Bonding-free anti-floating anchor rod system and monitoring method and construction method thereof

Abstract

The invention relates to an anchoring structure component in civil engineering buildings, in particular to a non-bonding anti-floating anchor rod system and a monitoring method and construction method thereof, the device comprises a lower anchoring body, a flexible anchor rod assembly, an upper anchoring mechanism and a non-bonding filling medium, and the method comprises the steps that whether the system has global abnormality or not is judged according to a deviation index; judging whether the point is a potential defect position or not according to the safety index; according to the system disclosed by the invention, pulling resistance is provided through the lower anchoring body at the bottom of the backfill soil, the flexible anchor rod assembly is separated from the backfill soil through the non-adhesive filling medium, the load sensing device and the distributed sensing optical cable are integrated, monitoring data are acquired, and the working state of the anchoring system is monitored based on the monitoring data; and meanwhile, the construction method adopts a process of backfilling layer by layer, synchronously filling a non-adhesive medium and lifting a temporary sleeve.

Description

Technical Field

[0001] The present invention relates to an anchoring structural member in a civil engineering building, and in particular to a non-bonding anti-floating anchor rod system, a monitoring method and a construction method thereof. Background Art

[0002] In modern civil engineering construction, underground or semi-underground structures such as basements, underground garages, and subway stations are becoming increasingly common. When subjected to groundwater, these structures generate significant hydrostatic buoyancy. To ensure the safety and stability of these structures, effective anti-buoyancy measures must be implemented.

[0003] Currently, anti-floating anchor rods are widely used in the engineering community to resist this upward pull. However, in areas with deep backfill, anti-floating anchor rods often need to be buried deeper to meet the required pullout resistance. Therefore, anchor rods in deep backfill areas are usually designed to be extra-long (extra-deep). However, existing construction practices anchor anti-floating anchor rods into the original soil, relying on the bond strength between the anchor rod and the original soil (old soil) to generate pullout resistance. Because these anchor rods are located in deep backfill areas, they need to be designed with a longer length to meet the required pullout resistance. Due to the deep depth of these anti-floating anchor rods, drilling and grouting are difficult, quality assurance is difficult, and the cost is high. They also consume a lot of materials, have low construction efficiency, and poor economic benefits. Summary of the Invention

[0004] The technical problem to be solved by the present invention is that the design and construction of ultra-long and ultra-deep anchor rods are difficult, the quality is difficult to ensure, and the maintenance cost is high. The purpose is to provide a non-bonded anti-floating anchor rod system, and its monitoring method and construction method, which utilizes the deadweight of backfill soil to resist floating, has no bonding between the anchor rod and the backfill, and the anchor rod hole is backfilled with sand. The construction operation is simple and the economic benefit is good.

[0005] The present invention is achieved through the following technical solutions:

[0006] A non-bonded anti-floating anchor system, comprising:

[0007] The lower anchor body is buried at the bottom of the backfill soil and is used to provide pull-out resistance by utilizing the deadweight of the backfill soil;

[0008] a flexible anchor assembly, the lower end of which is connected to the lower anchor body and the upper end of which passes through the backfill soil;

[0009] an upper anchoring mechanism connected to the upper end of the flexible anchor assembly and anchoring the flexible anchor assembly to the concrete structure to be anti-floating;

[0010] A non-bonding filling medium is filled in the gap between the flexible anchor assembly and the backfill soil, and the non-bonding filling medium is used to keep the flexible anchor assembly and the backfill soil in a non-bonding state.

[0011] Optionally, the flexible anchor rod assembly comprises a plurality of independently arranged flexible tendons, and the flexible tendon comprises:

[0012] A steel strand coated with anti-corrosion grease on the surface;

[0013] A protective sleeve sleeved on the steel strand;

[0014] A flexible sealing material filled between the steel strand and the protective sleeve.

[0015] Further comprising:

[0016] A load sensing device arranged at the upper anchoring mechanism for monitoring the anchoring force of the flexible anchor rod assembly;

[0017] A sensing optical cable arranged along the length direction of the steel strand in the flexible sealing material between the steel strand and the protective sleeve.

