CN101691840B - Water level observation well and construction method thereof - Google Patents

Abstract

The invention discloses a water level observation well. The well pipe of the well adopts a PVC pipe, and the pipe sections of the PVC pipe are connected by threaded casings. The water filtering part of the well pipe is provided with a water outlet hole. A rough cloth layer is fixed on the outer wall of the pipe, and the rough cloth layer is covered with a cement mortar layer, and the water outlet hole runs through the rough cloth layer, the cement mortar layer and the PVC pipe. The invention also discloses a construction method of a water level observation well. The manufacturing method of the pipe section of the well includes: a. fixing a rough cloth layer on the outer wall of the PVC pipe section and the threaded casing; b. The cloth layer is covered with a cement mortar layer to form the pipe section of the well pipe; c, before the final setting of the cement mortar layer, a water hole is drilled on the pipe section of the well pipe corresponding to the water filtering part, and the water outlet hole runs through the The coarse cloth layer and the cement mortar layer and the PVC pipe. The invention has accurate observation results and low construction cost.

Description

A water level observation well and its construction method

technical field

The invention relates to the field of engineering monitoring, in particular to a water level observation well and a construction method thereof.

Background technique

Groundwater level monitoring is often required in engineering monitoring of civil and water conservancy projects, and steel pipes or concrete sandstone filter pipes are commonly used in current water level observation wells.

The construction process of using steel pipe or concrete sandstone filter pipe to make a water level observation well includes the following steps: measuring and releasing the well position, burying the mouth protection pipe, installing the drilling rig, drilling into the hole, clearing the hole and changing the slurry, running the well pipe, filling gravel, filling Clay balls, filling clay around the well pipe, sealing the wellhead, washing the well, installing the pump and testing, draining, backfilling or sealing the well. The purpose of gravel filling in the above steps is to form a good water seepage channel in the filter pipe section of the well pipe, and the purpose of filling clay balls and filling clay around the well pipe is to block water seepage above the water filter pipe to avoid hydraulic collusion of various soil layers . The two steps of filling clay balls and filling clay around the well pipe are the key to the successful embedding of the water level observation well pipe.

Above-mentioned application of steel pipes or concrete sandstone filter pipes to make water level observation wells mainly has the disadvantage of high cost, especially the use of steel pipes to make water level observation wells. The use of PVC pipes to make well pipes can greatly save the cost.

PVC pipe is a good plastic product with low production cost, high strength and corrosion resistance. PVC pipe has good mechanical properties, and has excellent corrosion resistance, light weight during use, easy installation, easy to achieve sealed connection, not easy to break, no maintenance, well-processed PVC pipe, generally speaking, the service life It can last up to 50 years and is widely used in construction, sewage, waste water, ventilation pipes and agricultural irrigation.

In some projects, there are examples of using PVC pipes as well pipes for water level observation wells, but the biggest disadvantage of using PVC pipes as water level observation wells is that their outer walls are smooth and easy to leak, which leads to the collusion of various aquifers that the well pipes pass through, making PVC pipes The water level observation well is a mixed water level instead of the water level value of the aquifer in the filter pipe section, resulting in distortion of the observation results.

Contents of the invention

The invention provides a water level observation well with accurate observation results and low construction cost and a construction method thereof to solve the technical problems existing in the known technology.

A technical solution adopted by the present invention to solve the technical problems existing in the known technology is: a water level observation well, the well pipe of the well adopts PVC pipes, and the pipe sections of the PVC pipes are connected by threaded sleeves. The water filtering part of the well pipe is provided with a water outlet hole, and a rough cloth layer is fixed on the outer wall of the PVC pipe, and the rough cloth layer is covered with a cement mortar layer, and the water outlet hole runs through the rough cloth layer and the The cement mortar layer and the PVC pipe.

The pipe section of the PVC pipe has a nominal outer diameter of 50 mm to 200 mm and a thickness of 2.0 mm to 3.9 mm.

Another technical solution adopted by the present invention to solve the technical problems existing in the known technology is: a construction method of a water level observation well, comprising the following steps: measuring and releasing the well position, burying the mouth protection pipe, installing a drilling rig, drilling and forming a hole , hole cleaning and slurry replacement, well pipe running, gravel filling, clay ball filling, clay filling around the well pipe, well head sealing, well flushing, pump installation and test pumping, drainage, backfilling or well sealing, the well pipe is made of PVC pipe , the pipe sections of the PVC pipe are connected by threaded sleeves, and the pipe section of the well pipe is made in the following steps:

a. Fix the rough cloth layer on the outer wall of the PVC pipe section and the threaded sleeve respectively;

b. A cement mortar layer is covered on the rough cloth layer to form the pipe section of the well pipe;

c. Before the final setting of the cement mortar layer, a water hole is drilled on the well pipe section corresponding to the water filtering part, and the water outlet hole runs through the coarse cloth layer, the cement mortar layer and the PVC pipe.

