A soil core height monitoring device and monitoring method in a pipe pile

Abstract

A soil core height monitoring device and monitoring method in a pipe pile, wherein the device includes a first pulley, a second pulley, a drum assembly, a concentric cable, a resistance tester, a drum control integrated machine, a computer and a heavy ball, wherein the first pulley and the second pulley are set at the same height; the drum assembly includes a drum, a torque sensor, and a driving device; the drum control integrated machine is electrically connected to the torque sensor and the driving device; the heavy ball is connected to the concentric cable; the concentric cable is connected to the drum after passing through the first pulley and the second pulley in sequence; the concentric cable includes a third cable and a metal hose; the metal hose is insulated from the first pulley and electrically connected to the second pulley; the second pulley is electrically connected to the resistance tester through the first cable; the other end of the third cable is electrically connected to the resistance tester through the second cable; the computer is connected to the drum control integrated machine and the resistance tester. The present invention solves the problems that the existing soil core height measuring device and method are difficult to collect soil core height and have high safety risks.

Description

Technical Field

[0001] The invention belongs to the technical field of marine geotechnical engineering and pile foundation engineering, and in particular relates to a soil core height monitoring device and a monitoring method in a pipe pile. Background Art

[0002] Prefabricated pipe piles such as steel pipe piles and prestressed concrete pipe piles are commonly used pile foundation types for buildings, bridges, ports and docks, and offshore wind power projects. Prefabricated pipe piles are usually sunk into the foundation soil layer by impact, vibration, and static pressure. The pile tip of the prefabricated pipe pile is generally open or semi-closed. During the process of penetrating the soil layer, the inside of the pipe pile will be filled with soil core. Due to the friction resistance between the soil core and the inner wall of the pipe pile and the influence of soil arch effect, the pipe pile may be blocked during the pile sinking process, and the height of the soil core will not continue to increase with the increase of the depth of the pile penetration into the soil layer. After the pile sinking, the bearing characteristics of the pile end are basically the same as those of the closed pile. If the height of the soil core is still increasing at the end of the pile sinking, the bearing characteristics of the pile end after the pile sinking are closely related to the development height and development rate of the soil core at the end of the pile sinking. Therefore, it is necessary to monitor the development trend of the soil core height inside the pipe pile during the pile sinking process to provide data for the subsequent analysis of the bearing characteristics of the pile end, the calculation of the bearing capacity, and the study of the influence of the soil core inside the pipe pile on the pile sinking process.

[0003] There are two main methods for measuring the soil core height inside pipe piles. The first method is to directly measure the depth of the top surface of the soil core at the top of the pile after the pile is sunk. This method cannot obtain data on the development of the soil core height over time during the pile sinking process. The second method is to open a hole in the side wall of the pipe pile, and use ropes to connect a pair of weights set inside and outside the pipe pile. The inner weight is placed on the top surface of the soil core inside the pipe pile, and the outer weight is freely suspended. The height of the inner weight and the top surface of the soil core is obtained indirectly by measuring the height of the outer weight. In this method, the outer weight is susceptible to the adverse effects of vibration loads as the length of the outer rope increases during the dynamic pile driving process. In addition, the measurement of the position of the outer weight needs to be close to the pipe pile and achieved manually, which has a high safety risk and is difficult to achieve automated collection. In fact, it is also difficult to obtain real-time data on the development of the soil core height over time during the pile sinking process.

[0004] With the increasing application of prefabricated pipe piles such as steel pipe piles and prestressed concrete pipe piles, especially large-diameter and extra-long pipe piles in engineering, the study of the development law of the soil core in the pipe piles and its influence on the bearing characteristics of the pipe piles and the pile sinking process has become increasingly necessary and critical. It is urgent to propose a pipe pile soil core height monitoring device and monitoring method that can be applied to complex engineering environments, is simple, convenient and easy to operate, and can automatically monitor the height of the soil core in the pipe pile in real time. Summary of the invention

[0005] The purpose of the present invention is to provide a soil core height monitoring device and a monitoring method inside a pipe pile, which can be applicable to complex engineering environments, is simple, convenient and easy to operate, and can automatically monitor the soil core height inside the pipe pile in real time, so as to solve the problems that the existing soil core height measuring devices and methods are difficult to collect the soil core height and have high safety risks.

