Consolidation apparatus and consolidation method for marine deposition soft soil

Abstract

The invention relates to the technical field of physical property testing of soil or rock, and discloses a consolidometer and a consolidation method for marine sedimentary soft soil. The consolidometer comprises a consolidation chamber and a reaction frame; an opening of the consolidation chamber is upward, a sample preparation barrel is placed in the consolidation chamber, a lower permeable stone is placed in the sample preparation barrel, and a lower drainage hole is formed in the bottom of the consolidation chamber; the reaction frame is erected above the consolidation chamber, a pressurizing device is fixed below the reaction frame, a pressurizing cap is connected below the pressurizing device, an upper permeable stone is embedded in the pressurizing cap, an upper drainage hole is formed in the pressurizing cap, controllable valves are arranged in the upper drainage hole and the lower drainage hole, and the controllable valves are connected with a drainage hole controller; when the drain hole controller controls the controllable valve to be closed, slurry is prepared in the sample preparation barrel; when the drain hole controller controls the controllable valve to be opened, the pressurizing device pushes the pressurizing cap to move downwards, and the pressurizing cap, the sample preparation barrel and the bottom of the consolidation chamber form a gradually compressed closed space.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of soil or rock physical property testing, in particular to a consolidation apparatus and a consolidation method for marine sediment soft soil. BACKGROUND

[0002] Some coastal areas are widely distributed with soft soil strata due to sedimentation. Influenced by high groundwater level and seawater, these soft soils often have significant characteristics such as high water content and high compressibility. With the rapid economic development of these coastal areas, the number of projects such as roads, bridges and high-rise buildings built on soft soil foundations is increasing, and accurate testing of the engineering properties of soft soil has become a key link in the field of building technology.

[0003] As one of the commonly used test methods, consolidation test requires soft soil to be made into standard samples of a specific size. However, due to the extremely low strength of high water content soft soil, in-situ sampling in engineering is extremely difficult, and indoor sample preparation also faces many challenges. Even if the problem of sample preparation of high water content soft soil is solved, after the sample preparation is completed, the sample needs to be transferred to the consolidation apparatus. Due to the extremely poor strength of high water content soft soil in this state, the sample is easily disturbed during the transfer process, and this disturbance can seriously interfere with the accuracy and reliability of the consolidation test, and adversely affect the smooth progress of the test.

[0004] Therefore, it can be seen that in the prior art, the high water content soft soil sample is easily disturbed during the transfer process after sample preparation is completed, which affects the consolidation test. SUMMARY

[0005] The technical problem to be solved by the present application is how to solve the problem that the high water content soft soil sample is easily disturbed during the transfer process after sample preparation is completed, which affects the consolidation test.

[0006] In order to solve the above technical problems, the present application provides a consolidation apparatus and a consolidation method for marine sediment soft soil.

[0007] The first aspect of the present application provides a consolidation apparatus for marine sediment soft soil, which comprises: a consolidation chamber, which is open upward, and in which a sample preparation cylinder is placed, and a lower water-permeable stone is placed in the sample preparation cylinder; a bottom of the consolidation chamber is provided with a lower drainage hole, and the lower water-permeable stone covers the lower drainage hole; a counterforce frame is arranged above the consolidation chamber, and a pressurizing device is fixed below the counterforce frame; a pressurizing cap is connected below the pressurizing device, an outer diameter of the pressurizing cap is equal to an inner diameter of the sample preparation cylinder, an upper water-permeable stone is embedded in the pressurizing cap, and an upper drainage hole is arranged on the pressurizing cap and corresponds to the upper water-permeable stone; controllable valves are arranged in the upper drainage hole and the lower drainage hole, and a drainage hole controller is connected to the controllable valves; when the controllable valves are controlled to be closed by the drainage hole controller, mud is prepared in the sample preparation cylinder; when the controllable valves are controlled to be opened by the drainage hole controller, the pressurizing device drives the pressurizing cap to move downward, and the pressurizing cap, the sample preparation cylinder and the bottom of the consolidation chamber form a closed space which is gradually compressed, and the extruded liquid is discharged from the closed space through the upper drainage hole and the lower drainage hole.

[0008] In an embodiment, the consolidation apparatus further comprises a telescopic rod and an electric telescopic stirrer, and the telescopic rod is transversely arranged on a side wall of the counterforce frame or a side wall of the consolidation chamber; when the mud is prepared, the telescopic rod is used to drive the electric stirrer to move transversely above the sample preparation cylinder, and the electric stirrer is used to extend downward to stir the mud; when the consolidation is performed, the electric stirrer is used to retract upward, and the telescopic rod is used to drive the electric stirrer to move transversely out of the horizontal range of the sample preparation cylinder.