The step a is: first apply adhesive on the PVC pipe section and the outer wall of the threaded casing, and then paste 3-5 layers of rough cloth to form the rough cloth layer.

The step b is: dipping the PVC pipe segment fixedly connected with the rough fabric layer and the outer wall of the threaded sleeve in cement mortar to form the cement mortar layer.

The advantages and positive effects of the present invention are: by adopting a well pipe with a rough cloth layer fixed on the outer wall of the PVC pipe and the threaded casing, and the rough cloth layer is covered with a cement mortar layer, the smooth outer wall of the PVC pipe and easy leakage are effectively solved. The problem of collusion between the various aquifers that the well pipe passes through makes the water level observation well the water level value of the aquifer in the filter pipe section, and the observation results are accurate; the advantages of PVC pipes are better utilized, such as good mechanical properties such as resistance Pressure performance, excellent corrosion resistance, light weight, easy installation, easy to achieve sealed connection, not easy to break, no maintenance, long life, etc.; It can be arranged in multiple points while meeting the engineering purpose.

Description of drawings

Fig. 1 is the schematic diagram of the submerged layer water level observation well of the present invention;

Fig. 2 is a schematic diagram of a water level observation well in a confined aquifer of the present invention;

Fig. 3 is A-A (no drilling section) sectional view of Fig. 1 and Fig. 2;

Fig. 4 is a B-B (drilling section) sectional view of Fig. 1 and Fig. 2 .

In the figure: 1. PVC pipe, 2. fabric layer, 3. cement mortar layer, 4. water outlet hole.

Detailed ways

In order to further understand the invention content, characteristics and effects of the present invention, the following examples are given, and detailed descriptions are as follows in conjunction with the accompanying drawings:

Please refer to Fig. 1～Fig. 4, a kind of water level observation well of the present invention, the well pipe of this well adopts PVC pipe 1, and each pipe section of above-mentioned PVC pipe 1 is connected by threaded casing, is connected by above-mentioned PVC pipe section and threaded casing A rough cloth layer 2 is fixed on the outer wall of the formed PVC pipe 1, and the above rough cloth layer 2 is covered with a cement mortar layer 4, corresponding to the water filtering part, and a water hole 4 is drilled, and the water outlet hole 4 runs through the rough cloth layer 2 and the cement mortar layer. Mortar layer 3 and PVC pipe 1.

The nominal outer diameter of the above-mentioned PVC pipe section may be 50mm-200mm, and the thickness may be 2.0mm-3.9mm.

The construction method of the above-mentioned water level observation well includes the following steps: measuring and releasing the well position, burying the mouth protection pipe, installing the drilling rig, drilling into the hole, clearing the hole and changing the slurry, running the well pipe, filling gravel, filling clay balls, filling the periphery of the well pipe Cohesive soil, wellhead sealing, well cleaning, pump installation and testing, drainage, backfilling or well sealing, the well pipe is made of PVC pipe 1, and the pipe sections of PVC pipe 1 are connected by threaded sleeves. In order to prevent the outer wall of PVC pipe 1 from being smooth and seepage The present invention adopts following method to make the pipe section of well pipe:

a. Fix the rough cloth layer on the outer wall of the PVC pipe section and the threaded sleeve respectively;

b. A cement mortar layer is covered on the rough cloth layer to form the pipe section of the well pipe;

c. Before the final setting of the cement mortar layer, a water hole is drilled on the well pipe section corresponding to the water filtering part, and the water outlet hole runs through the coarse cloth layer, the cement mortar layer and the PVC pipe.

The method of respectively fixing the rough cloth layer on the outer wall of the PVC pipe section and the threaded casing includes: applying adhesive on the outer wall of the above-mentioned pipe fitting and pasting 3 to 5 layers of rough cloth; it can also be used on the outer wall of the above-mentioned pipe fitting. Steel wire binds multiple layers of coarse cloth.

The method of sticking the cement mortar layer on the rough cloth layer in the above step b includes: rotating the PVC pipe section and the outer wall of the threaded sleeve fixed to the rough cloth layer in the cement mortar; Apply cement mortar.

Example 1:

The excavation area of a high-rise residential building foundation pit project is 12,300 m ² , and the depth of the foundation pit is 15.130m. The surrounding of the foundation pit adopts an underground diaphragm wall, the depth of which is 34 meters, and the thickness of the wall is 1.0 meters. Water level observation wells in the aquifer layer are arranged around the foundation pit, and the structure of the water level observation wells is shown in Figure 1, Figure 3 and Figure 4.

