CN219033241U - Deep foundation pit water stop system - Google Patents

Abstract

The application relates to the field of building construction, in particular to a deep foundation pit water stop system. The deep foundation pit water stop system comprises a foundation pit, a wall protection layer, a ground continuous wall, a water blocking curtain and a construction channel, wherein the wall protection layer is arranged along the circumferential direction of the foundation pit and comprises an inner wall protection layer and an outer wall protection layer which are coaxially arranged, the inner diameter of the inner wall protection layer is equal to the diameter of the foundation pit, and the diameter of the outer wall protection layer is larger than the diameter of the inner wall protection layer; the ground connecting wall is arranged between the inner retaining wall layer and the outer retaining wall layer; the water retaining curtain is arranged on the ground continuous wall along the circumferential direction of the foundation pit, and is far away from the foundation pit; the construction passageway is arranged at the top ends of the underground continuous wall and the water retaining curtain. The embodiment of the application provides a deep foundation pit water stop system to solve the problem that the protective capability of the existing water stop system in the related art is weaker, and the water stop pressure in the flood season can not be dealt with.

Description

Deep foundation pit water stop system

Technical Field

The application relates to the field of building construction, in particular to a deep foundation pit water stop system.

Background

Deep foundation pit refers to an engineering where the depth of excavation is more than 5 meters (including 5 meters), or where the depth is not more than 5 meters, but where the geological conditions and surrounding environment and underground pipelines are particularly complex. The soil retaining enclosure structure is generally required to be arranged around the deep foundation pit to support the surrounding soil pressure or water pressure, so that the soil retaining enclosure structure is a temporary construction retaining wall structure for stabilizing the foundation pit.

The foundation is often in ultra-large deep foundation pit engineering construction in bridges, subway stations and large-scale houses, the foundation pit supporting form is required to meet the requirements of safety protection of the construction of the building foundation by a reverse construction method, and meanwhile leakage cannot be guaranteed when the foundation pit is excavated. Particularly in the Yangtze river basin area, the construction period of the oversized deep foundation pit is longer, flood control in the flood season is faced, and safety flood control of the foundation pit must be ensured.

The existing deep foundation pit water sealing system generally adopts a pile machine to drive a protection pile for supporting and waterproofing, but the existing water sealing system has weak protection capability and cannot cope with the water sealing pressure in the flood season.

Disclosure of Invention

The embodiment of the application provides a deep foundation pit water stop system to solve the problem that the protective capability of the existing water stop system in the related art is weaker, and the water stop pressure in the flood season can not be dealt with.

The application provides a deep basal pit stagnant water system, it includes:

a foundation pit;

the retaining wall layer is arranged along the circumferential direction of the foundation pit and comprises an inner retaining wall layer and an outer retaining wall layer which are coaxially arranged, wherein the inner diameter of the inner retaining wall layer is equal to the diameter of the foundation pit, and the diameter of the outer retaining wall layer is larger than that of the inner retaining wall layer;

the ground connecting wall is arranged between the inner retaining wall layer and the outer retaining wall layer;

the water retaining curtain is arranged on the ground continuous wall at a circle far away from the foundation pit along the circumferential direction of the foundation pit;

and the construction passageway is arranged at the top ends of the underground continuous wall and the water retaining curtain.

In some embodiments, the underground diaphragm comprises an underground diaphragm body and an underground diaphragm guide wall, the upper end and the lower end of the underground diaphragm body are flush with the upper end and the lower end of the foundation pit, and the bottom of the underground diaphragm guide wall is connected with the top end of the retaining wall layer.

In some embodiments, the diaphragm wall body includes first slot section, second slot section and mud jacking hole, first slot section and second slot section staggered connection, the mud jacking hole is arranged in first slot section and second slot section, just the length direction of mud jacking hole with the axis direction of foundation ditch is parallel.

In some embodiments, a grouting hole is formed in the outer retaining wall layer, the grouting hole extends in an axial direction parallel to the foundation pit, the grouting hole is located at a connection position of the first groove section and the second groove section, and the grouting hole is located at one side, far away from the inner retaining wall layer, of the outer retaining wall layer.

In some embodiments, the first trough section comprises a first reinforcement cage, the grouting holes are connected with the first reinforcement cage, and the grouting holes are closed at the bottom ends and exceed the length of the first reinforcement cage.

