A device and method for rapid saturation and consolidation of large-size clay samples based on a three-dimensional water permeable network

Abstract

The application discloses a large-size clay sample rapid saturation and consolidation device and method based on a three-dimensional water permeable network, wherein the device comprises a model box, a water permeable assembly and a vacuum assembly; the water permeable assembly comprises a plurality of branch water permeable plates; a layer of transverse branch water permeable plates and a layer of longitudinal branch water permeable plates are cyclically stacked in the model box to form a transverse-longitudinal three-dimensional water permeable network structure; the vacuum assembly is communicated with the model box through a second joint and is used for air extraction on the model box so that the clay sample is in a negative pressure environment. The transverse branch water permeable plates and the longitudinal branch water permeable plates are cyclically stacked in the clay sample to form the transverse-longitudinal three-dimensional water permeable network structure, all-around and multidirectional water permeation is realized, and the problem of poor saturation uniformity caused by a single seepage path in a traditional method is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of clay model test, and more particularly to a large-size clay sample rapid saturation and consolidation device and method based on a three-dimensional water permeation network. BACKGROUND

[0002] Soil model test is an important means to study the mechanical properties of soil and simulate the interaction between engineering structure and soil, and the reliability of the test results highly depends on the preparation quality of the soil sample, especially the uniformity and saturation of the sample. In the fields of marine engineering and underground engineering, soil is usually in a saturated state, so the indoor model test needs to prepare saturated samples to simulate the in-situ environment and provide technical support for the laying of submarine pipelines and the excavation of tunnels.

[0003] At present, the current saturated sample preparation methods mainly include vacuum preloading method and water injection method. Due to the low permeability of clay, the existing methods often take too long time in the sample preparation process. During this process, due to the limitation of the long drainage path, uneven pressure distribution is easily generated in the soil body, which affects the overall consistency of the sample. In addition, whether it is vacuum preloading or traditional one-way water injection, it is easy to form a preferential seepage path, resulting in uneven distribution of water in the soil body, and the saturation difference in the sample, especially the corner area cannot be saturated for a long time due to the difficulty of water permeation, which seriously affects the representativeness of the sample and the accuracy of the test data.

[0004] Therefore, the prior art needs to be improved. SUMMARY

[0005] The purpose of the present application is to provide a large-size clay sample rapid saturation and consolidation device and method based on a three-dimensional water permeation network, which aims to solve the technical problem of poor saturation uniformity caused by a single seepage path in the prior art.

[0006] To achieve the above purpose, the technical scheme adopted by the present application is:

[0007] In a first aspect, the present application provides a large-size clay sample rapid saturation and consolidation device based on a three-dimensional water permeation network, which comprises:

[0008] A model box, the model box is provided with a first joint and a second joint, and the model box is used for accommodating a clay sample;

[0009] The water permeable assembly comprises a multi-branch water permeable plate connected with the mold box through the first joint to insert into the clay sample in the mold box, and the multi-branch water permeable plate is used for directional transmission of fluid in the clay sample, and a layer of transverse multi-branch water permeable plate and a layer of longitudinal multi-branch water permeable plate are cyclically stacked in the mold box to form a three-dimensional water permeable network structure.

[0010] The vacuum assembly is communicated with the mold box through the second joint, and the vacuum assembly is used for air extraction of the mold box to make the clay sample in a negative pressure environment.

[0011] In an embodiment, the multi-branch water permeable plate comprises:

[0012] A water permeable base;

[0013] A plurality of water permeable bodies arranged side by side and connected with the water permeable base, the water permeable bodies are connected with the mold box through the first joint to insert into the clay sample in the mold box and to make the clay sample in the mold box for directional transmission of fluid;

[0014] A guide part laid along the extension direction of the water permeable body and wrapped on the insertion end of the water permeable body.

[0015] In an embodiment, the guide part comprises:

[0016] A guide probe connected with the water permeable body and laid along the extension direction of the water permeable body;

[0017] A guide probe head connected with the guide probe and wrapped on the insertion end of the water permeable body.

[0018] In an embodiment, the guide probe head comprises:

[0019] A probe body connected with the water permeable body away from the water permeable base;

[0020] A tip guide arranged on the side of the probe body away from the water permeable body.

[0021] In an embodiment, when the multi-branch water permeable plate is connected with the mold box, the distance between the guide probe head and the opposite inner wall of the mold box is 5-10 cm.

[0022] In an embodiment, the multi-branch water permeable plate is arranged in 3-4 layers.

[0023] In an embodiment, the model box comprises a rectangular base and a box cover plate, the box cover plate is detachably connected with the rectangular base, the rectangular base has a first side plate, a second side plate, a third side plate, a fourth side plate and a box bottom plate, the first side plate, the second side plate, the third side plate and the fourth side plate are sequentially and closely connected, and the first side plate, the second side plate, the third side plate and the fourth side plate are respectively located at four sides of the box bottom plate.

[0024] The first joint comprises a transverse through hole and a longitudinal through hole.

