CN110863502B - Construction method and plugging structure for dynamic adjustment of foundation pit dewatering and plugging of dewatering wells - Google Patents

Abstract

The invention relates to a construction method of a deep foundation pit of a building, in particular to a construction method for dynamically adjusting precipitation of a foundation pit and plugging a precipitation well, which comprises the following steps of reducing the groundwater level; constructing a formed cushion layer; constructing a raft foundation layer, and arranging a first water stop plate at the contact position of the dewatering well and the raft foundation layer; and a sealing plate is arranged, and the outer edge of the sealing plate is fixedly connected with the inner side wall of the dewatering well. The invention also relates to a dewatering well plugging structure, which comprises a dewatering well inserted on a foundation, and further comprises a cushion layer, a waterproof layer and a raft foundation layer which are sequentially laid on the foundation, wherein the dewatering well penetrates through the cushion layer, the waterproof layer and the raft foundation layer and protrudes out of the raft foundation layer, and expansion strips are wound at the contact positions of the outer edge of the dewatering well and the cushion layer. The cushion layer can play a waterproof role, and water in the dewatering well is prevented from seeping out of the well pipe. The raft foundation layer plays a role in protecting the cushion layer, and the cushion layer is prevented from being damaged. The sealing plate seals the wellhead of the dewatering well, and further strengthens the plugging effect of the dewatering well.

Description

Construction method and plugging structure for dynamic adjustment of foundation pit dewatering and plugging of dewatering wells

Technical Field

The invention relates to a method for constructing a deep foundation pit of a building, and in particular to a construction method and a blocking structure for dynamically adjusting foundation pit dewatering and blocking a dewatering well.

Background Art

For a long time, most deep foundation pit projects in my country have encountered the situation of too high groundwater level and too much surface water during earth excavation. In order to effectively improve construction conditions and ensure construction safety, precipitation wells are usually reasonably arranged outside the foundation pit. This method effectively reduces groundwater and pressurized water within the foundation pit, successfully lowers the groundwater level, and better solves the difficulties in deep foundation pit excavation and construction. At the same time, it also reduces the impact of foundation pit construction on peripheral buildings, pipelines and ground subsidence.

When the underground structure construction is completed and the earthwork backfill is completed, the groundwater level meets the anti-floating water level required by the design, and the precipitation can be stopped. After the precipitation well stops precipitation, the precipitation well at the raft position in the foundation pit needs to be blocked due to the building function requirements. In order to facilitate the blocking of the precipitation well, the precipitation well pipe is generally made of iron pipe, the outer periphery of the well pipe is welded with a water stop plate, cement mortar is injected into the well pipe, and the well pipe mouth is welded with a water stop plate to seal it.

The above-mentioned prior art solutions have the following defects: when setting up the precipitation well, the well pipe needs to penetrate the foundation raft, thus destroying the waterproof layer of the raft. When the precipitation well is blocked, only a water stop plate is welded on the outer periphery of the well pipe without any special waterproof treatment, which fails to achieve the water stop effect. Groundwater will penetrate through the damaged waterproof layer along the outer wall of the well pipe to the basement floor.

Summary of the invention

The purpose of the present invention is to provide a drainage well plugging structure and a construction method thereof, so as to solve the problem of water seepage after deep foundation pit plugging in the prior art.

To achieve the above object, the technical solution adopted by the present invention is: to provide a construction method for dynamic adjustment of foundation pit dewatering and plugging of dewatering wells, characterized in that the construction steps are as follows:

Lowering the groundwater level and dynamically adjusting the groundwater level by winding expansion strips around the outer edge of the precipitation well;

Constructing a formed cushion layer, laying a waterproof coating layer group and a waterproof coiled material on the cushion layer, and winding a water stop ring at the contact position between the waterproof coiled material and the precipitation well;

Constructing a raft foundation layer, constructing a formed raft foundation layer on the waterproof membrane, and arranging a first water stop plate at a contact position between the precipitation well and the raft foundation layer, wherein the first water stop plate is sleeved on the outer edge of the precipitation well;

A closing plate is arranged inside the precipitation well, and the outer edge of the closing plate is fixedly connected to the inner wall of the precipitation well.

Constructing a closed pier cover, after setting the closed plate, pouring a closed pier cover on the wellhead of the precipitation well, the closed pier cover is located on the wellhead of the precipitation well and closes the wellhead of the precipitation well.

Furthermore, the method further comprises the following construction steps:

After the raft foundation layer is constructed, a waterproof sealing coating is applied near the top of the raft foundation layer, and the waterproof sealing coating is applied around the precipitation well.