[0006] The present invention is achieved through the following technical solutions:

[0007] A soil core height monitoring device in a pipe pile comprises a first pulley, a second pulley, a reel assembly, a concentric cable, a resistance tester, a reel control integrated machine, a computer and a heavy ball, wherein the first pulley and the second pulley are respectively arranged on the inner side and the outer side of the wall of a reserved hole of the pipe pile to be tested, and the two are arranged at the same height;

[0008] The reel assembly includes a reel, a torque sensor, and a drive device, and the drive device is connected to the reel drive through the torque sensor;

[0009] The reel control integrated machine is electrically connected to the torque sensor and the driving device respectively;

[0010] The heavy ball is naturally lowered to the mud surface in the pile hole of the pipe pile to be tested, and is connected to a concentric cable;

[0011] The concentric cable is passed around the first pulley and the second pulley in sequence and then connected to the drum;

[0012] The concentric cable includes a third cable and a metal hose sleeved outside the third cable, and one end of the third cable connected to the weight ball is electrically connected to one end of the metal hose connected to the weight ball;

[0013] The metal hose is insulated from the first pulley and electrically connected to the second pulley;

[0014] The second pulley is electrically connected to the resistance tester via the first cable;

[0015] One end of the third cable away from the heavy ball is electrically connected to the resistance tester through the second cable;

[0016] The computer is connected with the reel control integrated machine and the resistance tester respectively.

[0017] Furthermore, it also includes a third pulley, which is arranged on the side of the second pulley away from the pipe pile to be tested, and its setting height is lower than the setting height of the second pulley. The coaxial cable is connected to the reel after passing under the third pulley, and the metal hose is insulated from the third pulley.

[0018] Furthermore, the first pulley, the second pulley and the third pulley all include bearings and wheel grooves arranged on the bearings, the wheel grooves of the first pulley and the third pulley are made of insulating materials, and the wheel groove of the second pulley is made of conductive material.

[0019] Furthermore, the first pulley is fixed to the wall of the reserved hole of the pipe pile to be tested through the first bracket, and the second pulley and the third pulley are fixed to the wall of the reserved hole of the pipe pile to be tested through the second bracket.

[0020] Furthermore, the first bracket and the second bracket are both provided with a steel plate base, the steel plate base is provided with a plurality of screw holes, and the wall of the reserved hole of the pipe pile to be tested is provided with a corresponding plurality of through holes. The first bracket and the second bracket are installed and fixed to the wall of the reserved hole of the pipe pile to be tested by bolts passing through the screw holes, the through holes and the screw holes of one steel plate base in sequence.

[0021] Furthermore, the drum assembly, resistance tester, drum control integrated machine and computer are all installed on the ground outside the pipe pile to be tested.

[0022] The present invention also provides a method for monitoring the height of the soil core in a pipe pile, comprising the following steps:

[0023] S1. Before piling, measure the full-length resistance R1 of the first cable, the full-length resistance R2 of the second circuit, the full-length resistance R3 of the third cable, the full-length resistance R0 of the metal hose, the diameter d of the heavy ball, the mass m of the heavy ball, the radius r1 of the first pulley, the radius r2 of the drum and the length L of the concentric cable, and calculate the average resistance value R per meter of the metal hose based on the full-length resistance of the metal hose and the length of the concentric cable. m ;

[0024] S2, assemble the soil core height monitoring device in the pipe pile as described in any of the above items, measure the center distance D between the first pulley and the second pulley, the distance H1 from the second pulley vertex to the pile top, and the concentric cable length L between the heavy ball and the second pulley vertex b , and obtain the resistance value R measured by the resistance tester b , according to the formula R4=R b -L b ×R m - R1-R2-R3 is calculated to obtain the resistance R4 generated by the second pulley;

[0025] S3, control the reel to retract and release, so that the heavy ball drops to the top surface of the soil core in the pipe pile to be tested, and the concentric cable between the heavy ball and the top of the second pulley is in a taut state, and obtain the resistance value R measured by the resistance tester i0 , and according to the formula L i0 =(R i0 -R1-R2-R3-R4) / R m Calculate the initial length L of the concentric cable from the heavy ball to the vertex of the second pulley i0 , and according to formula H i0 =L i0 -D-πr1 / 2+H1+r1+d calculates the initial height H of the top of the soil core from the top of the pile i0 ;

[0026] S4, start piling, the pile to be tested is driven into the soil, the weight ball is lifted up the soil core and the torque sensor collects the torque M transmitted from the drive device to the drum. i , according to the torque M i Control the reel to retract and release the concentric cable, so that the concentric cable between the heavy ball and the second pulley vertex is in a taut state, and obtain the resistance value R measured by the resistance tester at every preset monitoring time. i1 , and according to the formula L i1 =(R i0 -R1-R2-R3-R4) / R m Calculate the length L of the concentric cable from the heavy ball to the vertex of the second pulley i1 , and according to formula H i1 =L i1 -D-πr1 / 2+H1+r1+dCalculate the height H of the top of the soil core from the top of the pile i1 ;

[0027] S5. Calculate the soil core height H at the current moment i :H i =H i0 -H i1 .

