Engineering geology experiment device

Abstract

The invention belongs to the technical field of geological experiments, and discloses an engineering geological experiment device which is provided with an accommodating cavity for simulating test pile variable-temperature pressurization for a frozen soil coating experiment to carry out a simulation experiment and comprises a box body with an accommodating cavity and a test pile, and the top of the box body is provided with a fixing hole for the test pile to penetrate into the accommodating cavity; a frozen soil layer for simulating actual geological conditions is arranged in the accommodating cavity, and the test pile is inserted into the frozen soil layer; temperature adjusting systems are further arranged at the bottom and the top of the frozen soil layer in the box body, the state of the frozen soil layer is kept through bottom cooling, environment temperature rise is simulated through top heating, and an external structure for providing pressure for the test pile is further arranged in the box body. The device is simple in structure and provides a pile foundation construction simulation test aiming at the frozen soil geology.

Description

Technical Field

[0001] The invention belongs to the technical field of geological experiments, and in particular relates to an engineering geological experiment device. Background Art

[0002] Engineering geology is a science that studies the physical, chemical and mechanical properties of earth materials (such as rocks, soils, groundwater, etc.), and how these properties affect engineering structures and natural geological processes. It mainly serves engineering construction, and through the investigation, analysis and evaluation of the geological environment, it provides a scientific basis for engineering site selection, design, construction and maintenance to ensure engineering safety, economy and environmental protection. The contents of engineering geology include geological structure investigation, geotechnical engineering property testing, geological disaster assessment and prevention, rock and soil stability analysis, foundation treatment technology, environmental geological impact assessment, etc.

[0003] Engineering geological experiments are an important means of engineering geological research. They simulate, test and evaluate the engineering characteristics of geological bodies through indoor and outdoor test methods. The experimental content mainly includes the following aspects:

[0004] Soil experiment: Test the physical properties (such as density, moisture content, particle size distribution), mechanical properties (such as compressibility, shear strength) and chemical properties (such as pH value, organic matter content) of the soil to evaluate the engineering properties of the soil.

[0005] Rock experiment: Determine the physical properties (such as density, water absorption), mechanical properties (such as compressive strength, tensile strength, elastic modulus) and mineral composition of rocks, and analyze the hardness, stability and suitability of rocks.

[0006] Groundwater experiment: Analyze the chemical composition, water level, flow rate, water temperature, etc. of groundwater, and evaluate the impact of groundwater on the project.

[0007] Geological disaster simulation experiment: By simulating natural conditions such as rainfall and earthquakes, the occurrence mechanism and prevention and control measures of geological disasters such as landslides, mud-rock flows, and ground subsidence are studied.

[0008] Dynamic characteristics experiment of rock and soil: study the deformation and strength characteristics of rock and soil under dynamic effects such as cyclic loads and earthquakes.

[0009] Environmental geological experiments: evaluate the impact of engineering construction on the geological environment, such as soil erosion, land salinization, environmental pollution and other issues.

[0010] Among them, for engineering construction operations in plateaus or high-cold areas, it is necessary to understand the unique geological characteristics of frozen soil in this environment, especially the impact of temperature changes on the pile structure formed after the pile foundation construction, which causes partial melting of the frozen soil layer. It is necessary to verify its stability through early experimental verification. However, there are many studies on the structural characteristics of frozen soil in the existing technology, but in the early experimental simulation, most of them are calculated based on digital models in the software system, and no simulation experiments are used for verification, especially the impact of the internal conditions of the soil layer caused by temperature changes on the pile foundation, which cannot be obtained through existing technical means. Summary of the invention

[0011] In order to solve the problems existing in the prior art, the present invention provides an engineering geological experimental device, which can simulate the influence of frozen soil on the pile foundation structure in the real environment as much as possible through the simulation of the frozen soil layer and the structural characteristics of the coated test piles, and through the built-in equipment for simulating temperature changes and the external structure for applying external force on the top, so as to provide better research guidance effect.

[0012] The technical solution adopted by the present invention is:

[0013] In a first aspect, the present invention provides an engineering geological experiment device, which has a chamber for simulating a frozen soil layer covering experiment, and a test pile for variable temperature pressurization to perform a simulation experiment, comprising a box body with a chamber and a test pile, wherein the top of the box body has a fixing hole for the test pile to penetrate into the chamber;

[0014] A frozen soil layer simulating actual geological conditions is provided in the accommodation cavity, and the test pile is inserted into the frozen soil layer;

[0015] A temperature regulating system is also provided at the bottom and the top of the permafrost layer in the box. The permafrost state is maintained by cooling the bottom and simulating the increase in ambient temperature by heating the top. The box also has an external structure that provides pressure to the test piles.

