Prediction Method and System for Settlement of Existing Building Loess Foundation during Rising Groundwater Level

Abstract

The present invention discloses a method and system for predicting the settlement of the loess foundation of existing buildings when the groundwater level rises, belonging to the technical field of foundation settlement prediction. The prediction method disclosed by the present invention includes the following steps: S1: Stratify the loess foundation in the prediction area, and calculate the boundary stresses of each layer of the loess foundation under different moisture contents according to the basic physical property indexes of each layer of the loess foundation; S2: According to the obtained boundary stresses, calculate the compression stable strains of each layer of the loess foundation under the action of self-weight stress and during the use period of the building under different moisture contents respectively; S3: Predict the final settlement amount of the loess foundation affected by the rising groundwater level according to the compression stable strains of each layer of the loess foundation. This prediction method significantly solves the technical problem that it is difficult for the existing prediction methods to predict the influence of the rising groundwater level on the foundation settlement after the completion of the building.

Description

Technical Field

[0001] The present invention belongs to the technical field of foundation settlement prediction, and particularly relates to a method and system for predicting the settlement of the loess foundation of existing buildings when the groundwater level rises. Background Art

[0002] In the vast loess area, the geological conditions are complex and the soil structure is loose. Therefore, when constructing buildings in this area, the problem of foundation settlement and deformation is particularly prominent. The settlement of the foundation not only concerns the stability of the building, but also directly affects its normal use function. To ensure the safety and durability of the building, it is crucial to follow the strict requirements in the Code for Design of Building Foundation. The code clearly states that: "The calculated value of the foundation deformation of the building must be strictly controlled within the allowable value of the foundation deformation." Given the potential threat posed by foundation settlement to the safety of the building, it is particularly critical to conduct detailed and accurate foundation settlement prediction before the start of engineering design and construction. This step can not only help engineers evaluate the stability of the foundation, but also ensure that the building meets the established safety standards in terms of foundation deformation. Through scientific prediction, the structural damage and functional failure of the building caused by foundation settlement can be effectively avoided. In addition, the dynamic changes of groundwater in the loess area cannot be ignored. The rise of the groundwater level is often accompanied by an increase in the water content of the foundation, which may accelerate the settlement speed of the foundation and even cause the settlement amount to exceed expectations. Therefore, for existing buildings, it is particularly urgent to continuously monitor the change of the water content of the foundation and adjust the settlement prediction model accordingly. Only by closely monitoring the dynamics of the water content of the foundation, combining advanced prediction techniques and real-time monitoring data, can the trend of foundation settlement be predicted in a timely and accurate manner, providing a scientific basis for possible foundation reinforcement projects. This not only helps to ensure the safety and stability of the building, but also enables rapid reinforcement measures to be taken when necessary to minimize potential risks.

[0003] Currently, in the loess area, the foundations of most buildings mainly rely on the late Pleistocene loess layer. To ensure the stability and safety of the buildings, accurate prediction of their foundation settlement is particularly important. Generally, this kind of prediction work is carried out before the construction of the building, mainly by taking foundation soil samples and conducting compression tests in the laboratory. Through these tests, the compressibility indexes of the foundation soil can be obtained, and then the settlement of the foundation can be predicted according to relevant specifications. However, what this method reflects is only the corresponding situation of the foundation during the construction period of the building. It fails to fully consider the foundation settlement changes that may be brought about by the rise of the groundwater level after the completion of the building. The change of the groundwater level has an undeniable impact on the physical and mechanical properties of the foundation soil. Therefore, how to predict the foundation settlement more comprehensively and accurately, especially considering the change of the groundwater level, has become an urgent problem to be solved. Summary of the Invention

[0004] The object of the present invention is to provide a method and system for predicting the settlement of the loess foundation of existing buildings when the groundwater level rises, so as to solve the technical problem that it is difficult for existing prediction methods to predict the influence of the rise of the groundwater level on the foundation settlement after the completion of buildings in the loess area.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] The present invention discloses a method for predicting the settlement of the loess foundation of existing buildings when the groundwater level rises, including the following steps:

[0007] S1: Stratify the loess foundation of the prediction area, and calculate the boundary stress of each layer of the loess foundation under different water content conditions according to the basic physical property indexes of each layer of the loess foundation;

[0008] S2: According to the obtained boundary stress, calculate the compression stable strain of each layer of the loess foundation under the action of self-weight stress and during the building use period under different water content conditions respectively;

[0009] S3: Predict the final settlement amount of the loess foundation affected by the rise of the groundwater level according to the compression stable strain of each layer of the loess foundation.

