CN102680028B - Method for calculating water discharge amount and water discharge time during dynamic water fall process in submersible partially penetrating well or well group - Google Patents

Abstract

The invention discloses a method for calculating water discharge amount and water discharge time during a dynamic water fall process in a submersible partially penetrating well or a well group. From a basic theory and a basic rule of seepage of underground water, on the basis of an everyday water discharge amount calculation formula under the condition of retaining a stable water level during the water fall process in the pressure-bearing partially penetrating well and the well group, the specific method for calculating the water discharge amount and the water discharge time in a process that the underground water level in the pressure-bearing partially penetrating well or the well group is changed from an initial water level to a target water level is implemented. By using the method, the situation that the calculation of the water discharge amount depends on experience for a long time in a water level change stage during the design of the pressure-bearing partially penetrating well or the well group at the present is changed; and the calculation and the dynamic control for the water discharge amount in the full water fall process of the pressure-bearing partially penetrating well or the well group in engineering construction are realized.

Description

The computing method of water discharge and water discharge time in a kind of dive under water partially penetrating well or the dynamic Precipitation Process of gang of wells

Technical field

The present invention relates to a kind of computing method that are applicable to engineering construction dewatering and drainage amount, be specifically related to the computing method of water discharge and water discharge time in a kind of dive under water partially penetrating well or the dynamic Precipitation Process of gang of wells.

Background technology

The object of base pit dewatering is underground water table to be reduced to below a certain depth requirements, can meet foundation pit structure and apply under the condition of anhydrous interference, thereby reduce difficulty of construction, and guarantee to the full extent the safety of excavation of foundation pit and structure construction.

At present both at home and abroad the water discharge of every day has carried out a large amount of research when maintaining a certain fixed level in Precipitation Process.Theoretical side, for stable in confined aquifer, unsteady state flow through porous medium motion, has proposed the corresponding flow theory of underground water, has derived corresponding water discharge computing formula.For disturbing gang of wells base pit dewatering problem, also there is researcher to work out relative program, to foundation ditch and underground water table real-time estimate around.Whether numerical computation method is also widely used in engineering dewatering calculates, considering to have inside and outside various boundary, hole on the basis of hydraulic connection etc., can study the decline process in time of artesian groundwater water level in precipitation.Some scholars consider that the pumping test data of take in precipitation test is basis, the perviousness of underground water under different condition in research ground; Study the underground water table, aquifer yield, coverage of individual well well point and single well point under the different well points degree of depth, different external interference effect and along with the variation relation of time, so that the conventional typical calculation formula of well-points dewatering is supplemented and to be improved.But for engineering construction pressure-bearing partially penetrating well or the decline of gang of wells Precipitation Process middle water level or quantity of precipitation and the required time of precipitation of the every day in stage of ging up, also there is no at present relevant computing method both at home and abroad, in application, on many bases of taking out in examination according to field technician's experience, constantly adjust at the scene, final definite concrete water discharge, all can produce certain impact to aspects such as the duration of engineering, costs.

On the whole, engineering construction pressure-bearing partially penetrating well or gang of wells Precipitation Process middle water level decline or the quantity of precipitation of ging up every day in stage more than depend on engineering technical personnel's experience, cannot meet the requirement of engineering construction precipitation.

Therefore the computing method of, developing water discharge and water discharge time in a kind of novel pressure-bearing partially penetrating well or the dynamic Precipitation Process of gang of wells are for being badly in need of.

Summary of the invention

General technical problem to be solved by this invention is to overcome that existing pressure-bearing partially penetrating well or gang of wells precipitation dynamic process middle water level decline or the calculating of the stage water discharge that gos up depends on the present situation of experience for a long time, provides a kind of pressure-bearing partially penetrating well or gang of wells precipitation dynamic process middle water level to decline or the computing method of go up stage water discharge and water discharge time.