[0016] It should be noted that there are two ways to set up the permafrost layer. One is to directly sample the corresponding permafrost layer according to the soil structure of the target area, and then insulate and transport it to the experimental site for experiments (or directly conduct on-site experiments). The other is to simulate the permafrost layer structure formed according to the soil structure of the target area for experiments.

[0017] The test piles are test structures made of equivalent simulations of the actual pile foundation size and materials. During the test, the stress conditions of the full-size pile foundation in actual use and the collapse of the foundation will be obtained through calculation simulation. The temperature regulation system is a regulation module with two functions, one is set at the bottom of the permafrost layer, and the other is set at the top. The bottom mainly provides a low-temperature regulation function to form an ambient temperature below zero, so as to keep the lower part of the permafrost layer in a frozen state. The top mainly provides a warming regulation function to simulate the temperature rise in the change of ambient temperature, thereby providing conditions for the main test items in the test.

[0018] In combination with the first aspect, the present invention provides a first implementation of the first aspect, wherein the temperature adjustment system includes a control module and a conduction module;

[0019] The bottom of the box body is provided with a bottom cavity, and is provided with a bottom cover which covers and closes the bottom cavity. A control module of a temperature regulating system is provided in the bottom cavity, and is connected with a conduction module arranged in the box body through a pipeline.

[0020] In combination with the first embodiment of the first aspect, the present invention provides a second embodiment of the first aspect, wherein the conduction module includes a heat conductive block arranged at the bottom of the box body, and a bottom pipe for the flow of working fluid is provided in the heat conductive block, and the bottom pipe penetrates into the bottom cavity and communicates with the control module.

[0021] In combination with the first embodiment of the first aspect, the present invention provides a third embodiment of the first aspect, wherein the conduction module includes a heating tube layer arranged on the top of the box body, and the heating tube layer is connected to the control module in the bottom cavity through a pipeline.

[0022] In combination with the third embodiment of the first aspect, the present invention provides a fourth embodiment of the first aspect, wherein an openable door is provided at the opening at the top of the box body, and the heating tube layer is provided on the inner side of the door.

[0023] In combination with the fourth embodiment of the first aspect, the present invention provides a fifth embodiment of the first aspect, wherein the box door is rotatably connected to the box body, and the opening on the top of the box body is provided with two double-opening box doors, and the middle of the box door is provided with a semicircular groove. When the two box doors are closed, the two semicircular grooves are combined to form a fixing hole for the test pile to pass through.

[0024] In combination with the fifth implementation of the first aspect, the present invention provides a sixth implementation of the first aspect, wherein a rubber sleeve is sleeved in the fixing hole, and the test pile having a cross-sectional size smaller than the fixing hole is limited and fixed by the rubber sleeve.

[0025] In combination with the first embodiment of the first aspect, the present invention provides a seventh embodiment of the first aspect, wherein the conduction module includes a cooling pipe layer inside the box and buried in the frozen soil layer, a connecting pipe connecting the accommodating cavity and the bottom cavity is provided inside the inner wall of the box, the connecting pipe has a bottom opening in the bottom cavity and an inner opening on the inner wall of the box, and a pipeline connecting the control module and the cooling pipe layer is provided inside the connecting pipe.

[0026] In combination with the first embodiment of the first aspect, the present invention provides an eighth embodiment of the first aspect, wherein the external structure is a pressure mechanism arranged on the top of the box body, including a top plate installed away from the top of the box body through a screw, and a push cylinder arranged on the top plate, the push cylinder is arranged toward the box body and has a push rod that reciprocates toward the box body, and the push rod corresponds to the test pile inserted into the fixing hole.

[0027] In combination with the first implementation of the first aspect, the present invention provides a ninth implementation of the first aspect, wherein a window for observing the frozen soil layer in the box is provided on the side wall of the box.

