Method for maintaining verticality and stability of underwater grouting orifice pipe under deep water conditions

Abstract

The application discloses a method for maintaining the verticality and stability of a deep-water underwater grouting orifice pipe, which comprises the following steps: under the condition that the orifice pipe is fixed at the bottom end and free at the top end, the maximum deflection of the orifice pipe before optimization and the load borne by the top end of the orifice pipe are calculated; a hinged fixing device is arranged at the top end of the orifice pipe, the maximum deflection of the orifice pipe after optimization is calculated, and the maximum deflection of the orifice pipe after optimization is less than the maximum deflection of the orifice pipe before optimization; a maximum allowable deflection value is set, the maximum allowable deflection value is less than the maximum deflection of the orifice pipe after optimization, a multi-stage continuous simply-supported structure compensation model is established, the spacing between adjacent support structures and the support force of each stage unit are determined through the maximum allowable deflection value, and the overall maximum deflection value of the pipe body is ensured to be not more than the maximum allowable deflection value. The application is suitable for underwater grouting engineering of reservoirs with a water depth greater than 50 m, fundamentally reduces the maximum deflection value of the orifice pipe, and guarantees the verticality and structural stability of the orifice pipe.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of water conservancy and hydropower, in particular to a method for maintaining the verticality and stability of a grouting orifice pipe under deep water conditions. BACKGROUND

[0002] Leakage is one of the main causes of dam break of earth-rock dams, which seriously threatens the safety of the project.

[0003] Dam front grouting is the main means to deal with such dam foundation leakage problems, which generally needs to be carried out under dry land conditions during the construction period or emptying conditions after operation. Many reservoirs after impoundment basically do not have the conditions for emptying the reservoir and dry land construction. If emptying construction is carried out, the reservoir cannot operate normally, the water for production and life cannot be supplied, the reservoir ecology is damaged, and the economic, social and environmental impacts are huge.

[0004] However, under the condition of deep water without emptying the reservoir, dam front grouting faces the problem of difficult stability of the orifice pipe, mainly manifested in that the orifice pipe, as a carrier connecting the grouting platform on the water surface and the dam foundation, is a water super-long cantilever force structure, which needs to bear dynamic water and wave load during construction. Under the action of dynamic water and wave load, the orifice pipe as a cantilever structure has problems such as "suspension easy to move, easy to bend and easy to break". SUMMARY

[0005] In view of the shortcomings of the prior art, the present application provides a method for maintaining the verticality and stability of a grouting orifice pipe under deep water conditions, which fundamentally reduces the maximum deflection value of the orifice pipe, ensures the verticality and structural stability of the orifice pipe, and has wide applicability.

[0006] To achieve the above-mentioned purpose, the present application designs a method for maintaining the verticality and stability of a grouting orifice pipe under deep water conditions, characterized in that it comprises the following steps:

[0007] S1) Under the premise that the orifice pipe is fixed at the bottom end and free at the top end, the maximum deflection value of the orifice pipe before optimization and the load borne by the top end of the orifice pipe under the action of deep water dynamic load and wind load are calculated;

[0008] S2) A hinged fixing device is arranged at the top end of the orifice pipe, the orifice pipe body segment structure of the bottom end fixed-top end free is optimized to the orifice pipe body segment structure of the bottom end fixed-top end simply supported, the maximum deflection value of the orifice pipe after optimization is calculated, and the maximum deflection value of the orifice pipe after optimization is less than the maximum deflection value of the orifice pipe before optimization;

[0009] S3) A maximum allowable deflection value is set, the maximum allowable deflection value is less than the maximum deflection value of the orifice pipe after optimization, and a multi-stage continuous simply supported structure compensation model is established, the multi-stage continuous simply supported structure compensation model comprises arranging kThe multi-stage compensation hinge unit optimizes the structure of the orifice pipe rod segment, which is fixed at the bottom and simply supported at the top, into a continuous rod structure with fixed at the bottom and multiple simply supported in the middle. The spacing between adjacent support structures and the support force of each unit are determined by the maximum allowable deflection value, ensuring that the maximum deflection value of the entire pipe does not exceed the maximum allowable deflection value, and ultimately achieving that the orifice pipe always remains vertical and the rod is stable.

