CN115627770B

CN115627770B - Telescopic deep foundation pit support structure

Info

Publication number: CN115627770B
Application number: CN202211240660.8A
Authority: CN
Inventors: 范秋果; 张友良; 黑云朋
Original assignee: Hainan University
Current assignee: Hainan University
Priority date: 2022-10-11
Filing date: 2022-10-11
Publication date: 2025-08-29
Anticipated expiration: 2042-10-11
Also published as: CN115627770A

Abstract

The present invention discloses a telescopic deep foundation pit support structure, comprising a foundation pit and support plates. Several support plates are provided on the inner sidewalls of the foundation pit, a water-stop curtain is provided in the outer soil of the foundation pit, and prestressed anchor rods are provided obliquely along the edges of the support plates. The support plates comprise a transverse support panel for inserting into the pit wall and a vertical support panel for abutting the pit wall, wherein the transverse support panel and the vertical support panel share a common edge. The transverse support panel is composed of at least two layers of movable panels nested in sequence, and the two adjacent layers of movable panels are slidably connected. Small holes are provided on the vertical support panels for water permeability and for reducing stress concentration. This device utilizes the soil's own gravity and, through the use of telescopic support plates, improves the anti-collapse capability of the foundation pit sidewalls, thereby achieving a support effect for the foundation pit. The support plates are connected to form a whole by bolts, thereby improving the integrity and stability of the structure. The detachable support structure reduces the environmental impact of construction and the cost of the project.

Description

Telescopic deep foundation pit supporting structure

Technical Field

The invention relates to the technical field of foundation pit support, in particular to a telescopic deep foundation pit support structure.

Background

With the continuous improvement of the resident living standard and the technological development level in China, various high-rise and super-high-rise buildings are gradually increased, the underground structures bear larger loads, the requirements on the underground structures are higher and higher, and in order to better meet the requirements of various buildings, the deep foundation pit support with practicability is generated.

The underground water content in many areas is rich, and the supporting force of the soil body structure is insufficient due to the deep excavation depth, so that the foundation pit is collapsed in the construction process due to the fact that the sand flow and slope instability are easy to occur when the underground water amount is large or rainwater is encountered on day, and the bearing capacity of the structure is affected.

The foundation pit support is a measure for temporarily supporting, reinforcing and protecting the side wall of the foundation pit and the surrounding environment and controlling groundwater so as to ensure the safety of the underground structure construction and the surrounding environment of the foundation pit. The current deep foundation pit support, for example 201310082057.6 discloses a construction method for combined support of a pressure grouting pile and a prestressed anchor rod of an ultra-deep foundation pit, which is a common combined support structure adopting a bored pile and an anchor rod, has the advantages of large consumption of construction consumables, high manufacturing cost, easy bending of a transverse support rod after long-term stress, and large difficulty in installation and disassembly.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide a telescopic deep foundation pit supporting structure so as to solve the problems that the existing foundation pit supporting structure occupies a large space, the construction operation surface, the high manufacturing cost of supporting structures such as cast-in-place piles and the like are influenced, and the supporting structures cannot be reused.

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

the telescopic deep foundation pit supporting structure comprises a foundation pit and supporting plates, wherein a plurality of supporting plates are arranged on the inner side wall of the foundation pit, a waterproof curtain is arranged in the soil body on the outer side of the foundation pit, and a prestressed anchor rod is obliquely arranged along the edge of each supporting plate. The waterproof curtain can form a waterproof layer outside the foundation pit, water is prevented from flowing into the foundation pit, the prestressed anchor rod can enhance the supporting effect of the supporting plate, and the collapse resistance of the side wall of the foundation pit is enhanced.

The support plate comprises a transverse support panel for being inserted into the pit wall and a vertical support panel for being closely attached to the pit wall, wherein a common edge exists between the transverse support panel and the vertical support panel, the transverse support panel is composed of at least two layers of movable panels which are nested in sequence, and the adjacent two layers of movable panels are connected in a sliding mode.