In order to realize above-mentioned technical purpose, technical scheme of the present invention is, the computing method of water discharge and water discharge time in a kind of dive under water partially penetrating well or the dynamic Precipitation Process of gang of wells, for diving partially penetrating well, are calculated water level in dewatering well from S by following formula ₁decline or go up to S ₂the total displacement Q of required increase or minimizing in process:

$Q={\∫}_{S_2}^{S_1}\mathrm{\πKS}[\frac{l+S}{\ln \frac{R}{r_w}}+\frac{2H}{\frac{H}{2l}(2\ln \frac{4H}{r_w}-2.3A)-\ln \frac{4H}{R}}]\mathrm{dS}$

Wherein K is AQUIFER HYDRAULIC, and H is table water aquifer thickness, and S is design water level drawdown, and l is filtrator water inlet portion length, and R is Rainfall Influence radius, r _wfor dewatering well radius, A is coefficient, can obtain by pertinent literature, as the design and construction of < < engineering dewatering and high the writing of the theoretical > > Wu Lin of Seepage of Foundation Pit, People's Transportation Press;

For the incomplete gang of wells of diving, by following formula, calculate water level in dewatering well from S ₁decline or go up to S ₂the total displacement Q of required increase or minimizing in process:

$Q={\&Integral;}_{S_2}^{S_1}\frac{1.366K(2H-S)S)}{\lg [(R+r_0)/r_0]+(H-S-L)/L\&times;\lg (1+0.2(H-S)/r_0)}\mathrm{dS}$

Wherein K is AQUIFER HYDRAULIC, and H is table water aquifer thickness, and S is design water level drawdown, and R is Rainfall Influence radius, r ₀for foundation ditch conversion radius, L is foundation ditch length.

The computing method of water discharge and water discharge time in described a kind of dive under water partially penetrating well or the dynamic Precipitation Process of gang of wells, described AQUIFER HYDRAULIC K, if water-bearing zone is multilayer and vicinity, the desirable weighted mean value of K, computing method are K=∑ (K _ih _i)/∑ h _i, K wherein _ifor the infiltration coefficient in each water-bearing zone, h _ithickness for each water-bearing zone.

The computing method of water discharge and water discharge time in described a kind of dive under water partially penetrating well or the dynamic Precipitation Process of gang of wells, the computing method of described table water aquifer thickness H are: H=∑ h _i, h wherein _ithickness for each water-bearing zone.

The computing method of water discharge and water discharge time in described a kind of dive under water partially penetrating well or the dynamic Precipitation Process of gang of wells, it is characterized in that, described Rainfall Influence radius R can obtain by steady flow water pumping experiment, when not having condition to carry out steady flow water pumping experiment, and also can be by formula calculate.

In described a kind of dive under water partially penetrating well or the dynamic Precipitation Process of gang of wells, the computing method of water discharge and water discharge time, is characterized in that described foundation ditch conversion radius r ₀computing method be: when foundation ditch is carried out to precipitation, if the position of periphery dewatering well also design, by foundation ditch area, calculate, wherein F is foundation ditch area; If foundation ditch periphery dewatering well is arranged, preferentially by the position of well, calculate, wherein n is well point quantity.

The computing method of water discharge and water discharge time in described a kind of dive under water partially penetrating well or the dynamic Precipitation Process of gang of wells, according to the water level in tried to achieve dewatering well from S ₁decline or go up to S ₂the total displacement Q of required increase or minimizing in process, total displacement Q is dispensed to the every day of carrying out in water level decline or rise stages period, the method that the water discharge of pressure-bearing partially penetrating well or gang of wells every day superposes then and while maintaining fixed level is calculated the water discharge Q of every day in precipitation dynamic process _m1, required Q _m1computing formula be:

$Q_{m1}=Q_{S2}+\frac{Q}{m}$

Wherein Q is that the interior water level of well is by S ₁decline or go up to S ₂the total displacement of required increase or minimizing, m is total number of days of water level decline or rise stages period, for maintaining, stablize drawdown S ₂time needed draining every day

Amount, when being individual well: $Q_{S_2}=\mathrm{\&pi;KS}[\frac{l+S}{\ln \frac{R}{r_w}}+\frac{2H}{\frac{H}{2l}(2\ln \frac{4H}{r_w}-2.3A)-\ln \frac{4H}{R}}];$