[0009] In an embodiment, a detachable blade is arranged on the electric telescopic stirrer.

[0010] In an embodiment, a displacement meter is arranged between the pressurizing device and the pressurizing cap.

[0011] In an embodiment, the consolidation apparatus further comprises a water environment tank and a water pump, and a water injection hole is further arranged at the bottom of the consolidation chamber, and the water pump is connected between the water environment tank and the water injection hole, and is used to inject water into the consolidation chamber through the water injection hole.

[0012] In an embodiment, the water environment tank is communicated with the lower drainage hole, and is used to contain the liquid discharged from the consolidation chamber through the lower drainage hole; and the water environment tank is also communicated with the upper drainage hole, and is used to contain the liquid discharged from the consolidation chamber through the upper drainage hole.

[0013] In an embodiment, a pressure sensor is arranged between the water environment tank and the lower drainage hole, or between the water environment tank and the upper drainage hole, and is used to detect the water pressure connected to the water environment tank.

[0014] In an embodiment, the sample preparation cylinder is a cutter with a diameter of 61.8 mm and a height of 110 mm.

[0015] In an embodiment, the bottom of the consolidation chamber is provided with a clamping groove, the sample preparation cylinder is fixed to the bottom of the consolidation chamber through the clamping groove, and a sealing rubber ring is arranged between the sample preparation cylinder and the clamping groove.

[0016] In a second aspect of the present application, a consolidation method for marine sediment soft soil is provided, the consolidation method is applied to a computing device in communication connection with the consolidation instrument provided in the first aspect of the present application, and the consolidation method comprises the following steps: controlling the controllable valve in the upper drainage hole and the lower drainage hole to be closed; after the mud is poured into the sample preparation cylinder, and the upper drainage stone and the lower drainage stone are filled with water and the filter paper is laid, the controllable valve is controlled to be opened; the extension of the pressurizing device is controlled to push the pressurizing cap to extrude the moisture in the mud in the sample preparation cylinder downward.

[0017] Compared with the prior art, the consolidation instrument and the consolidation method for marine sediment soft soil provided in the embodiments of the present application have the following beneficial effects:

[0018] The consolidation instrument provided in the embodiments of the present application is integrated with the sample preparation cylinder and the consolidation chamber through the telescopic pressurizing device, so that the sample preparation and the consolidation are completed in the same space, the disturbance problem during the transfer of the soft soil with high water content is completely avoided, and the test accuracy is significantly improved. The upper and lower drainage holes are matched with the controllable valve, so that the leakage is prevented during the sample preparation stage, and the bidirectional drainage is realized during the consolidation, the drainage path and the test time are greatly shortened, the pressure distribution is uniform, and the sample deformation error is reduced. The precise cooperation between the pressurizing cap and the sample preparation cylinder forms a closed compression space, the lateral deformation is constrained, the side limit test standard is met, and external interference is avoided. The counterforce frame provides stable support, the permeable stone efficiently filters and drains water, the overall operation is convenient, the test efficiency and the data reliability are considered, and the consolidation test of the soft soil with high water content is particularly suitable. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 FIG. 1 is a structural schematic diagram of a consolidation instrument for marine sediment soft soil according to an embodiment of the present application.

[0020] Figure 2 FIG. 2 is another structural schematic diagram of a consolidation instrument for marine sediment soft soil according to an embodiment of the present application.

[0021] Figure 3 FIG. 3 is a flow schematic diagram of a consolidation method for marine sediment soft soil according to an embodiment of the present application.

[0022] REFERENCE SIGNS:

[0023] 1. Consolidation chamber, 2. Reaction frame, 3. Pressure rod, 4. Sample preparation cylinder, 5. Lower permeable stone, 6. Lower drainage hole, 7. Upper permeable stone, 8. Upper drainage hole, 9. Water injection hole, 10. Sealing ring, 11. Displacement controller, 12. Water pump, 13. Pressure sensor, 14. Water pressure controller, 15. Axial controller, 16. Water environment box, 17. Water tank outlet hole, 18. Telescopic rod, 19. Electric telescopic stirrer, 20. Pressure cap. DETAILED DESCRIPTION

[0024] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0025] In the description of this application, it should be understood that the words "including," "having," and any variations thereof in the specification, claims, and drawings are intended to cover non-exclusive inclusions. For example, a product or device comprising a series of components or units is not necessarily limited to those components or units explicitly listed, but may also include other components or units that are not explicitly listed but are inherent to the product or device.

