Large-section tunneling type rectangular tunnel grouting construction parameter optimization design method and system

Abstract

The invention relates to the technical field of grouting construction parameter design, in particular to a large-section tunneling type rectangular tunnel grouting construction parameter optimization design method and system.The method comprises the following steps that modeling is conducted according to design sizes of a rectangular jacking pipe, a pipe joint and a stratum to obtain a rectangular jacking pipe model, a pipe joint model and a stratum model; wherein a construction gap is formed between the pipe joint model and the stratum model; setting slurry simulation parameters and contact surface simulation parameters; setting different hole site slurry injection ratios, performing slurry filling simulation through SPH according to the set different hole site slurry injection ratios, so as to simulate the process of filling the construction gap with slurry and filling the construction gap, and obtaining a corresponding simulation result; and selecting different hole site slurry injection ratios with the shortest time for filling the construction gap and smooth circumferential pressure distribution curve from the simulation result, and outputting the different hole site slurry injection ratios. According to the method, adverse disturbance to the stratum can be reduced to a certain extent through optimization.

Description

Technical Field

[0001] This invention relates to the technical field of grouting construction parameter design, and specifically to a method and system for optimizing grouting construction parameters for large-section excavated rectangular tunnels. Background Technology

[0002] In the construction of urban rail transit, underground utility tunnels, power and communication projects, the mechanical tunneling method has become a widely used construction technology. The mechanical tunneling method has advantages such as fast construction speed, minimal construction disturbance, and minimal impact on the ground, making it particularly suitable for underground engineering under complex geological conditions. Currently, tunnel cross-sections are mainly divided into two types: circular and rectangular.

[0003] To reduce the frictional resistance on the outer wall of the tunnel construction pipe, synchronous grouting is required. As an effective construction procedure, synchronous grouting involves injecting thixotropic grout into the soil through pre-set grouting holes inside the construction equipment shell and pipe sections. This forms a protective mud sleeve between the pipe and the soil, which lubricates the shell and pipe sections, reduces friction between the pipe and the soil, fills gaps in the construction process, and minimizes disturbance to the underlying structure.

[0004] However, the effectiveness of tunnel grouting is influenced by many factors, among which the selection of grouting parameters is crucial. Traditional grouting processes often rely on engineering experience and field test data. In complex and variable geological environments, various problems may arise, leading to unsatisfactory grouting results. Therefore, how to scientifically and rationally optimize grouting construction parameters to improve grouting efficiency and quality has become a key issue that urgently needs to be addressed in modern tunnel construction. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method and system for optimizing the design of grouting construction parameters for large-section excavated rectangular tunnels. This solves the problem that traditional grouting processes rely on engineering experience and field test data, which may lead to various problems and unsatisfactory grouting results.

[0006] The technical solution to achieve the above objectives is:

[0007] This invention provides a method for optimizing the design of grouting construction parameters for large-section tunnel excavation, comprising the following steps:

[0008] Modeling is performed based on the design dimensions of the rectangular jacking pipe, pipe sections, and strata to obtain the rectangular jacking pipe model, pipe section model, and strata model, wherein a construction gap is formed between the pipe section model and the strata model.

[0009] Set the slurry simulation parameters and the contact surface simulation parameters;

[0010] Different grout injection ratios were set for different hole positions. Based on the set grout injection ratios for each hole position, grout filling simulation was performed using SPH to simulate the process of grout filling and filling the construction gap, and the corresponding simulation results were obtained.

[0011] Select and output the grout injection ratios for different pore locations that minimize the time required to fill the construction gaps and achieve the smoothest circumferential pressure distribution curves from the simulation results.

[0012] A further improvement to the method for optimizing the design of grouting construction parameters for large-section rectangular tunnels of the present invention is that it further includes:

[0013] Different grouting ratios were set, and grout filling simulations were performed using SPH according to each set grouting ratio to simulate the process of grout filling and filling the construction gaps, and the corresponding simulation results were obtained.

[0014] Select and output the grouting rate that takes the shortest time to fill the construction gap and has the smoothest circumferential pressure distribution curve from the simulation results.

[0015] A further improvement to the method for optimizing the design of grouting construction parameters for large-section rectangular tunnels of the present invention is that it further includes:

[0016] Different grouting hole layout schemes were set, and grout filling simulation was performed using SPH according to each grouting hole layout scheme to simulate the process of grout filling and filling the construction gap, and the corresponding simulation results were obtained.

[0017] The grouting hole layout scheme with the shortest time to fill the construction gap and the smoothest circumferential pressure distribution curve is selected from the simulation results and output.

[0018] The further improvement of the grouting construction parameter optimization design method for large-section tunneling rectangular tunnels of the present invention is that, when using SPH to simulate grout filling, the initial distribution state of grout is first constructed, the rectangular jacking pipe model and grouting hole are fixed, and then grout is injected into the construction gap through the grouting hole to fill the construction gap.

[0019] Then, the same jacking speed is set for the rectangular jacking pipe model and the grouting hole to simulate the actual construction. During the simulation of the actual construction, the grout filling is simulated.

