Method for monitoring compaction settlement of dynamically compacted foundation by means of multi-factor sensing

Abstract

A method for monitoring compaction settlement of a dynamically compacted foundation by means of multi-factor sensing. When a force sensor (2) senses the weight of a hammer (1-1), an automated system is started to hoist the hammer (1-1); a speed sensor (3) monitors the change condition of a speed along with time during a hoisting process of the hammer (1-1); when the hammer (1-1) is hoisted to a set height of a position detection switch (4), the position detection switch (4) controls the automated system to stop hoisting the hammer (1-1), and a central control system forms a hammer speed-time curve on the basis of the change condition of the speed along with time during the hoisting process of the hammer (1-1), and integrates the hammer speed-time curve to determine the displacement of the hammer (1-1) to the position detection switch (4); the hammer (1-1) is repeatedly hoisted, and a dynamic compaction construction worker monitors, by means of the central control system, the displacement of the hammer (1-1) every time when the hammer is hoisted to the position detection switch (4), calculates a displacement difference value of the hammer (1-1) between two consecutive operations of hoisting to the position detection switch (4), i.e., determining the compaction settlement of a dynamically compacted foundation and calculating an average value of the compaction settlement of two consecutive operations of dynamically compacting the foundation, and when the average value of the compaction settlement of two consecutive operations of dynamically compacting the foundation reaches a preset hammer retraction standard, controls the hammer (1-1) to stop hammering the foundation.

Description

A method for monitoring the settlement of dynamic compaction foundation using multi-element induction Technical Field

[0001] The present invention relates to the technical field of soft soil foundation reinforcement monitoring, and in particular to a method for monitoring the tamping amount of a strongly compacted foundation using multi-element induction. Background Art

[0002] Dynamic compaction is one of the most direct and effective methods for foundation reinforcement. It can effectively improve the mechanical properties of foundation soil and has the advantages of significant reinforcement results, simple and efficient construction, and a short reinforcement period. It is currently widely used in foundation reinforcement projects such as highway subgrades, land reclamation, airport and wharf construction.

[0003] In addition to strictly adhering to construction procedures, dynamic compaction construction should also involve dedicated personnel responsible for monitoring the construction process. During construction, the number of strikes and the amount of tamping per strike at each tamping point should be strictly checked according to design requirements. The accuracy of dynamic compaction settlement monitoring data is the standard for evaluating foundation reinforcement quality and determining the final strike of dynamic compaction. During construction, insufficient or excessive tamping is common, influenced by the construction personnel's operational level and the distribution of on-site soil layers. This makes it difficult to ensure the quality of foundation reinforcement and, in severe cases, affects the normal operation of the project during its operation. Furthermore, the traditional method of monitoring tamping settlement, leveling, is inefficient and poses significant safety risks to personnel during the monitoring process. Summary of the Invention

[0004] The purpose of this application is to address the technical defects in the existing technology and provide a method for monitoring the tamping settlement of a compacted foundation using multi-element sensing.

[0005] The technical solutions adopted to achieve the purpose of this application are:

[0006] A method for monitoring the amount of compaction settlement of a foundation using multiple sensing methods. The automated system for monitoring the amount of compaction settlement of a foundation using multiple sensing methods includes a compaction machine, a force sensor, a speed sensor, a position detection switch, and a central control system.

[0007] The dynamic tamping machine includes a rammer, a suspension wire, a boom, and a cab; a lifting lug is provided on the top of the rammer, and the lifting lug is connected to the boom via a suspension wire; a force sensor for sensing the weight of the rammer and a speed sensor for monitoring the change in speed of the rammer over time during the process of being lifted are provided on the suspension wire; when the force sensor senses the set weight of the rammer, the control automation system is activated;

[0008] The position detection switch is arranged on the boom of the dynamic tamping machine. When the rammer is hoisted to the height set by the position detection switch, the position detection switch controls the automation system to pause and stop hoisting the rammer.

[0009] The central control system is arranged in the driving cabin of the dynamic tamping machine and is used to collect the initial position of the tamping hammer when it is hoisted, the final position of the tamping hammer when it is hoisted, and the speed change of the tamping hammer over time during the hoisting process, and to form a tamping hammer speed time curve based on the speed change of the tamping hammer over time during the hoisting process;

[0010] The method for monitoring the amount of compaction settlement of a foundation by multi-element sensing comprises the following steps:

[0011] Step 1: Fix the force sensor and the speed sensor on the hanging wire of the dynamic compaction machine respectively, connect the rammer to the boom through the hanging wire, and fix the position detection switch on the boom;

[0012] Step 2: The weight of the rammer is set through the central control system. When the rammer is hoisted, the force sensor senses the weight of the rammer and sends it to the central control system, which activates the automation system.

