A method for rapidly evaluating the effect of dynamic compaction on coarse fill roadbed reinforcement

Abstract

This invention discloses a method for rapidly evaluating the effect of dynamic compaction reinforcement of coarse-fill roadbeds, comprising the following specific steps: S1: Obtaining cumulative settlement: Obtaining the cumulative settlement of the coarse-fill roadbed reinforced by dynamic compaction; S2: Obtaining effective reinforcement depth: Obtaining the effective reinforcement depth of the coarse-fill roadbed reinforced by dynamic compaction; S3: Obtaining initial compaction degree: Obtaining the initial compaction degree of the coarse-fill material within the reinforcement zone; S4: Establishing a calculation model: Based on the obtained cumulative settlement of the coarse-fill roadbed reinforced by dynamic compaction, the effective reinforcement depth of the coarse-fill roadbed reinforced by dynamic compaction, and the initial compaction degree of the coarse-fill material within the reinforcement zone, establishing a calculation model for the compaction degree within the effective reinforcement depth range of the coarse-fill roadbed reinforced by dynamic compaction; S5: Evaluating the reinforcement effect; The method for rapidly evaluating the effect of dynamic compaction reinforcement of coarse-fill roadbeds disclosed in this invention has strong practicality and overcomes the shortcomings of conventional methods in evaluating the effect of dynamic compaction reinforcement of coarse-fill roadbeds.

Description

Technical Field

[0001] This invention relates to the field of roadbed dynamic compaction reinforcement construction technology, and in particular to a method for rapidly evaluating the effect of dynamic compaction reinforcement on coarse fill roadbeds. Background Technology

[0002] Dynamic compaction is a method of reinforcing the foundation by dropping a heavy hammer from a certain height to impact and vibrate the foundation. At the moment of contact between the hammer and the soil, a large contact stress will be generated at the contact surface. This contact stress will propagate in the foundation soil below the hammer in the form of stress waves, causing changes in the soil density, stress, pore water pressure, etc., thereby achieving the effects of improving the bearing capacity and strength of the foundation, eliminating the collapsibility of the foundation, and controlling post-construction settlement and uneven settlement of the foundation.

[0003] Dynamic compaction, a foundation treatment method with "wide applicability, significant reinforcement effect, and simple construction equipment," is widely used for the reinforcement of building foundations. The effective reinforcement depth is often used to evaluate the effectiveness of dynamic compaction. Most building foundations are homogeneous, and there are relatively mature theoretical formulas for calculating the effective reinforcement depth of dynamic compaction. However, for mountainous highway subgrades with coarse filler material mainly composed of large-diameter boulders, the dynamic compaction reinforcement mechanism differs significantly from that of typical homogeneous building foundations due to the poor uniformity of the filler material and the large voids between the fillers. The reinforcement depth of coarse filler subgrades cannot be calculated using existing theoretical formulas and needs to be obtained through on-site measurements.

[0004] The effective reinforcement depth of dynamic compaction serves as an indicator of the reinforcement effect of foundations or subgrades, signifying the area of ​​effect of the compaction. Within this area, the corresponding physical and mechanical parameters of the soil change, but it is often difficult to quantitatively calculate the degree of change in these parameters within the effective reinforcement depth range. For homogeneous building foundations, dynamic penetration tests are often used to evaluate the depth-direction reinforcement effect of the compaction in the reinforced area below the tamping hammer. However, for mountainous coarse-fill subgrades, characterized by high filler strength and uneven particle size, the surface layer below the tamping hammer after dynamic compaction is a dense layer, making it difficult to advance further, while the deeper layers contain large, unbroken rocks, making depth-direction testing using gravity penetration tests challenging. Therefore, there is an urgent need for a method to rapidly evaluate the reinforcement effect of subgrade filler within the effective reinforcement depth range of coarse-filler subgrades and the variation law of subgrade filler compaction degree in the effective reinforcement depth direction. Summary of the Invention