[0010] Furthermore, in S1), under the premise that the orifice tube is fixed at the bottom and free at the top, the maximum deflection of the orifice tube before optimization is expressed by the following formula.

[0011] ;

[0012] In the formula,

[0013] y max1 To optimize the maximum deflection of the orifice pipe, m,

[0014] L The length of the orifice pipe, in meters.

[0015] p w The density of water is kg / m³ 3 ,

[0016] C d The coefficient of water flow resistance.

[0017] D The outer diameter of the orifice pipe is in meters (m).

[0018] U 1 The velocity of the water flow is in m / s.

[0019] U 2 Wind speed, m / s

[0020] E The elastic modulus of the orifice pipe body is given in Pa.

[0021] I Let m be the moment of inertia of the pipe section at the orifice. 4 .

[0022] Furthermore, in S1), under the premise that the orifice pipe is fixed at the bottom and free at the top, the load borne by the top of the orifice pipe is expressed by the following formula.

[0023] ;

[0024] In the formula,

[0025] q The load borne by the top of the orifice pipe, in N / m.

[0026] E The elastic modulus of the orifice pipe body is given in Pa.

[0027] I Let m be the moment of inertia of the pipe section at the orifice. 4 ,

[0028] L The length of the orifice pipe, in meters.

[0029] p w The density of water is kg / m³ 3 ,

[0030] C d The coefficient of water flow resistance.

[0031] D The outer diameter of the orifice pipe is in meters (m).

[0032] U 1 The velocity of the water flow is in m / s.

[0033] U 2 , where is the wind speed, in m / s.

[0034] Furthermore, in S2), under the premise that the orifice pipe is fixed at the bottom and simply supported at the top, the maximum deflection of the optimized orifice pipe is expressed by the following formula.

[0035] ;

[0036] In the formula,

[0037] y max2 To optimize the maximum deflection of the orifice pipe, m,

[0038] q The load borne by the pipe with the orifice tip at a free end, in N / m.

[0039] E The elastic modulus of the orifice pipe body is given in Pa.

[0040] I Let m be the moment of inertia of the pipe section at the orifice. 4 ,

[0041] L The length of the orifice pipe, in meters.

[0042] R 简支 The reaction force, N, provided to the hinged end of the orifice pipe.

[0043] Further, in S2, the counterforce provided by the top end hinged end of the orifice tube under the premise that the orifice tube is fixed at the bottom end and simply supported at the top end needs to satisfy the following formula

[0044] ;

[0045] wherein,

[0046] R 简支 N, the counterforce provided by the top end hinged end of the orifice tube,

[0047] q N / m, the load borne by the top end of the orifice tube when the top end is free,

[0048] L m, the length of the orifice tube.

[0049] Further, in S2, the hinged fixing device is a float installed at the top end of the orifice tube.

[0050] Further, in S3, the distance between the adjacent support structures under the premise that the orifice tube is fixed at the bottom end and simply supported at the middle is calculated by the following formula

[0051] ;

[0052] wherein,

[0053] △x m, the distance between the adjacent support structures,

[0054] E Pa, the elastic modulus of the orifice tube,

[0055] I m, the moment of inertia of the cross section of the orifice tube 4 ,

[0056] y 控制 , the maximum allowable deflection value,

[0057] q N / m, the load borne by the top end of the orifice tube when the top end is free,

[0058] L m, the length of the orifice tube.

[0059] Further, in S3, the support force of each unit under the premise that the orifice tube is fixed at the bottom end and simply supported at the middle is calculated by the following formula

[0060] ;

[0061] wherein,

[0062] F i unit support force,

[0063] y 控制 maximum allowable deflection value,

[0064] k compensation hinge unit level.

[0065] Further, in S3), the compensation hinge unit is a floating plate installed on the aperture pipe shaft body section.

