CN106759072A - Take into account the river model drainage system and method for designing of bed surface stability and Quick drainage - Google Patents

Abstract

The present invention provides a kind of river model drainage system and its method for designing for taking into account bed surface stability and Quick drainage, belongs to river dynamics, simulating river field.The present invention is set in general river model bottom oozes pipe, flowmeter and valve, can be changed to vertical ooze pipe draining by longitudinal tail-gate draining of routine by oozing pipe when needing to drain model water.Discharge area is significantly greater than the discharge area of longitudinal drainage when so due to vertical draining, in the case where flow is consistent, the former can be significantly less than the latter by flow velocity, sediment incipient motion when can avoid draining, it is beneficial to keep the stabilization of Shoal bar, and derived the vertical formula of incipient velocity of slope silt, by oozing pipe flow, vertical flow velocity and the triangular relation of sediment moving incipient velocity, propose oozing under silt stop and pipe maximum flow threshold value and ooze the computational methods of pipe caliber, to take into account bed surface stability and Quick drainage.Relatively conventional model bathymetric surveying, model drainage system and method for designing that the invention is proposed are the important prerequisites of river model dry river bed form fidelity, can effectively solve the bottleneck that model bed configuration is quickly measured.

Description

Take into account the river model drainage system and method for designing of bed surface stability and Quick drainage

Technical field

The present invention relates to the simulating river field of river dynamics subject, and in particular to one kind takes into account bed surface stability and quick The river model drainage system and method for designing of draining.

Background technology

River model is a kind of important simulating river means, is recent decades research river bed change and rule of sediment movement Ripe instrument, has formd industry code, i.e., on its modular concept, manufacturing process, measurement control and Analysis on Results at present《River Work model test code (SL99-2012)》.

Wherein, have certain in the closing of model tail-gate, model using needs to the general of river model bed configuration measurement Measured in the case of the depth of water, itself main reason is that, model during water is drained through tail-gate, can because flow velocity compared with Greatly, the smaller generation of the depth of water " small water draws husky " effect causes that bed surface model sasnd is started again, and therefore bed surface deforms, and causes whole riverbed The distortion of evolution process simulation.Because longitudinal drainage can cause river-bed deformation, so draining cannot be carried out, such riverbed will Keep certain depth of water.Meanwhile, conventional model topographic survey is carried out generally according to the method for section, and the measuring point spacing on each section is pressed It is controlled no more than 20cm, corresponding measuring instrument is generally Electroimpedance Topographical indicator, metering system is point-to-point measurement.And the depth of water Presence optical gauge will be allowed to produce the error that causes by refraction, cause more advanced at present total powerstation and with laser The optical gauges such as shape scanner cannot be applied in topography measurement so that current model bed configuration measurement effect Rate is relatively low.

So, because longitudinal drainage easily causes river-bed deformation, advanced optical gauge cannot be in river model landform The main cause applied in measurement is still model because of the water body of the certain depth that can not be carried out longitudinal drainage and must keep, and mould The presence of water body can then cause the refraction of light so that advanced optical gauge cannot be applied to bathymetric surveying in type.

The content of the invention

For deficiencies of the prior art, the present invention provides a kind of river for taking into account bed surface stability and Quick drainage Work model drainage system and method for designing, its by the conventional longitudinal tail-gate draining of model be changed to it is vertical ooze pipe draining, in general river Work model bottom sets and oozes the devices such as pipe, flowmeter and valve, using vertical flow velocity under drain discharge same case much smaller than vertical The characteristics of starting is difficult to flow velocity, silt, implementation model Quick drainage and bed surface stability are taken into account, effectively to solve model riverbed ground The technical bottleneck that shape is quickly measured.

A kind of river model drainage system for taking into account bed surface stability and Quick drainage, river model is generalized as a rectangle water Groove, to be followed successively by inducer, test section, tail-gate and outlet section, afterbay from left to right, test section is from upper for water (flow) direction in plane It is followed successively by that water body, model sasnd, a natural prose style free from parallelism be husky, gravel under, the drainage system includes laterally being embedded in gravel and oozes pipe, Ooze pipe and be provided with multiple water seepage holes, pipe is oozed for the water in river model to be imported, ooze the row that pipe lower section is communicated with backwater canal Water pipe, drainpipe is provided with flowmeter and valve, and the delivery port of backwater canal is connected with afterbay.

