Anti-pulling tower foundation in desert area and reliability evaluation method

Abstract

The invention belongs to the technical field of pole and tower foundations, and particularly relates to a desert area anti-pulling pole and tower foundation and a reliability evaluation method.In the desert area anti-pulling pole and tower foundation, a sliding hinge support is arranged at the bottom of a pole and tower independent foundation, a plurality of sliding grooves are formed in the bottom of the sliding hinge support, and a plurality of sliding blocks capable of sliding along the sliding grooves are arranged in the sliding grooves; the sliding block is hinged to the top of the one-way stress anchor rod, and a pressure stress sensor is arranged at the bottom of the one-way stress anchor rod and used for monitoring pressure stress of the anchor rod in real time. By additionally arranging the sliding hinged support, stress concentration can be relieved, the foundation stability is improved, the anchor rod can be prevented from being subjected to extra shear stress, and the service life of the anchor rod is prolonged; in the reliability evaluation method, a simulation model of the overall structure of the tower is constructed, the hemispherical stress safety coefficient is calculated by combining a model test result and an actual monitoring result and used for judging whether the overall structure of the tower exceeds the limit or not, and the calculation mode better conforms to the actual stress change state of the overall structure of the tower and is real and reliable.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of tower foundation, and particularly relates to a desert region uplift-resistant tower foundation and a reliability evaluation method. BACKGROUND

[0002] The soil in the desert region is mainly composed of loose materials such as sandy soil, gravel and clay. The soil compactness is low, the bearing capacity is poor, and due to frequent drought and sandstorm weather, the soil has poor uplift resistance and is easily affected by external loads such as wind, resulting in problems such as uplift or settlement of traditional foundations. In the desert region, conventional foundation types such as strip foundations and independent foundations often fail to fully consider the need for uplift resistance, and under the influence of external loads such as wind, traditional foundations are easily affected by problems such as uplift or tilting, thereby affecting the safety and reliability of the entire tower structure. In summary, the special environment in the desert region puts high requirements on the uplift capacity of the foundation and the reliable evaluation of the structural stability.

[0003] The document "Analysis of the Influence of External Loads on the Root Pile Foundation of a Transmission Line Tower", by the author Zhong Weijun, proposes a root pile foundation suitable for soft soil foundations and analyzes the design rationality and ability to withstand external loads of the root pile foundation in soft soil foundations through finite element analysis. The invention patent with application number 201910747418.1 provides a root system biomimetic foundation and construction method. The pile foundation includes a pile body part and a root system biomimetic structure. For different hydrogeological conditions and soil layering conditions, the position, cross-sectional size and length of the root system biomimetic structure in the pile body are adjusted to obtain a targeted root system biomimetic structure design scheme, thereby solving problems such as single pile settlement, connection failure between pile cap and pile, and soil body lateral displacement damage of traditional pile foundations during earthquakes. The utility model patent with application number 202222219785.4 provides an anti-pull intelligent positioning electronic pile for a power transmission line based on narrowband Internet of Things. The anti-pull flexible barb part includes a pile body and at least two anti-pull flexible barbs. The pile body is perpendicular to the installation surface, and the anti-pull flexible barbs form an angle with the pile body, making it difficult for the pile body to be pulled out. However, the above methods have the following problems:

[0004] 1. Although the root system biomimetic structure or anti-pull flexible barb can provide a certain uplift resistance, it cannot alleviate the stress concentration leading to the settlement of the sand layer, and it also destroys the structure of the sand layer, making it difficult for the foundation to share the uplift resistance with the sand layer, resulting in weak uplift resistance.

