A method for determining the grouting depth of cement slurry filling aeolian sand roadbed
By constructing a quantitative functional relationship model in aeolian sand roadbed, the problem of controlling the grouting depth in cement grouting reinforcement technology was solved, enabling precise design of the grouting depth and improving the reinforcement effect and economy.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HEBEI UNIV OF TECH
- Filing Date
- 2026-02-09
- Publication Date
- 2026-06-19
AI Technical Summary
The existing cement grouting reinforcement technology lacks quantitative methods for selecting grouting parameters and controlling grouting depth in aeolian sand roadbeds, resulting in poor reinforcement effects or waste of resources, and making it difficult to meet the design requirements under different road grades and traffic load conditions.
By constructing a quantitative functional relationship model between the equivalent resilient modulus Et of the top surface of the composite subgrade, the resilient modulus E0 of the compacted aeolian sand subgrade, the resilient modulus Ex of the cement grouting layer material, and the grouting depth hx, the minimum grouting depth that meets the design requirements is determined by using the theory of elastic layered systems and mechanical software.
It achieves precise design of grouting depth, improves the scientificity and rationality of reinforcement design, takes into account both structural safety and engineering economy, and avoids insufficient reinforcement or waste of resources.
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Figure CN122241802A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a method for determining the grouting depth of cement grout injection for aeolian sand roadbeds. It is applicable to determining the grouting depth for aeolian sand roadbed reinforcement in highways, urban roads and site engineering in aeolian sand areas, and belongs to the field of road engineering foundation treatment technology. Background Technology
[0002] Aeolian sand subgrades are characterized by fine particle size, weak interparticle cohesion, and a loose overall structure. Under the combined effects of vehicle dynamic loads and the natural environment, they are prone to excessive vertical deformation, often failing to meet the design requirements of highway engineering in terms of load-bearing capacity and deformation control. Especially in engineering conditions with high traffic volume and high axle load levels, the insufficient resilient modulus of aeolian sand subgrades leads to a deterioration of the pavement structure's stress state, a continuous increase in vertical deformation, and consequently, induces engineering defects such as subgrade settlement and pavement cracking, seriously affecting the service safety and lifespan of roads. Therefore, reinforcing aeolian sand subgrades to improve their load-bearing capacity and deformation resistance is a core engineering requirement for ensuring the structural safety and service performance of road engineering projects in aeolian sandy areas.
[0003] To improve the bearing capacity of aeolian sand roadbeds, various reinforcement technologies have been proposed in the engineering field. Among them, cement grout injection reinforcement technology, by infiltrating cement grout into the pores between aeolian sand particles and solidifying it to form a cemented structure, can significantly improve the overall stiffness and strength of the roadbed in the reinforced area. It also has the characteristics of strong geological adaptability, convenient engineering construction and operation, and stable reinforcement effect, and has a wide range of applications in aeolian sand roadbed reinforcement projects.
[0004] However, for roadbed bearing capacity design targets under different road grades and traffic load conditions, existing cement grouting reinforcement technology still has significant technical deficiencies in terms of grouting parameter selection and grouting depth control, specifically reflected in: 1. The resilient modulus of cement grouting layer materials is significantly affected by various factors such as the water-cement ratio of cement grout, the cement-cement ratio, and the compaction state of aeolian sand. The mechanical properties of the grouting layer corresponding to different parameter combinations vary greatly. However, the existing technology lacks a quantitative method for determining the parameters of grouting layer materials based on the target bearing capacity of the subgrade. It is difficult to achieve accurate selection and predictable control of the performance of grouting materials, and cannot provide reliable mechanical parameter support for the design of grouting depth. 2. Grouting depth is a key parameter determining the thickness of the load-bearing layer and its contribution to the load-bearing capacity of the composite subgrade. It directly affects the subgrade reinforcement effect and project cost. However, in existing projects, grouting depth often relies on subjective values based on engineering experience or is determined through repeated adjustments during on-site trial grouting. There is a lack of calculation methods to establish a quantitative correspondence between the design requirements for the load-bearing capacity of the subgrade top surface and the grouting depth, resulting in an inability to precisely control the grouting depth. If the grouting depth is too small, the subgrade reinforcement will be insufficient, and the load-bearing capacity will not meet the design requirements. If the grouting depth is too large, it will significantly increase the consumption of cement grout and construction costs, causing serious waste of engineering resources and failing to balance the structural safety and economic efficiency of the subgrade reinforcement.
