CN111622233A - Foundation pit support device - Google Patents

Abstract

The application relates to a foundation pit support device which comprises a plugging unit and a plurality of second support piles, wherein the plugging unit comprises two first support piles and a plugging mechanism, the two first support piles are arranged at intervals, and a junction is formed between the two first support piles; two sides of the plugging mechanism are respectively connected with the two first fender piles and used for plugging the que opening; one first fender pile of the self-plugging mechanism of the second fender piles is distributed towards the other first fender pile according to a preset track, and forms a closed building envelope together with the plugging unit. This application foundation ditch enclosure can play the effect to the good enclosure of foundation ditch and to que mouthful shutoff leak protection water.

Description

Foundation pit support device

Technical Field

The application relates to the field of construction of deep foundation pits of construction engineering, in particular to a foundation pit support device.

Background

At present, in the construction process of a construction engineering deep foundation pit, a foundation pit to be excavated is surrounded by a mode of inserting and beating fender posts, but in the construction of the deep foundation pit of subway station engineering, municipal pipelines are complex, and partial pipelines can not be changed frequently, so that the fender posts can not be inserted into the pipeline, the fender posts can not be completely sealed, and a limit opening exists between the fender posts. In the excavation process of the foundation pit, in order to ensure the safety of the foundation pit, a reverse construction method is required to be adopted for construction, and a supporting structure is adopted to block the opening of the back-ward side while excavation is carried out.

In the related technology, a general reverse construction method supporting structure adopts a reinforced concrete structure, reinforcing steel bars are installed after a section of depth is excavated, then concrete is poured in a vertical mold, and the next section of excavation is carried out after the strength is equal, but the single cycle construction period is long, and the requirement of fast sealing of foundation pit excavation is not met. The reinforced hanging net sprayed concrete is adopted as a local supporting structure, although a closed structure can be formed quickly after excavation, the stability of the sprayed concrete is poor, certain water seepage is caused at a position of a que opening, the enclosing effect is greatly reduced, the risk of water and soil loss at the position of the que opening is large, and a large safety risk is generated.

Disclosure of Invention

The embodiment of the application provides a foundation pit support device to solve among the correlation technique support device sealed effect poor, take place the infiltration at the position of the que crossing, cause the support effect poor, produce the problem of great safety risk.

In a first aspect, a foundation pit support device is provided, which includes:

a plugging unit, said plugging unit comprising:

two first fender posts, which are spaced apart from each other and form a threshold between them;

the two sides of the plugging mechanism are respectively connected with the two first guard piles and used for plugging the threshold;

and the second fender piles are distributed from one first fender pile of the plugging mechanism to the other first fender pile according to a preset track, and form a closed fender structure together with the plugging unit.

In some embodiments, the occlusion mechanism comprises:

two sides of the retaining plate are connected with the two first fender posts through anchoring mechanisms;

and one end of the grouting mechanism is fixed on the soil retaining plate, and the other end of the grouting mechanism is obliquely and downwards inserted into the threshold and is used for grouting the threshold.

In some embodiments, the retaining plate is provided with a grouting hole penetrating through the retaining plate, and the grouting mechanism includes:

the anchoring support is arranged on the soil blocking plate;

the grouting rod penetrates through the anchoring support and the grouting hole and extends into the threshold; and the grouting rod is fixed on the soil retaining plate through an anchoring support.

In some embodiments, the grout rod comprises:

one end of the grouting section is provided with a grouting opening, a plurality of grouting holes are formed in the grouting section, the grouting holes are communicated with the grouting opening, one end of the grouting section is fixed on the anchoring support, and the other end of the grouting section penetrates through the grouting holes and extends into the threshold;

and the grout stopping section is covered on the grouting opening and used for plugging the grouting opening.

In some embodiments, the angle between the upper surface of the anchoring support and the retaining plate is equal to the angle between the grouting rod and the horizontal plane.