[0005] 2. The finite element analysis simulates the stress changes of the pile body under external loads, which is a purely theoretical static analysis method, making it difficult for the evaluation results to match the actual construction and foundation use conditions, and also unable to monitor the real stress changes of the foundation during uplift. SUMMARY

[0006] The purpose of this invention is to address the aforementioned problems in the existing technology by providing a method for assessing the reliability of anti-uplift tower foundations in desert areas, which can alleviate stress concentration, improve foundation stability, prevent anchor bolts from being subjected to additional shear stress, and extend the service life of anchor bolts.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows:

[0008] In a first aspect, the present invention provides a pull-out resistant tower foundation for desert areas, including an independent tower foundation and multiple unidirectional stress anchors;

[0009] The bottom of the independent foundation of the tower is provided with a sliding hinge support. The bottom of the sliding hinge support is provided with multiple sliding grooves. Multiple sliders that can slide along the sliding grooves are provided inside the sliding grooves. The sliders are hinged to the top of the uniaxial stress anchor rod. The bottom of the uniaxial stress anchor rod is provided with a compressive stress sensor. The compressive stress sensor is used to monitor the compressive stress transmitted by the uniaxial stress anchor rod in real time.

[0010] Preferably, the uniaxial stress anchor bolt includes an anchor bolt sleeve, an anchor bolt force transmission shaft, multiple hollow barbs, and a retaining ring. The anchor bolt force transmission shaft passes through the anchor bolt sleeve, with its top hinged to a slider and its bottom connected to a pressure stress sensor. The multiple hollow barbs are located on the anchor bolt sleeve, and the retaining ring is located on the anchor bolt force transmission shaft and abuts against the bottom of the anchor bolt sleeve to prevent the anchor bolt sleeve from detaching from the anchor bolt force transmission shaft.

[0011] Preferably, the anchor sleeve includes a hollow inner cylinder and a hollow outer cylinder arranged coaxially. The side wall of the hollow outer cylinder is fixedly connected to the bottom end of the hollow barb. The gap between the hollow outer cylinder and the hollow inner cylinder is connected to the interior of the hollow barb. A sand consolidation liquid injection port is opened at the top of the hollow outer cylinder, and multiple sand consolidation liquid spray ports are opened on the hollow barb.

[0012] Preferably, the bottom of the sliding hinge support is a hemispherical structure, and the sliding groove is an arc-shaped groove.

[0013] Preferably, the angle between the hollow barb and the anchor sleeve is an acute angle.

[0014] Preferably, the hollow barbs are integrally formed with the anchor bolt sleeve.

[0015] Secondly, the present invention provides a reliability assessment method for anti-uplift tower foundations in desert areas. The reliability assessment method is based on the aforementioned anti-uplift tower foundations in desert areas and includes:

[0016] S1, for the tower overall structure based on the uplift tower foundation construction in the desert area to be evaluated, a simulation model is made according to the preset similarity ratio, and the simulation model is fixed in a test pit, wherein the test pit is obtained by layering and tamping the sand soil in the area where the uplift tower foundation in the desert area to be evaluated is located;

[0017] S2, the initial compressive stress of each compressive stress sensor is obtained, and then the simulation model is subjected to limit test to obtain the limit compressive stress of each compressive stress sensor; the initial compressive stress and the limit compressive stress of each compressive stress sensor are converted into equivalent initial compressive stress and equivalent limit compressive stress based on the similarity ratio;

[0018] S3, the normalized stress utilization of each compressive stress sensor is calculated based on the equivalent initial compressive stress and the equivalent limit compressive stress of each compressive stress sensor, and the current compressive stress of each compressive stress sensor obtained by the uplift tower foundation in the desert area to be evaluated; the calculation formula of the normalized stress utilization is:

[0019] ;

[0020] In the above formula, is the normalized stress utilization of the ith compressive stress sensor; 、 、 respectively, the equivalent initial compressive stress, the equivalent limit compressive stress and the current compressive stress of the ith compressive stress sensor;

[0021] Then, the hemispherical stress safety factor is calculated based on the normalized stress utilization of each compressive stress sensor; the calculation formula of the hemispherical stress safety factor is:

[0022] ;

[0023] In the above formula, is the hemispherical stress safety factor; is the number of compressive stress sensors;

[0024] S4, the reliability evaluation of the uplift tower foundation in the desert area is realized based on the hemispherical stress safety factor.

[0025] Preferably, the reliability evaluation of the uplift tower foundation in the desert area based on the hemispherical stress safety factor comprises:

[0026] It is judged whether the hemispherical stress safety factor is less than 0, if yes, it indicates that the uplift tower foundation in the desert area has exceeded the limit and entered the instability zone, otherwise it indicates that the uplift tower foundation in the desert area still has a safety margin.

