CN103696405A - Herringbone mud-rock flow water and stone separating system designing method - Google Patents

Abstract

The invention discloses a herringbone mud-rock flow water and stone separating system designing method. Structure of a herringbone mud-rock flow water and stone separating system is disclosed in the prior art, and no designing method of the system is disclosed yet, so that designing and application of the prevention and control system are limited. In engineering design of the herringbone mud-rock flow water and stone separating system, key parameters include span B of a water-stone separation grating, height H of the water-stone separation grating and length L of the water-stone separation grating. On the basis of basic parameters determined according to on-site inspection, experiments and mud-rock flow engineering investigation and design standards, a method for designing the span B, the height H and the length L of the water-stone separation grating in the engineering design method of the herringbone mud-rock flow water and stone separating system is provided. The herringbone mud-rock flow water and stone separating system designing method solves the technical problem that the herringbone mud-rock flow water and stone separating system cannot be accurately designed yet in engineering design, and is reliable in principle, scientific, simple and convenient in calculation process and adaptive to engineering construction requirements.

Description

Fish ridge mudstone flowing water stone piece-rate system method for designing

Technical field

The present invention relates to a kind of engineering design method, particularly relate to the method for designing of fish ridge mudstone flowing water stone piece-rate system, debris flow field, hydraulic engineering field.

Background technology

Mud-rock flow is to be formed at a kind of solid-liquid two-phase flow that mountain area is domatic or raceway groove comprises water, stone and thin particulate matter.Because debris flow occurrence is unexpected and carry a large amount of stones, there is great destructive power, often form disaster.Mud-rock flow Control Engineering is one of mitigation means the most efficiently and effectively.

Applicant is that ZL201120352219.X, publication number are that 202298575U, name disclose a kind of mudstone flowing water stone piece-rate system of fish ridge in being called a kind of Chinese utility model patent of mudstone flowing water stone piece-rate system in the patent No..Entire system is arranged on debris flow gully bed, and basic structure comprises drainage dam and the separated grid of water stone across debris flow gully bed two sides.The separated grid integral body of water stone is fish spine rack and panel construction, mainly spine and girt strip, consists of, and spine front end is immediately at drainage dam back side.System also can comprise that dredging flow groove and stone stop long-pending.This system can be further designed to multistage, along mud-rock flow raceway groove from upstream arranged with interval downstream, finally form fish ridge mudstone flowing water stone piece-rate system step by step.

Now still do not relate to this fish ridge mudstone flowing water stone piece-rate system method for designing open, limited this and prevented and treated design and the application of system.

Referenced patents: Chengdu Inst. of Mountain Disaster and Environment, Ministry of Water Resources. a kind of mudstone flowing water stone piece-rate system: China, ZL201120352219.X[P] .2012-07-04.

Summary of the invention

Object of the present invention is exactly for the deficiencies in the prior art, and fish ridge mudstone flowing water stone piece-rate system method for designing is provided, and solves the technical problem that it still can not more accurately design in engineering design.

The fish ridge mudstone flowing water stone piece-rate system the present invention is directed to, is arranged on debris flow gully bed, comprises drainage dam, at drainage dam back side, connects the separated grid of water stone; The separated grid of described water stone is across debris flow gully bed two sides, and anterior top and draining hole top, drainage dam are immediately.The separated grid of water stone is fish ridge structure, comprises the spine along mud-rock flow direction, spine both sides girt strip arranged side by side, and girt strip base portion is fixed on support pier; Spine front end and draining hole top, drainage dam are immediately.Further, the dredging flow groove immediately in drainage dam back side bottom, dredging flow groove comprises the abutment wall of arranging along debris flow gully bed both sides, and protection-apron is arranged in the ditch bed bottom between abutment wall, and dredging flow groove afterbody is arranged the power bank that disappears.In debris flow gully bed two sides, dredging flow groove two outsides, stone is set and stops long-pending.

Above-mentioned fish ridge mudstone flowing water stone piece-rate system is in engineering design, and critical parameter comprises the separated grid span of water stone B, the separated height of grid H of water stone, the separated grid length L of water stone.

