Dislocated belt creep testing device
By using a slip zone creep testing device to conduct shear creep tests inside the test tunnel, the problem of on-site testing was solved, and the creep parameters of the slip zone were reliably obtained, ensuring the long-term safety of hydropower projects.
Patent Information
- Application Number
- CN202520449828.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-14
- Publication Date
- 2026-02-24
- Estimated Expiration
- 2035-03-14
AI Technical Summary
Existing technologies make it difficult to conduct on-site creep tests of fault zones, especially due to the difficulty in obtaining rock samples from fault zones, which affects the long-term safe operation of hydropower projects.
A creep testing device for slip zones is provided, comprising a normal loading mechanism, a tangential loading mechanism, and a deformation monitoring and acquisition system. It can conduct shear creep tests in a test chamber, and combined with a pressure-stabilizing load system, it ensures the stability of the load and the scientific nature of the data acquisition.
It enables on-site shear creep testing, maintains the original state of the slip zone, is simple and easy to implement, provides highly reliable data, effectively obtains creep parameters, and ensures the long-term safety of hydropower projects.
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Figure CN223940700U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of geotechnical engineering, in particular to a dislocation zone creep testing device. BACKGROUND
[0002] Geological conditions and geotechnical properties determine the site selection, design, construction and operation of hydropower projects, and are key factors for the safety and stability of such large geotechnical projects. In addition to faults, fissures and other fracture structures, the geological structure of the hub area of many hydropower stations in Southwest China also includes interlayer dislocation zones and intralayer dislocation zones, and in particular when the interlayer dislocation zone crosses the underground powerhouse, the deep deformation of the surrounding rock caused by the interlayer dislocation zone has a major impact on the overall safety of the project. Dislocation zones often contain argillaceous fillings, and under the action of long-term load, they all have creep characteristics. Therefore, the creep properties of dislocation zones must be considered in the design and construction of hydropower stations, which is of great significance for long-term safe operation. The creep test in the related art is generally carried out indoors, but due to the difficulty in obtaining dislocation zone rock samples, a device and method for carrying out a creep test on site are needed. CONTENT OF THE UTILITY MODEL
[0003] The first aspect of the present application provides a dislocation zone creep testing device, which can carry out a creep test on site, has a simple structure and strong implementability.
[0004] The dislocation zone creep testing device provided by the first aspect of the present application is used to carry out a shear creep test on a test piece in a test hole and obtain dislocation zone creep parameters, and specifically comprises:
[0005] a normal loading mechanism, which is longitudinally arranged at the top of the test piece, and is configured to apply a predetermined constant normal load to the test piece;
[0006] a tangential loading mechanism, which is transversely arranged at one end of the test piece, and is configured to apply a stepwise changing tangential load to the test piece;
[0007] a deformation monitoring and collecting system, which comprises a marker, a normal dial gauge, a tangential dial gauge and a deformation data collecting module, the marker is arranged on the side surface of the test piece, and the normal dial gauge and the tangential dial gauge are in data connection with the deformation data collecting module and are respectively used to collect the normal and tangential displacement information of the marker.
[0008] In addition, the dislocation zone creep testing device provided by the present application can also have the following additional technical features:
[0009] In an alternative solution, the normal loading mechanism comprises a normal jack and a first force transmission column, the first force transmission column being arranged on the side of the normal jack away from the test piece; the tangential loading mechanism comprises a tangential jack and a second force transmission column, the second force transmission column being arranged on the side of the tangential jack away from the test piece.
[0010] In an alternative solution, the test piece is provided with a pad on the side facing the normal loading mechanism and the tangential loading mechanism respectively; the normal loading mechanism further comprises a ball bearing row arranged between the pad and the normal jack, and the tangential loading mechanism further comprises a push head arranged between the pad and the tangential jack.
[0011] In an alternative solution, the fault zone creep test device further comprises a constant load system connected with the normal jack and the tangential jack respectively, and used for ensuring that the normal jack and the tangential jack continuously and stably output the preset load.
[0012] In an alternative solution, the fault zone creep test device has a test state, in which the test piece is arranged on the pre-shear surface of the leaking fault zone, and the normal loading mechanism and the tangential loading mechanism are respectively in abutment with the test piece and apply load.
