CN110863502A - Construction method and plugging structure for dynamically adjusting foundation pit dewatering and plugging dewatering well - Google Patents

Abstract

The invention relates to a method for deep foundation pit construction of buildings, in particular to a construction method for dynamic adjustment of foundation pit dewatering and plugging of dewatering wells. A first water stop plate is arranged at the contact position between the dewatering well and the base layer of the raft; The invention also relates to a dewatering well plugging structure, which includes a dewatering well inserted on the foundation, and also includes a cushion layer, a waterproof layer and a raft base layer laid on the foundation in sequence, and the dewatering well passes through the cushion layer, the waterproof layer and the raft. The board base layer protrudes from the raft base layer, and an expansion strip is wound at the position where the outer edge of the dewatering well contacts the cushion. The cushion layer can play a waterproof role to prevent the water in the dewatering well from seeping out of the well pipe. The raft base layer protects the cushion and avoids damage to the cushion. The sealing plate seals the wellhead of the dewatering well, which further enhances the sealing 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, in particular to a construction method and a plugging structure for dynamic adjustment of foundation pit dewatering and plugging of dewatering wells.

Background technique

For a long time, in the process of earthwork excavation for most of the deep foundation pit projects in my country, the groundwater level is too high and the surface water volume is too large. In order to effectively improve the construction conditions and ensure the construction safety, usually Reasonable arrangement of dewatering wells outside, this method effectively reduces the diving and confined water within the foundation pit, successfully lowers the groundwater level, and better solves the difficulties in the excavation and construction of deep foundation pits. The impact of foundation pit construction on peripheral buildings, pipelines and ground settlement is reduced.

After the construction of the underground structure and the backfilling of earthwork are completed, the precipitation can be stopped when the groundwater level meets the anti-floating water level required by the design. After the dewatering well stops dewatering, the dewatering well at the position of the raft in the foundation pit needs to be blocked due to the functional requirements of the building. In order to facilitate the plugging of the dewatering well, the well pipe of the dewatering well is generally made of iron pipe.

The above-mentioned prior art solution has the following defects: when setting the dewatering well, the well pipe needs to penetrate the foundation raft, thus destroying the waterproof layer of the raft. When the dewatering well is plugged, only a water stop plate is welded on the periphery of the well pipe without special waterproof treatment, so the water stop effect cannot be achieved. The groundwater will penetrate into the basement floor along the outer wall of the well pipe through the damaged waterproof layer. .

SUMMARY OF THE INVENTION

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

In order to achieve the above object, the technical scheme adopted in 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, dynamically adjusting the groundwater level, and wrapping expansion strips around the outer edge of the dewatering well;

constructing a cushion layer, laying a waterproof coating layer group on the cushion layer and laying a waterproof coiled material, and wrapping a water stop collar at the contact position of the waterproof coiled material and the dewatering well;

The raft base layer is constructed, the raft base layer is constructed and formed on the waterproof membrane, and a first water stop plate is set at the contact position between the dewatering well and the raft base layer, and the first water stop plate is sleeved on the outer edge of the dewatering well;

A closing plate is arranged, and a closing plate is arranged inside the dewatering well, and the outer edge of the closing plate is fixedly connected with the inner side wall of the dewatering well.

The closed pier cover is constructed. After the closing plate is installed, the closed pier cover is poured on the wellhead of the dewatering well, and the closed pier cover is located on the wellhead of the dewatering well and seals the wellhead of the dewatering well.

Further, the following construction steps are also included:

After the raft base layer is constructed, a waterproof sealing paint is applied at a position near the top of the raft base layer, and the waterproof sealing paint is applied around the dewatering well.

Further, the following construction steps are also included:

After the waterproof sealing paint is applied, a second water stop plate is provided at the outer edge of the dewatering well, the second water stop plate is sleeved on the outer edge of the dewatering well, and the second water stop plate is installed at the outer edge of the dewatering well. A board is positioned over the waterproof sealant.

Further, the following construction steps are also included:

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

Further, the plugging material includes cement and impermeable self-compacting micro-expanded fine stone concrete. .

Further, when filling the blocking material into the dewatering well, the dewatering well is first filled with cement and then filled with impermeable self-compacting micro-expanded fine stone concrete.

