Water level observation well structure

Abstract

The utility model relates to a water level observation well structure which comprises an observation hole, a well casing and a gravel filling layer. The well pipe is arranged on the inner side of the observation hole, the well pipe penetrates through one or more than two upper confined aquifers, the bottom of the well pipe is located in the bottom confined aquifer, the well pipe is provided with a perforated pipe wall corresponding to the upper confined aquifers, the perforated pipe wall is provided with water permeable holes, the bottom of the perforated pipe wall is provided with a bottom plate, and the bottom plate is connected with a partition plate extending upwards; the gravel filling layer comprises an upper gravel filling layer and a lower gravel filling layer, the upper gravel filling layer is arranged between the partition plate and the perforated pipe wall, and the lower gravel filling layer is arranged below the opening in the bottom of the well pipe. Compared with the prior art, the water level elevation and confined water head measurement can be carried out on two or more confined aquifers in one observation hole.

Description

Technical Field

[0001] The utility model relates to the technical field of engineering geological survey and hydrogeological survey, in particular to a water level observation well structure. Background Art

[0002] In projects involving foundation pits, if the soil layers within the excavation depth range are susceptible to sudden inrush, the geological survey phase requires determining the site's confined water level and confined water head to provide calculation parameters for verifying the potential for sudden inrush. During the excavation and dewatering phases, water level observation wells should be installed outside the pit, if necessary, to ensure smooth construction.

[0003] Current methods for measuring confined water levels have drawbacks: a single observation hole can only measure the water level of a single confined aquifer. When measuring the water level of two or more confined aquifers, additional holes must be drilled to measure the water level of the next confined aquifer, resulting in long construction times and high costs. Furthermore, field hydrological surveys are often limited by site space, resulting in limited space for water level observation holes. Furthermore, the more holes drilled, the greater the damage to the field environment.

[0004] Based on the above reasons, there is a need for an observation well that can efficiently and quickly measure the water level of two or more layers of confined aquifers. Utility Model Content

[0005] The purpose of the utility model is to provide a water level observation well structure for efficiently and quickly measuring the water levels of two or more layers of confined aquifers.

[0006] The purpose of the utility model can be achieved through the following technical solutions: a water level observation well structure, including an observation hole, a well pipe and a gravel filling layer;

[0007] The well pipe is arranged inside the observation hole, passes through one or more upper confined aquifers, and the bottom of the well pipe is located in the bottom confined aquifer. The well pipe is provided with a perforated pipe wall corresponding to the upper confined aquifer, the perforated pipe wall is provided with water-permeable holes, and the bottom of the perforated pipe wall is provided with a bottom plate, which is connected to a partition extending upward;

[0008] The gravel filling layer comprises an upper gravel filling layer and a lower gravel filling layer. The upper gravel filling layer is arranged between the partition plate and the perforated pipe wall, and the lower gravel filling layer is arranged below the bottom opening of the well pipe.

[0009] Preferably, the well pipe passes through the first confined aquifer (i.e., the well pipe passes through an upper confined aquifer), and the bottom is located in the second confined aquifer (the bottom confined aquifer), and the well pipe is provided with a half circle of perforated pipe wall corresponding to the first confined aquifer, and a semicircular bottom plate is provided at the bottom of the perforated pipe wall, and a partition is provided between the perforated pipe wall and the other half circle of pipe wall, and the partition is connected to the bottom plate and extends upward to the top surface of the well pipe.

[0010] Further preferably, the well pipe includes an upper well pipe and a lower well pipe, which are connected by an annular water-stop clamp disposed in the second aquitard below the first confined aquifer.

[0011] Even more preferably, the bottom of the upper well pipe is inserted into the second aquitard below the first confined aquifer, and the bottom of the lower well pipe is inserted into the second confined aquifer.

[0012] Even more preferably, the semi-circular perforated pipe wall is provided on the upper well pipe, and a lower gravel pack layer is provided in the observation hole below the lower well pipe.

[0013] Even more preferably, the water-stop clamp includes an H-shaped splint, rivets and a water-proof cushion layer;

[0014] The upper well pipe and the lower well pipe are respectively fixed to the upper and lower flanges of the H-shaped splint by rivets, and a water-proof cushion layer is provided between the upper well pipe and the lower well pipe and the water-stop clamp.

