culvert.

[0050] Using the impermeable boundary as the reference plane, the groundwater level is z at a distance x from the right boundary of the culvert. Hydraulic gradient Cross-sectional average velocity The leakage rate per unit length on the right side of the culvert is q. h ,

[0051] The equation for the infiltration curve on the right side of the culvert is:

[0052]

[0053] When z equals the aquifer thickness H (i.e., the distance from the groundwater level to the impermeable boundary), x = R, where R is the radius of influence of the culvert. The formula for the leakage rate per unit length on the right side of the culvert is:

[0054]

[0055] In the formula, q H - When z = H, the seepage flow rate per unit length on the right side of the culvert;

[0056] The radius of influence of the R-channel is related to geological conditions and should be determined through pumping tests, or approximately estimated using the average hydraulic gradient Jave of the wetting curve, i.e., let...

[0057] J ave =H / R

[0058] Then R = H / J ave

[0059] J ave The value can be selected based on the soil properties and with reference to the table below.

[0060] coarse sand 3 / 1000～1 / 200 sand 1 / 200～3 / 200 Slightly cohesive sandy soil 3 / 100 Silty clay 1 / 20～1 / 10 clay 3 / 20

[0061] Let x0 be the horizontal distance from the right boundary of the culvert to the leakage point. The height of the free water surface at x0 can be calculated using Formula 6.

[0062]

[0063] Therefore, the corresponding hydraulic gradient is: J x =(z0-h0) / Δl;

[0064] The corresponding hydraulic gradient change is: ΔJ = J x -J0=(z0-H) / Δl;

[0065] The seepage rate at the leakage point is: q x =KAJ x =KA(z0-h0) / Δl;

[0066] The corresponding change in seepage flow rate: Δq = q x -q0=KA(z0-H) / Δl.

[0067] S6, q x Compare the values ​​with q0 to determine q. x Does it meet the requirements? If q x If the requirements are not met, adjust the assumed position of the leakage control equipment described in step S2 and recalculate q. x Until q x To achieve the desired result, repeat the above steps until the leakage at the treated leak point reaches a rate of q. x If the indoor moisture evaporation is less than the calculated amount, then the depth and location of the waterproof curtain and culvert are the final design.

[0068] S7. Actual construction shall be carried out according to the assumed location of the leakage control equipment that meets the leakage control requirements, specifically: constructing a water-stop curtain; constructing a culvert using methods such as directional drilling and pipe jacking, and draining groundwater through the culvert. As the groundwater level decreases, the leakage of the leakage points in the subway tunnel, railway tunnel and highway tunnel will decrease, and the seepage pressure will decrease or disappear.

[0069] Conventional leak-sealing methods such as grouting and sealing were used to plug the leaks in subway tunnels, railway tunnels, and highway tunnels. The leaks in these tunnels were thus resolved.

[0070] The invention also has the following specific features:

[0071] The aforementioned leakage control equipment is a stop curtain or culvert. The culvert is constructed using methods such as directional drilling and pipe jacking. Due to the reduction in groundwater level, the leakage volume and seepage pressure at the leakage points of subway tunnels, railway tunnels, and highway tunnels are reduced or eliminated. Subsequently, conventional leakage plugging methods such as grouting and sealing are used to seal the leakage points of subway tunnels, railway tunnels, and highway tunnels, thereby controlling the leakage at the leakage points of subway tunnels, railway tunnels, and highway tunnels.

[0072] Draw the seepage flow network Figure 1 and the seepage flow network Figure 2 The principle is:

[0073] With the groundwater level as the equipotential surface and the water-impermeable boundary as the equipotential surface, for soil layers with equal or very close permeability coefficient k values, streamlines and equipotential lines are perpendicular to each other, and the resulting flow network is a series of rectangular grids.

[0074] If the permeability coefficient k values ​​of the upper and lower soil layers are not equal, streamlines are drawn through the soil layer interface according to the refraction phenomenon. Streamlines are parallel to the water-impermeable boundary such as the water-stop curtain, and streamlines are perpendicular to the water head boundary such as lakes. For the boundary of rivers, the flow network should be drawn in combination with the water supply or discharge.

