CN114250801A

CN114250801A - Pipe well and light well point combined dewatering construction method

Info

Publication number: CN114250801A
Application number: CN202111682306.6A
Authority: CN
Inventors: 陶锋; 董丰博; 刘峰; 黄令翔; 饶应贵; 林小康; 赵志恒; 王河; 方彦由; 范兴旺; 杨国鹏
Original assignee: CCCC Seventh Engineering Co Ltd
Current assignee: CCCC Seventh Engineering Co Ltd
Priority date: 2021-12-31
Filing date: 2021-12-31
Publication date: 2022-03-29

Abstract

The embodiment of the disclosure relates to a pipe well and light well point combined dewatering construction method. The method comprises the following steps: arranging a pipe well position according to the actual hydrogeological data; laying pipe wells according to the pipe well positions, and dewatering the pipe wells; after the pipe well dewatering is completed, excavating a foundation pit, and excavating a foundation pit primary platform; arranging light well point well positions and light well point pipes; carrying out light well point dewatering; and after the light well point dewatering is completed, digging out a foundation pit secondary platform. The embodiment of the disclosure adopts the dewatering mode that the pipe well and the light well point are combined together in the deep and large foundation pit with the weakly permeable stratum, integrates the advantages of two dewatering modes, utilizes the pipe well to reduce the whole underground water level of the foundation pit, recycles the underground water of the aquifer above the negative pressure control depth in the light well point rapid drainage, solves the problem of water seepage retained on the upper part of the weakly permeable stratum, and thereby ensures the stability of the normal construction of the foundation and the side slope of the foundation pit.

Description

Pipe well and light well point combined dewatering construction method

Technical Field

The embodiment of the disclosure relates to the technical field of hydraulic engineering, in particular to a pipe well and light well point combined dewatering construction method.

Background

The purpose of the foundation pit dewatering is to provide underground engineering operation conditions for foundation engineering construction and keep the foundation pit slope stable. When the excavation depth of the foundation pit is less than 6.0m (the underground water burial depth is 6.0m), the foundation pit dewatering is usually carried out in a single-stage light well point mode. In the method, because the well point spacing is small (less than or equal to 2.0m), and the vacuum negative pressure type water pumping is adopted, the underground water of the aquifer above the negative pressure control depth in the foundation trench can be drained quickly, the water head of the underground water is reduced, the problem of water retention can be solved effectively, but the action range is small, and the limitation to deep and large foundation pits is large. The excavation depth of the foundation pit is larger than 6.0m, and a pipe well mode is often adopted due to the requirement of depth reduction. In this way, water in the soil layer flows into the well by gravity, and is pumped out of the well by the submerged electric pump, so that the speed of draining accumulated water in the foundation pit is slow. In addition, the distance between the well points is large (usually larger than 6.0m), and slope instability is often caused by the problem of lateral seepage of retained water in certain specific strata, so that an ideal precipitation effect cannot be achieved.

Accordingly, there is a need to ameliorate one or more of the problems with the related art solutions described above.

It is noted that this section is intended to provide a background or context to the disclosure as recited in the claims. The description herein is not admitted to be prior art by inclusion in this section.

Disclosure of Invention

An object of the disclosed embodiments is to provide a method of combined precipitation construction of a tube well and a light well point, thereby overcoming, at least to some extent, one or more of the problems due to the limitations and disadvantages of the related art.

According to the embodiment of the disclosure, a pipe well and light well point combined dewatering construction method is provided, which comprises the following steps:

arranging a pipe well position according to the actual hydrogeological data;

laying pipe wells according to the pipe well positions, and dewatering the pipe wells;

after the pipe well dewatering is completed, excavating a foundation pit, and excavating a foundation pit primary platform;

arranging light well points and well positions;

carrying out light well point dewatering;

and after the light well point dewatering is completed, digging out a foundation pit secondary platform.