[0066] The advantages of the present application are:

[0067] 1. The present application fundamentally reduces the maximum deflection value of the aperture pipe body as a whole by constructing an aperture pipe deflection maximum value calculation model, a boundary condition optimization model, a multi-level continuous simply supported structure compensation model, optimizing the top end of the aperture pipe from unconstrained to hinged constraint, and changing the shaft body section into a multi-level hinged constraint continuous rod structure, thereby ensuring the verticality and structural stability of the aperture pipe shaft.

[0068] 2. Based on the established aperture pipe deflection maximum value calculation model under the action of dynamic water load in deep water conditions, the present application realizes the quantification of the aperture pipe deflection maximum value under the premise of considering dynamic water load and wind load.

[0069] 3. Based on the established aperture pipe structure boundary condition optimization model, the present application optimizes the aperture pipe from a "bottom end fixed-top end free" structure to a "bottom end fixed-top end simply supported" structure, and after optimization, the aperture pipe deflection maximum value is reduced by 60%~90% compared to before optimization, and the deflection distribution is concentrated to the middle section.

[0070] 4. Based on the established multi-level continuous simply supported structure compensation model, the present application further optimizes the aperture pipe shaft body section structure from "bottom end fixed-top end simply supported" to "bottom end fixed-middle multi simply supported", ensures that the overall maximum deflection value of the pipe body does not exceed the maximum allowable deflection value, and finally realizes that the aperture pipe always maintains a vertical state and the rod body is stable.

[0071] The present application is applicable to underwater grouting engineering of reservoirs with water depth greater than 50m, fundamentally reduces the maximum deflection value of the aperture pipe, and ensures the verticality and structural stability of the aperture pipe shaft. BRIEF DESCRIPTION OF DRAWINGS

[0072] Figure 1 is a flowchart of the present application. DETAILED DESCRIPTION

[0073] The present application will be further described in detail below in combination with the drawings and specific embodiments.

[0074] In the description of the present application, it should be understood that the terms "length", "width", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application 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 application.

[0075] As Figure 1 shown, the present application is a method for maintaining the verticality and stability of a deep water underwater grouting orifice pipe, comprising the following steps:

[0076] S1) Under the premise that the orifice pipe is fixed at the bottom end and free at the top end, calculate the maximum deflection of the orifice pipe before optimization under the action of dynamic water load and wind load and the load borne by the top end of the orifice pipe.

[0077] Specifically, basic data is collected, a calculation model for the maximum deflection of the orifice pipe before optimization under the action of dynamic water load and wind load is established, the calculation model for the maximum deflection of the orifice pipe before optimization includes that under the premise that the orifice pipe is fixed at the bottom end and free at the top end, the maximum deflection of the orifice pipe before optimization is located at the top end of the orifice pipe, and the maximum deflection of the orifice pipe is calculated; a calculation model for the load borne by the top end of the orifice pipe under the action of dynamic water load and wind load is established, the calculation model for the load borne by the top end of the orifice pipe includes that under the premise that the orifice pipe is fixed at the bottom end and free at the top end, the load borne by the top end of the orifice pipe when the top end is free is calculated.

[0078] Specifically, basic data such as reservoir water flow velocity, reservoir area wind speed and resistance coefficient is collected, and the dynamic water and wind load borne by the orifice pipe is simplified as a uniform load in combination with the material properties of the pipe body, and a corresponding load calculation model is established.

[0079] Specifically, under the premise that the orifice pipe is fixed at the bottom end and free at the top end, the maximum deflection of the orifice pipe before optimization is represented by the following formula

[0080] ;

[0081] In the formula,

[0082] y max1 m is the maximum deflection of the orifice pipe before optimization,

[0083] L L is the length of the orifice pipe, m,

[0084] p w is the water density, kg / m 3 ,

[0085] C d is the water flow resistance coefficient,

[0086] D is the orifice pipe body outer diameter, m,

[0087] U 1 is the water flow velocity, m / s,

[0088] U 2 is the wind speed, m / s.

