Construction method for descending water pipe well under geological condition of sandy soil containing confined water

Abstract

The invention relates to the technical field of building construction, in particular to a construction method of a water pipe well with confined water sandy soil geological condition descending, which comprises the following steps: preparing for construction, drilling and installing a steel casing, cleaning silt in a hole, installing a sand-free pipe, filling a filter material and pulling out the steel casing. The step of drilling and installing the steel casing specifically comprises the steps that drilling operation is carried out through drilling equipment, a steel casing section is installed immediately after drilling is carried out by a set depth, and the steel casing section is installed while drilling is carried out till a drilled hole reaches the designed depth; the steel casing with certain strength is adopted, deformation caused by collision of a drilling machine and a drill bit in the construction process is avoided, side pressure of a soil layer and underground water can be effectively resisted, deformation is not prone to occurring, and follow-up repeated use can be achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of building construction, and particularly relates to a construction method of a dewatering tube well under a sand soil condition containing confined water. BACKGROUND

[0002] Coastal, river, and Yangtze River alluvial plains are rich in groundwater, and a large amount of fine sand and silt layer exists underground after long-term deposition, and the groundwater is extremely rich, and even confined water exists. Before the excavation of a basement of a building project, dewatering is generally required. When the water quantity of a phreatic water layer is small, vacuum well point dewatering can be used, and when the water quantity is large, tube well dewatering is generally used. However, the dewatering tube well under the sand soil condition has the problems of difficult hole forming, easy hole collapse, no sand pipe to be installed in place, and filter material to be filled. SUMMARY

[0003] In view of the above problems, the present application discloses a construction method of a dewatering tube well under a sand soil condition containing confined water, to solve the problems of difficult hole forming, easy hole collapse, no sand pipe to be installed in place, and filter material to be filled of the dewatering tube well under the sand soil condition in the prior art.

[0004] The dewatering tube well under the sand soil condition containing confined water has the problems of difficult hole forming, easy hole collapse, no sand pipe to be installed in place, and filter material to be filled.

[0005] A construction method of a dewatering tube well under a sand soil condition containing confined water, comprising the steps of construction preparation, drilling and installing a steel casing, cleaning mud in a hole, installing a sandless pipe, filling filter material, and pulling out the steel casing.

[0006] The step of the construction preparation specifically comprises the following steps: selecting drilling equipment according to the diameter and depth of the tube well, manufacturing a plurality of steel casing segments according to the size of the diameter of the tube well, and providing a sewage pump, a matched water pipe, an air compressor, and a matched gas pipeline.

[0007] The step of drilling and installing the steel casing specifically comprises the following steps: drilling by using the drilling equipment, and immediately installing the steel casing segment after drilling to the set depth, and installing the steel casing segment while drilling until the drilling reaches the design depth.

[0008] The step of cleaning the mud in the hole specifically comprises the following steps: discharging high-pressure air in the hole by using the air compressor, and after the sediment mud in the hole is fully mixed with the underground water in the hole, the mixed mud and water are discharged by using the sewage pump, and the hole is washed until the mud in the hole is cleaned.

[0009] The step of installing the sandless pipe specifically comprises the following steps: installing the sandless pipe in the steel casing from bottom to top segment by segment until the sandless pipe is installed to the ground.

[0010] The step of filling filter material and pulling out the steel casing tube specifically comprises: filling filter material into the gap between the sandless pipe and the steel casing tube, and synchronously pulling out the steel casing tube according to the filling height of the filter material, and pulling out along with filling until the filter material is filled to the ground.

[0011] In some embodiments, the drilling equipment is a spiral drill, a rotary drill or a reverse circulation drill.

[0012] In some embodiments, the length of the steel casing tube segment is 1-2 m.

[0013] In some embodiments, the diameter of the steel casing tube segment is 780-820 m.

[0014] In some embodiments, the filter material is a mixture of gravel / pebble and coarse sand.

[0015] In some embodiments, the particle size of the filter material is 0.5-5 cm.

[0016] In some embodiments, the step of circulating and washing the hole until the silt in the hole is cleaned specifically comprises: supplementing clean water into the hole by using the water supply pipeline, and circulating and washing the hole until the silt in the hole is cleaned, and the water in the hole is clear.

[0017] Compared with the prior art, the above-mentioned application has at least one of the following advantages or beneficial effects:

[0018] I. Simple operation, wide applicability, can be used for dewatering well construction operation under various basement geological conditions.

