Multi-axis loading structure and foundation prototype test device and method in whole environment

Abstract

The invention discloses a multi-axis loading structure and foundation prototype test device and method in a whole environment, and belongs to the technical field of civil engineering tests.The multi-axis loading structure and foundation prototype test device in the whole environment comprises a main body frame, a foundation prototype test device and a foundation prototype test device, the core tube is arranged in the containing groove in a liftable mode, the core tube comprises a plurality of core units, the core units are sequentially connected in the axial direction, and every two adjacent core units are movably connected; the loading mechanism is used for carrying out multi-axis loading on the soil body and the test structure; the monitoring mechanism is used for detecting data of the test structure; and the control system is used for controlling the loading mechanism and summarizing and analyzing test structure data. According to the invention, stress environments of a test structure and a foundation under different working conditions can be built, stress deformation characteristics of a soil body under a deep ground condition are truly simulated, and the accuracy of research on stress deformation rules of the structure and the foundation under various working conditions is improved.

Description

Technical Field

[0001] The invention relates to the technical field of civil engineering test, and in particular to a structure and foundation prototype test device and method under multi-axial loading in a full environment. Background Art

[0002] Due to their high bearing capacity and good economic efficiency, underground structures such as deep foundations have been widely used in various fields such as offshore wind power, ports and docks, rail transit, and high-rise buildings. The size of underground structures such as deep foundations depends on factors such as geological conditions, building types, and load size. Specifically, underground structures are generally subject to loads from all directions, including vertical compressive loads such as superstructures, vertical anti-buoyancy loads to resist other external forces such as water buoyancy and wind, and horizontal loads such as lateral earth pressure, wave force, wind force, and earthquakes.

[0003] There are two main types of test devices for underground structures or foundations. One is the model test device. The principle of this type of device is the similarity ratio theory. It is small and simple. It often uses a servo motor for loading. However, the load it applies is not in the same order of magnitude as the actual load. It cannot truly reflect the load response of the deep foundation under actual working conditions, and the test accuracy is not high. The other type is the full-scale test device. This type of device is often large in size, and the load is close to the actual working conditions. However, the existing devices of this type cannot simulate the real three-dimensional soil confining pressure at a depth of tens or even hundreds of meters underground. Some devices apply loads in a single direction, and cannot achieve cyclic loading or impact and vibration loading. The degree of automation is not high, and some devices cannot simulate deep foundation and structure tests under multi-field coupling. Summary of the invention

[0004] The purpose of the present invention is to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a structure and foundation prototype test device and method for multi-axial loading under full environment, which can truly simulate the interaction between underground structure, soil and water under deep underground working conditions, and ensure the accuracy of the study on the stress and deformation laws of deep foundations under various working conditions.

[0005] According to the first aspect of the present invention, a structure and foundation prototype test device with multi-axial loading in all environments includes: a main frame, the main frame has a containing groove; a core tube, the core tube is arranged in the containing groove in a liftable manner, the core tube has a test groove, the test groove is used to accommodate the test structure, soil and water to simulate the external stress environment of the test structure, the core tube includes a plurality of core units, the plurality of core units are spliced ​​to form a hollow cylindrical shape, the plurality of core units are connected in sequence along the axial direction, and two adjacent core units are movably connected; a loading mechanism, the loading mechanism is arranged on the main frame, the loading mechanism is located on the peripheral side of the core tube, and the loading mechanism is used to perform multi-axial loading on the core tube and the test structure; a monitoring mechanism, the monitoring system is connected to the test structure, and the monitoring system is used to monitor the displacement, deformation and stress change data of the test structure; a control system, the control system is connected to the loading mechanism, the control system is connected to the monitoring mechanism, the control system is used to control the loading mechanism and the monitoring mechanism, and to store, summarize and analyze the data obtained by the monitoring mechanism.

[0006] The structure and foundation prototype test device for multi-axial loading under full environment according to the embodiment of the present invention has at least the following beneficial effects: the soil is evenly filled into the test tank and water is added to the test tank. After the test structure is placed inside the soil, the loading mechanism is adjusted and started to simulate the real confining pressure of the three-dimensional soil. When the loading mechanism performs lateral loading on the core tube, two adjacent core units are relatively displaced and are not disconnected from each other, forming a flexible connection to ensure the sealing between the two. The load type, direction and size of the loading mechanism are adjusted according to different construction conditions, and then applied to the structure and foundation. Therefore, the stress response of the construction and operation of various structures throughout the entire life cycle can be simulated, and the stress environment of the structure and foundation under different working conditions such as changes in the surrounding additional load, excavation or backfilling of the stratum can be reproduced. The problem that the traditional test device cannot build the real stress environment of the structure and foundation in the deep ground is solved, and the real simulation of the stress deformation characteristics of the soil under the lateral limit conditions is realized, thereby improving the accuracy of the study on the stress deformation law of the structure and foundation under various working conditions.

[0007] According to some embodiments of the present invention, the core unit includes a plurality of unit plates, the plurality of unit plates are enclosed to form a hollow column, two adjacent unit plates are movably connected, and two upper and lower adjacent unit plates are movably connected.

[0008] According to some embodiments of the present invention, two adjacent core units are flexibly connected via a first folding connector, and the first folding connector is used to ensure that the two adjacent core units remain sealed when relative displacement occurs.

[0009] According to some embodiments of the present invention, two adjacent unit plates are flexibly connected via a second folding connector, and the second folding connector is used to ensure that two adjacent core units remain sealed when relative displacement occurs.