The lateral support panel and the vertical support panel are in a common edge, which means that the lateral support panel and the vertical support panel are connected with each other and the support plate has only a unique included angle. Under the condition that the contact areas are the same, the deeper transverse support panel receives the larger soil body gravity, so that the deeper transverse support panel can be properly reduced, and the consumable is reduced.

Further, the adjacent movable panels are connected with each other through a sliding block sliding groove structure, and move in a matched manner through a gear-rack structure, and the expansion and contraction of the movable panels are controlled through a second hydraulic rod;

The sliding blocks and the sliding grooves which are matched with each other are arranged on the two opposite outer side walls of the movable panel, and gears are meshed between racks on the outer wall of the movable panel of the inner layer and racks on the inner wall of the movable panel of the outer layer.

Further, the cylinder end of the second hydraulic rod is arranged on the moving panel of the outermost layer, and the tail end of the piston penetrates through the middle moving panel and is fixed on the moving panel of the innermost layer. When the second hydraulic rod works, the piston end of the second hydraulic rod is directly connected with the innermost movable panel, so that the innermost movable panel firstly extends out of the transverse support panel and contracts, and the overall length of the transverse support panel is changed.

Further, the vertical support panel is provided with small holes for water permeation and stress concentration reduction, the small holes penetrate through the panel, the bottom of the foundation pit is provided with drainage ditches, the drainage ditches are arranged along the circumference of the pit to collect water permeated out of the vertical support panel, and water collecting wells are arranged at the junction of the drainage ditches.

Further, the drainage ditch is obliquely arranged, and the inclination angle is 1% -2%. The small holes enable the vertical support panel to be uniformly stressed, reduce stress concentration and avoid damaging the plate. Meanwhile, rainwater can permeate into the drainage ditch with a certain inclination angle at the bottom of the foundation pit through the small holes after immersing in the soil.

The hydraulic system comprises a transverse support panel, a first hydraulic rod, a second hydraulic rod, a cylinder barrel and a piston rod, wherein the transverse support panel is connected with the first hydraulic rod through the first hydraulic rod, the cylinder barrel of the first hydraulic rod is hinged to the first hydraulic rod, the piston rod is hinged to the second hydraulic rod, and the piston rod is hinged to one side of the first hydraulic rod.

Further, the vertical support panel is further provided with a penetrating screw hole along the height direction, and the upper and lower adjacent support plates are connected through bolts. The upper and lower adjacent two guard plates are connected through bolts to form a support structure with strong stability and strong integrity, and the stress conditions of all parts of the side wall of the foundation pit are balanced, so that the foundation pit is not easy to collapse.

Further, the transverse support panel is wedge-shaped and terminates in a tip. The angle of the horizontal support panel can be set to be 15 degrees, and the pressure of the horizontal support panel to the soil body is increased by reducing the contact area, so that the horizontal support panel can smoothly enter the soil body.

Furthermore, the transverse support panel and the vertical support panel are integrally formed steel structures, and the corner of the common edge is subjected to rounding reinforcement treatment. By thickening the corner portions, the shearing resistance of the support plate is improved.

Further, the support plate is L-shaped.

Compared with the prior art, the invention has the following beneficial effects:

The device utilizes soil body self gravity to realize the supporting effect to the foundation ditch, and the independent supporting plate is integrated through bolted connection for supporting structure's wholeness improves, and stability improves. By using the telescopic support plate, the collapse resistance of the side wall of the foundation pit is improved. The installation volume is reduced, the installation and the use are convenient, the requirement on the supporting operation space is low, the larger space is provided, the foundation pit operation is facilitated, and the manufacturing cost is low.

The detachable supporting structure improves the repeated utilization rate of the supporting structure, reduces the influence on the environment and the waste of resources, and simultaneously greatly reduces the construction cost of engineering.

Drawings

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

FIG. 1 is a top view of the overall structure of the present invention;

FIG. 2 is a front cross-sectional view of the overall structure of the present invention;

FIG. 3 is a schematic view of the support plate connection of the present invention;

FIG. 4 is an internal block diagram of the transverse support panel of the present invention;

Fig. 5 is a structural view of the bidirectional hydraulic rod supporting mechanism of the present invention.