Further, the closed pier cover is a poured concrete pier, and the radius of the closed pier cover is 500mm to 750mm, and the thickness is 300mm to 500mm thick cylindrical pier cover.

Further, the method for dynamically adjusting the groundwater level includes 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 is determined, and the groundwater level is lowered to not higher than the initial control water level.

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

In the construction stage of the external main structure, the anti-floating capacity of the anti-floating object 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.

Further, the waterproof coating layer group includes any one or both of cement-based permeable crystalline waterproof coating and non-cured rubber asphalt waterproof coating.

The invention also discloses a dewatering well plugging structure, which comprises a dewatering well inserted on the foundation, and also includes a cushion layer, a waterproof layer and a raft foundation layer laid on the foundation in sequence, and the dewatering well penetrates The outer edge of the dewatering well is wound with an expansion strip at the position where the outer edge of the dewatering well contacts the cushion layer through the cushion layer, the waterproof layer and the raft base layer and protrudes from the raft base layer.

Further, it also includes a first water stop plate, the first water stop plate is sleeved on the outer edge of the dewatering well, and the first water stop plate is arranged on the dewatering well and the raft foundation layer Junction.

Further, the upper port of the dewatering well is provided with a closing plate, and the outer edge of the closing plate is fixed on the inner wall of the dewatering well.

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

Further, it also includes a closed pier cover for sealing the wellhead of the dewatering 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.

Further, the waterproof layer includes a waterproof coating layer group coated on the cushion layer and a waterproof coil material laid on the waterproof coating layer group.

Further, the waterproof coating layer group includes cement-based permeable crystalline waterproof coating and non-cured rubber asphalt waterproof coating.

Further, a water stop collar is sleeved at the position where the outer edge of the dewatering well is in contact with the waterproof membrane.

To sum up, the beneficial effects of the present invention are:

1. Lower the groundwater level to facilitate subsequent construction and better plugging of dewatering wells. The formed cushion can play a waterproof role, preventing the water in the dewatering well from seeping out of the well pipe and flowing into the basement. The base layer of the raft board plays a protective role on the cushion to avoid damage to the cushion and water seepage on the ground. The sealing plate seals the wellhead of the dewatering well, and the outer edge of the sealing plate is fixed on the inner wall of the dewatering well, which further strengthens the sealing effect of the dewatering well and prevents the water in the dewatering well from seeping into the basement of the building. The waterproof coating layer provided with the expansion strips can prevent the groundwater from infiltrating into the basement, which plays a role in strengthening the waterproofing. The expansion strip has the property of swelling in contact with water. When groundwater seeps out, the expansion strip expands, blocking the water seepage gap, slowing down the amount of water seepage, and avoiding water seepage in the basement. The first water stop plate is sleeved on the outer edge of the dewatering well, and the first water stop plate is arranged at the contact position between the dewatering well and the base layer of the raft. This setting can block the outer wall of the dewatering well and prevent the well water from flowing from the well. The outer wall of the dewatering well seeps.

2. The number of closing plates is at least two, and the closing plates are arranged on the inner wall of the well pipe. By this arrangement, the sealing of the well pipe is strengthened and the groundwater is prevented from seeping out from the well pipe.

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

4. By setting the waterproof sealing coating, the waterproofness of the well pipe is strengthened to prevent the groundwater from seeping out of the well pipe. By arranging the second water stop plate, the water resistance of the well pipe is enhanced. At the same time, the second water stop plate is located above the waterproof sealing coating, and plays a role in protecting the water waterproof sealing coating. When the concrete is poured in the subsequent construction, the direct impact of the concrete on the waterproof sealing coating is avoided, causing its damage.

5. From the start of underground precipitation to the stop of underground precipitation, the original precipitation 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 according to the highest groundwater level in the geological survey report, and the calculation result will be multiplied by a large safety factor, so the anti-floating design is very conservative. With the continuous construction of the external main structure, the constant design precipitation requirements make the precipitation work do a lot of useless work, resulting in unnecessary waste of resources. Therefore, by calculating the anti-floating capacity of the stage at different construction stages of the external main structure, determining the stage control water level elevation, and dynamically adjusting the precipitation water level of the foundation pit, the construction cost and labor maintenance cost are greatly saved.

