CN111428401A - Method for simulating damming process of barrier lake - Google Patents

Method for simulating damming process of barrier lake Download PDF

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CN111428401A
CN111428401A CN202010189555.0A CN202010189555A CN111428401A CN 111428401 A CN111428401 A CN 111428401A CN 202010189555 A CN202010189555 A CN 202010189555A CN 111428401 A CN111428401 A CN 111428401A
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water
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sand
terrain
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黄卫
段文刚
黄国兵
史德亮
黄明海
李静
韩松林
於思瀚
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Changjiang River Scientific Research Institute Changjiang Water Resources Commission
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Abstract

The invention discloses a water-sand coupling simulation method for a damming lake bursting process, which relates to the field of water disaster defense and comprises the steps of describing a damming lake bursting forming and developing process by adopting a complete water-sand coupling control equation, solving the complete water-sand coupling control equation by adopting a finite volume method in a high-precision MUSC L-TVD-H LL C format, reconstructing interface Riemann value variables by using MUSC L to enable the interface Riemann value variables to reach second-order precision, inhibiting numerical oscillation by using a TVD algorithm, calculating Riemann flux by using H LL C, dispersing terrain source items by using a local terrain correction and water depth reconstruction technology, dispersing resistance source items by adopting an implicit method, and processing a gravity collapse simulation bursting process by adopting a simple geometric method.

Description

Method for simulating damming process of barrier lake
Technical Field
The invention relates to the field of water disaster defense, in particular to a method for simulating a damming lake burst process.
Background
The dam formed by earthquake and rainstorm induced collapse and landslide river blockage is usually formed by stacking loose earth and rockfill, and most of the dam is in danger of water overflow and collapse. More than 400 Weissen lakes are recorded in China, and about 85% of the Weissen lakes occur in the upstream of the Yangtze river and in the southwest rivers. Currently, the frequency of barrier lake burst events is significantly increased under the multiple effects of earthquakes, climate change and human activities. Once the barrage dam is burst, extreme flood can be formed, for example, the maximum instantaneous flow of burst flood of Tibet Yigong barrage lake reaches 120000m in 20003S; the peak flow of the flood for damming the lake in Tangjiashan lake in 2008 reaches 6500m3Is (see figure 1) and is far larger than the historically measured maximum peak flow 4270m of the river reach3S; the peak value of the burst flood of the Baige dammed lake in 2018 reaches 33900m3And/s, the flow rate of the far-exceeding Jinshajiang upstream river reaches 10600m after meeting flood peak all the year3And/s, seriously threatens the safety of life and property of people in the downstream and hydraulic engineering.
The mathematical model of the damming dam bursting process mainly comprises a parameter model and a model based on a physical foundation. The physical basic model can be divided into a simplified physical model and a complete physical model according to the theoretical basic degree based on the physical basic model. Existing models are simplified physical models, introducing many unreasonable or unnecessary assumptions. The first assumption is that the breach flow is calculated by using the broad top weir formula. Because the downstream length of the natural barrage dam is generally far greater than that of the artificial dam body, the size of the break port is changed along the way, the applicability of the wide top weir formula is doubtful, and the horn-shaped break port characteristic common in the earth and rockfill dam cannot be reproduced by adopting the wide top weir formula. The second assumption is that the slope gradient is maintained constant during the crash. For loose stacks, the slope is washed by the water flow and the slope is continuously steeper until it collapses beyond a critical slope. The third assumption is that the partial model also artificially gives the residual dam height to control the scour termination elevation. Actually, the scouring stop elevation is determined by the soil property and the water flow condition, and when the water flow intensity is not enough to scour the soil, the breach can automatically stop scouring and undercutting. The fourth hypothesis is that a part of model back flow surfaces adopt a uniform flow hypothesis, however, both laboratory water tank tests and field observation of barrage dams show that the traceable scouring is an important mechanism for forming the break mouth and has important influence on the break time and the break mouth flow process, so that the hypothesis is not applicable in most cases. The complete physical model is based on the water-sand motion theory, simulates the dam erosion and riverbed sludging process in the damming dam bursting process, and simulates the bursting widening process by combining gravity collapse. Because the model introduces fewer assumed conditions and the physical mechanism is more sound, a more detailed and reasonable physical process of damming dam bursting can be provided.