[0018] Optionally, the lower anchoring body comprises a reinforced concrete member embedded in the backfill soil and a bottom anchoring assembly arranged in the reinforced concrete member;

[0019] The bottom anchoring assembly comprises a lower anchoring disc, and the lower end of the flexible anchor rod assembly is fixed to the lower anchoring disc by an anchor;

[0020] The upper anchoring mechanism comprises an upper anchoring disc, and a through hole is formed in the upper anchoring disc for the flexible anchor rod assembly to pass through, and the upper end of the flexible anchor rod assembly is fixed to the upper surface of the upper anchoring disc by an anchor.

[0021] Optionally, the bottom anchoring assembly further comprises a plurality of steel tendon hooks extending downward from the lower surface of the lower anchoring disc;

[0022] The upper anchoring mechanism further comprises:

[0023] A plurality of steel legs fixedly connected to the lower surface of the upper anchoring disc and embedded in the concrete structure to be anti-floated and supported on the surface of the backfill soil;

[0024] A plurality of stiffening ribs arranged on the upper surface of the upper anchoring disc.

[0025] A monitoring method of an adhesive-free anti-floating anchor rod system, based on an adhesive-free anti-floating anchor rod system, the monitoring method comprising the following steps:

[0026] Obtaining real-time total anchoring force data of the flexible anchor rod assembly through the load sensing device;

[0027] Obtaining distributed strain data of the flexible anchor rod assembly along the length direction thereof through the sensing optical cable;

[0028] The total anchoring force data and the distributed strain data obtained in the stable state after initial tension locking of the flexible anchor rod assembly are established as a reference data set;

[0029] The tensile rod body strain force is calculated according to the real-time obtained distributed strain data in combination with the preset elastic modulus and cross-sectional area parameters of the flexible anchor rod assembly;

[0030] The deviation index of the total anchoring force data and the tensile rod body strain force is calculated, and when the deviation index exceeds a first preset threshold, it is determined that there is a global anomaly in the system;

[0031] A safety index is determined according to the real-time obtained distributed strain data and the distributed strain data in the reference data set;

[0032] If the safety index exceeds a safety preset threshold, it is determined that the point is a potential defect position.

[0033] Optionally, the safety index includes a strain variation index and a safety margin index, and the safety preset threshold includes a second preset threshold and a third preset threshold;

[0034] If the strain variation index exceeds the second preset threshold or the safety margin index exceeds the third preset threshold, it is determined that the point is a potential defect position.

[0035] Optionally, the method for determining the existence of a global anomaly includes:

[0036] By performing operation on the real-time obtained distributed strain data within a preset effective calculation interval , the tensile rod body strain force is obtained: ;

[0037] The real-time deviation index at time is calculated: ;

[0038] When the real-time deviation index continuously exceeds the first preset threshold for a preset duration , it is determined that there is a global anomaly;

[0039] Wherein:

[0040] is the current monitoring time;

[0041] is the preset elastic modulus of the flexible anchor rod assembly;

[0042] a preset cross-sectional area of the flexible anchor assembly;

[0043] a position coordinate along a length direction of the flexible anchor assembly;

[0044] a distributed strain data acquired in real time at position and time .

[0045] a real-time total anchoring force data acquired by the load sensing device;

[0046] a preset duration window for determining abnormality.

[0047] Optionally, a strain variation index is calculated: ;

[0048] a safety margin index is calculated: ;

[0049] when the strain variation index exceeds a second preset threshold , or the safety margin index exceeds a third preset threshold , the position is determined as a potential defect position;

[0050] wherein:

[0051] a position coordinate along a length direction of the flexible anchor assembly;

[0052] a current monitoring time;

[0053] a distributed strain data acquired in real time at position and time ;

[0054] a reference strain data in the reference data set at position ;

[0055] a material preset yield strain of the flexible anchor assembly;

[0056] the second preset threshold for evaluating the strain variation degree;

[0057] The third preset threshold is used for evaluating the safety state of the material.