[0015] Preferably, the well pipe passes through two upper confined aquifers and its bottom is located in the bottom confined aquifer. The well pipe is provided with a one-third circular perforated pipe wall at the corresponding position of each confined aquifer. The bottom of the perforated pipe wall is provided with a one-third circular bottom plate, and the bottom plate is connected with a partition plate, and the partition plate is connected with the bottom plate and extends upward to the top surface of the well pipe. Preferably, the well pipe passes through N - 1 upper confined aquifers and its bottom is located in the bottom confined aquifer. The well pipe is provided with a one-Nth circular perforated pipe wall at the corresponding position of each confined aquifer. The bottom of the perforated pipe wall is provided with a one-Nth circular bottom plate, and the bottom plate is connected with a partition plate, and the partition plate is connected with the bottom plate and extends upward to the top surface of the well pipe.

[0016] In engineering practice, it is usually only necessary to measure the water levels of the confined aquifers within three layers. Therefore, N is usually a positive integer from 2 to 3.

[0017] Preferably, the well pipe is a steel pipe.

[0018] Preferably, the diameter of the well pipe is ≥70 cm, and the height of the perforated pipe wall is ≥0.5 m.

[0019] Preferably, the observation hole sequentially passes through the first aquitard, the first confined aquifer, the second aquitard from top to bottom and its bottom is located in the second confined aquifer below the second aquitard, and the well pipe is inserted into the observation hole.

[0020] Further preferably, the depth of the observation hole entering the second confined aquifer is 1 - 2 m.

[0021] Compared with the prior art, the present utility model has the following beneficial effects:

[0022] 1. For a site with two or more confined aquifers, the water level observation well of the present utility model can measure the water level elevation and confined water head of two or more confined aquifers in one observation hole;

[0023] 2. The present utility model can measure the water level elevation and water head of two or more layers of confined water in one observation well simultaneously, and can measure the confined water levels of two or more layers at the same time, greatly reducing the construction time and achieving efficient and rapid measurement;

[0024] 3. The present utility model can be used to measure the water level elevation of the confined aquifer and provide calculation parameters for the anti-heave stability check of the foundation pit;

[0025] 4. Through the cooperative setting of the perforated pipe wall, the bottom plate and the partition plate, the present utility model forms a cavity communicating with the confined aquifer, and can measure the water level elevation of each layer of confined aquifer simultaneously without affecting the observation of the well pipe on the other side, having the advantages of short construction period, small environmental disturbance and high economy. Description of the Drawings

[0026] Figure 1 is a schematic diagram of the structure of the two-layer water level observation well in Embodiment 3 of the present utility model;

[0027] Figure 2 is Figure 1 the sectional view of A-A' of

[0028] Figure 3 is a schematic diagram of the water stop clamp;

[0029] Figure 4 is a schematic diagram of the upper well pipe;

[0030] Figure 5 is a schematic diagram of the lower well pipe;

[0031] Figure 6 is a schematic diagram of the structure of the three-layer water level observation well in Embodiment 5 of the present utility model;

[0032] Figure 7 is the sectional view of the structure of the three-layer water level observation well in Embodiment 5 of the present utility model;

[0033] In the figure: 1 - observation hole, 2 - well pipe, 21 - upper well pipe, 22 - lower well pipe, 23 - partition plate, 24 - perforated pipe wall, 25 - bottom plate, 26 - water stop clamp, 261 - H-shaped splint, 262 - rivet, 263 - water isolation cushion layer, 3 - gravel filling layer, 31 - upper gravel filling layer, 32 - lower gravel filling layer, 4 - first water isolation layer, 5 - first confined aquifer, 6 - second water isolation layer, 7 - second confined aquifer. Detailed Embodiment

[0034] The present utility model will be described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented on the premise of the technical solution of the present utility model, and the detailed implementation manner and specific operation process are given. However, the protection scope of the present utility model is not limited to the following embodiments.

[0035] It should be noted that similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0036] Some embodiments of the present utility model will be described in detail below in conjunction with the accompanying drawings. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0037] Embodiment 1

[0038] A water level observation well structure includes an observation hole 1, a well pipe 2, and a gravel filling layer 3.

[0039] Among them, the well pipe 2 is inserted into the observation hole 1, passes through one or more upper confined aquifers and is inserted into the bottom confined aquifer, and an open-hole pipe wall 24 is provided at the corresponding upper confined aquifer. Permeable holes are provided on the open-hole pipe wall 24. A bottom plate 25 facing the axis of the well pipe 2 is provided at the bottom of the open-hole pipe wall 24. The bottom plate 25 is connected with a partition plate 23 extending upward, and together with the partition plate 23 forms a cavity communicating with the permeable holes. The water in the upper confined aquifer can enter the cavity through the permeable holes of the open-hole pipe wall 24.

