Spiral plate load test device and method

Abstract

The invention discloses a spiral plate load test device and method, and belongs to the technical field of geological prospecting, and the device comprises a spiral plate head, a dowel bar, a pressure sensor, a displacement sensor, a self-drilling spinning device, a counterforce assembly and an intelligent analysis platform, the intelligent analysis platform controls a telescopic arm of the self-drilling spinning device to move along a shaft and rotate around the shaft to provide power for the dowel bar, the pressure sensor and the spiral plate head, and the telescopic arm is detachably connected with the dowel bar by arranging a clamping device at the bottom of the telescopic arm. The telescopic arm drives the dowel bar, the pressure sensor and the spiral plate head to be screwed downwards together in the multiple reciprocating movement processes, and the spiral plate head can be fed into a deep soil layer. In the load test process, the hydraulic cavity of the self-drilling spinning device can realize graded loading or unloading of the spiral plate head, so that the pressure sensor and the displacement sensor respectively acquire pressure data and displacement data of the plate head in real time and transmit the pressure data and the displacement data to the intelligent analysis platform.

Description

Technical Field

[0001] The invention belongs to the technical field of geological exploration, and in particular relates to a spiral plate load test device and method. Background Art

[0002] In-situ testing is one of the most effective methods to accurately obtain the physical and mechanical properties of rock and soil, and it has significant advantages over indoor tests, model tests, numerical analysis and other means.

[0003] Load testing is the most classic and intuitive in-situ testing method for reflecting the deformation patterns of rock and soil. It includes flat plate load testing and spiral plate load testing. For undisturbed soil, the maximum test depth for flat plate load testing is generally about 5m, and for spiral plate load testing, about 10m. Conventional load testing is generally difficult to conduct in-situ testing of deep soil layers (20m and above). Furthermore, conducting load tests on deeper soil layers often requires equipment such as excavators and drills, which is extremely expensive and significantly restricts the widespread application of load testing in geotechnical engineering. Increasing the test depth of load tests and achieving continuous testing within the soil layer are key issues in promoting the application of load testing in deep geotechnical engineering investigations. Summary of the Invention

[0004] In response to one or more of the above-mentioned defects or improvement needs in the prior art, the present invention provides a spiral plate load testing device and method, which realizes the automatic penetration of the spiral plate load test, solves the problem that traditional load tests are unable to carry out deep load tests due to factors such as the influence of the stratum and insufficient manual drilling capacity, greatly improves the test depth and engineering survey depth of the spiral plate load test, and is suitable for in-situ testing and investigation of deep soil.

[0005] To achieve the above-mentioned object, the present invention provides a spiral plate load test device, which includes a spiral plate head, a force transmission rod, a pressure sensor, a displacement sensor, a self-drilling spinner, a reaction force component and an intelligent analysis platform; The self-drilling spinner includes a first cylinder and a second cylinder arranged coaxially, the first cylinder being provided with a first channel for accommodating the force transmission rod, a second channel being formed between the first cylinder and the second cylinder, a telescopic arm being provided in the second channel and being movable in the axial direction and rotatable about the axis, a clamp being provided at the bottom of the telescopic arm and being capable of clamping or releasing the force transmission rod, and a hydraulic chamber being formed by the top surface of the telescopic arm and the second channel, and a hydraulic sensor being provided corresponding to the hydraulic chamber; The reaction force assembly is fixedly mounted on the ground and is used to fix the self-drilling spinner during the test; The pressure sensor is arranged between the force transmission rod and the spiral plate head, and is used to measure the pressure exerted on the spiral plate head during the test; the displacement sensor is arranged at the bottom of the second cylinder, and is used to measure the vertical displacement of the telescopic arm during the test; The intelligent analysis platform is respectively connected to the hydraulic sensor, the pressure sensor and the displacement sensor signals, and is used to receive the oil pressure data of the hydraulic chamber, the plate head pressure data and the displacement data during the test in real time, and control the oil pressure in the hydraulic chamber according to the oil pressure data to make the telescopic arm move back and forth along the axial direction; and the intelligent analysis platform is also wirelessly connected to the rotation drive device of the telescopic arm, and is used to control the rotation of the telescopic arm around the axis.

[0006] As a further improvement of the present invention, the displacement sensor is a wire-type displacement sensor; a limiter is provided on a side of the clamp away from the force transmission rod, and one end of the limiter extends out of the outer side wall of the telescopic arm; The pull-wire displacement sensor and the limiter can be connected via a pull-wire extending vertically, so that the pull-wire displacement sensor can measure the vertical displacement of the telescopic arm during the test.

[0007] As a further improvement of the present invention, the pressure sensor is an electromagnetic pressure sensor, the spiral plate head is an electromagnetic spiral plate head, and an electromagnetic anchor is provided on the side of the pressure sensor facing the spiral plate head, which can adsorb the electromagnetic spiral plate head on the magnetic pressure sensor through electromagnetic action.

