Reservoir dam safety performance test method and device considering valley amplitude deformation

Abstract

The embodiment of the invention discloses a reservoir dam safety performance test method and device considering valley amplitude deformation, and the method comprises the steps: constructing a reservoir dam model, setting a displacement meter and a stress meter or a strain meter, and connecting the displacement meter and the stress or strain meter with a data collection device; a transverse loading and unloading device is arranged at the dam shoulder part of the reservoir dam model to induce the dam shoulder part to generate valley amplitude deformation, a longitudinal loading and unloading device is arranged on the reservoir dam model to simulate water stress, and a vertical loading and unloading device is arranged on the reservoir dam model to simulate self-weight stress of the reservoir dam model; the data of the displacement meter and the stress or strain meter in the whole process are collected in real time, and the stress or strain and valley amplitude deformation conditions of the dam body under different transverse loads are obtained, so that the safety margin of the dam is evaluated. The transverse load is applied to the dam model through the transverse loading and unloading system to simulate the valley amplitude deformation of the dam, so that the real stress-strain data of the dam body under the valley amplitude deformation are obtained, and a basis is provided for evaluating the safety of the dam.

Description

Technical Field

[0001] This invention belongs to the technical field of dam geomechanics, specifically relating to a test method and apparatus for the safety performance of reservoir dams considering valley deformation. Background Technology

[0002] Currently, water conservancy and hydropower projects are typically built in high mountain and canyon areas with complex geological conditions. The safety and stability of dams and their foundations and abutments are crucial and important, involving deformation and failure processes ranging from elastic to plastic and from continuous to discontinuous. The reservoir bank deformation induced by water impoundment after dam construction directly impacts the working performance of the dam structure and the overall safety of the project. Timely understanding of the actual deformation state of the reservoir bank rock mass and dam structure during reservoir impoundment is of great significance for project safety. When constructing high dams and reservoirs in high mountain and canyon areas, water impoundment alters the physical and mechanical properties of the rock mass in the reservoir area, causing contraction deformation of the rock mass on both sides of the valley towards the riverbed, known as "valley width deformation." This deformation applies additional horizontal constraint stress to the dam body, especially the abutments of arch dams, altering the original stress distribution and potentially leading to stress concentration, local yielding, crack development, and even overall stability problems. Traditional three-dimensional geomechanical model tests primarily focus on simulating loads such as dam body weight and water pressure, failing to effectively incorporate the crucial factor of valley deformation. This leads to discrepancies between model test results and actual engineering conditions, failing to accurately reflect the true working behavior of the dam body, especially its abutments. This discrepancy directly impacts the assessment of safety margins in dam design and the formulation of deformation control strategies during construction. Therefore, developing a model test method that can effectively simulate and consider the influence of valley deformation is of urgent practical significance and important theoretical value for improving the scientific design and construction safety of high dam projects. Summary of the Invention

[0003] One objective of this invention is to address the shortcomings of existing technologies by providing a test method for the safety performance of reservoir dams under valley deformation. This method applies lateral loads to the dam model using a lateral loading and unloading system to simulate valley deformation of the dam, thereby obtaining real stress and strain data of the dam body under valley deformation, and providing a reliable basis for evaluating dam safety.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0005] A test method for assessing the safety performance of a reservoir dam under valley deformation includes the following steps:

[0006] Step 1: Construct a reservoir dam model, embed stress gauges or strain gauges at the measuring points inside the reservoir dam model, install displacement gauges on the dam surface, and electrically connect the stress gauges or strain gauges and displacement gauges to the data acquisition device.

[0007] Step 2: Install a transverse loading and unloading device perpendicular to the river direction at the dam shoulder of the reservoir dam model, install a longitudinal loading and unloading device along the river direction on the reservoir dam model, and install a vertical loading and unloading device in the height direction of the reservoir dam model.

[0008] Step 3: Based on the water storage status of the reservoir dam, control the longitudinal loading and unloading device to apply corresponding longitudinal loads to the reservoir dam model to simulate water stress, and based on the dam's self-weight, control the vertical loading and unloading device to apply vertical loads to the reservoir dam model to simulate the dam's self-weight stress.

