Test device for simulating inertial load of pile foundation in liquefied ground

Abstract

The application relates to the technical field of mechanical testing, in particular to a testing device for simulating inertial load of a pile foundation in a liquefied site, wherein the testing device comprises a first load-bearing frame, a first installation layer of the first load-bearing frame, a central positioning frame, a pulley, a weight disc, a test box, a test fluid and a test pile foundation; the first installation layer is arranged above the first load-bearing frame; the central positioning frame is arranged on the first installation layer; the pulley is fixedly connected to the central position of the central positioning frame; one end of the weight disc is connected to a wire; the weight disc is arranged below the pulley; the other end of the wire is connected to the test box through the pulley; the test box comprises a box body; the test fluid is loaded in the box body; the test pile foundation is vertically inserted into the test fluid; the test pile foundation is higher than the box body; and the wire is connected to the part of the test pile foundation which is higher than the box body. The application can accurately obtain the inertial load and reduce the testing cost.

Description

Technical Field

[0001] This application relates to the field of mechanical testing technology, and in particular to a testing device and a viscosity measuring device for simulating the inertial load of pile foundations in liquefied sites. Background Technology

[0002] In today's engineering field, structural stability and safety are paramount, whether for skyscrapers or bridges. Factors such as earthquakes, strong winds, or mechanical vibrations inevitably subject structures to inertial loads. This study investigates the impact of inertial loads on pile foundations in liquefaction zones to infer the influence of inertial loads on buckling loads, thus analyzing the structural stability and safety. Currently, simulating liquefaction zones with saturated sand and applying dynamic loads using equipment such as shaking tables to achieve a liquefaction effect is a common technique. However, this method is costly and struggles to obtain accurate inertial loads for experimental results.

[0003] In summary, the technical problems existing in the relevant technologies need to be improved. Summary of the Invention

[0004] The main objective of this application is to propose a testing device and a viscosity measuring device for simulating the inertial load of pile foundations in liquefied sites, which can accurately obtain the inertial load and reduce testing costs.

[0005] To achieve the above objectives, one aspect of this application provides a testing device for simulating the inertial load of pile foundations in liquefied sites, comprising:

[0006] A first load-bearing frame, the first load-bearing frame including a first mounting layer, the first mounting layer being located above the first load-bearing frame;

[0007] A central positioning frame is disposed on the first mounting layer;

[0008] A pulley, which is fixedly connected to the center position of the central positioning frame;

[0009] A weight pan, one end of which is connected to a stranded wire, is located below a pulley, and the other end of the stranded wire is connected to a test chamber via the pulley;

[0010] The test chamber includes a chamber body, test fluid, and test pile foundation;

[0011] The test fluid is loaded inside the chamber;

[0012] The test pile foundation is vertically inserted into the test fluid, and the test pile foundation is higher than the box body;

[0013] The stranded wire connects the portion of the test pile foundation that is higher than the box body.

[0014] In some embodiments, the testing device for simulating the inertial load of pile foundations in a liquefaction site is further provided with a loading device, which includes a second load-bearing frame, a first limiting frame, a second limiting frame, and a third limiting frame.

[0015] The second load-bearing frame is disposed on the side of the first load-bearing frame;

[0016] Both the first limiting frame and the second limiting frame are connected to the second load-bearing frame;

[0017] The third limiting frame is connected to the first limiting frame and the second limiting frame respectively.

[0018] In some embodiments, a first slide rail is provided on the vertical beam of the first load-bearing frame, and a first limiting and fixing device is provided in the first slide rail. The two ends of the second load-bearing frame are respectively disposed in the first slide rail, and the first limiting and fixing device is used to fix the loading device in the position after height adjustment.

[0019] The second load-bearing frame is provided with a second slide rail, and a second limiting and fixing device is provided inside the second slide rail. One end of the first limiting frame and the second limiting frame are both provided inside the second slide rail. The second limiting and fixing device is used to fix the position of the first limiting frame and the second limiting frame inside the second slide rail.

[0020] The first limiting frame and the second limiting frame are provided with a third slide rail, and a third limiting fixing device is provided in the third slide rail. The two ends of the third limiting frame are respectively disposed in the third slide rail, and the third limiting fixing device is used to fix the position of the third limiting frame in the third slide rail.

[0021] The length of the third limiting frame can be adjusted by extending or retracting according to the distance between the first limiting frame and the second limiting frame.

[0022] In some embodiments, the vertical beam of the first support frame is provided with a fourth slide rail, and a fourth limiting and fixing device is provided in the fourth slide rail. The four sides of the central positioning frame are arranged in the fourth slide rail, and the fourth limiting and fixing device is used to fix the height of the central positioning frame in the first support frame.