[0005] Therefore, there is an urgent need to propose a method for determining the grouting depth of cement grout-filled aeolian sand subgrade. This method should be able to establish a quantitative relationship between the grouting depth and the equivalent resilient modulus of the subgrade top surface, based on a clear understanding of the design requirements for the bearing capacity of the subgrade top surface, and by comprehensively considering the mechanical parameters of the compacted undisturbed aeolian sand subgrade and the material parameters of the cement grout filling layer. This would enable the scientific and reasonable determination of the grouting depth and improve the design scientificity and economy of cement grout-filled reinforcement projects for aeolian sand subgrades. Summary of the Invention
[0006] This invention provides a method for determining the grouting depth of cement grout injection into aeolian sand roadbeds, achieving accurate and traceable determination of the grouting depth, taking into account both the structural safety and engineering economy of roadbed reinforcement, and solving the problem that existing cement grout injection depth for aeolian sand roadbeds relies on experience and lacks quantitative calculation methods, which can easily lead to insufficient bearing capacity or waste of engineering resources.
[0007] A method for determining the grouting depth of cement grouting for aeolian sand roadbed includes the following steps: S1: Based on road grade, traffic load, highway subgrade design specifications, and engineering design experience, determine the design target value of the equivalent resilient modulus of the top surface of the composite subgrade after grouting reinforcement [E]. t ]; S2: Constructing the resilient modulus E of cement grout-filled aeolian sand materials through indoor experiments. x The relationship model between the cement paste water-cement ratio, cement strength grade, cement admixture, aeolian sand compaction degree, aeolian sand non-uniformity coefficient, and aeolian sand curvature coefficient; S3: Set the grouting reinforcement depth h x Based on the theory of elastic layered systems, mechanical software is used to calculate the vertical deformation of the compacted aeolian sand undisturbed roadbed under different load levels, thereby obtaining the equivalent resilient modulus E0 of the compacted aeolian sand undisturbed roadbed. S4: Based on the theory of elastic layered systems, the equivalent resilient modulus E of the top surface of the composite subgrade is obtained by constructing and fitting using mechanical calculations. tEquivalent resilient modulus E0 of the original roadbed and resilient modulus E of the grouting layer material x and the injection depth h x The quantitative functional relationship model between them, i.e., E t =f(E0,E x ,h x ); S5: Select several candidate depths within the preset grouting depth range, and substitute each candidate depth into the quantitative function relationship model to calculate the corresponding E. t Value, in [E t [E] represents the constraint condition; filter those that satisfy E. t ≥[E t The candidate depths are selected, and the minimum value among them is determined as the minimum grouting depth h that meets the design requirements. min .
[0008] The specific process of constructing the relational model in S2 is as follows: The resilient modulus E of the cement grouting layer material is obtained according to the highway geotechnical testing procedures. x E was obtained through regression fitting using computational software. x With respect to the water-cement ratio (W / C) of cement paste and the cement strength grade (G) c Ash ratio m c Compaction degree of aeolian sand (K), uniformity coefficient of aeolian sand (C) u Aeolian sand curvature coefficient C c Functional relationship: E x =f(W / C, G c m c , K, C u C c )
[0009] The specific process for obtaining the equivalent resilient modulus E0 of the compacted aeolian sand undisturbed roadbed in S3 is as follows: S31. Divide the number of layers according to the height range corresponding to different degrees of compaction in the height direction of the original compacted aeolian sand roadbed. S32. Determine the resilient modulus E of the nth layer of aeolian sand material at compaction degree k. n，k ; S33. Use mechanical software to calculate the vertical deformation of the compacted aeolian sand undisturbed roadbed under different load levels; S34. Determine the value of the equivalent resilient modulus E0 based on the relationship between the stress level and the vertical deformation of the roadbed.
[0010] The specific process of constructing and fitting the quantitative functional relationship model in S4 is as follows: S41, Using E0, E x and h xAs a roadbed parameter, the vertical deformation of the top surface of the composite roadbed under different stress levels was calculated using mechanical analysis software; S42. Based on the stress-strain relationship, calculate the equivalent resilient modulus E of the composite subgrade after grouting. t ; S43, Based on multiple groups of E0, E x h x and corresponding E t The calculated data were used for regression analysis using statistical analysis software to obtain E. t With E0, E x h x A quantitative functional relationship model.
