A prestressed I-shaped retaining pile and a foundation pit retaining method

Abstract

The present invention discloses a prestressed I-shaped retaining pile and a foundation pit retaining method. The prestressed I-shaped retaining pile includes a precast I-shaped pile body, a lower connecting plate, a plurality of tensioning members, and a plurality of prestressed steel members. The prestressed steel members are selected from one or two of steel bars and steel strands. When the plurality of prestressed steel members include steel bars, the steel bars are inserted into the reserved installation holes of the precast I-shaped pile body, the lower ends of the steel bars are threadedly connected to the lower through holes on the lower connecting plate, and the upper ends of the steel bars are adjustably connected to the tensioning members. When the plurality of prestressed steel members include steel strands, the steel strands are bent into a U shape, and both ends of each steel strand respectively pass through the two lower through holes of the lower connecting plate and the two reserved installation holes of the precast I-shaped pile body, extend to the upper end of the precast I-shaped pile body, and both ends of the steel strands are adjustably connected to the tensioning members respectively. After the retaining is completed, the tensioning members can be removed, the steel bars can be rotated to realize the recovery of the steel bars, and the steel strands can be pulled to realize the recovery of the steel strands.

Description

Technical Field

[0001] The present invention relates to the technical field of foundation pit support, and particularly to a prestressed support pile and a foundation pit support method. Background Art

[0002] Foundation pit engineering is widely used in fields such as urban construction projects, subway projects, and underground integrated pipe gallery projects. At present, domestic foundation pit support structures include forms such as steel sheet pile construction methods, bored cast-in-place pile structures, and SMW construction method piles.

[0003] In the Chinese patent with the application number 201310030438.X, a post-tensioned I-shaped support pile based on in-situ casting is disclosed. This support pile has high stiffness, good durability, and high flexural and shear resistance, and can greatly reduce the deformation of the foundation pit. However, the support pile provided by this patent has the following disadvantages: the support pile needs to be cast in-situ, resulting in an extended construction period; after the support pile is installed, the recovery of steel cannot be achieved, resulting in a large amount of steel being wasted. Summary of the Invention

[0004] In order to overcome the deficiencies of the prior art, an object of the present invention is to provide a prestressed I-shaped support pile and a foundation pit support method, where the support pile does not need to be cast in-situ, and the steel in the support pile can be recycled.

[0005] According to one aspect of the present invention, a prestressed I-shaped support pile is provided, including:

[0006] A precast I-shaped pile body having a plurality of reserved installation holes that communicate the upper and lower ends of the precast I-shaped pile body;

[0007] A lower connecting plate having a plurality of lower through holes corresponding to each of the reserved installation holes;

[0008] A plurality of tensioning members; and

[0009] A plurality of prestressed steel members, where the plurality of prestressed steel members are selected from one or two of reinforcing bars and steel strands,

[0010] When the plurality of prestressed steel members include reinforcing bars, the reinforcing bars are inserted into a reserved installation hole of the precast I-shaped pile body, the lower end of the reinforcing bar is threadedly connected to a lower through hole of the lower connecting plate, and the upper end of the reinforcing bar is adjustably connected to one of the tensioning members,

[0011] When the plurality of prestressed steel members include steel strands, the steel strands are bent into a U shape, and both ends of the steel strands respectively pass through two lower through holes of the lower connecting plate and two reserved installation holes of the precast I-shaped pile body and extend above the precast I-shaped pile body, and both ends of the steel strands are respectively adjustably connected to one of the tensioning members.

[0012] Further, the plurality of tensioning members are selected from one or two of nuts and anchors. When the prestressed steel member is a steel bar, the corresponding tensioning member is a nut, and the tensioning member is threadedly connected to the upper end of the steel bar. When the prestressed steel member is a steel strand, the corresponding tensioning member is an anchor.

[0013] Further, the plurality of prestressed steel members include steel strands, and both ends of each steel strand respectively pass through two non-adjacent reserved installation holes.

