CN217174870U

CN217174870U - Foundation pit bottom drainage system

Info

Publication number: CN217174870U
Application number: CN202220233094.7U
Authority: CN
Inventors: 傅鑫晖; 袁杰; 肖翔; 李赞新; 王皓
Original assignee: Fujian Zhongjian Railway Construction Co ltd; China Construction Infrastructure Co Ltd
Current assignee: Fujian Zhongjian Railway Construction Co ltd; China Construction Infrastructure Co Ltd
Priority date: 2022-01-28
Filing date: 2022-01-28
Publication date: 2022-08-12
Anticipated expiration: 2032-01-28

Abstract

The utility model belongs to the technical field of building engineering, in particular to a foundation pit bottom drainage system, wherein the bottom of a foundation pit is provided with a precipitation well and a plurality of drainage ditches, the drainage ditches are uniformly arranged in a grid shape, first blind pipes are arranged in the drainage ditches, one end of each first blind pipe is communicated to the interior of the precipitation well, second blind pipes used for communicating a water pump are arranged in the precipitation well, and a permeable supporting layer is filled between the inner wall of the precipitation well and the outer wall of each second blind pipe; when the utility model is used, the bottom of the foundation pit can be ensured to be relatively dry, and the construction efficiency of the foundation pit is improved; the first blind pipe and the second blind pipe are light in weight, convenient to carry and simple to construct; the problem that the cushion layer is easy to crack and leak water when the thickness of the cushion layer is not enough and the water seepage quantity at the bottom is large is avoided, the construction period is saved, and the construction cost is reduced. The utility model discloses played cost reduction and efficiency improvement's effect at the practical application in-process, be worth using widely in a large number when the foundation ditch bottom drainage.

Description

Foundation pit bottom drainage system

Technical Field

The utility model belongs to the technical field of building engineering, especially, relate to a foundation ditch bottom drainage system.

Background

With the rapid development of the economy of China, the infrastructure construction is accelerated, and the heat tide of subway construction is raised for relieving the urban ground traffic jam. Because the excavation depth of the subway foundation pit is deep, the underground water level is high, and the underground water pressure is large. The water seepage in the residual soil stratum or the completely weathered stratum is very serious, and before the bottom plate is not completely poured, the bottom of the foundation pit is often foamed and softened, so that the bottom of the foundation pit is deeper and deeper, the design value is far beyond, and finally the phenomena of foundation pit deformation increase and large amount of concrete over-square are caused.

In the existing drainage system, a plurality of drainage ditches are generally arranged at the bottom of a foundation pit, groundwater is collected into a deeper water collection pit by using the drainage ditches, and then water in the water collection pit is pumped to the outer side of the foundation pit by using a water pump; when the foundation pit is deep or the water under the pit is more, a certain number of dewatering wells are usually needed to be arranged at the same time, and water is pumped outwards by one well. However, there are problems with existing drainage systems: firstly, if the quantity of the dewatering wells is not enough or the dewatering wells are not arranged at the crack of the substrate, the seepage water at the bottom of the foundation pit can not be fully discharged, and the seepage water is remained at the bottom of the foundation pit and the substrate can be softened by the foam. Secondly, before the sump pit and the dewatering well are constructed for subsequent concrete cushion layer, a large amount of broken stones are needed to be backfilled manually, if the thicknesses of the cushion layers in the sump pit and the dewatering well are not enough, the cushion layer is cracked and leaked due to large water seepage at the bottom, the cushion layer needs to be reworked, and further construction period delay and construction cost increase are caused.

SUMMERY OF THE UTILITY MODEL

The utility model discloses aim at solving above-mentioned problem to a can solve the foundation ditch and soften the problem is provided, reduce the risk that the foundation ditch was dug excessively, avoid the time limit for a project to delay and surpass the foundation ditch bottom drainage system of side.

Utility model solves the problem, the technical scheme who adopts is:

the utility model provides a foundation ditch bottom drainage system, foundation ditch bottom are equipped with precipitation well and a plurality of escape canal, and a plurality of escape canal is latticed and evenly arranges, is equipped with first blind pipe in the escape canal, and the one end intercommunication of first blind pipe is equipped with the second blind pipe that is used for the intercommunication water pump in the precipitation well, and it has the supporting layer that permeates water to fill between precipitation well inner wall and the second blind pipe outer wall.

Adopt above-mentioned technical scheme the utility model discloses, compare with prior art, its outstanding characteristics are:

when the utility model is used, the bottom of the foundation pit can be ensured to be relatively dry when the bottom of the foundation pit is closed, the problems of foundation pit deformation increase and the like caused by the softening of the bottom of the foundation pit are avoided, and the construction efficiency of the foundation pit is improved; the first blind pipe and the second blind pipe are light in weight, convenient to carry and simple to construct; the first blind pipe and the second blind pipe have certain strength and certain support property, so that the problem that the cushion layer is easy to crack and leak water when the thickness of the cushion layer is insufficient and the water seepage quantity at the bottom is large is solved, the construction period is shortened, and the construction cost is reduced. The utility model discloses played cost reduction and efficiency improvement's effect at the practical application in-process, be worth using widely in a large number when the foundation ditch bottom drainage.

Preferably, the present invention further provides:

the permeable supporting layer is composed of backfill gravel or a third blind pipe; guarantee hydrophobic effect, simple structure, construction convenience.

Geotextile is coated outside the first blind pipe and the second blind pipe; the geotextile plays a role in filtering, and can prevent soil from blocking the first blind pipe and the second blind pipe.

The dewatering well is arranged in the center of the bottom of the foundation pit; the first blind pipe can collect seepage water to the dewatering well most quickly, and the drainage efficiency is improved.