In some embodiments, the retaining plate is provided with a first threaded hole penetrating through the retaining plate, and the first fender post is provided with a second threaded hole penetrating through the first fender post; the anchoring mechanism comprises an anchor rod, one end of the anchor rod sequentially penetrates through the first threaded hole and the second threaded hole, and the other end of the anchor rod is in threaded connection with the soil retaining plate.

In some embodiments, the anchoring mechanism further comprises a bolt and an anchor pad, the diameter of the anchor pad is larger than that of the first threaded hole, and the bolt is screwed on the anchor rod through the anchor pad and is pressed on the retaining plate.

In some embodiments, the retaining plate comprises a plurality of retaining plate units, the plurality of retaining plate units being connected end to form the retaining plate.

In a second aspect, a foundation pit support device is provided, which includes:

at least two plugging units, the plugging unit includes:

two first fender posts, which are spaced apart from each other and form a threshold between them;

the two sides of the plugging mechanism are respectively connected with the two first guard piles and used for plugging the threshold;

the system comprises at least two groups of fender post groups, wherein each fender post group comprises a plurality of second fender posts, the second fender posts of each fender post group are distributed from the first fender post of one of the two adjacent plugging units to the first fender post of the other plugging unit according to a preset track, and the second fender posts and all the plugging units form a closed fender structure together.

In some embodiments, the occlusion mechanism comprises:

two sides of the retaining plate are connected with the two first fender posts through anchoring mechanisms;

and one end of the grouting mechanism is fixed on the soil retaining plate, and the other end of the grouting mechanism is obliquely and downwards inserted into the threshold and is used for grouting the threshold.

The beneficial effect that technical scheme that this application provided brought includes: can will be because the palace mouth that the pipeline formed carries out the shutoff to form confined envelope, the enclosure effect is good, can not be at palace mouth department infiltration, foundation ditch construction is safer.

The embodiment of the application provides a foundation pit enclosure device, because there is some pipelines can't change and move, consequently can form que kou in the place of pipeline, and can't insert the fender post, can't enclose and establish and form confined envelope, consequently this application adopts the shutoff unit to seal que kou, the both sides of shutoff mechanism link to each other with the inboard of two first fender posts respectively, and form confined envelope with all second fender posts jointly, consequently, this application foundation pit enclosure device can play the good enclosure of foundation pit and the effect to que kou shutoff leak protection water.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is an elevation view of a foundation pit support device provided in embodiment 1 of the present application;

fig. 2 is a schematic plan view of a foundation pit support device provided in embodiment 1 of the present application;

fig. 3 is a schematic plan view of a foundation pit support device provided in embodiment 2 of the present application;

FIG. 4 is a sectional view taken along line A-A of FIG. 2;

FIG. 5 is a schematic view of the construction of a retaining plate;

FIG. 6 is a schematic structural view of a grouting rod;

FIG. 7 is a sectional view taken along line B-B of FIG. 2;

FIG. 8 is a schematic structural view of the anchoring mechanism;

fig. 9 is a schematic structural view of a retaining plate unit.

In the figure: 1. a plugging unit; 10. a first fender post; 11. a threshold; 12. a plugging mechanism; 120. a soil guard plate; 1200. a first threaded hole; 1201. grouting holes; 1203. a soil guard plate unit; 121. an anchoring mechanism; 1210. an anchor rod; 1211. a bolt; 1212. an anchor pad; 122. A grouting mechanism; 1220. a grouting rod; 12200. a grouting section; 12201. a grouting port; 12202, slurry outlet; 12203. a pulp stopping section; 1221. anchoring the support; 2. a fender pile group; 20. And a second fender post.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in 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 obvious that the described embodiments are some embodiments of the present application, but not all embodiments. 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 application.

The embodiment of the application provides a foundation pit support device, which can solve the problems that in the related art, the sealing effect of the support device is poor, water seepage occurs at a threshold, the support effect is poor, and a large safety risk is generated.