[0010] According to some embodiments of the present invention, the core tube also includes: a base, which is arranged on the main frame, the base is located in the accommodating groove, and a plurality of core units and the base are enclosed to form a test groove, and the test groove is used to carry water, soil and a test structure; a pressure plate, the pressure plate is connected to the core unit, the pressure plate corresponds to the inner wall of the core unit, and the pressure plate is used to evenly transfer the load from the vertical direction to the soil in the test groove.

[0011] According to some embodiments of the present invention, at least one soil unloading plate is provided on the outer wall of each core unit, and the soil unloading plate is detachably provided on the outer wall of the core unit, and is used to unload the soil in the test tank.

[0012] According to some embodiments of the present invention, the loading mechanism includes: a plurality of horizontal loading assemblies, each of which is adjustably arranged on a main frame, each of which is evenly distributed along the circumference of the core tube, and each of which is used to apply radial horizontal pressure to the core tube and the test structure; a plurality of vertical loading assemblies, each of which is adjustably arranged on the main frame, each of which is located above the core tube, and each of which is used to apply axial pressure to the soil and the test structure.

[0013] According to some embodiments of the present invention, the horizontal loading assembly includes: a plurality of first horizontal loading members, which are adjustably arranged on the main frame, and are evenly distributed in the vertical direction, and the first horizontal loading members are used to horizontally load the test structure; a plurality of second horizontal loading members, which are adjustably arranged on the main frame, and are evenly distributed in the vertical direction, and the number of the second horizontal loading members is the same as the number of core units, and each unit plate is correspondingly provided with a second horizontal loading member, and the second horizontal loading member is used to horizontally load the corresponding unit plate.

[0014] According to some embodiments of the present invention, the vertical loading assembly includes: a second vertical loading member, which is adjustably disposed on the main frame, and is used to perform axial loading on the test structure; and a plurality of first vertical loading members, which are adjustably disposed on the main frame, and are circumferentially disposed on the circumferential side of the test structure loading member, and are used to perform axial loading on the soil.

[0015] The method for testing a multiaxial loading structure and a foundation prototype under full environment according to the second aspect of the present invention includes:

[0016] S1: Fill the soil evenly into the test tank, compact the soil in the test tank layer by layer until the overall height of the soil layer meets the test requirements, and add water into the test tank;

[0017] S2: Place the pressure plate, adjust the height of the reaction beam, ensure that the fourth hydraulic jack is in close contact with the pressure plate, adjust the height of the second hydraulic jack in the accommodating tank, ensure that each second hydraulic jack is against the corresponding unit plate, and design and apply the thrust of the second hydraulic jack and the fourth hydraulic jack of different heights according to the depth of the soil layer to be simulated, so as to form a true three-dimensional ground stress condition;

[0018] S3: Install and debug strain sensors, stress sensors and infrared laser displacement sensors, test the effectiveness of strain sensors, stress sensors and infrared laser displacement sensors, sink the test structure into the soil, and keep the test structure statically for curing to the set age;

[0019] S4: setting parameters of the first hydraulic jack and the third hydraulic jack, starting the monitoring mechanism and the loading mechanism, and real-time monitoring and collecting data such as displacement, deformation, and stress of the test structure;

[0020] S5: Reset the first hydraulic jack, the second hydraulic jack, the third hydraulic jack and the fourth hydraulic jack, remove the pressure plate, adjust the height of the core tube to pump out the water, open the soil unloading plate to unload the soil, and remove the test structure.

[0021] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention is further described below in conjunction with the accompanying drawings and embodiments:

[0023] Figure 1 It is a schematic diagram of the structure of a multi-axial loading structure and foundation prototype test device under full environment according to an embodiment of the first aspect of the present invention;

[0024] Figure 2 yes Figure 1 Schematic diagram of the structure of the middle core tube;

[0025] Figure 3 yes Figure 1 A cross-sectional diagram of the hidden core tube;

[0026] Figure 4 It is a flow chart of a test method for a multi-axial loading structure and a foundation prototype under full environment according to an embodiment of the second aspect of the present invention.

[0027] Reference numerals:

[0028] Main frame 100, receiving groove 110;

[0029] Core tube 200, core unit 210, unit plate 211, first folding connection member 212, second folding connection member 213, unloading plate 214, base 220, test tank 221, pressure plate 230, stabilizing member 240;

[0030] Loading mechanism 300, horizontal loading assembly 310, first horizontal loading member 311, first slide rail 3111, first hydraulic jack 3112, second horizontal loading member 312, second slide rail 3121, second hydraulic jack 3122, vertical loading assembly 320, first vertical loading member 321, third hydraulic jack 3211, second vertical loading member 322, fourth hydraulic jack 3221, moving member 323, reaction frame column 3231, reaction frame beam 3232;

[0031] Monitoring mechanism 400, infrared laser displacement sensor 410, strain sensor 420, stress sensor 430;

[0032] Test structure 10, soil 20. DETAILED DESCRIPTION

[0033] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it cannot be understood as a limitation on the scope of protection of the present invention.

[0034] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and 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 operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0035] In the description of the present invention, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed" etc. are understood as not including the number itself, and "above", "below", "within" etc. are understood as including the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0036] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0037] refer to Figures 1 to 4A structure and foundation prototype test device and method for multi-axial loading under full environment according to an embodiment of the present invention are described.