[0026] Soft soils are widely distributed in some coastal areas due to sedimentation. Influenced by high groundwater levels and seawater, these soft soils often exhibit significant properties such as high moisture content and high compressibility. With the rapid economic development of these coastal areas, the number of roads, bridges, high-rise buildings, and other projects built on soft soil foundations is increasing. Accurately testing the engineering properties of soft soils has become a critical aspect of construction technology.

[0027] As an important industrial instrument for measuring the compression properties of soil under different loads and confined conditions, the oedometer can deeply study the deformation behavior, compression characteristics and stability of soil by simulating the consolidation process of soil in actual engineering projects, providing a solid scientific basis for engineering design and construction.

[0028] Consolidation tests require soft soil to be prepared into standard specimens of specific dimensions. However, due to the extremely low strength of high-water-content soft soil, in-situ sampling in engineering projects is extremely difficult, and conventional indoor sample preparation methods also face many challenges. To this end, scholars have successively proposed methods such as the three-petal mold compaction method, static pressure method, and vibration method for preparing high-water-content soft soil specimens to meet the basic test specimen requirements.

[0029] Although these sample preparation methods solve the problem of sample preparation of high water content soft soil to some extent, in the consolidation test process, the sample needs to be transferred to the consolidation instrument after preparation. Because the strength of high water content soft soil is very poor in this state, the sample is easily disturbed during the transfer process, which seriously interferes with the accuracy and reliability of the consolidation test and adversely affects the smooth progress of the test.

[0030] Therefore, it can be seen that the problem of the high water content soft soil sample being easily disturbed in the process of being transferred to the consolidation instrument after sample preparation in the prior art needs to be solved.

[0031] Therefore, it can be seen that the problem of the high water content soft soil sample being easily disturbed in the process of being transferred to the consolidation instrument after sample preparation in the prior art needs to be solved. Figure 1 As shown in the preferred embodiment of the embodiment of the present application, a consolidation instrument for marine sediment soft soil, the consolidation instrument comprises: a consolidation chamber 1 and a counterforce frame 2.

[0032] The consolidation chamber 1 is open upward, a sample preparation cylinder 4 is placed in the consolidation chamber 1, a lower water permeable stone 5 is placed in the sample preparation cylinder 4, a lower drainage hole 6 is formed in the bottom of the consolidation chamber 1, and the lower water permeable stone 5 covers the lower drainage hole 6.

[0033] The counterforce frame 2 is erected above the consolidation chamber 1, a pressurizing device is fixed below the counterforce frame 2, a pressurizing cap 20 is connected below the pressurizing device, the outer diameter of the pressurizing cap 20 is equal to the inner diameter of the sample preparation cylinder 4, an upper water permeable stone 7 is embedded in the pressurizing cap 20, an upper drainage hole 8 is formed in the pressurizing cap 20, the upper drainage hole 8 corresponds to the upper water permeable stone 7, controllable valves are arranged in the upper drainage hole 8 and the lower drainage hole 6, and a drainage hole controller is connected to the controllable valves.

[0034] When the drainage hole controller controls the controllable valves to be closed, mud is prepared in the sample preparation cylinder 4. When the drainage hole controller controls the controllable valves to be opened, the pressurizing device pushes the pressurizing cap 20 to move downward, the pressurizing cap 20, the sample preparation cylinder 4 and the bottom of the consolidation chamber 1 form a gradually compressed closed space, and the extruded liquid is discharged from the closed space through the upper drainage hole 8 and the lower drainage hole 6.

[0035] The sample preparation cylinder 4 is placed in the consolidation chamber 1, and the sample preparation cylinder 4 and the consolidation chamber 1 form an open container that can directly contain the mud solution. The pressurizing device is telescopic, the outer diameter of the pressurizing cap 20 matches the inner diameter of the sample preparation cylinder 4, and the open container is further converted into a closed container.

[0036] Therefore, only the steps of closing the valves, preparing mud in the sample preparation cylinder 4, opening the valves and pushing the pressurizing cap 20 downward by the pressurizing device need to be performed, so that the whole process from sample preparation to consolidation can be realized. The sample does not need to be transferred, and the structural damage of high water content soft soil caused by transportation is reduced from the root.

[0037] Due to the synchronous opening of the upper and lower valves during the pressurization process, the pore water is discharged in both directions, the drainage path is shortened by more than half, the consolidation time is greatly shortened, the experimental time consumption is reduced, and the experimental efficiency is improved.

[0038] The upper water-permeable stone 7 and the lower water-permeable stone 5 cover the drainage holes, and during the drainage process, the upper water-permeable stone 7 and the lower water-permeable stone 5 filter fine particles to prevent the upper drainage hole 8 and the lower drainage hole 6 from being blocked during the drainage process.