[0014] Further, the plurality of prestressed steel members include steel strands, and the pairs of reserved installation holes for installing the steel strands and the lower through holes are arranged staggeredly to avoid interference of the bending portions of the steel strands.

[0015] Further, the prestressed I-shaped retaining pile further includes an upper fixing plate, which is arranged at the upper end of the precast I-shaped pile body. The upper fixing plate has a plurality of upper through holes corresponding to the reserved installation holes, and the upper ends of the prestressed steel members pass through the upper through holes.

[0016] Further, the precast I-shaped pile body is made of concrete, and the lower connecting plate and the upper fixing plate are made of steel.

[0017] Further, the reserved installation holes are distributed on both sides of the precast I-shaped pile body. The prestressed steel members in the reserved installation holes on one side are steel strands, and the prestressed steel members in the reserved installation holes on the other side are steel bars.

[0018] Further, the plurality of prestressed steel members include steel strands. The lower connecting plate has a plurality of guiding channels corresponding to the steel strands. The guiding channels are arc-shaped, and both ends of each guiding channel communicate with the two lower through holes. The bending portions of the steel strands are located in the guiding channels.

[0019] According to another aspect of the present invention, a foundation pit retaining method is provided, including

[0020] Providing the above-mentioned prestressed I-shaped retaining pile of the present invention, and adjusting the tensioning member to make the prestressed steel member in a tensioned state;

[0021] Installing the prestressed retaining pile on one side of the retaining soil body;

[0022] After the retaining is completed, removing the tensioning member and recycling the prestressed steel member. When the prestressed steel member is a steel bar, rotating the steel bar to achieve recycling. When the prestressed steel member is a steel strand, pulling out one end of the steel strand outward to achieve recycling.

[0023] Furthermore, the reserved installation holes of the prestressed I-shaped retaining piles are distributed on both sides of the precast I-shaped pile body. The prestressed steel members in the reserved installation holes on one side are steel strands, and the prestressed steel members in the reserved installation holes on the other side are steel bars. When installing the prestressed retaining pile in the foundation pit, the side with the steel strands is placed close to the retaining soil body.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] (1) In the foundation pit support, the I-shaped retaining pile can exert higher flexural performance with a small concrete cross-section, which can greatly save the amount of concrete used;

[0026] (2) By adopting the form of prestress tensioning, the flexural performance of the pile body can be further enhanced by relying on the pre-tensioned steel bars or steel strands, achieving the purpose of saving materials;

[0027] (3) The retaining pile provided by the present invention does not need to be cast on-site. After being precast in the factory, it can be directly installed on-site, which can greatly reduce the construction period;

[0028] (4) After the retaining pile completes its support function, the prestressed steel members in the retaining pile can be recycled, thus greatly reducing the support cost;

[0029] (5) Since the recycling operation of the prestressed steel members is simple and does not require the use of large machines, the recycling cost is low, and the recycling work can be quickly completed without affecting the surrounding environment or buildings. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a three-dimensional schematic diagram of the first preferred embodiment of the prestressed I-shaped retaining pile of the present invention;

[0031] Figure 2 is an exploded view of the first preferred embodiment of the prestressed I-shaped retaining pile of the present invention, in which the prestressed steel members are not shown;

[0032] Figure 3 is a three-dimensional schematic diagram of the second preferred embodiment of the prestressed I-shaped retaining pile of the present invention;

[0033] Figure 4 is a side perspective view of the second preferred embodiment of the prestressed I-shaped retaining pile of the present invention;

[0034] Figure 5A shows a preferred arrangement of the reserved installation holes on the precast I-shaped pile body;

[0035] Figure 5B shows another preferred arrangement of the reserved installation holes on the precast I-shaped pile body;

[0036] Figure 5C Shows another preferred arrangement of the reserved installation holes on the precast I-shaped pile body;

[0037] Figure 5D Shows another preferred arrangement of the reserved installation holes on the precast I-shaped pile body;

