A recharging well filter section recharging efficiency comparison test device and method

Abstract

The present application relates to a kind of recharging well filter water section recharging efficiency comparative test device and method, the double-layer bottom pipe in the device is placed on test device base, the lower portion of double-layer bottom pipe is connected with the different filter pipe in filter water system, double-layer bottom pipe is successively sleeved with inner and outer layer sand retaining filter water frame, filter pipe is connected with the lower portion of double-layer bottom pipe, filter material layer is placed between double-layer bottom pipe and filter pipe and inner layer sand retaining filter water frame, undisturbed soil layer is placed between inner layer sand retaining filter water frame and outer layer sand retaining filter water frame;Water level observation pipe is respectively arranged in filter water pipe, filter material layer and undisturbed soil layer, inlet pipe is placed in double-layer bottom pipe, and flow meter is provided with meter.The present application solves the quantitative comparative analysis of the selection of filter water section (filter and filter material layer) in recharging well structure design, can determine the water-blocking effect of different filter and different filter material layer respectively, can determine the relatively optimal filter and filter material layer combination through test, ensure the relative optimality of recharging well filter water section design.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of engineering hydrogeology, hydrology and water resources, and particularly relates to a recharging well filter section recharging efficiency comparison test device and method. BACKGROUND

[0002] In the control of stratum deformation caused by groundwater level drop, groundwater recharge technology is currently a commonly used measure, and has been widely used in the field of engineering construction and regional ground subsidence control. Many experts and scholars have studied the changes of seepage field caused by recharge and recharge blockage. However, there is a lack of quantitative comparison and analysis in the selection of filter section (filter and filter material layer) in the design of recharge well structure. In theory, the stronger the water passing capacity of the filter pipe is, the better it is. In the literature "Shanghai Hub Foundation Pit Engineering Shallow Confined Water Recharge Test Analysis", Lu Jian-sheng, Pan Wei-qiang, etc. introduced a simple cylinder test to analyze the water passing capacity of different filters. However, this test only analyzes the water passing capacity of the filter, ignoring the influence of the filter material layer and the stratum. Although the direct recharge test on site can also be compared, the cost is huge, and the actual data obtained by the test is obviously deviated due to the influence of stratum factors and construction factors around the well. SUMMARY

[0003] In view of the defects in the prior art, the technical problem to be solved by the present application is to provide a recharging well filter section recharging efficiency comparison test device and method. The recharging efficiency under different filter section structures can be compared by the corresponding test device and method, and the recharging pipe well design can be better performed according to different strata.

[0004] In order to solve the above technical problems, the technical scheme adopted by the present application is: a recharging well filter section recharging efficiency comparison test device, comprising a test rack system, a filter system and a monitoring system. The double-layer bottom pipe in the test rack system is placed on the test device base, the double-layer bottom pipe is connected with the lower part of different filter pipes in the filter system, and the double-layer bottom pipe is sequentially sleeved with an inner sand-blocking filter frame and an outer sand-blocking filter frame. The filter pipe in the filter system is connected with the lower part of the double-layer bottom pipe, the filter material layer is placed between the double-layer bottom pipe and the filter pipe and the inner sand-blocking filter frame, and the undisturbed soil layer is placed between the inner sand-blocking filter frame and the outer sand-blocking filter frame. The water level observation pipes in the monitoring system are respectively arranged in the filter pipe, the filter material layer and the undisturbed soil layer, the inlet pipe is arranged in the double-layer bottom pipe, and a flow meter is arranged.

[0005] Further, the test device base is provided with a water collecting tank, and the water collecting tank is provided with a drainage pipeline on the side.

[0006] Further, the inner layer sand blocking water filtering frame and the outer layer sand blocking water filtering frame are adjustable frames, and the thicknesses of the filtering material layer and the undisturbed soil layer are changed by adjusting the diameters of the inner layer sand blocking water filtering frame and the outer layer sand blocking water filtering frame.

[0007] Further, the water level observation pipe is connected with an automatic monitoring device for automatically monitoring the water level or manually monitoring the water level.

[0008] A kind of recharging well water filtering section recharging efficiency comparison test method, using recharging well water filtering section recharging efficiency comparison test device, first, according to undisturbed soil layer selection multiple water filtering section structure, including the type and diameter of filter tube, gradation and thickness of filter material layer, different water filtering sections are placed in test device respectively, then in water inlet pipe respectively according to two different fixed flow to the comparison test device, the water level in water level observation pipe is recorded respectively, the recharging comprehensive efficiency of water filtering section:

[0009] E=(Q2-Q1) / (H 11 -H 12 )

[0010] The blocking effect of filter tube:

[0011] E1=((H 21 -H 11 ) / Q1+(H 22 -H 12 ) / Q2) / 2

[0012] The blocking effect of filter material layer:

[0013] E2=((H 31 -H 21 ) / Q1+(H 32 -H 22 ) / Q2) / 2

[0014] In the formula, E is the recharging comprehensive effect value of water filtering section, E1 is the average value of the blocking effect of filter tube, E2 is the average value of the blocking effect of filter material layer, Q1 is the average flow value of low flow, Q1 is the average flow value of high flow, H 11 is the filter observation well water level depth value under low flow, H 12 is the filter observation well water level depth value under high flow, H 21 is the observation well water level depth value in filter material layer under low flow, H 22 is the observation well water level depth value in filter material layer under high flow, H 31 is the observation well water level depth value in undisturbed soil layer under low flow, H 22 is the observation well water level depth value in undisturbed soil layer under high flow,

[0015] The filter pipe type and filter material layer combination with minimum E2 and E1 are selected as the relatively optimal filter pipe structure, and the test is repeatedly carried out, and the recharge comprehensive effect is confirmed and calculated;

[0016] The water blocking effects of different filters are confirmed through the comparative test device, and the influence of the thickness of the filter material layer on the recharge comprehensive effect is analyzed.

[0017] The beneficial effects of the present application are:

[0018] The present application solves the quantitative comparative analysis of the selection of the filter water section (filter and filter material layer) in the recharge well structure design, can determine the water blocking effects of different filters and different filter material layers, and can determine the relatively optimal filter and filter material layer combination through test, to ensure the relative optimality of the recharge well filter water section design. BRIEF DESCRIPTION OF DRAWINGS

[0019] Fig. 1 is the recharge well filter water section recharge efficiency comparative test device structure top view of the present application;

[0020] Fig. 2 is the recharge well filter water section recharge efficiency comparative test device structure sectional view of the present application;

[0021] Fig. 3 is the recharge well filter water section recharge efficiency comparative test device and method schematic diagram of the present application;

[0022] In the figure: 11. filter pipe; 12. double-layer bottom pipe; 13. outer layer sand blocking filter water frame; 14. inner layer sand blocking filter water frame; 15. outer drainage pipeline; 16. water collecting tank; 17. test device base; 2. filter material layer; 3. undisturbed soil layer; 41. water level observation pipe one; 42. water level observation pipe two; 43. water level observation pipe three; 5. water inlet pipe; 6. flow meter. DETAILED DESCRIPTION

[0023] The embodiments of the present application will be further described in detail below with the help of the accompanying drawings, but the embodiments are not used to limit the present application, any similar structure and its similar changes adopted in the present application shall be included in the protection scope of the present application, and the dots in the present application all represent the relationship of and.

[0024] As shown in Figs. 1 to 3 , the recharge well filter water section recharge efficiency comparative test device of the present application comprises a test rack system, a filter water system and a monitoring system.

[0025] The test frame system comprises a test device base 17, a double-layer bottom pipe 12, an inner layer sand-blocking water filtering frame 14, an outer layer sand-blocking water filtering frame 13, a water collecting tank 16 and a drainage pipeline 15. The test device base 17 is provided with the water collecting tank 16, and the water collecting tank 16 is provided with the drainage pipeline 15 on the side. The double-layer bottom pipe 12 is arranged on the test device base 17, and the double-layer bottom pipe 12 is connected with the lower part of different filtering pipes 11 in the water filtering system. The double-layer bottom pipe 12 is sequentially sleeved with the inner layer sand-blocking water filtering frame 14 and the outer layer sand-blocking water filtering frame 13. The inner layer sand-blocking water filtering frame 14 and the outer layer sand-blocking water filtering frame 13 are adjustable frames, and the thickness of the filter material layer 2 and the undisturbed soil layer 3 can be changed by adjusting the diameters.

[0026] The water filtering system comprises the filter 11, the filter material layer 2 and the undisturbed soil layer 3. The filtering pipe 11 is connected with the lower part of the double-layer bottom pipe 12. The filter material layer 2 is arranged between the double-layer bottom pipe 12 and the filtering pipe 11 and the inner layer sand-blocking water filtering frame 14. The undisturbed soil layer 3 is arranged between the inner layer sand-blocking water filtering frame 14 and the outer layer sand-blocking water filtering frame 13. In the test, water flows through the filtering pipe 11, the filter material layer 2, the undisturbed soil layer 3, the water collecting tank 16 and finally flows out from the drainage pipeline 15.

[0027] The monitoring system comprises a water level observation pipe one 41, a water level observation pipe two 42, a water level observation pipe three 43, a water inlet pipe 5 and a flow meter 6. The water level observation pipe one 41 is arranged in the filtering pipe 11, the water level observation pipe two 42 is arranged in the filter material layer 2 and the water level observation pipe three 43 is arranged in the undisturbed soil layer 3. The water level observation can adopt automatic monitoring or manual monitoring. The water level observation pipe is connected with an automatic monitoring device and is used for automatically monitoring the water level. The automatic monitoring device adopts the water level monitoring device in the prior art. The water inlet pipe 5 is arranged in the double-layer bottom pipe 12 and is provided with the flow meter 6.