[0040] The gravel filling layer 3 includes an upper gravel filling layer 31 and a lower gravel filling layer 32. The upper gravel filling layer 31 is arranged between the open-hole pipe wall 24 and the partition plate 23, and the lower gravel filling layer 32 is arranged below the bottom opening of the well pipe 2.

[0041] Embodiment 2

[0042] A water level observation well structure is composed of an observation hole 1, a well pipe 2, and a gravel filling layer 3; the well pipe 2 adopts a modular design and is divided into an upper well pipe 21 and a lower well pipe 22; the upper well pipe 21 is inserted into the second aquitard 6 all the way, and semi-circular permeable holes are provided on the pipe wall of the well pipe 2 between the first confined aquifers 5. A semi-circular bottom plate 25 is provided at the bottom of the open-hole pipe wall 24, and a partition plate 23 is provided between it and the other half-circle pipe wall. The partition plate 23 extends upward to the ground height; the lower well pipe 22 is inserted into the second confined aquifer 7, and a gravel filling layer 3 is provided in the second confined aquifer 7 of the observation hole 1; the upper and lower well pipes are connected by a water stop clamp 26, and the position of the clamp is controlled in the aquitard.

[0043] The observation well structure of this embodiment can measure the water level elevation of two or more layers of confined water in one observation well, and can be carried out simultaneously, which can effectively reduce the construction cost and greatly shorten the construction time.

[0044] Example 3

[0045] A two - layer water - level observation well structure, as shown in reference to Figures 1 to 3 Figure [not provided in the original, assumed to be a reference figure], mainly includes an observation hole 1 and a well pipe 2. The observation hole 1 is cored to a depth of 1 - 2 m below the top surface of the second confined aquifer 7; the well pipe 2 is divided into an upper well pipe 21 and a lower well pipe 22, the diameter of the well pipe is ≥70 cm. The bottom of the upper well pipe 21 is inserted into the second aquitard 6 below the first confined aquifer 5, and the bottom of the lower well pipe 22 is inserted into the second confined aquifer 7; on the pipe wall of the upper well pipe 21 between the first confined aquifers 5, there is a semi - circular permeable hole. The height of the perforated pipe wall 24 section is at least 1 m, and its bottom is provided with a semi - circular bottom plate 25. Between the perforated pipe wall 24, the semi - circular bottom plate 25 and the other half - circle pipe wall, there is a fixedly connected partition plate 23. The partition plate 23 extends upward to the top surface of the well pipe. Between the partition plate 23 and the perforated pipe wall 24, there is an upper gravel - filled layer 31; in the observation hole 1 below the lower well pipe 22, there is a lower gravel - filled layer 32. The upper well pipe 21 and the lower well pipe 22 are connected by an annular water - stop clamp 26, and the water - stop clamp 26 is arranged in the second aquitard 6; the water - stop clamp 26 includes an H - type splint 261, rivets 262 and a water - proof cushion layer 263. The upper and lower well pipes (21, 22) are respectively fixed to the upper and lower flanges of the H - type splint 261 through the rivets 262, and a water - proof cushion layer 263 is arranged between the upper and lower well pipes (21, 22) and the clamp 26.

[0046] A method for measuring the water level of a two - layer water - level observation well, which is mainly characterized by:

[0047] (1) Measuring and setting out the lines to determine the position of the observation hole.

[0048] (2) Drilling and coring near the well position to determine the spatial distribution of soil layers such as aquitards and confined aquifers near the well position.

[0049] (3) Using a drilling rig to open the observation hole. The observation hole is cored into the second confined aquifer, and the mud in the observation hole is replaced and washed. Wait until the pumped groundwater changes from turbid to clear, and the well - washing work is completed.

[0050] (4) When manufacturing the well pipe, follow the modular idea: According to the common buried depth of the first confined aquifer, make upper pipe sections suitable for the common buried depth of the first aquifer in segments (the pipe length is based on regional engineering experience) for selection; According to the common buried depth of the second confined aquifer, make lower pipe sections suitable for the common buried depth of the second aquifer in segments (the pipe length is based on regional engineering experience) for selection.