Furthermore, the method further comprises the following construction steps:

After applying the waterproof sealing coating, a second water stop plate is arranged at the outer edge of the precipitation well, the second water stop plate is sleeved on the outer edge of the precipitation well, and the second water stop plate is located above the waterproof sealing coating.

Furthermore, the method further comprises the following construction steps:

Before setting the closing plate, the drainage well is filled with a plugging material until the height of the plugging material is 100 mm to 300 mm from the wellhead of the drainage well.

Furthermore, the plugging material includes cement and anti-seepage self-compacting micro-expanding fine stone concrete.

Furthermore, when filling the plugging material into the precipitation well, cement is firstly filled into the precipitation well and then the anti-seepage self-compacting micro-expanding fine stone concrete is filled into the precipitation well.

Furthermore, the closed pier cover is a cast concrete pier, and the closed pier cover has a radius of 500 mm to 750 mm and a thickness of 300 mm to 500 mm.

Furthermore, the method for dynamically adjusting the groundwater level comprises the following steps:

Before the construction of the external main structure, the anti-floating capacity of the initial anti-floating object is calculated, the initial control water level elevation is determined, and the groundwater level is lowered to no higher than the initial control water level elevation.

Furthermore, the method for dynamically adjusting the groundwater level includes:

During the external main structure construction phase, the anti-floating capacity of the anti-floating objects is calculated, the stage control water level elevation is determined, and the height of the groundwater level is adjusted to be no higher than the stage control water level elevation.

Furthermore, the waterproof coating layer group includes any one or both of a cement-based penetrating crystalline waterproof coating and a non-curing rubber asphalt waterproof coating.

The present invention also discloses a drainage well sealing structure, which includes a drainage well inserted on a foundation, and also includes a cushion layer, a waterproof layer and a raft foundation layer laid in sequence on the foundation, the drainage well passes through the cushion layer, the waterproof layer and the raft foundation layer and protrudes from the raft foundation layer, and an expansion strip is wrapped around the position where the outer edge of the drainage well contacts the cushion layer.

Furthermore, it also includes a first water stop plate, which is sleeved on the outer edge of the precipitation well, and the first water stop plate is arranged at the connection between the precipitation well and the raft foundation layer.

Furthermore, a closing plate is provided at the upper port of the precipitation well, and the outer edge of the closing plate is fixed to the inner wall of the precipitation well.

Furthermore, the number of the closing plates is at least two.

Furthermore, it also includes a closed pier cover for closing the wellhead of the precipitation well, and the closed pier cover has a radius of 500mm to 750mm and a cylindrical pier cover with a thickness of 300mm to 500mm.

Furthermore, the waterproof layer includes a waterproof coating layer group coated on the cushion layer and a waterproof coiled material laid on the waterproof coating layer group.

Furthermore, the waterproof coating layer group includes a cement-based penetrating crystalline waterproof coating and a non-curing rubber asphalt waterproof coating.

Furthermore, a water-stop ring is provided at a position where the outer edge of the precipitation well contacts the waterproof membrane.

In summary, the beneficial effects of the present invention are:

1. Lower the groundwater level to facilitate subsequent construction and better seal the precipitation well. The formed cushion layer can play a waterproof role and prevent the water in the precipitation well from seeping out of the well pipe and flowing into the basement. The raft foundation layer protects the cushion layer to prevent damage to the cushion layer and cause ground seepage. The closing plate closes the wellhead of the precipitation well, and the outer edge of the closing plate is fixed on the inner wall of the precipitation well, which further enhances the sealing effect of the precipitation well and prevents the water in the precipitation well from seeping into the basement of the building. Through the setting of the expansion strip waterproof coating layer, the groundwater is blocked to prevent the groundwater from seeping into the basement, which plays a role in strengthening waterproofing. The expansion strip has the property of expanding when it encounters water. When groundwater seeps out, the expansion strip expands, blocks the gap of water seepage, slows down the amount of water seepage, and prevents water seepage in the basement. The first water stop plate is sleeved on the outer edge of the precipitation well, and the first water stop plate is set at the contact position between the precipitation well and the raft foundation layer. This setting can block the outer wall of the precipitation well to prevent well water from seeping out of the outer wall of the precipitation well.

2. There are at least two closing plates, and the closing plates are arranged on the inner wall of the well pipe. This arrangement strengthens the sealing of the well pipe and prevents groundwater from seeping out of the well pipe.

3. By setting a water-stop ring made of rubber, the rubber water-stop ring plays a waterproof role and prevents groundwater from seeping out from the side wall of the well pipe.