Example 1:

referring to fig. 1 and 2, embodiment 1 provided by the present application provides a foundation pit support device, which includes a plugging unit 1 and a plurality of second fender posts 20, wherein the plugging unit 1 includes two first fender posts 10 and a plugging mechanism 12, the two first fender posts 10 are arranged at intervals, and a junction 11 is formed between the two first fender posts 10; two sides of the plugging mechanism 12 are respectively connected with the two first fender piles 10 and used for plugging the threshold 11; the second plurality of fender posts 20 are distributed from one of the first fender posts 10 of the blocking mechanism 12 to the other first fender post 10 according to a preset track, and form a closed building envelope together with the blocking unit 1.

Specifically, the method comprises the following steps: the pipeline in the foundation pit of embodiment 1 of this application only has one department, only need with this department the pipeline carry out the shutoff can. Firstly, a plurality of second fender piles 20 are inserted and driven into a foundation pit according to a preset track (namely, along the periphery of the foundation pit to be excavated), but because a part of pipelines cannot be changed, the second fender piles 20 cannot be inserted into the pipeline, and a closed enclosure structure cannot be formed by enclosing a plurality of second fender piles 20, therefore, in the embodiment 1 of the present application, a position with the pipelines is closed by using an encapsulation unit 1, two first fender piles 10 are arranged at intervals, and positions with the pipelines are reserved without inserting and driving the fender piles, so that a junction 11 is formed between the two first fender piles 10, the junction 11 cannot be inserted and driven to be closed through a steel sheet pile, then the junction 11 is encapsulated by using an encapsulation mechanism 12, two sides of the encapsulation mechanism 12 are respectively connected with the inner sides of the two first fender piles 10, the pipelines are encapsulated outside the foundation pit, and the encapsulation mechanism 12 does not need to be inserted and driven into the foundation pit from top to bottom, the second fender pile 20 and the pipeline can not interfere with each other, and a closed fender structure is formed together with all the second fender piles 20, so that the effects of well fencing the foundation pit and preventing water leakage by plugging the junction are achieved.

Example 2:

the pipeline of the embodiment 2 of the application has at least two positions, and pipelines at all positions need to be plugged. Referring to fig. 3, the application provides a foundation pit support device, which includes at least two plugging units 1 and at least two support pile groups 2, each plugging unit 1 is used for plugging a pipeline, each plugging unit 1 includes two first support piles 10, the two first support piles 10 are arranged at intervals, and a junction 11 is formed between the two first support piles 10; two sides of the plugging mechanism 12 are respectively connected with the two first fender piles 10 and used for plugging the threshold 11; the fender pile group 2 comprises a plurality of second fender piles 20, each fender pile group 2 is distributed between two adjacent plugging units 1, and the number of the second fender piles 20 of each fender pile group 2 can be the same or different. The plurality of second fender piles 20 of the fender post group 2 are distributed from the first fender post 10 of one plugging unit 1 of the two adjacent plugging units 1 to the first fender post 10 of the other plugging unit 1 according to a preset track, and form a closed fender structure together with all the plugging units 1.

Specifically, the method comprises the following steps: since the pipeline of example 2 of the present application has at least two locations, it is necessary to plug the pipeline at all locations. Firstly, inserting a plurality of second fender posts 20 of each group into a foundation pit according to a preset track (namely, along the periphery of the foundation pit to be excavated), but because a plurality of pipelines cannot be relocated, the second fender posts 20 cannot be inserted into all places with pipelines, and all fender post groups 2 cannot be encircled to form a closed fender structure, so that in the embodiment 2 of the present application, at least two plugging units 1 are adopted to close all positions with pipelines, the plugging units 1 are arranged between two adjacent fender post groups 2, two first fender posts 10 are arranged at intervals, positions with pipelines are reserved without inserting fender posts, so that a threshold 11 is formed between the two first fender posts 10, the threshold 11 cannot be inserted into the closed position through steel sheet piles, then, a plugging mechanism 12 is used to plug the threshold 11, two sides of the plugging mechanism 12 are respectively connected with the inner sides of the two first fender posts 10, the pipeline is plugged outside the foundation pit, and the plugging mechanism 12 does not need to be inserted into the foundation pit from top to bottom and does not interfere with the pipeline, so that after all the junction ports 11 are plugged by the plugging units 1, all the plugging units 1 and all the enclosure pile groups 2 form a closed enclosure structure together, and good enclosure and junction plugging effects on the foundation pit are achieved.