Disclosure of Invention
The invention provides a method for simulating a damming lake burst process, which provides a novel water-sand coupling complete physical model, simulates a breach forming and widening process of damming dam burst and a flow, water level and sand content process of the breach, can obviously improve the simulation precision of the damming dam burst process, and provides a more detailed burst physical process.
A method for simulating a barrier lake bursting process is characterized by comprising the following steps:
step one, describing the formation and development process of the breach of the barrier lake by adopting a complete water-sand coupling control equation, wherein the complete water-sand coupling control equation considers the influence of sediment transport and riverbed deformation on water flow in a traditional mass conservation equation and a momentum conservation equation, so that the physical coupling among water, sand and riverbed is realized, and the complete water-sand coupling control equation has the following expression:
Figure BDA0002415377100000021
in the formula, U is a conservation quantity vector; f and G are convection flux vectors in the x and y directions respectively, t is time, x and y are space coordinates, and S is a source item vector;
step two, solving the complete water-sand coupling control equation by adopting a Huang et al (2012) numerical format discrete control equation, namely adopting a finite volume method in a high-precision MUSC L-TVD-H LL C format, specifically, reconstructing variables for calculating an interface flux vector by adopting MUSC L, limiting reconstructed variable values by adopting a TVD algorithm, wherein the interface flux is Riemann flux, and calculating by adopting an H LL C Riemann operator;
dispersing terrain source items through local terrain correction and water depth reconstruction technology, so that flux calculation and the terrain source items are dispersed and harmonious;
dispersing the resistance source items by adopting an implicit method, so that the dispersion of the resistance source items is more accurate;
and step five, processing the collapse and expansion simulation breach process by adopting a simple geometric method.
Further, in the complete water-sand coupling control equation:
Figure BDA0002415377100000031
wherein η is the elevation of the water surface, h is the depth of water, u and v are the flow velocity of water in the x and y directions respectively, and c is the depth average volume sand content of the sediment;
Figure BDA0002415377100000032
wherein g is gravitational acceleration, and may be 9.8m/s2And z is riverbed elevation;
Figure BDA0002415377100000033
Figure BDA0002415377100000034
in the formula, SbFor topographic source item, SfIn order to be the source term of the resistance,
Figure BDA0002415377100000035
and
Figure BDA0002415377100000036
are respectively SbBed slope in x and y directions, Sfx＝-τbx/ρ,Sfy＝-τbyEach rho is SfResistance in the x and y directions; p is a radical of0Is the porosity of silt; rhowAnd ρsDensity of clear water and silt respectively, rho ═ rhow(1-c)+ρsc is the density of the water-sand mixture; rho0＝ρwp0+ρs(1-p0) Bed sand saturated wet density; n is a Manning roughness coefficient; e is the uplifting flux, and D is the total amount of the settling flux;
Figure BDA0002415377100000041
further, a relationship is provided to seal the system of equations to solve for some of the unknowns in the governing equation, wherein the bed-surface shear stress is calculated using the Mannich-rate formula:
Figure BDA0002415377100000042
the exchange of silt between the water flow near the bed surface and the river bed comprises two different mechanisms, namely silt rising caused by turbulent flow and silt settling caused by gravity, and the calculation expressions of the settling flux D and the rising flux E are respectively as follows:
D＝αwc，E＝αwce(5a,b)
wherein α is the difference coefficient between near-bottom sand concentration and vertical line sand concentration, the calculation method is Cao et al (2011), w is the hydrostatic settling velocity of single-particle sediment, the calculation is carried out by adopting a Zhang reinlo formula, and ceThe local water flow bed load saturation sand transport rate is calculated here using the Meyerpeter-Muller equation (1948):
Figure BDA0002415377100000043
in the formula qbTheta is a Hirtz parameter, which is the saturated bed transport rate,
Figure BDA0002415377100000044
θcfor the critical hiltz parameter, the meiyepeter-mueller equation takes 0.047.
Further, the control equation is solved by a finite volume method, specifically
Figure BDA0002415377100000045
Figure BDA0002415377100000046
Wherein Δ t is the time step; Δ x, Δ y are space step lengths; i and j are space node numbers; k is a time layer; p represents a state calculated by the formula (7);
Figure BDA0002415377100000047
is a conservation vector at the p moment; fi+1/2,j，Gi,j+1/2Is the interfacial flux vector.