[0023] By adjusting the height of the central positioning frame, the pulley fixed below the central positioning frame and the stranded wire connecting the test pile foundation are at the same height.

[0024] In some embodiments, the testing device for simulating the inertial load of pile foundations in a liquefaction site further includes a tension sensor;

[0025] One end of the tensile sensor is connected to the weight pan via the stranded wire, and the other end of the tensile sensor is connected to the test chamber via the stranded wire;

[0026] The tension sensor is located below the pulley.

[0027] To achieve the above objectives, another aspect of this application provides a viscosity measuring device for testing the test fluid within the test apparatus for simulating the inertial load of pile foundations in a liquefied site as described in the above embodiments; the viscosity measuring device includes:

[0028] A graduated cylinder, used to hold the test fluid;

[0029] The laser sensing unit includes a first laser emitter, a first laser sensor, a second laser emitter, and a second laser sensor, wherein:

[0030] The first laser emitter and the first laser sensor are respectively fixed on both sides of the measuring cylinder and are at the same height;

[0031] The second laser emitter and the second laser sensor are also fixed on both sides of the measuring cylinder at the same height, and are located below the first laser emitter and the first laser sensor;

[0032] A relay, which is connected to the first laser emitter, the first laser sensor, the second laser emitter, and the second laser sensor, respectively;

[0033] A timer, which is connected to the relay;

[0034] A test ball, the density of which is greater than that of the test fluid and the diameter of which is smaller than that of the measuring cylinder.

[0035] In some embodiments, the viscosity metering device further includes a test stand;

[0036] The test bracket includes a first fixed bracket and a second fixed bracket;

[0037] The first fixed bracket and the second fixed bracket are located on both sides of the measuring cylinder;

[0038] The first laser emitter and the first laser sensor are respectively connected to the first fixed bracket and the second fixed bracket, and the connection heights are the same.

[0039] The second laser emitter and the second laser sensor are respectively connected to the first fixed bracket and the second fixed bracket. The connection height of the first laser emitter and the first laser sensor is the same and they are located below the first laser emitter and the first laser sensor.

[0040] In some embodiments, the test bracket is further provided with positioning holes;

[0041] The positioning holes are all provided on the first fixed bracket and the second fixed bracket;

[0042] The first fixed bracket and the second fixed bracket each have multiple positioning holes, and the corresponding positioning holes on the first fixed bracket and the second fixed bracket are at the same height.

[0043] The positioning hole is used to fix the laser sensing unit.

[0044] In some embodiments, the test ball comprises a metal ball;

[0045] When the laser sensing unit, the relay, and the timer are activated and the metal ball is placed in the measuring cylinder containing the test fluid, the laser sensing unit is used to acquire the movement speed of the metal ball, and the movement speed is used to guide the process of plotting the viscosity-shear strain rate curve of the test fluid.

[0046] In some embodiments, the calculation formula corresponding to the viscosity-shear strain rate curve is:

[0047]

[0048] in, The shear strain rate of the test fluid is represented by r; the radius of the test sphere is represented by v; the velocity of the test sphere is represented by η; the viscosity of the test fluid is represented by ρ; the density of the test sphere is represented by ρ0; and g is represented by gravitational acceleration.

[0049] The embodiments of this application include at least the following beneficial effects:

[0050] This application provides a testing device and a viscosity measuring device for simulating the inertial load of pile foundations in liquefied environments. The method involves adding weights to a weight pan, converting the weight's gravity into tension in a strand, which pulls the test pile foundation connected to the other end of the strand, thus applying a lateral concentrated force to the test pile foundation. This lateral concentrated force effectively replaces the inertial load, and the influence of the inertial load on the critical buckling load of the pile foundation in liquefied environments is then used to determine the effect. Compared to existing technologies, this method simplifies the testing device structure, improves the accuracy and repeatability of test results, shortens the test cycle time, significantly increases test efficiency, and reduces test costs. Attached Figure Description

[0051] Figure 1 This is a schematic diagram of the load-bearing limit frame of the test device for simulating the inertial load of pile foundations in a liquefied site provided in the embodiments of this application;

[0052] Figure 2 This is a schematic diagram of the strand fixing device of the test device for simulating the inertial load of pile foundations in a liquefaction site provided in the embodiments of this application;

[0053] Figure 3 This is a schematic diagram of a test chamber for a test device that simulates the inertial load of pile foundations in a liquefied site, as provided in an embodiment of this application.

[0054] Figure 4 This is a schematic diagram of a viscosity metering device for simulating the inertial load of pile foundations in a liquefied site, provided in an embodiment of this application.

[0055] Figure 5 This is a circuit connection diagram of a viscosity metering device for simulating the inertial load of pile foundations in a liquefied site, provided in an embodiment of this application.

