CN217758974U

CN217758974U - Anti-seepage structure for ground wall joint position in ultra-deep foundation pit engineering

Info

Publication number: CN217758974U
Application number: CN202221497795.8U
Authority: CN
Inventors: 翁其平; 李靖; 王卫东; 戴斌
Original assignee: East China Architectural Design and Research Institute Co Ltd
Current assignee: East China Architectural Design and Research Institute Co Ltd
Priority date: 2022-06-15
Filing date: 2022-06-15
Publication date: 2022-11-08
Anticipated expiration: 2032-06-15

Abstract

The utility model belongs to a prevention of seepage structure that is arranged in ultra-deep foundation ditch engineering ground wall joint position of city underground space development field. The technical scheme is as follows: an interface exists between the first underground continuous wall and the second underground continuous wall; a first steel reinforcement cage of the first underground continuous wall and a second steel reinforcement cage of the second underground continuous wall are respectively provided with a first water stop buried part and a second water stop buried part at the positions, close to an interface, of the inner side of the foundation pit; the bottoms of the first water stopping embedded part and the second water stopping embedded part extend to the base position of the foundation pit; the stagnant water steel sheet sets up the seepage position at the interface, and the both sides of stagnant water steel sheet are buried the piece and are welded with first stagnant water respectively with the second stagnant water. The structure is applied to the development of ultra-deep underground space in high underground water level center urban areas, the risk of underground diaphragm wall water leakage can be effectively reduced, and the influence of foundation pit excavation on the surrounding environment is further reduced.

Description

Anti-seepage structure for ground wall joint position in ultra-deep foundation pit engineering

Technical Field

The utility model belongs to city underground space development field especially relates to an strengthen stagnant water structure in the super dark underground space development of high ground water level center urban area, ensures the effective protection of all ring edge borders and the safe smooth implementation of foundation ditch engineering.

Background

In recent years, china is accelerated along with economic development, city construction is different day by day, and particularly, city development enters a brand new stage under the promotion of a novel urbanization strategy in China in 2013. With the acceleration of the urbanization process, many cities begin to seek opportunities for space expansion towards deep underground spaces under the condition that shallow underground space development tends to be saturated. New projects for deep underground spaces have emerged with increasing space requirements for cities, expanding city capacity in the vertical direction. Shanghai is one of cities which develop and utilize underground spaces earlier in China, and deep underground spaces are utilized ahead of most cities in China. At present, the deepest subway station in the Shanghai region reaches more than 40 meters underground, and the depth of a foundation pit of the world Expo transformer substation reaches 34 meters underground. The depth of the underground space used by the north cross channel of the Shanghai as the second main artery of the Shanghai and the east-west trend reaches 48 meters, and the distance of the underground part exceeding the depth of 40 meters reaches 2.6 kilometers. In addition, a major project, namely a Suzhou river section deep drainage regulation and storage pipeline system project, which is developed in the Shanghai region, is constructed, wherein the test section project implemented in advance is a nursery-Yunling section primary regulation and storage pipeline and matched comprehensive facilities, the total length is about 1.67km, and the depths of the vertical shaft foundation pits at two ends are close to the excavation depth of 60 m.

The underground continuous wall has the outstanding advantages of high rigidity, deep wall forming depth, reliable quality and the like, and is a most widely applied enclosure structure form in ultra-deep foundation pit construction at present. Need divide the groove section to implement successively in the diaphragm wall work progress, the weak node of percolating water often can become in the joint position between the ground wall groove section. Particularly, for ultra-deep foundation pit engineering, the stratum conditions are more complicated, and the problem of water leakage at the position of a ground wall joint is more prominent in the stratum with stronger water permeability. Leakage water occurs in foundation pit engineering, on one hand, the water level outside the pit is reduced, and then soil outside the pit is solidified and settled; on the other hand, fine-grained silt can enter the pit along with the leakage water, so that soil outside the pit can be lost. Therefore, if water leakage occurs in the foundation pit engineering, the surrounding ground surface is inevitably settled, and the safety of surrounding structures, roads and underground pipelines is threatened. Meanwhile, the safe and smooth construction of foundation pit engineering is greatly influenced by water leakage of the underground diaphragm wall. In recent years, safety accidents such as inclination cracking of surrounding buildings and collapse of roads caused by water leakage from foundation pits have been continued. At present, the most common solution is to set a waterproof curtain on the outer side of the ground wall alone, or set a waterproof structure measure at the joint position of the outer side of the ground wall, but the problem of water leakage of the ground wall cannot be completely avoided by the existing technical measures, and meanwhile, the manufacturing cost of the foundation pit support structure is greatly increased.

