A method for evaluating pile bearing capacity using laser radar

Abstract

The invention discloses a method for evaluating pile bearing capacity by using laser radar, and relates to the technical field of data analysis. The method adopts an evaluation system to work. The system comprises a laser radar, a control terminal, a data analysis system and a pile hammer. A hammer core is arranged inside the pile hammer. The laser radar is arranged on the top of the aircraft head of the pile driving frame, directly above the center of the hammer core of the pile hammer. The control terminal is electrically connected to the laser radar. The control terminal is used to automatically record monitoring data and supply power to the radar. The control terminal data is copied to the data analysis system through a USB interface for analysis. The data analysis system comprises a motion trajectory generation module and an energy analysis module. The motion trajectory generation module is used to draw a position-time curve of the top of the hammer core by using the measured distance data from the radar launch port to the top surface of the hammer core. The invention has the characteristic of high certainty.

Description

Technical Field

[0001] The present invention relates to the technical field of data analysis, and in particular to a method for evaluating the bearing capacity of a pile by using a laser radar. Background Art

[0002] At present, in the process of hammer pile construction, the original recorded data mainly relies on manual recording, mainly recording parameters such as the number of hammer blows per meter, the total number of hammer blows, the penetration of the last three arrays, the pile length, and the elevation value. The recording method is mainly to draw lines on the pile body every meter, and then use a counter to count; these parameters are very rough, and the accuracy of the data is affected by many factors such as the marking and the seriousness of the recorder's work. The diesel hammer is started by compression ignition of diesel, so it is necessary to ensure that the closed gas in the cylinder reaches a certain compression ratio. Sometimes when piling on soft soil, it is often impossible to ignite and detonate due to the small reaction force and insufficient compression. It is necessary to use a hook to lift the hammer head several times to unhook and impact before it can start. Therefore, when constructing hammer piles, when the stratum is soft, the hammer jump is small; when the stratum is hard, the hammer jump will be high.

[0003] However, the current recording method can only record the number of hammer strikes. The number of hammer strikes per meter or the total number of hammer strikes can only roughly reflect the ground conditions and the construction conditions of the piles. It can only serve as a qualitative reference for the pile bearing capacity, and cannot be quantitatively analyzed. When the ground is difficult to strike, the number of hammer strikes is high, or the pile body cannot be sunk to the designed elevation, the final hammer standard is usually controlled by the penetration degree or the fatigue strength of the pile body. Moreover, the penetration degree or the fatigue strength of the pile body is only an empirical value, and there is no quantifiable standard. Therefore, it is necessary to design a method with high certainty to evaluate the bearing capacity of piles using lidar. Summary of the invention

[0004] The object of the present invention is to provide a method for evaluating the bearing capacity of a pile using a laser radar, so as to solve the problems raised in the above background technology.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: a method for evaluating the bearing capacity of a pile by using a laser radar, the method adopts an evaluation system to work, the system includes a laser radar, a control terminal, a data analysis system and a pile hammer, the pile hammer is provided with a hammer core inside, the laser radar is arranged on the top of the pile driving frame, directly above the center of the hammer core of the pile hammer, the control terminal is electrically connected to the laser radar, the control terminal is used to automatically record monitoring data and power the radar, and the control terminal data is copied to the data analysis system through a USB interface for analysis;

[0006] The data analysis system includes a motion trajectory generation module and an energy analysis module. The motion trajectory generation module is used to use the measured distance data from the radar launch port to the top surface of the hammer core to draw a position-time curve of the hammer core apex. The energy analysis module is used to use the number of hammer blows at each depth of burial and the hammer jump height during the hammer blow to calculate the hammer energy at each depth of burial.

[0007] According to the above technical solution, the following steps are included:

[0008] W0. After the pile driver enters the construction area and is in place, the pile frame remains stable and is in a static state relative to the pile body, which is used as a relatively fixed reference. After the laser radar is installed, the control terminal power is turned on and the measurement frequency is set. At this time, there is no pile hammer and pile under the radar, and there is no obstacle. The radar wave directly measures the distance S from the radar launch port to the ground;

[0009] W1. Hang the pile in place, press the pile cap under the hammer seat onto the pile top, straighten the pile driving frame, and place the hammer core on the hammer seat, directly below the radar. At this time, the downward laser is blocked and reflected by the top of the hammer core of the pile hammer. The distance S0 from the radar launch port to the top of the hammer core is measured and recorded as the starting distance.