[0009] Then, the transverse loading and unloading device is controlled to apply transverse loads to the reservoir dam model to induce valley deformation. During the application of transverse loads, the longitudinal and vertical loads are kept constant. By applying transverse loads in stages, the reservoir dam model will produce valley deformations of different degrees until the reservoir dam model cracks.

[0010] Step 4: Collect stress gauge or strain gauge and displacement gauge data in real time throughout the entire process using a data acquisition device. Based on the obtained data, obtain the dam body stress or strain and valley deformation under different lateral loading conditions, and evaluate the dam safety margin under different working conditions.

[0011] Furthermore, multiple stress gauges or strain gauges are installed along the height direction inside the dam.

[0012] Furthermore, the lateral loading and unloading device and the longitudinal loading and unloading device are applied at different heights according to the test results.

[0013] Furthermore, when collecting data, first collect data from stress gauges or strain gauges and displacement gauges when only longitudinal and vertical loads are applied, and then collect data from stress gauges or strain gauges and displacement gauges when lateral, longitudinal and vertical loads are applied simultaneously.

[0014] Furthermore, the stress data of the dam model is calculated using data obtained from stress gauges, the deformation data is calculated using data obtained from strain gauges, and the valley deformation is calculated using data obtained from displacement gauges. The lateral load, valley deformation, and stress or strain data are fitted to obtain the functional relationship between the lateral load of the dam model before cracking and the valley deformation and stress or deformation.

[0015] Furthermore, in step 4, the lateral load F of the reservoir dam model is obtained through curve fitting. h With valley deformation and stress or deformation The functional relationship between them is:

[0016] ;

[0017] Where a, b, c, and d are coefficients obtained through regression analysis of experimental data.

[0018] Furthermore, in step 4, the valley deformation threshold of the reservoir dam model is obtained through experiments, and the safety margin of the dam is evaluated based on the valley deformation threshold and the above functional relationship.

[0019] Another object of the present invention is to provide an apparatus for implementing the above-described test method for considering the safety performance of a reservoir dam under valley deformation, comprising:

[0020] The reservoir dam model was prepared in scale based on the actual data of the dam to be studied.

[0021] The data acquisition system includes a data acquisition device and a displacement gauge and a stress gauge or strain gauge electrically connected thereto. The displacement gauge is installed on the surface of the reservoir dam model, and the stress gauge or strain gauge is embedded inside the reservoir dam model.

[0022] The loading device includes a lateral loading / unloading device, a longitudinal loading / unloading device, and a vertical loading / unloading device. The lateral loading / unloading device is set perpendicular to the river direction at the abutment of the reservoir dam model. The longitudinal loading / unloading device is set along the river direction on the reservoir dam model. The vertical loading / unloading device is set along the height direction of the reservoir dam model. The lateral loading / unloading device is used to apply lateral loads to the reservoir dam model to induce valley deformation. The longitudinal loading / unloading device is used to apply longitudinal loads to the reservoir dam model to simulate water stress. The vertical loading / unloading device is used to apply vertical loads to the reservoir dam model to simulate the self-weight stress of the reservoir dam.

[0023] Furthermore, the displacement gauges are arranged along the river direction.

[0024] Compared with existing technologies, the beneficial effects of this invention are as follows: Valley deformation can cause horizontal stress redistribution in the dam abutment area, which may lead to stress concentration, local cracking, or even instability in the dam body. Traditional design methods do not fully consider this effect, which can easily lead to insufficient structural safety margin. This invention fully considers this point. It applies lateral loads to the dam model through a lateral loading and unloading system to accurately simulate the valley deformation induced by reservoir impoundment. By applying lateral loads in stages until the dam model cracks, the influence of different valley deformations on the dam stress and strain is obtained. This not only facilitates the study of dam abutment deformation and failure mechanisms, but also obtains stress and strain laws that are more in line with engineering practice. It provides data support for optimizing dam shape, strengthening dam abutment support, and adjusting material parameters, thereby improving the scientific nature and safety of the design. In addition, the method of this invention can obtain the valley deformation threshold of the dam. Based on this threshold, the safety margin of the dam can be evaluated. It can also be used to formulate scientific construction sequence and impoundment rate control schemes, and set deformation monitoring and early warning thresholds during the construction period. Attached Figure Description

[0025] Figure 1 This is a top view of the test apparatus for considering the safety performance of a reservoir dam under valley deformation, as described in an embodiment of the present invention.