[0056] Figure 6 This is a relay schematic diagram of a viscosity metering device for simulating the inertial load of pile foundations in a liquefied site, provided in an embodiment of this application.

[0057] Figure 7 This is a schematic diagram comparing the viscosity-shear strain rate curves. Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit it. In the following description, when referring to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with those of this application; they are merely examples of apparatuses and methods consistent with some aspects of the embodiments of this application.

[0059] It is understood that the terms “first,” “second,” etc., used in this application may be used herein to describe various concepts, but unless otherwise stated, these concepts are not limited by these terms. These terms are only used to distinguish one concept from another. For example, without departing from the scope of the embodiments of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the words “if,” “when,” or “in response to a determination” as used herein may be interpreted as “when…” or “when…” or “in response to a determination.”

[0060] As used in this application, the terms "at least one", "multiple", "each", "any", etc., "at least one" includes one, two or more, "multiple" includes two or more, "each" refers to each of the corresponding multiples, and "any" refers to any one of the multiples.

[0061] In the description of this application, unless otherwise expressly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0062] In the description of this application, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0063] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0064] Reference Figure 1 , Figure 2 and Figure 3 As shown, this embodiment of the invention provides a test device for simulating the inertial load of pile foundations in liquefied sites, including: a first load-bearing frame 101, a central positioning frame 201, a pulley 401, a weight pan 601, a box 803, a test pile foundation 801, a stranded wire 701, and a test fluid 802. The first load-bearing frame 101 includes a first mounting layer located above the first load-bearing frame 101; a central positioning frame 201 is disposed on the first mounting layer; a pulley 401 is fixedly connected to the lower part of the central positioning frame 201 and is located at the virtual positioning line 202 at the center position of the central positioning frame 201, i.e., the center position below the central positioning frame 201; a weight pan 601 is connected to one end of a stranded wire 701, the weight pan 601 is located below the pulley 401, and the other end of the stranded wire 701 is connected to the test chamber through the pulley 401; the test chamber includes a chamber body 803, a test fluid 802, and a test pile foundation 801, the chamber body 803 is filled with the test fluid 802; the test pile foundation 801 is vertically inserted into the test fluid 802, and the test pile foundation 801 is higher than the chamber body 803; the stranded wire 701 connects the part of the test pile foundation 801 that is higher than the chamber body 803.

[0065] In this embodiment, a liquefied site is simulated using a test fluid 802, and an inertial load is simulated by applying a lateral tensile force to the test pile foundation 801 using a stranded wire 701. Specifically, a fixed weight is placed on a weight pan 601. Since one end of the stranded wire 701 is connected to the weight pan 601, the weight of the weight is converted into a tensile force on the stranded wire 701. The direction of the stranded wire 701 is changed by the pulley 401 on the weight pan 601, thereby changing the direction of the tensile force. The other end of the stranded wire 701 is connected to the test pile foundation 801, specifically to the portion of the test pile foundation 801 that is higher than the box body 803. The connection height between the stranded wire 701 and the test pile foundation 801 is the same as the height of the pulley 401, ensuring that the tensile force exerted by the stranded wire 701 at the connection point with the test pile foundation 801 is horizontal. Because the test fluid 802 provides resistance within the test box, the test pile foundation 801 remains vertical. When the test pile 801 is inserted into the test fluid 802, a horizontal tension applied to the connection point of the test pile 801 by the stranded wire 701 can easily cause the test pile 801 to tilt. Simultaneously, the influence of the test fluid 802 provides corresponding resistance to the test pile 801, reducing the degree of tilt. When the weight of the weight is small, the resulting tension is relatively small. When the horizontal tension on the test pile 801 is less than or equal to the resistance of the test fluid 802, the test pile 801 will not tilt. When the weight of the weight is large, the resulting horizontal tension exceeds the resistance of the test fluid 802, causing the test pile 801 to tilt. The weight of the weight at the time of tilt is recorded. Applying a lateral tension force to the test pile 801 effectively replaces the inertial load; that is, the weight of the weight at this point corresponds to the inertial load of the test pile 801. This lateral tension force can also be called a lateral concentrated force.

