CN116401872B - Method for evaluating construction stability of small-clearance highway tunnel in complex geological environment - Google Patents

Abstract

The invention relates to the technical field of highway tunnels, and discloses a method for evaluating the construction stability of small clearance highway tunnels in complex geological environments, which includes the following steps: obtaining the corresponding engineering information of the small clearance highway tunnel; establishing based on the obtained engineering information. The construction geometric model of the small clear distance highway tunnel, the geometric model includes the tunnel body, surrounding rock mass and lining structure; according to the construction geometric model, as well as the obtained engineering information, and based on the Drucker‑Prager yield criterion, the small clear distance is established The construction physical model of the highway tunnel; according to the engineering information, based on the construction geometric model and the construction physical model, carry out numerical simulation simulation during the construction process of the small clearance highway tunnel, and generate the corresponding solution results; according to the solution results, based on Based on the lining structure strength parameters and standard regulations, the stability of the construction process of the small clearance highway tunnel is comprehensively evaluated and the corresponding evaluation results are generated.

Description

Construction stability assessment method for small clearance highway tunnels in complex geological environment

Technical field

The invention relates to the technical field of highway tunnels, and specifically relates to a method for evaluating the construction stability of small clearance highway tunnels in complex geological environments.

Background technique

With the rapid development of high-level highway construction, highway route selection is often restricted by terrain and other conditions, making the minimum clear distance between two adjacent tunnels unable to meet the requirements of the design specifications. Therefore, the thickness of the middle rock wall in the tunnel is less than A special tunnel layout with a minimum clear distance of separate independent double tunnels, that is, a small clear distance highway tunnel. When faced with complex geological conditions such as karst strata, gas-containing strata, and fractured strata, the construction difficulty of small clearance highway tunnels increases sharply. Therefore, it is very important to evaluate the construction stability.

The existing stability assessment during the construction process of small clearance highway tunnels focuses more on monitoring and stability assessment of the tunnel mileage sections that have been constructed, but cannot assess the stability of the entire process of small clearance highway tunnel construction. , this will inevitably cause unreasonable problems in the tunnel construction plan. For example, irreversible things such as unreasonable tunnel construction plans may occur halfway through the construction. At the same time, this will also make it impossible for the staff to carry out the entire small clearance highway tunnel. The comprehensive evaluation of the construction plan does not provide a good understanding of the subsequent problems, which greatly increases the uncertainty of the construction.

Contents of the invention

The present invention is intended to provide a method for evaluating the construction stability of small clear distance highway tunnels in complex geological environments, which can solve the limitations of the existing technology in the construction stability assessment of small clear distance highway tunnels, and achieve comprehensive evaluation of the construction of small clear distance highway tunnels. Assessment of process stability, thereby reducing uncertainty in the construction process.

In order to achieve the above purpose, the present invention adopts the following technical solution: a method for evaluating the construction stability of small clearance highway tunnels in complex geological environments, including the following steps:

S1. Obtain the engineering information of the corresponding small clearance highway tunnel. The engineering information includes design data information, construction data information and geological data information;

S2. Based on the obtained design data information, establish a construction geometric model of the small clearance highway tunnel. The geometric model includes the tunnel body, surrounding rock mass and lining structure;

S3. Based on the construction geometric model, as well as the obtained design data information, construction data information and geological data information, and based on the Drucker-Prager yield criterion, establish the construction physical model of the small clearance highway tunnel;

S4. According to the design data information, construction data information and geological data information, based on the construction geometric model and construction physical model, carry out numerical simulation simulation during the construction process of the small clearance highway tunnel, and generate corresponding solution results; The numerical simulation simulation solution includes the solution of the ground's self-gravity stress field and the solution of the tunnel construction process; the solution results include the maximum principal stress of the lining structure, the minimum principal stress of the lining structure, the horizontal displacement of the lining structure, and the vertical displacement of the lining structure ;

S5. According to the generated maximum principal stress of the lining structure, the minimum principal stress of the lining structure, the horizontal displacement of the lining structure and the vertical displacement of the lining structure, based on the strength parameters of the lining structure and the standard regulations, the stability of the construction process of the small clearance highway tunnel is determined. Conduct a comprehensive assessment and generate corresponding assessment results.