[0025] The transverse through hole is arranged on the first side plate, and the transverse multi-branch water permeable plate extends into the model box through the transverse through hole on the first side plate.

[0026] The longitudinal through hole is arranged on the second side plate, and the longitudinal multi-branch water permeable plate extends into the model box through the longitudinal through hole on the second side plate.

[0027] Rubber plugs are arranged in the transverse through hole and the longitudinal through hole, and the rubber plugs are used for sealing connection with the multi-branch water permeable plate.

[0028] In an embodiment,

[0029] The water permeable assembly further comprises:

[0030] A water delivery pipe comprises a first conduit, a second conduit and a branch conduit, the second conduit communicates with each of the multi-branch water permeable plates through the branch conduit.

[0031] A plurality of control valves are arranged on the first conduit, the second conduit and the branch conduit, respectively, and the control valves are used for controlling the first conduit, the second conduit and the branch conduit to be conducted.

[0032] A water pump is connected with the first conduit on one side and connected with the second conduit on the other side.

[0033] A water storage tank is connected with the water pump through the first conduit.

[0034] In an embodiment, the vacuum assembly comprises:

[0035] A vacuum pump;

[0036] A vacuum pipeline is connected with the vacuum pump.

[0037] A plurality of branch pipelines are connected with the vacuum pipeline, and the branch pipelines are used for communication with the second joint.

[0038] In addition, in order to achieve the above-mentioned purpose, the application also provides a clay sample preparation method based on the above-mentioned three-dimensional water permeable network large-size clay sample rapid saturation and consolidation device, which comprises the following steps:

[0039] Layer by layer, fill the clay sample in the model box;

[0040] Layer by layer, insert the multi-branch water permeable plate into the clay sample in the model box, so that a layer of transverse multi-branch water permeable plate and a layer of longitudinal multi-branch water permeable plate are cyclically stacked in the model box to form a transverse-longitudinal three-dimensional water permeable network structure;

[0041] Open the water permeable assembly, and make the fluid in the clay sample directional transmission through the multi-branch water permeable plate.

[0042] The application provides a three-dimensional water permeable network based large-size clay sample rapid saturation and consolidation device and method, which has at least the following beneficial effects:

[0043] The application discloses a three-dimensional water permeable network based large-size clay sample rapid saturation and consolidation device and method, wherein the three-dimensional water permeable network based large-size clay sample rapid saturation and consolidation device comprises a model box, a water permeable assembly and a vacuum assembly, the model box is provided with a first joint and a second joint, the model box is used for accommodating a clay sample, the water permeable assembly comprises a multi-branch water permeable plate, the multi-branch water permeable plate is connected with the model box through the first joint, so that the multi-branch water permeable plate is inserted into the clay sample in the model box, the multi-branch water permeable plate is used for directional transmission of fluid in the clay sample, a layer of transverse multi-branch water permeable plate and a layer of longitudinal multi-branch water permeable plate are cyclically stacked in the model box to form a transverse-longitudinal three-dimensional water permeable network structure, the vacuum assembly is communicated with the model box through the second joint, and the vacuum assembly is used for air extraction of the model box, so that the clay sample is in a negative pressure environment. Through cyclically stacking a layer of transverse multi-branch water permeable plate and a layer of longitudinal multi-branch water permeable plate in the clay sample, a transverse-longitudinal three-dimensional water permeable network structure is formed, all-around and multidirectional water permeation is realized, and the problem of poor saturation uniformity caused by a single seepage path in the traditional method is solved. BRIEF DESCRIPTION OF DRAWINGS

[0044] In order to more clearly illustrate the technical solutions in the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0045] Figure 1A three-dimensional structure schematic diagram of a device for rapid saturation and consolidation of large-size clay samples based on a three-dimensional water permeable network is provided for an embodiment of the present application.

[0046] Figure 2 A structure schematic diagram of a specific embodiment of the device for rapid saturation and consolidation of large-size clay samples based on a three-dimensional water permeable network is provided for an embodiment of the present application.

[0047] Figure 3 A structure schematic diagram of a model box is provided for an embodiment of the present application.

[0048] Figure 4 A structure schematic diagram of a specific embodiment of a first side plate is provided for an embodiment of the present application.

[0049] Figure 5 A structure schematic diagram of a specific embodiment of a third side plate is provided for an embodiment of the present application.

[0050] Figure 6 A structure schematic diagram of a multi-branch water permeable plate is provided for an embodiment of the present application.

[0051] Figure 7 A structure schematic diagram of a water permeable body is provided for an embodiment of the present application.

[0052] Figure 8 A structure schematic diagram of a water permeable body from a side view is provided for an embodiment of the present application.

[0053] Figure 9 A large-size clay sample preparation flowchart is provided for an embodiment of the present application.

[0054] Figure 10 A large-size clay sample preparation flowchart is provided for an embodiment of the present application.

[0055] Figure 11 A large-size clay sample preparation flowchart is provided for an embodiment of the present application.