[0008] As a further improvement of the present invention, the force transmission rod includes one probe rod, or the force transmission rod includes multiple probe rods, and adjacent probe rods are correspondingly connected at the top and bottom.

[0009] As a further improvement of the present invention, a signal receiver is provided in the probe rod; a signal sensor is provided on the side of the pressure sensor facing the force transmission rod, which can convert the pressure signal collected by the pressure sensor into a digital signal and transmit it to the intelligent analysis platform through several of the signal receivers.

[0010] As a further improvement of the present invention, the length of the probe rod is 2 to 3 times the length of the telescopic arm.

[0011] As a further improvement of the present invention, a plurality of cross beams are radially spaced apart on the outer side wall of the second cylinder; The reaction force assembly includes a bidirectional telescopic rod and a balancing suspension beam. The bidirectional telescopic rod can connect the crossbeam with one end of the balancing suspension beam, and the other end of the balancing suspension beam is fixed to the ground through a threaded rod ground anchor.

[0012] As a further improvement of the present invention, four cross beams are provided at intervals and are arranged at 90 degrees along the radial direction of the second cylinder; and / or A variable speed rotating bearing is provided at one end of the balance suspension beam away from the cross beam, and the variable speed rotating bearing can drive the threaded rod ground anchor to rotate.

[0013] Another aspect of the present invention provides a spiral plate load test method, which is implemented using the above-mentioned spiral plate load test device and includes the following steps: (1) Preparation S101: Level the test site and mark the test hole location according to the test hole location and surrounding terrain features; S102: Centering and leveling the self-drilling spinner, fixing the reaction force assembly on the ground, and connecting the reaction force assembly to the self-drilling spinner; S103: Pass the dowel rod through the first channel of the self-drilling spinner and connect it to the pressure sensor and the spiral plate head in sequence. Debug the intelligent analysis platform and calibrate the pre-loaded spiral plate head to ensure that the data signal can be transmitted normally. S104: The clamper clamps the dowel rod, and the intelligent analysis platform controls the telescopic arm to slowly bring the spiral plate head into the soil at the set movement speed and rotation speed. When the telescopic arm moves downward to the maximum limit, the clamper releases the dowel rod, and the intelligent analysis platform controls the telescopic arm to move upward to the set position. The clamper clamps the dowel rod again, and the intelligent analysis platform further controls the telescopic arm to slowly bring the spiral plate head into the soil at the set movement speed and rotation speed. This cycle continues until the spiral plate head reaches the test soil layer point. (2) Load test S201: The displacement sensor and the pressure sensor are reset to zero and the test is started. The intelligent analysis platform controls the oil pressure in the hydraulic chamber to perform graded loading. The pressure sensor and the displacement sensor provide real-time feedback of the collected plate head pressure data and displacement data S. The intelligent analysis platform analyzes the collected plate head pressure data and displacement data and draws a QS curve. S202: After the loading test is completed, the intelligent analysis platform controls the oil pressure in the hydraulic chamber to perform graded unloading. The pressure sensor and displacement sensor provide real-time feedback of the collected plate head pressure data and displacement data. The intelligent analysis platform analyzes the collected plate head pressure data and displacement data, draws a QS curve, and outputs a test report after the unloading test is completed.

[0014] As a further improvement of the present invention, the spiral plate load test method further includes the following process: (3) Continuous load test S301: After completing the previous set of load tests, repeat step S104 and continue screwing the spiral plate head to the next test soil layer point of the test hole; S302: Repeat steps S201 to S202; S303: Determine whether the test soil layer point is the last test soil layer point of the test hole. If so, the continuous load test ends; if not, return to step S301.

[0015] The above-mentioned improved technical features can be combined with each other as long as they do not conflict with each other.

[0016] In general, the above technical solutions conceived by the present invention have the following beneficial effects compared with the prior art: (1) The spiral plate load test device of the present invention comprises a spiral plate head, a force transmission rod, a pressure sensor, a displacement sensor, a self-drilling spinner, a reaction force assembly and an intelligent analysis platform, wherein the reaction force assembly provides a test reaction force for the load test, and the intelligent analysis platform controls the telescopic arm of the self-drilling spinner to move axially and rotate around the axis to provide power for the force transmission rod, the pressure sensor and the spiral plate head; a clamp is provided at the bottom of the telescopic arm to provide a detachable connection between the telescopic arm and the force transmission rod, so that the telescopic arm can drive the force transmission rod, the pressure sensor and the spiral plate head to move together when rotating and pressing down. It rotates downward and then rises alone, and uses the clamp to re-clamp another part of the force transmission rod. The telescopic arm drives the force transmission rod, pressure sensor, and spiral plate head to rotate downward again. Through multiple back and forth movements of the telescopic arm, the force transmission rod, pressure sensor, and spiral plate head can be sent into a deeper soil layer. During the load test stage, the hydraulic chamber of the self-drilling spinner can also load or unload the spiral plate head in stages, so that the pressure sensor and displacement sensor can respectively collect the plate head pressure data and displacement data in real time and transmit them to the intelligent analysis platform, and finally form a test report on the intelligent analysis platform. The spiral plate load test device of the present invention realizes the automatic penetration of the spiral plate load test through the self-drilling spinner, which solves the problem that the traditional load test is affected by the formation and the lack of manual drilling capacity, which makes it impossible to carry out deep load tests. It greatly improves the test depth and engineering survey depth of the spiral plate load test, and is suitable for in-situ testing and investigation of deep soil.