When being gang of wells: $Q_{S_2}=\frac{1.366K(2H-S)S)}{\lg [(R+r_0)/r_0]+(H-S-L)/L\&times;\lg (1+0.2(H-S)/r_0)}.$

The computing method of water discharge and water discharge time in described a kind of dive under water partially penetrating well or the dynamic Precipitation Process of gang of wells, according to the water level in tried to achieve dewatering well from S ₁decline or go up to S ₂the total displacement Q of required increase or minimizing in process, by dewatering well arrangement pitch and location positioning and make the dewatering well drainability Q of every day _nin definite situation, by calculating drainability Q _nwater discharge while maintaining fixed level with every day difference and determine with the method for the ratio of total displacement Q the total number of days m that is down to the needed cycle of target water level, the computing formula of required m is:

$m=\frac{Q}{Q_n-Q_{S_2}}$

Q wherein _nfor the dewatering well drainability of every day, Q is that the interior water level of well is by S ₁decline or go up to S ₂the total displacement of required increase or minimizing, for maintaining, stablize drawdown S ₂time every day needed water discharge, when being

During individual well: $Q_{S_2}=\mathrm{\&pi;KS}[\frac{l+S}{\ln \frac{R}{r_w}}+\frac{2H}{\frac{H}{2l}(2\ln \frac{4H}{r_w}-2.3A)-\ln \frac{4H}{R}}];$

When being gang of wells: $Q_{S_2}=\frac{1.366K(2H-S)S)}{\lg [(R+r_0)/r_0]+(H-S-L)/L\&times;\lg (1+0.2(H-S)/r_0)}.$

The computing method of water discharge and water discharge time in described a kind of dive under water partially penetrating well or the dynamic Precipitation Process of gang of wells, for two, A precipitation region in engineering construction and B precipitation region independently the water level in precipitation region from S ₁decline or go up to S ₂the total displacement Q of required increase or minimizing in process _aand Q _bby following formula, calculate respectively:

$Q_A={\&Integral;}_{S_1}^{S_2}{Q}_A\left(S\right)\&CenterDot;\mathrm{dS}$

$Q_B={\&Integral;}_{S_1}^{S_2}{Q}_B\left(S\right)\&CenterDot;\mathrm{dS}$

At A precipitation zone maintenance fixed level S ₂condition under, the water level in B precipitation region declines or gos up to S ₂the water discharge Q of required increase _b-Acan be expressed as:

Q _B-A＝Q _B-Q _A。

The computing method of water discharge and water discharge time in described a kind of dive under water partially penetrating well or the dynamic Precipitation Process of gang of wells, according to tried to achieve at A precipitation zone maintenance fixed level S ₂condition under, the water level in B precipitation region declines or gos up to S ₂the water discharge Q of required increase _b-A, by water discharge Q _b-Abe dispensed to and carry out the water level decline in B precipitation region or the every day in rise stages period, must maintain in a-quadrant fixed level S thus ₂condition under, B region is at m _bin it, be down to S ₂the water discharge Q of every day during water level _bmfor:

$Q_{\mathrm{Bm}}=Q_{{\mathrm{BS}}_2}+\frac{Q_{B-A}}{m}$

Wherein for maintaining, region B stablizes drawdown S ₂time every day needed water discharge,

$Q_{{\mathrm{BS}}_2}=\frac{1.366K(2H-S)S)}{\lg [(R+r_{B0})/r_{B0}]+(H-S-L_B)/L_B\&times;\lg (1+0.2(H-S)/r_{B0})},$ R in formula _b0for the conversion radius of region B foundation ditch, L _bfor the length of the foundation ditch of region B, all the other symbolic significances are the same.