Further, in step three, the terrain source item
Figure BDA00024153771000000511
Adopting a local water depth reconstruction and terrain correction method for dispersion:
there should be only a single terrain elevation at the cell interface (i +1/2, j), expressed as
Figure BDA0002415377100000051
Thus obtaining the Riemann state of the corresponding water depth variable:
Figure BDA0002415377100000052
from the above equation, the water depth can be always kept non-negative, and the Riemann state of the corresponding water flow variable is given by the following equation:
Figure BDA0002415377100000053
for the dry bed case, a numerical technique is used to obtain the conservation solution:
Figure BDA0002415377100000054
wherein SbRepresenting the terrain source term in the momentum equation, the first term to the right of the equal sign of equation (11) is discretized using the following method:
Figure BDA0002415377100000055
wherein
Figure BDA0002415377100000056
The other two are discrete:
Figure BDA0002415377100000057
Figure BDA0002415377100000058
in the formula:
Figure BDA0002415377100000059
Figure BDA00024153771000000510
for the wet bed case, the second and third terms are not required at the right end of equation (11), which is discrete as equation (12).
Further, in step four, the resistance source term in formula (8)
Figure BDA0002415377100000061
Dispersing the equivalent ordinary differential equation set of the full implicit format into
Figure BDA0002415377100000062
Taking the momentum equation in the x direction as an example:
Figure BDA0002415377100000063
the above formula is obtained by dispersing by adopting a full implicit method:
Figure BDA0002415377100000064
the y-direction momentum equations are discrete and similar;
in which the resistance source term
Figure BDA0002415377100000065
And (3) obtaining by Taylor series expansion:
Figure BDA0002415377100000066
wherein
Figure BDA0002415377100000067
Ignoring the high-order terms, substituting the high-order terms into formula (15), and obtaining an expression for updating qx to the p time layer:
Figure BDA0002415377100000068
wherein Dx＝1+Δt(2Cf|qx|/h2) Is an implicit coefficient, FxIs a resistance that contains an implicit coefficient;
the value of the implicit resistance is given by the following expression:
Figure BDA0002415377100000069
if calculating FxBeyond the above limits, the actual calculation is made from
Figure BDA00024153771000000610
Instead.
Further, in the fifth step, a simple geometric terrain processing method (Cao et al.2011) is adopted for gravity collapse in the model, namely when the calculated slope is larger than the critical slope, the terrain slope is corrected to be the critical slope, and soil above the water surface is added to the riverbed in an equal area.
Further, ρwAnd ρsRespectively take 1.0 × 103kg/m3And 2.65 × 103kg/m3
Compared with the prior art, the invention has the beneficial effects that:
(1) the invention fully considers the interaction among water, sand and the riverbed in the dam break process, realizes the physical coupling among the water, the sand and the riverbed, and avoids a plurality of unreasonable or unnecessary assumptions in the existing simplified model;
(2) the method adopts a high-precision MUSC L-TVD-H LL C numerical algorithm to solve a control equation, interface Riemann value variable reconstruction is carried out through MUSC L to enable the interface Riemann value variable reconstruction to achieve second-order precision, numerical oscillation is restrained through the TVD algorithm, and Riemann flux is calculated through H LL C, so that a model has stability and accuracy in numerical value;
(3) the invention disperses the terrain source items through local terrain correction and water depth reconstruction technology, so that the flux calculation and the source item dispersion are harmonious;
(4) according to the invention, the resistance source items are dispersed by an implicit method, so that the dispersion of the resistance source items is more accurate, the simulation of the speed is more accurate, and the accuracy of the damming process of the damming dam is ensured;
(5) the method can fully and accurately predict the process of the dam collapse of the damming dam.