For achieving the above object, technical scheme of the present invention is as follows:

Fish ridge mudstone flowing water stone piece-rate system method for designing, the separated grid span of design water stone B, is characterized in that: according to following steps, implement:

Step S1: parameter is determined

Field investigation, determines basic parameter according to mud-rock flow engineering investigation and design specifications, comprising: the natural angle of respose of solid particle in mud-rock flow

fish ridge mudstone flowing water stone piece-rate system build width B at the bottom of the raceway groove of position ', drainage dam draining hole width b,

Overflow degree of depth h while determining that according to prior art mud-rock flow is flowed through draining hole;

Step S2, the separated grid span of water stone B determine

The separated grid span of water stone B is according to formula 1 calculative determination:

B=hsin2 θ+b formula 1

In formula, the separated grid span of B-water stone, m,

Overflow degree of depth when h-mud-rock flow is flowed through draining hole, m, step S1 is definite,

θ-girt strip upper and lower two ends connecting line and mud-rock flow raceway groove base plane angle, ° equal the natural angle of respose of solid particle in mud-rock flow

B-drainage dam draining hole width, m, step S1 determines.

The basic principle of the separated grid span of above-mentioned water stone B method for designing is: the first, and span B affects the run duration of mud-rock flow on grid, thereby affects water stone separating effect.If span B is too small, the run duration of mud-rock flow on grid is short, just part debris flow body has had little time the separation of water stone, is slipped to and stops long-pending, causes the separation of water stone insufficient, affects structure result of use; If span B is excessive, just fully to complete water stone before stopping long-pending separated being slipped to for mud-rock flow, cause construction investment waste.So in engineering design, should select rational span B to make mud-rock flow just in time fully complete water stone under this span separated.Second; the desirable operational effect of structure is that solid particle that in mud-rock flow, particle diameter is greater than design particle separation diameter is split into as far as possible and stops long-pending; and all the other debris flow bodies see through as far as possible grid and flow into dredging flow groove, so mud-rock flow fully completes the critical condition of water stone separation on grid, be: the solid particle that particle diameter is greater than design particle separation diameter equals along the time of grid landing the time that all the other debris flow bodies see through grid.And then; suppose that first mud-rock flow drops to grid surface through parabolic motion from draining hole flows out; then along grid surface, glide; the debris flow body height of drop flowing out from draining hole both sides is maximum; and this part debris flow body distance is stopped long-pending recently, so the run duration of this part debris flow body on grid is the shortest.If it is separated that this part debris flow body can fully complete water stone on grid, all debris flow bodies all can fully complete the separation of water stone on grid.Comprehensive, the judgment condition of fitting span B is: the solid particle that the debris flow body flowing out from draining hole both sides, particle diameter is greater than design particle separation diameter equals along the time of grid landing the time that all the other debris flow bodies see through grid.

Based on above-mentioned principle analysis, gravitate only while supposing that mud-rock flow moves on grid, the dark h of overflow when its flow depth equals mud-rock flow by drainage dam, first, according to debris flow body, from flowing out, drainage dam makes parabolic motion under Action of Gravity Field, the vertical flow velocity v when calculating mud-rock flow and dropping to grid surface _z; Secondly, according to being slipped to, stop the solid particle of long-pending with v _zsin θ is initial velocity, gsin θ be acceleration along grid landing, calculate solid particle along the time t of grid landing ₁; Again, the debris flow body that is h according to the degree of depth is with v _zfor initial velocity, g is that acceleration sees through grid, calculates the time t that debris flow body sees through grid ₂; Finally, utilize t ₁=t ₂relation can obtain the separated grid span of water outlet stone B method for designing, formula 1.Wherein, overflow degree of depth h is according to the disclosed method calculative determination of list of references 1; Drainage dam draining hole width b is by site inspection, definite according to mud-rock flow engineering investigation and design specifications; Girt strip upper and lower two ends connecting line and mud-rock flow raceway groove base plane angle theta equal the solid particle natural angle of respose in mud-rock flow

According to pre-stage test result, the present invention does further optimization to the separated grid span of water stone in above-mentioned fish ridge mudstone flowing water stone piece-rate system method for designing B method for designing, and specifically, the separated grid span of water stone B is according to formula 2 calculative determinations:

B=λ ₁(hsin2 θ+b) formula 2

In formula, λ ₁-grid span correction factor, value 1.48～1.61.