[0005] This invention discloses a method for rapidly evaluating the effect of dynamic compaction reinforcement on coarse fill roadbeds, aiming to solve the technical problem of how to overcome the shortcomings of conventional methods in evaluating the effect of dynamic compaction reinforcement on coarse fill roadbeds.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A method for rapidly evaluating the effect of dynamic compaction reinforcement on coarse fill roadbeds includes the following specific steps:

[0008] S1: Obtain cumulative settlement: Obtain the cumulative settlement of the coarse fill subgrade reinforced by dynamic compaction;

[0009] S2: Obtain the effective reinforcement depth: Obtain the effective reinforcement depth of the coarse fill subgrade reinforced by dynamic compaction;

[0010] S3: Obtain initial compaction degree: Obtain the initial compaction degree of coarse fill material in the area reinforced by dynamic compaction;

[0011] S4: Establish a calculation model: Based on the obtained cumulative settlement of the coarse fill roadbed after dynamic compaction, the effective reinforcement depth of the coarse fill roadbed after dynamic compaction, and the initial compaction degree of the coarse fill in the applied dynamic compaction reinforcement zone, establish a calculation model for the compaction degree within the effective reinforcement depth range of the coarse fill roadbed after dynamic compaction.

[0012] S5: Evaluate the reinforcement effect: Use the established calculation model to obtain the distribution law of the compaction degree of the coarse fill subgrade below the tamping hammer with depth, and evaluate the reinforcement effect of the coarse fill subgrade by dynamic compaction.

[0013] By establishing a calculation model for the compaction degree within the effective reinforcement depth of the coarse-fill roadbed based on the accumulated settlement of the coarse-fill roadbed under dynamic compaction, the effective reinforcement depth of the coarse-fill roadbed under dynamic compaction, and the initial compaction degree of the coarse-fill material within the applied dynamic compaction reinforcement zone, this invention is used to evaluate the reinforcement effect. This method for rapidly evaluating the reinforcement effect of coarse-fill roadbed under dynamic compaction is simple in principle, capable of calculating not only the compaction degree of the roadbed material within the effective reinforcement depth range of the coarse-fill roadbed under dynamic compaction, but also further calculating the compaction degree of the roadbed material at different depths below the tamping hammer. It can quickly evaluate the reinforcement effect of coarse-fill roadbed under dynamic compaction, has strong practicality, and overcomes the shortcomings of conventional methods in evaluating the reinforcement effect of coarse-fill roadbed under dynamic compaction.

[0014] In a preferred embodiment, S1, the cumulative settlement is obtained by conducting on-site dynamic compaction reinforcement tests on coarse fill roadbed, taking the average settlement of two adjacent impacts less than 5cm as the standard for stopping the hammer, and calculating the cumulative settlement of the coarse fill roadbed after stopping the compaction.

[0015] The S1 test for obtaining the cumulative compaction amount of the on-site coarse fill roadbed dynamic compaction reinforcement test uses a 1.15m radius, 17T weight tamping hammer, which is dropped freely from a height of 17m, and the settlement amount per blow is measured using a level.

[0016] The effective reinforcement depth is obtained by measuring the dynamic stress response process at different depths in the coarse fill subgrade below the tamping hammer during the dynamic compaction process, and analyzing the attenuation law of the dynamic stress peak with depth.

[0017] S2, in obtaining the effective reinforcement depth, the dynamic stress response process at different depths in the coarse fill subgrade below the tamping hammer is obtained by measuring the dynamic earth pressure cell buried at the corresponding depth below the tamping hammer.

[0018] S3, the initial compaction degree is obtained by conducting indoor tests and analysis on coarse fill material taken from the field, and the calculation model for the compaction degree within the effective reinforcement depth of the coarse fill material subgrade is based on the volumetric strain ε of the subgrade fill material. V The calculation formula is established;

[0019] In the S4 calculation model, the area with effective reinforcement depth below the hammer during dynamic compaction is equivalent to a cylinder, and the coarse filler particles within the cylinder are regarded as a huge unit. The height of the cylinder is H and the radius is the hammer radius R.