[0028] The beneficial effects of the present invention are:

[0029] (1) The present invention provides a frozen soil layer covering the test pile, a temperature regulating system simulating the change of the external environment temperature, and an external structure providing pressure simulating the change of the stress condition of the test pile, so that the stress condition and foundation condition of the pile foundation structure in the frozen soil layer can be simulated and tested under various parameter conditions, thereby providing guidance for the actual engineering construction and engineering geological processing;

[0030] (2) The present invention provides control modules and different types of conduction modules, which are arranged at different positions in the box according to the characteristics of the frozen soil layer, thereby forming different temperature regulation effects. In particular, the additional cooling pipe layer is buried in the frozen soil layer, and cooperates with the heat conduction block at the bottom, so that the middle layer of the frozen soil layer is always kept in a frozen state. At the same time, the top is heated to simulate the temperature rise of the external environment, resulting in the effect of temperature conduction from the top to the bottom, providing more realistic simulation feedback;

[0031] (3) The present invention is suitable for test pile structures of different sizes and shapes through the design of a detachable box structure and a box door structure. The load changes on the test pile are simulated by a push cylinder provided on the top, thereby ensuring that even when the weight of the test pile itself is relatively small, the impact of a large load on the foundation structure of the frozen soil layer can be simulated. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a first axonometric diagram of the assembled engineering geological experiment device in an embodiment of the present invention;

[0033] Figure 2is a front view of an assembled engineering geological experiment device in an embodiment of the present invention;

[0034] Figure 3 is a side view of an assembled engineering geological experiment device in an embodiment of the present invention;

[0035] Figure 4 is a second axonometric diagram of the assembled engineering geological experiment device in an embodiment of the present invention;

[0036] Figure 5 It is a first axonometric diagram of the engineering geological experiment device in the embodiment of the present invention in a disassembled state;

[0037] Figure 6 It is a second axonometric diagram of the engineering geological experiment device in the embodiment of the present invention in a disassembled state;

[0038] Figure 7 It is an axonometric schematic diagram of a box body after being cut in an embodiment of the present invention.

[0039] In the figure: 1-box body, 2-window, 3-box door, 4-fixing hole, 5-screw, 6-top plate, 7-push cylinder, 8-side strip, 9-push rod, 10-heating tube layer, 11-cooling tube layer, 12-bottom cavity, 13-connecting tube, 14-bottom opening, 15-inner opening, 16-bottom cover. DETAILED DESCRIPTION

[0040] The present invention will be further explained below in conjunction with the accompanying drawings and specific embodiments.

[0041] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0042] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0043] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0044] In the description of this application, it should be noted that if the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the drawings, or the orientation or position relationship in which the product of the application is usually placed when in use. It is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. In addition, if the terms "first", "second", etc. appear in the description of this application, they are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0045] In addition, if the terms "horizontal" or "vertical" appear in the description of this application, it does not mean that the components are required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0046] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0047] Embodiment 1:

[0048] This embodiment provides an engineering geological experimental device for providing a reference for pile foundation construction under frozen soil geological conditions, especially for the influence of pile foundation load-bearing caused by the presence of a frozen soil layer and the temperature change affecting the change of its surface geological structure.

[0049] It should be noted that the frozen soil layer in this embodiment mainly includes a three-layer structure, including a soil base, a permafrost layer and a surface layer. The soil base is a stratum structure mixed with soil, gravel and stone. Because it has less groundwater infiltration, a lower water content and is not greatly affected by the external ambient temperature, it is similar to other geological structures. The permafrost layer has a higher water content and always remains frozen. The lower surface layer has a higher water content and may be partially frozen and partially melted as the external ambient temperature changes. This special frozen soil structure requires targeted treatment during pile foundation construction, otherwise it will cause the problem of unstable pile foundation under different ambient temperatures.

[0050] The experimental device in this embodiment is mainly based on a box body 1 structure, and its size is not limited. However, unlike the common desktop equipment in the experiment, the volume of the accommodating cavity in the box body 1 is not less than one cubic meter, in order to simulate the real pile foundation stress condition as much as possible.

[0051] The box body 1 itself is made of glass fiber reinforced plastics or a relatively light polymer material with high structural strength, and is provided with a certain thickness of thermal insulation material to provide a better thermal insulation effect.

[0052] The box 1 is generally a rectangular structure and is placed on the ground. In order to obtain the most realistic experimental effect as conveniently as possible, the equipment is generally located in the experimental area arranged at the construction site, and the frozen soil at the pile foundation construction site is taken and proportionally reduced by adjusting its moisture content to form a three-layer frozen soil structure and fill it in the box 1.