4. By setting the waterproof sealing coating, the waterproof property of the well pipe is enhanced to prevent groundwater from seeping out of the well pipe. By setting the second water stop plate, the waterproof property of the well pipe is enhanced. At the same time, the second water stop plate is located above the waterproof sealing coating, which plays a protective role for the waterproof sealing coating. When pouring concrete in the subsequent construction, it is prevented that the concrete directly impacts the waterproof sealing coating and causes damage to it.

5. From the beginning of underground water drop to the end of underground water drop, the original water drop power remains unchanged, and the groundwater level is always controlled at the same elevation. In fact, the design often calculates the anti-floating capacity of the structure based on the highest groundwater level in the geological survey report, and the calculation result will be multiplied by a large safety factor, and the anti-floating design is very conservative. With the continuous completion of the external main structure, the unchanged design water drop requirements have made a lot of water drop work useless, resulting in unnecessary waste of resources. Therefore, by calculating the anti-floating capacity of the different construction stages of the external main structure, determining the stage control water level elevation, and dynamically adjusting the foundation pit water drop level, the construction cost and labor maintenance cost are greatly saved.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

FIG1 is a schematic diagram of a partial cross-sectional structure of a drainage well plugging structure provided by an embodiment of the present invention;

FIG2 is another partial cross-sectional structural schematic diagram of the precipitation well plugging structure provided by an embodiment of the present invention;

Description of reference numerals:

1. Drainage well; 11. Expansion strip; 12. First waterstop; 13. Closing plate; 14. Waterstop collar; 15. Waterproof sealing coating; 16. Second waterstop; 17. Sealing material; 2. Foundation; 21. Cushion; 3. Raft foundation layer; 4. Waterproof layer; 41. Waterproof coating layer group; 411. Cement-based penetrating crystalline waterproof coating; 412. Non-curing rubber asphalt waterproof coating; 42. Waterproof membrane; 43. Protective layer; 5. Closed pier cover.

DETAILED DESCRIPTION

The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", etc. should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

1 and 2, the present invention also provides a construction method for dynamic adjustment of foundation pit dewatering and a dewatering well 1 plugging structure, which is used to implement the dewatering well 1 plugging structure in any of the above items. The construction method of the dewatering well 1 plugging structure has the following construction steps:

S1, lowering the groundwater level. When the water level drops to a preset value, the expansion strip 11 is wound around the outer edge of the precipitation well 1; one hour before construction, the precipitation power is increased to lower the groundwater level, and then the expansion strip 11 is installed. The expansion strip 11 has the property of expanding when it comes into contact with water. When groundwater seeps out, the expansion strip 11 expands to block the gaps for water seepage, thereby slowing down the amount of water seepage and avoiding water seepage in the basement.

S2, construct the formed cushion layer 21, lay the waterproof coating layer group 41 and the waterproof coiled material 42 on the cushion layer 21, and wind the water stop collar 14 around the contact position between the waterproof coiled material 42 and the precipitation well 1. The waterproof coating layer group 41 includes any one or both of the cement-based penetrating crystalline waterproof coating 411 and the non-curing rubber asphalt waterproof coating 412. In this embodiment, the cement-based penetrating crystalline waterproof coating 411 is first applied, and then the non-curing rubber asphalt waterproof coating 412 is applied on the cement-based penetrating crystalline waterproof coating 411; the rubber water stop collar 14 plays a waterproof role, preventing groundwater from seeping out from the side wall of the well pipe.

S3, construct a raft foundation layer 3, construct a formed raft foundation layer 3 on the waterproof membrane 42, and set a first waterstop plate 12 at the contact position between the precipitation well 1 and the raft foundation layer 3, and the first waterstop plate 12 is sleeved on the outer edge of the precipitation well 1; the first waterstop plate 12 is sleeved on the outer edge of the precipitation well 1, which can block the outer wall of the precipitation well 1 to prevent well water from seeping out from the outer wall of the precipitation well 1.

S4, apply a waterproof sealing coating 15 near the top of the raft foundation layer 3, and the waterproof sealing coating 15 is applied around the precipitation well 1. After applying the waterproof sealing coating 15, a second water stop plate 16 is provided at the outer edge of the precipitation well 1, and the second water stop plate 16 is sleeved on the outer edge of the precipitation well 1, and the second water stop plate 16 is located above the waterproof sealing coating 15. Among them, the second water stop plate 16 can also be installed first, and then the waterproof sealing coating 15 is applied, as long as the second water stop plate 16 is located above the waterproof sealing coating 15, and this is not the only limitation here. The second water stop plate 16 is a steel plate, which enhances the waterproof performance of the well pipe. At the same time, the second water stop plate 16 is located above the waterproof sealing coating 15, which protects the waterproof sealing coating 15.