In an embodiment of the present disclosure, the deployment pipe well includes:

the construction sequence sequentially comprises well point measurement and positioning, drilling, hole cleaning, lifting and lowering of a water pipe, backfilling of a filter layer, sealing, well washing, control circuit installation, water pump installation, water test pumping, normal operation of a dewatering well and well sealing.

In an embodiment of the present disclosure, the laying pipe well further includes:

the mud tank and the sedimentation tank are arranged for drilling and cleaning.

In an embodiment of the present disclosure, the setting pipe well further includes:

and when the hole protection pipe is embedded in the pipe well, the pipe well is vertically embedded, and is driven into undisturbed soil by 10-20cm, and the inclination of a drilling hole is less than 1%.

In one embodiment of the present disclosure, the downcomer is a double-walled corrugated filter tube.

In an embodiment of the present disclosure, the setting a light well point includes:

the construction sequence sequentially comprises the steps of paying off and positioning, punching and forming a hole, arranging a well point pipe, filling a filter material, laying and connecting a water collecting pipe, installing pumping equipment, performing a pumping test and formally pumping water.

In an embodiment of the present disclosure, the pipe well precipitation includes:

and after the pipe well is laid, carrying out pipe well precipitation in advance for a first preset number of days, and reducing the underground water level in the foundation pit in time.

In an embodiment of the present disclosure, the laying of the light well point further includes:

and when the foundation pit is dug to a preset distance from the water retaining layer, laying light well points.

In an embodiment of the present disclosure, the light well point precipitation comprises:

and after the light well points are arranged, the light well points are subjected to dewatering in advance for a second preset number of days, and the underground water of the aquifer above the depth is controlled by utilizing the negative pressure in the drainage of the light well points.

In an embodiment of the present disclosure, the deviation of the punching verticality is less than 1%, the hole diameter of the punched hole is not less than 150mm, and the final depth of the punched hole is greater than the design depth of 0.5 m.

The technical scheme provided by the embodiment of the disclosure can have the following beneficial effects:

in the embodiment of the disclosure, by the aid of the pipe well and light well point combined dewatering construction method, in a deep and large foundation pit with a weakly permeable stratum, a dewatering mode combining the pipe well and the light well point is adopted, advantages of two dewatering modes are integrated, the whole underground water level of the foundation pit is reduced by the pipe well, underground water of a water-containing stratum above a negative pressure control depth is drained rapidly by the light well point, the problem of water seepage retained at the upper part of the weakly permeable stratum is solved, and normal construction of a foundation and stability of a foundation pit slope are guaranteed.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and together with the description, serve to explain the principles of the disclosure. It is to be understood that the drawings in the following description are merely exemplary of the disclosure, and that other drawings may be derived from those drawings by one of ordinary skill in the art without the exercise of inventive faculty.

FIG. 1 is a diagram illustrating steps of a pipe well and light well point combined precipitation construction method according to the present disclosure;

FIG. 2 illustrates a flow chart of a pipe well and light well point combined precipitation construction method in an exemplary embodiment of the disclosure;

FIG. 3 illustrates a tubular well deployment flow diagram in an exemplary embodiment of the present disclosure;

FIG. 4 shows a flow chart for the deployment of the celebratory well point in an exemplary embodiment of the present disclosure.

Detailed Description

Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments may, however, be embodied in many different forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

Furthermore, the drawings are merely schematic illustrations of embodiments of the disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and thus their repetitive description will be omitted. Some of the block diagrams shown in the figures are functional entities and do not necessarily correspond to physically or logically separate entities.

In the embodiment, firstly, a combined precipitation construction method of a pipe well and a light well point is provided. Referring to fig. 1, the pipe well and light well point combined precipitation construction method may include: step S101 to step S105.

Step S101: arranging a pipe well position according to the actual hydrogeological data;

step S102: laying pipe wells according to the pipe well positions, and dewatering the pipe wells;

step S103: after the pipe well dewatering is completed, excavating a foundation pit, and excavating a foundation pit primary platform;

step S104: arranging light well points and well positions;

step S105: and (4) carrying out light well point dewatering, and digging out a foundation pit secondary platform after the light well point dewatering is completed.

