CN116927211A - Soft foundation ultra-deep pit supporting structure and construction method - Google Patents

Abstract

The invention discloses a soft foundation ultra-deep pit supporting structure, which comprises precast piles and precast supporting templates; the bottom of the precast pile is fixedly provided with precast tips which are pressed in the stabilizing layer, and the precast piles are provided with a plurality of groups and are connected in sequence; the prefabricated support templates are vertically and transversely provided with a plurality of groups and are connected in sequence; a waterproof structure is arranged between two adjacent prefabricated support templates; a first connecting rod group is arranged between two adjacent groups of precast piles, a second connecting rod group is arranged on one side of each precast pile, which is opposite to the precast supporting template, and one end of the second connecting rod group is suitable for installing the precast supporting template; a support is arranged on one side of the prefabricated support template, which is opposite to the prefabricated pile, a plurality of groups of support seats are vertically distributed, and the same group of connecting rod groups III and one end part of the connecting rod groups are vertically and slidably distributed on the upper and lower groups of support seats. The problem that the conventional deep foundation pit support structure cannot be vertically pressed and assembled, so that the stability and the reliability of the soft foundation pit support structure are poor, the turnover performance is poor and the cyclic utilization is difficult is easily caused.

Description

Soft foundation ultra-deep pit supporting structure and construction method

Technical Field

The invention relates to a soft foundation ultra-deep pit supporting technology, in particular to a soft foundation ultra-deep pit supporting structure and a construction method.

Background

The foundation pit support is used for ensuring the safety of underground structure construction and the surrounding environment of the foundation pit, and is used for supporting, reinforcing and protecting the side wall of the foundation pit and the surrounding environment. The common foundation pit supporting modes comprise various forms such as row pile supporting, underground continuous wall supporting, piles or wall adding supporting systems, reinforced concrete row piles and the like, and can be selected after comprehensive evaluation of working conditions such as depth, soil property and the like of the foundation pit, or various supporting modes are reasonably combined.

The deep foundation pit support is a measure for supporting, reinforcing and protecting the side wall of the deep foundation pit and the surrounding environment of the foundation pit in order to ensure the safety of the underground structure construction and the surrounding environment of the foundation pit. Deep foundation pit support is an important structure for ensuring the operation safety of the deep foundation pit, and is directly related to engineering safety and personal safety of related operators. The deep foundation pit support in the prior art can be divided into cast-in-place support requiring a cast-in-place pile machine, a retaining wall and the like, or an enclosure structure combined by piles, plates and the like. For soft soil geology, because the cast-in-situ piling and wall forming process has large difficulty, high cost and long construction period, a mode of directly erecting an enclosure structure is generally adopted. However, it is relatively difficult to erect the enclosure structure, and the enclosure structure cannot be ensured to be pressed and assembled vertically, so that stability and reliability of the enclosure structure cannot be ensured, and the problem that the existing enclosure structure is poor in turnover or difficult to recycle is also solved.

Disclosure of Invention

The invention solves the problems that the conventional deep foundation pit support structure cannot be vertically pressed and assembled, and the stability and reliability of the soft foundation pit support structure are poor, the turnover performance is poor and the cyclic utilization is difficult, so that the soft foundation ultra-deep pit support structure and the construction method are provided.

In order to achieve the above purpose, the present invention adopts the following technical scheme:

a soft foundation ultra-deep pit supporting structure comprises precast piles and precast supporting templates;

the bottom of the precast pile is fixedly provided with precast tips which are pressed in the stabilizing layer, and the precast pile is provided with a plurality of groups along the supporting direction and is connected in sequence;

the prefabricated support templates are vertically and transversely provided with a plurality of groups along the support direction and are sequentially connected;

a waterproof structure is arranged between two adjacent prefabricated support templates;

a first connecting rod group is arranged between two adjacent groups of precast piles, a second connecting rod group is arranged on one side of each precast pile, which is opposite to the precast supporting template, and one end of the second connecting rod group is suitable for installing the precast supporting template;

the support is installed to one side of prefabricated support template relative precast pile, and the support has vertically been laid the multiunit, and every group support has laid two at least along the transverse direction of prefabricated support template, installs same group connecting rod group III on two upper and lower groups supports, and connecting rod group III and connecting rod group one end vertical slip are laid.