[0039] Since the whole process of "sample preparation, pressurization, drainage, and pressure stabilization" is completed in the same container, a single person can complete the operation.

[0040] In summary, the consolidation apparatus of the present application realizes overall improvement in test accuracy, efficiency, standardization, and maintainability through structural innovation and operation process optimization, and is especially suitable for testing the mechanical properties of high-moisture and high-sensitivity soil such as marine sediment soft soil, providing more reliable data support for geotechnical engineering design.

[0041] In further embodiments, as shown in Figure 2 The consolidation apparatus of the present application can further include a telescopic rod 18 and an electric telescopic stirrer 19, and the telescopic rod 18 is transversely installed on the side wall of the counterforce frame 2 or the side wall of the consolidation chamber 1.

[0042] When the mud is configured, the telescopic rod 18 is used to move the electric stirrer transversely above the sample preparation cylinder 4, and the electric stirrer is used to extend downward to stir the mud.

[0043] During consolidation, the electric stirrer is used to retract upward, and the telescopic rod 18 is used to move the electric stirrer transversely to the horizontal range outside the sample preparation cylinder 4.

[0044] The design of the electric telescopic stirrer in the present application significantly improves the sample preparation quality and test efficiency of high-moisture soft soil through the synergistic optimization of structure and operation process. During the sample preparation stage, the electric stirrer can accurately enter the sample preparation cylinder 4, and through stable stirring, it ensures uniform mixing of the mud and eliminates texture differences caused by manual operation. During the consolidation stage, the stirrer can quickly retract and move transversely to the outside of the sample preparation area, completely avoiding the working path of the pressurizing device, realizing seamless connection of the sample preparation and consolidation processes, and avoiding equipment interference.

[0045] The overall design not only ensures the consistency of the test sample, but also simplifies the operation steps and reduces manual intervention, and is especially suitable for the consolidation test requirements of easily disturbed test samples such as marine sediment soft soil, improving the reliability of the test while improving the efficiency of the equipment.

[0046] On this basis, in order to further reduce the occupation of space and reduce the interference with the pressurizing cap 20 during consolidation, in an embodiment of the present application, a detachable cutter head is provided on the electric telescopic stirrer 19.

[0047] Moreover, the detachable cutter design further enhances the practicality and flexibility of the electric telescopic mixer 19. For different properties of marine sediment soft soil (such as sand content difference, viscosity change, etc.), the type of the cutter can be flexibly replaced (such as spiral type, paddle type, etc.), ensuring uniform mixing of various types of soft soil slurry and adapting to diversified sample requirements.

[0048] At the same time, the detachable feature of the cutter makes cleaning and maintenance more convenient. When the cutter is attached to the soil or appears to be worn, the entire mixer does not need to be disassembled, and only the cutter needs to be disassembled for cleaning or replacement, simplifying the maintenance process and reducing equipment downtime.

[0049] In addition, this design also facilitates the selection of special materials with better wear resistance and corrosion resistance for the cutter according to the use requirements, prolongs the service life of the key components, reduces the overall wear cost of the equipment, and keeps the consolidation instrument stable and reliable in long-term use.

[0050] In an embodiment, as shown in Figure 2 A displacement meter is installed between the pressurizing device and the pressurizing cap 20.

[0051] The installation of the displacement meter between the pressurizing device and the pressurizing cap 20 can directly and real-time capture the deformation of the sample during the consolidation and pressurization process. The installation position close to the pressurization path can reduce the interference of external environment or measurement links on the deformation data, making the recorded displacement change more consistent with the actual compression state of the sample, and improving the measurement accuracy.

[0052] At the same time, the displacement meter can be monitored synchronously with the pressurization process without additional manual intervention, which not only avoids the tediousness of manual measurement at regular intervals, but also continuously records the deformation rate at different pressure stages, fully presents the dynamic changes in the whole consolidation process, and facilitates accurate analysis of the consolidation characteristics of the sample. This integrated design also simplifies the test operation, eliminates the need for separate external measurement tools, reduces errors caused by tool displacement or improper calibration, and makes the test data more reliable, providing a more solid foundation for subsequent calculation of consolidation parameters.

[0053] In the present application, as shown in Figure 2 The consolidation instrument also includes a water environment tank 16 and a water pump 12, and the bottom of the consolidation chamber 1 is also provided with a water injection hole 9. The water pump 12 is connected between the water environment tank 16 and the water injection hole 9, and the water pump 12 is used to inject water into the consolidation chamber 1 through the water injection hole 9.

