Testing device and viscosity metering device for simulating inertia load of pile foundation of liquefaction site

Abstract

The invention relates to the technical field of mechanical testing, in particular to a testing device for simulating the inertial load of a pile foundation of a liquefaction site and a viscosity metering device.The testing device comprises a first bearing frame and a second bearing frame, the first bearing frame comprises a first mounting layer, and the first mounting layer is located above the first bearing frame; the central positioning frame is arranged on the first mounting layer; the pulley is fixedly connected to the central position of the central positioning frame; the weight disc is connected with one end of a stranded wire and located below the pulley, and the other end of the stranded wire is connected with the test box through the pulley; the test box comprises a box body, test fluid and a test pile foundation; a test fluid is loaded in the box body; a test pile foundation is vertically inserted into the test fluid and is higher than the box body; the stranded wire is connected with the part of the test pile foundation higher than the box body. The inertial load can be accurately obtained, and the test cost is reduced.

Description

Technical Field

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

[0002] In today's engineering field, whether it is a skyscraper or a bridge, the stability and safety of the structure are always the top priority. Factors such as earthquakes, strong winds or mechanical vibrations make it inevitable for the structure to bear inertial loads. The impact of the pile foundation on the liquefied site under the action of inertial loads is used to infer the impact of inertial loads on the buckling load in order to analyze the stability and safety of the structure. In the prior art, it is a common technical means to simulate the liquefied site by saturated sand and apply dynamic loads through equipment such as a vibration table to achieve the liquefaction effect, but it is costly and difficult to achieve the test effect to obtain accurate inertial loads.

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

[0004] The main purpose of the embodiments of the present application is to provide 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 the testing cost.

[0005] To achieve the above-mentioned purpose, one aspect of an embodiment of the present application provides a testing device for simulating the inertial load of a pile foundation of a liquefied site, comprising:

[0006] A first load-bearing frame, the first load-bearing frame comprising a first installation layer, and the first installation layer is located above the first load-bearing frame;

[0007] A center positioning frame, the center positioning frame is arranged on the first mounting layer;

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

[0009] A weight plate, the weight plate is connected to one end of the stranded wire, the weight plate is located below the pulley, and the other end of the stranded wire is connected to the test box through the pulley;

[0010] The test box comprises a box body, a test fluid and a test pile foundation;

[0011] The test fluid is loaded in the box;

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

[0013] The stranded wires connect the portion of the test pile foundation that is higher than the box.

[0014] In some embodiments, the test device for simulating the inertial load of pile foundation of liquefied site is further provided with a loading device, and the loading device 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 arranged on a side of the first load-bearing frame;

[0016] The first limiting frame and the second limiting frame are both 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, a first position-limiting fixing device is provided in the first slide rail, two ends of the second load-bearing frame are respectively arranged in the first slide rail, and the first position-limiting fixing device is used to fix the loading device in the position after the height is adjusted;

[0019] The second load-bearing frame is provided with a second slide rail, the second slide rail is provided with a second limit fixing device, one end of the first limit frame and the second limit frame are both arranged in the second slide rail, and the second limit fixing device is used to fix the positions of the first limit frame and the second limit frame in the second slide rail;

[0020] The first limiting frame and the second limiting frame are provided with a third slide rail, the third slide rail is provided with a third limiting fixing device, both ends of the third limiting frame are respectively arranged 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 telescoping 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, a fourth position-limiting fixture 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 position-limiting fixture is used to fix the height of the central positioning frame in the first support frame;

[0023] The height of the central positioning frame is adjusted so that the pulley fixed below the central positioning frame and the stranded wire connected to 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 liquefied sites further comprises a tension sensor;

[0025] One end of the tension sensor is connected to the weight plate through the twisted wire, and the other end of the tension sensor is connected to the test box through the twisted wire;

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

[0027] To achieve the above object, another aspect of the embodiment of the present application provides a viscosity metering device, which is used to test the test fluid in the test device for simulating the inertial load of pile foundation of liquefied site described in the above embodiment; the viscosity metering device includes:

[0028] a measuring cylinder, the measuring cylinder being used to hold the test fluid;

[0029] A laser sensing unit, the laser sensing unit comprising 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 two sides of the measuring cylinder and have 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, wherein the relay is respectively connected to the first laser emitter, the first laser sensor, the second laser emitter, and the second laser sensor;

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

[0034] A test ball having a density greater than the test fluid and a diameter less than the diameter of the graduated cylinder.