[0020] A further improvement of the method for optimizing the design of grouting construction parameters for large-section excavated rectangular tunnels in this invention is that the set grout simulation parameters include grouting speed parameters, resolution parameters, density parameters, internal pressure parameters, external pressure parameters, surface tension parameters, and viscosity parameters.

[0021] The simulated contact surface parameters include collision distance, action distance, friction, rebound, viscosity, roughness, and operating coefficient.

[0022] This invention also provides a system for optimizing the design of grouting construction parameters for large-section tunnel excavation rectangular tunnels, comprising:

[0023] The model building unit is used to model the rectangular jacking pipe, pipe section and stratum according to the design dimensions of the rectangular jacking pipe, pipe section and stratum to obtain the rectangular jacking pipe model, pipe section model and stratum model, wherein a construction gap is formed between the pipe section model and the stratum model.

[0024] The parameter setting unit is used to set the slurry simulation parameters, contact surface simulation parameters, and different slurry injection ratios for different hole positions.

[0025] The grout filling simulation unit is connected to the model building unit and the parameter setting unit. It is used to simulate grout filling through SPH according to the set grout injection ratio for each different hole position, so as to simulate the process of grout filling the construction gap and filling the construction gap, and obtain the corresponding simulation results.

[0026] The processing unit, connected to the grout filling simulation unit, is used to select and output the grout injection ratios for different holes that have the shortest time to fill the construction gap and the smoothest circumferential pressure distribution curve from the simulation results.

[0027] A further improvement of the grouting construction parameter optimization design system for large-section excavation rectangular tunnels of the present invention is that the parameter setting unit is also used to set different grouting rates;

[0028] The grout filling simulation unit is also used to simulate grout filling using SPH according to the set grouting rates, so as to simulate the process of grout filling the construction gap and filling the construction gap, and obtain the corresponding simulation results.

[0029] The processing unit is also used to select and output the grouting rate that takes the shortest time to fill the construction gap and has the smoothest circumferential pressure distribution curve from the simulation results.

[0030] A further improvement of the grouting construction parameter optimization design system for large-section excavation rectangular tunnels of the present invention is that the parameter setting unit is also used to set different grouting hole layout schemes.

[0031] The grout filling simulation unit is also used to simulate grout filling through SPH according to the set arrangement scheme of each grouting hole, so as to simulate the process of grout filling the construction gap and filling the construction gap, and obtain the corresponding simulation results.

[0032] The processing unit is also used to select the grouting hole layout scheme with the shortest time to fill the construction gap and the smoothest circumferential pressure distribution curve from the simulation results and output it.

[0033] A further improvement of the grouting construction parameter optimization design system for large-section tunneling rectangular tunnels of the present invention is that the grout filling simulation unit is also used to construct the initial distribution state of grout, fix the rectangular jacking pipe model and grouting hole, and inject grout into the construction gap through the grouting hole to fill the construction gap with grout.

[0034] Then, the same jacking speed was set for the rectangular jacking pipe model and the grouting hole to simulate the actual construction. During the simulation of the actual construction, the grout filling was simulated.

[0035] A further improvement of the grouting construction parameter optimization design system for large-section excavation rectangular tunnels of the present invention is that the grout simulation parameters set by the parameter setting unit include grouting speed parameters, resolution parameters, density parameters, internal pressure parameters, external pressure parameters, surface tension parameters, and viscosity parameters.

[0036] The contact surface simulation parameters set by the parameter setting unit include collision distance parameters, action distance parameters, friction parameters, rebound parameters, viscosity parameters, roughness parameters, and operating coefficients.

[0037] The beneficial effects of the present invention, namely the method and system for optimizing the design of grouting construction parameters for large-section rectangular tunnels, are as follows:

[0038] This invention uses SPH (Smooth Particle Hydrodynamics) to simulate grout filling under different grout injection ratios, grouting rates, and grouting hole layout schemes at different grouting locations. Then, it selects the parameters that minimize the time required to fill the construction gaps and achieve uniform circumferential pressure distribution from the simulation results as the parameter optimization design output. The parameter optimization design method of this invention is more targeted and can reduce adverse disturbances to the strata to a certain extent through optimization, prevent grout from concentrating in a certain direction, causing uneven settlement or grouting voids, and achieve more uniform filling over a wider range. It is suitable for large-section tunnels.

[0039] This invention constructs a grout filling simulation based on SPH theory, optimizes grouting construction parameters for the grouting filling diffusion effect under multiple working conditions, and realizes the reasonable allocation of parameters such as grouting rate, grouting hole layout and grout injection ratio at different hole positions, providing guidance for the grouting construction design of large-section tunnels. Attached Figure Description

[0040] Figure 1 This is a flowchart of the method for optimizing the design of grouting construction parameters for large-section rectangular tunnels according to the present invention.

[0041] Figure 2This is a system diagram of the grouting construction parameter optimization design system for large-section excavation rectangular tunnels according to the present invention.

