CN103437319A - Method for renovating movable-bed physical model design in upper Yangtze River pebble beach dangerous sea channel - Google Patents
Method for renovating movable-bed physical model design in upper Yangtze River pebble beach dangerous sea channel Download PDFInfo
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Abstract
The invention discloses a method for renovating the movable-bed physical model design in an upper Yangtze River pebble beach dangerous sea channel. The method comprises the following steps of: selecting proper model sand; determining a proper model scale; determining the geometrical morphology of the model. According to the method disclosed by the invention, the physical properties of light model sand and natural sand are compared; the motion characteristics of two model sands, i.e. the natural sand and the light sand, are compared from three aspects of sediment start, sand transmission rate and sand wave motion by a 28m flume experiment; the Chongqing urban city Zhuerqi river reach positioned on the Three Gorges varying backwater tail end is selected to research and compare the adaptation of the natural model sand and the light model sand when dredged channel scouring and siltation are simulated via the physical model experiment; the adaptation of the two types of model sand in a bed load movable-bed physical model is analyzed; the characteristics of different types of model sands are combined with the motion characteristics of the water flow and the dredged channel sediment of the upper Yangtze River pebble beach to analyze to obtain the method for renovating the movable-bed physical model design in the upper Yangtze River pebble beach dangerous sea channel.
Description
Technical field
The invention belongs to river cobble studying technological domain, relate in particular to a kind of Upper Yangtze River pebble beach danger waterway regulation movable bed design of physical model method.
Background technology
Complexity due to natural mountain stream ovum gravel motion, thereby carrying out before training works, to renovation scheme expound adequately research very necessary, at present, regulation for the complicated pebble shoal in Upper Yangtze River area, the general method of physical model simulation renovating effect that adopts is proved research to scheme, to before Yibin, the Changjiang river carried out altogether the physical experiments on 15 beaches during to three grades of waterway regulations of Chongqing reach, from the engineering practice effect, there is no which beach is just to renovate successfully after a research approach is implemented, wherein there are 5 beaches just to achieve success through 2 regulations, just achieve success through 3 regulations in 4 beaches, there are 4 beaches just to achieve success through 5 regulations, and the triangle moraine, the pig moraine is to also not achieving success at present, in addition, also have danger, 2 beaches successively to make 2 physical models.
Causing the reason of these differences, is because the complexity of natural mountain stream ovum gravel motion on the one hand; Be on the analogy method of physical model on the other hand, as a rule, physical experiments, when the current situation of change of simulation pebble shoal regulation front and back, has effect preferably; But consider in the design of physical model process, majority has adopted lightweight husky (as cleaned coal), distorted model etc., the simulation cobble wash away and back-silt aspect effect and actual variance larger.
Summary of the invention
The purpose of the embodiment of the present invention is to provide a kind of Upper Yangtze River pebble beach danger waterway regulation movable bed design of physical model method, is intended to solve washing away and the effect of the aspect of back-silting and the larger problem of actual variance of existing simulation cobble.
The embodiment of the present invention is achieved in that a kind of Upper Yangtze River pebble beach danger waterway regulation movable bed design of physical model method, and described Upper Yangtze River pebble beach danger waterway regulation movable bed design of physical model method comprises the following steps:
Select applicable model sasnd;
Determine and be applicable to model scale;
Determine the model geometric form.
Further, described Upper Yangtze River pebble beach danger waterway regulation movable bed design of physical model method concrete steps are:
The first step, select applicable model sasnd:
Due to Three Gorges Reservoir fluctuation backwater end segment ubiquity Movement of Sand Waves in the phase boat groove that disappears, when simulation has the Bed Load Movement of bed ripples form, natural model sand is better than light model sediment, should pay the utmost attention to when modelling and select natural sand as model sasnd;
Second step, definite model scale that is applicable to:
In Three Gorges Reservoir Fluctuating Backwater Area end segment boat groove, ovum gravel median particle diameter D50 is 52mm, because flow intensity is larger, the Bed Load Movement form transits directly to the longitudinal dune stage by smooth bed surface usually, when model testing, the particle diameter of model sasnd should not be less than 0.6mm, and model scale should be greater than 1: 90;
Determining of the 3rd step, model geometric form:
Three Gorges Reservoir fluctuation backwater section riverbed and water surface gradient are all larger, and the riverbed bed load is coarse grained ovum gravel, coarse grained sediment movement to relative smoothness h/D, bed sloped J and not your moral to count Fr quite responsive, after the model bed sloped increases e times than prototype, stream parameters differs greatly, directly cause the similar accurate number of current and silt to differ greatly, affect the simulation similitude of starting, sediment transport path and the erosion and deposition state of bed load sediment, therefore should adopt normal model.
Further, the research process of described Upper Yangtze River pebble beach danger waterway regulation movable bed design of physical model method, comprise the following steps:
Physical characteristic to light model sediment and natural sand compares research;
By the 28m flume test, from starting, silt discharge and three aspect investigation and comparisons of Movement of Sand Waves of silt the kinetic characteristic of natural sand, the husky two kinds of model sasnds of lightweight;
Selection is positioned at the system of Chongqing city pig moraine section of Three Gorges fluctuation backwater end and by physical experiments, and the husky and light model sediment of investigation and comparison natural model washes away the compliance when back-silting at the simulation groove that navigates;
Compliance to two kinds of model sasnds in bed load movable bed physical model is analyzed;
In conjunction with the characteristic of different model sasnds and current and the boat groove sediment movement characteristic analysis of Upper Yangtze River pebble beach danger, draw Upper Yangtze River pebble beach danger waterway regulation movable bed design of physical model method.
