Recyclable micro-rechargeable well without drilling and construction method

Abstract

This invention provides a recyclable, drill-free micro-recharge well and method. The micro-recharge well includes an outer steel pipe, an inner steel pipe, a connecting sleeve, a bottom sealing head, a filter screen, and barbed steel strips. The barbed steel strips are welded to the center of the bottom sealing head. A flexible filter screen is wrapped around the outside of the inner steel pipe and secured with fine steel wire. The bottom sealing head and inner steel pipe are tightened together and inserted into the outer steel pipe to form the bottom first section of the steel pipe. A back-pressure device is used to penetrate the first section of the steel pipe. Then, a second section of the outer steel pipe is screwed onto the first section, and the connecting sleeve is installed on the top of the outer steel pipe. The above steps are repeated until a specified penetration depth is reached. The back-pressure device is used to pull out the uppermost outer steel pipe, leaving the bottom sealing head and inner steel pipe in place, thus connecting the entire recharge well to external water. After recharge is completed, all outer steel pipes are pulled out and recycled. This invention uses a micro-penetration device, avoiding mud pollution, and features drill-free operation, recyclability, flexible layout, and low cost.

Description

Technical Field

[0001] This invention relates to the field of geotechnical engineering, and more particularly to the field of geotechnical engineering requiring recharge. Background Technology

[0002] Geotechnical engineering, as a crucial field of civil engineering, attracts significant attention from the engineering community due to the diverse engineering properties of its soil and rock masses. Underground engineering projects such as foundation pit excavation, underground tunnel construction, and pile foundation construction all present engineering challenges that geotechnical engineers must address. A major concern in geotechnical engineering is the impact of groundwater, such as high water heads during foundation pit excavation leading to foundation instability and heave. This necessitates groundwater dewatering to lower the water table and increase the foundation's heave resistance.

[0003] While groundwater depletion ensures the safety of underground engineering projects, it increases the effective stress of the surrounding soil, leading to consolidation settlement. This can cause deformation of surrounding structures, potentially resulting in cracked buildings, surface damage, and economic and personal losses. To control excessive rainfall and prevent damage to surrounding structures, recharge wells are often installed near the project to stabilize the groundwater level beneath them. Recharge also replenishes groundwater resources, preventing significant waste.

[0004] Recharge wells in engineering projects are often constructed using drilling technology. This involves drilling a hole with a drilling rig, then inserting sections of perforated steel pipe, which are wrapped with a filter screen, into the hole, and welding the sections together. After the perforated steel pipe is lowered, the gap between the borehole outer diameter and the perforated steel pipe is backfilled with sand or gravel. Traditional recharge well construction methods are complex, require large equipment for drilling, and generate a lot of mud, causing environmental problems. For example, the method mentioned in AU2021100056A4 allows mud to penetrate the borehole wall and enter the steel pipe during the pressure process, and the used steel pipe cannot be recycled. CN205502044U and CN218970086U cannot avoid the problem of mud and sand blocking the permeable holes on the side walls during the pressure process, making subsequent operations impossible. In addition, in spaces with limited height, such as under buildings or overpasses, the drilling machinery cannot meet the space requirements, making it impossible to construct recharge wells.

[0005] To address the aforementioned technical problems, this invention provides a recyclable, drill-free micro-recharge well and method. Employing a micro-penetration device, it offers the advantages of being drill-free and recyclable. Regarding the mud contamination issue, this invention utilizes a double-layered steel pipe structure. The outer steel pipe covers the inner steel pipe, effectively ensuring that the filter mesh holes in the inner steel pipe do not directly contact the soil during the pressing process, thus preventing mud contamination. Furthermore, this invention features flexible layout and low cost. Summary of the Invention

[0006] This invention provides a recyclable, drill-free micro-recharge well and method. It uses a micro-penetration device to construct the recharge well in a space with limited height. Furthermore, the penetration-type well construction method avoids mud pollution caused by drilling. It can effectively overcome the difficulties and pain points of existing technologies, realize groundwater recharge, and stabilize the groundwater level under surrounding buildings and structures.

