Method and equipment for judging critical instability conditions of dam stones for channel regulation structures

Abstract

The present invention mainly relates to a method and device for judging the critical instability conditions of the stone slabs used in dam construction of waterway regulation structures. The traditional judgment method only considers the effect of water flow force, and determines the relative positions of the stone slabs, water flow and vortex by establishing a coordinate system; the horizontal drag force, shear stress, gravity and torque of the stone slabs are calculated respectively; the vortex suction force and the torque generated by the vortex suction force acting on the stone slabs are calculated according to the relative size relationship between the vortex size and the geometric size of the stone slabs; and the starting flow velocity of the critical rolling instability of the stone slab and the starting flow velocity of the critical sliding instability of the stone slab are derived according to the judgment index of the critical rolling instability of the stone slab and the judgment index of the critical sliding instability of the stone slab, so as to further judge whether the stone slabs are unstable and improve the accuracy of the stone slab instability judgment.

Description

Technical Field

[0001] The present invention relates to the technical field of stability of hydraulic structures, and in particular to a method and equipment for judging critical instability conditions of dam stones in waterway regulation structures. Background Art

[0002] At present, in the actual inland waterway regulation project, when the flow velocity is greater than 3.0m / s, the formula in the "Waterway Engineering Design Code" (JTS 181-2016) is often used to determine the particle size of the rocks under the action of water flow. The isochoric particle size of the block stone is estimated. However, the above formula is used to regard the block stone as a sphere, and a sphere has only one dimension. The strip stone contains three dimensions: length, width, and height. Therefore, its instability mechanism under the action of water flow is relatively complex and cannot be simply answered by the above formula.

[0003] Channel constriction with spur dikes and spur dams is a common practice in mountain river waterway regulation. Due to the flow around the dike, the boundary layer separation at the dam head can easily generate a series of transient vortices. These vortices can make rock fragments more susceptible to instability due to the adsorption forces of these vortices. This has been observed in the channel regulation of the Jialing and Minjiang Rivers. Traditional research on rock fragment instability draws on methods used to study sediment initiation without considering cohesion, but only considers the effects of water flow and its own buoyant weight. Research on rock fragment instability under vortexes is relatively limited, and considers rock fragments as spheres. However, the dimensions of rock fragments are more complex than those of spheres, and no research has yet examined the instability of rock fragments under vortexes.

[0004] Ignoring the precise instability prediction of the stone dimensionality, the impact of the vortex on the stone cannot be accurately simulated, resulting in a large deviation between the calculated results and the actual situation.

[0005] Therefore, there is an urgent need for a method and equipment for determining the critical instability conditions of the stone dams used in channel regulation structures to improve the accuracy of stone instability determination. Summary of the Invention

[0006] In order to solve the above technical problems, the present invention provides a method and equipment for judging the critical instability conditions of the dam stones of waterway regulation structures, which can improve the accuracy of the stone block stability prediction by considering the influence of the vertical axis vortex on the dam stone blocks and the relative size relationship between the vortex size and the stone block geometric size.

[0007] A method for determining critical instability conditions of dam stones for channel regulation structures comprises the following steps:

[0008] S1: Establish a coordinate system to determine the relative positions of the stone, water flow and vortex;

[0009] S2: Calculating the stress state of the stone according to the relative position; the stress state includes horizontal drag force, shear stress, gravity, moment generated by the horizontal drag force, moment generated by the shear stress, and moment generated by gravity;

[0010] S3: Calculate the vortex suction force on the stone and the torque generated by the vortex suction force based on the size of the vortex and the geometric size of the stone;

[0011] S4: Calculating the critical rolling instability starting flow velocity of the stone according to the judgment index of the critical rolling instability of the stone and the torque generated by the horizontal drag force, the torque generated by the shear stress, the torque generated by the gravity, and the torque generated by the vortex suction force;

[0012] S5: Calculate the starting flow velocity of critical sliding instability of the stone according to the judgment index of critical sliding instability of the stone and the horizontal drag force, lifting force, gravity and vortex suction force on the stone;

[0013] S6: judging whether the stone block is unstable according to the critical rolling instability starting flow velocity of the stone block and the critical sliding instability starting flow velocity of the stone block.

[0014] As a preferred embodiment of the present invention, S1 comprises the following steps:

[0015] The center of the stone is taken as the origin 0, the X axis is along the direction of water flow, the Y axis is perpendicular to the direction of water flow, and the Z axis is perpendicular to the X and Y axes to establish a coordinate system;

[0016] The relative positions of the stone, water flow and vortex are determined according to the coordinate system.

[0017] As a preferred solution of the present invention, in S2, the horizontal drag force, shear stress, and moment generated by gravity on the stone are calculated using the following formula:

[0018] The calculation formula of the moment generated by the horizontal drag force on the stone is as follows:

[0019] ;

[0020] in, is the moment generated by the horizontal drag force on the stone; C D is the coefficient of horizontal drag force; ρ is the density of the water flow; b is the side length of the stone in the Y-axis direction; h is the side length of the stone in the Z-axis direction; u b is the water flow velocity at the stone slab;

[0021] The calculation formula of the moment generated by the shear stress on the stone is as follows:

[0022] ;

[0023] in, is the moment generated by the shear stress on the stone; C L is the coefficient of shear stress; l is the side length of the stone in the X-axis direction;

[0024] The calculation formula for the moment generated by the gravity on the stone is as follows:

[0025] ;

[0026] in, M W is the moment caused by the gravity acting on the stone, G S is the gravity of the stone; ρ s is the density of the stone; g is the acceleration due to gravity.