[0058] A construction method of an adhesive-free anti-floating anchor rod system, comprising:

[0059] Bottom construction: backfilling the backfill soil to a predetermined base elevation, and setting a lower anchoring body on the backfill soil, the lower anchoring body being connected with a lower end of the flexible anchor rod assembly;

[0060] Casing setting and backfilling: setting a temporary casing on the outer periphery of the flexible anchor rod assembly, and continuing the soil backfilling around the temporary casing;

[0061] Layered filling and casing lifting: after the soil backfilling reaches a predetermined layering height, filling the adhesive-free filling medium into the temporary casing, and simultaneously lifting the temporary casing by a distance;

[0062] Repeated construction: repeatedly performing the soil backfilling, medium filling and casing lifting steps in an alternating manner until the backfill soil reaches the design elevation, and finally completely removing the temporary casing;

[0063] Top anchoring: performing tension inspection on the upper end of the flexible anchor rod assembly, and finally anchoring it on the concrete structure to be anti-floating through the upper anchoring mechanism.

[0064] Compared with the prior art, the present application has the following advantages and beneficial effects:

[0065] The system disclosed in the present application provides uplift resistance through the lower anchoring body at the bottom of the backfill soil, and keeps the flexible anchor rod assembly separated from the backfill soil through the adhesive-free filling medium, and integrates the load sensing device and the distributed sensing optical cable to obtain monitoring data and perform working state monitoring of the anchoring system based on the monitoring data; meanwhile, the construction method adopts the process of layered backfilling, synchronous filling of the adhesive-free medium and lifting of the temporary casing.

[0066] The present application utilizes the self-weight of the soil body to resist the uplift force, changes the anchoring mode of the traditional anchor rod relying on the deep stable stratum, and can shorten the length and drilling depth of the anchor rod; through the construction method of layered backfilling, synchronous medium filling and casing lifting, the adhesive-free medium is filled in the slender channel, so as to ensure the compactness and uniformity of the filling, and ensure the reliable adhesive-free working state of the anchor rod.

[0067] The present application realizes the monitoring of the service state of the anchor rod in the whole life cycle by integrating the load sensing device and the distributed sensing optical cable in the anchor rod system, and provides early warning for the structure safety. BRIEF DESCRIPTION OF DRAWINGS

[0068] The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the principles of the application. In the drawings:

[0069] Figure 1 is a structural schematic diagram of a non-bonding anti-floating anchor rod system according to the present application.

[0070] Figure 2 is a structural schematic diagram of an upper anchoring mechanism according to the present application.

[0071] Figure 3 is a top view of the upper anchoring mechanism according to the present application.

[0072] Figure 4 is a structural schematic diagram of a bottom anchoring assembly according to the present application.

[0073] Figure 5 is a flowchart of a monitoring method of a non-bonding anti-floating anchor rod system according to the present application.

[0074] Figure 6 is a flowchart of a construction method of a non-bonding anti-floating anchor rod system according to the present application.

[0075] Reference signs: 1 - lower anchoring body, 2 - flexible anchor rod assembly, 3 - upper anchoring mechanism, 4 - non-bonding filling medium, 5 - load sensing device, 6 - sensing optical cable, 7 - anchoring member, 100 - backfill soil, 101 - concrete structure to be anti-floated, 11 - reinforced concrete member, 12 - bottom anchoring assembly, 21 - flexible tendon, 31 - upper anchoring disc, 32 - steel leg, 33 - stiffening rib, 121 - lower anchoring disc, 122 - steel pulling hook. DETAILED DESCRIPTION

[0076] In order to make the objects, technical solutions and advantages of the present application clearer, further detailed description will be made to the present application in combination with the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the related content, and are not a limitation to the present application.

[0077] In addition, it also needs to be explained that only the parts related to the present application are shown in the drawings for the convenience of description.

[0078] The embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0079] Embodiment one

[0080] AsFigure 1 As shown, the present embodiment provides a non-adhesive anti-floating anchor system to transfer the buoyant force of groundwater to the anchoring structure buried at the bottom of the backfill 100 through the tension assembly, and to resist the upward force by using the self-weight of the backfill 100, thereby achieving the effect of "resisting floating with soil".

[0081] The key structures of the system are described in detail below, including the lower anchoring body 1, the flexible anchor assembly 2, the upper anchoring mechanism 3, and the non-adhesive filling medium 4.