Further, the eyelet for oozing the water seepage hole on tube wall selects circular port, and aperture typically uses 10~20mm, arrangement Into plum blossom-shaped.

Further, the eyelet of water seepage hole arranges scope on 1/3~1/2 pipe perisporium for oozing more than the caliber of pipe.

Further, flowmeter and valve realize the control of drain discharge, the drain discharge according to drain discharge threshold value Threshold value Q, i.e., maximum flow limit value computing formula when silt is inoperative is：

Wherein θ is the domatic angle with horizontal plane of model bed ripples, typically refers to the model sasnd underwater information warfare and is taken Value, d is model sasnd representative diameter, γ_sIt is model sasnd unit weight, γ is model water body unit weight, and A is vertical discharge area.

Further, to meet displacement demand, the PIPE DIAMETER CALCULATION formula for oozing pipe is as follows：

Wherein, to ooze pipe width or diameter, T is water-bearing layer thickness to D, and H is earth's surface head, and α is silting index, and L is to ooze pipe Length, k is infiltration coefficient, and Q is to ooze pipe displacement.

A kind of method for designing of the river model drainage system for taking into account bed surface stability and Quick drainage, comprises the following steps： Added in conventional river model bottom and ooze pipe, flowmeter and valve, will longitudinal direction by oozing pipe when needing to drain model water Tail-gate draining be changed to it is vertical ooze pipe draining, pipe will be oozed laterally located at river model bottom, ooze and opened up on pipe multiple water seepage holes, be used for By in river model water import ooze pipe, ooze pipe lower section set connection backwater canal drainpipe, on drainpipe set flowmeter with Valve, the delivery port of backwater canal is connected with afterbay.

Further, river model is generalized as a Rectangular Water Trough, and water (flow) direction is to be followed successively by import from left to right in plane Section, test section, tail-gate and outlet section, afterbay, test section are followed successively by water body, model sasnd, natural prose style free from parallelism sand, gravel from top to bottom Stone, oozes pipe and is embedded in gravel, and flowmeter and valve realize the control of drain discharge, the blowdown stream according to drain discharge threshold value Threshold value Q is measured, i.e., maximum flow limit value computing formula when silt is inoperative is：

Wherein θ is the domatic angle with horizontal plane of model bed ripples, typically refers to the model sasnd underwater information warfare and is taken Value, d is model sasnd representative diameter, γ_sIt is model sasnd unit weight, γ is model water body unit weight, and A is vertical discharge area.

Further, to meet displacement demand, the PIPE DIAMETER CALCULATION formula for oozing pipe is as follows：

Wherein, to ooze pipe width or diameter, T is water-bearing layer thickness to D, and H is earth's surface head, and α is silting index, and L is to ooze pipe Length, k is infiltration coefficient, and Q is to ooze pipe displacement.

The present invention by longitudinal tail-gate draining be changed to it is vertical ooze pipe draining, so in the case where drain discharge is consistent, due to Discharge area is significantly greater than the discharge area of longitudinal drainage during vertical draining, and the former can be significantly less than the latter by flow velocity, while can lead to Excessively stream gauge and valve coordinate effectively regulation uninterrupted, it is ensured that model sasnd is inoperative, and Shoal bar keeps stabilization, and passes through Ooze pipe flow, model flow velocity and the triangular relation of sediment moving incipient velocity, can be given silt it is motionless under ooze pipe maximum flow Threshold value, to take into account bed surface stability and Quick drainage.

Brief description of the drawings

Fig. 1 is the plan of the river model drainage system that the present invention takes into account bed surface stability and Quick drainage；

Fig. 2 be Fig. 1 in A-A to profile；

Fig. 3 is B-B direction profile in Fig. 1；

Fig. 4 is slope silt force analysis schematic diagram.

