Device for actively inhibiting lateral deformation of adjacent pile group foundation under roadbed loading and implementation method of device

Abstract

The invention discloses a device for actively inhibiting lateral deformation of an adjacent pile group foundation under roadbed loading and an implementation method thereof, the device comprises at least one row of bag type anchor rods arranged in a foundation soil body under a lateral adjacent roadbed of a bearing platform foundation, the bag type anchor rods are provided with grouting solidified bags, and the bags are connected with the bearing platform foundation through the anchor rods; the bag is used for receiving vertical extrusion during subgrade settlement and driving the bag type anchor rod to move, and then active pulling force is generated on the bearing platform foundation so as to prevent the bearing platform foundation from generating lateral deformation away from the subgrade. The bag type anchor rods are specially arranged, the subgrade settlement effect is ingeniously converted into active acting force for resisting lateral deformation of the pile group bearing platform foundation, then the adverse effect of lateral extrusion force of the subgrade on the close pile group foundation is reduced, the limitation that a traditional anchor rod system can only conduct passive anchoring is broken through, and the bearing safety of the adjacent pile group foundation is guaranteed; and a new thought is provided for safety control over the bridge pile foundation close to the roadbed side in traffic road reconstruction and extension projects.

Description

Technical Field

[0001] This invention belongs to the field of highway and bridge engineering, and relates to an active suppression device for lateral deformation of near-pile foundation under roadbed surcharge and its implementation method. Background Technology

[0002] In bridge construction in areas with unfavorable geological conditions such as soft soil and silt, horizontal displacement of pile caps caused by subgrade settlement has become a major hidden danger threatening structural safety. Due to soil consolidation, groundwater fluctuations, and the long-term effects of traffic loads, the subgrade experiences continuous and uneven settlement, which exerts a significant lateral thrust on adjacent pile caps. This thrust is transmitted to the piles through soil-structure interaction, causing progressive horizontal displacement of the piles, which in turn leads to an abnormal increase in pile bending moment, cracking of the concrete cover, and even yielding of the reinforcing steel. More seriously, the additional moment generated by the displacement alters the stress state of the pile cap, causing the superstructure piers to tilt, bearings to become detached, and stress redistribution in the beams, ultimately significantly reducing the overall service life of the bridge. Summary of the Invention

[0003] Purpose of the invention: The first purpose of this invention is to address the technical problem of soil compression of pile foundations caused by roadbed settlement, and to provide an active device for suppressing lateral deformation of pile foundations in proximity under roadbed surcharge; the second purpose of this invention is to provide a method for implementing the active device for suppressing lateral deformation of pile foundations in proximity under roadbed surcharge.

[0004] Technical solution: The present invention provides an active device for suppressing lateral deformation of a pile foundation under surcharge, comprising at least one row of bladder-type anchor rods arranged in the foundation soil adjacent to the lateral subgrade of the pile cap foundation. The bladder-type anchor rods have grout-cured bladders, which are connected to the pile cap foundation through the anchor rods. The bladders are used to receive vertical compression during subgrade settlement and drive the bladder-type anchor rods to move, thereby generating active tension on the pile cap foundation to prevent the pile cap foundation from undergoing lateral deformation away from the subgrade.

[0005] Furthermore, within the width of the roadbed projection, the length of the bag located to the right of the roadbed projection centerline is greater than or equal to that to the left.

[0006] Furthermore, when the bladder-type anchor bolts are arranged in a single row, they are arranged horizontally or at a certain angle to the horizontal plane; when the bladder-type anchor bolts are arranged in multiple rows, they are arranged according to the principle that the bladder-type anchor bolts in each row do not overlap in the height direction.

[0007] Furthermore, when the bag-type anchor is arranged at a certain angle to the horizontal plane, the maximum burial depth of the end of the bag furthest from the foundation cap does not exceed the critical depth of the effective influence zone of roadbed settlement; the maximum tilt angle θ of the anchor arrangement max=arcsin[(25-h) / L], where h is the vertical height of the anchor point of the anchor rod and the foundation from the ground, and L is the length of the anchor rod.

