Three-dimensional trajectory reconstruction method for pile sinking process under complex stratum conditions

Abstract

The application provides a three-dimensional trajectory reconstruction method for pile sinking process under complex stratum conditions, and relates to the technical field of trajectory reconstruction. The method comprises the following steps: obtaining the pile body posture, penetration information, pile pressing load and force transmission state of the static pressure pile, determining the trajectory increment and force transmission switching period; converting the trajectory increments before and after the switching to the same pile body coordinate system, and extracting the cross-switching trajectory residual error; determining the to-be-verified deflection position according to the effective same-direction accumulation of the trajectory residual error and the load penetration response deviation; executing load reduction and reloading when the construction conditions permit, determining the displacement remaining after the load reduction and verified by the reloading as the irreversible trajectory increment, and using the irreversible trajectory increment to correct the initial three-dimensional trajectory to obtain the three-dimensional pile end sinking trajectory. The method can reduce the interference of the measurement change caused by the equipment clamp replacement on the continuous deflection identification, and improve the trajectory reconstruction reliability.

Description

Technical Field

[0001] This application relates to the field of trajectory reconstruction technology, and in particular to a three-dimensional trajectory reconstruction method for pile driving process under complex geological conditions. Background Technology

[0002] Static pressure pile construction utilizes the static pressure provided by pile driving equipment to drive precast piles into the strata segment by segment. During construction, the pile driving load, penetration depth, and pile inclination state can be recorded. In sites where soft clay, silt, sand, and local hard interlayers are distributed alternately, the pile end resistance and pile side friction change with the penetration depth. Inclined soil layer interfaces, local dense areas, or obstacles can also cause the forces on both sides of the pile end to become unbalanced. The resulting spatial posture changes of the pile body need to be expressed through the pile driving trajectory so that construction personnel can determine the position of the pile end.

[0003] In existing technologies, tilt sensors, inertial measurement units, or ranging devices are often installed on the pile body or pile top to read the displacement and hydraulic pressure data of the pile driving cylinder. This type of scheme generally uses the single pressing section as the calculation section, and calculates the pile end coordinates at the end of the section based on the pile body tilt angle and vertical displacement. After the clamping mechanism is released, the actuator returns and clamps again, the coordinates of each section are connected by attitude averaging, measurement zero point reset, or coordinate splicing. At the same time, the change curve of pile driving load with penetration depth is used to characterize the change of soil resistance.

[0004] Lateral resistance in complex strata can cause pile offset to continue to develop across multiple compression zones. The loosening and re-clamping of the clamping mechanism can also cause elastic rebound, changes in the measurement reference direction, and local coordinate changes. Attitude averaging can weaken continuous offset, while coordinate splicing can retain instantaneous changes caused by equipment clamping. Load changes are also affected by soil properties and pile stress state. Data changes caused by equipment movement and continuous offset caused by lateral forces of the strata are mixed together, which can easily lead to inaccurate identification of the true deflection position and offset in the three-dimensional pile driving trajectory. Summary of the Invention

[0005] This application provides a three-dimensional trajectory reconstruction method for pile driving under complex geological conditions, which solves the problem in the prior art where data changes caused by equipment movement and continuous offsets caused by lateral forces in complex geological conditions are mixed together, resulting in inaccurate identification of the true deflection position and offset in the three-dimensional pile driving trajectory at the pile tip.

[0006] To address the aforementioned technical problems, in a first aspect, this application provides a method for reconstructing the three-dimensional trajectory of pile driving under complex geological conditions, comprising:

[0007] Acquire the pile posture and penetration information of statically driven piles during continuous pile driving stroke, as well as the pile driving load and force transmission status of the pile driving equipment;

[0008] The trajectory increment of each driving stroke in the continuous driving stroke is determined based on the pile posture and penetration information;

[0009] Determine the force transmission switching period for the termination and reconstruction of the force transmission relationship between the pile driving equipment and the static pile based on the force transmission status;

[0010] The trajectory increments before and after the force transmission switching period are converted to the same pile coordinate system. The offset vectors that continue in the same direction are extracted as the cross-switching trajectory residuals. The cross-switching trajectory residuals are then subtracted from the converted trajectory increments to obtain the updated trajectory increments.

[0011] In response to the fact that the cross-switching trajectory residuals accumulate in the same direction during the subsequent pile driving stroke and the load-penetration relationship formed by the pile driving load and the penetration information deviates from the reference penetration relationship, the deflection position to be verified is determined according to the penetration depth corresponding to the same-direction accumulation.

[0012] In response to the current pile driving load of the pile driving equipment being lower than the upper limit of the construction load and the deflection position to be verified being outside the construction restriction area, the pile driving equipment is controlled to perform load reduction and reloading in sequence to determine the irreversible trajectory increment retained after load reduction and verified by reloading.

[0013] The initial three-dimensional trajectory is formed by connecting and updating the trajectory increment according to the penetration depth, and the trajectory segment corresponding to the deflection position to be verified in the initial three-dimensional trajectory is corrected by the irreversible trajectory increment, so as to obtain the three-dimensional pile driving trajectory of the static pressure pile tip.

[0014] Optionally, the trajectory increments before and after the force transmission switching period are transformed to the same pile coordinate system, and the offset vectors that continue in the same direction are extracted as the cross-switching trajectory residuals, including:

[0015] For each force transmission switching period, based on the force transmission status, the driving stroke segment in which the force transmission relationship between the driving equipment and the static pile is continuously maintained is determined before and after the force transmission switching period, thus obtaining the stroke segment before switching and the stroke segment after switching.

[0016] Extract the trajectory increment before and after the handover from the travel segment before and after the handover, respectively;

[0017] The pile coordinate system corresponding to the trajectory increment before switching is used as the reference pile coordinate system;

[0018] The switched trajectory increment is converted to the reference pile coordinate system to obtain the converted trajectory increment;

[0019] Determine the directional angle between the trajectory increment before switching and the trajectory increment after switching;

[0020] In response to the direction angle not being greater than a preset direction threshold, the projection vector of the converted trajectory increment in the direction of the original trajectory increment is determined as the cross-switching trajectory residual corresponding to the force transmission switching period. The cross-switching trajectory residual is deducted from the lateral component of the converted trajectory increment, and the resulting lateral component is combined with the original axial component to form the updated trajectory increment.

[0021] Optionally, the residuals across the switching trajectory accumulate in the same direction during subsequent pile driving strokes, including:

[0022] Arrange the residuals of each cross-switching trajectory according to the penetration depth in the penetration information to obtain an ordered residual sequence;

[0023] The direction of the cross-switching trajectory residual with the smallest penetration depth in the ordered residual sequence is determined as the reference residual direction;

[0024] The cross-switching trajectory residuals in the ordered residual sequence are projected onto the reference residual direction to obtain the directional projection amount of each cross-switching trajectory residual;

[0025] Extract the cross-switching trajectory residuals and their penetration depth indicators that have positive directional projection values ​​and are not less than the lateral displacement that the attitude measurement device can resolve, to obtain an effective in-direction residual sequence, and then sequentially accumulate the cross-switching trajectory residuals in the effective in-direction residual sequence along the reference residual direction to obtain a cumulative trajectory residual sequence.