Reference：1-ooze pipe, 2-drainpipe, 3-flowmeter, 4-valve, 5-backwater canal, 6-water seepage hole, 7- Import, 8-tail-gate.

Specific embodiment

Below in conjunction with the accompanying drawing in the present invention, the technical scheme in the present invention is clearly and completely described.

Fig. 1-3 are refer to, the present invention provides a kind of river model drainage system for taking into account bed surface stability and Quick drainage, bag Include and laterally ooze pipe 1 located at river model bottom, ooze pipe 1 and be provided with multiple water seepage holes 6, for the water in river model to be imported Ooze pipe 1.The drainpipe 2 that the lower section of pipe 1 is communicated with backwater canal 5 is oozed, drainpipe 2 is provided with flowmeter 3 and valve 4, backwater canal 5 Delivery port is connected with afterbay.

The present invention is added in conventional river model bottom oozes pipe 1, flowmeter 3 and valve 4, is needing to drain model water When longitudinal tail-gate draining is changed to vertical to ooze pipe draining by oozing pipe 1.So in the case where drain discharge is consistent, due to vertical Discharge area is significantly greater than the discharge area of longitudinal drainage during draining, and the former can be significantly less than the latter by flow velocity, while can be by stream Gauge 3 and valve 4 coordinate effectively regulation uninterrupted, it is ensured that model sasnd is inoperative, and Shoal bar keeps stabilization, according to slope Sediment incipient motion force analysis, has been derived from the vertical formula of incipient velocity of slope silt, and by ooze pipe flow, model flow velocity and The triangular relation of sediment moving incipient velocity, be given silt it is motionless under the calculating side for oozing pipe maximum stream flow threshold value and corresponding caliber Method, to take into account bed surface stability and Quick drainage.

As shown in figure 1, the river model of routine is generalized as a Rectangular Water Trough, in plane water (flow) direction for from left to right, according to Secondary to have inducer (end is provided with import 7), test section, tail-gate 8 and outlet section, afterbay, the present invention is changed to by the draining of tail-gate 8 Vertical draining, in model sasnd laying depth, one arranged below oozes pipe 1, while oozing pipe 1 flushes a drainpipe 2, drainpipe 2 goes out Mouthful it is provided with flowmeter 3 and valve 4 and directs water flow towards afterbay controlling to take back water channel 5 under drain discharge, valve.

On model sasnd laying depth and ooze pipe periphery paving and bury husky layering of a prose style free from parallelism etc. and all performed according to relevant Regulations, 《River model test code》The general laying depth of regulation river model model sasnd is 10cm, and the depth of water is not less than 5cm；《Water conservancy project is built Build thing Design of Filter Layer specification》Specify that general by-pass rivers building sandstone loaded filter particle diameter design principle is up-thin-low-thick.With As a example by the experimental tank that 6.5m is long, 1m is wide, 1.4m is high, its structural dimensions is：Import segment length 0.6m, tests segment length 5.2m, Outlet segment length 0.7m, afterbay is 1.2m (length) × 1.4m (width) × 1.3m (depth)；Model depth of water average out to 30cm, model sasnd paving If thickness is 10cm, it is divided into, and natural prose style free from parallelism sand 40cm is thick, then the thick gravels of the lower 60cm for particle diameter more than 1cm, oozes pipe 1 and buries In gravel (as shown in Figures 2 and 3), caliber is 20cm, and bottom is impervious foundation.Wherein, the infiltration on the tube wall of pipe 1 is oozed Eyelet typically selects circular port, and aperture typically uses 10~20mm, is arranged to plum blossom-shaped, and eyelet clear distance is that (D is hole to 2~2.5D Eye diameter).The eyelet for oozing the water seepage hole 6 on pipe 1 typically arranges the pipe that scope (is counted) more than 1/3~1/2 caliber from ttom of pipe On perisporium, bottom typically not apertured eye, to prevent bottom silt from flowing into pipe, the effect of catchmenting of pipe is oozed in influence.

Water force mainly considers two parts：First from the requirement for maintaining bed surface stability, pipe displacement is oozed in calculating Max-thresholds；Secondly from the requirement of Quick drainage, pipe caliber is oozed based on oozing pipe displacement and calculating.