[0017] (2) The spiral plate load test device of the present invention also improves the force mode of the force transmission rod in the traditional load test through the clamp, improves the overall stability of the structure, can greatly reduce the problem of eccentric pressure on the system, and improves the depth and accuracy of the spiral plate load test; through the integrated digital intelligent analysis platform, the automated operation of the spiral plate load test is realized, and the functions of automatic penetration, continuous testing, intelligent loading, unloading, digital collection, long-distance wireless transmission, intelligent analysis, etc. can be realized according to the operating instructions, which solves the problem that the traditional spiral plate load test is heavily dependent on manual operation, greatly improves the efficiency of the spiral plate load test, and reduces the test cost.

[0018] (3) The spiral plate load test device of the present invention is configured such that the force transmission rod is configured such that a plurality of probe rods are connected in sequence, so that the plurality of probe rods can be combined into force transmission rods of different lengths to adapt to load tests of different depths; the pressure sensor is configured such that the spiral plate head is configured such that the electromagnetic pressure sensor is used, the spiral plate head is configured such that the electromagnetic spiral plate head is used, and an electromagnetic anchor is provided on the side of the pressure sensor facing the spiral plate head. The electromagnetic spiral plate head is adsorbed on the magnetic pressure sensor by electromagnetic action, thereby preventing the spiral plate head from falling off during forward or reverse rotation, so as to facilitate the recovery of the spiral plate head.

[0019] (4) The spiral plate load test method of the present invention utilizes a signal sensor and a signal transceiver to realize wireless real-time transmission of spiral plate head pressure data. Through wireless real-time transmission, a wire-type displacement sensor, and a compact force transmission structure, high-precision collection and measurement of test loads and soil deformation are achieved, thereby improving the accuracy of the spiral plate load test.

[0020] (5) The spiral plate load test method of the present invention uses the above-mentioned spiral plate load test device to perform load tests, which greatly improves the engineering investigation depth of the spiral plate load test. Through the integrated digital intelligent analysis platform, the automatic operation of the spiral plate load test is realized, solving the problem that the traditional spiral plate load test is heavily dependent on manual operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 1 is a cross-sectional view of the overall structure of a spiral plate load test device according to an embodiment of the present invention; Figure 2 2. It is a top view of a spiral plate load test device according to an embodiment of the present invention; Figure 31 is a schematic structural diagram of a self-drilling spinner according to an embodiment of the present invention; Figure 4 Schematic diagram of the structure of the spiral plate head, pressure sensor and probe rod in an embodiment of the present invention; Figure 5 1 is a data collection flow chart of a load test in an embodiment of the present invention.

[0023] In all the drawings, the same reference numerals represent the same technical features, specifically: 1. spiral plate head; 2. force transmission rod; 21. probe rod; 22. signal receiver; 3. pressure sensor; 31. electromagnetic anchor; 32. signal sensor; 4. displacement sensor; 5. self-drilling spinner; 51. first cylinder; 511. first channel; 52. second cylinder; 521. crossbeam; 53. telescopic arm; 54. clamp; 55. hydraulic chamber; 56. hydraulic sensor; 57. limiter; 58. pull wire; 6. reaction force assembly; 61. bidirectional telescopic rod; 62. balanced suspension beam; 63. threaded rod ground anchor; 64. variable speed rotating bearing. DETAILED DESCRIPTION

[0024] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only intended to illustrate the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0025] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0026] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0027] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two components, or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0028] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0029] Example: See also Figures 1 to 4 The spiral plate load test device in the preferred embodiment of the present invention includes a spiral plate head 1, a force transmission rod 2, a pressure sensor 3, a displacement sensor 4, a self-drilling spinner 5, a reaction force component 6 and an intelligent analysis platform.

[0030] Specifically, if Figure 3 As shown, the self-drilling spinner 5 includes a first cylinder 51 and a second cylinder 52 arranged coaxially. The first cylinder 51 is provided with a first channel 511 for accommodating the force transmission rod 2. A second channel is formed between the first cylinder 51 and the second cylinder 52. A telescopic arm 53 that can move axially and rotate around the axis is provided in the second channel. A clamp 54 is provided at the bottom end of the telescopic arm 53. The clamp 54 can clamp or release the force transmission rod 2, and the top surface of the telescopic arm 53 and the second channel form a hydraulic chamber 55. The hydraulic chamber 55 is correspondingly provided with a hydraulic sensor 56.