[0082] The lower anchoring body 1 is buried at the bottom of the backfill 100 and is used to provide an upward resistance force by using the self-weight of the backfill 100; in operation, when the flexible anchor assembly 2 generates an upward force on it, the lower anchoring body 1 will form an anti-floating force due to the self-weight of the backfill 100 above it.

[0083] The lower end of the flexible anchor assembly 2 is connected to the lower anchoring body 1, and the upper end penetrates through the backfill 100 and is finally connected to the upper anchoring mechanism 3.

[0084] The upper anchoring mechanism 3 is connected to the upper end of the flexible anchor assembly 2 and anchors the flexible anchor assembly 2 to the concrete structure 101 to be resisted (such as the bottom plate of the basement); the upper end of the flexible anchor assembly 2 is fixed to the concrete structure, so that when the structure has a tendency to float upward, the upward force can be effectively transmitted to the flexible anchor assembly 2.

[0085] The non-adhesive filling medium 4 is filled in the gap between the flexible anchor assembly 2 and the backfill 100, and the non-adhesive filling medium 4 is used to maintain a non-adhesive state between the flexible anchor assembly 2 and the backfill 100. Non-adhesive means that the two components can slide freely relative to each other without transmitting shear friction, ensuring that the tensile force of the flexible anchor assembly 2 is only transmitted at the two end points, and the middle part of the rod does not have frictional force with the soil.

[0086] In order to further improve the durability and reliability of the system, the flexible anchor assembly 2 includes a plurality of independently arranged flexible tendon 21, which includes:

[0087] Steel strand, the surface of which is coated with anti-corrosion grease; the anti-corrosion grease serves as the first protective layer and plays a role in preventing rust and lubrication.

[0088] Protective sleeve, which is sleeved on the steel strand; usually made of high-density polymer material (such as HDPE), it serves as the second physical protective layer to isolate the steel strand from the external underground environment (moisture, chemicals, etc.).

[0089] Flexible sealing material, which is filled between the steel strand and the protective sleeve, is usually the same or compatible material as the anti-corrosion grease, ensuring that the steel strand is completely wrapped without any gaps.

[0090] Embodiment Two

[0091] This embodiment adds sensing components to the first embodiment to monitor the stress state and health condition of the anchor rod throughout its service life.

[0092] It also includes load sensing device 5 and sensing optical cable 6.

[0093] Load sensing device 5 is arranged at upper anchoring mechanism 3 to monitor the anchoring force of flexible anchor rod assembly 2; this position is the final force transmission node of the entire anchor rod system, and all the tensile force borne by flexible anchor rod assembly 2 is concentrated here. Therefore, by arranging load sensing device 5 here, the anchoring force borne by the entire flexible anchor rod assembly 2 can be directly measured and monitored.

[0094] Sensing optical cable 6 is arranged along the length direction of the steel strand in the flexible sealing material between the steel strand and the protective sleeve. Sensing optical cable 6 is a distributed optical fiber sensor integrated inside flexible tendon 21, specifically, it is encapsulated together with the steel strand in the flexible sealing material (such as anti-corrosion grease) between the steel strand and the external protective sleeve along the length direction of the steel strand, ensuring that sensing optical cable 6 can deform cooperatively with the steel strand and thus perceive its state changes.

[0095] In addition, the deployment method and working mode are described in detail to further optimize the cost, balance the performance and investment.

[0096] First, in terms of the deployment of sensing devices, key sampling deployment is adopted. Specifically, not every flexible tendon 21 in the project needs to be equipped with sensing optical cable 6 and load sensing device 5. According to engineering design and risk assessment, they can be laid in key flexible tendons 21, usually in the key positions of the structure with the largest design stress, complex geological conditions, or the most serious failure consequences, such as the corners of buildings, near settlement joints, etc.

[0097] Secondly, in terms of the working mode of the monitoring system, time-sharing monitoring is adopted. Under normal circumstances, load sensing device 5 and sensing optical cable 6 already embedded in the anchor rod system can not be powered on and work, and are in a "dormant" state. Only when structural safety assessment or regular maintenance is needed, technical personnel will carry portable demodulators to the site. By connecting the interface reserved at upper anchoring mechanism 3, the "dormant" sensing devices are temporarily activated to complete a monitoring, for example, once a month or once a quarter.