In the technical scheme of optimizing, introduce grid span correction factor λ ₁technical meaning be: because formula 1 is only to obtain on the basis of gravitate at hypothesis mud-rock flow, still, when mud-rock flow moves on grid, except being subject to gravity, be also subject to frictional force, impact force, holding power etc., so this formula has certain error.For the error of cancelling 1, according to result of the test, obtained the correction factor of formula 1, so introduce λ ₁can make result of calculation more accurate, more can meet engineering design requirement.Ordinary circumstance Under The Grille span correction factor λ ₁value 1.48～1.61, if mud-rock flow design discharge is larger, λ ₁value is larger.Further, in conditions permit situation, grid span correction factor λ ₁should be through testing definite exact value.

Based on the separated grid span of above-mentioned water stone B method for designing, the present invention further provides the separated height of grid H of water stone method for designing, its technical scheme is as follows:

A fish ridge mudstone flowing water stone piece-rate system method for designing, is characterized in that: the separated height of grid H of design water stone, complete on the separated grid span B of water stone basis,

Through experimental test, determine basic parameter, comprising: the solid particle that in mud-rock flow, particle diameter is greater than design particle separation diameter is separated to the ratio p that stops long-pending ₁, particle diameter is less than design particle separation diameter in mud-rock flow solid particle is separated to the ratio p that stops long-pending ₂, particle diameter is less than the solid particle ratio p of design particle separation diameter in mud-rock flow _d,

According to mud-rock flow engineering investigation and design specifications, determine basic parameter, comprising: mud-rock flow solid matter volumetric concentration c before the separation of water stone _v, mud-rock flow design discharge Q _c, the flow velocity v of mud-rock flow in dredging flow groove;

The separated height of grid H of water stone simultaneous formula 3, formula 4, formula 5 calculative determinations:

H=H ₁+ H ₂formula 3

H ₁=0.5Btan θ formula 4

$H_2=\frac{Q_c^{\′}}{\mathrm{Bv}}$ Formula 5

In formula, the separated height of grid of H-water stone, m,

H ₁on-girt strip, top is to the vertical height of plane on support pier, m,

The separated grid span of B-water stone, m, according to formula 1 or formula 2 calculative determinations

θ-girt strip gradient, ° equals the mud-rock flow solid particle natural angle of respose

H ₂-support pier height, m,

The flow velocity of v-mud-rock flow in dredging flow groove, m/s,

Q _cthe letdown flow of '-dredging flow groove, m ³/ s, according to formula 6 calculative determinations,

Q _c'=(1-pc _v) Q _cformula 6

In formula, c _vmud-rock flow solid matter volumetric concentration before the separation of-water stone,

Q _c-mud-rock flow design discharge, m ³/ s,

P-mud-rock flow solid matter is split into the ratio of stopping long-pending, by formula 7 calculative determinations,

P=(1-p _d) p ₁+ p _dp ₂formula 7

In formula, p _din-mud-rock flow, particle diameter is less than the solid particle ratio of design particle separation diameter,

P ₁the solid particle that in-mud-rock flow, particle diameter is greater than design particle separation diameter is separated to the ratio of stopping long-pending, and span is 0.85～1.00,

P ₂the solid particle that in-mud-rock flow, particle diameter is less than design particle separation diameter is separated to the ratio of stopping long-pending, and span is 0.25～0.35.

The separated height of grid H of above-mentioned water stone method for designing basic principle is: the first, because the separated grid of water stone is fixed on support pier by girt strip base portion, thus the separated height of grid H of water stone be on girt strip top to the vertical height H of plane on support pier ₁with the vertical height H of support pier ₂sum.The second, because girt strip gradient θ (being girt strip upper and lower top line and the mud-rock flow raceway groove base plane angle gradient) equals the mud-rock flow solid particle natural angle of respose

so H ₁with between the separated grid span of water stone B, can determine by trigonometric function relation.The 3rd, support pier height H ₂affect the conveyance capacity of dredging flow groove, therefore utilize dredging flow groove letdown flow Q _c' can inversion reckoning support pier height H ₂.According to mud-rock flow flow, be clear water flow and solid matter flow sum, can obtain dredging flow groove letdown flow Q _c' with piece-rate system design discharge Q _cbetween relation, i.e. formula