[0075] The streamlines in the flow network begin at the groundwater level and end at the seepage point of the underground structure;

[0076] Divide the vertical distance from the groundwater level to the leakage point of the underground structure into n equal parts, n = 5 to 10, and draw the corresponding horizontal lines. The intersection of the horizontal lines and the streamlines is the equal head point. Draw equipotential lines based on the equal head points. The equipotential lines are perpendicular to the streamlines. Adjust the direction of the streamlines if necessary.

[0077] The beneficial effects of this invention are as follows: This invention proposes a method for controlling leakage in subway tunnels, railway tunnels, and highway tunnels based on the seepage mechanism of groundwater, achieving excellent waterproofing results. Furthermore, with the increasing instability of summer rainfall in my country in recent years, traditional waterproofing methods are inefficient in addressing the increasing number of seepage points and the resulting increased seepage pressure in tunnels. This invention, however, can universally solve the problem of leakage along the entire tunnel length and has a good preventative effect against new seepage points. Compared to the traditional construction technique of "plugging to treat leakage," this invention proposes a leakage solution that prioritizes drainage while combining drainage with plugging, avoiding the phenomenon of "plugging one leak while another leaks" caused by tunnel wall defects, and thus more thoroughly solving the problem of tunnel leakage. Attached Figure Description

[0078] Figure 1 This is a longitudinal geological profile of the geological survey report in an embodiment of the present invention.

[0079] Figure 2 This is a transverse geological profile of the geological exploration report in an embodiment of the present invention. Figure 1 .

[0080] Figure 3 This is a transverse geological profile of the geological exploration report in an embodiment of the present invention. Figure 2 .

[0081] Figure 4 This is a seepage flow net without a water-stop curtain or culvert in an embodiment of the present invention. Figure 1 .

[0082] Figure 5 This is an embodiment of the present invention showing a seepage flow net with equipotential lines drawn on it, without a water-stop curtain or culvert. Figure 1 .

[0083] Figure 6 The leakage flow net with a water-stop curtain and a culvert is provided in an embodiment of the present invention. Figure 2 .

[0084] Figure 7 This embodiment of the invention features a seepage flow net with equipotential lines, a water-stop curtain, and a culvert. Figure 2 .

[0085] Figure 8 This invention provides a modified seepage flow net behind a water-stop curtain. Figure 2 .

[0086] In the diagram: 1. Groundwater level; 2. Surface; 3. Leakage point; 4. Tunnel; 5. Waterproof boundary; 6. Isopotin lines; 7. Streamlines; 8. Infiltration curve; 9. Water-stop curtain; 10. Culvert. Detailed Implementation

[0087] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0088] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0089] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0090] To clearly illustrate the technical features of this solution, the following detailed implementation method will be used to explain the solution.

[0091] Example 1

[0092] See Figure 1-8 A method for treating tunnel water leakage, the specific steps of which include:

[0093] S1. Measure the actual leakage q0 at leak point 3 before treatment;

[0094] S2. Draw longitudinal and transverse geological profiles of the leakage area based on the engineering geological survey report. The longitudinal geological profile should cover all leakage points in subway tunnels, railway tunnels, and highway tunnels. The transverse profile should cover the area with the largest leakage.

[0095] If there is no engineering geological survey report, the resistivity of the formation shall be tested by electrical sounding or electrical profiling, with the test depth 5 meters below the seepage point 3; based on the test results, the soil moisture content and groundwater level 1 elevation on the electrical sounding profile shall be calculated and marked on the electrical sounding profile map.