[0066] In some embodiments, such as Figure 1 As shown, to better fix the test chamber, the testing device for simulating the inertial load of pile foundations in a liquefied site is also equipped with a loading device. The loading device includes a second load-bearing frame 102, a first limiting frame 301, a second limiting frame 302, and a third limiting frame 303. The second load-bearing frame 102 is disposed on the side of the first load-bearing frame 101. The first load-bearing frame 101 is composed of vertical beams. The second load-bearing frame 102 is vertically connected to the first load-bearing frame 101, so that the second load-bearing frame 102 is embedded in the side of the first load-bearing frame 101. The load-bearing frame 102 is used to support the load of the loading device; both the first limiting frame 301 and the second limiting frame 302 are connected to the second load-bearing frame 102, and both the first limiting frame 301 and the second limiting frame 302 are placed vertically and connected to the second load-bearing frame 102 on their sides. The first limiting frame 301 and the second limiting frame 302 are used to limit and fix the front and rear sides of the test chamber; the third limiting frame 303 is connected to the first limiting frame 301 and the second limiting frame 302 respectively. There can be multiple third limiting frames 303, for example, such as... Figure 1As shown, there are three third limiting frames 303; the two sides of the third limiting frame 303 are connected to the first limiting frame 301 and the second limiting frame 302 respectively. The third limiting frame 303 closer to the second load-bearing frame 102 is used to limit and fix the left side of the test chamber, and the third limiting frame 303 farther away from the second load-bearing frame 102 compared to the other third limiting frames 303 is used to limit and fix the right side of the test chamber.

[0067] In this embodiment, when the test device simulating the inertial load of a pile foundation in a liquefied site is tested, the second load-bearing frame 102 bears the weight of the loading device, placing the test chamber on the ground or a test bench. The first limiting frame 301 and the second limiting frame 302 in the loading device limit and fix the front and rear sides of the test chamber, while the third limiting frame 303 limits and fixes the left and right sides of the test chamber. Specifically, the loading device is fixed around the portion of the test chamber containing the test fluid 802 corresponding to the chamber body 803 to ensure the stability of the test chamber's center of gravity. It is understood that during the test, the main focus is on measuring the stress load on the test pile foundation 801 within the test fluid 802. If the test chamber experiences significant stress, causing it to move or shake, it will affect the accuracy of the test data and lead to test failure. To avoid the influence of the test chamber during the test, the loading device is used to limit and fix the test chamber, effectively overcoming the impact of movement or shaking during the test.

[0068] In some embodiments, to accommodate test chambers of different specifications, a slide rail and a fixing device are provided in the loading device. Specifically, a first slide rail (not shown in the figure) is provided on the vertical beam of the first load-bearing frame 101, and a first limiting fixing device (not shown in the figure) is provided inside the first slide rail. The two ends of the second load-bearing frame are respectively provided inside the first slide rail. The first slide rail and the first limiting fixing device are used to adjust and fix the vertical height of the loading device according to the height of the test chamber. When the test chamber is placed on the ground or the test bench, since the height of the test chamber is not fixed, and the loading device needs to be fixed on the periphery of the test chamber containing the test fluid 802 corresponding to the box body 803 to stabilize the center of gravity of the test chamber, the overall height of the loading device needs to be adjusted. The first slide rail on the second load-bearing frame 102 can allow the loading device to move up and down, and the first limiting fixing device can fix the height when it is moved to a suitable height, so as to avoid the loading device falling off due to external forces during the test and affecting the test process.

[0069] The second load-bearing frame 102 is provided with a second slide rail (not shown in the figure), and a second limiting and fixing device (not shown in the figure) is provided inside the second slide rail. One end of the first limiting frame 301 and the second limiting frame 302 are both located inside the second slide rail. The second slide rail and the second limiting and fixing device are used to adjust the loading width of the loading device according to the width of the test chamber. Specifically, at least two second slide rails are laterally connected to the upper and lower sides of the second load-bearing frame 102, and the second limiting and fixing device is connected inside the second slide rail. According to the width of the test chamber, the distance between the first limiting frame 301 and the second limiting frame 302 is determined by adjusting the movement of the second slide rail. When the distance between the first limiting frame 301 and the second limiting frame 302 is determined, the distance is fixed by the second limiting and fixing device to avoid the distance between the first limiting frame 301 and the second limiting frame 302 from expanding due to the influence of the slide rail during the test, which would prevent the test chamber from being limited and fixed.

