Experimental device capable of simulating the impact of hammer vibration and flowing water on karst collapse

Abstract

The present invention designs an experimental device for studying the influence of hammering vibration and natural flowing water generated by people during construction on karst collapse. The experimental device comprises a main model structure, a water supply and drainage system and a vibration system. The main model structure is wrapped with a layer of transparent tempered glass for easy observation. The main model structure simulates a real karst cave. The water inlet and drainage of the main model structure by the water supply and drainage system simulate the influence of natural flowing water on karst collapse. The hammering of the main model structure by the vibration system simulates the influence of pile driving vibration on karst collapse. The two can act separately or simultaneously, and can more realistically simulate the development process of karst collapse under the action of hammering vibration and flowing water during construction, so as to provide a scientific basis for better studying karst collapse.

Description

Technical Field

[0001] The invention relates to a karst collapse experimental device, in particular to an experimental device capable of simulating the influence of hammer vibration and flowing water on karst collapse. Background Art

[0002] Karst is the general term for the geological action of water on soluble rocks (carbonate rocks, gypsum and rock salt, etc.) mainly through chemical dissolution, supplemented by mechanical actions such as erosion, subsidence and collapse of flowing water, as well as the phenomena produced by these actions. In my country, karst landforms are widely distributed and cover a large area, mainly in areas where carbonate rocks are exposed, covering an area of ​​about 910,000 to 1.3 million square kilometers. Guangxi, Guizhou and Yunnan occupy the largest area, and Tibet and some areas in the north also have karst areas, which is one of the largest karst areas in the world.

[0003] Karst collapse is a special type of geohazard in karst areas. It refers to the existence of karst cavities in soluble rocks hidden under the cover layer. Under the influence of natural or human factors, the cover layer material enters the karst cavity along the karst channel, causing the leakage of the covering soil and leading to the natural phenomenon of ground collapse. With the development of society and economic growth, human activities have an increasing impact on the karst area of ​​the cover layer, especially in recent years, the infrastructure construction in large areas of karst areas in my country has developed rapidly. During the continuous construction, this collapse occurs suddenly and quickly, causing great damage to roads, reservoirs and geotechnical engineering, and easily causing casualties and property losses. Therefore, it is of certain scientific significance to design an experimental device to simulate the impact of hammer vibration and water flow activities on karst collapse caused by people during the construction process, so as to better study karst collapse. Summary of the invention

[0004] The purpose of the present invention is to provide an experimental device that can simulate the influence of hammer vibration and flowing water on karst collapse, so as to simulate the development process of karst collapse under the action of hammer vibration and flowing water during construction, and is easy to observe and suitable for the study of geological disasters.

[0005] The technical solution adopted by the present invention to achieve the above technical purpose is:

[0006] An experimental device capable of simulating the impact of hammer vibration and flowing water on karst collapse includes a main model structure, a water supply and drainage system and a vibration system, wherein:

[0007] The main model structure includes a simulation box, a simulated rock layer, a karst cave and a covering soil layer. The simulation box is made of transparent organic tempered glass material. The simulated rock layer is arranged inside the simulation box and is cast by concrete. The karst cave is prefabricated in the bottom center of the simulated rock layer. An opening is arranged at the top of the simulated rock layer, and a fan blade with adjustable opening size is arranged at the opening. The covering soil layer is laid on the top of the simulated rock layer.

[0008] The water supply and drainage system includes a water tank, a water inlet pipe and a drain pipe, one end of the water inlet pipe is connected to the side of the covering soil layer, the other end of the water inlet pipe is connected to the water tank, one end of the drain pipe is connected to the bottom of the karst cave, and the other end of the drain pipe is connected to an external water collection tank;

[0009] The vibration system comprises tracks arranged in parallel on both sides of the long sides of the simulation box, a gantry arranged on the two tracks and a hanging hammer arranged on the gantry crossbeam, wherein the bottom end of the hanging hammer is detachably connected to a hammer head.

[0010] Preferably, the karst cave is a structure cut from a whole piece of limestone rock and has a small opening at the upper end and a bulging belly at the lower end.

[0011] Preferably, the water inlet pipe is provided with a flow meter and a water inlet valve.

[0012] Preferably, the drainage pipe is provided with a water pump and a water outlet valve.

