Method for measuring surrounding rock stress path in diversion tunnel excavation process
Through in-situ stress inversion and stress path analysis, the stress meter setting depth is determined based on the degree of risk, and the surrounding rock stress is monitored in real time. This solves the problem of insufficient accuracy and range of traditional monitoring methods and achieves more accurate stress state assessment and monitoring.
Patent Information
- Application Number
- CN202411249013.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-06
- Publication Date
- 2025-01-24
AI Technical Summary
The traditional surrounding rock stress monitoring methods have problems such as low measurement accuracy and limited monitoring range, and cannot fully reflect the changes in surrounding rock stress paths.
By obtaining the basic data of the geological conditions and geographical stress distribution of the water diversion tunnel construction site, the ground stress reaction is carried out to determine the degree of risk of all parts of the surrounding rocks, and the depth of the setting of the surrounding rock stress meter is determined according to the degree of risk.
It achieves a more accurate prediction and assessment of the stress state of the surrounding rock during tunnel excavation, comprehensively and accurately captures the changes in the stress state of the surrounding rock at different damage risk areas and different depths, and improves the range and reliability of stress measurement.
Smart Images
Figure CN119354387A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a method for measuring surrounding rock stress path during water diversion tunnel excavation, and is applicable to the technical field of tunnel excavation in water conservancy projects. Background Art
[0002] With the continuous advancement of water conservancy project construction, the safety and economy of the design and construction of water diversion tunnels, as key water conservancy hub structures, have received increasing attention. During the construction of underground projects such as water diversion tunnels, the monitoring and evaluation of the surrounding rock stress state is an important prerequisite for ensuring the safety, stability and long-term operation of the project. The measurement method of the surrounding rock stress path can reflect the dynamic changes of the surrounding rock stress during the tunnel excavation process in real time and accurately, providing an important basis for the design, construction and optimization of support measures of the tunnel. With the continuous development of underground engineering construction, the requirements for the accuracy and reliability of the surrounding rock stress path measurement method are becoming higher and higher.
[0003] Although the traditional surrounding rock stress monitoring arrangement can provide stress data to a certain extent, due to the limitation of measurement technology and the lack of monitoring equipment, there are often problems such as low measurement accuracy and limited monitoring range. In addition, the traditional monitoring arrangement usually only focuses on the stress change at a specific point, while ignoring the distribution of the entire surrounding rock stress field, and cannot fully reflect the changing law of the surrounding rock stress path. Summary of the invention
[0004] The technical problem to be solved by the present invention is: in view of the above-mentioned existing problems, a method for measuring the stress path of the surrounding rock during the excavation of a water diversion tunnel is provided.
[0005] The technical solution adopted by the present invention is: a method for measuring the surrounding rock stress path during the excavation of a water diversion tunnel, characterized in that it includes:
[0006] Obtain the basic data of geological conditions and geostress distribution at the water diversion tunnel construction site, and perform geostress inversion based on the basic data of geological conditions and geostress distribution;
[0007] Based on the in-situ stress inversion results of various parts of the surrounding rock of the diversion tunnel, determine the risk level of various parts of the surrounding rock of the diversion tunnel;
[0008] Based on the risk level of each part of the surrounding rock of the water diversion tunnel, determine the setting depth of the surrounding rock stress gauge at each part of the surrounding rock of the water diversion tunnel;
[0009] Based on the determined setting depths of surrounding rock stress gauges at various locations of the diversion tunnel surrounding rock, the arrangement of surrounding rock stress gauges is completed;
[0010] The surrounding rock stress gauge is used to monitor in real time the stress magnitude and direction of the surrounding rock at various locations and depths around the water diversion tunnel.
[0011] The obtaining of the basic data of geological conditions and geostress distribution at the water diversion tunnel construction site, and performing geostress inversion based on the basic data of geological conditions and geostress distribution, includes:
[0012] Excavation to form a cross tunnel that intersects with the unexcavated tunnel section of the diversion tunnel;
[0013] Conduct on-site geological surveys and preliminary geostress measurements based on cross-holes to obtain basic data on geological conditions and geostress distribution;
[0014] Based on the basic data of geological conditions and geostress distribution, combined with the numerical calculation model determined based on the test data, geostress inversion is carried out to obtain the numerical simulation parameters of each area of the surrounding rock of the water diversion tunnel.