S5, a closing plate 13 is provided inside the precipitation well 1, and the outer edge of the closing plate 13 is fixedly connected to the inner wall of the precipitation well 1. Specifically, the closing plates 13 are steel plates, and there are two of them, and the top closing plate 13 is flush with the upper end of the well pipe. The closing plate 13 closes the wellhead, preventing the water in the precipitation well 1 from overflowing, and also preventing the external water from entering the precipitation well 1.

S6, construct the closed pier cover 5. After setting the closing plate 13, cast the closed pier cover 5 on the wellhead of the precipitation well 1. The closed pier cover 5 is located on the wellhead of the precipitation well 1 and closes the wellhead of the precipitation well 1. The closed pier cover 5 is a cast concrete pier, and the radius of the closed pier cover 5 is 500mm to 750mm, and the thickness is 300mm to 500mm thick cylindrical pier cover. In this embodiment, the radius of the closed pier cover 5 is 600mm and the thickness is 400mm. The closed pier cover 5 is a cement pier set at the top of the precipitation well 1. It is a cover to close the precipitation well 1 after completion. The precipitation outlet can be closed by the cover, so as to ensure that water will not enter the interior of the precipitation well 1 from the top of the precipitation well 1. The shape of the closed pier cover 5 can be a cylindrical pier cover with a radius of 500mm to 750mm and a thickness of 300mm to 500mm, or a square pier cover or a pier cover of other shapes. Of course, according to actual conditions and specific needs, the size of the closed pier cover 5 can be larger, and this is not the only limitation here.

Lowering the groundwater level facilitates subsequent construction and better plugging of the precipitation well 1. The molded cushion layer 21 can play a waterproof role, preventing the water in the precipitation well 1 from seeping out of the well pipe and flowing into the basement. The raft foundation layer 3 protects the cushion layer 21, preventing the cushion layer 21 from being damaged and causing ground seepage. The closing plate 13 closes the wellhead of the precipitation well 1, and the outer edge of the closing plate 13 is fixed on the inner wall of the precipitation well 1, further strengthening the effect of plugging the precipitation well 1, and preventing the water in the precipitation well 1 from seeping into the basement of the building. By setting the expansion strip 11 and the waterproof coating layer, the groundwater is prevented from being blocked, and the groundwater is prevented from seeping into the basement, which plays a role in strengthening waterproofing. The expansion strip 11 has the property of swelling when it encounters water. When groundwater seeps out, the expansion strip 11 expands, blocks the gap of water seepage, slows down the amount of water seepage, and prevents water seepage in the basement. The first water stop plate 12 is sleeved on the outer edge of the precipitation well 1, and the first water stop plate 12 is set at the contact position between the precipitation well 1 and the raft foundation layer 3. This setting can block the outer wall of the precipitation well 1 to prevent well water from seeping out of the outer wall of the precipitation well 1.

Furthermore, the construction method of the plugging structure of the precipitation well 1 provided by the present invention also includes the following construction steps:

Before setting the closing plate 13, the plugging material 17 is filled into the precipitation well 1 until the height of the plugging material 17 is 100 mm to 300 mm away from the wellhead of the precipitation well 1. In this embodiment, the distance from the wellhead of the precipitation well 1 is 200 mm. The plugging material 17 includes cement and impermeable self-compacting micro-expanding fine stone concrete. When the plugging material 17 is filled into the precipitation well 1, cement is first filled into the precipitation well 1 and then the impermeable self-compacting micro-expanding fine stone concrete is filled.

Specifically, before filling the plugging material 17, the water pump in the precipitation well 1 needs to be pulled out. After the water pump is taken out, a bag of cement is put into the precipitation well 1, and then the anti-seepage self-compacting micro-expansion fine stone concrete is put in. Of course, according to construction requirements, cement and anti-seepage self-compacting micro-expansion fine stone concrete can also be replaced with other building materials that expand when exposed to water.

Furthermore, the construction method of the plugging structure of the precipitation well 1 provided by the present invention also includes the following construction steps:

Before the construction of the external main structure, the anti-floating capacity of the initial anti-floating object is calculated, the initial control water level elevation is determined, and the groundwater level is lowered to no higher than the initial control water level elevation. Then the external main structure construction phase is carried out.

During the external main structure construction phase, the anti-floating capacity of the anti-floating objects is calculated, the stage control water level elevation is determined, and the height of the groundwater level is adjusted to be no higher than the stage control water level elevation.

