Back-wall soil pressure unloading type pile supporting enclosure structure

Abstract

The utility model relates to the field of foundation pit engineering, in particular to a wall back soil pressure unloading type pile supporting enclosure structure which comprises an enclosure pile, an inclined strut and a wall back pressure relief device, the wall back pressure relief device is fixedly arranged in a soil body on the back side of the enclosure pile in a cast-in-place concrete mode, and the upper end of the wall back pressure relief device is not lower than a ring beam at the top of the enclosure pile. According to the utility model, the soil body is reinforced in the active deformation area of the enclosure structure by adopting the modes of the reinforcing body, the grouting steel pipe and the like, so that the horizontal pressure of the soil body on the enclosure structure is reduced, the pressure unloading of the soil behind the wall is realized, and the purposes of controlling deformation and ensuring the safety of the foundation pit are achieved.

Description

Technical Field

[0001] The utility model relates to the field of foundation pit engineering, in particular to a pile-supported enclosure structure of soil pressure unloading type behind a wall. Background Art

[0002] The combination of piles and supporting retaining structures is a common form of foundation pit retaining and is widely used in foundation pit engineering. For example, the Chinese patent document with publication number CN103410156A and publication date 2013.11.27 discloses "a recyclable vertical steel pipe front support retaining structure and its application method"; and the Chinese patent document with publication number CN216713049U and publication date 2022.06.10 discloses "a foundation pit retaining structure with steel sheet piles combined with advanced diagonal braces", which is composed of retaining piles and diagonal braces.

[0003] However, for soft soil layers, the retaining piles and front support piles are subjected to greater forces, resulting in the need to strengthen both the retaining piles and the diagonal support. In this case, two methods are usually used for strengthening:

[0004] 1. The diagonal braces are lengthened and encrypted. This method not only increases the cost and construction period, but also increases the difficulty and risk of diagonal bracing construction, and will also cause certain difficulties in excavation in the later stage;

[0005] 2. Strengthen the retaining piles, such as increasing the pile diameter or adding double rows of piles. This will increase the cost and may also encroach on the space outside the red line, so the plan may not be implemented;

[0006] Both of the above methods solve the problem by increasing the "resistance" of the retaining structure. Currently, there is still a lack of an active "load" reduction method to reduce the soil pressure behind the retaining structure. Summary of the invention

[0007] The utility model aims to provide a pile-supported retaining structure of the soil pressure unloading type behind a wall, which adopts the methods of reinforcement bodies, grouting steel pipes, etc. to reinforce the soil in the active deformation zone of the retaining structure, reduce the horizontal pressure of the soil on the retaining structure, realize the unloading of the soil pressure behind the wall, and achieve the purpose of controlling deformation and ensuring the safety of the foundation pit.

[0008] The utility model adopts the following technical solutions:

[0009] A pile-supported retaining structure with soil pressure unloading behind a wall comprises retaining piles, diagonal braces and a pressure relief device behind the wall. The pressure relief device behind the wall is fixed in the soil behind the retaining piles 3 by cast-in-place concrete, and the upper end is not lower than the ring beam 2 at the top of the retaining piles 3.

[0010] Preferably, the rear wall pressure relief device surrounds the grouting reinforcement body 1.

[0011] Furthermore, the grouting reinforcement body 1 is a highly uniform whole block structure.

[0012] Furthermore, the grouting reinforcement body 1 includes a plurality of blocks with different depths, and the depth of each block decreases from the direction adjacent to the retaining pile 3 to the direction away from the retaining pile 3.

[0013] Preferably, the post-wall pressure relief device comprises grouting steel pipes 5 which are inserted into the soil in an array and distributed manner.

[0014] Furthermore, the grouting steel pipes 5 have equal heights and equal spacings.

[0015] Furthermore, a grouting steel pipe 5 is inserted into each of the blocks, and the bottom of the grouting steel pipe 5 does not extend out of the block.

[0016] Preferably, the diagonal brace 4 is one of a steel pipe, a steel lattice column, a prefabricated pile or a screw pile.

[0017] Furthermore, a bag 9 is tied to the lower end of the diagonal brace 4 , and grouting is injected into the bag 9 to form a grouting body 10 .

[0018] Furthermore, a force adding device 8 is provided between the upper end of the diagonal brace 4 and the ring beam 2 .

