An experimental equipment for simulating reef limestone pore filling under marine environment

Abstract

The present application relates to reef limestone pore filling technical field, concretely for a kind of reef limestone pore filling experimental equipment under simulated marine environment, including box and be set in box for placing filling chamber of rock sample, filling chamber is bottom opening structure, the lower part of filling chamber is connected with water-permeable seat, the lower part of water-permeable seat and box abut, water-permeable seat is opened with water-permeable mouth in filling chamber bottom intercommunication, the upper part of filling chamber is equipped with water injection hole, water injection hole is communicated with the liquid storage tank located outside the box by water injection pipe, liquid storage tank is connected with pressurizing assembly, box is opened with drain outlet.The present application innovatively proposes a kind of experimental equipment for the reef limestone pore filling technology of seawater reaction, can explore pore filling technology based on seawater chemical reaction under laboratory scale, based on the present application can effectively simulate real marine environment, and realize repeatable reef limestone pore filling process, obtain effective technical index.

Description

Technical Field

[0001] This invention relates to the field of reef limestone pore filling technology, specifically to an experimental device for simulating reef limestone pore filling in a marine environment. Background Technology

[0002] As a typical soft and porous material, reef limestone is a special marine rock and soil body formed by the accumulation and cementation of the remains of various reef-attached organisms after the death of reef-building coral colonies, and through a long geological process. General marine geotechnical engineering, such as tunnels and underground caverns, needs to be excavated in reef limestone.

[0003] Reef limestone has extremely high porosity and therefore high permeability. To enhance the mechanical properties and pore density of reef limestone and reduce its permeability coefficient, thereby meeting the requirements for waterproofing, seepage prevention, and safety in marine underground structure construction, as well as the stability requirements during operation, it is often necessary to artificially improve the pores of reef limestone. The improvement method is pore filling.

[0004] Existing pore-filling technologies typically employ grouting, which involves permeating reef limestone with ultrafine cement or modified ultrafine cement. However, due to the coexistence of fine and micropores in the internal pore structure of reef limestone, the permeability of granular cement aggregates in the grout is poor, and the permeation range is highly limited. Furthermore, sulfate, chloride, and magnesium ions in seawater can undergo a series of chemical reactions with the filler, and some of the filler can decompose and re-form seepage channels, thereby weakening the reinforced structure and creating a vicious cycle. This also poses a serious threat to the stability of marine subsurface structures.

[0005] In summary, current grouting methods are insufficient for efficiently filling the pores of reef limestone, resulting in poor grouting effects, uneven distribution of the filler, and an inability to effectively stop water, prevent seepage, or reduce the permeability coefficient. Therefore, the problem of effectively addressing the high permeability characteristics of reef limestone is becoming increasingly prominent. Currently, there is an urgent need for an experimental device to simulate the pore filling behavior of reef limestone in a marine environment, in order to conduct a feasibility analysis of the pore filling behavior of reef limestone. Summary of the Invention

[0006] The purpose of this invention is to provide an experimental device for simulating the pore filling of reef limestone in a marine environment, addressing the shortcomings of existing technologies. Chemical filling experiments are first conducted at the laboratory scale to quantitatively and qualitatively analyze the different filling effects achievable by different filling methods. The advantages and disadvantages of chemical filling methods are comprehensively discussed in terms of permeability improvement and mechanical property improvement, thereby solving the problems existing in the above-mentioned existing technologies.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] An experimental device for filling pores in reef limestone under simulated marine conditions includes a box body and a filling chamber for placing rock samples inside the box body. The filling chamber has a bottom-opening structure. A permeable seat is connected to the lower part of the filling chamber. The lower part of the permeable seat abuts against the box body. A permeable port communicating with the bottom of the filling chamber is opened on the permeable seat. A water injection hole is provided at the upper part of the filling chamber. The water injection hole is connected to a liquid storage tank located outside the box body through a water injection pipe. A pressurization component is connected to the liquid storage tank. A drain outlet is opened on the box body.

[0009] Furthermore, the periphery of the filling chamber is provided with vent holes.

[0010] Furthermore, the permeable seat is provided with protrusions for supporting the rock sample in the circumferential direction of the permeable opening.

[0011] Furthermore, a through hole is provided on the peripheral side wall of the permeable seat, and the drain outlet of the box body is connected to the permeable seat.

[0012] Furthermore, a groove is provided at the bottom of the box, and the drainage outlet of the box extends horizontally through the groove and the box.

[0013] Furthermore, the filling chamber is detachably connected to the permeable seat.

[0014] Furthermore, the permeable seat is provided with a connecting groove, and a corresponding connecting ring is provided on the filling chamber.