[0031] Furthermore, the reaction force assembly 6 is fixedly installed on the ground, and is used to fix the self-drilling spinner 5 during the test; the pressure sensor 3 is arranged between the force transmission rod 2 and the spiral plate head 1, and is used to measure the pressure exerted on the spiral plate head 1 during the test; the displacement sensor 4 is arranged at the bottom of the second cylinder 52, and is used to measure the vertical displacement of the telescopic arm 53 during the test; the intelligent analysis platform is respectively connected to the pressure sensor 3, the displacement sensor 4 and the hydraulic sensor 56 signals, and is used to receive the oil pressure data of the hydraulic chamber 55, the plate head pressure data and the displacement data during the test in real time, and control the oil pressure in the hydraulic chamber 55 according to the oil pressure data to make the telescopic arm 53 move back and forth along the axial direction; and the intelligent analysis platform is also wirelessly connected to the rotation drive device of the telescopic arm 53, and is used to control the rotation of the telescopic arm 53 around the axis.

[0032] In this embodiment, the axial direction is the direction of the central axis of the first and second cylinders 51, 52, and the radial direction is perpendicular to the axial direction. The hydraulic chamber 55 corresponds to a hydraulic pump. The intelligent analysis platform controls the output pressure of the hydraulic pump to bidirectionally control the hydraulic oil pressure in the hydraulic chamber 55, providing the downward and upward forces required for the axial movement of the telescopic arm 53. Similarly, the intelligent analysis platform controls the rotational drive device to control the rotational speed and direction of the telescopic arm 53 around its axis. The clamp 54 is preferably an annular clamp.

[0033] The use of this device is divided into a preparation stage and a test stage. During the preparation stage, the reaction force assembly 6 is connected to the self-drilling spinner 5 and the self-drilling spinner 5 is fixed to the ground. One end of the force transmission rod 2 passes through the first channel 511 and is connected to the pressure sensor 3 and the spiral plate head 1 in sequence. Then the clamp 54 provides a detachable connection between the telescopic arm 53 and the force transmission rod 2. The movement of the telescopic arm 53 provides power for the force transmission rod 2, the pressure sensor 3, and the spiral plate head 1. The specific downward penetration process of this device is as follows: the clamper 54 clamps the force transmission rod 2, and the telescopic arm 53 rotates while the hydraulic chamber 55 presses downward, driving the force transmission rod 2, the pressure sensor 3, and the spiral plate head 1 to rotate into the soil layer. When the telescopic arm 53 drops to the maximum limit, the clamper 54 releases the force transmission rod 2, and the telescopic arm 53 rises to the highest position under the action of the upward pulling force provided by the hydraulic chamber. At this time, the clamper 54 re-clamps another part of the force transmission rod 2, and the telescopic arm 53 re-drives the force transmission rod 2, the pressure sensor 3, and the spiral plate head 1 to rotate downward. By utilizing multiple back and forth movements of the telescopic arm 53, the force transmission rod 2, the pressure sensor 3, and the spiral plate head 1 can be sent into a deeper soil layer, and the penetration depth into the soil layer can reach more than 40 meters. During the load test phase, the intelligent analysis platform controls the oil pressure in the hydraulic chamber 55 in the self-drilling spinner 5 according to the real-time data of the hydraulic sensor 56 to load or unload the force transmission rod 2 in stages, thereby transferring the load to the spiral plate head 1 and receiving the plate head pressure data and displacement data collected by the pressure sensor 3 and the displacement sensor 4 respectively.

[0034] The spiral plate load test device of the present invention realizes automatic penetration of the spiral plate load test through a self-drilling rotary press, which solves the problem that the traditional load test is affected by the stratum, the lack of manual drilling capacity and other factors that make it impossible to carry out deep load tests, and greatly improves the test depth and engineering survey depth of the spiral plate load test, and is suitable for in-situ testing and investigation of deep soil. The spiral plate load test device of the present invention also improves the force mode of the force transmission rod in the traditional load test through the clamp, improves the overall stability of the structure, can greatly reduce the problem of eccentric compression of the system, and improves the depth and accuracy of the spiral plate load test. In addition, through the integrated digital intelligent analysis platform, the automated operation of the spiral plate load test is realized, and the functions of automatic penetration, continuous testing, intelligent loading, unloading, digital collection, long-distance wireless transmission, intelligent analysis and the like can be realized according to the operating instructions, which solves the problem that the traditional spiral plate load test is heavily dependent on manual operation, greatly improves the efficiency of the spiral plate load test, and reduces the test cost.

[0035] In a preferred embodiment, the force transmission rod 2 includes one probe rod 21 ; alternatively, the force transmission rod includes multiple probe rods 21 , which are selected based on the depth of the load test and the length of the probe rods 21 .