[0035] In some embodiments, the viscosity metering device further comprises 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 fixing bracket and the second fixing bracket and the connection heights are consistent;

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

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

[0041] The positioning holes are both arranged on the first fixing bracket and the second fixing bracket;

[0042] There are a plurality of positioning holes on the first fixing bracket and the second fixing bracket, respectively, and the corresponding positioning holes on the first fixing bracket and the second fixing bracket are of the same height;

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

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

[0045] When the laser sensor unit, the relay and the timer are started and the metal ball is placed in the measuring cylinder loaded with the test fluid, the laser sensor unit is used to obtain the movement speed of the metal ball, and the movement speed is used to guide the process of drawing 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, represents the shear strain rate of the test fluid; r represents the radius of the test ball; v represents the movement speed of the test ball; η represents the viscosity of the test fluid; ρ represents the density of the test ball; ρ0 represents the density of the test fluid; and g represents the acceleration of gravity.

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

[0050] The present application provides a test device and viscosity metering device for simulating the inertial load of pile foundations in liquefaction sites. The solution adds weights to the weight plate, converts the weight of the weights into the tension of the stranded wire, pulls the test pile foundation connected to the other end of the stranded wire, and applies lateral concentrated force to the test pile foundation. The lateral concentrated force is used to replace the inertial load, and then the influence of the inertial load on the critical buckling load of the pile foundation in the liquefaction site is judged. Compared with the existing technology, the structure of the test device is simplified, the accuracy and repeatability of the test results are improved, the test cycle time is compressed, the test efficiency is greatly improved, and the test cost is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 It is a schematic diagram of a load-bearing limit frame of a test device for simulating the inertial load of a pile foundation of a liquefied site provided in an embodiment of the present application;

[0052] Figure 2 It is a schematic diagram of a stranded wire fixing device of a test device for simulating the inertial load of a pile foundation in a liquefied site provided in an embodiment of the present application;

[0053] Figure 3 It is a schematic diagram of a test box of a test device for simulating the inertial load of pile foundation in a liquefied site provided in an embodiment of the present application;

[0054] Figure 4 It is a structural schematic diagram of a viscosity metering device for simulating the inertial load of pile foundation in a liquefied site provided in an embodiment of the present 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 the present application;

[0056] Figure 6 It is a relay schematic diagram of a viscosity metering device for simulating the inertial load of pile foundation of a liquefied site provided in an embodiment of the present application;

[0057] Figure 7 It is a schematic diagram of the viscosity-shear strain rate curve comparison. DETAILED DESCRIPTION

[0058] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is further described in detail below in conjunction with the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. When the following description refers to the 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 the embodiments of the present application, they are only examples of devices and methods consistent with some aspects of the embodiments of the present application.

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

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

[0061] In the description of this application, 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.

[0062] In the description of this application, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

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

[0064] Reference Figure 1 , Figure 2 and Figure 3 As shown, an embodiment of the present invention provides a test device for simulating the inertial load of a pile foundation of a liquefied site, including: a first load-bearing frame 101, a center positioning frame 201, a pulley 401, a weight plate 601, a box 803, a test pile foundation 801, a stranded wire 701 and a test fluid 802. Among them, the first load-bearing frame 101 includes a first installation layer, and the first installation layer is located above the first load-bearing frame 101; the center positioning frame 201 is arranged on the first installation layer; the pulley 401 is fixedly connected to the bottom of the center positioning frame 201, and at the virtual positioning line 202 of the center position of the center positioning frame 201, that is, the center position below the center positioning frame 201; the weight plate 601 is connected to one end of the stranded wire 701, the weight plate 601 is located below the pulley 401, and the other end of the stranded wire 701 is connected to the test box through the pulley 401; the test box includes a box body 803, a test fluid 802 and a test pile foundation 801, and the test fluid 802 is loaded in the box body 803; the test pile foundation 801 is vertically inserted into the test fluid 802, and the test pile foundation 801 is higher than the box body 803; the stranded wire 701 connects the part of the test pile foundation 801 that is higher than the box body 803.