[0020] In S4, the parameters of the large unit below the tamping hammer in the calculation model include: unit volume V0, dry density ρ0, and compaction degree K0 before dynamic compaction; unit volume V1 after dynamic compaction (at this time, lateral deformation during soil compression is not considered, and a correction factor k is used in later calculations to consider the influence of lateral deformation), dry density ρ1, and compaction degree K1; and maximum dry density ρ of coarse filler particles. max The cumulative settlement h after the tamping is completed; and the parameters of the huge unit below the tamping hammer are expressed as: V0 = πR 2 H; V1 = πR 2 (Hh);

[0021] In S4, the calculation formula for the compaction degree of the subgrade fill within the effective reinforcement depth range of the coarse fill subgrade in the calculation model includes:

[0022]

[0023]

[0024] In S4, the distribution of post-compaction degree of the coarse fill subgrade below the tamping hammer with depth in the calculation model is obtained by the following formula:

[0025] Where H1 is any depth in the subgrade within the dynamic compaction reinforcement zone, and H1 is taken as 1.4m, 1.9m, 2.4m, 2.9m, 3.4m, 3.9m, 4.4m, 4.9m, 5.4m, 5.9m, and 6.4m, taking into account the cumulative settlement of the dynamic compaction.

[0026] By establishing a calculation model to obtain the distribution law of compaction degree with depth, the effective reinforcement depth of coarse fill roadbed by dynamic compaction can also be obtained. The result shows a high degree of agreement with the effective reinforcement depth measured in the field dynamic compaction test. This proves the effectiveness and correctness of the calculation formula for evaluating the reinforcement effect of coarse fill roadbed by dynamic compaction established in this invention and the distribution law of compaction degree of coarse fill under the tamping hammer with depth obtained after dynamic compaction.

[0027] As shown above, a method for rapidly evaluating the effect of dynamic compaction on coarse fill roadbed includes the following specific steps:

[0028] S1: Obtain cumulative settlement: Obtain the cumulative settlement of the coarse fill subgrade reinforced by dynamic compaction;

[0029] S2: Obtain the effective reinforcement depth: Obtain the effective reinforcement depth of the coarse fill subgrade reinforced by dynamic compaction;

[0030] S3: Obtain initial compaction degree: Obtain the initial compaction degree of coarse fill material in the area reinforced by dynamic compaction;

[0031] S4: Establish a calculation model: Based on the obtained cumulative settlement of the coarse fill roadbed after dynamic compaction, the effective reinforcement depth of the coarse fill roadbed after dynamic compaction, and the initial compaction degree of the coarse fill in the applied dynamic compaction reinforcement zone, establish a calculation model for the compaction degree within the effective reinforcement depth range of the coarse fill roadbed after dynamic compaction.

[0032] S5: Evaluate the reinforcement effect: Using the established calculation model, obtain the distribution law of post-compaction degree of coarse fill subgrade with depth below the tamping hammer, and evaluate the reinforcement effect of dynamic compaction of coarse fill subgrade. The method for rapidly evaluating the reinforcement effect of dynamic compaction of coarse fill subgrade provided by this invention has the technical advantage of being able to quickly evaluate the reinforcement effect of dynamic compaction of coarse fill subgrade, having strong practicality, and overcoming the shortcomings of conventional methods in evaluating the reinforcement effect of dynamic compaction of coarse fill subgrade. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the overall process of a method for rapidly evaluating the effect of dynamic compaction reinforcement of coarse fill roadbed proposed in this invention.

[0034] Figure 2 This invention presents a curve showing the cumulative settlement of a coarse fill roadbed reinforced by dynamic compaction as a function of the number of compaction blows, which is used to quickly evaluate the effect of dynamic compaction on the roadbed reinforced by coarse fill.

[0035] Figure 3 This is a schematic diagram of the dynamic earth pressure cell used to collect dynamic stress response data in the subgrade below the tamping hammer during the dynamic compaction process, which is part of a method for rapidly evaluating the effect of coarse fill subgrade dynamic compaction proposed in this invention.