[0026] Optionally, the load-penetration relationship formed by the pile driving load and penetration information deviates from the benchmark penetration relationship, and the deflection position to be verified is determined based on the penetration depth corresponding to the cumulative penetration in the same direction, including:

[0027] For each span switching trajectory residual in the effective same-direction residual sequence, the load penetration response deviation of the pile stroke corresponding to the penetration depth identifier of the span switching trajectory residual is determined according to the pile driving load, penetration information and benchmark penetration relationship. The load penetration response deviations are arranged according to the same penetration depth identifier to obtain a load penetration response deviation sequence that is consistent with the number of elements and depth order of the cumulative trajectory residual sequence.

[0028] Based on the cumulative trajectory residual sequence and the load penetration response deviation sequence, extract the continuous penetration depth intervals where the incremental increase of the cumulative trajectory residual magnitude between adjacent penetration depths is not less than the lateral displacement that the attitude measurement device can resolve and the absolute value of the load penetration response deviation increases with the penetration depth. The continuous penetration depth interval with the smallest initial penetration depth is determined as the common increasing depth interval.

[0029] The pile position corresponding to the initial penetration depth of the common increasing depth range is determined as the deflection position to be verified.

[0030] Optionally, in response to the current pile driving load of the pile driving equipment being lower than the upper limit of the construction load and the deflection position to be verified being outside the construction restriction area, the pile driving equipment is controlled to perform load reduction to determine the displacement vector retained after load reduction, including:

[0031] Extract the cumulative trajectory residual corresponding to the end penetration depth of the common increasing depth interval from the cumulative trajectory residual sequence to obtain the cumulative trajectory residual at the verification time point;

[0032] The direction of the cumulative trajectory residual at the verification time point is determined as the offset direction before load reduction.

[0033] In response to determining the deflection position to be verified, the increase in penetration is paused and the pile attitude is recorded to obtain the attitude before load reduction.

[0034] Using the pre-load reduction posture as a comparison benchmark, the current pile driving load of the pile driving equipment is reduced to the holding load that maintains the force transmission relationship between the pile driving equipment and the static pile according to the force transmission state, and the pile posture under the holding load is recorded to obtain the post-load reduction posture.

[0035] The change in pile end position before and after unloading is determined based on the attitude before and after unloading.

[0036] The cumulative trajectory residual at the verification time point is superimposed with the change in pile end position before and after load reduction, and the positive component of the superposition result along the offset direction before load reduction is extracted to obtain the displacement vector retained after load reduction.

[0037] Optionally, the pile driving equipment is controlled to perform reloading to determine the irreversible trajectory increment verified by the reloading, including:

[0038] Using the displacement vector retained after unloading as the comparison benchmark for reloading, the load is increased to a verification load that does not exceed the upper limit of the construction load, and the pile posture under the verification load is recorded to obtain the posture after reloading.

[0039] The same-direction reload displacement vector is determined based on the attitude after unloading and the attitude after reloading. When the same-direction reload displacement vector is offset along the direction before unloading, the displacement vector retained after unloading is determined as the irreversible trajectory increment.

[0040] Optionally, the process for determining the pile driving stroke can be referenced, including:

[0041] For the pile driving stroke to be compared, based on the force transmission state and the survey data of the construction area, the pile driving strokes that are located in the same stratum segment as the pile driving stroke to be compared, have the same force transmission state, and have overlapping relative penetration ranges within the stroke are extracted from the continuous pile driving strokes to obtain a set of candidate pile driving strokes.

[0042] Based on the pile posture, determine the angle between the first and last pile axis directions of each candidate pile driving stroke in the candidate pile driving stroke set, and obtain the sequence of pile axis direction change angles;

[0043] The candidate pile driving stroke corresponding to the minimum value of the sequence of pile axis direction change angles in the candidate pile driving stroke set is determined as the reference pile driving stroke;

[0044] The benchmark penetration relationship is determined based on the pile driving load and penetration information corresponding to the reference pile driving stroke.

[0045] Optionally, the same-direction reload displacement vector is determined based on the attitude after unloading and the attitude after reloading, and when the same-direction reload displacement vector is offset along the direction before unloading, the displacement vector retained after unloading is determined as the irreversible trajectory increment, including:

[0046] The reload displacement vector is determined based on the change in the pile end position represented by the attitude after reloading relative to the pile end position represented by the attitude after unloading.

[0047] The projection vector of the reload displacement vector in the offset direction before unloading is determined as the same-direction reload displacement vector;

[0048] In response to the displacement vector of the same direction of reloading offset along the direction before unloading, the displacement vector retained after unloading is determined as the irreversible trajectory increment.

[0049] Optionally, the trajectory segment corresponding to the deflection position to be verified in the initial three-dimensional trajectory is corrected with irreversible trajectory increments to obtain the three-dimensional pile driving trajectory at the pile tip of the static pressure pile, including:

[0050] Based on the penetration depth corresponding to the deflection position to be verified, the penetration depth is used as the boundary for dividing the trajectory segment; when there are trajectory coordinates with the same penetration depth in the initial three-dimensional trajectory, the trajectory coordinates are used as the dividing point; when there are no trajectory coordinates with the same penetration depth, linear interpolation is performed between two adjacent trajectory coordinates according to the penetration depth to generate the dividing point; the trajectory segment extending from the dividing point along the direction of increasing penetration depth to the trajectory coordinates at the pile end is determined as the trajectory segment to be corrected.

[0051] According to the penetration depth of each trajectory coordinate in the trajectory segment to be corrected, the irreversible trajectory increment is superimposed on the corresponding trajectory coordinate in a distribution ratio that gradually increases from zero to one, so as to obtain the corrected trajectory segment.

[0052] The corrected trajectory segment is used to replace the trajectory segment to be corrected to obtain the three-dimensional pile driving trajectory at the pile tip of the static pressure pile.

[0053] Optionally, an initial 3D trajectory is formed by connecting and updating the trajectory increment according to the penetration depth, including:

[0054] The updated trajectory increments are arranged according to the penetration depth in the penetration information to obtain an ordered trajectory increment sequence.

[0055] By sequentially summing the updated trajectory increments in the ordered trajectory increment sequence, a trajectory coordinate sequence is obtained;

[0056] Connect the trajectory coordinates in the trajectory coordinate sequence to obtain the initial three-dimensional trajectory.

[0057] Optionally, after obtaining the three-dimensional pile driving trajectory at the pile tip, the method further includes:

[0058] The deflection position to be verified and the irreversible trajectory increment are marked on the three-dimensional pile driving trajectory at the pile tip to obtain the marked three-dimensional pile driving trajectory at the pile tip.

[0059] The technical solution provided in this application has the following beneficial effects:

[0060] Compared with the prior art, this application first uses the force transmission state to determine the time range for the equipment to release force transmission and re-establish force transmission, and then compares the trajectory increments of adjacent pile driving strokes under a unified coordinate reference. From the continuously collected measurement results, the lateral displacement component that crosses the equipment movement still developing in the original direction is extracted, thereby forming a geometric basis for distinguishing between changes in equipment movement and continuous offset.