[0042] Figure 3 This is a schematic diagram of the rectangular jacking pipe model, pipe section model, and stratum model established in the large-section excavation rectangular tunnel grouting construction parameter optimization design method and system of the present invention.

[0043] Figure 4 This is a schematic diagram of the grout filling stage, which represents the initial distribution state of the grout in the grouting construction parameter optimization design method and system for large-section excavated rectangular tunnels, as described in this invention.

[0044] Figure 5 This is a schematic diagram of the grout filling stage, which represents the initial distribution state of the grout in the grouting construction parameter optimization design method and system for large-section excavated rectangular tunnels, as described in this invention.

[0045] Figure 6 This is a schematic diagram of the grout filling stage, which represents the initial distribution state of the grout in the grouting construction parameter optimization design method and system of the present invention for large-section tunnel excavation.

[0046] Figure 7 This is a schematic diagram of the structure of the large-section tunnel grouting construction parameter optimization design method and system of the present invention during the 150s stage of tunnel jacking, which is the gap between the forward jacking of the pipe and the grout filling and diffusion construction.

[0047] Figure 8 The present invention provides a schematic diagram of the structure of the method for optimizing the design of grouting construction parameters for large-section rectangular tunnels and the system during the 300s stage of tunnel jacking, showing the gap between the forward jacking of the pipe and the grout filling and diffusion.

[0048] Figure 9 This invention relates to an optimized design method for grouting construction parameters in a large-section rectangular tunnel and a grout pressure distribution diagram on different sections at different injection ratios.

[0049] Figure 10 This is a schematic diagram of the relevant parameters for rectangular jacking pipe jacking in this invention.

[0050] Figure 11 This is a schematic diagram of the geometric dimensions of the rectangular jacking pipe cross-section in this invention.

[0051] Figure 12 This is a schematic diagram of the rectangular jacking pipe geometry in the present invention using a rectangular coordinate system.

[0052] Figure 13 This is a schematic diagram of the rectangular coordinate system at the rounded corner of the rectangular top pipe in this invention.

[0053] Figure 14 This is a force analysis diagram of the slurry unit in this invention. Detailed Implementation

[0054] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0055] See Figure 1 This invention provides a method and system for optimizing grouting construction parameters in large-section rectangular tunnels. Based on the SPH method, this invention simulates the diffusion process of tunnel grout, providing reasonable grouting construction parameters for tunnel construction. The invention optimizes the grouting rate, grouting hole layout, and grout injection ratio at different hole locations. A reasonable grouting rate ensures timely and sufficient filling of construction gaps, effectively supporting the surrounding strata, preventing soil rebound or collapse, and significantly reducing the risk of surface settlement and disturbance to adjacent structures. The location and injection ratio of the grouting holes determine the starting point of grout diffusion, thus affecting its diffusion path and distribution range within the construction gaps. A reasonable hole layout and injection ratio can prevent grout deviation or local voids, improving grout density. Optimizing the location of the grouting holes can effectively improve grout diffusion, increase filling density, and reduce disturbance to the underlying layers. This invention employs a grout filling simulation method to analyze the diffusion behavior under different grouting volumes and grouting hole locations. By changing the location of the grouting holes, it achieves synergistic optimization of the grouting path, diffusion pattern, and grouting pressure, thereby improving the construction quality and efficiency of tunnel grouting. The following description, in conjunction with the accompanying drawings, illustrates the optimization design method and system for grouting construction parameters in large-section rectangular tunnels according to this invention.

[0056] See Figure 2 This diagram shows the system diagram of the large-section rectangular tunnel grouting construction parameter optimization design system of the present invention. The following is in conjunction with... Figure 2 This paper describes the optimization design system for grouting construction parameters of large-section rectangular tunnels.

[0057] like Figure 2As shown, the large-section rectangular tunnel grouting construction parameter optimization design system of the present invention includes a model building unit 21, a parameter setting unit 22, a grout filling simulation unit 23, and a processing unit 24. The model building unit 21 and the parameter setting unit 22 are both connected to the grout filling simulation unit 23, and the processing unit 24 is connected to the grout filling unit 23. The model building unit 21 is used to model the rectangular jacking pipe, pipe section, and stratum according to their design dimensions to obtain a rectangular jacking pipe model, a pipe section model, and a stratum model, wherein a construction gap is formed between the pipe section model and the stratum model. The parameter setting unit 22 is used to set grout simulation parameters, contact surface simulation parameters, and different grout injection ratio parameters for different borehole locations. The grout filling simulation unit 23 is used to perform grout filling simulation using SPH according to the set grout injection ratios for each different borehole location, to simulate the process of filling the construction gap with grout and obtaining corresponding simulation results. The processing unit 24 is used to select and output the grout injection ratios for different borehole locations that have the shortest time to fill the construction gap and the smoothest circumferential pressure distribution curve from the simulation results.