[0010] Furthermore, according to the basic physical property indexes of each layer of the loess foundation, the calculation formula for calculating the boundary stress of each layer of the loess foundation under different water content conditions is as follows:

[0011] ;

[0012] Where: - Boundary stress, unit: kPa; - Water content of the loess foundation, unit: %; - Plastic limit of the loess foundation, unit: %; - Dry density of the loess foundation, unit: g / cm 3 ; - Saturated density of the loess foundation, unit: g / cm 3 ; - Base of the natural logarithm;

[0013] Wherein, the water content of the loess foundation is the natural water content or the water content of the loess foundation after the change of the groundwater level.

[0014] Furthermore, when the water content of the loess foundation is equal to the natural water content , the calculated boundary stress is , as shown in the following formula:

[0015] ;

[0016] When the water content of the loess foundation is equal to the water content of the loess foundation after the change of the groundwater level , the calculated boundary stress is , as shown in the following formula:

[0017] .

[0018] Furthermore, according to the obtained boundary stress, the calculation formulas for the compression stable strain of each layer of loess foundation under the action of self-weight stress and during the service period of the building under different water content conditions are as follows:

[0019] ;

[0020] Where: - Compression stable strain; - Initial porosity of the loess foundation; - Load on the loess foundation; - Base of the natural logarithm; , , Are parameters related to the compression stage respectively.

[0021] Furthermore, , , The value relationship is as follows:

[0022] When ≤ , , , The values are 1.0, -0.1, 0.8 respectively;

[0023] When > , , , The values are 1.6, -0.57, 0.26 respectively.

[0024] Furthermore, when is equal to , is equal to , the calculated compression stable strain is , as shown in the following formula:

[0025] ;

[0026] When equals , equals and the sum of, the calculated compression stable strain is , as shown in the following formula:

[0027] ;

[0028] When equals , equals and the sum of, the calculated compression stable strain is , as shown in the following formula:

[0029] ;

[0030] Where: is equals when, the compression stable strain of the loess foundation after unloading and then under the action of self-weight stress;

[0031] is equals when, during the service life of the building, the compression stable strain of the loess foundation without being affected by the rising groundwater level under the combined action of and ;

[0032] is equals when, during the service life of the building, the compression stable strain of the loess foundation under the condition of being affected by the rising groundwater level;

[0033] Among them, is the self-weight stress of the loess foundation; is the additional stress of the loess foundation after building the building.

[0034] Furthermore, the calculation formula for predicting the final settlement of the loess foundation affected by the rising groundwater level based on the compression stable strain of each layer of the loess foundation is as follows:

[0035] ;

[0036] Where, - the final settlement of the loess foundation affected by the rising groundwater level, unit is mm;

[0037] - The compression of the loess foundation of the

[0038] - The compression stable strain of the loess foundation of the

[0039] - After the building is completed, and under the combined action of the compression stable strain of the loess foundation of the

[0040] - The thickness of the loess foundation of the

[0041] - The number of layers of the loess foundation;

[0042] - After the building is completed, and under the combined action of the type of compression stable strain of the loess foundation of the

[0043] Furthermore, when the loess foundation is divided into layers, any layer is denoted as the layer. When the loess foundation of the layer is not affected by the rising groundwater level, = 2; when the loess foundation of the layer is affected by the rising groundwater level, = 3.

[0044] The present invention also discloses a prediction system for the settlement of the loess foundation of an existing building when the groundwater level rises, including:

[0045] The first calculation module: used to layer the loess foundation of the prediction area and calculate the boundary stresses of each layer of the loess foundation under different moisture contents according to the basic physical property indexes of each layer of the loess foundation;

[0046] The second calculation module: used to calculate the compression stable strains of each layer of the loess foundation under the action of self-weight stress and during the building use period under different moisture contents respectively according to the obtained boundary stresses;

[0047] The prediction module: used to predict the final settlement amount of the loess foundation affected by the rising groundwater level according to the compression stable strains of each layer of the loess foundation.