[0027] As a preferred embodiment of the present invention, S3 specifically includes:

[0028] Calculate the pressure in the vortex region based on the Euler equation for ideal liquid;

[0029] The vortex suction force exerted by the vortex on the stone is calculated based on the pressure in the vortex area and the relative size relationship between the vortex size and the stone's geometric size.

[0030] According to the vortex suction force and the lever arm acting on the stone, the torque generated by the vortex suction force acting on the stone is calculated.

[0031] As a preferred embodiment of the present invention, the relative size relationship between the vortex size and the geometric size of the stone strips includes:

[0032] The vortex diameter is larger than the geometric size of the stone strip, the vortex diameter is smaller than the geometric size of the stone strip, the vortex diameter is larger than the short side of the stone strip and smaller than the long side of the stone strip, and the vortex diameter is larger than the long side of the stone strip and smaller than the diagonal of the stone strip.

[0033] As a preferred solution of the present invention, in S4, the judging index of the critical rolling instability of the stone is:

[0034] ;

[0035] is the moment generated by the horizontal drag force on the stone; is the moment generated by the shear stress on the stone; The moment generated by the vortex suction force acting on the stone; M W is the moment caused by the gravity acting on the stone.

[0036] As a preferred embodiment of the present invention, the calculation formula for the critical rolling instability starting flow rate of the stone is:

[0037] The vortex diameter is larger than the geometric dimensions of the stone:

[0038] ,

[0039] The vortex diameter is smaller than the geometric dimensions of the stone:

[0040] ,

[0041] The vortex diameter is larger than the short side of the stone and smaller than the long side of the stone:

[0042] when hour:

[0043] ,

[0044] when hour;

[0045] ,

[0046] The vortex diameter is larger than the long side of the stone and smaller than the diagonal of the stone:

[0047] ,

[0048] in, U c is the unstable starting flow rate, r 0 is the vortex diameter, H For water depth, m To set the index, ω is the vortex angular velocity, C 3. C 4. C 5. C 6 are the values ​​calculated by S3 when the vortex diameter is smaller than the geometric size of the stone, the vortex diameter is larger than the short side of the stone and smaller than the long side of the stone, and , the vortex diameter is larger than the short side of the stone and smaller than the long side of the stone; , vortex suction torque parameter when the vortex diameter is larger than the long side of the stone and smaller than the diagonal of the stone, C 7 is the rolling instability calculation parameter.

[0049] As a preferred solution of the present invention, in S5, the judgment index of critical sliding instability of the stone is:

[0050] ;

[0051] in, F Dis the horizontal drag force on the stone, G S is the gravity of the stone; F L is the shear stress on the stone, F V It is the vortex suction force exerted by the vortex on the stone.

[0052] As a preferred embodiment of the present invention, the calculation formula for the critical sliding instability starting flow velocity of the stone is:

[0053] The vortex diameter is larger than the geometric dimensions of the stone:

[0054] ,

[0055] The vortex diameter is smaller than the geometric dimensions of the stone:

[0056] ,

[0057] The vortex diameter is larger than the short side of the stone and smaller than the long side of the stone:

[0058] when hour:

[0059] ,

[0060] when hour;

[0061] ,

[0062] The vortex diameter is larger than the long side of the stone and smaller than the diagonal of the stone:

[0063] ,

[0064] in, U c is the unstable starting flow rate, r 0 is the vortex diameter, H For water depth, m To set the index, ω is the vortex angular velocity, C 3. C 4. C 5. C 6 are the values ​​calculated by S3 when the vortex diameter is smaller than the geometric size of the stone, the vortex diameter is larger than the short side of the stone and smaller than the long side of the stone, and , the vortex diameter is larger than the short side of the stone and smaller than the long side of the stone; , vortex suction torque parameter when the vortex diameter is larger than the long side of the stone and smaller than the diagonal of the stone, C 8 is the sliding instability calculation parameter.

[0065] A device for determining critical instability conditions of dam stones for channel regulation structures comprises at least one processor and a memory communicatively connected to the at least one processor; the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute any one of the methods described above.

[0066] The embodiments of the present invention have the following technical effects:

[0067] 1. The mechanical equation for the instability of the stone block was derived by considering the vortex suction of the vertical axis vortex, the upward force of the water flow, the thrust of the water flow, gravity, and multiple geometric dimensions of the stone block. The expression for the average critical instability velocity of the vertical line of the stone block was obtained, and a comprehensive assessment of the stability of the stone block was conducted, avoiding the errors that may be caused by single-factor judgment and ensuring the comprehensiveness and accuracy of the instability judgment.