[0028] Further, according to the torque M i The steps of controlling the drum to retract and release the coaxial cable so that the coaxial cable between the heavy ball and the vertex of the second pulley is in a taut state include:

[0029] Judge M i / r2 is greater than or equal to 0.8×(m·g-ρ·g·π·D 3 / 6), where g is the acceleration due to gravity and ρ is the mass density of the heavy ball;

[0030] If so, the control drum is reversed to loosen the concentric cable until 0.5×(m·g-ρ·g·π·D 3 / 6)<M i / r2<0.8×(m·g-ρ·g·π·D 3 / 6), control the reel to stop;

[0031] If not, then judge M i / r2 is less than or equal to 0.5×(m·g-ρ·g·π·D 3 / 6);

[0032] If so, the drum is controlled to rotate forward and tighten the concentric cable until 0.5×(m·g-ρ·g·π·D 3 / 6)<M i / r2<0.8×(m·g-ρ·g·π·D3 / 6) to control the reel to stop.

[0033] Furthermore, after the step of calculating the soil core height at the current moment, the method further comprises:

[0034] According to the current time t i and soil core height H i , draw the soil core height H i With the current time t i The relationship curve, where the current moment t i The time starts from the beginning of piling as zero hour.

[0035] Compared with the prior art, the beneficial effects of the present invention are: it can quickly monitor in real time the change of the soil core height in the pipe pile during the pile sinking process with the pile sinking time, it can be applied to complex engineering environments, is simple, convenient and easy to operate, can automatically monitor the soil core height in the pipe pile in real time, has a high degree of automation and low safety risks, so as to solve the problems that the existing soil core height measurement devices and methods are difficult to collect the soil core height and have high safety risks. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a structural schematic diagram of the soil core height monitoring device in a pipe pile of the present invention;

[0037] Figure 2 It is a schematic structural diagram of the integrated reel in the soil core height monitoring device in the pipe pile of the present invention;

[0038] Figure 3 It is a cross-sectional schematic diagram of a concentric cable in a device for monitoring the height of a soil core in a pipe pile according to the present invention;

[0039] Figure 4 It is a schematic diagram of the structure of a pulley in the device for monitoring the height of the soil core in a pipe pile of the present invention;

[0040] Figure 5 It is a structural schematic diagram of the steel plate base of the first bracket and the second bracket in the device for monitoring the height of the soil core in the pipe pile of the present invention.

[0041] In the figure, 1-first pulley, 2-second pulley, 3-drum integration, 31-drum, 32-torque sensor, 33-driving device, 4-concentric cable, 41-third cable, 42-metal hose, 5-resistance tester, 6-drum control integrated machine, 7-computer, 8-weight ball, 9-pipe pile to be tested, 10-first cable, 11-second cable, 12-third pulley, 13-bearing, 14-wheel groove, 15-first bracket, 16-second bracket, 17-steel plate base, 171-screw hole, 18-ground, 19-soil core. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0043] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. At the same time, in the description of the present invention, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0045] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0046] In the description of the present invention, it should be noted that the terms "upper", "lower", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are directions or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0047] See also Figures 1 to 3 , Figure 1 It is a schematic diagram of the structure of the soil core height monitoring device in the pipe pile of the present invention. Figure 2This is a schematic diagram of the structure of the integrated reel in the soil core height monitoring device in the pipe pile of the present invention. Figure 3 A cross-sectional schematic diagram of a concentric cable in a device for monitoring the height of soil core in a pipe pile of the present invention. A device for monitoring the height of soil core in a pipe pile comprises a first pulley 1, a second pulley 2, a drum assembly 33, a concentric cable 4, a resistance tester 5, a drum control integrated machine 6, a computer 7 and a heavy ball 8. The computer 7 controls the heavy ball 8 to be lowered to the mud surface in the pipe pile 9 to be tested through the drum control integrated machine 6, the drum assembly 33 and the concentric cable 4 according to the torque collected by the drum assembly 33, and calculates the height of the soil core 19 in the pipe pile 9 to be tested through the resistance value collected by the resistance tester 5.

[0048] Specifically, the computer 7 is connected to the drum control integrated machine 6 and the resistance tester 5 respectively, the first pulley 1 and the second pulley 2 are respectively arranged on the inner side and the outer side of the reserved hole wall of the pipe pile 9 to be tested, and the two are arranged at the same height; the drum assembly 33 includes a drum 31, a torque sensor 32, and a driving device 33, and the driving device 33 is connected to the drum 31 through the torque sensor 32; the drum control integrated machine 6 is electrically connected to the torque sensor 32 and the driving device 33 respectively; the drum control integrated machine 6 is used to transmit the rotational torque collected by the torque sensor 32 and transmitted to the drum 31 by the driving device 33 to the computer 7, and control the driving device 33 to drive the drum 31 to rotate forward, reverse or stop according to the control instructions sent by the computer 7.

