Ultra-soft soil vibration pressurization drainage consolidation test device and method

Abstract

The invention discloses a vibration pressurization drainage consolidation test device for ultra-soft soil. The vibration pressurization drainage consolidation test device comprises a consolidation container, a vibration unit, a pressurization system and a test unit, wherein a water outlet hole is formed in the bottom of the consolidation container, and a vertical drainage belt is arranged on the side wall of the consolidation container; the vibration unit comprises a vibrator; the test unit comprises a pressurizing frame, a pressurizing sensor, a displacement meter and a pressurizing cover plate, and the pressurizing cover plate covers the top of the consolidation container and applies pressure to the ultra-soft soil sample; the test system comprises a pore water pressure sensor and a displacement meter; a pore water pressure sensor is arranged on the side wall of the consolidation container, and a displacement meter is used for monitoring the downward moving distance of the pressurizing cover plate along with consolidation of the ultra-soft soil in real time. The invention further provides a vibration pressurizing drainage consolidation test method for the ultra-soft soil, water permeable plates are arranged on the upper portion and the lower portion of the ultra-soft soil sample, and a drainage belt is arranged on the side face of the ultra-soft soil sample; a complete drainage channel is formed, water can be drained in time, and rapid drainage consolidation is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of geotechnical engineering geotechnical testing, and more specifically, to a vibration pressurization drainage consolidation testing device and method in ultra-soft soil drainage consolidation. Background Art

[0002] As land resources become increasingly scarce, the number of land reclamation projects at home and abroad is increasing. Every year, my country produces a large amount of super-soft soil in waterways, rivers, lakes, etc., which has high natural water content, poor water permeability, high compressibility, low strength, and is in a state from soft plastic to fluid plastic. Using these super-soft soils as materials for land reclamation solves the problem of the disposal of super-soft soils and has huge environmental, social and economic benefits.

[0003] The traditional static drainage consolidation method for ultra-soft soil sites has good results and small post-construction settlement, but the construction period is long; the dynamic drainage consolidation method based on strong compaction has a rapid attenuation of the force acting on the foundation surface by strong compaction, and its treatment depth is limited. In order to solve the problems that the strong compaction applies instantaneous loads to the foundation, the action time is short, and the attenuation is rapid, scholars have proposed vibration boosting drainage consolidation. Vibration boosting drainage consolidation refers to burying vibrators at certain intervals in the soft soil foundation to be treated, turning on the vibrators to generate a periodic exciting force, which acts on the soil, that is, applying dynamic periodic loads inside the ultra-soft soil layer, with a large treatment depth and small post-construction settlement. It can not only treat sand and silt, but also silt and silty soil. However, the design theory and design method of vibration boosting are still imperfect, and some parameters used in the design lack experimental basis. Summary of the invention

[0004] In order to achieve these purposes and other advantages according to the present invention, on the one hand, a preferred embodiment of the present invention provides a super-soft soil vibration pressurization drainage consolidation test device, including a consolidation container, a vibration unit, a pressurization system and a test unit; wherein,

[0005] The bottom of the consolidation container is provided with a water outlet hole, the side wall of the consolidation container is provided with a vertical drainage belt, the super-soft soil sample is placed in the consolidation container, and the top and bottom of the consolidation container are respectively an upper permeable plate and a lower permeable plate that are water-permeable;

[0006] The vibration unit comprises a vibrator, and the vibrator is installed in the consolidation container;

[0007] The test unit comprises a pressure frame, a pressure sensor, a displacement meter and a pressure cover plate, wherein the consolidation container is arranged in the pressure frame, the pressure cover plate is arranged on the top of the consolidation container to apply pressure to the super-soft soil sample, and the pressure sensor is used to monitor in real time the pressure value of the pressure applied by the pressure cover plate to the super-soft soil sample;

[0008] The test system comprises a pore water pressure sensor and a displacement meter; the pore water pressure sensor is arranged on the side wall of the consolidation container, and the displacement meter is used for real-time monitoring of the distance the pressurized cover plate moves downward as the super-soft soil is consolidated.

[0009] According to a preferred embodiment of the present invention, the vibrator is installed in the consolidation container via a vibrator frame.

[0010] According to a preferred embodiment of the present invention, a base is provided at the bottom of the pressurizing frame, and the consolidation container is arranged on the base.