[0026] Figure 2 This is a side view of the test apparatus for assessing the safety performance of a reservoir dam under valley deformation, as described in an embodiment of the present invention. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0028] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0029] The present invention will be further described below with reference to specific embodiments, but these are not intended to limit the scope of the invention.

[0030] like Figure 1 and Figure 2 As shown in the figure, this invention discloses an experimental device for assessing the safety performance of a reservoir dam under valley deformation, comprising a reservoir dam model 1, a data acquisition system, and a loading device. The reservoir dam model 1 is fabricated proportionally based on the actual structure and material properties of the dam under study. The data acquisition system includes a data acquisition device 2 and displacement gauges 3 and stress gauges or strain gauges 4 electrically connected to it. The stress gauges or strain gauges 4 are pre-embedded inside the dam model 1 to measure the stress or deformation of the dam model 1. In this embodiment, to improve measurement accuracy, multiple stress gauges or strain gauges 4 are installed along the height direction of the dam model 1. The displacement gauges 3 are installed on the surface of the dam model 1 to measure the valley deformation of the dam model 1. In this embodiment, the displacement gauges 1 are arranged along the river direction.

[0031] The loading device includes a lateral loading / unloading device 5, a longitudinal loading / unloading device 6, and a vertical loading / unloading device. The lateral loading / unloading device 5 is positioned perpendicular to the river direction at the abutment of the reservoir dam model 1. The longitudinal loading / unloading device 6 is positioned along the river direction on one side of the reservoir dam model 1. The vertical loading / unloading device is positioned on the top of the reservoir dam model. The lateral loading / unloading device 5 applies a lateral load to the reservoir dam model 1 to induce valley deformation. The longitudinal loading / unloading device 6 applies a longitudinal load to the reservoir dam model 1 to simulate water stress. The vertical loading / unloading device applies a vertical load to the reservoir dam model 1 to simulate the self-weight stress of the reservoir dam. A reaction frame 7 is erected outside the reservoir dam model 1 to provide reaction support for lateral and longitudinal loading. The lateral loading / unloading device 5, the longitudinal loading / unloading device 6, and the vertical loading / unloading device are all connected to a high-pressure oil pump 8 via high-pressure oil pipes. A pressure sensor 9 and a pressure gauge 10 are also installed on the high-pressure oil pipes. The pressure sensor 9 is electrically connected to a data acquisition device 2 to collect loading data.

[0032] The method for testing the safety performance of a reservoir dam using the above-mentioned testing apparatus includes the following steps:

[0033] Step 1: Construct a reservoir dam model 1 based on the actual structure and material properties of the reservoir dam, and embed stress gauges or strain gauges 4 at the measuring points inside the reservoir dam. Set multiple displacement gauges 3 on the surface of the dam model. All displacement gauges 3 and stress gauges or strain gauges 4 are electrically connected to the data acquisition device 2 via cables.

[0034] Step 2: Install a lateral loading and unloading device 5 perpendicular to the river direction at the abutment of the reservoir dam model 1, and install a longitudinal loading and unloading device 6 along the river direction on the reservoir dam model 1. The longitudinal loading and unloading device 6 is located upstream of the reservoir dam model 1 to simulate upstream water pressure. Install a vertical loading and unloading device in the height direction of the reservoir dam model 1. Finally, install a reaction frame 7 on the outside of the dam model 1 to provide reaction support for lateral and longitudinal loading.