[0036] Preferably, when the dowel rod 2 is composed of multiple probe rods 21, adjacent probe rods 21 are connected to each other at their tops and bottoms. In this embodiment, when the dowel rod 2 is penetrated downward, after one probe rod 21 penetrates to a certain depth, the next probe rod 21 can be connected and continued to penetrate, gradually increasing the length of the dowel rod 2 until the spiral plate head 1 is delivered to the designed soil layer position, so that the length of the dowel rod 2 can be flexibly matched with the test depth of the load test.

[0037] Preferably, the length of the probe rod 21 is 2 to 3 times the length of the telescopic arm 53. At this time, a probe rod 21 needs to be spun downward by the telescopic arm 53 at least 2 or 3 times before connecting to the next probe rod 21 and continuing to be spun downward.

[0038] In a specific embodiment, the length of the probe rod is 1 meter, and the length of the telescopic arm is 0.5 meter.

[0039] Furthermore, if Figure 4 As shown, a signal receiver 22 is preferably provided in the probe rod 21, and a signal sensor 32 is preferably provided on the side of the pressure sensor 3 facing the force transmission rod 2. The signal sensor 32 can convert the pressure signal collected by the pressure sensor 3 into a digital signal, and further transmit it to the intelligent analysis platform through the signal receiver 22 in the probe rod 21.

[0040] In this embodiment, real-time long-distance wireless transmission of digital signals in the soil environment is achieved through the signal sensor 32 and the signal receivers 22 in several probe rods 21, so that the intelligent analysis platform can receive the load data collected by the pressure sensor 3 during the test in real time, thereby realizing the digital collection of deep spiral plate load tests.

[0041] Further preferably, the pressure sensor 3 is an electromagnetic pressure sensor, the spiral plate head 1 is an electromagnetic spiral plate head, and an electromagnetic anchor 31 is provided on the side of the pressure sensor 3 facing the spiral plate head 1, which can adsorb the electromagnetic spiral plate head on the magnetic pressure sensor through electromagnetic action.

[0042] In this embodiment, the electromagnetic anchor 31 is turned on during the penetration or extraction phase, and the electromagnetic pressure sensor and the electromagnetic spiral plate head are tightly attached together through electromagnetic action to prevent the spiral plate head 1 from falling off during forward or reverse rotation, thereby facilitating the recovery of the spiral plate head 1. During the load test, the electromagnetic anchor 31 is turned off.

[0043] Further preferably, the displacement sensor 4 is a pull-wire displacement sensor; a limiter 57 is provided on the side of the clamp 54 away from the force transmission rod 2, and one end of the limiter 57 extends out of the outer wall of the telescopic arm 53; the pull-wire displacement sensor and the limiter 57 can be connected by a vertically extending pull wire 58, so that the pull-wire displacement sensor can measure the vertical displacement of the telescopic arm 53 during the test.

[0044] In this embodiment, the limiter 57 can limit the position of the clamp 54, ensuring the safe and stable operation of the clamp 54. During the load test, the spiral plate head 1, pressure sensor 3, force transmission rod 2 and telescopic arm 53 will displace together with the deformation of the soil. Therefore, the vertical displacement of the telescopic arm 53 is the deformation of the soil. The pull wire 58 connects the pull wire displacement sensor and the limiter 57 in the vertical direction, so that the pull wire displacement sensor can directly collect accurate data on soil deformation, thereby improving the accuracy of the spiral plate load test. In addition, the pull wire displacement sensor can transmit the soil deformation data during the test to the intelligent analysis platform in real time, realizing the efficient collection of soil deformation data and improving the efficiency of the spiral plate load test.

[0045] Exemplarily, the pull wire 58 is a high-strength, low-strain pull wire.

[0046] Preferably, a plurality of draw-wire displacement sensors are provided to collect a plurality of sets of soil deformation data. In a specific embodiment, two draw-wire displacement sensors are provided, axially symmetrically disposed at the bottom of the second cylinder 52. At each moment, two sets of soil deformation data, symmetrically distributed along the axis, are collected to determine any accidental errors in the data.

[0047] Preferably, a plurality of cross beams 521 are radially spaced apart on the outer wall of the second cylinder 52, and the reaction force assembly 6 includes a bidirectional telescopic rod 61 and a balancing suspension beam 62. The bidirectional telescopic rod 61 can connect the cross beam 521 to one end of the balancing suspension beam 62, and the other end of the balancing suspension beam 62 is fixedly installed on the ground through a threaded rod anchor 63.

[0048] In this embodiment, the balancing beam 62 is connected to a threaded rod anchor 63 via a threaded hole. The threaded rod anchor 63 can be screwed into the ground to a certain depth to provide a test reaction force for the spiral plate load test. The ends of the bidirectional telescopic rod 61 are preferably connected to the balancing beam 62 and the crossbeam 521 of the self-drilling spinner respectively via threads. The number of turns of the threads connecting the two ends can be adjusted to achieve free extension and retraction of the force arm of the test device.