Further, the research process concrete steps of described Upper Yangtze River pebble beach danger waterway regulation movable bed design of physical model method are:
The physical characteristic comparative studies of the first step, light model sediment and natural sand:
At 47 point bar natural pebble samples of the random selection in nine heap sections of system of Chongqing city, with 196,198 samples of randomly drawing in natural model sand, light model sediment, measure its geometric scale of contrast and quality, adopt form coefficient, flatness, sphericity parameter to be added up
Second step, kinetic characteristic comparative studies:
By the 28m flume test, from starting, silt discharge and three aspect investigation and comparisons of Movement of Sand Waves of silt the kinetic characteristic of natural sand, the husky two kinds of model sasnds of lightweight;
The comparative study of the 3rd step, model sasnd simulation erosion and deposition characteristic:
Selection is positioned at the system of Chongqing city pig moraine section of Three Gorges fluctuation backwater end and by physical experiments, and the husky and light model sediment of investigation and comparison natural model washes away the compliance when back-silting at the simulation groove that navigates;
Consider model sasnd, place and simulated object reason, the navigated erosion and deposition contrast test of groove of the normal state Local physical model of setting up 1: 60 mainly for the main boat groove in phase pig moraine section that disappears;
The model testing result shows, while adopting natural model sand to be tested, its bed load is defeated moves path, the erosion and deposition position is basic conforms to the navigate situation of groove of prototype; While adopting light model sediment to be tested, model Sediment Transport path conforms to prototype boat groove substantially, but silt is difficult to form the alluvial body under alluvial in the boat groove fast through boat groove and beach face, and the boat groove back-silts phenomenon with actual far apart;
The 4th step, the Adaptability Analysis of two kinds of model sasnds in bed load movable bed physical model:
Comparison test analysis from model sasnd physical characteristic, kinetic characteristic and erosion and deposition characteristic aspect, when natural model sasnd and light model sediment are applied to movable bed model test, because Upper Yangtze River section flow intensity is large, bed material forms thicker, the husky physical characteristic of natural model, kinetic characteristic and erosion and deposition characteristic aspect have better similitude, simulate Bed Load Movement with natural sand and more can reflect the motion state of natural river ovum gravel;
The 5th step, Upper Yangtze River pebble beach danger waterway regulation movable bed design of physical model method:
In conjunction with the characteristic of different model sasnds and current and the boat groove sediment movement characteristic analysis of Upper Yangtze River pebble beach danger.
Further, the concrete steps of described second step are:
Carried out altogether the starting test of 2 kinds of natural sands, a kind of lightweight sand in tank, with the dimensionless silt discharge of Parker
as the starting discrimination standard, obtain the starting conditions result of the test of natural sand and lightweight sand,
To test flow condition according to being converted to the dimensionless starting power, can find out that the starting conditions data point of natural sand and lightweight sand is distributed on same straight line substantially, all meet same starting power formula,
The starting conditions of the husky two kinds of model sasnds of natural sand and lightweight is the wide dimensionless flow number of available list q all
*mean, this starting formula with Upper Yangtze River ovum gravel is consistent, when the starting that two kinds of model sasnds simulate bed load sediment in physical experiments is described, all is suitable for;
The comparison of step 2, silt discharge:
In flume test, adopt the natural sand of 2 kinds of particle diameters, the lightweight sand of 3 kinds of particle diameters, control the tank ratio and fall J, flow Q, measure water level H and single wide bed load discharge g
bcarry out altogether totally 87 groups of bed load discharge tests, the measured experimental data of Einstein formula analysis that employing is revised by the Upper Yangtze River measured data, by stream parameters Ψ and the sediment discharge intensity Φ point of handling well, visible, the sediment discharge intensity of natural sand and lightweight sand all meets the Einstein correction formula substantially, and experimental data point is near the tight distribution formula calculated value all;
Husky and the natural sand of lightweight is followed identical rule at sediment discharge intensity, also can adopt same equation expression, natural sand and lightweight sand all when the sediment discharge intensity that carries out movable bed model test is tested difference little;
The comparison of step 3, Bed Load Movement form:
When flow intensity larger, bed load sediment will be with the bed ripples gestalt movement, in order to contrast light model sediment and the natural sand similitude when the Movement of Sand Waves, in the 28m varible slope flume, utilize lightweight sand and natural sand to carry out bed ripples form contrast test, the critical flow condition, wave height, wavelength, the bed ripples form aspect that form bed ripples from the two are contrasted;
The critical condition formed from bed ripples, the lightweight that particle diameter is identical is husky compares with natural sand, forms the flow intensity of Movement of Sand Waves much smaller than natural sand; When flow intensity increases gradually, the wave height of natural sand bed ripples has gradually and to increase and trend that wavelength reduces, but that the bed ripples wave height of lightweight sand and wavelength increase variation tendency with flow intensity is slower; Natural sand morphological parameters θ=λ
upstream face/ λ
back sideincrease excursion with flow intensity is larger, and the husky morphological parameters of lightweight is less with the increase excursion of flow intensity, reinforcement along with flow intensity, lightweight sand more easily forms the bed ripples form than natural sand, and all there are obvious difference in the wavelength between natural sand and lightweight sand, wave height and bed ripples form, therefore occur that at bed surface the bed ripples stage selects natural sand as model sasnd as far as possible.