Drawings
FIG. 1 is a schematic diagram showing the comparison between the flow calculation process and field observation data in the break process of a white check dam;
FIG. 2 shows terrain conditions at different times, wherein FIG. 2(a) shows terrain conditions at an initial time, FIG. 2(b) shows terrain conditions at 7.2 hours, and FIG. 2(c) shows terrain conditions at 18 hours;
fig. 3 shows the local flow velocity distribution of the breach at different times, wherein fig. 3(a) shows the local flow field distribution of the breach of the barrage dam when t is 7.2 hours, and fig. 3(b) shows the local flow field distribution of the breach of the barrage dam when t is 18 hours;
FIG. 4 is a flow chart of one embodiment of the simulation method of the dam lake break process of the present invention.
Detailed Description
The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings.
As shown in fig. 4, an embodiment of the present invention provides a method for simulating a dam lake break process, including the following steps:
step one, describing the formation and development process of the dam lake break by adopting a complete water-sand coupling control equation; the invention establishes a complete water-sand coupling control equation based on the basic conservation law of hydrodynamics, which comprises a mass conservation equation and a momentum conservation equation of water flow and sediment.
The complete water-sand coupling control equation considers the influence of sediment transport and riverbed deformation on water flow in the traditional mass conservation equation and momentum conservation equation, and realizes the physical coupling among water, sand and riverbed. The expression of the control equation is as follows:
Figure BDA0002415377100000081
in the formula, U is a conservation quantity vector; f and G are convection flux vectors in the x and y directions respectively, t is time, x and y are space coordinates, and S is a source item vector;
Figure BDA0002415377100000082
wherein η is the elevation of the water surface, h is the depth of water, u and v are the flow velocity of water in the x and y directions respectively, and c is the depth average volume sand content of the sediment;
Figure BDA0002415377100000083
wherein g is gravitational acceleration, and may be 9.8m/s2And z is riverbed elevation;
Figure BDA0002415377100000084
Figure BDA0002415377100000091
in the formula, SbFor topographic source item, SfIn order to be the source term of the resistance,
Figure BDA0002415377100000092
and
Figure BDA0002415377100000093
are respectively SbBed slope in x and y directions, Sfx＝-τbx/ρ,Sfy＝-τbyEach rho is SfResistance in the x and y directions; p is a radical of0Is the porosity of silt; rhowAnd ρsThe densities of clear water and silt are respectively 1.0 × 103kg/m3And 2.65 × 103kg/m3，ρ＝ρw(1-c)+ρsc is the density of the water-sand mixture; rho0＝ρwp0+ρs(1-p0) Bed sand saturated wet density; n is a Manning roughness coefficient; e is the uplifting flux, and D is the total amount of the settling flux;
Figure BDA0002415377100000094
the embodiment of the invention additionally provides a relational expression to close the equation set so as to solve part of unknowns in the control equation, wherein the shearing stress of the bed surface is calculated by adopting a Manning roughness formula:
Figure BDA0002415377100000095
the exchange of silt between the water flow near the bed surface and the river bed comprises two different mechanisms, namely silt rising caused by turbulent flow and silt settling caused by gravity, and the calculation expressions of the settling flux D and the rising flux E are respectively as follows:
D＝αwc，E＝αwce(5a,b)
wherein α is the difference coefficient between near-bottom sand concentration and vertical line sand concentration, the calculation method is Cao et al (2011), w is the hydrostatic settling velocity of single-particle sediment, the calculation is carried out by adopting a Zhang reinlo formula, and ceThe local water flow bed load saturation sand transport rate is calculated here using the Meyerpeter-Muller equation (1948):
Figure BDA0002415377100000101
in the formula qbTheta is a Hirtz parameter, which is the saturated bed transport rate,
Figure BDA0002415377100000102
θcfor the critical hiltz parameter, the meiyepeter-mueller equation takes 0.047.
Step two, solving the complete water-sand coupling control equation by adopting a Huang et al (2012) numerical format discrete control equation, namely a finite volume method in a high-precision MUSC L-TVD-H LL C format, specifically, reconstructing interface Riemann value variables by MUSC L to ensure that the interface Riemann value variables achieve second-order precision in space, inhibiting numerical oscillation by a TVD algorithm, and calculating Riemann flux by adopting H LL C (Toro 2001);
the control equation is solved by finite volume method
Figure BDA0002415377100000103
Figure BDA0002415377100000104
Where Δ t is the time step; Δ x, Δ y are space step lengths; i and j are space node numbers; k is timeA layer; p represents a state calculated by the formula (7);
Figure BDA0002415377100000105
is a conservation vector at the p moment; fi+1/2,j，Gi,j+1/2And (3) reconstructing variables for calculating the interface flux vector by MUSC L, and limiting the reconstructed variable values by a TVD algorithm, wherein the interface flux is the Riemann flux and is calculated by an H LL C Riemann operator (Toro 2001).