[0008] Furthermore, multiple bladder-type anchor bolts in the same row are arranged in parallel or radial patterns within the same plane.

[0009] Furthermore, when the number of a row of bladder-type anchors is odd, a reference anchor is arranged at the central axis position extending along the length direction of the foundation, and the remaining anchors are symmetrically distributed about the reference anchor.

[0010] Furthermore, when the number of a row of bladder-type anchors is even, each anchor is arranged symmetrically about the central axis extending along the length of the foundation.

[0011] Furthermore, the anchoring points of each pocket-type anchor rod in a row are arranged at equal intervals along the connecting edge of the foundation, with a spacing of B / (N+1), where B is the width of the connecting edge and N is the number of pocket-type anchor rods in the same row.

[0012] The implementation method of the active suppression device for lateral deformation of adjacent pile foundations under surcharge load of the present invention includes the following steps:

[0013] (1) According to the arrangement of the bag-type anchor bolts, holes are drilled in sequence on the side wall of the foundation pit near the roadbed and bag-type anchor bolts are inserted, and high-pressure grouting is injected into the bag.

[0014] (2) Connect all the anchor rods to the foundation in sequence.

[0015] Furthermore, when the anchor rod is anchored to the foundation, a certain preload is applied to keep the anchor rod under tension.

[0016] Beneficial Effects: Compared with existing technologies, this invention has the following significant advantages: The core technical concept of this invention lies in actively preventing pile foundation misalignment by converting settlement potential energy into corrective force. This invention utilizes a capsule-like structure pre-embedded beneath the roadbed to transform unavoidable roadbed settlement into a reverse traction force on the pile cap foundation. When the soil settles, the settlement pressure acts on the capsule, generating vertical displacement, which is transmitted through anchor bolts to form horizontal tension, precisely offsetting the lateral earth pressure that causes pile misalignment. This mechanical conversion mechanism breaks through the lag limitations of traditional passive correction technologies. Furthermore, while maintaining the normal function of the roadbed, this invention significantly improves the long-term stability of the pile foundation system, effectively preventing chain reactions such as pile cap cracking and pier tilting caused by pile misalignment, providing an economical and reliable long-term maintenance solution for bridge engineering in soft soil areas. Attached Figure Description

[0017] Figure 1 and Figure 2This is an elevation view of the arrangement of pocket-type anchor bolts in the foundation soil adjacent to the roadbed on the side of the pier foundation in an embodiment of the present invention, wherein... Figure 1 The centrally located anchor bolts are arranged in a row. Figure 2 The central-cell anchor bolts are arranged in multiple rows;

[0018] Figure 3 and Figure 4 This is a plan view of the arrangement of pocket-type anchor bolts in the foundation soil adjacent to the roadbed on the side of the pier foundation in an embodiment of the present invention, wherein... Figure 3 The various bladder-type anchor bolts are arranged in parallel on the same plane. Figure 4 The bladder-type anchors on the same plane are arranged radially. Detailed Implementation

[0019] The invention will now be further described with reference to the accompanying drawings.

[0020] Appendix Figures 1 to 4 The accompanying figure labels are as follows:

[0021] 1. Foundation cap; 2. Burg anchor; 3. Roadbed.

[0022] like Figure 1 and Figure 2 As shown, this embodiment of the invention provides an active device for suppressing lateral deformation of a pile foundation under surcharge load. It includes a number of bladder-type anchor rods 2 installed in the foundation soil adjacent to the roadbed 3 on the side of the pile cap foundation 1. Each bladder-type anchor rod 2 has a grout-cured bladder, which is connected to the pile cap foundation 1 via the anchor rod. When the roadbed 3 settles, it vertically compresses the bladder, causing the bladder-type anchor rods 2 to move together. At this time, the bladder-type anchor rods 2 exert an active tensile force on the pile cap foundation 1, thereby preventing the pile cap foundation 1 from undergoing lateral deformation away from the roadbed 3.