Preferably, the mounting holes are arranged on the support, the support is installed on the prefabricated support template through the bolt penetrating through the mounting holes, the connecting rod group III comprises a connecting pipe sleeve, the connecting pipe sleeve is installed on one side of the support, opposite to the prefabricated pile, and the vertical position retaining rod is installed inside the connecting pipeline.

Preferably, the first connecting rod group and the second connecting rod group are telescopic rod pieces with lengths capable of being freely adjusted, one end of the second connecting rod group is provided with a connecting structure, and the connecting structure is suitable for vertical sliding fit of the vertical position maintaining rod.

Preferably, the connection structure comprises a mounting plate arranged at two ends of the connecting rod group, a guide plate is movably arranged on the mounting plate, a through notch is arranged on the guide plate, a mounting groove is arranged on the mounting plate and is suitable for mounting the guide plate, a first guide groove and a second guide groove are arranged on the side wall of the mounting groove, a guide pin shaft is arranged in the first guide groove and the second guide groove, the two guide pin shafts are arranged on the side wall of the guide plate, a torsion spring is arranged between the guide pin shaft and the guide plate, and a first spring abutting against the guide plate is arranged in the second guide groove.

Preferably, the passing notch is in an inclined state in the free state of the guide plate and is only used for passing the vertical position maintaining rod, and the guide plate is used for passing the connecting pipe sleeve when the guide plate is in a horizontal state under the action of the connecting pipe sleeve.

Preferably, the waterproof structure between the prefabricated support templates comprises a convex part and a tongue-and-groove which are arranged on the side parts of the prefabricated support templates, a groove which is suitable for clamping the side parts of the convex part and is used for clamping the clamping structure is arranged in the tongue-and-groove, an elastic locking piece which is suitable for locking the clamping structure is arranged in the tongue-and-groove, and a sealing strip is arranged between two adjacent prefabricated support templates.

Preferably, the clamping structure comprises clamping claws, rotating grooves, a first sliding groove and a second sliding groove, wherein the first sliding groove and the second sliding groove are arranged in parallel, a sliding block is arranged in the first sliding groove and the second sliding groove, the rotating grooves are arranged on one side, away from the protruding portions, of the first sliding groove and one end, away from the second sliding groove, of the first sliding groove is communicated with one end, away from the second sliding groove, of the first sliding groove, the sliding block is arranged on two sides of the clamping claws, a pressing joint is arranged on the clamping claws and is suitable for being driven by the protruding portions to rotate by the action of the end portions of the protruding portions, a second spring is arranged between the back surface of the clamping claws and the inner wall of the tongue-and-groove, and a locking groove matched with the end portions of the elastic locking pieces is arranged on one side, opposite to the inner arm of the tongue-and-groove.

Preferably, water seepage holes are formed in the outer wall of the prefabricated support template, water through holes communicated with the water seepage holes are formed in the prefabricated support template, and water guiding belts are arranged in the water seepage holes and the water through holes.

Preferably, the bottom of the prefabricated support templates at the bottommost part is provided with prefabricated tips which are pressed into the stabilizing layer.

The construction method of the soft foundation ultra-deep pit supporting structure comprises the following construction steps:

step one: drawing a lofting picture on a soft foundation section according to the design requirement of a drawing, drawing a position area line of a precast pile and a precast supporting template, and press-fitting the precast pile into the soft foundation section through press-fitting equipment and ensuring that a bottom precast tip is press-fitted into a stabilizing layer;

step two: installing a first connecting rod assembly between two adjacent precast piles, then vertically press-fitting the precast support templates layer by layer according to the position area line of the precast support templates, installing a support before press-fitting each layer of precast support templates, assembling by using a connecting pipeline on the support through a vertical position retaining rod, and ensuring the stability of the vertical press-fitting of the precast support templates by virtue of the sliding fit formed by the connecting structure on the second connecting rod assembly until the precast tips on the precast support templates are press-fitted in the stabilizing layer;

when the prefabricated support template is pressed, the vertical position retaining rod is in a vertical stable sliding state under the action of the guide plate in an inclined state, when the guide plate is acted by the connecting pipe sleeve, the guide plate rotates under the action of the two guide pin shafts and moves at a small distance to one side far away from the connecting pipe sleeve, when the guide plate is in a horizontal state under the action of the connecting pipe sleeve, the connecting pipe sleeve can vertically and stably pass through the through notch, and when the connecting pipe sleeve passes through the through notch, the guide plate is reset to an initial state under the action of the first spring and the torsion spring so as to vertically and stably slide the vertical position retaining rod;