[0053] The top of the box 1 has an opening to facilitate filling soil into it to form a frozen soil layer. Figure 1 The opening is provided with a double-leaf door 3 structure. The door 3 is rotatably connected to the box body 1 through a hinge, and a sealing strip is provided at the edge of the opening to form a certain sealing effect. The door 3 itself is made of the same material as the box body 1, but since it has no load-bearing requirements, its material is relatively light and is mainly filled with polyurethane foam to form a thermal insulation layer.

[0054] Reference Figure 1 When the two doors 3 are closed and snapped onto the opening, the semicircular grooves in the middle of the two doors 3 merge to form a fixing hole 4, in which a test pile is placed and inserted into the box body 1 and immersed in the frozen soil layer, thereby forming a pile foundation structure.

[0055] The test pile structure is not shown in the drawings. The test pile in this embodiment can be a concrete structure with the same grade and number of steel bars as those used in pile foundation construction, or can be simulated by other materials. The cross-sectional size of the test pile is smaller than the size of the fixing hole 4, so a rubber sleeve is set at the fixing hole 4, and a smaller inner hole with a certain thickness is formed on the fixing hole 4 by the rubber sleeve. The test pile is inserted into the inner hole to form a better limiting effect, and it can also be applied to test piles of different sizes for testing.

[0056] Further, see Figure 2-Figure 7 A temperature regulating system is arranged inside the box 1, and an external structure for providing external force is arranged on the top of the box 1.

[0057] The bottom of the box 1 has a concave bottom cavity 12 structure, which is arc-shaped and concave, so as to form a certain installation space at the bottom of the box 1 and have good structural strength. A bottom cover 16 is provided on the bottom cavity 12 to close it, and a detachable fixing method is formed by bolts.

[0058] The temperature regulation system in this embodiment includes a control module arranged in the bottom cavity 12 and a conduction structure arranged in the box body 1. The control module is divided into a cold control part and a hot control part. The cold control part is a refrigeration system mainly based on a compressor controlled by a PLC, and a cooling pipe layer 11 buried in the frozen soil layer is provided in the box body 1. The cooling pipe layer 11 is a plate-type structure formed by a single bent and folded pipe as the main component, and the surface is wrapped with a waterproof and sealed soft material, and an inlet and an outlet are provided at one end, which is convenient for connecting with the cold control part to realize active circulation of the working fluid and achieve a refrigeration effect through the compressor.

[0059] The cooling pipe layer 11 in this embodiment is arranged in the permafrost layer, or between the permafrost layer and the soil base layer, so as to achieve a constant temperature of the permafrost layer.

[0060] The heat control part is mainly composed of an internally arranged electric heating control module and a heating pipe layer 10 connected by lines and arranged on the door 3 at the top of the box body 1. In other embodiments, the cold control part with a compressor can also be connected to realize a single control module to control two sets of structures at the same time, but this method cannot achieve the effect of simultaneous heating and cooling, so it is best to adopt a separate control method.

[0061] The heating tube layer 10 is mainly an electric heating wire, which is fitted on the inner side of the box door 3 with a certain gap from the surface of the frozen soil layer, so as to simulate the change of ambient temperature. Heat is continuously conducted downward from the surface of the frozen soil layer through air heat exchange and heat radiation, thereby forming a melting process from the surface to the inside.

[0062] Reference Figure 7 It can be seen that several connecting pipes 13 are built into the inner wall of the box body 1, and the connecting pipes 13 are for the pipelines of the cooling control part and the heat control part to pass through. There is a bottom opening 14 in the bottom cavity 12, and several inner openings 15 are provided on the inner wall of the box body 1.

[0063] Furthermore, the external structure arranged on the top of the box body 1 is used to provide an external force to simulate the load condition of the test pile.

[0064] Among them, the external structure is a pressure mechanism arranged on the top of the box body 1, including a top plate 6 installed away from the top of the box body 1 through a screw rod 5, and a push cylinder 7 arranged on the top plate 6. The push cylinder 7 is arranged toward the box body 1 and has a push rod 9 that reciprocates toward the box body 1. The push rod 9 corresponds to the test pile inserted into the fixing hole 4.