[0056] In the drawings, various reference numerals refer to various identical or similar elements.

[0057] 100, model box; 200, water permeable assembly; 300, vacuum assembly; 400, clay sample; 110, rectangular base; 120, box cover plate; 130, first joint; 140, second joint; 111, first side plate; 112, second side plate; 113, third side plate; 114, fourth side plate; 115, box bottom plate; 116, vacuum bottom plate; 131, transverse through hole; 132, longitudinal through hole; 133, rubber plug; 210, multi-branch water permeable plate; 220, water delivery pipe; 230, control valve; 240, water pump; 250, water storage tank; 211, water permeable base; 212, water permeable body; 213, guide part; 214, guide probe rod; 215, guide probe; 216, probe body; 217, tip guide; 221, first conduit; 222, second conduit; 223, branch conduit; 310, vacuum pump; 320, vacuum conduit; 330, branch conduit. DETAILED DESCRIPTION

[0058] In order to make the technical problems to be solved by the present application, technical solutions and beneficial effects clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not intended to limit the present application.

[0059] It should be noted that when a component is referred to as "fixed to" or "disposed on" another component, it can be directly or indirectly on the other component. When a component is referred to as "connected to" another component, it can be directly or indirectly connected to the other component. The terms "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate the orientation or position based on the orientation or position shown in the drawings, and are only for the convenience of description, and cannot be understood as a limitation on the technical solutions. The terms "first", "second" are only for the purpose of convenient description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features. The meaning of "a plurality of" is two or more, unless otherwise specifically limited. Embodiment 1

[0060] Referring to Figure 1 and Figure 2 The present embodiment provides a kind of based on three-dimensional water permeable network Large size clay sample rapid saturation and consolidation device, comprising: model box 100, water permeable assembly 200 and vacuum assembly 300.

[0061] Referring to Figure 3The model box 100 is provided with a first joint 130 and a second joint 140, the model box 100 is used for accommodating the clay sample 400, the water permeable assembly 200 includes a plurality of branch water permeable plates 210, the plurality of branch water permeable plates 210 are connected with the model box 100 through the first joint 130, so that the plurality of branch water permeable plates 210 are inserted into the clay sample 400 in the model box 100, the plurality of branch water permeable plates 210 are used for directional transmission of fluid in the clay sample 400, and a layer of transverse plurality of branch water permeable plates 210 and a layer of longitudinal plurality of branch water permeable plates 210 are cyclically stacked in the model box 100, forming a three-dimensional water permeable network structure, and the vacuum assembly 300 is communicated with the model box 100 through the second joint 140, and the vacuum assembly 300 is used for pumping the model box 100, so that the clay sample 400 is in a negative pressure environment.

[0062] Please refer to Figure 2 In the embodiment, by means of the hierarchical longitudinal and transverse arrangement of the plurality of branch water permeable plates 210, the water permeable path is greatly shortened, the penetration time is shortened by combining with the vacuum negative pressure driving, and the large-size clay sample efficiency can be improved; and the hierarchical longitudinal and transverse arrangement of the plurality of branch water permeable plates 210 realizes omnidirectional and multidirectional water permeation, avoids the preferential seepage problem caused by the single seepage path in the traditional method, eliminates the unsaturated “dead zone”, cooperates with the pressure uniform distribution in the negative pressure environment, ensures that the saturation or consolidation degree of each part of the clay sample 400 is consistent, and the edge and corner regions can also be fully saturated and consolidated, and the problem of poor saturation uniformity caused by the single seepage path is solved.

[0063] Therefore, the hierarchical longitudinal and transverse arrangement of the plurality of branch water permeable plates 210 in the clay sample 400 forms a three-dimensional water permeable network structure, realizes omnidirectional and multidirectional water permeation, and solves the problem of poor saturation uniformity caused by the single seepage path in the traditional method.

[0064] Please refer to Figure 2Specifically, the model box 100 comprises a rectangular base 110 and a box cover plate 120, the box cover plate 120 is detachably connected with the rectangular base 110, the rectangular base 110 has a first side plate 111, a second side plate 112, a third side plate 113, a fourth side plate 114 and a box bottom plate 115, the first side plate 111, the second side plate 112, the third side plate 113 and the fourth side plate 114 are sequentially and closely connected, and the first side plate 111, the second side plate 112, the third side plate 113 and the fourth side plate 114 are respectively located at four sides of the box bottom plate 115; a vacuum bottom plate 116 is located above the box bottom plate 115, the first joint 130 comprises a transverse through port 131 and a longitudinal through port 132; the transverse through port 131 is arranged on the first side plate 111, and the transverse multi-branch water-permeable plate 210 extends into the model box 100 through the transverse through port 131 on the first side plate 111; the longitudinal through port 132 is arranged on the second side plate 112, and the longitudinal multi-branch water-permeable plate 210 extends into the model box 100 through the longitudinal through port 132 on the second side plate 112; the rubber plug 133 is arranged in the transverse through port and the longitudinal through port 132, and the rubber plug 133 is used for sealingly connecting with the multi-branch water-permeable plate 210.