The principles and advantages of this program are: In this program, the engineering information of the small clearance highway tunnel is first obtained. In order to ensure the comprehensiveness of the information obtained, the engineering information includes not only design data information, but also construction data. Information and geological data information, and then use the corresponding design data information to establish the construction geometry model of the small clearance highway tunnel, and then use the engineering information and the corresponding construction geometric model to establish the construction physical model of the small clearance highway tunnel In this process, the corresponding criterion is based on the Drucker-Prager yield criterion, which can restore reality more accurately and greatly improve the authenticity and accuracy of model establishment. Then, through these established models, the corresponding Numerical simulation and simulation solutions, specifically including the solution of the formation's self-gravity field and the solution of the tunnel construction process. The solution of the formation's self-gravity field can effectively analyze the original deformation and stress conditions of the formation, which is a small analysis tool. The basic conditions for the stability analysis of the clear-distance highway tunnel construction process. After all calculations are completed, the corresponding maximum principal stress of the lining structure, the minimum principal stress of the lining structure, the horizontal displacement of the lining structure, and The vertical displacement of the lining structure. Through the generation of these calculation results, the stability of the construction process of the small clearance highway tunnel can be quickly judged based on the lining structure strength parameters and standard regulations.

1. The existing small clearance highway tunnel evaluation method can only monitor the tunnel mileage section that has been constructed, but cannot predict and evaluate the tunnel construction stability during the full dynamic process of small clearance highway tunnel construction. In this application, numerical simulation is used to evaluate the safety and stability of the small clearance highway tunnel construction process, and the early data collection is based on the actual on-site geological data of the small clearance highway tunnel. information, related data information and construction data information, so as to ensure the uniqueness and practicality of the model establishment. In this way, the entire small clear distance highway tunnel can be timely and quickly analyzed before construction and during the entire construction process. The rationality of the construction plan of the clear-distance highway tunnel is judged, which provides an important basis for the selection of construction methods and lining methods.

2. The establishment of the physical model is based on the Drucker-Prager yield criterion, which can ensure the accuracy and precision in describing the deformation of the material.

3. When evaluating the stability of the construction process of small-clearance highway tunnels, the basis for the evaluation includes the maximum principal stress of the lining structure, the minimum principal stress of the lining structure, the horizontal displacement of the lining structure, and the vertical displacement of the lining structure, that is, through the lining stress The two aspects of field and displacement field comprehensively assess the stability of tunnel construction, which greatly improves the accuracy and reliability of stability assessment.

4. Before building the model, the data used is design data information, and also includes construction data information and geological data information. Through the actual collection of these data, the corresponding data is not only real but also comprehensive, which greatly improves the efficiency of model construction. Later it became more realistic.

Preferably, as an improvement, the S3 includes the following steps:

S30. Based on the obtained geological data information and geometric model, and based on the Drucker-Prager yield criterion, construct a material constitutive model suitable for the small clearance highway tunnel;

S31. According to the material constitutive model, select the material units of the tunnel body, surrounding rock mass and lining structure, and assign the corresponding material physical and mechanical parameters to the corresponding material units;

S32. According to the preset model initial conditions and boundary conditions, based on the principle of dense key parts and gradually sparse outwards, the material constitutive model is meshed to obtain the corresponding construction physical model.

Beneficial effects: In this scheme, a series of guidelines and principles are used to achieve a true restoration of the physical model of small clearance highway tunnels, which greatly improves the authenticity and reliability of model construction; when establishing the physical model , this plan is based on the geology, design, and construction data of the on-site engineering, and has the uniqueness and practicality of the object. At the same time, in the process of establishing the physical model, the model is given different structures, that is, it is divided into corresponding tunnel bodies, surrounding rocks body and lining structure, and then through the setting of the yield criterion, the deformation of the model structure can be accurately described, which greatly improves the authenticity and accuracy of the physical model construction. At the same time, specific materials are selected according to the characteristics of each structure, so that the corresponding The structure is more in line with the real scene, so that the simulated physical model will be more realistic, providing more accurate data for the calculation of the final result, and greatly improving the accuracy of later stability assessment.

Preferably, as an improvement, the Drucker-Prager yield criterion is:

in the formula is the average stress;/> is the bias stress;/> is the material constant;/> For Mises in the yield criterion/> ,C is cohesion,/> is the internal friction angle.

Beneficial effects: In this scheme, the deformation of materials such as rocks, concrete and soil can be accurately described through the setting of the Drucker-Prager yield criterion, thereby achieving the accuracy of material deformation and being more realistic. .

Preferably, as an improvement, the lining structure needs to be passivated during the calculation of the formation's self-gravity field, and the lining structure needs to be activated during the calculation of the tunnel construction process.

Beneficial effects: Reasonable activation and passivation of the lining structure can make the respective solution results more realistic and realistic.