Upper Yangtze River pebble beach danger waterway regulation movable bed design of physical model method of the present invention, compare research by the physical characteristic to light model sediment and natural sand; By the 28m flume test, from starting, silt discharge and three aspect investigation and comparisons of Movement of Sand Waves of silt the kinetic characteristic of natural sand, the husky two kinds of model sasnds of lightweight; Selection is positioned at the system of Chongqing city pig moraine section of Three Gorges fluctuation backwater end and by physical experiments, and the husky and light model sediment of investigation and comparison natural model washes away the compliance when back-silting at the simulation groove that navigates; Compliance to two kinds of model sasnds in bed load movable bed physical model is analyzed; In conjunction with the characteristic of different model sasnds and current and the boat groove sediment movement characteristic analysis of Upper Yangtze River pebble beach danger, draw Upper Yangtze River pebble beach danger waterway regulation movable bed design of physical model method.
The accompanying drawing explanation
Fig. 1 is the research flow chart of the Upper Yangtze River pebble beach danger waterway regulation movable bed design of physical model method that provides of the embodiment of the present invention;
Fig. 2 is the flow chart of the Upper Yangtze River pebble beach danger waterway regulation movable bed design of physical model method that provides of the embodiment of the present invention;
Fig. 3 is the husky schematic diagram compared with the natural sand starting rule of lightweight that the embodiment of the present invention provides;
Fig. 4 is the rock mass of the husky comparison with the natural sand silt discharge of the lightweight that provides of the embodiment of the present invention;
Fig. 5 is the rustle schematic diagram of comparative analysis of the long and wave height of wave-wave of the natural sand that provides of the embodiment of the present invention and lightweight;
Fig. 6 is river, the Chongqing City pig moraine section gesture schematic diagram that the embodiment of the present invention provides.
The specific embodiment
In order to make purpose of the present invention, technical scheme and advantage clearer, below in conjunction with embodiment, the present invention is further elaborated.Should be appreciated that specific embodiment described herein, only in order to explain the present invention, is not intended to limit the present invention.
Fig. 2 shows the flow process of Upper Yangtze River pebble beach danger waterway regulation movable bed design of physical model method provided by the invention.For convenience of explanation, only show part related to the present invention.
Upper Yangtze River pebble beach danger waterway regulation movable bed design of physical model method of the present invention, this Upper Yangtze River pebble beach danger waterway regulation movable bed design of physical model method comprises the following steps:
Select applicable model sasnd;
Determine and be applicable to model scale;
Determine the model geometric form.
As a prioritization scheme of the embodiment of the present invention, Upper Yangtze River pebble beach danger waterway regulation movable bed design of physical model method concrete steps are:
The first step, select applicable model sasnd:
Due to Three Gorges Reservoir fluctuation backwater end segment ubiquity Movement of Sand Waves in the phase boat groove that disappears, when simulation has the Bed Load Movement of bed ripples form, natural model sand is better than light model sediment, should pay the utmost attention to when modelling and select natural sand as model sasnd;
Second step, definite model scale that is applicable to:
In Three Gorges Reservoir Fluctuating Backwater Area end segment boat groove, ovum gravel median particle diameter D50 is 52mm, because flow intensity is larger, the Bed Load Movement form transits directly to the longitudinal dune stage by smooth bed surface usually, when model testing, the particle diameter of model sasnd should not be less than 0.6mm, and model scale should be greater than 1: 90;
Determining of the 3rd step, model geometric form:
Three Gorges Reservoir fluctuation backwater section riverbed and water surface gradient are all larger, and the riverbed bed load is coarse grained ovum gravel, coarse grained sediment movement to relative smoothness h/D, bed sloped J and not your moral to count Fr quite responsive, after the model bed sloped increases e times than prototype, stream parameters differs greatly, directly cause the similar accurate number of current and silt to differ greatly, affect the simulation similitude of starting, sediment transport path and the erosion and deposition state of bed load sediment, therefore should adopt normal model.
As a prioritization scheme of the embodiment of the present invention, the research process of Upper Yangtze River pebble beach danger waterway regulation movable bed design of physical model method comprises the following steps:
Physical characteristic to light model sediment and natural sand compares research;
By the 28m flume test, from starting, silt discharge and three aspect investigation and comparisons of Movement of Sand Waves of silt the kinetic characteristic of natural sand, the husky two kinds of model sasnds of lightweight;
Selection is positioned at the system of Chongqing city pig moraine section of Three Gorges fluctuation backwater end and by physical experiments, and the husky and light model sediment of investigation and comparison natural model washes away the compliance when back-silting at the simulation groove that navigates;
Compliance to two kinds of model sasnds in bed load movable bed physical model is analyzed;
In conjunction with the characteristic of different model sasnds and current and the boat groove sediment movement characteristic analysis of Upper Yangtze River pebble beach danger, draw Upper Yangtze River pebble beach danger waterway regulation movable bed design of physical model method.