(formula 8) is expressed, wherein, and ρ _cfor mud-rock flow unit weight before the separation of water stone, kg/m ³, ρ _sfor mud-rock flow solid matter density, kg/m ³, the two is determined by experimental test, ρ _c' be mud-rock flow unit weight after the separation of water stone, kg/m ³, while supposing that mud-rock flow is flowed through the separated grid of water stone, be split into and stop the material of long-pending and entirely by solid particle, formed, can obtain ρ _c' expression formula

(formula 9), in formula, symbolic significance is the same.Simultaneous formula 8, formula 9 just can obtain the letdown flow Q of dredging flow groove _c' calculating formula, formula 6.

In said method, under general condition, the solid particle that in mud-rock flow, particle diameter is greater than design particle separation diameter is separated to the ratio p that stops long-pending ₁span is 0.85～1.00, more regular if particle diameter is greater than the solid particle of design particle separation diameter, p ₁larger.The solid particle that in mud-rock flow, particle diameter is less than design particle separation diameter is separated to the ratio p that stops long-pending ₂span is 0.25～0.35, if particle diameter is greater than 0.5 times and be less than design particle separation diameter to obtain solid content more in mud-rock flow, and p ₂larger.The in the situation that of conditions permit, p ₁, p ₂exact value all can be determined by test.

Based on the separated grid span of above-mentioned water stone B method for designing, the present invention further provides the separated grid length L of water stone method for designing, its technical scheme is as follows:

A fish ridge mudstone flowing water stone piece-rate system method for designing, is characterized in that: the separated grid length L of design water stone, complete on the separated grid span B of water stone basis,

According to mud-rock flow engineering investigation and design specifications, determine basic parameter, comprising: draining hole slope coefficient m;

The separated grid length L of water stone is according to formula 10 calculative determinations:

$L=\frac{Q_c}{(b+\mathrm{mh})h}\·\sqrt{\frac{B}{g\sin \mathrm{\θ}\cos \mathrm{\θ}}}$ Formula 10

In formula, the separated grid length of L-water stone, m,

Q _c-mud-rock flow design discharge, m ³/ s, according to design parameter determination,

B-drainage dam draining hole width, m, step S1 is definite,

M-draining hole slope coefficient,

The separated grid span of B-water stone, m,

G-acceleration of gravity, gets constant,

θ-girt strip gradient, °, equal the mud-rock flow solid particle natural angle of respose

The separated grid length L of above-mentioned water stone method for designing basic principle is:

The first, about grill designs length.The separated grill designs length of water stone depends on the largest motion distance of mud-rock flow on grid.As long as the separated grid length of water stone equals the largest motion distance of mud-rock flow on grid; can guarantee that mud-rock flow all can be separated to both sides through separated grid and stops long-pending field and can not fall into downstream raceway groove, the long construction investment that causes of reason grill designs is wasted again simultaneously.

The second, about the definition of largest motion distance.When mud-rock flow moves on the separated grid of water stone, the solid particle that most of particle diameter is greater than design particle separation diameter is slipped to and stops long-pending along grid surface, and remainder sees through grid and flows into dredging flow groove.The former run duration on grid is longer, and its move distance along grid length direction on grid is also larger.Simultaneously; be slipped in the solid particle that stops long-pending, the solid particle flowing out from draining hole center and the distance of stopping between long-pending are maximum, under identical flow velocity; the run duration of these solid particles on grid surface is the longest, and its move distance along grid length direction is also just maximum.Therefore, the separated grill designs length of water stone should equal these solid particles along the move distance of grid length direction.