[0051] (5) When assembling and burying the well pipe, control the depth of the perforated pipe wall of the upper well pipe within the depth range of the first confined aquifer; control the buried depth of the water - stop clamp connecting the upper and lower well pipes within the second aquitard; insert the bottom of the lower well pipe into the second confined aquifer. Before the well pipe sinks, bury the lower gravel - filled layer in the second confined aquifer.

[0052] (6) Replace the washing well and conduct a test pumping. When the pumped groundwater becomes clear, the well washing is completed.

[0053] (7) After the pumping stops, start measuring the piezometric water level elevation and piezometric head: First, measure the elevation of the wellhead, then measure the distance from the top surface of the well pipe to the ground surface of the observation well hole. Use a sounding rope and, with the top surface of the well pipe as the reference, measure the piezometric water levels of the two sides of the observation hole respectively, that is, the water level of the first confined aquifer and the water level of the second confined aquifer. Record the water levels at 5, 10, 15, and 30 minutes after the pumping stops, and then measure once every hour. After obtaining the stable water level of the confined aquifer, the water level measurement is completed.

[0054] (8) After the test is completed, pull out the well pipe and seal the hole by backfilling with clay balls or cement slurry.

[0055] Example 4

[0056] A two-layer water level observation well structure, the observation well includes an observation hole 1, a well pipe 2 and a gravel filling layer 3; the well pipe 2 adopts a modular design, as Figures 4 to 5 shown, including an upper well pipe 21 and a lower well pipe 22. The bottom of the upper well pipe 21 is inserted into the second aquitard 6 below the first confined aquifer 5, and the bottom of the lower well pipe 22 is inserted into the second confined aquifer 7; a semi-circular permeable hole is provided on the pipe wall of the upper well pipe 21 between the first confined aquifers 5. A semi-circular bottom plate 25 is provided at the bottom of the perforated pipe wall 24. A partition 23 with a fixed connection is provided between the perforated pipe wall 24, the semi-circular bottom plate 25 and the other half of the pipe wall. The partition 23 extends upward to the top surface of the well pipe, and an upper gravel filling layer 31 is provided between the partition 23 and the perforated pipe wall 24; a lower gravel filling layer 32 is provided in the observation hole 1 below the lower well pipe 22.

[0057] The well pipe 2 is a steel pipe made of impermeable material (the material can be selected according to the actual situation of the project). The upper well pipe 21 and the lower well pipe 22 are connected by an annular water stop clamp 26, and the water stop clamp 26 is arranged in the second aquitard 6.

[0058] The water stop clamp 26 includes an H-shaped splint 261, a rivet 262 and a water isolation cushion layer 263; the upper and lower well pipes (21, 22) are respectively fixed to the upper and lower flanges of the H-shaped splint 261 by rivets 262, and a water isolation cushion layer 263 is provided between the upper and lower well pipes (21, 22) and the clamp 26.

[0059] The diameter of the well pipe 2 is ≥70 cm, the height of the perforated pipe wall 24 section is ≥0.5 m, and the depth of the observation hole 1 into the second confined aquifer 7 is 1 - 2 m.

[0060] Example 5

[0061] A three-layer water level observation well structure, including an observation hole 1, a well pipe 2 and a gravel filling layer 3.

[0062] Among them, as Figure 6 shown, the well pipe 2 is inserted into the observation hole 1, successively passing through two upper confined aquifers (the first confined aquifer 5) and inserted all the way into the bottom confined aquifer (the second confined aquifer 7), and there is a one-third circle of perforated pipe wall 24 at the corresponding positions of each upper confined aquifer. As Figure 7 shown, the perforated pipe walls 24 corresponding to the two upper confined aquifers are staggered in the cross-sectional direction and can form a complete annular structure with the remaining well pipe 2.

[0063] The perforated pipe wall 24 is provided with water-permeable holes. At the bottom of the perforated pipe wall 24, there is a one-third circle bottom plate 25 facing the axis of the well pipe 2. The bottom plate 25 is connected with a partition plate 23 extending upward, and together with the partition plate 23, it forms a cavity communicating with the water-permeable holes. The water in each upper confined aquifer can enter the corresponding cavity through the water-permeable holes of the corresponding perforated pipe wall 24.

[0064] Moreover, in this embodiment, the perforated pipe walls of the two upper confined aquifers respectively correspond to a first bottom plate and a second bottom plate. The adjacent sides of the first bottom plate and the second bottom plate in the cross-sectional direction share a partition plate. The vertical distance between the two bottom plates varies according to the thickness of the aquitard layer between them. Therefore, the observation well is also set as two upper and lower modules, and the modules are fixed and waterproofed by a water-stop clamp.