As a prioritization scheme of the embodiment of the present invention, the research process concrete steps of Upper Yangtze River pebble beach danger waterway regulation movable bed design of physical model method are:
The physical characteristic comparative studies of the first step, light model sediment and natural sand:
At 47 point bar natural pebble samples of the random selection in nine heap sections of system of Chongqing city, with 196,198 samples of randomly drawing in natural model sand, light model sediment, measure its geometric scale of contrast and quality, adopt form coefficient, flatness, sphericity parameter to be added up
Second step, kinetic characteristic comparative studies:
By the 28m flume test, from starting, silt discharge and three aspect investigation and comparisons of Movement of Sand Waves of silt the kinetic characteristic of natural sand, the husky two kinds of model sasnds of lightweight;
The comparative study of the 3rd step, model sasnd simulation erosion and deposition characteristic:
Selection is positioned at the system of Chongqing city pig moraine section of Three Gorges fluctuation backwater end and by physical experiments, and the husky and light model sediment of investigation and comparison natural model washes away the compliance when back-silting at the simulation groove that navigates;
Consider model sasnd, place and simulated object reason, the navigated erosion and deposition contrast test of groove of the normal state Local physical model of setting up 1: 60 mainly for the main boat groove in phase pig moraine section that disappears;
The model testing result shows, while adopting natural model sand to be tested, its bed load is defeated moves path, the erosion and deposition position is basic conforms to the navigate situation of groove of prototype; While adopting light model sediment to be tested, model Sediment Transport path conforms to prototype boat groove substantially, but silt is difficult to form the alluvial body under alluvial in the boat groove fast through boat groove and beach face, and the boat groove back-silts phenomenon with actual far apart;
The 4th step, the Adaptability Analysis of two kinds of model sasnds in bed load movable bed physical model:
Comparison test analysis from model sasnd physical characteristic, kinetic characteristic and erosion and deposition characteristic aspect, when natural model sasnd and light model sediment are applied to movable bed model test, because Upper Yangtze River section flow intensity is large, bed material forms thicker, the husky physical characteristic of natural model, kinetic characteristic and erosion and deposition characteristic aspect have better similitude, simulate Bed Load Movement with natural sand and more can reflect the motion state of natural river ovum gravel;
The 5th step, Upper Yangtze River pebble beach danger waterway regulation movable bed design of physical model method:
In conjunction with the characteristic of different model sasnds and current and the boat groove sediment movement characteristic analysis of Upper Yangtze River pebble beach danger.
As a prioritization scheme of the embodiment of the present invention, the concrete steps of second step are:
Carried out altogether the starting test of 2 kinds of natural sands, a kind of lightweight sand in tank, with the dimensionless silt discharge of Parker
as the starting discrimination standard, obtain the starting conditions result of the test of natural sand and lightweight sand,
To test flow condition according to being converted to the dimensionless starting power, can find out that the starting conditions data point of natural sand and lightweight sand is distributed on same straight line substantially, all meet same starting power formula,
The starting conditions of the husky two kinds of model sasnds of natural sand and lightweight is the wide dimensionless flow number of available list q all
*mean, this starting formula with Upper Yangtze River ovum gravel is consistent, when the starting that two kinds of model sasnds simulate bed load sediment in physical experiments is described, all is suitable for;
The comparison of step 2, silt discharge:
In flume test, adopt the natural sand of 2 kinds of particle diameters, the lightweight sand of 3 kinds of particle diameters, control the tank ratio and fall J, flow Q, measure water level H and single wide bed load discharge g
bcarry out altogether totally 87 groups of bed load discharge tests, the measured experimental data of Einstein formula analysis that employing is revised by the Upper Yangtze River measured data, by stream parameters Ψ and the sediment discharge intensity Φ point of handling well, visible, the sediment discharge intensity of natural sand and lightweight sand all meets the Einstein correction formula substantially, and experimental data point is near the tight distribution formula calculated value all;
Husky and the natural sand of lightweight is followed identical rule at sediment discharge intensity, also can adopt same equation expression, natural sand and lightweight sand all when the sediment discharge intensity that carries out movable bed model test is tested difference little;
The comparison of step 3, Bed Load Movement form:
When flow intensity larger, bed load sediment will be with the bed ripples gestalt movement, in order to contrast light model sediment and the natural sand similitude when the Movement of Sand Waves, in the 28m varible slope flume, utilize lightweight sand and natural sand to carry out bed ripples form contrast test, the critical flow condition, wave height, wavelength, the bed ripples form aspect that form bed ripples from the two are contrasted;
The critical condition formed from bed ripples, the lightweight that particle diameter is identical is husky compares with natural sand, forms the flow intensity of Movement of Sand Waves much smaller than natural sand; When flow intensity increases gradually, the wave height of natural sand bed ripples has gradually and to increase and trend that wavelength reduces, but that the bed ripples wave height of lightweight sand and wavelength increase variation tendency with flow intensity is slower; Natural sand morphological parameters θ=λ
upstream face/ λ
back sideincrease excursion with flow intensity is larger, and the husky morphological parameters of lightweight is less with the increase excursion of flow intensity, reinforcement along with flow intensity, lightweight sand more easily forms the bed ripples form than natural sand, and all there are obvious difference in the wavelength between natural sand and lightweight sand, wave height and bed ripples form, therefore occur that at bed surface the bed ripples stage selects natural sand as model sasnd as far as possible.
Below in conjunction with drawings and the specific embodiments, application principle of the present invention is further described.