[0048] Compared with the prior art, the present invention has the following beneficial effects:

[0049] The present invention discloses a method for predicting the settlement of the loess foundation of existing buildings when the groundwater level rises. By using the basic physical properties of the loess foundation, the boundary stress under different water contents is calculated, and then the strain of the loess foundation under self-weight stress and the compression stable strain during the use of the building under different water contents are calculated, so as to predict the final settlement amount of the loess foundation affected by the rising groundwater level. This method does not require indoor compression experiments, and only through the basic physical properties of the loess foundation, the foundation settlement at the calculation point can be predicted, which can realize the prediction of the foundation settlement of existing buildings under the condition of rising groundwater level, improve the analysis efficiency of foundation settlement, and significantly solve the technical problem that the existing prediction methods are difficult to predict the influence of the rising groundwater level on the foundation settlement after the completion of the building. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 It is a flow chart of the method for predicting the settlement of the loess foundation of existing buildings when the groundwater level rises according to the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0051] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0052] The present invention discloses a method for predicting the settlement of the loess foundation of existing buildings when the groundwater level rises, as Figure 1 shown, which includes the following steps:

[0053] Step 1: Layer the loess foundation in the prediction area, and calculate the boundary stress of each layer of loess foundation under different water contents according to the basic physical properties of each layer of loess foundation. The main formulas are as follows:

[0054] (1);

[0055] Where: - The boundary stress, in kPa; - The water content of the loess foundation, in %; - The plastic limit of the loess foundation, in %; - The dry density of the loess foundation, in g / cm3 ; - Saturation density of loess foundation, unit: g / cm 3 ; - Base of natural logarithm;

[0056] When equals , the boundary stress of natural loess is calculated and denoted as , as shown in the following formula:

[0057] (2);

[0058] When equals , the boundary stress of loess foundation after the change of groundwater level can be calculated and denoted as , as shown in the following formula:

[0059] (3);

[0060] Where: Is the natural moisture content, Is the moisture content of loess foundation after the change of groundwater level;

[0061] Step 2: According to the obtained boundary stress, calculate the compression stable strain of each layer of loess foundation under self-weight stress and during the service period of the building under different moisture content conditions respectively. The main formulas are as follows:

[0062] (4);

[0063] Where: - Compression stable strain; - Initial porosity of loess foundation; - Load on loess foundation; - Base of natural logarithm; , , Are parameters related to the compression stage respectively; , , The value relationship is shown in Table 1.

[0064] Table 1: A, B, C Value relationship of

[0065] .

[0066] When there is no influence of water level change, at this time equals , Equal to , the compression stable strain of the loess foundation under the action of self-weight stress after unloading can be obtained from Equation (4), denoted as ; when there is no influence of water level change and during the service period after the completion of the building, at this time is the self-weight stress of the loess foundation and the additional stress of the loess foundation after building the building The sum of them. From Equation (4), during the service period of the building, the compression stable strain of the loess foundation without being affected by the rising groundwater level under the combined action of and can be obtained, denoted as ;

[0067] When the loess foundation is affected by the rising groundwater level, at this time is equal to , is the self-weight stress of the loess foundation and the additional stress of the loess foundation after building the building The sum of them. From Equation (4), during the service period of the building, the compression stable strain of the loess foundation under the condition of being affected by the rising groundwater level can be obtained, denoted as ;

[0068] Step 3: Predict the final settlement of the loess foundation affected by the rising groundwater level according to the compression stable strain of each layer of the loess foundation. The main formula is as follows:

[0069] (5);

[0070] Among them, - The final settlement of the loess foundation affected by the rising groundwater level, with the unit of mm;

[0071] - The compression of the

[0072] - th layer of the loess foundation, with the unit of mm;

[0073] - After the completion of the building, and The combined action of the th layer of the loess foundation's compression stable strain;

[0074] - The The thickness of the loess foundation layer, in mm;

[0075] - The number of layers of the loess foundation;

[0076] - After the building is completed, and acting together, the type of compression stable strain of the layer of loess foundation, with a value of 2 or 3.