Description of drawings

In order to illustrate the specific embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the specific embodiments or the prior art. Obviously, the accompanying drawings in the following description The drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

1 is a partial cross-sectional structural schematic diagram of a dewatering well plugging structure provided in an embodiment of the present invention;

Fig. 2 is another partial cross-sectional structural schematic diagram of the dewatering well plugging structure provided by the embodiment of the present invention;

Description of reference numbers:

1. Dewatering well; 11. Expansion strip; 12. The first water stop plate; 13, The closing plate; 14, The water stop collar; 15, The waterproof sealing coating; 2. Foundation; 21. Cushion; 3. Raft base layer; 4. Waterproof layer; 41. Waterproof coating layer group; 411. Cement-based permeable crystalline waterproof coating; Coiled material; 43, protective layer; 5, closed pier cover.

Detailed ways

The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope 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. The indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation or a specific orientation. construction and operation, and therefore should not be construed as limiting the invention. Furthermore, the terms "first", "second", and "third" are used for descriptive purposes only and should not be construed to indicate or imply relative importance.

In the description of the present invention, it should be noted that the terms "installed", "connected", "connected" and the like should be understood in a broad sense, unless otherwise expressly specified and limited, for example, it may be a fixed connection or a Detachable connection, or integral connection; may be mechanical connection or electrical connection; may be direct connection, or indirect connection through an intermediate medium, or internal communication between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

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 the dynamic adjustment of foundation pit dewatering and the plugging structure of the dewatering well 1, which is used to implement the dewatering well 1 plugging structure in any of the above, and the dewatering well 1 plugging structure. The construction method, the construction steps are as follows:

S1, lowering the groundwater level, when the water level drops to a preset value, that is, wrapping the expansion strip 11 on the outer edge of the dewatering well 1; one hour before construction, increase the precipitation power, lower the groundwater level, and then install the expansion strip 11 , The expansion strip 11 has the property of swelling in contact with water. When there is groundwater seepage, the expansion strip 11 expands, blocking the gap of water seepage, slowing the amount of water seepage, and avoiding water seepage in the basement.

S2, constructing the cushion layer 21, laying the waterproof coating layer group 41 on the cushion layer 21 and laying the waterproof coil material 42, and wrapping the water stop collar 14 at the contact position of the waterproof coil material 42 and the dewatering well 1 . The waterproof coating layer group 41 includes any one or both of a cement-based permeable crystalline waterproof coating 411 and a non-cured rubber asphalt waterproof coating 412. In this embodiment, the cement-based permeable crystalline waterproof coating The non-curing rubber asphalt waterproof coating 412 is applied on the permeable crystalline waterproof coating 411; the rubber water stop collar 14 plays a waterproof role, preventing the groundwater from seeping out from the side wall of the well pipe.

S3, constructing the raft base layer 3, constructing the raft base layer 3 on the waterproof membrane 42, and setting the first water stop plate 12 at the contact position of the dewatering well 1 and the raft base layer 3 , the first water stop plate 12 is sleeved on the outer edge of the dewatering well 1; the first water stop plate 12 is sleeved on the outer edge of the dewatering well 1, which can block the outer wall of the dewatering well 1 to avoid well water Seepage from the outer wall of the dewatering well 1.

S4 , apply waterproof sealing paint 15 on the position near the top of the raft base layer 3 , and apply the waterproof sealing paint 15 around the dewatering well 1 . After the waterproof sealing paint 15 is applied, a second water stop plate 16 is arranged at the outer edge of the dewatering well 1, and the second water stop plate 16 is sleeved on the outer edge of the dewatering well 1, so The second water stop plate 16 is located above the waterproof sealing paint 15 . Wherein, the second water stop plate 16 can also be installed first, and then the waterproof sealing paint 15 is applied, as long as the second water stop plate 16 is ensured to be located above the waterproof sealing paint 15, which is not limited 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 paint 15 to protect the waterproof sealing paint 15 .

S5 , a closing plate 13 is arranged, and a closing plate 13 is arranged inside the dewatering well 1 , and the outer edge of the closing plate 13 is fixedly connected with the inner side wall of the dewatering well 1 . Specifically, the closing plate 13 is a steel plate, and the number is two, and the closing plate 13 on the top is flush with the upper end of the well pipe. The closing plate 13 closes the wellhead, preventing the water in the dewatering well 1 from overflowing, and also preventing external water from entering the dewatering well 1 .