Among them, the initial controlled water level elevation refers to the water level height on the lower surface of the raft foundation layer 3. When the water level drops below the raft foundation layer 3, it will not generate buoyancy on the main structure such as the raft. The stage controlled water level elevation refers to the anti-floating water level elevation of the main structure and anti-floating objects after construction. When controlling the groundwater level, water is pumped out by a water pump to discharge the water in the precipitation well 1 penetrating the raft foundation layer 3 into the precipitation well 1 outside the raft foundation layer 3, thereby realizing water level control during construction, that is, realizing groundwater level control by well point precipitation method.

The calculation method of the initial control water level elevation is as follows: first, an anti-floating object is selected. The anti-floating object in this implementation is an anti-floating anchor rod. The calculation method of the initial control water level elevation of the anti-floating anchor rod is as follows:

The number of anti-floating anchors in the calculation unit is m, and the characteristic value of the pull-out bearing capacity of each anchor is FkN. The weight of the structural beam of this technology is not calculated as an anti-floating safety reserve. An axis grid line is a calculation unit. Before drawing the building plan, it is necessary to draw the axis grid line first. The axis grid line is a network composed of the building axis. It is artificially set up in the building drawings according to general customary standards to indicate the detailed dimensions of the components. It is usually marked on the center line of the symmetrical interface or section component.

Therefore, the water level that the anti-floating anchor can resist in the general area is h meters, so the water level elevation that can be resisted in this area only under the action of the anchor alone is hp1 meter:

hp1 is the stage control water level elevation

hs is the initial controlled water level elevation

At this time, no matter what the water level is, the water level is below the foundation slab, because the main structure has not been constructed yet and the anti-floating anchor rods are not effective.

The calculation method of the stage control water level elevation during the external main structure construction stage is as follows:

First, the cushion layer and foundation structure are converted:

At the construction completion stage, the external main structure is converted into:

So the resistible water level at this time is:

The anti-floating anchor rod in the general area can resist the water level height of h meters. Therefore, the anti-floating water level elevation of this area is hp2 meters when the underground main structure construction is completed;

Therefore, when the construction of the external main structure is completed, the foundation pit dewatering height is adjusted from the original water level not exceeding hs to hp2 meters.

As the construction of the external main structure proceeds, the stage water level elevations of different construction stages are calculated. When the stage water level elevation is lower than the relative water level elevation and the water level is relatively stable, the conditions for stopping precipitation are met and precipitation in the precipitation well can be stopped. The precipitation well can then be sealed.

From the beginning of underground watering to the end of underground watering, the original watering power remains unchanged, and the groundwater level is always controlled at the same elevation. In fact, the design often calculates the anti-buoyancy capacity of the structure based on the highest groundwater level in the geological survey report, and the calculation result will be multiplied by a large safety factor, and the anti-buoyancy design is very conservative. With the continuous completion of the external main structure, the unchanged design watering requirements have made a lot of useless work in the watering work, resulting in unnecessary waste of resources. Therefore, by calculating the anti-buoyancy capacity of the stage at different construction stages of the external main structure, determining the stage control water level elevation, and dynamically adjusting the foundation pit watering level, the construction cost and labor maintenance cost are greatly saved, and the foundation pit can also be dewatered in advance. From the beginning of underground watering to the end of underground watering, the original watering power remains unchanged, and the groundwater level is always controlled at the same elevation. In fact, the design often calculates the anti-buoyancy capacity of the structure based on the highest groundwater level in the geological survey report, and the calculation result will be multiplied by a large safety factor, and the anti-buoyancy design is very conservative. With the continuous completion of the external main structure, the unchanged design watering requirements have made a lot of useless work in the watering work, resulting in unnecessary waste of resources. Therefore, by calculating the anti-floating capacity of the different construction stages of the external main structure, determining the stage control water level elevation, and dynamically adjusting the foundation pit dewatering water level, the construction cost and labor maintenance cost are greatly saved, and the foundation pit can also be dewatered in advance.