[0038] Figure 6 Schematic diagram of the lower connecting plate of the fourth preferred embodiment of the prestressed I-shaped retaining pile of the present invention;

[0039] Figure 7 Partial schematic diagram of the fourth preferred embodiment of the prestressed I-shaped retaining pile of the present invention;

[0040] In the figure: 1, precast I-shaped pile body; 10, reserved installation holes; 2, lower connecting plate; 20, lower through holes; 21, guiding channels; 3, prestressed steel members; 31, steel bars; 32, steel strands; 4, tensioning members; 5, upper fixing plate; 50, upper through holes. Specific embodiments

[0041] Next, in combination with the drawings and specific embodiments, the present invention will be further described. It should be noted that, on the premise of no conflict, the following-described embodiments or technical features can be arbitrarily combined with each other to form new embodiments.

[0042] In the description of the present invention, it should be noted that for orientation terms, such as the terms "center", "lateral", "longitudinal", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., the indicated orientation and position relationships are based on the orientation or position relationships shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and should not be construed as limiting the specific protection scope of the present invention.

[0043] As Figures 1-4 shown, the prestressed I-shaped retaining pile provided by the present invention includes a precast I-shaped pile body 1, a lower connecting plate 2, a plurality of prestressed steel members 3 and a plurality of tensioning members 4.

[0044] The precast I-shaped pile body 1 is adapted to be inserted into the soil body and retain the soil body on one side thereof. The precast I-shaped pile body 1 has a plurality of reserved installation holes 10, and the reserved installation holes 10 communicate with the upper and lower ends of the precast I-shaped pile body 1.

[0045] The lower connecting plate 2 is arranged at the lower end of the precast I-shaped pile body 1, and the lower connecting plate 2 has a plurality of lower through holes 20 corresponding to the reserved installation holes 10 one by one.

[0046] The prestressed steel members 3 are selected from one or two of the reinforcing bars 31 and the steel strands 32. That is, multiple prestressed steel members 3 can all be reinforcing bars 31, or all be steel strands 32, or a part be reinforcing bars 31 and a part be steel strands 32.

[0047] When the prestressed steel member 3 is a reinforcing bar 31, each reinforcing bar 31 is inserted through a reserved installation hole 10, the lower end of the reinforcing bar 31 is threadedly connected to the corresponding lower through hole 20, and the upper end of the reinforcing bar 31 is adjustably connected to the tensioning member 4. By adjusting the tensioning member 4, the reinforcing bar 31 is tensioned. Since the lower end of the reinforcing bar 31 is threadedly connected to the lower connecting plate 2, when the I-shaped retaining pile completes the retaining task, the reinforcing bar 31 can be separated from the lower connecting plate 2 by rotating the reinforcing bar 31, and then the reinforcing bar 31 can be withdrawn from the reserved installation hole 10 to realize the recovery of the reinforcing bar 31.

[0048] When the prestressed steel member 3 is a steel strand 32, the steel strand 32 is bent into a U shape. Both ends of each steel strand 32 respectively pass through two lower through holes 20 and two reserved installation holes 10 and extend to the upper end of the precast I-shaped pile body 1. Both ends of the steel strand 32 are respectively adjustably connected to a tensioning member 4. By adjusting the tensioning member 4, both ends of the steel strand 32 are tensioned. In addition, when the I-shaped retaining pile completes the retaining task, the tensioning member 4 at one end of the steel strand 32 is removed, and the other end of the steel strand 32 is pulled outwards, and the steel strand 32 can be withdrawn from the two reserved installation holes 10 to realize the recovery of the steel strand 32.

[0049] Considering that the steel strand 32 needs to be bent within the range of elastic deformation, the radian of the bent part of the steel strand 32 should be increased as much as possible. Preferably, both ends of the steel strand 32 respectively pass through two non-adjacent reserved installation holes 10, as Figure 4 shown, by increasing the distance between both ends of the steel strand 32, the radian of the bent part of the steel strand 32 is enlarged.