[0096] S3. Draw the corresponding leakage flow network based on the relevant data in S2. Figure 1 Based on relevant theories of groundwater hydraulics, the theoretical seepage flow rate q at seepage point 3 before treatment was carried out was calculated. L And compare q0 and q L The value, through q0 and q L The accuracy of the calculations in this treatment method was determined by comparison;

[0097] The groundwater hydraulics theory used in this step is Darcy's law, specifically:

[0098]

[0099] The seepage flow rate is calculated as follows:

[0100]

[0101] In the formula:

[0102] Q – Infiltration rate;

[0103] k — The overall permeability coefficient of the subway tunnel wall (considering the permeability coefficients of each lining layer and structure);

[0104] b—width of the crack at the widest point of leakage point 3;

[0105] l——Total length of crack at leakage point 3.

[0106] Considering that the cracks at the leakage point are generally wider in the middle and narrower at the two ends, the leakage area is...

[0107] ΔH—the vertical distance from groundwater level 1 to leakage point 3, which can be determined by the cross-sectional view in step S2;

[0108] ΔL—Construction thickness of leakage point 3, including the total thickness of the lining and structure;

[0109] V – Flow velocity;

[0110] s — penetration path;

[0111] h — water head height (m).

[0112] Alternatively, the seepage flow calculation formula can be used:

[0113]

[0114] In the formula:

[0115] Q – Infiltration rate (cubic meters);

[0116] k — The overall permeability coefficient of the subway tunnel wall (considering the permeability coefficients of each lining layer and structure).

[0117] b——The width of the crack at the widest point of leakage point 3 (m);

[0118] l——Total length of crack at leakage point 3 (m);

[0119] Considering that the cracks at the leakage point are generally wider in the middle and narrower at the two ends, the leakage area is...

[0120] g — gravitational acceleration 9.8 m / s² 2 ;

[0121] h——Height (m) from seepage point 3 to groundwater level 1.

[0122] The final seepage flow rate is based on the calculation results of Formulas 2 and 3 being close to the actual measured seepage flow rate.

[0123] Drawing a seepage flow network Figure 1 Applying formulas 2 and 3 above, perform the following calculations:

[0124] Without a water-stop curtain 9 and an underground channel 10, the hydraulic gradient is...

[0125]

[0126] Theoretical seepage flow rate q at leakage point 3 L :

[0127]

[0128] In the formula,

[0129] k - Soil permeability coefficient;

[0130] A - The area of ​​leakage point 3;

[0131] H - The vertical distance between the free water surface and the watertight boundary 5;

[0132] h0 - The vertical distance between the water surface of the seepage point 3 and the water-proof boundary 5 when no water-stop curtain 9 and culvert 10 are installed;

[0133] Δl - The wall thickness at the leakage point 3.

[0134] S4. Design the water-stopping and drainage boundaries for treating leakage in tunnel 4, i.e., the leakage treatment equipment. The leakage treatment equipment is specifically a water-stopping curtain 9, a culvert 10, or a combination of a water-stopping curtain 9 and a culvert 10, and draw a leakage flow network assuming that the leakage treatment equipment is installed. Figure 2 That is, to draw the flow net after the water-stop curtain 9 and the culvert 10 are set;

[0135] S5. According to the leakage flow net Figure 2 Based on theoretical calculations related to groundwater hydraulics, the seepage flow rate q at the seepage point 3 equipped with seepage control equipment was determined. x That is, to calculate the reduction in hydraulic gradient and the leakage q at leakage point 3 after the installation of the water-stop curtain 9 and the culvert 10. x The relevant theories of groundwater hydraulics applied include Darcy's law and the infiltration curve equation;

[0136] After the water-stop curtain 9 and the culvert 10 are installed, the water depth h1 in the culvert 10 will remain constant after a period of drainage, and an approximate constant gradual seepage without pressure will be formed. The shape and position of the wetting curves 8 on both sides will remain basically unchanged, and the situation will be consistent on each water-passing section perpendicular to the axis of the culvert 10.