[0058] The rectangular pipe jacking model, pipe section model, and formation model established by model building unit 21 are as follows: Figure 3 As shown, in Figure 3 The yellow solid cuboid represents the pipe section model, the green grid frame represents the stratum model, the orange grid frame represents the pipe jacking machine model, the gap between the grid frame and the pipe section model represents the construction gap of the pipe jacking, and the gray solid arrows indicate the grouting holes and the direction of grout injection.

[0059] Furthermore, the model building unit 21 of the present invention can use RealFlow to realize geometric modeling. First, a 3D geometric solid model is built in AutoCAD, then meshed, and then the model is exported as an obj format file using 3ds Max. The obj format file is sent to the model building unit 21, which imports the obj format file into RealFlow to realize the model building, that is, to realize the building of the rectangular pipe jacking model, the pipe section model and the formation model.

[0060] Furthermore, the design dimensions of the rectangular jacking pipe, pipe sections, and strata can be selected according to actual construction parameters. In this way, the present invention can simulate the grout filling situation in actual construction.

[0061] The filling and diffusion of grout in the construction gap involves multi-physics coupling and irregular boundary changes, making it difficult to perform a comprehensive and accurate simulation using numerical methods. When using RealFlow to perform numerical simulation modeling of grout filling and diffusion, it is necessary to appropriately simplify the actual working conditions in order to improve the computability and stability of the model. The present invention makes the following basic assumptions in the modeling process: (1) The grout is regarded as an incompressible, homogeneous and isotropic Bingham fluid, and the grout penetration effect and mass loss during the diffusion process are not considered; (2) During the grouting process, the grout flow state remains stable, and its flow pattern is considered constant, and the grout viscosity does not change with the grouting time; (3) Abnormal effects caused by segment assembly errors, stratum cavities or local collapses during construction are not considered, and the construction environment is assumed to be geometrically continuous and with regular boundaries.

[0062] Figure 3 The rectangular jacking pipe in the model measures 24.8m x 9.05m, with a rounded corner radius of 1.675m, a construction gap thickness of 0.025m, and a grout injection port diameter of 0.05m. The pipe section has a longitudinal length of 20m along the tunnel, with a tunnel depth of approximately 10m and an external environmental pressure of 0.15–0.27 MPa. Since the internal space of the pipe section does not significantly affect the filling and diffusion process of the grout within the construction gap, the internal region is simplified as a solid structure during modeling to reduce computational load and improve simulation efficiency. Furthermore, this invention does not consider the grout's penetration and diffusion into the underlying strata; therefore, the stratum is modeled as a rectangular solid surrounding the pipe section, with its geometric dimensions appropriately enlarged to ensure the boundary is far from the grouting area, thus avoiding interference with the simulation results. This simplification helps to highlight the primary diffusion characteristics of the grout within the construction gap, improving model stability and computational efficiency.

[0063] Furthermore, when the grout filling unit 21 performs grout filling simulation, each simulation process selects the same grouting rate and the same grouting hole arrangement scheme. The only difference between each simulation process is the grout injection ratio at different holes. In this way, the simulation results can reflect the influence of different grout injection ratios at different holes on the grout filling effect.

[0064] When setting the grout injection ratio for different hole positions, the parameter setting unit 22 can be set manually or automatically based on the set logic. The grout injection ratio for different hole positions refers to the ratio of the grout flow rate on the upper surface, lower surface, left surface, and right surface of the rectangle. The set logic is that the grout injection ratios on the left and right surfaces of the rectangle are the same, and the grout flow rate on the upper surface of the rectangle should be greater than or equal to the grout flow rate on the lower surface of the rectangle.

[0065] The following are examples of different grout injection ratios at different borehole locations: Condition 1, with a grout injection ratio of 1:1:1:1 and injection rates of 0.35, 0.35, 0.35, and 0.35 m / s respectively; Condition 2, with a grout injection ratio of 3:1:2:2 and injection rates of 0.42, 0.14, 0.28, and 0.28 m / s respectively; Condition 3, with a grout injection ratio of 4:1:1:1 and injection rates of 0.56, 0.14, 0.14, and 0.14 m / s respectively; Condition 4, with a grout injection ratio of 4:1:2:2 and injection rates of 0.56, 0.14, 0.28, and 0.28 m / s respectively.

[0066] Based on the above example and the simulation results of SPH, the time for grout filling and diffusion to form a complete mud sleeve and subsequent filling, as well as the circumferential pressure distribution pattern, were selected for result analysis. The grouting diffusion efficiency is shown in Table 1 below:

[0067] Grout injection ratio at different hole locations Slurry filling and diffusion stage diffusion time / s 1:1:1:1 The mud sleeve is completely closed / filled 237:20 3:1:2:2 The mud sleeve is completely closed / filled 220:20 4:1:2:2 The mud sleeve is completely closed / filled 194:10 4:1:1:1 The mud sleeve is completely closed / filled 206:00

[0068] Table 1—Grouting diffusion timetable corresponding to different grout injection ratios at different pore locations.