[0061] After the geometric basis is formed, this application examines the common changes of the cross-switching trajectory residual and the load penetration response deviation along the penetration depth. The correspondence between geometric changes and force changes expands the attitude fluctuation in a single pile driving cycle into the identification result of continuous development in multiple pile driving cycles, thereby locating the deflection position to be verified.

[0062] After location identification is completed, this application utilizes unloading to release recoverable displacement. The displacement retained after unloading is taken as irreversible displacement, and reloading is used to check whether this displacement continues to respond along the original offset direction. Reloading is only used to verify the directional consistency of the displacement retained after unloading, and the displacement generated by reloading is not included in the irreversible trajectory increment. Subsequently, the irreversible trajectory increment verified by reloading is written into the trajectory segment after the deflection position to be verified, so that the deflection position and offset have progressive evidence formed by continuous measurement, load response and construction feedback, thereby improving the reliability of reconstructing the three-dimensional pile driving trajectory at the pile end in complex strata. Attached Figure Description

[0063] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0064] Figure 1 This is a flowchart illustrating a three-dimensional trajectory reconstruction method for pile driving under complex geological conditions, according to one embodiment of this application.

[0065] Figure 2 This is a schematic diagram illustrating the relationship between pile driving data acquisition and processing in one embodiment of this application.

[0066] Figure 3 This is a schematic diagram of the process of extracting residuals and incrementally updating trajectory across switching paths in one embodiment of this application.

[0067] Figure 4 This is a schematic diagram illustrating the variation of the cumulative trajectory residual modulus and the absolute value of the load penetration response deviation with penetration depth in one embodiment of this application.

[0068] Figure 5 This is a schematic diagram of the load reduction and reload verification process in one embodiment of this application. Detailed Implementation

[0069] The embodiments of this application are described below with reference to the accompanying drawings. The described embodiments are used to explain the technical solutions of this application and are not intended to limit the scope of protection of this application. Where they are compatible, the technical features of each embodiment can be combined.

[0070] The static pressure piles in this embodiment need to pass through complex strata composed of soft clay, silt, sand, and local hard interlayers. The pile driving equipment applies axial load through clamping or jacking mechanisms. When the pile tip enters different soil layers, the pile tip resistance and pile side friction change. The different densities of the soil at the inclined soil layer interface or on both sides of the pile tip will also cause the pile to shift laterally.

[0071] Due to the limited stroke of the actuator, the pile driving equipment needs to periodically complete clamping, pressing down, releasing clamping, returning, and re-clamping. One pile driving cycle includes the pile driving stroke in which the force transmission relationship is continuously maintained, as well as the force transmission switching period that follows. Multiple pile driving cycles are arranged continuously according to the construction time to form a continuous pile driving stroke. The displacement caused by the lateral action of the stratum can continue into subsequent pile driving cycles. The data changes caused by the equipment clamping are concentrated in the force transmission switching period. Therefore, in this embodiment, the pile driving trajectory is reconstructed layer by layer with the pile driving cycle as the data organization unit.

[0072] In response to the above construction scenario, this embodiment needs to distinguish between the data changes caused by equipment clamping and the continuous offset caused by the lateral action of the stratum during continuous pile driving. It also needs to determine the starting position of the deflection and the lateral displacement amount that needs to be written into the trajectory from the measurement results of multiple pile driving cycles, so that the reconstructed trajectory can continuously reflect the changes in the pile end position of the static pile.

[0073] To achieve the above effect, such as Figure 1 As shown, the method in this embodiment includes steps S101 to S107, and each step is executed in the order of data acquisition, single-cycle trajectory calculation, cross-cycle offset extraction, deflection position identification, force verification, and trajectory correction.

[0074] S101: Obtain the pile posture and penetration information of the statically pressed pile during the continuous pile driving stroke, as well as the pile driving load and force transmission status of the pile driving equipment.

[0075] like Figure 2 As shown, the pile attitude can be obtained by an inclination sensor or an inertial measurement unit, the penetration information can be formed based on the detection results of the pile driving cylinder stroke sensor, displacement encoder or laser rangefinder, the pile driving load can be obtained by a load sensor set in the force transmission path, and the force transmission state comes from the clamping, pressing, releasing and return control signals output by the pile driving equipment controller; the trajectory reconstruction processor receives the aforementioned information and sends the measurement results of the same pile driving cycle into the subsequent trajectory increment calculation and force transmission state judgment process.

[0076] The pile attitude represents the spatial position of the reference point on the static pressure pile and the pile axis direction. It can be a combination of three-axis position with roll angle, pitch angle and yaw angle, or a combination of three-axis position with quaternion. When the attitude measurement device only outputs the pile axis direction, the position of the reference point is provided by a displacement encoder, laser rangefinder or construction measurement device.

[0077] Penetration information includes penetration depth and penetration volume. Penetration depth represents the cumulative driving position of the statically driven pile relative to the construction reference surface, while penetration volume represents the additional driving distance between adjacent sampling times or within a single driving stroke. For adjacent sampling times, the current penetration depth equals the sum of the penetration depth at the previous sampling time and the current penetration volume. For a single driving stroke, the penetration volume equals the difference between the penetration depth at the end of the stroke and the penetration depth at the beginning of the stroke. When the direction of driving into the stratum is taken as positive, continuing to drive corresponds to a positive penetration volume, while moving back corresponds to a negative penetration volume. When a pile splice occurs, the trajectory reconstruction processor updates the axial distance from the measurement reference point to the pile tip according to the length of the newly added pile segment, ensuring that the penetration depth before and after the splice uses the same construction reference surface.

[0078] The pile driving load represents the axial load applied by the pile driving equipment to the static pile. It can be directly measured by the load sensor or calculated based on the pile driving oil pressure and the effective working area of ​​the pile driving mechanism. When using oil pressure conversion, the existing pressure-area conversion method can be called, and the equipment calibration curve can be used to compensate for mechanism friction and oil circuit hysteresis.

[0079] The force transmission state indicates the action stage of the pile driving equipment and the transmission state of the pile driving load. Table 1 shows the correspondence between action events and force transmission states. The trajectory reconstruction processor identifies the pile driving stroke and force transmission switching period in the same pile driving cycle according to the order of occurrence of control signals.

[0080] Table 1. Correspondence between the action and force transmission state of pile driving equipment

[0081]

[0082] After receiving the above four types of information, the trajectory reconstruction processor first establishes the correspondence between the various types of information based on the sampling time, and then associates the measurement results within the same pile driving cycle with the corresponding penetration depth, thereby forming the same-cycle data group required for subsequent trajectory calculation. When the sampling frequencies of each sensor are different, the existing linear interpolation method, namely Linear Interpolation, can be used to align the continuous measurement results in time, while the discrete force transmission state uses the most recent valid state before the corresponding sampling time.