SUMMERY OF THE UTILITY MODEL

For solving the technical problem, the utility model provides a prevention of seepage structure that is arranged in ultradeep foundation ditch engineering ground wall to connect the position, this structure is used in the development of the ultradeep underground space of high ground water level center urban area, can effectively reduce the risk of secret diaphragm wall percolating water, and then reduces the influence of foundation ditch excavation to all ring edge borders.

The technical proposal of the utility model comprises two types.

The first technical scheme is as follows: an anti-seepage structure for a ground wall joint position in ultra-deep foundation pit engineering is disclosed, wherein an underground continuous wall comprises a first underground continuous wall constructed in a first period and a second underground continuous wall constructed in a later period, and an interface exists between the first underground continuous wall and the second underground continuous wall; a first steel reinforcement cage of the first underground continuous wall and a second steel reinforcement cage of the second underground continuous wall are respectively provided with a first water stop buried part and a second water stop buried part at the positions, close to an interface, of the inner side of the foundation pit; the bottoms of the first water stopping embedded part and the second water stopping embedded part extend to the base position of the foundation pit; the stagnant water steel sheet sets up the seepage position at the interface, and the both sides of stagnant water steel sheet weld with first stagnant water buries piece and second stagnant water buries the piece respectively.

Based on the technical characteristics: and a compressible water stopping material is arranged between the water stopping steel plate and the wall surface of the underground continuous wall.

Based on the technical characteristics: the surface of the water stop steel plate is provided with holes and is provided with a drainage filter screen.

The second technical scheme is as follows: the underground continuous walls comprise a first underground continuous wall constructed in the early period and a second underground continuous wall constructed in the later period, and an interface exists between the first underground continuous wall and the second underground continuous wall; the first underground continuous wall is a rigid joint, and a second steel reinforcement cage of the second underground continuous wall is provided with a second water stop embedded part at the position, close to the interface, of the inner side of the foundation pit; the bottom of the second water stop embedded part extends to the position of the foundation pit base; the water stop steel plate is arranged at the leakage position of the interface, and the two sides of the water stop steel plate are respectively welded with the rigid joint and the second water stop embedded part.

For the underground continuous wall in the form of the conventional fore shaft pipe joint, an interface is inevitably formed between the underground continuous wall constructed in the early stage and the underground continuous wall constructed in the later stage. In the construction process of the ultra-deep foundation pit in the high-underground water level area, particularly when the foundation pit is excavated into a stratum with high water permeability, the interface of the two underground continuous walls often becomes a weak link of water leakage. The water stop embedded part is arranged on the reinforcement cage close to the interface at the inner side of the foundation pit, and when water leakage occurs in the underground diaphragm wall, the water stop steel plate is welded in time, so that the water leakage can be quickly blocked. As the surface of the underground continuous wall is uneven in actual construction, compressible water stopping materials such as foam plastics or rubber sheets can be placed between the water stopping steel plate and the underground continuous wall, and the reliability of water stopping is further ensured. Through the construction measure, the leakage position can be effectively blocked in time, so that the underground water level outside the foundation pit can not be reduced and the soil body can not be lost due to the leakage of the underground diaphragm wall in the process of excavation of the foundation pit and precipitation in the pit, and the peripheral building, roads and underground pipelines can not generate large additional deformation due to stratum settlement. Meanwhile, the technology can also reduce the construction cost of foundation pit enclosure increased by independently adding the waterproof curtain. When the stratum water yield of seepage position place is very abundant, the great direct construction that covers the stagnant water steel sheet that leads to of water yield, nevertheless under the local seepage can not cause the circumstances of the outer decline of water level in hole, can be on the stagnant water steel sheet trompil to at downthehole drainage filter screen that sets up. The drainage filter screen has the functions of preventing fine-particle silt outside the pit from entering the pit along with leakage water on one hand, so that stratum settlement caused by loss of soil outside the pit is prevented; on the other hand, the quick construction of the welding connection between the water stop steel plate and the water stop embedded part can be ensured.

The utility model has the advantages that: firstly, the settlement of peripheral stratums caused by water leakage of underground continuous walls can be avoided in the construction process of foundation pit engineering, and the safety of peripheral building structures, roads and underground pipelines can be further ensured; secondly, the technical measures can ensure that when the underground continuous wall has the problem of water leakage, effective plugging treatment can be carried out in time, and the normal construction of the foundation pit is ensured; in addition, by adopting the technical measures, the waterproof curtain measures on the outer side of the conventional underground continuous wall can be further optimized, so that the construction cost is saved.

Drawings

Fig. 1 is a plan view of the construction measure of the underground diaphragm wall and the joint water-stop and seepage-proofing node in the first technical scheme of the utility model.