[0049] Preferably, four crossbeams 521 are spaced apart and arranged at 90° along the radial direction of the second cylinder. In this case, there are also two groups of four balancing beams 62, which are connected to each crossbeam 521 of the self-drilling spinner 5 via four bidirectional telescopic rods 61. The end of the balancing beam 62 away from the crossbeam 521 is preferably provided with a variable speed rotary bearing 64. The variable speed rotary bearing 64 can drive the threaded rod anchor 63 to rotate into the soil layer to a certain depth, providing a test reaction force for the deep spiral plate load test. By simultaneously adjusting the penetration of each threaded rod anchor 63 through each variable speed rotary bearing 64, the self-drilling spinner 5 can be aligned and leveled, ensuring the vertical drilling of the subsequent spiral plate head 1 and avoiding eccentric compression of the spiral plate head 1 during the test.

[0050] Preferably, the intelligent analysis platform is wirelessly connected to the variable speed rotary bearing 64 on the balance suspension beam 62 to control the screwing in and out of the threaded rod anchor 63 .

[0051] In actual use, the preferred embodiment provides a spiral plate load test method, which includes at least the following steps: (1) Preparation S101: Level the test site and mark the test hole location according to the test hole location and surrounding terrain features; S102: Centering and leveling the self-drilling spinner, fixing the reaction force assembly on the ground, and connecting the reaction force assembly to the self-drilling spinner; S103: Pass the force transmission rod through the first channel of the self-drilling spinner and connect it to the electromagnetic anchor and the spiral plate head in sequence. Debug the intelligent analysis platform and calibrate the pre-loaded spiral plate head to ensure that the data signal can be transmitted normally. S104: The clamper clamps the dowel rod, and the intelligent analysis platform controls the telescopic arm to slowly bring the spiral plate head into the soil at the set movement speed and rotation speed. When the telescopic arm moves downward to the maximum limit, the clamper releases the dowel rod, and the intelligent analysis platform controls the telescopic arm to move upward to the set position. Furthermore, the clamper clamps the dowel rod again, and the intelligent analysis platform controls the telescopic arm to slowly bring the spiral plate head into the soil at the set movement speed and rotation speed. This cycle continues until the spiral plate head reaches the test soil layer point. (2) Load test S201: The displacement sensor and the pressure sensor are reset to zero, and the test is started. The intelligent analysis platform controls the oil pressure in the hydraulic chamber to perform graded loading. The pressure sensor and the displacement sensor provide real-time feedback of the collected plate head pressure data and displacement data. The intelligent analysis platform analyzes the collected plate head pressure data and displacement data and draws a QS curve. S202: After the loading test is completed, the intelligent analysis platform controls the oil pressure in the hydraulic chamber to perform graded unloading. The pressure sensor and displacement sensor provide real-time feedback of the collected plate head pressure data and displacement data. The intelligent analysis platform analyzes the collected plate head pressure data and displacement data, draws a QS curve, and outputs a test report after the unloading test is completed.

[0052] Preferably, in step S103, the pre-stressing of the spiral plate head is controlled by the intelligent analysis platform to apply a certain pressure to the spiral plate head so as to facilitate the data signal test. In step S104, the intelligent analysis platform controls the spiral plate head to rotate into the soil at a speed of preferably 10 cm / s.

[0053] During the load test, the pressure applied to the spiral plate head in steps S201 and S202 is provided by the oil pressure in the hydraulic chamber in the self-drilling screwdriver, transmitted to the force transmission rod through the clamp, and finally gradually transmitted to the spiral plate head through the force transmission rod. During the transmission process, part of the pressure is consumed by the friction resistance of the soil around the force transmission rod, and the remaining force is transmitted to the plate head and acts on the test soil layer.

[0054] Preferably, step S200 is further provided before step S201: inputting engineering information (soil layer type, depth, groundwater level, test load, number of graded loading, number of unloading, data collection time interval, stability judgment and convergence conditions (fast method, slow method), supplementary loading conditions) on the intelligent analysis platform to check whether the engineering information is accurate.

[0055] In step S201, graded loading can generally be divided into 8 to 10 levels of loading according to the stratum, and the first loading is twice the graded load; in step S202, the graded load of graded unloading is generally twice the loading graded load. Preferably, during the load test, when the difference between the plate head pressure data detected by the pressure sensor and the set graded load reaches the set supplementary load limit, supplementary loading is performed. The intelligent analysis platform can automatically judge based on the spiral plate head pressure data fed back by the pressure sensor, determine the loading amount, unloading amount, and supplementary load amount, and analyze the soil deformation data to determine whether the load test has reached the stability convergence condition. If the soil deformation reaches the convergence condition, the test can be terminated in advance without having to perform the remaining levels of loading / unloading. For the detailed process of data collection in step S201 and step S202, see Figure 5 .