[0011] In S41, the Kenpave program is used to calculate the vertical deformation of the top surface of the composite subgrade. The calculated load is a circular uniformly distributed load with a diameter of 31.5 cm. The load is applied in 5 levels. The first level of load is 0.02 MPa, and each subsequent level of load increases by 0.04 MPa compared to the previous level. The vertical deformation of the top surface of the subgrade under each level of load is calculated.
[0012] The quantitative function relationship model obtained from the regression analysis in S43 is as follows: ,
[0013] Among them, E t h is the equivalent resilient modulus of the top surface of the composite subgrade, in MPa. x E0 represents the grouting depth in meters (m); E0 represents the equivalent resilient modulus of the compacted aeolian sand undisturbed subgrade in MPa. x This refers to the resilient modulus of the cement grouting layer material, expressed in MPa.
[0014] Specifically, by fitting the equivalent resilient modulus conversion formula, we first determine that the equivalent resilient modulus Et of the composite subgrade top is the resilient modulus E0 of the compacted aeolian sand undisturbed subgrade and the resilient modulus E of the grouted aeolian sand subgrade. x A function of the cement grouting depth hx is established, and the functional relationship is: Et=f(E0,Ex,hx); Then, Minitab statistical analysis was applied to perform regression analysis on a series of data under different combinations of parameters E0, E1, and hx, thereby obtaining the corresponding conversion regression formula between the dependent and independent variables. Referring to the form of the calculation formula in the road specifications, let: , Where a, b, and c are regression coefficients, where a is the composite coefficient, b is the coefficient related to hx, and c is the regression coefficient related to Ex / E0; Finally, regression analysis was performed based on the calculation results from the theory of elastic layered systems to obtain the following: , The preset grouting depth range in S5 is [0, 0.8m], or the subgrade depth area of aeolian sand roadbed.
[0015] In step S5, several candidate values for grouting depth are selected within a preset range at equal intervals.
[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. Achieved quantitative and precise design of grouting depth: This invention establishes for the first time the equivalent resilient modulus E of the top surface of composite roadbed. t Compared with the resilient modulus E0 of the original compacted aeolian sand roadbed and the resilient modulus E of the cement grouting layer material x Grouting depth h x The quantitative functional relationship model between them is based on the design target value of the equivalent resilient modulus of the subgrade top surface [E]. t With this constraint, the grouting depth that meets the design requirements can be directly calculated, changing the current situation where existing technologies rely on subjective values based on experience. This enables the calculable and traceable determination of the grouting depth, significantly improving the scientificity and accuracy of grouting reinforcement design for aeolian sand roadbeds.
[0017] 2. Improved the rationality and reliability of reinforcement design: This invention is based on the theory of elastic layered systems and uses the principle of equivalent vertical deformation to complete the conversion of the equivalent resilient modulus of the top surface of the composite subgrade. This ensures that the grouting depth design is highly matched with the actual load-bearing deformation response of the subgrade, while the resilient modulus E of the grouting layer material is also improved. x The equivalent resilient modulus E0 of the original subgrade was quantitatively determined through indoor tests and regression analysis. It was calculated based on the actual compaction state of the subgrade. The parameters were sourced from the standard and the calculation process was consistent with the actual engineering situation, which effectively improved the rationality and reliability of the evaluation and design results of the subgrade reinforcement effect.
[0018] 3. Balancing structural safety and engineering economy: This invention selects the minimum grouting depth h that meets design requirements. min This approach avoids the problems of insufficient roadbed reinforcement and failure to meet design requirements due to shallow grouting depth, while also eliminating the waste of engineering resources caused by increased cement grout consumption and construction costs due to excessively deep grouting depth. Under the premise of ensuring structural safety and service performance after wind-blown sand roadbed reinforcement, it minimizes engineering costs and achieves an organic unity of structural safety and engineering economy.
