A foundation pit reinforced concrete support structure

Abstract

The application relates to a foundation pit reinforced concrete support structure arranged in a groove of a surrounding purlin to provide support for a lateral surrounding ground wall, which comprises a jack, two first wedge blocks and two second wedge blocks, the bottom surface of the first wedge block is in contact with the bottom surface of the groove, the two first wedge blocks are oppositely arranged, and the jack is installed between the opposite surfaces of the two first wedge blocks; the inclined surface of the first wedge block is located above and is inclined to the obliquely lower side from the middle part of the groove; the inclined surface of the second wedge block is in contact with the inclined surface of the first wedge block, and the side surface of the second wedge block is in contact with the side wall of the groove; and the top surface of the second wedge block is in contact with the surrounding ground wall. The application realizes the effect of generating large-tonnage supporting force by small-tonnage jacks based on the small-angle wedge block principle, meets the small-displacement target, and realizes the limited active loading between the reinforced concrete support and the surrounding ground wall.

Description

Technical Field

[0001] This invention relates to the field of foundation pit support engineering, and more particularly to a reinforced concrete support structure for foundation pits. Background Technology

[0002] The foundation pit support system includes reinforced concrete supports and steel supports. The former has the characteristics of high stiffness, high bearing capacity and simple structure, but it needs to be dismantled and broken one by one during the construction of the basement structure and cannot be reused. The latter has the characteristics of high reusability and flexible layout, but compared with reinforced concrete supports, it has disadvantages such as low stiffness, low stability and complex node structure.

[0003] The reinforced concrete support system for foundation pits is generally a passive loading mode. That is, after the support is formed and reaches its strength, the reinforced concrete support is passively loaded when the retaining structure deforms into the pit. Once the deformation of the retaining structure is too large, the deformation of the retaining structure cannot be controlled by the reinforced concrete support.

[0004] Chinese patent application number 202121654653.3 and publication number CN 215857743U discloses an automatically adjustable deformation reinforced concrete support structure. This structure uses large-tonnage jacks installed on the walers between the reinforced concrete internal support and the retaining wall to adjust the supporting force of the reinforced concrete internal support on the retaining wall, introducing adjustable internal forces into the reinforced concrete support system of the foundation pit. This structure can reduce the deformation of the retaining wall into the pit. However, due to the large load between the walers and the retaining wall, a sufficient number of large-tonnage jacks are required to achieve the desired effect. Furthermore, concentrated loading by a single large-tonnage jack may cause cracking in the retaining wall or waler beam due to stress concentration. Summary of the Invention

[0005] This invention provides a reinforced concrete support structure for foundation pits to solve the above-mentioned technical problems.

[0006] To address the aforementioned technical problems, this invention provides a reinforced concrete support structure for foundation pits, installed within the groove of the waler to provide support for the lateral retaining walls. The structure includes jacks, two first wedge blocks, and two second wedge blocks.

[0007] The bottom surface of the first wedge block contacts the bottom surface of the groove, the two first wedge blocks are arranged opposite each other, and the jack is installed between the opposite surfaces of the two first wedge blocks; the inclined surface of the first wedge block is located on top and slopes downward from the middle of the groove;

[0008] The inclined surface of the second wedge is in contact with the inclined surface of the first wedge, and the side surface of the second wedge is in contact with the side wall of the groove; the top surface of the second wedge is in contact with the retaining wall.

[0009] Preferably, the inclination angle θ of the inclined surfaces of the second wedge and the first wedge is 5° to 30°.

[0010] Preferably, when the jack is activated, the second wedge block provides a load amplification factor of β to the retaining wall. F The supporting force; when the jack is displaced horizontally, the displacement amplification factor of the second wedge block is β. d The out-of-plane normal displacement of the enclosure structure, wherein:

[0011]

[0012]

[0013] In the formula, F is the pressure provided by the jack; N is the supporting force of the second wedge block on the retaining wall; δ h The displacement is half of the horizontal displacement of the jack; δ v This represents the vertical displacement of the second wedge block.

[0014] Preferably, the jack is a hydraulic jack.

[0015] Preferably, a lubricating layer is provided between the bottom surface of the first wedge block and the bottom surface of the groove, between the inclined surface of the second wedge block and the inclined surface of the first wedge block, and between the side surface of the second wedge block and the side wall of the groove.

[0016] Preferably, the lubricating layer is made of PTFE sheet.

[0017] Preferably, the reinforced concrete support structure of the foundation pit is an axisymmetric structure, and the two first wedge blocks are made of the same material and have the same specifications; the two second wedge blocks are made of the same material and have the same specifications.

[0018] Preferably, the first wedge block and the second wedge block form a wedge loading structure, and the horizontal center line of the wedge loading structure coincides with the horizontal center line of the waler.