[0013] The second aspect of the present application provides a fault zone creep test method, which adopts the fault zone creep test device in the first aspect of the present application to perform creep test, and comprises the following steps:
[0014] 1) Selecting a fault zone outcrop position suitable for in-situ shear creep test, and selecting a pre-shear surface position for in-situ shear creep test;
[0015] 2) Preparing a test piece with a target size, and performing curing;
[0016] 3) Installing the fault zone creep test device;
[0017] 4) Setting the load of the normal loading mechanism and the tangential loading mechanism, and performing creep test;
[0018] 5) Performing data analysis on the data obtained in the test, and obtaining shear creep long-term strength.
[0019] In an alternative solution, the step 4) specifically comprises the following steps:
[0020] The normal stress loaded by the normal loading mechanism is not more than 1 MPa, so as to prevent mud or rock debris from being squeezed out from around the shear surface, the normal load is set as a fixed value of 0.1-0.9 MPa, the shear strength of the dislocation zone is estimated according to the set normal load, and the shear stress is applied in stages by the tangential loading mechanism according to the shear strength, the shear stress is divided into five gradients, until failure, the first four load gradients are maintained for 10 days, and the last load gradient is loaded until failure, and the test is stopped;
[0021] During the test, deformation data are recorded, and the data recording interval is: 1 min for recording data once within 1 day after loading, and 10 min for recording displacement data once thereafter, when the displacement data fluctuation is less than or equal to 2 μm at 48 h, the displacement is considered to be stable, and the data interval is 1 h.
[0022] In an alternative scheme, the step 2) comprises the following steps when preparing the test piece:
[0023] The test piece is prepared in a square column shape, the control pre-shear surface is a dislocation zone mudification dislocation surface, and the shear surface area is 2100-2500 cm 2 A 20-60 cm thick protective layer is reserved on the pre-shear surface; in order to make the dislocation surface remain as much as possible, the test hole is an anti-vibration hole to reduce the influence of blasting, and is manually dug during sample preparation; the test sample is prepared by cutting a groove at a test point with a load of 0.2 MPa, the dislocation zone is relaxed, and attention is paid to digging a ditch for drainage, so that the test piece remains in the original state with water.
[0024] In an alternative scheme, the step 5) comprises the following steps:
[0025] According to the test time and displacement data, the time-deformation curve under each gradient shear load is obtained, and each stress value and deformation at the same creep time is intercepted to draw an isochronous stress-strain curve cluster; the yield turning point of the isochronous curve cluster is intercepted, and the long-term shear strength obtained by the shear creep test can be obtained; the test data can also be used to fit a creep model to obtain related model parameters.
[0026] In an alternative scheme, the step 3) comprises the following steps when installing the dislocation zone creep test device:
[0027] First, a base plate is installed on the test piece, then a normal loading mechanism and a tangential loading mechanism are installed, the normal loading mechanism abuts against the top of the test hole, the tangential loading mechanism abuts against the sidewall of the test hole to apply a load, and finally, a mark point is calibrated on the test piece, and a normal dial gauge and a tangential dial gauge are installed.
[0028] The application has the following beneficial effects:
[0029] The slip zone creep testing device and method described in this application allow for on-site shear creep testing, avoiding the sampling difficulties of slip zones encountered in indoor testing. Furthermore, on-site sample preparation preserves the original state of the slip zone to the greatest extent possible. The testing principle is simple and easy to implement. This test method considers the weak nature of the slip zone under directional load and employs a stable load system to ensure the implementation of the creep load. The data acquisition interval is reasonable, scientific, and effective, effectively guaranteeing the reliability of the test results.
[0030] It should be understood that the above general description and the following detailed description are merely exemplary and do not limit this application. Attached Figure Description
[0031] Figure 1 A schematic diagram of the structure of the slip zone creep testing device provided in this application in a specific embodiment;
[0032] Figure 2 A schematic flowchart of the creep test method for the slip zone provided in this application;
[0033] Figure 3 Schematic diagram of shear curves under various loads;
[0034] Figure 4 This is a schematic diagram of a typical isochronous cluster curve.