As shown in Figure 1, the research process of the Upper Yangtze River pebble beach danger waterway regulation movable bed design of physical model method that the invention process case provides, the method comprises:
In step S101, the physical characteristic of light model sediment and natural sand is compared to research;
In step S102, by the 28m flume test, from starting, silt discharge and three aspect investigation and comparisons of Movement of Sand Waves of silt the kinetic characteristic of natural sand, the husky two kinds of model sasnds of lightweight;
In step S103, select to be positioned at the system of Chongqing city pig moraine section of Three Gorges fluctuation backwater end and by physical experiments, the husky and light model sediment of investigation and comparison natural model washes away the compliance when back-silting at the simulation groove that navigates;
In step S104, the compliance to two kinds of model sasnds in bed load movable bed physical model is analyzed;
Comparison test analysis from aspects such as model sasnd physical characteristic, kinetic characteristic and erosion and deposition characteristics, when natural model sasnd and light model sediment are applied to movable bed model test, because Upper Yangtze River section flow intensity is large, bed material forms thicker, the husky physical characteristic of natural model, kinetic characteristic and erosion and deposition characteristic aspect have better similitude, simulate Bed Load Movement with natural sand and more can reflect the motion state of natural river ovum gravel;
In step S105, in conjunction with the characteristic of different model sasnds and current and the boat groove sediment movement characteristic analysis of Upper Yangtze River pebble beach danger, draw Upper Yangtze River pebble beach danger waterway regulation movable bed design of physical model method.
As shown in Figure 2, the Upper Yangtze River pebble beach danger waterway regulation movable bed design of physical model method that the invention process case provides, the method comprises:
In step S1051, select applicable model sasnd;
In step S1052, determine and be applicable to model scale;
In step S1053, determine the model geometric form.
Operating principle of the present invention is:
Consider that the Upper Yangtze River navigation channel is mainly that ovum ruckle danger hinders the boat problem at present, during physical experiments, adopt the model sasnd of different qualities will produce considerable influence to result of the test, the effect that finally is related to the waterway regulation works measure, thereby, by many-sided experimental study, compared the impact on movable bed model test of natural sand and lightweight sand
(1) the physical characteristic comparative studies of light model sediment and natural sand
At 47 point bar natural pebble samples of the random selection in nine heap sections of system of Chongqing city, with 196,198 samples of randomly drawing in natural model husky (gravel), light model sediment (Rongchang County's cleaned coal), measure its geometric scale of contrast and quality, adopt the parameters such as form coefficient, flatness, sphericity to be added up (design formulas is in Table 1)
These three parameters of form coefficient, flatness and sphericity are all from the ratio of three shaft lengths, the particle shape characteristic has been described qualitatively, be not difficult to find when three shaft lengths one timings, three parameter values of this of trying to achieve are constant, according to the determined particle shape of above three parameter, just should determine so, yet in actual measurement process, find, even according between these three determined sand grains of parameter, still existing difference
When a, b are equal with c tri-shaft lengths, granular mass is larger, the full degree of particle is higher, the arris edge number is fewer, appearance is more smooth, proposes the spheroid plumpness according to this actual phenomenon this paper and describes the full grains degree, by the ratio of relatively surveying weight and theoretical calculated weight, is judged, the weight ratio of definition is converted into to the size ratio relevant to three shaft lengths, and the concept of proposition plumpness Π is as follows:
In formula: M
1for particle actual measurement weight, M
0for standard spheroid body particle weight,
Table 2 has been added up respectively the assembly average of above-mentioned four parameters of natural pebble, natural model sand and lightweight sand, comprehensive four parameters, and the husky physical characteristic of natural model more approaches the prototype cobble, and light model sediment differs greatly with the prototype cobble,
Table 1 sand grain form parameter design formulas
Table 2 natural model is husky to be compared with the light model sediment physical characteristic
(2) kinetic characteristic comparative studies
By the 28m flume test, from starting, silt discharge and three aspect investigation and comparisons of Movement of Sand Waves of silt the kinetic characteristic of natural sand, the husky two kinds of model sasnds of lightweight,
A, starting rule are relatively
Carried out altogether the starting test of 2 kinds of natural sands, a kind of lightweight husky (cleaned coal) in tank, with the dimensionless silt discharge of Parker
as the starting discrimination standard, the starting conditions result of the test that obtains natural sand and lightweight sand is as shown in table 3,
Table 3 bed load starting test achievement statistics
To test flow condition according to being converted to the dimensionless starting power, can find out that the starting conditions data point of natural sand and lightweight sand is distributed on same straight line substantially, all meet same starting power formula.
As shown in Figure 3, the equal wide dimensionless flow number of the available list q of the starting conditions of the husky two kinds of model sasnds of natural sand and lightweight
*mean, this starting formula with Upper Yangtze River ovum gravel is consistent, when being described, the starting that two kinds of model sasnds simulate bed load sediment in physical experiments all is suitable for,
The comparison of b, silt discharge
In flume test, adopt the natural sand of 2 kinds of particle diameters, the lightweight sand of 3 kinds of particle diameters, control the tank ratio and fall J, flow Q, measure water level H and single wide bed load discharge g
bcarry out altogether totally 87 groups of bed load discharge tests, the measured experimental data of Einstein formula analysis that employing is revised by the Upper Yangtze River measured data, stream parameters Ψ and the sediment discharge intensity Φ point handled well are plotted in Fig. 4, visible, the sediment discharge intensity of natural sand and lightweight sand all meets the Einstein correction formula substantially, and experimental data point is near the tight distribution formula calculated value all;
Husky and the natural sand of lightweight is followed identical rule at sediment discharge intensity, also can adopt same equation expression, natural sand and lightweight sand all when the sediment discharge intensity that carries out movable bed model test is tested difference little,
The comparison of c, Bed Load Movement form
When flow intensity larger, bed load sediment will be with the bed ripples gestalt movement, in order to contrast light model sediment and the natural sand similitude when the Movement of Sand Waves, in the 28m varible slope flume, utilize lightweight husky (Rongchang County's cleaned coal) and natural sand to carry out bed ripples form contrast test, the aspects such as critical flow condition, wave height, wavelength, bed ripples form that form bed ripples from the two are contrasted
The critical condition formed from bed ripples, the lightweight that particle diameter is identical is husky compares with natural sand, and its flow intensity that forms Movement of Sand Waves is much smaller than natural sand; When flow intensity increases gradually, the wave height of natural sand bed ripples has gradually and to increase and trend that wavelength reduces, but that the bed ripples wave height of lightweight sand and wavelength increase variation tendency with flow intensity is slower; Natural sand morphological parameters θ=λ
upstream face/ λ
back sideincrease excursion with flow intensity is larger, and the husky morphological parameters of lightweight is less with the increase excursion of flow intensity,
As shown in Figure 5, as can be seen here, along with the reinforcement of flow intensity, lightweight sand more easily forms the bed ripples form than natural sand, and all there are obvious difference in the wavelength between natural sand and lightweight sand, wave height and bed ripples form, therefore occur that at bed surface the bed ripples stage selects natural sand as model sasnd as far as possible.