[0065] In this embodiment, the test fluid 802 is used to simulate the liquefied site, and the inertial load applied to the pile foundation is simulated by applying lateral tension to the test pile foundation 801 through the stranded wire 701. Specifically, by placing a fixed weight on the weight plate 601, since one end of the stranded wire 701 is connected to the weight plate 601, the gravity of the weight is converted into a tension on the stranded wire 701, and the direction of the stranded wire 701 is changed by the pulley 401 on the weight plate 601, thereby changing the direction of the tension; the other end of the stranded wire 701 is connected to the test pile foundation 801, and the part of the test pile foundation 801 that is higher than the box 803 is connected. The connection height of the stranded wire 701 and the test pile foundation 801 is consistent with the height of the pulley 401, so that the tension applied by the stranded wire 701 to the connection with the test pile foundation 801 is in the horizontal direction; in the test box, since the test fluid 802 has resistance, the test pile foundation 801 is vertical. Inserted into the test fluid 802, when the stranded wire 701 gives a horizontal pulling force to the connection of the test pile foundation 801, it is easy to make the test pile foundation 801 tilt. At the same time, due to the influence of the test fluid 802, the test pile foundation 801 will be given a corresponding resistance to reduce the tilt degree of the test pile foundation 801; when the weight of the weight is small, the pulling force generated will also be relatively small. When the horizontal pulling force on the test pile foundation 801 is less than or equal to the resistance of the test fluid 802 to the test pile foundation 801, the test pile foundation 801 will not tilt. When the horizontal pulling force converted by the larger weight is greater than the resistance of the test fluid 802 to the test pile foundation 801, the test pile foundation 801 tilts, and the weight of the weight when the tilt occurs is recorded. By applying a pulling force to the test pile foundation 801 laterally, the effect of the inertial load is equivalently replaced, that is, the conversion of the weight of the weight at this time is the inertial load corresponding to the test pile foundation 801. Among them, the lateral pulling force can also be called lateral concentrated force.

[0066] In some embodiments, Figure 1 As shown, in order to better fix the test box, the test device for simulating the inertial load of the pile foundation of the liquefied site is also provided with a loading device, which 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 arranged on the side of the first load-bearing frame 101, the first load-bearing frame 101 is composed of vertical beams, and 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, and the second load-bearing frame 102 is embedded in the side of the first load-bearing frame 101. The weight frame 102 is used to bear the weight of the loading device; the first limiting frame 301 and the second limiting frame 302 are both connected to the second load-bearing frame 102, the first limiting frame 301 and the second limiting frame 302 are both placed vertically and connected to the second load-bearing frame 102 on the side, and the first limiting frame 301 and the second limiting frame 302 are used to limit and fix the front and back sides of the test box; the third limiting frame 303 is respectively connected to the first limiting frame 301 and the second limiting frame 302, and there can be multiple third limiting frames 303, for example, Figure 1As shown, there are three third limiting frames 303; the two sides of the third limiting frames 303 are respectively connected to the first limiting frame 301 and the second limiting frame 302, the third limiting frame 303 close to the second load-bearing frame 102 is used to limit and fix the left side of the test box, and the third limiting frame 303 farther away from the second load-bearing frame 102 than the other third limiting frames 303 is used to limit and fix the right side of the test box.

[0067] In this embodiment, when the test device simulating the inertial load of the pile foundation of the liquefied field is tested, the second load-bearing frame 102 bears the weight of the loading device, and the test box is placed on the ground or on the test bench table. 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 box, and the third limiting frame 303 limits and fixes the left and right sides of the test box. Specifically, the loading device should be fixed around the box body 803 corresponding to the part of the test box filled with the test fluid 802 to ensure the stability of the center of gravity of the test box. It can be understood that when the test device is tested, the stress load of the test pile foundation 801 in the test fluid 802 is mainly measured. If the test box is affected by a large force and causes the test box to move or shake, it will affect the inaccuracy of the test data and cause the test failure. In order to avoid the influence of the test box during the test, the loading device is set to limit and fix the test box, which undoubtedly overcomes the influence of the movement or shaking of the test box during the test.