[0068] 2. By clarifying the relative relationship between vortex size and the geometric dimensions of the stone (for example, whether the vortex diameter is larger or smaller than the stone size, etc.), the influence of vortex suction can be calculated more accurately, and the assessment of stone stability under different vortex conditions is optimized. This refinement can improve the accuracy of critical instability judgment, because the influence of vortex size on stone will vary depending on their size relationship. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0070] Figure 1 This is a flow chart of a method for determining critical instability conditions of dam stones for channel regulation structures according to Example 1 of the present invention;

[0071] Figure 2 This is a schematic diagram of the relative positions of a slab, water flow, and vortex in a method for determining critical instability conditions of a slab of a waterway regulation structure dam according to Example 2 of the present invention;

[0072] Figure 3 This is a schematic diagram of the relative positions of the horizontal projection of a vortex and a stone having a vortex diameter greater than the geometric dimensions of the stone, in a method for determining critical instability conditions of a stone dam for a waterway regulation structure according to Example 2 of the present invention;

[0073] Figure 4This is a schematic diagram of the relative positions of the horizontal projection of a vortex and a stone having a vortex diameter smaller than the geometric dimensions of the stone in a method for determining critical instability conditions of a dam stone for a channel regulation structure according to Example 2 of the present invention;

[0074] Figure 5 This is a schematic diagram of the relative positions of the horizontal projections of the vortex and the stone whose vortex diameter is larger than the short side of the stone and smaller than the long side of the stone in the method for determining the critical instability conditions of the stone for damming a waterway regulation structure according to Example 2 of the present invention;

[0075] Figure 6 This is a schematic diagram of the relative positions of the horizontal projections of the vortex and the stone, wherein the vortex diameter is larger than the long side of the stone and smaller than the diagonal of the stone, in a method for determining the critical instability conditions of the stone for damming a waterway regulation structure according to Example 2 of the present invention;

[0076] Figure 7 This is a schematic diagram of the principle of the dam head separation vortex and induced velocity in a method for determining critical instability conditions of dam stone blocks for channel regulation structures according to Example 2 of the present invention;

[0077] Figure 8 The method for judging the critical instability condition of the stone damming stone in a waterway regulation structure according to embodiment 2 of the present invention is the average critical instability velocity of the vertical line of the stone damming ... l / h Relationship diagram;

[0078] Figure 9 The present invention is a method for judging the critical instability condition of the stone damming of a waterway regulation structure in embodiment 2, wherein the difference between the average critical instability velocity of the vertical line of the stone damming structure with or without vortex and l / h Relationship diagram;

[0079] Figure 10 The method for judging the critical instability condition of the stone damming of a channel regulation structure described in Example 2 of the present invention is based on the average critical instability velocity of the vertical line of the stone damming at the spur dam head and the narrowing rate of the spur dam. η 、 b / h 、 l / h Schematic diagram of the correlation relationship;

[0080] Figure 11 This is a schematic structural diagram of an electronic device according to embodiment 3 of the present invention that utilizes the method for determining critical instability conditions of dam stones for channel regulation structures according to the aforementioned embodiment. DETAILED DESCRIPTION

[0081] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention are described clearly and completely below. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are also within the scope of protection of the present invention.

[0082] Example 1

[0083] like Figure 1 As shown, a method for determining the critical instability condition of the dam stone of a channel regulation structure includes the following steps:

[0084] S1: Establish a coordinate system to determine the relative positions of the stone, water flow and vortex;

[0085] S2: Calculating the stress state of the stone according to the relative position; the stress state includes horizontal drag force, shear stress, gravity, moment generated by the horizontal drag force, moment generated by the shear stress, and moment generated by gravity;

[0086] S3: Calculate the vortex suction force on the stone and the torque generated by the vortex suction force based on the size of the vortex and the geometric size of the stone;

[0087] S4: Calculating the critical rolling instability starting flow velocity of the stone according to the judgment index of the critical rolling instability of the stone and the torque generated by the horizontal drag force, the torque generated by the shear stress, the torque generated by the gravity, and the torque generated by the vortex suction force;

[0088] S5: Calculate the starting flow velocity of critical sliding instability of the stone according to the judgment index of critical sliding instability of the stone and the horizontal drag force, lifting force, gravity and vortex suction force on the stone;

[0089] S6: judging whether the stone block is unstable according to the critical rolling instability starting flow velocity of the stone block and the critical sliding instability starting flow velocity of the stone block.

[0090] Example 2

[0091] This embodiment is a specific implementation of the method for determining critical instability conditions of dam stones for channel regulation structures described in Example 1, comprising the following steps:

[0092] S1: Establish a coordinate system to determine the relative positions of the stone, water flow and vortex;

[0093] The center of the stone is taken as the origin 0, the X axis is along the direction of water flow, the Y axis is perpendicular to the direction of water flow, and the Z axis is perpendicular to the X and Y axes to establish a coordinate system;

[0094] The relative positions of the stone, water flow and vortex are determined according to the coordinate system.

[0095] For details, see Figure 2 The relative positions of the stone, water flow and vortex are relatively complicated. To simplify the calculation, it is assumed that the rectangular stone is facing the direction of water flow. Therefore, under the action of water flow, the compressive stress along the direction of water flow is the horizontal drag force, and the shear stress perpendicular to the direction of water flow is the lifting force. At the same time, it is assumed that the central axis of the stone completely coincides with the axis of the vortex.

[0096] S2: Calculating the stress state of the stone according to the relative position; the stress state includes horizontal drag force, shear stress, gravity, moment generated by the horizontal drag force, moment generated by the shear stress, and moment generated by gravity.