[0013] Preferably, an interface for a monitoring sensor is reserved on the simulation box.

[0014] Preferably, the experimental device also includes a control system, and the control system is electrically connected to the flow meter, the water inlet valve, the water pump, the water outlet valve and the monitoring sensor.

[0015] Preferably, the control system is also electrically connected to the drive motors of the fan blades and the gantry.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. The present invention supplies water through a water tank and a water inlet pipe, and the water flows through the covering soil layer and the fan blades arranged at the top opening of the simulated rock layer to penetrate, which can simulate the influence of natural water on karst collapse. The flow rate can be controlled by the flow meter and the water inlet valve on the water inlet pipe to simulate the influence of different hydrodynamic conditions on karst collapse;

[0018] 2. After the present invention passes water into the karst cave through the water tank, the groundwater level in the cave is raised, which can simulate the karst collapse process of the covering layer caused by the rise of the groundwater level;

[0019] 3. The present invention releases water through a drainage pipe and a water outlet valve. After the water is released, the groundwater level in the karst cave drops, which can simulate the karst collapse process of the overburden layer caused by artificial pumping;

[0020] 4. The present invention realizes arbitrary striking on the covering soil layer through the gantry, hanging hammer and hammer head, and the hammer head can be replaced with hammer heads of different weights to simulate the influence of vibrations generated by different pile driving on karst collapse;

[0021] 5. The present invention can simulate the process of karst collapse of the overburden layer caused by the drop of groundwater level, the rise of groundwater level and hammer vibration, or the combined action of multiple conditions;

[0022] 6. The simulation box of the present invention is made of transparent organic tempered glass material, so the user can observe the simulation situation in the simulation box at any time, which is convenient for observation.

[0023] In summary, the device of the present invention can simulate the development process of karst collapse under the separate effects of surface natural water and hammer vibration and their combined effects, is easy to observe, and is suitable for the study of geological disasters. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of the overall structure of the experimental device of the present invention.

[0025] As shown in the figure:

[0026] 1-simulation box, 2-simulated rock layer, 3-karst cave, 4-covering soil layer, 5-fan blades, 6-water tank, 7-water inlet pipe, 8-drainage pipe, 9-track, 10-gantry, 11-hanging hammer, 12-hammer head, 13-flow meter, 14-water inlet valve, 15-pump, 16-water outlet valve. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0028] like Figure 1 As shown, this embodiment provides an experimental device that can simulate the impact of hammer vibration and flowing water on karst collapse. The entire experimental device consists of a main model structure, a water supply and drainage system, and a vibration system, wherein:

[0029] The main model structure includes a simulation box 1, a simulated rock layer 2, a karst cave 3 and a covering soil layer 4. The simulated rock layer 2 is arranged inside the simulation box 1 and is cast by concrete. The karst cave 3 is prefabricated at the bottom center of the simulated rock layer 2. An opening is provided at the top of the simulated rock layer 2, and a fan blade 5 with adjustable opening size is provided at the opening. The covering soil layer 4 is laid on the top of the simulated rock layer 2.

[0030] Specifically, in order to facilitate observation by the experimenter, the simulation box 1 is a rectangular box made of thickened transparent organic tempered glass material, and the simulated rock layer 2 and the karst cave 3 are arranged therein.

[0031] Specifically, the karst cave 3 has a small opening at the upper end and a bulging belly at the lower end, and is cut from a whole piece of limestone. The karst cave 3 is 1 meter high, 1 meter deep, and the widest part of the belly is about 0.6 meters.

[0032] Specifically, in order to enhance the electrical difference between the simulated rock layer 2 and the karst cave 3, the simulated rock layer 2 is a rectangular box structure cast by concrete. The simulated rock layer 2 is 3 meters long, 1.2 meters wide and 1.1 meters high. The fan blades 5 on the top of the simulated rock layer 2 are in the form of electric shutters. The rotation of the fan blades 5 is controlled by electrical connection with the control system, and then the size of the opening at the top of the simulated rock layer 2 is adjusted to meet the needs of different amounts of mud and water entering the karst cave 3. Here, the fan blades 5 are made of polymer materials and have certain strength and hardness.