[0019] 4. Strong engineering applicability and high promotion value: The calculation logic of this invention is clear and the steps are simple. All parameters involved can be obtained through indoor tests, standard references, or conventional mechanics software calculations, without the need for complex field tests. Construction technicians can easily master and operate it. At the same time, this invention is applicable to the grouting reinforcement design of aeolian sand roadbeds under different road grades and traffic load conditions. It can be widely used in the foundation treatment of highways, urban roads, and site engineering in aeolian sand areas, and has good engineering application value and promotion prospects. Attached Figure Description
[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0021] Figure 1 This is a schematic diagram of the overall process of the method for determining the grouting depth of a cement grouting aeolian sand roadbed according to the present invention; Figure 2 This is a cross-sectional view of the roadbed and pavement structure of the method for determining the grouting depth of a cement grout-filled aeolian sand roadbed according to the present invention. Detailed Implementation
[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0023] Reference Figure 1 The diagram shows an overall flow chart of a method for determining the grouting depth of a cement grout-filled aeolian sand roadbed. This invention provides a method for determining the grouting depth of a cement grout-filled aeolian sand roadbed. In practical engineering applications, the method of this invention can be implemented according to the following steps: S1. Determine the design target value of the equivalent resilient modulus of the top surface of the composite subgrade after grouting reinforcement based on road grade, traffic load, the "Highway Subgrade Design Code", and design experience. t ]; S2. Construct the resilient modulus E of the cement grouting layer material through indoor experiments. x A model showing the relationship between water-cement ratio, cement grade, admixture dosage, and subgrade compaction degree; The resilient modulus E of the cement grouting layer material was determined according to the "Specifications for Testing Geotechnical Engineering on Highways". xThen, the resilient modulus E of the cement grout injection layer material was fitted by regression using calculation software. x With respect to the water-cement ratio (W / C) of cement paste and the cement strength grade (G) c Ash ratio m c And the compaction degree K and the uniformity coefficient C of aeolian sand. u curvature coefficient C c Functional relationship: E x =f(W / C, G c m c , K,C u C c ).
[0024] S3, Set the grouting reinforcement depth h x Based on the theory of elastic layered systems, mechanical software is used to calculate the vertical deformation of the subgrade below the cement grouting layer under different load levels, thereby obtaining the equivalent resilient modulus E0 of the compacted aeolian sand undisturbed subgrade. E0 is first determined by dividing the original aeolian sand subgrade into layers based on the height range corresponding to different compaction degrees in the vertical direction; then, the resilient modulus E of the nth layer of aeolian sand material at compaction degree k is determined. n，k Secondly, mechanical software was used to calculate the deformation of the original aeolian sand roadbed under different load levels, and finally the E0 value was determined based on the relationship between stress level and roadbed deformation.
[0025] S4. Using mechanical calculations, construct the equivalent resilient modulus E of the top surface of the composite roadbed. t Equivalent resilient modulus E0 of the original roadbed and resilient modulus E of the grouting layer material x and the injection depth h x The functional relationship model between them, i.e., E t =f(E0,E x ,h x ); S41. Calculate the vertical deformation of the top surface of the roadbed. The Kenpave program was used for calculation. The calculated load was 31.5 cm in diameter. The first level of load was 0.02 MPa, and each subsequent level was increased by 0.04 MPa of circular uniformly distributed load. The load was divided into 5 levels, and the vertical deformation of the roadbed top surface was calculated under each level of load.
[0026] S42. Calculate the equivalent resilient modulus E of the composite subgrade after grouting. t Then, based on the stress-strain relationship, the equivalent resilient modulus E of the composite subgrade after grouting is determined. t value.
[0027] Table 1. Calculation results of the resilient modulus of the composite subgrade after cement grouting treatment.
[0028] S43. Fitting formula for equivalent resilient modulus conversion; Design value of equivalent resilient modulus E of roadbed t The resilient modulus E0 of compacted aeolian sand subgrade and the resilient modulus E of grouting aeolian sand subgrade are both measured. x Cement grouting depth h x Establish functional relationships between functions: E t =f(E0,E x ,h x ) In the formula: E t = Equivalent resilient modulus of the roadbed top (MPa); E0 = Resilient modulus of compacted aeolian sand subgrade (MPa). E x =Resilient modulus of cement grouting layer material (MPa); h x = Cement grouting depth (m).