S6, constructing the closed pier cover 5, after setting the closing plate 13, pouring the closed pier cover 5 on the wellhead of the dewatering well 1, the closed pier cover 5 is located on the wellhead of the dewatering well 1 and has a The wellhead of the dewatering well 1 is sealed. The closed pier cover 5 is a poured concrete pier, and the radius of the closed pier cover 5 is 500mm to 750mm, and the thickness is a cylindrical pier cover with a thickness of 300mm to 500mm. In this embodiment, the radius of the closed pier cover 5 is 600mm , the thickness is 400mm. The closed pier cover 5 is a cement pier set at the top of the dewatering well 1 , which is a cover for sealing the dewatering well 1 after completion, through which the dewatering opening can be closed, so as to ensure that water will not flow from the dewatering well 1 . The top of the pier enters the interior of the dewatering well 1, and 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 other shape of the pier cover. Of course, according to the actual situation and specific requirements, the size of the closed pier cover 5 can be larger, which is not limited here.

The groundwater level is lowered, the subsequent construction is facilitated and the plugging of the dewatering well 1 is better achieved. The formed cushion layer 21 can play a waterproof role to prevent the water in the dewatering well 1 from seeping out of the well pipe and flowing into the basement. The raft base layer 3 protects the cushion layer 21 to avoid damage to the cushion layer 21 and water seepage on the ground. The sealing plate 13 seals the wellhead of the dewatering well 1, and the outer edge of the sealing plate 13 is fixed on the inner wall of the dewatering well 1, which further strengthens the sealing effect of the dewatering well 1 and prevents the water in the dewatering well 1 from infiltrating the building. in the basement of the object. By arranging the expansion strip 11 and the waterproof coating layer, the groundwater is prevented from being blocked, and the groundwater is prevented from infiltrating into the basement, which plays the role of strengthening waterproofing. The expansion strip 11 has the property of expanding in contact with water. When groundwater seeps out, the expansion strip 11 expands to block the water seepage gap, slow down the water seepage amount, and avoid the basement water seepage. 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 contact position between the dewatering well 1 and the raft foundation layer 3 . Blocking to avoid well water seepage from the outer wall of the dewatering well 1.

Further, as the construction method of the plugging structure of the dewatering well 1 provided by the present invention, it also comprises the following construction steps:

Before installing the closing plate 13, fill the dewatering well 1 with a plugging material 17 until the height of the plugging material 17 is 100mm to 300mm from the wellhead of the dewatering well 1. The distance between the wellhead of the dewatering well 1 is 200mm. The plugging material 17 includes cement and impermeable self-compacting micro-expanded fine stone concrete. When filling the plugging material 17 into the dewatering well 1 , the dewatering well 1 is first filled with cement and then filled with impermeable self-compacting micro-expanded fine stone concrete.

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

Further, as the construction method of the plugging structure of the dewatering well 1 provided by the present invention, it also comprises 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 is determined, and the groundwater level is lowered to not higher than the initial control water level. Then proceed to the construction phase of the external main structure

In the construction stage of the external main structure, the anti-floating capacity of the anti-floating object 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 control water level elevation refers to the height of the water level on the lower surface of the raft base layer 3. If the water level drops below the raft base layer 3, buoyancy will not be generated on the main structure such as the raft. The stage control 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, the water in the dewatering well 1 drilled in the raft foundation layer 3 is discharged into the dewatering well 1 outside the raft foundation layer 3 by pumping water through a water pump, so as to realize the water level control during construction, that is, In order to realize the control of groundwater level through the method of well point precipitation.

Among them, the calculation method of the initial control water level elevation is as follows: first select the anti-floating object, the anti-floating object in this implementation is the anti-floating anchor rod, and the calculation method of the initial control water level elevation of the anti-floating anchor rod is as follows:

The number of anti-floating anchor rods in the calculation unit is m, and the characteristic value of the pull-out bearing capacity of each anchor rod is FkN. The weight of the structural beam of this technology is not calculated as the anti-floating safety reserve. One axis line is a calculation unit. Before the floor plan, you need to draw the grid line first. The grid line is a network composed of building axes. It is artificially used in the architectural drawings to indicate the detailed dimensions of the components. It is dummy according to the general customary standard and is customarily marked on the symmetrical interface or section components. on the center line.