Optionally, referring to fig. 1 and fig. 2, the blocking mechanism 12 includes a soil blocking plate 120, an anchoring mechanism 121 and a grouting mechanism 122, both sides of the soil blocking plate 120 are connected to two first fender piles 10 through the anchoring mechanism 121, so as to fix the soil blocking plate 120 and the first fender piles 10; one end of the grouting mechanism 122 is fixed on the retaining plate 120, the other end of the grouting mechanism is obliquely downwards inserted into the back of the opening 11 and is used for grouting the soil body behind the opening 11 and the next excavation section, the soil body behind the opening 11 and the next excavation section are effectively reinforced after grouting, the stability of the soil body and the safety of excavation of the next section are guaranteed, the plugging effect on water seepage in the soil body is also achieved, and the problem of water seepage at the opening 11 in the foundation pit excavation process is effectively solved.

Referring to fig. 4 and 5, the retaining plate 120 is provided with a grouting hole 1201 penetrating through the retaining plate 120, the grouting mechanism 122 includes an anchoring seat 1221 and a grouting rod 1220, and the anchoring seat 1221 is provided on the retaining plate 120; the grouting rod 1220 obliquely penetrates through the anchoring support 1221 and the grouting hole 1201 and extends into the threshold 11; and grouting rod 1220 is fixed on retaining plate 120 through anchor support 1221, and grouting is carried out to the back of que kou 11 and the next excavation section soil body through grouting rod 1220, consolidates the soil body. Along with the increase of foundation ditch excavation depth, the soil body lateral pressure increases, and the soil stability is especially important to foundation ditch safety, has effectively consolidated behind the back of the district mouth 11 and the next excavation section soil body after the slip casting, has guaranteed the stability of the soil body, carries out the shutoff to infiltration in the soil body simultaneously, has reduced the soil body lateral pressure, and the advantage is obvious when the foundation ditch excavation depth is darker. When the excavation depth of foundation ditch is less, soil body lateral pressure is less, and this moment at que kou 11 department installation keep off the native board 120 and carry out the fender can to the soil body.

Referring to fig. 6, the grouting rod 1220 includes a grouting section 12200 and a grout stopping section 12203, one end of the grouting section 12200 is a grouting opening 12201, the grouting section 12200 is provided with a plurality of grout outlet holes 12202, the grout outlet holes 12202 are communicated with the grouting opening 12201, one end of the grouting section 12200 is fixed on the anchoring support 1221, and the other end of the grouting section 12200 penetrates through the grouting hole 1201 and extends into the threshold 11; the grout stopping section 12203 covers the grouting opening 12201 and is used for plugging the grouting opening 12201. Concrete slurry is injected into the grouting section 12200 through the grouting opening 12201 and flows out of the plurality of slurry outlet holes 12202 into the threshold 11, so that the threshold 11 is reinforced and is waterproof. After grouting, the grout stopping section 12203 is covered on the grouting opening 12201 for plugging the grout.

Preferably, the angle between the upper surface of the anchoring seat 1221 and the soil guard 120 is equal to the angle between the grouting rod 1220 and the horizontal plane. Thus, the oblique insertion of the grouting rod 1220 into the orifice 11 can be realized by only opening the upper surface of the anchoring seat 1221 and directly inserting the grouting rod 1220.

Further, as shown in fig. 5 and 7, the retaining plate 120 is provided with a first threaded hole 1200 penetrating through the retaining plate 120, and the first fender post 10 is provided with a second threaded hole penetrating through the first fender post 10; the anchoring mechanism 121 includes an anchor rod 1210, one end of the anchor rod 1210 sequentially penetrates through the first threaded hole 1200 and the second threaded hole, and the other end is screwed to the soil blocking plate 120. The anchor rods 1210 extend into the first fender pile 10 and are connected with concrete in the first fender pile 10 in a chemical bonding mode, so that stable connection between the retaining plate 120 and the first fender pile 10 is realized.