[0035] Reference numerals: Test hole 1, Specimen 2, Normal loading mechanism 3, Normal jack 31, First force transmission column 32, Ball bearing 33, Tangential loading mechanism 4, Tangential jack 41, Second force transmission column 42, Push head 43, Deformation monitoring and acquisition system 5, Marker 51, Normal dial gauge 52, Tangential dial gauge 53, Deformation data acquisition module 54, Pad 6, Stabilizing load system 7, Leakage slip zone 8, Pre-shear surface 81.
[0036] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. Detailed Implementation
[0037] To better understand the technical solution of this application, the embodiments of this application will be described in detail below with reference to the accompanying drawings.
[0038] It should be understood that the described embodiments are merely some embodiments of this application, and not all embodiments. All other technical solutions obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.
[0039] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.
[0040] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.
[0041] It should be noted that the directional terms such as "upper," "lower," "left," and "right" described in the embodiments of this application are used to describe the angles shown in the accompanying drawings and should not be construed as limiting the embodiments of this application. Furthermore, in the context, it should be understood that when it is mentioned that an element is connected "upper" or "lower" to another element, it can be directly connected to the other element "upper" or "lower," or indirectly connected to the other element "upper" or "lower" through an intermediate element.
[0042] like Figure 1 As shown, the first aspect of this application provides a slip zone creep testing device. This slip zone creep testing device is used to conduct shear creep tests on specimen 2 in a test hole 1 and obtain slip zone creep parameters. It has a simple structure and is highly feasible. Specifically, it includes a normal loading mechanism 3, a tangential loading mechanism 4, and a deformation monitoring and acquisition system 5. The normal loading mechanism 3 is longitudinally arranged at the top of specimen 2 and is configured to apply a preset constant normal load to specimen 2. The tangential loading mechanism 4 is laterally arranged at one end of specimen 2 and is configured to apply a stepped tangential load to specimen 2. The deformation monitoring and acquisition system 5 includes a marker 51, a normal micrometer 52, a tangential micrometer 53, and a deformation data acquisition module 54. The marker 51 is arranged on the side of specimen 2. The normal micrometer 52 and the tangential micrometer 53 are connected to the deformation data acquisition module 54 and are used to collect the normal and tangential displacement information of the marker 51, respectively.
[0043] like Figure 1 As shown, in one specific embodiment, the normal loading mechanism 3 includes a normal jack 31 and a first force transmission column 32, the first force transmission column 32 being disposed on the side of the normal jack 31 away from the specimen 2; the tangential loading mechanism 4 includes a tangential jack 41 and a second force transmission column 42, the second force transmission column 42 being disposed on the side of the tangential jack 41 away from the specimen 2.
[0044] like Figure 1As shown, in one specific embodiment, the specimen 2 has a pad 6 on one side facing the normal loading mechanism 3 and the tangential loading mechanism 4 respectively; the normal loading mechanism 3 also includes a ball bearing row 33, which is disposed between a pad 6 and a normal jack 31; the tangential loading mechanism 4 also includes a pusher head 43, which is disposed between another pad 6 and the tangential jack 41. The ball bearing row 33 and the pusher head 43 can ensure that the pressure applied by the corresponding loading mechanism can be evenly transmitted to the specimen 2, avoiding the problem of inaccurate test results due to excessive local pressure.
[0045] In addition, the slip zone creep test device also includes a pressure stabilizing load system 7, which is connected to the normal jack 31 and the tangential jack 41 respectively, and is used to ensure that the normal jack 31 and the tangential jack 41 continuously and stably output the preset load.
[0046] like Figure 1 As shown, in one specific embodiment, the slip zone creep testing device has a test state. In the test state, the specimen 2 is arranged on the pre-shear surface 81 of the slip zone 8, and the normal loading mechanism 3 and the tangential loading mechanism 4 respectively abut against the specimen 2 and apply load.
[0047] like Figures 2-4 As shown, a second aspect of this application provides a method for testing the creep of a slip zone. This method uses the slip zone creep testing device from the first aspect embodiment to perform creep testing. The method includes the following steps:
[0048] 1) Select a suitable location for the outcrop of the fault zone to conduct the in-situ shear creep test, and select the pre-shear surface 81 location for conducting the in-situ shear creep test.