The 3rd, about definite method of largest motion distance.Suppose that the solid particle flowing out from draining hole center only glides along grid surface under Action of Gravity Field, stops long-pending until be slipped to.The flow velocity v when solid particle flows out draining hole _x, in the separated grid span of water stone B, the separated height of grid H of water stone or girt strip upper and lower two ends connecting line and the known situation of mud-rock flow raceway groove base plane angle theta, can calculate these solid particles at grid surface the move distance S along grid length direction _maxthereby, obtain the separated grid length L of water outlet stone.S _maxcan be expressed as solid particle with flow velocity v _xat maximum duration t _maxthe distance of middle motion, i.e. S _max=v _xt _max(formula 11).V _xcan be by

(formula 12) calculative determination, wherein, Q _cfor mud-rock flow design discharge (m ³/ s), A is the area of passage (m of mud-rock flow while passing through draining hole ²), b is draining hole bottom width (m), and m is draining hole slope coefficient, and h is overflow dark (m).

T _maxthe time that to be solid particle glide along grid surface with acceleration a=gsin θ, can be by

(formula 13) calculative determination, wherein, g is acceleration of gravity (m/s ²), θ be girt strip upper and lower two ends connecting line and mud-rock flow raceway groove base plane angle (°), B is the separated grid span (m) of water stone.

By formula 11, formula 12, formula 13, can be obtained

(formula 14), and obtain the separated grid L of water stone calculating formula, formula 10.

According to pre-stage test result, the present invention does further optimization to the separated grid length L of the water stone in above-mentioned fish ridge mudstone flowing water stone piece-rate system method for designing method for designing, and concrete technical scheme is:

According to mud-rock flow engineering investigation and design specifications, determine basic parameter, comprising: mud-rock flow unit weight ρ before the separation of water stone _c;

The separated grid span L of water stone is according to formula 15 calculative determinations:

$L={\mathrm{\λ}}_2\·\frac{Q_c}{(b+\mathrm{mh})h}\·\sqrt{\frac{B}{g\sin \mathrm{\θ}\cos \mathrm{\θ}}}$ Formula 15

In formula, λ ₂-grid length correction coefficient, according to formula 16 calculative determinations;

λ ₂=2.131-0.0005 ρ _cformula 16

In formula, ρ _cmud-rock flow unit weight before the separation of-water stone, kg/m ³.

In the technical scheme of optimizing, introduce grid length safety factor λ ₂technical meaning be: because formula 10 is that hypothesis mud-rock flow only obtains on the basis of gravitate while moving on grid, this formula is not considered the frictional force between mud-rock flow and grid, so this formula has certain error, in order to eliminate error, according to result of the test, obtained the correction factor of formula 10, so, introduce λ ₂can make result more accurate, more can meet engineering design requirement.

Compared with prior art, the invention has the beneficial effects as follows: provide the method for designing of fish ridge mudstone flowing water stone piece-rate system, for selecting this debris flow structure that the concrete technical scheme in conjunction with engineering specifications complete design is provided in Practical Project.

List of references 1: Lin Xueping. debris flow dam overfall conveyance capacity experimental study [D]. Chengdu: Chinese Academy of Sciences's Chengdu mountain region disaster and Environmental Research Institute, 2013

Accompanying drawing explanation

Fig. 1 is the separated grid span of water stone B, height H ₁, H ₂design diagram.

Fig. 2 is the separated grid length L of water stone design diagram.

Figure notation in accompanying drawing is respectively:

21 spine 22 girt strip 23 support piers

The specific embodiment

Below in conjunction with accompanying drawing, the preferred embodiments of the present invention are further described.

Embodiment mono-

As Fig. 1, by the preferred process of the present invention, be a fish ridge mudstone flowing water stone piece-rate system of certain debris flow gully design.

1, the separated grid span of water stone B design

Step S1, parameter are determined

According to mud-rock flow engineering investigation and design specifications, test, determine each basic parameter, comprising: the natural angle of respose of raceway groove bottom width B '=40m, mud-rock flow solid particle

water stone piece-rate system design discharge Q _c=500m ³/ s, grid span correction factor λ ₁=1.6(determines according to mud-rock flow design discharge size), drainage dam draining hole width b=10m, flow coefficient C=0.6.By Q _c=500m ³in/s, C=0.6, b=10m substitution list of references 1, the dark h calculating formula of overflow, obtains

$h={\left(\frac{3Q}{2C\sqrt{2g}b}\right)}^{\frac{2}{3}}={\left(\frac{3\×500}{2\×0.6\×\sqrt{2\×10}\×10}\right)}^{\frac{2}{3}}=9.2m.$

Step S2, separated grid (2) the span B of water stone determine

By λ ₁=1.6, h=9.2m, θ=38 °, b=10m substitution formula 2, have B=λ ₁(hsin2 θ+b)=1.63 * (9.2 * sin (38 * 2) °+10)=30.85m.