[0029] Minitab statistical analysis was applied to different parameters E0, E1, and h. x A series of combined data are used for regression analysis to obtain the corresponding regression formulas for the conversion between the dependent and independent variables. Referring to the form of the calculation formulas in road specifications, let: , Where a, b, and c are regression coefficients, where a is the composite coefficient, b is the coefficient related to h. x Correlation coefficients, c and E x The regression coefficients related to / E0 are obtained through regression analysis based on calculations from the theory of elastic layered systems. , S5. Within the preset range of grouting depth values, select several candidate grouting depth values h at equal intervals. x Substituting each candidate value into the relational model, the corresponding equivalent resilient modulus E of the roadbed top surface is calculated. t (h x The design target value of the equivalent resilient modulus of the roadbed top surface is [E]. t [E] represents the constraint condition; filter those that satisfy E. t (h x )≥[E t The candidate depths were determined, and the smallest one was selected as the minimum grouting depth h that meets the design requirements. min The preset grouting depth range is [0, 0.8m] or the subgrade depth area.
[0030] Example 1 A new Class I highway subgrade project in a region with aeolian sand distribution was constructed using a layered compaction process. After the subgrade was laid, testing predicted that its bearing capacity would be insufficient to meet design standards. Therefore, it is proposed to reinforce the aeolian sand subgrade using cement grouting technology. The pavement structure from top to bottom is as follows: — Cement grouting reinforcement of aeolian sand layers —Original compacted aeolian sand roadbed The compaction degree and thickness of each layer of the roadbed structure are shown in Table 2 below (from bottom to top).
[0031] Table 2
[0032] In this embodiment, the roadbed reinforcement treatment adopts a surface grouting process, using cement grade G. c The PO42.5, water-cement ratio W / C = 0.30, and cement admixture m c A fixed-ratio cement grout of 8% was injected into an aeolian sand layer with a compaction degree of 96%. Calculations showed that the average resilient modulus of the original aeolian sand subgrade below the cement grout layer was E0 = 45 MPa. Indoor test results indicate that the resilient modulus of the reinforced cement grout-filled aeolian sand layer is E0 = 45 MPa. x =150MPa.
[0033] In this embodiment, based on standard calculations and similar engineering experience, [Et] is taken as 80 MPa. The injection depth is determined using the following formula: .
[0034] Table 3
[0035] According to E t (h x )≥[E t From the discriminant condition, we can obtain: h min =0.54m.
[0036] In this embodiment, the grouting depth determined by the method of the present invention is 0.54m. After on-site construction and testing, the measured equivalent resilient modulus of the top surface of the grout-reinforced composite subgrade is 80.2MPa, which meets the design target value [E]. t The method of this invention reduces the grouting depth by 32.5% compared to the traditional empirical value of 0.8m, significantly reducing cement grout material consumption and construction costs, and achieving the dual goals of engineering safety and economy.
[0037] This invention establishes a quantitative relationship between the equivalent resilient modulus of the subgrade top, the resilient modulus of the original subgrade, the resilient modulus of the grouting layer material, and the grouting depth. The minimum grouting depth is obtained by using the design value of the equivalent resilient modulus as a constraint, thereby realizing the calculable and traceable determination of the grouting depth.
[0038] This invention is based on an elastic layered system and uses the principle of equivalent vertical deformation to complete the conversion of equivalent resilient modulus, so that the grouting depth design corresponds to the roadbed load deformation response, thereby improving the rationality of reinforcement effect evaluation and design results.
[0039] This invention can output the minimum grouting depth that meets the design requirements, avoiding insufficient reinforcement due to shallow grouting and waste of materials and construction costs due to excessive grouting. It balances structural safety and economy and has good engineering application value.
[0040] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and these variations still fall within the protection scope of the present invention.
