阅读说明：本技术 一种应用于岩溶富水区深基坑的抗浮防水系统及方法 (Anti-floating waterproof system and method applied to deep foundation pit in karst water-rich area ) 是由 蒋腾飞 李兴盛 薛永锋 姜谙男 侯拉平 杜华林 李玉宏 侯保俊 王传嘉 高俊峰 于 2019-11-15 设计创作，主要内容包括：本发明公开了一种应用于岩溶富水区深基坑的抗浮防水系统及方法,该系统包括：基坑主体和降水井,所述基坑主体包括：顶板、底板和侧墙；所述顶板与所述底板分别设置于所述基坑本体的顶面及底面,所述顶板与所述底板平行并均与所述侧墙垂直固定；多个所述降水井设置于所述底板底部,其特征在于,所述降水井内设置有用于抽水和注浆的管道,所述管道从所述侧墙外壁延伸至所述降水井底部；本发明采用若干个相互连通的降水井实现排水与注浆结合,进而有效的防止开挖基坑的上浮以及涌水等问题的发生,为基坑的安全施工提供保障。(The invention discloses an anti-floating waterproof system and an anti-floating waterproof method applied to a deep foundation pit in a karst water-rich area, wherein the system comprises the following components: foundation ditch main part and precipitation well, the foundation ditch main part includes: a top plate, a bottom plate and side walls; the top plate and the bottom plate are respectively arranged on the top surface and the bottom surface of the foundation pit body, and the top plate and the bottom plate are parallel and are both vertically fixed with the side wall; the plurality of dewatering wells are arranged at the bottom of the bottom plate, and the dewatering wells are internally provided with pipelines for pumping water and grouting, and the pipelines extend from the outer wall of the side wall to the bottom of the dewatering wells; the invention adopts a plurality of interconnected dewatering wells to realize the combination of drainage and grouting, thereby effectively preventing the problems of upward floating, water inrush and the like of the excavated foundation pit and providing guarantee for the safe construction of the foundation pit.)

1. The utility model provides an anti waterproof system that floats for deep basal pit in karst rich water district, includes, foundation ditch main part and precipitation well (27), the foundation ditch main part includes: the top plate (3), the bottom plate (6) and the side walls (10); the top plate (3) and the bottom plate (6) are respectively arranged on the top surface and the bottom surface of the foundation pit body, and the top plate (3) and the bottom plate (6) are parallel and are both vertically fixed with the side wall (10); a plurality of precipitation well (27) set up in bottom plate (6) bottom, characterized in that, be provided with in precipitation well (27) and be used for the pipeline (28) of water extraction and slip casting, pipeline (28) follow side wall (10) outer wall extends to precipitation well (27) bottom.

2. The system as claimed in claim 1, wherein a plurality of said precipitation wells (27) are evenly distributed under said floor (6), a plurality of said precipitation wells (27) are connected by said pipes (28), the height of the surface of a plurality of said precipitation wells (27) is gradually reduced from the center to the edge, water flows from the precipitation well (27) at the center to the precipitation well (27) at the edge through said pipes (28), and slurry flows from the precipitation well (27) at the edge to the precipitation well at the center through said pipes (28).

3. The system according to claim 2, characterized in that a plurality of said precipitation wells (27) are uniformly distributed in a rectangular shape below said bottom plate (6), and the pipes (28) in the precipitation wells (27) at the four corners of said rectangular shape are communicated with the outside.

4. The system according to claim 2, characterized in that the diameter of the pipeline (28) is 1/3 of the diameter of the dewatering well (27).

5. The system according to claim 2, characterized in that the end of the pipeline (28) at the bottom of the dewatering well (27) is fixedly provided with a filter screen (30) for filtering sand and mud.

6. The system according to claim 2, characterized in that anti-floating toes (21) are arranged at the bottom of the foundation pit main body, steel pipe piles are arranged between the anti-floating toes (21) and the foot locking beams (26), one ends of the steel pipe piles (7) are fixed on the foot locking beams (26), and the other ends of the steel pipe piles (7) are fixed on the anti-floating toes (21).

7. The system according to claim 1, characterized in that the side wall of the pipeline (28) is provided with a through hole (31), the inner wall of the pipeline (28) is provided with a slide way (34) in the vertical direction, the slide way (34) crosses the through hole (31), and the slide way (34) is provided with a sliding stopper (32) which opens and closes the through hole (31).

8. The anti-floating waterproof method applied to the deep foundation pit in the karst water-rich area is characterized by comprising the following steps of:

s1: after the foundation pit body is excavated to the bottom, excavating anti-floating toes by extending outwards along the periphery of the bottom of the side wall of the foundation pit body, and connecting the foundation pit body and surrounding rock mass into a whole by pouring concrete;

s2: excavating precipitation wells at the bottom of the foundation pit body, and arranging pipelines among the precipitation wells so as to enable adjacent precipitation wells to be communicated;

s3: respectively arranging a top plate and a bottom plate at the top and the bottom of the foundation pit body;

s4: a filter screen is fixed at one end of the pipeline, which is arranged in the precipitation well;

s5: and carrying out water pumping and grouting operation on the pipeline communicated with the outside.