[0019] Compared with the prior art, the reinforced concrete support structure for foundation pits provided by the present invention has the following advantages:

[0020] 1. This invention is based on the principle of small-angle wedge blocks, which transforms the pressure generated by small-tonnage jacks into large-tonnage supporting force, thereby actively and disperses the load on the retaining wall. It makes full use of the high bearing capacity of concrete support to achieve limited active loading on the retaining wall and reduce the deformation of the retaining wall into the pit. It avoids stress concentration caused by directly applying large-tonnage concentrated loading at a single point between the waler and the retaining wall.

[0021] 2. This invention achieves distributed loading of two large tonnage loads by symmetrical wedge block arrangement, thereby reducing the level of load concentration. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the reinforced concrete support structure for the foundation pit in a specific embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the mechanical model of the reinforced concrete support structure for the foundation pit in a specific embodiment of the present invention;

[0024] Figure 3 This is a curve showing the change of load amplification factor with the inclination angle θ of the inclined plane in a specific embodiment of the present invention.

[0025] Figure 4 This is a curve showing the change of displacement amplification factor with the inclination angle θ of the inclined plane in a specific embodiment of the present invention;

[0026] Figure 5 This is a schematic diagram of the layout of the reinforced concrete support structure for the foundation pit in a specific embodiment of the present invention;

[0027] Figure 6 for Figure 5 Schematic diagram of AA section.

[0028] In the diagram: 01-Wallet, 02-Groove, 03-Retaining wall, 04-Concrete support in the pit, 05-Horizontal centerline; 10-Jack, 20-First wedge block, 30-Second wedge block, 40-Lubricating layer. Detailed Implementation

[0029] To illustrate the technical solutions of the invention in more detail, specific embodiments are listed below to demonstrate the technical effects; it should be emphasized that these embodiments are used to illustrate the invention and are not intended to limit the scope of the invention.

[0030] The reinforced concrete support structure for foundation pits provided by this invention, such as Figures 1 to 6 As shown, the groove 02, located within the waler 01, provides support for the lateral retaining wall 03. In some embodiments, please refer to [the relevant documentation]. Figure 5Multiple reinforced concrete support structures for the foundation pit can be set up according to the specifications and weight of the upper retaining wall 03, so as to provide uniform and effective support for the retaining wall 03.

[0031] Please refer to this carefully. Figure 1 The reinforced concrete support structure for the foundation pit includes a jack 10, two first wedge blocks 20, and two second wedge blocks 30. The bottom surface of the first wedge block 20 contacts the bottom surface of the groove 02. The two first wedge blocks 20 are arranged opposite each other, and the jack 10 is installed between the opposite surfaces of the two first wedge blocks 20. The inclined surface of the first wedge block 20 is located at the top and slopes downward from the middle of the groove 02. The inclined surface of the second wedge block 30 contacts the inclined surface of the first wedge block 20, and the side surface of the second wedge block 20 contacts the side wall of the groove 02. The top surface of the second wedge block 30 contacts the retaining wall 03.

[0032] This invention utilizes two sets of matching small-angle wedge blocks (the first wedge block 20 and the second wedge block 30 located on the same side form a set) to achieve the effect of a single small-tonnage jack 10 generating two large-tonnage support forces, thereby actively applying loads to the retaining wall 03, making full use of the high bearing capacity of concrete supports, reducing the deformation of the retaining wall 03 into the pit; and avoiding stress concentration caused by directly applying large-tonnage concentrated loading at a single point between the waler 01 and the retaining wall 03.

[0033] In some embodiments, please refer to the following: Figures 2 to 4 The inclination angle θ of the inclined surfaces of the second wedge block 30 and the first wedge block 20 is 5° to 30°, so that the load and displacement provided by the jack 10 can be smoothly transmitted to the first wedge block 20 and the second wedge block 30.

[0034] In some embodiments, please refer to Figure 2 When the jack 10 is activated, the second wedge block 30 provides the retaining wall 03 with a load amplification factor of β. F The supporting force; when the jack 10 is displaced horizontally, the displacement amplification factor of the second wedge block 30 is β. d The out-of-plane normal displacement of the enclosure structure, wherein:

[0035]

[0036]

[0037] In the formula, F is the pressure provided by the jack 10; N is the supporting force of the second wedge block 30 on the retaining wall 03; δ h The displacement is half of the horizontal displacement of the jack 10; δ vThis represents the vertical displacement of the second wedge block 30.

[0038] From the above equations (1) and (2) and Figure 3 and Figure 4 It can be seen that the load amplification factor β F The tilt angle θ of the inclined surfaces of the second wedge block 30 and the first wedge block 20 is negatively correlated, while the displacement amplification factor β d The inclination angle θ of the inclined surfaces of the second wedge block 30 and the first wedge block 20 is positively correlated. During application, the appropriate angle θ can be selected according to specific needs.

[0039] In some embodiments, the jack 10 can be a hydraulic jack, which has the characteristics of compact structure, stable operation, large supporting force, and self-locking.