2, the separated grid spine of water stone and the design of junction, drainage dam height H

Field investigation and experimental test, determine that particle diameter is greater than the solid particle segregation ratio p of design particle separation diameter ₁=0.9, particle diameter is less than the solid particle segregation ratio p of design particle separation diameter ₂=0.3, in mud-rock flow, particle diameter is less than the solid particle ratio p that designs particle separation diameter _d=0.8, mud-rock flow solid matter volumetric concentration c before the separation of water stone _v=0.6, the flow velocity v=10m/s of mud-rock flow in dredging flow groove.

By p ₁=0.9, p ₂=0.3, p _d=0.8 substitution formula 7 has p=(1-0.8) * 0.9+0.8 * 0.3=0.42.

By B=30.3m, θ=38 ° substitution formula 4, obtain H ₁=0.5Btan θ=0.5 * 30.3 * tan38 °=11.8m.

By c _v=0.6, p=0.42, Q _c=500m ³/ s substitution formula 6, has Q _c'=(1-0.6 * 0.42) 500=374m ³/ s.

By Q _c'=374m ³/ s, v=10m/s, B=30.3m substitution formula 5, have $H_2=\frac{Q_c^{\′}}{\mathrm{Bv}}=\frac{374}{30.3\×10}=1.2m.$

By H ₁=11.8m, H ₂=1.2m substitution formula 3, has H=11.8+1.2=13m.

3, the separated grid length L design of water stone

Field investigation and experimental test, determine that draining hole is designed to rectangle, mud-rock flow unit weight ρ before slope coefficient m=0, the separation of water stone _c=1800kg/m ³.

By ρ _c=1800kg/m ³substitution formula 16 has λ ₂=2.131-0.0005 * 1800=1.23.

By Q _c=500m ³/ s, b=10m, h=9.2m, B=30.3m, θ=38 °, m=0 substitution formula 15, have,

$L={\mathrm{\λ}}_2\·\frac{Q_c}{(b+\mathrm{mh})h}\·\sqrt{\frac{B}{g\sin \mathrm{\θ}\cos \mathrm{\θ}}}$

$=16.7m$ 。

Claims (7)

1. fish ridge mudstone flowing water stone piece-rate system method for designing, is characterized in that: the separated grid span of design water stone B, implements according to following steps:

Step S1: parameter is determined

Field investigation, determines basic parameter according to mud-rock flow engineering investigation and design specifications, comprising: the natural angle of respose of solid particle in mud-rock flow

fish ridge mudstone flowing water stone piece-rate system build width B at the bottom of the raceway groove of position ', drainage dam draining hole width b, the overflow degree of depth h while determining that according to prior art mud-rock flow is flowed through draining hole;

Step S2, the separated grid span of water stone B determine

The separated grid span of water stone B is according to formula 1 calculative determination:

B=hsin2 θ+b formula 1

In formula, the separated grid span of B-water stone, m,

Overflow degree of depth when h-mud-rock flow is flowed through draining hole, m, step S1 is definite,

θ-girt strip upper and lower two ends connecting line and mud-rock flow raceway groove base plane angle, ° equal the natural angle of respose of solid particle in mud-rock flow

B-drainage dam draining hole width, m, step S1 determines.

2. method according to claim 1, is characterized in that: the separated grid span of water stone B is according to formula 2 calculative determinations:

B=λ ₁(hsin2 θ+b) formula 2

In formula, λ ₁-grid span correction factor value 1.48～1.61.

3. method according to claim 2, is characterized in that: λ ₁value is determined through result of the test.