The computing method of water discharge and water discharge time in described a kind of dive under water partially penetrating well or the dynamic Precipitation Process of gang of wells, it is characterized in that, the unit of AQUIFER HYDRAULIC K is rice every day, the unit of confined aquifer thickness H is rice, the unit of design water level drawdown S is rice, the unit of Rainfall Influence radius R is rice, dewatering well radius r _wunit be rice, the unit of filtrator water inlet portion length l be meter, foundation ditch conversion radius r ₀unit be rice, the unit of foundation ditch length L be meter, the coefficient of permeability K in each water-bearing zone _iunit be rice an every day, the thickness h in each water-bearing zone _iunit be rice, the unit of foundation ditch area F be square metre that the interior water level of well is by S ₁decline or go up to S ₂the unit of the total displacement Q of required increase or minimizing is cubic meter, maintains and stablizes drawdown S ₂time every day needed water discharge unit be cubic meter, the drainability Q of dewatering well every day _nunit be cubic meter, maintain and stablize drawdown S ₂time every day needed water discharge unit be cubic meter, the water discharge Q of every day in precipitation dynamic process _m1unit be cubic meter, A precipitation region water discharge Q _aunit be cubic meter, B precipitation region water discharge Q _bunit be cubic meter, the water level in B precipitation region declines or gos up to S ₂the water discharge Q of required increase _b-Aunit be cubic meter, the water discharge Q of B region every day _bmunit be cubic meter, region B maintains and stablizes drawdown S ₂time every day needed water discharge unit be cubic meter, region B maintains and stablizes drawdown S ₂time every day needed water discharge unit be cubic meter, the conversion radius r of region B foundation ditch _b0unit be rice, the length L of the foundation ditch of region B _br _b0unit be rice.

Technique effect of the present invention is, traditional foundation ditch diving partially penetrating well or gang of wells precipitation computing method can only obtain maintaining a certain fixed level needed water discharge every day, and to water level decline and rise change procedure in every day water discharge and be down to the needed time of target water level and lack research.The present invention can calculate the stability maintenance water yield of each water level in diving partially penetrating well or gang of wells Precipitation Process and the increasing water discharge in Precipitation Process in good time, grasp accordingly the multidate information of precipitation, and be down to the needed time of target water level by determining that the well number of participation work and the layout of dewatering well are determined, and then reach dive under water partially penetrating well or gang of wells precipitation overall process are dynamically controlled.

Below in conjunction with accompanying drawing, the invention will be further described.

Accompanying drawing explanation

Fig. 1 is single sinking funnel curve synoptic diagram of the present invention

Fig. 2 is planar range precipitation area extension schematic diagram of the present invention

In figure: 1---pumped well; 2---initial water level oozes and falls funnel curve; 3---target water level is oozed and is fallen funnel curve; 4---foundation ditch; 5---water-resisting layer; 6---precipitation region; 7---S ₂the drawdown place radius of influence; 8---S ₁the drawdown place radius of influence; 9---drawdown S ₁; 10---drawdown S ₂; 11---water table aquifer thickness; 12---infinitesimal d S; A---precipitation region A; B---the precipitation region B after expansion.

Embodiment

(1) computing method of water discharge and water discharge time in individual well water level decline process

First get individual well analysis, Fig. 1 is single sinking funnel curve synoptic diagram of the present invention, and as shown in Figure 1, the periphery at well after precipitation forms precipitation funnel curve, because the surrounding of dewatering well constantly has the recharge of ground water to arrive in this precipitation region, for guaranteeing that in well, water level maintains a certain fixed level S ₁, need to maintain stable water discharge Q (S every day ₁), precipitation funnel curve is now X ₁, when further the water level in well being down to S ₂time, form precipitation funnel curve X ₂, now need every day at original stable water discharge Q (S ₁) basis on add the water discharge in well, also increase precipitation funnel curve X ₁and X ₂between water discharge.

As shown in Figure 1, get small drawdown dS and analyze, when precipitation depth dS is tending towards infinitely small, can think precipitation funnel X ₁on vertical hopper direction of a curve, evenly expanded dS, precipitation funnel curve X ₁and X ₂between water discharge can approximate representation be:

dQ(S)＝Q(S ₁)·dS (a)

Thus, the water level in dewatering well is from S ₁be down to S ₂the water discharge of required increase can be expressed as:

$Q={\&Integral;}_{S_1}^{S_2}Q\left(S\right)\&CenterDot;\mathrm{dS}---\left(b\right)$

In formula: Q (S) is interior for maintaining a certain fixed level needed water discharge every day for dewatering well, and it is the function of precipitation depth S in well, changes along with the variation of precipitation depth.Existing a large amount of document is studied this both at home and abroad at present, and the expression formula that diving partially penetrating well water discharge calculates can directly be applied.