Fig. 2 is a schematic view of the vertical arrangement of the construction measures of the underground diaphragm wall and the joint water-stop and seepage-proofing node in the first technical scheme of the utility model.

Fig. 3 is a plan layout schematic diagram of the construction measures of the underground diaphragm wall and the joint water-stop seepage-proofing node in the second technical scheme of the utility model.

The reference numbers in the figures denote: a first underground diaphragm wall 1; a second underground continuous wall 2; an interface 3; a first reinforcement cage 41; a second reinforcement cage 42; a first water stop buried member 51; a second water stop buried member 52; a foundation pit base position 6; a highly water permeable formation 7; a water stop steel plate 8; a compressible water stopping material 9; a drainage strainer 10; h-shaped steel joint structure 11.

Detailed Description

The following describes the present invention in further detail with reference to the accompanying drawings. These embodiments are only for illustrating the present invention and are not to be construed as limiting the present invention.

In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplification of the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; may be a mechanical connection; the two components can be directly connected or indirectly connected through an intermediate medium, and the two components can be communicated with each other. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In addition, in the description of the present invention, "a plurality" means two or more unless otherwise specified.

The utility model can ensure the safety of surrounding buildings, roads and underground pipelines in the construction process of the foundation pit engineering by arranging the anti-seepage structure at the position of the ground wall joint in the ultra-deep foundation pit engineering; the method ensures that the underground continuous wall can be effectively blocked and treated in time when the problem of water leakage occurs, and ensures the normal construction of the foundation pit; meanwhile, waterproof curtain measures on the outer side of the conventional underground diaphragm wall can be optimized, and the construction cost is saved. The following two technical schemes are specifically explained by combining the accompanying drawings respectively:

1. technical scheme one

As shown in fig. 1 to 2, an interface 3 between a first underground continuous wall 1 constructed in advance and a second underground continuous wall 2 constructed in later stage often becomes a weak link of water leakage in the process of excavation construction of a foundation pit; arranging water-stop buried parts at positions, close to an interface 3, of reinforcement cages of a first underground continuous wall 1 constructed in the early stage and a second underground continuous wall 2 constructed in the later stage, close to the inner side of a foundation pit; namely, a first water stop embedded part 51 is arranged at the first reinforcement cage 41 of the first underground continuous wall 1; a second water stop insert 52 is provided at the second reinforcement cage 42 of the second underground diaphragm wall 2.

The water-stopping embedded part is connected with a reinforcement cage of the underground continuous wall to form a whole, after grooving of the underground continuous wall is finished, the water-stopping embedded part and the reinforcement cage are together transferred into a groove section of the underground continuous wall, and the bottom depths of the first water-stopping embedded part 51 and the second water-stopping embedded part 52 are the same as the position 6 of the foundation pit base. In the subsequent excavation process of the foundation pit, when the foundation pit is excavated to a stratum 7 with strong water permeability, the problem of water leakage often occurs at the position of an interface 3 between a first underground continuous wall 1 constructed in the previous period and a second underground continuous wall 2 constructed in the later period, at this time, a water stop steel plate 8 can be arranged at the position where the water leakage occurs, and the water stop steel plate 8 is respectively connected with the first water stop embedded part 51 and the second water stop embedded part 52 through welding to complete the leakage plugging construction; the top and the bottom of the water stop steel plate 8 are covered with the stratum 7 with strong water permeability. The highly permeable stratum 7 is typically silt or sandy soil; or strong water permeability of the soil layer due to external environmental reasons, such as geographical reasons of being arranged at the edge of a river, etc.

Due to the fact that the surface of the underground continuous wall is not flat, a compressible water stopping material 9 is arranged between the water stopping steel plate 8 and the underground continuous wall.

When the water amount at the leakage position of the interface 3 is large, a hole is formed on the water stop steel plate 8 at the corresponding position, and a drainage filter screen 10 is arranged in the hole. After the water stop steel plate 8 and the water stop embedded part 5 are connected, the leaked water can be guided and drained through the drainage filter screen 10, and then the water can be naturally drained out of the water stop steel plate 8 through the drainage filter screen 10; measures can be taken to close the drainage screen 10, i.e. to block the openings in the water-stop steel plate 8.

2. Technical scheme two

As shown in fig. 3, the first underground diaphragm wall 1 is a rigid joint, and as shown in fig. 3, the H-beam joint structure 11, the interface 3 between the pre-constructed underground diaphragm wall 1 and the post-constructed underground diaphragm wall 2 also becomes a weak link for water leakage. In this case, the second water stop embedded part 52 is only required to be arranged at the position of the second reinforcement cage 42 of the second underground continuous wall 2 constructed at the later stage, which is close to the interface 3. The water stop steel plate 8 is arranged at the leakage position of the interface 3, and both sides of the water stop steel plate 8 are respectively welded with the H-shaped steel joint structure 11 and the second water stop buried piece 52.