[0011] According to a preferred embodiment of the present invention, it further comprises a water discharge measurement container, which is arranged below the water outlet and is used to receive the water discharged through the water outlet.

[0012] According to a preferred embodiment of the present invention, the length of the vertical drainage belt is the initial height of the supersoft soil sample, and there are multiple vertical drainage belts, which are symmetrically arranged with the vibrator as the center.

[0013] According to a preferred embodiment of the present invention, the diameter of the vibrator is 1 / 5 to 1 / 4 of the diameter of the consolidation container.

[0014] According to a preferred embodiment of the present invention, the pressurized cover plate is in complete contact with the top surface of the supersoft soil sample.

[0015] According to a preferred embodiment of the present invention, it also includes a collector, which is connected to the pressure sensor, the displacement meter and the pore water pressure sensor, collects the electrical signals transmitted by each sensor, and converts them into pressure values, displacement values ​​and pore water pressure values.

[0016] On the other hand, another preferred embodiment of the present invention provides a test method based on the ultra-soft soil vibration pressurization drainage consolidation test device, comprising the following steps:

[0017] The super-soft soil sample to be tested is placed in a consolidation container, and different loads are applied to the super-soft soil sample through a pressure cover plate to collect the excess pore water pressure, displacement and drainage, and the relationship curves of excess pore water pressure, displacement and drainage with time are obtained. The curves are analyzed to obtain the soil consolidation degree, consolidation coefficient and permeability coefficient.

[0018] When applying the load, ensure that the load is vertical, and load the cover plate vertically, and load in stages; after static load is applied for a certain period of time, vibration loading is performed, and the excitation frequency, excitation force and excitation duration are adjusted.

[0019] According to a preferred embodiment of the present invention, the super-soft soil sample needs to be left to stand for 24 hours before being placed in the consolidation container.

[0020] The present invention includes at least the following beneficial effects: the present invention provides a super-soft soil vibration pressurization drainage consolidation test device and method, by arranging permeable plates above and below the super-soft soil sample and arranging drainage belts on the side to form a complete drainage channel, water can be discharged in time to achieve rapid drainage and consolidation; the present invention can obtain the pore water pressure, settlement, and drainage in real time by arranging pore water pressure sensors, displacement meters, and drainage measurement containers; the test device and test method of the present invention have a high degree of automation, and can provide vibration-enhanced drainage consolidation reinforcement design parameters and theoretical basis for super-soft soil foundations.

[0021] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic structural diagram of the ultra-soft soil vibration pressurization drainage consolidation test device of the present invention.

[0023] Figure 2 A top view of the consolidation container of the present invention;

[0024] Figure 3 It is the displacement and time relationship curve under the given vibration frequency of the present invention;

[0025] Figure 4 It is the displacement and time relationship curve under different vibration frequencies of the present invention;

[0026] Figure 5 This is a curve showing the relationship between excess pore water pressure and time under the vibration pressurization described in the present invention. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0028] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations. The basic principles of the present invention defined in the following description can be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not deviate from the spirit and scope of the present invention.

[0029] Those skilled in the art should understand that, in the disclosure of the present invention, the orientation or position relationship indicated by the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are based on the orientation or position relationship shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the above terms should not be understood as limiting the present invention.

[0030] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0031] like Figure 1-5 As shown, a preferred embodiment of the present invention provides a super-soft soil vibration pressurization drainage consolidation test device, including a consolidation container 5, a vibration unit, a pressurization system and a test unit; wherein,

[0032] A water outlet 2 is provided at the bottom of the consolidation container 5, and a vertical drainage belt 7 is provided on the side wall of the consolidation container 5. The super soft soil sample 6 is placed in the consolidation container 5. The top and bottom of the consolidation container are respectively a water-permeable upper permeable plate 8 and a lower permeable plate 3; a base 1 is provided at the bottom of the pressure frame 11, and the consolidation container 5 is arranged on the base 1.

[0033] The vibration unit comprises a vibrator 14, and the vibrator 14 is installed in the consolidation container 5;

[0034] The test unit includes a pressure frame 11, a pressure sensor 10, a displacement meter 12 and a pressure cover plate 9. The consolidation container 5 is arranged in the pressure frame 11. The pressure cover plate 9 is covered on the top of the consolidation container 5 to apply pressure to the super-soft soil sample 6. The pressure sensor 10 is used to monitor in real time the pressure value of the pressure applied by the pressure cover plate 9 to the super-soft soil sample 6.