[0027] Preferably, the limit test on the simulation model to obtain the limit compressive stress of each compressive stress sensor comprises:

[0028] The simulation model is subjected to hierarchical or uniform loading in the wind load direction, and the stress changes of the pressure stress sensors and the test pit conditions during the loading process are recorded; the wind load direction of the simulation model corresponds to the actual wind load direction of the uplift tower foundation in the desert area;

[0029] When the following conditions are met at the same time, it is judged that the model has exceeded the limit, and the pressure stress of each pressure stress sensor at this time is taken as the corresponding limit pressure stress:

[0030] Condition one: the stress change of the pressure stress sensor changes from stable rise to obvious platform or sudden drop, and the change is not restored after continuous loading;

[0031] Condition two: the test pit condition is that the ground surface is slightly bulged, the local sand soil is loosened or cracked.

[0032] Preferably, the initial pressure stress and the limit pressure stress of each pressure stress sensor are converted into equivalent initial pressure stress and equivalent limit pressure stress based on the similarity ratio, which comprises: multiplying the initial pressure stress and the limit pressure stress of each pressure stress sensor by the similarity ratio respectively to obtain the equivalent initial pressure stress and the equivalent limit pressure stress, and the similarity ratio , wherein , are the geometric sizes of the uplift tower foundation in the desert area and the simulation model respectively.

[0033] Compared with the prior art, the beneficial effects of the present application are:

[0034] 1. In the uplift tower foundation in the desert area, a sliding hinge support is additionally arranged at the bottom of the tower independent foundation, which allows a small rotation between the lower sliding hinge support and the root-shaped anchoring system formed by a plurality of one-way stress anchor rods when subjected to wind load, so that the pressure at the bottom of the tower independent foundation is redistributed, thereby relieving the stress concentration problem and avoiding the destruction of stability due to excessive local stress; at the same time, since the one-way stress anchor rod does not rotate with the rotation of the tower independent foundation, the additional load borne by the one-way stress anchor rod is reduced, ensuring that the one-way stress anchor rod can effectively play the uplift effect and increasing the service life of the anchor rod.

[0035] 2. In the uplift tower foundation in the desert area, the hollow barb is connected with the anchor rod sleeve, which can inject sand soil consolidation liquid into the sand soil around the hollow barb through the catheter after the anchor rod is installed, form a consolidation layer around the hollow barb through the mechanical interlocking force provided by the hollow barb itself and active reinforcement, so that the barb and the sand soil jointly bear the uplift force through the consolidation layer, thereby improving the overall uplift performance, and is particularly suitable for use in loose strata such as deserts and aeolian sand.

[0036] 3. The reliability evaluation method of the anti-pulling tower foundation in the desert area, the model test result and the actual monitoring result are combined, the semi-spherical stress safety factor of the tower overall structure based on the anti-pulling tower foundation construction in the desert area is calculated, and whether the tower overall structure is out of limit is judged, and the calculation method is more reliable than the traditional finite element simulation calculation, and is more in line with the actual stress change state of the tower overall structure under the natural working condition. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 It is a structural schematic diagram of the anti-pulling tower foundation in the desert area.

[0038] Figure 2 It is a structural schematic diagram of the anti-pulling tower foundation in the desert area. Figure 1

[0039] Figure 3 It is an assembly schematic diagram of the single-way stress anchor and the sliding hinge support. Figure 1

[0040] Figure 4 It is a simulation model structure diagram prepared by the reliability evaluation method.

[0041] In the drawing, the tower independent foundation 1, the single-way stress anchor 2, the anchor sleeve 21, the hollow inner cylinder 211, the hollow outer cylinder 212, the anchor force transmission shaft 22, the hollow barb 23, the clamping ring 24, the sliding hinge support 3, the sliding groove 31, the sliding block 32, and the compressive stress sensor 4 are shown. DETAILED DESCRIPTION

[0042] The application will be further described in detail below in combination with specific embodiments and drawings.