[0068] In some embodiments, in order to cope with test boxes 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, a first limit fixing device (not shown in the figure) is provided in the first slide rail, and both ends of the second load-bearing frame are respectively provided in the first slide rail; the first slide rail and the first limit fixing device are used to adjust the upper and lower heights of the loading device according to the height of the test box and fix it. When the test box is placed on the ground or on the table of the test bench, due to the non-fixed height of the test box, and the loading device must be fixed to the periphery of the box body 803 corresponding to the part of the test box containing the test fluid 802 in order to stabilize the center of gravity of the test box, the overall height of the loading device needs to be adjusted; the second load-bearing frame 102 is provided with a first slide rail so that the loading device can be moved up and down, and the first limit fixing device can be provided to fix the height when it moves to an appropriate height, so as to avoid the loading device falling off due to external force during the test and affecting the test process.

[0069] A second slide rail (not shown in the figure) is provided on the second load-bearing frame 102, and a second limit fixing device (not shown in the figure) is provided in the second slide rail, and one end of the first limit frame 301 and the second limit frame 302 are both arranged in the second slide rail; the second slide rail and the second limit fixing device are used to adjust the loading width of the loading device according to the width of the test box. Specifically, at least two second slide rails are transversely connected to the upper and lower sides of the second load-bearing frame 102, and the second limit fixing device is connected in the second slide rail. According to the width of the test box, the spacing between the first limit frame 301 and the second limit frame 302 is determined by moving and adjusting the second slide rail. When the spacing between the first limit frame 301 and the second limit frame 302 is determined, the spacing is fixed by the second limit fixing device to avoid the expansion of the spacing between the first limit frame 301 and the second limit frame 302 due to the influence of the slide rail during the test, and the test box cannot be limited and fixed.

[0070] The first limiting frame 301 and the second limiting frame 302 are provided with a third slide rail (not shown in the figure), and a third limiting fixture (not shown in the figure) is provided in the third slide rail. The two ends of the third limiting frame 303 are respectively provided in the third slide rail; the third slide rail and the third limiting fixture are used to adjust the loading length of the loading device according to the length of the test box and fix it, so as to prevent the box body 803 from shaking due to the tension of the stranded wire 701. Influenced by test boxes of different specifications, in order to adapt to the lengths of different test boxes, the third limiting frame 303 is provided between the first limiting frame 301 and the second limiting frame 302. According to the length of the test box, the distance between the third limiting frame 303 close to the second load-bearing frame 102 and the third limiting frame 303 far from the second load-bearing frame 102 is adjusted by the third slide rail. After determining the distance, the third limiting fixture is used to limit and fix it, so as to prevent the box body 803 from shaking due to the force of the test box during the test. Specifically, the third slide rail can make the third limit frame 303 move left and right, and the third slide rail can be multiple according to the number of the third limit frames 303. Since the test box is subjected to lateral pulling force, the third limit frame 303 close to the second load-bearing frame 102 is subjected to greater force than the first limit frame 301 and the second limit frame 302. In order to avoid direct contact between the test box and the second load-bearing frame 102, causing damage to the box body 803 or shaking of the test box affecting the test data, the third limit frame 303 is set between the test box and the second load-bearing frame 102. The length of the third limit frame 303 can be extended or retracted according to the distance between the first limit frame 301 and the second limit frame 302. In order to avoid the third limit frame 303 falling off or shortening due to the change in the distance between the first limit frame 301 and the second limit frame 302 when subjected to force, the length of the third limit frame 303 is determined and fixed when the distance between the first limit frame 301 and the second limit frame 302 is determined. The connection between the third limit frame 303 and the first limit frame 301 and the second limit frame 302 can be detachable. When the distance tends to increase or decrease, it is limited by the change in the fixed distance of the length of the third limit frame 303, thereby controlling the distance between the first limit frame 301 and the second limit 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 fixture (not shown in the figure) is provided in the fourth slide rail, and the four sides of the center positioning frame 201 are arranged in the fourth slide rail; the fourth slide rail and the fourth limiting fixture are used to adjust the height of the center positioning frame 201, so as to control the pulley 401 and the stranded wire 701 fixed under the center positioning frame 201 to be connected to the test pile foundation 801 at the same height, so as to ensure that the pulling force on the test pile foundation 801 is in the horizontal direction. Specifically, when conducting a test to simulate the inertial load of the pile foundation of a liquefied site, it is necessary to apply a horizontal force to the connection of the test pile foundation 801 to simulate the inertial load. In order to ensure that the direction of the force is horizontal, it is necessary to control the connection between the pulley 401 and the stranded wire 701 and the test pile foundation 801 to remain horizontal; due to the different specifications of the test boxes, the height of the pulley 401 is controlled by controlling the height of the center positioning frame 201, thereby controlling the height of the pulley 401, which is more convenient to control the relative height of the connection with the test pile foundation 801. When the height of the pulley 401 is the same as the height of the connection between the test pile foundation 801 and the stranded wire 701, the height of the center positioning frame 201 is fixed by the fourth limit fixing device to ensure the stability of the height of the pulley 401 during the test.