[0015] Furthermore, the housing is provided with a water inlet, the liquid storage tank is connected to the water inlet through a water injection pipe, and the water inlet is connected to the water injection hole of the filling chamber through a water injection pipe.

[0016] Furthermore, a water pressure monitoring port is provided on the enclosure.

[0017] Furthermore, the pressurization assembly includes an air compressor, which is connected to the liquid storage tank via a pressurization pipe.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] This invention innovatively proposes an experimental apparatus for reef limestone pore-filling technology based on seawater reactions. It allows for the investigation of pore-filling techniques based on seawater chemical reactions at a laboratory scale. This invention effectively simulates the real marine environment and achieves a repeatable reef limestone pore-filling process, yielding effective technical indicators. Specifically, this invention enables stable injection and dynamic reaction of seawater and the filling solution under controlled conditions, allowing sediment to form inside the reef limestone pores rather than on the surface. It also enables process visualization and result repeatability, ensuring the controllability, stability, and scientific verifiability of the reef limestone pore-filling experiment.

[0020] This invention, by setting up a filling chamber, ensures that the filling solution is directly injected into the rock sample located within the filling chamber, avoiding premature reaction between the filling solution and seawater. Furthermore, the filling chamber is designed with a porous structure, allowing precipitates generated from the reaction between the filling solution and seawater to escape into the seawater outside the filling chamber, while also enabling seawater replacement to replenish the ions required for the chemical reaction. This fully simulates the migration phenomena of multiple ions and the release behavior of reactants in a real marine environment. Simultaneously, by monitoring water pressure, the injection pressure of the filling solution is precisely controlled, allowing for precise quantitative discussion of the pore-filling effect of the corresponding filling solution, providing experimental evidence for the development of a widely applicable technical process on an engineering scale. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0022] Figure 2 This is a cross-sectional view of the box body in this invention;

[0023] Figure 3 This is a schematic diagram of the internal structure of the box in this invention;

[0024] Figure 4 This is a schematic diagram of the filling chamber structure in this invention;

[0025] Figure 5 This is a schematic diagram of the permeable seat in this invention.

[0026] The attached figures are labeled as follows:

[0027] 1. Box body; 11. Top plate; 111. Water inlet; 12. Side plate; 13. Bottom plate; 131. Drain outlet; 132. Water pressure monitoring port; 133. Groove; 2. Filling chamber; 21. Connecting ring; 22. Water injection hole; 23. Drain hole; 3. Rock sample; 4. Permeable seat; 41. Water inlet; 42. Protrusion; 43. Connecting groove; 44. Through hole; 5. Water injection pipe; 6. Liquid storage tank; 7. Pressurization pipe. Detailed Implementation

[0028] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0029] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0030] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0031] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature.

[0032] For easier understanding, please refer to Figures 1 to 5This embodiment provides an experimental device for filling pores in reef limestone under simulated marine conditions. It includes a square box 1, which further comprises a top plate 11, side plates 12, and a bottom plate 13, all detachably connected. Waterproofing is applied at the joints to ensure the overall waterproof performance of the box 1. The bottom plate 13 of the box 1 has a drain outlet 131. The box 1 contains a hollow filling chamber 2 with an opening at the top and bottom. The filling chamber 2 houses a rock sample 3 (reef limestone sample) to be filled. Preferably, the filling chamber 2 matches the shape of the rock sample 3; for example, if the rock sample 3 is columnar, the filling chamber 2 is a hollow columnar structure. The filling solution flows directly through the filling chamber 2, effectively injecting the filling solution into the rock sample 3. A permeable seat 4 is connected to the lower part of the filling chamber 2. The lower part of the permeable seat 4 is fixedly connected to the bottom plate 13 of the box 1. A permeable outlet 41 is located at the upper part of the permeable seat 4, communicating with the filling chamber 2. Furthermore, the filling chamber 2 and the permeable seat 4 are detachably connected. Specifically, the upper part of the permeable seat 4 has an annular connecting groove 43, and a connecting ring 21 is provided on the bottom of the filling chamber 2. The filling chamber 2 and the permeable seat 4 are relatively fixed by inserting the connecting ring 21 into the connecting groove 43. The permeable seat 4 separates the filling chamber 2 from the bottom of the box body 1, allowing the filling solution flowing through the rock sample 3 to flow smoothly out of the filling chamber 2. The opening at the top of the filling chamber 2 is a water injection hole 22, which is connected to the storage tank 6 through the water injection pipe 5. The storage tank 6 is located outside the box body 1 and is connected to a pressurizing component. The pressurizing component applies pressure to the filling solution stored in the storage tank 6, causing the filling solution to be transported into the filling chamber 2 through the water injection pipe 5. Specifically, the pressurizing component includes an air compressor (not shown in the figure), which is connected to the storage tank 6 through a pressurizing pipe 7.