[0019] The beneficial effect of the utility model is that the soil is reinforced in the active deformation area of ​​the retaining structure by adopting the pressure relief device behind the wall (reinforcement body, grouting steel pipe, etc.), reducing the horizontal pressure of the soil on the retaining structure, realizing the unloading of the soil pressure behind the wall, and achieving the purpose of controlling deformation and ensuring the safety of the foundation pit. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of Example 1 of a pile-supported enclosure structure of the utility model with soil pressure unloading behind a wall.

[0021] Figure 2 It is a structural schematic diagram of Example 2 of a pile-supported enclosure structure of the utility model with soil pressure unloading behind a wall.

[0022] Figure 3 It is a structural schematic diagram of Example 3 of the pile-supported enclosure structure of the utility model with soil pressure unloading behind the wall.

[0023] Figure 4 It is a structural schematic diagram of Example 4 of the pile-supported enclosure structure of the utility model with soil pressure unloading behind the wall.

[0024] In the figure, 1. grouting reinforcement body, 2. ring beam, 3. retaining piles, 4. diagonal bracing, 5. grouting steel pipe, 6. tree root piles, 7. lattice column, 8. force-adding device, 9. bladder bag, 10. grouting body. DETAILED DESCRIPTION

[0025] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0026] Embodiment 1:

[0027] See also Figure 1 A pile-supported retaining structure with soil pressure unloading behind a wall includes retaining piles, diagonal braces, and a pressure relief device behind the wall. The pressure relief device behind the wall is fixed in the soil behind the retaining pile 3 by cast-in-place concrete, and the upper end is not lower than the ring beam 2 at the top of the retaining pile 3.

[0028] In this embodiment, the wall back pressure relief device surrounds the grouting reinforcement body 1. The grouting reinforcement body 1 is a highly uniform whole block structure.

[0029] Specifically, the diagonal brace 4 is one of a steel pipe, a steel lattice column, a prefabricated pile or a screw pile.

[0030] Continue to attend Figure 1 , Regarding the structural details: the excavation depth of the foundation pit is about 6m;

[0031] The upper part of the retaining pile 3 is connected to the ring beam 2; the retaining pile 3 can be a steel pipe, a steel section, a precast pile, a cast-in-place pile, a precast sheet pile, etc. The ring beam 2 is generally a concrete ring beam, or a steel material. The specific dimensions are: the retaining pile 3 is a precast pile, with a diameter of 600mm and a depth of 12m, and the top beam 2 is 0.8m high;

[0032] The ring beam 2 is connected to the diagonal brace 4; the diagonal brace 4 can be a steel pipe, a steel lattice column, a prefabricated pile, a screw pile, etc.; the specific size: the diagonal brace 4 is a 273*10 steel pipe, the length is 18m, the angle with the horizontal direction is 45 degrees, and the spacing is 6m;

[0033] The lower part of the diagonal brace 4 enters the soil, and the soil provides the diagonal bearing capacity; specific dimensions: the length of the diagonal brace 4 entering the soil is 11m;

[0034] After the retaining piles 3 (away from the foundation pit side), the reinforcement body 1 is constructed; the reinforcement body can be a mixing pile, a rotary jet pile, a grouting steel pipe, or a combination of the above; specific dimensions: the reinforcement body is 6m long and 3m wide.

[0035] Embodiment 2:

[0036] See attached Figure 2 A pile-supported retaining structure with soil pressure unloading behind a wall includes retaining piles, diagonal braces, and a pressure relief device behind the wall. The pressure relief device behind the wall is fixed in the soil behind the retaining pile 3 by cast-in-place concrete, and the upper end is not lower than the ring beam 2 at the top of the retaining pile 3.

[0037] In this embodiment, the post-wall pressure relief device is surrounded by a grouting reinforcement body 1, and the grouting reinforcement body 1 includes a plurality of blocks with different depths. The depth of each block decreases from the direction adjacent to the retaining pile 3 to the direction away from the retaining pile 3.

[0038] Specifically, the diagonal brace 4 is one of a steel pipe, a steel lattice column, a prefabricated pile or a screw pile.

