Rock aging deformation test system under combined action of continuous water environment and variable temperature
Technical Field
The invention belongs to the technical field of rock mechanical tests, and relates to an aging deformation test system for rocks in a continuous and temperature-variable water environment, which is suitable for analyzing the whole process of aging deformation and damage of the rocks under the environment conditions of different solutions, different temperatures and the like.
Background
The long-term strength of rock is an important index for measuring the stability of rock engineering. The long-term mechanical properties and behaviors of rocks and rock masses in an engineering state always obviously show time-dependent characteristics, wherein environmental factors such as water, temperature and the like have great influence on the long-term mechanical properties of the rocks. At present, a plurality of tests related to the influence of high-temperature creep or moisture content of rock on the mechanical properties of the rock exist, but the following defects exist: (1) the migration of the aqueous solution in the rock (body) is not considered to be a time-varying process, so that the influence of the dynamic migration process of the aqueous solution in the rock on the aging deformation characteristics of the rock is difficult to study, and the change of the state of the aqueous solution in the rock caused by the change of acid and alkali content and mineral components in the aqueous solution is difficult to study, so that the influence on the aging deformation characteristics is further produced; (2) the fact that the rock (body) is a poor conductor and the conduction time of the temperature in the rock is slow is not considered, so that the long-term stability of the rock under the condition of dynamic temperature change is difficult to study; (3) the influence of the dynamic migration of the aqueous solution and the temperature in the rock on the aging deformation characteristics of the rock under the combined influence of multiple environments with the influence of the aqueous solution and the temperature is not considered. The rock mass in actual engineering is mostly influenced by continuous aqueous solution and temperature change, and how to truly reflect the complex environment of the rock mass and research the long-term mechanical characteristics of the rock mass influenced by the environment is very necessary for objectively and reasonably evaluating the reliability, safety and service life of the rock mass engineering.
Disclosure of Invention
The invention aims to provide a system which is simple in structure and convenient to operate and can carry out aging deformation failure test on a rock sample in real time under various water quality environments, anhydrous environments and variable temperature environments respectively, and the defects of the prior art are overcome.
The invention relates to a rock aging deformation test system under the combined action of a continuous water environment and variable temperature, which comprises a base, wherein an upright post is fixed on the base, a cross beam is arranged at the upper end of the upright post, a hydraulic cylinder connected with a hydraulic control device is arranged on the cross beam, the outer end of a piston rod matched with the hydraulic cylinder is sequentially connected with a pressure sensor and a pressure head, a plurality of overlapped adjusting blocks are arranged below the pressure head on the base, a bearing platform column is fixed on the adjusting block at the upper end, and a test box body is arranged at the upper end of the bearing platform column;
the test box body comprises a shell made of ceramic materials, a hole matched with the bearing platform column is formed in the bottom surface of the shell, a step for supporting the shell is arranged on the bearing platform column, an inner container is arranged in the shell, the middle of the bottom surface of the inner container is in contact with the upper end face of the bearing platform column, a groove for placing a lower padding plate is formed in the inner side of the bottom surface of the inner container, heating elements connected with a control device are arranged inside the side wall of the shell, an upper cover is arranged at the upper opening of the shell, an exhaust hole and a water replenishing pipe for replenishing water into the inner container are formed in the upper cover, and bosses are arranged at the upper surface and the lower middle position of the upper cover.
When the rock aging deformation test system under the combined action of the continuous water environment and the variable temperature is used, a tested rock body, namely a columnar rock sample is vertically arranged at the middle position of an inner container on the inner side of a test box body, the lower end face of the rock sample is located on a lower cushion plate, an upper cushion plate is arranged at the upper end of the rock sample, a boss below an upper cover is located on the upper cushion plate, a pressure head moves downwards under the driving of a hydraulic cylinder, the upper cover, the upper cushion plate and the rock sample are pressed and maintain set pressure, test water is added into the test box body according to needs, an acoustic emission sensor and a stress-strain acquisition sensor are arranged on the rock sample, the acoustic emission sensor is connected with an acoustic emission instrument and a control device, the stress-strain acquisition sensor is connected with a dynamic stress-strain acquisition instrument and a control device, and the control device comprises a; the heating element heats the water in the inner container under the control of the control device, so that the water temperature is kept in a set temperature range or the temperature change is controlled according to the requirement, the gas generated in the inner container can be discharged through the vent hole, when the water amount in the inner container is reduced, the water can be supplemented through the water supplementing pipe and the water supply device, and the liquid level is controlled through the liquid level sensor and the control device in the inner container. The deformation and destruction processes of the rock sample under different water environments and different water temperatures can be recorded in real time in the whole test process. And finally, displaying the stress-strain state of the rock and the internal crack propagation process in real time on a computer. If the test is not required to be carried out in the water environment, the inner container can be taken out (as shown in figure 2), and the rock creep test under the action of only temperature is realized. The system of the invention has simple integral structure and easy operation.