[0089] E is the orifice pipe body elastic modulus, Pa,

[0090] I is the orifice pipe cross-sectional moment of inertia, m 4 .

[0091] Specifically, under the premise that the orifice pipe is fixed at the bottom end and free at the top end, the load borne by the top end of the orifice pipe is represented by the following formula

[0092] ;

[0093] In the formula,

[0094] q is the load borne by the top end of the orifice pipe, N / m,

[0095] E is the orifice pipe body elastic modulus, Pa,

[0096] I is the orifice pipe cross-sectional moment of inertia, m 4 ,

[0097] L is the orifice pipe length, m,

[0098] p w is the water density, kg / m 3 ,

[0099] C d is the water flow resistance coefficient,

[0100] D is the orifice pipe body outer diameter, m,

[0101] U 1 is the water flow velocity, m / s,

[0102] U 2 is the wind speed, m / s.

[0103] The present application is based on the established calculation model of the maximum deflection of the orifice pipe under the action of dynamic water load, and realizes the quantification of the maximum deflection of the orifice pipe under the premise of considering dynamic water load and wind load.

[0104] According to the above-mentioned calculation model of the maximum deflection of the orifice pipe before optimization, the maximum deflection of the top end is the largest, and the orifice pipe is easy to deviate and lose stability. In view of this situation, an optimization model of the boundary conditions of the orifice pipe structure is established, as follows.

[0105] S2) arranging a hinged fixing device at the top end of the orifice pipe, optimizing the structure of the orifice pipe rod section from the bottom fixed-top free to the bottom fixed-top simply supported, calculating the maximum deflection of the optimized orifice pipe, and the maximum deflection of the optimized orifice pipe is less than the maximum deflection of the orifice pipe before optimization. Step S2) is the optimization model of the boundary conditions of the orifice pipe structure.

[0106] In view of the situation that the maximum deflection of the top end is the largest and the orifice pipe is easy to deviate and lose stability in step S1), an optimization model of the boundary conditions of the orifice pipe structure is established. Specifically, under the premise that the orifice pipe is fixed at the bottom and simply supported at the top, the maximum deflection of the optimized orifice pipe is represented by the following formula,

[0107] ;

[0108] In the formula,

[0109] y max2 m is the maximum deflection of the optimized orifice pipe,

[0110] q is the load borne by the top end of the orifice pipe when the top end is free, N / m,

[0111] E is the elastic modulus of the pipe body of the orifice pipe, Pa,

[0112] I is the moment of inertia of the cross section of the orifice pipe, m 4 ,

[0113] L is the length of the orifice pipe, m,

[0114] R 简支 is the counterforce provided by the hinged end of the top end of the orifice pipe, N.

[0115] Specifically, under the premise that the orifice pipe is fixed at the bottom and simply supported at the top, the counterforce provided by the hinged end of the top end of the orifice pipe needs to satisfy the following formula

[0116] ;

[0117] In the formula,

[0118] R 简支 Counterforce provided for the hinged end of the orifice tube top end, N,

[0119] q Load borne by the orifice tube top end when it is a free end, N / m,

[0120] L Length of the orifice tube, m.

[0121] The maximum value of the deflection of the orifice tube after optimization y max2 The maximum value of the deflection of the orifice tube before optimization in step S1) y max1 is reduced by 60% to 90%, and the deflection distribution is concentrated in the middle section.

[0122] Preferably, the hinged fixing device is a float installed at the top end of the orifice tube.

[0123] To further reduce the maximum deflection value of the orifice tube and meet the requirement of the maximum allowable deflection value, a multi-stage continuous simply supported structure compensation model in the following step S3) needs to be established.

[0124] S3) Set the maximum allowable deflection value, and the maximum allowable deflection value is less than the maximum value of the deflection of the orifice tube after optimization, and establish a multi-stage continuous simply supported structure compensation model, which includes arranging k a compensation hinged unit at each stage in the orifice tube body section along the pipe, and optimizing the structure of the orifice tube body section with the bottom fixed and the top simply supported into a continuous rod body structure with the bottom fixed and multiple simply supported in the middle, wherein the spacing between adjacent support structures and the support force of each unit are determined by the maximum allowable deflection value, to ensure that the maximum deflection value of the whole pipe body does not exceed the maximum allowable deflection value, and finally realize that the orifice tube always maintains a vertical state and the rod body is stable.