[0035] Step 3: Based on the water storage status of the reservoir dam, control the longitudinal loading and unloading device 6 to apply the corresponding longitudinal load to the reservoir dam model 1 to simulate water stress, and based on the dam's self-weight, control the vertical loading and unloading device 7 to apply the vertical load to the reservoir dam model 1 to simulate the dam's self-weight stress.

[0036] Then, the transverse loading and unloading device 5 is controlled to apply transverse load to the reservoir dam model 1 to induce valley deformation. During the application of transverse load, the longitudinal load and vertical load are kept constant. By applying transverse load step by step, the reservoir dam model will produce valley deformation of different degrees until the reservoir dam model cracks.

[0037] In this step, the magnitude of the longitudinal load is first determined based on the dam's water level, and the magnitude of the vertical load is determined based on the dam's self-weight. After determining the longitudinal and vertical loads, the longitudinal loading / unloading device 6 and the vertical loading / unloading device are activated to apply the corresponding loads to the dam model 1. Once the dam model 1 stabilizes, the data acquisition device 2 collects data from the stress gauge or strain gauge 4 and the displacement gauge 3. Then, the lateral loading / unloading device 5 is activated to apply lateral loading to the dam model 1 to accurately measure the valley deformation generated during dam impoundment. During the lateral loading process, the valley deformation of the dam model 1 is gradually increased by progressively increasing the lateral loading until the dam model 1 cracks. Throughout the lateral loading process, the longitudinal and vertical loads remain constant. Furthermore, the lateral loading / unloading device 5 and the longitudinal loading / unloading device 6 are applied at different heights on the dam model during the experiment, depending on the specific circumstances.

[0038] Step 4: Collect displacement gauge and stress gauge or strain gauge data in real time throughout the entire lateral loading process using a data acquisition device. Based on the obtained data, obtain the dam body stress or strain and valley deformation under different lateral loading conditions, and evaluate the dam safety margin under different working conditions.

[0039] During the gradual increase of lateral loading, the valley deformation and internal stress or strain of dam model 1 also gradually increase. Data collected by stress gauges can quantitatively determine the stress distribution in the dam abutment and dam body caused by valley deformation, and identify high stress concentration areas; data collected by strain gauges can reveal the dam's deformation. Furthermore, to investigate the relationship between lateral loading, valley deformation, and internal stress or deformation of the dam, data from each displacement gauge 3 (used to measure valley deformation of dam model 1) is acquired, along with data from each stress gauge or strain gauge 4. The stress or deformation data after loading is obtained by subtracting the stress or strain gauge data before lateral loading from the data collected during lateral loading. Similarly, the valley deformation data after loading is obtained by subtracting the data collected during lateral loading from the data before lateral loading. Finally, each set of lateral loading data is fitted with its corresponding post-loading stress or deformation data and valley deformation data to obtain the following relationship:

[0040] ;

[0041] Among them, F h For horizontal loading size, For the internal stress or deformation of the dam model, Let denot represent the valley deformation of the dam model, and let a, b, c, and d be coefficients obtained through regression analysis of experimental data.

[0042] Furthermore, this experiment allows us to obtain the valley deformation threshold of the dam model. Based on this threshold and the aforementioned functional relationship, the dam's safety margin under different working conditions can be evaluated. Simultaneously, the lateral loading threshold of the dam can also be obtained, enabling the development of scientific water storage control schemes and the setting of deformation monitoring and early warning thresholds during construction.

[0043] The above are merely preferred embodiments of the present invention and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should recognize that any equivalent substitutions and obvious changes made based on the content of this specification should be included within the protection scope of the present invention.