[0077] The prediction method of the present invention can more accurately simulate and predict the specific process of settlement of the loess foundation when the groundwater level rises by analyzing in detail the boundary stress and compression stable strain of the loess foundation under different water content conditions; the settlement amount of each layer of soil is calculated through the strain under different conditions, and a more refined prediction result can be obtained; in practical applications, the water content of the loess foundation is greatly affected by the change of the groundwater level; this method not only considers the natural water content and the water content after the change of the groundwater level, but also improves the simulation ability of the influence of the change of the groundwater level on the soil by calculating the boundary stress and strain under different water contents, and can better cope with the dynamic environmental changes; by analyzing the loess foundation layer by layer, it can be accurate to the settlement performance of each layer of soil. The compression stable strains of different soil layers are different, and the layer-by-layer analysis can avoid the errors caused by rough assumptions and improve the accuracy of settlement amount prediction; this prediction method not only considers the influence of self-weight stress, but also considers the additional stress during the use of the building, which is crucial for long-term settlement prediction. The dynamic changes during the use of the building will also affect the foundation settlement. In the method, the influence of the use of the building is considered through specific load calculations.

[0078] At the same time, this prediction method integrates various factors (such as initial porosity, boundary stress, load, etc.) through multi-step calculations and accurately calculates the compression stable strain and settlement amount of the loess foundation using formulas; especially through the combination of strain and soil layer thickness, the final settlement amount prediction of the loess foundation can be obtained, enhancing the application value in practical engineering. By considering the influence of the rise of the groundwater level on the soil water content and stress distribution, it effectively predicts the possible settlement changes of the foundation under the background of the change of the groundwater level. This provides an important basis for designing prevention and control measures and the structural safety of buildings; it can be adjusted according to different soil characteristics, different groundwater level change situations and the actual situations of different buildings, has high adaptability, and can provide accurate predictions in different geological environments and engineering backgrounds.

[0079] The present invention also discloses a prediction system for the settlement of the loess foundation of an existing building when the groundwater level rises, including:

[0080] The first calculation module: used to layer the loess foundation in the prediction area, and calculate the boundary stresses of each layer of the loess foundation under different water content conditions according to the basic physical property indexes of each layer of the loess foundation;

[0081] The second calculation module: respectively calculate the compression stable strains of each layer of the loess foundation under the action of self-weight stress and during the use of the building under different water content conditions according to the obtained boundary stresses;

[0082] The prediction module: used to predict the final settlement amount of the loess foundation affected by the rising groundwater level according to the compression stable strains of each layer of the loess foundation.

[0083] This prediction system performs layer-by-layer processing on the loess foundation in the prediction area through the first calculation module. This refined layer-by-layer method can more accurately reflect the physical property differences between different soil layers, thereby improving the accuracy of settlement prediction; and it can calculate according to the boundary stresses under different water content conditions, which reflects the actual influence of the rising groundwater level on the water content and mechanical properties of the loess foundation, making the prediction results closer to the actual situation; the second calculation module therein not only considers the compression stable strain under the action of self-weight stress, but also considers the influence of additional stresses that may occur during the use of the building. This comprehensive stress analysis helps to improve the reliability of settlement prediction; this prediction system is applicable to the settlement prediction of loess foundations under various geological and environmental conditions, has strong generality and practicability, and can provide strong technical support for engineering design and construction.

[0084] It should be noted that the terms "first", "second", etc. in the description, claims and above-mentioned drawings of the present invention are used to distinguish similar objects, and do not have to be used to describe a specific order or sequence. It should be understood that such used data can be interchanged under appropriate circumstances so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0085] Embodiment 1

[0086] Taking the loess foundation of the teaching building of College A in a certain place as an example, the basic physical property indexes of its loess foundation are shown in Table 2; the teaching building of College A in a certain place was built in 1956, and the building area is 15200m 2, the foundation embedment depth is 2.7 - 3.7 m, the foundation width is 0.6 - 2.2 m, the base pressure is 250 kPa, and the buried depth of the groundwater level is 15 m; after the water storage of Lake A began in 1958, the water level gradually rose to 2 - 4 m in 1985, and the water level generally rose from the depth of 12 m of the foundation below the base to the base position (the average moisture content in this depth range rose from 16.1% to 29%), causing a large settlement of the loess foundation of this teaching building; the settlement observation results of this teaching building over 25 years show that the maximum settlement has reached 495.9 mm, and then the settlement rate slows down and tends to be stable.