[0033] Specifically, the covering soil layer 4 is filled on the top of the simulated rock layer 2, with a length of 3 meters, a width of 1.2 meters, and a height of 0.5 meters. There is no base plate under the covering soil layer 4, which is directly laid on the simulated rock layer 2, overlaps with the top plane of the simulated rock layer 2 and is sealed with glue. A water inlet is set at the left end of the covering soil layer 4, which is connected to the water tank 6 through a water inlet pipe 7. The covering soil layer 4 can be filled with different soils to simulate different soil layers.

[0034] The water supply and drainage system includes a water tank 6, a water inlet pipe 7 and a drainage pipe 8, one end of the water inlet pipe 7 is connected to the side of the covering soil layer 4, the other end of the water inlet pipe 7 is connected to the water tank 6, one end of the drainage pipe 8 is connected to the bottom of the karst cave 3, and the other end of the drainage pipe 8 is connected to an external water collecting tank.

[0035] Specifically, the water inlet pipe 7 is provided with a flow meter 13 and a water inlet valve 14 to control the water flow rate and calculate the water flow rate, and the drainage pipe 8 is provided with a pump 15 and a water outlet valve 16 to control the water outlet and the water outlet flow rate.

[0036] The vibration system includes rails 9 arranged in parallel on both sides of the long side of the simulation box 1, a gantry 10 arranged on the two rails 9 and a pendant 11 arranged on the crossbeam of the gantry 10, and a hammer head 12 is detachably connected to the bottom end of the pendant 11.

[0037] Specifically, the two tracks 9 are directly set on the ground or the experimental platform, and are parallel to the two long sides of the simulation box 1. The length of each track 9 is 3 meters. The gantry 10 is movably set on the two tracks 9, and the two support arms of the gantry 10 are 2.5 meters high. The length of the beam connecting the two support arms is 1.5 meters. A pendulum 11 is movably connected to the beam of the gantry 10, and the pendulum 11, the gantry 10 and the two tracks 9 constitute a small gantry crane, which is equipped with a drive motor, and the drive motor is electrically connected to the control system, so that the pendulum 11 can be moved in the X and Y directions.

[0038] Furthermore, a hammer head 12 is provided at the end of the hanging hammer 11, and is matched with a trigger mechanism, and the trigger mechanism is electrically connected to the control system. The control system controls the action of the trigger mechanism, so that the hammer head 12 is connected to the hanging hammer 11 to perform a free fall action to simulate the hammering of the pile foundation, and the descending height of the hammer head 12 can be accurately controlled by the control system. The connection between the hammer head 12 and the hanging hammer 11 is detachable, so that hammer heads of different weights can be replaced to simulate the influence of vibrations generated by different pile driving on karst collapse.

[0039] Specifically, an interface for a monitoring sensor is reserved on the simulation box 1, and the monitoring sensor is electrically connected to the control system.

[0040] Specifically, the water inlet valve 14, flow meter 13, water pump 15, water outlet valve 16, drive motor of fan blade 5, drive motor of gantry 10 and trigger mechanism in this embodiment are all electrically connected to the control system, and the control system can be installed on a control panel to complete the control of corresponding actions through the control buttons on the control panel.

[0041] In summary, the experimental device provided in this embodiment that can simulate the impact of hammer vibration and flowing water on karst collapse generally requires an area of ​​about 4 meters in length and 2 meters in width, and has the advantage of small size. By controlling the water flow rate, the impact of different hydrodynamic conditions on karst collapse can be simulated. By observing the natural flow, the impact of artificial pumping on karst collapse can be understood. The impact of pile driving vibration on karst collapse can be simulated by the hammer vibration of the hammer head 12. The experimental device can perform the following experiments:

[0042] Experiment 1: Simulating the impact of natural water flow on karst collapse

[0043] Fill the water tank 6 with water, open the water inlet valve 14, and the water flows into the covering soil layer 4, enters the karst cave 3 through the opening at the fan blade 5 at the top of the simulated rock layer 2, and is finally discharged through the drain pipe 8. Since the water flow can carry away a certain amount of soil, after a period of observation, the influence of natural water on karst collapse can be understood. Furthermore, by controlling the flow rate of the water flow through the flow meter 13, the influence of different hydrodynamic conditions on karst collapse can be simulated.