[0069] Table 1 shows that when the grout injection ratio at different borehole locations is 4:1:2:2, the minimum time for the grout to fill and diffuse to form a complete mud sleeve is 194 seconds. Therefore, this grout injection ratio at different borehole locations is the most reasonable among the four working conditions. Since the upper surface of the rectangular tunnel is relatively flat, the grout flow under its own weight is not significant. More grout needs to be pumped from the upper grouting holes to increase the upper grout pressure and quickly fill the flat upper surface. Because the environmental pressure at the bottom of the tunnel is high, the grout injection volume can be appropriately reduced. The side grout injection ratio is between the upper and lower surfaces, making this ratio reasonable. Under this injection ratio condition, three cross-sections at different locations were further selected for analysis of the circumferential pressure distribution pattern.

[0070] After grouting to form a complete mud sleeve on the outer surface of the pipe wall, grout is continuously injected until the grout volume is saturated. The circumferential pressure distribution at different cross-sections is analyzed, and grout injection ratios are selected for different borehole locations with uniform or nearly uniform circumferential pressure distribution. For example... Figure 9 As shown, grout pressures at different grout injection ratios at different borehole locations were selected on cross-sections of rings 0, 2, and 4. When the grout injection ratio at different borehole locations was 1:1:1:1, the pressure was higher at the lower part of the tunnel and lower at the upper part. The initial grout pressure at the lower grouting holes exceeded 0.38 MPa, and the grouting pressure fluctuated significantly. Considering that the grout diffuses towards the bottom due to gravity, the grout pressure redistributes, and the grout pressure at the bottom of the tunnel gradually increases. Figure 9(a) to (c) are shown in the figures. The pressure distribution curves corresponding to the grout injection ratios at other different borehole locations are relatively smooth. When the grout injection volume at the top of the tunnel is greater than that at the lower borehole locations, the displacement of grout pressure can be appropriately reduced, thereby reducing the adverse disturbance of grouting to the strata. Figure 9 As shown in g) to j), when the injection ratio of grout at different borehole locations is 4:1:2:2, the final internal pressure of the grout and the surrounding water and soil pressure tend to be balanced, and eventually remain at half of the initial value. Therefore, from the four working conditions in the above examples, the simulation results of working condition 4 are better, and the system outputs the grout injection ratio of different borehole locations of working condition 4:1:2:2 as the optimized design value of the grout injection ratio at different borehole locations.

[0071] In one specific embodiment of the present invention, the parameter setting unit 22 is also used to set different grouting rates;

[0072] The grout filling simulation unit 23 is also used to simulate grout filling through SPH according to each set grouting rate, so as to simulate the process of grout filling the construction gap and filling the construction gap, and obtain the corresponding simulation results.

[0073] Processing unit 24 is also used to select and output the grouting rate that takes the shortest time to fill the construction gap and has the smoothest circumferential pressure distribution curve from the simulation results.

[0074] Furthermore, when the grout filling simulation unit 23 performs grout filling simulations with different grouting rates, the grout injection ratio at different hole positions is set to the optimized injection ratio selected in the previous step for each simulation process. The same grouting hole arrangement scheme is selected for each simulation process. The only difference between each simulation process is the grouting rate. In this way, the influence of different grouting rates on the grout filling effect can be reflected through the simulation results.

[0075] When setting different grouting rates, the parameter setting unit 22 can be set manually or automatically according to the set generation logic. The grouting rate is usually selected to be greater than 100% and less than or equal to 200% so that the grout can fully fill the construction gap.

[0076] Below is an example of different grouting ratios: 130%, 150%, and 180%. The grouting speed is set to 0.35 m / s. Then, based on the simulation results of SPH, the grouting ratio that minimizes the time required for grout to fill and diffuse to form a complete mud sleeve and for subsequent filling, as well as the circumferential pressure distribution that is uniform or nearly uniform, is selected as the optimized design value for the grouting ratio.

[0077] In one specific embodiment of the present invention, the parameter setting unit 22 is also used to set different grouting hole arrangement schemes;

[0078] The grout filling simulation unit 23 is also used to simulate grout filling through SPH according to the set arrangement scheme of each grouting hole, so as to simulate the process of grout filling the construction gap and filling the construction gap, and obtain the corresponding simulation results.

[0079] Processing unit 24 is also used to select the grouting hole layout scheme with the shortest time to fill the construction gap and the smoothest circumferential pressure distribution curve from the simulation results and output it.

[0080] Furthermore, when the grout filling simulation unit 23 simulates grout filling under different grouting hole arrangement schemes, the grout injection ratio of different hole positions is set to the optimized injection ratio selected in the previous step in each simulation process. The same grouting rate is selected in each simulation process. The only difference between each simulation process is the different grouting hole arrangement scheme. In this way, the influence of different grouting hole arrangement schemes on the grout filling effect can be reflected through the simulation results.

[0081] When setting different grouting hole layout schemes, the parameter setting unit 22 can be set manually or automatically according to the set generation logic. The design logic of the grouting hole layout scheme is that the grouting holes on the upper, lower, left, and right surfaces of the rectangle are not arranged at equal intervals, but the intervals can be varied, that is, different intervals can form corresponding grouting hole layout schemes. The arrangement position of the grouting holes can also be set, for example, the arrangement position of the grouting holes can be in the middle, front, rear, front-middle, and rear-middle, etc.