Dispersing terrain source items through local terrain correction and water depth reconstruction technology, so that flux calculation and the terrain source items are dispersed and harmonious;
wherein the terrain source item
Figure BDA0002415377100000106
And dispersing by adopting a local water depth reconstruction and terrain correction method. There should be only a single terrain elevation at the cell interface (i +1/2, j), expressed as
Figure BDA0002415377100000107
Thus, the Riemann state of the corresponding water depth variable can be obtained:
Figure BDA0002415377100000108
from the above formula, the water depth can be always kept non-negative. The Riemann state of the corresponding water flow variable may be given by:
Figure BDA0002415377100000111
for the dry bed case, numerical techniques must be employed to obtain the conservation solution:
Figure BDA0002415377100000112
wherein SbRepresenting the terrain source term in the momentum equation. The first term on the right of the equal sign of the above formula is discretized by the following method:
Figure BDA0002415377100000113
wherein
Figure BDA0002415377100000114
The other two are discrete:
Figure BDA0002415377100000115
Figure BDA0002415377100000116
in the formula:
Figure BDA0002415377100000117
Figure BDA0002415377100000118
for the wet bed case, the second and third terms are not required at the right end of equation (11), which is discrete as equation (12).
And fourthly, dispersing the resistance source items by adopting an implicit method, so that the dispersion of the resistance source items is more accurate.
Specifically, the term of the source of resistance in the formula (8)
Figure BDA0002415377100000119
Dispersing the equivalent ordinary differential equation set of the full implicit format into
Figure BDA00024153771000001110
Taking the momentum equation in the x direction as an example:
Figure BDA0002415377100000121
the above formula is obtained by dispersing by adopting a full implicit method:
Figure BDA0002415377100000122
the y-direction momentum equations are similarly discretized.
In which the resistance source term
Figure BDA0002415377100000123
And (3) obtaining by Taylor series expansion:
Figure BDA0002415377100000124
wherein
Figure BDA0002415377100000125
Ignoring the high-order terms, substituting them into equation (15), we can get the expression of updating qx to p temporal level:
Figure BDA0002415377100000126
wherein Dx＝1+Δt(2Cf|qx|/h2) Is an implicit coefficient, FxIs a resistance that contains an implicit coefficient. To ensure numerical stability, the source term of resistance FxThe physical property of shallow water must be a finite value, the greatest effect of which is to prevent the flow of water and not to reverse the flow, i.e. to reverse the direction of flow
Figure BDA0002415377100000127
Thus, according to equation (12), the value of the implicit resistance is easily given by the following expression:
Figure BDA0002415377100000128
if calculating FxBeyond the above limit, its value in the actual calculation will be determined by
Figure BDA0002415377100000129
Instead. Similarly, y-direction values are also calculated in this way.
Since the numerical format used is explicit, in order to ensure the numerical stability, the Courant-Fredrichs-L ewy condition is adopted for limitation, in this embodiment, the Crant number Cr (Courant number) is uniformly set to 0.45.
Figure BDA00024153771000001210
And step five, processing the collapse and expansion simulation breach process by adopting a simple geometric method.
After the water-sand coupling control equation is solved, whether collapse occurs or not needs to be judged according to the stability of the breach slope. The gravity collapse in the model adopts a simple geometric terrain processing method (Cao et al.2011), namely when the calculated side slope is larger than the critical slope, the terrain slope is corrected to be the critical slope, and soil mass above the water surface is added to the riverbed in an equal area mode.