For diving partially penetrating well, the water level in dewatering well is from S ₁be down to S ₂the water discharge expression formula of required increase is:

$Q={\&Integral;}_{S_2}^{S_1}\mathrm{\&pi;KS}[\frac{l+S}{\ln \frac{R}{r_w}}+\frac{2H}{\frac{H}{2l}(2\ln \frac{4H}{r_w}-2.3A)-\ln \frac{4H}{R}}]\mathrm{dS}---\left(c\right)$

Wherein K is AQUIFER HYDRAULIC, and unit is a rice every day, if water-bearing zone is multilayer and vicinity, and the desirable weighted mean value of K, computing method are K=∑ (K _ih _i)/∑ h _i, K wherein _ifor the infiltration coefficient in each water-bearing zone, unit is rice every day, h _ifor the thickness in each water-bearing zone, unit is rice, and H is table water aquifer thickness, and unit is rice, and computing method are: H=∑ h _i, h wherein _ithickness for each water-bearing zone, unit is rice, S is design water level drawdown, unit is rice, l is filtrator water inlet portion length, unit is rice, R is Rainfall Influence radius, unit is rice, can obtain by steady flow water pumping experiment, steady flow water pumping experiment is application steady flow theoretical analysis Pumping Test Data, draw at any time the curves such as flow-drawdown, and obtain accordingly the radius of influence in water-bearing zone, in test, flow must be reached and drawdown is relatively stable, and determine and need continuity necessarily not for a long time according to water-bearing zone lithology, just can stop, when not having condition to carry out steady flow water pumping experiment, also can be by formula calculate r _wfor dewatering well radius, A is coefficient, can obtain by pertinent literature, as the design and construction of < < engineering dewatering and high the writing of the theoretical > > Wu Lin of Seepage of Foundation Pit, People's Transportation Press.

While calculating with above formula, can directly carry out Integration Solving, if direct integral calculates while being difficult to solve, can adopt the method for numerical integration to calculate.

The water discharge that more than calculate to be take to maintain every day fixed level in well is basis, calculate should be water level in dewatering well in one day from S ₁be down to S ₂needed water discharge, for Practical Project, can not within one day, just water level can be down to desired value, generally need within a period of time, complete, now just need to maintain on the basis of quantity of precipitation of fixed level in every day, the water discharge of increase is dispensed to every day, supposes in m days in well that water level is by S ₁be down to S ₂, in water level decline process, the water discharge of every day can calculate with following formula.

$Q_{m1}=Q_{S2}+\frac{Q}{m}---\left(d\right)$

In formula: Q _m1for the water discharge of every day water level decline stage, unit is cubic meter,

for maintaining, stablize drawdown S ₂time every day needed water discharge, unit be cubic meter, when being individual well:

$Q_{S_2}=\mathrm{\&pi;KS}[\frac{l+S}{\ln \frac{R}{r_w}}+\frac{2H}{\frac{H}{2l}(2\ln \frac{4H}{r_w}-2.3A)-\ln \frac{4H}{R}}];$

When being gang of wells: $Q_{S_2}=\frac{1.366K(2H-S)S)}{\lg [(R+r_0)/r_0]+(H-S-L)/L\&times;\lg (1+0.2(H-S)/r_0)}.$ Q is that the interior water level of well is by S ₁be down to S ₂the total displacement of required increase or minimizing, unit is cubic meter, m is precipitation number of days.

Under the definite condition of the drainability of dewatering well every day, underground water table declines or gos up to the required time of desired value and can calculate with following formula.