[0082] Below is an example of different grouting hole arrangement schemes: the grouting hole intervals are 1.5m, 2m, and 2.5m, and the grouting hole positions mentioned above are arranged in combination at the middle, front, rear, front-middle, and rear-middle locations. Then, based on the SPH simulation results, the grouting hole arrangement scheme with the shortest time for grout filling and diffusion to form a complete mud sleeve and subsequent filling, as well as the most uniform or nearly uniform circumferential pressure distribution, is selected as the optimized design value for the grouting hole arrangement scheme.

[0083] In one specific embodiment of the present invention, the grout filling simulation unit 23 is also used to construct the initial distribution state of the grout, fix the rectangular jacking pipe model and the grouting hole, and inject grout into the construction gap through the grouting hole to fill the construction gap with grout.

[0084] Then, the same jacking speed was set for the rectangular jacking pipe model and the grouting hole to simulate the actual construction. During the simulation of the actual construction, the grout filling was simulated.

[0085] When constructing the initial distribution state of the grout, the key is to completely fill the construction gap area with grout to reproduce the initial grout morphology and boundary conditions formed during actual grouting construction. Therefore, the first stage of the grout filling simulation unit 23 is the initial state establishment stage.

[0086] By injecting grout into the construction gaps until the entire void area is filled, the initial conditions of the model are ensured to accurately reflect the grout distribution at the construction site. The pipe jacking machine and grouting holes are then fixed, and grout is injected through the grouting holes to fill the construction gaps completely. Figures 4 to 6 As shown. In this first stage, a certain number of grouting holes are set on the pipe section model. That is, the system first gives a default grouting hole layout scheme to complete the simulation of the initial distribution state and the simulation of different hole positions, grouting ratios, and different grouting rates.

[0087] After establishing the initial distribution of the grout, the second stage of the simulation focuses on the process of filling the construction gaps with grout during the forward jacking of the pipe jacking machine. For example... Figure 7 and Figure 8 As shown, in this stage, the pipe jacking machine and the grouting holes are set to the same jacking speed to simulate actual construction. As the pipe jacking machine moves forward, grout is continuously injected through the grouting holes, gradually filling the ever-growing shield tail gap area behind it. This setup not only realistically reflects the grouting filling and diffusion process during construction, but also provides a good simulation basis for subsequent observation of the flow trajectory and diffusion pattern of the newly injected grout.

[0088] In one specific embodiment of the present invention, the slurry simulation parameters set by the parameter setting unit 22 include grouting speed parameters, resolution parameters, density parameters, internal pressure parameters, external pressure parameters, surface tension parameters, and viscosity parameters.

[0089] The contact surface simulation parameters set by parameter setting unit 22 include collision distance parameters, action distance parameters, friction parameters, rebound parameters, viscosity parameters, roughness parameters, and operating coefficients.

[0090] The relevant slurry simulation parameters and contact surface simulation parameters are configured as shown in Tables 2 and 3 below.

[0091]

[0092] Table 2—Slurry Simulation Parameter Configuration Table.

[0093]

[0094] Table 3—Contact Surface Simulation Parameter Configuration Table.

[0095] According to Table 3, the contact friction coefficient between the pipe section model and the grout is set to 0.1, and the contact friction coefficient between the formation and the outer shell of the pipe jacking machine is set to 0.01.

[0096] The slurry filling simulation unit 23 of this invention uses a Dyverso particle system to numerically simulate slurry filling and diffusion. This Dyverso system can effectively simulate the complex interactions between particulate matter, viscous fluids, and viscoelastic materials, making it particularly suitable for flow analysis of grouting materials. In the specific simulation, the Liquid-SPH model, which has high computational accuracy, is selected for the slurry particles to ensure the accuracy of the slurry dynamics during the simulation.

[0097] The basic principles of SPH are explained below.

[0098] The SPH method is essentially an interpolation technique that solves for macroscopic physical quantities f(x) such as density, pressure, and temperature by integrating values ​​at a set of disordered points. The mathematical calculations of SPH exhibit higher stability compared to traditional finite difference methods. This is mainly due to the smoothing effect inherent in integral methods, which effectively suppresses numerical oscillations and local discontinuities, making the established model closer to the actual physical process. In numerical simulations, this integral representation can be considered a weak form of partial differential equations, which is beneficial for improving solution accuracy and numerical stability. Therefore, the following expression is obtained:

[0099] f(x)=∫ Ω f(x')W(x-x',h)dx' (0-1)

[0100] In the formula:

[0101] f(x) — a function of any spatial variable x;

[0102] Ω—the interval of integration for x;

[0103] W(x-x',h) — A smooth function, also known as an interpolation function or kernel function;

[0104] h — the smooth length of the smooth function W(·).