Through the pipe well and light well point combined dewatering construction method, in a deep and large foundation pit with a weakly permeable stratum, a dewatering mode combining the pipe well and the light well point is adopted, the advantages of two dewatering modes are integrated, the whole underground water level of the foundation pit is reduced by using the pipe well, the underground water of the aquifer above the depth is quickly drained by using the light well point, the problem of water seepage caused by retention on the upper part of the weakly permeable stratum is solved, and the normal construction of a foundation and the stability of a foundation pit slope are guaranteed.

Next, the steps of the above-described pipe well and light well point combined precipitation construction method in the present exemplary embodiment will be described in more detail with reference to fig. 1 to 4.

Step S101: and arranging the well position of the pipe well according to the actual hydrogeological data.

Specifically, related parameters (well position arrangement distance, pipe well depth, pipe well filtering part length, well water inlet and outlet amount and the like) are calculated according to actual hydrogeological data before well positions are arranged, the positions of underground pipelines need to be considered when the well positions are arranged, and underground obstacles are staggered. And (4) before excavation, manually excavating an exploratory well, wherein the exploratory well depth is not less than 3 m. The well location should be marked.

Step S102: and laying pipe wells according to the pipe well positions, and dewatering the pipe wells.

In one embodiment, as shown in FIG. 3, the deployment tube well comprises: the construction sequence sequentially comprises well point measurement and positioning, drilling, hole cleaning, lifting and lowering of a water pipe, backfilling of a filter layer, sealing, well washing, control circuit installation, water pump installation, water test pumping, normal operation of a dewatering well and well sealing.

Specifically, the pipe well layout process is as shown in fig. 3, and after the well drilling position is determined, the drill rig is stably and horizontally placed, and the center of the hole protecting pipe, the center of the grinding disc and the hook form a vertical line. The buried hole protection pipe is required to be vertical and is driven into undisturbed soil by 10-20cm, the periphery of the buried hole protection pipe is tamped by clay, a well pipe and sand can be drilled after the well pipe and the sand are in place, the inclination of a drilling hole is not more than 1 percent (a rotary disc is leveled by a level ruler), the wall of the whole drilling hole is required to be round and smooth, and a bent drilling rod is not allowed to be adopted during drilling.

During drilling, proper slurry proportion is selected according to field geological conditions, stratum natural slurry making is adopted as much as possible, a large hook is required to be hung tightly and then slowly follow the drilling tool (the drilling tool is always in a pressure reduction mode) in the whole drilling process, one-time bending of the drilling tool is avoided, and particularly, the drilling tool and a water joint on the drilling machine cannot swing greatly due to the opening. And (3) repeatedly cleaning the hole once when drilling one drill rod, cleaning mud blocks in the hole, connecting a new drill rod, and completely cleaning the hole after finishing the hole until the returned mud does not contain the mud blocks, and lifting the drill after the sand content of the returned mud is less than 12%.

The well pipes are arranged and combined in advance according to the designed well depth, the bottoms of all deep wells are strictly controlled according to the elevation during pipe discharging, and the elevation of the well mouth is kept consistent. The tubular well tubular product adopts double-walled corrugated filter tube, in order to guarantee that the well casing does not lean on the wall of a well and guarantee to pack sand thickness, respectively add a set of centralizer 4 on the lower part of filter tube, guarantee that cyclic annular sand-pack clearance thickness is greater than 150mm, about the pipe top than the natural ground height 300mm, double-walled corrugated filter tube outsourcing one deck 80 ~ 100 mesh filter screen. The lower tube is to be accurately positioned. Naturally falls down, slightly rotates to fall in place, and cannot be pressed down by strong force so as to avoid damaging the filtering structure. And after the well pipe is in place, the mud in the lower drill rod is diluted to about 1.05, and the dilution of the mud is gradually and slowly carried out.