[0137] Using the impermeable boundary 5 as the reference plane, at a distance x from the right boundary of the culvert 10, the groundwater level 1 is z. Hydraulic gradient Cross-sectional average velocity The leakage rate per unit length on the right side of culvert 10 is q. h ,

[0138] The equation for the infiltration curve on the right side of culvert 10 is:

[0139]

[0140] When z equals the aquifer thickness H, x = R, where R is the radius of influence of culvert 10. The formula for the leakage rate per unit length on the right side of culvert 10 is:

[0141]

[0142] In the formula, q H - When z = H, the seepage flow rate per unit length on the right side of culvert 10;

[0143] The radius of influence of R-culvert 10 is related to geological conditions and should be determined through pumping tests, or approximately estimated by the average hydraulic gradient Jave of the wetting curve 8, i.e., let

[0144] J ave =H / R

[0145] Then R = H / J ave

[0146] J ave The value can be selected based on the soil properties and with reference to the table below.

[0147] coarse sand 3 / 1000～1 / 200 sand 1 / 200～3 / 200 Slightly cohesive sandy soil 3 / 100 Silty clay 1 / 20～1 / 10 clay 3 / 20

[0148] Let x0 be the horizontal distance from the right boundary of the culvert 10 to the leakage point 3. The height of the free water surface at x0 can be calculated using formula 6.

[0149]

[0150] Therefore, the corresponding hydraulic gradient is: J x =(z0-h0) / Δl;

[0151] The corresponding hydraulic gradient change is: ΔJ = J x -J0=(z0-H) / Δl;

[0152] The seepage flow rate at leakage point 3 is: q x =KAJ x =KA(z0-h0) / Δl;

[0153] The corresponding change in seepage flow rate: Δq = q x -q0=KA(z0-H) / Δl.

[0154] S6, q x Compare the values ​​with q0 to determine q. x Does it meet the requirements? If q x If the requirements are not met, adjust the assumed position of the leakage control equipment described in step S2 and recalculate q. x Until q x To achieve the desired result, repeat the above steps until the leakage at point 3 is resolved and the leakage rate is q. x If the indoor moisture evaporation is less than the calculated amount, the depth and position of the water-stop curtain 9 and the culvert 10 at this point are the final design.

[0155] S7. Actual construction is carried out according to the assumed location of the leakage control equipment that meets the leakage control requirements, specifically: constructing a water-stop curtain 9; constructing a culvert 10 using methods such as directional drilling and pipe jacking, and draining groundwater through the culvert 10. As the groundwater level 1 decreases, the leakage amount at the leakage point 3 of the subway tunnel, railway tunnel and highway tunnel decreases, and the seepage pressure decreases or disappears.

[0156] Conventional leak-sealing methods such as grouting and sealing were used to seal the seepage points 3 in the subway tunnel, railway tunnel, and highway tunnel. The seepage points 3 in the subway tunnel, railway tunnel, and highway tunnel were thus resolved.

[0157] The invention also has the following specific features:

[0158] The leakage control equipment is a stop curtain 9 or a culvert 10. The culvert 10 is constructed using methods such as directional drilling and pipe jacking. As the groundwater level 1 decreases, the leakage at the leakage points 3 in the subway tunnel, railway tunnel, and highway tunnel decreases, and the seepage pressure decreases or disappears. Then, conventional leak-sealing methods such as grouting and sealing are used to seal the leakage points 3 in the subway tunnel, railway tunnel, and highway tunnel, thus controlling the leakage at the leakage points 3 in the subway tunnel, railway tunnel, and highway tunnel.

[0159] Draw the seepage flow network Figure 1 and the seepage flow network Figure 2 The principle is:

[0160] Taking the groundwater level 1 below the surface 2 as the equipotential surface and the water-blocking boundary 5 as the equipotential surface, for soil layers with equal or very close permeability coefficient k values, streamlines 7 and equipotential lines 6 are perpendicular to each other, and the flow network formed is a series of rectangular grids.

[0161] If the permeability coefficient k values ​​of the upper and lower soil layers are not equal, streamline 7 is drawn through the soil layer interface according to the refraction phenomenon. Streamline 7 is parallel to the water-proof boundary 5, such as the water-stop curtain 9, etc. Streamline 7 is perpendicular to the water head boundary of lakes, etc. For the boundary of rivers, etc., the flow network should be drawn in combination with the water supply or discharge.