[0065] Furthermore, a window 2 for observing the frozen soil layer in the box 1 is provided on the side wall of the box 1, and a side bar 8 structure is provided on the adjacent side with the window 2, which is used to support the entire top plate 6. Two screw holes are provided on the side bar 8 for fixing the screw rod 5, and the top plate 6 is supported by the screw rod 5. The push cylinder 7 is powered by an external hydraulic system, thereby providing downward pressure to the test pile inserted into the box 1.

[0066] In other embodiments, a push cylinder 7 with a rotating mechanism may be used to provide both downward force and rotational force, thereby providing more testing functions.

[0067] The present invention is not limited to the above optional implementations, and anyone can derive other various forms of products under the enlightenment of the present invention. The above specific implementations should not be understood as limiting the scope of protection of the present invention. The scope of protection of the present invention should be based on the definition in the claims, and the description can be used to interpret the claims.

Claims

1. An engineering geological experiment device, having a test pile with a chamber for simulating frozen soil layer covering experiment, and variable temperature and pressurization for simulation experiment, characterized in that: It comprises a box body (1) having a receiving cavity and a test pile, wherein the top of the box body (1) has a fixing hole (4)(4) for the test pile to penetrate into the receiving cavity; A frozen soil layer simulating actual geological conditions is provided in the accommodation cavity, and the test pile is inserted into the frozen soil layer; A temperature regulating system is also provided at the bottom and the top of the frozen soil layer in the box (1), which maintains the frozen soil layer state by cooling the bottom and simulates the increase of ambient temperature by heating the top. The box (1) is also provided with an external structure for providing pressure to the test pile.

2. An engineering geological experimental device according to claim 1, characterized in that: The temperature regulation system includes a control module and a conduction module; The bottom of the box (1) has a bottom cavity (12), and is provided with a bottom cover (16) that covers and seals the bottom cavity (12). A control module of a temperature regulation system is provided in the bottom cavity (12) and is connected to a conduction module provided in the box (1) through a pipeline.

3. An engineering geological experimental device according to claim 2, characterized in that: The conduction module comprises a heat conduction block arranged at the bottom of the box body (1), a bottom pipe for the flow of working fluid is arranged in the heat conduction block, and the bottom pipe penetrates into the bottom cavity (12) and communicates with the control module.

4. An engineering geological experimental device according to claim 2, characterized in that: The conduction module comprises a heating tube layer (10) arranged on the top of the box body (1), and the heating tube layer (10) is connected to the control module in the bottom cavity (12) through a pipeline.

5. An engineering geological experimental device according to claim 4, characterized in that: An openable door (3) is provided at the opening at the top of the box body (1), and the heating tube layer (10) is arranged on the inner side of the door (3).

6. An engineering geological experimental device according to claim 5, characterized in that: The box door (3) is rotatably connected to the box body (1); the top opening of the box body (1) is provided with two double-opening box doors (3); the middle of the box door (3) is provided with a semicircular groove; when the two box doors (3) are closed, the two semicircular grooves are combined to form a fixing hole (4) for the test pile to pass through.

7. An engineering geological experimental device according to claim 6, characterized in that: The fixing hole (4) is sleeved with a rubber sleeve, and a test pile having a cross-sectional size smaller than that of the fixing hole (4) is fixed in position by the rubber sleeve.

8. An engineering geological experimental device according to claim 2, characterized in that: The conduction module comprises a cooling pipe layer (11) inside a box (1) and buried in a frozen soil layer, a connecting pipe (13) connecting the accommodating cavity and the bottom cavity (12) is provided inside the inner wall of the box (1), the connecting pipe (13) has a bottom opening (14) in the bottom cavity (12), and has an inner opening (15) on the inner wall of the box (1), and a pipeline connecting the control module and the cooling pipe layer (11) is provided inside the connecting pipe (13).

9. An engineering geological experimental device according to claim 2, characterized in that: The external structure is a pressure mechanism arranged on the top of the box body (1), comprising a top plate (6) installed away from the top of the box body (1) through a screw rod (5), and a push cylinder (7) arranged on the top plate (6), wherein the push cylinder (7) is arranged toward the box body (1) and has a push rod (9) that reciprocates toward the box body (1), and the push rod (9) corresponds to the test pile inserted into the fixing hole (4).

10. An engineering geological experimental device according to claim 2, characterized in that: A window (2) for observing the frozen soil layer in the box (1) is provided on the side wall of the box (1).

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