[0054] The water environment box 16 and the water pump 12 further strengthen the simulation capability of the consolidation instrument on the marine sediment soft soil test environment. By injecting water into the consolidation chamber 1 through the water pump 12, a water environment consistent with the original environment of the soft soil (such as seawater immersion conditions) can be accurately created, ensuring that the sample is always in a humid state consistent with the actual geological background during the consolidation process, avoiding changes in sample properties due to water loss, and making the test results more close to the actual engineering.

[0055] Meanwhile, the water injection process can be flexibly controlled, which can not only adjust the moisture conditions in the consolidation chamber 1 in the sample preparation stage, but also continuously maintain the required water environment during the consolidation test, reducing the operation error of manual water supplement and ensuring the stability of the test conditions. This design not only enables the equipment to complete the integrated operation of sample preparation and consolidation, but also accurately reproduces the original environment of marine soft soil, broadens its application range under complex geological conditions, and improves the scientificity and reliability of the test.

[0056] Furthermore, the water environment box 16 can be in communication with the lower drainage hole 6, and the water environment box 16 is used to contain the liquid discharged from the consolidation chamber 1 through the lower drainage hole 6. The water environment box 16 can also be in communication with the upper drainage hole 8, and the water environment box 16 is also used to contain the liquid discharged from the consolidation chamber 1 through the upper drainage hole 8.

[0057] The communication design of the water environment box 16 and the upper and lower drainage holes 6 further optimizes the environmental simulation capability and operation convenience of the consolidation instrument. The discharged liquid can be recycled back to the water environment box 16, which can not only maintain the stability of the composition of the water environment (such as seawater medium), avoid the fluctuation of environmental parameters caused by frequent replacement of liquid, and be more close to the original geological conditions of marine soft soil, but also reduce the need for external liquid supplement and simplify the liquid management process in the test.

[0058] Meanwhile, the centralized recovery of liquid to the water environment box 16 avoids pollution and cleaning burden caused by random discharge of waste liquid, making the whole test process more clean and orderly. This design enables the equipment to form a synergistic advantage in simulating the real environment, saving resources, and simplifying the operation, further improving the adaptability and scientificity of the consolidation test of marine sediment soft soil.

[0059] In an embodiment, a pressure sensor 13 is arranged between the water environment box 16 and the lower drainage hole 6, or between the water environment box 16 and the upper drainage hole 8, and the pressure sensor 13 is used to detect the water pressure connected to the water environment box 16.

[0060] The pressure sensor 13 is arranged between the water environment box 16 and the drainage hole, so that the change of water pressure in the drainage process can be monitored in real time, and key environmental parameter feedback for the consolidation test is provided. By capturing the water pressure dynamics in real time, the matching of the pore water discharge rate and the consolidation process can be accurately judged, and abnormal fluctuations of the water pressure (such as sudden pressure rise caused by pipeline blockage) can be found in time, so that the operator can quickly adjust, and the test effect is not affected by poor drainage.

[0061] Meanwhile, the water pressure data can be used as a basis for evaluating the stability of the water environment, so as to ensure that the liquid pressure in the circulation system always meets the original environmental characteristics of the marine soft soil, and the interference of environmental factors on the test result is reduced.

[0062] It can be understood that the sample preparation cylinder 4 can be designed according to the actual project requirements, and any size of the sample preparation cylinder 4 corresponds to a scheme within the protection scope of the present application. In the present application, the sample preparation cylinder 4 can be a cutting ring with a diameter of 61.8 mm and a height of 110 mm.

[0063] In the present application, the consolidation chamber 1 can be connected and fixed with the sample preparation cylinder 4 in any sealing manner. In order to improve the portability and facilitate the replacement of different specifications of parts, in an embodiment of the present application, a clamping groove is arranged at the bottom of the consolidation chamber 1, the sample preparation cylinder 4 is fixed at the bottom of the consolidation chamber 1 through the clamping groove, and a sealing rubber ring is arranged between the sample preparation cylinder 4 and the clamping groove.

[0064] The cooperation design of the clamping groove at the bottom of the consolidation chamber 1 and the sample preparation cylinder 4 significantly improves the disassembly and assembly convenience and the part universality of the equipment. Through the clamping groove structure, the sample preparation cylinder 4 can be quickly embedded or taken out without the aid of complex tools, so that different specifications of the sample preparation cylinder 4 can be replaced according to the test requirements, and the sample size can be flexibly adapted to diversification. Meanwhile, the combination of the clamping groove and the sealing rubber ring can form reliable sealing between the sample preparation cylinder 4 and the consolidation chamber 1, so as to effectively prevent liquid leakage during the sample preparation or consolidation process.