the prefabricated support templates are vertically and transversely assembled in the support direction, through connection and assembly of the rabbets and the convex parts, after the end parts of the convex parts enter the rabbets, the clamping claws are acted and driven to rotate along the rotating grooves to finish the action of clamping the convex parts, the clamping claws and the convex parts move together along with the continuous entering of the convex parts, after the locking grooves on the clamping claws move to the positions where the locking grooves are matched with the elastic locking parts, the convex parts and the rabbets are connected, at the moment, the second springs are in a stretching state and can be in a free stretching state, and meanwhile, the sealing strips are in a compression joint state;

step three: and excavating a foundation pit and backfilling, and hoisting and dismantling the prefabricated support templates and the prefabricated piles by hoisting equipment.

Compared with the prior art, the invention has the following beneficial effects: the prefabricated pile is firstly pressed in the stabilizing layer, then the prefabricated support template is pressed until the bottom of the prefabricated support template is also pressed in the stabilizing layer, under the working condition of an ultra-deep foundation pit, the prefabricated support template is required to be vertically pressed, and a support, a connecting pipe sleeve and a vertical position retaining rod are arranged on the back of the prefabricated support template to realize the structural integrity, stability and reliability of the whole prefabricated support template. The invention is further innovative in that the connecting pipe sleeve and the vertical position maintaining rod can pass through the connecting structure freely while vertical installation is ensured, so that only the installation step of the vertical position maintaining rod can be carried out, and the problem that the press-mounting action can be continued after the connecting structure and the vertical position maintaining rod are removed before the press-mounting of each layer of prefabricated support templates is not required. The guide plate is rotated to the horizontal direction under the action of the connecting pipe sleeve, and is enabled to move to one side far away from the support template, so that the axis position of the guide plate passing through the through notch is always coincident with the axis of the connecting pipe sleeve and the vertical position retaining rod, and the front-back offset motion of the prefabricated support template is not caused. In order to achieve the water stopping effect, a waterproof structure is arranged at the splicing seam, water seepage holes and inner water through holes are distributed on the outer side of the prefabricated support template, and water stopping treatment of the periphery of the support is achieved through the water diversion belt. The adjacent splice joints adopt clamping claws and locking structures to complete structural splicing and waterproof treatment.

Drawings

FIG. 1 is a schematic cross-sectional view of the overall structure of the present invention;

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

FIG. 3 is a diagram showing the connection between the guide plate and the mounting plate of FIG. 2;

FIG. 4 is a schematic view of the overall structure of the guide plate of FIG. 2;

FIG. 5 is a diagram of the connection relationship between the left and right sets of prefabricated support templates;

FIG. 6 is a schematic view of the position of the gripper jaw in FIG. 5 during operation;

FIG. 7 is a schematic view of the position structure of the gripper jaw of FIG. 5 in a non-operating condition.

In the figure:

10. precast piles; 11. prefabricating the tip;

20. prefabricating a support template; 21. a support; 22. a connecting pipe sleeve; 23. a vertical position maintaining rod; 24. a convex portion; 25. a tongue-and-groove; 26. an elastic locking member; 27. clamping claws; 28. a rotary groove; 29. a first chute; 210. a second chute; 211. a slide block; 212. a second spring; 213. a locking groove; 214. a water through hole; 215. water seepage holes;

30. a stabilization layer;

40. a first connecting rod group;

50. a second connecting rod group; 51. a mounting plate; 52. a guide plate; 53. a mounting groove; 54. crossing the notch; 55. a first guide groove; 56. a second guide groove; 57. a guide pin shaft; 58. and a first spring.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments.

In the description of the present invention, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "top," "bottom," "inner," "outer," and the like indicate or are based on the orientation or positional relationship shown in the drawings, merely to facilitate description of the present invention and to simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention.