[0015] The risk level of each part of the surrounding rock of the water diversion tunnel is determined based on the in-situ stress inversion results of each part of the surrounding rock of the water diversion tunnel, including:
[0016] Based on the inversion results of geostress and combined with the preset risk level classification standard values, the surrounding rock is divided into high-risk, medium-risk and low-risk areas.
[0017] Also includes:
[0018] Based on the changing patterns of stress magnitude and direction of the surrounding rock at various locations and depths around the water diversion tunnel, a generalized stress path diagram was summarized and drawn to intuitively display the changing patterns of surrounding rock stress during the excavation process.
[0019] The beneficial effects of the present invention are as follows: the present invention adopts a numerical calculation model to perform ground stress inversion and stress path analysis, which can more accurately predict and evaluate the stress state of the surrounding rock during tunnel excavation, and provide a scientific basis for construction decisions.
[0020] The present invention determines the risk degree of each part of the surrounding rock based on the inversion results of the ground stress, and determines the setting depth of the surrounding rock stress gauge at each part of the surrounding rock. Through the monitoring arrangement of the present invention, the changes in the stress state of different damage risk areas and different depths of the surrounding rock can be fully and accurately captured, thereby improving the range and reliability of stress measurement.
[0021] The present invention has the characteristics of simple operation, wide monitoring range, strong real-time performance, etc., and can meet the needs of water diversion tunnel excavation projects of different scales and complexities. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Figure 1 Schematic diagram of the plan layout of the embodiment.
[0023] Figure 2 It is a cross-sectional view of an embodiment.
[0024] 1. Cross-through hole; 2. Installation hole; 3. Surrounding rock stress gauge; 4. Excavated tunnel; 5. Unexcavated tunnel; 6. Auxiliary tunnel. DETAILED DESCRIPTION
[0025] This embodiment is a method for measuring surrounding rock stress path during water diversion tunnel excavation, which specifically includes the following steps:
[0026] S1. Obtain the basic data of geological conditions and geostress distribution at the water diversion tunnel construction site, and perform geostress inversion based on the basic data of geological conditions and geostress distribution.
[0027] S1-1. Before the diversion tunnel is excavated, auxiliary tunnels and cross tunnels are excavated. The cross tunnels intersect with the unexcavated tunnel section of the diversion tunnel to facilitate the subsequent monitoring arrangement.
[0028] S1-2. Conduct detailed on-site geological surveys and preliminary geostress measurements based on cross-holes to obtain basic data on geological conditions and geostress distribution.
[0029] S1-3. Determine the mechanical parameters of the surrounding rock through indoor tests, which provides an important basis for the establishment of the numerical calculation model. On the basis of the numerical calculation model, combined with the basic data of geological conditions and ground stress distribution, conduct ground stress inversion to obtain more reliable numerical simulation parameters.
[0030] S2. Based on the inversion results of the geostress of various parts of the surrounding rock of the water diversion tunnel, determine the risk level of various parts of the surrounding rock of the water diversion tunnel.
[0031] According to the numerical simulation parameters and the preset risk classification standard values, the surrounding rock of the diversion tunnel is divided into high-risk, medium-risk and low-risk areas.
[0032] S3. Based on the risk level of each part of the surrounding rock of the water diversion tunnel, determine the installation depth of the surrounding rock stress gauge at each part of the surrounding rock of the water diversion tunnel.
[0033] The specific relationship between the risk level and the setting depth in this embodiment is based on the principle of optimizing the monitoring network layout based on the risk assessment results.
[0034] Specifically, in high-risk areas, due to the high risk of surrounding rock instability, more dense monitoring points are needed to capture subtle stress changes. Therefore, the stress gauges are set up at multiple monitoring points at different depths to fully grasp the three-dimensional distribution and dynamic changes of surrounding rock stress at different depths in the area. This is convenient for obtaining the stress evolution law and stress difference change in the damaged area after the surrounding rock ruptures, thereby providing data support for the subsequent engineering surrounding rock stability analysis.
[0035] In the medium-risk area, the density of monitoring points can be appropriately reduced, but it is still necessary to ensure that the stress changes at key locations are effectively monitored. At this time, the setting depth of the stress gauge should focus on the key depths that are most likely to reflect the changes in the surrounding rock stability.
[0036] In low-risk areas, confirmatory monitoring is mainly carried out. The stress gauges can be set relatively sparsely and selectively arranged at representative depths to verify the results of the surrounding rock stability analysis and provide basic data for possible future engineering adjustments or expansions.
