Method for calculating non-Darcy diffusion radius of grouting fluid of degraded base of operating road

Abstract

The invention provides an operation road degraded base grouting fluid non-Darcy diffusion radius calculation method, and belongs to the technical field of road repairing. Based on a road degraded base grouting fluid non-Darcy diffusion model, road degraded base data and grouting data are collected, and the non-Darcy diffusion radius of the operation road degraded base grouting fluid is calculated; and calculating the grouting fluid non-Darcy diffusion radius under the fixed grouting time based on the grouting fluid non-Darcy diffusion model output data covering the grouting diffusion radius R (t) related to the grouting time t. According to the method, based on the road degraded base grouting fluid non-Darcy diffusion model, the non-Darcy diffusion radius of the grouting fluid under the fixed grouting time can be accurately calculated by collecting the road degraded base data and the grouting data, and technical support is provided for engineers to scientifically grout and reinforce the road degraded base.

Description

Technical Field

[0001] The invention relates to the technical field of road repair, and in particular to a method for calculating the non-Darcy diffusion radius of a deteriorated base grouting liquid of an operating road. Background Art

[0002] The calculation method of the non-Darcy diffusion radius of the grouting liquid for the deteriorated base of operating roads is mainly based on the non-Darcy diffusion model of the grouting liquid for the deteriorated base of roads. The existing calculation methods of the diffusion radius of the grouting liquid are often obtained by experience, such as the "Technical Guidelines for Grouting Reinforcement of Highway Pavement Base" (DBJT45 / T 030-2021), which lacks scientificity. Some other calculation methods of the diffusion radius of the grouting liquid are obtained by assuming that the slurry is in a Darcy flow state. However, the permeability of the road base is between soil and stone, and it is a low-permeability medium. The diffusion of the slurry in the base conforms to the non-Darcy flow state. Therefore, the existing calculation method of the diffusion radius of the grouting liquid for the deteriorated base of roads does not conform to the actual situation, which makes it difficult to accurately grasp the diffusion radius of the grouting liquid, resulting in poor grouting treatment effect of the deteriorated base of roads or waste of materials.

[0003] Grouting technology is an effective trenchless technology for treating deteriorated bases of operating roads. However, since the road base is a concealed structure, in the trenchless treatment scenario, grouting technology has a certain degree of blindness, and the grouting effect is difficult to accurately grasp, resulting in poor treatment effects of many road deterioration base grouting projects. The diffusion radius of the grouting liquid is an extremely critical indicator of grouting technology. Construction personnel often implement grouting projects based on the diffusion radius of the grouting liquid. If the diffusion radius of the grouting liquid is improperly determined, two situations may occur: First, the grouting liquid does not completely cover the area to be treated, resulting in poor grouting effect; Second, the slurry diffusion range is too large, resulting in waste of grouting materials. Therefore, the diffusion radius of the grouting liquid needs to be as accurate as possible. The existing calculation methods of the diffusion radius of the grouting liquid are often obtained by experience, such as the "Technical Guidelines for Grouting Reinforcement of Highway Pavement Base" (DBJT45 / T030-2021), which lacks scientificity. Some other calculation methods of the diffusion radius of the grouting liquid are obtained by assuming that the slurry is a Darcy flow state. However, the permeability of the road base is between that of soil and rock, which is a low-permeability medium. The diffusion of slurry in the base conforms to the non-Darcy flow state. Therefore, it is necessary to design a method for calculating the non-Darcy diffusion radius of grouting liquid in the deteriorated base of an operating road. Summary of the invention

[0004] The purpose of the present invention is to provide a method for calculating the non-Darcy diffusion radius of grouting liquid for deteriorated base of operating roads, and solve the technical problems mentioned in the background technology. Based on the non-Darcy diffusion model of grouting liquid for deteriorated base of roads, the non-Darcy diffusion radius of grouting liquid under fixed grouting time can be calculated more accurately by collecting the data of deteriorated base of roads and grouting data, providing technical support for engineering personnel to scientifically grout and reinforce the deteriorated base of roads.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] The calculation method of the non-Darcy diffusion radius of the grouting fluid for the deteriorated base of operating roads is based on the non-Darcy diffusion model of the grouting fluid for the deteriorated base of roads. By collecting the deteriorated base data and grouting data of the road, the output data of the non-Darcy diffusion model of the grouting fluid for the deteriorated base of roads covers the grouting diffusion radius R(t) related to the grouting time t, and the non-Darcy diffusion radius of the grouting fluid under a fixed grouting time is calculated.

[0007] Furthermore, the input parameters of the non-Darcy diffusion model of the grouting fluid for road deterioration base include the grouting parameters: grouting pipe radius r0, grouting pressure p g , slurry density ρ g , dynamic viscosity of the slurry μ g and the compressibility coefficient c of the slurry g ; Road base parameters: base grouting depth H, base permeability β, base porosity Compression coefficient of base layer c s , initial water pressure of the base layer p0, and empirical coefficient of the base layer related to seepage m.