Embodiment 1 as shown in fig. 1 to 7, a soft foundation ultra-pit supporting structure comprises precast piles 10 and precast supporting templates 20;

the bottom of the precast pile 10 is fixedly provided with precast tips 11, the precast tips 11 are pressed in the stabilizing layer 30, and the precast pile 10 is provided with a plurality of groups along the supporting direction and is connected in sequence;

the prefabricated support templates 20 are vertically and transversely provided with a plurality of groups along the support direction and are sequentially connected;

a waterproof structure is installed between two adjacent prefabricated support templates 20;

a first connecting rod group 40 is arranged between two adjacent precast piles 10, a second connecting rod group 50 is arranged on one side of the precast pile 10 opposite to the precast support template 20, and one end of the second connecting rod group 50 is suitable for installing the precast support template 20; the first connecting rod set 40 and the second connecting rod set 50 are telescopic rods with freely adjustable lengths, and the structure is the same as that of the first connecting rod set and the second connecting rod set in CN 114809008A.

As shown in fig. 2 and 3, a support 21 is installed on one side of the prefabricated support template 20 opposite to the prefabricated pile 10, multiple groups of supports 21 are vertically distributed, each group of supports 21 is at least two in the transverse direction of the prefabricated support template 20, the same group of connecting rod groups three are installed on the upper group of supports 21 and the lower group of supports 21, and the connecting rod groups three and the end parts of the connecting rod groups one 40 are vertically and slidably distributed. The bottom of the bottom-most prefabricated support templates 20 are fitted with prefabricated tips that are press fit into stabilizing layers 30.

As shown in fig. 1, the bottom prefabricating tips of the prefabricating support templates 20 and the bottom prefabricating tips 11 of the prefabricating piles 10 are pressed into the stabilizing layer 30, and the top of the support structure can ensure the transverse stability of the support structure under the impact of soft foundation soil through the second connecting rod group 50 and the third vertical connecting rod group between the prefabricating support templates 20.

As shown in fig. 2 and 3, the support 21 is provided with mounting holes, the support 21 is mounted on the prefabricated support template 20 by bolts penetrating through the mounting holes, the connecting rod group three comprises a connecting sleeve 22, the connecting sleeve 22 is mounted on one side of the support 21 opposite to the prefabricated pile 10, and a vertical position maintaining rod 23 is mounted inside the connecting pipeline. The vertical integrity of the entire prefabricated support form 20 can be ensured by the vertical position holding rod 23, and the left-right integrity is completed by the waterproof structure. The bottom end of the connecting sleeve 22 is arranged in a conical structure.

As shown in fig. 3, a connection structure is mounted at one end of the second connecting rod set 50, the connection structure is suitable for vertical sliding fit of the vertical position maintaining rod 23, the connection structure comprises a mounting plate 51 mounted at the end of the second connecting rod set 50, a guide plate 52 is movably mounted on the mounting plate 51, a through notch 54 is arranged on the guide plate 52, a mounting groove 53 is arranged on the mounting plate 51, the mounting groove 53 is suitable for mounting the guide plate 52, a first guide groove 55 and a second guide groove 56 are arranged on the side wall of the mounting groove 53, a guide pin 57 is mounted in the first guide groove 55 and the second guide groove 56, two guide pins 57 are mounted on the side wall of the guide plate 52, a torsion spring is mounted between the guide pin 57 and the guide plate 52, and a first spring 58 abutting the guide plate 52 is mounted in the second guide groove 56.

The guide plate 52 is in a free state and in an inclined state through the through notch 54, and is only used for passing through the vertical position maintaining rod 23, and is used for passing through the connecting pipe sleeve 22 when the guide plate 52 is in a horizontal state under the action of the connecting pipe sleeve 22.

When the prefabricated support template 20 is pressed, the vertical position maintaining rod 23 is in a vertical stable sliding state under the action of the guide plates 52 in an inclined state, namely, the passing through notch 54 on the vertical position maintaining rod 23 is in an inclined state, the top of the passing through notch 54 acts on the vertical position maintaining rod 23 towards the side close to the prefabricated pile 10, the bottom of the passing through notch 54 acts on the vertical position maintaining rod 23 towards the side far away from the prefabricated pile 10, the guide plates 52 are in a stable state, when the guide plates 52 are vertically acted on the guide plates 52 by the connecting pipe sleeve 22, the guide plates 52 rotate under the action of the two guide pins 57 and simultaneously move to a small distance towards the side far away from the connecting pipe sleeve 22, when the guide plates 52 are horizontally acted on by the connecting pipe sleeve 22, the connecting pipe sleeve 22 can vertically stably pass through the passing through notch 54, and after the connecting pipe sleeve 22 passes through the passing through notch 54, the guide plates 52 are reset to an initial state under the action of the first spring 58 and the torsion spring for the vertical stable sliding of the vertical position maintaining rod 23.