In some embodiments, the grouting holes comprise an inner ring grouting hole close to the inner retaining wall layer and an outer ring grouting hole close to the outer retaining wall layer, and the inner ring grouting hole and the outer ring grouting hole are arranged in the circumferential direction of the underground continuous wall body.

In some embodiments, the first groove section and the second groove section overlap each other, and an overlapping section is formed at the overlapping position.

In some embodiments, the retaining wall layer comprises a plurality of retaining piles, the plurality of retaining piles having overlapping portions in a radial direction.

In some embodiments, the level of the construction passageway near the end of the wall is higher than the level of the construction passageway near the end of the water retaining curtain.

In some embodiments, the water retaining curtain comprises a curtain body and a curtain guide wall, the curtain guide wall comprises an inner guide wall and an outer guide wall, a backfill part is arranged between the inner guide wall and the outer guide wall, and the backfill part is positioned below the curtain body.

The beneficial effects that technical scheme that this application provided brought include:

the embodiment of the application provides a deep foundation pit water stop system, because the underground diaphragm wall is arranged in the circumferential direction of a foundation pit, and the inner wall and the outer wall of the underground diaphragm wall are respectively provided with an inner wall protection layer and an outer wall protection layer, two water stop lines are added on the basis of the underground diaphragm wall; the periphery of the diaphragm wall and the retaining wall layer is also provided with a water retaining curtain, so that peripheral water can be prevented or reduced from entering the diaphragm wall and the foundation pit, the pressure on the diaphragm wall is reduced temporarily in the flood season, and the safe construction of the foundation pit in the flood season is ensured;

on the other hand, the top between the diaphragm wall and the water retaining curtain is provided with a construction passageway, so that when rainwater falls, the construction passageway is convenient, the range between the diaphragm wall and the water retaining curtain is covered, and water accumulation is reduced, and therefore the problem that the protection capability of the existing water stopping system in the related art is weak and water stopping pressure in the flood season cannot be dealt with can be solved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a plan view of a deep foundation pit water stop system provided in an embodiment of the present application;

FIG. 2 is an enlarged view of FIG. 1 at A;

FIG. 3 is a cross-sectional elevation view of a diaphragm wall and a water retaining curtain in a deep foundation pit water stop system according to an embodiment of the present application;

fig. 4 is a schematic diagram of the positions of a diaphragm wall and a dewatering well in a deep foundation pit water stop system according to an embodiment of the present application;

fig. 5 is a schematic diagram of a first slot segment and a second slot segment according to an embodiment of the present disclosure.

In the figure: 1. a foundation pit; 2. a wall protection layer; 21. an inner retaining wall layer; 22. an outer retaining wall layer; 3. a ground connecting wall; 31. a wall body connected with the ground; 311. a first trough section; 312. a second trough section; 313. overlapping sections; 32. a ground connecting wall guide wall; 4. a water-retaining curtain; 41. a curtain body; 42. curtain guide walls; 43. a backfill section; 5. constructing a temporary road; 6. grouting holes; 61. inner ring grouting holes; 62. outer ring grouting holes; 7. grouting holes; 8. pile protection; 9. dewatering well.

Detailed Description

For the purposes of making the objects, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present application based on the embodiments herein.

The embodiment of the application provides a deep foundation pit water stop system, which can solve the problems that the protection capability of the existing water stop system in the related technology is weak and the water stop pressure in the flood season cannot be dealt with.

Referring to fig. 1 to 5, the embodiment of the present application provides a deep foundation pit water stop system, which includes a foundation pit 1, a retaining wall layer 2, a diaphragm wall 3, a water retaining curtain 4 and a construction passageway 5, wherein, with the foundation pit 1 as the center, the diaphragm wall 3 and the water retaining curtain 4 are sequentially arranged on the circumferential direction of the foundation pit 1, and specifically:

the retaining wall layer 2 is arranged along the circumferential direction of the foundation pit 1, and as shown in fig. 1 and 2, the retaining wall layer 2 comprises an inner retaining wall layer 21 and an outer retaining wall layer 22, and the inner retaining wall layer 21 and the outer retaining wall layer 22 are coaxially arranged, wherein the inner retaining wall layer 21 is attached to the foundation pit 1, the inner diameter of the inner retaining wall layer 21 is equal to the diameter of the foundation pit 1, and the diameter of the outer retaining wall layer 22 is larger than the diameter of the inner retaining wall layer 21, namely, the outer ring of the inner retaining wall layer 21 is arranged;