[0010] W2. After each blow, the pile and hammer will sink, and the distance S measured when the hammer core falls to the lowest point i , and S i -S0 is the depth of the pile into the soil. The hammer core is lifted by a hook, and then unhooked and impacted downward to compress the air enclosed in the cylinder, and pile driving begins. The laser radar starts working and automatically records.

[0011] W3. During the piling process, as the pile sinks and the hammer core rises and falls, the movement trajectory of the hammer core during the entire construction process will be measured and recorded by the radar according to the set frequency. Based on the recorded data, the position-time curve of the hammer core vertex is drawn with time and distance S as the coordinate axes;

[0012] W4. Analyze the data by compiling software, calculate all the trough values ​​and peak values, and obtain the total hammer energy;

[0013] W5. Record the construction data of each pile, and then combine it with the static load test of the test pile to calculate the hammer loss coefficient of the same type of equipment, and evaluate other pile foundations that have not been static load tested during the construction of the engineering pile.

[0014] According to the above technical solution, W4 includes the following specific steps:

[0015] W4-1, the criterion for determining the trough is t i -t i-1 >0 and t i -t i+1<0; the peak judgment standard is t i -t i-1 <0 and t i -t i+1 >0, the wave crest indicates the moment when the hammer jumps to the highest point during the hammering process; the wave trough indicates the moment when the hammer drops to the lowest point and contacts the hammer pad and the cylinder explodes;

[0016] W4-2, suppose the distance values ​​corresponding to the moments t1, t2, t3, and t4 are S1, S2, S3, and S4 respectively. According to the calculation results, S3 is identified as the trough value and S7 is the peak value. All trough values ​​and peak values ​​are calculated in the software and recorded as T i and P i ;

[0017] W4-3. When a trough value appears, it is recorded as a hammer blow. The jump height of this hammer blow is the trough value minus the peak value, that is, h i =T i -P i , and the pile penetration depth d during this hammering is obtained i =T i -S0, d = S3-S0;

[0018] W4-4, get the number of hammer blows at each depth of the pile and the hammer jump height at each hammer blow, so as to calculate the depth of each depth of the pile d i Hammer energy E i =qh i , the total hammering energy of the pile is E = Σqh i , where q is the weight of the hammer core, h i The height of each hammer jump.

[0019] According to the above technical solution, W5 includes the following specific steps:

[0020] W5-1. When the project conducts pile tests, the construction data of each pile is recorded and the total hammer energy E of each pile is calculated; then combined with the static load test of the test pile, the calculated total hammer energy of the pile is matched with the static load test pile body bearing capacity Q. By accumulating enough data, the hammer loss coefficient λ = Q / E of the same type of equipment can be calculated;

[0021] W5-2. Use the hammer loss coefficient obtained to evaluate other pile foundations that have not been subjected to static load tests during the construction of the engineering piles, i.e., Q = λE, to verify the construction of the pile foundation.

[0022] According to the above technical solution, the data analysis system also includes a pile top model comparison module, a pile body strength calculation module, an ultrasonic scanning unit, and a bearing capacity analysis module. The ultrasonic scanning unit is used to scan the internal structure of the pile using ultrasonic scanning technology and generate an ultrasonic detection model; the pile top model comparison module is used to compare the ultrasonic detection models of the damaged pile and the initial pile, and calculate the damaged position mark and the damaged area; the pile body strength calculation module is used to calculate the hammer energy according to the detected pile body strength; the bearing capacity analysis module is used to analyze the damage of the pile under the current number of hammer blows and hammer energy to determine whether it has reached its bearing capacity.

[0023] According to the above technical solution, the data analysis system includes the following working steps:

[0024] W6. When used at the top of piles during pile foundation construction, scan the concrete at the top of the pile, build an ultrasonic detection model of the pile, and analyze its vulnerable locations;

[0025] W7. Before the new pile is formed, it is matched to the specific pile foundation to be applied, and the ultrasonic detection model of piles damaged by pile foundation construction is brought in;

[0026] W8. Automatically adjust the pile strength according to the optimization target to reduce the probability of the vulnerable position being damaged first.