[0039] See the attached Figure 2 , the excavation depth of the foundation pit is about 5m;

[0040] The upper part of the retaining pile 3 is connected to the ring beam 2; the retaining pile 3 can be a steel pipe, a steel section, a precast pile, a cast-in-place pile, a precast sheet pile, etc. The ring beam 2 is generally a concrete ring beam, or a steel material. The specific dimensions are: the retaining pile 3 is a precast pile, with a diameter of 600mm and a depth of 12m, and the top beam 2 is 0.8m high;

[0041] The ring beam 2 is connected to the lattice column 7, and the lattice column 7 is connected to the diagonal brace 4; the diagonal brace 4 can be a steel pipe, a steel lattice, a precast pile, a screw pile, etc.; the specific dimensions are: the lattice column 7 is 8m long, the diagonal brace 4 is a PC400 precast pile, the length is 9m, the angle with the horizontal direction is 50 degrees, and the horizontal spacing is 6m;

[0042] The lower part of the diagonal brace 4 enters the soil, and the soil provides the diagonal bearing capacity; specific dimensions: the length of the diagonal brace 4 entering the soil is 9m;

[0043] After the retaining piles 3 (away from the foundation pit side), the reinforcement body 1 is constructed; (the reinforcement body can be a mixing pile, a rotary jet pile, a grouting steel pipe, or a combination of the above); specific dimensions: the reinforcement body 1 is three sections of unequal length rectangles, each section is 1.2m wide, and the lengths are 2m, 4m and 6m respectively.

[0044] Embodiment 3:

[0045] See attached Figure 3 A pile-supported retaining structure with soil pressure unloading behind a wall includes retaining piles, diagonal braces, and a pressure relief device behind the wall. The pressure relief device behind the wall is fixed in the soil behind the retaining pile 3 by cast-in-place concrete, and the upper end is not lower than the ring beam 2 at the top of the retaining pile 3.

[0046] In this embodiment, the post-wall pressure relief device includes an array of distributed grouting steel pipes 5 inserted into the soil.

[0047] In this embodiment, the grouting steel pipes 5 have the same height and the same spacing.

[0048] Specifically, the diagonal brace 4 is one of a steel pipe, a steel lattice column, a prefabricated pile or a screw pile.

[0049] In another embodiment, a force adding device 8 is provided between the upper end of the diagonal brace 4 and the ring beam 2 .

[0050] Continue to see Figure 3 The excavation depth of the foundation pit is about 6m.

[0051] The upper part of the root pile 6 is connected to the ring beam 2; the root pile 6 can be a steel pipe, a steel section, a prefabricated pile, a cast-in-place pile, a prefabricated sheet pile, etc. The ring beam 2 is generally a concrete ring beam, or a steel material. The specific dimensions are: the root pile 6 has a diameter of 350mm, a depth of 12m, and a top beam 2 height of 0.7m;

[0052] The ring beam 2 is connected to the force adding device 8, and the force adding device 8 is connected to the diagonal brace 4; the diagonal brace 4 can be a steel pipe, a steel lattice, a prefabricated pile, a screw pile, etc.; the specific size: the diagonal brace 4 is a 273*10 steel pipe, the length is 18m, the angle with the horizontal direction is 45 degrees, and the spacing is 6m; the force adding device can be a jack;

[0053] The lower part of the diagonal brace 4 enters the soil, and the soil provides the diagonal bearing capacity; specific dimensions: the length of the diagonal brace 4 entering the soil is 11m;

[0054] After the root pile 6 (away from the foundation pit side), the grouting steel pipe 5 is constructed; specific size: the grouting steel pipe 5 can be single row or multiple rows, the diameter of the grouting steel pipe is 48-60mm, and the length is 6m.

[0055] Embodiment 4:

[0056] This embodiment is the most preferred embodiment.

[0057] See attached Figure 4 A pile-supported retaining structure with soil pressure unloading behind a wall includes retaining piles, diagonal braces, and a pressure relief device behind the wall. The pressure relief device behind the wall is fixed in the soil behind the retaining pile 3 by cast-in-place concrete, and the upper end is not lower than the ring beam 2 at the top of the retaining pile 3.

[0058] In this embodiment, the wall back pressure relief device is surrounded by a grouting reinforcement body 1. The grouting reinforcement body 1 includes a plurality of blocks of different depths, and the depth of each block decreases from the direction close to the retaining pile 3 to the direction away from the retaining pile 3. A grouting steel pipe 5 is inserted into each of the blocks, and the bottom of the grouting steel pipe 5 does not extend out of the block.

[0059] In this embodiment, the grouting steel pipes 5 have the same height and the same spacing.

[0060] Specifically, the diagonal brace 4 is one of a steel pipe, a steel lattice column, a prefabricated pile or a screw pile.

[0061] In this embodiment, a bag 9 is tied to the lower end of the diagonal brace 4, and grouting is injected into the bag 9 to form a grouting body 10.

[0062] Continue to see Figure 4 The excavation depth of the foundation pit is about 5m.