as shown in fig. 1 and 2, the diaphragm wall 3 is disposed between the inner retaining wall layer 21 and the outer retaining wall layer 22; the water retaining curtain 4 is disposed on a circle of the diaphragm wall 3 far away from the foundation pit 1 along the circumferential direction of the foundation pit 1, specifically, the water retaining curtain 4 is disposed on an outer ring of the outer wall protection layer 22 and has a distance from the outer wall protection layer 22, and is used for setting the construction passageway 5, as shown in fig. 3, the construction passageway 5 is disposed on top of the diaphragm wall 3 and the water retaining curtain 4, and as seen from the top view of fig. 1, the construction passageway 5 covers the circumference between the water retaining curtain 4 and the circle formed by the diaphragm wall 3, and prevents water from entering between the water retaining curtain 4 and the diaphragm wall 3.

The embodiment of the application provides a deep foundation pit water stop system and a construction method, because the underground continuous wall 3 is arranged in the circumferential direction of the foundation pit 1, and the inner wall and the outer wall of the underground continuous wall 3 are respectively provided with an inner protective wall layer 21 and an outer protective wall layer 22, which is equivalent to adding two water stop lines on the basis of the underground continuous wall 3, and meanwhile, the construction of the underground continuous wall 3 is convenient; the periphery of the diaphragm wall 3 and the periphery of the retaining wall layer 2 are also provided with water retaining curtains 4, so that peripheral water can be prevented or reduced from entering the diaphragm wall 3 and the foundation pit 1, the pressure on the diaphragm wall 3 is reduced temporarily in the flood season, and the safety construction of the foundation pit in the flood season is ensured;

on the other hand, the top between the diaphragm wall 3 and the water retaining curtain 4 is provided with the construction passageway 5, so that when rainwater falls, the range between the diaphragm wall 3 and the water retaining curtain 4 is shielded, and ponding is reduced, and the problem that the protection capability of the existing water stopping system in the related art is weak and the water stopping pressure in the flood season cannot be dealt with can be solved.

In some alternative embodiments, referring to fig. 3, the diaphragm wall 3 includes a diaphragm wall body 31 and a diaphragm wall guide wall 32, wherein the upper and lower ends of the diaphragm wall body 31 are flush with the upper and lower ends of the foundation pit 1, and serve as supports for the foundation pit 1, and the bottom of the diaphragm wall guide wall 32 is connected to the top end of the retaining wall layer 2, and serves as a guide and support when the diaphragm wall body 31 is constructed.

Specifically, the wall body 31 has a certain thickness, and the two wall guide walls 32 are separately arranged at two circumferences of the wall body 31 in the circumferential direction, so that the wall body 31 is conveniently poured.

In some alternative embodiments, referring to fig. 5, the diaphragm wall body 31 includes a first slot section 311 and a second slot section 312, specifically, the first slot section 311 and the second slot section 312 are both in reinforced concrete structures, the first slot section 311 and the second slot section 312 are staggered, and during construction, firstly, the reinforcement cage of the first slot section 311 is uniformly lowered, then the reinforcement cage of the second slot section 312 is lowered, and finally, the reinforcement cages of the first slot section 311 and the second slot section 312 are uniformly poured with concrete;

further, referring to fig. 4 and 5, the diaphragm wall body 31 further includes a grouting hole 6, specifically, when concrete is poured into the reinforcement cages of the first tank section 311 and the second tank section 312, the grouting hole 6 needs to be reserved, specifically, the grouting hole 6 is located in the first tank section 311 and the second tank section 312, and the grouting hole 6 penetrates through the first tank section 311 and the second tank section 312, and the length direction of the grouting hole is parallel to the axial direction of the foundation pit 1;

optionally, the grouting holes 6 can be reserved by adopting a round steel pipe mode, and the grouting holes 6 can be reserved when the first trough section 311 and the second trough section 312 are synchronously lowered when the reinforcement cage is lowered; specifically, when the round steel pipe is used, the bottom of the round steel pipe is required to be wrapped or sealed, so that mud is prevented from entering in the concrete pouring process;

specifically, the ultrasonic detection can be performed on the wall body of the underground continuous wall 3 through the grouting holes 6, a sound detection pipe is not needed, the underground continuous wall 3 is constructed, and the construction of the water retaining curtain 4 is performed after the detection of the wall body is completed.