[0056] Further preferably, when the test requires the presence of multiple test points of different depths at the same test hole, the spiral plate load test method further includes the following process: (3) Continuous load test S301: After completing the previous set of load tests, repeat step S104 and continue screwing the spiral plate head to the next test soil layer point of the test hole; S302: Repeat steps S201 to S202; S303: Determine whether the test soil layer point is the last test soil layer point of the test hole. If so, the continuous load test ends; if not, return to step S301.

[0057] Furthermore, after the load test is completed at all test points of the test hole, it is determined whether the electromagnetic spiral plate head needs to be recovered according to needs. If necessary, the electromagnetic anchor is opened, and the self-drilling spinner is used to slowly lift the force transmission rod by rotating in the reverse direction to recover the force transmission rod, the electromagnetic pressure sensor and the electromagnetic spiral plate head; if the electromagnetic spiral plate head does not need to be recovered, the electromagnetic anchor is closed, and the self-drilling spinner is used to lift the force transmission rod.

[0058] In the spiral plate load test method of the present invention, the data processing process is as follows: The stress analysis process of the load test is actually a slow change process in which the loading and soil load reach a relatively stable state. As time goes by, the deformation of the soil gradually tends to be stable under each level of load. At this time, the loading can continue to the next level of load or the test can be terminated.

[0059] Apply each level of load :

[0060] in, Loading pressure for each stage ( ); is the load on the spiral plate head ( ), is the effective area of the spiral plate head ( ).

[0061] During the test, the axial force exerted by the hydraulic cylinder of the self-drilling spinner on the dowel rod :

[0062] in, is the axial pressure on the dowel rod ( ), is the lateral friction resistance of the dowel rod ( ).

[0063] Friction resistance of the dowel rod side wall :

[0064] in, is the friction coefficient between the dowel rod and the soil layer, is the outer diameter of the dowel rod ( ), is the test depth ( ).

[0065] Test depth :

[0066] in, is the length of the dowel rod ( ); is the remaining length of the dowel rod on the ground ( ); is the length of the electromagnetic pressure sensor ( ).

[0067] Applied axial force The load acting on the spiral plate head is :

[0068] in, for t The actual pressure on the spiral plate head at the moment ( ).

[0069] When each load The actual pressure on the spiral plate head The difference reaches the set reload limit ( ) The self-drilling spinner will automatically reload when

[0070] Each load level is judged as stable and convergent condition: when the deformation of the soil within 2 hours When the deformation is less than 0.1 mm, the loading test can be terminated. and soil cumulative deformation The calculation formula is:

[0071]

[0072] in, for t The deformation of the soil at the moment ( ); is the cumulative deformation of 1# displacement sensor ( ); is the cumulative deformation of the 2# displacement sensor ( ); is the cumulative deformation of n# displacement sensor ( ).

[0073] The spiral plate load test device of the present invention realizes automatic penetration of the spiral plate load test through a self-drilling rotary press, which solves the problem that the traditional load test is affected by the stratum, the lack of manual drilling capacity and other factors that make it impossible to carry out deep load tests, and greatly improves the test depth and engineering survey depth of the spiral plate load test, and is suitable for in-situ testing and investigation of deep soil. The spiral plate load test device of the present invention also improves the force mode of the force transmission rod in the traditional load test through the clamp, improves the overall stability of the structure, can greatly reduce the problem of eccentric compression of the system, and improves the depth and accuracy of the spiral plate load test. In addition, through the integrated digital intelligent analysis platform, the automated operation of the spiral plate load test is realized, and the functions of automatic penetration, continuous testing, intelligent loading, unloading, digital collection, long-distance wireless transmission, intelligent analysis and the like can be realized according to the operating instructions, which solves the problem that the traditional spiral plate load test is heavily dependent on manual operation, greatly improves the efficiency of the spiral plate load test, and reduces the test cost.

[0074] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A spiral plate load test device, characterized in that: It includes a spiral plate head, a force transmission rod, a pressure sensor, a displacement sensor, a self-drilling spinner, a reaction force component and an intelligent analysis platform; The self-drilling spinner includes a first cylinder and a second cylinder arranged coaxially, the first cylinder being provided with a first channel for accommodating the force transmission rod, a second channel being formed between the first cylinder and the second cylinder, a telescopic arm being provided in the second channel and being movable in the axial direction and rotatable about the axis, a clamp being provided at the bottom of the telescopic arm and being capable of clamping or releasing the force transmission rod, and a hydraulic chamber being formed by the top surface of the telescopic arm and the second channel, and a hydraulic sensor being provided corresponding to the hydraulic chamber; The reaction force assembly is fixedly mounted on the ground and is used to fix the self-drilling spinner during the test; The pressure sensor is arranged between the force transmission rod and the spiral plate head, and is used to measure the pressure exerted on the spiral plate head during the test; the displacement sensor is arranged at the bottom of the second cylinder, and is used to measure the vertical displacement of the telescopic arm during the test; The intelligent analysis platform is respectively connected to the hydraulic sensor, the pressure sensor and the displacement sensor signals, and is used to receive the oil pressure data of the hydraulic chamber, the plate head pressure data and the displacement data during the test in real time, and control the oil pressure in the hydraulic chamber according to the oil pressure data to make the telescopic arm move back and forth along the axial direction; and the intelligent analysis platform is also wirelessly connected to the rotation drive device of the telescopic arm, and is used to control the rotation of the telescopic arm around the axis.