[0023] In this embodiment, the horizontal projection length of the bag is within the projection width of the roadbed 3, and the length of the bag located to the right of the projection centerline of the roadbed 3 is greater than or equal to that to the left.

[0024] Depending on factors such as the height of the foundation cap, the thickness of the soft soil foundation, and the size of the surcharge, the bladder-type anchor bolts 2 can be arranged in a row, such as... Figure 1 As shown, it can also be arranged in multiple rows, such as Figure 2 As shown.

[0025] When only one row of pocket-type anchor bolts 2 is arranged, this row of pocket-type anchor bolts 2 can be arranged horizontally or at a certain angle to the horizontal plane. When multiple rows of pocket-type anchor bolts 2 are arranged, they are arranged according to the principle that the pocket-type anchor bolts 2 in each row do not cross or overlap in the height direction (i.e., different rows of pocket-type anchor bolts 2 are not coplanar). For example, a combination of horizontal and inclined arrangements can be used, or a combination of different inclination angles can be used.

[0026] When the bladder-type anchor 2 is arranged at a certain angle to the horizontal plane, spatial constraints must be met. Specifically, the maximum burial depth of the end of the bladder furthest from the foundation 1 (i.e., the rightmost control point) must not exceed 25m (this depth is the critical value of the effective influence zone of roadbed settlement); the maximum tilt angle θ of the anchor arrangement must also be considered. max Determined through geometric relationships, the specific calculation formula is θ. max =arcsin[(25-h) / L], where h is the vertical height (in meters) of the anchor point of the anchor rod to the foundation 1 from the ground, and L is the length of the anchor rod (in meters). The angle of inclination θ between the anchor rod and the horizontal plane should be ≤ θ. max .

[0027] A row of pocket-type anchor bolts 2 can be arranged in multiples on the same plane. When the number of pocket-type anchor bolts 2 in a row is odd, a reference anchor bolt is arranged at the position of the central axis extending along the length direction of the foundation 1, and the remaining anchor bolts are symmetrically distributed about the reference anchor bolt; when the number of pocket-type anchor bolts 2 in a row is even, each anchor bolt is arranged symmetrically about the central axis extending along the length direction of the foundation 1.

[0028] Multiple pocket-type anchor bolts 2 in the same row are arranged in the same plane to avoid intersection and collision. For example, they can be arranged in parallel, such as... Figure 3 As shown, it can also be arranged radially, such as... Figure 4 As shown. When the foundation width is small, it is recommended to use... Figure 3 The arrangement method, and when the foundation width is relatively wide, Figure 3 and Figure 4 Any arrangement method is acceptable.

[0029] The anchor points of each pocket-type anchor rod 2 in a row and the foundation 1 are arranged at equal intervals along the connecting edge of the foundation 1, with a spacing of B / (N+1), where B is the width of the connecting edge and N is the number of pocket-type anchor rods 2 in the same row.

[0030] This invention also provides a method for implementing the active suppression device for lateral deformation of a nearby pile group foundation under surcharge load, comprising the following steps:

[0031] (1) According to the arrangement of the bag-type anchor bolts, holes are drilled in sequence on the side wall of the foundation pit near the roadbed 3 to insert the bag-type anchor bolts 2, and high-pressure grouting is injected into the bag.

[0032] (2) Anchor all the anchor rods installed in sequence to the foundation 1. To make the anchor rods work better, apply a certain preload when anchoring the anchor rods to the foundation 1, so that the anchor rods are in a taut state.