[0105] In the SPH method, the system is discretized into a finite number of particles. This process essentially discretizes the continuous medium into a series of particle units with mass and volume properties. Within the influence range of each particle, a kernel function is used to weighted average the physical quantities of its neighboring particles, thereby achieving a numerical approximation of the field variables. The specific discretization expression is shown below:

[0106]

[0107] In the formula:

[0108] i — the particle symbol for calculation;

[0109] j—the symbol for the nearest mass;

[0110] m j —The mass of particle j;

[0111] ρ j —Density of particle j;

[0112] N—the total number of particles;

[0113] W(x i -x j ,h)——The value of the smooth function defined at particle i at particle j.

[0114] For equation (5-38)x i Taking the derivative, we get f'(x) as shown in the following equation.

[0115]

[0116] It is usually simplified and notated as W ij =W(x) ij ,h)=W(x i -x j If the function is a constant, then the expression on the right side of equation (0-3) is not zero. Using the antisymmetry of the derivative, we obtain the following equation:

[0117]

[0118] Since the above equation is identical, equation (0-4) can be rewritten as follows:

[0119]

[0120] By examining equation (0-2), we can see that discretizing the SPH of any function f(x) within the spatial coordinate range yields the SPH form of the Navier-Stokes equations for incompressible fluids, as shown below:

[0121] The mass conservation equation is:

[0122]

[0123] The momentum conservation equation is:

[0124]

[0125] The energy conservation equation is:

[0126]

[0127] In the formula,

[0128] DA / Dt — the material derivative with respect to any physical quantity A (scalar or tensor);

[0129] σ — Total stress tensor, σ αβ =-pδ αβ +τ αβ Furthermore, there is no influence of external forces in the momentum equation (0-7).

[0130] This invention also provides a method for optimizing the design of grouting construction parameters for large-section excavated rectangular tunnels, which will be described below.

[0131] like Figure 1 As shown, the optimization design method for grouting construction parameters of this large-section excavated rectangular tunnel includes the following steps:

[0132] Execute step S101, model the rectangular jacking pipe, pipe section and stratum according to the design dimensions to obtain the rectangular jacking pipe model, pipe section model and stratum model, wherein a construction gap is formed between the pipe section model and the stratum model; then execute step S102.

[0133] Execute step S102 to set the slurry simulation parameters and the contact surface simulation parameters; then execute step S103.

[0134] Execute step S103, set different grout injection ratios for different hole positions, and simulate grout filling using SPH according to the set grout injection ratios for each hole position to simulate the process of grout filling and filling the construction gap, and obtain the corresponding simulation results; then execute step S104.

[0135] Execute step S104, select from the simulation results the grout injection ratios of different holes that have the shortest time to fill the construction gap and the smoothest circumferential pressure distribution curve, and output them.

[0136] In one specific embodiment of the present invention, the parameter optimization design method further includes:

[0137] Different grouting ratios were set, and grout filling simulations were performed using SPH according to each set grouting ratio to simulate the process of grout filling and filling the construction gaps, and the corresponding simulation results were obtained.

[0138] Select and output the grouting rate that takes the shortest time to fill the construction gap and has the smoothest circumferential pressure distribution curve from the simulation results.

[0139] In one specific embodiment of the present invention, the parameter optimization design method further includes:

[0140] Different grouting hole layout schemes were set, and grout filling simulation was performed using SPH according to each grouting hole layout scheme to simulate the process of grout filling and filling the construction gap, and the corresponding simulation results were obtained.

[0141] The grouting hole layout scheme with the shortest time to fill the construction gap and the smoothest circumferential pressure distribution curve is selected from the simulation results and output.

[0142] In one specific embodiment of the present invention, when the parameter optimization design method uses SPH to simulate grout filling, it first constructs the initial distribution state of grout, fixes the rectangular jacking pipe model and grouting hole, and then injects grout into the construction gap through the grouting hole to fill the construction gap.

[0143] Then, the same jacking speed is set for the rectangular jacking pipe model and the grouting hole to simulate the actual construction. During the simulation of the actual construction, the grout filling is simulated.

[0144] In one specific embodiment of the present invention, the set slurry simulation parameters include grouting speed parameters, resolution parameters, density parameters, internal pressure parameters, external pressure parameters, surface tension parameters, and viscosity parameters.

[0145] The simulated contact surface parameters include collision distance, action distance, friction, rebound, viscosity, roughness, and operating coefficient.

[0146] The present invention has been described in detail above with reference to the accompanying drawings and embodiments. Those skilled in the art can make various modifications to the present invention based on the above description. Therefore, certain details in the embodiments should not be construed as limiting the present invention, and the scope of protection of the present invention shall be defined by the appended claims.

Claims

1. A method for optimizing the design of grouting construction parameters for large-section rectangular tunnels, characterized in that, Includes the following steps: Modeling is performed based on the design dimensions of the rectangular jacking pipe, pipe sections, and strata to obtain the rectangular jacking pipe model, pipe section model, and strata model, wherein a construction gap is formed between the pipe section model and the strata model. Set the slurry simulation parameters and the contact surface simulation parameters; Different grout injection ratios were set for different hole positions. Based on the set grout injection ratios for each hole position, grout filling simulation was performed using SPH to simulate the process of grout filling and filling the construction gap, and the corresponding simulation results were obtained. Select and output the grout injection ratios for different pore locations that minimize the time required to fill the construction gaps and achieve the smoothest circumferential pressure distribution curves from the simulation results.