In the drawings, each reference numeral is:

1-waterproof curtain, 2-support plate, 201-transverse support panel, 201 a-gear, 201 b-rack, 201 c-chute, 201 d-second hydraulic rod, 202-vertical support panel, 203-bolt, 204-small hole, 3-prestress anchor rod, 4-drain well, 5-water collecting well, 6-drain ditch, 7-water suction pump, 8-drain pipe, 9-bidirectional hydraulic rod support mechanism, 901-push-pull panel, 902-first hydraulic rod and 903-connecting rod mechanism.

Detailed Description

In order to more clearly illustrate the present invention, the present invention will be described in further detail below with reference to examples and with reference to the accompanying drawings. It is to be understood by persons skilled in the art that the following detailed description is illustrative and not restrictive, and that this invention is not limited to the details given herein.

In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "inner", "outer", "upper", "lower", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present invention and simplifying the description, and do not indicate or imply that the apparatus or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention. Furthermore, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, integrally connected, mechanically connected, electrically connected, directly connected, indirectly connected via an intervening medium, or in communication between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

Examples:

the telescopic deep foundation pit supporting structure shown in the figures 1-5 comprises a foundation pit, wherein a slope is firstly laid when the foundation pit is excavated, and a suitable slope laying coefficient is designed according to a corresponding soil body and a designed excavation depth. The underground water level depth near the foundation pit is reduced by a well point water-reducing method, and the bearing capacity of the soil body is improved. Then, a waterproof curtain 1 is arranged on the soil around the foundation pit to form a waterproof layer, and the waterproof curtain 1 is a continuous waterproof body used for preventing or reducing the groundwater on the side wall of the foundation pit and the bottom of the foundation pit from flowing into the foundation pit, and cement-soil stirring piles or compaction grouting can be adopted.

The foundation ditch in this embodiment is the square form, and the inside wall of foundation ditch all is equipped with support plate 2. The support plate 2 is composed of a transverse support panel 201 for being inserted into the pit wall and a vertical support panel 202 for being closely attached to the pit wall, wherein the transverse support panel 201 and the vertical support panel 202 are vertically arranged in an L shape and are of an integrally formed steel structure. And the corner is rounded to strengthen, and the shearing resistance of the structure is improved by thickening the corner.

In order to enhance the supporting effect of the supporting plate 2 and enhance the collapse resistance of the side wall of the foundation pit, the prestressed anchor rods 3 are obliquely arranged along the edge of the transverse supporting panel 201 for anchoring, so that the supporting effect of soil body is enhanced. And a drain well 4 is arranged between the waterproof curtain 1 and the prestressed anchor rod 3 along the circumference of the pit, so that the groundwater level of the foundation pit is controlled within a reasonable range, and the foundation pit can be constructed under the dry condition.

The vertical support panel 202 is provided with a plurality of small holes 204 penetrating through the panel, and the small holes 204 enable the vertical support panel 202 to be uniformly stressed, reduce stress concentration and avoid damage to the plate. Meanwhile, after the rainwater is immersed in the soil body, the rainwater can permeate into the drainage ditch 6 with a certain inclination angle at the bottom of the foundation pit through the small holes 204. The drainage ditch 6 is arranged along the periphery of the pit, and the inclination angle is generally set to be 1% -2%, so that the collection and collection of water in the soil body are facilitated. The junction (foundation ditch four corners department) of escape canal 6 is provided with the sump pit 5 of connecting drain pipe 8, and sump pit 5 is connected with suction pump 7 through drain pipe 8, is favorable to the timely discharge of water. The water pump 7 is arranged above the foundation pit, so that the water pump 7 is prevented from being covered due to the collapse of soil around the pit wall in rainy days.

The vertical support panel 202 is further provided with penetrating screw holes along the height direction, and after each two rows of support plates 2 are punched, the screw holes on the vertical support panel 202 of the lower row are aligned with the screw holes of the upper row, and are fixedly connected through bolts 203. The upper and lower adjacent two support plates 2 are fixedly connected through bolts 203 to form a support structure with strong stability and strong integrity, and the stress conditions of all parts are balanced, so that the side wall of the foundation pit is not easy to collapse.