[0097] Furthermore, the horizontal drag force, shear stress, and moment caused by gravity on the stone blocks are calculated using the following formula:

[0098] The calculation formula of the moment generated by the horizontal drag force on the stone is as follows:

[0099] ;

[0100] in, is the moment generated by the horizontal drag force on the stone; C D is the coefficient of horizontal drag force; ρ is the density of the water flow; b is the side length of the stone in the Y-axis direction; h is the side length of the stone in the Z-axis direction; u b is the water flow velocity at the stone slab;

[0101] The calculation formula of the moment generated by the shear stress on the stone is as follows:

[0102] ;

[0103] in, is the moment generated by the shear stress on the stone; C L is the coefficient of shear stress; l is the side length of the stone in the X-axis direction;

[0104] The calculation formula for the moment generated by the gravity on the stone is as follows:

[0105] ;

[0106] in, M W is the moment caused by the gravity acting on the stone, G S is the gravity of the stone; ρs is the density of the stone; g is the acceleration due to gravity.

[0107] S3: Calculate the vortex suction force on the stone and the torque generated by the vortex suction force based on the size of the vortex and the geometric size of the stone;

[0108] The magnitude of the vortex suction force exerted on the stone slabs depends on the relative size relationship between the vortex size and the geometric size of the stone slabs, and can be analyzed and calculated one by one.

[0109] Furthermore, the relative size relationship between the vortex size and the geometric size of the stone strip includes: the vortex diameter is larger than the geometric size of the stone strip, the vortex diameter is smaller than the geometric size of the stone strip, the vortex diameter is larger than the short side of the stone strip and smaller than the long side of the stone strip, and the vortex diameter is larger than the long side of the stone strip and smaller than the diagonal of the stone strip.

[0110] Furthermore, the step S3 specifically includes the following steps:

[0111] S31: Calculate the pressure in the vortex region based on the Euler equation for ideal liquid;

[0112] Specifically, the vortex is regarded as a Rankine vortex, and the vortex radius is r 0, there is a "vortex core" inside the vortex that rotates like a rigid body, that is, the uniform circular motion of the rigid body; the flow velocity outside the vortex is the same as r Inversely proportional, so according to Stocks' circulation theorem, the distance from the vortex axis is r The flow velocity on the circumference u It can be expressed as:

[0113] (r≤r0);

[0114] (r>r0);

[0115] in, u x is the flow rate u about x The first-order partial derivative of u y is the flow rate u about y The first-order partial derivative of ω is the angular velocity; x Represents the horizontal distance from the center of the vortex to a point on the circumference; y Represents the vertical distance from the center of the vortex to a point on the circumference;

[0116] The Euler equation for an ideal liquid is:

[0117] ;

[0118] ;

[0119] in, ρ is the density of flowing water; F x 、 F y They are x 、 y Directional mass force.

[0120] Distance from vortex axis r The flow velocity on the circumference u Substitute the Euler equation for ideal liquid to obtain the internal pressure of the vortex P 1 and the internal pressure of the vortex P 2:

[0121] ;

[0122] ;

[0123] in, C 1 is a constant; C 2 is a constant;

[0124] Because the pressure distribution inside and outside the vortex is continuous, the vortex radius r 0 places, P 1 =P 2; At the same time r→∞ When the fluid at infinity is not affected by the vortex, then at the water depth z Relative pressure at is the hydrostatic pressure, so , , from the above, we can get the pressure distribution inside and outside the vortex satisfying the following formula:

[0125] .

[0126] S32: Calculating the vortex suction force exerted by the vortex on the stone according to the pressure in the vortex area and the relative size relationship between the vortex size and the geometric size of the stone;

[0127] (1) When the vortex diameter is larger than the geometric size of the stone, see Figure 3 ,Right now 2r 0 >l and 2r 0 >b , the vortex suction force calculation formula is as follows:

[0128] ,

[0129] (2) When the vortex diameter is smaller than the geometric size of the stone, see Figure 4 ,Right now 2r 0<l and 2r 0 <b , polar coordinates are used to solve the vortex suction force, and the calculation formula is as follows:

[0130] ;

[0131] in, is the angle between the diagonal line of the stone and the horizontal direction of the X axis, .

[0132] (3) When the vortex diameter is larger than the short side of the stone and smaller than the long side of the stone, see Figure 5 , can be divided into two cases;

[0133] ① When When , the polar coordinates are used to solve the vortex suction force calculation formula as follows:

[0134] ;

[0135] in, is the angle between the connecting line of the intersection of the vortex and the stone and the X-axis direction, .

[0136] ②When When , the polar coordinates are used to solve the vortex suction force calculation formula as follows:

[0137] ;

[0138] in, is the angle between the connecting line of the intersection of the vortex and the stone and the X-axis direction, ;

[0139] (4) When the vortex diameter is larger than the long side of the stone and smaller than the diagonal of the stone, see Figure 6 ,Right now , the calculation formula of vortex suction force using polar coordinates is as follows:

[0140] ;

[0141] S33: Calculate the torque generated by the vortex suction force acting on the stone according to the vortex suction force and the lever arm.

[0142] (1) When the vortex diameter is larger than the geometric size of the stone, see Figure 3 ,Right now 2r 0 >l and 2r 0 >b The torque calculation formula of the vortex suction force is as follows:

[0143] .