Specifically, the purpose of the reserved grouting holes 6 is to fill the residual space by injecting cement slurry into the underground diaphragm wall body 31, wrap the prestressed reinforcement cage framework, and prevent the influence of the harmful medium on the service life of the structure due to the corrosion of the prestressed reinforcement.

Alternatively, as shown in fig. 4 and 5, the grouting holes 6 include an inner ring grouting hole 61 near the inner retaining wall layer 21 and an outer ring grouting hole 62 near the outer retaining wall layer 22, and the inner ring grouting hole 61 and the outer ring grouting hole 62 are both provided in the circumferential direction of the diaphragm wall body 31. Alternatively, the inner ring grouting holes 61 and the outer ring grouting holes 62 have a plurality of numbers, and are spaced apart in the circumferential direction of the diaphragm wall 3 and uniformly disposed in the diaphragm wall 3.

Further, as shown in fig. 5, the inner ring grouting holes 61 and the outer ring grouting holes 62 are arranged in a staggered manner, so that a good grouting effect is achieved. Specifically, when grouting holes 6, construction is performed by adopting the sequence of the inner ring and the outer ring, so that grouting plumpness of the inner side and grouting effect are ensured.

Optionally, as shown in fig. 4, the bottom end length of the grouting hole 6 exceeds the burial depth of the diaphragm wall 3, so as to ensure the water stopping effect during excavation, prevent water from entering the foundation pit 1 through the diaphragm wall 3 and influence the construction of the foundation pit 1, wherein the part of the grouting hole 6 in the diaphragm wall 3 can be obtained by pre-burying a steel pipe when pouring the diaphragm wall 3, and the part exceeding the burial depth of the diaphragm wall 3 can be obtained by drilling an opening on a soil layer; or when the steel pipes are pre-buried in the underground continuous wall 3, the steel pipes with the length longer than the height of the underground continuous wall 3 are selected, so that the steel pipes extend beyond the bottom ends of the reinforcement cages of the first trough section 311 and the second trough section 312, and holes are formed in the soil layer below through gravity and pressure.

Preferably, the grouting depth in the final grouting hole 6 is 1m below the wall bottom of the diaphragm wall 3.

In some alternative embodiments, as shown in fig. 4 and 5, the outer retaining wall layer 22 is provided with grouting holes 7, and the grouting holes 7 extend parallel to the axial direction of the foundation pit 1 and penetrate the outer retaining wall layer 22;

specifically, as shown in fig. 5, the grouting hole 7 is located at the connection position of the first groove section 311 and the second groove section 312, and is used for performing water sealing construction on the joint position of the first groove section 311 and the second groove section 312, and preferably, the water sealing range is 1m from the wall bottom of the diaphragm wall 3 to the bottom of the retaining wall layer 2.

Specifically, since the diaphragm wall guide wall 32 is located above the retaining wall layer 2 and both have overlapping portions in the vertical direction, as shown in fig. 4, the grouting holes 7 pass through the diaphragm wall guide wall 32 and are provided through the retaining wall layer 2; preferably, the part of the grouting holes 7 penetrating through the wall guide 32 can be reserved in the wall guide 32 by embedding PVC pipes when the wall guide 32 is poured, and the grouting holes 7 in the outer wall protection layer 22 can be formed by embedding PVC pipes or drilling by a drilling machine.

Further, the grouting holes 7 are located on one side of the outer retaining wall layer 22 far away from the inner retaining wall layer 21, as shown in fig. 5, because the diaphragm wall 3 is arranged around the foundation pit 1, and the cross section of the foundation pit 1 is circular, the diaphragm wall 3 is also circular, and because the diaphragm wall 3 comprises a plurality of first groove sections 311 and second groove sections 312 which are arranged at intervals, the joint of the first groove sections 311 and the second groove sections 312 has a cracking tendency when being subjected to water accumulation pressure, and the side of the diaphragm wall 3 close to the inner retaining wall layer 21 is difficult to crack due to the fact that the diameter is smaller than the diameter close to the outer retaining wall layer 22 due to extrusion, the grouting holes 7 are only arranged on one side of the diaphragm wall 3 close to the outer retaining wall layer 22, and water sealing construction is performed on the joint of the first groove sections 311 and the second groove sections 312.

In some alternative embodiments, referring to fig. 5, the first groove section 311 and the second groove section 312 overlap each other, and an overlapping section 313 is formed at the overlapping portion, specifically, the overlapping section 313 can increase the connection strength of the first groove section 311 and the second groove section 312.