[0049] Please refer to Figure 4 , Figure 4The schematic diagram of the structure of the pulley in the soil core height monitoring device in the pipe pile of the present invention. The heavy ball 8 is naturally dropped to the mud surface in the pile hole of the pipe pile 9 to be tested, and the heavy ball 8 is connected to the coaxial cable 4; the concentric cable 4 is connected to the drum 31 after passing through the first pulley 1 and the second pulley 2 in sequence; the concentric cable 4 includes a third cable 41 and a metal hose 42 sleeved on the outside of the third cable 41, and the end of the third cable 41 connected to the heavy ball 8 is electrically connected to the end of the metal hose 42 connected to the heavy ball 8. Except for the end of the third cable 41 connected to the heavy ball 8, the other part of the third cable 41 is insulated and isolated from the metal hose 42 by the insulating layer on the outer surface of the third cable 41; the metal hose 42 is insulated from the first pulley 1 and electrically connected to the second pulley 2; the second pulley 2 is electrically connected to the resistance tester 5 through the first cable 10; the end of the third cable 41 away from the heavy ball 8 is electrically connected to the resistance tester 5 through the second cable 11. In one embodiment, the drum assembly 33, the resistance tester 5, the drum control integrated machine 6, and the computer 7 are all mounted on the ground 18 outside the pipe pile 9 to be tested. In one embodiment, the first pulley 1, the second pulley 2, and the third pulley 12 all include a bearing 13 and a wheel groove 14 arranged on the bearing 13, and the wheel groove 14 of the first pulley 1 and the third pulley 12 is made of insulating material, and the wheel groove 14 of the second pulley 2 is made of conductive material. In order to achieve insulation between the metal hose 42 and the first pulley 1 and the third pulley 12, and electrical connection between the metal hose 42 and the second pulley 2. Further, the second pulley 2 is provided with a conductive shaft made of conductive material, and the second pulley 2 is rotatably arranged on the conductive shaft, and is electrically connected to the first cable 10 through the conductive shaft. When the second pulley 2 rotates, the first cable 10 is prevented from being wound around the second pulley 2.

[0050] Please refer to Figure 5 , Figure 5The structural schematic diagram of the steel plate base of the first bracket and the second bracket in the device for monitoring the height of the soil core in the pipe pile of the present invention. Considering that when the pile is sunk in the water area, when the pipe pile 9 to be tested is sunk to a certain depth, the height of the second pulley 2 will be lower than the height of the drum 31, and the concentric cable 4 may be separated from the second pulley 2, resulting in failure to test. In one embodiment, the device for monitoring the height of the soil core in the pipe pile of the present invention also includes a third pulley 12, which is arranged on the side of the second pulley 2 away from the pipe pile 9 to be tested, and its setting height is lower than the setting height of the second pulley 2, and the concentric cable 4 is connected to the drum 31 after passing under the third pulley 12, and the metal hose 42 is insulated from the third pulley 12. The third pulley 12 is set, and the concentric cable 4 passes through the first pulley 1 and the second pulley 2 in sequence, and then passes under the third pulley 12 and is connected to the drum 31. This setting can keep the concentric cable 4 in a continuous contact state with the second pulley 2, and the third pulley 12 can better ensure that the starting contact point of the concentric cable 4 and the second pulley 2 remains unchanged. In one embodiment, the first bracket 15 and the second bracket 16 are detachably fixed to the inner and outer sides of the reserved hole wall of the pipe pile 9 to be tested, respectively. The first pulley 1 is fixed to the reserved hole wall of the pipe pile 9 to be tested through the first bracket 15, and the second pulley 2 and the third pulley 12 are fixed to the reserved hole wall of the pipe pile 9 to be tested through the second bracket 16. Further, the first bracket 15 and the second bracket 16 are both provided with a steel plate base 17, and the steel plate base 17 is provided with a plurality of screw holes 171. The reserved hole wall of the pipe pile 9 to be tested is provided with a corresponding plurality of through holes. The first bracket 15 and the second bracket 16 are fixed to the reserved hole wall of the pipe pile 9 to be tested by bolts passing through the screw holes 171 of one steel plate base 17, the through holes and the screw holes 171 of another steel plate base 17 in sequence. The first bracket 15 and the second bracket 16 are quickly disassembled and assembled by the screw holes 171 being threadedly connected with the bolts.