[0038] like Figures 1 to 4 As shown, according to the first aspect of the present invention, the structure and foundation prototype test device for multi-axial loading under full environment includes: a main frame 100, the main frame 100 has a receiving groove 110; a core tube 200, the core tube 200 is arranged in the receiving groove 110 in a liftable manner, the core tube 200 has a test groove 221, the test groove 221 is used to accommodate the test structure 10, the soil 20 and the water body to simulate the external force environment of the test structure 10, the core tube 200 includes a plurality of core units 210, the plurality of core units 210 are spliced ​​to form a hollow cylinder, the plurality of core units 210 are connected in sequence along the axial direction, and the space between two adjacent core units 210 is 1 / 4 of the core unit 210. Active connection; a loading mechanism 300, which is arranged on the main frame 100, and is located on the peripheral side of the core tube 200, and is used to perform multi-axis loading on the core tube 200 and the test structure 10; a monitoring mechanism 400, a monitoring system connected to the test structure 10, and is used to monitor the displacement, deformation and stress change data of the test structure 10; a control system, a control system connected to the loading mechanism 300, and a control system connected to the monitoring mechanism 400, and is used to control the loading mechanism 300 and the monitoring mechanism 400, and to store, summarize and analyze the data obtained by the monitoring mechanism 400.

[0039] like Figure 1 and Figure 2As shown, the main frame 100 is a rectangular frame structure, and its receiving groove 110 is a rectangular groove. The core barrel 200 is coaxially arranged in the receiving groove 110, and the core barrel 200 can move in the vertical direction in the receiving groove 110. A loading mechanism 300 is arranged on the peripheral side of the core barrel 200, and the loading mechanism 300 can perform multi-axis loading on the core barrel 200 in the vertical direction and the horizontal direction. Specifically, the core barrel 200 includes a plurality of core units 210, and the plurality of core units 210 are all cylindrical, and the plurality of core units 210 are connected in sequence along the axial direction. In this specific embodiment, four core units 210 are provided, and the four core units 210 are connected in sequence in the vertical direction to form a cylindrical shape, wherein two upper and lower adjacent core units 210 are movably connected. Thus, the soil 20 is evenly filled into the test groove 221, the test structure 10 is placed inside the soil 20, and water is added into the test groove 221 to simulate the real confining pressure of the three-dimensional soil 20, and the loading mechanism 300 is adjusted and started. When the loading mechanism 300 loads the core tube 200, the two adjacent core units 210 are movably connected to form a test groove 221 that can be deformed freely, and the soil 20 is evenly filled into the test groove 221, and water is added into the test groove 221 to simulate the real confining pressure of the three-dimensional soil 20, and then the test structure 10 is placed inside the soil 20, and the loading mechanism 300 is adjusted and started. The loading degree is adjusted according to the construction environment. When the loading mechanism 300 performs multi-directional loading on the core tube 200, the two adjacent core units 210 are relatively displaced and are not disconnected from each other, forming a flexible connection to ensure the sealing between the two. This can simulate the stress response of various structures during construction and operation throughout their life cycle, and reproduce the stress environment of the foundation and structure under different working conditions such as changes in surrounding additional loads, excavation or backfilling of the stratum. This solves the problem that traditional test equipment cannot construct the real stress environment of pile foundations in deep earth, and realizes the real simulation of the stress-deformation characteristics of the soil 20 under lateral limit conditions, thereby improving the accuracy of research on the stress-deformation law of deep foundations under various working conditions.

[0040] Specifically, the monitoring mechanism 400 includes an infrared laser displacement sensor 410 for monitoring the displacement of the test structure 10, a stress sensor 430 for monitoring the stress change of the test structure 10, and a strain sensor 420 for monitoring the deformation data of the test structure 10. In this specific embodiment, Figure 1 As shown, the infrared laser displacement sensor 410 is arranged on the main frame 100 , and the stress sensor 430 and the strain sensor 420 are arranged on the test structure 10 exposed from the soil 20 .

[0041] In some specific embodiments of the present invention, the core unit 210 includes a plurality of unit plates 211, which are enclosed to form a hollow column, and two adjacent unit plates 211 are movably connected, and two upper and lower adjacent unit plates 211 are movably connected. Figure 2 As shown, in this specific embodiment, each core unit 210 is provided with four unit plates 211, and two adjacent unit plates 211 are movably connected, and the unit plates 211 of two upper and lower adjacent core units 210 are movably connected. Thus, the core tube 200 is composed of multiple layers and multiple unit plates 211, and the adjacent unit plates 211 are movably connected to form a cylindrical structure with freely deformable side walls. When the loading mechanism 300 performs multi-axial loading on the core tube 200, the freely deformable side walls can better simulate the stress-deformation characteristics of the soil 20 under the side limit conditions, making the load transfer path more realistic, so that the test results are closer to the actual engineering situation, which is helpful to study the stress-deformation law of the deep foundation in the actual soil 20.

[0042] In some specific embodiments of the present invention, two adjacent core units 210 are flexibly connected via a first folding connector 212 , and the first folding connector 212 is used to ensure that the two adjacent core units 210 remain sealed when relative displacement occurs.

[0043] In some specific embodiments of the present invention, two adjacent unit plates 211 are flexibly connected via a second folding connector 213 , and the second folding connector 213 is used to ensure that two adjacent core units 210 remain sealed when relative displacement occurs.

[0044] like Figure 2 As shown, two vertically adjacent core units 210 are connected by a bellows, and two horizontally adjacent unit plates 211 are connected by a bellows connector. It should be noted that the wave shape of the bellows can make it have a certain flexibility, which can absorb the vibration and displacement of the soil 20. Therefore, when the loading mechanism 300 loads the core tube 200, the core tube 200 will deform under the action of the bellows and the bellows connector. On the one hand, it can better simulate the stress-deformation characteristics of the soil 20 under the side limit condition, and on the other hand, each unit plate 211 can remain connected to each other during the entire loading process.