With reference to Fig. 1 and Fig. 2, the plugging structure of the precipitation well 1 provided by the present invention is now described. The plugging structure of the precipitation well 1 comprises a precipitation well 1 inserted in the foundation 2 and a cushion layer 21, a waterproof layer 4 and a raft foundation layer 3 sequentially laid on the foundation 2, the precipitation well 1 passes through the cushion layer 21, the waterproof layer 4 and the raft foundation layer and protrudes from the raft foundation layer 3, the outer edge of the precipitation well 1 is wound with an expansion strip 11 at the position where the cushion layer 21 contacts the outer edge of the precipitation well 1, the foundation 2 is generally an existing, i.e., laid foundation member, and the precipitation well 1 is inserted in the foundation 2, the cushion layer 21, the waterproof layer 4 and the raft foundation layer 3 are sequentially laid on the foundation 2, the height of the top of the precipitation well is generally higher than the height of the raft foundation layer 3, the expansion strip 11 is arranged around the outside of the cushion layer 21, and the expansion strip 11 needs to be installed before the cushion layer 21 is laid, and the expansion strip 11 in this embodiment is a putty-type expansion strip. The expansion strip 11 has the property of water expansion. When groundwater seeps out, the expansion strip 11 blocks the gap of water seepage, slows down the amount of water seepage, and avoids water seepage in the basement. According to actual conditions and specific needs, the putty-type expansion strip can also be replaced with other types of expansion strips 11, such as concrete sealing strips, and the top of the precipitation well 1 can also be flush with the top of the raft foundation layer 3.

Furthermore, as a specific embodiment of the plugging structure of the precipitation well 1 provided by the present invention, the outer edge of the precipitation well 1 is provided with a first water stop plate 12, and the first water stop plate 12 is arranged at the connection between the precipitation well 1 and the raft foundation layer 3. Among them, the precipitation well 1 and the first water stop plate 12 are fixedly connected, and the fixed connection can be by bonding, bolting and welding, etc. The first water stop plate 12 is arranged at the connection between the precipitation well 1 and the raft foundation layer 3, either near the top or below, and the first water stop plate 12 can meet the conditions as long as it is located in the raft foundation layer 3, so the specific position of the first water stop plate 12 is not limited. The first water stop plate 12 blocks the outer wall of the precipitation well 1 to prevent well water from seeping out from the outer wall of the precipitation well 1, and plays a role of preliminary water stopping.

Furthermore, as a specific embodiment of the blocking structure of the precipitation well 1 provided by the present invention, a closing plate 13 is provided at the upper port of the precipitation well 1, and the outer edge of the closing plate 13 is fixed on the inner wall of the precipitation well 1. The number of the closing plates 13 is at least two. In this embodiment, the closing plates 13 are steel plates, and the number is two, and the closing plate 13 at the top is flush with the upper end of the well pipe. Among them, the closing plate 13 can be fixed by pasting, bolting, welding, etc., and the steel plate can also be replaced by a plate of other waterproof materials, and the closing plate 13 at the top can also be lower than the upper end of the well pipe. The closing plate 13 closes the wellhead, preventing the water from overflowing from the precipitation well 1, and also preventing the external water from entering the precipitation well 1. Of course, according to the actual situation and specific needs, in other embodiments of the present invention, the number of the closing plate can also be one, which is not the only limitation here.

Furthermore, as a specific embodiment of the blocking structure of the precipitation well 1 provided by the present invention, it also includes a closed pier cover 5 for closing the wellhead of the precipitation well 1, and the closed pier cover 5 has a radius of 500mm to 750mm and a thickness of 300mm to 500mm. In this embodiment, the radius of the closed pier cover 5 is 600mm and the thickness is 400mm. The closed pier cover is a cement pier set at the top of the precipitation outlet. It is a cover for closing the precipitation well after completion. The wellhead can be closed by the cover to ensure that water does not enter the interior of the precipitation well 1 from the top of the precipitation well 1. The closed pier cover 5 can be a cylindrical pier cover with a radius of 500mm to 750mm and a thickness of 300mm to 500mm, or it can be set as a prism or other irregular cube-shaped pier cover, as long as it meets the requirements of closing the wellhead. Of course, according to actual conditions and specific needs, the size of the closed pier cover 5 can be larger, and it is not the only limitation here.

Further, as a specific embodiment of the plugging structure of the precipitation well 1 provided by the present invention, the raft foundation layer 3 is coated with a waterproof sealing coating 15 surrounding the precipitation well 1 near the top. In this embodiment, the waterproof sealing coating 15 is a water-proof coating. A second water stop plate 16 is provided at the outer edge of the precipitation well 1. The second water stop plate 16 is sleeved on the outer edge of the precipitation well 1. The second water stop plate 16 is located above the waterproof sealing coating 15. Water-proof coating is a waterproof and moisture-proof material. It can not only effectively prevent moisture, seepage, and plug leaks, but also can be bonded with a variety of materials; the material is divided into slow-setting type and quick-setting type, both of which are single-component gray powder. The slow-setting type is mainly used for moisture-proof and anti-seepage; the quick-setting type is mainly used for anti-seepage and plugging leaks, which is a prior art. Among them, the waterproof sealing coating 15 can also be replaced by other waterproof coatings such as asphalt, and the precipitation well 1 is fixedly connected to the second water stop plate 16, and the fixed connection can be in the form of pasting, bolting, and welding. The second water stop plate 16 strengthens the waterproof performance of the well pipe. At the same time, the second water stop plate 16 is located above the waterproof sealing coating 15, which protects the waterproof sealing coating 15. When pouring concrete in subsequent construction, it is avoided that the concrete directly impacts the waterproof sealing coating 15 and causes damage to it.