Further, referring to fig. 8, the anchoring mechanism 121 further includes a bolt 1211 and an anchor pad 1212, the anchor pad 1212 has a diameter larger than that of the first threaded hole 1200, and the bolt 1211 is screwed to the anchor rod 1210 through the anchor pad 1212 and is pressed against the retaining plate 120. Concrete is prevented from leaking from the first threaded hole 1200, and the foundation pit is protected more closely. The anchoring mechanism 121 has quick strength rise, and can realize quick excavation, quick sealing and supporting at the position of the threshold 11 of the foundation pit enclosure structure. And the chemical anchoring mode of the anchoring mechanism 121 is adopted to anchor the retaining plate 120 on site, so that the construction efficiency is greatly improved, and the construction cost is saved.

Preferably, as shown in fig. 9, the retaining plate 120 includes a plurality of retaining plate units 1203, and the plurality of retaining plate units 1203 are connected end to form the retaining plate 120. Soil guard plate 120 sets up according to the width of que kou 11, and vertical processing becomes 1-2m according to construction convenience and soil property condition and keeps off soil plate unit 1203, can both be suitable for to the que kou 11 of different construction conditions and geological conditions, through processing into and keep off soil plate unit 1203, it is also comparatively convenient that the field segmentation is assembled. The retaining plate units 1203 are connected by groove welding and reinforced by connecting steel plates. The four sides of the retaining plate units 1203 are processed into grooves in advance, the grooves are directly welded on site, the connection quality between the retaining plate units 1203 is effectively guaranteed, the connecting steel plates are equidistantly welded in a reinforcing mode, and the rigidity of a retaining structure formed by the retaining plates 120 is effectively guaranteed.

In addition, both the embodiment 1 and the embodiment 2 of the present application adopt a local reverse method to construct the foundation pit, and the specific construction steps in the embodiment 1 of the present application are as follows:

s1: inserting and driving a plurality of second fender piles 20 along the periphery of a foundation pit to be constructed, inserting and driving first fender piles 10 at two ends of a position with a pipeline, wherein the pipeline is arranged between the two first fender piles 10, and inserting and driving the fender piles at the part with the pipeline;

s2: digging a first layer of earthwork, wherein two first fender posts 10 form a threshold 11 of the first layer, and a pipeline is arranged in the threshold 11;

s3: installing a soil retaining plate unit 1203 at the first layer of the opening 11, anchoring two ends of the soil retaining plate unit 1203 with two first fender posts 10 through anchoring mechanisms 121 to form a closed enclosure structure with all second fender posts 20, obliquely inserting a grouting mechanism 122 into the opening 11, and grouting the back of the opening 11 and the soil body of the second layer of the excavated section;

s4: a second layer of soil body is dug downwards, and the two first fender posts 10 form a threshold 11 of the second layer;

s5: installing a soil retaining plate unit 1203 at the position of the threshold 11 of the second layer, anchoring two ends of the soil retaining plate unit 1203 with the two first fender posts 10 through anchoring mechanisms 121, obliquely inserting grouting mechanisms 122 into the threshold 11, and grouting soil behind the threshold 11 of the second layer and at the excavation section of the third layer;

s6: and analogizing in turn, adopting a mode of installing the plugging mechanism 12 while digging till the foundation pit construction is finished.

In the description of the present application, it should be noted that the terms "upper", "lower", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, which are only for convenience in describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and operate, and thus, should not be construed as limiting the present application. Unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are intended to be inclusive and mean, for example, that they may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

It is noted that, in the present 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. Also, 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 an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The above description is merely exemplary of the present application and is presented to enable those skilled in the art to understand and practice the present 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 foundation pit support device is characterized by comprising:

a plugging unit (1), said plugging unit (1) comprising:

-two first fender posts (10), the two first fender posts (10) being spaced apart and a threshold (11) being formed between the two first fender posts (10);

-an occlusion means (12) connected on both sides to the two first bollards (10) and adapted to occlude the orifice (11);

a plurality of second fender posts (20), wherein the plurality of second fender posts (20) are distributed from one first fender post (10) of the plugging mechanism (12) to the other first fender post (10) according to a preset track, and form a closed enclosure together with the plugging unit (1).