And (3) uniformly and slowly filling the sand filling (2-4 mm graded quartz sand) along the periphery of the well wall, and measuring the height of the top surface of the sand filling along with the filling, wherein the horizontal sand filling thickness is not less than 150 mm.

The well washing must be carried out in time after the completion of the work of lowering the well pipe, filling gravel, sealing holes, stopping water and the like. The well is preferably progressively deeper from the top.

The well-flushing strength should meet the following regulations:

(1) the well washing of the sand aquifer pipe well is gradually strengthened from weak, and the well washing of the gravel aquifer pipe well and the pebble aquifer pipe well is always carried out with the maximum strength;

(2) the maximum water level drop of the well washing should approach or exceed the maximum water level depth during the water pumping test.

For example, the air compressor vibration method is adopted for well washing, the submergence ratio of the air pipe is more than 50%, and the well washing quality meets the following requirements:

(1) the water outlet of the pipe well is clean and does not contain construction substances such as slurry and the like;

(2) the water yield is preferably close to the design requirement or the difference of the unit water yields of two continuous well cleanups is not less than 10%;

(3) in the continuous well washing process, the sand content of well water tends to be stable;

(4) the observation well is washed until the water level change response is sensitive.

Before the submersible pump is installed, the submersible pump and a control system are subjected to comprehensive and careful inspection once. And (3) checking the rotation direction of the motor, whether bolts of all parts are screwed down, whether lubricating oil is sufficient, whether the seal of a cable joint is loosened, whether a cable is damaged or not, breaking and the like, and then rotating the cable on the ground for 3-5 min, if no problem exists, so that the cable can be put into a well for use. The submerged electric pump is installed in deep well and can be hung into the water filtering layer by using rope, and each pump is equipped with a control switch. The main power line is arranged along the deep well drainage pipeline. After the installation, trial water pumping is carried out, and normal work is started after the requirements are met.

Step S103: and after the pipe well is subjected to precipitation, excavating a foundation pit and excavating a foundation pit first-level platform.

Specifically, precipitation is carried out 20 days before excavation of the foundation pit, and the underground water level in the foundation pit can be timely reduced. When the dewatering well pumps water, the pumping interval time of the submersible pump is from short to long, the pump should be stopped immediately after each pumping in the dewatering well, and the pumping times of the well with large water yield per day are correspondingly increased. And in the precipitation running process, the water level observation work of each well is well done, and the change condition of the water head of the aquifer is mastered in time. When the confined water head is reduced to the design requirement in the process of reducing the water drop of the lower water head, the water pumping amount of the pressure reduction well can be properly regulated and controlled or the operation number of the pressure reduction wells can be adjusted to control the falling amplitude of the water head so as to reduce the ground settlement caused by the water drop. During the operation period of the precipitation, the on-site 24-hour duty system is implemented, and the duty personnel need to carefully make various quality records, so that the data are complete and the data are accurate. The recording of the precipitation operation in the precipitation operation process is analyzed and sorted in time, and various necessary charts are drawn so as to reasonably guide the precipitation operation and improve the precipitation operation effect. And submitting one precipitation operation record every day, and measuring the water level of the pumping-stopped well in time for 1-2 times every day.

Precipitation construction is the auxiliary work of structural engineering construction, belongs to the temporary engineering category, and precipitation pipe well should in time take necessary measure to seal and pack after accomplishing its use purpose. After the precipitation stops, the precipitation well finishes the use purpose, firstly, the power supply is cut off, the cable and the pump pipe are removed, and then the well hole is filled with medium sand to completely seal the whole well hole.

In addition, the pipe well is embedded with a hole protection pipe which is required to be vertical and is driven into undisturbed soil for 10-20cm, the periphery of the pipe well is filled with clay and tamped, the well pipe and sand can be drilled after the well pipe and the sand are in place, and the inclination of a drilling hole is not more than 1%.