As shown in fig. 5 to 7, sealing strips are arranged between two vertically adjacent prefabricated support templates 20, the sealing installation is completed by matching a connecting pipe sleeve 22 and a vertical position retaining rod 23, the waterproof structure between the two vertically adjacent prefabricated support templates 20 comprises a convex part 24 and a tongue-and-groove 25 which are arranged on the side parts of the prefabricated support templates 20, a groove which is suitable for clamping the side parts of the convex part 24 and is used for clamping the clamping structure is arranged in the tongue-and-groove 25, an elastic locking piece 26 which is suitable for locking the clamping structure is arranged in the tongue-and-groove 25, and sealing strips are arranged between the two adjacent prefabricated support templates 20.

As shown in fig. 5 to 7, the clamping structure includes a clamping claw 27, a rotating groove 28, a first chute 29 and a second chute 210, wherein the first chute 29 and the second chute 210 are arranged in parallel, a sliding block 211 is installed in the first chute 29 and the second chute 210, the rotating groove 28 is arranged on one side of the first chute 29 far away from the convex part 24, one end part of the rotating groove is communicated with one end part of the first chute 29 far away from the second chute 210, the sliding block 211 is installed on two sides of the clamping claw 27, a pressing joint is installed on the clamping claw 27 and is suitable for being driven by the end part of the convex part 24 to rotate by the clamping claw 27, a second spring 212 is installed between the back surface of the clamping claw 27 and the inner wall of the tongue-and-groove 25, and a locking groove 213 matched with the end part of the elastic locking piece 26 is distributed on one side of the clamping claw 27 opposite to the inner arm of the tongue-and-groove 25.

Through the inside of the tongue-and-groove 25 of convex part 24 entering, the convex part 24 can act on the crimping joint of gripper jaw 27 earlier for gripper jaw 27 centre gripping casts the recess in the outside of convex part 24, and then gripper jaw 27 moves and compresses the sealing strip to tongue-and-groove 25 depths along with convex part 24, and when locking groove 213 and elastic locking piece are adapted, gripper jaw 27 can stabilize gripper jaw 24 and be in steady state, and the sealing strip is in compression state after the centre gripping.

Water seepage holes 215 are formed in the outer wall of the prefabricated support template 20, water through holes 214 communicated with the water seepage holes 215 are formed in the prefabricated support template 20, and water guiding belts are arranged in the water seepage holes 215 and the water through holes 214. And water outside the prefabricated support template is led out by utilizing the outside water seepage holes 215 and the inside water through holes 214 in cooperation with water guiding belts, and the water stopping effect is finished by cooperation with a waterproof structure.

The construction method of the soft foundation ultra-deep pit supporting structure comprises the following construction steps:

step one: drawing out the position area lines of the precast pile 10 and the precast support template 20 on the soft foundation section according to the design requirement of the drawing, and pressing the precast pile 10 into the soft foundation section by using pressing equipment and ensuring that the bottom precast tip 11 is pressed into the stabilizing layer 30;

step two: installing a first connecting rod assembly between two adjacent precast piles 10, then vertically press-fitting the precast support templates 20 layer by layer according to the position area line of the precast support templates 20, installing a support 21 before press-fitting each layer of precast support templates 20, assembling by using a connecting pipeline on the support 21 through a vertical position retaining rod 23, and ensuring the stability of the vertical press-fitting of the precast support templates 20 by the sliding fit of the vertical position retaining rod 23 through the connecting structure on the second connecting rod assembly 50 until the precast tips on the precast support templates 20 are press-fitted in the stabilizing layer 30;

when the prefabricated support template 20 is pressed, the vertical position maintaining rod 23 is in a vertical stable sliding state under the action of the guide plate 52 in an inclined state, when the connecting pipe sleeve 22 acts on the guide plate 52, the guide plate 52 rotates under the action of the two guide pins 57 and moves at a small distance to one side far away from the connecting pipe sleeve 22, when the guide plate 52 is in a horizontal state under the action of the connecting pipe sleeve 22, the connecting pipe sleeve 22 can vertically stably pass through the through notch 54, and when the connecting pipe sleeve 22 passes through the through notch 54, the guide plate 52 returns to an initial state under the action of the first spring 58 and the torsion spring so as to vertically stably slide the vertical position maintaining rod 23;