Drawings
FIG. 1 is a schematic structural diagram of an embodiment of the present invention;
FIG. 2 is a schematic structural view of the present invention when the inner container is taken out and a rock sample is tested in a certain temperature field.
Detailed Description
As shown in fig. 1: the invention discloses a rock aging deformation test system under the combined action of a continuous water environment and variable temperature, which comprises a base 1, wherein symmetrically arranged stand columns 2 are fixed on the base 1, a cross beam 10 is arranged at the upper end of each stand column 2, a hydraulic cylinder 9 connected with a hydraulic control device is arranged on each cross beam 10, the outer end of a piston rod matched with each hydraulic cylinder 9 is sequentially connected with a pressure sensor 8 and a pressure head 21 connected with the control device, a plurality of stacked adjusting blocks 3 are arranged below the pressure head 21 on the base 1, a bearing platform column 4 is fixed on each adjusting block 3 at the upper end, and a test box body is arranged at the upper end of each bearing platform column 4.
The test box body comprises a shell 19 made of ceramic materials, a hole matched with the bearing platform column 4 is formed in the bottom surface of the shell 19, a step for supporting the shell 19 is arranged on the bearing platform column 4, the shell 19 is located on the bearing platform column 4, an inner container 18 is arranged in the shell 19, and the middle of the bottom surface of the inner container 18 is in contact with the upper end face of the bearing platform column 4. A groove for placing the lower cushion plate 20 is arranged on the inner side of the bottom surface of the inner container 18, and the lower cushion plate 20 is positioned in the groove. An electric heating element 16 connected with a control device is arranged in the side wall of the shell 19 and is fixedly arranged through a side cover 17. The upper opening of the shell 19 is provided with an upper cover 12, and an opening insertion structure is arranged between the upper opening of the shell 19 and the upper cover 12. The upper cover 12 is provided with an air vent 11 and a water replenishing pipe 7 for replenishing water into the inner container 18, and a water outlet 6 of the water replenishing pipe 7 faces the inner side of the inner container 18 so as to conveniently replenish water into the inner cavity of the inner container 18. Bosses are provided at the middle positions of the upper and lower surfaces of the upper cover 12.
The using process is as follows: vertically placing a rock body to be measured, namely a columnar rock sample 14 at the middle position of an inner container 18 on the inner side of a test box body, placing the lower end face of the rock sample 14 on a lower cushion plate 20, placing an upper cushion plate 13 at the upper end of the rock sample 14, positioning a boss below an upper cover 12 on the upper cushion plate 13, driving a pressure head 21 to move downwards under the driving of a hydraulic cylinder 9, applying pressure to the upper cover 12, the upper cushion plate 13 and the rock sample 14 and keeping the set pressure, adding test water into the test box body (an inner cavity of the inner container 18) according to needs, arranging an acoustic emission sensor 5 and a stress-strain acquisition sensor 15 on the rock sample 14, connecting the acoustic emission sensor 5 with an acoustic emission instrument and a control device, connecting the stress-strain acquisition sensor 15 with a dynamic stress-strain acquisition instrument and the control device, wherein the control device comprises a digital controller and a; the heating element 16 heats the water in the inner container 18 under the control of the control device, so that the water temperature is kept in a set temperature range or the temperature change is controlled as required, the gas generated in the inner container can be discharged through the exhaust hole 11, when the water amount in the inner container is reduced, the water can be supplemented through the water supplementing pipe 7 and the water supply device, and the liquid level is controlled through the liquid level sensor and the control device in the inner container. The deformation and destruction processes of the rock sample under different water environments and different water temperatures can be recorded in real time in the whole test process. The response of the rock sample 14 after being loaded is converted into a signal and transmitted to an acoustic emission instrument and a dynamic stress-strain acquisition instrument which are externally connected with the test box, and finally the stress-strain state of the rock and the internal crack propagation process are displayed on a computer in real time. If testing in an aquatic environment is not desired, liner 18 (shown in FIG. 2) can be removed and tested only at a certain temperature.