[0044] Experiment 2: Simulating the impact of artificial water pumping on karst collapse

[0045] Fill the water tank 6 and the karst cave 3 with water. The water surface must at least cover the simulated rock layer 2. Open the outlet valve 16 and the pump 15 of the drain pipe 8. After working for a period of time, close the pump 15 and the outlet valve 16, and then open the inlet valve 14. This experiment simulates artificial underground water pumping for a period of time, and then observes for a period of time under natural water flow conditions. This can simulate the impact of artificial water pumping on karst collapse.

[0046] Experiment 3: Simulating the impact of pile foundation vibration on karst collapse

[0047] The control system controls the trigger mechanism to work, so that the hanging hammer 11 and the hammer head 12 perform the up and down pile driving action together, and then the control system can control the movement of the hanging hammer 11 in the X and Y directions, so as to realize the hammering of the hammer head 12 at any point on the covering soil layer 4 to simulate the vibration caused by pile driving. During the hammering process, part of the soil will enter the karst cave 3 through the opening of the fan blade 5 at the top of the simulated rock layer 2. After observing for a period of time, the influence of the surrounding hammering vibration on the karst collapse can be understood.

[0048] The experimental device of this embodiment can be operated individually when performing the above-mentioned experimental operations, or the above-mentioned experiments can be carried out simultaneously. That is, the experimental device provided by this embodiment can simulate the effects of natural water and hammer vibration on karst collapse alone, and can also simulate the effects of natural water and hammer vibration on karst collapse together. The transparent simulation box is convenient for observation and is suitable for the study of geological disasters.

[0049] It should be understood that the parts not described in the specification are prior art or common knowledge. This embodiment is only used to illustrate the invention, and is not used to limit the scope of the invention. Modifications such as equivalent substitution made by those skilled in the art to the invention are considered to fall within the scope of protection of the claims of the invention.

Claims

1. An experimental device capable of simulating the effects of hammer vibration and flowing water on karst collapse, characterized in that: The experimental device comprises a main model structure, a water supply and drainage system and a vibration system, wherein the main model structure comprises a simulation box (1), a simulated rock layer (2), a karst cave (3) and a covering soil layer (4); the simulation box (1) is made of a transparent organic tempered glass material; the simulated rock layer (2) is arranged inside the simulation box (1) and is cast by concrete; the karst cave (3) is prefabricated at the bottom center of the simulated rock layer (2); an opening is arranged at the top of the simulated rock layer (2); a fan blade (5) whose size can be adjusted is arranged at the opening; the covering soil layer (4) is laid on the top of the simulated rock layer (2); the water supply and drainage system comprises a water tank (6), a water inlet pipe (7) and a drainage pipe (8); the water inlet pipe (7) is One end of the water inlet pipe (7) is connected to the side of the covering soil layer (4), the other end of the water inlet pipe (7) is connected to the water tank (6), one end of the water discharge pipe (8) is connected to the bottom of the karst cave (3), and the other end of the water discharge pipe (8) is connected to the external water collection tank; the vibration system comprises tracks (9) arranged in parallel on both sides of the long side of the simulation box (1), a gantry (10) arranged on the two tracks (9), and a hanging hammer (11) arranged on the crossbeam of the gantry (10), and the bottom end of the hanging hammer (11) is detachably connected to a hammer head (12); the karst cave (3) is a structure cut from a whole piece of limestone rock with a small opening at the upper end and a bulging belly at the lower end; the water inlet pipe (7) is provided with a flow meter (13) and a water inlet valve (14).

2. The experimental device capable of simulating the effects of hammer vibration and flowing water on karst collapse according to claim 1, characterized in that: The drainage pipe (8) is provided with a water pump (15) and a water outlet valve (16).

3. The experimental device capable of simulating the effects of hammer vibration and flowing water on karst collapse according to claim 1, characterized in that: An interface for a monitoring sensor is reserved on the simulation box (1).

4. An experimental device capable of simulating the effects of hammer vibration and flowing water on karst collapse according to any one of claims 1 to 3, characterized in that: The experimental device also includes a control system, which is electrically connected to the flow meter (13), the water inlet valve (14), the water pump (15), the water outlet valve (16) and the monitoring sensor.

5. The experimental device capable of simulating the effects of hammer vibration and flowing water on karst collapse according to claim 4, characterized in that: The control system is also electrically connected to the drive motors of the fan blades (5) and the gantry (10).

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