Telescopic deep foundation pit support structure

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

Technical Field

[0001] The present invention relates to the technical field of foundation pit support, in particular to a telescopic deep foundation pit support structure. Background Art

[0002] With the continuous improvement of the living standards of Chinese residents and the level of scientific and technological development, various types of high-rise and super-high-rise buildings are gradually increasing. Underground structures are bearing greater loads, and the requirements for underground structures are becoming higher and higher. In order to better meet the requirements of various types of buildings, more practical deep foundation pit support has come into being.

[0003] Many areas have abundant groundwater. Due to the deep excavation depth, the soil structure itself lacks supporting capacity. When the groundwater volume is large or it rains, sand flow and slope instability are prone to occur, causing foundation pit collapse during construction and affecting the bearing capacity of the structure.

[0004] Foundation pit support is a temporary measure used to support, reinforce, protect, and control groundwater in the pit sidewalls and surrounding environment to ensure the safety of underground structure construction and the surrounding environment. Current deep foundation pit support, such as the ultra-deep foundation pit combined support construction method using bored piles and prestressed anchor rods disclosed in 201310082057.6, is a common combined support structure using bored piles and anchor rods. This structure consumes a large amount of construction materials and is costly. Furthermore, the transverse support rods are prone to bending after long-term stress, making installation and removal difficult. Summary of the Invention

[0005] In order to overcome the shortcomings of the existing technology, the purpose of the present invention is to provide a telescopic deep foundation pit support structure to solve the problems of the current foundation pit support structure occupying a large space, affecting the construction working surface, the high cost of support structures such as cast-in-place piles and non-reusability.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] The telescopic deep foundation pit support structure consists of a foundation pit and support plates. Several support plates are installed on the inner sidewalls of the foundation pit, and a water-stop curtain is installed in the soil outside the foundation pit. Prestressed anchor rods are installed diagonally along the edges of the support plates. The water-stop curtain forms a water barrier outside the foundation pit, preventing water from flowing into the pit. The prestressed anchor rods enhance the support effect of the support plates and strengthen the collapse resistance of the foundation pit sidewalls.

[0008] The support plate includes a transverse support panel for inserting into the pit wall and a vertical support panel for sticking to the pit wall, and 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 can be slidably connected.

[0009] The horizontal and vertical support panels share a common edge, meaning they are connected and have a single angle between them. Given the same contact area, deeper horizontal support panels experience greater soil gravity. Therefore, deeper horizontal support panels can be reduced in size to minimize material consumption.

[0010] Furthermore, the adjacent movable panels are connected to each other through 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 the rack is the same as the extension and retraction direction of the second hydraulic rod;

[0011] 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.

[0012] Furthermore, the cylinder end of the second hydraulic rod is mounted on the outermost movable panel, while the piston end passes through the middle movable panel and is fixed to the innermost movable panel. When the second hydraulic rod is in operation, because its piston end is directly connected to the innermost movable panel, the innermost movable panel is the first to extend or retract from the transverse support panel, thereby changing the overall length of the transverse support panel.

[0013] Furthermore, the vertical support panel is provided with small holes for water permeation and reducing stress concentration, and the small holes pass through the panel; a drainage ditch is set at the bottom of the foundation pit, and the drainage ditch is set along the circumference of the pit to collect water permeating from the vertical support panel, and a water collection well is set at the intersection of the drainage ditch.

[0014] Furthermore, the drainage ditch is tilted at an angle of 1%-2%. The small holes evenly distribute stress on the vertical support panels, reducing stress concentration and preventing damage to the panels. Furthermore, rainwater that penetrates the soil can penetrate through these small holes into the tilted drainage ditch at the bottom of the foundation pit.

[0015] Furthermore, 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.

[0016] Furthermore, the vertical support panels are provided with screw holes extending along their height, and the upper and lower adjacent support panels are connected by bolts. The bolts connect the upper and lower adjacent support panels to form a highly stable and integrated support structure, balancing the stresses on the various parts of the foundation pit sidewalls and preventing them from collapsing.

[0017] Furthermore, the lateral support panel is wedge-shaped with a pointed end, and its angle can be set to 15 degrees, which reduces the contact area and increases the pressure on the soil, so that the lateral support panel can enter the soil more smoothly.

[0018] Furthermore, the horizontal support panels and vertical support panels are integrally formed steel structures, and the corners of the common edges are rounded and reinforced. By thickening the corners, the shear resistance of the support panels is improved.

[0019] Furthermore, the supporting plate is L-shaped.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] This device utilizes the soil's own gravity to achieve effective support for the foundation pit. Individual support plates are bolted together to form a single unit, enhancing the integrity and stability of the support structure. The use of retractable support plates improves the collapse resistance of the foundation pit sidewalls. The device reduces installation volume, facilitating installation and use, and requires minimal space for support operations, providing more space for pit operations while maintaining a low cost.