[0050] Considering that interference may occur in the bent parts when multiple steel strands 32 are installed, preferably, a pair of reserved installation holes 10 and a pair of lower through holes 20 corresponding to each steel strand 32 are arranged staggeredly with a pair of reserved installation holes 10 and a pair of lower through holes 20 corresponding to another steel strand 32. Figures 5A-5D Shows several arrangement ways of the staggered reserved installation holes 10. The arrangement way of the corresponding lower through holes 20 is the same as that of the reserved installation holes 10. Of course, the arrangement way of the reserved installation holes 10 is not limited to the way shown in the figure. Forming multiple pairs of staggered reserved installation holes 10 can avoid the interference of the bent parts of two adjacent steel strands 32.

[0051] In some embodiments, in order to avoid the interference of the bent parts of the steel strands 32 with each other, preferably, the lower connecting plate 2 is provided with a plurality of guiding channels 21, asFigure 6 , 7 As shown in 7 , the guiding channels are arc-shaped. Both ends of each guiding channel 21 communicate with two lower through holes 20, and the bent portions of the steel strands 32 are located in the respective guiding channels 21. The guiding channels 21 can be completely enclosed or semi-enclosed. On the one hand, the guiding channels 21 make the installation of the steel strands 32 more convenient. On the other hand, when the steel strands 32 are recovered, it can avoid the difficulty of pulling out the steel strands 32 due to excessive local bending.

[0052] When the prestressed steel member 3 is a steel bar 31, in some embodiments, the tensioning member 4 is a nut with internal threads. The upper end of the steel bar 31 has external threads, and the tensioning member 4 is threadedly connected to the upper end of the steel bar 31. When the tensioning member 4 is connected to the steel bar 31, its lower end abuts against the upper end of the precast I-shaped pile body 1, and the tension of the steel bar 31 is adjusted by rotating the tensioning member 4.

[0053] When the prestressed steel member 3 is a steel strand 32, in some embodiments, the tensioning member 4 is an anchor. The anchor includes an anchor plate and locking pieces (not shown in the figure). The anchor plate has a plurality of anchor holes. Each steel wire of the steel strand 32 is adapted to pass through the respective anchor holes on the anchor plate, and the locking pieces are adapted to be inserted into the gaps between the steel wires and the anchor holes to lock the steel wires in the anchor holes. When the tensioning member 4 is connected to the steel strand 32, the lower end of the anchor plate abuts against the upper end of the precast I-shaped pile body 1.

[0054] In some embodiments, the prestressed I-shaped retaining pile further includes an upper fixing plate 5. The upper fixing plate 5 is arranged at the upper end of the precast I-shaped pile body 1. The upper fixing plate 5 has a plurality of upper through holes 50 corresponding one by one to the respective reserved installation holes 10. The upper ends of the respective prestressed steel members 3 extend upward through the corresponding upper through holes 50. When each tensioning member 4 is connected to the prestressed steel member 3, the tensioning member 4 abuts against the upper fixing plate 5, and the upper fixing plate 5 makes the acting forces of the respective tensioning members 4 evenly distributed on the top surface of the precast I-shaped pile body 1.

[0055] In some embodiments, the respective reserved installation holes 10 are distributed on one side of the precast I-shaped pile body 1 close to the retaining soil mass, and this side serves as the stress-bearing surface. By arranging the prestressed steel members 3, the bending and shear resistance capabilities can be significantly improved. The prestressed steel members 3 can be steel bars 31 and / or steel strands 32.