The top-to-bottom vertical distribution of strata within the excavation depth range of the foundation pit is:

①Artificial fill and miscellaneous fill, with a thickness of 2.3m ;

② Silty clay, thickness 5.1m;

③ Silt, thickness 11.4m ;

④ Silty clay, thickness 5.7m ;

⑤silt, thickness 9.80m ;

⑥silt, thickness 8.10m ;

⑦silty clay, thickness 14.5m ;

⑧ Silt, thickness 16.30m .

The above-mentioned aquifer water level observation well adopts PVC pipe. The nominal outer diameter of the pipe section of the PVC pipe is 50mm, the thickness is 2.0mm, the total pipe length is 9m, the first pipe section is 6m, and the second pipe section is 3m. The threaded casing is used between the two pipe sections of the PVC pipe connect. Apply adhesive on the outer wall of the PVC pipe section and the threaded casing, and paste 3 layers of cotton fabric, and then dip the outer wall of the above-mentioned pipe fittings in the cement mortar, and drill holes in the water filtration part when the cement mortar on the outer wall of the well pipe is quickly solidified. A well pipe screen section is formed.

The construction method of using PVC pipes to make water level observation wells includes the following steps: measuring and releasing the well position, burying the mouth protection pipe, installing the drilling rig, drilling into the hole, clearing the hole and changing the slurry, running the well pipe, filling gravel, filling clay balls, in the well Filling with cohesive soil around the pipe, sealing the wellhead, flushing the well, installing the pump for pumping test, draining, backfilling or sealing the well.

After the aquifer water level observation well made of PVC pipe was successfully buried, the 101-type water level gauge was used to observe the water level. No hydraulic collusion occurred on the outer wall of the well pipe, and the test results met the requirements.

Example 2:

The excavation project of a subway tunnel is 260m long, 20.5m wide, and the excavation depth is 15.420m. An underground continuous wall is adopted around the foundation pit, the ground connection wall is 35 meters deep and the wall thickness is 1.2 meters. Water level observation wells in the aquifer and confined aquifer are arranged around the foundation pit, see Figures 1 to 4.

The top-to-bottom vertical distribution of strata within the excavation depth range of the foundation pit is:

①Artificial fill and miscellaneous fill, thickness 3.4m ;

② Silt, thickness 12.1m ;

③ Silty clay, thickness 3.6m;

④ Silt, thickness 2.5m;

⑤ Silt, thickness 10.0m ;

⑥silty clay, thickness 12.5m ;

⑦silt, thickness 10.3m ;

⑧silt, thickness 5.4m .

The water level observation well in the aquifer uses PVC pipes. The nominal outer diameter of the PVC pipe section is 90mm, the thickness is 3.0mm, the total pipe length is 10m, the first pipe section is 6m, and the second pipe section is 4m. The two pipe sections of the PVC pipe are connected by threaded sleeves .

The water level observation well in the confined aquifer uses PVC pipes. The nominal outer diameter of the PVC pipe section is 90mm, the thickness is 3.0mm, and the total pipe length is 24m. connect.

After smearing adhesive on the outer wall of the PVC pipe section and the threaded casing, paste 4 layers of cotton cloth, and then dip the outer wall of the above-mentioned pipe fittings in the cement mortar, and when the cement mortar on the outer wall is quickly solidified, drill holes in the water filter part to form Well pipe filter pipe section.

The construction method of using PVC pipes to make water level observation wells includes the following steps: measuring and releasing the well position, burying the mouth protection pipe, installing the drilling rig, drilling into the hole, clearing the hole and changing the slurry, running the well pipe, filling gravel, filling clay balls, in the well Filling with cohesive soil around the pipe, sealing the wellhead, flushing the well, installing the pump for pumping test, draining, backfilling or sealing the well.

After the aquifer water level observation wells and confined aquifer water level observation wells made of PVC pipes were successfully buried, the water level was observed with a 101-type water level gauge. No hydraulic collusion occurred on the outer wall of the well pipes, and the test results met the requirements.

Example 3:

The foundation pit project of a subway station is 463m long, 19.35m wide, and 18.590m deep. An underground continuous wall is adopted around the foundation pit, the ground connection wall is 38 meters deep and the wall thickness is 1.2 meters. Water level observation wells in the aquifer and confined aquifer are arranged around the foundation pit, see Figures 1 to 4.

The top-to-bottom vertical distribution of strata within the excavation depth range of the foundation pit is:

①Artificial fill and miscellaneous fill, thickness 4.50m;

② Silt, thickness 13.00m;

③ Silty clay, thickness 4.0m;

④ Silt, thickness 2.80m;

⑤silt, thickness 13.10m;

⑥Silly clay with a thickness of 21.5m.