(3) comparative study of model sasnd simulation erosion and deposition characteristic
As shown in Figure 6, select to be positioned at the system of Chongqing city pig moraine section of Three Gorges fluctuation backwater end and by physical experiments, the husky and light model sediment of investigation and comparison natural model washes away the compliance when back-silting at the simulation groove that navigates,
Consider the reasons such as model sasnd, place and simulated object, the navigated erosion and deposition contrast test of groove of the normal state Local physical model of setting up 1: 60 mainly for the main boat groove in phase pig moraine section that disappears,
Table 4 natural model is husky, light model sediment erosion and deposition characteristic form general model guide
The generalization phase that disappears in 2010 is excavated the silt discharge process that rear boat groove returns, and adopts 2 kinds of model sasnds, and the model tail-gate adopts the measured water level of Xuan Tan mausoleum gaging station to control by the calculated value than falling the interpolation gained,
Table 5 simulated conditions of back-silting
The model testing result shows, while adopting natural model sand to be tested, its bed load is defeated moves path, the erosion and deposition position is basic conforms to the navigate situation of groove of prototype; While adopting light model sediment to be tested, model Sediment Transport path conforms to prototype boat groove substantially, but silt is difficult to form the alluvial body under alluvial in the boat groove fast through boat groove and beach face, and the boat groove back-silts phenomenon with actual far apart,
Because lightweight grains of sand footpath is large, unit weight is less; leave the bed and be difficult to form sequestration in the face of silt in the movable bed condition; once causing the silt starting just to be difficult to stop or under static state to be difficult to stablizes; thereby make the sediment bypassing of lightweight sand more general; wider; speed is faster, thereby usually can over-evaluate washing away of groove of boat and underestimate boat the back-silting of groove
The Adaptability Analysis of (4) two kinds of model sasnds in bed load movable bed physical model
Comparison test analysis from aspects such as model sasnd physical characteristic, kinetic characteristic and erosion and deposition characteristics, when natural model sasnd and light model sediment are applied to movable bed model test, because Upper Yangtze River section flow intensity is large, bed material forms thicker, the husky physical characteristic of natural model, kinetic characteristic and erosion and deposition characteristic aspect have better similitude, simulate Bed Load Movement with natural sand and more can reflect the motion state of natural river ovum gravel
(5) Upper Yangtze River pebble beach danger waterway regulation movable bed design of physical model method
In conjunction with the characteristic of different model sasnds and current and the boat groove sediment movement characteristic analysis of Upper Yangtze River pebble beach danger, Upper Yangtze River pebble beach danger waterway regulation movable bed design of physical model method is:
The first step, select applicable model sasnd:
Due to Three Gorges Reservoir fluctuation backwater end segment ubiquity Movement of Sand Waves in the phase boat groove that disappears, when simulation has the Bed Load Movement of bed ripples form, natural model sand is better than light model sediment; While adopting lightweight husky (in the majority with cleaned coal again), situation while because of model testing, being mostly the regulation of research low water, this becomes very little with regard to the relative smoothness that causes the model inherence, H/D in water flow<2 if o'clock (this situation very easily occurs), now model belongs to the coarse or large-scale roughness of mesoscale, and its drag characteristic is fully different from prototype current (small scale is coarse); Simultaneously, lightweight sand tends to over-evaluate washing away of groove of boat and underestimates the alluvial of groove of navigating, thereby may over-evaluate the actual effect of renovation scheme, and therefore when modelling, should pay the utmost attention to and select natural sand as model sasnd,
Second step, definite model scale that is applicable to:
In Three Gorges Reservoir Fluctuating Backwater Area end segment boat groove, ovum gravel median particle diameter D50 is about 52mm, because of flow intensity larger, its Bed Load Movement form transits directly to the longitudinal dune stage by smooth bed surface usually, and, when model testing, when natural grains of sand footpath is less than 0.6mm, bed surface there will be the sediment ripples form, this and actual bed ripples form are not inconsistent, therefore the particle diameter of model sasnd should not be less than 0.6mm, and model scale should be greater than 1: 90
Determining of the 3rd step, model geometric form:
Three Gorges Reservoir fluctuation backwater section riverbed and water surface gradient are all larger, and the riverbed bed load is coarse grained ovum gravel, coarse grained sediment movement to relative smoothness h/D, bed sloped J and not your moral to count Fr quite responsive, after the model bed sloped increases e times than prototype, stream parameters (as not your moral number, relative smoothness) differs greatly, directly cause the similar accurate number of current and silt to differ greatly, affect the simulation similitude of starting, sediment transport path and the erosion and deposition state of bed load sediment, therefore should adopt normal model.