[0008] Furthermore, the control equation based on the non-Darcy diffusion model of the road deterioration base grouting fluid is as follows:

[0009]

[0010] where c t =c s +c g ;

[0011] At the initial time of grouting, i.e., time t = 0, p(r, t) obeys the following initial conditions:

[0012] p(r,0)=p0 (25)

[0013] The slurry is injected into the road base from the grouting pipe. During the grouting process, the grouting pressure remains constant. For the radius of the grouting pipe, that is, r = r0, p(r, t) obeys the following boundary conditions:

[0014] p(r=r0,t)=p g (26)

[0015] During the slurry transmission process in the base layer, the grouting pressure at the front edge of the slurry has the following specific relationship:

[0016] p(r=R(t),t)=p0 (27)

[0017]

[0018] The above equations (1) to (5) together constitute a mathematical model based on the non-Darcy diffusion model of the grouting fluid for the road deterioration base.

[0019] Furthermore, by solving the above equations (1) to (5), the non-Darcy diffusion model of the grouting fluid based on the deteriorated road base can be obtained. The specific process is:

[0020] Construct a new function as follows

[0021]

[0022] Substituting equation (6) into the mathematical model based on the non-Darcy diffusion model of the road deterioration base grouting fluid, that is, equations (1) to (5), the following five equations can be obtained:

[0023]

[0024] p(η=0)=p0 (31)

[0025] p(η=η0)=p g (32)

[0026] p(η=η R )=p0 (33)

[0027]

[0028] in and

[0029] Set dp / dη=P and reduce the order of equation (7) to the following:

[0030]

[0031] The above equation is a Bernoulli form equation, and its general solution is:

[0032]

[0033] Substituting the above formula (11) into formula (13), we can determine that c in formula (13) is:

[0034]

[0035] Therefore, we rewrite equation (13) as follows:

[0036]

[0037] Further processing the above formula (15) can be rewritten as follows:

[0038]

[0039] in,

[0040] The corresponding rewrites of equations (9) to (10) are as follows:

[0041]

[0042] Integrating equation (16) and combining it with equation (18) yields the following equation:

[0043]

[0044] Substituting formula (17) into formula (19) we can further obtain:

[0045]

[0046] Rearranging equation (20), we get η R The values ​​are:

[0047]

[0048] By combining equation (6) and equation (21), it can be deduced that the non-Darcy diffusion radius R(t) of the slurry on the deteriorated road base is:

[0049]

[0050] Let t in formula (22) be equal to the set grouting time T, and the calculation method of the non-Darcy diffusion radius of the grouting fluid for the deteriorated base of the operating road can be obtained, as shown in the following formula:

[0051]

[0052] Furthermore, the specific process of calculating the non-Darcy diffusion radius of the grouting liquid under a fixed grouting time is:

[0053] (1) Using MATLAB programming software, the calculation process of the non-Darcy diffusion radius of the grouting fluid for the deteriorated base of the operating road is compiled into a program.

[0054] (2) Determine the grouting parameters, including the grouting pipe radius r0, grouting pressure p g , slurry density ρ g , dynamic viscosity of the slurry μ g and the compressibility coefficient c of the slurry g ;

[0055] (3) Determine the relevant information of the deteriorated road base, including the base grouting depth H, the permeability β of the base, and the porosity of the base Compression coefficient of base layer c s , initial water pressure of the base p0, empirical coefficient of the base related to seepage m;

[0056] (4) Determine the grouting time T. You can set several grouting times T to obtain the corresponding non-Darcy diffusion radius R(T) of the grouting liquid for selection;

[0057] (5) Substituting (2) to (4) into (1) can obtain the non-Darcy diffusion radius R(T) of the grouting fluid for the deteriorated base of the operating road at the corresponding grouting time T.

[0058] If the diffusion radius of the grouting liquid is not determined properly, two situations may occur: First, the grouting liquid does not completely cover the area to be treated, resulting in poor grouting effect; Second, the slurry diffusion range is too large, resulting in waste of grouting materials. Therefore, the diffusion radius of the grouting liquid needs to be as accurate as possible. The existing calculation methods of the diffusion radius of the grouting liquid are often obtained by experience and lack scientificity. There are also some calculation methods of the diffusion radius of the grouting liquid that are obtained by assuming that the slurry is a Darcy flow state. However, the permeability of the road base is between soil and stone, and it is a low-permeability medium. The diffusion of the slurry in the base conforms to the non-Darcy flow state.