[0065] In the embodiment, the model box 100 is used for accommodating the clay sample 400 as a large-size cavity structure, and comprises the rectangular base 110 and the box cover plate 120. It can be understood that the box cover plate 120 is detachably connected with the rectangular base 110 to form a closed cavity.

[0066] The rectangular base 110 has the first side plate 111, the second side plate 112, the third side plate 113, the fourth side plate 114 and the box bottom plate 115, the first side plate 111, the second side plate 112, the third side plate 113 and the fourth side plate 114 are sequentially and closely connected, and are respectively and vertically fixed to four sides of the box bottom plate 115.

[0067] The vacuum bottom plate 116 is located above the box bottom plate 115, and a cavity is formed between the vacuum bottom plate 116 and the box bottom plate 115, the second joint 140 is connected with the vacuum assembly 300, and is used for air extraction when the clay sample is saturated.

[0068] The model box 100 is provided with the first joint 130 and the second joint 140, the first joint 130 comprises the transverse through port 131 and the longitudinal through port 132, the transverse through port 131 is arranged on the first side plate 111, and the longitudinal through port 132 is arranged on the second side plate 112, and the water-permeable assembly 200 is inserted.

[0069] Please refer to Figure 4 The rubber plug 133 is arranged in the longitudinal through port 132 and the transverse through port 131, and the rubber plug 133 is used for sealingly connecting with the multi-branch water-permeable plate 210 to prevent gas or fluid leakage.

[0070] Referring to Figure 5 The second joint 140 is arranged on the fourth side plate 114 and is used to connect the vacuum assembly 300. Optionally, the number of the second joint 140 is four, and the four second joints 140 are uniformly distributed on the fourth side plate 114 to form a global vacuum negative pressure channel and realize rapid formation of negative pressure.

[0071] Optionally, the model box 100 is a transparent acrylic model box 100, that is, the model box 100 is made of transparent acrylic material. The transparent acrylic model is used for visual monitoring. For example, the saturation change of the clay sample 400 can be observed in real time through the transparent acrylic model box 100.

[0072] Specifically, referring to Figure 6 The multi-branch water permeable plate 210 includes a water permeable base 211, a plurality of water permeable bodies 212 arranged side by side, and a guide part 213. The water permeable body 212 is connected with the water permeable base 211. The water permeable body 212 is used to be connected with the model box 100 through the first joint 130, so that the water permeable body 212 is inserted into the clay sample 400 in the model box 100 and the fluid in the clay sample 400 is directionally transmitted. The guide part 213 is laid along the extension direction of the water permeable body 212 and is wrapped on the insertion end of the water permeable body 212.

[0073] Referring to Figure 7 The guide part 213 includes a guide probe 214 and a guide probe head 215. The guide probe 214 is connected with the water permeable body 212 and is laid along the extension direction of the water permeable body 212. The guide probe head 215 is connected with the guide probe 214 and is wrapped on the insertion end of the water permeable body 212.

[0074] Referring to Figure 8 The guide probe head 215 includes a probe body 216 and a tip guide 217. The probe body 216 is connected with the side of the water permeable body 212 away from the water permeable base 211. The tip guide 217 is arranged on the side of the probe body 216 away from the water permeable body 212.

[0075] In the embodiment, the multi-branch water permeable plate 210 is used as a core permeable component, which comprises a water permeable base 211, a plurality of water permeable bodies 212 arranged side by side, and a guide part 213. The water permeable body 212 is internally penetrated by a fluid channel, and the surface is wrapped with a water permeable filter membrane, which can block clay particles from entering the channel while ensuring smooth passage of fluid. The multi-branch water permeable plate 210 is connected to the model box 100 through the first joint 130. The transverse multi-branch water permeable plate 210 extends into the model box 100 through the transverse penetration opening 131 of the first side plate 111. The longitudinal multi-branch water permeable plate 210 extends into the model box 100 through the longitudinal penetration opening 132 of the second side plate 112. A layer of transverse multi-branch water permeable plate 210 and a layer of longitudinal multi-branch water permeable plate 210 are stacked in cycles to form a three-dimensional water permeable network structure.

[0076] The guide part 213 is laid along the extension direction of the water permeable body 212 and wrapped on the insertion end of the water permeable body 212. The guide part 213 comprises a guide probe 214 and a guide probe head 215. The guide probe 214 is connected to the water permeable body 212 and laid along the extension direction of the water permeable body 212. The guide probe head 215 is connected to the guide probe 214 and wrapped on the insertion end of the water permeable body 212. The guide probe head 215 comprises a probe body 216 and a tip guide 217. The probe body 216 is connected to the side of the water permeable body 212 away from the water permeable base 211. The tip guide 217 is arranged on the side of the probe body 216 away from the water permeable body 212. The tip guide 217 can be a conical structure or a triangular shape, which can facilitate the insertion of the water permeable body 212 into the clay sample 400.