[0056] In some other embodiments, each reserved installation hole 10 is distributed on one side of the precast I-shaped pile body 1 close to the retaining soil body and on the other side away from the retaining soil body. By arranging prestressed steel members 3 on both sides of the precast I-shaped pile body 1, the bending and shear resistance of the I-shaped retaining pile can be further improved. When prestressed steel members 3 are arranged on both sides of the precast I-shaped pile body 1, preferably, the prestressed steel member 3 in the reserved installation hole 10 on the side close to the retaining soil body is a steel strand 32, and the prestressed steel member 3 in the reserved installation hole 10 on the side away from the retaining soil body is a steel bar 31. The steel strand 32 mainly bears the tensile force, and the steel bar 31 mainly bears the extrusion force, thereby greatly improving the bending and shear resistance of the retaining pile.

[0057] In some other embodiments, each reserved installation hole 10 is distributed not only on one side of the precast I-shaped pile body 1 close to the retaining soil body and on the other side away from the retaining soil body, but also in the middle of the precast I-shaped pile body 1. The prestressed steel member 3 also strengthens the middle part of the I-shaped retaining pile to further improve the bending and shear resistance performance of the retaining pile.

[0058] The prestressed I-shaped retaining pile of the present invention can be precast in a factory and directly installed on site after being transported to the site, which can greatly shorten the construction time. In addition, after the retaining task is completed, the tensioning member 4, the prestressed steel member 3, and the upper fixing plate 5 can be recycled, that is, most of the steel materials can be recycled and reused, greatly reducing the cost of the retaining pile; in addition, the recycling step of the prestressed steel member 3 is simple, does not require large machinery assistance, and has a low recycling cost, and the recycling work can be quickly completed without affecting the surrounding environment or buildings.

[0059] The present invention also provides a foundation pit retaining method, including the following steps:

[0060] Provide the above-mentioned prestressed I-shaped retaining pile of the present invention, and adjust the tensioning member 4 to make the prestressed steel member 3 in a tensioned state;

[0061] Install the above-mentioned prestressed retaining pile on one side of the retaining soil body;

[0062] After the retaining is completed, remove the tensioning member 4 and recycle the prestressed steel member 3. When the prestressed steel member 3 is a steel bar 31, rotate the steel bar 31 to achieve recycling. When the prestressed steel member 3 is a steel strand 32, pull out one end of the steel strand 32 outward to achieve recycling.

[0063] Each reserved installation hole 10 of the prestressed I-shaped retaining pile is distributed on both sides of the precast I-shaped pile body 1. The prestressed steel member 3 in the reserved installation hole 10 on one side is a steel strand 32, and the prestressed steel member 3 in the reserved installation hole 10 on the other side is a steel bar 31. When the prestressed retaining pile is installed in the foundation pit, the side provided with the steel strand 32 is close to the retaining soil body.

[0064]

Embodiment 1

[0065] As Figure 1 , 2 shown, the prestressed I-shaped retaining pile includes a precast I-shaped pile body 1, a lower connecting plate 2, a plurality of steel bars 31, a plurality of tensioning members 4, and an upper fixing plate 5.

[0066] A plurality of reserved installation holes 10 are respectively provided on both sides of the precast I-shaped pile body 1. The upper fixing plate 5 and the lower connecting plate 2 are respectively arranged on the upper and lower end faces of the precast I-shaped pile body 1. The lower connecting plate 2 has lower through holes 20 corresponding to the reserved installation holes 10 one by one, and the lower through holes 20 have internal threads. The upper fixing plate 5 has upper through holes 50 corresponding to the reserved installation holes 10 one by one. The upper and lower ends of the steel bar 31 have external threads. The tensioning member 4 has an internal thread.

[0067] The precast I-shaped pile body 1 is first cast with plain concrete and cured by steam, and reserved holes are provided. When it reaches a certain strength, the installation of the steel bars 31 can be carried out; when installing the steel bars 31, first set the upper fixing plate 5 and the lower connecting plate 2 on the upper and lower ends of the precast I-shaped pile body 1, then insert the steel bars 31 into the reserved installation holes 10 through the upper through holes 50 of the upper fixing plate 5, and then rotate the steel bars 31 so that their lower ends are threadedly connected to the lower through holes 20 of the lower connecting plate 2; then screw the tensioning members 4 tightly on the upper ends of the steel bars 31 and make the tensioning members 4 abut against the upper fixing plate 5, so that the steel bars 31 are in a prestressed state.