[0019] II. By using a steel casing tube with certain strength, the steel casing tube will not be deformed due to collision with the drill and the drill bit during construction, can effectively resist the lateral pressure of the soil layer and underground water, is not easy to deform and can be reused subsequently.

[0020] III. The problems of hole collapse, failure to form a hole, no sand pipe to reach the designed depth, and filter material unable to effectively fill are solved under the conditions of rich underground water, sand layer with confined water and soil layer. BRIEF DESCRIPTION OF DRAWINGS

[0021] The present application and its features, shapes and advantages will become more apparent by reading the detailed description of the non-limiting embodiments with reference to the following drawings. The same reference signs indicate the same layers throughout the drawings. The drawings are not necessarily drawn to scale, and the emphasis is on illustrating the main idea of the present application.

[0022] Figure 1 The flowchart of the construction method of the dewatering well under the geological conditions of the sand layer with confined water in the embodiments of the present application;

[0023] Figure 2 The structural schematic diagram of the drilling equipment in the embodiments of the present application;

[0024] Figure 3 is a structural schematic view of a steel casing segment in an embodiment of the present application;

[0025] Figure 4 is a structural schematic view of a drilling device drilling in an embodiment of the present application;

[0026] Figure 5 is a structural schematic view of a construction structure for cleaning silt in a hole in an embodiment of the present application;

[0027] Figure 6 is a structural schematic view of a construction structure for installing a sandless pipe in an embodiment of the present application;

[0028] Figure 7 is a structural schematic view of a construction structure for filling filter material and pulling out a steel casing in an embodiment of the present application;

[0029] Figure 8 is a structural schematic view of a construction structure of a dewatering pipe well under a bearing water and sand soil geological condition after construction in an embodiment of the present application;

[0030] Among them, 1, drilling equipment; 2, steel casing segment; 3, air compressor; 4, sewage pump; 5, sandless pipe; 6, filter material. DETAILED DESCRIPTION

[0031] The present application will be further described below in conjunction with the drawings and specific embodiments, but not as a limitation of the present application.

[0032] As shown in Figure 1 , the embodiment discloses a construction method of a dewatering pipe well under a bearing water and sand soil geological condition, the bearing water and sand soil geological condition can be backfill soil, clay, sand layer (containing phreatic water) and fine sand layer (containing bearing water) from top to bottom; the construction method comprises the following steps:

[0033] Step S1, construction preparation: as shown in Figure 2 and 3 , select a drilling equipment 1 according to the diameter and depth of the pipe well, the drilling equipment 1 can be a spiral drill, a rotary drill or a reverse circulation drill, and the specific selection of the drilling equipment 1 is determined according to the actual situation. A plurality of steel casing segments 2 are made according to the size of the diameter of the pipe well, and one end of the steel casing segment 2 is provided with an internal thread, and the other end is provided with an external thread, so as to facilitate lengthening in the later period, the length of each steel casing segment 2 is 1-2 m, and the diameter of the steel casing segment 2 can be adjusted according to the size of the diameter of the pipe well, and the conventional diameter is 800 mm, and a sewage pump 4 and a supporting water pipe and an air compressor 3 and a supporting gas pipeline are provided; wherein, the sewage pump 4 can be equipped according to the actual situation, and is mainly used for removing sewage in the pipe well; the air compressor 3 is mainly used for removing high-pressure air, and fully mixing the silt and underground water in the well, and cooperating with the sewage pump 4 to clean the silt.

[0034] Step S2, Drill holes and install steel casing: as shown Figure 4 As shown, drilling equipment 1 is used for drilling operations, and steel casing section 2 is installed immediately after drilling to the set depth. Steel casing section 2 is installed while drilling until the design depth is reached. Specifically, drilling equipment 1 is positioned to carry out drilling operations. The appropriate drilling equipment 1 is selected according to the geological conditions and the size and depth of the well. After drilling to the appropriate depth according to the length of steel casing section 2, steel casing section 2 is installed in a timely manner. Steel casing section 2 is installed while drilling to prevent sand layer collapse and loss until the design depth is reached. The upper and lower steel casing sections 2 are connected to form a steel casing.

[0035] Step S3, cleaning the mud and sand in the hole: As shown in 5, after drilling is completed and the steel casing is fully installed, promptly install the air compressor 3 and its matching air supply pipeline, sewage pump 4 and its matching water pipe and water supply pipeline. Use the air compressor 3 to discharge the high-pressure air in the hole, and after fully mixing the sediment in the hole with the groundwater in the hole, use the sewage pump 4 to remove the mixed mud and sand water. Use the water supply pipeline to replenish the hole with clean water and circulate the hole until the mud and sand in the hole are completely cleaned and the water in the hole is clear.

