CN102778260B - Calculation method for water drainage and water drainage time in dynamic precipitation process of submersible fully penetrating well or well group - Google Patents

Abstract

The invention discloses a calculation method for water drainage and water drainage time in dynamic precipitation process of a submersible fully penetrating well or well group. According to the method, a specific calculation method for the water drainage and the water drainage time in a process of changing underground water level from an initial water level to a target water level (the water level drops or rises again) and a calculation method for the water drainage and the water drainage time under variable conditions of the water precipitation region by integrating a water precipitation region on the basis of a water drainage calculation formula when a stable water level is maintained in the water precipitation process of the submersible fully penetrating well or well group. According to the calculation method, the present situation that the calculation of the water drainage at a water level change stage during the design of the conventional submersible fully penetrating well or well group depends on experience for long time, and calculation and dynamic control of the water drainage in the overall water precipitation process of the submersible fully penetrating well or well group of engineering construction are realized.

Description

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

Technical field

The present invention relates to a kind of computing method being 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 complete penetration of 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, thus reduces difficulty of construction, and ensures the safety of excavation of foundation pit and structure construction to the full extent.

Domestic and international at present large quantifier elimination is carried out to the water discharge of every day when maintaining a certain fixed level in Precipitation Process.Theoretical side, for stable in confined aquifer, unsteady state flow through porous medium motion, proposes the corresponding flow theory of underground water, is deduced corresponding water discharge computing formula.For disturbed wells base pit dewatering problem, researcher is also had to work out relative program, to foundation ditch and surrounding underground water table real-time estimate.Whether numerical computation method is also widely used in engineering dewatering calculates, have on the basis of hydraulic connection etc., can study the decline process in time of artesian groundwater water level in precipitation inside and outside consideration various boundary, hole.Some scholars consider based on the pumping test data in well pumping test, underground water perviousness at different conditions in research ground; Study the underground water table of individual well well point and single well point under the different well points degree of depth, different external interference effect, aquifer yield, coverage and the variation relation along with the time thereof, carry out supplementing and improving to commonly use typical calculation formula to well-points dewatering.But quantity of precipitation engineering construction pressure-bearing partially penetrating well or wells group dewatering process middle water level declined or go up every day in stage and the time needed for precipitation, computing method also not relevant both at home and abroad at present, in application, many experiences according to field technician are being tried the basis of taking out constantly adjusts at the scene, finally determine concrete water discharge, all can produce certain impact to the aspect such as duration, cost of engineering.

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

Therefore, the computing method of 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 developed for being badly in need of.

Summary of the invention

General technical problem to be solved by this invention overcomes existing pressure-bearing partially penetrating well or wells group dewatering dynamic process middle water level to 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 wells group dewatering 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 complete penetration of well or the dynamic Precipitation Process of gang of wells, for diving complete penetration of well, by the water level in following formulae discovery dewatering well from S ₁decline or go up to S ₂the required total displacement Q increasing or reduce in process:

$Q={\∫}_{S_2}^{S_1}1.366K\frac{(2H-S)S}{\lg \frac{R}{r_w}}\mathrm{dS}$

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 _wfor dewatering well radius;

For the complete gang of wells of diving, by the water level in following formulae discovery dewatering well from S ₁decline or go up to S ₂the required total displacement Q increasing or reduce in process:

$Q={\∫}_{S_2}^{S_1}\frac{1.366K(2H-S)S}{\lg [(R+r_0)/r_0]}\mathrm{dS}$

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.

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

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

The computing method of water discharge and water discharge time in described a kind of dive under water complete penetration of well or the dynamic Precipitation Process of gang of wells, 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, also can by formula calculate.

The computing method of water discharge and water discharge time in described a kind of dive under water complete penetration of well or the dynamic Precipitation Process of gang of wells, described foundation ditch conversion radius r ₀computing method be: when precipitation is carried out to foundation ditch, if the position of periphery dewatering well is not also designed, then calculate by foundation ditch area, wherein F is foundation ditch area; If foundation ditch periphery dewatering well is arranged, then the preferential position by well calculates, wherein n is well point quantity.