[0049] The exposed position has sufficient dimensions to meet the preparation standards of specimen 2, and there is enough space in this position for the scheduling of equipment and personnel; the pre-shear surface 81 needs to be typical, and both the upper and lower plates have a certain thickness.
[0050] 2) Prepare specimen 2 of the target size and cure it;
[0051] Manual excavation was carried out using the pre-shear surface 81 as a reference. Specimen 2, with the target dimensions, was prepared according to the "Standard for Testing Methods of Engineering Rock Mass" and then cured. Specifically, specimen 2 was prepared as a square prism, with the pre-shear surface controlled as a muddy slip surface of the slip zone, and the shear surface area ranging from 2100 to 2500 cm². 2A 20-60cm thick protective layer is reserved on the upper part of the pre-shear surface 81. In order to keep the slip surface as intact as possible, the test hole 1 adopts a shock-absorbing hole to reduce the impact of blasting. It is manually excavated during sample preparation. When sampling, a 0.2MPa load is pre-applied to the pilot part to cut the groove and prepare the sample to reduce the loosening of the slip zone. At the same time, attention should be paid to digging a ditch for drainage to keep the specimen 2 in its original water-containing state.
[0052] 3) Install a creep testing device for slip zones;
[0053] During installation, first install the pad 6 on the specimen 2, then install the normal loading mechanism 3 and the tangential loading mechanism 4. The normal loading mechanism 3 abuts against the top of the test hole 1, and the tangential loading mechanism 4 abuts against the side wall of the test hole 1 to apply load. Finally, mark the calibrated point 51 at the specimen 2 and install the normal dial indicator 52 and the tangential dial indicator 53.
[0054] 4) Set the loads for the normal loading mechanism 3 and the tangential loading mechanism 4, and conduct a creep test;
[0055] The specimens were subjected to a constant normal load and a stepped tangential load, with each step maintaining a constant load. The displacement of specimen 2 was recorded throughout the process. Specifically, the normal stress applied by the normal loading mechanism 3 did not exceed 1 MPa to prevent mud or rock debris from being squeezed out from around the shear surface. The normal load was set at a fixed value of 0.1–0.9 MPa. Based on the set normal load, the shear strength of the slip zone was estimated, and based on the shear strength, shear stress was applied in stages through the tangential loading mechanism 4. The shear stress was applied in five gradients until failure. The first four load gradients were maintained for 10 days, and the last load gradient was applied until failure, at which point the test was stopped.
[0056] Deformation data was recorded during the experiment. The data recording intervals were as follows: data was recorded once every 1 minute within 1 day after loading, and then once every 10 minutes thereafter. When the displacement data fluctuation was ≤2μm after 48 hours, the displacement was considered stable, and data was recorded at 1-hour intervals.
[0057] 5) Analyze the data obtained from the experiment to obtain the long-term shear creep strength.
[0058] Based on the test time and displacement data, the time-deformation curves under each level of shear load are obtained, and stress values and deformations at the same creep time are extracted to plot a cluster of isochronous stress-strain curves. The yield inflection point of the isochronous curve cluster is extracted, and the long-term shear strength obtained by the shear creep test can be obtained. The test data can also be used to fit a creep model and obtain relevant model parameters.
[0059] The slip zone creep testing device and method in this application embodiment can conduct shear creep tests on-site, avoiding the sampling difficulties of slip zones in indoor tests. Furthermore, on-site sample preparation preserves the original state of the slip zone to the greatest extent possible. The testing principle is simple and easy to implement. The normal load test takes into account the weak nature of the slip zone, and the use of a stabilizing load system 7 ensures the implementation of the creep load. The data acquisition interval is reasonable, scientific, and effective, effectively guaranteeing the reliability of the test results.
[0060] Example 1:
[0061] This embodiment involves conducting horizontal tunnel exploration for the geology of a hydropower project and identifying the fault zone for on-site testing.