Description of drawings

Figure 1 is a flow chart of the construction stability evaluation method of small clearance highway tunnels in complex geological environments in Embodiment 1 of the present invention.

Figure 2 is a schematic diagram of the geometric model in Embodiment 1 of the present invention.

Figure 3 is a unit structure diagram of silicond92 in Embodiment 1 of the present invention.

Figure 4 is a schematic diagram of the minimum principal stress of the lining structure in Embodiment 1 of the present invention.

Figure 5 is a schematic diagram of the maximum principal stress of the lining structure in Embodiment 1 of the present invention.

FIG. 6 is a schematic diagram of vertical displacement increment in Embodiment 1 of the present invention.

FIG. 7 is a schematic diagram of horizontal displacement increment in Embodiment 1 of the present invention.

Figure 8 is a schematic diagram of physical model constraints in Embodiment 1 of the present invention.

Detailed ways

The following is further detailed through specific implementation methods:

The embodiment is basically as shown in Figure 1: a construction stability assessment method for small clearance highway tunnels in complex geological environments, including the following steps:

S1. Obtain the engineering information of the corresponding small clearance highway tunnel. The engineering information includes design data information, construction data information and geological data information; in this embodiment, the design data information includes tunnel design plan, design cross-section, left and right The location relationship characteristics of line tunnels, construction data and information include construction methods, support methods, and support material properties; geological data and information include stratigraphic lithology, physical and mechanical properties of surrounding rocks, geological structures, and hydrogeological conditions.

S2. Based on the obtained design data information, establish a construction geometric model of the small clearance highway tunnel. The geometric model includes the tunnel body, surrounding rock mass and lining structure; in this embodiment, ANSYS simulation software is used, combined with the objects Based on the construction design data of the project, a small clearance highway tunnel construction geometric model is established. The geometric model unit must include the tunnel body, surrounding rock mass, and lining structure. The geometric module is shown in Figure 2.

S3. Based on the construction geometric model, as well as the obtained design data information, construction data information and geological data information, and based on the Drucker-Prager yield criterion, establish the construction physical model of the small clearance highway tunnel;

The S3 includes the following steps:

S30. Based on the obtained geological data information and geometric model, and based on the Drucker-Prager yield criterion, construct a material constitutive model suitable for the small clearance highway tunnel; specifically, the Drucker-Prager yield criterion is:

in the formula is the average stress;/> is the bias stress;/> is the material constant;/> For Mises in the yield criterion/> ,C is cohesion,/> is the internal friction angle.

S31. According to the material constitutive model, select the material units of the tunnel body, surrounding rock mass and lining structure, and assign the corresponding material physical and mechanical parameters to the corresponding material units; in this embodiment, the tunnel and surrounding rock use the siold92 unit , as shown in Figure 3, this unit is a 10-node quadratic high-precision unit with a coordinated displacement property function that can adapt to irregular shapes without losing too much accuracy. The lining structure is thin and hard and can The shell63 unit is used, and the corresponding material physical and mechanical parameters are assigned to the structural unit. In this embodiment, after the corresponding model is obtained, the model will be divided into blocks, that is, divided according to the actual structure of the project, and divided into tunnel body, surrounding rock body and lining structure. Still not enough, this embodiment also uses the yield criterion to actually express and display the deformation of these structures, making it more realistic. At the same time, when selecting materials for these structures, different structures correspond to different materials, that is, according to The actual materials corresponding to the structure are selected, which greatly improves the authenticity and accuracy of the entire physical model construction and provides accurate information for subsequent stability assessment.

S32. According to the preset model initial conditions and boundary conditions, based on the principle of dense key parts and gradually sparse outwards, the material constitutive model is meshed to obtain the corresponding construction physical model. In this embodiment, as shown in Figure 8, generally, corresponding horizontal fixed constraints are applied to the left, right, front, and back of the model, that is, constraints in the three directions of X, Y, and Z, and vertical constraints are applied to the bottom of the model. fixed constraints, and the upper surface of the model is the free surface.

S4. According to the design data information, construction data information and geological data information, based on the construction geometric model and construction physical model, carry out numerical simulation simulation during the construction process of the small clearance highway tunnel, and generate corresponding solution results; The numerical simulation simulation solution includes the solution of the ground's self-gravity stress field and the solution of the tunnel construction process; the solution results include the maximum principal stress of the lining structure, the minimum principal stress of the lining structure, the horizontal displacement of the lining structure, and the vertical displacement of the lining structure ; In this embodiment, the lining structure needs to be passivated when calculating the self-gravity field of the formation, and the lining structure needs to be activated when calculating the tunnel construction process after the excavation is completed.