[0077] When the multi-branch water permeable plate 210 is connected to the model box 100, the distance between the guide probe head 215 and the opposite inner wall of the model box 100 is 5-10 cm, ensuring full coverage without dead angles. For example, the distance between the guide probe head 215 and the opposite inner wall of the model box 100 is 5 cm, or 6 cm, or 7 cm, or 8 cm, or 9 cm, or 10 cm.

[0078] Alternatively, the width of the water permeable body 212 is set to 8-10 cm, for example, the width of the water permeable body 212 is set to 8 cm, or 9 cm, or 10 cm, which can ensure that the water permeable body 212 provides sufficient effective water permeable area to improve permeation efficiency. In addition, the insertion resistance is moderate, and the water permeable body 212 can be easily inserted into the clay under the cooperation of the guide part 213, and the disturbance range is controlled within 2 cm, which does not affect the structure of the clay sample 400. A width that is too wide will result in a dramatic increase in friction with the clay during insertion, requiring more external force and easily disturbing the surrounding compacted clay sample 400.

[0079] For example, in the saturated scenario, the wide water-permeable area can quickly introduce a large amount of degassed water, which, in combination with the flow of the water pump 240, avoids the saturation delay caused by the insufficient introduction amount of the narrow plate. In the consolidation scenario, the wide plate body can collect a larger range of pore water at the same time, reduce the retention of water in the water-permeable body 212, accelerate the discharge efficiency, and is not prone to filter membrane blockage caused by excessive pore water. After the water-permeable body 212 with a width of 8-10 cm is extracted, the hole volume left is moderate, and subsequent negative pressure homogenization processing can quickly eliminate the hole traces without affecting the uniformity of the sample. Preferably, the width of the water-permeable body 212 is set to 10 cm.

[0080] Optionally, the number of layers of the multi-branch water-permeable plate 210 is 3-4 layers.

[0081] For example, the number of layers of the multi-branch water-permeable plate 210 is 3 layers or 4 layers, so that the 3-4 layers of the cyclically stacked multi-branch water-permeable plate 210 realize full-area dead-angle-free coverage, fluid penetrates or discharges from multiple nodes to the interior of the soil body, avoids the formation of preferential seepage channels, improves the uniformity of the clay sample 400, and avoids too many layers of the multi-branch water-permeable plate 210, which will cause serious stratification of the soil body and affect the uniformity of the final sample.

[0082] Specifically, referring to Figure 1 and Figure 3 , the water-permeable assembly 200 further comprises a water delivery pipe 220, a plurality of control valves 230, a water pump 240, and a water storage tank 250. The water delivery pipe 220 comprises a first conduit 221, a second conduit 222, and branch conduits 223. One side of the water pump 240 is in communication with the first conduit 221, and the other side of the water pump 240 is in communication with the second conduit 222. The second conduit 222 is in communication with each multi-branch water-permeable plate 210 through the branch conduits 223. The branch conduits 223 are used to communicate with each multi-branch water-permeable plate 210. The control valves 230 are respectively arranged on the first conduit 221, the second conduit 222, and the branch conduits 223. The control valves 230 are used to control the conduction of the first conduit 221, the second conduit 222, and the branch conduits 223. The water pump 240 is in communication with the water storage tank 250 through the first conduit 221.

[0083] In this embodiment, the branch conduits 223 are in communication with the water-permeable bases 211 of the multi-branch water-permeable plates 210, realizing the penetration of the external water source and the internal water-permeable network. The control valves 230 are respectively arranged on the first conduit 221, the second conduit 222, and the branch conduits 223, and are used to independently control the conduction and closing of each pipeline, adapt to different sample preparation requirements, and the water pump 240 is used to control the water injection and water extraction rate.

[0084] Specifically, referring to Figure 1The vacuum assembly 300 comprises a vacuum pump 310, a vacuum pipe 320 connected with the vacuum pump 310, and a plurality of branch pipes 330 in communication with the vacuum pipe 320, and the branch pipes 330 are used to communicate with the second joint 140.

[0085] In the embodiment, the vacuum assembly 300 is used to pump the model box 100 to make the clay sample 400 in a negative pressure environment, so as to accelerate the fluid transmission efficiency, which comprises the vacuum pump 310, the vacuum pipe 320 and the plurality of branch pipes 330. One end of the vacuum pipe 320 is connected with the vacuum pump 310, the other end of the vacuum pipe 320 is in communication with the plurality of branch pipes 330, and each branch pipe 330 is connected with the second joint 140 of the model box 100 one by one, so as to realize the uniform application and stable control of the negative pressure in the model box 100. Embodiment 2

[0086] Please refer to Figure 9 Based on the above large-size clay sample 400 rapid saturation and consolidation device based on the three-dimensional water permeable network, the application further provides a clay sample preparation method, which comprises the following steps:

[0087] S100, layer-by-layer filling of the clay sample in the model box.