[0083] After the above processing, the four types of information have been established in correspondence according to the pile driving cycle, sampling time and penetration depth. Therefore, we can proceed to step S102 to calculate the spatial displacement generated by each pile driving stroke.

[0084] S102: Determine the trajectory increment of each pile driving stroke in the continuous pile driving stroke based on the pile posture and penetration information.

[0085] In step S102, the trajectory reconstruction processor extracts the pile posture and penetration information that has been aligned with the time and depth according to the pile driving stroke, determines the pile end position at the beginning and end of the stroke respectively, and uses the difference between the two pile end positions to characterize the spatial displacement generated by the pile driving stroke; the aforementioned spatial displacement is recorded as the trajectory increment, which is the three-dimensional displacement vector of the pile end position at the end of a pile driving stroke relative to the pile end position at the beginning of the pile driving stroke. The trajectory increment is associated with the starting penetration depth, ending penetration depth and construction time of the same pile driving stroke.

[0086] To determine the pile tip positions at the beginning and end of the travel distance under the same spatial reference, the trajectory reconstruction processor establishes a construction fixed coordinate system, using the construction reference point as the origin, the designed pile axis direction as the depth direction, and two mutually perpendicular horizontal directions to represent the lateral position. Subsequently, based on the pile's attitude, the position and pile axis direction of the measurement reference point in the construction fixed coordinate system are determined. Then, the axial distance from the measurement reference point to the pile tip is extended along the pile axis direction, and the pile tip position is obtained from the extended end coordinates. When the pile attitude is represented by quaternions, the existing quaternion-to-rotation matrix method can be used to convert the pile axis direction recorded by the quaternion into a direction vector in the construction fixed coordinate system before performing the aforementioned pile tip position calculation.

[0087] When using a single attitude measurement device, the centerline of the pile body between the measurement reference point and the pile tip can be treated as a straight line. When the pile body curvature needs to be represented in segments, multiple attitude measurement devices can be set along the length of the pile body, and the pile segments between adjacent measurement positions can be connected sequentially. The end position of the last pile segment is taken as the pile tip position. The trajectory reconstruction processor subtracts the pile tip position at the beginning from the pile tip position at the end of the pile driving stroke to obtain the trajectory increment of the pile driving stroke, and uses the penetration depth to check the axial component of the trajectory increment.

[0088] After the trajectory increment of each pile driving stroke is determined, it is also necessary to use the force transmission state to divide the equipment clamping process between adjacent pile driving strokes, and then proceed to step S103 accordingly.

[0089] S103: Determine the time period for the force transmission switching between the pile driving equipment and the static pile to be disconnected and rebuilt based on the force transmission status.

[0090] After entering step S103, the trajectory reconstruction processor reads the force transmission status adjacent to each pile driving stroke, first identifies the moment when the pile driving equipment starts to release load transmission and resume load transmission, and then defines the force transmission switching period by the two moments; here, the force transmission relationship represents the force connection of the pile driving equipment to transmit axial load to the static pile. When the clamping mechanism loosens or the top pressing mechanism disengages, the corresponding force transmission is released. When it is clamped again and enters the pressing state or the top pressing mechanism re-contacts and transmits load, the corresponding force transmission is rebuilt. Thus, a pile driving cycle is divided into pile driving stroke and force transmission switching period.

[0091] For each force transmission switching period, the trajectory reconstruction processor extracts the pre-switching travel segment where the force transmission relationship is continuously maintained and effective penetration occurs, and extracts the post-switching travel segment where effective penetration occurs after the force transmission relationship is reconstructed. It also obtains the pre-switching trajectory increment and the post-switching trajectory increment from the two travel segments. The displacement during the return stroke belongs to the equipment operation process and does not enter the trajectory increment of the pile driving stroke.

[0092] The travel segments before and after the switch and their trajectory increments have been determined. The following step S104 eliminates the difference in the directional reference used in the two travel segments and determines whether the lateral offset continues to develop across the force transmission switching period.

[0093] S104: Convert the trajectory increments before and after the force transmission switching period to the same pile coordinate system, and extract the offset vectors that continue in the same direction as the cross-switching trajectory residuals.

[0094] Before performing coordinate transformation, the coordinate reference used in this embodiment should be explained. The pile coordinate system is a local coordinate system that changes with the static pressure pile posture and is set along the pile axis with one coordinate axis. The reference pile coordinate system is a common representation coordinate system established with the pile coordinate system corresponding to the trajectory increment before the switch as the reference, which is used to unify the direction reference of the trajectory increment before and after the switch.

[0095] After determining the coordinate references mentioned above, according to Figure 3 The processing sequence shown is as follows: the trajectory reconstruction processor obtains the rotational relationship between the two pile coordinate systems based on the pile posture before and after the switch, and converts the trajectory increment after the switch to the reference pile coordinate system to obtain the converted trajectory increment.

[0096] After obtaining the converted trajectory increment, the trajectory reconstruction processor extracts the lateral components perpendicular to the design pile axis from both the pre-switch trajectory increment and the converted trajectory increment. These lateral components constitute the offset vector used to determine the offset direction. When the angle between two offset vectors is within the allowable range, the lateral offset of adjacent pile driving cycles is determined to be continuous in the same direction. The preset direction threshold is determined based on the equipment calibration record. Specifically, the angles of multiple pile driving cycles are extracted from the reference pile driving record that has never experienced continuous deflection, and the upper limit of the angle that can cover attitude measurement error, clamping reconstruction repeatability error, and fluctuation of the reference pile driving direction is used as the preset direction threshold.

[0097] When the directional angle is not greater than the preset directional threshold, the trajectory reconstruction processor determines the projection vector of the converted trajectory increment in the direction of the trajectory increment before the switch as the cross-switching trajectory residual; the aforementioned projection process can be expressed according to the following cross-switching trajectory residual projection formula (1): In the formula, r represents the cross-switching trajectory residual, with the unit being m; This represents the lateral component of the trajectory increment before the switch, in meters (m). This represents the lateral component of the trajectory increment after switching to the reference pile coordinate system, in meters (m). The unit vector is dimensionless, and the calculated result is a length vector. If the lateral component before switching is less than the lateral displacement that the attitude measurement device can resolve, no direction reference is established for this pile driving cycle, and the next pile driving cycle continues.

[0098] To avoid the displacements after verification being superimposed again, the trajectory reconstruction processor, after extracting the cross-switching trajectory residuals, subtracts the cross-switching trajectory residuals from the lateral component of the converted trajectory increment, and retains the obtained lateral component and the original axial component as the updated trajectory increment. The updated trajectory increment is used to form the initial three-dimensional trajectory, and the cross-switching trajectory residuals are saved separately according to the penetration depth, waiting for the cumulative judgment and stress verification of subsequent pile driving cycles.

[0099] The local directional reference used in each pile driving cycle may be different. The trajectory reconstruction processor converts the cross-switching trajectory residual to the construction fixed coordinate system according to the attitude before the switch, and uses the penetration depth when the force transmission relationship is reconstructed as the depth identifier of the cross-switching trajectory residual.