[0007] This invention provides a recyclable, drill-free micro-recharge well, comprising multiple outer steel pipes, a connecting sleeve, an inner steel pipe, a bottom sealing head, a filter screen, and barbed steel bars;

[0008] Each of the outer steel pipes has threads on the inner walls at both ends for connection with the connecting sleeve;

[0009] The outer walls at both ends of the connecting sleeve are threaded for connecting two adjacent outer steel pipes;

[0010] The inner wall of the bottom end of the inner steel pipe is threaded for connection with the upper part of the sealing head; the inner steel pipe wall is provided with water-permeable holes for water to flow freely through.

[0011] The structure of the bottom sealing head includes an upper part, a middle part, and a lower part connected in sequence; the upper part is a threaded cylinder used to connect to the threads inside the inner steel pipe; the middle part is a cylinder located outside the outer steel pipe, and the diameter of the middle part is equal to or greater than the outer diameter of the outer steel pipe; the lower part is a cone to reduce the resistance to travel in the soil.

[0012] When the outer steel pipe penetrates the soil, the inner steel pipe and the upper part of the bottom sealing head are located in the outer steel pipe; along the direction of soil penetration, the front end of the outer steel pipe abuts against the middle of the bottom sealing head to push the bottom sealing head forward.

[0013] The filter screen is placed between the outer wall of the inner steel pipe and the inner wall of the outer steel pipe, and the filter screen covers the water permeable holes; it plays a role in filtering sand and soil and preventing the micro-recharge well from becoming clogged.

[0014] One end of the barbed steel strip is welded to the middle of the bottom sealing head, and the other end is inclined towards the outer steel pipe. During the upward pulling process of the outer steel pipe, the barbed steel strip wedges into the surrounding soil to prevent the inner steel pipe from moving upward together with the outer steel pipe, thereby helping to separate the inner steel pipe from the outer steel pipe. It plays a role in assisting in fixing the inner steel pipe.

[0015] When the outer steel pipe is inserted, it acts as a force-transmitting body, transferring the jacking force to the bottom sealing head; during recharge, the internal space provides a transport channel for the recharge water.

[0016] Preferably, the outer diameter of the inner steel pipe is at least 1 cm smaller than the inner diameter of the outer steel pipe, thereby avoiding excessive friction on the inner steel pipe during the extraction of the outer steel pipe. The inner diameter of the outer steel pipe, the inner diameter of the inner steel pipe, and the number of perforations meet the requirements of the reinjection water volume. The inner diameter of the inner steel pipe and the number of perforations must meet the water flow requirements of the reinjection water volume.

[0017] Preferably, the ratio of the outer diameter of the inner steel pipe to the inner diameter of the outer steel pipe is 2:3.

[0018] Preferably, the bottom end is made of iron block to increase its weight, thereby helping to fix the inner steel pipe.

[0019] Preferably, the filter is a flexible filter.

[0020] On the other hand, the present invention provides a method for penetration well completion operations using the aforementioned micro-recharge well, comprising the following steps:

[0021] Step 1: Weld the barbed steel strip to the middle of the bottom sealing head, wrap the flexible filter mesh around the outside of the inner steel pipe, and secure it with thin steel wire; tighten the bottom sealing head and the inner steel pipe together, and insert it into the outside steel pipe to form the first section of the bottom steel pipe; in addition, install the connecting sleeve on the top of the first section of the steel pipe.

[0022] Step 2: Select the back pressure equipment for the injection well and remove the hard surface layer of soil at the designated injection location;

[0023] Step 3: Use a counter-pressure device to penetrate the first section of steel pipe;

[0024] Step 4: Connect the second outer steel pipe section to the first steel pipe section using a connecting sleeve, and install another connecting sleeve onto the top of the second outer steel pipe section;

[0025] Step 5: Repeat steps 3 and 4 similarly until the target depth is reached;

[0026] Step 6: Using the counter-pressure equipment, pull up the outermost steel pipe, with the lifting height not exceeding the length of the inner steel pipe; the bottom cap and inner steel pipe are subjected to resistance provided by their own weight, the barbed steel bars inserted into the soil, etc., so that the bottom cap and inner steel pipe remain in place during the lifting process and naturally detach from the outer steel pipe; thereby realizing the connection between the entire reinjection well and the outside water.