[0068] Both the lower connecting plate 2 and the upper fixing plate 5 are made of steel to ensure sufficient strength.

[0069] After the retaining is completed, the steel bars 31 can be recycled. First, unscrew the tensioning members 4 from the upper ends of the steel bars 31, then rotate the steel bars 31 to separate the steel bars 31 from the lower connecting plate 2, and then draw out the steel bars 31 to realize the recycling of the steel bars 31.

[0070]

Embodiment 2

[0071] As Figure 3 , 4 shown, the prestressed I-shaped retaining pile includes a precast I-shaped pile body 1, a lower connecting plate 2, a plurality of steel bars 31, a plurality of steel strands 32, a plurality of tensioning members 4, and an upper fixing plate 5.

[0072] A plurality of reserved installation holes 10 are respectively provided on both sides of the precast I-shaped pile body 1. The upper fixing plate 5 and the lower connecting plate 2 are respectively arranged on the upper and lower end faces of the precast I-shaped pile body 1. The lower connecting plate 2 has lower through holes 20 corresponding to the reserved installation holes 10 one by one, and the upper fixing plate 5 has upper through holes 50 corresponding to the reserved installation holes 10 one by one.

[0073] Each steel bar 31 is arranged in the reserved installation hole 10 on one side of the precast I-shaped pile body 1. The upper and lower ends of the steel bar 31 have external threads, and each lower through hole 20 opposite to the steel bar 31 has internal threads. The lower end of the steel bar 31 is arranged in the corresponding lower through hole 20. The tensioning member 4 corresponding to each steel bar 31 has internal threads, and the upper end of the steel bar 31 is threadedly connected to the tensioning member 4. The tensioning member 4 abuts against the upper fixing plate 5.

[0074] Each steel strand 32 is arranged in the reserved installation hole 10 on the other side of the precast I-shaped pile body 1. Each steel strand 32 is bent into a U shape. The two ends of the steel strand 32 respectively pass through the two lower through holes 20, the two reserved installation holes 10 and the two upper through holes 50 from below the lower connecting plate 2 and extend above the upper fixing plate 5. The two upper ends of the steel strand 32 are respectively adjustably connected to a tensioning member 4. The tensioning member 4 abuts against the upper end of the upper fixing plate 5. The tensioning member 4 corresponding to the steel strand 32 is an anchor. The anchor includes an anchor plate and locking pieces (not shown in the figure). The anchor plate has a plurality of anchor holes. Each steel wire of the steel strand 32 is adapted to pass through each anchor hole on the anchor plate, and the locking pieces are adapted to be inserted into the gaps between the steel wires and the anchor holes to lock the steel wires in the anchor holes.

[0075] The precast I-shaped pile body 1 is first poured with plain concrete and cured by steam, leaving reserved holes. When it reaches a certain strength, the installation of the steel bars 31 and the steel strands 32 can be carried out. When installing the steel bars 31, first set the upper fixing plate 5 and the lower connecting plate 2 at the upper and lower ends of the precast I-shaped pile body 1, then insert the steel bars 31 into the reserved installation holes 10 from the upper through holes 50 of the upper fixing plate 5, then rotate the steel bars 31 so that their lower ends are threadedly connected to the lower through holes 20 of the lower connecting plate 2, and then screw the tensioning members 4 tightly onto the upper ends of the steel bars 31 and make the tensioning members 4 abut against the upper fixing plate 5, so that the steel bars 31 are in a prestressed state. When installing the steel strands 32, first set the upper fixing plate 5 and the lower connecting plate 2 at the upper and lower ends of the precast I-shaped pile body 1, bend the steel strands 32 into a U shape, and make the two ends of the steel strands 32 respectively pass through the two lower through holes 20, the two reserved installation holes 10 and the two upper through holes 50 from below the lower connecting plate 2 and extend above the upper fixing plate 5, and then install the tensioning members 4 at the two ends of the steel strands 32 and make the tensioning members 4 abut against the upper fixing plate 5, so that the steel strands 32 are in a prestressed state.