(1) pipe displacement max-thresholds are oozed

In model draining process, it is necessary to clear and definite drain discharge threshold value, to control flow rate of water flow, to ensure that Shoal bar is asked Topic, i.e., flow velocity is necessarily less than the initial velocity of silt.By calculating the relation of grains of sand initial velocity and flow, draining can be provided The max-thresholds of amount.First, during vertical draining, by current continuity equation, its vertical flow rate of water flow is

In formula：V is flow rate of water flow (m/s), and Q is drain discharge (m³/ s), A is vertical discharge area, for being generalized as square The model of shape section, it is definite value, i.e. the area of plane of model.

The one-dimensional generalized equation of plane Parallel to the flow direction is due to general Incipient Velocity of Sediment Transport, and works as river model When ooze pipe draining from top to bottom, its flow velocity direction for vertical, therefore existing sediment incipient motion formula be cannot be in vertical row It is being used during water, it is necessary to derive vertical sediment incipient motion formula.Consider that model sasnd is a husky prose style free from parallelism, ignore its viscous force shadow Ring, according to《River load dynamics》(Wuhan University, Zhang Ruijin, 1998), sand grain is mainly effectively weighed in water body Power, current uplift force and drag influence, such as Fig. 4, its force analysis are as follows：

Effective gravity W=α under water₁(γ_s-γ)d³ (2)

Current uplift force

Current drag power

In formula, α₁、α₂、α₃It is sand grain form factor；γ_sWith the unit weight that γ is respectively silt and water；D is silt Particle diameter；C_DIt is drag force coefficient；C_LIt is vertical lift coefficient, u_rxIt is sand grain in the component velocity in x directions.

According to general sediment incipient motion it is assumed that the grains of sand generally are generalized as into ellipse grains, in the presence of current, generally adopt The form for taking rolling is started, if being center of rotation with 0 point, the power balance equation that the expression grains of sand start critical condition is：

K₂dF_L+K₃dF_D=K₁dW (5)

In formula, K₁d、K₂d、K₃D is respectively W, F_D、F_LThe corresponding arm of force.Bring formula (2), (3), (4) into formula (5), mud can be obtained Sand start effect velocity formula be：

According to the research of sinus state benevolence academician, when silt is spheroid, take thirdly the score of axle and same volume sphere diameter Wei not 4/3,3/3,2/3, desirable C_D=0.4, C_L=0.1, other geometric parameters also can class take it is as follows：

α₁=π/6

α₂=π/3

α₃=2 π/9

K₁=1/2

K₂=1/2

K₃=1/3

Gained formula (6) is the sediment moving incipient velocity that can be used to build all directions accordingly, for the present invention, required The vertical sediment incipient motion pattern being directed under the influence of river model Shoal bar to be set up.Due to Shoal bar be generally bed ripples, The forms such as husky Gansu Province, cause sediment incipient motion to move downward, cause bed deformation in the case where bed ripples slope is easily acted in vertical flow velocity. Therefore slope (underwater information warfares of the ramp slope θ typically with silt is relevant) vertical vehicle start wave of silt need to be set up, in this pattern Under, its slope direction effect flow velocity is the component of vertical flow velocity, and does not deposit vertical characteristics problem, and relation is between the two：

u_rx=Vsin θ (7)

By formula (7) and formula (6) simultaneous, the vertical formula of incipient velocity of slope silt is obtained final product：

By formula (1) and the formula simultaneous of formula (8) two, and relevant geometric parameter is brought into, you can obtain drain discharge threshold value, i.e. silt Maximum flow limit value computing formula when inoperative：

In formula：V_cIt is flow rate of water flow, d is model sasnd representative diameter, γ_sIt is model sasnd unit weight, γ is model water body unit weight, Q It is drain discharge (m³/ s), θ is slope and horizontal plane angle, is 24 ° -36 ° with reference to all kinds of model sasnd angles of repose, and its counit is adopted With kg, m, s, symbolic significance is the same.