[0036] Step S4, Install Sand-Free Pipe 5: As shown in 6, install the sand-free pipe 5 section by section from bottom to top inside the steel casing until it reaches the ground. Specifically, after the well is cleaned, install the sand-free pipe 5 in a timely manner. Install the pipe section by section from bottom to top until it reaches the ground. When installing, pay attention to centering the installation to avoid eccentric installation, which would prevent the subsequent filter material 6 from filling. The sand-free pipe 5 can be selected according to the well diameter and design requirements.

[0037] Step S5, Filling Filter Media 6 and Removing the Steel Casing: As shown in Figure 7, after the sand-free pipe 5 is installed, remove the sewage pump 4 and its associated water pipes, air compressor 3 and its associated air supply pipes. Fill the gap between the sand-free pipe 5 and the steel casing with filter media 6, and simultaneously remove the steel casing according to the filling height of the filter media 6. Continue filling and removing until the filter media 6 fills to the ground. The filter media 6 is usually a mixture of crushed stone / pebbles and coarse sand, which can be selected according to design requirements. The particle size of the filter media 6 is 0.5-5cm. After all the filter media 6 is filled, the single-well construction is completed. Figure 8 As shown, water pumps were installed promptly according to the site conditions to carry out dewatering operations.

[0038] Those skilled in the art should understand that variations can be implemented by combining existing technology with the above embodiments, which will not be elaborated here. Such variations do not affect the essence of the present invention, and will not be elaborated here either.

[0039] The preferred embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and the devices and structures not described in detail should be understood as being implemented in a conventional manner in the art. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention using the methods and techniques disclosed above, or modify them into equivalent embodiments with equivalent changes, without departing from the scope of the present invention. This does not affect the essential content of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the present invention's technical solutions still fall within the protection scope of the present invention.

Claims

1. A construction method for a downwater well in sandy soil with confined water, characterized in that, This includes construction preparation, drilling and installing steel casing, cleaning mud and sand from the hole, installing sand-free pipe, filling filter material and pulling out steel casing; The specific steps of the construction preparation include: selecting drilling equipment according to the diameter and depth of the well; making multiple steel casing sections according to the diameter of the well; one end of the steel casing section is provided with internal thread and the other end is provided with external thread; and providing sewage pumps and matching water pipes, air compressors and matching gas pipelines. The specific steps of drilling and installing steel casing include: using drilling equipment to perform drilling operations, and immediately installing steel casing sections after drilling to a set depth, installing steel casing sections as drilling continues until the drilling reaches the designed depth; The steps for cleaning the mud and sand inside the hole specifically include: using an air compressor to discharge high-pressure air from the hole, and after fully mixing the sediment and sand inside the hole with the groundwater inside the hole, using a sewage pump to remove the mixed mud and sand water, and circulating the hole until the mud and sand inside the hole are completely cleaned. The steps for installing the sand-free pipe specifically include: installing the sand-free pipe section by section from bottom to top inside the steel casing until it reaches the ground; The steps of filling the filter material and pulling out the steel casing specifically include: filling the gap between the sand-free pipe and the steel casing with filter material, and simultaneously pulling out the steel casing according to the filling height of the filter material, filling and pulling out simultaneously until the filter material is filled to the ground.

2. The construction method for downwater wells in sandy soil conditions containing confined water, as described in claim 1, is characterized in that... The drilling equipment is a auger drilling rig, rotary drilling rig, or reverse circulation drilling rig.

3. The construction method for downwater wells in sandy soil conditions containing confined water, as described in claim 1, is characterized in that... The length of the steel casing section is 1 to 2 meters.

4. The construction method of a downwater well in sandy soil with confined water as described in claim 1, characterized in that, The diameter of the steel casing section is 780–820 m.

5. The construction method for downwater wells in sandy soil conditions containing confined water, as described in claim 1, is characterized in that... The filter media is a mixture of crushed stone / pebbles and coarse sand.

6. The construction method of a downwater well in sandy soil with confined water as described in claim 1, characterized in that, The filter media has a particle size of 0.5 to 5 cm.

7. The construction method for downwater wells in sandy soil conditions containing confined water, as described in claim 1, is characterized in that... The specific steps for circulating and washing the hole until the mud and sand inside the hole are completely removed include: using a water supply pipe to replenish clean water into the hole, circulating and washing the hole until the mud and sand inside the hole are completely removed and the water inside the hole is clear.

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