[0035] The test system includes a pore water pressure sensor 15 and a displacement meter 12; the pore water pressure sensor 15 is arranged on the side wall of the consolidation container 5, and the displacement meter 12 is used to monitor in real time the distance that the pressurized cover plate 9 moves downward as the super soft soil is consolidated.

[0036] In the above technical scheme, a complete drainage channel is formed by arranging permeable plates above and below the ultra-soft soil sample and arranging drainage belts on the side, so that water can be discharged in time to achieve rapid drainage and consolidation; the present invention can obtain the pore water pressure, settlement, and drainage in real time by arranging pore water pressure sensors, displacement meters, and drainage measurement containers;

[0037] The consolidation container 5 is cylindrical, with a seamless organic glass cylinder body, a water outlet 2 at the bottom, a wall thickness of 10 mm, an inner diameter of 190 mm, a height of 200 mm, and a vertical drainage belt 7 and a pore water pressure sensor 15 on the wall.

[0038] The pore water pressure sensor 15 has a measuring range of 0-100 kPa, a measuring accuracy of 2 / 1000, a power supply of 12-24 VDC, and an output of 0-5 VDC. The pore water pressure sensor 15 can be a fiber optic pore water pressure sensor or other pressure sensor, with a measuring range of 0 kPa-500 kPa, a maximum allowable error of ±0.5% FS, and a volume factor of less than 1.5E10 -5 cm 3 / kPa. Used to measure the relationship between excess pore water pressure and time.

[0039] The vibrator 14 has a diameter of 1 / 5 to 1 / 4 of the diameter of the consolidation container 5, and is externally a seamless organic glass cylinder with upper and lower covers for waterproof sealing. An adjustable frequency DC motor with an eccentric block is encapsulated internally, and the motor body is bonded and fixed to the organic tempered glass cylinder.

[0040] The vibrator frame 13 is located at the lower end of the vibrator and is fixed at the bottom center of the consolidation container 5 .

[0041] The pressure frame 11 is a square frame structure, which supports and fixes the entire device.

[0042] The displacement meter 12 may be a strain gauge displacement sensor with a measuring range of 0 mm to 100 mm, a collection frequency of 1 Hz, and a maximum allowable error of ±0.5% FS, and is used to measure the relationship between settlement and time.

[0043] In another technical solution, the vibrator 14 is installed in the consolidation container 5 through a vibrator frame 13, and the vibrator frame is mainly used to support the vibrator 14 and play a supporting and fixing role.

[0044] Another technical solution further includes a water discharge measurement container 17 , which is disposed below the water outlet 2 and is used to receive the water discharged through the water outlet 2 .

[0045] In another technical solution, the length of the vertical drainage belt 7 is the initial height of the super-soft soil sample. There are multiple vertical drainage belts 7, which are symmetrically arranged with the vibrator as the center, so that the squeezed water can be evenly discharged.

[0046] In another technical solution, the diameter of the vibrator 14 is 1 / 5 to 1 / 4 of the diameter of the consolidation container 5, which can ensure a relatively good vibration effect without affecting the stability of the entire device during vibration.

[0047] In another technical solution, the pressurized cover plate is in full contact with the top surface of the super-soft soil sample 6, ensuring that every corner of the super-soft soil sample 6 is pressurized and consolidated.

[0048] Another technical solution also includes a collector 16, which is connected to the pressure sensor, displacement meter and pore water pressure sensor, collects the electrical signals transmitted by each sensor, converts them into pressure values, displacement values ​​and pore water pressure values, and displays them.

[0049] Another technical solution provides a super-soft soil vibration pressurization drainage consolidation test method, comprising the following steps:

[0050] The super-soft soil sample 6 to be tested is placed in a consolidation container 5, and different loads are applied to the super-soft soil sample through a pressure cover plate 9 to collect the excess pore water pressure, displacement and drainage, and obtain the relationship curve between the excess pore water pressure, displacement and drainage and time, and the curve is analyzed to obtain the soil consolidation degree, consolidation coefficient and permeability coefficient;

[0051] When applying the load, ensure that the load is vertical, and load the cover plate vertically, and load in stages; after static load is applied for a certain period of time, vibration loading is performed, and the excitation frequency, excitation force and excitation duration are adjusted.