[0013] Step 3: The speed sensor monitors the speed change of the rammer during the lifting process and sends the data to the central control system;

[0014] Step 4: When the rammer is hoisted to the height set by the position detection switch, the position detection switch is used to control the automation system to pause and stop hoisting the rammer. The central control system forms a rammer speed-time curve based on the change in speed of the rammer over time during the hoisting process, and integrates the rammer speed-time curve to determine the displacement of the rammer until it reaches the position detection switch.

[0015] Step 5. Repeat steps 2-4. The compaction construction personnel monitor the displacement of the rammer each time it is hoisted to the position detection switch through the central control system, and calculate the difference in displacement of the rammer two adjacent times when it is hoisted to the position detection switch, that is, determine the compaction settlement of the foundation, and calculate the average of the compaction settlements of two adjacent foundations. When the average of the compaction settlements of two adjacent foundations reaches the pre-set hammer withdrawal standard, control the rammer to stop compacting the foundation.

[0016] In the above technical solution, the position detection switch is an electromagnetic induction control switch, and an electromagnetic induction element is provided on the outside of the lifting ear. When the rammer provided with the electromagnetic induction element is lifted to the setting height of the electromagnetic induction control switch, the electromagnetic induction control switch and the electromagnetic induction element produce an electromagnetic reaction, and the electromagnetic induction control switch controls the automation system to pause and stop lifting the rammer.

[0017] In the above technical solution, the position detection switch is a laser detection switch. When the rammer is lifted to the set height of the laser detection switch, the laser detection switch detects the rammer and controls the automation system to pause and stop lifting the rammer.

[0018] In the above technical solution, the central control system is provided with a display screen for displaying the speed-time curve, the displacement of the rammer each time it is lifted to the position detection switch, the displacement difference between two adjacent times the rammer is lifted to the position detection switch, and the cumulative displacement of the rammer when it is lifted to the position detection switch.

[0019] In the above technical solution, the setting height of the position detection switch is determined according to the preset ramming energy and the weight of the rammer. The calculation formula for the setting height of the position detection switch is as follows: Where, Represents the installation height of the position detection switch, Represents the pre-set impact energy, Represents the weight of the rammer.

[0020] In the above technical solution, a pulley is provided at the top of the boom of the ramming machine to facilitate lifting or lowering the rammer.

[0021] The beneficial effects of the present invention are as follows:

[0022] 1. The force sensor, speed sensor and position detection switch of the present invention cooperate with the central control system to realize the automatic monitoring of the tamping amount during and after construction. The application of the present invention solves the problem that traditional level monitoring is time-consuming and labor-intensive and has a great potential safety hazard for personnel, and the monitoring data is accurate and reliable with high precision. In addition, the present invention is easy to operate, the monitoring results are accurate, time-saving and labor-saving, and the manufacturing cost is low, and the controllability and real-time performance are strong.

[0023] 2. When the central control system of the present invention calculates that the average of the tamping amounts of two adjacent strongly compacted foundations reaches a preset hammer stop standard, the tamping hammer stops hitting the foundation, which can avoid insufficient or excessive tamping and ensure the quality of foundation reinforcement. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the present application or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] FIG1 is a schematic structural diagram of an automated system for measuring the amount of compaction settlement of a compacted foundation using multi-element sensing as shown in the invention.

[0026] FIG2 is a schematic diagram of the central control system and functional interface shown in the invention.

[0027] In the figure: 1- dynamic compactor, 1-1- compactor, 1-1-1- lifting ear, 1-2- lifting line, 1-2-1- first section of lifting line, 1-2-2- second section of lifting line, 1-3- boom, 1-3-1- pulley, 1-4- cockpit, 2- force sensor, 3- speed sensor, 4- position detection switch. DETAILED DESCRIPTION

[0028] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention are further described below with reference to specific embodiments.