F ₀ =F*m

G=0KN F ₁ =r*h=F ₀

PF=F/S

h=P/Y

G+F ₀ ≥F ₁

G is the gravity of the structure itself; F ₀ is the pull-out force of the anti-floating anchor

_F1 is water buoyancy

h is the water level height; P is the pressure; S is the bottom area of the base layer of the raft;

Y is the weight of water

Therefore, the water level height of the anti-floating anchor in the ordinary area is h meters, so the water level of this area only under the single action of the anchor is hp1 meter:

hp1=hs+h

hp1 is the stage to control the water level elevation

hs is the initial control water level elevation

At this time, no matter what the water-resistant elevation is, the precipitation height is below the base plate, because the main structure has not been constructed at this time, and the anti-floating anchor rod does not work.

The calculation method of the controlled water level elevation in the construction phase of the external main structure is as follows:

First, convert the cushion and foundation structure:

h1=H*n

H is the thickness of the concrete structure;

n is the weight ratio of concrete to water;

At the completion stage of construction, the conversion of the external main structure:

h2=H*n

H is the thickness of the concrete structure; n is the weight ratio of concrete to water;

Therefore, the water-resistant elevation at this time is:

h=h1+h2

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

hp2=hp1+h

hp2 is the stage to control the water level elevation

Controlling water level elevation under the action of hp1 anti-floating anchor

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

As the construction of the external main structure progresses, calculate the stage water level elevations in different construction stages. When the stage water level elevation is lower than the relative water level elevation and the water level is relatively stable, and the conditions for stopping precipitation are met, the precipitation well can be stopped. Dewatering wells can be plugged.

From the start of underground precipitation to the stop of underground precipitation, the original precipitation power remained unchanged, and the groundwater level was always controlled at the same elevation. In fact, the design often calculates the anti-floating capacity of the structure according to the highest groundwater level in the geological survey report, and the calculation result will be multiplied by a large safety factor, so the anti-floating design is very conservative. With the continuous construction of the external main structure, the constant design precipitation requirements make the precipitation work do a lot of useless work, resulting in unnecessary waste of resources. Therefore, by calculating the anti-floating capacity in different stages of the external main structure, determining the stage to control the water level elevation, and dynamically adjusting the precipitation water level of the foundation pit, the construction cost and labor maintenance cost can be greatly saved, and the foundation pit can be made ahead of schedule. precipitation. From the start of underground precipitation to the stop of underground precipitation, the original precipitation power remained unchanged, and the groundwater level was always controlled at the same elevation. In fact, the design often calculates the anti-floating capacity of the structure according to the highest groundwater level in the geological survey report, and the calculation result will be multiplied by a large safety factor, so the anti-floating design is very conservative. With the continuous construction of the external main structure, the constant design precipitation requirements make the precipitation work do a lot of useless work, resulting in unnecessary waste of resources. Therefore, by calculating the anti-floating capacity of the stage at different construction stages of the external main structure, determining the stage to control the water level elevation, and dynamically adjusting the precipitation water level of the foundation pit, the construction cost and labor maintenance cost can be greatly saved, and the foundation pit can be made ahead of schedule. precipitation.

1 and 2, the plugging structure of the dewatering well 1 provided by the present invention will now be described. The blocking structure of the dewatering well 1 includes a dewatering well 1 inserted on the foundation 2 and a cushion layer 21, a waterproof layer 4 and a raft foundation layer 3 laid on the foundation 2 in sequence, and the dewatering well 1 passes through The cushion layer 21 , the waterproof layer 4 and the raft base layer protrude from the raft base layer 3 , and the position where the outer edge of the dewatering well 1 contacts the cushion layer 21 is wound with expansion. In Article 11, the foundation 2 is generally an existing foundation that is laid, and the dewatering 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, and the dewatering well The height of the top of the raft is generally higher than the height of the base layer 3 of the raft. The expansion strip 11 is arranged on the outer side of the cushion layer 21, and the expansion strip 11 needs to be installed before the cushion layer 21 is laid. The expansion strip in this embodiment 11 is a putty-type expansion strip. Due to the water swelling property of the expansion strip 11, when groundwater seeps out, the expansion strip 11 blocks the water seepage gap, slows down the amount of water seepage, and avoids water seepage in the basement. According to the actual situation 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 drainage well 1 can also be flush with the top of the raft foundation layer 3.