[0036] Figure 4The graph shows the variation of the peak dynamic stress with depth in the coarse material subgrade below the tamping hammer, which is part of a method for rapidly evaluating the reinforcement effect of coarse fill subgrade proposed in this invention.

[0037] Figure 5 This is a schematic diagram of a calculation model for the compaction degree of coarse fill material in the effective reinforcement depth area of ​​a roadbed after dynamic compaction, which is a method for rapidly evaluating the effect of dynamic compaction on coarse fill roadbed proposed in this invention.

[0038] Figure 6 This is a schematic diagram showing the distribution of compaction degree of coarse fill material under the tamping hammer as a function of depth after dynamic compaction, which is a method for rapidly evaluating the effect of dynamic compaction on coarse fill roadbed proposed in this invention. Detailed Implementation

[0039] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0040] The method for rapidly evaluating the effect of dynamic compaction reinforcement of coarse fill roadbed disclosed in this invention is mainly applied to scenarios where the effect of dynamic compaction reinforcement of coarse fill roadbed is rapidly predicted.

[0041] Reference Figure 1 A method for rapidly evaluating the effect of dynamic compaction reinforcement on coarse fill roadbed includes the following specific steps:

[0042] S1: Obtain cumulative settlement: Obtain the cumulative settlement of the coarse fill subgrade reinforced by dynamic compaction;

[0043] S2: Obtain the effective reinforcement depth: Obtain the effective reinforcement depth of the coarse fill subgrade reinforced by dynamic compaction;

[0044] S3: Obtain initial compaction degree: Obtain the initial compaction degree of coarse fill material in the area reinforced by dynamic compaction;

[0045] S4: Establish a calculation model: Based on the obtained cumulative settlement of the coarse fill roadbed after dynamic compaction, the effective reinforcement depth of the coarse fill roadbed after dynamic compaction, and the initial compaction degree of the coarse fill in the applied dynamic compaction reinforcement zone, establish a calculation model for the compaction degree within the effective reinforcement depth range of the coarse fill roadbed after dynamic compaction.

[0046] S5: Evaluation of Reinforcement Effect: The distribution law of post-compaction compaction degree of coarse fill roadbed below the tamping hammer with depth is obtained using the established calculation model to evaluate the reinforcement effect of coarse fill roadbed by dynamic compaction. Based on the obtained cumulative settlement of coarse fill roadbed by dynamic compaction, effective reinforcement depth of coarse fill roadbed by dynamic compaction, and initial compaction degree of coarse fill in the applied dynamic compaction reinforcement zone, a calculation model of compaction degree within the effective reinforcement depth range of coarse fill roadbed by dynamic compaction is established for the evaluation of reinforcement effect. This invention makes the method for quickly evaluating the reinforcement effect of coarse fill roadbed by dynamic compaction simple in principle, and can not only calculate the compaction degree of roadbed fill within the effective reinforcement depth range of coarse fill roadbed by dynamic compaction, but also further calculate the compaction degree of roadbed fill at different depths below the tamping hammer. It can quickly evaluate the reinforcement effect of coarse fill roadbed by dynamic compaction and has strong practicality, overcoming the shortcomings of conventional methods that are difficult to evaluate the reinforcement effect of coarse fill roadbed by dynamic compaction.

[0047] Reference Figure 1 and Figure 2 In a preferred embodiment, S1, the cumulative settlement is obtained by conducting on-site dynamic compaction tests on coarse fill roadbeds. The average settlement of two adjacent compaction blows is less than 5 cm, which is used as the criterion for stopping the hammer. The cumulative settlement of the coarse fill roadbed after the compaction is stopped is then calculated. Figure 2 As shown, under a certain impact energy level provided on site, the cumulative settlement of the dynamic compaction gradually increases with the increase of the number of impacts and becomes stable in the region. The average settlement of two adjacent impacts is less than 5cm, which is used as the standard for stopping compaction. The cumulative settlement h of the compaction pit after stopping compaction is calculated.