The computing method of water discharge and water discharge time in described a kind of dive under water complete penetration of 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 required total displacement Q increasing or reduce in process, total displacement Q is dispensed to the every day of carrying out in water level decreasing or rise stages period, the method then carrying out superposing with pressure-bearing partially penetrating well or the water discharge of gang of wells every day when maintaining fixed level calculates 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 be in well water level by S ₁decline or go up to S ₂the required total displacement increased, m is total number of days of water level decreasing or rise stages period, for maintaining stable drawdown S ₂time water discharge required for every day, when for individual well: $Q_{S_2}=1.366K\frac{(2H-S)S}{\lg \frac{R}{r_2}};$

When for gang of wells: $Q_{S_2}=\frac{1.366K(2H-S)S}{\lg [(R+r_0)/r_0]}.$

The computing method of water discharge and water discharge time in described a kind of dive under water complete penetration of 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 required total displacement Q increasing or reduce in process, at the drainability Q of pressure-bearing partially penetrating well or gang of wells _nwhen determining, by calculating drainability Q _nwith water discharge when maintaining fixed level every day difference and determine total number of days m in the cycle required for target water level of being down to the method for the ratio of total displacement Q, the computing formula of required m is:

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

Wherein Q _nfor the drainability of dewatering well every day, Q be in well water level by S ₁decline or go up to S ₂the required total displacement increased, for maintaining stable drawdown S ₂time water discharge required for every day, when for individual well: $Q_{S_2}=1.366K\frac{(2H-S)S}{\lg \frac{R}{r_w}};$

When for gang of wells: $Q_{S_2}=\frac{1.366K(2H-S)S}{\lg [(R+r_0)/r_0]}.$

The computing method of water discharge and water discharge time in described a kind of dive under water complete penetration of well or the dynamic Precipitation Process of gang of wells, for the water level in A precipitation region in engineering construction and two, B precipitation region independently precipitation region from S ₁decline or go up to S ₂the required total displacement Q increasing or reduce in process _aand Q _brespectively by following formulae discovery:

$Q_A={\∫}_{S_1}^{S_2}{Q}_A\left(S\right)\·\mathrm{dS}$

$Q_B={\∫}_{S_1}^{S_2}{Q}_B\left(S\right)\·\mathrm{dS}$

Then at A precipitation zone maintenance fixed level S ₂condition under, the water level decreasing in B precipitation region or go up to S ₂the required water discharge Q increased _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 complete penetration of 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 decreasing in B precipitation region or go up to S ₂the required water discharge Q increased _b-A, by water discharge Q _b-Abe dispensed to carry out B precipitation region water level decreasing or rise stages period in every day, fixed level S must be maintained in a-quadrant thus ₂condition under, B region is at m _bs is down in it ₂the water discharge Q of every day during water level _bmfor:

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

Wherein drawdown S is stablized for region B maintains ₂time water discharge required for every day, R in formula _b0for the conversion radius of region B foundation ditch, 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 complete penetration of well or the dynamic Precipitation Process of gang of wells, 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, foundation ditch conversion radius r ₀unit be the coefficient of permeability K in rice, each water-bearing zone _iunit be rice every day, the thickness h in each water-bearing zone _iunit be rice, the unit of foundation ditch area F is square metre, and in well, water level is by S ₁decline or go up to S ₂the unit of the required total displacement Q increased is cubic meter, maintains and stablizes drawdown S ₂time water discharge required for every day unit be cubic meter, the drainability Q of dewatering well every day _nunit be cubic meter, maintain stablize drawdown S ₂time water discharge required for every day 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 decreasing in B precipitation region or go up to S ₂the required water discharge Q increased _b-Aunit be cubic meter, the water discharge Q of B region every day _bmunit be cubic meter, region B maintain stablize drawdown S ₂time water discharge required for every day unit be cubic meter, the conversion radius r of region B foundation ditch _b0unit is rice.

Technique effect of the present invention is, traditional foundation ditch diving complete penetration of well or wells group dewatering computing method can only obtain maintaining the water discharge required for a certain fixed level every day, and lack research to the water discharge of every day in water level decreasing and rise change procedure and the time of being down to required for target water level.The present invention can calculate the increasing water discharge in diving complete penetration of well or wells group dewatering process in the stability maintenance water yield of each water level and Precipitation Process in good time, grasp the multidate information of precipitation accordingly, and determined time of being down to required for target water level by the layout of the well number and dewatering well of determining participation work, and then reach Dynamic controlling is carried out to diving complete penetration of well or wells group dewatering overall process.