The foregoing is only preferred embodiment of the present invention, not in order to limit the present invention, all any modifications of doing within the spirit and principles in the present invention, be equal to and replace and improvement etc., within all should being included in protection scope of the present invention.
Claims (5)
1. a Upper Yangtze River pebble beach danger waterway regulation movable bed design of physical model method, is characterized in that, described Upper Yangtze River pebble beach danger waterway regulation movable bed design of physical model method comprises the following steps:
Select applicable model sasnd;
Determine and be applicable to model scale;
Determine the model geometric form.
2. Upper Yangtze River pebble beach danger waterway regulation movable bed design of physical model method as claimed in claim 1, is characterized in that, described Upper Yangtze River pebble beach danger waterway regulation movable bed design of physical model method concrete steps are:
The first step, select applicable model sasnd:
Due to Three Gorges Reservoir fluctuation backwater end segment ubiquity Movement of Sand Waves in the phase boat groove that disappears, when simulation has the Bed Load Movement of bed ripples form, natural model sand is better than light model sediment, should pay the utmost attention to when modelling and select natural sand as model sasnd;
Second step, definite model scale that is applicable to:
In Three Gorges Reservoir Fluctuating Backwater Area end segment boat groove, ovum gravel median particle diameter D50 is 52mm, because flow intensity is larger, the Bed Load Movement form transits directly to the longitudinal dune stage by smooth bed surface usually, when model testing, the particle diameter of model sasnd should not be less than 0.6mm, and model scale should be greater than 1: 90;
Determining of the 3rd step, model geometric form:
Three Gorges Reservoir fluctuation backwater section riverbed and water surface gradient are all larger, and the riverbed bed load is coarse grained ovum gravel, coarse grained sediment movement to relative smoothness h/D, bed sloped J and not your moral to count Fr quite responsive, after the model bed sloped increases e times than prototype, stream parameters differs greatly, directly cause the similar accurate number of current and silt to differ greatly, affect the simulation similitude of starting, sediment transport path and the erosion and deposition state of bed load sediment, therefore should adopt normal model.
3. Upper Yangtze River pebble beach danger waterway regulation movable bed design of physical model method as claimed in claim 1, is characterized in that, the research process of described Upper Yangtze River pebble beach danger waterway regulation movable bed design of physical model method comprises the following steps:
Physical characteristic to light model sediment and natural sand compares research;
By the 28m flume test, from starting, silt discharge and three aspect investigation and comparisons of Movement of Sand Waves of silt the kinetic characteristic of natural sand, the husky two kinds of model sasnds of lightweight;
Selection is positioned at the system of Chongqing city pig moraine section of Three Gorges fluctuation backwater end and by physical experiments, and the husky and light model sediment of investigation and comparison natural model washes away the compliance when back-silting at the simulation groove that navigates;
Compliance to two kinds of model sasnds in bed load movable bed physical model is analyzed;
In conjunction with the characteristic of different model sasnds and current and the boat groove sediment movement characteristic analysis of Upper Yangtze River pebble beach danger, draw Upper Yangtze River pebble beach danger waterway regulation movable bed design of physical model method.
4. Upper Yangtze River pebble beach danger waterway regulation movable bed design of physical model method as claimed in claim 3, is characterized in that, the research process concrete steps of described Upper Yangtze River pebble beach danger waterway regulation movable bed design of physical model method are:
The physical characteristic comparative studies of the first step, light model sediment and natural sand:
At 47 point bar natural pebble samples of the random selection in nine heap sections of system of Chongqing city, with 196,198 samples of randomly drawing in natural model sand, light model sediment, measure its geometric scale of contrast and quality, adopt form coefficient, flatness, sphericity parameter to be added up
Second step, kinetic characteristic comparative studies:
By the 28m flume test, from starting, silt discharge and three aspect investigation and comparisons of Movement of Sand Waves of silt the kinetic characteristic of natural sand, the husky two kinds of model sasnds of lightweight;
The comparative study of the 3rd step, model sasnd simulation erosion and deposition characteristic:
Selection is positioned at the system of Chongqing city pig moraine section of Three Gorges fluctuation backwater end and by physical experiments, and the husky and light model sediment of investigation and comparison natural model washes away the compliance when back-silting at the simulation groove that navigates;
Consider model sasnd, place and simulated object reason, the navigated erosion and deposition contrast test of groove of the normal state Local physical model of setting up 1: 60 mainly for the main boat groove in phase pig moraine section that disappears;
The model testing result shows, while adopting natural model sand to be tested, its bed load is defeated moves path, the erosion and deposition position is basic conforms to the navigate situation of groove of prototype; While adopting light model sediment to be tested, model Sediment Transport path conforms to prototype boat groove substantially, but silt is difficult to form the alluvial body under alluvial in the boat groove fast through boat groove and beach face, and the boat groove back-silts phenomenon with actual far apart;
The 4th step, the Adaptability Analysis of two kinds of model sasnds in bed load movable bed physical model:
Comparison test analysis from model sasnd physical characteristic, kinetic characteristic and erosion and deposition characteristic aspect, when natural model sasnd and light model sediment are applied to movable bed model test, because Upper Yangtze River section flow intensity is large, bed material forms thicker, the husky physical characteristic of natural model, kinetic characteristic and erosion and deposition characteristic aspect have better similitude, simulate Bed Load Movement with natural sand and more can reflect the motion state of natural river ovum gravel;
The 5th step, Upper Yangtze River pebble beach danger waterway regulation movable bed design of physical model method:
In conjunction with the characteristic of different model sasnds and current and the boat groove sediment movement characteristic analysis of Upper Yangtze River pebble beach danger.