Step S104: and arranging light well points and well positions.

In one embodiment, as shown in FIG. 4, the deploying a light well point comprises: the construction sequence sequentially comprises the steps of paying off and positioning, punching and forming a hole, arranging a well point pipe, filling a filter material, laying and connecting a water collecting pipe, installing pumping equipment, performing a pumping test and formally pumping water.

Specifically, light well point dewatering needs to be reasonably arranged according to a geological survey report and excavation geology, the well point position is determined according to the actual situation on site, then a small soil pit is dug at the well position, the depth is about 0.5m, so that water collection during drilling and sand filling during pipe burying are facilitated, the small pit and the water pit are connected through a ditch, so that redundant water is drained, and the distance between a well point pipe and a well point pipe is 1.5 m.

Drilling, installing and burying a well point pipe:

(1) moving the self-made movable derrick to a well point position, aligning a casing water gun to the well point position, starting a high-pressure water pump, controlling the water pressure to be 0.4-0.8 MPa, enabling the casing to sink under the impact of high-pressure water jet of the water gun, and continuously lifting the casing and the water gun.

(2) According to the general clay containing sand, the casing drop distance is within 1m according to experience, under the action of water jetting and casing punching, a well point pipe can sink by about 10m within about 10-15 min, if thick pure clay is met, the pipe sinking time needs to be prolonged, and the pressure of a high-pressure water pump can be increased at the moment so as to accelerate the pipe sinking speed. The diameter of the formed hole of the impact hole is required to reach 30-35 cm, a certain gap is ensured between the pipe wall and the well point pipe, so that sand and stone can be filled, the punching depth is required to be lower than the designed installation depth of the filter pipe by more than 50cm, partial soil collapse is prevented when the impact sleeve is lifted and pulled out, and sufficient sand and stone are stored at the bottom of the filter pipe.

(3) The chisel hole strikes the pipe and should keep perpendicular when reciprocating, just so enables well point dewatering wall of a well and keeps perpendicular, if meet great stone or fragment of brick when the chisel hole, the slope phenomenon can appear, and the diameter of pore-forming should also keep the longitudinal consistency as far as possible this moment.

(4) After the well hole is impacted and formed, the impact pipe is pulled out, the well point pipe is inserted into the well hole, the upper end of the well point pipe is plugged by a wood plug to prevent sand and stone or other impurities from entering, and a sand and stone filter layer is filled between the well point pipe and the wall of the well hole. The well point pipe adopts a double-sleeve type light well point dewatering filter pipe device which mainly comprises a double-sleeve part, a filter screen part and a sleeve sealing part. The double-sleeve part comprises an inner core pipe, an outer sleeve and a filter hole. Pumping water by a vacuum pump, firstly forming vacuum in the pump to generate negative pressure, enabling underground water to enter a pipeline from a filtering hole of an outer sleeve pipe, then enter a drainage pipeline system through a filtering hole of an inner core pipe, and then be discharged from an outlet drainage pipe after entering the water pump; the filter screen part comprises an inner filter screen, a double-layer outer filter screen and an iron wire. The underground water passes through the reverse filtration layer, is filtered by the double-layer outer filter screen, enters the inner pipe, is filtered by the inner filter screen, and enters the drain pipe, the outer filter screen is used for filtering part of the soil particles with large particle size, and the outer filter screen is used for filtering the rest of the soil particles, so that double filtration is formed, the soil particle loss is avoided, and the purposes of precipitation and soil body loss protection are achieved; the sleeve closed part comprises a bottom sealing rubber cap and an upper sealing ring. The bottom sealing rubber cap and the upper sealing ring are used as key fittings for pipeline sealing, and mainly ensure that a filter pipe part forms a closed system, so that air leakage is avoided, and the requirement of precipitation is met.