[0029] Referring to FIG1 , an automated system for monitoring the amount of compaction settlement using multi-sensor technology includes: a compaction machine 1, a force sensor 2, a speed sensor 3, a position detection switch 4, and a central control system, wherein:

[0030] The ramming machine 1 includes a rammer 1-1, a suspension line 1-2, a boom 1-3 and a cab 1-4; a lifting ear 1-1-1 is provided on the top of the rammer 1-1, and the lifting ear 1-1-1 is connected to the boom 1-3 through the suspension line 1-2, so as to realize the connection between the rammer 1-1 and the boom 1-3; the suspension line 1-2 is divided into a first section suspension line 1-2-1 and a second section suspension line 1-2-2 by the boom 1-3, and as the rammer 1-1 is lowered, the length of the first section suspension line 1-2-1 gradually decreases, and the length of the second section suspension line 1-2-2 gradually increases; a force sensor 2 for sensing the weight of the rammer 1-1 (collecting the tension signal of the rammer 1-1 during the lifting process) and a speed sensor 3 for monitoring the change of the speed of the rammer 1-1 over time during the lifting process are provided on the first section suspension line 1-2-1, and when the force sensor 2 senses the set weight of the rammer 1-1, the control automation system starts and determines the initial position of the rammer 1-1 after it is lifted. The central control system is wirelessly connected to the force sensor 2 , the speed sensor 3 , the position detection switch 4 and the electromagnetic induction element.

[0031] The position detection switch 4 is provided on the boom 1-3 of the dynamic tamping machine 1. When the rammer 1-1 is hoisted to the height set by the position detection switch 4, the position detection switch 4 controls the automation system to pause, stop hoisting the rammer 1-1, and determine the final hoisted position of the rammer 1-1. The position detection switch 4 is an electromagnetic induction control switch. An electromagnetic induction element is provided on the outer side of the lifting lug 1-1-1. When the rammer 1-1 provided with the electromagnetic induction element is hoisted to the height set by the electromagnetic induction control switch, the electromagnetic induction control switch and the electromagnetic induction element generate an electromagnetic reaction, and the electromagnetic induction control switch controls the automation system to pause, and stop hoisting the rammer 1-1. The position detection switch 4 can also be a laser detection switch. When the rammer 1-1 is hoisted to the height set by the laser detection switch, the laser detection switch detects the rammer 1-1 and controls the automation system to pause, and stop hoisting the rammer 1-1.

[0032] The central control system is disposed within the cab 1-4 of the dynamic tamping machine 1 and is used to collect information about the initial position of the rammer 1-1 when it is hoisted, the final position of the rammer 1-1 when it is hoisted, and the time-varying speed of the rammer 1-1 during the hoisting process. The central control system also generates a speed-time curve for the rammer 1-1 based on the time-varying speed of the rammer 1-1 during the hoisting process (the speed-time curve for the rammer 1-1 includes two stages: the rammer 1-1 being hoisted at an accelerated speed and the rammer being hoisted at a constant speed). Referring to FIG2 , the central control system is provided with a display screen for displaying the speed-time curve for the rammer 1-1, the displacement of the rammer 1-1 each time it is hoisted to the position detection switch 4, the difference in displacement between two consecutive times the rammer 1-1 is hoisted to the position detection switch 4, and the cumulative displacement of the rammer 1-1 when it is hoisted to the position detection switch 4. The height at which the position detection switch 4 is set is determined based on the pre-set tamping energy and the weight of the rammer.

[0033] Furthermore, a pulley 1-3-1 is provided at the top of the boom 1-3 of the dynamic ramming machine 1 to facilitate lifting or lowering the rammer 1-1.

[0034] A method for operating an automated system for monitoring the amount of compaction settlement of a compacted foundation using multi-element sensing technology includes the following steps:

[0035] Step 1: The force sensor 2 and the speed sensor 3 are respectively fixedly mounted on the suspension wire 1-2 of the dynamic tamping machine 1, the rammer 1-1 is connected to the suspension arm 1-3 via the suspension wire 1-2, and the position detection switch 4 is fixedly mounted on the suspension arm 1-3;

[0036] Step 2, setting the weight of the rammer 1-1 through the central control system. When the rammer 1-1 is hoisted, the force sensor 2 senses the weight of the rammer 1-1 and sends it to the central control system, which starts the automation system.

[0037] Step 3: The speed sensor 3 monitors the speed change of the rammer 1-1 during the lifting process and sends the data to the central control system;

[0038] Step 4: When the rammer 1-1 is hoisted to the set height of the position detection switch 4, the position detection switch 4 is used to control the automation system to pause and stop hoisting the rammer 1-1. The central control system forms a speed-time curve of the rammer 1-1 according to the change in speed of the rammer 1-1 over time during the hoisting process, and integrates the speed-time curve of the rammer 1-1 to determine the displacement of the rammer 1-1 when it reaches the position detection switch 4;

[0039] Step 5, repeat steps 2-4, and the compaction construction personnel monitor the displacement of the rammer 1-1 each time it is hoisted to the position detection switch 4 through the central control system, and calculate the displacement difference between two adjacent rammers 1-1 being hoisted to the position detection switch 4, that is, determine the compaction settlement of the foundation, and calculate the average of the compaction settlements of two adjacent compaction foundations. When the average of the compaction settlements of two adjacent compaction foundations reaches the pre-set hammer withdrawal standard, control the rammer 1-1 to stop compacting the foundation.