$m=\frac{Q}{Q_n-Q_{S_2}}---\left(e\right)$

In formula: Q _nfor the dewatering well drainability of every day, unit is cubic meter, for maintaining, stablize drawdown S ₂time every day needed water discharge, unit be cubic meter, when being individual well:

$Q_{S_2}=\mathrm{\&pi;KS}[\frac{l+S}{\ln \frac{R}{r_w}}+\frac{2H}{\frac{H}{2l}(2\ln \frac{4H}{r_w}-2.3A)-\ln \frac{4H}{R}}];$

When being gang of wells: $Q_{S_2}=\frac{1.366K(2H-S)S)}{\lg [(R+r_0)/r_0]+(H-S-L)/L\&times;\lg (1+0.2(H-S)/r_0)}.$ Q is that the interior water level of well is by S ₁decline or go up to S ₂the total displacement of required increase or minimizing, unit is cubic meter, m is precipitation number of days.

(2) computing method of water discharge and water discharge time in the outer gang of wells water level decline process in hole

Water discharge for Metro station excavation gang of wells in water level decline process, can calculate by the identical method of individual well water discharge, and it is as follows that the quantity of precipitation of partially penetrating well gang of wells in water level decline process of diving under water is thus expressed formula.

Water level in diving partially penetrating well is from S ₁be down to S ₂the water discharge expression formula of required increase is:

$Q={\&Integral;}_{S_2}^{S_1}\frac{1.366K(2H-S)S)}{\lg [(R+r_0)/r_0+(H-S-L)/L\&times;\lg (1+0.2(H-S)/r_0)}\mathrm{dS}---\left(f\right)$

Wherein K is AQUIFER HYDRAULIC, and unit is rice every day, and H is table water aquifer thickness, and unit is rice every day, and S is design water level drawdown, and unit is rice every day, and R is Rainfall Influence radius, and unit is rice every day, r ₀for foundation ditch conversion radius, unit is rice, and computing method are: when foundation ditch is carried out to precipitation, if the position of periphery dewatering well is not also designed, by foundation ditch area, calculate, wherein F is foundation ditch area, and unit is square metre; If foundation ditch periphery dewatering well is arranged, preferentially by the position of well, calculate, wherein n is well point quantity.L is foundation ditch length, and unit is rice.

In like manner, more than calculate be also water level in precipitation foundation ditch in one day from S ₁be down to S ₂needed water discharge for Practical Project, need to be down to desired value by water level equally within a period of time, in m days the water level in foundation ditch by S ₁be down to S ₂time, in water level decline process, the same available formula of the water discharge of every day (d) is calculated.

In Practical Project, if determined precipitation time, can determine according to the water discharge of the every day calculating quantity and the concrete arrangement requirement of dewatering well, if determined quantity and the arrangement of dewatering well, can according to (e) formula, calculate underground water table is down to the needed time of desired value according to the water discharge calculating, carry out accordingly the design of engineering construction tissue.

(3) computing method of water discharge and water discharge time in the outer gang of wells rising of groundwater level process in hole

The rise of underground water table is the inverse process of precipitation, and the water yield alimentation facies outside precipitation funnel is same, thus,

Water level is by S ₂go back up to S ₁the water discharge of required minimizing can be expressed as:

$Q_j={\&Integral;}_{S_2}^{S_1}Q\left(S\right)\&CenterDot;\mathrm{dS}---\left(g\right)$

In formula: Q (S) meaning is the same, for maintaining a certain fixed level needed water discharge every day.

In like manner, above calculating is also to take the water discharge that maintains fixed level in well every day to be basis, calculate be water level in dewatering well in one day by S ₂go back up to S ₁the water discharge of required minimizing, for Practical Project, also can not one day within by rising of groundwater level desired value, now just need to maintain on the basis of quantity of precipitation of fixed level in every day, the water discharge of minimizing is dispensed to every day, supposes in m days in well that water level is by S ₂go back up to S ₁, in rising of groundwater level process, the water discharge of every day can calculate with following formula.

$Q_{m2}=Q_{S1}+\frac{Q_j}{m}---\left(h\right)$

In formula: Q _m2for the water discharge of every day in rising of groundwater level stage, unit is cubic meter, for maintaining, stablize drawdown S ₁time every day needed water discharge, unit be cubic meter, Q _jfor water level in well is by S ₂go up to S ₁the total displacement of required minimizing, unit is cubic meter, m is precipitation number of days.