[0100] After obtaining unified coordinates and depth identifiers from the cross-trajectory residuals, the conditions for cross-pile driving cycle arrangement and comparison are met. Subsequently, the deflection start position is determined by combining the load penetration response in step S105.

[0101] S105: In response to the cross-switching trajectory residual accumulating in the same direction during subsequent pile driving strokes and the load penetration relationship formed by the pile driving load and penetration information deviating from the reference penetration relationship, the deflection position to be verified is determined based on the penetration depth corresponding to the accumulating in the same direction.

[0102] After the cross-trajectory residual is transformed to the construction fixed coordinate system, the trajectory reconstruction processor, based on the force transmission state and the survey data of the construction area, extracts pile driving trips from the continuous pile driving trips that are located in the same stratum segment as the pile driving trips to be compared, have the same force transmission state, and have overlapping relative penetration ranges within the trip, forming a candidate pile driving trip set. Then, it calculates the angle between the first and last pile axis directions of each candidate pile driving trip, obtaining a sequence of pile axis direction change angles. The candidate pile driving trips are arranged in ascending order of pile axis direction change angles, and the candidate pile driving trip corresponding to the smallest pile axis direction change angle is determined as the reference pile driving trip. The benchmark penetration relationship is the correspondence formed by the pile driving load within the reference pile driving trip and the change in relative penetration within the trip, used to compare with the load penetration relationship of the pile driving trip to be compared. If there are no candidate pile driving trips that meet the aforementioned comparability conditions, the load penetration response joint judgment is not performed on the pile driving trip to be compared.

[0103] To compare load changes at different pile driving strokes, the trajectory reconstruction processor subtracts the initial penetration depth of the current pile driving stroke from the current penetration depth to obtain the relative penetration within the stroke. Then, it establishes a correspondence between the pile driving load and the relative penetration within the stroke; this correspondence is called the load-penetration relationship. For example, the existing finite difference method can be used to calculate the load change per unit penetration between adjacent sampling points, and the load change at the same relative penetration between the pile driving stroke to be compared and the reference pile driving stroke can be compared according to the following load-penetration response deviation formula (2): , In the formula, and This represents the pile driving load at adjacent sampling points, in kN. and Indicates the corresponding penetration depth, in meters (m). Indicates the relative penetration within the stroke, in meters; and These represent the unit penetration load variation of the pile driving stroke to be compared and the reference pile driving stroke, respectively, in kN / m; This represents the load penetration response deviation, expressed in kN / m. When a pile driving stroke includes multiple sampling point pairs, the arithmetic mean of the load penetration response deviations for each sampling point pair is calculated, so that each pile driving stroke corresponds to a load penetration response deviation.

[0104] Based on this, the trajectory reconstruction processor arranges the cross-switching trajectory residuals according to the penetration depth to obtain an ordered residual sequence, and takes the cross-switching trajectory residual direction with the smallest penetration depth in the ordered residual sequence as the reference residual direction. Then, the cross-switching trajectory residuals in the ordered residual sequence are projected onto the reference residual direction to obtain the directional projection amount of each cross-switching trajectory residual. The cross-switching trajectory residuals with positive directional projection amounts and not less than the lateral displacement that the attitude measurement device can resolve, along with their penetration depth identifiers, are extracted to obtain an effective co-directional residual sequence. The effective co-directional residual sequence is then accumulated sequentially along the reference residual direction to obtain the cumulative trajectory residual sequence.

[0105] Once the load penetration response deviation for a pile driving stroke is determined, the trajectory reconstruction processor extracts the load penetration response deviation for each span switching trajectory residual in the effective unidirectional residual sequence, based on its corresponding penetration depth identifier. These deviations are then arranged according to the same penetration depth identifier to obtain the load penetration response deviation sequence. Pile driving strokes not included in the effective unidirectional residual sequence are not considered for joint increase. Therefore, the cumulative trajectory residual sequence and the load penetration response deviation sequence have the same number of elements and depth order.

[0106] After the two sequences are depth-aligned, as follows: Figure 4 As shown, the cumulative trajectory residual magnitude increment and the absolute value of the load penetration response deviation are compared between adjacent depths from shallow to deep. When the cumulative trajectory residual magnitude increment is not less than the lateral displacement that the attitude measurement device can resolve, and the absolute value of the load penetration response deviation increases relative to the previous depth, adjacent depths are connected into a common increasing depth interval. The current interval ends when any condition is not met. When multiple common increasing depth intervals exist, the trajectory reconstruction processor selects the common increasing depth interval with the smallest initial penetration depth and determines the pile position corresponding to the initial penetration depth of this interval as the deflection position to be verified. The ending penetration depth of the common increasing depth interval is used to determine the verification point for load reduction and reloading. The trajectory reconstruction processor extracts the cumulative trajectory residual corresponding to the ending penetration depth from the cumulative trajectory residual sequence to obtain the cumulative trajectory residual at the verification point. As subsequent pile driving strokes generate new measurement results, the common increasing depth interval can continue to extend or reform.

[0107] After the deflection position is verified, it is also necessary to use the feedback of changes in construction load to distinguish between recoverable displacement and continuously retained displacement. For this purpose, step S106 is executed.

[0108] S106: In response to the current pile driving load of the pile driving equipment being lower than the upper limit of the construction load and the deflection position to be verified being outside the construction restriction area, the pile driving equipment is controlled to perform load reduction and reloading in sequence to determine the irreversible trajectory increment retained after load reduction and verified by reloading.

[0109] When performing verification condition judgment, the upper limit of construction load and the construction restriction area define the permissible load conditions and spatial conditions, respectively. The upper limit of construction load is used to constrain the reloading load during verification. The construction restriction area represents the spatial range within which the construction plan stipulates no active load reduction or reloading, which may include the protection range of underground pipelines or existing buildings, the section corresponding to the pile splice connection, and sections requiring continuous pressure maintenance. For example, the upper limit of construction load can be set to 80% to 95% of the permissible axial load of the static pressure pile. The actual percentage is set according to the design safety factor adopted in the construction plan; a value closer to 80% is selected when the design safety factor is large.

[0110] When the current pile driving load is lower than the upper limit of the construction load and the deflection position to be verified is outside the construction restriction area, the trajectory reconstruction processor sends a verification command to the pile driving equipment controller; when the current pile driving load reaches the upper limit of the construction load, the deflection position to be verified is retained and the subsequent pile driving load is reduced; when the deflection position to be verified is within the construction restriction area, the position is retained as a monitoring mark, and when a new deflection position to be verified is formed outside the construction restriction area in a subsequent pile driving cycle, the new position is verified.

[0111] When the deflection position meets the construction load and construction area conditions, such as Figure 5 As shown, the trajectory reconstruction processor extracts the cumulative trajectory residual corresponding to the end penetration depth of the common increasing depth interval from the cumulative trajectory residual sequence, and determines the direction of the cumulative trajectory residual at the verification time point as the offset direction before load reduction; the pile driving equipment pauses the increase of penetration, and waits for the pile driving equipment controller to output the load stable state, and the change of the pile end position within the continuous sampling period does not exceed the position resolution of the attitude measurement device, then the trajectory reconstruction processor records the attitude before load reduction, and uses the attitude before load reduction as the comparison benchmark for the subsequent load reduction process.