The sand must be coarse sand to prevent clogging of the filter tubes. The filter tube should be placed in the centre of wellhole, and the thickness of grit filter bed should be between 60 ~ 100mm to improve the water permeability, and prevent that the mesh of filter tube is blockked up to the soil grain infiltration filter tube. The sand filling thickness is uniform, the speed is high, and the sand filling is not interrupted in the midway so as to prevent the hole wall from collapsing.

And secondly, the filling height of the sandstone filtration layer is at least 1-1.8 m above the top of the ultrafiltration pipe, and the sandstone filtration layer is generally filled to be above an in-situ underwater line so as to ensure that water flow of a soil layer is smooth up and down.

Thirdly, after sand is filled at the well point, sealing and compacting 1.0-1.5 m below the well mouth by using clay, and preventing air leakage and reducing dewatering effect.

(5) Inserting a novel PP-R rubber pipe with the diameter of 25mm into the bottom of the well point pipe for water injection and cleaning until clear water flows out. Cleaning should be performed one by one to avoid 'dead wells'.

Arranging and installing a main pipe and connecting the main pipe with a well point pipe, firstly laying a water collecting pipe along the outer side of the well point pipeline, connecting the main pipe with a rubber mat bolt, connecting the main pipe with a water tank water pump, then pulling off a wooden plug at the upper end of the well point pipe, connecting the main pipe with a rubber pipe, and tying the main pipe with 8# lead wire to prevent the pipeline from leaking air tightly and reduce the vacuum degree of the whole pipeline.

Specifically, light well point dewatering is carried out 5 days before lower floor's excavation, accomplishes to utilize light well point in time to dredge rapidly the groundwater of the aquifer more than negative pressure control depth in, solves the upper portion of the weak permeable stratum and is detained the infiltration problem. During the light well point dewatering operation, the on-site 24-hour duty system is implemented, and the duty personnel need to carefully make various quality records, so that the data are complete and the data are accurate. The recording of the precipitation operation in the precipitation operation process is analyzed and sorted in time, and various necessary charts are drawn so as to reasonably guide the precipitation operation and improve the precipitation operation effect.

In addition, the light well pipe is buried by a punching method, and the construction of the light well pipe meets the following requirements:

(1) the perpendicularity deviation of the punched hole is less than 1%;

(2) the hole diameter of the punching hole is preferably 200mm and not less than 150 mm;

(3) the final depth of the punching is preferably 0.5m beyond the design depth.

The light well pipe embedding of the point well meets the following regulations:

(1) after the punching is finished, the hole depth is immediately checked, and a well pipe is immediately embedded after the hole depth meets the requirement;

(2) before embedding the well pipe, filling a small amount of filter material to the depth of the bottom end of the well pipe, wherein the vertical thickness of the filter material is not less than 200 mm;

(3) the well pipe should be placed centrally in the hole, and the internode connection should be firm and sealed;

(4) immediately filling a filter material after the well pipe is arranged in place, wherein the top surface of the filter material is higher than the top end of the filter pipe by more than 1.5m, and a clay sealing height not less than 1.0m is reserved from the top surface of the filter material to an orifice;

(5) the clay sealing and filling should be tamped layer by layer to ensure the sealing effect.

The light well point dewatering and water outlet pipeline system is preferably provided with the water collecting main pipe firstly and fixed. The joints of the pipe joints (the joint of the collector pipe itself and the joints of the pump and well pipe) must be sealed so that no air leaks.

After each group of point wells of the light well points are installed, water is pumped immediately, the quality of a pipeline joint, the water outlet effect of the point wells and the operation condition of water pumping equipment are checked, and the phenomena of water leakage, air leakage and siltation are timely treated.