[0098] Embodiment Three

[0099] As Figure 2 , Figure 3 and Figure 4As shown, this embodiment, based on the first embodiment, describes in detail the structures of the lower anchoring body 1 and the upper anchoring mechanism 3.

[0100] The lower anchoring body 1 comprises: a reinforced concrete component 11 pre-buried in the backfill soil 100 and a bottom anchoring assembly 12 arranged in the reinforced concrete component 11;

[0101] The bottom anchor assembly 12 includes: a lower anchor plate 121, and the lower end of the flexible anchor rod assembly 2 is fixed to the lower anchor plate 121 through an anchor 7; the lower anchor plate 121 is usually a thick steel plate in a circular or square shape, and the lower end of the flexible anchor rod assembly 2 is fixed to the lower anchor plate 121 through an anchor 7 (referring to a fastening element such as a clip, bolt, nut, etc. for locking the cable).

[0102] In order to enhance the bonding strength between the lower anchor plate 121 and the surrounding reinforced concrete components 11, the bottom anchor assembly 12 may further include a plurality of steel bar hooks 122 extending downward from the lower surface of the lower anchor plate 121. One end of the steel bar hook 122 is welded to the lower surface of the lower anchor plate 121 or connected in other ways, and the other end is extended into and anchored in the concrete component like a steel bar, thereby providing a mechanical interlocking force to ensure that the lower anchor plate 121 and the concrete component form a solid whole, effectively preventing slippage or detachment between the two.

[0103] Correspondingly, the upper anchoring mechanism 3 includes an upper anchoring plate 31 , which is provided with a through hole for the flexible anchor rod assembly 2 to pass through. The upper end of the flexible anchor rod assembly 2 is fixed to the upper surface of the upper anchoring plate 31 by an anchor 7 .

[0104] In order to improve the bearing capacity and stability of the upper anchoring mechanism 3 , it may further include steel legs 32 and stiffening ribs 33 .

[0105] A plurality of steel legs 32 are fixedly connected to the lower surface of the upper anchor plate 31, buried in the concrete structure 101 to be de-floating, and supported on the surface of the backfill soil 100; the steel legs 32 (support legs made of H-shaped steel, I-shaped steel and other profiles) are fixedly connected to the lower surface of the upper anchor plate 31, dispersing and transferring the pressure of the upper anchor plate 31 to the concrete structure 101 to be de-floating, thereby expanding the pressure-bearing area.

[0106] A plurality of stiffening ribs 33 are provided on the upper surface of the upper anchor plate 31 , which can enhance the structural rigidity of the upper anchor plate 31 and prevent it from bending and deforming under high-strength tensile forces.

[0107] Example 4

[0108] like Figure 5As shown, the monitoring method of the provided non-adhesive anti-floating anchor rod system establishes a double-channel multi-criteria diagnostic system. Global integrity checking is used to determine whether the entire monitoring system and anchor rod system have overall abnormalities. Local defect positioning is used to check whether the anchor rod body has local abnormalities.

[0109] The key steps of the method are described in detail below.

[0110] Data acquisition and reference establishment:

[0111] Through the load sensing device 5, the real-time total anchoring force data of the flexible anchor rod assembly 2 is obtained;

[0112] Through the sensing optical cable 6, the distributed strain data of the flexible anchor rod assembly 2 along its length direction is obtained;

[0113] The total anchoring force data and the distributed strain data obtained in the stable state after the initial tension locking of the flexible anchor rod assembly 2 are established as the reference data set. The reference data set represents the healthiest state of the anchor rod.

[0114] First channel: global integrity checking.

[0115] According to the real-time obtained distributed strain data, the elastic modulus and cross-sectional area parameters of the flexible anchor rod assembly 2 are calculated.

[0116] The deviation index of the total anchoring force data and the tensile rod body strain force is calculated. When the deviation index exceeds the first preset threshold, it is determined that the system has global abnormalities.

[0117] Second channel: local defect positioning.

[0118] According to the real-time obtained distributed strain data and the distributed strain data in the reference data set, the safety index is determined. The safety index includes the strain variation index and the safety margin index,

[0119] If the safety index exceeds the safety preset threshold, the safety preset threshold includes the second preset threshold and the third preset threshold.