9. The method according to claim 8, wherein in step S5: when water is pumped, the filter screen filters out the sediment deposited at the bottom; and after the water in a plurality of precipitation wells is extracted, injecting slurry into the precipitation wells through pipelines communicated with the outside.

10. The method as claimed in claim 8, wherein the slurry in step S5 is a cement-water glass two-fluid slurry, the cement water cement ratio is 0.8:1, the two-fluid slurry ratio parameter is 1:0.8, the water glass modulus is 3.0, the water glass concentration is 35 baume degree, and the grouting pressure is 2.5 MPa-3.5 MPa.

Technical Field

The invention relates to the field of foundation pit waterproofing, in particular to an anti-floating waterproof system and an anti-floating waterproof method applied to a deep foundation pit in a karst water-rich area.

Background

The existing method for anti-floating and waterproof treatment of deep foundation pits in karst water-rich areas adopts a drainage or water plugging method, drainage needs to be carried out between every two dewatering wells during drainage, time and labor are wasted, the effect is poor, the whole situation cannot be considered, the situation of water overflow and water burst of other dewatering wells is easily caused in the drainage treatment process, karst fracture water is communicated with each other and is supplemented with each other, and local dewatering cannot be effectively controlled; in addition, the anti-floating mainly adopts a drainage and water plugging method, the integral structure of the foundation pit and the surrounding rock-soil body are not connected into a whole, so that the buoyancy of water borne by the underground structure of the foundation pit is greater than the gravity of the underground structure in a karst water-rich area, and the foundation pit floats upwards finally.

Disclosure of Invention

The invention provides an anti-floating waterproof system and an anti-floating waterproof method applied to a deep foundation pit in a karst water-rich area, and aims to overcome the technical problems.

The invention comprises a foundation pit main body and a dewatering well, wherein the foundation pit main body comprises: a top plate, a bottom plate and side walls; the top plate and the bottom plate are respectively arranged on the top surface and the bottom surface of the foundation pit body, and the top plate and the bottom plate are parallel and are both vertically fixed with the side wall; a plurality of the precipitation well set up in the bottom plate bottom, its characterized in that, be provided with the pipeline that is used for drawing water and slip casting in the precipitation well, the pipeline is followed the side wall outer wall extends to precipitation well bottom.

Furthermore, a plurality of precipitation wells evenly distributed in the bottom plate below, a plurality of precipitation wells pass through the pipeline intercommunication, a plurality of the well face height of precipitation well reduces from the center to the edge gradually, and water passes through the pipeline from the precipitation well in center department to the precipitation well in edge department, and the thick liquid passes through the pipeline from the precipitation well in edge department to the precipitation well in center department.

Furthermore, a plurality of precipitation wells are uniformly distributed in a rectangular mode below the bottom plate, and pipelines in the precipitation wells at the four corners of the rectangular mode are communicated with the outside.

Further, the diameter of the pipeline is 1/3 of the diameter of the dewatering well.

Furthermore, one end of the pipeline, which is positioned at the bottom of the dewatering well, is fixedly provided with a filter screen for filtering sand and mud.

Furthermore, anti-floating toes are arranged at the bottom of the foundation pit main body, a steel pipe pile is arranged between the anti-floating toes and the foot locking beam, one end of the steel pipe pile is fixed on the foot locking beam, and the other end of the steel pipe pile is fixed on the anti-floating toes.

Furthermore, a through hole is formed in the side wall of the pipeline, a slide way is arranged in the vertical direction of the inner wall of the pipeline and transversely penetrates through the through hole, and a sliding stopper which enables the through hole to be opened and closed is arranged on the slide way.

The invention also provides an anti-floating waterproof method applied to the deep foundation pit in the karst water-rich area, which is characterized by comprising the following steps of:

s1: after the foundation pit body is excavated to the bottom, excavating anti-floating toes by extending outwards along the periphery of the bottom of the side wall of the foundation pit body, and connecting the foundation pit body and surrounding rock mass into a whole by pouring concrete;

s2: excavating precipitation wells at the bottom of the foundation pit body, and arranging pipelines among the precipitation wells so as to enable adjacent precipitation wells to be communicated;

s3: respectively arranging a top plate and a bottom plate at the top and the bottom of the foundation pit body;

s4: a filter screen is fixed at one end of the pipeline, which is arranged in the precipitation well;

s5: and carrying out water pumping and grouting operation on the pipeline communicated with the outside.