[0051] The present invention also provides a method for monitoring the height of the soil core in a pipe pile, comprising the following steps:

[0052] S1. Before piling, measure the full-length resistance R1 of the first cable 10, the full-length resistance R2 of the second circuit, the full-length resistance R3 of the third cable 41, the full-length resistance R0 of the metal hose 42, the diameter d of the heavy ball 8, the mass m of the heavy ball 8, the radius r1 of the first pulley 1, the radius r2 of the drum 31 and the length L of the concentric cable 4, and calculate the average resistance value R per meter of the metal hose 42 based on the full-length resistance of the metal hose 42 and the length of the concentric cable 4. m ;

[0053] S2. Assemble the soil core height monitoring device in the pile as described in any of the above items, and measure the center distance D between the first pulley 1 and the second pulley 2, the distance H1 from the top of the second pulley 2 to the pile top, and the length L of the concentric cable 4 between the heavy ball 8 and the top of the second pulley 2. b , and obtain the resistance value R measured by the resistance tester 5b , according to the formula R4=R b -L b ×R m - R1-R2-R3 is calculated to obtain the resistance R4 generated by the second pulley 2;

[0054] S3, control the reel 31 to be retracted and extended, so that the heavy ball 8 descends to the top surface of the soil core 19 in the pipe pile 9 to be tested, and the concentric cable 4 between the heavy ball 8 and the vertex of the second pulley 2 is in a taut state, and the resistance value R measured by the resistance tester 5 is obtained. i0 , and according to the formula L i0 =(R i0 -R1-R2-R3-R4) / R m Calculate the initial length L of the concentric cable 4 between the heavy ball 8 and the vertex of the second pulley 2 i0 , and according to formula H i0 =L i0 -D-πr1 / 2+H1+r1+d calculates the initial height H of the top surface of the soil core 19 from the top of the pile i0 ;

[0055] S4, start piling, the pile 9 to be tested is driven into the soil, the heavy ball 8 is lifted up the soil core 19, and then the torque sensor 32 collects the rotational torque M transmitted to the drum 31 by the driving device 33. i , according to the torque M i The control drum 31 retracts and releases the concentric cable 4, so that the concentric cable 4 between the weight ball 8 and the vertex of the second pulley 2 is in a taut state, and the resistance value R measured by the resistance tester 5 is obtained at every preset monitoring time. i1 , and according to the formula L i1 =(R i0 -R1-R2-R3-R4) / R m Calculate the length L of the concentric cable 4 between the heavy ball 8 and the vertex of the second pulley 2 i1 , and according to formula H i1 =L i1 -D-πr1 / 2+H1+r1+dCalculate the height H of the top surface of the soil core 19 from the top of the pile i1 ;

[0056] S5, calculate the height H of the soil core 19 at the current moment i :H i =H i0 -H i1 .

[0057] In the above step S1, before the pile driving starts, the full-length resistance R1 of the first cable 10, the full-length resistance R2 of the second circuit, the full-length resistance R3 of the third cable 41 and the full-length resistance R0 of the metal hose 42 are directly measured by the resistance tester 5, and the diameter d of the heavy ball 8, the radius r1 of the first pulley 1, the radius r2 of the drum 31 and the length L of the concentric cable 4 are respectively measured by a ruler or other length measuring equipment, and the mass m of the heavy ball 8 is measured by a weighing equipment, and according to the formula R m = R0 / L to calculate the average resistance value R per meter of the metal hose 42 m All the above data are input into the computer 7 in advance for subsequent calculation of the height of the soil core 19 in the pipe pile 9 to be tested.

[0058] In the above step S2, the soil core height monitoring device in the pipe pile as described in any of the above items is assembled: the drum assembly 33, the resistance tester 5, the drum control integrated machine 6, and the computer 7 are all set on the ground 18 outside the pipe pile 9 to be tested, the first pulley 1 and the second pulley 2 are respectively installed and fixed to the wall of the reserved hole of the pipe pile 9 to be tested through the first bracket 15 and the second bracket 16, and the setting height is the same, the third pulley 12 is installed and fixed to the side of the second pulley 2 away from the pipe pile 9 to be tested through the second bracket 16, and its setting height is lower than the setting height of the second pulley 2. The heavy ball 8 is connected to the concentric cable 4, and the heavy ball 8 is placed in the pipe pile 9 to be tested. After the concentric cable 4 bypasses the first pulley 1 and the second pulley 2 in sequence, it bypasses from the bottom of the third pulley 12 and is connected to the drum 31. The rotating shaft of the drum 31 is connected to the output end of the driving device 33 through the torque sensor 32. The driving device 33 can use a motor, and the motor controls the drum 31 to rotate forward and reverse to realize the retraction and release of the concentric cable 4. The drum control integrated machine 6 is electrically connected to the torque sensor 32 and the driving device 33 through the fourth cable and the fifth cable respectively, and the second pulley 2 is electrically connected to the resistance tester 5 through the first cable 10; the end of the third cable 41 away from the heavy ball 8 is electrically connected to the resistance tester 5 through the second cable 11, and the computer 7 is connected to the drum control integrated machine 6 and the resistance tester 5 through the sixth cable and the seventh cable respectively. After the assembly is completed, the drum 31 is controlled to be retracted and extended so that the heavy ball 8 remains in a suspended state, and the center distance D between the first pulley 1 and the second pulley 2, the distance H1 from the vertex of the second pulley 2 to the pile top, and the length L of the concentric cable 4 between the heavy ball 8 and the vertex of the second pulley 2 bIn the soil core height monitoring device in the pile of the present invention, one end of the metal hose 42 connected to the heavy ball 8 is electrically connected to the resistance tester 5 through the third cable 41 and the second cable 11, and at the same time, the contact point of the metal hose 42 and the second pulley 2 is electrically connected to the resistance tester 5 through the second pulley 2 and the first cable 10, so that a loop is formed between the metal hose 42, the third cable 41, the second cable 11, the resistance tester 5, the first cable 10 and the second pulley 2, and the resistance value measured by the resistance tester 5 is the resistance value of the entire loop, so the resistance R4 generated by the second pulley 2 = R b -L b ×R m -R1-R2-R3, and the starting contact point between the metal hose 42 and the second pulley 2 remains unchanged during the pile driving test. The resistance generated by the second pulley 2 may change to a certain extent due to the movement of the balls between the inner and outer rings of the bearing 13. However, when a bearing 13 with a smaller ball diameter and a denser arrangement in the annular direction is used, the corresponding length of the electric path remains basically unchanged. Therefore, the corresponding electric path remains basically unchanged, and the resistance value generated by the second pulley 2 changes little. In addition, the resistance generated by the second pulley 2 is much smaller than the average resistance per meter of the metal hose 42. The resistance value generated by the second pulley 2 can be regarded as unchanged.