[0162] The streamline 7 in the flow network begins at the groundwater level 1 and ends at the seepage point 3 of the underground structure;

[0163] Divide the vertical distance from the groundwater level 1 to the leakage point 3 of the underground structure into n equal parts, n = 5 to 10, and draw the corresponding horizontal lines. The intersection of the horizontal lines and the streamline 7 is the equal head point. Draw the equipotential line 6 based on the equal head point. The equipotential line 6 is perpendicular to the streamline 7. Adjust the direction of the streamline 7 if necessary.

[0164] Example 2

[0165] See Figure 1-8 A method for treating tunnel water leakage, the specific steps of which include:

[0166] The first step is to determine the actual seepage flow rate q0 at seepage point 3, which is 1 liter / day; the permeability coefficient of each soil layer in the geological survey report is k = 3.0 × 10⁻⁴ cm / s = 0.2592 m / d. The distance from groundwater level 1 to the impermeable boundary 5 is H = 15.5 m, and the distance from seepage point 3 to the impermeable boundary 5 is h0 = 5 m.

[0167] The second step, according to Figure 1-3 And Darcy's Law, calculated as follows:

[0168] The head difference ΔH is: ΔH = 203.5 - 193 = 10.5 m;

[0169] The permeation path ΔL = 500 mm = 0.5 m;

[0170] The width of the seepage fracture b = 0.5 mm; the length of the seepage fracture l = 500 mm = 0.5 m; the seepage area A = 0.0005 * 0.5 = 0.00025 square meters = 2.5 × 10⁻⁴ square meters;

[0171] Derived seepage coefficient of lining cracks

[0172] In the formula:

[0173] q0 — The actual leakage amount measured at leakage point 3;

[0174] k—the seepage coefficient of the lining crack;

[0175] b—width of the crack at leakage point 3;

[0176] l—Length of the crack at leakage point 3;

[0177] ΔH—Vertical distance from groundwater level 1 to seepage point 3;

[0178] ΔL—Construction thickness of leakage point 3, including the thickness of the lining and structure;

[0179] The seepage flow rate is calculated using Formula 3 as follows:

[0180]

[0181] The third step is to draw a seepage flow network before treatment, using the groundwater level 1 as the isostatic surface, which is perpendicular to streamline 7, and seepage point 3 as the sink point. Figure 1 And calculate as follows:

[0182] Hydraulic gradient:

[0183]

[0184] Where h0 is the vertical distance from the leakage point 3 to the waterproof boundary 5;

[0185] Theoretical seepage flow rate at leak point 3 before treatment:

[0186]

[0187] The calculated results are consistent with the measured results.

[0188] The soil in the project is sandy soil with Jave = 1 / 200 to 3 / 200, therefore R = H / Jave = 2100 to 700m; due to the large area of ​​influence, a water-stop curtain 9 needs to be installed.

[0189] The fourth step is to design the water-stop curtain 9 and / or the culvert 10 to control leakage in tunnel 4, and to draw the leakage flow network after the water-stop curtain 9 and the culvert 10 are installed. Figure 2 The distance h1 from the water level in the culvert 10 to the water-resistant boundary 5 is 5m. Calculate the reduction in hydraulic slope and the leakage rate at seepage point 3 after the installation of the water-stop curtain 9 and the culvert 10:

[0190] Leakage per unit length on the right side of culvert 10:

[0191]

[0192] If x0 = 6m, then the height of the free water surface at x0 is:

[0193]

[0194] Therefore, the corresponding hydraulic gradient

[0195] J x =(z0-h0) / Δl=(z0-5) / 0.5=0.146~0.046

[0196] Corresponding hydraulic gradient changes

[0197] ΔJ=J x -J0=J x -11 = -10.854 to -10.954

[0198] The seepage flow rate per unit length at three leakage points after the treatment equipment was installed:

[0199]

[0200] Corresponding changes in seepage flow:

[0201] Δq=q x -q0=0.0000139065-0.001000125=-0.0009862185m 3 / sky

[0202] The calculations above show that the theoretical seepage rate is 13.9 ml per day, which is essentially negligible and far less than the evaporation rate, thus preventing further leakage. Therefore, installing a 1-meter-long underground drainage channel is sufficient to prevent leakage.