By the aid of the pipe well and light well point combined dewatering construction method, the pipe well and light well point combined dewatering construction method is adopted in dewatering operation of the deep and large foundation pit with the weak permeable layer, water retention on the upper layer and diving on the lower layer of the foundation pit can be quickly drained, when the foundation pit is dug to a designed depth, no water is accumulated at the bottom of the foundation pit, no water seepage occurs in a side slope, the dewatering effect is obvious, conditions are created for earthwork excavation and subsequent engineering construction, and the construction period is shortened. The pipe well and the light well point are combined to lower water, the lower layer of the foundation pit is submerged by utilizing the pipe well water, the risks of sudden gushing at the bottom of the foundation pit, uplifting at the bottom of the foundation pit and the like are reduced, and the integral stability of the foundation pit is enhanced; by utilizing light well point dewatering, the problems of outward water seepage and sand gushing along the slope surface of the foundation pit, slope instability and the like of the stagnant water layer at the upper part of the weakly permeable layer are effectively solved, and the possibility of soft soil quicksand flowing is reducedAnd the stability of the foundation pit side slope is enhanced. The ring rigidity of the pipe well water-filtering well pipe is more than or equal to 10kN/m²The PVC double-wall corrugated pipe comprises a filter pipe, wherein a group of centralizers 4 are respectively added on the upper part and the lower part of the filter pipe in order to ensure that a well pipe does not lean against a well wall and ensure the sand filling thickness, the thickness of an annular sand filling gap is ensured to be larger than 150mm, the top of the filter pipe is higher than the natural ground by about 300mm, and a layer of 80-100-mesh filter screen is wrapped outside the double-wall corrugated filter pipe. The light well point adopts a double-sleeve light well point dewatering method, an inner sleeve is connected with a water collecting pipe, vacuum negative pressure is manufactured between the inner sleeve and the outer sleeve by a vacuum pump, the bottom of the inner sleeve and the outer sleeve are lower than a water suction port of a water pump together with the position, so the inner sleeve is always submerged by water, and the inner sleeve is of an airtight structure, so that a working area of a vacuum area and a working area of the pump are completely separated by accumulated water at the bottom of the well point, the vacuum can be stably kept between the inner sleeve and the outer sleeve, underground water enters the well point under the action of stable vacuum, and the dewatering efficiency can be effectively improved.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples described in this specification can be combined and combined by those skilled in the art.

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. This application is intended to cover any variations, uses, or adaptations of the disclosure following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

Claims

1. A pipe well and light well point combined dewatering construction method is characterized by comprising the following steps:

arranging a pipe well position according to the actual hydrogeological data;

arranging light well points and well positions;

and (4) carrying out light well point dewatering, and digging out a foundation pit secondary platform after the light well point dewatering is completed.

2. The pipe well and light well point combined precipitation construction method of claim 1, wherein said laying the pipe well comprises:

3. The pipe well and light well point combined precipitation construction method of claim 2, wherein said laying the pipe well further comprises:

the mud tank and the sedimentation tank are arranged for drilling and cleaning.

4. The pipe well and light well point combined precipitation construction method of claim 2, wherein laying the pipe well further comprises:

5. The method of combined well-light well-point dewatering construction according to claim 2, wherein the dewatering pipe is a double-wall corrugated filter pipe.

6. The pipe well and light well point combined dewatering construction method of claim 1, wherein the laying of the light well point comprises:

the construction sequence sequentially comprises the steps of paying off and positioning, punching and forming holes, arranging well point pipes below, filling filter materials, laying and connecting water collecting pipes, installing pumping equipment, performing a pumping test and formally pumping water.

7. The pipe well and light well point combined precipitation construction method of claim 1, wherein the pipe well precipitation comprises:

8. The pipe well and light well point combined dewatering construction method of claim 1, wherein the laying of light well points further comprises:

9. The pipe well and light well point combined precipitation construction method of claim 8, wherein the light well point precipitation comprises:

10. The pipe well and light well point combined dewatering construction method according to claim 1, wherein the punching perpendicularity deviation is less than 1%, the hole diameter of the punching is not less than 150mm, and the final depth of the punching is greater than the designed depth of 0.5 m.