4. a fish ridge mudstone flowing water stone piece-rate system method for designing of utilizing the method described in claim 1 or 2 or 3 to realize, is characterized in that: the separated height of grid H of design water stone, complete on the separated grid span B of water stone basis,

Through experimental test, determine basic parameter, comprising: the solid particle that in mud-rock flow, particle diameter is greater than design particle separation diameter is separated to the ratio p that stops long-pending ₁, particle diameter is less than design particle separation diameter in mud-rock flow solid particle is separated to the ratio p that stops long-pending ₂, particle diameter is less than the solid particle ratio p of design particle separation diameter in mud-rock flow _d,

According to mud-rock flow engineering investigation and design specifications, determine basic parameter, comprising: mud-rock flow solid matter volumetric concentration c before the separation of water stone _v, mud-rock flow design discharge Q _c, the flow velocity v of mud-rock flow in dredging flow groove;

The separated height of grid H of water stone simultaneous formula 3, formula 4, formula 5 calculative determinations:

H=H ₁+ H ₂formula 3

H ₁=0.5Btan θ formula 4

$H_2=\frac{Q_c^{\′}}{\mathrm{Bv}}$ Formula 5

In formula, the separated height of grid of H-water stone, m,

H ₁on-girt strip, top is to the vertical height of plane on support pier, m,

The separated grid span of B-water stone, m, according to formula 1 or formula 2 calculative determinations

θ-girt strip gradient, ° equals the mud-rock flow solid particle natural angle of respose

H ₂-support pier height, m,

The flow velocity of v-mud-rock flow in dredging flow groove, m/s,

Q _cthe letdown flow of '-dredging flow groove, m ³/ s, according to formula 6 calculative determinations,

Q _c'=(1-pc _v) Q _cformula 6

In formula, c _vmud-rock flow solid matter volumetric concentration before the separation of-water stone

Q _c-mud-rock flow design discharge, m ³/ s,

P-mud-rock flow solid matter is split into the ratio of stopping long-pending, by formula 7 calculative determinations,

P=(1-p _d) p ₁+ p _dp ₂formula 7

In formula, p _din-mud-rock flow, particle diameter is less than the solid particle ratio of design particle separation diameter,

P ₁the solid particle that in-mud-rock flow, particle diameter is greater than design particle separation diameter is separated to the ratio of stopping long-pending, and span is 0.85～1.00

P ₂the solid particle that in-mud-rock flow, particle diameter is less than design particle separation diameter is separated to the ratio of stopping long-pending, and span is 0.25～0.35.

5. method according to claim 4, is characterized in that: described p ₁, p ₂value is determined by result of the test.

6. a fish ridge mudstone flowing water stone piece-rate system method for designing of utilizing the method described in claim 1 or 2 or 3 to realize, is characterized in that: the separated grid length L of design water stone, complete on the separated grid span B of water stone basis,

According to mud-rock flow engineering investigation and design specifications, determine basic parameter, comprising: draining hole slope coefficient m;

The separated grid length L of water stone is according to formula 10 calculative determinations:

$L=\frac{Q_c}{(b+\mathrm{mh})h}\·\sqrt{\frac{B}{g\sin \mathrm{\θ}\cos \mathrm{\θ}}}$ Formula 10

In formula, the separated grid length of L-water stone, m,

Q _c-mud-rock flow design discharge, m ³/ s, according to design parameter determination,

B-drainage dam draining hole width, m, step S1 is definite,

M-draining hole slope coefficient,

The separated grid span of B-water stone, m,

G-acceleration of gravity, gets constant,

θ-girt strip gradient, °, equal the mud-rock flow solid particle natural angle of respose

7. method according to claim 6, is characterized in that:

According to mud-rock flow engineering investigation and design specifications, determine basic parameter, comprising: mud-rock flow unit weight ρ before the separation of water stone _c;

The separated grid span L of water stone is according to formula 15 calculative determinations:

$L={\mathrm{\λ}}_2\·\frac{Q_c}{(b+\mathrm{mh})h}\·\sqrt{\frac{B}{g\sin \mathrm{\θ}\cos \mathrm{\θ}}}$ Formula 15

In formula, λ ₂-grid length correction coefficient, according to formula 16 calculative determinations;

λ ₂=2.131-0.0005 ρ _cformula 16

In formula, ρ _cmud-rock flow unit weight before the separation of-water stone, kg/m ³.

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