The lateral support panel 201 is wedge-shaped, terminating in a tip, typically at an angle of 15 °. By reducing the contact area, the pressure of the soil body is increased, so that the soil body can be smoothly entered. The movement of the transverse support panel 201 in the soil mass is achieved by the bi-directional hydraulic rod support mechanism 9. The bidirectional hydraulic rod supporting mechanism 9 comprises two push-pull panels 901, a connecting rod mechanism 903 and a first hydraulic rod 902, wherein the two push-pull panels 901 are connected through the connecting rod mechanism 903, and the connecting rod mechanism 903 is composed of a plurality of hinged connecting rods. The cylinder barrel of the first hydraulic rod 902 is hinged on the push-pull panel at one side, the tail end of the piston rod is hinged on one connecting rod of the connecting rod mechanism 903, when the first hydraulic rod 902 stretches, the connecting rod can be driven to move, then the whole length of the connecting rod mechanism 903 is changed, displacement is transmitted to the vertical support panel 202 through the push-pull panel 901, and the distance between two opposite vertical support panels 202 is changed. The linkage 903 in this embodiment adopts a planar linkage with a single degree of freedom, so only one first hydraulic lever 902 needs to be provided as a power source, and a certain movement path can be provided.

And a bidirectional hydraulic rod supporting mechanism 9 is arranged between the two opposite sides of the foundation pit, after the transverse supporting panels 201 are placed in preset positions, the first hydraulic rods 902 push the connecting rod mechanisms 903 to move, and the push-pull panels 901 on the two sides of the connecting rod mechanisms 903 are clung to the vertical supporting panels 202, so that the transverse supporting panels 201 on the two sides are driven into soil on the two sides of the foundation pit.

The side wall of the foundation pit needs a plurality of support plates 2 to be spliced and protected, and under the condition of the same contact area, the deeper the transverse support panel 201 receives the larger the gravity of the soil body, so the deeper the transverse support panel 201 can be properly reduced, and the consumable is reduced. In this embodiment, therefore, the supporting plates 2 at different depth positions have different depths of driving the lateral supporting panels 201 into the soil. The closer the support plate 2 is to the bottom of the foundation pit, the shorter the transverse support panel 201 is.

The above-described demand can be satisfied by providing the support plates 2 with the lateral support panels 201 having different lengths, but this increases the complexity of construction, so that the telescopic lateral support panel 201 is employed in the present embodiment. The transverse support panel 201 is composed of a plurality of layers of telescopic movable panels which are nested in sequence, and the movable panels are hollow structures. The two adjacent movable panels are connected with each other through a sliding block sliding chute structure, are matched and move through a gear rack structure, and are controlled to move through a second hydraulic rod 201 d. The outer walls of the two opposite sides of the movable panels are provided with sliding blocks and sliding grooves 201c which are matched with each other, so that the two adjacent movable panels can relatively displace. The outer wall and the inner wall of the movable panel are provided with racks 201b along the extending and contracting direction, and meshed gears 201a are arranged between the racks 201b of the outer wall of the movable panel of the inner layer and the racks 201b of the inner wall of the movable panel of the outer layer. The cylinder end of the second hydraulic rod 201d is disposed on the outermost moving panel, and the piston end passes through the middle barrier moving panel and is fixed on the innermost moving panel. Taking the extension of the second hydraulic rod 201d as an example, when the piston of the second hydraulic rod 201d starts to move, the innermost moving panel is first protruded from the lateral support panel 201 because it is directly connected to the innermost moving panel and the adjacent two moving panels can relatively move. When the slide block of the inner moving panel reaches the other end of the sliding groove 201c, if the piston continues to extend, the outer moving panel will continue to move outwards to extend the whole length of the transverse supporting panel 201. The shrinkage of the lateral support panel 201 is the same.