S5. According to the generated maximum principal stress of the lining structure, the minimum principal stress of the lining structure, the horizontal displacement of the lining structure and the vertical displacement of the lining structure, based on the strength parameters of the lining structure and relevant standards, the construction process of the small clearance highway tunnel is stable Conduct a comprehensive assessment and generate corresponding assessment results. In this embodiment, after the solution is completed, the maximum principal stress and minimum principal stress of the lining structure will be analyzed based on the solution, so that the maximum compressive stress and maximum tensile stress suffered by the lining structure can be obtained. Determine whether these two ratios exceed the strength of the material corresponding to the lining structure. If they exceed, it means that the stability of the tunnel construction project is relatively poor. At the same time, the vertical and horizontal displacements of the lining structure will also be analyzed, and Compare the corresponding horizontal displacement amount of the lining structure and the vertical displacement amount of the lining structure with the standard regulations to determine whether they meet the standards. In this embodiment, the corresponding standard regulations are a series of regulations during the construction process of the corresponding lining structure. In this way, the stability of the tunnel construction process can be evaluated. Through the dual and comprehensive judgment of the stress field and displacement field, the stability of the construction process of the small clearance highway tunnel can be judged, which greatly improves the accuracy of the stability evaluation. The maximum principal stress and minimum principal stress of the lining structure, as well as the horizontal displacement of the lining structure and the vertical displacement of the lining structure are shown in Figures 4, 5, 6, and 7.

The above are only embodiments of the present invention, and common knowledge such as specific technical solutions and/or characteristics that are known in the scheme are not described in detail here. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the technical solution of the present invention. These should also be regarded as the protection scope of the present invention and will not affect the implementation of the present invention. The effect and practicality of the patent. The scope of protection claimed in this application shall be based on the content of the claims, and the specific implementation modes and other records in the description may be used to interpret the content of the claims.

Claims (3)

1. The construction stability assessment method of small clearance highway tunnels in complex geological environment is characterized by: including the following steps: S1. Obtain the engineering information of the corresponding small clearance highway tunnel. The engineering information includes design data information, construction data information and geological data information; S2. Based on the obtained design data information, establish a construction geometric model of the small clearance highway tunnel. The geometric model includes the tunnel body, surrounding rock mass and lining structure; S3. Based on the construction geometric model, as well as the obtained design data information, construction data information and geological data information, and based on the Drucker-Prager yield criterion, establish the construction physical model of the small clearance highway tunnel; S4. According to the design data information, construction data information and geological data information, based on the construction geometric model and construction physical model, carry out numerical simulation simulation during the construction process of the small clearance highway tunnel, and generate corresponding solution results; The numerical simulation simulation solution includes the solution of the ground's self-gravity stress field and the solution of the tunnel construction process; the solution results include the maximum principal stress of the lining structure, the minimum principal stress of the lining structure, the horizontal displacement of the lining structure, and the vertical displacement of the lining structure ; S5. According to the generated maximum principal stress of the lining structure, the minimum principal stress of the lining structure, the horizontal displacement of the lining structure and the vertical displacement of the lining structure, based on the strength parameters of the lining structure and the standard regulations, the stability of the construction process of the small clearance highway tunnel is determined. Conduct comprehensive assessment and generate corresponding assessment results; The S3 includes the following steps: S30. Based on the obtained geological data information and geometric model, and based on the Drucker-Prager yield criterion, construct a material constitutive model suitable for the small clearance highway tunnel; S31. According to the material constitutive model, select the material units of the tunnel body, surrounding rock mass and lining structure, and assign the corresponding material physical and mechanical parameters to the corresponding material units; S32. According to the preset model initial conditions and boundary conditions, based on the principle of dense key parts and gradually sparse outwards, the material constitutive model is meshed to obtain the corresponding construction physical model. 2. The method for evaluating the construction stability of small clearance highway tunnels in complex geological environments according to claim 1, characterized in that: the Drucker-Prager yield criterion is: in the formula is the average stress;/> is the bias stress;/> is the material constant;/> For Mises in the yield criterion/> ,C is cohesion,/> is the internal friction angle. 3. The method for evaluating the construction stability of small clear-distance highway tunnels in complex geological environments according to claim 2, characterized in that: when calculating the self-gravity field of the formation, it is necessary to passivate the lining structure. The lining structure needs to be activated when calculating.