[0112] The cumulative trajectory residual at the verification point corresponds to the end penetration depth of the common increasing depth interval. The trajectory reconstruction processor uses the pile end position corresponding to this end penetration depth as the verification reference position. The position of the same pile end under the three load states is determined according to the attitude before load reduction, the attitude after load reduction, and the attitude after reloading, so that the displacement change during load reduction and reloading corresponds to the same pile end as the cumulative trajectory residual at the verification point.

[0113] In practice, the trajectory reconstruction processor controls the pile driving equipment to reduce the current pile driving load based on the force transmission status. When the force transmission status indicates that the pile driving equipment and the static pile maintain a force transmission relationship, the corresponding pile driving load is determined as the holding load. After the pile driving equipment controller outputs a stable load status, and the change in the pile end position during the continuous sampling period does not exceed the position resolution of the attitude measurement device, the trajectory reconstruction processor records the attitude after load reduction. The holding load is used to maintain the force transmission contact between the pile driving equipment and the static pile. As a numerical example, the holding load can be taken as 50% to 70% of the current pile driving load before load reduction. The actual proportion is determined based on whether the force transmission relationship indicated by the force transmission status is continuously maintained. When the force transmission status indicates that the force transmission relationship is released, the holding load proportion is increased until the force transmission status indicates that the force transmission relationship is continuously maintained.

[0114] The trajectory reconstruction processor determines the change in pile tip position relative to its pre-load position based on the pre-load and post-load attitudes, thus obtaining the change in pile tip position before and after load reduction. The processor then superimposes the cumulative trajectory residual at the verification time point with the change in pile tip position before and after load reduction, and takes the positive component of the superimposed result along the pre-load offset direction to obtain the retained displacement vector after load reduction. When the positive component is zero or reversed, the verification of this pile driving cycle ends, and subsequent pile driving cycles are monitored.

[0115] After the displacement vector retained after load reduction is determined, the pile driving equipment will maintain the load increased to the verification load, using the displacement vector retained after load reduction as the comparison benchmark for reloading. The verification load is preferentially taken as the current pile driving load before load reduction and is constrained by the upper limit of the construction load. After the load output by the pile driving equipment controller is stable and the change in pile end position during the continuous sampling period does not exceed the position resolution of the attitude measurement device, the trajectory reconstruction processor records the attitude after reloading. The pile end position represented by the attitude after reloading is subtracted from the pile end position represented by the attitude after load reduction to obtain the reload displacement vector. The reload displacement vector is then projected onto the offset direction before load reduction to obtain the same-direction reload displacement vector.

[0116] When the displacement vector of the reload is offset along the direction before the load is removed, the trajectory reconstruction processor determines the displacement vector retained after the load removal as the irreversible trajectory increment. Reloading is used to verify that the displacement retained after the load removal still corresponds to the original offset direction after the load is restored. The displacement generated during the reloading process is not included in the irreversible trajectory increment. The irreversible trajectory increment represents the continuous lateral displacement increment that is retained after the load removal releases the recoverable displacement and has been verified by reloading. During the verification period, the penetration information is continuously checked. The verification is terminated when the penetration depth increases or changes in the opposite direction. The pile attitude, penetration information, and pile driving load recorded during the verification period are not written into the initial three-dimensional trajectory as new pile driving strokes.

[0117] After the irreversible trajectory increment is determined by unloading and verified by reloading, the verification result can be written into the initial three-dimensional trajectory, and the trajectory segment after the deflection position to be verified is corrected in step S107.

[0118] S107: The initial three-dimensional trajectory is formed by connecting and updating the trajectory increment according to the penetration depth, and the trajectory segment corresponding to the deflection position to be verified in the initial three-dimensional trajectory is corrected with the irreversible trajectory increment to obtain the three-dimensional pile driving trajectory of the static pressure pile end.

[0119] After the stress verification is completed, the trajectory reconstruction processor converts the updated trajectory increments of each pile driving cycle to the construction fixed coordinate system, arranges the updated trajectory increments according to the penetration depth to obtain an ordered trajectory increment sequence, and sequentially accumulates the updated trajectory increments in the ordered trajectory increment sequence to obtain a trajectory coordinate sequence. Then, it connects the adjacent trajectory coordinates to form an initial three-dimensional trajectory. The cross-switching trajectory residual is saved separately before verification, so the same lateral displacement will not be superimposed repeatedly when the irreversible trajectory increment is written to the trajectory.

[0120] The trajectory reconstruction processor uses the penetration depth corresponding to the deflection position to be verified as the boundary for dividing the trajectory segment; when there are trajectory coordinates with the same penetration depth in the initial three-dimensional trajectory, the trajectory coordinates are used as the dividing point; when there are no trajectory coordinates with the same penetration depth, linear interpolation is performed between two adjacent trajectory coordinates according to the penetration depth to generate the dividing point; the part extending from the dividing point along the direction of increasing penetration depth to the current pile end trajectory coordinate constitutes the trajectory segment to be corrected, and the trajectory part before the dividing point remains unchanged. The trajectory reconstruction processor allocates irreversible trajectory increments according to the penetration depth of each trajectory coordinate in the trajectory segment to be corrected; the aforementioned allocation and coordinate correction process can be expressed according to the following trajectory correction allocation formula (3): , In the formula, This indicates the penetration depth corresponding to the deflection position to be verified, in meters (m). This indicates the penetration depth corresponding to the current pile tip trajectory coordinates, in meters (m). This represents the penetration depth corresponding to the j-th trajectory coordinate in the trajectory segment to be corrected, in meters; This represents the proportion of the irreversible trajectory increments allocated; and These represent the trajectory coordinates before and after the correction, in meters (m). This represents the irreversible trajectory increment, in meters (m). The allocation ratio gradually increases from zero at the deflection position to one at the current pile tip, ensuring the continuity of the corrected trajectory segment.

[0121] After superimposing the irreversible trajectory increment onto the trajectory coordinates in the trajectory segment to be corrected according to the aforementioned allocation ratio, the corrected trajectory segment is obtained. The trajectory reconstruction processor replaces the trajectory segment to be corrected with the corrected trajectory segment to obtain the three-dimensional pile driving trajectory of the static pressure pile tip, and associates each trajectory coordinate with the penetration depth and construction time. The output results can be a three-dimensional polyline, a trajectory coordinate table, or a data file that can be read by the construction monitoring system. The deflection position to be verified and the irreversible trajectory increment can also be marked on the three-dimensional pile driving trajectory at the pile tip to obtain the marked three-dimensional pile driving trajectory at the pile tip.