[0045] In some specific embodiments of the present invention, the core tube 200 further includes: a base 220, which is arranged on the main frame 100, and is located in the accommodating tank 110. A plurality of core units 210 and the base 220 enclose a test tank 221, and the test tank 221 is used to carry water, soil 20 and the test structure 10; a pressure plate 230, which is connected to the core unit 210, and corresponds to the inner wall of the core unit 210, and is used to uniformly transfer the load from the vertical direction to the soil 20 in the test tank 221. Figure 2As shown, four core units 210 are arranged axially on the base 220, and the outer diameter of the pressure plate 230 corresponds to the inner diameter of the core unit 210. When the soil 20 and the test structure 10 are arranged in the test trough 221, the pressure plate 230 is covered on the soil 20. When the loading mechanism 300 loads the soil 20 in the vertical direction, the pressure plate 230 can disperse the load and reduce the compressed area of ​​the soil 20, thereby reducing the bearing pressure of the soil 20, preventing the soil 20 from locally bearing excessive pressure and causing the soil 20 to settle or deform excessively, thereby protecting the stability and safety of the soil 20 and the loading mechanism 300.

[0046] In some specific embodiments of the present invention, the core tube 200 further includes a stabilizing member 240 , which is connected to the core unit 210 , and the stabilizing member 240 is connected to the base 220 , and the stabilizing member 240 is used to maintain the overall stability of all the core units 210 .

[0047] like Figure 2 As shown, a plurality of stabilizing members 240 are circumferentially arranged on the side wall of the core unit 210 located at the lower end. In the present specific embodiment, four stabilizing members 240 are arranged, and the four stabilizing members 240 are respectively arranged on four unit plates 211. One end of the stabilizing member 240 is fixedly connected to the unit plate 211, and the other end is fixedly connected to the base 220, so that all the core units 210 can be stably arranged on the base 220 to further ensure the safety and stability of the test.

[0048] In some specific embodiments of the present invention, at least one unloading plate 214 is disposed on the outer wall of each core unit 210 . The unloading plate 214 is detachably disposed on the outer wall of the core unit 210 , and is used to unload the soil 20 in the test trough 221 .

[0049] In some specific embodiments of the present invention, a soil unloading plate 214 is provided on the outer wall of each unit plate 211 in the core unit 210 located at the bottom.

[0050] like Figure 2As shown, each core unit 210 is provided with a soil unloading plate 214 on the outer wall, wherein the three core units 210 located at the upper part are provided with only one soil unloading plate 214, and the core unit 210 located at the bottom is provided with four soil unloading plates 214, and the four soil unloading plates 214 are evenly arranged along the circumference of the side wall of the bottom core unit 210. Specifically, in the core unit 210 located at the bottom, each unit plate 211 is provided with a soil unloading plate 214. It should be noted that the soil 20 at the bottom is usually more dense and compact than the soil 20 at the upper part. Therefore, more soil unloading plates 214 are provided at the bottom to ensure that the soil 20 can be discharged smoothly to avoid accumulation and resistance. Of course, through different research conditions, the distribution of the unit plates 211 can also be designed according to the actual conditions such as the density of the soil 20, so as to improve the efficiency of the test when unloading the soil 20 by reasonably arranging the unit plates 211 with soil unloading plates 214 and the unit plates 211 without soil unloading plates 214.

[0051] In some specific embodiments of the present invention, the loading mechanism 300 includes: a plurality of horizontal loading assemblies 310, each of which is adjustably arranged on the main frame 100, and the plurality of horizontal loading assemblies 310 are evenly distributed along the circumference of the core tube 200, and the plurality of horizontal loading assemblies 310 are used to apply radial horizontal pressure to the core tube 200 and the test structure 10; a plurality of vertical loading assemblies 320, each of which is adjustably arranged on the main frame 100, and the vertical loading assemblies 320 are located above the core tube 200, and the vertical loading assemblies 320 are used to apply axial pressure to the soil 20 and the test structure 10.

[0052] In some specific embodiments of the present invention, the horizontal loading assembly 310 includes: a plurality of first horizontal loading members 311, which are adjustably arranged on the main frame 100, and are evenly distributed in the vertical direction. The first horizontal loading members 311 are used to horizontally load the test structure 10; a plurality of second horizontal loading members 312, which are adjustably arranged on the main frame 100, and are evenly distributed in the vertical direction. The number of second horizontal loading members 312 is the same as the number of core units 210, and each unit plate 211 is correspondingly provided with a second horizontal loading member 312, and the second horizontal loading member 312 is used to horizontally load the corresponding unit plate 211.

[0053] like Figure 1 and Figure 3As shown, the horizontal loading assembly 310 includes a first horizontal loading member 311 and a second horizontal loading member 312 arranged on the main frame 100, and a first slide rail 3111 and a second slide rail 3121 vertically arranged on the main frame 100, wherein the first horizontal loading member 311 is used to horizontally load the side wall of the test structure 10, and the second horizontal loading member 312 is used to horizontally load the side wall of the core tube 200. Specifically, the first horizontal loading member 311 is a first hydraulic jack 3112 slidably arranged on the first slide rail 3111. In this specific embodiment, four horizontal loading assemblies 310 are provided, and four first slide rails 3111 are provided on the main frame 100, and the four first slide rails 3111 are respectively located at the upper ends of the four side walls of the main frame 100, and each first slide rail 3111 is provided with a first hydraulic jack 3112, so as to evenly load the test structure 10 horizontally from four directions. The second horizontal loading member 312 is a second hydraulic jack 3122 slidably disposed on a second slide rail 3121, and the second slide rail 3121 is disposed on the wall of the accommodating groove 110. The number of the second slide rails 3121 on the wall of the accommodating groove 110 corresponds to the number of the first slide rails 3111, and a second slide rail 3121 is correspondingly disposed at the lower end of each first slide rail 3111 along the length direction. A plurality of second hydraulic jacks 3122 are arranged on each second slide rail 3121. In the present specific embodiment, in order to more realistically simulate the stress-deformation characteristics of the soil 20 under the lateral limit conditions, each unit plate 211 is correspondingly provided with a second hydraulic jack 3122. That is, on the same second slide rail 3121, the number of second hydraulic jacks 3122 corresponds to the number of unit plates 211 in the vertical direction, so as to ensure that during the loading process, each unit plate 211 can be loaded by the second hydraulic jack 3122 in the horizontal direction, so that the load transfer path is more realistic, thereby making the test results closer to the actual engineering conditions.