The embodiment of the invention is illustrated by taking a bay dam as an example, and is shown in fig. 4:
(1) collecting the topography of a dam body of a first-time dammed lake ('10.10') of a white lattice dammed dam and the topography of an upstream river channel and a downstream river channel, and splicing the two topographic data to obtain a calculated topography;
(2) giving the median particle size of the silt particles of the dam body;
(3) dividing a calculation area grid into 5m × 5 m;
(4) initial conditions and boundary conditions are given. The initial time is calculated to be 10 months, 12 days, 17:15 minutes, the water level of the upstream lake region of the corresponding dam is 2932m, and the downstream dry river bed is initially. The boundary condition of the upstream inlet is given by the flow, the water level reservoir capacity curve and the water quantity balance equation together, and the boundary condition of the downstream outlet adopts the critical flow boundary condition.
(5) And calculating and processing calculation results, wherein the calculation results comprise a burst development process (geometric dimensions at different moments), a flow process (flow size at different moments), a water level process (water level value at different moments), a sand content process (sand content size at different moments), flow velocity distribution and the like.
FIG. 1 shows the comparison of the flow calculation process and field observation data in the break process of the white check dam. As can be seen from the figure, the calculated peak flow rate is better consistent with the field observation value. The model can simulate the development process of the breach better.
Figure 2 shows the terrain at different times. In which fig. 2a shows the terrain at the initial moment, fig. 2b shows the terrain for 7.2 hours, and fig. 2c shows the terrain for 18 hours. At t 7.2 hours, it can be seen that the breach has progressed to the upstream slope and a new channel has formed downstream of the barrage. And when t is 18 hours, the breach widening is basically completed, and a new river channel is formed at the position of the barrage. It is shown that the model herein is able to recapitulate all the physical processes of breach formation and development.
The local flow velocity distribution of the breach at different times is shown in fig. 3, and it can be seen from the figure that the flow velocity at the breach is greater than that of the upstream reservoir area, and the main flow velocity at the breach is close to the right bank. Meanwhile, non-physical large flow velocity is not generated under the condition of a large bottom slope in the whole simulation process, and the model terrain source item processing is reasonable.
The above description is only an embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims (8)

1. A method for simulating a barrier lake bursting process is characterized by comprising the following steps:
step one, describing the formation and development process of the breach of the barrier lake by adopting a complete water-sand coupling control equation, wherein the complete water-sand coupling control equation considers the influence of sediment transport and riverbed deformation on water flow in a traditional mass conservation equation and a momentum conservation equation, so that the physical coupling among water, sand and riverbed is realized, and the complete water-sand coupling control equation has the following expression:
Figure FDA0002415377090000011
in the formula, U is a conservation quantity vector; f and G are convection flux vectors in the x and y directions respectively, t is time, x and y are space coordinates, and S is a source item vector;
step two, solving the complete water-sand coupling control equation by adopting a Huang et al (2012) numerical format discrete control equation, namely adopting a finite volume method in a high-precision MUSC L-TVD-H LL C format, specifically, reconstructing variables for calculating an interface flux vector by adopting MUSC L, limiting reconstructed variable values by adopting a TVD algorithm, wherein the interface flux is Riemann flux, and calculating by adopting an H LL C Riemann operator;
dispersing terrain source items through local terrain correction and water depth reconstruction technology, so that flux calculation and the terrain source items are dispersed and harmonious;
dispersing the resistance source items by adopting an implicit method, so that the dispersion of the resistance source items is more accurate;
and step five, processing the collapse and expansion simulation breach process by adopting a simple geometric method.