[0059] In the above step S3, the reel 31 is controlled to be retracted and released, so that the heavy ball 8 is lowered to the top surface of the soil core 19 in the pipe pile 9 to be tested, and the concentric cable 4 between the heavy ball 8 and the vertex of the second pulley 2 is in a taut state. According to the formula L i0 =(R i0 -R1-R2-R3-R4) / R m Calculate the initial length L of the concentric cable 4 between the heavy ball 8 and the vertex of the second pulley 2 i0 , where the resistance tester 5 measures the resistance value of the entire circuit, so according to the resistance value R measured by the resistance tester 5 i0 , by R i0 -R1-R2-R3-R4 calculates the resistance value of the metal hose 42 between the heavy ball 8 and the vertex of the second pulley 2, and then divides the calculated resistance value of the metal hose 42 by the average resistance value R per meter of the metal hose 42 m , the initial length L of the concentric cable 4 between the heavy ball 8 and the vertex of the second pulley 2 can be calculated i0 . And according to the formula H i0 =L i0 -D-πr1 / 2+H1+r1+d calculates the initial height H of the top surface of the soil core 19 from the top of the pile i0 , where πr1 / 2 is one quarter of the circumference of the first pulley 1, and the initial height H of the top surface of the soil core 19 from the top of the pile i0 That is, the length of the pipe pile 9 to be measured, and the above data is input into the computer 7 in advance.

[0060] In the above step S4, piling is started, the pipe pile 9 to be tested is driven into the soil to form a soil core 19, and after the heavy ball 8 is lifted by the soil core 19, the torque sensor 32 collects the rotational torque M transmitted to the drum 31 by the driving device 33. i According to the torque M i The control drum 31 retracts and releases the concentric cable 4, so that the concentric cable 4 between the weight ball 8 and the vertex of the second pulley 2 is in a taut state. The automatic monitoring time is preset, and the resistance value R measured by the resistance tester 5 is obtained at every preset monitoring time according to the preset monitoring time. i1 , and according to the formula L i1 =(R i0 -R1-R2-R3-R4) / R m Calculate the length L of the concentric cable 4 between the heavy ball 8 and the vertex of the second pulley 2 i1 , and according to formula H i1 =L i1 -D-πr1 / 2+H1+r1+dCalculate the height H of the top surface of the soil core 19 from the top of the pile i1 The calculation process is the same as step S3 and will not be repeated here.

[0061] Further, in step S4, according to the rotational torque M i The steps of controlling the drum 31 to retract and release the coaxial cable 4 so that the coaxial cable 4 between the weight ball 8 and the vertex of the second pulley 2 is in a taut state include:

[0062] S41, judge M i / r2 is greater than or equal to 0.8×(m·g-ρ·g·π·D 3 / 6), where g is the acceleration due to gravity and ρ is the mass density of the heavy ball 8;

[0063] S42, if yes, then control the reel 31 to reverse and release the concentric cable 4 until 0.5×(m·g-ρ·g·π·D 3 / 6)<M i / r2<0.8×(m·g-ρ·g·π·D 3 / 6), control the reel 31 to stop;

[0064] S43, if not, then judge M i / r2 is less than or equal to 0.5×(m·g-ρ·g·π·D 3 / 6);

[0065] S44, if yes, then control the reel 31 to rotate forward, tighten the concentric cable 4, until 0.5×(m·g-ρ·g·π·D 3 / 6)<M i / r2<0.8×(m·g-ρ·g·π·D 3 / 6), control the reel 31 to stop.