[0144] (2) When the vortex diameter is smaller than the geometric size of the stone, see Figure 4 ,Right now 2r 0 <l and 2r 0 <b , the calculation formula of the torque generated by the vortex suction force is as follows:

[0145] ;

[0146] ;

[0147] The integral term in the above formula can be approximated by using Taylor expansion to obtain:

[0148] ;

[0149] in:

[0150] .

[0151] (3) The vortex diameter is larger than the short side of the stone and smaller than the long side of the stone, see Figure 5 , can be divided into two cases;

[0152] ① When When , the torque generated by the vortex suction force is calculated as follows:

[0153] ;

[0154] ;

[0155] The integral term of the above formula can be approximated by using Taylor expansion to obtain:

[0156] ;

[0157] in:

[0158] .

[0159] ②When When , the torque generated by the vortex suction force is calculated as follows:

[0160] ;

[0161] ;

[0162] The integral term of the above formula is approximated by Taylor expansion to obtain:

[0163] ;

[0164] in:

[0165] ;

[0166] (4) When the vortex diameter is larger than the long side of the stone and smaller than the diagonal of the stone, see Figure 6 ,Right now , the calculation formula of the torque generated by the vortex suction force is as follows:

[0167] ;

[0168] The integral term of the above formula is approximated by Taylor expansion to obtain:

[0169] ;

[0170] in:

[0171] .

[0172] S4: Calculating the starting flow velocity for critical rolling instability of the stone according to the judgment index for critical rolling instability of the stone and the torque generated by the horizontal drag force, the torque generated by the shear stress, the torque generated by the gravity, and the torque generated by the vortex suction force;

[0173] Furthermore, in S4, the judgment index of critical rolling instability of the stone block is:

[0174] ;

[0175] is the moment generated by the horizontal drag force on the stone; is the moment generated by the shear stress on the stone; The moment generated by the vortex suction force acting on the stone; M W is the moment caused by the gravity acting on the stone.

[0176] Specifically, the flow rate of the stone It is difficult to determine in actual work. For the convenience of use, the vertical average flow velocity is used. U Instead, use the exponential velocity distribution formula:

[0177] ;

[0178] in: u is the flow rate, H For water depth, m is an index, the characteristic height of the flow velocity acting on the stone z=ah , then the average critical instability velocity of the vertical line of the stone is:

[0179] (1) Not considering the influence of vertical axis vortex:

[0180] The starting flow velocity of critical rolling instability of stone blocksU c0 : ;

[0181] (2) Considering the influence of vertical axis vortex:

[0182] (1) When the vortex diameter is larger than the geometric size of the stone, that is, 2r 0 >l and 2r 0 >b :

[0183] The starting flow velocity of critical rolling instability of stone blocks U c :

[0184] ;

[0185] (2) When the vortex diameter is smaller than the geometric size of the stone, that is, 2r 0 <l and 2r 0 <b :

[0186] The starting flow velocity of critical rolling instability of stone blocks U c :

[0187] ;

[0188] (3) When the vortex diameter is larger than the short side of the stone but smaller than the long side of the stone, there are two cases;

[0189] when hour:

[0190] The starting flow velocity of critical rolling instability of stone blocks U c :

[0191] ;

[0192] when hour;

[0193] The starting flow velocity of critical rolling instability of stone blocks U c :

[0194] ;

[0195] (4) When the vortex diameter is larger than the long side of the stone and smaller than the diagonal of the stone, :

[0196] The starting flow velocity of critical rolling instability of stone blocks U c :

[0197] ;

[0198] In the above formula:

[0199] ,

[0200] in, C 3. C 4. C 5. C 6 are the values ​​calculated by S3 when the vortex diameter is smaller than the geometric size of the stone, the vortex diameter is larger than the short side of the stone and smaller than the long side of the stone, and , the vortex diameter is larger than the short side of the stone and smaller than the long side of the stone; , vortex suction torque parameter when the vortex diameter is larger than the long side of the stone and smaller than the diagonal of the stone, C 7 is the rolling instability calculation parameter, specifically about m , a , , , l , b function, for natural river channels m =1 / 6. According to the load specification for river and port engineering, the action point is located at the centroid, so a =0.5, C D is the horizontal drag coefficient, C L is the shear stress resistance coefficient perpendicular to the direction of water flow. 、 There are many influencing factors. According to the research, 、 The law of change of The value shows a trend of increasing first and then decreasing from the bottom to the water surface along the vertical water depth. The value shows a trend of monotonically decreasing from the bottom to the water surface along the vertical water depth. This embodiment adopts the research results that the stone is at the bed surface. 、 Value, that is , , then the above formula can be simplified to: .

[0201] S5: Calculate the starting flow velocity of critical sliding instability of the stone according to the judgment index of critical sliding instability of the stone and the horizontal drag force, lifting force, gravity and vortex suction force on the stone;

[0202] Furthermore, in S5, the judgment index of critical sliding instability of the stone block is:

[0203] ;

[0204] in, F D is the horizontal drag force on the stone, G S is the gravity of the stone; F L is the shear stress on the stone, F V It is the vortex suction force exerted by the vortex on the stone.