2. A method for simulating a breach process of a barrage lake as claimed in claim 1, wherein: in the complete water-sand coupling control equation:
Figure FDA0002415377090000012
wherein η is the elevation of the water surface, h is the depth of water, u and v are the flow velocity of water in the x and y directions respectively, and c is the depth average volume sand content of the sediment;
Figure FDA0002415377090000021
wherein g is gravitational acceleration, and may be 9.8m/s2And z is riverbed elevation;
Figure FDA0002415377090000022
Figure FDA0002415377090000023
in the formula, SbFor topographic source item, SfIn order to be the source term of the resistance,
Figure FDA0002415377090000024
and
Figure FDA0002415377090000025
are respectively SbBed slope in x and y directions, Sfx＝-τbx/ρ,Sfy＝-τbyEach rho is SfResistance in the x and y directions; p is a radical of0Is the porosity of silt; rhowAnd ρsDensity of clear water and silt respectively, rho ═ rhow(1-c)+ρsc is the density of the water-sand mixture; rho0＝ρwp0+ρs(1-p0) Bed sand saturated wet density; n is a Manning roughness coefficient; e is the uplifting flux, and D is the total amount of the settling flux;
Figure FDA0002415377090000026
3. a method for simulating a breach process of a barrage lake as claimed in claim 2, wherein: a relationship is also provided to seal the system of equations to solve for some of the unknowns in the governing equation, wherein the bed-surface shear stress is calculated using the Mannich-rate formula:
Figure FDA0002415377090000027
the exchange of silt between the water flow near the bed surface and the river bed comprises two different mechanisms, namely silt rising caused by turbulent flow and silt settling caused by gravity, and the calculation expressions of the settling flux D and the rising flux E are respectively as follows:
D＝αwc，E＝αwce(5a,b)
wherein α is the difference coefficient between near-bottom sand concentration and vertical line sand concentration, the calculation method is Cao et al (2011), w is the hydrostatic settling velocity of single-particle sediment, the calculation is carried out by adopting a Zhang reinlo formula, and ceThe local water flow bed load saturation sand transport rate is calculated here using the Meyerpeter-Muller equation (1948):
Figure FDA0002415377090000031
in the formula qbTheta is a Hirtz parameter, which is the saturated bed transport rate,
Figure FDA0002415377090000032
θcfor the critical hiltz parameter, the meiyepeter-mueller equation takes 0.047.
4. A method for simulating a breach process of a barrage lake as claimed in claim 1, wherein:
the control equation is solved by finite volume method
Figure FDA0002415377090000033
Figure FDA0002415377090000034
Wherein Δ t is the time step; Δ x, Δ y are space step lengths; i and j are space node numbers; k is a time layer; p represents a state calculated by the formula (7);
Figure FDA0002415377090000035
is a conservation vector at the p moment; fi+1/2,j，Gi,j+1/2Is the interfacial flux vector.
5. As claimed inSolving 2 the simulation method of the damming process of the dammed lake, which is characterized in that: in step three, the source item of the terrain
Figure FDA0002415377090000036
Adopting a local water depth reconstruction and terrain correction method for dispersion:
there should be only a single terrain elevation at the cell interface (i +1/2, j), expressed as
Figure FDA0002415377090000037
Thus obtaining the Riemann state of the corresponding water depth variable:
Figure FDA0002415377090000038
from the above equation, the water depth can be always kept non-negative, and the Riemann state of the corresponding water flow variable is given by the following equation:
Figure FDA0002415377090000041
for the dry bed case, a numerical technique is used to obtain the conservation solution:
Figure FDA0002415377090000042
wherein SbRepresenting the terrain source term in the momentum equation, the first term to the right of the equal sign of equation (11) is discretized using the following method:
Figure FDA0002415377090000043
wherein
Figure FDA0002415377090000044
The other two are discrete:
Figure FDA0002415377090000045
Figure FDA0002415377090000046
in the formula:
Figure FDA0002415377090000047
Figure FDA0002415377090000048
for the wet bed case, the second and third terms are not required at the right end of equation (11), which is discrete as equation (12).
6. A method for simulating a damming process of a dammed lake according to claim 4, wherein: in step four, the source term of resistance in equation (8)
Figure FDA0002415377090000049
Dispersing the equivalent ordinary differential equation set of the full implicit format into
Figure FDA00024153770900000410
Taking the momentum equation in the x direction as an example:
Figure FDA0002415377090000051
the above formula is obtained by dispersing by adopting a full implicit method:
Figure FDA0002415377090000052
the y-direction momentum equations are discrete and similar;
in which the resistance source term
Figure FDA0002415377090000053
And (3) obtaining by Taylor series expansion:
Figure FDA0002415377090000054
wherein
Figure FDA0002415377090000055
Ignoring the higher order terms, substituting them into equation (15) yields the result of substituting qxUpdating to p time layers to obtain an expression:
Figure FDA0002415377090000056
wherein Dx＝1+Δt(2Cf|qx|/h2) Is an implicit coefficient, FxIs a resistance that contains an implicit coefficient;
the value of the implicit resistance is given by the following expression:
Figure FDA0002415377090000057
if calculating FxBeyond the above limits, the actual calculation is made from
Figure FDA0002415377090000058
Instead.