[0072] In some embodiments, the test device for simulating the inertial load of the pile foundation of the liquefied site further includes a tension sensor 501; one end of the tension sensor 501 is connected to the weight plate 601 through a stranded wire 701, and the other end of the tension sensor 501 is connected to the test box through a stranded wire 701; the tension sensor 501 is located below the pulley 401. It can be understood that the tension sensor 501 is connected between the pulley 401 and the weight plate 601 through the stranded wire 701. The traditional method is to determine the magnitude of the tension by calculating the weight of the weight. After adding the tension sensor 501, the real-time tension can be determined more accurately, thereby determining the specific value of the inertial load, thereby improving the accuracy and efficiency of the test process.

[0073] In some embodiments, a scratch-proof ring is provided at the junction of the strand 701 and the frame of the center positioning frame 201, and the scratch-proof ring is fixedly connected to the center positioning frame 201. The upper and lower sides of the inside of the scratch-proof ring are respectively fixedly connected to the first fixed pulley and the second fixed pulley, and the strand 701 passes through the gap between the first fixed pulley and the second fixed pulley and is connected to the test box. When the weight plate 601 is placed with weights to generate tension on the strand 701, if the height of the pulley 401 is lower than the connection between the strand 701 and the test pile foundation 801 due to the error of the test personnel, the strand 701 will rub against the frame of the center positioning frame 201 to form friction, which will indirectly affect the tension value and cause inaccurate test data. The anti-scratch ring strand 701 is arranged to pass through the gap between the first fixed pulley and the second fixed pulley inside the anti-scratch ring. Even if the pulley 401 at the center position of the center positioning frame 201 is higher or lower than the position of the connection between the strand 701 and the test pile foundation 801, the strand 701 will contact the first fixed pulley and the second fixed pulley inside the anti-scratch ring. When the strand 701 contacts the first fixed pulley and the second fixed pulley inside the anti-scratch ring, the first fixed pulley and the second fixed pulley arranged inside the anti-scratch ring will rotate with the movement of the strand 701, and will not cause additional friction to affect the test data. At the same time, the anti-scratch ring also has a certain guiding effect on the strand 701.

[0074] In some embodiments, in order to complete the test of the pile foundation inertia load of the simulated liquefied site, the test fluid 802 needs to be loaded in the test box. In order to ensure the effectiveness of the test, saturated sand is often used to replace the test fluid 802 in traditional tests, but it takes a long time for the sand to reach a saturated state through the water sinking method. In the process of preparing saturated sand, water flow or stirring and other operations will introduce voids and bubbles to the sand, affecting the saturation and consistency of the sand, thereby affecting the accuracy and repeatability of the test results. The water quality and environmental requirements in the process of preparing saturated sand by the water sinking method are also high, and there must be no impurities and chemical components. At the same time, the operating environment must also be kept clean and stable. Based on the above disadvantages of saturated sand, non-Newtonian fluids are used to replace saturated sand to avoid the above disadvantages. However, there are many types of non-Newtonian fluids, and it is necessary to find the requirements of the test fluid 802 in the test device for simulating the inertial load of the pile foundation of the liquefied site through the test of the viscosity measuring device, so that it can be used for the test fluid in the test device for simulating the inertial load of the pile foundation of the liquefied site.