[0043] Referring to Figure 1 , the application provides an anti-pulling tower foundation in a desert area, which comprises a tower independent foundation 1 and a plurality of single-way stress anchors 2, the bottom of the tower independent foundation 1 is provided with a sliding hinge support 3, the bottom of the sliding hinge support 3 is provided with a plurality of sliding grooves 31, the sliding grooves 31 are internally provided with a plurality of sliding blocks 32 which can slide along the sliding grooves 31, the sliding blocks 32 are hingedly connected to the top of the single-way stress anchors 2, the bottom of the single-way stress anchors 2 is provided with a compressive stress sensor 4, and the compressive stress sensor 4 is used for monitoring the compressive stress transmitted by the single-way stress anchors 2 in real time.

[0044] ​​When the lateral wind comes, the overall structure of the tower will rotate slightly with the tower independent foundation 1 as the center of rotation, the application adds a sliding hinge support 3 at the bottom of the tower independent foundation 1, when the wind load acts, the sliding hinge support 3 below is allowed to rotate slightly with the root-shaped anchoring system formed by the plurality of one-way stress anchor rods 2, at this time the bottom pressure of the tower independent foundation 1 will be redistributed, thereby relieving the stress concentration problem, avoiding the problem of sand layer subsidence caused by local excessive stress and stability damage. At the same time, the one-way stress anchor rod 2 will not be damaged by bearing a large shear force due to the rotation of the tower independent foundation 1, reducing the additional load required to be borne by the one-way stress anchor rod 2, ensuring that the one-way stress anchor rod 2 can effectively play the anti-pulling effect, and increasing the service life of the anchor rod. After unloading, the overall structure of the tower will return to the working interval close to the middle under the combined action of the self-weight, the foundation / ground elastic rebound and the symmetrical friction.

[0045] In another embodiment, referring to Figure 2 , the one-way stress anchor rod 2 comprises an anchor rod sleeve 21, an anchor rod force transmission shaft 22, a plurality of hollow barbs 23, and a snap ring 24, the anchor rod force transmission shaft 22 is arranged in the anchor rod sleeve 21, the top of the anchor rod force transmission shaft 22 is hingedly connected with the sliding block 32, the bottom of the anchor rod force transmission shaft 22 is connected with the compressive stress sensor 4, the plurality of hollow barbs 23 are arranged on the anchor rod sleeve 21, and the snap ring 24 is arranged on the anchor rod force transmission shaft 22 and abuts against the bottom of the anchor rod sleeve 21, so as to prevent the anchor rod sleeve 21 from being separated from the anchor rod force transmission shaft 22.

[0046] The hollow barbs 23 are distributed on the one-way stress anchor rod 2 in a tree root structure, when a slight rotation occurs, the anchor rod sleeve 21 is abutted by the snap ring 24 on the anchor rod force transmission shaft 22, so that the hollow barbs 23 provide a large amount of anti-pulling force; and the anchor rod sleeve 21 and the anchor rod force transmission shaft 22 are arranged separately, only providing anti-pulling force for the tower independent foundation 1, and not providing anti-pressure, so that the position of the anchor rod sleeve 21 and the hollow barbs 23 in the soil layer is not easily changed by the pressure caused by the load.

[0047] In another embodiment, referring to Figure 3 , the anchor rod sleeve 21 comprises a hollow inner cylinder 211 and a hollow outer cylinder 212 arranged coaxially, the side wall of the hollow outer cylinder 212 is fixedly connected with the bottom end of the hollow barb 23, the gap between the hollow outer cylinder 212 and the hollow inner cylinder 211 is communicated with the inside of the hollow barb 23, the top end of the hollow outer cylinder 212 is provided with a sand soil consolidation liquid injection port, and the hollow barb 23 is provided with a plurality of sand soil consolidation liquid injection ports.

[0048] A consolidated layer is formed around the hollow barb 23 by injecting a sand soil consolidation liquid under high pressure, and the loose porous sand soil is converted into a consolidated layer by active reinforcement, so that the hollow barb 23 can bear the uplift force together with the sand soil layer through the consolidated layer, which not only effectively enhances the foundation uplift resistance, but also significantly improves the overall stability, and is particularly suitable for use in desert, aeolian sand and other loose strata.