[0027] Step 7: Connect external recharge equipment and perform recharge;

[0028] Step 8: After the backfilling is completed, use a counter-pressure device or crane to pull up and retrieve the outer steel pipe, and backfill and seal the hole after it has been pulled up.

[0029] Preferably, the counter-pressure device is a tracked penetration machine or a hydrostatic reaction frame.

[0030] The main advantages of this invention are:

[0031] 1. Environmentally friendly construction: This invention adopts a penetration-type well drilling method, which avoids problems such as mud pollution caused by traditional reinjection well drilling.

[0032] 2. Improved construction efficiency: The use of interconnected steel pipes results in high construction efficiency, reducing construction time and labor costs.

[0033] 3. Recyclable and low-cost: The final steel pipe can be recycled and reused, reducing unnecessary material waste and resource consumption, while also reducing costs.

[0034] 4. High adaptability: It can use different types of counter-pressure equipment, is not limited by construction space, and has flexibility and creativity. It can be adjusted according to different specific working conditions. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of a recyclable, drill-free micro-recharge well structure.

[0036] Figure 2 Example diagram showing the installation of components such as the bottom cap, inner steel pipe, and filter screen.

[0037] Figure 3 This is a flowchart of a method for constructing micro-recharge wells based on recyclable, drill-free technology.

[0038] Figure 4 These are photos of the connecting sleeve at the site.

[0039] Figure 5 Photos of the steel pipes used for the recharge well.

[0040] Figure 6 Photos taken at the site where the steel pipe was inserted.

[0041] Figure 7 Photos of the scene where the reaction equipment pulls up the steel pipe.

[0042] The attached diagram is labeled as follows: 1-Outer steel pipe; 2-Connecting sleeve; 3-Water permeable hole; 4-Filter screen; 5-Inner steel pipe; 6-Barbed steel strip; 7-Bottom cap. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments.

[0044] Example 1

[0045] This implementation case involves a foundation pit project requiring external recharge, which was carried out using the micro recharge well of this invention. The micro recharge well consists of an outer steel pipe, an inner steel pipe, permeable holes, a filter screen, barbed steel strips, and a bottom sealing head assembly. The outer steel pipe has threads on the inner walls at both ends, with inner and outer diameters of 100mm and 110mm respectively, and a length of 2m. The inner steel pipe has threads on the inner side of its bottom, with an outer diameter of 80mm and an inner diameter of 70mm; permeable holes are drilled on its wall, one hole every 20cm; the inner steel pipe is 2m long. The connection method for the various parts of the micro recharge well of this invention is as follows: barbed steel strips are welded to the middle of the bottom sealing head; a flexible filter screen is wrapped around the outside of the inner steel pipe and securely tied to the outer steel pipe with thin steel wire; the bottom sealing head and the inner steel pipe are tightened together; and the inner steel pipe is then inserted into the outer steel pipe. The outer steel pipes are connected to each other using connecting sleeves.

[0046] Example 2

[0047] This example uses the micro-recharge well structure from Example 1 for the penetration operation. The main steps are as follows:

[0048] Step 1: Weld a 20cm long barbed steel strip to the middle of the bottom sealing head. Wrap a flexible filter mesh around the outside of the inner steel pipe and secure it with thin steel wire. Tighten the bottom sealing head and the inner steel pipe together and insert them into the outer steel pipe to form the first section of the bottom steel pipe. Install the connecting sleeve on the top of the first section of the steel pipe.

[0049] Step 2: Select a static pressure reaction frame to provide back pressure for the injection well. At the designated injection location, remove the hard surface layer of soil.

[0050] Step 3: Insert the first section of steel pipe using a static pressure reaction frame.

[0051] Step 4: Screw the second outer steel pipe onto the first steel pipe and install the connecting sleeve onto the top of the second outer steel pipe.

[0052] Step 5: Repeat steps 3 and 4 similarly until penetrating to 30m, which is when the water-rich layer is reached.

[0053] Step 6: Using a static pressure reaction frame, pull up the top outer steel pipe to a height of 1.8m.