[0065] It can be understood that the action elements such as the displacement controller 11, the water pump 12 and the pressure sensor 13 in the present application can be controlled by electric signals. According to the type of the element used, the calculation equipment (computer) can be directly controlled, or other controllers and acquisition instruments can be indirectly controlled and data acquisition. No matter which form is adopted, it does not affect the implementation of the scheme of the present application, and therefore it falls within the protection scope of the present application.

[0066] As shown in Figure 2 , the on-off and flow of the drainage hole and the water environment box 16 can be controlled by the water pressure controller 14. The extension distance and pressure of the pressurizing device can be realized by the axial controller 15.

[0067] Correspondingly, as shown in Figure 3As shown, the application also provides a consolidation method for marine sediment soft soil, the consolidation method is applied to a computing device in communication with the consolidation instrument of any embodiment of the application, and the consolidation method comprises:

[0068] S1, control the controllable valve in the upper drainage hole 8 and the lower drainage hole 6 to close.

[0069] S2, after pouring the mud into the sample preparation cylinder 4, and filling the upper and lower drainage stones with water and laying the filter paper, control the controllable valve to open.

[0070] S3, control the extension of the pressurizing device to push the pressurizing cap 20 downward to squeeze out the moisture in the mud in the sample preparation cylinder 4.

[0071] Based on the consolidation instrument in the application, the exemplary detailed steps are as follows.

[0072] Sample preparation process:

[0073] S11, the size of the sample used in the common one-dimensional consolidation test is 61.8mm in diameter and 20mm in height, and accordingly the volume of the sample V1 can be obtained. Assuming that the dry density of the marine sediment soft soil is p, the mass m1 of the required soil is pV1, and the soil sample of m1 grams is weighed.

[0074] S12, open the lower drainage hole 6, fill the lower water-permeable stone 5 with the aqueous solution, and lay a layer of filter paper on the water-permeable stone, and then close the lower drainage hole 6.

[0075] S13, the size of the sample preparation cylinder 4 is 61.8mm in diameter and 110mm in height, and the thickness of the water-permeable stone is 10mm, so the volume available for filling the soil and water in the sample preparation cylinder 4 is only V2 (61.8mm in diameter and 100mm in height). In order to leave space for the cleaning liquid for cleaning the cutter disc of the stirrer, first pour an aqueous solution with a height of 70mm into the sample preparation cylinder.

[0076] S14, control the electric telescopic stirrer 19 base to move to the middle of the sample preparation cylinder 4 through the computing device, then install the cutter disc, and extend the cutter disc into the aqueous solution, and start the stirrer to start stirring.

[0077] S15, slowly pour the weighed soil into the sample preparation cylinder 4, and after stirring for 5 minutes, close the stirrer, then raise the cutter disc, and clean the cutter disc with the same aqueous solution, and ensure that the cleaning liquid flows into the sample preparation cylinder 4; after cleaning, disassemble and store the cutter disc, and move the stirrer base to the rightmost side.

[0078] S16, open the upper drainage hole 8, fill the upper water permeable stone 7 with water, and paste a layer of filter paper on the upper water permeable stone 7, then open the upper drainage hole 8, control the pressurizing cap 20 to just contact the top of the sample preparation cylinder 4, then make the pressurizing cap 20 slowly descend 80mm through displacement control, close the upper drainage hole 8, and the corresponding marine sediment soft soil sample can be prepared at this time.

[0079] Consolidation process:

[0080] S21, open the water injection hole 9, inject the corresponding marine water solution into the consolidation chamber 1, and close the water injection hole 9 after the water solution covers the sample preparation cylinder 4;

[0081] S22, open the upper and lower drainage holes 6 according to the need, select the stress control mode through the computing device, and set the corresponding load level and loading time to apply the corresponding consolidation stress to the sample;

[0082] S23, record the changes of drainage amount, pore water pressure and other parameters with time through the computing device until the test is completed;

[0083] S24, after the test is completed, take out the sample preparation cylinder 4 from the clamping groove, push the sample out of the sample preparation cylinder 4 through the pressurizing cap 20, and then clean the sample preparation cylinder 4 and put it back into the clamping groove after cleaning.