[0120] If the strain variation index exceeds the second preset threshold or the safety margin index exceeds the third preset threshold, it is determined that the point is a potential defect position.

[0121] The strain variation index is used to evaluate the deterioration degree of the point relative to the initial reference state, which is sensitive to progressive damage such as corrosion.

[0122] The safety margin index is used to evaluate the proximity of the current strain value of the point to the material yield limit, which is sensitive to sudden overload.

[0123] Example five

[0124] The embodiment gives specific mathematical model and quantification criteria in example four.

[0125] The method for determining the existence of global anomaly includes:

[0126] By operating the real-time acquired distributed strain data in the preset effective calculation interval , the tension rod body strain force is obtained. The purpose of the effective calculation interval is to avoid the area close to the upper and lower two ends of the anchor, and the data may be disturbed by complex stress state, and only the middle section data capable of truly reflecting the axial force of the rod body is selected for calculation.

[0127] The real-time deviation index at time is calculated. ;

[0128] In order to avoid false positives caused by instantaneous signal interference, a time window judgment mechanism is introduced. When the real-time deviation index is continuously greater than the first preset threshold for a preset duration , it is determined that there is a global anomaly.

[0129] Wherein:

[0130] is the current monitoring time;

[0131] is the preset elastic modulus of the flexible anchor rod assembly;

[0132] is the preset cross-sectional area of the flexible anchor rod assembly;

[0133] is the position coordinate along the length direction of the flexible anchor rod assembly;

[0134] is the real-time distributed strain data acquired at position and time .

[0135] is the real-time total anchoring force data acquired by the load sensing device 5;

[0136] is the preset duration window for determining anomaly.

[0137] The local defect positioning is performed by a double-criterion diagnosis model. The first criterion is to evaluate the change degree of the anchor rod body relative to its initial health state by calculating a strain variation index. The second criterion is to evaluate the proximity of the current state of the anchor rod body to the material performance limit by calculating a safety margin index.

[0138] Calculating the strain variation index

[0139] Calculating the safety margin index

[0140] When the strain variation index exceeds a second preset threshold , or the safety margin index exceeds a third preset threshold , the position is determined as a potential defect position.

[0141] wherein:

[0142] is a position coordinate along the length direction of the flexible anchor rod assembly;

[0143] is the current monitoring time;

[0144] is the distributed strain data obtained in real time at the position and the time

[0145] is the reference strain data of the reference data set at the position , and the index is very sensitive to progressive damage such as corrosion.

[0146] is a preset yield strain of the material of the flexible anchor rod assembly;

[0147] is the second preset threshold for evaluating the strain variation degree;

[0148] is the third preset threshold for evaluating the safety state of the material.

[0149] Embodiment Six

[0150] The embodiment provides a construction method of an adhesive-free anti-floating anchor rod system, and adopts a "from bottom to top and layer-by-layer synchronization" process.

[0151] Specifically, the method comprises the following steps:

[0152] ​​​​​Bottom construction: backfilling the backfill soil 100 to the predetermined base elevation, and setting the lower anchoring body 1 on the backfill soil 100, which is connected with the lower end of the flexible anchor rod assembly 2;

[0153] Casing setting and backfilling: setting a temporary casing on the outer periphery of the flexible anchor rod assembly 2, and continuing the soil backfilling around the temporary casing; the temporary casing refers to the protective pipe material temporarily used in the construction process, which provides a safe space for the internal flexible anchor rod assembly 2 in the subsequent large-area soil backfilling and compaction operation.

[0154] Layered filling and lifting casing: after the soil backfilling reaches the predetermined layering height (for example, 2-3 meters), the earthwork operation is suspended. At this time, the temporary casing is filled with non-adhesive filling medium 4 (such as sand) from the upper part, and at the same time, the temporary casing is lifted upward by a predetermined distance using lifting equipment, so that the non-adhesive filling medium 4 at the lower part can flow out smoothly from the bottom of the casing and fill around the flexible anchor rod assembly 2 under the constraint of the surrounding backfill soil 100.