Claims

1. A test method for the safety performance of a reservoir dam considering valley deformation, characterized in that, Includes the following steps: Step 1: Construct a reservoir dam model, embed stress gauges or strain gauges at the measuring points inside the reservoir dam model, install displacement gauges on the dam surface, and electrically connect the stress gauges or strain gauges and displacement gauges to the data acquisition device. Step 2: Install a transverse loading and unloading device perpendicular to the river direction at the dam shoulder of the reservoir dam model, install a longitudinal loading and unloading device along the river direction on the reservoir dam model, and install a vertical loading and unloading device in the height direction of the reservoir dam model. Step 3: Based on the water storage status of the reservoir dam, control the longitudinal loading and unloading device to apply corresponding longitudinal loads to the reservoir dam model to simulate water stress, and based on the dam's self-weight, control the vertical loading and unloading device to apply vertical loads to the reservoir dam model to simulate the dam's self-weight stress. Then, the lateral loading and unloading device is controlled to apply lateral loads to the reservoir dam model to induce valley deformation. During the application of lateral loads, the longitudinal and vertical loads are kept constant. Lateral loads are applied in stages to cause the reservoir dam model to undergo different degrees of valley deformation until the reservoir dam model cracks. Step 4: Collect stress gauge or strain gauge and displacement gauge data in real time throughout the entire process using a data acquisition device. Based on the obtained data, obtain the dam body stress or strain and valley deformation under different lateral loading conditions, and evaluate the dam safety margin under different working conditions.

2. The test method for the safety performance of a reservoir dam considering valley deformation according to claim 1, characterized in that, Multiple stress gauges or strain gauges are installed along the height direction inside the dam.

3. The test method for the safety performance of a reservoir dam considering valley deformation according to claim 1, characterized in that, The lateral loading and unloading device and the longitudinal loading and unloading device are applied at different heights according to the test conditions.

4. The test method for the safety performance of a reservoir dam considering valley deformation according to claim 1, characterized in that, When collecting data, first collect data from stress gauges or strain gauges and displacement gauges when only longitudinal and vertical loads are applied, and then collect data from stress gauges or strain gauges and displacement gauges when lateral, longitudinal and vertical loads are applied simultaneously.

5. The test method for the safety performance of a reservoir dam considering valley deformation according to claim 1, characterized in that, In step 4, the magnitude of each group of lateral loads and its corresponding stress gauge or strain gauge and displacement gauge data are obtained. The stress data of the dam model is calculated using data obtained from stress gauges, the deformation data is calculated using data obtained from strain gauges, and the valley deformation is calculated using data obtained from displacement gauges. The lateral load, valley deformation, and stress or strain data are fitted to obtain the functional relationship between the lateral load of the dam model before cracking and the valley deformation and stress or deformation.

6. The test method for the safety performance of a reservoir dam considering valley deformation according to claim 5, characterized in that, In step 4, the lateral load F of the reservoir dam model is obtained through curve fitting. h With valley deformation and stress or deformation The functional relationship between them is: ； Where a, b, c, and d are coefficients obtained through regression analysis of experimental data.

7. The test method for the safety performance of a reservoir dam considering valley deformation according to claim 6, characterized in that, In step 4, the valley deformation threshold of the reservoir dam model is obtained through experiments, and the safety margin of the dam is evaluated based on the valley deformation threshold and the above functional relationship.

8. An apparatus for implementing the test method for the safety performance of a reservoir dam considering valley deformation as described in any one of claims 1-7, characterized in that, include: The reservoir dam model was prepared in scale based on the actual data of the dam to be studied. The data acquisition system includes a data acquisition device and a displacement gauge and a stress gauge or strain gauge electrically connected thereto. The displacement gauge is installed on the surface of the reservoir dam model, and the stress gauge or strain gauge is embedded inside the reservoir dam model. The loading device includes a lateral loading / unloading device, a longitudinal loading / unloading device, and a vertical loading / unloading device. The lateral loading / unloading device is set perpendicular to the river direction at the abutment of the reservoir dam model. The longitudinal loading / unloading device is set along the river direction on the reservoir dam model. The vertical loading / unloading device is set along the height direction of the reservoir dam model. The lateral loading / unloading device is used to apply lateral loads to the reservoir dam model to induce valley deformation. The longitudinal loading / unloading device is used to apply longitudinal loads to the reservoir dam model to simulate water stress. The vertical loading / unloading device is used to apply vertical loads to the reservoir dam model to simulate the self-weight stress of the reservoir dam.

9. The apparatus for the test method considering the safety performance of a reservoir dam under valley deformation according to claim 1, characterized in that, The displacement gauges are deployed along the river.

Images