[0205] Specifically, the calculation formula for the starting flow velocity of critical sliding instability of stone is:

[0206] (1) Not considering the influence of vertical axis vortex:

[0207] The starting flow velocity of critical sliding instability of stone blocks U c0 :

[0208] .

[0209] (2) Considering the influence of vertical axis vortex:

[0210] (1) When the vortex diameter is larger than the geometric size of the stone, that is, 2r 0 >l and 2r 0 >b :

[0211] The starting flow velocity of critical sliding instability of stone blocks U c :

[0212] ;

[0213] (2) When the vortex diameter is smaller than the geometric size of the stone, that is, 2r 0 <l and 2r 0 <b :

[0214] The starting flow velocity of critical sliding instability of stone blocks U c :

[0215] ;

[0216] (3) When the vortex diameter is larger than the short side of the stone but smaller than the long side of the stone, there are two cases;

[0217] when hour:

[0218] The starting flow velocity of critical sliding instability of stone blocks U c :

[0219] .

[0220] when hour;

[0221] The starting flow velocity of critical sliding instability of stone blocks U c :

[0222] ;

[0223] (4) When the vortex diameter is larger than the long side of the stone and smaller than the diagonal of the stone, :

[0224] The starting flow velocity of critical sliding instability of stone blocks U c :

[0225] .

[0226] In the above formula:

[0227] ;

[0228] in, C 8 is about m , a , , , l , b function, for natural river channels m =1 / 6. According to the load specification for river and port engineering, the action point is located at the centroid, so a =0.5. 、 There are many influencing factors. According to the research, 、 The law of change of The value shows a trend of increasing first and then decreasing from the bottom to the water surface along the vertical water depth. The value shows a trend of monotonically decreasing from the bottom to the water surface along the vertical water depth. This embodiment adopts the research results that the stone is at the bed surface. 、 Value, that is , , then the above formula can be simplified to: .

[0229] S6: judging whether the stone block is unstable according to the critical rolling instability starting flow velocity of the stone block and the critical sliding instability starting flow velocity of the stone block.

[0230] This embodiment can also increase the critical instability flow velocity of the stone blocks by increasing the geometric dimensions of the stone blocks, thereby enhancing the stability of the stone blocks.

[0231] Furthermore, the vertical axis vortex scale calculation at the spur dike head: The vortex scale and intensity indicators in the river are difficult to quantify, but there are some studies on the vortex generated by water flow separation at the spur dike head. According to Gao Dongguang's research results, Figure 7 As shown in the figure, the size of the vertical axis vortex at the head of the non-submerged spur dike (vortex radius r 0) and the maximum flow velocity around the dam head Satisfies the following formula:

[0232]

[0233]

[0234] In the above formula L D is the length of the spur dike perpendicular to the direction of water flow, B is the river width, V is the average flow velocity of the river section under natural conditions, where the vortex angular velocity and the maximum flow velocity around the dam head satisfy the formula Substituting the formulas related to the vortex size and angular velocity at the spur dike head into the average critical instability velocity of the vertical line of the stone spur dike, the formulas for the average critical instability velocity of the vertical line of the stone spur dike head under various conditions can be obtained.

[0235] For example, in order to analyze the instability of the stone at the spur dam head, a dangerous section of the Jialing River was selected as the basic experimental condition for research. B =300m, average water depth H =3m, average flow velocity in section V =0.67m / s, length of spur dike perpendicular to water flow direction L D =90m, that is, beam narrowing rate η=L D / B =0.3. In the early channel regulation structures of Minjiang River and Jialing River, h =0.5m, b =0.5m stone, for l The length of the dam is not fixed and is often appropriately combined according to the width of the dam top of the renovated building. Figure 8 for h=b When the spur dike has different narrowing ratios, the average critical instability velocity of the vertical line of the stone at the spur dike head is U C Follow l / h In general, under different spur dike narrowing rates, the average critical instability velocity of the vertical line of the stone l / h It shows a monotonically increasing trend, and the gradient of change increases with l / h Increase gradually decrease, basically l / h>3, only by increasing l / h Due to the relative size of the stone, it is difficult to significantly increase the average critical instability velocity of the vertical line to ensure its overall stability.

[0236] The present invention provides an expression for the average critical instability velocity of the vertical line of the stone block at the spur dike head with or without considering the vortex. In order to further analyze the influence of the vertical axis vortex on the instability of the stone block and its mechanism, Figure 9 for h=b The difference in the average critical instability velocity of the vertical line of the stone with and without considering the vortex under different spur dike narrowing rates is U C0 -U C Follow l / h Overall, the difference in the average critical instability velocity of the vertical line of the stone with and without considering the vortex changes with l / h It shows a monotonically increasing trend, and the gradient of change increases with l / h However, when the narrowing ratio is relatively small and the rock mass is relatively large, the above trend does not show a monotonic change, but instead increases first and then decreases. As the narrowing ratio of the spur dike increases, the intensity and size of the vertical axis vortex at the dam head increase, the vortex suction increases, and the influence of the vortex is significantly enhanced, so the above velocity difference becomes more obvious.