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 that plane precipitation region of the present invention expands schematic diagram

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 decreasing process

First individual well analysis is got, Fig. 1 is single sinking funnel curve synoptic diagram of the present invention, as shown in Figure 1, forms precipitation funnel curve after precipitation at the periphery of well, surrounding due to dewatering well constantly has the recharge of ground water to arrive in this precipitation region, for ensureing that in well, water level maintains a certain fixed level S ₁, need every day to maintain stable water discharge Q (S ₁), precipitation funnel curve is now X ₁, be down to S when needing the water level by well further ₂time, then form precipitation funnel curve X ₂, now need every day at original stable water discharge Q (S ₁) basis on increase water discharge in well, also namely 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, precipitation funnel X can be thought ₁vertical hopper direction of a curve evenly expands dS, then precipitation funnel curve X ₁and X ₂between water discharge can approximate representation be:

dQ(S)=Q(S ₁)·dS （1）

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

$Q={\∫}_{S_1}^{S_2}Q\left(S\right)\·\mathrm{dS}---\left(2\right)$

In formula: Q (S) in dewatering well for maintaining the water discharge required for a certain fixed level every day, it is the function of precipitation depth S in well, changes along with the change 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 complete penetration of well water discharge calculates can directly be applied.

For diving complete penetration of well, the water level in dewatering well is from S ₁be down to S ₂the required water discharge expression formula increased is:

$Q={\∫}_{S_2}^{S_1}1.366k\frac{(2H_0-S)S}{\lg \frac{R}{r_2}}\mathrm{dS}---\left(3\right)$

Wherein k is AQUIFER HYDRAULIC, and unit is rice every day, if water-bearing zone is multilayer and vicinity, then the desirable weighted mean value of K, computing method are K=∑ (K _ih _i)/∑ h _i, wherein K _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.H is table water aquifer thickness, and unit is rice, and the computing method of table water aquifer thickness H are: H=∑ h _i, wherein h _ifor the thickness in each water-bearing zone, unit is rice, S is design water level drawdown, unit is rice, R is Rainfall Influence radius, unit is rice, Rainfall Influence radius R can obtain by steady flow water pumping experiment, and steady flow water pumping experiment is application steady flow theoretical analysis Pumping Test Data, draws the curves such as flow-drawdown at any time, and obtain the radius of influence in water-bearing zone accordingly, must flow be reached in test and drawdown is relatively stable, and determine to continue a fixed length time according to water-bearing zone lithology, could stop, when not having condition to carry out steady flow water pumping experiment, also can by formula calculate, r _wfor dewatering well radius, unit is rice.

When calculating with above formula, directly can carry out Integration Solving, if when direct integral calculating is difficult to solve, the method for numerical integration can be adopted to calculate.

More than calculate and be based on the water discharge that every day maintains fixed level in well, calculate should be water level in dewatering well in one day from S ₁be down to S ₂required water discharge, for Practical Project, just water level can not can be down to desired value within one day, general needs complete within a period of time, now just need on the basis that every day maintains the quantity of precipitation of fixed level, the water discharge of increase is dispensed to every day, assuming that in m days in well water level by S ₁be down to S ₂, then in water level decreasing process, the water discharge of every day can calculate with following formula.

$Q_{m1}=Q_{S2}+\frac{Q}{m}---\left(4\right)$

In formula: Q _m1for the water discharge of every day in water level decreasing stage, unit is cubic meter, for maintaining stable drawdown S ₂time water discharge required for every day, unit is cubic meter, for maintaining stable drawdown S ₂time water discharge required for every day, for maintaining stable drawdown S ₂time water discharge required for every day, unit is cubic meter, when for individual well: $Q_{S_2}=1.366K\frac{(2H-S)S}{\lg \frac{R}{r_w}};$

When for gang of wells: q be in well water level by S ₁be down to S ₂the required total displacement increased, unit is cubic meter, and m is precipitation number of days.

Under the condition that the drainability of dewatering well is determined, then underground water table (or rise) to the time needed for desired value that declines can calculate with following formula.

$m=\frac{Q}{Q_n-Q_{S_2}}---\left(5\right)$

In formula: Q _nfor the drainability of dewatering well every day, unit is cubic meter, for maintaining stable drawdown S ₂time water discharge required for every day, for maintaining stable drawdown S ₂time water discharge required for every day, unit is cubic meter, when for individual well: $Q_{S_2}=1.366K\frac{(2H-S)S}{\lg \frac{R}{r_w}};$

When for gang of wells: q be in well water level by S ₁decline (or rise) to S ₂the required total displacement increased, unit is cubic meter, and m is precipitation number of days.