[0054] In some specific embodiments of the present invention, the vertical loading assembly 320 includes: a second vertical loading member 321, which is adjustably disposed on the main frame 100, and is used to perform axial loading on the test structure; and a plurality of first vertical loading members 322, which are adjustably disposed on the main frame 100, and are circumferentially disposed on the circumferential side of the test structure loading member, and are used to perform axial loading on the soil 20.

[0055] like Figure 3As shown, the vertical loading assembly 320 includes a first vertical loading member 321, a second vertical loading member 322 and a moving member 323 arranged on the main frame 100, wherein the first vertical loading member 321 is used to load the test structure 10 in the vertical direction, and the second vertical loading member 322 loads the dense soil 20 in the test trough 221 in the vertical direction through the pressure plate 230. The moving member 323 includes a reaction frame column 3231 and a reaction frame beam 3232, the first vertical loading member 321 includes a third hydraulic jack 3211 arranged on the reaction frame beam 3232, and the second vertical loading member 321 includes a fourth hydraulic jack 3221 arranged on the reaction frame beam 3232. Specifically, there are four reaction columns 3231, which are respectively arranged at the top of the four side walls of the main frame 100, and each reaction column 3231 corresponds to a first slide rail 3111, that is, each reaction column 3231 is located on the same straight line as a first slide rail 3111 and a second slide rail 3121. Specifically, the first slide rail 3111 is coaxially penetrated in the corresponding reaction column 3231. There are two reaction beams 3232, which are arranged at the upper end of the reaction column 3231. The two oppositely arranged reaction columns 3231 are connected by the reaction beams 3232, and the reaction beams 3232 are arranged on the corresponding reaction columns 3231 in a liftable manner. Figure 3 As shown, the two reaction beams 3232 are perpendicular to each other and overlap. Specifically, the reaction beams 3232 and the reaction columns 3231 are connected by a motor screw. A third hydraulic jack 3211 is arranged at the bottom of the reaction beam 3232 at the lower end. The third hydraulic jack 3211 is arranged coaxially with the core tube 200. When the test structure 10 is placed in the test tank 221 filled with soil 20, the test structure 10 needs to be placed on the axis of the core tube 200 so that the third hydraulic jack 3211 can correspond coaxially with the test structure 10, so that the third hydraulic jack 3211 can accurately load the test structure 10 in the vertical direction. The fourth hydraulic jacks 3221 are evenly arranged around the third hydraulic jack 3211. In this specific embodiment, there are four fourth hydraulic jacks 3221, wherein two fourth hydraulic jacks 3221 located in the front and rear directions of the third hydraulic jack 3211 are located on the same reaction beam 3232, and two fourth hydraulic jacks 3221 located in the left and right directions of the third hydraulic jack 3211 are located on the same reaction beam 3232. It should be noted that, as Figure 3 As shown, in order to achieve free lifting, the core tube 200 is connected to the main frame 100 through a screw structure, wherein each reaction column 3231 is provided with two screw structures, and the two screw structures are respectively located on both sides of the reaction column 3231.

[0056] Furthermore, the pressure plate 230 is composed of four identical pressure plates, which are separated from each other, and each pressure plate corresponds to a fourth hydraulic jack 3221. When the fourth hydraulic jack 3221 is pressed down, each fourth hydraulic jack 3221 can load the soil 20 independently, and two adjacent fourth hydraulic jacks 3221 do not interfere with each other.

[0057] Therefore, a slide rail system and a servo hydraulic loading system capable of applying large loads are adopted to make the loading position flexible and adjustable, and to be able to carry out simulation tests of large loads and deep foundations, and to achieve high automation of the test by cooperating with a PLC control system and an electronic data acquisition system. Specifically, the test tank 221 carries soil 20 and water, and the core tube 200 can move vertically as a whole. Loading structures are set in the transverse and vertical directions of the core tube 200 and inside and outside the test structure 10 to simulate horizontal and vertical cyclic loads, and to achieve multi-axis loading under multi-field coupling, which can not only simulate the stress conditions of the pile foundation in the ocean, but also simulate the whole process construction of the riprap base bed of the gravity riprap wharf, and also simulate the influence of additional loads, backfilling and excavation on the foundation and structure during construction.