[0237] From the above, we can see that the main factor that determines the instability of the stone block at the spur dike head is the narrowing ratio of the spur dike. η , h , b and l The following will discuss the average critical instability velocity of the vertical line of the stone and the narrowing rate of the spur dike. η , h , b and l According to the characteristics of the aforementioned project section, the narrowing rate of the spur dike is η The values ​​are 0.1, 0.2, 0.3, and 0.4 respectively; h With reference to engineering examples, the value range is 0.2m~1.0m; b and l relatively h The change rate is between 0.5 and 5.0. η Under the condition, the average critical instability velocity of the vertical line of the stone is b / h and l / h See the relationship Figure 10 .

[0238] In summary, the beam narrowing rate of the spur dike η The larger it is, the larger the vortex size and intensity are, and the easier it is for the stone to become unstable, that is, the smaller the vertical average critical instability velocity is. Figure 10is the average critical instability velocity of the vertical line of the stone at the spur dam head Uc and spur beam narrowing ratio η 、 b / h 、 l / h The correlation diagram shows that Uc about b / h The sensitivity to changes is weak, and l / h The sensitivity of the stone to changes is relatively strong, so if you want to increase the geometric size of the stone to enhance its stability and thus improve its ability to resist water flow, you should first consider increasing l / h The value of .

[0239] Example 3

[0240] like Figure 11 As shown, a device for determining critical instability conditions of dam-stone blocks for channel regulation structures includes at least one processor, a memory communicatively connected to the at least one processor, and at least one input / output interface communicatively connected to the at least one processor. The memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform a method described in the aforementioned embodiment. The input / output interface may include a display, a keyboard, a mouse, and a USB interface for inputting and outputting data.

[0241] Furthermore, the device for determining the critical instability conditions of the dam stones of the channel regulation building can be a desktop computer, a mobile phone, a tablet computer, a wearable device for determining the critical instability conditions of the dam stones of the channel regulation building, etc., which can perform in-depth information recognition.

[0242] Furthermore, the processor may include one or more processing cores. The processor utilizes various interfaces and circuits to connect various components within the entire device for determining critical instability conditions of dam-shaped stonework for channel regulation structures. By running or executing instructions, programs, code sets, or instruction sets stored in memory, and accessing data stored in memory, the processor performs various functions and processes data within the device. Optionally, the processor may be implemented using at least one of the following hardware forms: a digital signal processing (DSP), a field-programmable gate array (FPGA), or a programmable logic array (PLA). The processor may integrate one or a combination of a central processing unit (CPU), a graphics processing unit (GPU), and a modem. The CPU primarily processes the operating system, user interface, and application programs; the GPU is responsible for rendering and drawing display content; and the modem handles wireless communications. It is understood that the modem may not be integrated into the processor and may be implemented separately via a communications chip.

[0243] The memory may include random access memory (RAM) or read-only memory (ROM). The memory may be used to store instructions, programs, codes, code sets, or instruction sets, such as instructions or code sets for implementing a method provided in an embodiment of the present application. The memory may include a program storage area and a data storage area, wherein the program storage area may store instructions for implementing an operating system, instructions for implementing at least one function, instructions for implementing each of the above-mentioned method embodiments, etc. The data storage area may also store data (such as a mapping table of modulation sequence and depth, image data, and spectrum data) created during use by the device for determining critical instability conditions of damming stone blocks for channel regulation structures.

[0244] Those skilled in the art will understand that all or part of the steps of the above-mentioned method embodiment can be completed by hardware related to program instructions, and the aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps of the above-mentioned method embodiment; and the aforementioned storage medium includes: mobile storage devices, read-only memories (ROM), magnetic disks or optical disks, and other media that can store program codes.

[0245] When the integrated unit described above is implemented as a software functional unit and sold or used as a standalone product, it can also be stored in a computer-readable storage medium containing program code that can be invoked by a processor to execute the methods described in the above-mentioned method embodiments. Based on this understanding, the technical solutions of the embodiments of the present invention, or the portion that contributes to the prior art, can be embodied in the form of a software product. This computer software product, stored in a storage medium, includes instructions for enabling a computer device (such as a personal computer, server, or network device) to execute all or part of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes electronic memory such as flash memory, EEPROM (Electrically Erasable Programmable Read-Only Memory), EPROM, hard disk, or ROM. Optionally, the computer-readable storage medium includes non-transitory computer-readable storage medium. The computer-readable storage medium has storage space for program code for executing any of the method steps described above. This program code can be read from or written to one or more computer program products. The program code can be compressed, for example, in a suitable form.