(2) computing method of water discharge and water discharge time in outer gang of wells water level decreasing process are cheated

For the water discharge of Metro station excavation gang of wells in water level decreasing process, can calculate by the method that individual well water discharge is identical, the quantity of precipitation expression formula of complete penetration of well gang of wells in water level decreasing process of diving under water thus is as follows.

Water level in diving complete penetration of well is from S ₁be down to S ₂the required water discharge expression formula increased is:

$Q={\∫}_{S_2}^{S_1}\frac{1.366K(2H-S)S}{\lg [(R+r_0)/r_0]}\mathrm{dS}---\left(6\right)$

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

In like manner, more than calculate be also water level in precipitation foundation ditch in one day from S ₁be down to S ₂required water discharge, for Practical Project, water level is down to desired value by same needs within a period of time, then the water level in m days in foundation ditch is by S ₁be down to S ₂time, in water level decreasing process, the same available formula (4) of the water discharge of every day calculates.

In Practical Project, if determine precipitation time, then can determine the quantity of dewatering well and concrete arrangement requirement according to the water discharge of the every day calculated, if determine quantity and the arrangement of dewatering well, then can calculate the time of underground water table to be down to required for desired value according to (5) formula according to the water discharge calculated, carry out engineering construction organization design accordingly.

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

The rise of underground water table is the inverse process of precipitation, and the water yield alimentation facies outside precipitation funnel is same, and thus, water level is by S ₂go back up to S ₁the required water discharge reduced then can be expressed as:

$Q_j={\∫}_{S_2}^{S_1}Q\left(S\right)\·\mathrm{dS}---\left(7\right)$

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

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

$Q_{m2}=Q_{S1}+\frac{Q_j}{m}---\left(8\right)$

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

When dewatering well arrangement pitch and position are determined, the drainability of dewatering well is determined also just to determine, and corresponding precipitation time calculates according to (5) formula equally.

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

In engineering construction, excavate that normally branch's piecemeal carries out, therefore propose in engineering construction to need subregion to carry out precipitation.Fig. 2 be plane precipitation region of the present invention expand schematic diagram, as shown in Figure 2, first carry 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, then fixed level S is maintained in a-quadrant ₂condition under, B is down to S in region ₂the required water discharge increased can calculate by the following method.

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

$Q_A={\∫}_{S_1}^{S_2}{Q}_A\left(S\right)\·\mathrm{dS}---\left(9\right)$

$Q_B={\∫}_{S_1}^{S_2}{Q}_B\left(S\right)\·\mathrm{dS}---\left(10\right)$

Then maintain fixed level S in a-quadrant ₂condition under, B is down to S in region ₂the required water discharge increased can be expressed as:

Q _B-A=Q _B-Q _A （11）

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

$Q_{\mathrm{Bm}}=Q_{{\mathrm{BS}}_2}+\frac{Q_{B-A}}{m_B}---\left(12\right)$

In formula: Q _bmfor the water discharge of region B water level decreasing every day in stage, unit is cubic meter, drawdown S is stablized for region B maintains ₂time water discharge required for every day, unit is cubic meter, Q _b-Afor a-quadrant maintains fixed level S ₂condition under, unit is cubic meter, and B is down to S in region ₂the required water discharge increased, unit is cubic meter, m _bfor target water level S is down in B region ₂time precipitation number of days.

When dewatering well arrangement pitch and position are determined, the drainability of dewatering well is determined also just to determine, and corresponding precipitation time calculates according to (5) formula equally.

Claims (9)

1. to dive under water the computing method of water discharge and water discharge time in complete penetration of well or the dynamic Precipitation Process of gang of wells, it is characterized in that, for diving complete penetration of well, by the water level in following formulae discovery dewatering well from S ₁decline or go up to S ₂the required total displacement Q increasing or reduce in process:

$Q={\∫}_{S_2}^{S_1}1.366k\frac{(2H-S)S}{1g\frac{R}{r_w}}\mathrm{dS}$

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 _wfor dewatering well radius;

For the complete gang of wells of diving, by the water level in following formulae discovery dewatering well from S ₁decline or go up to S ₂the required total displacement Q increasing or reduce in process:

$Q={\∫}_{S_2}^{S_1}\frac{1.366k(2H-S)S}{1g[(R+r_0)/r_0]}\mathrm{dS}$

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;

According to the water level in tried to achieve dewatering well from S ₁decline or go up to S ₂the required total displacement Q increasing or reduce in process, at the drainability Q of complete penetration of well or gang of wells that dives under water _nwhen determining, by calculating drainability Q _nwith water discharge when maintaining fixed level every day difference and determine total number of days m in the cycle required for target water level of being down to the method for the ratio of total displacement Q, the computing formula of required m is:

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

Wherein Q _nfor the drainability of dewatering well every day, Q be in well water level by S ₁decline or go up to S ₂the required total displacement increased, for maintaining stable drawdown S ₂time water discharge required for every day, when for individual well: $Q_{S_2}=1.366k\frac{(2H-S)S}{1g\frac{R}{r_w}};$

When for gang of wells: $Q_{S_2}=\frac{1.366k(2H-S)S}{1g[(R+r_0)/r_0]}.$

2. the computing method of water discharge and water discharge time in a kind of dive under water complete penetration of 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 then desirable weighted mean value of K, computing method are K=∑ (K _ih _i)/∑ h _i, wherein K _ifor the infiltration coefficient in each water-bearing zone, h _ifor the thickness in each water-bearing zone.

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

4. the computing method of water discharge and water discharge time in a kind of dive under water complete penetration of well or the dynamic Precipitation Process of gang of wells according to claim 1, 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 by formula calculate.

5. the computing method of water discharge and water discharge time in a kind of dive under water complete penetration of 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 precipitation is carried out to foundation ditch, if the position of periphery dewatering well is not also designed, then calculate by foundation ditch area, wherein F is foundation ditch area; If foundation ditch periphery dewatering well is arranged, then the preferential position by well calculates, wherein n is well point quantity.

6. the computing method of water discharge and water discharge time in a kind of dive under water complete penetration of 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 required total displacement Q increasing or reduce in process, total displacement Q is dispensed to the every day of carrying out in water level decreasing or rise stages period, the method then carrying out superposing with diving complete penetration of well or the water discharge of gang of wells every day when maintaining fixed level calculates 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 be in well water level by S ₁decline or go up to S ₂the required total displacement increased, m is total number of days of water level decreasing or rise stages period, for maintaining stable drawdown S ₂time water discharge required for every day, when for individual well: $Q_{S_2}=1.366k\frac{(2H-S)S}{1g\frac{R}{r_w}};$

When for gang of wells: $Q_{S_2}=\frac{1.366k(2H-S)S}{1g[(R+r_0)/r_0]}.$

7. the computing method of water discharge and water discharge time in a kind of dive under water complete penetration of well or the dynamic Precipitation Process of gang of wells according to claim 1, is characterized in that, for the water level in A precipitation region in engineering construction and two, B precipitation region independently precipitation region from S ₁decline or go up to S ₂the required total displacement Q increasing or reduce in process _aand Q _brespectively by following formulae discovery:

$Q_A={\∫}_{S_1}^{S_2}{Q}_A\left(S\right)\·\mathrm{dS}$

$Q_B={\∫}_{S_1}^{S_2}{Q}_B\left(S\right)\·\mathrm{dS}$

Then at A precipitation zone maintenance fixed level S ₂condition under, the water level decreasing in B precipitation region or go up to S ₂the required water discharge Q increased _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 complete penetration of 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 decreasing in B precipitation region or go up to S ₂the required water discharge Q increased _b-A, by water discharge Q _b-Abe dispensed to carry out B precipitation region water level decreasing or rise stages period in every day, fixed level S must be maintained in a-quadrant thus ₂condition under, S was down in B region in mB days ₂the water discharge Q of every day during water level _bmfor:

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

Wherein drawdown S is stablized for region B maintains ₂time water discharge required for every day, r in formula _b0for the conversion radius of region B foundation ditch.

9. according to the computing method of water discharge and water discharge time in claim 1-8 arbitrary described a kind of dive under water complete penetration of 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, foundation ditch conversion radius r ₀unit be the coefficient of permeability K in rice, each water-bearing zone _iunit be rice every day, the thickness h in each water-bearing zone _iunit be rice, the unit of foundation ditch area F is square metre, and in well, water level is by S ₁decline or go up to S ₂the unit of the required total displacement Q increased is cubic meter, maintains and stablizes drawdown S ₂time water discharge required for every day unit be cubic meter, the drainability Q of dewatering well every day _nunit be cubic meter, maintain stablize drawdown S ₂time water discharge required for every day 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 decreasing in B precipitation region or go up to S ₂the required water discharge Q increased _b-Aunit be cubic meter, the water discharge Q of B region every day _bmunit be cubic meter, region B maintain stablize drawdown S ₂time water discharge required for every day unit be cubic meter, the conversion radius r of region B foundation ditch _b0unit is rice.