[0027] According to the above technical solution, in the above steps W6-W7, the specific method for establishing the ultrasonic detection model is:

[0028] Wa, before the pile is used, it is scanned by an ultrasonic scanning unit to obtain an initial three-dimensional ultrasonic detection model of the pile;

[0029] Wb, using an ultrasonic scanning unit to scan the pile top after the pile foundation construction is damaged, and establish a three-dimensional ultrasonic detection model of the damaged pile, compare the three-dimensional ultrasonic detection model with the initial pile three-dimensional ultrasonic detection model, mark the defective parts and calculate the proportion of the defective area;

[0030] Wc, first determine the design area size and initial pile strength, the initial pile strength is fixed;

[0031] Wd. According to the current pile body strength, the ultrasonic detection model of the damaged piles in the current pile foundation construction is brought in to mark the pile top areas with different degrees of damage to update the pile body strength requirements.

[0032] According to the above technical solution, the specific method for updating the pile strength requirement is as follows: when it is detected that the actual volume proportion B of the damaged part of the pile top exceeds the theoretical value B n When the pile body is made stronger, the volume proportion of the damaged part at the top of the pile is reduced. The specific formula is:

[0033]

[0034] In the formula

[0035] B n The theoretical value of the volume proportion of the damaged part of the pile top when the hammering is stopped is between 5-8%;

[0036] k is the pile type influence coefficient;

[0037] C is the concrete strength grade value, in MPa.

[0038] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: the present invention monitors the movement trajectory of the hammer core through a laser radar, and through analysis and calculation, can obtain the penetration depth of each hammer blow and the hammer jump height of each blow, thereby calculating the total hammer energy of a pile; then the total hammer energy data of the same pile is compared and matched with the load test of the pile, and this is used as a method for evaluating the bearing capacity of the pile, which can greatly improve the accuracy of the evaluation. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0040] Figure 1 It is the motion trajectory diagram of the hammer core of the present invention;

[0041] Figure 2 It is a schematic diagram of the installation of the laser radar of the present invention;

[0042] Figure 3 It is a schematic diagram of the height and distance of the hammer jump of the present invention. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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] See also Figure 1-Figure 3The present invention provides a technical solution: a method for evaluating the bearing capacity of a pile by using a laser radar, the method adopts an evaluation system to work, the system includes a laser radar, a control terminal, a data analysis system and a pile hammer, a hammer core is arranged inside the pile hammer, the laser radar is arranged on the top of the aircraft head of the pile driving frame, directly above the center of the hammer core of the pile hammer, the control terminal is electrically connected to the laser radar, the control terminal is used to automatically record monitoring data and supply power to the radar, and the control terminal data is copied to the data analysis system through a USB interface for analysis;

[0045] The data analysis system includes a motion trajectory generation module and an energy analysis module. The motion trajectory generation module is used to draw a position-time curve of the top of the hammer core using the measured distance data from the radar launch port to the top surface of the hammer core. The energy analysis module is used to calculate the hammer energy at each burial depth using the number of hammer strikes at each burial depth and the hammer jump height at each hammer strike.

[0046] The following steps are involved:

[0047] W0. After the pile driver enters the construction area and is in place, the pile frame remains stable and is in a static state relative to the pile body, which is used as a relatively fixed reference. After the laser radar is installed, the control terminal power is turned on and the measurement frequency is set. At this time, there is no pile hammer and pile under the radar, and there is no obstacle. The radar wave directly measures the distance S from the radar launch port to the ground;

[0048] W1. Hang the pile in place, press the pile cap under the hammer seat onto the pile top, straighten the pile driving frame, and place the hammer core on the hammer seat, directly below the radar. At this time, the downward laser is blocked and reflected by the top of the hammer core of the pile hammer. The distance S0 from the radar launch port to the top of the hammer core is measured and recorded as the starting distance.

[0049] W2. After each blow, the pile and hammer will sink, and the distance S measured when the hammer core falls to the lowest point i , and S i -S0 is the depth of the pile into the soil. The hammer core is lifted by a hook, and then unhooked and impacted downward to compress the air enclosed in the cylinder, and pile driving begins. The laser radar starts working and automatically records.

[0050] W3. During the piling process, as the pile sinks and the hammer core rises and falls, the movement trajectory of the hammer core during the entire construction process will be measured and recorded by the radar according to the set frequency. Based on the recorded data, the position-time curve of the hammer core vertex is drawn with time and distance S as the coordinate axes;

[0051] W4. Analyze the data by compiling software, calculate all the trough values ​​and peak values, and obtain the total hammer energy;

[0052] W5. Record the construction data of each pile, and then combine it with the static load test of the test pile to calculate the hammer loss coefficient of the same type of equipment, and evaluate other pile foundations that have not been statically tested during the construction of the engineering pile;

[0053] W4 includes the following specific steps:

[0054] W4-1, the criterion for determining the trough is t i -t i-1 >0 and t i -t i+1 <0; the peak judgment standard is t i -t i-1 <0 and t i -t i+1 >0, the wave crest indicates the moment when the hammer jumps to the highest point during the hammering process; the wave trough indicates the moment when the hammer drops to the lowest point and contacts the hammer pad and the cylinder explodes;

[0055] W4-2, suppose the distance values ​​corresponding to the moments t1, t2, t3, and t4 are S1, S2, S3, and S4 respectively. According to the calculation results, S3 is identified as the trough value and S7 is the peak value. All trough values ​​and peak values ​​are calculated in the software and recorded as T i and P i ;

[0056] W4-3. When a trough value appears, it is recorded as a hammer blow. The jump height of this hammer blow is the trough value minus the peak value, that is, h i =T i -P i , and the pile penetration depth d during this hammering is obtained i =T i -S0, d = S3-S0;

[0057] W4-4, get the number of hammer blows at each depth of the pile and the hammer jump height at each hammer blow, so as to calculate the depth of each depth of the pile d i Hammer energy E i =qh i , the total hammering energy of the pile is E = Σqh i , where q is the weight of the hammer core, h i The height of each hammer jump;

[0058] W5 includes the following specific steps:

[0059] W5-1. When the project conducts pile tests, the construction data of each pile is recorded and the total hammer energy E of each pile is calculated; then combined with the static load test of the test pile, the calculated total hammer energy of the pile is matched with the static load test pile body bearing capacity Q. By accumulating enough data, the hammer loss coefficient λ = Q / E of the same type of equipment can be calculated;

[0060] W5-2. Use the hammer loss coefficient obtained to evaluate other pile foundations that have not been subjected to static load tests during the construction of engineering piles, i.e., Q = λE, to verify the construction of pile foundations;

[0061] The data analysis system also includes a pile top model comparison module, a pile body strength calculation module, an ultrasonic scanning unit, and a bearing capacity analysis module. The ultrasonic scanning unit is used to scan the internal structure of the pile using ultrasonic scanning technology and generate an ultrasonic detection model; the pile top model comparison module is used to compare the ultrasonic detection models of the damaged pile and the initial pile, and calculate the damaged position mark and the damaged area; the pile body strength calculation module is used to calculate the hammer energy according to the detected pile body strength; the bearing capacity analysis module is used to analyze the damage of the pile under the current number of hammer blows and hammer energy to determine whether it has reached the bearing capacity;

[0062] The data analysis system includes the following working steps:

[0063] W6. When used at the top of piles during pile foundation construction, scan the concrete at the top of the pile, build an ultrasonic detection model of the pile, and analyze its vulnerable locations;

[0064] W7. Before the new pile is formed, it is matched to the specific pile foundation to be applied, and the ultrasonic detection model of piles damaged by pile foundation construction is brought in;

[0065] W8. Automatically adjust the pile strength according to the optimization target to reduce the probability of the vulnerable position being damaged first;

[0066] In the above steps W6-W7, the specific method for establishing the ultrasonic detection model is:

[0067] Wa, before the pile is used, it is scanned by an ultrasonic scanning unit to obtain an initial three-dimensional ultrasonic detection model of the pile;

[0068] Wb, using an ultrasonic scanning unit to scan the pile top after the pile foundation construction is damaged, and establish a three-dimensional ultrasonic detection model of the damaged pile, compare the three-dimensional ultrasonic detection model with the initial pile three-dimensional ultrasonic detection model, mark the defective parts and calculate the proportion of the defective area;

[0069] Wc, first determine the design area size and initial pile strength, the initial pile strength is fixed;

[0070] Wd, according to the current pile body strength, then bring in the ultrasonic detection model of the damaged piles in the current pile foundation construction, mark the pile top areas with different degrees of damage, and update the pile body strength;

[0071] In Wd, the specific method for updating the pile strength requirement is as follows: when it is detected that the volume proportion of the actual damaged part of the pile top B exceeds the theoretical value B nWhen the pile body is made stronger, the volume proportion of the damaged part at the top of the pile is reduced. The specific formula is:

[0072]

[0073] In the formula

[0074] B n The theoretical value of the volume proportion of the damaged part of the pile top when the hammering is stopped is between 5-8%;

[0075] k is the pile type influence coefficient;

[0076] C is the concrete strength grade value, in MPa. When the hammering energy is greater, the requirements for the pile body are higher and the damage is smaller. The theoretical value is B n is dynamic, the actual detection value B needs to be based on B n Perform dynamic comparison.