Alternatively, the length of the overlapping section 313 may be 25cm. Specifically, as shown in fig. 5, for the grouting holes 6, the grouting holes 6 need to be arranged to avoid the overlapping sections 313 so as not to weaken the connection strength of the first groove section 311 and the second groove section 312;

as for the grouting holes 7, the grouting holes 7 are provided on one side of the diaphragm wall 3 near the outer retaining wall layer 22 and have a plurality of groups, specifically, as shown in fig. 5, two grouting holes 7 are provided in one group and at both ends of the overlapping section 313 in the outer retaining wall layer 22, alternatively, the grouting holes 7 are provided at a position 40cm from the junction of the outer retaining wall layer 22 and the diaphragm wall 3.

In some alternative embodiments, see fig. 1 and 2, the retaining wall layer 2 comprises a plurality of retaining piles 8, the plurality of retaining piles 8 being arranged in engagement with each other, in particular having overlapping portions in the radial direction, as shown in fig. 2. Specifically, the pile protector 8 can adopt cement stirring piles, the diameter of each pile can be 600cm, the length of each pile can be 15m, and each pile is meshed with each other for 10cm.

In some alternative embodiments, referring to fig. 3, the water blocking curtain 4 includes a curtain body 41 and curtain guide walls 42, the curtain guide walls 42 having an inner guide wall and an outer guide wall, a space formed between the inner guide wall and the outer guide wall for limiting the setting of the curtain body 41, and a backfill portion 43 provided between the curtain guide walls 42 above the curtain body 41 for backfilling clay above the curtain body 41 to keep the curtain body 41 moist.

Optionally, the bottom of the water retaining curtain 4 penetrates into the impermeable layer by not less than 2m, so that the communication with the underground water in the sand layer can be blocked. When flood season comes, the underground water level between the underground continuous wall 3 and the water retaining curtain 4 can be rapidly reduced, the stress of the underground continuous wall 3 is reduced, and the safe construction of the foundation pit in flood season is ensured. Further, the distance between the water retaining curtain 4 and the underground continuous wall 3 is 10m, and a buffer space for the water level in the flood season is reserved.

In some alternative embodiments, referring to fig. 3, the construction passageway 5 is disposed obliquely, and in particular, the construction passageway 5 is disposed at a higher level near one end of the diaphragm wall 3 than at one end thereof near the water curtain 4.

Specifically, the elevation of the top surface of the curtain guide wall 42 is slightly higher than that of the top surface of the diaphragm wall guide wall 32, an annular construction passageway 5 is arranged between the curtain guide wall 42 and the diaphragm wall guide wall, the construction passageway 5 can meet construction requirements, and rainwater can flow to one side of the water-retaining curtain 4 along the inclined construction passageway 5 while shielding the part between the water-retaining curtain 4 and the diaphragm wall 3 and preventing water from entering the foundation pit 1.

In some alternative embodiments, referring to fig. 1 and 4, the deep foundation pit water stop system further comprises a dewatering well 9, specifically, the dewatering well 9 is arranged inside the foundation pit 1 and is used for dewatering when the foundation pit 1 is excavated, so as to ensure the implementation of dry operation. Optionally, the precipitation wells 9 are multiple, and are uniformly distributed in the foundation pit 1, so as to ensure the precipitation effect in the foundation pit 1.

Specifically, the application provides a construction method of the deep foundation pit water stop system, which provides the deep foundation pit water stop system, and the construction method comprises the following steps:

s1, locating the position of a foundation pit 1;

s2, constructing a retaining wall layer 2 and a diaphragm wall 3 along the circumferential direction of the foundation pit 1;

specifically, cleaning the construction areas of the diaphragm wall 3 and the retaining wall layer 2, and sequentially constructing the retaining wall layer 2 along the two sides of the diaphragm wall 3;

further, the retaining wall layer 2 comprises an inner retaining wall layer 21 and an outer retaining wall layer 22, wherein the inner retaining wall layer 21 is arranged close to the foundation pit 1, the outer retaining wall layer 22 is arranged far away from the foundation pit 1, the inner retaining wall layer 21 and the outer retaining wall layer 22 are coaxial, and the part between the inner retaining wall layer 21 and the outer retaining wall layer 22 is used for constructing the diaphragm wall 3; the setting position of the good continuous wall 3 is determined in advance during construction, and the protection wall layer 2 is constructed in sections:

as shown in fig. 1 and 2, the retaining wall layer 2 includes a plurality of retaining piles 8, and the retaining piles 8 are engaged with each other, so that the strength of the retaining wall layer 2 is enhanced.