[0048] Reference Figure 1 In a preferred embodiment, S1, the on-site coarse fill roadbed dynamic compaction test for obtaining the cumulative compaction amount uses a 1.15m radius, 17T weight tamping hammer, which is dropped freely from a height of 17m, and the settlement amount per blow is measured using a level.

[0049] Reference Figure 1 In a preferred embodiment, S2, the effective reinforcement depth is obtained by measuring the dynamic stress response process at different depths in the coarse fill subgrade below the ramming hammer during the dynamic compaction process, and analyzing the attenuation law of the dynamic stress peak with depth.

[0050] Reference Figure 1 , Figure 3 and Figure 4 In a preferred embodiment, S2, the dynamic stress response process at different depths within the coarse fill subgrade below the tamper during the effective reinforcement depth is obtained by measuring the dynamic earth pressure cell embedded at the corresponding depth below the tamper. Figure 3 As shown, the first strain gauge earth pressure cell is buried 1.0m below the tamping hammer, and then 10 strain gauge earth pressure cells are buried at 0.5m intervals. Figure 4As shown, with increasing depth, the dynamic stress of the dynamic compaction rapidly decreases from 320 kPa at 1.0 m below the hammer to 1 kPa at 6.0 m below the hammer. This indicates that the compaction effect of the vibration shock wave on the soil below the hammer gradually weakens with increasing depth. If 10 kPa is taken as the boundary, from the top... Figure 4 It can be seen that when the impact energy is 3000 kN·m, the effective vertical reinforcement depth is about 5.0 m.

[0051] Reference Figure 1 In a preferred embodiment, S3, the initial compaction degree is obtained by conducting laboratory tests on coarse fill material taken from the field, and the calculation model for the compaction degree within the effective reinforcement depth range of the coarse fill material subgrade is based on the volumetric strain ε of the subgrade fill material. V The calculation formula is established.

[0052] Reference Figure 1 In a preferred embodiment, S4, in establishing the calculation model, the area with effective reinforcement depth below the hammer during dynamic compaction is equivalent to a cylinder, and the coarse filler particles within the cylinder are regarded as a huge unit, with the height of the cylinder being H and the radius being the hammer radius R.

[0053] Reference Figure 1 , Figure 5 and Figure 6 In a preferred embodiment, S4, in establishing the calculation model, the parameters of the large unit below the tamping hammer include: the unit volume V0, dry density ρ0, and compaction degree K0 before dynamic compaction; the unit volume V1 after dynamic compaction, where lateral deformation during soil compression is not considered, and a correction factor k is used in later calculations to consider the influence of lateral deformation; dry density ρ1 and compaction degree K1; and the maximum dry density ρ of the coarse filler particles. max The cumulative settlement h after the tamping is completed; and the parameters of the huge unit below the tamping hammer are expressed as: V0 = πR 2 H; V1 = πR 2 (Hh).

[0054] Reference Figure 1 and Figure 3 In a preferred embodiment, S4, the calculation formula for the compaction degree of the subgrade fill within the effective reinforcement depth range of the coarse fill subgrade in the calculation model includes:

[0055]

[0056]

[0057] Reference Figure 1 and Figure 3In a preferred embodiment, S4, in establishing the calculation model, the distribution law of post-compaction degree of the coarse fill subgrade below the tamper with depth is obtained by the following formula:

[0058] Where H1 represents any depth in the subgrade within the dynamic compaction reinforcement zone, and considering the cumulative settlement of the dynamic compaction, H1 is taken as 1.4m, 1.9m, 2.4m, 2.9m, 3.4m, 3.9m, 4.4m, 4.9m, 5.4m, 5.9m, and 6.4m. By establishing a calculation model to obtain the distribution law of compaction degree with depth, the effective reinforcement depth of the coarse fill subgrade with dynamic compaction can also be obtained. The results show a high degree of agreement with the effective reinforcement depth measured in the field dynamic compaction test, proving the effectiveness and correctness of the calculation formula for evaluating the reinforcement effect of coarse fill subgrade with dynamic compaction established in this invention and the distribution law of compaction degree of coarse fill material with depth in the subgrade below the tamping hammer after dynamic compaction.