[0087] Table 2: Basic physical properties of the loess foundation of the teaching building of College A in a certain place (in 1957)

[0088] 。

[0089] Using the prediction method disclosed in the present invention, based on the basic physical property indexes in Table 2 and combined with the change of moisture content, the calculation is carried out, including the following steps: First, the boundary stress equal to when) of the natural foundation and the boundary stress equal to when) after the groundwater level rises are calculated through formulas (2) and (3); then, the compression stable strain under the action of the self-weight stress ( ) after unloading the loess foundation within the depth of 12 m of the foundation and the compression stable strain ) of the self-weight stress ( ) and the additional stress ( ) of the loess foundation after building the building under the condition of the influence of the rising groundwater level are calculated through formula (4), the compression stable strain under the action of the self-weight stress ( ) after unloading the loess foundation within the depth range of 13 - 15 m of the foundation and the compression stable strain ) of the self-weight stress ( ) and the additional stress ( ) of the loess foundation after building the building without being affected by the rising groundwater level are calculated; the specific calculation data are shown in Table 3. It can be seen that using the prediction method of the present invention, only the moisture content, plastic limit, dry density, and saturated density of the loess foundation at different depths of each layer of loess before building the building need to be known, and the final settlement of the existing building's loess foundation when the groundwater level rises can be calculated according to the moisture content of each layer of loess at different depths of the loess foundation after the change of the groundwater level during use. This method does not need to take soil for indoor compression tests, has high analysis efficiency, and can provide a basis for foundation treatment in a timely manner.

[0090] In Table 3, it represents the average self-weight stress of the loess foundation at the th layer counted from the foundation ground surface, and the calculation formula is as follows:

[0091] (6);

[0092] Where: is the foundation embedment depth; is the unit weight of the soil within the foundation embedment depth; , are respectively the unit weight and thickness of each soil layer within the depth range above the loess foundation at the th layer below the foundation bottom surface; , are respectively the unit weight and thickness of the loess foundation at the th layer below the foundation bottom surface.

[0093] It represents the average additional stress of the loess foundation at the th layer counted from the foundation bottom surface, and the calculation formula is as follows:

[0094] (7);

[0095] Where: is the additional stress distribution coefficient at the calculation point on the top surface of the th layer; is the additional stress distribution coefficient at the calculation point on the bottom surface of the th layer; is the additional foundation pressure at the foundation bottom.

[0096] The prediction method for the settlement of the existing building loess foundation when the groundwater level rises disclosed by the present invention comprehensively considers the changes in the physical and mechanical properties of the loess foundation under different water contents, as well as the combined action of the self-weight stress and the load during the building use period, so as to be able to predict the foundation settlement situation more comprehensively and accurately; and by calculating the compression stable strain of each layer of the loess foundation layer by layer and considering the influence after the groundwater level rises, this method can dynamically reflect the change process of the foundation settlement and improve the adaptability of the prediction; parameters related to the compression stage , , , and the calculation formula of the boundary stress, making the prediction process more quantitative and modeled, facilitating the implementation of computer programs and automated processing; furthermore, this method is not only applicable to the foundation settlement prediction of newly built buildings, but also applicable to the foundation settlement prediction of existing buildings under the condition of rising groundwater level, with strong practicability; the present invention provides a complete prediction system framework, including the whole process from data input, parameter calculation to final settlement prediction, making the prediction work more systematic and standardized. This method has strong scalability in terms of basic principles and framework, and can be further refined or other influencing factors can be introduced according to actual situations to improve the prediction accuracy and scope of application.