[0033] This invention employs a unique arrangement of bladder-type anchor bolts, cleverly transforming the subgrade settlement into an active force resisting the lateral deformation of the pile foundation, thereby reducing the adverse effects of lateral subgrade compression on the adjacent pile foundation. It overcomes the limitation of traditional anchor bolt systems that can only passively anchor, ensuring the bearing safety of adjacent pile foundations and providing a new approach for the safety control of bridge pile foundations adjacent to the subgrade in traffic road reconstruction and expansion projects.

Claims

1. A device for actively suppressing lateral deformation of a nearby pile group foundation under surcharge load, characterized in that, It includes at least one row of bladder-type anchors (2) arranged in the foundation soil adjacent to the roadbed (3) on the side of the foundation (1). The bladder-type anchors (2) have grout-cured bladders, which are connected to the foundation (1) through the anchors. The bladders are used to receive the vertical compression when the roadbed (3) settles and drive the bladder-type anchors (2) to move, thereby generating an active tensile force on the foundation (1) to prevent the foundation (1) from lateral deformation away from the roadbed (3).

2. The active suppression device for lateral deformation of near-pile foundation under surcharge load as described in claim 1, characterized in that, The horizontal projection length of the bag is within the projection width of the roadbed (3), and the length of the bag located to the right of the projection centerline of the roadbed (3) is greater than or equal to that to the left.

3. The active suppression device for lateral deformation of near-pile foundation under surcharge load as described in claim 1, characterized in that, When the bladder anchors (2) are in a row, they are arranged horizontally or at a certain angle to the horizontal plane; when the bladder anchors (2) are in multiple rows, they are arranged according to the principle that the bladder anchors (2) in each row do not cross or overlap in the height direction.

4. The active suppression device for lateral deformation of near-pile foundation under surcharge load as described in claim 3, characterized in that, When the bag-type anchor (2) is arranged at a certain angle to the horizontal plane, the maximum burial depth of the end of the bag away from the foundation (1) does not exceed the critical depth of the effective influence zone of roadbed settlement; the maximum tilt angle θ of the anchor is as follows: max =arcsin[(25-h) / L], where h is the vertical height of the anchor point of the anchor rod and the foundation (1) from the ground, and L is the length of the anchor rod.

5. The active suppression device for lateral deformation of near-pile foundation under surcharge load as described in claim 1, characterized in that, Multiple bladder-type anchor bolts (2) in the same row are arranged in parallel or radial patterns in the same plane.

6. The active suppression device for lateral deformation of near-pile foundation under surcharge load as described in claim 5, characterized in that, When the number of a row of bladder anchors (2) is odd, a reference anchor is arranged at the position of the central axis extending along the length direction of the foundation (1), and the remaining anchors are symmetrically distributed about the reference anchor.

7. The active suppression device for lateral deformation of near-pile foundation under surcharge load as described in claim 5, characterized in that, When the number of a row of bladder-type anchors (2) is even, each anchor is arranged symmetrically about the central axis extending along the length of the foundation (1).

8. The active suppression device for lateral deformation of adjacent pile foundations under surcharge load according to claim 6 or 7, characterized in that, The anchor points of each of the pocket anchors (2) in a row and the foundation (1) are arranged at equal intervals along the connecting edge of the foundation (1), with a spacing of B / (N+1), where B is the width of the connecting edge and N is the number of pocket anchors (2) in the same row.

9. A method for implementing the active suppression device for lateral deformation of a nearby pile group foundation under surcharge load as described in claim 1, characterized in that, The steps include the following: (1) According to the arrangement of the bag anchor bolts, the bag anchor bolts (2) are drilled in sequence on the side wall of the foundation pit near the roadbed (3) and grout is injected into the bag under high pressure. (2) Anchor all the anchor rods installed in sequence to the foundation (1) of the pier.

10. The method for implementing the active suppression device for lateral deformation of adjacent pile foundations under surcharge load as described in claim 9, characterized in that, When the anchor rod is anchored to the foundation (1), a certain pre-tension force is applied to keep the anchor rod in a tensioned state.

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