[0059] The present invention has the following beneficial effects due to the adoption of the above technical solution:

[0060] (1) The present invention is based on the non-Darcy diffusion model of the grouting liquid for the road deterioration base. By collecting the road deterioration base data and the grouting data, the non-Darcy diffusion radius of the grouting liquid under a fixed grouting time can be calculated more accurately, providing technical support for engineering personnel to scientifically grout the road deterioration base.

[0061] (2) The method for calculating the non-Darcy diffusion radius of the grouting liquid for the deteriorated base of an operating road proposed in the present invention is not only scientific, but also takes into account the non-Darcy flow state of the grouting liquid in the road base, which can more accurately guide the grouting reinforcement of the deteriorated base of the road. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 is a flow chart for implementing the calculation method of the present invention;

[0063] Figure 2 It is a relationship diagram between the grouting time T and the non-Darcy diffusion radius R(T) of the grouting liquid of the present invention;

[0064] Figure 3 It is a grouting construction site diagram of the present invention;

[0065] Figure 4 It is the detection effect before and after grouting in the grouting area of ​​the present invention. DETAILED DESCRIPTION

[0066] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and preferred embodiments. However, it should be noted that many details listed in the specification are only for the purpose of enabling the reader to have a thorough understanding of one or more aspects of the present invention, and these aspects of the present invention can be implemented even without these specific details.

[0067] like Figure 1 As shown, the method for calculating the non-Darcy diffusion radius of the grouting fluid for the deteriorated base of the operating road is as follows: (1) using programming software such as MATLAB, the calculation process of the non-Darcy diffusion radius of the grouting fluid for the deteriorated base of the operating road (the process in the manual content) is compiled into a program.

[0068] (2) Determine the grouting parameters, including the grouting pipe radius r0, grouting pressure p g , slurry density ρ g , dynamic viscosity of the slurry μ g and the compressibility coefficient c of the slurry g .

[0069] (3) Determine the relevant information of the deteriorated road base, including the base grouting depth H, the permeability β of the base, and the porosity of the base Compression coefficient of base layer c s , initial water pressure of the base layer p0, and empirical coefficient of the base layer related to seepage m.

[0070] (4) Determine the grouting time T. Multiple grouting times T can be set to obtain the corresponding non-Darcy diffusion radius R(T) of the grouting liquid for selection.

[0071] (5) Substituting (2) to (4) into (1) can obtain the non-Darcy diffusion radius R(T) of the grouting fluid for the deteriorated base of the operating road at the corresponding grouting time T.

[0072] Non-Darcy diffusion radius of grouting fluid for deteriorated base of operating roads

[0073] Based on a real road deterioration base grouting project, according to the grouting situation and road base conditions, the following set of measured calculation parameters are given: grouting pipe radius r0 = 0.019m, grouting pressure p g =10 6 Pa, slurry density ρ g =2038.1kg / m 3 , dynamic viscosity of the slurry μ g =258.5Pa·s and the compressibility coefficient of the slurry c g =4.6×10 -10 Pa -1 , base grouting depth H = 0.8m, base permeability β = 2.16×10 -14 m 2, the porosity of the base layer Compression coefficient of base layer c s =8×10 - 10 Pa -1 , the initial water pressure of the base layer p0 = 0Pa, and the empirical coefficient of the base layer related to seepage m = 1.65. Substitute the above data into Figure 1 By implementing the calculation method flow chart shown in the figure, the non-Darcy diffusion radius R(T) of the grouting liquid corresponding to the grouting time T can be obtained. Table 1 gives the non-Darcy diffusion radius R(T) of the grouting liquid when the grouting time is 60s, 90s, 120s, 150s and 180s.

[0074] Table 1 Non-Darcy diffusion radius of grouting liquid at different grouting times T

[0075] T R(T) 60s 1.26879m 90s 1.47235m 120s 1.63659m 150s 1.77667m 180s 1.90009m

[0076] Based on the calculation method of non-Darcy diffusion radius of grouting fluid for deteriorated base of operating roads, the above actual grouting projects are applied. Figure 3 The grouting construction site is shown. The road corresponding to the actual grouting project is a cement concrete pavement. Before grouting, there are a lot of slab bottom voids (such as Figure 4 The data shows that the slab bottom void test is carried out according to the "Field Test Method for Highway Roadbed and Pavement" (JTG3450-2019). When the intercept value b exceeds 50μm, the slab bottom voids. The grouting time T is 156s, and the corresponding grouting liquid non-Darcy diffusion radius R (T) is 1.8m for grouting construction. Figure 4 The results of the bottom slab degassing test in the grouting area after construction are shown. It can be found that the bottom slab degassing has been eliminated after grouting, which shows the effectiveness of the calculation method of the non-Darcy diffusion radius of the grouting liquid based on the deteriorated base of the operating road.