[0070] A third slide rail (not shown in the figure) is provided on the first limiting frame 301 and the second limiting frame 302. A third limiting fixing device (not shown in the figure) is provided inside the third slide rail. The two ends of the third limiting frame 303 are respectively set inside the third slide rail. The third slide rail and the third limiting fixing device are used to adjust and fix the loading length of the loading device according to the length of the test chamber, thereby avoiding the shaking of the chamber 803 caused by the tension of the stranded wire 701. Due to the influence of different specifications of test chambers, in order to adapt to the length of different test chambers, a third limiting frame 303 is set between the first limiting frame 301 and the second limiting frame 302. According to the length of the test chamber, the distance between the third limiting frame 303 closer to the second load-bearing frame 102 and the third limiting frame 303 farther away from the second load-bearing frame 102 is adjusted by the third slide rail. After the distance is determined, the third limiting fixing device is used for limiting and fixing to avoid the shaking of the chamber 803 caused by the force on the test chamber during the test. Specifically, the third slide rail allows the third limiting frame 303 to move left and right. The number of third slide rails depends on the number of third limiting frames 303. Since a lateral pulling force is applied to the test chamber, the third limiting frame 303, which is closer to the second load-bearing frame 102, experiences a greater force than the first limiting frame 301 and the second limiting frame 302. To prevent the test chamber from directly contacting the second load-bearing frame 102 and causing damage to the chamber body 803 or shaking of the test chamber that affects the test data, a third limiting frame 303 is provided between the test chamber and the second load-bearing frame 102. The length of the third limiting frame 303 can be extended or retracted according to the distance between the first limiting frame 301 and the second limiting frame 302. To prevent the third limiting frame 303 from falling off or shortening due to changes in the distance between the first limiting frame 301 and the second limiting frame 302 under stress, the length of the third limiting frame 303 is determined and fixed when the distance between the first limiting frame 301 and the second limiting frame 302 is determined. The connection between the third limiting frame 303 and the first limiting frame 301 and the second limiting frame 302 can be detachable. When the distance tends to increase or decrease, it is limited by the fixed distance change of the length of the third limiting frame 303, thereby controlling the distance between the first limiting frame 301 and the second limiting frame 302 to remain unchanged.

[0071] In some embodiments, the vertical beam of the first support frame 101 is provided with a fourth slide rail (not shown in the figure), and a fourth limiting and fixing device (not shown in the figure) is provided inside the fourth slide rail. The center positioning frame 201 is arranged around the fourth slide rail. The fourth slide rail and the fourth limiting and fixing device are used to adjust the height of the center positioning frame 201, thereby controlling the position height of the pulley 401 and the stranded wire 701 fixed below the center positioning frame 201 to be consistent with that of the test pile foundation 801, so as to ensure that the tension on the test pile foundation 801 is in the horizontal direction. Specifically, when conducting tests simulating the inertial load of pile foundations in a liquefied site, a horizontal force needs to be applied to the connection of the test pile foundation 801 to simulate the inertial load. To ensure that the direction of the force is horizontal, the connection between pulley 401 and strand 701 and the test pile foundation 801 needs to be kept horizontal. Since the test chambers have different specifications, the height of pulley 401 is controlled by controlling the height of the central positioning frame 201, which makes it easier to control the relative height with the connection of the test pile foundation 801. When the height of pulley 401 is the same as the height of the connection between the test pile foundation 801 and strand 701, the height of the central positioning frame 201 is fixed by the fourth limiting and fixing device to ensure the stability of the height of pulley 401 during the test.

[0072] In some embodiments, the testing device for simulating the inertial load of pile foundations in liquefied environments further includes a tension sensor 501; one end of the tension sensor 501 is connected to the weight pan 601 via a stranded wire 701, and the other end of the tension sensor 501 is connected to the test chamber via a stranded wire 701; the tension sensor 501 is located below the pulley 401. It is understood that the tension sensor 501, connected via the stranded wire 701 between the pulley 401 and the weight pan 601, traditionally determines the magnitude of the tension by calculating the weight of the weights. Adding the tension sensor 501 allows for a more accurate determination of the real-time tension, thereby determining the specific value of the inertial load and improving the accuracy and efficiency of the test process.

[0073] In some embodiments, a scratch-resistant ring is provided at the junction of the stranded wire 701 and the frame of the central positioning frame 201. The scratch-resistant ring is fixedly connected to the central positioning frame 201. A first fixed pulley and a second fixed pulley are fixedly connected to the upper and lower sides of the inside of the scratch-resistant ring, respectively. The stranded wire 701 passes through the gap between the first fixed pulley and the second fixed pulley and is connected to the test chamber. When weights are placed on the weight pan 601 to generate tension in the stranded wire 701, if the height of the pulley 401 is lower than the connection point between the stranded wire 701 and the test pile foundation 801 due to the error of the test personnel, the stranded wire 701 will rub against the frame of the central positioning frame 201, generating friction and indirectly affecting the tension value, resulting in inaccurate test data. The anti-scratch ring stranded wire 701 is set through the gap between the first and second fixed pulleys inside the anti-scratch ring. Even if the pulley 401 at the center of the center positioning frame 201 is higher or lower than the connection point between the stranded wire 701 and the test pile foundation 801, the stranded wire 701 will contact the first and second fixed pulleys inside the anti-scratch ring. When the stranded wire 701 contacts the first and second fixed pulleys inside the anti-scratch ring, the first and second fixed pulleys inside the anti-scratch ring will rotate with the movement of the stranded wire 701, without causing additional friction that would affect the test data. At the same time, the anti-scratch ring also has a certain guiding effect on the stranded wire 701.