After the support is completed, the connecting bolts between the two support plates 2 can be removed, the push-pull panel 901 of the bidirectional hydraulic rod support mechanism 9 is fixed on the vertical support panel 202 of the support plate 2, and the first hydraulic rod 902 is started to pull out the horizontal part of the support plate 2 from the soil body. At the same time, the telescopic mechanism in the transverse support panel 201 is started, so that the transverse support panel 201 is contracted.

It should be understood that the foregoing examples of the present invention are merely illustrative of the present invention and not limiting of the embodiments of the present invention, and that various other changes and modifications can be made by those skilled in the art based on the above description, and it is not intended to be exhaustive of all the embodiments of the present invention, and all obvious changes and modifications that come within the scope of the invention are defined by the following claims.

Claims

1. A telescopic deep foundation pit support structure, comprising a foundation pit and support plates, wherein a plurality of support plates are provided on the inner sidewall of the foundation pit. The structure is characterized in that a water-stop curtain is provided in the soil outside the foundation pit, and prestressed anchor rods are provided obliquely along the edges of the support plates.

The support plate includes a transverse support panel for inserting into the pit wall and a vertical support panel for adhering to the pit wall, wherein the transverse support panel and the vertical support panel have a common edge; the transverse support panel is composed of at least two layers of movable panels nested in sequence, and the two adjacent layers of movable panels are slidably connected;

The side walls of the foundation pit are protected by several support panels. The depths of the horizontal support panels driven into the soil at different depths are different for support panels at different depths. The closer the support panels are to the bottom of the foundation pit, the shorter the horizontal support panels driven into the soil.

The prestressed anchor rods are arranged obliquely along the edges of the transverse supporting panels.

2. The telescopic deep foundation pit support structure according to claim 1 is characterized in that adjacent movable panels are interconnected by a slider chute structure, move in coordination with a gear rack structure, and are controlled to extend and retract by a second hydraulic rod; the length direction of the chute and rack is the same as the extension and retraction direction of the second hydraulic rod;

The two opposite outer side walls of the movable panel are provided with sliding blocks and sliding grooves that cooperate with each other, and a gear is meshed between the rack on the outer wall of the inner movable panel and the rack on the inner wall of the outer movable panel.

3. The telescopic deep foundation pit support structure according to claim 2 is characterized in that the cylinder end of the second hydraulic rod is arranged on the outermost movable panel, and the piston end passes through the middle movable panel and is fixed to the innermost movable panel.

4. The telescopic deep foundation pit support structure according to claim 1, wherein the vertical support panel is provided with small holes for water permeability and stress concentration reduction, and the small holes penetrate the panel;

Drainage ditches are arranged at the bottom of the foundation pit, and the drainage ditches are arranged along the circumference of the pit to collect water that penetrates the vertical support panels. A water collection well is arranged at the intersection of the drainage ditches.

5. The telescopic deep foundation pit supporting structure according to claim 4, characterized in that the drainage ditch is arranged at an inclination angle of 1%-2%.

6. The telescopic deep foundation pit support structure according to claim 1 is characterized in that it also includes a bidirectional hydraulic rod support mechanism, which includes a push-pull panel, a connecting rod mechanism and a first hydraulic rod. The push-pull panel is arranged on the transverse support panel, and the opposite push-pull panels are connected by a connecting rod mechanism; the cylinder of the first hydraulic rod is hinged to the push-pull panel on one side, and the end of the piston rod is hinged to any connecting rod of the connecting rod mechanism.

7. The telescopic deep foundation pit support structure according to claim 1 is characterized in that the vertical support panel is further provided with penetrating screw holes along the height direction, and the upper and lower adjacent support panels are connected by bolts.

8. The telescopic deep foundation pit supporting structure according to claim 1, wherein the transverse supporting panel is wedge-shaped with a pointed end.

9. The telescopic deep foundation pit supporting structure according to any one of claims 1 to 8, characterized in that the transverse support panel and the vertical support panel are integrally formed steel structures, and the common corners are chamfered and reinforced.

10. The telescopic deep foundation pit supporting structure according to any one of claims 1 to 8, wherein the supporting plate is L-shaped.