[0088] Specifically, the required clay mass is calculated according to the preset dry density and the volume of the model box, the clay is uniformly mixed with degassed water, and the clay is allowed to stand for 24 hours to ensure uniform distribution of water in the clay; the pretreated clay is filled into the model box in 5 layers, each layer is compacted to a preset height, and scraping is performed between layers to remove floating dust and increase the interlayer bonding force, so as to avoid layering cracks in the later stage, and finally form a complete clay sample.

[0089] S200, layer-by-layer insertion of the multi-branch water permeable plate into the clay sample in the model box, so that a layer of transverse multi-branch water permeable plate and a layer of longitudinal multi-branch water permeable plate are cyclically stacked in the model box to form a three-dimensional water permeable network structure.

[0090] Specifically, after the multi-branch water permeable plate and the guide part are assembled, the multi-branch water permeable plate is inserted layer by layer into the clay sample through the transverse through hole of the first side plate and the longitudinal through hole of the second side plate of the model box, and the multi-branch water permeable plate is guided by the sharp end of the guide part, wherein the transverse through hole and the longitudinal through hole are embedded with rubber plugs to ensure the airtightness of the model box; the layers are cyclically stacked in the order of one layer of transverse and one layer of longitudinal, a total of 3-4 layers are provided, and the transverse water permeable body and the longitudinal water permeable body are ensured to form staggered nodes to construct a three-dimensional water permeable network covering the whole soil body; after installation, the water permeable base is sealed and connected with the branch conduit.

[0091] S300, opening the water permeable assembly to make the fluid in the clay sample transmit directionally through the multi-branch water permeable plate.

[0092] Specifically, the water permeable assembly is turned on, and the fluid in the clay sample is transmitted in a directional manner through the multi-branch water permeable plate, for example, the fluid in the clay sample is penetrated in multiple directions through the water permeable filter membrane on the surface of the water permeable body, or the pore water in the clay sample enters the fluid channel through the water permeable filter membrane of the water permeable body, and is discharged to the external water collecting tank through the branch conduit and the second conduit.

[0093] In the embodiment, the saturation or consolidation mode is selected according to the sample preparation requirement, and the clay sample is quickly prepared.

[0094] If the saturation mode is selected: the water pump and the control valves on the conduits are turned on, the degassed water in the water storage tank enters the fluid channel of the multi-branch water permeable plate through the first conduit, the second conduit and the branch conduit under the joint action of the water pump and the negative pressure, and penetrates into the clay sample in multiple directions through the water permeable filter membrane on the surface of the water permeable body; then saturation determination is performed, for example, when the water content detected by the borehole sampling reaches the preset saturation, the water pump and the control valves are turned off, the multi-branch water permeable plate is pulled out, and the rubber plug is pressed by the cover plate to realize sealing of the penetration port, and the negative pressure is continuously maintained for 10-12 hours to eliminate the stratification marks, and the saturation is ended, and the saturation sample preparation is completed.

[0095] If the consolidation mode is selected: the water permeable assembly is turned on, and the water pump is started, and under the action of the water pump, the pore water in the clay sample enters the fluid channel through the water permeable filter membrane of the water permeable body, and is discharged to the external water collecting tank through the branch conduit, the second conduit and the first conduit; when the drainage amount is less than or equal to 0.1 L / h for 8-12 hours continuously and the sample drainage time reaches a preset value, the multi-branch water permeable plate is pulled out, and the rubber plug is pressed by the cover plate to seal the penetration port, and the negative pressure is continuously maintained for 6-8 hours to eliminate the voids, and the consolidation sample preparation is completed.

[0096] Compared with the prior art, the application has the following beneficial effects:

[0097] 1. The sample preparation efficiency is significantly improved: the multidirectional fluid transmission channel is constructed through the horizontal and vertical staggered three-dimensional water permeable network, the water permeable path is greatly shortened, the transmission power is strengthened in the negative pressure environment, compared with the traditional method, the saturation and consolidation time is shortened, and the bottleneck of large-size clay sample preparation efficiency is broken through.

[0098] 2. The sample uniformity is excellent: the multi-branch water permeable plate of 3-4 layers of circular stacking realizes full-area dead-angle-free coverage, the fluid penetrates or is discharged from multiple nodes to the interior of the soil body, the preferential seepage channel is avoided, the saturation or consolidation degree difference between the corner area and the center area is small, and the uniformity of the sample is significantly improved.

[0099] 3. Compatible with saturation and consolidation: the same device can realize the saturation and consolidation sample preparation functions through pipeline control, without replacing the core components, simplifying the test process, reducing the equipment investment cost, and adapting to different soil test requirements.