7. A method for simulating a breach process of a barrage lake as claimed in claim 1, wherein: and fifthly, adopting a simple geometric terrain processing method (Cao et al.2011) for gravity collapse in the model, namely correcting the terrain gradient into a critical gradient when the calculated slope is larger than the critical gradient, and adding the soil above the water surface to the riverbed in an equal area manner.
8. A method for simulating a breach process of a barrage lake as claimed in claim 2, wherein: rhowAnd ρsRespectively take 1.0 × 103kg/m3And 2.65×103kg/m3。
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Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111815195A (en) * 2020-07-20 2020-10-23 四川大学 Landslide barrier lake burst risk assessment method
CN111984914A (en) * 2020-08-17 2020-11-24 中国科学院、水利部成都山地灾害与环境研究所 Method for measuring and calculating height of dam body of collapsing type damming dam and application
CN112381319A (en) * 2020-11-27 2021-02-19 四川大学 Mountain torrent disaster type prediction method based on riverbed slope and water-sand coupling water level
CN112861263A (en) * 2021-02-22 2021-05-28 西北工业大学 Calculation simulation method suitable for compressible two-phase flow
CN113373861A (en) * 2021-07-14 2021-09-10 中国科学院、水利部成都山地灾害与环境研究所 Numerical value measuring and calculating method for dam body bursting space-time evolution of damming dam
CN114120590A (en) * 2021-11-08 2022-03-01 四川农业大学 Damming dam burst risk grading and early warning method based on different burst modes
CN118087446A (en) * 2024-04-22 2024-05-28 中国科学院、水利部成都山地灾害与环境研究所 Method for reducing risk of blocking river barrier lake by debris flow

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110533884A (en) * 2019-07-19 2019-12-03 四川农业大学 Barrier lake grade of risk and breaking mud flow and mountain torrents dangerous situation method for early warning

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110533884A (en) * 2019-07-19 2019-12-03 四川农业大学 Barrier lake grade of risk and breaking mud flow and mountain torrents dangerous situation method for early warning

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
WEI HUANG等: "Coupled modelling of flood due to natural landslide dam breach" *
姜治兵;崔丹;程子兵;: "坝体溃决过程与溃坝洪水演进耦合数值模拟" *
岳志远: "自然坝体溃决机理与水沙动力学过程——试验与耦合数学模拟研究" *
王光谦;王永强;刘磊;王大宇;: "堰塞坝及其溃决模拟研究评述" *

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CN111815195A (en) * 2020-07-20 2020-10-23 四川大学 Landslide barrier lake burst risk assessment method
CN111815195B (en) * 2020-07-20 2023-04-18 四川大学 Landslide barrier lake burst risk assessment method
CN111984914A (en) * 2020-08-17 2020-11-24 中国科学院、水利部成都山地灾害与环境研究所 Method for measuring and calculating height of dam body of collapsing type damming dam and application
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CN112381319A (en) * 2020-11-27 2021-02-19 四川大学 Mountain torrent disaster type prediction method based on riverbed slope and water-sand coupling water level
CN112381319B (en) * 2020-11-27 2023-04-07 四川大学 Mountain torrent disaster type prediction method based on riverbed slope and water-sand coupling water level
CN112861263A (en) * 2021-02-22 2021-05-28 西北工业大学 Calculation simulation method suitable for compressible two-phase flow
CN112861263B (en) * 2021-02-22 2024-02-13 西北工业大学 Calculation simulation method suitable for compressible two-phase flow
CN113373861A (en) * 2021-07-14 2021-09-10 中国科学院、水利部成都山地灾害与环境研究所 Numerical value measuring and calculating method for dam body bursting space-time evolution of damming dam
CN113373861B (en) * 2021-07-14 2022-08-30 中国科学院、水利部成都山地灾害与环境研究所 Numerical value measuring and calculating method for dam body bursting space-time evolution of damming dam
CN114120590A (en) * 2021-11-08 2022-03-01 四川农业大学 Damming dam burst risk grading and early warning method based on different burst modes
CN118087446A (en) * 2024-04-22 2024-05-28 中国科学院、水利部成都山地灾害与环境研究所 Method for reducing risk of blocking river barrier lake by debris flow

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