[0075] In some embodiments, Figure 4 and Figure 5As shown, a viscosity metering device is used to test the test fluid 802 in the test device for simulating the inertial load of the pile foundation of the liquefied site. The fluid tested by the viscosity metering device can be used as the test fluid in the test device for simulating the inertial load of the pile foundation of the liquefied site only after it meets the requirements; the viscosity metering device includes: a measuring cylinder 1001, a laser sensor 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 sensor 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 sensor unit 2 are respectively fixed on both sides of the measuring cylinder 1001 and have the same height; the second laser emitter 903 and the second laser sensor 904 are also respectively fixed on both sides of the measuring cylinder 1001 and have the same height, and are located below the first laser emitter 901 and the first laser sensor 902; the relay 1201 is respectively connected to the first laser emitter 901, the first laser sensor 902, the second laser emitter 903 and the second laser sensor 904; 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 the test fluid 802 to ensure that the test ball can fall in 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, which form a group and can receive the laser of the laser emitter at the same height. The measuring cylinder 1001 is arranged in two groups, upper and lower, and are located below the liquid level of the test fluid 802 in the measuring cylinder 1001. The height difference between the two groups is sufficient for the test ball to fall a certain distance completely within the height.

[0076] When the viscosity metering device is measuring, the non-Newtonian fluid to be measured is poured into the measuring cylinder 1001. Because it is detected 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 5CM higher than the highest laser sensor unit. The power is turned on to connect the relay 1201, the timer 1301 and the laser sensor unit. The test ball is put into the measuring cylinder 1001 and the test ball falls slowly. When it reaches the first laser emitter 901 and the first laser sensor 902, it blocks the laser so that the first laser sensor 902 cannot receive the laser. The timer 1301 starts timing and 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 to obtain the falling time of the test ball in a fixed distance, and the falling speed of the test ball can be further calculated.

[0077] In some embodiments, Figure 4 As shown, the viscosity metering device further 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 the connection height is consistent; 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 connection height of the first laser emitter 901 and the first laser sensor 902 is consistent and located below the first laser emitter 901 and the first laser sensor 902. It can be understood that directly fixing the laser sensor unit at the measuring cylinder 1001 is likely to cause the laser emitter or laser sensor to fall off or the laser is difficult to align, so the test bracket 1101 is provided to fix the laser sensor unit.

[0078] In some embodiments, the test bracket 1101 is also provided with positioning holes; the positioning holes are both 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 sensor unit. It can be understood that holes of the same height are provided on the first fixed bracket and the second fixed bracket respectively, and 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 to control the spacing 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 enough falling distance to ensure the effectiveness of the test.

[0079] In some embodiments, the test ball includes a metal ball; when the laser sensor unit, the relay 1201 and the timer 1301 are activated and the metal ball is placed in the measuring cylinder 1001 loaded with the test fluid 802, the laser sensor unit is used to obtain the movement speed of the metal ball, and the movement speed is used to guide the process of drawing the viscosity-shear strain rate curve of the test fluid 802. It can be understood that the metal ball has a higher density than other materials and is more suitable for viscosity measurement tests.

[0080] In some embodiments, preferably, an aluminum ball can be selected as the test ball, because the density of metal aluminum is generally higher than that of non-Newtonian fluids, and metal aluminum material is not easy to chemically react with other materials, and has high stability, which is convenient for application in viscosity measurement tests.

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

[0082]

[0083] in, represents the shear strain rate of the test fluid 802; r represents the radius of the test ball; v represents the movement speed of the test ball; η represents the viscosity of the test fluid 802; ρ represents the density of the test ball; ρ0 represents the density of the test fluid 802; and g represents the acceleration of gravity.

[0084] Specifically, before the viscosity measurement test is performed, the radius of the test ball, the 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 by a solid density meter, and the density of the test fluid 802 can be measured by a hydrometer. When the viscosity measurement test is performed, the movement time of the test ball within a fixed distance is obtained by a timer 1301, so that the movement speed of the test ball can be calculated. The above data is substituted into formula (1) to obtain the shear strain rate of the test fluid 802, and the above data is substituted into formula (2) to obtain the viscosity of the test fluid 802. According to 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 sensor unit, the non-Newtonian fluid includes a polyisobutylene-white oil solution. Figure 7 The figure shows the viscosity-shear strain rate curve comparison of 47% saturated Nanjing sand and 25% polyisobutylene-white oil solution. It can be seen from the figure that the viscosity-shear strain rate curves of 47% saturated Nanjing sand and 25% polyisobutylene-white oil solution are measured under the same environment, and the viscosity-shear strain rate curves of the two substances are the closest. Polyisobutylene-white oil solution is a colorless non-Newtonian fluid with a high molecular weight that increases the viscosity of the solution and has good chemical stability. It is very suitable to replace saturated sand as the test fluid 802 in the test device for simulating the inertial load of pile foundations in liquefied sites.