[0033] For easier understanding, please refer to Figures 2 to 4 Multiple vent holes 23 are formed on the side walls of the filling chamber 2. When the filling solution is injected into the filling chamber 2, most of the filling solution flows directly downwards through the permeable port 41 into the permeable seat 4, while a small portion of the filling solution escapes to the outside of the filling chamber 2 through the vent holes 23. The vent holes 23 can simulate the reactant escape behavior under real marine engineering conditions and also act as ion exchange channels. Specifically, in practical applications, the filling solution used for reaction will generate precipitates in local areas, changing the ion concentration inside and outside the rock sample 3, and thus causing ion migration. This is consistent with the real marine environment. For example, if CaCO3 is generated in a local area, then the Ca in that area will be affected. 2+ The concentration will decrease, at which point the Ca concentration outside this region will also decrease. 2+Migration will occur, which is a natural phenomenon and therefore needs to be considered by setting up the vent hole 23. In practical applications, ions that do not react in time may be released outside the target area, thus undergoing chemical reactions outside the target area and generating precipitates. In addition, precipitates generated within the target area may also be migrated outside the target area under the action of seepage force, so the escape behavior of reactants needs to be considered. Furthermore, the outer diameter of the columnar rock sample 3 is slightly smaller than the inner diameter of the filling chamber 2, ensuring that the filling solution flows directly through the rock sample 3 after entering the filling chamber 2 from the water injection hole 22, and a small portion of the filling solution will escape outside the filling chamber 2 through the vent hole 23 during downward flow.

[0034] For easier understanding, please refer to Figures 2 to 5 The permeable seat 4 has multiple protrusions 42 extending inward around the permeable outlet 41. These protrusions 42 support the rock sample 3 above, allowing the filling solution to flow smoothly from the permeable outlet 41 out of the filling chamber 2. The drain outlet 131 of the box body 1 is connected to the permeable seat 4. Multiple through holes 44 are provided on the peripheral side wall of the permeable seat 4, allowing communication between the interior of the permeable seat 4 and the interior of the box body 1. This facilitates the exchange of solutions between the box body 1 and the permeable seat 4, allowing the solution in the box body 1 to be discharged through the drain outlet 131. A groove 133 is provided at the center of the bottom of the box body 1. The groove 133, the permeable outlet 41 of the permeable seat 4, and the filling chamber 2 are all coaxially arranged. The drain outlet 131 is connected to the groove 133. Specifically, the drain outlet 131 extends laterally through the box body 1 and the groove 133, buffering the solution in the permeable seat 4 and allowing it to flow smoothly out of the box body 1 through the drain outlet 131. Furthermore, a water pressure monitoring port 132 is provided at the bottom of the box body 1, and the water pressure monitoring port 132 extends horizontally through the box body 1 and the groove 133.

[0035] For easier understanding, please refer to Figure 1The upper part of the housing 1 has a water inlet 111. The storage tank 6 is connected to the water inlet 111 via a water injection pipe 5, and the water inlet 111 is in turn connected to the water injection hole 22 of the filling chamber 2 via the water injection pipe 5. Furthermore, there are multiple storage tanks 6, and the number of water inlets 111 in the housing 1 and water injection holes 22 in the filling chamber 2 are the same as the number of storage tanks 6. In this embodiment, there are two storage tanks 6, corresponding to two water inlets 111 in the housing 1 and two water injection holes 22 in the filling chamber 2. Users can store different solutions in the storage tanks 6 according to their actual needs to meet different experimental requirements. Specifically, for example, when storage tank 6 is filled with clean seawater and sodium bicarbonate solution respectively, calcium ions in the seawater react with carbonate ions to form calcium carbonate precipitate, but the precipitation efficiency is low; for example, when storage tank 6 is filled with calcium chloride solution and sodium bicarbonate solution respectively, calcium ions are artificially added to react with carbonate ions, which greatly promotes precipitation efficiency. Since the ions involved in the injected solutions are all ions abundant in the ocean, it can be considered a green filler material; for example, when storage tank 6 is filled with sodium silicate solution and calcium chloride solution respectively, calcium silicate colloid is rapidly generated, greatly improving the filling timeliness.

[0036] Preferably, the filling chamber 2 includes a cover plate and a main body, with the main body and cover plate being detachably connected. Specifically, the detachable connection method between the main body and cover plate can refer to the detachable connection method between the main body and the permeable seat 4, i.e., both adopt slot connection. The water injection pipe 5 has a fixed structure, which can stabilize the flow state of the solution.