The diaphragm wall 3 comprises a diaphragm wall body 31 and a diaphragm wall guide wall 32, when in construction, the diaphragm wall guide wall 32 is firstly arranged on the diaphragm wall layer 2, and the diaphragm wall body 31 is constructed between the inner diaphragm wall layer 21 and the outer diaphragm wall layer 22 by guiding the diaphragm wall guide wall 32.

S3, constructing a water retaining curtain 4 along the circumferential direction of the foundation pit 1;

the water retaining curtain 4 comprises a curtain body 41 and a curtain guide wall 42, specifically, the curtain guide wall 42 is firstly constructed during construction, and then the curtain body 41 is constructed;

further, as shown in fig. 3, a backfill portion 43 is formed between the curtain guide walls 42, the upper end of the backfill portion 43 does not exceed the height of the upper end of the curtain guide wall 42, and clay is backfilled into the backfill portion 43 to preserve moisture after the curtain body 41 is constructed.

Alternatively, the water curtain 4 may be made of cement, bentonite, retarder and water using a self-setting mortar system.

S4, a construction passageway 5 is arranged between the diaphragm wall 3 and the water retaining curtain 4.

In the above step S2, when constructing the protected diaphragm wall 3, the diaphragm wall guide wall 32 is constructed first, specifically, the diaphragm wall guide wall 32 is constructed in sections, and the diaphragm wall body 31 is constructed after the construction is completed:

the wall body 31 is connected to the ground and includes first slot section 311 and second slot section 312, and first slot section 311 and second slot section 312 are crisscross to be set up, when the construction, can unify the steel reinforcement cage of lowering first slot section 311 earlier, and the steel reinforcement cage of lowering second slot section 312 again, unifies the steel reinforcement cage pouring concrete to first slot section 311 and second slot section 312 at last. Optionally, a hydraulic grab bucket can be used for digging a groove before the reinforcement cage is lowered, so that the reinforcement cage can be lowered conveniently.

Preferably, when constructing the diaphragm wall body 31, firstly lowering the reinforcement cage of the first groove section 311, pouring concrete into the first groove section 311, and after the concrete in the first groove section 311 reaches a certain strength, lowering the reinforcement cage of the second groove section 312, and pouring concrete; preferably, when the second trough section 312 is cast with concrete, a section, such as 15-20 cm, may be cut off from two ends of the adjacent first trough section 311 to ensure the joint quality between the first trough section 311 and the second trough section 312.

Further, the diaphragm wall body 31 further includes a grouting hole 6, specifically, the grouting hole 6 is located in the first groove section 311 and the second groove section 312, and the grouting hole 6 penetrates through the first groove section 311 and the second groove section 312, and the length direction of the grouting hole is parallel to the axial direction of the foundation pit 1;

when the diaphragm wall body 31 is constructed, the hollow steel pipes are fixed on the reinforcement cages of the first groove section 311 and the second groove section 312, optionally, the hollow steel pipes are welded and fixed on the reinforcement cages, and rubber covers are wound on the bottoms of the hollow steel pipes to wrap the bottoms of the hollow steel pipes, so that mud is prevented from entering in the concrete pouring process.

Specifically, referring to fig. 5, the grouting holes 6 include an inner ring grouting hole 61 and an outer ring grouting hole 62, and the inner ring grouting hole 61 and the outer ring grouting hole 62 are provided in the diaphragm wall 3 in the circumferential direction of the diaphragm wall 3. Specifically, when pouring into the grouting holes 6, grouting construction is performed according to the sequence of the inner ring and the outer ring.

In the construction of the retaining wall layer 2, grouting holes 7 are also required to be arranged, specifically, as shown in fig. 4, the grouting holes 7 are positioned in the retaining wall layer 2, alternatively, the grouting holes 7 are arranged in the retaining wall layer 2 by embedding PVC pipes in the retaining wall layer 2; as shown in connection with fig. 4, the grouting holes 7 are located in the outer retaining wall layer 22, i.e. outside the diaphragm wall 3.