the prefabricated support templates 20 are vertically and transversely assembled in the support direction, through the connection and assembly of the rabbets 25 and the convex parts 24, after entering the rabbets 25 through the end parts of the convex parts 24, the clamping claws 27 are acted and driven to rotate along the rotating grooves 28 to rotate, the action of clamping the convex parts 24 is completed, the clamping claws 27 and the convex parts 24 move together along with the continued entering of the convex parts 24, after the locking grooves 213 on the clamping claws 27 move to the positions where the elastic locking parts 26 are matched, the connection of the convex parts 24 and the rabbets 25 is completed, at the moment, the second spring 212 is in a stretched state and can be in a free stretching state, and meanwhile, the sealing strip is in a crimping state;

step three: and excavating a foundation pit and backfilling, and hoisting and dismantling the prefabricated support templates 20 and the prefabricated piles 10 by hoisting equipment.

The above description is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto. The substitutions may be partial structures, devices, or method steps, or may be a complete solution. The technical proposal and the invention concept are equivalent to or changed in accordance with the invention, and the invention is covered in the protection scope of the invention.

Claims (10)

1. The soft foundation ultra-deep pit supporting structure is characterized by comprising precast piles (10) and precast supporting templates (20);

the bottom of the precast pile (10) is fixedly provided with precast tips (11), the precast tips (11) are pressed in the stabilizing layer (30), and the precast piles (10) are provided with a plurality of groups along the supporting direction and are connected in sequence;

the prefabricated support templates (20) are vertically and transversely provided with a plurality of groups along the support direction and are connected in sequence;

a waterproof structure is arranged between two adjacent prefabricated support templates (20);

a first connecting rod group (40) is arranged between two adjacent groups of precast piles (10), a second connecting rod group (50) is arranged on one side of the precast piles (10) opposite to the precast support template (20), and one end of the second connecting rod group (50) is suitable for installing the precast support template (20);

one side of the prefabricated support template (20) opposite to the prefabricated pile (10) is provided with a support (21), a plurality of groups of supports (21) are vertically distributed, each group of supports (21) is at least distributed with two supports along the transverse direction of the prefabricated support template (20), the upper support (21) and the lower support (21) are provided with the same group of connecting rod groups III, and the end parts of the connecting rod groups III and the connecting rod groups I (40) are vertically and slidably distributed.

2. The soft foundation ultra-deep pit supporting structure according to claim 1, wherein the supporting seat (21) is provided with a mounting hole, the supporting seat (21) is mounted on the prefabricated supporting template (20) through a bolt penetrating the mounting hole, the connecting rod group three comprises a connecting pipe sleeve (22), the connecting pipe sleeve (22) is mounted on one side of the supporting seat (21) opposite to the prefabricated pile (10), and a vertical position retaining rod (23) is mounted in the connecting pipeline.

3. The soft foundation ultra-pit supporting structure according to claim 2, wherein the first connecting rod group (40) and the second connecting rod group (50) are telescopic rods with lengths capable of being freely adjusted, one end of the second connecting rod group (50) is provided with a connecting structure, and the connecting structure is suitable for vertical sliding fit of the vertical position maintaining rod (23).

4. A soft foundation ultra-pit supporting structure according to claim 3, characterized in that the connecting structure comprises a mounting plate (51) mounted at the end part of the second connecting rod group (50), a guide plate (52) is movably mounted on the mounting plate (51), a penetrating notch (54) is arranged on the guide plate (52), a mounting groove (53) is arranged on the mounting plate (51), the mounting groove (53) is suitable for mounting the guide plate (52), a first guide groove (55) and a second guide groove (56) are arranged on the side wall of the mounting groove (53), a guide pin (57) is mounted in each of the first guide groove (55) and the second guide groove (56), a torsion spring is mounted between the guide pin (57) and the guide plate (52), and a first spring (58) abutting against the guide plate (52) is mounted in the second guide groove (56).

5. The soft foundation ultra-pit supporting structure according to claim 4, wherein the guide plate (52) is inclined through the through notch (54) for passing through only the vertical position maintaining rod (23) in a free state, and is passed through by the connecting sleeve (22) when the guide plate (52) is horizontally acted on by the connecting sleeve (22).