The water level observation well in the aquifer uses PVC pipes. The nominal outer diameter of the PVC pipe section is 200mm, the thickness is 3.9mm, the total pipe length is 10m, the first pipe section is 6m, and the second pipe section is 4m. The two pipe sections of the PVC pipe are connected by threaded sleeves .

The water level observation well in the confined aquifer uses PVC pipes. The nominal outer diameter of the PVC pipe section is 200mm, the thickness is 3.9mm, and the total pipe length is 30m.

After smearing adhesive on the outer wall of the PVC pipe section and the threaded casing, paste 4 layers of cotton fabric, and then dip the outer wall of the above-mentioned pipe fitting in the cement mortar, and drill the water filter part when the cement mortar on the outer wall of the above-mentioned pipe fitting is fast solidified. holes to form the well pipe filter pipe section.

The construction method of using PVC pipes to make water level observation wells includes the following steps: measuring and releasing the well position, burying the mouth protection pipe, installing the drilling rig, drilling into the hole, clearing the hole and changing the slurry, running the well pipe, filling gravel, filling clay balls, in the well Filling with cohesive soil around the pipe, sealing the wellhead, flushing the well, installing the pump for pumping test, draining, backfilling or sealing the well.

After the aquifer water level observation wells and confined aquifer water level observation wells made of PVC pipes were successfully buried, the water level was observed with a 101-type water level gauge. No hydraulic collusion occurred on the outer wall of the well pipes, and the test results met the requirements.

The basic principle of the present invention is: adopt PVC pipe to make water level observation well pipe, the connection mode between the pipe sections of PVC pipe adopts threaded bushing, the anti-seepage treatment method of sticking cloth outside PVC pipe and brushing cement mortar. The well pipe production method utilizes the advantages of PVC pipes such as good mechanical properties such as pressure resistance, excellent corrosion resistance, light weight, easy installation, easy connection and sealing, not easy to break, no maintenance, long life, etc. . The anti-seepage treatment method of sticking cloth on the outside of the PVC pipe and painting cement mortar overcomes the disadvantage that the smooth pipe wall is easy to cause hydraulic collusion in the application. Compared with steel pipes and concrete sandstone filter pipes, PVC pipe water level observation wells are inexpensive and can be arranged in multiple points while meeting the engineering purpose.

Although the preferred embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific embodiments. The above-mentioned specific embodiments are only illustrative and not restrictive. Those of ordinary skill in the art Under the enlightenment of the present invention, people can also make many forms without departing from the purpose of the present invention and the scope of protection of the claims, and these all belong to the protection scope of the present invention.

Claims (5)

1. a kind of water level observation well, the well pipe of this well adopts PVC pipe, is connected by threaded casing between each pipe section of described PVC pipe, and the water filtering position of described well pipe is provided with water outlet, it is characterized in that, all A rough cloth layer is fixed on the outer wall of the PVC pipe, and the rough cloth layer is covered with a cement mortar layer, and the water outlet hole runs through the rough cloth layer, the cement mortar layer and the PVC pipe. 2 . The water level observation well according to claim 1 , characterized in that, the pipe section of the PVC pipe has a nominal outer diameter of 50 mm to 200 mm and a thickness of 2.0 mm to 3.9 mm. 3. A construction method of a water level observation well, comprising the following steps: measuring and releasing the well position, burying the mouth protection pipe, installing a drilling rig, drilling into a hole, clearing the hole and changing slurry, lowering the well pipe, filling gravel, filling clay balls, Fill the well pipe with cohesive soil, seal the wellhead, wash the well, install the pump for test pumping, drain, backfill or seal the well. The well pipe is made of PVC pipe, and the pipe sections of the PVC pipe are connected by threaded casings. It is characterized in that , the method for making the pipe section of the well pipe is: a. Fix the rough cloth layer on the outer wall of the PVC pipe section and the threaded sleeve respectively; b. A cement mortar layer is covered on the rough cloth layer to form the pipe section of the well pipe; c. Before the final setting of the cement mortar layer, a water hole is drilled on the well pipe section corresponding to the water filtering part, and the water outlet hole runs through the coarse cloth layer, the cement mortar layer and the PVC pipe. 4. The construction method of the water level observation well according to claim 3, characterized in that, the step a is: first apply adhesive on the outer wall of the PVC pipe section and the threaded casing, and then paste 3 to 5 A layer of coarse cloth, forming the layer of coarse cloth. 5. The construction method of the water level observation well according to claim 3, characterized in that, the step b is: rotating the PVC pipe section and the threaded casing respectively fixed with a rough cloth layer in cement mortar dipping in slurry to form the cement mortar layer on the coarse cloth layer.

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