[0049] In another embodiment, the bottom of the sliding hinge support 3 is a hemispherical structure, and the sliding groove 31 is an arc-shaped groove.

[0050] By designing the bottom of the sliding hinge support 3 as a hemispherical structure, the layout area of the one-way stress anchor rod 2 can be increased, and the arc-shaped sliding groove 31 is distributed along the hemispherical surface of the bottom of the sliding hinge support 3, and the arc line is concentric with the hemispherical surface, and the sliding block 32 can slide along the arc line in the sliding groove 31.

[0051] In another embodiment, the included angle between the hollow barb 23 and the anchor rod sleeve 21 is an acute angle. The hollow barb 23 can be integrally formed with the anchor rod sleeve 21, and the hollow barb 23 arranged in an acute angle helps to improve the foundation uplift performance. Preferably, the included angle between the hollow barb 23 and the anchor rod sleeve 21 is 30°.

[0052] The construction steps of the above-mentioned desert area uplift tower foundation are as follows: first, arrange the pressure stress sensor 4 at the bottom of the sand foundation pit according to the preset position, then contact the bottom of the anchor rod force transmission shaft 22 to the contact point of the pressure stress sensor 4, put the anchor rod sleeve 21 on the anchor rod force transmission shaft 22 so that the anchor rod sleeve 21 just abuts against the snap ring 24, then bury the one-way stress anchor rod 2 and the pressure stress sensor 4 with sand, select appropriate sand soil consolidation liquid according to the properties of the local sand soil, inject the sand soil consolidation liquid through the sand soil consolidation liquid injection port under high pressure, and wait for consolidation success; leave the top of the anchor rod force transmission shaft 22 to realize hinged connection with the sliding block 32, place the sliding block 32 in the sliding groove 31 at the bottom of the sliding hinge support 3, and seal and prevent sand; then bind the reinforcement cage and pour the tower independent foundation 1 on the sliding hinge support 3, and further complete the installation of the upper tower structure. After the overall structure of the tower is stable, a simulation model is made according to the preset similarity ratio to restore the existing overall structure of the tower for analyzing the reliability of the overall structure of the tower under wind load.

[0053] The embodiment also provides a reliability evaluation method for the above-mentioned desert area uplift tower foundation, and the reliability evaluation method is performed according to the following steps in sequence:

[0054] S1, for the overall structure of the tower obtained based on the construction of the desert area uplift tower foundation to be evaluated, a simulation model is made according to the preset similarity ratio, such as Figure 4As shown, the simulation model is fixed in the test pit, which is obtained by layering and tamping in the test box using the sand soil in the region where the uplift tower foundation to be evaluated in the desert region is located; the similarity ratio , , are the geometric sizes of the uplift tower foundation in the desert region and the simulation model, respectively;

[0055] S2, first, the initial compressive stress of each compressive stress sensor 4 is obtained, then the limit test is performed on the simulation model to obtain the limit compressive stress of each compressive stress sensor 4; then the initial compressive stress and the limit compressive stress of each compressive stress sensor 4 are multiplied by the similarity ratio respectively to obtain the equivalent initial compressive stress and the equivalent limit compressive stress, and the equivalent limit compressive stress of each compressive stress sensor 4 is mapped to the corresponding position in the mathematical model of the hemisphere bottom to obtain the equivalent limit compressive stress distribution, which is used to reflect the actual compressive stress state of the overall foundation of the tower under the action of lateral wind load reaching the limit bearing;

[0056] The limit test is specifically: the simulation model is loaded in a stepwise or uniform manner in the direction of lateral wind load, and the stress change of each compressive stress sensor 4 and the test pit during the loading process are recorded; the direction of lateral wind load of the simulation model corresponds to the actual wind load direction of the uplift tower foundation in the desert region; when the following conditions are met at the same time, it is judged that the model has exceeded the limit, and the compressive stress of each compressive stress sensor 4 measured at this time is taken as the corresponding limit compressive stress:

[0057] Condition one: the stress change of the compressive stress sensor 4 changes from stable rise to obvious platform or sudden drop, and the change is not restored after continuous loading; specifically, the bottom of the sliding hinge support 3 is evenly divided into multiple zones, and an equal number of compressive stress sensors 4 are arranged in each zone; if 70% to 80% of the number of compressive stress sensors 4 in any one zone change from stable rise to obvious platform or sudden drop, it is considered that condition one is met;