[0246] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for determining the critical instability conditions of dam stones for channel regulation structures, characterized in that: The steps include: S1: Establish a coordinate system to determine the relative positions of the stone, water flow and vortex; S2: Calculating the stress state of the stone according to the relative position; the stress state includes horizontal drag force, shear stress, gravity, moment generated by the horizontal drag force, moment generated by the shear stress, and moment generated by gravity; The following formula is used to calculate the horizontal drag force, shear stress, and moment caused by gravity on the stone: The calculation formula of the moment generated by the horizontal drag force on the stone is as follows: ； in, is the moment generated by the horizontal drag force on the stone; C D is the coefficient of horizontal drag force; ρ is the density of the water flow; b is the side length of the stone in the Y-axis direction; h is the side length of the stone in the Z-axis direction; u b is the water flow velocity at the stone slab; The calculation formula of the moment generated by the shear stress on the stone is as follows: ； in, is the moment generated by the shear stress on the stone; C L is the coefficient of shear stress; l is the side length of the stone in the X-axis direction; The calculation formula for the moment generated by the gravity on the stone is as follows: ； in, M W is the moment caused by the gravity acting on the stone, G S is the gravity of the stone; ρ s is the density of the stone; g is the acceleration due to gravity; S3: Calculate the vortex suction force on the stone and the torque generated by the vortex suction force based on the size of the vortex and the geometric size of the stone; S4: Calculating the critical rolling instability starting flow velocity of the stone according to the judgment index of the critical rolling instability of the stone and the torque generated by the horizontal drag force, the torque generated by the shear stress, the torque generated by the gravity, and the torque generated by the vortex suction force; Among them, the judgment index of critical rolling instability of stone blocks is: ； is the moment generated by the horizontal drag force on the stone; is the moment generated by the shear stress on the stone; The moment generated by the vortex suction force acting on the stone; M W is the moment caused by the gravity acting on the stone; S5: Calculate the starting flow velocity of critical sliding instability of the stone according to the judgment index of critical sliding instability of the stone and the horizontal drag force, lifting force, gravity and vortex suction force on the stone; S6: judging whether the stone block is unstable according to the critical rolling instability starting flow velocity of the stone block and the critical sliding instability starting flow velocity of the stone block.

2. The method for determining the critical instability conditions of dam stones for channel regulation structures according to claim 1 is characterized in that: Said S1 comprises the following steps: The center of the stone is taken as the origin 0, the X axis is along the direction of water flow, the Y axis is perpendicular to the direction of water flow, and the Z axis is perpendicular to the X and Y axes to establish a coordinate system; The relative positions of the stone, water flow and vortex are determined according to the coordinate system.

3. The method for determining the critical instability conditions of dam stones for channel regulation structures according to claim 2, characterized in that: Said S3 specifically includes: Calculate the pressure in the vortex region based on the Euler equation for ideal liquid; The vortex suction force exerted by the vortex on the stone is calculated based on the pressure in the vortex area and the relative size relationship between the vortex size and the stone's geometric size. According to the vortex suction force and the lever arm acting on the stone, the torque generated by the vortex suction force acting on the stone is calculated.

4. The method for determining the critical instability conditions of dam stones for channel regulation structures according to claim 3 is characterized in that: The relative size relationship between the vortex size and the geometric size of the stone strips includes: The vortex diameter is larger than the geometric size of the stone strip, the vortex diameter is smaller than the geometric size of the stone strip, the vortex diameter is larger than the short side of the stone strip and smaller than the long side of the stone strip, and the vortex diameter is larger than the long side of the stone strip and smaller than the diagonal of the stone strip.

5. The method for determining the critical instability conditions of dam stones for channel regulation structures according to claim 4, characterized in that: The calculation formula for the critical rolling instability starting velocity of the stone is: The vortex diameter is larger than the geometric dimensions of the stone: ， The vortex diameter is smaller than the geometric dimensions of the stone: ， The vortex diameter is larger than the short side of the stone and smaller than the long side of the stone: when hour: ， when hour; ， The vortex diameter is larger than the long side of the stone and smaller than the diagonal of the stone: ， in, U c is the unstable starting flow rate, r 0 is the vortex diameter, H For water depth, m To set the index, ω is the vortex angular velocity, C 3. C 4. C 5. C 6 are the values ​​calculated by S3 when the vortex diameter is smaller than the geometric size of the stone, the vortex diameter is larger than the short side of the stone and smaller than the long side of the stone, and , the vortex diameter is larger than the short side of the stone and smaller than the long side of the stone; , vortex suction torque parameter when the vortex diameter is larger than the long side of the stone and smaller than the diagonal of the stone, C 7 is the rolling instability calculation parameter.

6. The method for determining the critical instability conditions of dam stones for channel regulation structures according to claim 3, characterized in that: In S5, the judgment index of critical sliding instability of the stone block is: ； in, F D is the horizontal drag force on the stone, G S is the gravity of the stone; F L is the shear stress on the stone, F V It is the vortex suction force exerted by the vortex on the stone.

7. A method for determining critical instability conditions of dam stones for channel regulation structures according to claim 6, characterized in that: The calculation formula for the critical sliding instability starting flow velocity of the stone is: The vortex diameter is larger than the geometric dimensions of the stone: ， The vortex diameter is smaller than the geometric dimensions of the stone: ， The vortex diameter is larger than the short side of the stone and smaller than the long side of the stone: when hour: ， when hour; ， The vortex diameter is larger than the long side of the stone and smaller than the diagonal of the stone: ， in, U c is the unstable starting flow rate, r 0 is the vortex diameter, H For water depth, m To set the index, ω is the vortex angular velocity, C 3. C 4. C 5. C 6 are the values ​​calculated by S3 when the vortex diameter is smaller than the geometric size of the stone, the vortex diameter is larger than the short side of the stone and smaller than the long side of the stone, and , the vortex diameter is larger than the short side of the stone and smaller than the long side of the stone; , vortex suction torque parameter when the vortex diameter is larger than the long side of the stone and smaller than the diagonal of the stone, C 8 is the sliding instability calculation parameter.

8. A device for determining critical instability conditions of dam stones for channel regulation structures, characterized by: The invention comprises at least one processor and a memory communicatively connected to the at least one processor; the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the method according to any one of claims 1 to 7.

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