Claims
1. A method for determining the grouting depth of a cement grout-filled aeolian sand roadbed, characterized in that: Includes the following steps: S1: Based on road grade, traffic load, highway subgrade design specifications, and engineering design experience, determine the design target value of the equivalent resilient modulus of the top surface of the composite subgrade after grouting reinforcement [E]. t ]; S2: Constructing the resilient modulus E of cement grout-filled aeolian sand materials through indoor experiments. x The relationship model between the cement paste water-cement ratio, cement strength grade, cement admixture, aeolian sand compaction degree, aeolian sand non-uniformity coefficient, and aeolian sand curvature coefficient; S3: Set the grouting reinforcement depth h x Based on the theory of elastic layered systems, mechanical software is used to calculate the vertical deformation of the compacted aeolian sand undisturbed roadbed under different load levels, thereby obtaining the equivalent resilient modulus E0 of the compacted aeolian sand undisturbed roadbed. S4: Based on the theory of elastic layered systems, the equivalent resilient modulus E of the top surface of the composite subgrade is obtained by constructing and fitting using mechanical calculations. t Equivalent resilient modulus E0 of the original roadbed and resilient modulus E of the grouting layer material x and the injection depth h x The quantitative functional relationship model between them, i.e., E t =f(E0,E x ,h x ); S5: Select several candidate depths within the preset grouting depth range, and substitute each candidate depth into the quantitative function relationship model to calculate the corresponding E. t Value, in [E t [E] represents the constraint condition; filter those that satisfy E. t ≥[E t The candidate depths are selected, and the minimum value among them is determined as the minimum grouting depth h that meets the design requirements. min .
2. The method for determining the grouting depth of a cement grout-filled aeolian sand roadbed according to claim 1, characterized in that: The specific process of constructing the relational model in S2 is as follows: The resilient modulus E of the cement grouting layer material is obtained according to the highway geotechnical testing procedures. x E was obtained through regression fitting using computational software. x With respect to the water-cement ratio (W / C) of cement paste and the cement strength grade (G) c Ash ratio m c Compaction degree of aeolian sand (K), uniformity coefficient of aeolian sand (C) u Aeolian sand curvature coefficient C c Functional relationship: E x =f(W / C,G c m c , K, C u C c ).
3. The method for determining the grouting depth of a cement grout-filled aeolian sand roadbed according to claim 1, characterized in that: The specific process for obtaining the equivalent resilient modulus E0 of the compacted aeolian sand undisturbed roadbed in S3 is as follows: S31. Divide the number of layers according to the height range corresponding to different degrees of compaction in the height direction of the original compacted aeolian sand roadbed. S32. Determine the resilient modulus E of the nth layer of aeolian sand material at compaction degree k. n，k ; S33. Use mechanical software to calculate the vertical deformation of the compacted aeolian sand undisturbed roadbed under different load levels; S34. Determine the value of the equivalent resilient modulus E0 based on the relationship between the stress level and the vertical deformation of the roadbed.
4. The method for determining the grouting depth of a cement grout-filled aeolian sand roadbed according to claim 1, characterized in that: The specific process of constructing and fitting the quantitative functional relationship model in S4 is as follows: S41, Using E0, E x and h x As a roadbed parameter, the vertical deformation of the top surface of the composite roadbed under different stress levels was calculated using mechanical analysis software; S42. Based on the stress-strain relationship, calculate the equivalent resilient modulus E of the composite subgrade after grouting. t ; S43, Based on multiple groups of E0, E x h x and corresponding E t The calculated data were used for regression analysis using statistical analysis software to obtain E. t With E0, E x h x A quantitative functional relationship model.
5. The method for determining the grouting depth of a cement grout-filled aeolian sand roadbed according to claim 4, characterized in that: In S41, the Kenpave program is used to calculate the vertical deformation of the top surface of the composite roadbed. The calculated load is a circular uniformly distributed load with a diameter of 31.5 cm. The load is applied in 5 levels. The first level of load is 0.02 MPa, and each subsequent level of load increases by 0.04 MPa compared to the previous level. The vertical deformation of the top surface of the roadbed under each level of load is calculated respectively.
6. The method for determining the grouting depth of a cement grout-filled aeolian sand roadbed according to claim 4, characterized in that: The quantitative function relationship model obtained from the regression analysis in S43 is as follows: ， Among them, E t h is the equivalent resilient modulus of the top surface of the composite subgrade, in MPa. x E0 represents the grouting depth in meters (m); E0 represents the equivalent resilient modulus of the compacted aeolian sand undisturbed subgrade in MPa. x This refers to the resilient modulus of the cement grouting layer material, expressed in MPa.
7. The method for determining the grouting depth of a cement grout-filled aeolian sand roadbed according to claim 1, characterized in that: The preset grouting depth range in S5 is [0, 0.8m], or the subgrade depth area of aeolian sand roadbed.
8. The method for determining the grouting depth of a cement grout-filled aeolian sand roadbed according to claim 1, characterized in that: In step S5, several candidate values for grouting depth are selected within a preset range at equal intervals.