[0077] The calculation method of the non-Darcy diffusion radius of the grouting fluid for the deteriorated base of operating roads is based on the non-Darcy diffusion model of the grouting fluid for the deteriorated base of roads. By collecting the data of the deteriorated base of roads and the grouting data, the non-Darcy diffusion radius of the grouting fluid under a fixed grouting time can be calculated more accurately, providing technical support for engineering personnel to scientifically grouting and reinforce the deteriorated base of roads.

[0078] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. The calculation method of non-Darcy diffusion radius of grouting fluid for deteriorated base of operating roads is characterized by: Based on the non-Darcy diffusion model of grouting fluid for road deteriorated base, by collecting road deteriorated base data and grouting data, the non-Darcy diffusion radius of the grouting fluid under fixed grouting time is calculated based on the output data of the non-Darcy diffusion model of grouting fluid for road deteriorated base, which covers the grouting diffusion radius R(t) related to the grouting time t.

2. The method for calculating the non-Darcy diffusion radius of the grouting liquid for deteriorated base of an operating road according to claim 1 is characterized by: The input parameters of the non-Darcy diffusion model of the grouting fluid for road deterioration base include grouting parameters: grouting pipe radius r0, grouting pressure p g , slurry density ρ g , dynamic viscosity of the slurry μ g and the compressibility coefficient c of the slurry g ; Road base parameters: base grouting depth H, base permeability β, base porosity Compression coefficient of base layer c s , initial water pressure of the base layer p0, and empirical coefficient of the base layer related to seepage m.

3. The method for calculating the non-Darcy diffusion radius of the grouting liquid for deteriorated base of an operating road according to claim 2 is characterized by: The control equation based on the non-Darcy diffusion model of the road deterioration base grouting fluid is as follows: where c t =c s +c g ; At the initial time of grouting, i.e., time t = 0, p(r, t) obeys the following initial conditions: p(r,0)=p0 (2) The slurry is injected into the road base from the grouting pipe. During the grouting process, the grouting pressure remains constant. For the radius of the grouting pipe, that is, r = r0, p(r, t) obeys the following boundary conditions: p(r=r0,t)=p g (3) During the slurry transmission process in the base layer, the grouting pressure at the front edge of the slurry has the following specific relationship: p(r=R(t),t)=p0 (4) The above equations (1) to (5) together constitute a mathematical model based on the non-Darcy diffusion model of the grouting fluid for the road deterioration base.

4. The method for calculating the non-Darcy diffusion radius of the grouting liquid for deteriorated base of an operating road according to claim 3 is characterized by: By solving the above equations (1) to (5), the non-Darcy diffusion model of grouting fluid based on road deterioration base can be obtained. The specific process is: Construct a new function as follows Substituting equation (6) into the mathematical model based on the non-Darcy diffusion model of the road deterioration base grouting fluid, that is, equations (1) to (5), the following five equations can be obtained: p(η=0)=p0 (8) p(η=η0)=p g (9) p(η=η R )=p0 (10) in and Set dp / dη=P and reduce the order of equation (7) to the following: The above equation is a Bernoulli form equation, and its general solution is: Substituting the above formula (11) into formula (13), we can determine that c in formula (13) is: Therefore, we rewrite equation (13) as follows: Further processing the above formula (15), rewrite it as follows: in, The corresponding rewrites of equations (9) to (10) are as follows: Integrating equation (16) and combining it with equation (18) yields the following equation: Substituting formula (17) into formula (19) we can further obtain: Rearranging equation (20), we get η R The values ​​are: By combining equation (6) and equation (21), it can be deduced that the non-Darcy diffusion radius R(t) of the slurry on the deteriorated road base is: Let t in formula (22) be equal to the set grouting time T, and the calculation method of the non-Darcy diffusion radius of the grouting fluid for the deteriorated base of the operating road can be obtained, as shown in the following formula:

5. The method for calculating the non-Darcy diffusion radius of the grouting liquid for deteriorated base of an operating road according to claim 1 is characterized by: The specific process of calculating the non-Darcy diffusion radius of the grouting liquid under a fixed grouting time is: (1) Using MATLAB programming software, the calculation process of the non-Darcy diffusion radius of the grouting fluid for the deteriorated base of the operating road is compiled into a program. (2) Determine the grouting parameters, including the grouting pipe radius r0, grouting pressure p g , slurry density ρ g , dynamic viscosity of the slurry μ g and the compressibility coefficient c of the slurry g ; (3) Determine the relevant information of the deteriorated road base, including the base grouting depth H, the permeability β of the base, and the porosity of the base Compression coefficient of base layer c s , initial water pressure of the base p0, empirical coefficient of the base related to seepage m; (4) Determine the grouting time T. You can set several grouting times T to obtain the corresponding non-Darcy diffusion radius R(T) of the grouting liquid for selection; (5) Substituting (2) to (4) into (1) can obtain the non-Darcy diffusion radius R(T) of the grouting fluid for the deteriorated base of the operating road at the corresponding grouting time T.

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