[0058] Condition two: the test pit condition is that the ground surface is slightly bulged, the sand soil is locally loose or cracked;

[0059] S3, first, the normalized stress utilization of each compressive stress sensor 4 is calculated based on the equivalent initial compressive stress and the equivalent limit compressive stress of each compressive stress sensor 4, and the current compressive stress of each compressive stress sensor 4 of the uplift tower foundation to be evaluated in the desert region; the calculation formula of the normalized stress utilization is:

[0060] ;

[0061] In the above formula, is the normalized stress utilization of the i-th compressive stress sensor 4; , , respectively, the equivalent initial compressive stress, the equivalent ultimate compressive stress, the current compressive stress of the i-th compressive stress sensor 4;

[0062] Then, the hemispherical stress safety factor is calculated based on the normalized stress utilization of each compressive stress sensor 4; the calculation formula of the hemispherical stress safety factor is:

[0063] ;

[0064] In the above formula, is the hemispherical stress safety factor; is the number of compressive stress sensors 4;

[0065] S4, based on the hemispherical stress safety factor, the reliability of the uplift tower foundation in the desert area is evaluated; specifically, it is judged whether the hemispherical stress safety factor is less than 0, if yes, it indicates that the uplift tower foundation in the desert area has exceeded the limit and entered the instability zone, otherwise it indicates that the uplift tower foundation in the desert area still has a safety margin.

[0066] In the present application, the overall structure of the tower is first constructed, and then the model test is carried out according to the construction results. This process does not depend on complex numerical simulation, can truly reflect the stress change in the uplift process, is more in line with the engineering practice, can identify the compressive stress concentration area by using the equivalent ultimate compressive stress distribution, and timely adjust the construction technology or the injection amount of the consolidation liquid in the area, and provide real-time guidance and safety warning for the construction site in the reverse direction, and improve the structural safety and reliability.

Claims

1. A type of anti-uplift tower foundation for desert areas, comprising an independent tower foundation (1) and multiple unidirectional stress anchors (2), characterized in that: The bottom of the independent foundation (1) of the tower is provided with a sliding hinge support (3). The bottom of the sliding hinge support (3) is provided with multiple sliding grooves (31). The sliding grooves (31) are provided with multiple sliders (32) that can slide along the sliding grooves (31). The sliders (32) are hinged to the top of the uniaxial stress anchor rod (2). The bottom of the uniaxial stress anchor rod (2) is provided with a compressive stress sensor (4). The compressive stress sensor (4) is used to monitor the compressive stress transmitted by the uniaxial stress anchor rod (2) in real time.

2. The anti-uplift tower foundation for desert areas according to claim 1, characterized in that: The unidirectional stress anchor (2) includes an anchor sleeve (21), an anchor force transmission shaft (22), multiple hollow barbs (23), and a retaining ring (24). The anchor force transmission shaft (22) is mounted on the anchor sleeve (21), with its top hinged to the slider (32) and its bottom connected to the compressive stress sensor (4). The multiple hollow barbs (23) are mounted on the anchor sleeve (21), and the retaining ring (24) is mounted on the anchor force transmission shaft (22) and abuts against the bottom of the anchor sleeve (21) to prevent the anchor sleeve (21) from coming off the anchor force transmission shaft (22).

3. The anti-uplift tower foundation for desert areas according to claim 2, characterized in that: The anchor sleeve (21) includes a hollow inner cylinder (211) and a hollow outer cylinder (212) arranged coaxially. The side wall of the hollow outer cylinder (212) is fixedly connected to the bottom end of the hollow barb (23). The gap between the hollow outer cylinder (212) and the hollow inner cylinder (211) is connected to the interior of the hollow barb (23). The top of the hollow outer cylinder (212) is provided with a sand consolidation liquid injection port, and the hollow barb (23) is provided with multiple sand consolidation liquid spray ports.