[0062] This study included one set of shear creep tests on the fault zone. The test site was located at the bottom of the PD157 horizontal tunnel at a depth of 103m. The test object was the fault zone within the LS337 layer. The fault zone in the test section was 20–80cm thick, with an orientation of N35°E and SE∠30°. The zone was filled mainly with grayish-white mudstone and rock fragments mixed with mud, and secondary mud was observed on the fault surface. The test section showed severe water seepage, with continuous water flow observed on the tunnel floor.
[0063] Specimen 2 is a square prism shape. The controlled pre-shear surface is a slip-formed slip surface with a shear surface size of 0.5m × 0.5m and an area of 2500cm². 2 The shear load is directed along the fault plane (SE direction). The following measures were taken to maintain the original state of the fault plane: when excavating the test tunnel, anti-vibration holes were used in the tunnel floor to reduce the impact of blasting; a 20-60cm thick protective layer was reserved and manually removed during sample preparation; a preload of 0.2MPa was applied to the test site, and then the groove was cut to prepare the sample to reduce the relaxation of the fault zone; drainage was carried out by digging a trench, and the test site was not submerged in water, remaining in its original water-containing state.
[0064] Test loads: The normal pressure range for 6 points in group 1 was 0.154–0.958 MPa. Shear loads were applied in stages according to the estimated shear strength until failure. Both normal and shear loads were applied using an in-situ creep testing system, which could automatically compensate for pressure to maintain the stability of the test load. The actual test load fluctuation was less than 1.5%.
[0065] Displacement data was automatically collected using a numerical dial gauge. Data was recorded every 1 minute within the first day after loading, and then every 10 minutes thereafter. When the displacement data fluctuation was ≤2μm over 48 hours, the displacement was considered stable, and data was recorded at 1-hour intervals.
[0066] Conduct the experiment and record the data according to the above steps.
[0067] like Figures 3-4As shown, for the shear creep curves under various shear loads, the shear stress and shear displacement values at different times (e.g., t=0h, t=0.5h, t=1h, t=10h, t=100h, etc.) are used to plot the shear displacement u-shear stress τ isochronous cluster curves. Connecting the yield points of the u-τ relationship curves with different durations yields the yield strength curve. This curve tends to flatten with increasing duration, and the intersection of its horizontal asymptote with the τ axis is the creep strength τ∞.
[0068] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A slip zone creep testing device, used to conduct shear creep tests on specimens in a test cavity and obtain slip zone creep parameters, characterized in that, include: A normal loading mechanism is longitudinally disposed at the top of the specimen, and the normal loading mechanism is configured to apply a preset normal constant load to the specimen; A tangential loading mechanism is laterally disposed at one end of the specimen, and the tangential loading mechanism is configured to apply a stepped tangential load to the specimen; A deformation monitoring and acquisition system includes markers, a normal dial gauge, a tangential dial gauge, and a deformation data acquisition module. The markers are located on the side of the specimen. The normal dial gauge and the tangential dial gauge are connected to the deformation data acquisition module and are used to acquire the normal and tangential displacement information of the markers, respectively.
2. The creep testing device for slip zones according to claim 1, characterized in that, The normal loading mechanism includes a normal jack and a first force transmission column, the first force transmission column being disposed on the side of the normal jack away from the specimen; the tangential loading mechanism includes a tangential jack and a second force transmission column, the second force transmission column being disposed on the side of the tangential jack away from the specimen.
3. The creep testing device for slip zones according to claim 2, characterized in that, The specimen has a pad on one side facing the normal loading mechanism and the tangential loading mechanism respectively; the normal loading mechanism also includes a ball bearing row, which is disposed between one of the pads and the normal jack; the tangential loading mechanism also includes a pusher, which is disposed between the other pad and the tangential jack.
4. The creep testing device for slip zones according to claim 2 or 3, characterized in that, The slip zone creep testing device also includes a pressure stabilizing load system, which is connected to the normal jack and the tangential jack respectively, and is used to ensure that the normal jack and the tangential jack continuously and stably output the preset load.
5. The creep testing device for slip zones according to any one of claims 1-3, characterized in that, The creep testing device for the slip zone has a testing state. In the testing state, the specimen is arranged on the pre-shear surface of the slip zone, and the normal loading mechanism and the tangential loading mechanism respectively abut against the specimen and apply load.