[0100] 4. Easy operation and strong stability: The multi-branch water permeable plate is equipped with a guide part, the insertion process slightly disturbs the clay sample, and the distance between the guide probe and the model box is designed to ensure the completeness of the network coverage; the model box is sealed with a rubber plug, and the vacuum assembly uniformly applies pressure through multiple branch pipes to ensure the stability and sealing performance during sample preparation. Example 3

[0101] Please refer to Figure 10 , based on the example 1, the three-dimensional water permeable network based large size clay sample rapid saturation and consolidation device, the embodiment provides a kind of large size clay rapid saturation sample preparation method, in order to facilitate understanding the embodiment of the present application, first introduce large size clay sample in the embodiment description of the present application. Generally speaking, indoor test includes unit test and model test, unit test is taken as an example, triaxial test, sample volume is generally 39.1mm in diameter height 80mm, large triaxial sample is generally 100mm in diameter, height 200mm, when sample size needs to be further increased to simulate specific boundary condition or engineering scale, then large size sample needs to be made.

[0102] The large size clay rapid saturation sample preparation method provided by the application comprises the following steps:

[0103] S1, clay pretreatment: calculate the required clay mass, and provide the required clay, mix with degassed water, and soak for 24 hours.

[0104] S2, filling: fill into the model box in 5 layers, each layer is compacted, and the interlayer is scraped.

[0105] S3, multi-branch water permeable plate installation: according to the "horizontal-longitudinal-horizontal-longitudinal" four-layer stacking, the horizontal multi-branch water permeable plate is inserted through the horizontal through hole of the first side plate, the longitudinal multi-branch water permeable plate is inserted through the longitudinal through hole of the second side plate, the distance between the guide probe and the opposite model box is 8cm, and the multi-branch water permeable plate is sealed connected with the branch pipe.

[0106] S4, vacuum start: cover the box cover, start the vacuum pump, adjust the negative pressure to 90-100kPa, and stabilize for 30 minutes.

[0107] S5, water injection saturation: open the water pump and all control valves on the water delivery pipe, set the water injection rate to 3L / min, the degassed water enters the multi-branch water permeable plate through the water delivery pipe, and penetrates into the soil body in multiple directions.

[0108] S6, saturation determination: after 48 hours, the saturation of 5 measuring points detected by drilling reaches 98% (preset saturated water content).

[0109] S7, homogenization treatment: remove the multi-branch water permeable plate, seal the through hole, continue to maintain 90-100kPa negative pressure for 12 hours, the stratification marks in the soil body disappear, and the saturation sample preparation is completed.

[0110] The embodiment realizes all-directional and multi-directional water permeation by forming a horizontal-vertical three-dimensional water permeation network structure through cyclically stacking a layer of horizontal multi-branch water permeation plates and a layer of vertical multi-branch water permeation plates in the clay sample, and solves the problem of poor saturation uniformity caused by a single seepage path in the traditional method. Embodiment 4

[0111] Please refer to Figure 11 Based on the large-size clay sample rapid saturation and consolidation device based on the three-dimensional water permeation network of embodiment 1, the embodiment provides a large-size clay rapid consolidation sample preparation method, which comprises the following steps:

[0112] S1, clay pretreatment: calculate the required clay mass, and provide the required clay, mix with degassed water, and soak for 24 h.

[0113] S2, filling: fill into the model box in 5 layers, each layer is compacted, and the interlayer is scraped.

[0114] S3, multi-branch water permeation plate installation: stack according to “horizontal-vertical-horizontal-vertical” four layers, the horizontal multi-branch water permeation plate is inserted through the horizontal through hole of the first side plate, the vertical multi-branch water permeation plate is inserted through the vertical through hole of the second side plate, the guide probe is spaced apart from the model box by 8 cm, and the multi-branch water permeation plate is sealingly connected with the branch pipe.

[0115] S4, water pumping start: open the water permeation assembly, under the action of the water pump, the pore water in the clay sample is discharged through the multi-branch water permeation plate, and the drainage amount is continuously monitored.

[0116] S5, consolidation determination: after 36 h, when the drainage amount of the clay sample is ≤0.1 L / h for 8-12 h continuously, the consolidation degree is 92%.

[0117] S6, homogenization treatment: remove the multi-branch water permeation plate, seal the through hole, start the vacuum pump, and maintain a negative pressure of 90-100 kPa for 12 h, until the voids in the soil body disappear, and the consolidation sample preparation is completed.

[0118] The embodiment realizes all-directional and multi-directional water permeation by forming a horizontal-vertical three-dimensional water permeation network structure through cyclically stacking a layer of horizontal multi-branch water permeation plates and a layer of vertical multi-branch water permeation plates in the clay sample, and solves the problem of poor saturation uniformity caused by a single seepage path in the traditional method.