The construction method comprises the following steps: the H-shaped steel joint structure 11 and the second reinforcement cage 42 of the first underground diaphragm wall 1 which is constructed in advance are connected into a whole and are together placed into the groove section of the underground diaphragm wall; at this time, the second water stop embedded part 52 is only required to be arranged at the end part of the reinforcement cage 4 of the second underground continuous wall 2 constructed in the later period; when the foundation pit is excavated to the stratum 7 with strong water permeability, if the problem of water leakage occurs, arranging a water stop steel plate 8 at the position where the water leakage occurs; one end of the water stop steel plate 8 is connected with the H-shaped steel joint structure 11, and the other end is connected with the second water stop embedded part 52; due to the fact that the surface of the underground continuous wall is not flat, a compressible water stopping material 9 is arranged between the water stopping steel plate 8 and the underground continuous wall.

Of course, the water stop steel plate 8 may be perforated and the drainage filter screen 10 may be disposed in the hole, similarly to the first embodiment.

To sum up, the utility model, through the technical measure of arranging the anti-seepage node structure at the ground wall joint position in the ultra-deep foundation pit engineering, firstly, can ensure that the peripheral stratum can not subside due to the leakage water of the ground wall in the construction process of the foundation pit engineering, thereby ensuring the safety of the peripheral building, road and underground pipeline; secondly, the technical measures can ensure that when the underground continuous wall has the problem of water leakage, effective plugging treatment can be carried out in time, and the normal construction of the foundation pit is ensured; in addition, the waterproof curtain measures on the outer side of the conventional underground continuous wall can be further optimized by adopting the technical measures, so that the construction cost is saved.

The above is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of modifications and substitutions can be made without departing from the technical principle of the present invention, and these modifications and substitutions should also be regarded as the protection scope of the present invention.

Claims

1. An anti-seepage structure for a ground wall joint position in ultra-deep foundation pit engineering is disclosed, wherein an underground continuous wall comprises a first underground continuous wall (1) constructed in advance and a second underground continuous wall (2) constructed in a later period, and an interface (3) is formed between the first underground continuous wall (1) and the second underground continuous wall (2); the method is characterized in that: a first steel reinforcement cage (41) of the first underground continuous wall (1) and a second steel reinforcement cage (42) of the second underground continuous wall (2) are respectively provided with a first water stop embedded part (51) and a second water stop embedded part (52) at positions which are on the inner side of the foundation pit and are adjacent to the interface (3); the bottoms of the first water stopping embedded part (51) and the second water stopping embedded part (52) extend to a foundation pit base position (6); the water stop steel plate (8) is arranged at the leakage position of the interface (3), and two sides of the water stop steel plate (8) are respectively welded with the first water stop embedded part (51) and the second water stop embedded part (52).

2. The anti-seepage construction for the ground wall joint position in the ultra-deep foundation pit engineering according to claim 1, characterized in that: and a compressible water stopping material (9) is arranged between the water stopping steel plate (8) and the wall surface of the underground continuous wall.

3. The seepage-proofing structure for the position of the ground wall joint in the ultra-deep foundation pit engineering according to claim 1 or 2, wherein: the surface of the water stop steel plate (8) is provided with holes and is provided with a drainage filter screen (10).

4. An anti-seepage structure for a ground wall joint position in ultra-deep foundation pit engineering is disclosed, wherein an underground continuous wall comprises a first underground continuous wall (1) constructed in advance and a second underground continuous wall (2) constructed in a later period, and an interface (3) is formed between the first underground continuous wall (1) and the second underground continuous wall (2); the method is characterized in that: the first underground continuous wall (1) is a rigid joint, and a second steel reinforcement cage (42) of the second underground continuous wall (2) is provided with a second water-stop embedded part (52) at the position, close to the interface (3), on the inner side of the foundation pit; the bottom of the second water stop embedded part (52) extends to a foundation pit base position (6); the water stop steel plate (8) is arranged at the leakage position of the interface (3), and two sides of the water stop steel plate (8) are respectively welded with the rigid joint and the second water stop embedded part (52).

5. The seepage-proofing structure for the ground wall joint position in the ultra-deep foundation pit engineering according to claim 4, wherein: and a compressible water stopping material (9) is arranged between the water stopping steel plate (8) and the wall surface of the underground continuous wall.

6. The seepage-proofing structure for the ground wall joint position in the ultra-deep foundation pit engineering according to claim 4 or 5, wherein: the surface of the water stop steel plate (8) is provided with holes and is provided with a drainage filter screen (10).