[0040] Furthermore, the calculation formula for the setting height of the position detection switch 4 is as follows: Where, Represents the installation height of the position detection switch, Represents the pre-set impact energy, Represents the weight of the rammer.

[0041] The above is an exemplary description of the present invention. It should be noted that, without departing from the core of the present invention, any simple deformation, modification or other equivalent replacement that can be made by other skilled in the art without expending creative labor falls within the scope of protection of the present invention.

Claims

1. A method for monitoring the amount of compaction settlement of a foundation using multi-element sensing, characterized in that: The automated system for monitoring the compaction amount of foundation using multiple sensors includes a compactor, a force sensor, a speed sensor, a position detection switch, and a central control system. The dynamic tamping machine includes a rammer, a suspension wire, a boom, and a cab; a lifting lug is provided on the top of the rammer, and the lifting lug is connected to the boom via a suspension wire; a force sensor for sensing the weight of the rammer and a speed sensor for monitoring the change in speed of the rammer over time during the process of being lifted are provided on the suspension wire; when the force sensor senses the set weight of the rammer, the control automation system is activated; The position detection switch is arranged on the boom of the dynamic tamping machine. When the rammer is hoisted to the height set by the position detection switch, the position detection switch controls the automation system to pause and stop hoisting the rammer. The central control system is arranged in the driving cabin of the dynamic tamping machine and is used to collect the initial position of the tamping hammer when it is hoisted, the final position of the tamping hammer when it is hoisted, and the speed change of the tamping hammer over time during the hoisting process, and to form a tamping hammer speed time curve based on the speed change of the tamping hammer over time during the hoisting process; The method for monitoring the amount of compaction settlement of a foundation by multi-element sensing comprises the following steps: Step 1: Fix the force sensor and the speed sensor on the hanging wire of the dynamic compaction machine respectively, connect the rammer to the boom through the hanging wire, and fix the position detection switch on the boom; Step 2: The weight of the rammer is set through the central control system. When the rammer is hoisted, the force sensor senses the weight of the rammer and sends it to the central control system, which activates the automation system. Step 3: The speed sensor monitors the speed change of the rammer during the lifting process and sends the data to the central control system; Step 4: When the rammer is hoisted to the height set by the position detection switch, the position detection switch is used to control the automation system to pause and stop hoisting the rammer. The central control system forms a rammer speed-time curve based on the change in speed of the rammer over time during the hoisting process, and integrates the rammer speed-time curve to determine the displacement of the rammer until it reaches the position detection switch. Step 5. Repeat steps 2-4. The compaction construction personnel monitor the displacement of the rammer each time it is hoisted to the position detection switch through the central control system, and calculate the difference in displacement of the rammer two adjacent times when it is hoisted to the position detection switch, that is, determine the compaction settlement of the foundation, and calculate the average of the compaction settlements of two adjacent foundations. When the average of the compaction settlements of two adjacent foundations reaches the pre-set hammer withdrawal standard, control the rammer to stop compacting the foundation.

2. The method according to claim 1, wherein The position detection switch is an electromagnetic induction control switch, and an electromagnetic induction element is provided on the outside of the lifting ear. When the rammer provided with the electromagnetic induction element is lifted to the setting height of the electromagnetic induction control switch, the electromagnetic induction control switch and the electromagnetic induction element produce an electromagnetic reaction, and the electromagnetic induction control switch controls the automation system to pause and stop lifting the rammer.

3. The method according to claim 1, wherein The position detection switch is a laser detection switch. When the rammer is hoisted to the set height of the laser detection switch, the laser detection switch detects the rammer and controls the automation system to pause and stop hoisting the rammer.

4. The method according to claim 1, wherein The central control system is provided with a display screen for displaying the speed change curve over time, the displacement of the rammer each time it is hoisted to the position detection switch, the displacement difference between two adjacent times the rammer is hoisted to the position detection switch, and the cumulative displacement of the rammer when it is hoisted to the position detection switch.

5. The method according to claim 1, wherein The setting height of the position detection switch is determined according to the preset ramming energy and the weight of the rammer. The calculation formula for the setting height of the position detection switch is as follows: Where, Represents the installation height of the position detection switch, Represents the pre-set impact energy, Represents the weight of the rammer.

6. The method according to claim 1, characterized in that A pulley is provided at the top of the boom of the dynamic ramming machine to facilitate lifting or lowering the rammer.

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