[0063] The upper part of the retaining pile 3 is connected to the ring beam 2; the retaining pile 3 can be a steel pipe, a steel section, a precast pile, a cast-in-place pile, a precast sheet pile, etc. The ring beam 2 is generally a concrete ring beam, or a steel material. Specific dimensions: the retaining pile 3 is a precast pile with a diameter of 600mm and a depth of 12m. The top beam 2 is 0.8m high.

[0064] The ring beam 2 is connected to the diagonal brace 4; the diagonal brace 4 can be a steel pipe, a steel lattice, a precast pile, a screw pile, etc.; the specific size: the diagonal brace 4 is a 273*10 steel pipe, the length is 18m, the angle with the horizontal direction is 45 degrees, and the spacing is 6m.

[0065] A bag 9 is tied under the diagonal support 4, and grouting is injected into the bag 9 to form a grouting body; specific dimensions: the bag length is 3-6m.

[0066] The lower part of the diagonal brace 4 enters into the soil, and the soil provides the diagonal bearing capacity; specific dimensions: the length of the diagonal brace 4 entering into the soil is 11m.

[0067] Behind the retaining piles 3 (away from the foundation pit side), a reinforcement body 1 is constructed, into which a grouting steel pipe 5 is inserted; specific dimensions: the reinforcement body 1 is three sections of unequal length rectangles, each section is 1.2m wide, and the lengths are 2m, 4m and 6m respectively; a grouting steel pipe 5 is inserted into the reinforcement body 1, and the length of the grouting steel pipe 5 is the same as that of the reinforcement body 1.

[0068] In summary, multiple embodiments of the utility model all adopt a pressure relief device behind the wall (reinforcement body, grouting steel pipe, etc.) to reinforce the soil in the active deformation zone of the retaining structure, reduce the horizontal pressure of the soil on the retaining structure, realize the unloading of the soil pressure behind the wall, and achieve the purpose of controlling deformation and ensuring the safety of the foundation pit.

[0069] The above are optional embodiments of the present invention. Ordinary technicians in this field can also make various changes or improvements on this basis. Without departing from the overall concept of the present invention, these changes or improvements should fall within the scope of protection required by the present invention.

Claims

1. A pile-supported enclosure structure of earth pressure unloading type behind a wall, comprising enclosure piles and diagonal braces, characterized in that: It also comprises a pressure relief device behind the wall, which is fixedly arranged in the soil behind the retaining pile (3) by means of cast-in-place concrete, and the upper end of which is not lower than the ring beam (2) at the top of the retaining pile (3).

2. The pile-supported enclosure structure of the earth pressure unloading type behind the wall as claimed in claim 1, characterized in that: The wall rear pressure relief device surrounds the grouting reinforcement body (1).

3. The pile-supported enclosure structure of the earth pressure unloading type behind the wall as claimed in claim 2, characterized in that: The grouting reinforcement body (1) is in the form of a highly uniform whole block structure.

4. The pile-supported enclosure structure of the earth pressure unloading type behind the wall as claimed in claim 2, characterized in that: The grouting reinforcement body (1) comprises a plurality of blocks of different depths, and the depth of each block decreases from the direction close to the retaining pile (3) to the direction away from the retaining pile (3).

5. The pile-supported enclosure structure of the earth pressure unloading type behind the wall as claimed in claim 1, characterized in that: The behind-the-wall pressure relief device comprises grouting steel pipes (5) which are distributed in an array and inserted into the soil.

6. The pile-supported enclosure structure of the earth pressure unloading type behind the wall as claimed in claim 5, characterized in that: The grouting steel pipes (5) have the same height and the same spacing.

7. The pile-supported enclosure structure of the earth pressure unloading type behind the wall as claimed in claim 4, characterized in that: A grouting steel pipe (5) is inserted into each of the blocks, and the bottom of the grouting steel pipe (5) does not extend out of the block.

8. The pile-supported enclosure structure of the type of unloading earth pressure behind the wall according to any one of claims 1 to 7, characterized in that: The diagonal brace (4) is one of a steel pipe, a steel lattice column, a prefabricated pile or a screw pile.

9. The pile-supported enclosure structure of the earth pressure unloading type behind the wall as claimed in claim 8, characterized in that: The lower end of the diagonal brace (4) is tied to a bag (9), and grouting is injected into the bag (9) to form a grouting body (10).

10. The pile-supported enclosure structure of the earth pressure unloading type behind the wall as claimed in claim 8, characterized in that: A force adding device (8) is provided between the upper end of the diagonal brace (4) and the ring beam (2).

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