[0084] Determination of soil permeability coefficient:

[0085] S31, after the sample preparation is completed, open the upper and lower drainage holes 6, slowly inject water into the sample through the water pressure controller 14 connected with the upper drainage hole 8, and record the changes of drainage amount Q of the lower drainage hole 6 and pore water pressures u1, u2 at the upper and lower drainage holes 6 with time;

[0086] S32, draw the Q-t curve, select the time period of linear increase of drainage amount Q with time t to calculate the permeability coefficient of the soil, assuming that the starting time of linear increase of drainage amount Q with time t is t0, the terminal time is t1, the corresponding drainage amounts are Q1 and Q2 respectively, the height of the sample is h, and the cross-sectional area of the sample is A, then the permeability coefficient of the soil can be calculated by the following formula:

[0087]

[0088] In formula one, k is the permeability coefficient of the soil, Q is the drainage amount, h is the height of the sample, γ ω is the gravity per unit volume of water, t0 is the starting time, t1 is the terminal time, u1 and u2 are the pore water pressures at the upper and lower drainage holes.

[0089] Steps of exploring the influence of sedimentation process in different water environments on the consolidation and compression characteristics of soil:

[0090] S41, the size of the sample of the commonly used one-dimensional consolidation test is 61.8mm in diameter and 20mm in height, and the volume of the sample is V1. Assuming that the dry density of the marine sediment soft soil is p, the mass m1 of the required soil is pV1, and the soil sample is weighed m1 grams.

[0091] S42, open the lower drainage hole 6, fill the lower water-permeable stone 5 with the aqueous solution, and lay a layer of filter paper on the water-permeable stone, then close the lower drainage hole 6.

[0092] S43, the size of the sample cylinder 4 is 61.8mm in diameter and 110mm in height, and the thickness of the water-permeable stone is 10mm, so the volume of the sample cylinder 4 available for filling the soil and water is only V2 (61.8mm in diameter and 100mm in height). In order to leave space for the cleaning liquid to clean the cutter disc of the stirrer, pour 70mm high aqueous solution into the sample barrel.

[0093] S44, control the electric telescopic stirrer 19 base to move to the middle of the sample cylinder 4 through the computing device, then install the cutter disc, and extend the cutter disc into the aqueous solution, start the stirrer to start stirring.

[0094] S45, slowly pour the weighed soil into the sample cylinder 4, turn off the stirrer after stirring for 5 minutes, then raise the cutter disc, and clean the cutter disc with the same aqueous solution, make sure that the cleaning liquid flows into the sample cylinder 4; after cleaning, disassemble and save the cutter disc, and move the stirrer base to the rightmost position.

[0095] S46, let the stirred mud deposit naturally for 24 hours, open the upper drainage hole 8 after 24 hours, fill the upper water-permeable stone 7 with water, and paste a layer of filter paper on the upper water-permeable stone 7, then open the upper drainage hole 8, control the pressurizing cap 20 to just contact the top of the sample cylinder 4, then slowly lower the pressurizing cap 20 by 80mm through displacement control, close the upper drainage hole 8, and the corresponding marine sediment soft soil sample is obtained at this time.

[0096] S47, open the water injection hole 9, and inject the corresponding marine aqueous solution into the consolidation chamber 1, and close the water injection hole 9 after the aqueous solution covers the sample cylinder 4;

[0097] S48, open the upper and lower drainage holes 6 as needed, select the stress control mode through the computing device, and set the corresponding load level and loading time to apply the corresponding consolidation stress to the sample;

[0098] S49, record the changes of drainage volume, pore water pressure and other parameters with time through the computing device until the test is completed;

[0099] After the test is completed, the sample preparation cylinder 4 is taken out of the clamping groove, the sample is pushed out of the sample preparation cylinder 4 through the pressure cap 20, and then the sample preparation cylinder 4 is cleaned and placed back in the clamping groove.

[0100] Compared with the prior art, the consolidation apparatus and the consolidation method for marine sediment soft soil according to the embodiments of the present application have the beneficial effects that:

[0101] The consolidation apparatus according to the embodiments of the present application is integrated with the sample preparation cylinder 4 and the consolidation chamber 1 through the telescopic pressure device, so that the sample preparation and consolidation are completed in the same space, the disturbance problem during the transfer of the soft soil with high water content is completely avoided, and the test accuracy is significantly improved. The upper and lower drainage holes are matched with the controllable valve, which can not only be closed to prevent leakage during the sample preparation stage, but also can realize bidirectional drainage during the consolidation, so that the drainage path and the test time are greatly shortened, the pressure distribution is uniform, the sample deformation error is reduced, and the consolidation apparatus meets the side limit test standard while avoiding external interference. The counterforce frame 2 provides stable support, and the permeable stone efficiently filters and drains water, so that the overall operation is convenient, the test efficiency and the data reliability are considered, and the consolidation apparatus is particularly suitable for the consolidation test of the soft soil with high water content.

[0102] The above description is only the preferred embodiments of the present application, and it should be pointed out that, for ordinary skilled in the art, without departing from the technical principles of the present application, a number of improvements and replacements can be made, and these improvements and replacements should be considered as the protection scope of the present application.