[0076] After the support is completed, the steel bars 31 and the steel strands 32 can be recycled. Remove the tensioning members 4 from the steel bars 31 and the steel strands 32; by rotating the steel bars 31, separate the steel bars 31 from the lower connecting plate 2 to achieve recycling; by pulling out one end of the steel strand 32 outward, make the other end of the steel strand 32 sequentially pass through the two reserved installation holes 10, and finally the entire steel strand 32 is pulled out to achieve recycling.

[0077]

Example 3

[0078] The prestressed I-shaped retaining pile comprises a precast I-shaped pile body 1, a lower connecting plate 2, a plurality of steel strands 32, a plurality of tensioning members 4, and an upper fixing plate 5.

[0079] A plurality of reserved installation holes 10 are respectively arranged on both sides of the precast I-shaped pile body 1. The upper fixing plate 5 and the lower connecting plate 2 are respectively arranged on the upper and lower end faces of the precast I-shaped pile body 1. As Figure 6 shown, the lower connecting plate 2 has lower through holes 20 corresponding to each of the reserved installation holes 10 one by one, and the upper fixing plate 5 has upper through holes 50 corresponding to each of the reserved installation holes 10 one by one. The lower connecting plate 2 also has a plurality of guiding channels 21 corresponding to each of the steel strands 32. The guiding channels 21 are arc-shaped, and both ends of each guiding channel 21 communicate with the two lower through holes 20. The guiding channels 21 are semi-open groove-shaped.

[0080] Each steel strand 32 is bent into a U shape. Both ends of the steel strand 32 respectively pass through the two lower through holes 20, the two reserved installation holes 10, and the two upper through holes 50 from below the lower connecting plate 2 and extend above the upper fixing plate 5. The bent portions of the steel strands 32 are kept in the respective guiding channels 21. As Figure 7 shown, the two upper ends of the steel strand 32 are respectively adjustably connected to a tensioning member 4, and the tensioning member 4 abuts against the upper end of the upper fixing plate 5. The tensioning member 4 corresponding to the steel strand 32 is an anchor. The anchor includes an anchor plate and locking pieces (not shown in the figure). The anchor plate has a plurality of anchor holes. Each steel wire of the steel strand 32 is adapted to pass through each anchor hole on the anchor plate, and the locking pieces are adapted to be inserted into the gaps between the steel wires and the anchor holes to lock the steel wires in the anchor holes.

[0081] The precast I-shaped pile body 1 is first cast with plain concrete and cured by steam, and reserved holes are provided. When it reaches a certain strength, the installation of the steel strands 32 can be carried out. When installing the steel strands 32, first set the upper fixing plate 5 and the lower connecting plate 2 at the upper and lower ends of the precast I-shaped pile body 1, bend the steel strands 32 into a U shape, and make both ends of the steel strands 32 respectively pass through the two lower through holes 20, the two reserved installation holes 10, and the two upper through holes 50 from below the lower connecting plate 2 and extend above the upper fixing plate 5, so that the bent portions of the steel strands 32 are kept in the corresponding guiding channels 21. Then install the tensioning members 4 at both ends of the steel strands 32 and make the tensioning members 4 abut against the upper fixing plate 5, so that the steel strands 32 are in a prestressed state.

[0082] After the retaining is completed, the steel strands 32 can be recycled. Remove the tensioning members 4 from the steel strands 32; by pulling out one end of the steel strand 32 outward, make the other end of the steel strand 32 pass through the two reserved installation holes 10 in turn, and finally the whole steel strand 32 is pulled out to achieve recycling.

[0083] The above embodiments are only preferred embodiments of the present invention, and the scope of protection of the present invention cannot be limited thereby. Any non-substantive changes and substitutions made by those skilled in the art based on the present invention fall within the scope of protection required by the present invention.