[0028] The application provides a kind of recharging well water filtering section recharging efficiency comparison test method, using the recharging well water filtering section recharging efficiency comparison test device of the application: according to the structure of undisturbed soil layer 3 selection multiple filter water section, including the type and diameter of filtering pipe 11, the gradation of filter material and the thickness of filter material layer 2. Different filter water sections are placed in the test device, then in water inlet pipe 5 respectively according to two different fixed flow into the device, respectively record the water level depth in observation pipe.

[0029] The recharging comprehensive efficiency of filter water section:

[0030] E=(Q2-Q1) / (H 11 -H 12 )

[0031] The blocking effect of filter 11:

[0032] E1=((H 21 -H 11 ) / Q1+(H 22-H 12 ) / Q2) / 2

[0033] Barrier effect of filter material layer 2:

[0034] E2 = ((H 31 -H 21 ) / Q1 + (H 32 -H 22 ) / Q2) / 2

[0035] In the formula, E is the comprehensive effect value of the filter water section, E1 is the average value of the barrier effect of the filter, E2 is the average value of the barrier effect of the filter material layer, Q1 is the average flow value of low flow, Q2 is the average flow value of high flow, H 11 is the observed well water level depth value of the filter under low flow, H 12 is the observed well water level depth value of the filter under high flow, H 21 is the observed well water level depth value in the filter material layer under low flow, H 22 is the observed well water level depth value in the filter material layer under high flow, H 31 is the observed well water level depth value in the undisturbed soil layer under low flow, H 22 is the observed well water level depth value in the undisturbed soil layer under high flow,

[0036] Select the filter pipe type and filter material layer with the smallest E2 and E1 to combine a relatively optimal new filter water pipe structure, repeat the test, and confirm and calculate the comprehensive effect of the recharge.

[0037] The barrier effect of different filters can be confirmed through the test device, and the influence of the thickness of the filter material layer on the comprehensive effect of recharge can be analyzed.

[0038] Through the application of the recharge well filter water section recharge efficiency comparison test method, a more reasonable recharge well structure is optimized and determined, which provides a research basis for further in-situ tests.

Claims

1. A method for comparative testing of the reinjection efficiency of a filter section in a reinjection well, comprising a test apparatus for comparative testing of the reinjection efficiency of a filter section in a reinjection well, the apparatus including a test frame system, a filtration system, and a monitoring system, characterized in that: The double-layer bottom pipe in the test frame system is placed on the base of the test device. The double-layer bottom pipe is connected to the lower part of different filter pipes in the water filtration system. An inner sand-blocking and water-filtering frame and an outer sand-blocking and water-filtering frame are sequentially sleeved on the outside of the double-layer bottom pipe. The filter pipe in the water filtration system is connected to the lower part of the double-layer bottom pipe. The filter media layer is placed between the double-layer bottom pipe and the filter pipe and the inner sand-blocking and water-filtering frame. The undisturbed soil layer is placed between the inner sand-blocking and water-filtering frame and the outer sand-blocking and water-filtering frame. The water level observation pipe in the monitoring system is respectively set in the filter pipe, the filter media layer and the undisturbed soil layer. The water inlet pipe is placed in the double-layer bottom pipe and is equipped with a flow meter. Both the inner and outer sand-blocking and water-filtering frames are adjustable frames, and the thickness of the filter media layer and the original soil layer can be changed by adjusting the diameter of the inner and outer sand-blocking and water-filtering frames. The experimental procedure is as follows: First, select the structure of various filter sections according to the original soil layer, including the type and diameter of the filter pipe, the gradation of the filter media and the thickness of the filter media layer. Place different filter sections in the test device. Then, introduce water into the comparative test device at different fixed flow rates twice in the inlet pipe and record the water level depth in the water level observation pipe. The overall effect of recharge in the filtration section: ； Barrier effect of filter tube: ； Barrier effect of filter media layer: ； In the formula, E is the comprehensive effect value of the filtration section recharge, E1 is the average barrier effect value of the filter pipe, E2 is the average barrier effect value of the filter media layer, Q1 is the average flow rate value at low flow rate, Q2 is the average flow rate value at high flow rate, and H... 11 H represents the water level depth of the filter observation well under low flow conditions. 12 H represents the water level depth of the filter observation well under high flow rate conditions. 21 H represents the depth of the water level in the observation well within the filter media layer under low flow conditions. 22 H represents the depth of the water level in the observation well within the filter media layer under high flow conditions. 31 H represents the depth of the well water level in the undisturbed soil layer under low flow conditions. 22 The depth of the observation well in the undisturbed soil layer under high flow conditions; The filter pipe type and filter media layer combination with the lowest E2 and E1 values ​​were selected to form the relatively optimal water filter pipe structure. The test was repeated, and its comprehensive recharge efficiency was confirmed and calculated. The water-blocking effect of different filters was confirmed by comparing experimental setups, and the influence of filter layer thickness on the overall recharge effect was analyzed.

2. The test method according to claim 1, characterized in that: The base of the test device is equipped with a water collection tank, and a drainage pipe is provided on the side of the water collection tank.

3. The test method according to claim 1, characterized in that: The water level observation tube is connected to an automated monitoring device for automated or manual monitoring of the water level.

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