Claims

1. A consolidation instrument for marine sedimentary soft soil, characterized in that: The oedometer comprises: A consolidation chamber (1), the consolidation chamber (1) opening upwards, a sample preparation tube (4) placed in the consolidation chamber (1), a lower permeable stone (5) placed in the sample preparation tube (4), a lower drainage hole (6) opened at the bottom of the consolidation chamber (1), and the lower permeable stone (5) covering the lower drainage hole (6); A reaction frame (2), wherein the reaction frame (2) is erected above the consolidation chamber (1), a pressure device is fixed below the reaction frame (2), a pressure cap (20) is connected below the pressure device, the outer diameter of the pressure cap (20) is equal to the inner diameter of the sample preparation cylinder (4), an upper permeable stone (7) is embedded in the pressure cap (20), an upper drainage hole (8) is opened on the pressure cap (20), the upper drainage hole (8) corresponds to the upper permeable stone (7), and controllable valves are provided in the upper drainage hole (8) and the lower drainage hole (6), and the controllable valves are connected to a drainage hole controller; When the drain hole controller controls the controllable valve to be closed, mud is prepared in the sample preparation cylinder (4); when the drain hole controller controls the controllable valve to be opened, the pressurizing device pushes the pressurizing cap (20) to move downward, and the pressurizing cap (20) and the bottom of the sample preparation cylinder (4) and the consolidation chamber (1) form a gradually compressed closed space, and the squeezed liquid is discharged from the closed space through the upper drain hole (8) and the lower drain hole (6).

2. The oedometer according to claim 1, characterized in that The consolidation instrument further comprises a telescopic rod (18) and an electric telescopic stirrer (19), wherein the telescopic rod (18) is transversely mounted on the side wall of the reaction frame (2) or the side wall of the consolidation chamber (1); When preparing the slurry, the telescopic rod (18) is used to drive the electric stirrer to move horizontally to the top of the sample preparation cylinder (4), and the electric stirrer is used to extend downward to stir the slurry; During solidification, the electric stirrer is used to retract upward, and the telescopic rod (18) is used to drive the electric stirrer to move laterally to outside the horizontal range of the sample preparation cylinder (4).

3. The oedometer according to claim 2, characterized in that The electric telescopic stirrer (19) is provided with a detachable knife disc.

4. The oedometer according to claim 1, characterized in that A displacement meter is installed between the pressurizing device and the pressurizing cap (20).

5. The oedometer according to claim 1, characterized in that: The consolidation instrument further comprises a water environment box (16) and a water pump (12); a water injection hole (9) is further provided at the bottom of the consolidation chamber (1); the water pump (12) is connected between the water environment box (16) and the water injection hole (9); and the water pump (12) is used to inject water into the consolidation chamber (1) through the water injection hole (9).

6. The oedometer according to claim 5, characterized in that The water environment box (16) is connected to the lower drainage hole (6), and the water environment box (16) is used to accommodate the liquid discharged from the consolidation chamber (1) through the lower drainage hole (6); the water environment box (16) is connected to the upper drainage hole (8), and the water environment box (16) is also used to accommodate the liquid discharged from the consolidation chamber (1) through the upper drainage hole (8).

7. The oedometer according to claim 6, characterized in that A pressure sensor (13) is provided between the water environment box (16) and the lower drainage hole (6), or between the water environment box (16) and the upper drainage hole (8). The pressure sensor (13) is used to detect the water pressure connected to the water environment box (16).

8. The oedometer according to claim 1, characterized in that The sample preparation cylinder (4) is a circular knife with a diameter of 61.8 mm and a height of 110 mm.

9. The oedometer according to claim 1, characterized in that A card slot is provided at the bottom of the consolidation chamber (1), and the sample preparation cylinder (4) is fixed to the bottom of the consolidation chamber (1) via the card slot. A sealing rubber ring is provided between the sample preparation cylinder (4) and the card slot.

10. A consolidation method for marine sedimentary soft soil, characterized in that: The consolidation method is applied to a computing device that is communicatively connected to the oedometer according to any one of claims 1 to 9, and the consolidation method comprises: Controlling the controllable valves in the upper drain hole (8) and the lower drain hole (6) to close; After the slurry is poured into the sample preparation cylinder (4), the upper drainage stone and the lower drainage stone are filled with water and filter paper is laid, the controllable valve is controlled to open; The pressurizing device is controlled to extend so as to push the pressurizing cap (20) downward to squeeze out the moisture of the slurry in the sample preparation cylinder (4).

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