[0058] like Figure 4 As shown, the test method of the multi-axial loading structure and foundation prototype under full environment according to the second aspect of the present invention includes:

[0059] S1: evenly fill the soil 20 into the test trough 221, compact the soil 20 in the test trough 221 layer by layer until the overall height of the soil layer meets the test requirements, and add water into the test trough 221;

[0060] S2: Place the pressure plate 230, adjust the height of the reaction beam 3232, ensure that the fourth hydraulic jack 3221 is in close contact with the pressure plate 230, adjust the height of the second hydraulic jack 3122 in the accommodating tank 110, ensure that each second hydraulic jack 3122 is against the corresponding unit plate 211, and design and apply the thrust of the second hydraulic jack 3122 and the fourth hydraulic jack 3221 of different heights according to the depth of the soil layer to be simulated, so as to form a true three-dimensional ground stress condition;

[0061] S3: Install and debug the strain sensor 420, the stress sensor 430 and the infrared laser displacement sensor 410, detect the effectiveness of the strain sensor 420, the stress sensor 430 and the infrared laser displacement sensor 410, adjust the position of the test structure 10 to be coaxially aligned with the third hydraulic jack 3211, adjust the height of the reaction beam 3232 to make the third hydraulic jack 3211 contact with the top of the test structure 10, sink the test structure 10 into the soil 20 through the third hydraulic jack 3211, and maintain the test structure 10 to a set age;

[0062] S4: adjusting and starting the parameters of the first hydraulic jack 3112 and the third hydraulic jack 3211, starting the monitoring structure 400 and the loading mechanism 300, and real-time monitoring and collecting the displacement, deformation, stress and other data of the test structure 10;

[0063] S5: Reset the first hydraulic jack 3112, the second hydraulic jack 3122, the third hydraulic jack 3211 and the fourth hydraulic jack, remove the pressure plate 230, adjust the height of the core tube 200 to pump out the water, open the soil unloading plate 214 to unload the soil 20, and remove the test structure 10. The following three specific embodiments are used to specifically illustrate the test method of the multi-axial loading structure and foundation prototype under the full environment.

[0064] Embodiment 1:

[0065] In the first embodiment, the test structure 10 is a pile structure.

[0066] First, the soil 20 is filled into the core tube 200 in layers and uniformly by mechanical or manual means; then, according to the density standard set in the test, the soil 20 is compacted in layers using professional tools. After each filling to a certain height, the surface of the soil layer needs to be leveled and the density of the soil layer is strictly checked; the above operations are repeated until the overall height of the soil layer meets the test requirements; according to the test needs, an appropriate amount of water is added to the core tube 200 to form a certain water depth environment, and the water level is measured and recorded.

[0067] Place the pressure plate 230, adjust the height of the reaction beam 3232, ensure that the fourth hydraulic jack 3221 is in close contact with the pressure plate 230, prepare for loading, connect the control box and control system, adjust the height of the second hydraulic jack 3122 in the accommodating groove 110, and ensure that each second hydraulic jack 3122 accurately corresponds to the core tube 200 unit block; according to the depth of the soil layer to be simulated, design the thrust of the second hydraulic jack 3122 and the fourth hydraulic jack 3221 of different heights, apply oil pressure, and form true three-dimensional ground stress conditions.

[0068] The strain sensor 420 and the stress sensor 430 are fixed to the pile body, and the infrared laser displacement sensor 410 is debugged to ensure that it can accurately monitor the deformation, force and displacement of the pile body; after installation, the effectiveness of the sensor is detected by using acquisition equipment, and after confirming that it is working properly, the position of the pile body is adjusted to ensure accurate alignment with the third hydraulic jack 3211, and then the height of the reaction beam 3232 is adjusted again until the third hydraulic jack 3211 contacts the top of the pile body, and then the third hydraulic jack 3211 is controlled by the control system to sink into a certain depth inside the soil body 20 by static pressure, impact or vibration, and the pile is maintained to a certain age.

[0069] The monitoring mechanism 400 is connected to the control system, and the load type, size, action time and other parameters of the third hydraulic jack 3211 and the first hydraulic jack 3112 are set on the control system, wherein the load types include static load, impact load, cyclic reciprocating load, vibration load, etc., and the data acquisition device is turned on to ensure that the connection with the control system is correct, and data recording begins. The loading program is started to monitor and collect the displacement, deformation, stress and other data of the pile body in real time; when the load or displacement of the pile body reaches the preset threshold, or the number of load impacts, the relationship threshold between the settlement and the number of impacts, the number of cycles, the vibration time, etc. reach the set value, the test device is promptly closed and data acquisition is stopped.

[0070] Adjust each hydraulic jack to the initial position through the control system and remove the pressure plate 230; control the screw rod to adjust the height of the core tube 200 through the control system, pump out the water, open the soil unloading plate 214, unload the soil 20, remove the pile, and use mechanical equipment or manpower to clear the soil 20 out of the site; thoroughly clean the test site to ensure that all equipment is restored to its original state and prepare for subsequent tests.

[0071] Embodiment 2:

[0072] In the second embodiment, the test structure 10 is a cast-in-place pile structure.

[0073] First, the soil 20 is filled into the core tube 200 in layers and uniformly by mechanical or manual means; then, according to the density standard set in the test, the soil 20 is compacted in layers using professional tools. After each filling to a certain height, the surface of the soil layer needs to be leveled and the density of the soil layer is strictly checked; the above operations are repeated until the overall height of the soil layer meets the test requirements; according to the test needs, an appropriate amount of water is added to the core tube 200 to form a certain water depth environment, and the water level is measured and recorded.

[0074] Place the pressure plate 230, adjust the height of the reaction beam 3232, ensure that the fourth hydraulic jack 3221 is in close contact with the pressure plate 230, prepare for loading, connect the control box and control system, adjust the height of the second hydraulic jack 3122 in the accommodating groove 110, and ensure that each second hydraulic jack 3122 accurately corresponds to the core tube 200 unit block; according to the depth of the soil layer to be simulated, design the thrust of the second hydraulic jack 3122 and the fourth hydraulic jack 3221 of different heights, apply oil pressure, and form true three-dimensional ground stress conditions.