[0065] The gravel pack layer 3 includes an upper gravel pack layer 31 and a lower gravel pack layer 32. The upper gravel pack layer 31 is arranged between the perforated pipe wall 24 and the partition plate 23, and the lower gravel pack layer 32 is arranged below the bottom opening of the well pipe 2, that is, in the bottom confined aquifer.

[0066] It should be noted that the structure of the observation hole for more than three confined waters is a deformation and extension of the listed cases of the present invention and is also within the protection scope of the present invention.

[0067] The above description of the embodiments is for the convenience of those of ordinary skill in the art to understand and use the utility model. Those who are familiar with the technology in this field can obviously make various modifications to these embodiments easily and apply the general principles described here to other embodiments without creative labor. Therefore, the present invention is not limited to the above embodiments, and the improvements and modifications made by those skilled in the art according to the disclosure of the present invention without departing from the scope of the present invention should be within the protection scope of the present invention.

Claims

1. A water level observation well structure, characterized in that, It includes an observation hole (1), a well pipe (2) and a gravel packing layer (3). The well pipe (2) is arranged inside the observation hole (1). The well pipe (2) penetrates through one or more upper confined aquifers and its bottom is located in the bottom confined aquifer. The well pipe (2) is provided with an open-hole pipe wall (24) corresponding to the upper confined aquifer. The open-hole pipe wall (24) is provided with water-permeable holes. The bottom of the open-hole pipe wall (24) is provided with a bottom plate (25), and the bottom plate (25) is connected with a partition plate (23) extending upward. The gravel packing layer (3) includes an upper gravel packing layer (31) and a lower gravel packing layer (32). An upper gravel packing layer (31) is arranged between the partition plate (23) and the open-hole pipe wall (24), and a lower gravel packing layer (32) is arranged below the bottom opening of the well pipe (2).

2. The water level observation well structure according to claim 1, characterized in that, The well pipe (2) penetrates through the first confined aquifer (5) and its bottom is located in the second confined aquifer (7). The well pipe (2) is provided with a semi-circular open-hole pipe wall (24) corresponding to the first confined aquifer (5). The bottom of the open-hole pipe wall (24) is provided with a semi-circular bottom plate (25). A partition plate (23) is arranged between the open-hole pipe wall (24) and the other semi-circular pipe wall. The partition plate (23) is connected with the bottom plate (25) and extends upward to the top surface of the well pipe.

3. The water level observation well structure according to claim 2, wherein The well pipe (2) includes an upper well pipe (21) and a lower well pipe (22). The upper well pipe (21) and the lower well pipe (22) are connected by an annular water-stop clamp (26), and the water-stop clamp (26) is arranged in the second aquitard (6) below the first confined aquifer (5).

4. The water level observation well structure according to claim 3, characterized in that, The bottom of the upper well pipe (21) is inserted into the second aquitard (6) below the first confined aquifer (5), and the bottom of the lower well pipe (22) is inserted into the second confined aquifer (7).

5. The water level observation well structure according to claim 3, characterized in that, The semi-circular open-hole pipe wall (24) is arranged on the upper well pipe (21), and a lower gravel packing layer (32) is arranged in the observation hole (1) below the lower well pipe (22).

6. The water level observation well structure according to claim 3, characterized in that The water-stop clamp (26) includes an H-shaped clamping plate (261), rivets (262) and a water-proof cushion layer (263). The upper well pipe (21) and the lower well pipe (22) are respectively fixed to the upper and lower flanges of the H-shaped clamping plate (261) by rivets (262), and a water-proof cushion layer (263) is arranged between the upper well pipe (21), the lower well pipe (22) and the water-stop clamp (26).

7. The water level observation well structure according to claim 1, characterized in that, The well pipe (2) is a steel pipe.

8. The water level observation well structure according to claim 1, characterized in that, The diameter of the well pipe (2) is ≥70 cm, and the height of the open-hole pipe wall (24) is ≥0.5 m.

9. The water level observation well structure according to claim 1, characterized in that, The observation hole (1) sequentially penetrates through the first aquitard (4), the first confined aquifer (5), the second aquitard (6) from top to bottom, and its bottom is located in the second confined aquifer (7) below the second aquitard (6). The well pipe (2) is inserted into the observation hole (1).

10. The water level observation well structure according to claim 9, characterized in that, The depth of the observation hole (1) entering the second confined aquifer (7) is 1 - 2 m.

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