[0155] Repeated construction: the steps of soil backfilling, medium filling and casing lifting are repeatedly performed in an alternating manner until the backfill soil 100 reaches the design elevation, and the temporary casing is finally completely removed; by repeatedly performing the steps of soil backfilling, medium filling and casing lifting in an alternating manner, the anchor rod system is constructed layer by layer upward as the backfill soil 100 rises until the backfill soil 100 reaches the final design elevation. At this time, the temporary casing has also been completely lifted out of the ground and finally completely removed.

[0156] Top anchoring: the upper end of the flexible anchor rod assembly 2 is tension tested and finally anchored to the concrete structure 101 to be anti-floated by the upper anchoring mechanism 3. After all backfilling and filling operations are completed, the upper concrete structure is constructed and reaches the design strength, the upper end of the flexible anchor rod assembly 2 extending from the structure is tension tested, and a predetermined prestress is applied. After the test is passed, it is locked by the upper anchoring mechanism 3 and finally anchored to the concrete structure 101 to be anti-floated, so that the entire anchor rod system enters the formal working state. In the description of the present specification, the description of the terms "one embodiment / way", "some embodiments / ways", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment / way or example are included in at least one embodiment / way or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment / way or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments / ways or examples. In addition, different embodiments / ways or examples described in the present specification and the features of different embodiments / ways or examples can be combined and combined by those skilled in the art without contradiction.

[0157] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "multiple" is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0158] Those skilled in the art should understand that the above embodiments are only for the purpose of clearly illustrating the present application, and are not intended to limit the scope of the present application. Other changes or modifications can be made on the basis of the above invention, and these changes or modifications are still within the scope of the present application.

Claims

1. A non-bonded anti-floating anchor system, characterized in that: include: A lower anchor body (1) is buried at the bottom of the backfill soil (100) and is used to provide pull-out resistance using the deadweight of the backfill soil (100); A flexible anchor rod assembly (2), the lower end of which is connected to the lower anchor body (1) and the upper end of which passes through the backfill soil (100); An upper anchoring mechanism (3) connected to the upper end of the flexible anchor rod assembly (2) and anchoring the flexible anchor rod assembly (2) to the concrete structure (101) to be resistant to floating; A non-adhesive filling medium (4) is filled in the gap between the flexible anchor rod assembly (2) and the backfill soil (100), and the non-adhesive filling medium (4) is used to maintain a non-adhesive state between the flexible anchor rod assembly (2) and the backfill soil (100).

2. The non-bonded anti-floating anchor system according to claim 1, characterized in that: The flexible anchor rod assembly (2) comprises a plurality of independently arranged flexible tendon bundles (21), wherein the flexible tendon bundles (21) comprise: Steel strands, the surface of which is coated with anti-corrosion grease; A protective sleeve, which is sleeved on the steel strand; A flexible sealing material is filled between the steel strands and the protective sleeve.

3. The non-bonded anti-floating anchor system according to claim 2, characterized in that: Also includes: A load sensing device (5) is provided at the upper anchoring mechanism (3) and is used to monitor the anchoring force of the flexible anchor rod assembly (2); A sensing optical cable (6) is arranged in the flexible sealing material between the steel strand and the protective sleeve along the length direction of the steel strand.

4. The non-bonded anti-floating anchor system according to claim 1, characterized in that: The lower anchor body (1) comprises: a reinforced concrete component (11) pre-buried in the backfill soil (100) and a bottom anchoring assembly (12) arranged in the reinforced concrete component (11); The bottom anchoring assembly (12) comprises: a lower anchoring plate (121), and the lower end of the flexible anchor rod assembly (2) is fixed to the lower anchoring plate (121) via an anchoring piece (7); The upper anchoring mechanism (3) comprises an upper anchoring plate (31) on which a through hole is provided for the flexible anchor rod assembly (2) to pass through, and the upper end of the flexible anchor rod assembly (2) is fixed to the upper surface of the upper anchoring plate (31) via an anchoring piece (7).

5. The non-bonded anti-floating anchor system according to claim 4, characterized in that: The bottom anchor assembly (12) further includes: a plurality of steel bar hooks (122) extending downward from the lower surface of the lower anchor plate (121); The upper anchoring mechanism (3) further comprises: A plurality of steel legs (32) fixedly connected to the lower surface of the upper anchor plate (31), embedded in the concrete structure (101) to be anti-floating, and supported on the surface of the backfill soil (100); A plurality of stiffening ribs (33) are provided on the upper surface of the upper anchor plate (31).