2. The spiral plate load test device according to claim 1, characterized in that: The displacement sensor is a wire-type displacement sensor; a limiter is provided on a side of the clamp away from the force transmission rod, and one end of the limiter extends out of the outer side wall of the telescopic arm; The pull-wire displacement sensor and the limiter can be connected via a pull-wire extending vertically, so that the pull-wire displacement sensor can measure the vertical displacement of the telescopic arm during the test.

3. The spiral plate load test device according to claim 1, characterized in that: The pressure sensor is an electromagnetic pressure sensor, the spiral plate head is an electromagnetic spiral plate head, and an electromagnetic anchor is provided on the side of the pressure sensor facing the spiral plate head, which can adsorb the electromagnetic spiral plate head onto the magnetic pressure sensor through electromagnetic action.

4. The spiral plate load test device according to claim 1, characterized in that: The force transmission rod includes one probe rod, or the force transmission rod includes multiple probe rods, and adjacent probe rods are correspondingly connected at the top and the bottom.

5. The spiral plate load test device according to claim 4, characterized in that: A signal receiver is provided in the probe rod; a signal sensor is provided on the side of the pressure sensor facing the force transmission rod, which can convert the pressure signal collected by the pressure sensor into a digital signal and further transmit it to the intelligent analysis platform through the signal receiver in the probe rod.

6. The spiral plate load test device according to claim 4, characterized in that: The length of the probe rod is 2 to 3 times the length of the telescopic arm.

7. The spiral plate load test device according to claim 1, characterized in that: A plurality of cross beams are arranged on the outer wall of the second cylinder at intervals in the radial direction; The reaction force assembly includes a bidirectional telescopic rod and a balancing suspension beam. The bidirectional telescopic rod can connect the crossbeam with one end of the balancing suspension beam, and the other end of the balancing suspension beam is fixed to the ground through a threaded rod ground anchor.

8. The spiral plate load test device according to claim 7, characterized in that: There are four cross beams spaced apart and arranged at 90 degrees along the radial direction of the second cylinder; and / or A variable speed rotating bearing is provided at one end of the balance suspension beam away from the cross beam, and the variable speed rotating bearing can drive the threaded rod ground anchor to rotate.

9. A spiral plate load test method, characterized in that: The method is implemented using the spiral plate load test device described in any one of claims 1 to 8, and includes the following process: (1) Preparation S101: Level the test site and mark the test hole location according to the test hole location and surrounding terrain features; S102: Centering and leveling the self-drilling spinner, fixing the reaction force assembly on the ground, and connecting the reaction force assembly to the self-drilling spinner; S103: Pass the dowel rod through the first channel of the self-drilling spinner and connect it to the pressure sensor and the spiral plate head in sequence. Debug the intelligent analysis platform and calibrate the pre-loaded spiral plate head to ensure that the data signal can be transmitted normally. S104: The clamper clamps the dowel rod, and the intelligent analysis platform controls the telescopic arm to slowly bring the spiral plate head into the soil at the set movement speed and rotation speed. When the telescopic arm moves downward to the maximum limit, the clamper releases the dowel rod, and the intelligent analysis platform controls the telescopic arm to move upward to the set position. The clamper clamps the dowel rod again, and the intelligent analysis platform further controls the telescopic arm to slowly bring the spiral plate head into the soil at the set movement speed and rotation speed. This cycle continues until the spiral plate head reaches the test soil layer point. (2) Load test S201: The displacement sensor and the pressure sensor are reset to zero, and the test is started. The intelligent analysis platform controls the oil pressure in the hydraulic chamber to perform graded loading. The pressure sensor and the displacement sensor provide real-time feedback of the collected plate head pressure data and displacement data. The intelligent analysis platform analyzes the collected plate head pressure data and displacement data and draws a QS curve. S202: After the loading test is completed, the intelligent analysis platform controls the oil pressure in the hydraulic chamber to perform graded unloading. The pressure sensor and displacement sensor provide real-time feedback of the collected plate head pressure data and displacement data. The intelligent analysis platform analyzes the collected plate head pressure data and displacement data, draws a QS curve, and outputs a test report after the unloading test is completed.

10. A spiral plate load test method according to claim 9, characterized in that: It also includes the following processes: (3) Continuous load test S301: After completing the previous set of load tests, repeat step S104 and continue screwing the spiral plate head to the next test soil layer point of the test hole; S302: Repeat steps S201 to S202; S303: Determine whether the test soil layer point is the last test soil layer point of the test hole. If so, the continuous load test ends; if not, return to step S301.

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