Further, as a specific embodiment of the plugging structure of the dewatering well 1 provided by the present invention, the outer edge of the dewatering well 1 is sleeved with a first water stop plate 12, and the first water stop plate 12 is provided with At the junction of the dewatering well 1 and the raft foundation layer 3 . Wherein, the dewatering well 1 and the first water stop plate 12 are fixedly connected, and the fixed connection can be in the form of pasting, bolting, welding, etc. The first water stop plate 12 is arranged near the connection between the dewatering well 1 and the raft foundation layer 3 . The position of the first water stop plate 12 can be either above or below, as long as the first water stop plate 12 is located in the raft foundation layer 3 , the condition can be satisfied, 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 dewatering well 1 to prevent the well water from seeping out from the outer wall of the dewatering well 1 , and plays the role of preliminary water stop.

Further, as a specific embodiment of the plugging structure of the dewatering well 1 provided by the present invention, the upper port of the dewatering well 1 is provided with a closing plate 13 , and the outer edge of the closing plate 13 is fixed to the dewatering well 1 On the inner wall of the casing, 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 on the top is flush with the upper end of the well pipe. The fixing method of the closing plate 13 can be sticking, bolting and welding, etc. The steel plate can also be replaced with other waterproof material plates, 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 the dewatering well 1 from overflowing, and also preventing external water from entering the dewatering well 1 . Of course, according to the actual situation and specific requirements, in other embodiments of the present invention, the number of the closing plate may also be one, which is not limited here.

Further, as a specific embodiment of the plugging structure for the dewatering well 1 provided by the present invention, it also includes a closed pier cover 5 that seals the wellhead of the dewatering well 1, and the radius of the closed pier cover 5 is 500 mm to 500 mm. 750mm and a cylindrical pier cover with 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 dewatering well, which is a cover that seals the dewatering well after completion, through which the wellhead can be sealed, so as to ensure that water will not enter the dewatering well from the top of the dewatering well 1 1, in which 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 pier cover in the shape of a prism or other irregular cubes, as long as the wellhead is closed. . Of course, according to the actual situation and specific requirements, the size of the closed pier cover 5 can be larger, which is not limited here.

Further, as a specific embodiment of the plugging structure for the dewatering well 1 provided by the present invention, the position of the base layer 3 of the raft near the top is coated with a waterproof sealing paint 15 that surrounds the dewatering well 1 for a week. This embodiment The medium waterproof sealing paint 15 is a water-tight paint. The outer edge of the dewatering well 1 is provided with a second water stop plate 16, 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 located in the waterproof Above the sealant paint 15. Waterproof coating is a waterproof and moisture-proof material. It can not only effectively prevent moisture, seepage, and block leakage, but also bond with a variety of materials. The slow-setting type is mainly used for moisture-proof and anti-seepage; the fast-setting type is mainly used for anti-seepage plugging, which is the prior art. Wherein, the waterproof sealing coating 15 can also be replaced with other waterproof coating such as asphalt. The second water stop plate 16 enhances the waterproof performance of the well pipe. At the same time, the second water stop plate 16 is located above the waterproof sealing paint 15 , and plays a role in protecting the water and waterproof sealing paint 15 . When pouring concrete in the subsequent construction, it is avoided that the concrete directly impacts the waterproof sealing coating 15 and causes its damage.

Further, as a specific embodiment of the plugging structure for the dewatering well 1 provided by the present invention, the waterproof layer 4 includes a waterproof coating layer group 41 coated on the cushion layer 21, and the waterproof coating layer is laid on the waterproof coating layer. The waterproof membrane 42 on the group 41 and the protective layer 43 laid on the waterproof membrane 42 . Wherein, the waterproof coating layer group 41 includes any one or more of cement-based permeable crystalline waterproof coating 411 and non-cured rubber asphalt waterproof coating 412, and the cement-based permeable crystalline waterproof coating 411 can be applied first, The non-cured rubber asphalt waterproof coating 412 is applied on the permeable crystalline waterproof coating 411 , and only one of the cement-based permeable crystalline waterproof coating 411 or the non-cured rubber asphalt waterproof coating 412 can be applied. Wherein, the waterproofing membrane 42 may be a waterproofing material commonly used in construction, such as a bitumen waterproofing material or a polymer-modified bitumen waterproofing membrane. The protective layer 43 can be laid with materials such as concrete or sand to protect the waterproof membrane 42 .