According to the form general model tank given by the present invention, the maximum flow threshold value for maintaining silt stabilization can be calculated.

(2) pipe PIPE DIAMETER CALCULATION is oozed

With reference to by-pass rivers building-ooze pipe water withdrawal computing formula, i.e., Ah's Ravigneaux Nu Meinuofu formula (formula 10, 11st, it is 12) as follows：

Q=α Lkq_r (10)

In formula：χ is coefficient；To ooze pipe displacement, (unit is m to Q herein³/d)；H is earth's surface head (m)；L is to ooze length of tube (m)；H₀To ooze water surface head value (m) in pipe, typically when caliber presses Most Economical Control, it can be equal to caliber, i.e. D；D is to ooze pipe Width or diameter (m)；T is water-bearing layer thickness (m)；α is silting index, and typically not muddy river uses 0.8, is adopted when medium muddy With 0.6,0.3 is used when muddy；Other symbolic significances are the same.By formula (10,11,12) simultaneous solution, can meet water withdrawal will The PIPE DIAMETER CALCULATION formula asked is as follows.

Osmotic coefficient k is the physical quantity for characterizing permeability of aquifer matter, reference《Geohydrology principle》(Yu Zhongbo, Huang Yongzhu), loose rock mass cobble-stone, rough sand, the infiltration coefficient (unit is m/s) of middle husky and fine sand are respectively：3×10^-4~3 × 10^-2, 9 × 10^-7~6 × 10^-3, 9 × 10^-7~5 × 10^-4, 2 × 10^-7~2 × 10^-4；Loaded filter of the present invention is layered water bearing strata, Its osmotic coefficient k size and each layer osmotic coefficient k₁、k₂、k₃…k_nEtc. relevant, osmotic coefficient k can be calculated as follows：

k、k₁、k₂、k₃…k_nIt is respectively total infiltration coefficient, the 1st, 2,3 ... n-layer loaded filter infiltration coefficients；T、T₁、T₂、T₃…T_n It is respectively the 1st, 2,3 ... n-layer loaded filter thickness.

Loaded filter of the present invention is set to rough sand+gravel, and infiltration coefficient is calculated as 518m through k³/ d, can be taken as 500m³/d。

So, formula (9) and formula (13) are solved respectively, you can the displacement under the premise of the bed surface stability that is maintained is most Big threshold value and meet the maximum caliber of displacement demand and refer to value.It is worthy of note that, in the starting stage of model draining, Its depth of water is maximum, flow threshold is also maximum, in requisition for caliber it is also maximum, then pipe diameter determing value is that can use this maximum caliber, To meet the Quick drainage requirement under the conditions of bed surface stability is kept.

According to the sink size that one of embodiment of the invention is provided, displacement controlling curve and pipe diameter determing can be calculated It is worth, its known parameters is：

1. model area of plane A=5.2 × 1=5.2m²；

2. length of tube L=5.2m is oozed；

3. model sasnd representative diameter d=0.01mm；

4. model sasnd γ_sUnit weight is 1.05t/m³, water body unit weight γ is 1t/m³

5. θ is 35 °

6. gravity acceleration g=9.8m/s²

7. initial depth of water h=0.3m

8. initial earth's surface head H=1.4m

9. water-bearing layer thickness T=0.9m

10. silting index α=0.8

Formula (9) and formula (13) are substituted into, then the flow threshold under holding bed surface stability, the i.e. silt being calculated is inoperative It is 0.038m to be worth³/ s (upper limit), and the caliber reference value of this drain discharge demand is met for 0.208cm, pipe diameter determing value can 0.2m is taken, to meet maximum displacement demand.

Claims (8)

1. a kind of river model drainage system for taking into account bed surface stability and Quick drainage, river model is generalized as a Rectangular Water Trough, Water (flow) direction is to be followed successively by inducer, test section, tail-gate (8) and outlet section, afterbay from left to right in plane, and test section is from upper Water body, model sasnd, natural prose style free from parallelism sand, gravel are followed successively by under, it is characterised in that：The drainage system includes laterally being embedded in gravel Pipe (1) is oozed in stone, pipe (1) is oozed and is provided with multiple water seepage holes (6), pipe (1) is oozed for the water in river model to be imported, ooze pipe (1) lower section is communicated with the drainpipe (2) of backwater canal (5), and drainpipe (2) is provided with flowmeter (3) and valve (4), backwater canal (5) delivery port is connected with afterbay.