2. A foundation pit support apparatus as claimed in claim 1, wherein the plugging mechanism (12) comprises:

two sides of the retaining plate (120) are connected with the two first fender piles (10) through anchoring mechanisms (121);

and one end of the grouting mechanism (122) is fixed on the retaining plate (120), and the other end of the grouting mechanism is obliquely inserted downwards into the threshold (11) and is used for grouting the threshold (11).

3. A foundation pit support apparatus as claimed in claim 2, wherein the retaining plate (120) is provided with a grouting hole (1201) penetrating the retaining plate (120), and the grouting mechanism (122) comprises:

an anchoring seat (1221) provided on the soil guard plate (120);

a grouting rod (1220) which penetrates through the anchoring support (1221) and the grouting hole (1201) and extends into the orifice (11); and the grouting rod (1220) is fixed on the soil blocking plate (120) through an anchoring support (1221).

4. A foundation pit support apparatus as claimed in claim 3, wherein the grouting rod (1220) comprises:

the grouting section (12200) is provided with a grouting opening (12201) at one end, a plurality of grout outlet holes (12202) are formed in the grouting section (12200), the grout outlet holes (12202) are communicated with the grouting opening (12201), one end of the grouting section (12200) is fixed on the anchoring support (1221), and the other end of the grouting section penetrates through the grouting hole (1201) and extends into the threshold (11);

and the grout stopping section (12203) is covered on the grouting opening (12201) and is used for plugging the grouting opening (12201).

5. A foundation pit support apparatus as claimed in claim 3, wherein the angle between the upper surface of the anchoring support (1221) and the retaining plate (120) is equal to the angle between the grouting rod (1220) and the horizontal plane.

6. A foundation pit support apparatus as claimed in claim 2, wherein the retaining plate (120) is provided with a first threaded hole (1200) penetrating through the retaining plate (120), and the first fender post (10) is provided with a second threaded hole penetrating through the first fender post (10); the anchoring mechanism (121) comprises an anchor rod (1210), one end of the anchor rod (1210) penetrates through the first threaded hole (1200) and the second threaded hole in sequence, and the other end of the anchor rod is in threaded connection with the soil retaining plate (120).

7. A foundation pit support device according to claim 6, characterized in that the anchoring mechanism (121) further comprises a bolt (1211) and an anchor pad (1212), the diameter of the anchor pad (1212) is larger than that of the first threaded hole (1200), and the bolt (1211) is screwed on the anchor rod (1210) through the anchor pad (1212) and is pressed on the soil guard plate (120).

8. A foundation pit support apparatus as claimed in claim 2, wherein said retaining plate (120) comprises a plurality of retaining plate units (1203), said plurality of retaining plate units (1203) being connected end to form said retaining plate (120).

9. A foundation pit support device is characterized by comprising:

at least two plugging units (1), the plugging units (1) comprising:

-two first fender posts (10), the two first fender posts (10) being spaced apart and a threshold (11) being formed between the two first fender posts (10);

-an occlusion means (12) connected on both sides to the two first bollards (10) and adapted to occlude the orifice (11);

the construction method comprises the following steps that at least two groups of fender post groups (2) are arranged, each fender post group (2) comprises a plurality of second fender posts (20), each group of fender post groups (2) is formed by distributing a plurality of second fender posts (20) from two adjacent first fender posts (10) of one plugging unit (1) in the plugging units (1) towards the first fender posts (10) of the other plugging unit (1) according to a preset track, and forming a closed fender structure together with all the plugging units (1).

10. A foundation pit support apparatus as claimed in claim 9, wherein the plugging mechanism (12) comprises:

two sides of the retaining plate (120) are connected with the two first fender piles (10) through anchoring mechanisms (121);

and one end of the grouting mechanism (122) is fixed on the retaining plate (120), and the other end of the grouting mechanism is obliquely inserted downwards into the threshold (11) and is used for grouting the threshold (11).

Images