[0052] When applying the load, ensure that the load is vertical, and load the cover plate vertically, and load in stages; after static load is applied for a certain period of time, vibration loading is performed, and the excitation frequency, excitation force and excitation duration are adjusted.

[0053] In addition, after the load is applied, the relationship between excess pore water pressure, displacement and drainage and time needs to be recorded. After the test is completed, the curve is analyzed to obtain consolidation parameters such as soil consolidation degree, consolidation coefficient, and permeability coefficient.

[0054] The super-soft soil sample 6 needs to be left to stand for 24 hours before being placed in the consolidation container 5 .

[0055] Before the test, the entire device needs to be debugged and tested, including debugging the pore water pressure sensor, displacement meter, and pressure sensor to ensure normal connection with the collector; insert the vibration unit and check whether the vibrator is operating normally.

[0056] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes, and they can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A super-soft soil vibration pressurization drainage consolidation test device, characterized in that: It includes a consolidation container, a vibration unit, a pressurization system and a test unit; wherein, The bottom of the consolidation container is provided with a water outlet hole, the side wall of the consolidation container is provided with a vertical drainage belt, the super-soft soil sample is placed in the consolidation container, and the top and bottom of the consolidation container are respectively an upper permeable plate and a lower permeable plate that are water-permeable; The vibration unit comprises a vibrator, and the vibrator is installed in the consolidation container; The test unit comprises a pressure frame, a pressure sensor, a displacement meter and a pressure cover plate, wherein the consolidation container is arranged in the pressure frame, the pressure cover plate is arranged on the top of the consolidation container to apply pressure to the super-soft soil sample, and the pressure sensor is used to monitor in real time the pressure value of the pressure applied by the pressure cover plate to the super-soft soil sample; The test system comprises a pore water pressure sensor and a displacement meter; the pore water pressure sensor is arranged on the side wall of the consolidation container, and the displacement meter is used for real-time monitoring of the distance the pressurized cover plate moves downward as the super-soft soil is consolidated.

2. The ultra-soft soil vibration pressurization drainage consolidation test device according to claim 1 is characterized in that: The vibrator is installed in the consolidation container through a vibrator frame.

3. The ultra-soft soil vibration pressurization drainage consolidation test device according to claim 1 is characterized in that: A base is arranged at the bottom of the pressurizing frame, and the consolidation container is arranged on the base.

4. The ultra-soft soil vibration pressurization drainage consolidation test device according to claim 1 is characterized in that: It also includes a water discharge measurement container, which is arranged below the water outlet and is used to receive the water discharged through the water outlet.

5. The ultra-soft soil vibration pressurization drainage consolidation test device according to claim 1 is characterized in that: The length of the vertical drainage belt is the initial height of the super-soft soil sample. There are multiple vertical drainage belts, which are symmetrically arranged with the vibrator as the center.

6. The ultra-soft soil vibration pressurization drainage consolidation test device according to claim 1 is characterized in that: The diameter of the vibrator is 1 / 5 to 1 / 4 of the diameter of the consolidation container.

7. The ultra-soft soil vibration pressurization drainage consolidation test device according to claim 1 is characterized in that: The pressure cover plate is in full contact with the top surface of the super-soft soil sample.

8. The ultra-soft soil vibration pressurization drainage consolidation test device according to claim 1 is characterized in that: It also includes a collector, which is connected to the pressure sensor, displacement meter and pore water pressure sensor, collects the electrical signals transmitted by each sensor, and converts them into pressure values, displacement values ​​and pore water pressure values.

9. A test method based on the ultra-soft soil vibration pressurization drainage consolidation test device according to any one of claims 1 to 7, characterized in that: The following steps are involved: The super-soft soil sample to be tested is placed in a consolidation container, and different loads are applied to the super-soft soil sample through a pressure cover plate to collect the excess pore water pressure, displacement and drainage, and the relationship curves of excess pore water pressure, displacement and drainage with time are obtained. The curves are analyzed to obtain consolidation parameters, including soil consolidation degree, consolidation coefficient and permeability coefficient. When applying the load, ensure that the load is vertical, and load the cover plate vertically, and load in stages; after static load is applied for a certain period of time, vibration loading is performed, and the excitation frequency, excitation force and excitation duration are adjusted.

10. The ultra-soft soil vibration pressurization drainage consolidation test device according to claim 9, characterized in that: The super-soft soil sample needs to be left to stand for 24 hours before being placed in the consolidation container.

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