[0122] To facilitate the explanation of the calculation process, a set of exemplary data is used below. The preset direction threshold is 12°. The lateral trajectory increment before switching at a penetration depth of 18m is (10.00, 0) mm, and the lateral trajectory increment after switching is (9.00, 1.27) mm. The angle between the directions of the two lateral trajectory increments is 8.03°, which satisfies the condition of continuation in the same direction. Substituting the two lateral trajectory increments into the cross-switching trajectory residual projection formula (1), the unit direction vector corresponding to the lateral trajectory increment before switching is (1, 0). Therefore, the cross-switching trajectory residual is [(9.00, 1.27)·(1, 0)]×(1, 0)=(9.00, 0) mm. After deducting the cross-switching trajectory residual from the lateral trajectory increment after switching, the updated lateral component is obtained as (9.00, 1.27)-(9.00, 0)=(0, 1.27) mm.

[0123] Continuing with the example data mentioned above, at the same stroke relative to the penetration depth of 0m, 0.10m and 0.20m, the pile driving loads of the reference pile driving stroke are 1800kN, 1850kN and 1902kN respectively, and the pile driving loads of the pile driving stroke to be compared are 1820kN, 1880kN and 1945kN respectively. According to the load penetration response deviation formula (2), the change of the previous unit penetration load of the reference pile driving stroke is (1850-1800) / 0.10=500kN / m, and the change of the previous unit penetration load of the pile driving stroke to be compared is (1880-1820) / 0.10=600kN / m. The corresponding load penetration response deviation is 600-500=100kN / m. The next load penetration response deviation is obtained in the same way as 650-520=130kN / m. The average value of the two deviation values ​​is 115kN / m. The average load penetration response deviations for the subsequent two pile driving strokes were 142 kN / m and 168 kN / m, corresponding to cumulative trajectory residual moduli of 17 mm and 26 mm, respectively. The incremental values ​​of the cumulative trajectory residual moduli between adjacent depths were 8 mm and 9 mm, respectively, both of which were not less than the lateral displacement that the attitude measurement device could resolve. Furthermore, the absolute value of the load penetration response deviation increased continuously. Therefore, the pile position corresponding to the 18 m penetration depth was determined as the deflection position to be verified, and the end penetration depth of the common increasing depth interval of 20 m was determined as the verification point. The cumulative trajectory residual of (26, 0, 0) mm corresponding to the 20 m penetration depth was determined as the cumulative trajectory residual at the verification point.

[0124] After determining the deflection position and the cumulative trajectory residual at the verification time, the load is kept at 60% of the current pile driving load before the load reduction. The cumulative trajectory residual at the verification time is (26, 0, 0) mm. The change in pile end position caused by the load reduction is (-3, 0, 0) mm. The change in pile end position is superimposed with the cumulative trajectory residual at the verification time to obtain the retained displacement vector after the load reduction of (23, 0, 0) mm. The change in pile end position caused by the reloading is (3, 0, 0) mm. The projection of this position change along the offset direction before the load reduction is (3, 0, 0) mm, indicating that the retained displacement after the load reduction still corresponds to the original offset direction after the load is restored. The reloading displacement is not included in the irreversible trajectory increment. Therefore, the retained displacement vector after the load reduction of (23, 0, 0) mm is determined as the irreversible trajectory increment.

[0125] Continuing with the trajectory correction process, when the current pile tip penetration depth is 20m, the trajectory segment to be corrected extends from 18m to 20m. According to the trajectory increment allocation formula (3), the 18m penetration depth is taken as the correction starting point, with an allocation ratio of 0 and a corresponding correction amount of 0mm. The allocation ratio at the 19m penetration depth is (19-18) / (20-18)=0.5, with a corresponding correction amount of 0.5×23=11.5mm. The allocation ratio at the 20m penetration depth is 1, with a corresponding correction amount of 23mm. The trajectory reconstruction processor replaces the trajectory segment to be corrected with the corrected trajectory segment and marks the deflection position to be verified and the irreversible trajectory increment at the 18m penetration depth. As a new pile driving cycle is generated, the trajectory reconstruction processor repeats the aforementioned data update, position identification, and verification process, extending the three-dimensional pile driving trajectory at the pile tip to the latest penetration depth.

[0126] The above provides a detailed description of a three-dimensional trajectory reconstruction method for pile driving under complex geological conditions, as provided in this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are merely for the purpose of helping to understand the method and its core ideas. It should be noted that those skilled in the art can make various improvements and modifications to this application without departing from its principles, and these improvements and modifications also fall within the protection scope of this application.

Claims

1. A method for reconstructing the three-dimensional trajectory of pile driving under complex geological conditions, used to reconstruct the three-dimensional pile driving trajectory at the pile tip of a static pressure pile, characterized in that, include: Acquire the pile posture and penetration information of statically driven piles during continuous pile driving stroke, as well as the pile driving load and force transmission status of the pile driving equipment; The trajectory increment of each pile driving stroke in the continuous pile driving stroke is determined based on the pile posture and the penetration information; Determine the force transmission switching period during which the force transmission relationship between the pile driving equipment and the static pile is terminated and rebuilt based on the force transmission state; The trajectory increments before and after the force transmission switching period are converted to the same pile coordinate system. The offset vectors that continue in the same direction are extracted as the cross-switching trajectory residuals. The cross-switching trajectory residuals are then subtracted from the converted trajectory increments to obtain the updated trajectory increments. In response to the cross-switching trajectory residual accumulating in the same direction during subsequent pile driving strokes and the load-penetration relationship formed by the pile driving load and the penetration information deviating from the reference penetration relationship, the deflection position to be verified is determined based on the penetration depth corresponding to the same-direction accumulation. In response to the current pile driving load of the pile driving equipment being lower than the upper limit of the construction load and the deflection position to be verified being outside the construction restriction area, the pile driving equipment is controlled to sequentially perform load reduction and reloading to determine the irreversible trajectory increment retained after load reduction and verified by reloading. The initial three-dimensional trajectory is formed by connecting the updated trajectory increments according to the penetration depth, and the trajectory segment in the initial three-dimensional trajectory corresponding to the deflection position to be verified is corrected by the irreversible trajectory increments to obtain the three-dimensional pile driving trajectory at the pile tip of the static pressure pile.

2. The method according to claim 1, characterized in that, The step of converting the trajectory increments before and after the force transmission switching period to the same pile coordinate system and extracting the offset vectors that continue in the same direction as the cross-switching trajectory residuals includes: For each of the force transmission switching periods, based on the force transmission state, the driving stroke segment in which the force transmission relationship between the driving equipment and the static pile is continuously maintained is determined before and after the force transmission switching period, thus obtaining the stroke segment before switching and the stroke segment after switching. Extract the trajectory increment before switching and the trajectory increment after switching from the travel segment before switching and the travel segment after switching, respectively; The pile coordinate system corresponding to the trajectory increment before the switch is used as the reference pile coordinate system; The switched trajectory increment is converted to the coordinate system of the reference pile body to obtain the converted trajectory increment; Determine the directional angle between the trajectory increment before switching and the trajectory increment after switching; In response to the fact that the included angle of the direction is not greater than a preset direction threshold, the projection vector of the converted trajectory increment in the direction of the trajectory increment before the switch is determined as the cross-switching trajectory residual corresponding to the force transmission switching period, and the cross-switching trajectory residual is subtracted from the lateral component of the converted trajectory increment, and the resulting lateral component is combined with the original axial component to form the updated trajectory increment.