[0077] A stainless steel rain and dustproof cover is set on the top of the base; when assembling the pile driver, the laser radar is installed on the fixed base; through the RS485 communication cable, it goes down along the main tower of the pile driver into the cab and is connected to the control terminal set in the cab.

[0078] Since the frequency of pile hammers is mostly 38-45 hits / minute, or about 1.4 seconds per hit, the radar can be set to measure once every 140 milliseconds, that is, 10 times per hammer hit.

[0079] The S1, S2, S3, and S4 graphs all reflect the distance from the radar launch port to the top surface of the hammer core measured at different starting heights at different time points. The distance S3 measured at the trough at this time, and the difference S3-S0 from the initial value S0 is the depth of the pile into the soil. The trough value-peak value is h=S3-S7.

[0080] When difficult strata are crossed or unexpected final hammers occur during construction, the reliability of this method for evaluating the final hammer will greatly exceed the final hammer standard determined by penetration or hammer count. The laser radar data has high accuracy, automatic recording, little external interference, and relatively reliable data. It quantifies parameter data that cannot be reflected in previous records, and can deduce the hammer energy and depth of each hammer hit; it avoids the drawback that each hammer hit of different hammer energies in the current construction records is recorded as one hit, which cannot accurately reflect the actual construction of the pile. The radar recording time interval can be adjusted, and it can be adjusted specifically for different frequency hammer types such as barrel hammers, guide rod hammers, and hydraulic hammers. It has strong adaptability, and the data can reflect the entire construction process. It can accurately reflect the differences in different strata, different hammer gears, and different hammer types at various depths. The amount of data obtained is large and has strong support. When encountering difficult strata, it can reduce the large uncertainty in judging the final hammer standard based on penetration and hammer count.

[0081] 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.

[0082] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for evaluating pile bearing capacity using laser radar, characterized in that: The method uses an evaluation system to work, which includes a laser radar, a control terminal, a data analysis system and a pile hammer. The pile hammer is provided with a hammer core inside. The laser radar is arranged on the top of the aircraft head of the pile driving frame, directly above the center of the hammer core of the pile hammer. The control terminal is electrically connected to the laser radar. The control terminal is used to automatically record monitoring data and supply power to the radar. The control terminal data is copied to the data analysis system through a USB interface for analysis. The data analysis system includes a motion trajectory generation module and an energy analysis module. The motion trajectory generation module is used to draw a position-time curve of the top of the hammer core by using the measured distance data from the radar launch port to the top surface of the hammer core. The energy analysis module is used to calculate the hammer energy at each burial depth by using the number of hammer strikes at each burial depth and the hammer jump height at each hammer strike. The data analysis system also includes a pile top model comparison module, a pile body strength calculation module, an ultrasonic scanning unit, and a bearing capacity analysis module. The ultrasonic scanning unit is used to scan the internal structure of the pile using ultrasonic scanning technology and generate an ultrasonic detection model; the pile top model comparison module is used to compare the ultrasonic detection models of the damaged pile and the initial pile, and calculate the damaged position mark and the damaged area; the pile body strength calculation module is used to calculate the hammer energy according to the detected pile body strength; the bearing capacity analysis module is used to analyze the damage of the pile under the current number of hammer blows and hammer energy to determine whether it has reached the bearing capacity; The following steps are involved: W0. After the pile driver enters the construction area and is in place, the pile frame remains stable and is in a static state relative to the pile body, which is used as a relatively fixed reference. After the laser radar is installed, the control terminal power is turned on and the measurement frequency is set. At this time, there is no pile hammer and pile under the radar, and there is no obstacle. The radar wave directly measures the distance S from the radar launch port to the ground; W1. Hang the pile in place, press the pile cap under the hammer seat onto the pile top, straighten the pile driving frame, and place the hammer core on the hammer seat, directly below the radar. At this time, the downward laser is blocked and reflected by the top of the hammer core of the pile hammer. The distance S0 from the radar launch port to the top of the hammer core is measured and recorded as the starting distance. W2. After each blow, the pile and hammer will sink, and the distance S measured when the hammer core falls to the lowest point i , and S i -S0 is the depth of the pile into the soil. The hammer core is lifted by a hook, and then unhooked and impacted downward to compress the air enclosed in the cylinder, and pile driving begins. The laser radar starts working and automatically records. W3. During the piling process, as the pile sinks and the hammer core rises and falls, the movement trajectory of the hammer core during the entire construction process will be measured and recorded by the radar according to the set frequency. Based on the recorded data, the position-time curve of the hammer core vertex is drawn with time and distance S as the coordinate axes; W4. Analyze the data by compiling software, calculate all the trough values ​​and peak values, and obtain the total hammer energy; W5. Record the construction data of each pile, and then combine it with the static load test of the test pile to calculate the hammer loss coefficient of the same type of equipment, and evaluate other pile foundations that have not been statically tested during the construction of the engineering pile; The data analysis system includes the following working steps: W6. During pile foundation construction, scan the concrete on the top of the pile, build an ultrasonic detection model of the pile, and analyze its vulnerable locations; W7. Before the new pile is formed, it is matched to the specific pile foundation to be applied, and the ultrasonic detection model of piles damaged by pile foundation construction is brought in; W8. Automatically adjust the pile strength according to the optimization target to reduce the probability of the vulnerable position being damaged first.