Further, in the step S5: when water is pumped, the filter screen filters out the sediment deposited at the bottom; and after the water in a plurality of precipitation wells is extracted, injecting slurry into the precipitation wells through pipelines communicated with the outside.

Further, in the step S5, the slurry is a cement-water glass double-liquid slurry, the cement water cement ratio is 0.8:1, the double-liquid slurry proportioning parameter is 1:0.8, the water glass modulus is 3.0, the water glass concentration is 35 baume, and the grouting pressure is 2.5 MPa-3.5 MPa.

The invention adopts a plurality of interconnected dewatering wells to realize the combination of drainage and grouting, thereby effectively preventing the problems of upward floating, water inrush and the like of the excavated foundation pit and providing guarantee for the safe construction of the foundation pit.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is a schematic view of the piping structure of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention comprises a foundation pit main body and a dewatering well 27, wherein the foundation pit main body comprises: a top plate 3, a bottom plate 6 and side walls 10; the top plate 3 and the bottom plate 6 are respectively arranged on the top surface and the bottom surface of the foundation pit body, and the top plate 3 and the bottom plate 6 are parallel and are both vertically fixed with the side wall 10; a top plate waterproof layer 17 and top plate backfill 18 are arranged at the top of the top plate 3; the bottom plate 6 is fixed at the bottom of the foundation pit body through bottom plate stressed steel bars 22, a bottom plate concrete cushion layer 25 is arranged below the bottom plate 6, a bottom plate concrete waterproof layer 24 is arranged below the bottom plate concrete cushion layer, and a bottom plate concrete leveling cushion layer 23 is arranged below the bottom plate concrete waterproof layer 24; the upper part of the foundation pit body is provided with a prestressed anchor cable 19 anchored towards the lower part of the periphery of the foundation pit main body, and the lower part of the side surface of the foundation pit body is provided with a rock anchor rod 20 anchored towards the lower part of the periphery of the foundation pit body; an underground first-layer bottom plate 4 and an underground second-layer bottom plate 5 are arranged between the top plate 3 and the bottom plate 6; side wall 10 department is equipped with side wall waterproof layer 9, be equipped with the secant pile (including meat stake 13 and the plain pile 11 that the interval set up) around foundation ditch body upper portion, the top of secant pile is equipped with guan liang 15, the top of guan liang 15 is fixed with can enclose retaining wall 16 that keeps off roof plate backfill 18.

A plurality of precipitation well 27 set up in bottom plate 6 bottom, be provided with the pipeline 28 that is used for drawing water and slip casting in the precipitation well 27, pipeline 28 follows the side wall 10 outer wall extends to precipitation well 27 bottom.

Furthermore, a plurality of the dewatering wells 27 are uniformly distributed below the bottom plate 6, a plurality of the dewatering wells 27 are communicated through the pipeline 28, the well surface height of the plurality of the dewatering wells 27 is gradually reduced from the center to the edge, water flows from the dewatering well 27 at the center to the dewatering well 27 at the edge through the pipeline 28, and slurry flows from the dewatering well 27 at the edge to the dewatering well at the center through the pipeline 28.

Furthermore, a plurality of the precipitation wells 27 are uniformly distributed below the bottom plate 6 in a rectangular shape, and pipelines 28 in the precipitation wells 27 at the four corners of the rectangular shape are communicated with the outside.

Specifically, as shown in fig. 1, which is a cross-sectional view of the present invention, the dewatering wells 27 in the present invention are sixteen, and a plurality of dewatering wells 27 are communicated through a pipeline 28, wherein the dewatering wells 27 on both sides have the lowest well surface height, the dewatering wells 27 in the middle have the highest well surface height, and the pipeline 28 arranged in the dewatering well 27 with the lowest well surface height can extract water of the dewatering wells 27 from the center of the lower part of the foundation pit body by using a water pump.

Further, in order to achieve higher pumping and grouting efficiency, the diameter of the pipeline 28 is 1/3 of the diameter of the dewatering well 27.

Furthermore, in order to prevent the extracted water from blocking the pipeline 28 due to containing a large amount of sand and mud, a filter screen 30 is fixedly arranged at one end of the pipeline 28 at the bottom of the dewatering well 27, and the filter screen 30 is used for filtering the sand and mud.

Furthermore, anti-floating toes 21 are arranged at the bottom of the foundation pit main body, steel pipe piles are arranged between the anti-floating toes 21 and the foot locking beams 26, one ends of the steel pipe piles 7 are fixed on the foot locking beams 26, and the other ends of the steel pipe piles 7 are fixed on the anti-floating toes 21; the weight of the upper rock mass is utilized to press the anti-floating toes 21, the anti-floating force of the whole structure of the foundation pit body is provided, and the anti-floating structure is integrated with the surrounding rock mass and meets the durability of the anti-floating structure by adopting reinforced concrete construction.