[0074] In some embodiments, to conduct tests simulating the inertial load of pile foundations in liquefied environments, a test fluid 802 needs to be loaded into the test chamber. To ensure the validity of the test, saturated sand is commonly used in traditional tests instead of test fluid 802. However, sand requires a long time to reach saturation through water settling. During the preparation of saturated sand, water flow or stirring can introduce voids and air bubbles, affecting the saturation and consistency of the sand, thus impacting the accuracy and repeatability of the test results. Furthermore, the water quality and environmental requirements for preparing saturated sand using water settling are high; it must be free of impurities and chemical components, and the operating environment must be clean and stable. Based on these drawbacks of saturated sand, non-Newtonian fluids are used to replace saturated sand to avoid these disadvantages. However, there are many types of non-Newtonian fluids, and tests using a viscosity measuring device are needed to find a test fluid 802 that meets the requirements of the test fluid used in the test device simulating the inertial load of pile foundations in liquefied environments before it can be used.

[0075] In some embodiments, such as Figure 4 and Figure 5As shown, a viscosity measuring device is used to test the test fluid 802 in a test device simulating the inertial load of pile foundations in a liquefied site. Only fluids that meet the requirements tested by the viscosity measuring device can be used as test fluids in the test device simulating the inertial load of pile foundations in a liquefied site. The viscosity measuring device includes: a measuring cylinder 1001, a laser sensing unit, a relay 1201, a timer 1301, and a test ball; wherein: the measuring cylinder 1001 is used to load the test fluid 802; the laser sensing unit includes a first laser emitter 901, a first laser sensor 902, a second laser emitter 903, and a second laser sensor 904; the first laser emitter 901 and the first laser sensor 904 in the laser sensing unit... 2. The first laser emitter 903 and the second laser sensor 904 are fixed on both sides of the measuring cylinder 1001 at the same height, respectively, and are located below the first laser emitter 901 and the first laser sensor 902. The relay 1201 is connected to the first laser emitter 901, the first laser sensor 902, the second laser emitter 903 and the second laser sensor 904 respectively. The timer 1301 is connected to the relay 1201. The diameter of the test ball is smaller than the diameter of the measuring cylinder 1001 to ensure that the test ball can move inside the measuring cylinder 1001, and the density of the test ball is greater than that of the test fluid 802 to ensure that the test ball can fall inside the measuring cylinder 1001. Specifically, the first laser emitter 901, the first laser sensor 902, the second laser emitter 903, and the second laser sensor 904 are respectively fixed on both sides of the measuring cylinder 1001. At the same height, one side is the laser emitter and the other side is the laser sensor, forming a group. The laser sensors can receive the laser from the laser emitter at the same height. The measuring cylinder 1001 is set with two groups, one above the other, and located below the liquid surface of the test fluid 802 inside the measuring cylinder 1001. The height difference between the two groups is sufficient for the test ball to fall completely a certain distance within that height.

[0076] When the viscosity measuring device performs measurement, the non-Newtonian fluid to be measured is poured into the measuring cylinder 1001. Since the measurement is performed by laser, the non-Newtonian fluid needs to be transparent. The amount of non-Newtonian fluid poured into the measuring cylinder 1001 needs to be at least 5 cm higher than the highest laser sensing unit. The power is turned on to connect the relay 1201, timer 1301 and laser sensing unit. The test ball is put into the measuring cylinder 1001 and falls slowly. When it reaches the first laser emitter 901 and the first laser sensor 902, blocking the laser and preventing the first laser sensor 902 from receiving the laser, the timer 1301 starts timing. The test ball continues to fall. When the test ball blocks the second laser emitter 903 and the second laser sensor 904, the timer 1301 stops timing. The time it takes for the test ball to fall within a fixed distance is obtained, and the falling speed of the test ball can be calculated.

[0077] In some embodiments, such as Figure 4 As shown, the viscosity measuring device also includes a test bracket 1101; the test bracket 1101 includes a first fixed bracket and a second fixed bracket; the first fixed bracket and the second fixed bracket are located on both sides of the measuring cylinder 1001; the first laser emitter 901 and the first laser sensor 902 are respectively connected to the first fixed bracket and the second fixed bracket and are connected at the same height; the second laser emitter 903 and the second laser sensor 904 are respectively connected to the first fixed bracket and the second fixed bracket, and the first laser emitter 901 and the first laser sensor 902 are connected at the same height and are located below the first laser emitter 901 and the first laser sensor 902. It is understood that directly fixing the laser sensing unit at the measuring cylinder 1001 may easily cause the laser emitter or laser sensor to fall off or the laser to be difficult to align. Therefore, the test bracket 1101 is set up to fix the laser sensing unit.