Claims

1. A prestressed I-shaped retaining pile, characterized in that, Comprising: A precast I-shaped pile body, which has a plurality of reserved installation holes that communicate with the upper and lower ends of the precast I-shaped pile body; A lower connecting plate, which has a plurality of lower through holes corresponding to each of the reserved installation holes; A plurality of tensioning members; and A plurality of prestressed steel members, and the plurality of prestressed steel members are selected from one or two of steel bars and steel strands. When the plurality of prestressed steel members include steel bars, the steel bars are inserted into a reserved installation hole of the precast I-shaped pile body, the lower end of the steel bar is threadedly connected to a lower through hole of the lower connecting plate, and the upper end of the steel bar is adjustably connected to one of the tensioning members, and the steel bar can be recycled; When the plurality of prestressed steel members include steel strands, the steel strands are bent into a U shape, and both ends of the steel strands respectively pass through two lower through holes of the lower connecting plate and two reserved installation holes of the precast I-shaped pile body and extend above the precast I-shaped pile body. Both ends of the steel strands are respectively adjustably connected to one of the tensioning members, and the steel strands can be recycled; the lower connecting plate is provided with a plurality of guiding channels corresponding to each of the steel strands, the guiding channels are arc-shaped, and both ends of each guiding channel communicate with the two lower through holes, and the bent portion of the steel strand is located in the guiding channel; Each of the reserved installation holes is distributed on both sides of the precast I-shaped pile body, and the prestressed steel members in the reserved installation holes on one side are steel strands, and the prestressed steel members in the reserved installation holes on the other side are steel bars.

2. The prestressed I-shaped retaining pile according to claim 1, wherein, The plurality of tensioning members are selected from one or two of nuts and anchors. When the prestressed steel member is a steel bar, the corresponding tensioning member is a nut, and the tensioning member is threadedly connected to the upper end of the steel bar. When the prestressed steel member is a steel strand, the corresponding tensioning member is an anchor.

3. The prestressed I-shaped retaining pile according to claim 1, wherein The plurality of prestressed steel members include steel strands, and both ends of the steel strands respectively pass through two non-adjacent reserved installation holes.

4. The prestressed I-shaped retaining pile according to claim 1, characterized in that The plurality of prestressed steel members include steel strands, and the pairs of reserved installation holes and the lower through holes for installing each of the steel strands are arranged staggeredly to avoid interference of the bent portions of each of the steel strands.

5. The prestressed I-shaped retaining pile according to any one of claims 1-4, characterized in that, It further includes an upper fixing plate, the upper fixing plate is arranged on the upper end surface of the precast I-shaped pile body, the upper fixing plate has a plurality of upper through holes corresponding to each of the reserved installation holes, and the upper ends of the prestressed steel members pass through each of the upper through holes.

6. The prestressed I-shaped retaining pile according to claim 5, wherein, The precast I-shaped pile body is made of concrete, and the lower connecting plate and the upper fixing plate are made of steel.

7. A foundation pit support method, characterized in that, Including the following steps: Providing the prestressed I-shaped retaining pile according to any one of claims 1-6, and adjusting the tensioning member to make the prestressed steel member in a tensioned state; Installing the prestressed retaining pile on one side of the retaining soil body; After the retaining is completed, removing the tensioning member and recycling the prestressed steel member. When the prestressed steel member is a steel bar, rotating the steel bar to achieve recycling. When the prestressed steel member is a steel strand, pulling out one end of the steel strand outward to achieve recycling. The reserved installation holes of the prestressed I-shaped retaining piles are distributed on both sides of the precast I-shaped pile body. The prestressed steel members in the reserved installation holes on one side are steel strands, and the prestressed steel members in the reserved installation holes on the other side are steel bars. When installing the prestressed retaining pile in the foundation pit, the side with the steel strands is placed close to the retaining soil body.

Images