[0066] In the above steps S41 to S44, ρ·g·π·D 3 / 6 is the buoyancy of the heavy ball 8 placed in the water. This is mainly because when the tested pipe pile 9 is driven in the water, the mud surface is below the water surface, so the buoyancy effect needs to be considered. When driving piles on land, the buoyancy will not have any effect. i =(m·g-ρ·g·π·D 3 / 6)×rotor radius r2, where (m·g-ρ·g·π·D 3 / 6) is the tension on the concentric cable 4. The tension on the concentric cable 4 is limited to a range, and the minimum value of the range is 0.5×(m·g-ρ·g·π·D 3 / 6), the maximum value of the interval is 0.8×(m·g-ρ·g·π·D 3 / 6), the purpose is to keep the concentric cable 4 in a taut state without lifting the heavy ball 8. In addition, considering that the reel control integrated machine 6 can quickly control the reel 31 through the driving device 33 to quickly control the retraction and extension of the concentric cable 4, it cannot control the bending connection. Therefore, the tension of the concentric cable 4 is limited to a range, so that the tension of the concentric cable 4 can quickly reach the condition to enter the calculation to obtain the height H of the top surface of the soil core 19 from the pile top i1 steps.

[0067] In the above S5, the length H of the pipe pile 9 to be measured is i0 Subtract the height H from the top of the soil core 19 to the top of the pile i1 The height of the soil core 19 in the pipe pile 9 to be measured can be obtained. The present invention can automatically monitor the height of the soil core 19 in the pipe pile in real time, with a high degree of automation and low safety risk, so as to solve the problems that the existing soil core 19 height measurement device and method are difficult to collect the height of the soil core 19 and have high safety risks.

[0068] Further, after the step of calculating the height of the soil core 19 at the current moment, the method further comprises:

[0069] S6. According to the current time t i and soil core 19 height H i , draw the soil core 19 height H i With the current time t i The relationship curve, where the current moment t i The time starts from the beginning of piling as zero hour.

[0070] In the above step S6, after obtaining the resistance value R measured by the resistance tester 5 i1When , record the current time t i , current time t i The time starts from the beginning of piling as zero, and the time is based on the current time t i and the corresponding soil core 19 height H i , draw the soil core 19 height H i With the current time t i The relationship curve is used to monitor the change of the height of the soil core 19 in the pipe pile with the pile sinking time during the pile sinking process of the pipe pile 9 to be tested in real time and intuitively.

[0071] Compared with the prior art, the beneficial effects of the present invention are: it can quickly monitor in real time the change of the height of the soil core 19 in the pipe pile 9 to be tested during the pile sinking process as the pile sinking time increases, it can be applied to complex engineering environments, is simple and convenient to operate, can automatically monitor the height of the soil core 19 in the pipe pile in real time, has a high degree of automation, and has low safety risks, so as to solve the problems of the existing soil core 19 height measurement devices and methods being difficult to collect the height of the soil core 19 and having high safety risks.