[0125] Specifically, under the premise that the orifice tube is fixed at the bottom and simply supported in the middle, the spacing between adjacent support structures is calculated by

[0126] ;

[0127] In the formula,

[0128] △x is the spacing between adjacent support structures, m,

[0129] E is the elastic modulus of the orifice tube, Pa,

[0130] I is the moment of inertia of the orifice tube cross section, m 4 ,

[0131] y 控制 is the maximum allowable deflection value,

[0132] q is the load borne by the free end of the orifice pipe, N / m,

[0133] L is the length of the orifice pipe, m.

[0134] Specifically, under the premise that the orifice pipe is fixed at the bottom end and simply supported at the middle, the support force of each unit is calculated by the following formula

[0135] ;

[0136] In the formula,

[0137] F i is the support force of each unit,

[0138] y 控制 is the maximum allowable deflection value,

[0139] k is the number of compensation hinge units.

[0140] The present application is based on the established multi-stage continuous simply supported structure compensation model, which optimizes the orifice pipe shaft segment structure from "bottom end fixed-top end simply supported" to "bottom end fixed-middle multi simply supported", ensures that the maximum deflection value of the pipe body as a whole does not exceed the maximum allowable deflection value, and finally realizes that the orifice pipe always maintains a vertical state and the rod body is stable.

[0141] Preferably, the compensation hinge unit is a floating plate or a floating box installed on the orifice pipe shaft segment.

[0142] This embodiment takes a deep water underwater grouting project of a reservoir in Hubei as an example,

[0143] (1) The basic parameters of the orifice pipe are,

[0144] ‌Length L‌: 20m (composed of 10 sections of 2m standard pipes),

[0145] ‌Pipe body outer diameter D‌: 0.2m,

[0146] ‌Elastic modulus E‌: 200GPa,

[0147] ‌Sectional moment of inertia I‌: 1.16×10 -5 m 4 ;

[0148] (2) The environmental parameters are,

[0149] ‌Water density ρ w: 1025 kg / m3 (typical value of seawater),

[0150] ‌Water flow resistance coefficient C d ‌: 1.0 (typical value of flow around a cylinder),

[0151] ‌Water flow velocity U1: 1.2 m / s (typical flow rate in deep water environment),

[0152] ‌Wind speed U2: 12 m / s (6-level wind);

[0153] Substituting the above into the maximum deflection calculation formula of the optimized orifice pipe before optimization can obtain:

[0154] ;

[0155] The load borne by the top end of the orifice pipe is:

[0156] ;

[0157] The optimized orifice pipe:

[0158] ,

[0159] ,

[0160] ,

[0161] The calculated maximum deflection of the optimized orifice pipe is y max2 70.84% lower than the maximum deflection of the orifice pipe before optimization. y max1

[0162] Therefore, the verticality and stability control method of the underwater grouting orifice pipe under deep water conditions of the present application is suitable for underwater grouting projects with reservoir water depth greater than 50 m, which fundamentally reduces the maximum deflection value of the orifice pipe and ensures the verticality and structural stability of the orifice pipe.

[0163] The above embodiments are the preferred embodiments of the present application, but the embodiments of the present application are not limited by the above embodiments, and any changes, modifications, substitutions, combinations, simplifications made without departing from the spirit and principles of the present application are equivalent replacement methods, which are all included in the protection scope of the present application.​