[0059] Example 1:

[0060] The method for rapidly evaluating the effect of dynamic compaction reinforcement of coarse fill roadbed provided in this embodiment of the invention is used to evaluate and analyze the effect of dynamic compaction reinforcement of coarse fill roadbed of a certain expressway.

[0061] A section of the proposed expressway is located in Xingyi City, Guizhou Province. The expressway's subgrade fill material consists of excavated riprap from tunnel cuts, with most riprap ranging from 40cm to 70cm in diameter and the largest approaching 1m in size. The uniformity of the coarse fill material is extremely poor. To control post-construction settlement of the high embankment with coarse fill material, dynamic compaction (impact energy level 3000kN·m) will be used to reinforce the subgrade with coarse fill material.

[0062] To evaluate the effectiveness of dynamic compaction in reinforcing coarse fill roadbeds, combined with attached... Figure 2-6 The relevant parameters are shown in the table below:

[0063]

[0064] After dynamic compaction of a rockfill embankment on a highway, the cumulative settlement was 0.932m and the effective reinforcement depth was 5.0m. Considering that the lateral deformation of the fill material under dynamic compaction is generally small, the correction factor k is taken as 0.90. The compaction degree of the embankment before compaction was 80%. Substituting into the formula, the compaction degree of the coarse fill material in the effective reinforcement depth area after compaction is 97.2% > 93%, which meets the requirements of the current specifications.

[0065] In addition, from Figure 6The distribution of compaction degree of the coarse fill material below the tamping hammer after dynamic compaction shows a clear pattern with depth. Using a compaction degree of 93% as a threshold, the effective reinforcement depth of the coarse fill subgrade after dynamic compaction can be quickly determined to be approximately 5.4m, which is largely consistent with field measurements. In similar subgrade or foundation dynamic compaction reinforcement projects, as long as the cumulative settlement of the dynamic compaction and the initial compaction degree of the fill material are obtained, the method proposed in this invention can be used to quickly obtain the distribution of compaction degree of the fill material below the tamping hammer with depth, thereby determining the effective reinforcement depth of the dynamic compaction.

[0066] Working Principle: When evaluating the effect of dynamic compaction reinforcement of roadbeds in the field, the cumulative settlement of the compaction pit and the effective reinforcement depth of the coarse-fill roadbed are measured through field tests. Combined with the initial compaction degree of the coarse-fill material, and based on the volumetric strain calculation formula, an evaluation model for the compaction degree of the coarse-fill material in the post-compaction reinforcement zone of the coarse-fill roadbed is established. Finally, the compaction degree of the coarse-fill material in the effective reinforcement zone after dynamic compaction is calculated, and the distribution law of the compaction degree of the coarse-fill material below the tamping hammer with depth is obtained. The dynamic compaction reinforcement effect of the coarse-fill roadbed is comprehensively evaluated. This invention provides a method for rapidly evaluating the effect of dynamic compaction reinforcement of coarse-fill roadbeds. The method is simple and overcomes the shortcomings of conventional methods in detecting the reinforcement effect of coarse fill roadbeds by dynamic compaction. It can quickly calculate the post-compaction degree of coarse fill in the effective reinforcement area of ​​the roadbed by dynamic compaction, and has strong applicability. In addition, the distribution law of compaction degree with depth obtained from this method can also be used to obtain the effective reinforcement depth of coarse fill roadbeds by dynamic compaction, and it has a high degree of agreement with the effective reinforcement depth measured by field dynamic compaction test. This proves the effectiveness and correctness of the calculation formula for evaluating the reinforcement effect of coarse fill roadbeds by dynamic compaction established by this invention and the distribution law of compaction degree of roadbed coarse fill with depth below the tamping hammer after dynamic compaction.