[0075] According to the set pile diameter, pile length and other parameters, a hole is drilled in the soil 20. Certain wall protection measures can be taken during the drilling process to prevent the hole wall from collapsing. Strain sensors 420 such as distributed optical fiber sensors are fixed on the steel skeleton to ensure that they can accurately monitor the deformation of the pile body. After installation, the effectiveness of each sensor is detected using acquisition equipment. After confirming that it is working properly, the steel skeleton is placed in the hole, and then the structural materials are poured and cured to a certain age.

[0076] The monitoring mechanism 400 is connected to the control system, and the load type, size, action time and other parameters of the third hydraulic jack 3211 and the first hydraulic jack 3112 are set on the control system, wherein the load type may include static load, impact load, cyclic reciprocating load, vibration load, etc., and the data acquisition device is turned on to ensure that the connection with the control system is correct, and data recording begins. The loading program is started to monitor and collect the displacement, deformation, stress and other data of the pile body in real time; when the load or displacement of the pile body reaches the preset threshold, or the number of load impacts, the relationship threshold between the settlement and the number of impacts, the number of cycles, the vibration time, etc. reach the set value, the test device is promptly closed and data acquisition is stopped.

[0077] Adjust each hydraulic jack to the initial position through the control system and remove the pressure plate 230; control the screw rod to adjust the height of the core tube 200 through the control system, pump out the water, open the soil unloading plate 214, unload the soil 20, remove the pile, and use mechanical equipment or manpower to clear the soil 20 out of the site; thoroughly clean the test site to ensure that all equipment is restored to its original state and prepare for subsequent tests.

[0078] Embodiment three:

[0079] In addition to piles, this full-environment multi-axial loading structure and foundation prototype test device can also use underground structures as test structures 10 to simulate the stress response of the entire life cycle of underground structure construction and operation, and realize the true simulation of the stress-deformation characteristics of the soil under lateral confinement conditions.

[0080] The soil 20 is filled into the core tube 200 in layers and uniformly by mechanical or manual means; then, the soil 20 is compacted in layers using professional tools according to the density standard set in the test; after each filling to a certain height, the surface of the soil layer needs to be leveled and the density of the soil layer needs to be strictly checked.

[0081] After the soil 20 is filled to a certain height, the underground structure equipped with stress sensors 430, strain sensors 420 and other equipment is placed on the soil 20, and the infrared laser displacement sensor 410 is debugged. Then, according to the density standard set in the test, the soil 20 is compacted layer by layer using professional tools again until the overall height of the soil layer meets the test requirements. The pressure plate 230 is placed, and according to the test needs, an appropriate amount of water is added to the core tube 200 to form a certain water depth environment, and the water level is measured and recorded.

[0082] Adjust the height of the second hydraulic jack 3122 to ensure that each second hydraulic jack 3122 accurately corresponds to the unit block, adjust the height of the fourth hydraulic jack 3221 to ensure that each fourth hydraulic jack 3221 is in close contact with the corresponding pressure plate 230, and design different jack thrusts according to the depth of the soil layer to be simulated.

[0083] The monitoring mechanism 400 is connected to the control system, and the load arrangement, size and action time of the first hydraulic jack 3112, the second hydraulic jack 3122, the third hydraulic jack 3211 and the fourth hydraulic jack 3221 are set on the control system. The data acquisition device is turned on through the control system to ensure that it is correctly connected to the control system and start recording data.

[0084] The loading mechanism 300 is started through the control system, and oil pressure is applied to each second hydraulic jack 3122 and each fourth hydraulic jack 3221 according to the designed thrust, thereby generating thrust and forming true three-dimensional geostress conditions.

[0085] Monitor and collect the displacement, deformation and stress data of underground structures in real time. When the test termination conditions are met, shut down the test device in time and stop data collection.

[0086] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the technical field without departing from the purpose of the present invention.

Claims

1. A prototype test device for structures and foundations under multi-axial loading in all environments, characterized in that: include: A main frame (100), the main frame (100) having a receiving groove (110); A core tube (200), the core tube (200) is movably arranged in the accommodating groove (110), the core tube (200) has a test groove (221), the test groove (221) is used to accommodate the test structure (10), the soil (20) and the water body to simulate the external stress environment of the test structure (10), the core tube (200) includes a plurality of core units (210), the plurality of core units (210) are spliced ​​to form a hollow cylindrical shape, the plurality of core units (210) are connected in sequence along the axial direction, and two adjacent core units (210) are movably connected; A loading mechanism (300), the loading mechanism (300) is arranged on the main frame (100), the loading mechanism (300) is located on the peripheral side of the core tube (200), and the loading mechanism (300) is used to perform multi-axis loading on the core tube (200) and the test structure (10); A monitoring mechanism (400), wherein the monitoring system is connected to the test structure (10), and the monitoring system is used to monitor displacement, deformation and stress change data of the test structure (10); A control system is connected to the loading mechanism (300), and the control system is connected to the monitoring mechanism (400). The control system is used to control the loading mechanism (300) and the monitoring mechanism (400), and to store, summarize and analyze data acquired by the monitoring mechanism (400).

2. The structure and foundation prototype test device under full environment multi-axial loading according to claim 1 is characterized in that: The core unit (210) comprises a plurality of unit plates (211), wherein the plurality of unit plates (211) are enclosed to form a hollow column, wherein two adjacent unit plates (211) are movably connected to each other, and two unit plates (211) adjacent to each other above and below each other are movably connected to each other.