[0022] The detachable support structure improves the reuse rate of the support structure, reduces the impact on the environment and the waste of resources, and greatly reduces the cost of the project. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 It is a top view of the overall structure of the present invention;

[0025] Figure 2 It is a front cross-sectional view of the overall structure of the present invention;

[0026] Figure 3 It is a schematic diagram of the connection of the support plate of the present invention;

[0027] Figure 4 is a diagram of the internal structure of the transverse support panel of the present invention;

[0028] Figure 5 It is a structural diagram of the bidirectional hydraulic rod support mechanism of the present invention.

[0029] In the figures, the reference numerals are:

[0030] 1-water-stop curtain; 2-support plate; 201-horizontal support panel; 201a-gear; 201b-rack; 201c-chute; 201d-second hydraulic rod; 202-vertical support panel; 203-bolt; 204-small hole; 3-prestressed anchor rod; 4-drainage well; 5-collection well; 6-drainage ditch; 7-water pump; 8-drainage pipe; 9-bidirectional hydraulic rod support mechanism; 901-push-pull panel; 902-first hydraulic rod; 903-connecting rod mechanism. DETAILED DESCRIPTION

[0031] In order to more clearly illustrate the present invention, the present invention is further described in detail below in conjunction with embodiments and with reference to the accompanying drawings. It should be understood by those skilled in the art that the following specific description is illustrative rather than restrictive and should not be used to limit the scope of protection of the present invention.

[0032] In the description of the present invention, it should be noted that the terms "inside", "outside", "upper", "lower", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings, and are 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 therefore cannot be understood as a limitation on the present invention. In addition, unless otherwise clearly specified and limited, the terms "installation", "connection", etc. should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, an indirect connection through an intermediate medium, or the internal connection of the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0033] Example:

[0034] like Figure 1-5 The telescopic deep foundation pit support structure shown includes a foundation pit. During excavation, the pit is first sloped, with an appropriate slope coefficient designed based on the soil and the designed excavation depth. Wellpoint dewatering is used to lower the groundwater level near the foundation pit, improving the soil's bearing capacity. A waterstop curtain 1 is then installed in the soil surrounding the pit to form a water barrier. This continuous waterstop is used to prevent or reduce groundwater inflow from the pit's sidewalls and bottom. Cement-soil mixing piles or compacted grouting can be used.

[0035] The foundation pit in this embodiment is square-shaped, with support panels 2 installed on the inner walls. These panels consist of a horizontal support panel 201 inserted into the pit wall and a vertical support panel 202 positioned against the pit wall. These panels 201 and 202 are arranged vertically in an L-shape, forming an integrated steel structure. Corners are rounded for reinforcement, and thickened corners enhance the structure's shear resistance.

[0036] To enhance the support effectiveness of the support panels 2 and the collapse resistance of the foundation pit sidewalls, prestressed anchor rods 3 are installed diagonally along the edges of the transverse support panels 201 for anchoring, thus enhancing soil support. Drain wells 4 are arranged along the circumference of the pit between the water-stop curtain 1 and the prestressed anchor rods 3 to control the groundwater level within a reasonable range and ensure that the foundation pit can be constructed under dry conditions.

[0037] The vertical support panel 202 is provided with a number of small holes 204 that pass through the panel. The small holes 204 make the vertical support panel 202 evenly stressed, reduce stress concentration, and avoid damage to the plate. At the same time, after rainwater penetrates the soil, it can penetrate through these small holes 204 into the drainage ditch 6 with a certain inclination angle at the bottom of the foundation pit. The drainage ditch 6 is arranged along the circumference of the pit, and the inclination angle is usually set to 1%-2%, which is conducive to the collection and collection of water in the soil. A water collection well 5 connected to the drainage pipe 8 is provided at the intersection of the drainage ditch 6 (at the four corners of the foundation pit). The water collection well 5 is connected to the water pump 7 through the drainage pipe 8, which is conducive to the timely discharge of water. The water pump 7 is arranged above the foundation pit to prevent the water pump 7 from being covered due to the collapse of the soil around the pit wall on rainy days.

[0038] The vertical support panels 202 are also provided with screw holes running through them along the height direction. After each two rows of support panels 2 are installed, the screw holes on the vertical support panels 202 in the lower row are aligned with the screw holes on the upper row and fixed together with bolts 203. The upper and lower adjacent support panels 2 are fixedly connected by bolts 203, forming a highly stable and integrated support structure, which balances the stress conditions of each part and prevents the side walls of the foundation pit from collapsing.