5. require 4 described Upper Yangtze River pebble beach danger waterway regulation movable bed design of physical model methods as claim, it is characterized in that, the concrete steps of described second step are:
Step 1, starting rule compare:
Carried out altogether the starting test of 2 kinds of natural sands, a kind of lightweight sand in tank, with the dimensionless silt discharge of Parker
as the starting discrimination standard, obtain the starting conditions result of the test of natural sand and lightweight sand,
To test flow condition according to being converted to the dimensionless starting power, can find out that the starting conditions data point of natural sand and lightweight sand is distributed on same straight line substantially, all meet same starting power formula,
The starting conditions of the husky two kinds of model sasnds of natural sand and lightweight is the wide dimensionless flow number of available list q all
*mean, this starting formula with Upper Yangtze River ovum gravel is consistent, when the starting that two kinds of model sasnds simulate bed load sediment in physical experiments is described, all is suitable for;
The comparison of step 2, silt discharge:
In flume test, adopt the natural sand of 2 kinds of particle diameters, the lightweight sand of 3 kinds of particle diameters, control the tank ratio and fall J, flow Q, measure water level H and single wide bed load discharge g
bcarry out altogether totally 87 groups of bed load discharge tests, the measured experimental data of Einstein formula analysis that employing is revised by the Upper Yangtze River measured data, by stream parameters Ψ and the sediment discharge intensity Φ point of handling well, visible, the sediment discharge intensity of natural sand and lightweight sand all meets the Einstein correction formula substantially, and experimental data point is near the tight distribution formula calculated value all;
Husky and the natural sand of lightweight is followed identical rule at sediment discharge intensity, also can adopt same equation expression, natural sand and lightweight sand all when the sediment discharge intensity that carries out movable bed model test is tested difference little;
The comparison of step 3, Bed Load Movement form:
When flow intensity larger, bed load sediment will be with the bed ripples gestalt movement, in order to contrast light model sediment and the natural sand similitude when the Movement of Sand Waves, in the 28m varible slope flume, utilize lightweight sand and natural sand to carry out bed ripples form contrast test, the critical flow condition, wave height, wavelength, the bed ripples form aspect that form bed ripples from the two are contrasted;
The critical condition formed from bed ripples, the lightweight that particle diameter is identical is husky compares with natural sand, forms the flow intensity of Movement of Sand Waves much smaller than natural sand; When flow intensity increases gradually, the wave height of natural sand bed ripples has gradually and to increase and trend that wavelength reduces, but that the bed ripples wave height of lightweight sand and wavelength increase variation tendency with flow intensity is slower; Natural sand morphological parameters θ=λ
upstream face/ λ
back sideincrease excursion with flow intensity is larger, and the husky morphological parameters of lightweight is less with the increase excursion of flow intensity, reinforcement along with flow intensity, lightweight sand more easily forms the bed ripples form than natural sand, and all there are obvious difference in the wavelength between natural sand and lightweight sand, wave height and bed ripples form, therefore occur that at bed surface the bed ripples stage selects natural sand as model sasnd as far as possible.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104897874A (en) * | 2015-05-19 | 2015-09-09 | 四川大学 | Method for detecting correlation between mountain river pebble beaches |
| CN107238483A (en) * | 2017-08-09 | 2017-10-10 | 重庆交通大学 | For defeated harvester, the system and method for moving pressure and defeated shifting audio of boulder and cobble |
| CN116108773A (en) * | 2023-03-06 | 2023-05-12 | 交通运输部天津水运工程科学研究所 | Simulation prediction method for silt back-siltation of water intake open channel under influence of flexible dirt blocking net |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1174061A (en) * | 1966-04-29 | 1969-12-10 | White Bruce Gordon Sir | Improvements in or relating to Hydrographic Models |
| CN102298706A (en) * | 2011-08-12 | 2011-12-28 | 河海大学 | Inland waterway ship large-scale prediction method in restricted conditions |
-
2013
- 2013-05-24 CN CN2013102042555A patent/CN103437319A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1174061A (en) * | 1966-04-29 | 1969-12-10 | White Bruce Gordon Sir | Improvements in or relating to Hydrographic Models |
| CN102298706A (en) * | 2011-08-12 | 2011-12-28 | 河海大学 | Inland waterway ship large-scale prediction method in restricted conditions |
Non-Patent Citations (1)
| Title |
|---|
| 颜雪丽: "推移质动床模拟模型沙研究", 《中国优秀硕士学位论文全文数据库》 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104897874A (en) * | 2015-05-19 | 2015-09-09 | 四川大学 | Method for detecting correlation between mountain river pebble beaches |
| CN107238483A (en) * | 2017-08-09 | 2017-10-10 | 重庆交通大学 | For defeated harvester, the system and method for moving pressure and defeated shifting audio of boulder and cobble |
| CN116108773A (en) * | 2023-03-06 | 2023-05-12 | 交通运输部天津水运工程科学研究所 | Simulation prediction method for silt back-siltation of water intake open channel under influence of flexible dirt blocking net |
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Application publication date: 20131211 |