Claims

1. A method for maintaining the verticality of a deep water subsea grouting spool piece, comprising: Comprise the following steps: S1) under the premise of the orifice tube fixed at the bottom end and free at the top end, calculate the maximum deflection of the orifice tube before optimization under the action of hydrodynamic load and wind load in deep water conditions and the load borne by the top end of the orifice tube; The maximum deflection of the orifice tube before optimization is represented by the following formula In the formula, y max1 To optimize the maximum deflection of the front orifice tube, m, L is the length of the orifice tube, m, p w ρ 3 , C d is the water flow resistance coefficient, D is the outer diameter of the orifice tube body, m, U1 is the water flow velocity, m / s, U2 is the wind speed, m / s, E is the elastic modulus of the orifice tube body, Pa, I is the orifice tube cross-sectional moment of inertia, m 4 ; The load borne by the top end of the orifice tube is represented by the following formula In the formula, q is the load borne by the top end of the orifice tube, N / m, E is the elastic modulus of the orifice tube body, Pa, I is the orifice tube cross-sectional moment of inertia, m 4 , L is the length of the orifice tube, m, p w ρ 3 , C d is the water flow resistance coefficient, D is the outer diameter of the orifice tube body, m, U1 is the water flow velocity, m / s, U2 is the wind speed, m / s; S2) arrange a hinged fixing device at the top end of the orifice tube, optimize the orifice tube body section structure from the bottom end fixed-top end free to the bottom end fixed-top end simply supported, calculate the maximum deflection of the orifice tube after optimization, and the maximum deflection of the orifice tube after optimization is less than the maximum deflection of the orifice tube before optimization; S3) set the maximum allowable deflection value, and the maximum allowable deflection value is less than the maximum deflection of the orifice tube after optimization, establish a multi-stage continuous simply supported structure compensation model, the multi-stage continuous simply supported structure compensation model comprises arranging k stages of compensation hinged units along the tube length of the orifice tube body section, and optimizing the orifice tube body section structure from the bottom end fixed-top end simply supported to the bottom end fixed-intermediate multi-supported continuous rod body structure, wherein the spacing between adjacent support structures and the support force of each stage of units are determined by the maximum allowable deflection value, the overall maximum deflection value of the tube body is ensured to be not more than the maximum allowable deflection value, and finally the orifice tube always maintains a vertical state and the rod body is stable.

2. The method of claim 1, wherein: In S2, under the premise of the orifice tube fixed at the bottom end and simply supported at the top end, the maximum deflection of the orifice tube after optimization is represented by the following formula In the formula, y max2 To optimize the maximum value of the post-orifice tube deflection, m, q is the load borne by the top end of the orifice tube when the top end is free, N / m, E is the elastic modulus of the orifice tube body, Pa, I is the orifice tube cross-sectional moment of inertia, m 4 , L is the length of the orifice tube, m, R 简支 Counter force provided to the hinged end of the orifice tube tip, N.

3. The method of claim 2, wherein: In S2, under the premise of the orifice tube fixed at the bottom end and simply supported at the top end, the counterforce provided by the hinged end of the top end of the orifice tube needs to satisfy the following formula In the formula, R 简支 Counter force provided to the hinged end of the orifice tube tip, N, q is the load borne by the top end of the orifice tube when the top end is free, N / m, L is the length of the orifice tube, m.

4. The method of claim 3, wherein: In S2, the hinged fixing device is a float installed at the top end of the orifice tube.

5. The method of claim 1, wherein: In S3, under the premise of the orifice tube fixed at the bottom end and multi-supported at the intermediate, the spacing between adjacent support structures is calculated by the following formula In the formula, △x is the spacing between adjacent support structures, m, E is the elastic modulus of the orifice tube body, Pa, I is the orifice tube cross-sectional moment of inertia, m 4 , y 控制 is the maximum allowed deflection value, q is the load borne by the top end of the orifice tube when the top end is free, N / m, L is the length of the orifice tube, m.

6. The method of claim 5, wherein: In S3, under the premise of the orifice tube fixed at the bottom end and multi-supported at the intermediate, the support force of each stage of units is calculated by the following formula F i = k | y 控制 | In the formula, F i Support force for each level of cells, y 控制 is the maximum allowed deflection value, k is the number of stages of compensation hinged units.

7. The method of claim 6, wherein: In S3, the compensation hinged unit is a floating plate installed on the body section of the orifice tube.

Images