[0086] In some embodiments, Figure 5 As shown, the laser sensor unit can be connected to the relay 1201, the timer 1301 and the power supply through Figure 5 Make connections as shown in the circuit diagram.

[0087] In some embodiments, Figure 5 and Figure 6As shown, the relay 1201 can be YF-7 two-way relay 1201, and the timer 1301 can be JDM11-6T cumulative timer 1301. After ensuring that the circuit connection is correct, adjust the switch power supply to output 12V. The setting method of relay 1201 is as follows: long press the K1 button on the relay 1201 for more than 1 second, and then "P-11" will appear on the screen. By short pressing the K2 and K3 buttons, the relay 1201 is adjusted to the P-12 mode, and then short press the K1 button 3 times, and wait until the screen displays "----". The setting method of timer 1301 is as follows: when the power is off, long press the reset button of timer 1301 and hold it, and at the same time turn on the power of timer 1301. When the letters are displayed on the screen of timer 1301, press the reset button again to adjust timer 1301 to minute-second-millisecond mode (that is, "3" is displayed on the far right of the screen). Since the relay 1201 and the timer 1301 have their own memory function, it is only necessary to adjust the required mode before the first use. The above steps are only for the adjustment and use of the YF-7 two-way relay 1201 delay module and the JDM11-6T cumulative timer 1301. After receiving the first command signal from the laser sensor unit, the YF-7 two-way relay 1201 in the P-12 mode can output a continuous high-level signal to maintain the timing of the JDM11-6T cumulative timer 1301 until the laser sensor unit sends the second command signal. The time displayed by the JDM11-6T cumulative timer 1301 at this time is the time taken for the object to be measured to pass between the two laser sensors.

[0088] In some embodiments, during the experiment, the test pile foundation 801 is also provided with a tilt sensor. When the test is carried out, weights are placed on the weight plate 601, and horizontal tension is generated on the test pile foundation 801 vertically in the test fluid 802 through the twisted wire 701. When the test pile foundation 801 tilts during the process of increasing the tension, the tilt sensor is used to detect the tilt state and tilt degree. The accuracy of the tilt sensor can reach a very high level, and the state monitoring of the test pile foundation 801 is more accurate than naked eye observation. In the monitoring of the test pile foundation 801, the tilt sensor can be installed on the top or side of the pile foundation to monitor the tilt of the pile foundation in the vertical direction in real time.

[0089] The embodiments described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application and do not constitute a limitation on the technical solutions provided in the embodiments of the present application. Those skilled in the art will appreciate that with the evolution of technology and the emergence of new application scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

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

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

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

[0093] The terms "first", "second", "third", "fourth", etc. (if any) in the specification of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0094] It should be understood that in the present application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the objects associated before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0095] In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the above units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

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

[0097] The preferred embodiments of the present invention are described above with reference to the accompanying drawings, but the scope of the rights of the present invention is not limited thereto. Any modification, equivalent substitution and improvement made by a person skilled in the art without departing from the scope and essence of the present invention should be within the scope of the rights of the present invention.

Claims

1. A test device for simulating the inertial load of pile foundation in liquefied sites, characterized in that: include: A first load-bearing frame, the first load-bearing frame comprising a first installation layer, and the first installation layer is located above the first load-bearing frame; A center positioning frame, the center positioning frame is arranged on the first mounting layer; A pulley, the pulley is fixedly connected to the center position of the central positioning frame; A weight plate, the weight plate is connected to one end of the stranded wire, the weight plate is located below the pulley, and the other end of the stranded wire is connected to the test box through the pulley; The test box comprises a box body, a test fluid and a test pile foundation; The test fluid is loaded in the box; The test pile foundation is vertically inserted into the test fluid, and the test pile foundation is higher than the box; The stranded wires connect the portion of the test pile foundation that is higher than the box.

2. The testing device for simulating the inertial load of pile foundation in liquefied sites according to claim 1, characterized in that: The test device for simulating the inertial load of pile foundation of liquefied site is also provided with a loading device, and 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 arranged on a side of the first load-bearing frame; The first limiting frame and the second limiting frame are both connected to the second load-bearing frame; The third limiting frame is connected to the first limiting frame and the second limiting frame respectively.