3. The method according to claim 2, characterized in that, The response to the accumulation of the cross-switching trajectory residual in the same direction during subsequent pile driving strokes includes: Arrange the cross-switching trajectory residuals according to the penetration depth in the penetration information to obtain an ordered residual sequence; The direction of the cross-switching trajectory residual with the smallest penetration depth in the ordered residual sequence is determined as the reference residual direction; The cross-switching trajectory residuals in the ordered residual sequence are projected onto the reference residual direction to obtain the directional projection amount of each cross-switching trajectory residual. Extract the cross-switching trajectory residuals and their penetration depth identifiers that have positive directional projection values ​​and are not less than the lateral displacement that the attitude measurement device can resolve, and obtain an effective in-direction residual sequence. The cross-switching trajectory residuals in the effective same-direction residual sequence are sequentially accumulated along the reference residual direction to obtain the cumulative trajectory residual sequence.

4. The method according to claim 3, characterized in that, In response to the current pile driving load of the pile driving equipment being lower than the upper limit of the construction load and the deflection position to be verified being outside the construction restriction area, the pile driving equipment is controlled to perform load reduction to determine the displacement vector retained after load reduction, including: Extract the cumulative trajectory residual corresponding to the end penetration depth of the common increasing depth interval from the cumulative trajectory residual sequence to obtain the cumulative trajectory residual at the verification time point; The direction of the cumulative trajectory residual at the verification time point is determined as the offset direction before load reduction; In response to determining the deflection position to be verified, the increase in penetration is paused and the pile attitude is recorded to obtain the attitude before load reduction. Using the pre-load reduction posture as a comparison benchmark, and based on the force transmission state, the current pile driving load of the pile driving equipment is reduced to a holding load that maintains the force transmission relationship between the pile driving equipment and the static pile, and the pile posture under the holding load is recorded to obtain the post-load reduction posture. Based on the attitude before and after the load reduction, determine the change in pile end position before and after the load reduction. The cumulative trajectory residual at the verification time point is superimposed with the change in pile end position before and after the load reduction, and the positive component of the superposition result along the offset direction before the load reduction is extracted to obtain the displacement vector retained after the load reduction.

5. The method according to claim 1, characterized in that, The process for determining the reference pile driving stroke includes: For the pile driving stroke to be compared, based on the force transmission state and the survey data of the construction area, the pile driving strokes that are located in the same stratum segment as the pile driving stroke to be compared, have the same force transmission state, and have overlapping relative penetration ranges within the stroke are extracted from the continuous pile driving strokes to obtain a set of candidate pile driving strokes; Based on the pile posture, determine the included angle between the first and last pile axis directions of each candidate pile driving stroke in the candidate pile driving stroke set, and obtain the pile axis direction change angle sequence; The candidate pile driving stroke corresponding to the minimum value of the pile axis direction change angle sequence in the candidate pile driving stroke set is determined as the reference pile driving stroke; The reference penetration relationship is determined based on the pile driving load and penetration information corresponding to the reference pile driving stroke.

6. The method according to claim 4, characterized in that, The step of determining the same-direction reload displacement vector based on the attitude after unloading and the attitude after reloading, and determining the retained displacement vector after unloading as an irreversible trajectory increment when the same-direction reload displacement vector is along the offset direction before unloading, includes: The reload displacement vector is determined based on the change in the pile end position represented by the reload attitude relative to the pile end position represented by the unload attitude. The projection vector of the reload displacement vector in the offset direction before the load reduction is determined as the same-direction reload displacement vector; In response to the same-direction reload displacement vector offset along the direction before load reduction, the displacement vector retained after load reduction is determined as an irreversible trajectory increment.

7. The method according to claim 4, characterized in that, The step of correcting the trajectory segment in the initial three-dimensional trajectory corresponding to the deflection position to be verified by the irreversible trajectory increment to obtain the three-dimensional pile driving trajectory at the pile tip of the static pressure pile includes: Based on the penetration depth corresponding to the deflection position to be verified, in the initial three-dimensional trajectory, the trajectory segment that starts from the trajectory coordinates corresponding to the deflection position to be verified and extends along the direction of increasing penetration depth to the trajectory coordinates at the pile end is determined as the trajectory segment to be corrected. According to the penetration depth of each trajectory coordinate in the trajectory segment to be corrected, the irreversible trajectory increment is superimposed on the corresponding trajectory coordinate in a distribution ratio that gradually increases from zero to one, to obtain the corrected trajectory segment. The corrected trajectory segment is used to replace the trajectory segment to be corrected to obtain the three-dimensional pile driving trajectory at the pile tip of the static pressure pile.

8. The method according to claim 7, characterized in that, The step of connecting the updated trajectory increments according to the penetration depth to form the initial three-dimensional trajectory includes: The updated trajectory increments are arranged according to the penetration depth in the penetration information to obtain an ordered trajectory increment sequence; By sequentially summing the updated trajectory increments in the ordered trajectory increment sequence, a trajectory coordinate sequence is obtained; Connect the trajectory coordinates in the trajectory coordinate sequence to obtain the initial three-dimensional trajectory.

9. The method according to claim 3, characterized in that, The load-penetration relationship formed by the pile driving load and the penetration information deviates from the benchmark penetration relationship. The deflection position to be verified is determined based on the penetration depth corresponding to the cumulative penetration in the same direction, including: For each span switching trajectory residual in the effective unidirectional residual sequence, the load penetration response deviation of the pile driving stroke represented by the corresponding penetration depth identifier is determined according to the pile driving load, the penetration information and the benchmark penetration relationship. Arrange the load penetration response deviations according to the penetration depth identifier to obtain a load penetration response deviation sequence that is consistent with the number of elements and depth order of the cumulative trajectory residual sequence; Based on the cumulative trajectory residual sequence and the load penetration response deviation sequence, extract a continuous penetration depth range where the incremental value of the cumulative trajectory residual modulus between adjacent penetration depths is not less than the lateral displacement that the attitude measurement device can resolve, and the absolute value of the load penetration response deviation increases with the penetration depth. The continuous penetration depth interval with the smallest initial penetration depth is determined as the common increasing depth interval, and the pile position corresponding to the initial penetration depth of the common increasing depth interval is determined as the deflection position to be verified.

10. The method according to claim 4, characterized in that, Controlling the pile driving equipment to perform reloading to determine the irreversible trajectory increment verified by the reloading includes: Using the displacement vector retained after the load reduction as the comparison benchmark for reloading, the holding load is increased to a verification load that is not higher than the upper limit of the construction load, and the pile posture under the verification load is recorded to obtain the posture after reloading. The reload displacement vector is determined based on the pile end position represented by the attitude after unloading and the pile end position represented by the attitude after reloading. The projection vector of the reload displacement vector in the offset direction before the load reduction is determined as the same-direction reload displacement vector; In response to the same-direction reload displacement vector offset along the direction before load reduction, the displacement vector retained after load reduction is determined as an irreversible trajectory increment.

Images