2. The method for evaluating pile bearing capacity using laser radar according to claim 1, characterized in that: The W4 comprises the following specific steps: W4-1, the criterion for determining the trough is t i -t i-1 >0 and t i -t i+1 <0; the peak judgment standard is t i -t i-1 <0 and t i -t i+1 >0, the wave crest indicates the moment when the hammer jumps to the highest point during the hammering process; the wave trough indicates the moment when the hammer drops to the lowest point and contacts the hammer pad and the cylinder explodes; W4-2, suppose the distance values ​​corresponding to the moments t1, t2, t3, and t4 are S1, S2, S3, and S4 respectively. According to the calculation results, S3 is identified as the trough value and S7 is the peak value. All trough values ​​and peak values ​​are calculated in the software and recorded as T i and P i ; W4-3. When a trough value appears, it is recorded as a hammer blow. The jump height of this hammer blow is the trough value minus the peak value, that is, h i =T i -P i , and the pile penetration depth d during this hammering is obtained i =T i -S0, d = S3-S0; W4-4, get the number of hammer blows at each depth of the pile and the hammer jump height at each hammer blow, so as to calculate the depth of each depth of the pile d i Hammer energy E i =qh i , the total hammering energy of the pile is E = Σqh i , where q is the weight of the hammer core, h i The height of each hammer jump.

3. The method for evaluating pile bearing capacity using laser radar according to claim 2, characterized in that: The W5 comprises the following specific steps: W5-1. When the project conducts pile tests, the construction data of each pile is recorded and the total hammer energy E of each pile is calculated; then combined with the static load test of the test pile, the calculated total hammer energy of the pile is matched with the static load test pile body bearing capacity Q. By accumulating enough data, the hammer loss coefficient λ = Q / E of the same type of equipment can be calculated; W5-2. Use the hammer loss coefficient obtained to evaluate other pile foundations that have not been subjected to static load tests during the construction of the engineering piles, i.e., Q = λE, to verify the construction of the pile foundation.

4. The method for evaluating pile bearing capacity using laser radar according to claim 3, characterized in that: In the above steps W6-W7, the specific method for establishing the ultrasonic detection model is: Wa, before the pile is used, it is scanned by an ultrasonic scanning unit to obtain an initial three-dimensional ultrasonic detection model of the pile; Wb, using an ultrasonic scanning unit to scan the pile top after the pile foundation construction is damaged, and establish a three-dimensional ultrasonic detection model of the damaged pile, compare the three-dimensional ultrasonic detection model with the initial pile three-dimensional ultrasonic detection model, mark the defective parts and calculate the proportion of the defective area; Wc, first determine the design area size and initial pile strength, the initial pile strength is fixed; Wd. According to the current pile body strength, the ultrasonic detection model of the damaged piles in the current pile foundation construction is brought in to mark the pile top areas with different degrees of damage to update the pile body strength requirements.

5. The method for evaluating pile bearing capacity using laser radar according to claim 4, characterized in that: In the Wd, the specific method for updating the pile strength requirement is as follows: when it is detected that the volume proportion B of the actual damaged part of the pile top exceeds the theoretical value B n When the pile body is made stronger, the volume proportion of the damaged part at the top of the pile is reduced. The specific formula is: In the formula B n The theoretical value of the volume proportion of the damaged part of the pile top when the hammering is stopped is between 5-8%; k is the pile type influence coefficient; C is the concrete strength grade value, unit is MPa.

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