3. The testing device for simulating the inertial load of pile foundation in liquefied sites according to claim 2, characterized in that: A first slide rail is provided on the vertical beam of the first load-bearing frame, a first position-limiting fixing device is provided in the first slide rail, two ends of the second load-bearing frame are respectively arranged in the first slide rail, and the first position-limiting fixing device is used to fix the loading device in the position after the height is adjusted; The second load-bearing frame is provided with a second slide rail, the second slide rail is provided with a second limit fixing device, one end of the first limit frame and the second limit frame are both arranged in the second slide rail, and the second limit fixing device is used to fix the positions of the first limit frame and the second limit frame in the second slide rail; The first limiting frame and the second limiting frame are provided with a third slide rail, the third slide rail is provided with a third limiting fixing device, both ends of the third limiting frame are respectively arranged 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 by telescoping according to the distance between the first limiting frame and the second limiting frame.

4. The testing device for simulating the inertial load of pile foundation in liquefied sites according to claim 1, characterized in that: The vertical beam of the first support frame is provided with a fourth slide rail, and a fourth limit 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 limit fixing device is used to fix the height of the central positioning frame in the first support frame; The height of the central positioning frame is adjusted so that the pulley fixed below the central positioning frame and the stranded wire connected to the test pile foundation are at the same height.

5. The testing device for simulating the inertial load of pile foundation in liquefied sites according to claim 1, characterized in that: The testing device for simulating the inertial load of pile foundation in liquefied site also includes a tension sensor; One end of the tension sensor is connected to the weight plate through the twisted wire, and the other end of the tension sensor is connected to the test box through the twisted wire; The tension sensor is located below the pulley.

6. A viscosity measuring device, characterized in that: The viscosity metering device is used to test the test fluid in the test device for simulating the inertial load of pile foundation of liquefied site according to any one of claims 1 to 5; the viscosity metering device comprises: a measuring cylinder, the measuring cylinder being used to hold the test fluid; A laser sensing unit, the laser sensing unit comprising a first laser emitter, a first laser sensor, a second laser emitter and a second laser sensor, wherein: The first laser emitter and the first laser sensor are respectively fixed on two sides of the measuring cylinder and have the same height; 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; a relay, wherein the relay is respectively connected to the first laser emitter, the first laser sensor, the second laser emitter, and the second laser sensor; A timer, wherein the timer is connected to the relay; A test ball having a density greater than the test fluid and a diameter less than the diameter of the graduated cylinder.

7. A viscosity measuring device according to claim 6, characterized in that: The viscosity metering device also includes a test bracket; The test bracket 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; The first laser emitter and the first laser sensor are respectively connected to the first fixing bracket and the second fixing bracket and the connection heights are consistent; The second laser emitter and the second laser sensor are connected to the first fixed bracket and the second fixed bracket respectively, and the connection height of the first laser emitter and the first laser sensor is consistent and located below the first laser emitter and the first laser sensor.

8. A viscosity measuring device according to claim 7, characterized in that: The test bracket is also provided with a positioning hole; The positioning holes are both arranged on the first fixing bracket and the second fixing bracket; There are a plurality of positioning holes on the first fixing bracket and the second fixing bracket, respectively, and the corresponding positioning holes on the first fixing bracket and the second fixing bracket are of the same height; The positioning hole is used to fix the laser sensor unit.

9. A viscosity measuring device according to claim 6, characterized in that: The test ball comprises a metal ball; When the laser sensor unit, the relay and the timer are started and the metal ball is placed in the measuring cylinder loaded with the test fluid, the laser sensor unit is used to obtain the movement speed of the metal ball, and the movement speed is used to guide the process of drawing the viscosity-shear strain rate curve of the test fluid.

10. A viscosity measuring device according to claim 9, characterized in that: The calculation formula corresponding to the viscosity-shear strain rate curve is: in, represents the shear strain rate of the test fluid; r represents the radius of the test ball; v represents the movement speed of the test ball; η represents the viscosity of the test fluid; ρ represents the density of the test ball; ρ0 represents the density of the test fluid; and g represents the acceleration of gravity.

Images