[0097] Table 3: Prediction of the loess foundation settlement of the teaching building of College A in a certain place (prediction method of the present invention)

[0098] 。

[0099] The above content is only for explaining the technical idea of the present invention, and the protection scope of the present invention cannot be limited thereby. Any changes made on the basis of the technical solution according to the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A prediction method for the settlement of the loess foundation of existing buildings when the groundwater level rises, characterized in that, It includes the following steps: S1: Layer the loess foundation in the prediction area, and calculate the boundary stresses of each layer of loess foundation under different water contents according to the basic physical property indexes of each layer of loess foundation; S2: According to the obtained boundary stresses, calculate the compression stable strains of each layer of loess foundation under the action of self-weight stress and during the use of the building under different water contents respectively; S3: Predict the final settlement of the loess foundation affected by the rising groundwater level according to the compression stable strains of each layer of loess foundation; The calculation formula for calculating the boundary stresses of each layer of loess foundation under different water contents according to the basic physical property indexes of each layer of loess foundation is as follows: ； Wherein: - The boundary stress, in kPa; - The moisture content of the loess foundation, in %; - The plastic limit of the loess foundation, in %; - The dry density of the loess foundation, in g / cm 3 ; - The saturated density of the loess foundation, in g / cm 3 ; - The base of the natural logarithm; Among them, the water content of the loess foundation is the natural water content or the water content of the loess foundation after the change of the groundwater level; When the water content of the loess foundation is equal to the natural water content , the calculated boundary stress is , as shown in the following formula: ； When the water content of the loess foundation is equal to the water content of the loess foundation after the change of the groundwater level , the calculated critical stress is , as shown in the following formula: ； The calculation formula for calculating the compression stable strains of each layer of loess foundation under the action of self-weight stress and during the use of the building under different water contents respectively according to the obtained boundary stresses is as follows: ； Wherein: - Compression stable strain; - Initial porosity of loess foundation; - Load on loess foundation; - Base of natural logarithm; and and are parameters related to the compression stage respectively; When equals , equals , the calculated compressive stable strain is , as shown in the following formula: ； When equals , equals plus , the calculated compressive stability strain is , as shown in the following equation: ； When equals , equals and the sum of, the calculated compressive stability strain is as shown in the following equation: ； Wherein: is equal to the compressive stable strain of the loess foundation under self-weight stress after unloading; When equals during the service life of the building, the compression stability strain of the loess foundation under the combined action of and is not affected by the rising groundwater level; is equal to During the service life of the building, the compressive stable strain of the loess foundation under the influence of the rising groundwater level; Among them, is the self-weight stress of the loess foundation; is the additional stress of the loess foundation after the construction of the building; The calculation formula for predicting the final settlement of the loess foundation affected by the rising groundwater level according to the compression stable strains of each layer of loess foundation is as follows: ； Among them, - The final settlement of the loess foundation affected by the rising groundwater level, in mm; - The compression of the loess foundation in the layer, unit: mm; - The compression stable strain of the loess foundation in the self-weight stress after unloading the upper layer; - After the building is completed, and under the combined action of, the compressive stable strain of the loess foundation on the th floor; - The thickness of the loess foundation of the layer, unit: mm; - The number of layers of the loess foundation; - After the building is completed, Acting jointly with The types of compression stable strain of the loess foundation on the layer are 2 or 3.

2. A prediction method for the settlement of the loess foundation of existing buildings when the groundwater level rises, as described in claim 1, characterized in that , , The value relationship is as follows: When ≤ then , , take the values of 1.0, -0.1, and 0.8 respectively; When > , , , take the values of 1.6, -0.57, and 0.26 respectively.

3. A prediction method for the settlement of the loess foundation of existing buildings when the groundwater level rises according to claim 1, characterized in that, Wherein, When the loess foundation is divided into layers, any layer is denoted as the th layer. When the th layer of loess foundation is not affected by the rising groundwater level, = 2; when the th layer of loess foundation is affected by the rising groundwater level, = 3.

4. A system for implementing the prediction method of the settlement of the loess foundation of existing buildings when the groundwater level rises according to any one of claims 1 to 3, characterized in that, It includes: The first calculation module: used to layer the loess foundation in the prediction area and calculate the boundary stresses of each layer of loess foundation under different water contents according to the basic physical property indexes of each layer of loess foundation; The second calculation module: used to calculate the compression stable strains of each layer of loess foundation under the action of self-weight stress and during the use of the building under different water contents respectively according to the obtained boundary stresses; The prediction module: used to predict the final settlement of the loess foundation affected by the rising groundwater level according to the compression stable strains of each layer of loess foundation.

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