The in the situation that of dewatering well arrangement pitch and location positioning, drainability every day of dewatering well is determined also just definite, and corresponding precipitation time calculates according to (e) formula equally.

(4) computing method of water discharge and water discharge time during plane precipitation regional change

In engineering construction, excavate that branch's piecemeal normally carries out, so in engineering construction, propose to need subregion to carry out precipitation.Fig. 2 is that plane precipitation of the present invention region expands schematic diagram, as shown in Figure 2, first carries out a-quadrant construction, in this region by underground water table by S ₁be down to a certain target water level S ₂, after having constructed in a-quadrant, and then construction area is extended to B, and this region water level is also by S ₁be down to same target water level S ₂, in a-quadrant, maintain fixed level S ₂condition under, B is down to S in region ₂the water discharge of required increase can calculate by the following method.

When A precipitation region and B precipitation region are two independently during precipitation region, it is by water level S ₁be down to a certain target water level S ₂the water discharge Q of Shi Zengjia _aand Q _bbe respectively:

$Q_A={\&Integral;}_{S_1}^{S_2}{Q}_A\left(S\right)\&CenterDot;\mathrm{dS}---\left(i\right)$

$Q_B={\&Integral;}_{S_1}^{S_2}{Q}_B\left(S\right)\&CenterDot;\mathrm{dS}---\left(j\right)$

In a-quadrant, maintain fixed level S ₂condition under, B is down to S in region ₂the water discharge Q of required increase _b-Acan be expressed as:

Q _B-A＝Q _B-Q _A (k)

More than calculate be also water level in the B of region in one day by S ₁drop to S ₂the water discharge of required increase, also needs the water discharge of increase to distribute within the time period of precipitation, must maintain in a-quadrant fixed level S thus ₂condition under, B region is at m _bin it, be down to S ₂during water level, the water discharge of every day is:

$Q_{\mathrm{Bm}}=Q_{{\mathrm{BS}}_2}+\frac{Q_{B-A}}{m_B}---\left(m\right)$

In formula: Q _bmfor the region B water level water discharge of every day decline stage, unit is cubic meter, for maintaining, region B stablizes drawdown S ₂time every day needed water discharge, unit be cubic meter, $Q_{{\mathrm{BS}}_2}=\frac{0.366K(2H-S)S)}{\lg [(R+r_{B0})/r_{B0}]+(H-S-L_B)/L_B\&times;\lg (1+0.2(H-S)/r_{B0})},$ Q _b-Afor a-quadrant maintains fixed level S ₂condition under, B is down to S in region ₂the water discharge of required increase, unit is cubic meter, m _bfor being down to target water level S in B region ₂time precipitation number of days.

The in the situation that of dewatering well arrangement pitch and location positioning, the drainability of dewatering well every day also just determined, corresponding precipitation time calculates according to (e) formula equally.

Claims (8)

1. the dive under water computing method of water discharge and water discharge time in the dynamic Precipitation Process of partially penetrating well or gang of wells, is characterized in that, for diving partially penetrating well, by following formula, calculate water level in dewatering well from S ₁decline or go up to S ₂the total displacement Q of required increase or minimizing in process:

Wherein K is AQUIFER HYDRAULIC, and H is table water aquifer thickness, and S is design water level drawdown, and l is filtrator water inlet portion length, and R is Rainfall Influence radius, r _wfor dewatering well radius, A is coefficient;

For the incomplete gang of wells of diving, by following formula, calculate water level in dewatering well from S ₁decline or go up to S ₂the total displacement Q of required increase or minimizing in process:

Wherein K is AQUIFER HYDRAULIC, and H is table water aquifer thickness, and S is design water level drawdown, and R is Rainfall Influence radius, r ₀for foundation ditch conversion radius, L is foundation ditch length;

According to the water level in tried to achieve dewatering well from S ₁decline or go up to S ₂the total displacement Q of required increase or minimizing in process, by dewatering well arrangement pitch and location positioning and make the dewatering well drainability Q of every day _nin definite situation, by calculating drainability Q _nwater discharge while maintaining fixed level with every day difference and determine with the method for the ratio of total displacement Q the total number of days m that is down to the needed cycle of target water level, the computing formula of required m is:

Q wherein _nfor the dewatering well drainability of every day, Q is that the interior water level of well is by S ₁decline or go up to S ₂the total displacement of required increase or minimizing, for maintaining, stablize drawdown S ₂time every day needed water discharge, when being individual well:

When being gang of wells: .