Further, as a specific embodiment of the plugging structure of the precipitation well 1 provided by the present invention, the waterproof layer 4 includes a waterproof coating layer group 41 coated on the cushion layer 21, a waterproof coiled material 42 laid on the waterproof coating layer group 41, and a protective layer 43 laid on the waterproof coiled material 42. Among them, the waterproof coating layer group 41 includes any one or more of a cement-based penetrating crystalline waterproof coating 411 and a non-curing rubber asphalt waterproof coating 412. The cement-based penetrating crystalline waterproof coating 411 can be applied first, and then the non-curing rubber asphalt waterproof coating 412 can be applied on the cement-based penetrating crystalline waterproof coating 411. It is also possible to apply only one of the cement-based penetrating crystalline waterproof coating 411 or the non-curing rubber asphalt waterproof coating 412. Among them, the waterproof coiled material 42 can be a commonly used waterproof material in construction, such as an asphalt waterproof material or a polymer-modified asphalt waterproof coiled material. The protective layer 43 can be laid with materials such as concrete or sand, and plays a protective role on the waterproof coiled material 42.

Further, as a specific embodiment of the plugging structure of the precipitation well 1 provided by the present invention, a water stop collar 14 is sleeved at the position where the outer edge of the precipitation well 1 contacts the waterproof coiled material 42, and the water stop collar 14 is made of rubber. The water stop collar 14 is an annular structure, which is sleeved at the connection between the waterproof coiled material 42 and the precipitation well 1, and the rubber water stop collar 14 can also be replaced with other elastic waterproof materials.

Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the protection scope of the invention.

Claims (13)

1. The construction method for dynamically adjusting foundation pit precipitation and plugging a precipitation well is characterized by comprising the following construction steps:

lowering the ground water level, dynamically adjusting the ground water level, and winding expansion strips (11) on the outer edge of the dewatering well (1);

Constructing a formed cushion layer (21), paving a waterproof coating layer group (41) on the cushion layer (21) and paving a waterproof coiled material (42), and winding a water stop collar (14) at the contact position of the waterproof coiled material (42) and the dewatering well (1);

Constructing a raft foundation layer (3), constructing a formed raft foundation layer (3) on the waterproof coiled material (42), and arranging a first water stop plate (12) at the contact position of the dewatering well (1) and the raft foundation layer (3), wherein the first water stop plate (12) is sleeved on the outer edge of the dewatering well (1);

The method comprises the steps of arranging a sealing plate (13), arranging the sealing plate (13) in the dewatering well (1), and fixedly connecting the outer edge of the sealing plate (13) with the inner side wall of the dewatering well (1);

After the sealing plate (13) is arranged, pouring the sealing pier cover (5) on the wellhead of the dewatering well (1), wherein the sealing pier cover (5) is positioned on the wellhead of the dewatering well (1) and seals the wellhead of the dewatering well (1);

The method for dynamically adjusting the underground water level comprises the following steps: before the construction of an external main body structure, calculating the anti-floating capacity of an initial anti-floating object, determining an initial control water level elevation, and reducing the underground water level to be not higher than the initial control water level elevation; in the construction stage of the external main body structure, calculating the anti-floating capacity of an anti-floating object in the stage, determining the stage control water level elevation, and adjusting the height of the underground water level to be not higher than the stage control water level elevation;

When the anti-floating object is selected as the anti-floating anchor rod, the calculation method of the initial control water level elevation of the anti-floating anchor rod is as follows:

The number of the anti-floating anchors in the calculation unit is m, and the characteristic value FkN of the anti-pulling bearing capacity of each anti-floating anchor is calculated;

wherein G is the self gravity of the structure, F0 is the pulling resistance of the anti-floating anchor rod, F1 is the water buoyancy, h is the water level height, P is the pressure, S is the substrate area, and Y is the water gravity;

The water-resistant level height of the anti-floating anchor rod in the common area is h meters, so that the water-resistant level elevation of the anti-floating anchor rod in the area under the independent action of the anti-floating anchor rod is hp1 meters, and the following formula is satisfied:

Hp1=hs+h

wherein hp1 is the stage control water level elevation, hs is the initial control water level elevation;