2. The method for optimizing the design of grouting construction parameters for large-section rectangular tunnels as described in claim 1, characterized in that, Also includes: Different grouting ratios were set, and grout filling simulations were performed using SPH according to each set grouting ratio to simulate the process of grout filling and filling the construction gaps, and the corresponding simulation results were obtained. Select and output the grouting rate that takes the shortest time to fill the construction gap and has the smoothest circumferential pressure distribution curve from the simulation results.

3. The method for optimizing the design of grouting construction parameters for large-section rectangular tunnels as described in claim 1, characterized in that, Also includes: Different grouting hole layout schemes were set, and grout filling simulation was performed using SPH according to each grouting hole layout scheme to simulate the process of grout filling and filling the construction gap, and the corresponding simulation results were obtained. The grouting hole layout scheme with the shortest time to fill the construction gap and the smoothest circumferential pressure distribution curve is selected from the simulation results and output.

4. The method for optimizing the design of grouting construction parameters for large-section rectangular tunnels as described in claim 1, characterized in that, When using SPH to simulate grout filling, first construct the initial distribution state of the grout, fix the rectangular jacking pipe model and grouting hole, and then inject grout into the construction gap through the grouting hole to fill the construction gap. Then, the same jacking speed is set for the rectangular jacking pipe model and the grouting hole to simulate the actual construction. During the simulation of the actual construction, the grout filling is simulated.

5. The method for optimizing the design of grouting construction parameters for large-section rectangular tunnels as described in claim 1, characterized in that, The parameters set for grout simulation include grouting speed, resolution, density, internal pressure, external pressure, surface tension, and viscosity. The simulated contact surface parameters include collision distance, action distance, friction, rebound, viscosity, roughness, and operating coefficient.

6. A system for optimizing grouting construction parameters in a large-section rectangular tunnel, characterized in that, include: The model building unit is used to model the rectangular jacking pipe, pipe section and stratum according to the design dimensions of the rectangular jacking pipe, pipe section and stratum to obtain the rectangular jacking pipe model, pipe section model and stratum model, wherein a construction gap is formed between the pipe section model and the stratum model. The parameter setting unit is used to set the slurry simulation parameters, contact surface simulation parameters, and different slurry injection ratios for different hole positions. The grout filling simulation unit is connected to the model building unit and the parameter setting unit. It is used to simulate grout filling through SPH according to the set grout injection ratio for each different hole position, so as to simulate the process of grout filling the construction gap and filling the construction gap, and obtain the corresponding simulation results. The processing unit, connected to the grout filling simulation unit, is used to select and output the grout injection ratios for different holes that have the shortest time to fill the construction gap and the smoothest circumferential pressure distribution curve from the simulation results.

7. The grouted construction parameter optimization design system for large-section rectangular tunnels as described in claim 6, characterized in that, The parameter setting unit is also used to set different grouting rates; The grout filling simulation unit is also used to simulate grout filling using SPH according to the set grouting rates, so as to simulate the process of grout filling the construction gap and filling the construction gap, and obtain the corresponding simulation results. The processing unit is also used to select and output the grouting rate that takes the shortest time to fill the construction gap and has the smoothest circumferential pressure distribution curve from the simulation results.

8. The grouting construction parameter optimization design system for large-section tunneling rectangular tunnels as described in claim 6, characterized in that, The parameter setting unit is also used to set different grouting hole arrangement schemes; The grout filling simulation unit is also used to simulate grout filling through SPH according to the set arrangement scheme of each grouting hole, so as to simulate the process of grout filling the construction gap and filling the construction gap, and obtain the corresponding simulation results. The processing unit is also used to select the grouting hole layout scheme with the shortest time to fill the construction gap and the smoothest circumferential pressure distribution curve from the simulation results and output it.

9. The grouting construction parameter optimization design system for large-section tunneling rectangular tunnels as described in claim 6, characterized in that, The grout filling simulation unit is also used to construct the initial distribution state of the grout, fix the rectangular jacking pipe model and grouting hole, and inject grout into the construction gap through the grouting hole to fill the construction gap with grout. Then, the same jacking speed was set for the rectangular jacking pipe model and the grouting hole to simulate the actual construction. During the simulation of the actual construction, the grout filling was simulated.

10. The grouting construction parameter optimization design system for large-section tunneling rectangular tunnels as described in claim 6, characterized in that, The slurry simulation parameters set by the parameter setting unit include grouting speed parameters, resolution parameters, density parameters, internal pressure parameters, external pressure parameters, surface tension parameters, and viscosity parameters. The contact surface simulation parameters set by the parameter setting unit include collision distance parameters, action distance parameters, friction parameters, rebound parameters, viscosity parameters, roughness parameters, and operating coefficients.

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