[0078] In some embodiments, the test bracket 1101 is further provided with positioning holes; the positioning holes are all provided on the first fixed bracket and the second fixed bracket; there are multiple positioning holes on the first fixed bracket and the second fixed bracket respectively, and the corresponding positioning holes on the first fixed bracket and the second fixed bracket are at the same height; the positioning holes are used to fix the laser sensing unit. It can be understood that by providing holes of the same height on the first fixed bracket and the second fixed bracket respectively, the heights of the first laser emitter 901, the first laser sensor 902, the second laser emitter 903 and the second laser sensor 904 are adjusted according to different test requirements, so as to control the distance between the first laser emitter 901 and the first laser sensor 902 and the second laser emitter 903 and the second laser sensor 904, so that the test ball has a sufficient falling distance to ensure the effectiveness of the test.

[0079] In some embodiments, the test sphere comprises a metal sphere. When the laser sensing unit, relay 1201, and timer 1301 are activated and the metal sphere is placed in the measuring cylinder 1001 containing the test fluid 802, the laser sensing unit acquires the velocity of the metal sphere. This velocity guides the plotting of the viscosity-shear strain rate curve of the test fluid 802. It is understood that the metal sphere has a relatively high density compared to other materials, making it more suitable for viscosity measurement tests.

[0080] In some embodiments, aluminum spheres are preferably selected as test spheres because aluminum generally has a higher density than non-Newtonian fluids, and aluminum is not easily chemically reacted with other materials, has high stability, and is easy to use in viscosity measurement tests.

[0081] In some embodiments, the calculation formula corresponding to the viscosity-shear strain rate curve is:

[0082]

[0083] in, η represents the shear strain rate of the test fluid 802; r represents the radius of the test sphere; v represents the velocity of the test sphere; η represents the viscosity of the test fluid 802; ρ represents the density of the test sphere; ρ0 represents the density of the test fluid 802; g represents the acceleration due to gravity.

[0084] Specifically, before conducting the viscosity measurement test, the radius and density of the test ball and the density of the test fluid 802 are measured and calculated. The density of the test ball can be measured using a solid density meter, and the density of the test fluid 802 can be measured using a hydrometer. During the viscosity measurement test, the time taken for the test ball to move within a fixed distance is obtained using a timer 1301, thereby calculating the speed of the test ball. The data obtained above are substituted into formula (1) to obtain the shear strain rate of the test fluid 802, and the data above are substituted into formula (2) to obtain the viscosity of the test fluid 802. Based on the obtained shear strain rate and the viscosity of the test fluid 802, a viscosity-shear strain rate curve is obtained.

[0085] In some embodiments, the test fluid 802 is a non-Newtonian fluid. To meet the requirements of the laser sensing unit, the non-Newtonian fluid includes a polyisobutylene-white oil solution. For example... Figure 7 The figure shows a comparison of the viscosity-shear strain rate curves of 47% saturated Nanjing sand and 25% polyisobutylene-white oil solution. As can be seen from the figure, the viscosity-shear strain rate curves of 47% saturated Nanjing sand and 25% polyisobutylene-white oil solution measured under the same conditions are very similar. Polyisobutylene-white oil solution is a colorless non-Newtonian fluid. Its high molecular weight increases the viscosity of the solution, and it exhibits good chemical stability, making it very suitable as a replacement for saturated sand as the test fluid 802 in the testing device for simulating the inertial load of pile foundations in liquefied environments.

[0086] In some embodiments, such as Figure 5 As shown, the laser sensing unit can communicate with the relay 1201, the timer 1301, and the power supply. Figure 5 Connect the circuits shown in the diagram.

[0087] In some embodiments, such as Figure 5 and Figure 6As shown, relay 1201 can be a YF-7 dual-channel relay 1201, and timer 1301 can be a JDM11-6T accumulator timer 1301. After ensuring the circuit connection is correct, adjust the switching power supply to output 12V. The relay 1201 is set as follows: Press and hold the K1 button on the relay 1201 for more than 1 second. At this time, "P-11" will appear on the screen. By short-pressing the K2 and K3 buttons, the relay 1201 is adjusted to P-12 mode. Then, short-press the K1 button 3 times. When the screen displays "----", the timer 1301 is ready. The timer 1301 is set as follows: With the power off, press and hold the reset button on the timer 1301 while turning on the power. When the timer 1301 screen displays letters, press the reset button again to adjust the timer 1301 to minute-second-millisecond mode (i.e., "3" will be displayed on the far right of the screen). Since relays 1201 and timer 1301 have built-in memory functions, the desired mode only needs to be adjusted before the first use. The above steps only apply to the adjustment of the YF-7 two-channel relay 1201 delay module and the JDM11-6T accumulator timer 1301. In P-12 mode, after receiving the first command signal from the laser sensing unit, the YF-7 two-channel relay 1201 can output a continuous high-level signal to maintain the timing of the JDM11-6T accumulator timer 1301 until the laser sensing unit issues the second command signal. The time displayed by the JDM11-6T accumulator timer 1301 at this time is the time it takes for the object under test to pass between the two laser sensors.