6. The soft foundation ultra-deep pit supporting structure according to claim 5, wherein the waterproof structure between the prefabricated supporting templates (20) comprises a convex part (24) and a tongue-and-groove (25) which are arranged on the side parts of the prefabricated supporting templates (20), a groove which is suitable for clamping the side parts of the convex part (24) is arranged in the tongue-and-groove (25), an elastic locking piece (26) which is suitable for locking the clamping structure is arranged in the tongue-and-groove (25), and a sealing strip is arranged between two adjacent prefabricated supporting templates (20).

7. The soft foundation ultra-pit supporting structure according to claim 6, wherein the clamping structure comprises a clamping claw (27), a rotating groove (28), a first sliding groove (29) and a second sliding groove (210), wherein the first sliding groove (29) and the second sliding groove (210) are arranged in parallel, a sliding block (211) is arranged in the first sliding groove (29) and the second sliding groove (210), the rotating groove (28) is arranged on one side of the first sliding groove (29) away from the convex part (24) and one end of the first sliding groove (29) is communicated with one end of the first sliding groove (29) away from the second sliding groove (210), the sliding block (211) is arranged on two sides of the clamping claw (27), a pressing joint is arranged on the clamping claw (27) and is suitable for being driven by the end of the convex part (24) to rotate, a second spring (212) is arranged between the back surface of the clamping claw (27) and the inner wall of the rabbet (25), and one side of the clamping claw (27) opposite to the inner arm of the rabbet (25) is provided with a locking groove (213) which is matched with the end of the elastic locking piece (26).

8. The soft foundation ultra-deep pit supporting structure according to claim 7, wherein water seepage holes (215) are formed in the outer wall of the prefabricated supporting template (20), water through holes (214) communicated with the water seepage holes (215) are formed in the prefabricated supporting template (20), and water guiding belts are arranged in the water seepage holes (215) and the water through holes (214).

9. A soft foundation ultra pit support structure according to claim 8, wherein the bottom of the prefabricated support form (20) at the very bottom is fitted with prefabricated tips which are press fit into the stabilising layer (30).

10. The construction method of the soft foundation ultra-deep pit supporting structure is characterized by comprising the following construction steps:

step one: drawing out a precast pile (10) and a precast support template (20) position area line on a soft foundation section according to the design requirement of a drawing, and pressing the precast pile (10) into the soft foundation section through a pressing device and ensuring that a bottom precast tip (11) is pressed into a stabilizing layer (30);

step two: installing a first connecting rod assembly between two adjacent precast piles (10), then vertically pressing the precast support templates (20) layer by layer according to the position area line of the precast support templates (20), installing a support (21) before pressing each layer of precast support templates (20), assembling by using a connecting pipeline on the support (21) through a vertical position retaining rod (23), and ensuring the stability of the vertical pressing of the precast support templates (20) by sliding fit formed by the connecting structure on a second connecting rod assembly (50) until the precast tips on the precast support templates (20) are pressed in a stabilizing layer (30);

when the prefabricated support template (20) is pressed and assembled, the vertical position retaining rod (23) is in a vertical stable sliding state under the action of the guide plate (52) in an inclined state, when the connecting pipe sleeve (22) acts on the guide plate (52), the guide plate (52) rotates under the action of the two guide pins (57) and moves at a small distance to one side far away from the connecting pipe sleeve (22), when the guide plate (52) is in a horizontal state under the action of the connecting pipe sleeve (22), the connecting pipe sleeve (22) can vertically and stably pass through the passing through notch (54), and after the connecting pipe sleeve (22) passes through the passing through notch (54), the guide plate (52) returns to an initial state under the action of the first spring (58) and the torsion spring so as to vertically and stably slide the vertical position retaining rod (23);

the prefabricated support templates (20) are vertically and transversely assembled in the support direction, through connection and assembly of the rabbets (25) and the convex parts (24), after the ends of the convex parts (24) enter the rabbets (25), the clamping claws (27) are acted and driven to rotate along the rotating grooves (28) to complete the action of the clamping convex parts (24), the clamping claws (27) and the convex parts (24) move together along with the continuous entering of the convex parts (24), after the locking grooves (213) on the clamping claws (27) move to the positions where the locking grooves (213) are matched with the elastic locking pieces (26), the connection of the convex parts (24) and the rabbets (25) is completed, at the moment, the second spring (212) is in a stretching state and can be in a free stretching state, and the sealing strip is in a crimping state;

step three: and excavating a foundation pit and backfilling, and hoisting and dismantling the prefabricated support templates (20) and the prefabricated piles (10) through hoisting equipment.