[0039] The lateral support panel 201 is wedge-shaped, with a pointed end and an angle of generally 15°. By reducing the contact area, the pressure on the soil is increased, allowing it to enter the soil more smoothly. The movement of the lateral support panel 201 in the soil is achieved by a bidirectional hydraulic rod support mechanism 9. The bidirectional hydraulic rod support mechanism 9 includes two push-pull panels 901, a connecting rod mechanism 903 and a first hydraulic rod 902. The two push-pull panels 901 are connected by a connecting rod mechanism 903, which is composed of a number of hinged connecting rods. The cylinder of the first hydraulic rod 902 is hinged to the push-pull panel on one side, and the end of the piston rod is hinged to a connecting rod of the connecting rod mechanism 903. When the first hydraulic rod 902 is extended or retracted, it can drive the connecting rod to move, thereby changing the overall length of the connecting rod mechanism 903, and transmitting the displacement to the vertical support panel 202 through the push-pull panel 901, thereby changing the distance between the two relative vertical support panels 202. The connecting rod mechanism 903 in this embodiment adopts a single-degree-of-freedom planar connecting rod mechanism, so only one first hydraulic rod 902 needs to be provided as a power source to have a definite movement route.

[0040] A bidirectional hydraulic rod support mechanism 9 is set between the two opposite sides of the foundation pit. After the horizontal support panel 201 is placed in the preset position, the first hydraulic rod 902 pushes the connecting rod mechanism 903 to move, and the push-pull panels 901 on both sides of the connecting rod mechanism 903 are tightly attached to the vertical support panel 202, thereby driving the horizontal support panels 201 on both sides into the soil on both sides of the foundation pit.

[0041] The sidewalls of the foundation pit require several support panels 2 spliced ​​together for protection. Given the same contact area, the deeper the lateral support panels 201 are, the greater the weight of the soil. Therefore, the deeper the lateral support panels 201 are, the smaller they can be, thus reducing material consumption. Therefore, in this embodiment, support panels 2 at different depths are driven into the soil to different depths. The closer the support panels 2 are to the bottom of the foundation pit, the shorter the lateral support panels 201 are driven into the soil.

[0042] The above requirements can be met by configuring the support plate 2 as a transverse support panel 201 of different lengths, but this approach increases the complexity of construction. Therefore, a telescopic transverse support panel 201 is used in this embodiment. The transverse support panel 201 is composed of several layers of retractable and nested movable panels, all of which are hollow structures. Adjacent layers of movable panels are connected to each other via a slider and chute structure, which move in coordination via a gear rack structure, and are controlled by a second hydraulic rod 201d. Mutually cooperating sliders and chute 201c are provided on the outer walls of the opposite sides of the movable panels to allow relative displacement between the adjacent movable panels. Racks 201b are provided on the outer and inner walls of the movable panels along the telescopic direction, and a meshing gear 201a is provided between the rack 201b on the outer wall of the inner movable panel and the rack 201b on the inner wall of the outer movable panel. The cylinder end of the second hydraulic rod 201d is provided on the outermost movable panel, and the piston end passes through the intermediate interlayer movable panel and is fixed to the innermost movable panel. Taking the extension of second hydraulic rod 201d as an example, when the piston of second hydraulic rod 201d begins to move, because it is directly connected to the innermost movable panel and the two adjacent movable panels can move relative to each other, the innermost movable panel is the first to extend from transverse support panel 201. When the slider of the innermost movable panel reaches the other end of the slide groove 201c, if the piston continues to extend, the outer movable panels will continue to move outward, extending the overall length of transverse support panel 201. The same principle applies to the contraction of transverse support panel 201.

[0043] After the support is completed, the connecting bolts between the two support panels 2 can be removed, and the push-pull panel 901 of the bidirectional hydraulic rod support mechanism 9 can be fixed to the vertical support panel 202 of the support panel 2. The first hydraulic rod 902 can be activated to pull the horizontal part of the support panel 2 out of the soil. At the same time, the telescopic mechanism in the horizontal support panel 201 can be activated to retract the horizontal support panel 201.

[0044] Obviously, the above embodiments of the present invention are merely examples to more clearly illustrate the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to enumerate all implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the scope of protection of the present invention.

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 side wall of the foundation pit, 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 edge of the support plate; 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 supporting structure according to claim 1, characterized in that: The adjacent movable panels are connected to each other through 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 supporting structure according to claim 2, 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 supporting structure according to claim 1, characterized in that: The vertical support panel is provided with small holes for water permeability and reducing stress concentration, 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 inclined, and the inclination angle is 1%-2%.

6. The telescopic deep foundation pit supporting structure according to claim 1, 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 supporting structure according to claim 1, characterized in that: The vertical support panel is also provided with screw holes penetrating 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, characterized in that: 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 horizontal support panel and the vertical support panel are an integrally formed steel structure, and the corners of the common edges are rounded and reinforced.

10. The telescopic deep foundation pit supporting structure according to any one of claims 1 to 8, characterized in that: The supporting plate is L-shaped.

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