Further, as shown in fig. 2, a through hole 31 is formed in a side wall of the pipeline 28, a slide 34 is vertically arranged on an inner wall of the pipeline 28, the slide 34 traverses the through hole 31, and a sliding stopper 32 for opening and closing the through hole 31 is arranged on the slide 34; the sliding stopper 32 is a structure formed by beveling from the edge of the end face of the cylinder to the length direction of the cylinder, a pulley is fixed on the circular end face of the sliding stopper 32 and can slide on the slideway 34 (the concrete structure of the slideway is not shown in the figure), the long side of the sliding stopper 32 faces upwards, the length of the long side is smaller than the diameter of the pipeline 28, the short side faces downwards, when water pumping is started, under the action of water pressure, the sliding stopper 32 slides upwards and is stopped by a limiting part at the upper end of the slideway 34 to stop advancing, so that the through hole 31 is blocked, water in the dewatering well 27 is prevented from being left to the bottom from the through hole again, after water pumping is finished, grouting is performed from the pipeline 28 arranged in the dewatering well 27 with the lowest well face height, at the moment, the sliding stopper 32 moves downwards under the pressure of grout and is stopped by the limiting part at the lower end of the slideway 34, when the downward movement is stopped, the slurry flows out of the pipeline 28 through the through holes 31, so that the slurry is uniformly distributed, and the grouting efficiency is accelerated.

The invention also provides an anti-floating waterproof method applied to the deep foundation pit in the karst water-rich area, which is characterized by comprising the following steps of,

s1: after the foundation pit body is excavated to the bottom, excavating anti-floating toes by extending outwards along the periphery of the bottom of the side wall of the foundation pit body, and connecting the foundation pit body and surrounding rock mass into a whole by pouring concrete;

the bottom of the foundation pit main body is provided with anti-floating toes 21, a steel pipe pile is arranged between the anti-floating toes 21 and a foot locking beam 26, one end of the steel pipe pile 7 is fixed on the foot locking beam 26, and the other end of the steel pipe pile 7 is fixed on the anti-floating toes 21; the weight of the upper rock mass is utilized to press the anti-floating toes 21, the anti-floating force of the whole structure of the foundation pit body is provided, and the anti-floating structure is integrated with the surrounding rock mass and meets the durability of the anti-floating structure by adopting reinforced concrete construction.

S2: excavating precipitation wells at the bottom of the foundation pit body, and arranging pipelines among the precipitation wells so as to enable adjacent precipitation wells to be communicated;

the plurality of dewatering wells 27 are communicated through pipelines 28, the heights of the dewatering wells 27 on two sides are the lowest in the figure, the heights of the two dewatering wells 27 in the middle are the highest, and the pipelines 28 arranged in the dewatering wells 27 with the lowest height of the well surface can extract water of the dewatering wells 27 from the center of the lower part of the foundation pit body by using a water pump.

S3: respectively arranging a top plate and a bottom plate at the top and the bottom of the foundation pit body;

s4: a filter screen is fixed at one end of the pipeline, which is arranged in the precipitation well; the possibility of extracting the water that comes up, without having to block the pipe 28 due to the presence of a large amount of sand and mud,

s5: and carrying out water pumping and grouting operation on the pipeline communicated with the outside.

Further, in the step S5: when water is pumped, the filter screen filters out the sediment deposited at the bottom; and after the water in a plurality of precipitation wells is extracted, injecting slurry into the precipitation wells through pipelines communicated with the outside.

Further, the slurry in the step S5 is cement-water glass double-liquid slurry, the water cement ratio of the cement is 0.8:1, the proportioning parameter of the double-liquid slurry is 1:0.8, the water glass modulus is 3.0, the water glass concentration is 35 baume, and the grouting pressure is 2.5 MPa-3.5 MPa; the parameters can enable the slurry to be quickly solidified after injection, and the slurry has a good water plugging effect.

The invention has the beneficial effects that:

(1) compared with the existing foundation pit anti-floating structure, the foundation pit anti-floating structure has the advantages that the foundation pit body and the surrounding rock mass are integrated by adopting anti-floating toes, and the risk of floating of the foundation pit is effectively eliminated by adopting a pumping and discharging mode;

(2) a plurality of dewatering wells are communicated for pumping water and discharging the water, so that the blindness of local drainage and the outburst of other potential hidden danger areas are effectively avoided, and a beneficial drainage effect is achieved;

(3) the well plugging and karst crack filling mode of reverse high-pressure grouting filling after water pumping effectively avoids engineering hidden dangers and provides safety guarantee for stability and long-term operation of the foundation pit body structure.

(4) The wall of the pumping grouting pipeline is additionally provided with rock mass fracture grouting holes around the foundation pit, so that the rock mass fracture around the foundation pit can be effectively plugged.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.