3. The structure and foundation prototype test device under full environment multi-axial loading according to claim 1 is characterized in that: Two adjacent core units (210) are flexibly connected via a first folding connection member (212), and the first folding connection member (212) is used to ensure that the two adjacent core units (210) remain sealed when relative displacement occurs.

4. The structure and foundation prototype test device under full environment multi-axial loading according to claim 2 is characterized in that: Two adjacent unit plates (211) are flexibly connected via a second folding connection member (213), and the second folding connection member (213) is used to ensure that two adjacent core units (210) remain sealed when relative displacement occurs.

5. The structure and foundation prototype test device under full environment multi-axial loading according to claim 1 is characterized in that: The core tube (200) further includes: A base (220), the base (220) is arranged on the main frame (100), the base (220) is located in the accommodating groove (110), a plurality of core units (210) and the base (220) are enclosed to form a test groove (221), and the test groove (221) is used to carry water, soil (20) and the test structure (10); A pressure plate (230) is connected to the core unit (210), the pressure plate (230) corresponds to the inner wall of the core unit (210), and the pressure plate (230) is used to uniformly transfer the load from the vertical direction to the soil (20) in the test trough (221).

6. The structure and foundation prototype test device under full environment multi-axial loading according to claim 2 is characterized in that: At least one soil unloading plate (214) is arranged on the outer wall of each core unit (210). The soil unloading plate (214) is detachably arranged on the outer wall of the core unit (210). The soil unloading plate (214) is used to unload the soil (20) in the test trough (221).

7. The structure and foundation prototype test device under full environment multi-axial loading according to claim 6 is characterized in that: The loading mechanism (300) comprises: A plurality of horizontal loading assemblies (310), each of which is adjustably arranged on the main frame (100), the plurality of horizontal loading assemblies (310) being evenly distributed along the circumference of the core tube (200), and the plurality of horizontal loading assemblies (310) being used to apply radial horizontal pressure to the core tube (200) and the test structure (10); A plurality of vertical loading assemblies (320) are adjustably arranged on the main frame (100), the vertical loading assemblies (320) are located above the core tube (200), and the vertical loading assemblies (320) are used to apply axial pressure to the soil (20) and the test structure (10).

8. The structure and foundation prototype test device under full environment multi-axial loading according to claim 7 is characterized in that: The horizontal loading assembly (310) comprises: A plurality of first horizontal loading members (311), the plurality of first horizontal loading members (311) are adjustably arranged on the main frame (100), the plurality of first horizontal loading members (311) are evenly distributed along the vertical direction, and the first horizontal loading members (311) are used to perform horizontal loading on the test structure (10); A plurality of second horizontal loading members (312) are adjustably arranged on the main frame (100), the plurality of second horizontal loading members (312) are evenly distributed along the vertical direction, the number of the second horizontal loading members (312) is the same as the number of the core units (210), each unit plate (211) is correspondingly provided with a second horizontal loading member (312), and the second horizontal loading member (312) is used to perform horizontal loading on the corresponding unit plate (211).

9. The structure and foundation prototype test device under full environment multi-axial loading according to claim 7, characterized in that: The vertical loading assembly (320) includes: A second vertical loading member (321), the second vertical loading member (321) is adjustably disposed on the main frame (100), and the second vertical loading member (321) is used to axially load the test structure; A plurality of first vertical loading members (322) are adjustably arranged on the main frame (100), and the plurality of first vertical loading members (322) are all arranged on the peripheral side of the test structure loading member along the circumferential direction. The first vertical loading members (322) are used to axially load the soil (20).

10. A method for testing a structure and foundation prototype under multi-axial loading in a full environment, using a structure and foundation prototype testing device under multi-axial loading in a full environment according to any one of claims 1 to 9, characterized in that: include: S1: evenly filling the soil (20) into the test trough (221), compacting the soil (20) in the test trough (221) in layers until the overall height of the soil layer meets the test requirements, and adding water into the test trough (221); S2: placing the pressure plate (230), adjusting the height of the reaction beam (3232) to ensure that the fourth hydraulic jack (3221) is in close contact with the pressure plate (230), adjusting the height of the second hydraulic jack (3122) in the receiving groove (110) to ensure that each second hydraulic jack (3122) is against the corresponding unit plate (211), and designing and applying the thrust of the second hydraulic jack (3122) and the fourth hydraulic jack (3221) of different heights according to the depth of the soil layer to be simulated, so as to form a true three-dimensional ground stress condition; S3: installing and debugging the strain sensor (420), the stress sensor (430) and the infrared laser displacement sensor (410), detecting the effectiveness of the strain sensor (420), the stress sensor (430) and the infrared laser displacement sensor (410), adjusting the position of the test structure (10) to be coaxially aligned with the third hydraulic jack (3211), adjusting the height of the reaction beam (3232) to make the third hydraulic jack (3211) contact the top of the test structure (10), sinking the test structure (10) into the soil (20) through the third hydraulic jack (3211), and allowing the test structure (10) to be statically cured to a set age; S4: setting parameters of the first hydraulic jack (3112) and the third hydraulic jack (3211), starting the monitoring mechanism (400) and the loading mechanism (300), and monitoring and collecting data such as displacement, deformation, and stress of the test structure (10) in real time; S5: Reset the first hydraulic jack (3112), the second hydraulic jack (3122), the third hydraulic jack (3211) and the fourth hydraulic jack, remove the pressure plate (230), adjust the height of the core tube (200) to pump out the water, open the soil unloading plate (214) to unload the soil (20), and remove the test structure (10).

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