2. computing method of water discharge and water discharge time in a kind of dive under water partially penetrating well or the dynamic Precipitation Process of gang of wells according to claim 1, it is characterized in that, described AQUIFER HYDRAULIC K, if water-bearing zone is multilayer and vicinity, the desirable weighted mean value of K, computing method are K=∑ (K _ih _i)/∑ h _i, K wherein _ifor the infiltration coefficient in each water-bearing zone, h _ithickness for each water-bearing zone.

3. the computing method of water discharge and water discharge time in a kind of dive under water partially penetrating well or the dynamic Precipitation Process of gang of wells according to claim 1, is characterized in that, the computing method of described table water aquifer thickness H are: H=∑ h _i, h wherein _ithickness for each water-bearing zone.

4. computing method of water discharge and water discharge time in a kind of dive under water partially penetrating well or the dynamic Precipitation Process of gang of wells according to claim 1, it is characterized in that, described Rainfall Influence radius R obtains by steady flow water pumping experiment, when not having condition to carry out steady flow water pumping experiment, by formula calculate.

5. the computing method of water discharge and water discharge time in a kind of dive under water partially penetrating well or the dynamic Precipitation Process of gang of wells according to claim 1, is characterized in that described foundation ditch conversion radius r ₀computing method be: when foundation ditch is carried out to precipitation, if the position of periphery dewatering well also design, by foundation ditch area, calculate, wherein F is foundation ditch area; If foundation ditch periphery dewatering well is arranged, preferentially by the position of well, calculate, wherein n is well point quantity.

6. the computing method of water discharge and water discharge time in a kind of dive under water partially penetrating well or the dynamic Precipitation Process of gang of wells according to claim 1, is characterized in that, according to the water level in tried to achieve dewatering well from S ₁decline or go up to S ₂the total displacement Q of required increase or minimizing in process, total displacement Q is dispensed to the every day of carrying out in water level decline or rise stages period, then and the method that superposes of the water discharge of diving under water while maintaining fixed level partially penetrating well or gang of wells every day calculate the water discharge Q of every day in precipitation dynamic process _m1, required Q _m1computing formula be:

Wherein Q is that the interior water level of well is by S ₁decline or go up to S ₂the total displacement of required increase or minimizing, m is total number of days in water level decline or the stage of ging up, for maintaining, stablize drawdown S ₂time every day needed water discharge, when being individual well:

When being gang of wells: .

7. the computing method of water discharge and water discharge time in a kind of dive under water partially penetrating well or the dynamic Precipitation Process of gang of wells according to claim 1, is characterized in that, for two, A precipitation region in engineering construction and B precipitation region independently the water level in precipitation region from S ₁decline or go up to S ₂the total displacement Q of required increase or minimizing in process _aand Q _bby following formula, calculate respectively:

At A precipitation zone maintenance fixed level S ₂condition under, the water level in B precipitation region declines or gos up to S ₂the water discharge Q of required increase or minimizing _b-Acan be expressed as:

Q _B-A＝Q _B-Q _A。

8. the computing method of water discharge and water discharge time in a kind of dive under water partially penetrating well or the dynamic Precipitation Process of gang of wells according to claim 7, is characterized in that, according to tried to achieve at A precipitation zone maintenance fixed level S ₂condition under, the water level in B precipitation region declines or gos up to S ₂the water discharge Q of required increase _b-A, by water discharge Q _b-Abe dispensed to and carry out the water level decline in B precipitation region or the every day in rise stages period, must maintain in a-quadrant fixed level S thus ₂condition under, B region is at m _bin it, be down to S ₂the water discharge Q of every day during water level _bmfor:

Wherein for maintaining, region B stablizes drawdown S ₂time every day needed water discharge, , r in formula _b0for the conversion radius of region B foundation ditch, L _blength for the foundation ditch of region B.