[0119] In summary, the application discloses a kind of based on three-dimensional water-permeable network large-size clay sample rapid saturation and consolidation device and method, wherein the based on three-dimensional water-permeable network large-size clay sample rapid saturation and consolidation device includes model box, water-permeable component and vacuum component, model box is provided with first joint and second joint, model box is used to accommodate clay sample, water-permeable component includes multiple branch water-permeable plate, multiple branch water-permeable plate is connected with model box by first joint, so that multiple branch water-permeable plate is inserted into clay sample in model box, multiple branch water-permeable plate is used for fluid directional transmission in clay sample, and a layer of transverse multiple branch water-permeable plate and a layer of longitudinal multiple branch water-permeable plate are cyclically stacked in model box, form horizontal-vertical three-dimensional water-permeable network structure, vacuum component is communicated with model box by second joint, and vacuum component is used for air extraction to model box, so that clay sample is in negative pressure environment.The application is stacked in clay sample by a layer of transverse multiple branch water-permeable plate and a layer of longitudinal multiple branch water-permeable plate, forms horizontal-vertical three-dimensional water-permeable network structure, realizes all-around, multidirectional water-permeable, solves the problem of poor saturation uniformity caused by single seepage path in traditional method.

Claims

1. A device for rapid saturation and consolidation of large-size clay samples based on a three-dimensional permeable network, characterized in that, include: A model box, which is provided with a first joint and a second joint, is used to hold a clay sample. A permeable component, comprising multiple permeable slabs, which are connected to the model box via the first connector to allow the permeable slabs to be inserted into a clay sample inside the model box. The permeable slabs are used for directional fluid transport within the clay sample, and a layer of transverse permeable slabs and a layer of longitudinal permeable slabs are stacked in a loop within the model box to form a transverse and longitudinal three-dimensional permeable network structure. A vacuum assembly is connected to the model box via the second connector. The vacuum assembly is used to evacuate the model box so that the clay sample is in a negative pressure environment. The multi-branch permeable slab includes: Permeable base; Several permeable bodies are arranged side by side. The permeable bodies are connected to the permeable base. The permeable bodies are used to connect to the model box through the first connector, so that the permeable bodies are inserted into the clay sample in the model box and the fluid in the clay sample is transported in a directional manner. A guide portion, which is laid along the extension direction of the permeable body and covers the insertion end of the permeable body; The guide section includes: A guide probe is connected to the permeable body and is laid along the extension direction of the permeable body; A guide probe is connected to the guide probe rod, and the guide probe covers the insertion end of the permeable body; The model box includes a rectangular base and a box cover plate. The box cover plate is detachably connected to the rectangular base. The rectangular base has a first side plate, a second side plate, a third side plate, a fourth side plate, and a box bottom plate. The first side plate, the second side plate, the third side plate, and the fourth side plate are sequentially closed and connected, and the first side plate, the second side plate, the third side plate, and the fourth side plate are respectively located on the four sides of the box bottom plate. The first joint includes a transverse inlet and a longitudinal inlet; The first side plate has a transverse inlet, through which the multiple transverse permeable slabs extend into the model box. The second side plate has a longitudinal inlet, through which the multiple longitudinal permeable slabs extend into the model box; Both the transverse and longitudinal inlets are equipped with rubber plugs, which are used to seal the connection with the multiple permeable slabs.

2. The rapid saturation and consolidation device for large-size clay samples based on a three-dimensional permeable network as described in claim 1, characterized in that, The guiding probe includes: The probe body is connected to the side of the permeable body away from the permeable base; Tip guide, wherein the tip guide is disposed on the side of the probe body away from the permeable body.

3. The rapid saturation and consolidation device for large-size clay samples based on a three-dimensional permeable network as described in claim 1, characterized in that, When the multiple permeable slabs are connected to the model box, the distance between the guide probe and the inner wall of the model box is 5-10cm.

4. The rapid saturation and consolidation device for large-size clay samples based on a three-dimensional permeable network as described in claim 1, characterized in that, The permeable slab with multiple branches has 3-4 layers.

5. The rapid saturation and consolidation device for large-size clay samples based on a three-dimensional permeable network as described in claim 1, characterized in that, The permeable component also includes: A water supply pipe, comprising a first conduit, a second conduit, and a branch conduit, wherein the second conduit is connected to each of the multiple permeable drainage panels via the branch conduit; A plurality of control valves are respectively disposed on the first conduit, the second conduit and the branch conduit, and the control valves are used to control the opening of the first conduit, the second conduit and the branch conduit; A water pump, one side of which is connected to the first conduit and the other side of which is connected to the second conduit; A water storage tank, which is connected to the water pump via the first conduit.

6. The rapid saturation and consolidation device for large-size clay samples based on a three-dimensional permeable network as described in claim 1, characterized in that, The vacuum assembly includes: Vacuum pump; A vacuum pipe, which is connected to the vacuum pump; A plurality of branch pipes, all of which are connected to the vacuum pipe, and the branch pipes are used to connect to the second connector.

7. A method for preparing clay samples based on the rapid saturation and consolidation device for large-size clay samples based on a three-dimensional permeable network as described in any one of claims 1-6, characterized in that, Includes the following steps: Clay samples were filled into the model box layer by layer; Multiple permeable slabs are inserted into the clay sample in the model box layer by layer, so that a layer of horizontal permeable slabs and a layer of vertical permeable slabs are stacked in the model box in a loop to form a three-dimensional permeable network structure. The permeable components are activated, allowing fluid to be transported directionally within the clay sample via the multiple permeable branches.

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