Preferably, the grouting holes 7 are arranged at the outer side of the diaphragm wall body 31 (the side of the diaphragm wall 3 far away from the foundation pit 1) and are arranged at intervals along the circumferential direction of the diaphragm wall body 31, and as shown in fig. 5, the overlapping part of the first groove section 311 and the second groove section 312 is provided with an overlapping section 313, one group of grouting holes 7 is provided with two grouting holes 7, and the two grouting holes 7 are respectively arranged at two ends of the overlapping section 313 in the outer protective wall layer 22 so as to seal water at the joint of the first groove section 311 and the second groove section 312.

In some alternative embodiments, referring to fig. 3, the water blocking curtain 4 includes a curtain body 41 and a curtain guide wall 42, and in the above step S3, the water blocking curtain 4 is constructed, including the steps of:

dividing the position of the water retaining curtain 4, and respectively arranging curtain guide walls 42 on two circumferential sides of the water retaining curtain 4, wherein the curtain guide walls 42 are constructed in sections, and the construction mode of the diaphragm guide walls 32 can be referred to for construction;

after the curtain guide walls 42 reach a certain strength, the curtain body 41 is arranged between the curtain guide walls 42, specifically, the construction mode of the curtain body 41 can be constructed according to the construction mode of the underground diaphragm body 31, namely, the construction is divided into a plurality of sections, and overlapping parts, grouting holes and the like are arranged between the sections.

Optionally, after the curtain body 41 is constructed, the following steps are further included:

the backfill 43 between the curtain guide walls 42 is filled with clay to provide a moisturizing effect to the water retaining curtain 4.

Optionally, after the wall body of the diaphragm wall 3 reaches 80% of the design strength, the construction of the water retaining curtain 4 is performed.

Optionally, the thickness of the wall body of the water retaining curtain 4 is 80cm, the bottom of the water retaining curtain penetrates into the impermeable layer to be not less than 2m, and the water retaining curtain can be isolated from communicating with the underground water in the sand layer. When flood season comes, the underground water level between the underground continuous wall 3 and the water retaining curtain 4 can be rapidly reduced, the stress of the underground continuous wall 3 is reduced, and the safe construction of the foundation pit in flood season is ensured.

In some alternative embodiments, referring to fig. 3, the elevation of the top surface of the curtain guide wall 42 is slightly higher than the elevation of the top surface of the diaphragm guide wall 32, so that in the step S4, when the construction passageway 5 is constructed, the construction passageway 5 is located at one end of the curtain guide wall 42 higher than one end of the diaphragm guide wall 32, and rainwater accumulated on the construction passageway 5 can flow to one side of the water retaining curtain 4 along the inclined construction passageway 5, thereby preventing rainwater from entering the foundation pit 1.

In some alternative embodiments, referring to fig. 1 and 4, the deep foundation pit water stop system further comprises a dewatering well 9, specifically, after the step S4, the method further comprises the steps of:

constructing a dewatering well 9;

specifically, the depth of the dewatering well 9 is 1m deeper than the bottom depth of the foundation pit 1, dewatering is performed in advance when the foundation pit 1 is excavated, the water level is ensured to be lower than the bottom 1m of the foundation pit 1, and dry operation construction is realized.

The application provides a deep foundation pit water stop system and a construction method, wherein a retaining wall layer 2 and a diaphragm wall 3 are arranged in the circumferential direction of a foundation pit 1, the diaphragm wall 3 is formed by a plurality of first groove sections 311 and second groove sections 312 alternately as a supporting structure for excavation of the foundation pit 1, and overlapping sections 313 are formed at the overlapping positions of the first groove sections 311 and the second groove sections, so that the strength of the diaphragm wall 3 is enhanced; a grouting hole 6 is reserved in the diaphragm wall 3 to perform grouting construction on the bottom of the diaphragm wall 3, a grouting hole 7 is arranged at the overlapping section 313, and water sealing construction is performed on the joint of the trough section;

the foundation pit 1 is internally provided with a plurality of dewatering wells 9, dewatering is carried out while excavation, dry operation construction in the foundation pit 1 can be realized, the outer side of the underground continuous wall 3 is provided with a water retaining curtain 4, when flood season comes, the underground water level between the underground continuous wall 3 and the water retaining curtain 4 can be rapidly reduced, the stress of the underground continuous wall 3 is reduced, and safe construction of the foundation pit 1 in flood season is ensured.

The deep foundation pit water stop system and the construction method are good in anti-seepage effect, and can reduce the safety risk of the deep foundation pit construction process in the Yangtze river basin area.