[0037] This relationship is designed to improve monitoring efficiency and accuracy, ensure that limited resources are used in areas that need the most attention, and avoid wasting resources by overinvesting in low-risk areas. By adjusting the monitoring density and depth according to the risk level, key changes in surrounding rock stress can be captured more accurately, providing strong support for engineering safety warning and decision-making.
[0038] According to this relationship setting, high-risk areas are given priority to ensure that key information is not missed, while reducing unnecessary monitoring in low-risk areas to improve overall monitoring efficiency. Monitoring resources are rationally allocated according to the degree of risk to avoid waste of resources, while ensuring the scientificity and effectiveness of monitoring data. Through the refined layout of the monitoring network, abnormal surrounding rock stress can be discovered earlier, providing sufficient time for engineering safety warning. Based on comprehensive monitoring data, the stability of the surrounding rock can be evaluated more accurately, providing a scientific basis for engineering design, construction adjustment and later maintenance.
[0039] S4. Based on the determined setting depths of surrounding rock stress gauges at various locations of the surrounding rock of the water diversion tunnel (radial arrangement depth of the tunnel), the arrangement of surrounding rock stress gauges is completed.
[0040] After the risk area is divided, surrounding rock stress meters at different depths are set up in the three risk areas to monitor in real time the changes in the stress magnitude and direction of the surrounding rock at different locations and depths around the excavated tunnel.
[0041] In this embodiment, an installation hole is set in the surrounding rock of the water diversion tunnel through a cross-hole, and a surrounding rock stress meter is arranged in the installation hole.
[0042] S5. Use surrounding rock stress gauges to monitor in real time the stress magnitude and direction of the surrounding rocks at different locations and depths around the water diversion tunnel.
[0043] During the tunnel excavation process, these monitoring data are transmitted to the data processing center in real time through the data transmission system, and the precise stress magnitude and direction change law at different parts and depths around the excavated tunnel are obtained. Finally, based on the stress path data, a stress path generalization diagram is summarized and drawn to intuitively show the change law of surrounding rock stress during the excavation process, providing an important reference basis for indoor test research on the safe construction of tunnels.
Claims
1. A method for measuring surrounding rock stress path during water diversion tunnel excavation, characterized in that: include: Obtain the basic data of geological conditions and geostress distribution at the water diversion tunnel construction site, and perform geostress inversion based on the basic data of geological conditions and geostress distribution; Based on the in-situ stress inversion results of various parts of the surrounding rock of the diversion tunnel, determine the risk level of various parts of the surrounding rock of the diversion tunnel; Based on the risk level of each part of the surrounding rock of the water diversion tunnel, determine the setting depth of the surrounding rock stress gauge at each part of the surrounding rock of the water diversion tunnel; Based on the determined setting depths of surrounding rock stress gauges at various locations of the diversion tunnel surrounding rock, the arrangement of surrounding rock stress gauges is completed; The surrounding rock stress gauge is used to monitor in real time the stress magnitude and direction of the surrounding rock at various locations and depths around the water diversion tunnel.
2. The method for measuring surrounding rock stress path during diversion tunnel excavation according to claim 1, characterized in that: The obtaining of the basic data of geological conditions and geostress distribution at the water diversion tunnel construction site, and performing geostress inversion based on the basic data of geological conditions and geostress distribution, includes: Excavation to form a cross tunnel that intersects with the unexcavated tunnel section of the diversion tunnel; Conduct on-site geological surveys and preliminary geostress measurements based on cross-holes to obtain basic data on geological conditions and geostress distribution; Based on the basic data of geological conditions and geostress distribution, combined with the numerical calculation model determined based on the test data, geostress inversion is carried out to obtain the numerical simulation parameters of each area of the surrounding rock of the water diversion tunnel.
3. The method for measuring surrounding rock stress path during diversion tunnel excavation according to claim 1, characterized in that: The risk level of each part of the surrounding rock of the water diversion tunnel is determined based on the in-situ stress inversion results of each part of the surrounding rock of the water diversion tunnel, including: Based on the inversion results of geostress and combined with the preset risk level classification standard values, the surrounding rock is divided into high-risk, medium-risk and low-risk areas.
4. The method for measuring surrounding rock stress path during diversion tunnel excavation according to claim 1, characterized in that: Also includes: Based on the changing patterns of stress magnitude and direction of the surrounding rock at various locations and depths around the water diversion tunnel, a generalized stress path diagram was summarized and drawn to intuitively display the changing patterns of surrounding rock stress during the excavation process.