[0054] Step 7: Depending on the construction situation, use a water pump to pump and pressurize water in the reinjection wells to clean the pipe walls. In this embodiment, cleaning the pipe walls is not required. Repeat steps 1 to 6. After completing the construction of all reinjection wells, connect the external reinjection equipment and carry out reinjection.

[0055] Step 8: After the reinjection is completed, use a counter-pressure device or a crane to pull up and retrieve the outer steel pipes of all the reinjection wells, and backfill and seal the holes after they are pulled up.

[0056] Based on the embodiments of the present invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

Claims

1. A recyclable, drill-free micro-recharge well, comprising multiple outer steel pipes, a connecting sleeve, an inner steel pipe, a bottom sealing head, a filter screen, and barbed steel bars; Each outer steel pipe has threads on the inner walls at both ends for connection with the connecting sleeve; The outer walls at both ends of the connecting sleeve are threaded for connecting two adjacent outer steel pipes; The inner wall of the bottom end of the inner steel pipe is threaded for connection with the upper part of the sealing head; the inner steel pipe wall is provided with water-permeable holes. The structure of the bottom sealing head includes an upper part, a middle part, and a lower part connected in sequence; the upper part is a threaded cylinder used to connect to the threads inside the inner steel pipe; the middle part is a cylinder located outside the outer steel pipe, and the diameter of the middle part is equal to or greater than the outer diameter of the outer steel pipe; the lower part is a cone to reduce the resistance to travel in the soil. When the outer steel pipe penetrates the soil, the inner steel pipe and the upper part of the bottom sealing head are located in the outer steel pipe; along the direction of soil penetration, the front end of the outer steel pipe abuts against the middle of the bottom sealing head to push the bottom sealing head forward. The filter screen is placed between the outer wall of the inner steel pipe and the inner wall of the outer steel pipe, and the filter screen covers the water-permeable holes. One end of the barbed steel strip is welded to the middle of the bottom head, and the other end is inclined towards the outer steel pipe; during the process of pulling the outer steel pipe up, the barbed steel strip jams the surrounding soil, thereby helping the inner steel pipe to separate from the outer steel pipe.

2. In the micro-recharge well according to claim 1, the outer diameter of the inner steel pipe is more than 1 cm smaller than the inner diameter of the outer steel pipe, and the inner diameter of the outer steel pipe, the inner diameter of the inner steel pipe, and the number of permeable holes meet the requirements of the recharge water volume.

3. In the micro-recharge well according to claim 2, the ratio of the outer diameter of the inner steel pipe to the inner diameter of the outer steel pipe is 2:

3.

4. In the micro-recharge well according to claim 1, the bottom sealing head is made of iron block to increase the weight of the bottom sealing head, thereby assisting in fixing the inner steel pipe.

5. The micro-recharge well according to claim 1, wherein the filter screen is a flexible filter screen.

6. A method for performing penetration well completion operations using the micro-recharge well as described in any one of claims 1-5, comprising the following steps: Step 1: Weld the barbed steel strip to the middle of the bottom sealing head, wrap the flexible filter mesh around the outside of the inner steel pipe, and secure it with thin steel wire; tighten the bottom sealing head and the inner steel pipe together, and insert it into the outside steel pipe to form the first section of the bottom steel pipe; in addition, install the connecting sleeve on the top of the first section of the steel pipe. Step 2: Select the back pressure equipment for the injection well and remove the hard surface layer of soil at the designated injection location; Step 3: Use a counter-pressure device to penetrate the first section of steel pipe; Step 4: Connect the second outer steel pipe section to the first steel pipe section using a connecting sleeve, and install another connecting sleeve onto the top of the second outer steel pipe section; Step 5: Repeat steps 3 and 4 similarly until the target depth is reached; Step 6: Using the back pressure equipment, pull up the uppermost outer steel pipe, with the lifting height not exceeding the length of the inner steel pipe; during the lifting process, the bottom cap and the inner steel pipe are separated from the outer steel pipe; thus realizing the connection between the entire recharge well and the outside water. Step 7: Connect external recharge equipment and perform recharge; Step 8: After the recharge is completed, use a back pressure device or a crane to pull up and recycle the outer steel pipe.

7. The method according to claim 6, wherein the counter-pressure device is a tracked penetration machine or a hydrostatic reaction frame.

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