[0203] The fifth step is to construct the water-stop curtain 9; and to construct the underground channel 10 using methods such as directional drilling and pipe jacking. The underground channel 10 is used to drain groundwater. As the groundwater level 1 decreases, the leakage at the seepage point 3 in the subway tunnel, railway tunnel and highway tunnel decreases, and the seepage pressure decreases or disappears.

[0204] Conventional leak-sealing methods such as grouting and sealing were used to seal the seepage points 3 in the subway tunnel, railway tunnel, and highway tunnel. The seepage points 3 in the subway tunnel, railway tunnel, and highway tunnel were thus resolved.

[0205] The technical features of this invention not described can be implemented by or using existing technology, and will not be repeated here. Of course, the above description is not a limitation of this invention, and this invention is not limited to the examples above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of this invention should also be within the protection scope of this invention.

Claims

1. A method for treating tunnel water leakage, characterized in that, The specific steps include S1. Measure the actual leakage q0 at the leak point before any treatment is carried out; S2. Draw longitudinal and transverse geological profiles of the leakage area based on the engineering geological survey report; If there is no engineering geological survey report, the resistivity of the formation shall be tested by electrical sounding or electrical profiling, with the test depth 5 meters below the seepage point; based on the test results, the soil moisture content and groundwater level elevation on the electrical profile shall be calculated and marked on the electrical profile map. S3. Draw the corresponding seepage flow network diagram based on the relevant data in S2, and calculate the theoretical seepage flow rate q of the seepage point before treatment based on relevant groundwater hydraulics theories. L And compare q0 and q L The value; S4. Draw a second leakage flow network diagram assuming that leakage control equipment is installed. S5. Calculate the seepage flow rate q at the seepage point equipped with seepage control equipment based on the seepage flow network diagram 2 and relevant groundwater hydraulic theories. x That is, to calculate the reduction in hydraulic gradient and the leakage q at the leakage point after the installation of the water-stop curtain and culvert. x The relevant theories of groundwater hydraulics include Darcy's law and the infiltration curve equation. After the water-stop curtain and culvert are set up, and after a period of drainage, the water depth h1 in the culvert remains constant, approximately forming a constant, gradually varying seepage flow without pressure. The shape and position of the infiltration curves on both sides remain basically unchanged, and the situation is consistent on each cross-section perpendicular to the culvert axis. The formula for the leakage per unit length on the right side of the culvert is as follows: R is the radius of influence of the culvert; Let x0 be the horizontal distance from the right boundary of the culvert to the leakage point. Then the height of the free water surface at x0 is: Thus, it is determined that: The corresponding hydraulic gradient is: ; The seepage rate at the leakage point is: ; In the formula, k - Soil permeability coefficient; A - The area of ​​the leakage point; H - The vertical distance between the free water surface and the watertight boundary; h0 - The vertical distance between the water surface at the leakage point and the water-proof boundary when no water-stop curtain or culvert is installed; Δl - Wall thickness at the location of the leak; S6, q x Compare the values ​​with q0 to determine q. x Does it meet the requirements? If q x If the requirements are not met, adjust the assumed position of the leakage control equipment described in step S4 and recalculate q. x Until q x The requirements have been met; S7. Perform actual construction according to the assumed location of the leakage control equipment that meets the leakage control requirements.

2. The method for treating tunnel water leakage according to claim 1, characterized in that, The leakage control equipment is a stop curtain or a culvert or a combination of a stop curtain and a culvert.

3. The method for treating tunnel water leakage according to claim 1, characterized in that, The relevant theory of groundwater hydraulics in S3 is Darcy's law.

4. The method for treating tunnel water leakage according to claim 1, characterized in that, The relevant theories of groundwater hydraulics in S5 are Darcy's law and the infiltration curve equation.

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