6. A monitoring method for a non-bonded anti-floating anchor system, characterized in that: Based on the non-bonded anti-floating anchor system according to claim 3, the monitoring method comprises the following steps: Obtaining real-time total anchoring force data of the flexible anchor rod assembly through the load sensing device (5); Obtaining distributed strain data of the flexible anchor assembly along its length direction through the sensing optical cable; Establishing the total anchoring force data and the distributed strain data obtained when the flexible anchor assembly is in a stable state after initial tensioning and locking as a benchmark data set; Calculating the strain force of the tie rod body based on the distributed strain data acquired in real time and in combination with the elastic modulus and cross-sectional area parameters preset for the flexible anchor assembly; Calculating a deviation index between the total anchoring force data and the strain force of the tie rod body, and determining that a global abnormality exists in the system when the deviation index exceeds a first preset threshold; determining a safety index based on the distributed strain data acquired in real time and the distributed strain data in the reference data set; If the safety index exceeds the preset safety threshold, the point is determined to be a potential defect location.

7. The monitoring method of a non-bonded anti-floating anchor system according to claim 6, characterized in that: The safety index includes a strain variation index and a safety margin index, and the safety preset threshold includes a second preset threshold and a third preset threshold; If the strain variation index exceeds the second preset threshold or the safety margin index exceeds the third preset threshold, the point is determined to be a potential defect location.

8. The monitoring method of a non-bonded anti-floating anchor system according to claim 6, characterized in that: Methods for determining the presence of global anomalies include: By setting the preset effective calculation interval The distributed strain data acquired in real time is calculated to obtain the strain force of the tie rod body. : ; Calculation in time Real-time deviation index : ; When the real-time deviation index Continuously for a preset duration within the period, and continuously exceeds the first preset threshold When , it is determined that there is a global anomaly; in: is the current monitoring time; is a preset elastic modulus of the flexible anchor assembly; is a preset cross-sectional area of ​​the flexible anchor assembly; is the position coordinate along the length direction of the flexible anchor assembly; For the location and time Distributed strain data acquired in real time; The real-time total anchoring force data is obtained by the load sensing device (5); It is a preset duration window used to determine anomalies.

9. The monitoring method of a non-bonded anti-floating anchor system according to claim 7, characterized in that: Calculate the strain variation index : ; Calculate the safety margin index : ; When the strain variation index Exceeds the second preset threshold , or the safety margin index Exceeds the third preset threshold When the position Determined as a potential defect location; in: is the position coordinate along the length direction of the flexible anchor assembly; is the current monitoring time; For the location and time Distributed strain data acquired in real time; For benchmark data set in location Baseline strain data; Presetting a yield strain for the material of the flexible anchor assembly; is the second preset threshold, used to evaluate the degree of strain variation; It is the third preset threshold value, which is used to evaluate the safety status of the material.

10. A construction method for a non-bonded anti-floating anchor system, characterized in that: Based on the non-bonded anti-floating anchor system according to claim 3, the construction method includes: Bottom construction: backfilling the backfill soil (100) to a predetermined base elevation, and setting a lower anchor body (1) on the backfill soil (100), wherein the lower anchor body (1) is connected to the lower end of the flexible anchor rod assembly (2); Casing installation and backfilling: a temporary casing is installed on the outer periphery of the flexible anchor rod assembly (2), and soil backfilling is continued around the temporary casing; Layered filling and casing lifting: After the soil backfill reaches a predetermined layer height, a non-adhesive filling medium (4) is filled into the temporary casing, and the temporary casing is simultaneously lifted upward for a certain distance; Repeated construction: Repeat the steps of soil backfilling, medium filling and casing lifting in an alternating manner until the backfill soil (100) reaches the design elevation and the temporary casing is finally completely removed; Top anchoring: The upper end of the flexible anchor rod assembly (2) is tensioned and tested, and finally anchored to the concrete structure (101) to be anti-floating through the upper anchoring mechanism (3).

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