[0037] The assembly method of the present invention is as follows: First, connect the bottom plate 13 and the side plate 12 of the box body 1, and fix the permeable seat 4 on the bottom plate 13 of the box body 1 so that the permeable port 41 of the permeable seat 4 is coaxial with the groove 133 on the bottom plate 13 of the box body 1. Then, install the main body of the filling chamber 2 on the top of the permeable seat 4, and put the pre-prepared rock sample 3 into the main body of the filling chamber 2 from top to bottom, so that the bottom of the rock sample 3 abuts against the protrusion 42 at the permeable port 41. Then, install the cover plate on the top of the main body, and connect the water inlet of the filling chamber 2 to the water inlet 111 on the top plate 11 of the box body 1 through the water injection pipe 5. Finally, install the top plate 11 of the box body 1 on the side plate 12, and connect the water inlet 111 on the top plate 11 of the box body 1 to the liquid storage tank 6 through the water injection pipe 5, thus completing the overall assembly of the equipment.

[0038] The experimental method of this invention is as follows: First, both storage tanks 6 are filled with clean seawater, and the tank 1 is pressurized with an air compressor to simulate a real marine environment (marine reef limestone is generally considered saturated, and its high permeability allows seawater to easily seep in; the basic conditions for ion migration must be met during the reaction). During this process, the valve of the water pressure monitoring port 132 is opened to monitor the water pressure in real time (monitoring water pressure can quantitatively express the flow rate parameter of the injected solution; the water pressure environment is also one of the variables to be studied in the experiment, such as the difference in filling efficiency between 1 kPa and 2 kPa). The power of the air compressor is then adjusted until the preset experimental value is reached, at which point the air compressor is stopped and the valve of the water pressure monitoring port 132 is closed. Second, the solution in the storage tanks 6 is changed according to experimental requirements. In this embodiment, one storage tank 6 stores clean seawater, and the other storage tank 6 stores nitrate solution. The third step involves using an air compressor to simultaneously inject the solutions from the two storage tanks 6 into the filling chamber 2 inside the housing 1, and simultaneously opening the drain outlet 131 to drain the water. During this process, clean seawater and carbonate solution will be injected into the rock sample 3 placed in the filling chamber 2 and react in its pores, thereby generating precipitates in the pores and finally completing the pore filling work.

[0039] Although the present invention has been described using the above preferred embodiments, it is not intended to limit the scope of protection of the present invention. Any changes and modifications made by those skilled in the art to the above embodiments without departing from the spirit and scope of the present invention shall still fall within the scope of protection of the present invention.

Claims

1. An experimental apparatus for simulating the pore filling of reef limestone in a marine environment, characterized in that, It includes a box body (1) and a filling chamber (2) set inside the box body (1) for placing rock samples (3). The filling chamber (2) has a bottom opening structure. A permeable seat (4) is connected to the lower part of the filling chamber (2). The lower part of the permeable seat (4) abuts against the box body (1). A permeable port (41) communicating with the bottom of the filling chamber (2) is opened on the permeable seat (4). A water injection hole (22) is provided at the upper part of the filling chamber (2). The water injection hole (22) is connected to a liquid storage tank (6) located outside the box body (1) through a water injection pipe (5). A pressurization component is connected to the liquid storage tank (6). A drain outlet (131) is opened on the box body (1). The filling chamber (2) has an escaping hole (23) on its peripheral sidewall; The permeable seat (4) has a protrusion (42) for supporting the rock sample (3) in the circumferential direction of the permeable port (41); The permeable seat (4) has a through hole (44) on its peripheral side wall, and the drain outlet (131) of the box body (1) is connected to the permeable seat (4); A water pressure monitoring port (132) is provided on the box (1); The pressurization assembly includes an air compressor, which is connected to the liquid storage tank (6) via a pressurization pipe (7).

2. The experimental apparatus for filling pores in reef limestone under simulated marine conditions according to claim 1, characterized in that, The bottom of the box (1) is provided with a groove (133), and the drain outlet (131) of the box (1) is horizontally connected to the groove (133) and the box (1).

3. The experimental apparatus for filling pores in reef limestone under simulated marine conditions according to claim 1, characterized in that, The filling chamber (2) is detachably connected to the permeable seat (4).

4. The experimental apparatus for filling pores in reef limestone under simulated marine conditions according to claim 3, characterized in that, The permeable seat (4) is provided with a connecting groove (43), and a connecting ring (21) is provided on the filling chamber (2).

5. The experimental apparatus for filling pores in reef limestone under simulated marine conditions according to claim 1, characterized in that, The box (1) is provided with a water inlet (111), and the liquid storage tank (6) is connected to the water inlet (111) through the water injection pipe (5). The water inlet (111) is connected to the water injection hole (22) of the filling chamber (2) through the water injection pipe (5).

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