2. river model drainage system as claimed in claim 1, it is characterised in that：Ooze water seepage hole (6) on pipe (1) tube wall Eyelet selects circular port, and aperture typically uses 10~20mm, is arranged to plum blossom-shaped.

3. river model drainage system as claimed in claim 1, it is characterised in that：The eyelet arrangement scope of water seepage hole (6) exists On pipe perisporium more than 1/3~1/2 caliber for oozing pipe (1).

4. river model drainage system as claimed in claim 1, it is characterised in that：Flowmeter (3) and valve (4) are according to draining Flow threshold realizes the accurate control of drain discharge, the drain discharge threshold value Q, i.e., maximum flow limit value when silt is inoperative Computing formula is：

$Q=1.9\sec \mathrm{\θ}\·\sqrt{\frac{{\mathrm{\γ}}_s-\mathrm{\γ}}{\mathrm{\γ}}gd}\·A$

Wherein θ is the domatic angle with horizontal plane of model bed ripples, and d is model sasnd representative diameter, γ_sIt is model sasnd unit weight, γ is mould Type water body unit weight, A is vertical discharge area.

5. river model drainage system as claimed in claim 1, it is characterised in that：To meet displacement demand, pipe (1) is oozed PIPE DIAMETER CALCULATION formula is as follows：

$D=\frac{8T}{\mathrm{\π}}arc\cot \left({10}^{\frac{(H-D)\mathrm{\α}Lk}{0.73Q}}\right)$

Wherein, to ooze pipe width or diameter, T is water-bearing layer thickness to D, and H is earth's surface head, and α is silting index, and L is to ooze length of tube, K is infiltration coefficient, and Q is to ooze pipe displacement.

6. a kind of method for designing of the river model drainage system for taking into account bed surface stability and Quick drainage, it is characterised in that：Normal Rule river model bottom adds oozes pipe (1), flowmeter (3) and valve (4), when needing to drain model water by oozing pipe (1) by longitudinal tail-gate draining be changed to it is vertical ooze pipe draining, pipe (1) will be oozed laterally located at river model bottom, ooze and opened up on pipe (1) Multiple water seepage holes (6), pipe (1) is oozed for the water in river model to be imported, and is oozed pipe (1) lower section and is set connection backwater canal (5) Drainpipe (2), sets flowmeter (3) and valve (4) on drainpipe (2), the delivery port of backwater canal (5) is connected with afterbay.

7. the method for designing of river model drainage system as claimed in claim 1, it is characterised in that：Flowmeter (3) and valve (4) the accurate control of drain discharge is realized according to drain discharge max-thresholds, the drain discharge threshold value Q, i.e. silt is inoperative When maximum flow limit value computing formula be：

$Q=1.9\sec \mathrm{\θ}\·\sqrt{\frac{{\mathrm{\γ}}_s-\mathrm{\γ}}{\mathrm{\γ}}gd}\·A$

Wherein θ is the domatic angle with horizontal plane of model bed ripples, and typically referring to the model sasnd underwater information warfare carries out value, d It is model sasnd representative diameter, γ_sIt is model sasnd unit weight, γ is model water body unit weight, and A is vertical discharge area.

8. the method for designing of river model drainage system as claimed in claim 1, it is characterised in that：To meet displacement need Ask, the PIPE DIAMETER CALCULATION formula for oozing pipe (1) is as follows：

$D=\frac{8T}{\mathrm{\π}}arc\cot \left({10}^{\frac{(H-D)\mathrm{\α}Lk}{0.73Q}}\right)$

Wherein, to ooze pipe width or diameter, T is water-bearing layer thickness to D, and H is earth's surface head, and α is silting index, and L is to ooze length of tube, K is infiltration coefficient, and Q is to ooze pipe displacement.