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

Obviously, the above-mentioned embodiments are only examples for clear description, and are not intended to limit the implementation manner. For those of ordinary skill in the art, changes or modifications in other different forms can also be made on the basis of the above description. There is no need and cannot be exhaustive of all implementations here. And the obvious changes or changes derived from this are still within the protection scope of the present invention.

Claims (15)

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

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

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

constructing a raft foundation layer (3), constructing and forming the raft foundation layer (3) on the waterproof coiled material (42), arranging a first water stop plate (12) at the contact position of the precipitation well (1) and the raft foundation layer (3), and sleeving the first water stop plate (12) on the outer edge of the precipitation well (1);

arranging a closing plate (13), arranging the closing plate (13) in the dewatering well (1), and fixedly connecting the outer edge of the closing plate (13) with the inner side wall of the dewatering well (1);

constructing a closed pier cover (5), and pouring the closed pier cover (5) on the well mouth of the dewatering well (1) after the closed plate (13) is arranged, wherein the closed pier cover (5) is positioned on the well mouth of the dewatering well (1) and is used for closing the well mouth of the dewatering well (1).

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

after the raft foundation layer (3) is constructed, waterproof sealing coating (15) is smeared at the position, close to the top, of the raft foundation layer (3), and the waterproof sealing coating (15) surrounds the dewatering well (1) to be smeared.

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

after the waterproof sealing coating (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 at the outer edge of the dewatering well (1), and the second water stop plate (16) is located above the waterproof sealing coating (15).

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

before the closing plate (13) is arranged, plugging materials (17) are filled into the dewatering well (1) until the distance between the height of the plugging materials (17) and the wellhead of the dewatering well (1) is 100 mm-300 mm.

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

6. The construction method for dynamically adjusting foundation pit rainfall and plugging a precipitation well according to claim 5, wherein when the plugging material (17) is filled into the precipitation well (1), the precipitation well (1) is filled with cement and then filled with impervious self-compacting micro-expansive fine stone concrete.

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

8. The construction method for dynamically adjusting the precipitation of the foundation pit and plugging the precipitation well according to any one of claims 1 to 7, wherein 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 an initial anti-floating object is calculated, an initial control water level elevation is determined, and the underground water level is reduced to be not higher than the initial control water level elevation.

9. The construction method for dynamically adjusting the precipitation of the foundation pit and plugging the precipitation well according to the claim 8, wherein the method for dynamically adjusting the groundwater level comprises the following steps:

and in the external main structure construction stage, calculating the anti-floating capacity of the 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.

10. The construction method for dynamically adjusting foundation pit dewatering and plugging a dewatering well according to any one of claims 1 to 7, wherein the waterproof coating layer group (41) comprises one or both of a cement-based permeable crystalline waterproof coating (411) and a non-cured rubberized asphalt waterproof coating (412).

11. A precipitation well plugging structure, which is constructed by adopting the foundation pit precipitation dynamic adjustment and precipitation well plugging structure construction method according to any one of claims 1 to 10, and which comprises a precipitation 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 precipitation 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 a position where the outer edge of the precipitation well (1) is in contact with the cushion layer (21).

12. The plugging structure of a dewatering well according to claim 11, 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 connection position of the dewatering well (1) and the raft foundation layer (3).

13. Dewatering well plugging structure according to claim 11, characterized in that the upper port of the dewatering well (1) is provided with a closing plate (13), the outer edge of the closing plate (13) is fixed on the inner wall of the dewatering well (1).

14. A dewatering well plugging structure according to claim 11, characterized in that the waterproof layer (4) comprises a waterproof paint layer group (41) coated on the cushion layer (21) and a waterproof coiled material (42) laid on the waterproof paint layer group (41); the waterproof coating layer group (41) comprises a cement-based permeable crystallization type waterproof coating (411) and/or an uncured rubber asphalt waterproof coating (412).

15. A dewatering well plugging structure according to claim 14, characterized in that a water stopping collar (14) is sleeved at the position where the outer edge of the dewatering well (1) contacts with the waterproof coiled material (42).

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