In the description of the present application, it should be noted that the azimuth or positional relationship indicated by the terms "upper", "lower", etc. are based on the azimuth or positional relationship shown in the drawings, and are merely for convenience of description of the present application and simplification of the description, and are not indicative or implying that the apparatus or element in question must have a specific azimuth, be configured and operated in a specific azimuth, and thus should not be construed as limiting the present application. Unless specifically stated or limited otherwise, the terms "mounted," "connected," and "coupled" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the terms in this application will be understood by those of ordinary skill in the art as the case may be.

It should be noted that in this application, relational terms such as "first" and "second" and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

The foregoing is merely a specific embodiment of the application to enable one skilled in the art to understand or practice the application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (10)

1. A deep foundation pit water stop system, comprising:

a foundation pit (1);

the retaining wall layer (2) is arranged along the circumferential direction of the foundation pit (1) and comprises an inner retaining wall layer (21) and an outer retaining wall layer (22) which are coaxially arranged, wherein the inner diameter of the inner retaining wall layer (21) is equal to the diameter of the foundation pit (1), and the diameter of the outer retaining wall layer (22) is larger than the diameter of the inner retaining wall layer (21);

a diaphragm wall (3) provided between the inner retaining wall layer (21) and the outer retaining wall layer (22);

the water retaining curtain (4) is arranged on one circle of the ground connecting wall (3) far away from the foundation pit (1) along the circumferential direction of the foundation pit (1);

and the construction passageway (5) is arranged at the top ends of the underground continuous wall (3) and the water retaining curtain (4).

2. The deep foundation pit water stop system of claim 1, wherein:

the underground diaphragm wall (3) comprises an underground diaphragm wall body (31) and an underground diaphragm wall guide wall (32), the upper end and the lower end of the underground diaphragm wall body (31) are flush with the upper end and the lower end of the foundation pit (1), and the bottom of the underground diaphragm wall guide wall (32) is connected with the top end of the retaining wall layer (2).

3. The deep foundation pit water stop system of claim 2, wherein:

the underground diaphragm wall body (31) comprises a first groove section (311), a second groove section (312) and a grouting hole (6), wherein the first groove section (311) and the second groove section (312) are connected in a staggered mode, the grouting hole (6) is located in the first groove section (311) and the second groove section (312), and the length direction of the grouting hole (6) is parallel to the axis direction of the foundation pit (1).

4. The deep foundation pit water stop system of claim 3, wherein:

be provided with grouting hole (7) in outer dado layer (22), grouting hole (7) are to being on a parallel with the axial extension of foundation ditch (1), grouting hole (7) are located first tank section (311) are connected department with second tank section (312), just grouting hole (7) are located outer dado layer (22) keep away from one side of interior dado layer (21).

5. The deep foundation pit water stop system of claim 3, wherein:

the first groove section (311) comprises a first reinforcement cage, the grouting holes (6) are connected with the first reinforcement cage, and the bottom ends of the grouting holes (6) are closed and exceed the length of the first reinforcement cage.

6. The deep foundation pit water stop system of claim 3, wherein:

the grouting holes (6) comprise inner ring grouting holes (61) close to the inner retaining wall layer (21) and outer ring grouting holes (62) close to the outer retaining wall layer (22), and the inner ring grouting holes (61) and the outer ring grouting holes (62) are all arranged in the circumferential direction of the diaphragm wall body (31).

7. The deep foundation pit water stop system of claim 3, wherein:

the first groove section (311) and the second groove section (312) are mutually overlapped, and an overlapped section (313) is formed at the overlapped part.

8. The deep foundation pit water stop system of claim 1, wherein:

the retaining wall layer (2) comprises a plurality of retaining piles (8), and the plurality of retaining piles (8) are provided with overlapping parts along the radial direction.

9. The deep foundation pit water stop system of claim 1, wherein:

the horizontal height of one end of the construction channel (5) close to the underground continuous wall (3) is higher than the horizontal height of one end of the construction channel close to the water retaining curtain (4).

10. The deep foundation pit water stop system of claim 1, wherein:

the water retaining curtain (4) comprises a curtain body (41) and a curtain guide wall (42), the curtain guide wall (42) comprises an inner guide wall and an outer guide wall, a backfill part (43) is arranged between the inner guide wall and the outer guide wall, and the backfill part (43) is located below the curtain body (41).

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