4. The anti-uplift tower foundation for desert areas according to claim 1, characterized in that: The bottom of the sliding hinge support (3) is a hemispherical structure, and the sliding groove (31) is an arc groove.

5. The anti-uplift tower foundation for desert areas according to claim 2, characterized in that: The angle between the hollow barb (23) and the anchor sleeve (21) is an acute angle.

6. The anti-uplift tower foundation for desert areas according to claim 2, characterized in that: The hollow barb (23) is integrally formed with the anchor sleeve (21).

7. A reliability assessment method for anti-uplift tower foundations in desert areas, characterized in that: The reliability assessment method is based on the anti-uplift tower foundation in desert areas as described in claim 1, and includes: S1. For the overall structure of the tower obtained based on the construction of the anti-uplift tower foundation in the desert area to be evaluated, a simulation model is made according to the preset similarity ratio. The simulation model is fixed in the test pit. The test pit is obtained by layering and compacting the sand soil in the area where the anti-uplift tower foundation in the desert area to be evaluated is located. S2. First, obtain the initial compressive stress of each compressive stress sensor (4), then perform a limit test on the simulation model to obtain the ultimate compressive stress of each compressive stress sensor (4); based on the similarity ratio, convert the initial compressive stress and ultimate compressive stress of each compressive stress sensor (4) into equivalent initial compressive stress and equivalent ultimate compressive stress. S3. First, based on the equivalent initial compressive stress and equivalent ultimate compressive stress of each compressive stress sensor (4), and the current compressive stress of each compressive stress sensor (4) obtained from the anti-uplift tower foundation in the desert area to be evaluated, calculate the normalized stress utilization of each compressive stress sensor (4); the formula for calculating the normalized stress utilization is: ； In the above formula, The normalized stress utilization of the i-th compressive stress sensor (4); , , These are the equivalent initial compressive stress, equivalent ultimate compressive stress, and current compressive stress of the i-th compressive stress sensor (4), respectively. Then, the hemispherical stress safety factor is calculated based on the normalized stress utilization of each compressive stress sensor (4); the formula for calculating the hemispherical stress safety factor is: ； In the above formula, The safety factor for hemispherical stress; The number of compressive stress sensors (4); S4. Reliability assessment of anti-uplift tower foundations in desert areas based on hemispherical stress safety factor.

8. The reliability assessment method for anti-uplift tower foundations in desert areas according to claim 7, characterized in that: The reliability assessment of anti-uplift tower foundations in desert areas based on hemispherical stress safety factor includes: Determine if the hemispherical stress safety factor is less than 0. If it is, it means that the anti-uplift tower foundation in the desert area has exceeded the limit and entered the instability zone. Otherwise, it means that the anti-uplift tower foundation in the desert area still has a safety margin.

9. The reliability assessment method for anti-uplift tower foundations in desert areas according to claim 7, characterized in that: The extreme test of the simulation model to obtain the ultimate compressive stress of each compressive stress sensor (4) includes: The simulation model was subjected to graded or uniform loading in the direction of wind load, and the stress changes of each compressive stress sensor (4) and the test pit were recorded during the loading process; the direction of wind load of the simulation model corresponds to the actual wind load direction of the anti-uplift tower foundation in the desert area; When the following conditions are met simultaneously, the model is judged to have exceeded the limit, and the compressive stress of each compressive stress sensor (4) at this time is taken as the corresponding ultimate compressive stress: Condition 1: The stress change of the compressive stress sensor (4) changes from a steady increase to a significant plateau or sudden drop, and this change does not recover after continued loading; Condition 2: The test pit shows slight bulging of the ground surface, local loosening of sandy soil, or cracks.

10. The reliability assessment method for anti-uplift tower foundations in desert areas according to claim 7, characterized in that: The method of converting the initial compressive stress and ultimate compressive stress of each compressive stress sensor (4) into equivalent initial compressive stress and equivalent ultimate compressive stress based on the similarity ratio includes: multiplying the initial compressive stress and ultimate compressive stress of each compressive stress sensor (4) by the similarity ratio to obtain the equivalent initial compressive stress and equivalent ultimate compressive stress. ,in , These are the geometric dimensions of the anti-uplift tower foundation and simulation model in the desert region.

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