[0072] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Therefore, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A method for monitoring the height of soil core in a pipe pile, characterized in that: The device comprises a soil core height monitoring device in a pipe pile, the soil core height monitoring device in the pipe pile comprises a first pulley, a second pulley, a reel assembly, a concentric cable, a resistance tester, a reel control integrated machine, a computer and a heavy ball, the first pulley and the second pulley are respectively arranged on the inner side and the outer side of the reserved hole wall of the pipe pile to be tested, and the two are arranged at the same height; The reel assembly includes a reel, a torque sensor, and a driving device, wherein the driving device is connected to the reel drive through the torque sensor; The reel control integrated machine is electrically connected to the torque sensor and the driving device respectively; The heavy ball is naturally placed in the pile hole of the pipe pile to be tested to the mud surface inside the pipe, and is connected to a concentric cable; The concentric cable is connected to the drum after winding around the first pulley and the second pulley in sequence; The concentric cable comprises a third cable and a metal hose sleeved outside the third cable, one end of the third cable connected to the weight ball is electrically connected to one end of the metal hose connected to the weight ball, and the rest of the third cable except the end connected to the weight ball is insulated and isolated from the metal hose; The metal hose is insulated from the first pulley and electrically connected to the second pulley; The second pulley is electrically connected to the resistance tester via a first cable; The end of the third cable away from the heavy ball is electrically connected to the resistance tester through the second cable; The computer is connected to the reel control integrated machine and the resistance tester respectively; The method comprises the following steps: S1. Before piling, measure the full-length resistance of the first cable R1, the full-length resistance of the second cable R2, the full-length resistance of the third cable R3, the full-length resistance of the metal hose R0, the diameter of the heavy ball d, the mass of the heavy ball m, the radius of the first pulley r1, the radius of the drum r2 and the length of the concentric cable L, and calculate the average resistance value R per meter of the metal hose based on the full-length resistance of the metal hose and the length of the concentric cable m ; S2, assemble the soil core height monitoring device in the pipe pile, measure the center distance D between the first pulley and the second pulley, the distance H1 from the second pulley vertex to the pile top, and the concentric cable length L between the heavy ball and the second pulley vertex b , and obtain the resistance value R measured by the resistance tester b , according to the formula R4= R b -L b ×R m - R1- R2- R3 is used to calculate the resistance R4 generated by the second pulley; S3, control the reel to retract and release, so that the heavy ball drops to the top surface of the soil core in the pipe pile to be tested, and the concentric cable between the heavy ball and the top of the second pulley is in a taut state, and the resistance value R measured by the resistance tester is obtained. i0 , and according to the formula L i0 =(R i0 -R1-R2-R3-R4) / R m Calculate the initial length L of the concentric cable from the heavy ball to the vertex of the second pulley i0 , and according to formula H i0 = L i0 - D-πr1 / 2+H1+ r1+d calculates the initial height H of the top of the soil core from the top of the pile i0 ; S4, start piling, the pile to be tested is driven into the soil, the weight ball is lifted up the soil core and the torque sensor collects the torque M transmitted from the drive device to the drum. i , according to the torque M i Control the reel to retract and release the concentric cable, so that the concentric cable between the heavy ball and the second pulley vertex is in a taut state, and obtain the resistance value R measured by the resistance tester at every preset monitoring time. i1 , and according to the formula L i1 =(R i1 - R1-R2-R3-R4) / R m Calculate the length L of the concentric cable from the heavy ball to the vertex of the second pulley i1 , and according to formula H i1 = L i1 - D-πr1 / 2+H1+ r1+d calculates the height H of the top of the soil core from the top of the pile i1 ; S5. Calculate the soil core height H at the current moment i :H i =H i0 -H i1 .

2. The method for monitoring the soil core height in a pipe pile according to claim 1, characterized in that: The torque M i The steps of controlling the drum to retract and release the coaxial cable so that the coaxial cable between the heavy ball and the vertex of the second pulley is in a taut state include: Judge M i / r2 is greater than or equal to 0.8×(m•g-ρ•g•π•D 3 / 6), where g is the acceleration due to gravity and ρ is the mass density of the heavy ball; If so, the control drum is reversed to loosen the concentric cable until 0.5×(m·g-ρ·g·π·D 3 / 6)<M i / r2<0.8×(m·g-ρ·g·π·D 3 / 6), control the reel to stop; If not, then judge M i / r2 is less than or equal to 0.5×(m·g-ρ·g·π·D 3 / 6); If so, the drum is controlled to rotate forward and tighten the concentric cable until 0.5×(m·g-ρ·g·π·D 3 / 6)<M i / r2<0.8×(m·g-ρ·g·π·D 3 / 6) to control the reel to stop.

3. The method for monitoring the soil core height in a pipe pile according to claim 1, characterized in that: After the step of calculating the soil core height at the current moment, the method further comprises: According to the current time t i and soil core height H i , draw the soil core height H i With the current time t i The relationship curve, where the current moment t i The timing starts from the time when piling starts.

4. The method for monitoring the soil core height in a pipe pile according to claim 1, characterized in that: It also includes a third pulley, which is arranged on a side of the second pulley away from the pipe pile to be tested, and its setting height is lower than the setting height of the second pulley. The coaxial cable is connected to the drum after passing under the third pulley, and the metal hose is insulated from the third pulley.

5. The method for monitoring the soil core height in a pipe pile according to claim 4, characterized in that: The first pulley, the second pulley and the third pulley all include bearings and wheel grooves arranged on the bearings. The wheel grooves of the first pulley and the third pulley are made of insulating materials, and the wheel groove of the second pulley is made of conductive material.

6. The method for monitoring the soil core height in a pipe pile according to claim 4, characterized in that: The first pulley is fixed to the wall of the reserved hole of the pipe pile to be tested through the first bracket, and the second pulley and the third pulley are fixed to the wall of the reserved hole of the pipe pile to be tested through the second bracket.

7. The method for monitoring the soil core height in a pipe pile according to claim 6, characterized in that: The first bracket and the second bracket are both provided with a steel plate base, the steel plate base is provided with a plurality of screw holes, and the wall of the reserved hole of the pipe pile to be tested is provided with a corresponding plurality of through holes. The first bracket and the second bracket are installed and fixed to the wall of the reserved hole of the pipe pile to be tested by bolts passing through the screw holes, the through holes and the screw holes of one steel plate base in sequence.

8. The method for monitoring the soil core height in a pipe pile according to claim 1, characterized in that: The reel assembly, resistance tester, reel control integrated machine and computer are all set up on the ground outside the pipe pile to be tested.

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