[0088] In some embodiments, during the experiment, the test pile foundation 801 is also equipped with a tilt sensor. When the experiment is conducted, weights are placed on the weight pan 601, and a horizontal tension is generated on the test pile foundation 801, which is perpendicular to the test fluid 802, through the stranded wire 701. When the test pile foundation 801 tilts during the increase of tension, the tilt sensor detects the tilt status and degree of tilt. The tilt sensor can achieve a very high level of accuracy, which is more accurate than visual observation for monitoring the state of the test pile foundation 801. In monitoring the test pile foundation 801, the tilt sensor can be installed on the top or side of the pile foundation to monitor the vertical tilt of the pile foundation in real time.

[0089] The embodiments described in this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided by the embodiments of this application. As those skilled in the art will know, with the evolution of technology and the emergence of new application scenarios, the technical solutions provided by the embodiments of this application are also applicable to similar technical problems.

[0090] Those skilled in the art will understand that the technical solutions shown in the figures do not constitute a limitation on the embodiments of this application, and may include more or fewer steps than shown, or combine certain steps, or different steps.

[0091] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0092] Those skilled in the art will understand that all or some of the steps in the methods disclosed above, as well as the functional modules / units in the systems and devices, can be implemented as software, firmware, hardware, or suitable combinations thereof.

[0093] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0094] It should be understood that in this application, "at least one (item)" means one or more, and "more than" means two or more. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0095] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of the units described above is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0096] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0097] The preferred embodiments of the present application have been described above with reference to the accompanying drawings, but this does not limit the scope of the claims of the present application. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and substance of the embodiments of the present application shall be within the scope of the claims of the present application.

Claims

1. A testing device for simulating the inertial load of pile foundations in liquefied land, characterized in that, include: A first load-bearing frame, the first load-bearing frame including a first mounting layer, the first mounting layer being located above the first load-bearing frame; A central positioning frame is disposed on the first mounting layer; A pulley, which is fixedly connected to the center position of the central positioning frame; A weight pan, one end of which is connected to a stranded wire, is located below a pulley, and the other end of the stranded wire is connected to a test chamber via the pulley; The test chamber includes a chamber body, test fluid, and test pile foundation; The test fluid is loaded inside the chamber; The test pile foundation is vertically inserted into the test fluid, and the test pile foundation is higher than the box body; The stranded wire connects the portion of the test pile foundation that is higher than the box body; The loading device includes a second load-bearing frame, a first limiting frame, a second limiting frame, and a third limiting frame; The second load-bearing frame is disposed on the side of the first load-bearing frame; Both the first limiting frame and the second limiting frame are connected to the second load-bearing frame; The third limiting frame is connected to the first limiting frame and the second limiting frame respectively; The first load-bearing frame has a first slide rail on its vertical beam, and a first limiting and fixing device is provided inside the first slide rail. The two ends of the second load-bearing frame are respectively set inside the first slide rail. The first limiting and fixing device is used to fix the loading device in the position after the height adjustment. The second load-bearing frame is provided with a second slide rail, and a second limiting and fixing device is provided inside the second slide rail. One end of the first limiting frame and the second limiting frame are both provided inside the second slide rail. The second limiting and fixing device is used to fix the position of the first limiting frame and the second limiting frame inside the second slide rail. The first limiting frame and the second limiting frame are provided with a third slide rail, and a third limiting fixing device is provided in the third slide rail. The two ends of the third limiting frame are respectively disposed in the third slide rail, and the third limiting fixing device is used to fix the position of the third limiting frame in the third slide rail. The length of the third limiting frame can be adjusted according to the distance between the first limiting frame and the second limiting frame; The vertical beam of the first load-bearing frame is provided with a fourth slide rail, and a fourth limiting and fixing device is provided in the fourth slide rail. The four sides of the central positioning frame are arranged in the fourth slide rail, and the fourth limiting and fixing device is used to fix the height of the central positioning frame in the first load-bearing frame. By adjusting the height of the central positioning frame, the pulley fixed below the central positioning frame and the stranded wire connecting the test pile foundation are at the same height.

2. The testing device for simulating the inertial load of pile foundations in a liquefied site according to claim 1, characterized in that, The testing device for simulating the inertial load of pile foundations in a liquefaction site also includes a tension sensor. One end of the tensile sensor is connected to the weight pan via the stranded wire, and the other end of the tensile sensor is connected to the test chamber via the stranded wire; The tension sensor is located below the pulley.

Images