[0067] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for quickly evaluating the reinforcement effect of dynamic compaction on a coarse-filling subgrade, characterized in that, The method comprises the following specific steps: S1: obtaining cumulative ramming amount: obtaining the cumulative ramming amount of the coarse filler subgrade reinforced by the dynamic compaction; S2: obtaining effective reinforcement depth: obtaining the effective reinforcement depth of the coarse filler subgrade reinforced by the dynamic compaction; S3: obtaining initial compaction degree: obtaining the initial compaction degree of the coarse filler in the dynamic compaction reinforced area; S4: establishing a calculation model: according to the obtained cumulative ramming amount of the coarse filler subgrade reinforced by the dynamic compaction, the effective reinforcement depth of the coarse filler subgrade reinforced by the dynamic compaction, and the initial compaction degree of the coarse filler in the dynamic compaction reinforced area, a calculation model of the compaction degree in the effective reinforcement depth range of the coarse filler subgrade reinforced by the dynamic compaction is established; S5: evaluating the reinforcement effect: the distribution rule of the post-ramming compaction degree of the coarse filler subgrade under the rammer with depth is obtained by using the established calculation model, and the reinforcement effect of the coarse filler subgrade reinforced by the dynamic compaction is evaluated; In the S1, the cumulative ramming amount is calculated by carrying out the field dynamic compaction reinforcement test of the coarse filler subgrade, taking the average value of the ramming amount of the adjacent two times less than 5 cm as the stop ramming standard, and calculating the cumulative ramming amount of the coarse filler subgrade after stopping ramming. In the S1, the field dynamic compaction reinforcement test of the coarse filler subgrade is carried out by using a rammer with a radius of 1.15 m and a weight of 17 T, free falling from a height of 17 m, and using a level to measure the settlement of each time. In the S2, the effective reinforcement depth is obtained by measuring the dynamic stress response process of the coarse filler subgrade under the rammer at different depths during the dynamic compaction ramming process, and analyzing the depth attenuation rule of the dynamic stress peak value. In the S2, the dynamic stress response process of the coarse filler subgrade under the rammer at different depths is obtained by measuring the dynamic soil pressure box at the corresponding depth under the rammer. The S3, the initial compaction degree is obtained by taking coarse filler on site for indoor test analysis, and the calculation model of compaction degree in the effective reinforcement depth range of the subgrade filler is based on the volume strain ε V The calculation formula is established; In the S4, the area of the effective reinforcement depth under the rammer during the dynamic compaction ramming is equivalent to a cylinder, and the coarse filler particles in the cylinder range are regarded as a huge unit body, and the height of the cylinder is H and the radius of the cylinder is the radius R of the rammer. The S4, in the establishment of the calculation model, the parameters of the huge unit body under the rammer include: the unit body volume V0, the dry density ρ0, the compaction degree K0 before the dynamic compaction reinforcement; the unit body volume V1, the dry density ρ1, the compaction degree K1 after the dynamic compaction reinforcement; the maximum dry density ρ of the coarse filler particles max ; the cumulative ramming amount h after the end of ramming; and the parameters of the huge unit body under the rammer are expressed as: V0=πR 2 H; V1=πR 2 (H-h) In the S4, the compaction degree calculation formula of the subgrade filler in the effective reinforcement depth range of the coarse filler subgrade reinforced by the dynamic compaction comprises: ； ； ； ； 。 2. The method for quickly evaluating the dynamic consolidation effect of coarse filler subgrade according to claim 1, characterized in that, In the S4, the distribution rule of the post-ramming compaction degree of the coarse filler subgrade under the rammer with depth is calculated by the following formula: ; wherein H1 is any depth in the subgrade within the dynamic consolidation reinforced area, combined with the cumulative ramming amount of dynamic consolidation, H1 takes 1.4 m, 1.9 m, 2.4 m, 2.9 m, 3.4 m, 3.9 m, 4.4 m, 4.9 m, 5.4 m, 5.9 m, 6.4 m.

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