[0040] In some embodiments, please refer to the following: Figure 1 A lubrication layer 40 is provided between the bottom surface of the first wedge block 20 and the bottom surface of the groove 02, between the inclined surface of the second wedge block 30 and the inclined surface of the first wedge block 20, and between the side surface of the second wedge block 30 and the side wall of the groove 02, to reduce friction between the contact surfaces. In some embodiments, the lubrication layer 40 may be made of PTFE sheet (or coated with grease), or other lubrication methods may be used as long as they do not affect the mutual sliding of the contact surfaces.

[0041] In some embodiments, please refer to the following: Figure 1 and Figure 5 The reinforced concrete support structure of the foundation pit is an axisymmetric structure. The two first wedge blocks 20 are made of the same material and have the same specifications. The two second wedge blocks 30 are made of the same material and have the same specifications. This ensures that the load and displacement generated by the jack 10 can be evenly distributed to the two sets of small-angle wedge blocks on both sides, avoiding problems such as uneven force or inconsistent displacement on both sides leading to structural instability.

[0042] In some embodiments, please refer to the following: Figure 6 The first wedge block 20 and the second wedge block 30 form a wedge loading structure. The horizontal center line of the wedge loading structure coincides with the horizontal center line of the waler 01, further ensuring that the structure is subjected to uniform and stable forces.

[0043] In summary, the reinforced concrete support structure for the foundation pit provided by the present invention is installed in the groove 02 of the waler 01 to provide support for the lateral retaining wall 03. It includes a jack 10, two first wedge blocks 20, and two second wedge blocks 30. The bottom surface of the first wedge block 20 contacts the bottom surface of the groove 02. The two first wedge blocks 20 are arranged opposite each other, and the jack 10 is installed between the opposite surfaces of the two first wedge blocks 20. The inclined surface of the first wedge block 20 is located at the top and slopes downwards from the middle of the groove 02. The inclined surface of the second wedge block 30 contacts the inclined surface of the first wedge block 20, and the side surface of the second wedge block 20 contacts the side wall of the groove 02. The top surface of the second wedge block 30 contacts the retaining wall 03. This invention utilizes two sets of matching small-angle wedge blocks to achieve the effect of a single small-tonnage jack 10 generating two large-tonnage support forces, thereby actively applying loads to the retaining wall 03, making full use of the high bearing capacity of concrete support, and reducing the deformation of the retaining wall 03 into the pit; this invention can also avoid stress concentration caused by directly applying large-tonnage concentrated loading at a single point between the waler 01 and the retaining wall 03.

[0044] Obviously, those skilled in the art can make various modifications and variations to the invention without departing from the spirit and scope of the invention. Therefore, if these modifications and variations fall within the scope of the claims of the invention and their equivalents, the invention is also intended to include these modifications and variations.

Claims

1. A reinforced concrete support structure for a foundation pit, disposed within a groove in the waler, providing support for the lateral retaining walls, characterized in that, Includes a jack, two first wedge blocks, and two second wedge blocks. The bottom surface of the first wedge block contacts the bottom surface of the groove, the two first wedge blocks are arranged opposite each other, and the jack is installed between the opposite surfaces of the two first wedge blocks; the inclined surface of the first wedge block is located on top and slopes downward from the middle of the groove; The inclined surface of each second wedge block contacts the inclined surface of the corresponding first wedge block, and the side surface of the second wedge block contacts the side wall of the groove; the top surface of the second wedge block contacts the retaining wall. A lubricating layer is provided between the bottom surface of the first wedge block and the bottom surface of the groove, between the inclined surface of the second wedge block and the inclined surface of the first wedge block, and between the side surface of the second wedge block and the side wall of the groove; The reinforced concrete support structure of the foundation pit is an axisymmetric structure, and the two first wedge blocks are made of the same material and have the same specifications; the two second wedge blocks are made of the same material and have the same specifications. The first wedge block and the second wedge block form a wedge loading structure, and the horizontal center line of the wedge loading structure coincides with the horizontal center line of the waler; When the jack is activated, the second wedge provides a load amplification factor to the retaining wall. β F The supporting force; when the jack moves horizontally, the displacement amplification factor of the second wedge block is... β d The out-of-plane normal displacement of the enclosure structure, wherein: In the formula, F is the pressure provided by the jack; N is the supporting force of the second wedge block on the retaining wall; δ h This is half of the horizontal displacement of the jack. δ v This represents the vertical displacement of the second wedge block.

2. The reinforced concrete support structure for the foundation pit as described in claim 1, characterized in that, Inclination angles of the inclined surfaces of the second wedge and the first wedge θ The range is 5° to 30°.

3. The reinforced concrete support structure for the foundation pit as described in claim 1, characterized in that, The jack is a hydraulic jack.

4. The reinforced concrete support structure for the foundation pit as described in claim 1, characterized in that, The lubricating layer is made of PTFE sheet.

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