The stage control water level elevation calculation method in the construction stage of the external main body structure comprises the following steps:

firstly, converting a cushion layer and a basic structure:

and at the construction completion stage, converting an external main body structure:

so the water-resistant level at this time is:

The height of the water level of the anti-floating anchor rod in the common area is h meters, so that the elevation of the water level of the anti-floating anchor rod in the area is hp2 meters when the construction of the underground main body structure is completed;

therefore, when the construction of the external main body structure is completed, the precipitation height of the foundation pit is adjusted to hp2 m from the original water level of not more than hs;

along with the construction of outside major structure goes on, calculate the stage water level elevation of different construction stages, be less than relative water level elevation when stage water level elevation, and the water level is more stable, satisfies the condition that stops the precipitation this moment, can stop the precipitation to the precipitation well, can carry out the shutoff to the precipitation well afterwards.

2. The construction method for dynamically adjusting foundation pit precipitation and plugging a precipitation well according to claim 1, further comprising the following construction steps:

After the raft foundation layer (3) is constructed, waterproof sealing paint (15) is smeared at the position, close to the top, of the raft foundation layer (3), and the waterproof sealing paint (15) is smeared around the dewatering well (1).

3. The construction method for dynamically adjusting foundation pit precipitation and plugging a precipitation well according to claim 2, further comprising the following construction steps:

After the waterproof sealing paint (15) is smeared, a second water stop plate (16) is arranged at the outer edge of the dewatering well (1), the second water stop plate (16) is sleeved on the outer edge of the dewatering well (1), and the second water stop plate (16) is positioned above the waterproof sealing paint (15).

4. The construction method for dynamically adjusting foundation pit precipitation and plugging a precipitation well according to claim 1, further comprising the following construction steps:

Before the sealing plate (13) is arranged, plugging material (17) is filled into the dewatering well (1) until the distance from the height of the plugging material (17) to the wellhead of the dewatering well (1) is 100mm to 300mm.

5. The construction method for dynamically adjusting foundation pit precipitation and plugging a precipitation well according to claim 4, wherein the plugging material (17) comprises cement and impervious self-compacting micro-expansive fine stone concrete.

6. The construction method for dynamically adjusting foundation pit dewatering and plugging a dewatering well according to claim 5, wherein when the plugging material (17) is filled into the dewatering well (1), cement is filled into the dewatering well (1) first, and impervious self-compaction micro-expansion fine stone concrete is filled.

7. The construction method for dynamically adjusting foundation pit precipitation and plugging a precipitation well according to claim 1, wherein the closed pier cover (5) is a poured concrete pier, and the radius of the closed pier cover (5) is 500-750 mm, and the thickness of the closed pier cover is 300-500 mm.

8. A method of dynamically adjusting precipitation in a pit and plugging a precipitation well according to any of claims 1 to 7, wherein said water-resistant coating layer (41) comprises either or both of a cement-based penetrating crystalline water-resistant coating (411) and a non-curing rubber asphalt water-resistant coating (412).

9. The dewatering well plugging structure is constructed by adopting the construction method of the foundation pit dewatering dynamic adjustment and dewatering well plugging structure according to any one of claims 1 to 7, and comprises a dewatering well (1) inserted on a foundation (2), and is characterized by further comprising a cushion layer (21), a waterproof layer (4) and a raft foundation layer (3) which are sequentially laid on the foundation (2), wherein the dewatering well (1) penetrates through the cushion layer (21), the waterproof layer (4) and the raft foundation layer (3) and protrudes out of the raft foundation layer (3), and an expansion strip (11) is wound at the contact position of the outer edge of the dewatering well (1) and the cushion layer (21).

10. The dewatering well plugging structure according to claim 9, further comprising a first water stop plate (12), wherein the first water stop plate (12) is sleeved on the outer edge of the dewatering well (1), and the first water stop plate (12) is arranged at the joint of the dewatering well (1) and the raft foundation layer (3).

11. A dewatering well plugging structure according to claim 9, wherein the upper port of the dewatering well (1) is provided with a closing plate (13), the outer edge of the closing plate (13) being fixed to the inner wall of the dewatering well (1).

12. A dewatering well plugging structure according to claim 9, wherein the waterproof layer (4) comprises a waterproof coating layer group (41) coated on the cushion layer (21) and a waterproof coiled material (42) laid on the waterproof coating layer group (41); the waterproof coating layer group (41) comprises a cement-based permeable crystalline waterproof coating (411) and/or a non-cured rubber asphalt waterproof coating (412).

13. A dewatering well plugging structure according to claim 12, wherein a water stop collar (14) is sleeved at a position where the outer edge of the dewatering well (1) contacts the waterproof coiled material (42).