The depth and the width of the drainage ditch are 18-22cm, the diameter of the first blind pipe is 13-17cm, and the diameter of the second blind pipe is 20-25 cm; avoid the escape canal too wide, too deep, need backfill a large amount of backfill soil, guarantee that the suction pump can be high efficiency take out the water that oozes from the second blind pipe.

Drawings

Fig. 1 is a schematic structural view of a foundation pit bottom drainage system according to an embodiment of the present invention;

fig. 2 is a schematic side view of a drainage ditch according to an embodiment of the present invention;

fig. 3 is a schematic side view of the dewatering well according to the embodiment of the present invention;

fig. 4 is a schematic view of an upper layer structure of a precipitation well according to an embodiment of the present invention.

In the figure: 1. a foundation pit; 2. A drainage ditch; 3. a first blind pipe; 4. a dewatering well; 5. a second blind pipe; 6. a water permeable supporting layer; 7. backfilling; 8. a cushion layer; 9. a waterproof layer; 10. a protective layer; 11. a base plate.

Detailed Description

The invention will be further described with reference to the following examples, which are intended only for better understanding of the invention and therefore do not limit the scope of the invention.

As shown in fig. 1, a drainage system at the bottom of a foundation pit comprises a precipitation well 4 arranged at the center of the bottom of the foundation pit 1, wherein the size of the precipitation well 4 is 1m × 1 m; still include a plurality of escape canal 2, a plurality of escape canal 2 is latticed evenly and arranges in 1 bottom of foundation ditch, and the width and the degree of depth of escape canal 2 are 20cm, and the slope is 0.002 ~ 0.003. Be equipped with the first blind pipe 3 that the diameter is 15cm in the escape canal 2, the one end of first blind pipe 3 communicates to in the precipitation well 4, is equipped with the second blind pipe 5 that the diameter is 20cm in the precipitation well 4, and the upper end intercommunication of second blind pipe 5 has the suction pump. A permeable supporting layer 6 is filled between the inner wall of the dewatering well 4 and the outer wall of the second blind pipe 5. The permeable supporting layer 6 can be formed by backfilling macadam, the strength grade of the macadam is required to be more than 60MPa, and the integral permeability coefficient of the permeable supporting layer 6 is required to be more than 4500 m/d. The water-permeable supporting layer 6 can also be formed by a third blind pipe with a diameter of 8 cm. The underground seepage water sequentially passes through the first blind pipe 3, the permeable supporting layer 6 and the second blind pipe 5 and is finally pumped out of the foundation pit 1 by the water suction pump.

Furthermore, in order to prevent silt from blocking, the outer sides of the first blind pipe 3 and the second blind pipe 5 are coated with geotextile.

As shown in fig. 2 to 4, during construction, firstly, drainage ditches 2 arranged transversely and longitudinally at intervals are dug at the bottom of a foundation pit 1, and a dewatering well 4 is dug at the center of the bottom of the foundation pit 1; then, the first blind pipe 3 is placed in the drainage ditch 2, the second blind pipe 5 is vertically placed in the dewatering well 4, and the pipe orifice at the upper end of the second blind pipe 5 is upward, so that the connection of a water suction pipe of a water suction pump is facilitated; then, backfilling soil 7 in the drainage ditch 2, and backfilling broken stones in the dewatering well 4; a water pumping pipe of the water pump extends into the water pump from the upper pipe opening of the second blind pipe 5 to continuously pump water outwards; next, leaving the position of the second blind pipe 5 in the foundation pit 1, laying a cushion layer 8, pulling out the second blind pipe 5, and filling backfill soil 7 in the broken stones and the cushion layer 8; and finally, constructing a waterproof layer 9, a protective layer 10 and a bottom plate 11 from bottom to top in sequence. The construction steps can be changed according to actual conditions, and when water seepage is serious, the second blind pipe 5 can be pulled out after the waterproof layer 9 is constructed.

When the utility model is used, the bottom of the foundation pit can be ensured to be relatively dry, and the construction efficiency of the foundation pit is improved; the first blind pipe and the second blind pipe have certain strength, so that the problem that the cushion layer is easy to crack and leak water when the thickness of the cushion layer is insufficient and the water seepage amount at the bottom is large is avoided, the construction period is shortened, and the construction cost is reduced.

The above description is only a preferred and practical embodiment of the present invention, and not intended to limit the scope of the present invention, and all equivalent variations made by using the contents of the specification and the drawings are included in the scope of the present invention.

Claims

1. The utility model provides a foundation ditch bottom drainage system, foundation ditch bottom is equipped with precipitation well and a plurality of escape canal, its characterized in that: a plurality of escape canal is latticed and evenly arranges, is equipped with first blind pipe in the escape canal, and the one end of first blind pipe communicates to in the precipitation well, is equipped with the second blind pipe that is used for communicateing the water pump in the precipitation well, and it has the supporting layer that permeates water to fill between precipitation well inner wall and the second blind pipe outer wall.

2. The foundation pit bottom drainage system of claim 1, wherein: the permeable supporting layer is composed of backfill gravel or a third blind pipe.

3. The foundation pit bottom drainage system of claim 1, wherein: the first blind pipe and the second blind pipe are coated with geotextile.

4. The foundation pit bottom drainage system of claim 1, wherein: the dewatering well is arranged in the center of the bottom of the foundation pit.

5. The foundation pit bottom drainage system of claim 1, wherein: the depth and the width of the drainage ditch are 18-22cm, the diameter of the first blind pipe is 13-17cm, and the diameter of the second blind pipe is 20-25 cm.